bluuebunny/crossref_metadata_2025 huggingface dataset:
Comportamiento del Consumidor Receptor del Regalo durante el Proceso de Toma de Decisiones
Authors: Cruz Cárdenas Jorge Aníbal
Published: June 2011

El comportamiento del consumidor receptor del regalo ha sido poco estudiado. En la presente investigacin se realiz entrevistas a profundidad a 24 jvenes universitarios, obteniendo 153 acontecimientos de regalos en los que participaron como receptores. Surgieron cuatro formas de actuacin del receptor durante el proceso de compra del regalo: Colaborar con el dador, manipular al dador, influir de forma no deliberada y no influir en modo alguno. Estos patrones de actuacin condujeron a diferentes niveles de involucramiento, fueron en general de baja agresividad y estaran vinculados con el menor poder del receptor frente al dador y con factores culturales. DOI: 10.5585/remark.v9i3.2193
A Content Analysis of the Roles Portrayed by Women in Commercials: 1973 - 2008
Authors: Acevedo Claudia Rosa , Ramuski Carmen Lidia , Nohara Jouliana Jordan , Trindade Luiz Valério De Paula
Published: June 2011

The principal objective of this paper was to examine female roles portrayed in advertising. More specifically, the question that stimulated this research project was: What message has been signaled to society through advertisements about women? Have these portrayals altered throughout the past decades? The study consisted of a systematic content analysis of Brazilian commercials between 1973 and 2008. A probabilistic sample procedure was adopted. 95 pieces of material were selected. Our results have revealed that certain specific images have changed over the years; however, they continue to be stereotyped and idealized. DOI: 10.5585/remark.v9i3.2201
Symmetry and Steric Effects on Spin States in Transition Metal Complexes
Authors: Meier Ryan M. , Hanusa Timothy P.
Published: June 2011

Changes in the magnetic characteristics of transition metal complexes, particularly, their metal spin states, are most commonly achieved by varying the electron donor/acceptor properties of coordinated ligands. In some systems, it is possible to increase the steric bulk of ligands so that intramolecular crowding leads to changes in metal‐ligand bond distances; longer bonds produce weaker ligand fields and stabilize high‐spin or spin‐crossover complexes. Steric effects are also often associated, albeit indirectly, with a mechanism for influencing spin states that relies on modifying the symmetry‐based interactions of metal and ligand orbitals. Particular ligand orientations, as in bis(indenyl) compounds [M(R
9
C
7
)
2
], can be changed as the result of interligand steric pressure or crystal packing effects; such differences can alter metal d‐orbital energy levels and hence the stability of spin states. Both steric and symmetry effects add to the repertoire of techniques that can be used to control magnetic properties in transition metal complexes.
Enzymatic Polymerization
Authors: Kobayashi Shiro
Published: June 2011

Developments in enzymatic polymerization, a method of polymer synthesis, are comprehensively reviewed. The method, which has been developed over the past few decades, utilizes enzymes as catalysts forin vitroreactions. Characteristics of enzymatic catalysis are discussed. Synthesis of natural and unnatural polysaccharides employs hydrolase enzyme catalysts for polycondensation and ring‐opening polyaddition. Some of these polysaccharides are difficult to synthesize by a conventional chemical method. A variety of functionalized polyesters are synthesized in most cases by lipase catalysts via polycondensation as well as ring‐opening polymerization. Some new polymer synthesis approaches have been developed. Enzyme‐catalyzed modification is also mentioned for polyester synthesis. Oxidative polymerizations of aromatic compounds like phenols and anilines produce various functional aromatic polymers. Owing to the characteristic nature of enzymatic polymerization, the opportunity for “green polymer chemistry” is emphasized.
Interfacial Polymerization
Authors: Morgan Paul W.
Published: June 2011

In interfacial polymerization, typically a condensation reaction between a diamine or diol and a diacid, the two fast‐reacting intermediates are dissolved in a pair of immiscible liquids, one of which is preferably water. The water phase contains the diamine or diol and usually an inorganic base to activate any diol and neutralize the by‐product acid. The other phase consists of the diacid chloride and an organic liquid such as dichloromethane, toluene, or hexane. Polymer formation takes place at or near the liquid–liquid interface when the two solutions are brought in contact or stirred together. By this process and its variations, thousands of polymers have been synthesized.
Aspects of the Chemistry of Species with Carbon–Polonium Bonds
Authors: Ponikvar‐Svet Maja , Liebman Joel F.
Published: June 2011

The chemistry of compounds with carbon‐polonium bonds remains, not surprisingly, rather unstudied because of the high level of radioactivity, and hence scarcity, danger and expense, associated with polonium itself. Attempts to enlighten this understanding have rarely investigated the same species experimentally and theoretically; the former are emphasized in this chapter. Approaches to the syntheses of dialkyl polonides, aryl polonium derivatives and other types of compounds with carbon‐polonium bonds are discussed.
Implicit alcohol‐aggression scripts and alcohol‐related aggression on a laboratory task in 11‐ to 14‐year‐old adolescents
Authors: Brown Stephen L. , Lipka Sigrid , Coyne Sarah M. , Qualter Pamela , Barlow Alexandra , Taylor Paul
Published: June 2011

Social scripts are commonly shared representations of behavior in social contexts, which are seen to be partly transmitted through social and cultural media. Research suggests that people hold scripts associated with alcohol‐related aggression, but, unlike general aggression scripts, there is little evidence of social transmission. To demonstrate social transmission of alcohol‐related aggression scripts, learning mechanisms based on personal experience should be minimized. We used a lexical decision task to examine implicit links between alcohol and aggression in alcohol‐naïve adolescents who have limited personal or vicarious experience of alcohol‐related aggression. One hundred and four 11–14 year old adolescents made lexical decisions on aggressive or nonaggressive words preceded by 40‐ms alcohol or nonalcohol word primes. Repeated measures analyses of group data showed that alcohol word primes did not lead to faster responses to aggressive words than to nonaggressive words, nor were responses to aggressive words faster when they were preceded by alcohol word primes than by nonalcohol word primes. However, at an individual level, faster recognition times to the alcohol prime/aggression target word combination predicted aggression on a competitive laboratory task in 14 year olds only. This occurred only when the competitive aggression task was preceded by a visual presentation of alcoholic, but not nonalcoholic beverage, images. We concluded that alcohol‐related aggression scripts are not strongly developed in this age group, but individual differences in script strength are linked to alcohol‐related laboratory aggression. Aggr. Behav. 37:430–439, 2011. © 2011 Wiley‐Liss, Inc.
The role of adult learning in coping with chronic illness
Authors: Baumgartner Lisa M.
Published: June 2011

This chapter demonstrates the role of learning in coping with chronic illness and provides recommendations for health educators.
“It looks after me”: How older patients make decisions about analgesics for osteoarthritis
Authors: Milder Tamara Y. , Lipworth Wendy L. , Williams Kenneth M. , Ritchie Jan E. , Day Richard O.
Published: June 2011

Objective

To explore the key motivators behind selection of analgesics (nonsteroidal antiinflammatory drugs [NSAIDs], acetaminophen, and complementary medications [CMs]) by patients with osteoarthritis (OA).

Methods

We performed a qualitative study in which in‐depth semistructured interviews were conducted with 15 OA patients recruited from 4 general practices in Sydney, Australia. Patients were ages ≥65 years, and were currently taking or had recently taken an NSAID for OA.

Results

Three key themes emerged from the data: reliance, routine, and pill load. Patients were strongly reliant upon NSAIDs because they consistently satisfied their needs. By contrast, they were much less reliant upon acetaminophen because of uncertainty or skepticism about its effectiveness. They were not reliant upon CMs but were willing to take them indefinitely because they were perceived as being without risk. Many patients took an NSAID as well as CMs as part of a “daily routine.” By contrast, patients had difficulty developing a routine around using acetaminophen at the recommended maximum dose because of the implicit frequency of dosing required and an aversion to the associated “pill load.”

Conclusion

The results highlight the importance of exploring the perceptions and preferences of patients with regard to analgesics for OA. Clinician advice regarding analgesia for OA should take account of the possible reliance of the patient upon an NSAID, their medicine routines, and their potential concern about the pill load associated, in particular, with acetaminophen.
Effect of oral vitamin C supplementation on serum uric acid: A meta‐analysis of randomized controlled trials
Authors: Juraschek Stephen P. , Miller Edgar R. , Gelber Allan C.
Published: June 2011

Objective

To assess the effect of vitamin C supplementation on serum uric acid (SUA) by pooling the findings from published randomized controlled trials (RCTs).

Methods

A total of 2,082 publications identified through systematic search were subjected to the following inclusion criteria: 1) RCTs conducted on human subjects, 2) reported end‐trial SUA means and variance, 3) study design with oral vitamin C supplementation and concurrent control groups, and 4) trial duration of at least 1 week. Trials that enrolled children or patients receiving dialysis were excluded. Two investigators independently abstracted trial and participant characteristics. SUA effects were pooled by random‐effects models and weighted by inverse variance.

Results

Thirteen RCTs were identified in the Medline, EMBase, and Cochrane Central Register of Controlled Trials databases. The total number of participants was 556, the median dosage of vitamin C was 500 mg/day, trial size ranged from 8–184 participants, and the median study duration was 30 days. Pretreatment SUA values ranged from 2.9–7.0 mg/dl (Système International d'Unités [SI units]: 172.5–416.4 μmoles/liter). The combined effect of these trials was a significant reduction in SUA of −0.35 mg/dl (95% confidence interval −0.66, −0.03 [P = 0.032]; SI units: −20.8 μmoles/liter). Trial heterogeneity was significant (I2 = 77%, P < 0.01). Subgroup analyses based on trial characteristics indicated larger reductions in uric acid in trials that were placebo controlled.

Conclusions

In aggregate, vitamin C supplementation significantly lowered SUA. Future trials are needed to determine whether vitamin C supplementation can reduce hyperuricemia or prevent incident and recurrent gout.
Dual‐Gate Thin‐Film Transistors, Integrated Circuits and Sensors
Authors: Spijkman Mark‐Jan , Myny Kris , Smits Edsger C. P. , Heremans Paul , Blom Paul W. M. , de Leeuw Dago M.
Published: June 2011

The first dual‐gate thin‐film transistor (DGTFT) was reported in 1981 with CdSe as the semiconductor. Other TFT technologies such as a‐Si:H and organic semiconductors have led to additional ways of making DGTFTs. DGTFTs contain a second gate dielectric with a second gate positioned opposite of the first gate. The main advantage is that the threshold voltage can be set as a function of the applied second gate bias. The shift depends on the ratio of the capacitances of the two gate dielectrics. Here we review the fast growing field of DGTFTs. We summarize the reported operational mechanisms, and the application in logic gates and integrated circuits. The second emerging application of DGTFTs is sensitivity enhancement of existing ion‐sensitive field‐effect transistors (ISFET). The reported sensing mechanism is discussed and an outlook is presented.
Metal‐Free Efficient, General and Facile Iododecarboxylation Method with Biodegradable Co‐Products
Authors: Kulbitski Kseniya , Nisnevich Gennady , Gandelman Mark
Published: June 2011

The development of a novel, efficient and robust method for the general conversion of aliphatic and aromatic carboxylic acids to organic iodides without the use of heavy metals or strong oxidizing agents is reported. Commercially available N‐iodoamides were used for both initiation and halogen donation under irradiative conditions. Isolation of the product is extremely simple and the major co‐product is removed as a water‐soluble biodegradable material.
High Performance Organic Photovoltaic Cells Using Polymer‐Hybridized ZnO Nanocrystals as a Cathode Interlayer
Authors: Jo Sae Byeok , Lee Ji Hwang , Sim Myungsun , Kim Min , Park Jong Hwan , Choi Yeong Suk , Kim Yungi , Ihn Soo‐Ghang , Cho Kilwon
Published: June 2011

Solution‐processed zinc oxide nanocrystals (ZnO NCs) hybridized with insulating poly(ethylene glycol) (PEG) are introduced as a cathode interlayer in bulk heterojunction organic photovoltaic cells based on poly(3‐hexylthiophene) (P3HT):(6,6)‐phenyl‐C61 butyric acid methyl ester (PC61BM) blends. The performance of devices with ZnO‐PEG interlayers exhibit an excellent maximum power conversion efficiency (PCE) of 4.4% with a fill factor (FF) of 0.69 under optimized conditions. This enhanced device performance is attributed to decreased series resistance from the hole blocking properties of ZnO, as well as the facilitated electron transport due to the reduced area of ZnO domain boundaries upon addition of PEG. The addition of PEG also lowers the electron affinity of ZnO, which leads to a nearly Ohmic contact at the polymer/metal interface. Moreover, the ZnO‐PEG interlayer serves as an optical spacer that enhances light absorption and thereby increases the photocurrent. The addition of PEG permits control over layer thickness and refractive indices. Improved photon energy absorption is supported by optical simulations. Devices with highly stable metals such as Ag and Au also show dramatically enhanced performance comparable to conventional devices with Al cathode. Due to its simplicity and excellent characteristics, this multifunctional interlayer is suitable for high performance printed photovoltaic cells.
Perylene Sensitization of Fullerenes for Improved Performance in Organic Photovoltaics
Authors: Hesse Holger C. , Weickert Jonas , Hundschell Christian , Feng Xinliang , Müllen Klaus , Nickel Bert , Mozer Attila J. , Schmidt‐Mende Lukas
Published: June 2011

We present the addition of an energy relay dye to fullerenes resulting in increased light harvesting and significantly improved power conversion efficiency for organic photovoltaic (OPV) devices. Although exhibiting excellent properties as electron acceptors, visible light absorption of fullerenes is limited. Strongly light absorbing donor materials are needed for efficient light harvesting in the thin active layer of OPV devices. Therefore, photocurrent generation and thus power conversion efficiency of this type of solar cell is confined by the overlap of the relatively narrow absorption band of commonly used donor molecules with the solar spectrum. Herein the concept of fullerene dye sensitization is presented, which allows increased light harvesting on the electron acceptor side of the heterojunction. The concept is exemplarily shown for an UV absorbing small molecule and a near infrared absorbing polymer, namely hexa‐peri‐hexabenzocoronene (HBC) and Poly[2,1,3‐benzothiadiazole‐4,7‐diyl[4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b:3,4‐b']dithiophene‐2,6‐diyl]] (PCPDTBT), respectively. In both systems remarkably higher power conversion efficiency is achieved via perylene sensitization of the fullerene acceptor. Steady state photoluminescence, transient absorption and transient photocurrent decay studies reveal pathways of the additionally generated excited states at the sensitizer molecule. The findings suggest fluorescence resonance energy transfer from the photo‐excited dye to the fullerene enabling decoupling of light absorption and charge transport. The presented sensitization method is proposed as a viable new concept for performance enhancement in organic photovoltaic devices.
Corrosion behavior of titania films coated by liquid‐phase deposition on AISI304 stainless steel substrates
Authors: Cai Yongwei , Liu Mingyan
Published: June 2011

Fouling deposition and localized corrosion on the heat‐transfer surfaces of the stainless steel equipments often simultaneously exist, which can introduce additional thermal resistance to heat‐transfer and damage heat‐transfer surfaces. It is a good anticorrosion way to coat a barrier layer of certain materials on the metal surface. In this article, the TiO2 coatings with nanoscale thicknesses were obtained by liquid‐phase deposition method on the substrates of AISI304 stainless steel (ASS). The coating thickness, surface roughness, surface morphology, crystal phase, and chemical element were characterized with the film thickness measuring instrument, roughmeter, atomic force microscopy, field emission scanning electron microscopy, X‐ray diffraction, and energy‐dispersive X‐ray spectroscopy analyzer, respectively. Corrosion behavior of the TiO2 coatings was evaluated by potentiodynamic polarization, cyclic voltammograms scanning, and electrochemical impedance spectroscopy tests with the mixed corrosion solution composed of 3.5 wt. % NaCl and 0.05 M NaOH. It is shown that the TiO2 coating is composed of the nanoparticles with smooth, crack‐free, dense, and uniform surface topography; the roughness of coating surface increases slightly compared with that of the polished ASS substrate. The anatase‐phase TiO2 coatings are obtained when sintering temperature being varied from 573.15 to 923.15 K and exhibit better anticorrosion behavior compared with ASS surfaces. The corrosion current density decreases and the polarization resistance increases with the increase of the coating thickness. The corrosion resistance of the TiO2 coatings deteriorates with the increase of the corrosion time. The capacitance and the resistance of the corrosion product layer between the interface of the ASS substrate and the TiO2 coating are found after the corrosion time of 240 h. A corrosion model was introduced, and a possible new explanation on the anticorrosion mechanisms of the TiO2 coating was also analyzed. The corrosion mechanism of the TiO2 coating might comply with the multistage corrosion process. © 2011 American Institute of Chemical Engineers AIChE J, 58: 1907–1920, 2012
Demography of squirrel monkeys (Saimiri sciureus) in captive environments and its effect on population growth
Authors: Zimbler‐DeLorenzo Heather S. , Dobson F. Stephen
Published: June 2011

Understanding which life‐history variables have the greatest influence on population growth rate has great ecological and conservation importance. Applying models of population regulation and demographic mechanisms can aid management and conservation of both wild and captive populations. By comparisons of sensitivity, elasticity, and life‐table response analyses, we identified demographic processes that were most likely to produce changes in population size (via prospective analyses) and the traits that actually influenced population changes (via retrospective analyses) among sexes, zoological facilities, and generations of captive squirrel monkey populations (Saimiri sciureus). Variation in life‐history traits occurs within each group analyzed. Those traits that vary the most include age at maturity, age at last reproduction, and fertility. Zoos with increasing population growth rates maintain earlier ages of maturity, later ages of last reproduction, high rates of juvenile and adult survival, and most importantly greater fertility, reflecting shorter inter‐birth intervals. Using prospective analyses, juvenile and adult survivals were predicted to be demographic traits with the greatest effect on population growth. Surprisingly, and despite predictions, retrospective analyses revealed that fertility was the life‐history characteristic trait that contributed the most to changes in population size. Am. J. Primatol. 73:1041–1050, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis and characterization of poly(urethane‐ether)s from calcium salt of p‐hydroxybenzoic acid
Authors: Nair Priya A. , Ramesh P.
Published: June 2011

The synthesis and characterization of calcium‐containing poly(urethane‐ether)s, having ionic links in the main chain, is reported. Calcium salt of p‐hydroxybenzoic acid (HBA‐Ca) was prepared from p‐hydroxybenzoic acid (HBA) and used as the chain extender in the preparation of calcium‐containing poly(urethane‐ether)s. Poly(urethane‐ether)s, having two different compositions, were prepared by varying the mole ratios of poly(tetramethylene glycol), hexamethylene diisocyanate, and HBA‐Ca. The synthesized poly(urethane‐ether)s were characterized by infrared spectroscopy, thermogravimetric analysis, and dynamic mechanical analysis. The presence of calcium in the polymer chain was confirmed by energy‐dispersive X‐ray analysis. The inherent viscosity of metal‐containing polymers decreased with the increase in the metal content of the polymer. The introduction of metal into the polymer lowers the thermal stability of the polymers as indicated by the decreased initial decomposition temperature. The glass transition temperature (Tg) and the storage modulus of the metal‐containing polymers increase with the increase in metal content presumably due to the formation of physical crosslink's in the polymer. From the mechanical studies of the polymer, it was observed that the metal‐containing polymers exhibit high tensile strength and modulus. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
The effect of clay type and of clay–masterbatch product in the preparation of polypropylene/clay nanocomposites
Authors: Rodríguez‐Llamazares Saddys , Rivas Bernabé L. , Pérez Mónica , Perrin‐Sarazin Florence , Maldonado Alvaro , Venegas Carola
Published: June 2011

Clay containing polypropylene (PP) nanocomposites were prepared by direct melt mixing in a twin screw extruder using different types of organo‐modified montmorillonite (Cloisite 15 and Cloisite 20) and two masterbatch products, one based on pre‐exfoliated clays (Nanofil SE 3000) and another one based on clay–polyolefin resin (Nanomax‐PP). Maleic anhydride‐grafted polypropylene (PP‐g‐MA) was used as a coupling agent to improve the dispersability of organo‐modified clays. The effect of clay type and clay–masterbatch product on the clay exfoliation and nanocomposite properties was investigated. The effect of PP‐g‐MA concentration was also considered. Composite morphologies were characterized by X‐ray diffraction (XRD), field emission gun scanning electron microscopy (FEG‐SEM), and transmission electron microscopy (TEM). The degree of dispersion of organo‐modified clay increased with the PP‐g‐MA content. The thermal and mechanical properties were not affected by organo‐modified clay type, although the masterbatch products did have a significant influence on thermal and mechanical properties of nanocomposites. Intercalation/exfoliation was not achieved in the Nanofil SE 3000 composite. This masterbatch product has intercalants, whose initial decomposition temperature is lower than the processing temperature (T ∼ 180°C), indicating that their stability decreased during the process. The Nanomax‐PP composite showed higher thermal and flexural properties than pure PP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Structure characterization of cold drawn high density polyethylene thin film
Authors: Fouda I. M. , El‐Tonsy M. M. , Seisa E. A. , Felfel R. M.
Published: June 2011

This work throws light to study the changes of optical birefringence for cold drawn high density polyethylene (HDPE) thin film at different stresses. A stress–strain device connected to a scattering optical system was used to investigate the dynamical behavior of opto‐mechanical properties at room temperature (27°C ± 1°C). Some structural parameters, optical and mechanical orientation factors, f(θ), f2(θ), f4(θ), f6(θ), Fav, P2(θ), P4(θ), fc, and fm, were calculated. Also, the distribution segments at an angle (θ), the number of random links per chain (N1), the number of chains per unit volume (Nc), and the average work per chain W′ were calculated. The average value of the maximum birefringence was evaluated. The obtained studies demonstrate changes to the molecular orientation functions and evaluated micro structural parameters as a result of the applied cold‐drawing process on (HDPE) thin film. Relationships between the calculated parameters and draw ratios were presented for illustration. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Greatly improved adsorption of N‐methylated modified macroporous cross‐linked polyacrylamide toward tannin from aqueous solution
Authors: Xu Mancai , Hu Liping , Huang Jianhan , Huang Kelong
Published: June 2011

Macroporous cross‐linked poly(N‐methylacrylamide) (PMAM) was prepared and the adsorption behaviors of PMAM toward tannin from aqueous solution was studied in comparison with polyacrylamide (PAM). The swollen property indicated that PMAM had a higher hydrophobicity than PAM while the adsorption showed that PMAM had a greatly improved adsorption toward tannin. The adsorption data could be fitted well by Freundlich model and the values of the thermodynamic parameters of PMAM toward tannin were more negative than PAM. The multiple hydrogen bonding and hydrophobic interaction between PAM/PMAM and tannin were shown to be responsible for the adsorption, whereas a stronger hydrogen bonding and a higher hydrophobicity of PMAM had a contribution to the greatly improved adsorption of PMAM toward tannin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Heavy metals removal from solution by polyaniline/palygorskite composite
Authors: Kong Yong , Wei Jingxuan , Wang Zhiliang , Sun Tao , Yao Chao , Chen Zhidong
Published: June 2011

Batch adsorption experiments were carried out to remove heavy metal ions such as Cu (II), Ni (II), Cd (II), and Cr (VI) from single‐metal solutions using a polyaniline/palygorskite (PP) composite. Different parameters affecting the adsorption capacity such as contact time and pH of the solution have been investigated. The structural characteristics of the PP composite were studied in this work. Atomic absorption spectroscopy was used for the measurement of heavy metal contents, and the adsorption capacity (qe) calculated were 114 mg Cu (II) g−1, 84 mg Ni (II) g−1, 56 mg Cd (II) g−1, and 198 mg Cr (VI) g−1 under optimal conditions. The removal of the metal ions from solutions was assigned to chelation, ionic exchange, and electrostatic attraction. Data from this study proved that the novel organic/inorganic composite presents great potential in the recovery and elimination of noble or heavy metal ions from industrial wastewater. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Effect of silica modification on the chemical interactions in NBR‐based composites
Authors: Lopez Juan F. , Perez Leon D. , Lopez Betty L.
Published: June 2011

Fillers are modified with the purpose of increasing their interactions with polymer matrices; however it is necessary to determine the impact that those modifications have on the composite performance and morphology. In this work, the strength of the chemical interactions between silica with different chemical characteristics and acrylonitrile butadiene rubber (NBR) is studied by infrared spectroscopy measuring the increase of C≡N fundamental vibration frequency and by density functional theory (DFT) and ab initio methods. The results from the chemical interactions were compared with the morphology and thermal behavior of composites based on those components. Good agreement between the molecular parameters estimated theoretically and the shifting of the absorption frequency due to C≡N stretching was observed. Morphological studies revealed that the steric hindrance exerted by modifier moieties on silica surface favors the filler dispersion. Functional groups on the surface strongly interacting with NBR play an important role in the compatibility of immiscible blends of NBR copolymers studied in this work. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Isoconversional and thermal methods of kinetic analysis of 2,4‐dihydroxybenzophenone copolymer resin
Authors: Gurnule Wasudeo B. , Butoliya S. S.
Published: June 2011

A copolymer (2,4‐DHBPOF) synthesized by the condensation of 2,4‐dihydroxybenzophenone and oxamide with formaldehyde in the presence of acid catalyst with varying the molar proportions of the reacting monomer. Composition of the copolymer has been determined by elemental analysis. The copolymer has been characterized by UV–visible, FTIR, and 1H NMR spectroscopy. The morphology of synthesized copolymer was studied by scanning electron microscopy (SEM). The activation energy (Ea) and thermal stability calculated by using Sharp‐Wentworth, Freeman–Carroll, and Freidman's method. Thermogravimetric analysis (TGA) data were analyzed to estimate the characteristic thermal parameters. Freeman–Carroll and Sharp Wentworth methods have been used to calculate activation energy and thermal stability. The activation energy (Ea) calculated by using the Sharp‐Wentworth has been found to be in good agreement with that calculated by Freeman–Carroll method. Thermodynamic parameters such as free energy change (ΔF), entropy change (ΔS), apparent entropy change (S*), and frequency factor (Z) have also been evaluated based on the data of Freeman–Carroll method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Injectable thermosensitive hydrogels for intra‐articular delivery of methotrexate
Authors: Miao Bolong , Song Cunxian , Ma Guilei
Published: June 2011

Intra‐articular drug delivery is the preferred approach for targeting pharmacologic treatment directly at the joints to reduce undesirable side effects associated with systemic drug delivery. In this study, a controlled delivery system of methotrexate (MTX) based on injectable thermosensitive poly(ε‐caprolactone)‐poly(ethylene glycol)‐poly(ε‐caprolactone) (PCL‐PEG‐PCL, PEP) hydrogels was developed for the intra‐articular drug delivery. The thermosensitive PEP copolymers were prepared by ring‐opening polymerization. The synthesized PEP copolymers were characterized for their structure, composition, and the sol‐to‐gel transition. The in vitro MTX release from the PEP hydrogels was studied. MTX plasma concentration following intra‐articular injection into healthy rats was determined by HPLC. Biocompatibility was confirmed by histology analysis after the intra‐articular injection. The synthesized PEP copolymers aqueous solutions formed in situ gel rapidly after the injection. PEP hydrogels showed the ability to control the release of incorporated MTX. Following intra‐articular injection, the PEP hydrogels decreased the clearance rate of MTX in the joint cavity. The maximum plasma concentrations of MTX in rats injected with free MTX were threefold higher than that of the groups injected with MTX hydrogels. These results suggest that the intra‐articular delivery of the PEP hydrogels may be a viable strategy for the controlled release of drugs for treating arthritis diseases. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effects of processing route on morphology and mechanical behavior of polypropylene in equal channel angular extrusion
Authors: Wang Tinglan , Tang Songchao , Chen Jianding
Published: June 2011

Changes of morphology and mechanical behavior of isotactic polypropylene (iPP) due to equal channel angular extrusion (ECAE) were investigated. The iPP specimens were processed for up to two passes in the same direction (route A), with the specimens rotate 180°around loading axis after the previous pass (route C). The macroscopic observation showed that high level of shear strain is introduced in iPP extruded twice in route A. Reflected optical microscopy revealed that the original spherulites are elongated into ellipsoidal shape along the shear direction in route A, and the recovery of the spherulitic shape occurred in iPP extruded in route C. X‐ray diffraction results and the dynamic mechanical analysis showed that the crystalline and amorphous phase are prone to orientation more favorably via route A than route C. The increase of the dynamic storage modulus (E′) indicated that iPP becomes stiffer than other samples when extruded twice in route A. Izod impact testing results demonstrated that the ECAE‐deformed spherulites influence the crack propagation direction. The impact strength of iPP is greatly improved to 490.5 J/m after processed twice in route A, 10 times of that of un‐deformed reference sample. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improvement of the Cytotoxicity and Tumor Selectivity of Glycyrrhetinic Acid by Derivatization with Bifunctional Aminoacids
Authors: Csuk René , Schwarz Stefan , Kluge Ralph , Ströhl Dieter
Published: June 2011

Glycyrrhetinic acid (GA) is a major ingredient of the dried extract of licorice roots; its antitumor activity is low compared to other members of the triterpenoic family. For example, oleanolic acid, betulin or betulinic acid are more cytotoxic with a pronounced activity for tumor cells. GA, however, is easily to earn, cheap and shows apoptotic effects on tumor cells – like the other triterpenoic acids. These facts bring GA and derivatives in the focus of our scientific interest. Here we tried to improve the poor cytotoxicity of GA by simple derivatization. Thus, we selected various glutamyl and aspartyl substituents for the synthesis of C(3) esters of GA methyl ester. A short (3‐5 steps) synthesis was elaborated that allowed to access more effective compounds. One compound, methyl 3β 3‐(O‐benzyl‐L‐glutamyl)‐11‐oxo‐olean‐12‐en‐30‐oate (5), having a glutamyl substituent with a benzyl protected side chain showed up to 67‐fold higher cytoxicity and an up to 140‐fold better selectivity towards tumor cells than parent GA. All compounds were evaluated by a sulforhodamine B assay as well as by a trypan blue test and extra acridine orange/ethidium bromide tests for apoptosis.
Synthesis, Structure, and Reactivity of Hydridoiridium Complexes Bearing a Pincer‐Type PSiP Ligand
Authors: Fang Hongyun , Choe Yoong‐Kee , Li Yonghua , Shimada Shigeru
Published: June 2011

A series of iridium tetrahydride complexes [Ir(H)4(PSiP‐R)] bearing a tridentate pincer‐type bis(phosphino)silyl ligand ([{2‐(R2P)C6H4}2MeSi]−, PSiP‐R, R=Cy, iPr, or tBu) were synthesized by the reduction of [IrCl(H)(PSiP‐R)] with Me4N⋅BH4 under argon. The same reaction under a nitrogen atmosphere afforded a rare example of thermally stable iridium(III)–dinitrogen complexes, [Ir(H)2(N2)(PSiP‐R)]. Two isomeric dinitrogen complexes were produced, in which the PSiP ligand coordinated to the iridium center in meridional and facial orientations, respectively. Attempted substitution of the dinitrogen ligand in [Ir(H)2(N2)(PSiP‐Cy)] with PMe3 required heating at 150 °C to give the expected [Ir(H)2(PMe3)(PSiP‐Cy)] and a trigonal bipyramidal iridium(I)–dinitrogen complex, [Ir(N2)(PMe3)(PSiP‐Cy)]. The reaction of [Ir(H)4(PSiP‐Cy)] with three equivalents of 2‐norbornene (nbe) in benzene afforded [IrI(nbe)(PSiP‐Cy)] in a high yield, while a similar reaction of [Ir(H)4(PSiP‐R)] with an excess of 3,3‐dimethylbutene (tbe) in benzene gave the CH bond activation product, [IrIII(H)(Ph)(PSiP‐R)], in high yield. The oxidative addition of benzene is reversible; heating [IrIII(H)(Ph)(PSiP‐Cy)] in the presence of PPh3 in benzene resulted in reductive elimination of benzene, coordination of PPh3, and activation of the CH bond of one aromatic ring in PPh3. [IrIII(H)(Ph)(PSiP‐R)] catalyzed a direct borylation reaction of the benzene CH bond with bis(pinacolato)diboron. Molecular structures of most of the new complexes in this study were determined by a single‐crystal X‐ray analysis.
The new IRSOL solar telescope control system
Authors: Küveler G. , Dao V.D. , Ramelli R.
Published: June 2011

We would like to present a new control system for the solar telescope now in operation at the Swiss institute, Istituto Ricerche Solari Locarno (IRSOL). The control software is multi‐client capable, and optionally uses the primary image of the sun projected on a position sensor or the axis encoder for guiding. The hardware and software consist of three completely separate levels, which communicate with each other via ASCII commands. We shall describe the general principles implemented in the course of the development. We consider it important that this text is also applicable to other astronomical device controls. Therefore we explain our specific solution next to general principles (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Alleviation of catastrophic quenching in solar dynamo model with nonlocal alpha‐effect
Authors: Kitchatinov L.L. , Olemskoy S.V.
Published: June 2011

The nonlocal alpha‐effect of Babcock‐Leighton type is not prone to the catastrophic quenching due to conservation of magnetic helicity. This is shown with a dynamo model, which jointly applies the nonlocal alpha‐effect, the diamagnetic pumping, and dynamical equation for the magnetic alpha‐effect. The same model shows catastrophic quenching when the alpha‐effect is changed to its local formulation. The nonlocal model shows a preferred excitation of magnetic fields of dipolar symmetry, which oscillate with a period of about ten years and have a toroidal‐to‐polar fields ratio of about a thousand (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Speckle observations with PISCO in Merate: X. Astrometric measurements of visual binaries in 2009
Authors: Scardia M. , Prieur J.‐L. , Pansecchi L. , Argyle R.W. , Sala M.
Published: June 2011

We present relative astrometric measurements of visual binaries, made in 2009 with the speckle camera PISCO at the 102 cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained 345 new measurements of 259 objects, with angular separations in the range 0.″18–4.″6, and an average accuracy of 0.″011. The mean error on the position angles is 0.°6. Most of the position angles were determined without the usual 180° ambiguity with the application of triple‐correlation techniques and/or by inspection of the long integration files. We have found a possible new close component for ADS 2377, which would be a new quadruple star system. We also present new revised orbits for ADS 8035, 9982, 11484, and MLR 198, partly derived from those observations, and infer estimated values for the masses of those systems that are compatible with the spectral types (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Water in star‐forming regions with Herschel
Authors: Kristensen L.E. , van Dishoeck E.F.
Published: June 2011

The Herschel Space Observatory is well suited to address several important questions in star‐ and planet formation, as is evident from its first year of operation. This paper focuses on observations of water, a key molecule in the physics and chemistry of star‐formation. In the WISH Key Program, a comprehensive set of water lines is being obtained with the HIFI and PACS instruments toward a large sample of well‐characterized protostars, covering a wide range of luminosities and evolutionary stages. Lines of H2O, CO and their isotopologues, as well as chemically related hydrides, [O I] and [C II] are observed. Together, the data determine the abundance of water in cold and warm gas, reveal the entire CO ladder up to 4000 K above ground, elucidate the physical processes responsible for the warm gas (passive heating, UV or X‐ray‐heating, shocks), quantify the main cooling agents, and probe dynamical processes associated with forming stars and planets (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sandwichfassaden aus Textilbeton — Numerik und Ingenieurmodelle (Teil 2)
Authors: Hegger Josef , Horstmann Michael
Published: June 2011

Im ersten Teil dieses Beitrages [1] wurden experimentelle Untersuchungen an Sandwich fassaden aus Textilbeton vorgestellt. Diese werden durch nichtlineare numerische Simulationen zum Einfluss maßgebender Parameter auf das Tragverhalten von Sandwichquerschnitten ergänzt. Auf Basis von hergeleiteten Ingenieurmodellen, die das Tragverhalten von Sandwichkonstruktionen aus Textilbeton unter Zug‐, Schub‐ und Biegebeanspruchung zutreffend beschreiben, werden zur baupraktischen Anwendung das Biegetragmodell für Beanspruchungen aus Flächenlasten und Temperaturzwang erweitert sowie grund legende Empfehlungen für die Bemessung der Sandwichtragwirkung gegeben.

Sandwich facades made of Textile Reinforced Concrete — numerical investigations and engineering models. In part one of this paper [1], experimental investigations on sandwich facades have been presented. They are amended by non‐linear FE‐simulations to identify the influence of major parameters on the load‐bearing behavior of sandwich sections. Based on the derived engineering models describing the load‐bearing behavior of sandwich sections subjected to tensile, shear and bending forces, the model for bending has been supplemented by distributed loads and temperature loads for practical application. Further on, basic recommendations for the design of the sandwich action are stated.
Prediction and postdiction preferences in guessing
Authors: Brun Wibecke , Teigen Karl Halvor
Published: June 2011

In three studies, it is shown that most subjects when asked to guess the outcome of an uncertain event (a die toss, the sex of a child, the winner of a match) will prefer to do so before the event. This holds regardless of consequences of the guess, or of variations in waiting time from the guess being made to the outcome being known. In a chance situation, a guess‐first preference may be partly explained by a ‘magical control’ hypothesis, but the preference persists in situations where such influences are less thinkable (sex of a child, die thrown by another person). When asked how prediction and postdiction guesses differ, most subjects agree that predictions are most exciting, and that postdiction failures cause more discomfort than prediction failures. Such differences are interpreted as due to the relative amount of perceived internal and external uncertainty in the task at hand. It is speculated that internal uncertainty is felt most acceptable when matched by a corresponding external uncertainty, and most aversive when contrasted to an externally established fact.
Risk perception in a simulated industrial purchasing task: The Effects of single versus multi‐play decisions
Authors: Joag Shreekant G. , Mowen John C. , Gentry James W.
Published: June 2011

An experiment was conducted to test hypotheses concerning the impact of single‐play versus multiple‐play decisions made under risk in a simulated industrial purchasing setting. Results revealed that when a decision had multiple plays (e.g., purchase 100 personal computers), decision makers combined probabilities and outcomes to form their risk perceptions in a manner consistent with a multiplicative information integration model. In contrast, when a decision had a single trial (e.g., purchase one large mainframe computer), information was combined in a manner consistent with a non‐multiplicative integration pattern. In addition, when multiple trials of the decision occurred, subjects perceived lower risk than if the decision had a single play, even though the expected values of the decisions were the same. The results were discussed in terms of their relation to the use of expected value analysis as a decision‐making tool and in terms of their implications for industrial and consumer buying behavior.
A Review of research on Groupthink
Authors: Park Won‐Woo
Published: June 2011

Despite an extensive use of the groupthink model in various areas of social science, there are few empirical studies testing groupthink and many criticisms of it. In order to better understand the concept of groupthink, and to set a foundation for future research, this paper summarizes previous empirical studies on group‐think and indicates problems (e.g., limited inclusion of variables and an inappropriate usage of measurement modes) that exist throughout those studies. Recommendations for future research are then provided.
Circles and triangles an experimental estimation of indifference lines in the marschak‐machina triangle
Authors: Hey John D. , Cagno Daniela Di
Published: June 2011

An experiment in which 68 subjects are asked 60 pairwise preference questions involving random prospects from 4 Marschak‐Machina Triangles is used to estimate 3 preference functional: Subjective Expected Utility, Difference Regret and Generalized Regret. The Difference Regret formulation fits significantly worse than the other two but Generalized Regret does not appear to fit significantly better than SEU, at least for the majority of the subjects.
Essential fatty acid supplementation of DHA and ARA and effects on neurodevelopment across animal species: a review of the literature
Authors: Davis‐Bruno Karen , Tassinari Melissa S.
Published: June 2011

Docosahexanoic acid (DHA) and arachidonic acid (ARA) are long chain essential fatty acids used as supplements in commercial infant formula. DHA/ARA deficient states are associated with adverse neurological outcomes in animals and humans. Preterm infants are at risk for DHA/ARA deficiency. A few clinical reports on the effects of fatty acid supplementation have shown benefit in preterm, low birth weight, and normal infants in the first year of life, whereas others did not. Studies in animals have reported shortened gestation, fetal growth retardation, reduced infant body mass, and increased fetal mortality with consumption of fatty acids during pregnancy. To understand the data that support fatty acid supplementation in infant formula, a review of the animal model literature was undertaken, to examine the effects of DHA/ARA on neurodevelopment, including the effects on visual acuity. Several points emerged from this review. (1) Animal studies indicate that requirements for DHA/ARA vary depending on developmental age. Alterations of the ratio of DHA/ARA can impact developmental outcome. (2) The available studies suggest that while supplementation of DHA/ARA in an appropriate ratio can increase tissue levels of these fatty acids in the brain and retina, tissues sensitive to depletion of fatty acids, the benefit of routine supplementation remains unclear. Few studies measure functional outcome relative to changes in physiologic pools of DHA/ARA after supplementation. (3) Animal literature does not support a clear long‐term benefit of replenishing DHA/ARA tissue levels and administration of these fatty acids at concentrations above those in human milk suggests adverse effects on growth, survival, and neurodevelopment. Birth Defects Res (Part B) 92:240–250, 2011. © 2011 Wiley‐Liss, Inc.