Smart

Distribution by Scientific Domains
Distribution within Polymers and Materials Science

Terms modified by Smart

  • smart material

  • Selected Abstracts


    Genotoxicity of three mouthwash products, Cepacol®, Periogard®, and Plax®, in the Drosophila wing-spot test

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2007
    Fábio Rodrigues
    Abstract Antiseptic mouthwashes used in biofilm control are widely available in the marketplace, despite inconsistent data concerning their genetic and cellular toxicity. In the present study, we investigated the genotoxic potential of three antiseptics currently used for odontologic treatment, Cepacol® (containing cetylpyridinium chloride), Periogard® (chlorhexidine digluconate), and Plax® (triclosan). Genotoxicity was evaluated using the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster, employing flies having normal bioactivation (the standard cross) and flies with increased cytochrome P450-dependent biotransformation capacity (the high bioactivation cross). Periogard and Plax produced negative responses in both types of flies; however, Cepacol (75 and 100%) produced positive responses in both the standard and high bioactivation assays, with the genotoxic responses mainly due to the induction of mitotic recombination. Assays performed with ethanol and cetylpirydinium chloride, two major ingredients of Cepacol, indicated that the genotoxity of the mouthwash is likely to be due to ethanol. Environ. Mol. Mutagen., 2007. © 2007 Wiley-Liss, Inc. [source]


    Assessing the impact of pollution on the Japaratuba river in Brazil using the Drosophila wing spot test

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2007
    Silmara de Moraes Pantaleão
    Abstract The Drosophila melanogaster somatic mutation and recombination test (SMART) was used to assess the genotoxicity of surface (S) and bottom (B) water and sediment samples collected from Sites 1 and 2 on the Japaratuba River (Sergipe, Brazil), an area impacted by a petrochemical industrial complex that indirectly discharges treated effluent (produced water) into the river. The genotoxicity tests were performed in standard (ST) cross and high bioactivation (HB) cross flies and were conducted on samples taken in March (dry season) and in July (rainy season) of 2003. Mutant spot frequencies found in treatments with unprocessed water and sediment samples from the test sites were compared with the frequencies observed for similar samples taken from a clean reference site (the Jacarecica River in Sergipe, Brazil) and those of negative (ultrapure water) controls. While samples from the Japaratuba River generally produced greater responses than those from the Jacarecica River, positive responses were detected for both the test and reference site samples. All the water samples collected in March 2003 were genotoxic. In July 2003, the positive responses were restricted to water samples collected from Sites 1 B and 2 S in the ST cross. The genotoxicity of the water samples was due to mitotic recombination, and the samples produced similar genotoxic responses in ST and HB flies. The spot frequencies found in the July water samples were considerably lower than those for the March water samples, suggesting a seasonal effect. The only sediment samples that were genotoxic were from Site 1 (March and July) and from the Jacarecica River (March). The genotoxins in these samples produced both somatic mutation (limited to the Site 1 sample in HB flies) and recombination. The results of this study indicate that samples from both the Japaratuba and Jacarecica Rivers were genotoxic, with the most consistently positive responses detected with Site 1 samples, the site closest to the putative pollution source. Environ. Mol. Mutagen. 48:, 2007. © 2007 Wiley-Liss, Inc. [source]


    Completing the hypusine pathway in Plasmodium

    FEBS JOURNAL, Issue 20 2009
    Deoxyhypusine hydroxylase is an E-Z type HEAT repeat protein
    In searching for new targets for antimalarials we investigated the biosynthesis of hypusine present in eukaryotic initiation factor-5A (eIF-5A) in Plasmodium. Here, we describe the cloning and expression of deoxyhypusine hydroxylase (DOHH), which completes the modification of eIF-5A through hydroxylation of deoxyhypusine. The dohh cDNA sequence revealed an ORF of 1236 bp encoding a protein of 412 amino acids with a calculated molecular mass of 46.45 kDa and an isoelectric point of 4.96. Interestingly, DOHH from Plasmodium has a FASTA SCORE of only 27 compared with its human ortholog and contains several matches similar to E-Z-type HEAT-like repeat proteins (IPR004155 (InterPro), PF03130 (Pfam), SM00567 (SMART) present in the phycocyanin lyase subunits of cyanobacteria. Purified DOHH protein displayed hydroxylase activity in a novel in vitro DOHH assay, but phycocyanin lyase activity was absent. dohh is present as a single-copy gene and is transcribed in the asexual blood stages of the parasite. A signal peptide at the N-terminus might direct the protein to a different cellular compartment. During evolution, Plasmodium falciparum acquired an apicoplast that lost its photosynthetic function. It is possible that plasmodial DOHH arose from an E/F-type phycobilin lyase that gained a new role in hydroxylation. Structured digital abstract ,,MINT-7255047: DHS (uniprotkb:P49366) enzymaticly reacts (MI:0414) with eIF-5A (uniprotkb:Q710D1) by enzymatic studies (MI:0415) ,,MINT-7255326: DOHH (uniprotkb:Q8I701) enzymaticly reacts (MI:0414) with eIF-5A (uniprotkb:Q710D1) by enzymatic studies (MI:0415) [source]


    A comparison of budesonide/formoterol maintenance and reliever therapy vs. conventional best practice in asthma management

    INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 10 2009
    R. Louis
    Summary Objective:, To study the effectiveness and safety of budesonide/formoterol (Symbicort®) Maintenance And Reliever Therapy (Symbicort SMART®, AstraZeneca, Södertalje, Sweden), a simplified management approach with one inhaler compared with conventional best practice (CBP) with multiple inhalers in patients with persistent asthma. Design:, Open-label randomised controlled parallel group trial, 6-month treatment. Participants:, A total of 908 patients , 12 years of age, with persistent asthma receiving treatment with inhaled corticosteroids (ICS), either alone or in conjunction with long-acting ,2 -agonist. Main outcome measures:, Time to first severe asthma exacerbation and number of severe asthma exacerbations. Results:, No difference between groups was seen in time to first severe exacerbation (p = 0.75). Exacerbation rates were low in both groups. A total of 12 patients in the Symbicort SMART® group experienced a total of 14 severe asthma exacerbations, and 19 patients in the CBP group experienced a total of 25 severe asthma exacerbations (annual rate 0.07 vs. 0.13 p = 0.09). The mean daily dose of ICS expressed in BDP equivalent was significantly lower in the Symbicort SMART® group (including as-needed use) vs. in the CBP group (749 ,g vs. 1059 ,g; p < 0.0001). Mean scores in Asthma Control Questionnaire, 5 question version improved significantly in the SMART group compared with the CBP group (p = 0.0026). Symbicort SMART and CBP were equally well tolerated. The mean drug cost/patient/month was significantly lower for the patients in the Symbicort SMART group compared with patients receiving CBP (51.3 , vs. 66.5 ,; p < 0.0001). Conclusions:, In Belgian patients, a simplified regimen using budesonide/formoterol maintenance and reliever therapy was at least as effective at improving clinical control compared with CBP with a significantly lower ICS dose and significantly lower drug costs. [source]


    The Supervised Methadone and Resettlement Team nurse: an effective approach with opiate-dependent, homeless people

    INTERNATIONAL NURSING REVIEW, Issue 2 2001
    W. Mistral BSC.
    Abstract Homelessness and substance misuse have risen dramatically over the past 30 years in the UK. The role of the primary care nurse has been signalled as important in working with people who have drug and alcohol problems, and for improving the general health of homeless people. This article focuses on the role of the primary care nurse in a Supervised Methadone and Resettlement Team (SMART). The team works in central Bristol, in southwest England, with people who are homeless and using illegal opiates. The aim of this report is to provide descriptive information that demonstrates the value of the primary care nurse, working in a multiagency partnership, in dealing with the problems of this homeless population, many of whom have problems associated with illicit drug use. Client outcomes from a small sample of homeless persons are also described. [source]


    Nanosensor Design Packages: A Smart and Compact Development for Metal Ions Sensing Responses,

    ADVANCED FUNCTIONAL MATERIALS, Issue 18 2007
    A. El-Safty
    Abstract With recent advances in mesostructured materials and nanotechnologies, new methods are emerging to design optical sensors and biosensors, and to develop highly sensitive solid sensors. Here, highly sensitive, low cost, simple nanosensor designs for naked-eye detection of toxic metal ions are successfully developed by the immobilization of commercially available ,,,,,,,-tetrakis(1-methylpyridinium-4-yl)porphine p -toluenesulfonate (TMPyP) and diphenylcarbazide (DPC), and chemically synthesized 4- n -dodecyl-6-(2-thiazolylazo) resorcinol (DTAR) and 4- n -dodecyl-6-(2-pyridylazo) phenol (DPAP) chromophore molecules into spherical nanosized cavities and surfaces. A rational strategy was crucial to develop optical nanosensors that can be used to control accurate recognition and signaling abilities of analyte species for ion-sensing purposes. This is the first reported evidence of the significant key factors of the development of receptors as ,indicator dyes' and surface-confinement materials as ,carriers' to broadening the applicability of optical chemical sensors for selective discrimination of trace levels of toxic analytes. In all the nanosensor design techniques presented here, a dense pattern of immobilized hydrophobic ,neutral' and hydrophilic ,charged' chromophores with intrinsic mobility, as a result of extremely robust constructed sequences on nanoscale structures, is a key to enhancing the sensing functionality of optical nanosensors. These nanosensor designs can be used as cage probe sinks with reliable control, for the first time, over the colorimetric recognition of cadmium ions to low levels of concentration in the range of 10,9 to 10,10M. Optimization of control sensing conditions is established to achieve enhanced signal response and color intensities. These chemical nanosensors are reversible and have the potential to serve effectively in on-site field analysis of environmental samples, which eliminates the necessity for instrument-dependent analysis. Moreover, these new classes of optical cage sensors exhibit long-term stability of signaling and recognition functionalities that in general provide extraordinary sensitivity, selectivity, reusability, and fast kinetic detection and quantification of various deleterious metal ions in our environment. [source]


    Erratum: In memoriam: Philip St. John Smart, 1961,2008

    INTERNATIONAL INSOLVENCY REVIEW, Issue 2 2009
    Article first published online: 26 JUN 200
    The article above (DOI: 10.1002/iir.167) was published in IIR18:1on pages 1,4. The article was attributed in error to Harold Hsiao-Wo Lee. Harold Hsiao-Wo Lee is the name of the Chair that Philip St. John Smart held at the University of Hong Kong. The correct attribution should have been to two authors only: AndrewJ. Halyard of the University ofHong Kong, Hong Kong and Charles D. Booth of the University of Hawaii, USA. We apologise to Andrew J. Halyard and Charles D. Booth for this oversight. [source]


    Bio-Inspired, Smart, Multiscale Interfacial Materials,

    ADVANCED MATERIALS, Issue 15 2008
    Fan Xia
    Abstract In this review a strategy for the design of bioinspired, smart, multiscale interfacial (BSMI) materials is presented and put into context with recent progress in the field of BSMI materials spanning natural to artificial to reversibly stimuli-sensitive interfaces. BSMI materials that respond to single/dual/multiple external stimuli, e.g., light, pH, electrical fields, and so on, can switch reversibly between two entirely opposite properties. This article utilizes hydrophobicity and hydrophilicity as an example to demonstrate the feasibility of the design strategy, which may also be extended to other properties, for example, conductor/insulator, p-type/n-type semiconductor, or ferromagnetism/anti-ferromagnetism, for the design of other BSMI materials in the future. [source]


    Testing the Long-Term Effects of the Go Sun Smart Worksite Health Communication Campaign: A Group-Randomized Experimental Study

    JOURNAL OF COMMUNICATION, Issue 3 2008
    Peter A. Andersen
    This study examined the long-term effects of the Go Sun Smart (GSS) campaign, a large-scale health communication intervention designed to promote sun safety to employees at 26 ski areas in western North America. Employees were enrolled in a pair-matched group-randomized pretest,posttest controlled design with 2 follow-up surveys. Half of the ski areas were randomly assigned to implement GSS in the winter. This article reports analyses of a hierarchical linear design with responses from 1,463 employees who completed the second follow-up survey at the end of the following summer (69% of those who completed the first posttest). GSS continued to have positive effects on employees who worked at intervention ski areas into the summer. Employees exposed to GSS reported less sunburning, engaged in more sun safety behaviors, were more aware of the program, and had more discussions of sun safety at home than employees at matched control group resorts. The long-term effects of GSS support recommending that sun protection programs be implemented at workplaces, but such programs should be implemented with high fidelity to achieve maximum benefits. Despite limitations due to nonresponse, geography, measurement, and ethnicity, the hierarchical clustered design improved the internal validity and generalizability of the findings. [source]


    Legal Feminism and Foucault , A Critique of the Expulsion of Law

    JOURNAL OF LAW AND SOCIETY, Issue 4 2001
    Vanessa E. Munro
    Contemporary theorists have become increasingly receptive to the selective incorporation of Foucaultian theory within feminist frameworks. However, the reception of Foucault within feminist legal critique has been less enthusiastic. The most celebrated theorist to argue for the incorporation of Foucaultian insight within the feminist analysis of law is Carol Smart. While conceding the significant contribution of her work, this article will argue that her interpretation of the Foucaultian thesis on law is considerably more problematic. Illustrating the extent to which she adopts an unnecessarily pessimistic prognosis for the development of Foucault within legal analysis and reform, this article will examine an emerging counter-interpretation of Foucault that presents the possibility for a more promising application, seeking to provide a defence both of the utility of Foucault for feminist jurisprudence, and of the utility of legal reform strategies being exercised for feminist purposes. [source]


    When a Grandiose Self-Image Is Threatened: Narcissism and Self-Concept Clarity as Predictors of Negative Emotions and Aggression Following Ego-Threat

    JOURNAL OF PERSONALITY, Issue 4 2002
    Tanja S. Stucke
    ABSTRACT Two studies examined the relation between narcissism, self-concept clarity, negative emotions, and aggression based on theoretical assumptions proposed by Baumeister, Smart, and Boden (1996). Narcissism and self-concept clarity were examined as predictors for anger, depression, and verbal aggression following ego-threat, which was operationalized by a bogus performance feedback on an intelligence test. The second study also examined the mediating effects of participants' negative emotions to provide an additional explanation for the aggressive reactions after failure. As expected, narcissism and self-concept clarity were significant predictors of negative emotions and aggression after failure. In accordance with our hypothesis, high narcissists with low self-concept clarity reacted with anger and aggression after failure, whereas less narcissistic individuals with high self-concept clarity showed feelings of depression and no aggression. The results also indicated that aggression was always directed toward the source of the ego-threatening feedback. Additionally, anger and depression could predict the aggressive response after failure but they did not mediate the relation between narcissism, self-concept clarity, performance feedback, and aggression. [source]


    The crystallography beamline I711 at MAX,II

    JOURNAL OF SYNCHROTRON RADIATION, Issue 4 2000
    Y. Cerenius
    A new X-ray crystallographic beamline is operational at the MAX,II synchrotron in Lund. The beamline has been in regular use since August 1998 and is used both for macro- and small molecule diffraction as well as powder diffraction experiments. The radiation source is a 1.8,T multipole wiggler. The beam is focused vertically by a bendable mirror and horizontally by an asymmetrically cut Si(111) monochromator. The wavelength range is 0.8,1.55,Å with a measured flux at 1,Å of more than 1011,photons,s,1 in 0.3,mm × 0.3,mm at the sample position. The station is currently equipped with a Mar345 imaging plate, a Bruker Smart 1000 area CCD detector and a Huber imaging-plate Guinier camera. An ADSC 210 area CCD detector is planned to be installed during 2000. [source]


    Smart Assays in Combinatorial Chemistry

    MOLECULAR INFORMATICS, Issue 10 2005
    Morten Meldal
    No abstract is available for this article. [source]


    SCHOLARLY COLLABORATION AND PRODUCTIVITY PATTERNS IN PUBLIC ADMINISTRATION: ANALYSING RECENT TRENDS

    PUBLIC ADMINISTRATION, Issue 3 2010
    ELIZABETH A. CORLEY
    Previous studies have confirmed the interdisciplinary nature of the field of public administration (Mosher 1956; Ventriss 1991; Forrester 1996; Rodgers and Rodgers 2000; Schroeder et al. 2004) and encouraged the exploration of one important indicator of interdisciplinarity: research collaboration. One way that collaboration patterns are explored is through the study of co-authorship among faculty members (Smart and Bayer 1986; Forrester 1996; Katz and Martin 1997). In the field of public administration, studies on co-authorship and productivity of scholars are sparse. In this article, we use bibliometric data to explore collaboration patterns as they relate to productivity levels and quality of publications within the field of public administration. Our study finds that more productive scholars, as well as those with the highest impact, are less likely to collaborate than their colleagues. Our results also indicate that there are gender differences in collaboration patterns and productivity within the field of public administration. [source]


    Street Smarts and Urban Myths: Women, Sex Work, and the Role of Storytelling in Risk Reduction and Rationalization

    MEDICAL ANTHROPOLOGY QUARTERLY, Issue 2 2005
    BRENDA ROCHE
    Storytelling has a strong tradition in inner-city American communities. In this article, we examine patterns of storytelling among a sample of drug-using women from New York City who engage in street-based sex work. We consider two particular formats of storytelling for analysis: "street smarts" and "urban myths." Street smarts are stories of survival, and urban myths are compilations of street legends spread by word of mouth. The narratives are filled with tales of extreme risk across situations. The women used the stories to delineate the boundaries of risk as well as to rationalize risks they deemed to be inevitable but temporary in their lives. Few of the women capitalized on the greater instructive quality of the stories toward increased risk reduction, which may relate to the women's distance from an identity of "sex worker." If properly harnessed, the strength of storytelling suggests new avenues for risk-reduction interventions. [source]


    Information Technology and Emergency Medical Care during Disasters

    ACADEMIC EMERGENCY MEDICINE, Issue 11 2004
    Theodore C. Chan MD
    Abstract Disaster response to mass-casualty incidents represents one of the greatest challenges to a community's emergency response system. Rescuers, field medical personnel, and regional emergency departments and hospitals must often provide care to large numbers of casualties in a setting of limited resources, inadequate communication, misinformation, damaged infrastructure, and great personal risk. Emergency care providers and incident managers attempt to procure and coordinate resources and personnel, often with inaccurate data regarding the true nature of the incident, needs, and ongoing response. In this chaotic environment, new technologies in communications, the Internet, computer miniaturization, and advanced "smart devices" have the potential to vastly improve the emergency medical response to such mass-casualty incident disasters. In particular, next-generation wireless Internet and geopositioning technologies may have the greatest impact on improving communications, information management, and overall disaster response and emergency medical care. These technologies have applications in terms of enhancing mass-casualty field care, provider safety, field incident command, resource management, informatics support, and regional emergency department and hospital care of disaster victims. [source]


    Six Ages towards a Learning Region , A Retrospective

    EUROPEAN JOURNAL OF EDUCATION, Issue 3 2010
    NORMAN LONGWORTH
    Learning Cities and Learning Regions are terms now in common use as a result of the growing importance of lifelong learning concepts to the economic, social and environmental future of people and places. Why ,learning' regions? Why not intelligent, creative, clever, smart or knowledge regions? In truth, all of these can, and some do, also exist, but we argue that this is not a semantic debate. The basis of intelligence, smartness, cleverness, creativity and knowledge is effective learning and its intelligent application in creating a better future. We can, we believe, only learn our way into the future and the same is true, in developmental terms, of cities, towns, regions and communities. What therefore is a learning region? Definitions tend to differ according to perception, situation, occupation and objective. Where the focus is on technology a learning region will emphasise the advantages of hi-tech for the development of a physical infrastructure that will assist regeneration and be useful for more efficient behaviour and learning by people and organisations. Hence the growth of ,smart cities,' mainly in North America. Where it is on employment, employability, organisational management and training for industry, the development of human and social capital for economic gain and competitive edge tends to predominate. Most regions concentrate on this aspect. Where the motivation is based on the use of valuable resources, it will concentrate on volunteering, active citizenship and the building of social capital. Such an approach is not well developed in many regions and the optimum balance between economic, community and personal growth is poorly understood. Where the goal is the competent use of organisational potential a learning region will mobilise all its stakeholder institutions as partners in the service of the region as a whole. Here, very little is understood or implemented. This article argues that all of these approaches and others in the fields of environment, personal and cultural growth, innovation, diversity and communication are a holistic part and parcel of learning region development. Its meaning and its characteristics will become clear as it charts the development of ideas about learning regions, particularly those that have occurred during the past 20 years. It suggests the existence of a paradigm shift at work , the age of education and training, which has served us well in the late 20th century in satisfying the needs of a growing, upwardly mobile proportion of the population, has now given way to the era of lifelong learning, in which the means, the tools and techniques are employed to target and motivate everyone in a city, town or region. Those regions that achieve this nirvana will be the winners in the apparent paradox that intelligent local action leads to success in a globalised world, a version of the concept of ,glocalisation' coined by Robertson (1995). [source]


    Solar Energy Collectors with Tunable Transmission

    ADVANCED FUNCTIONAL MATERIALS, Issue 9 2010
    Michael G. Debije
    Abstract A new type of "smart" window is proposed that makes use of fluorescent dye guests in a liquid-crystal host sandwiched between glass panels. The dye absorbs a variable amount of light depending on its orientation, and re-emits this light, of which a significant fraction is trapped by total internal reflection at the glass,air interface, and becomes concentrated along the edges. Such a device could both generate electricity via an attached photovoltaic as well as allow user control of the amount of transmitted light. By applying a voltage across the cell, absorption could be varied 31%, while the usable light output only varied 11% due to the increased efficiency of light collection at homeotropic dye orientation. [source]


    Why Is the Intelligence Community So Difficult to Redesign?

    GOVERNANCE, Issue 3 2007
    Conflicting Goals, Smart Practices, the Creation of Purpose-Based Organizations
    The adoption of "smart practices" requires that smart practices can actually be identified for the areas of public policy in which we are interested. For the problem of designing structures for public agencies, however, identifying smart practices is not easy. This article explores the reasons for the substantial conservativism, lasting over 50 years, regarding the structural design of the U.S. intelligence community. One central argument is simply that it was very difficult to discover a clearly superior structure; in fact, the long-standing structure may have had some unrecognized virtues. But the other central argument is that one smart practice may have emerged since the 9/11 attacks: It involves the creation of problem-focused interagency centers that are intended to enhance the sharing and integration of information within the intelligence community. These conclusions about redesigning the structure of the intelligence community are based on the arguments of Luther Gulick on methods of departmentalization and Martin Landau on redundancy and system reliability. [source]


    Smart Drug-Loaded Polymer Gold Nanoshells for Systemic and Localized Therapy of Human Epithelial Cancer

    ADVANCED MATERIALS, Issue 43 2009
    Jaemoon Yang
    Near-infrared-light-sensitive multifunctional smart drug-loaded polymer gold nanoshells are fabricated as advanced prototypes, composed of chemotherapeutic agents (therapeutic antibody and anticancer drug-loaded polymeric nanoparticles) for systemic chemotherapy of human epithelial cancer and a polymer-based gold nanoshell for localized photothermal treatment by NIR light. [source]


    Multiresponsive, Hierarchically Structured Membranes: New, Challenging, Biomimetic Materials for Biosensors, Controlled Release, Biochemical Gates, and Nanoreactors

    ADVANCED MATERIALS, Issue 2 2009
    Ihor Tokarev
    Multifunctional responsive gel membranes present a new and promising platform for the development of "smart" devices for bioseparation, biosensors, and "smart" drug release. These membranes combine the functions of stimuli-responsive control and regulation of the mass transport with a range of properties, such as storage, catalysis of chemical reactions, antimicrobial activity, and optical signal transduction. [source]


    Bio-Inspired, Smart, Multiscale Interfacial Materials,

    ADVANCED MATERIALS, Issue 15 2008
    Fan Xia
    Abstract In this review a strategy for the design of bioinspired, smart, multiscale interfacial (BSMI) materials is presented and put into context with recent progress in the field of BSMI materials spanning natural to artificial to reversibly stimuli-sensitive interfaces. BSMI materials that respond to single/dual/multiple external stimuli, e.g., light, pH, electrical fields, and so on, can switch reversibly between two entirely opposite properties. This article utilizes hydrophobicity and hydrophilicity as an example to demonstrate the feasibility of the design strategy, which may also be extended to other properties, for example, conductor/insulator, p-type/n-type semiconductor, or ferromagnetism/anti-ferromagnetism, for the design of other BSMI materials in the future. [source]


    Lower critical solution temperature determination of smart, thermosensitive N -isopropylacrylamide- alt -2-hydroxyethyl methacrylate copolymers: Kinetics and physical properties

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
    Mohammad M. Fares
    Abstract The lower critical solution temperatures (LCSTs) were verified and determined for different molar feed ratios of N -isopropylacrylamide (NIPAAm) and 2-hydroxyethyl methacrylate (HEMA) monomers with ultraviolet spectroscopy and differential scanning calorimetry techniques. Increases in the NIPAAm monomer content played a crucial role in the LCST, which increased up to 36.7°C at 50 mol %. However, a further increase in the NIPAAm monomer content steadily reduced the LCST, which decreased to 33°C at 100 mol % NIPAAm [i.e., pure poly(N -isopropylacrylamide)]. The rate of copolymerization, assessed by the conventional conversion (%),time method, and the apparent activation energies were determined. The reactivity ratios of the monomers, determined by the Kelen,Tudos and Fineman,Ross techniques, together with the results of an equation, showed that the copolymer which formed was an alternating copolymer. The Q,e values for the NIPAAm monomer were determined. The equation showed the linear Arrhenius behavior of ln(r1r2) versus the reciprocal of the temperature (where r1 and r2 are the reactivity ratios of NIPAAm and HEMA, respectively): the activation energy difference [i.e., (E12 + E21) , (E11 + E22), where E12, E21, E11, and E22 are various activation energies] was found to be ,109 kJ/mol. The copolymers were characterized with 1H-NMR, 13C-NMR, Fourier transform infrared, ultraviolet,visible, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy techniques. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


    Smart Labels for Waste and Resource Management

    JOURNAL OF INDUSTRIAL ECOLOGY, Issue 2 2008
    An Integrated Assessment
    Summary This article explores the potential of RFID (radio frequency identification device) for improving the current waste and resource management system in Switzerland. It presents the following three possible options for utilizing RFID tags to support waste management processes: "at source automation" (using a "smart" trash can), "end of pipe I" (combination of the current system with an additional separation of recyclables before incineration), and "end of pipe II" (replacement of the current recycling infrastructure by sorting at the incineration plant). These options tackle the waste and resource management chain during different processes (i.e., waste generation, waste separation, and treatment). Based on an MFA (material flow analysis), we performed a multicriteria assessment of these options with experts from the waste management sector. The assessment of ten experts in the waste management field regarding the proposed options for batteries and electrical appliances showed that, from an ecological perspective, the implementation of RFID in waste management would be desirable and would lead to an improvement in the current recycling rate in Switzerland for the goods studied. From an economic perspective, new investments would be required in the range of 1 to 5 times the maintenance costs of the current separate collection system. From a social perspective, the utilization of RFID tags in the waste management process was ambiguous. In particular, the end of pipe II option would, on the one hand, significantly improve convenience for consumers. On the other hand, experts see privacy and, what is more, social responsibility as being under threat. The experts considered the ecological and social aspects to be more relevant than the economic ones, preferring the end of pipe I option over the other options and the status quo. [source]


    Thermoresponsive hydrogel of poly(glycidyl methacrylate- co - N -isopropylacrylamide) as a nanoreactor of gold nanoparticles

    JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2007
    Xiaowei Jiang
    Abstract The synthesis of a thermoresponsive hydrogel of poly(glycidyl methacrylate- co - N -isopropylacrylamide) (PGMA- co -PNIPAM) and its application as a nanoreactor of gold nanoparticles are studied. The thermoresponsive copolymer of PGMA- co -PNIPAM is first synthesized by the copolymerization of glycidyl methacrylate and N -isopropylacrylamide using 2,2,-azobis(isobutyronitrile) as an initiator in tetrahydrofuran at 70 °C and then crosslinked with diethylenetriamine to form a thermoresponsive hydrogel. The lower critical solution temperature (LCST) of the thermoresponsive hydrogel is about 50 °C. The hydrogel exists as 280-nm spheres below the LCST. The diameter of the spherical hydrogel gradually decreases to a minimum constant of 113 nm when the temperature increases to 75 °C. The hydrogel can act as a nanoreactor of gold nanoparticles because of the coordination of nitrogen atoms of the crosslinker with gold ions, on which a hydrogel/gold nanocomposite is synthesized. The LCST of the resultant hydrogel/gold nanocomposite is similar to that of the hydrogel. The size of the resultant gold nanoparticles is about 15 nm. The hydrogel/gold nanocomposite can act as a smart and recyclable catalyst. At a temperature below the LCST, the thermoresponsive nanocomposite is a homogeneous and efficient catalyst, whereas at a temperature above the LCST, it becomes a heterogeneous one, and its catalytic activity greatly decreases. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2812,2819, 2007 [source]


    Cement-Based 0-3 Piezoelectric Composites

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2002
    Zongjin Li
    To meet the requirements of development for smart or intelligent structures in civil engineering, new functional materials that have good compatibility with civil engineering structural materials are needed. In this study, for the first time in the field of piezoelectric materials, cement-based 0-3 piezoelectric (PZT) composites were fabricated by the normal mixing and spreading method. The new materials have very good compatibility with portland cement concrete. The cement-based 0-3 piezoelectric composites were shown to have a slightly higher piezoelectric factor and electromechanical coefficient than those of 0-3 PZT/polymer composites with a similar content of PZT particles; thus, they are adequate for sensor application. There is potential for the application of cement-based 0-3 PZT composites in civil engineering because of their better piezoelectric properties and good compatibility with portland cement concrete. [source]


    Using Metallo-Supramolecular Block Copolymers for the Synthesis of Higher Order Nanostructured Assemblies

    MACROMOLECULAR RAPID COMMUNICATIONS, Issue 1 2010
    Adam O. Moughton
    Abstract Many research groups have explored the properties and solution self-assembly of main chain metallo-supramolecular multiblock copolymers. Until recently, these metal complexes have been used to prepare mainly micelle type structures. However, the self-assembly of such copolymers has been exploited further to create more advanced architectures which utilize the reversible supramolecular linkage of their building blocks as a key component in their synthesis. Furthermore, the incorporation of multiple orthogonal interactions and stimuli responsive polymers into their design, enables more precise external control of their properties. This feature article discusses recent developments and provides an insight into their potential exploitation and development for the creation of novel, smart, and responsive nanostructures. [source]


    Triangular planar array of a pyramidal adaptive antenna for satellite communications at 1.7 GHz

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2009
    J. L. Masa-Campos
    Abstract Nowadays, satellite communications are basic for the human lifestyle. In this way, a smart, conformal, and multiarray antenna (GEODA) is being developed in order to receive signals from several satellites simultaneously in the 1.7 GHz working band. An adaptive beam system is able to follow the signals from the satellite constellation. The complex structure of the antenna is based in a 3D composition of planar arrays with triangular shape. These arrays are divided into subarrays of three patches (Cells), composing the single control element for the arrays main beam direction management. Fifteen cells (45 radiating elements) compose each triangular array of the GEODA antenna. In this article, a triangular array prototype is implemented and measured. Likewise, an individual characterization of the array components is presented. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2633,2639, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24692 [source]


    Identification of desulphoglucosinolates in Brassicaceae by LC/MS/MS: Comparison of ESI and atmospheric pressure chemical ionisation-MS

    MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 12 2007
    Nadine S. Zimmermann
    Abstract In order to develop a sensitive method for the detection of desulphoglucosinolates by HPLC-MS, the two most common interfaces for HPLC-MS, atmospheric pressure chemical ionisation (APCI) and ESI, were compared. While working with the APCI-interface the evaporation temperature and corona amperage were optimised. In doing so 300°C and 6 ,A proved to be most suitable for aliphatic and indole desulphoglucosinolates. The use of formic acid instead of water in the eluent in HPLC-ESI-MS measurements increased the sensitivity for the indole desulphoglucosinolates in the presence of 1 mM formic acid, while the sensitivity for the aliphatic desulphoglucosinolate desulphoglucoraphanin was substantially increased by the presence of 5 mM formic acid. Using an Agilent ion trap, two optimisation procedures for the MS parameters, smart and expert mode, were available. In smart mode the software optimises several parameters automatically, which is much more time efficient than expert mode, in which the optimisation is done manually. It turned out that ESI-MS is most sensitive in smart mode, while for APCI-MS a higher sensitivity could be gained using the expert mode. Comparing both interfaces, APCI-MS was more sensitive than ESI-MS. However, no additional information, in terms of structure determination, was obtained by APCI-MS. [source]


    Changing assumptions about who can learn

    NEW DIRECTIONS FOR HIGHER EDUCATION, Issue 119 2002
    George Campbell
    When students at any level fail to learn, we don't ask, "What are we doing wrong?" or "Should we attempt a different pedagogical approach or a different motivational strategy?" We simply deduce that they are not smart enough. [source]