Innovation,competition and change in international business: Emergent research trajectories

Abstract and Key Results

Technofunctional Properties of Films Made From Ethylene Vinyl Acetate/Whey Protein Isolate Compounds

One challenge faced by the plastics industry is that crude oil will become scarcer and more expensive in the future. Furthermore, an increase in plastic waste is leading to a strongly growing demand for sustainable alternatives to traditional, crude oil‐based polymers in the packaging sector. The aim of this study was to investigate the influence of the incorporation of whey protein isolates (WPIs) on the technofunctional properties of ethylene vinyl acetate (EVA) films. The compounding EVA with WPI was conducted in a co‐rotating twin‐screw extruder at varying processing temperatures. WPI and hydrolysed WPI with a degree of hydrolysis of 10% were used up to 35% (w/w) as filler. The tensile strength and elongation at break of the resulting EVA‐based films decreased significantly with increasing filler content. Because of the hydrophilicity of WPI, the water vapour permeability of the films increased. Advantageously, the oxygen barrier was enhanced by 50–80% compared with that of pure EVA films, which offered the potential of using whey proteins as a filler in compounds for packaging materials for their oxygen barrier properties. In addition, this study provides a promising perspective on the thermoplastic processing of whey protein formulations in the future. Copyright © 2013 John Wiley & Sons, Ltd.     

Structural studies on some doped CdS thin films deposited by thermal evaporation

The influence of the Mn, Se and Sb impurities on the structure and morphology of CdS thin films grown on p⁺ Si wafers was studied. The starting powders were mixed in the same molar ratios (0.3%) and deposited in the same conditions by vacuum thermal evaporation. X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and reflectance studies made on thermal treated thin films (573 K, 2 h in air) evidenced that thin films have a hexagonal oriented structure, and that dopants enter into the CdS lattice merely by substitution. The dopant nature influences the thin film thickness and chemical composition. The doped CdS thin films have roughness in nanometer region and a reflectivity lower than 40%. Silicon substrate acts as a template and favors the retention of Mn and scatters the Sb dopants. The CdS:Se thin film is thicker than CdS:Mn and CdS:Sb ones and is a mixture of doped and undoped nanocrystals.     

Investigation of structural properties of ITO thin films deposited on different substrates

The influence of the substrate nature on the structure and morphology of ITO thin films grown by thermal evaporation in vacuum is investigated. The as-prepared metal films with Sn/In molar ratio of 0.1 were subsequently annealed for 2 h at 723 K in air (to obtain tin doped indium oxide), then annealed in vacuum at 523 K, followed by UV irradiation (to reduce the electrical resistivity). Irrespective of substrate nature, XRD data evidence a (222) preferential orientation in films. Substrate nature, annealing in vacuum and UV irradiation influence the structure, morphology, optical, electrical and surface wetting properties of the films' surface.     

Innovation,competition and regulatory change: Assessing interrelationships at the industry level

Abstract and Key Results

Structure and gas sensing properties of nanocrystalline Fe-doped ZnO films prepared by spin coating method

Nanocrystalline Fe-doped ZnO films were obtained by spin coating, using zinc acetate and iron acetate as starting materials and N,N-dimethylformamide as solvent. Characteristic XRD patterns indicate that the films under study are single phase with the ZnO-like wurtzite structure. There are not any secondary phases and Fe²⁺ as well as Fe³⁺ substitutes for Zn²⁺ of ZnO host. Atomic force microscopy analysis revealed that the studied films are characterized by high-density columnar structure and the incorporation of Fe atoms into the ZnO lattice modified the surface morphology. The sensitivity, at three different gases, was investigated and it was observed that acetone is the test gas that produces the most significant changes in the electrical resistance of all studied samples. Experimental results indicate that the optimum operating temperature increases for Fe-doped ZnO films by comparison with the undoped one. Also, the values of sensitivity were found to depend on the dopant concentration in ZnO films.     

Plasmonic enhancement of molecular fluorescence

Metallic nanoparticles are known to dramatically modify the spontaneous emission of nearby fluorescent molecules and materials. Here we examine the role of the nanoparticle plasmon resonance energy and nanoparticle scattering cross section on the fluorescence enhancement of adjacent indocyanine green (ICG) dye molecules. We find that enhancement of the molecular fluorescence by more than a factor of 50 can be achieved for ICG next to a nanoparticle with a large scattering cross section and a plasmon resonance frequency corresponding to the emission frequency of the molecule.     

Light interactions with gold nanorods and cells: implications for photothermal nanotherapeutics

Gold nanorods (AuNR) can be tailored to possess an intense and narrow longitudinal plasmon (LP) absorption peak in the far-red to near-infrared wavelength region, where tissue is relatively transparent to light. This makes AuNRs excellent candidates as contrast agents for photoacoustic imaging, and as photothermal therapeutic agents. The favorable optical properties of AuNR which depend on the physical parameters of shape, size and plasmonic coupling effects, are required to be stable during use. We investigate the changes that are likely to occur in these physical parameters in the setting of photothermal therapeutics, and the influence that these changes have on the optical properties and the capacity to achieve target cell death. To this end we study 3 sets of interactions: pulsed light with AuNR, AuNR with cells, and pulsed light with cells incubated with AuNR. In the first situation we ascertain the threshold value of fluence required for photothermal melting or reshaping of AuNR to shorter AuNR or nanospheres, which results in drastic changes in optical properties. In the second situation when cells are exposed to antibody-conjugated AuNR, we observe using transmission electron microscopy (TEM) that the particles are closely packed and clustered inside vesicles in the cells. Using dark-field microscopy we show that plasmonic interactions between AuNRs in this situation causes blue-shifting of the LP absorption peak. As a consequence, no direct lethal damage to cells can be inflicted by laser irradiation at the LP peak. On the other hand, using irradiation at the transverse peak (TP) wavelength in the green, at comparative fluences, extensive cell death can be achieved. We attribute this behavior on the one hand to the photoreshaping of AuNR into spheres and on the other hand to clustering of AuNR inside cells. Both effects create sufficiently high optical absorption at 532 nm, which otherwise would have been present at the LP peak. We discuss implications of these finding on the application of these particles in biomedicine.     

A music-based HIV prevention intervention for urban adolescents.

Objective: This research examines the process of conducting and evaluating a music-based HIV prevention intervention among urban adolescents, and is informed by the information, motivation, behavioral skills (IMB) model. Design: Musically talented opinion leaders were recruited to write, record, and distribute HIV prevention themed music to their peers to increase HIV prevention motivation, behavioral skills, and behaviors. In this 3-month field experiment, participants were 306 students enrolled in health classes at each of three large multiracial urban high schools (one treatment school; two control schools). Main Outcome Measures: Measures of HIV prevention information, motivation, behavioral skills, and behaviors, both pre- and postintervention. Results and Conclusion: Results indicate that the intervention influenced several aspects of HIV prevention motivation, behavioral skills, and condom use and HIV testing behaviors. This research demonstrates that the incorporation of music into HIV prevention interventions for adolescents has the potential to be effective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)