WorldWideScience

Sample records for active dispersion tailored

  1. Dispersion-tailored active-fiber solitons

    Science.gov (United States)

    van Tartwijk, Guido H. M.; Essiambre, René-Jean; Agrawal, Govind P.

    1996-12-01

    We show analytically that tailoring the fiber dispersion appropriately can cause optical solitons to propagate unperturbed, without emission of dispersive waves, in a distributed-gain fiber amplifier with a nonuniform gain profile. We apply our scheme to a bidirectionally pumped fiber amplifier and discuss the importance of higher-order nonlinear and dispersive effects for short solitons.

  2. Tailoring Dispersion properties of photonic crystal waveguides by topology optimization

    DEFF Research Database (Denmark)

    Stainko, Roman; Sigmund, Ole

    2007-01-01

    The paper describes a systematic method for the tailoring of dispersion properties of slab-based photonic crystal waveguides. The method is based on the topology optimization method which consists in repeated finite element frequency domain analyzes, analytical sensitivity analyzes and gradient...... based design updates. The goal of the optimization process is to come up with slow light, zero group velocity dispersion photonic waveguides or photonic waveguides with tailored dispersion properties for dispersion compensation purposes. Two examples concerning reproduction of a specific dispersion...

  3. Low-loss and bendable THz fiber with tailored dispersion

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Rasmussen, Henrik K.; Adam, Aurèle J. L.;

    2009-01-01

    A polymer THz fiber made of Topas and having a Photonic Crystal Fiber structure is demonstrated. It has low broadband loss and the dispersion of the fiber can be tailored by adjusting the structural parameters.......A polymer THz fiber made of Topas and having a Photonic Crystal Fiber structure is demonstrated. It has low broadband loss and the dispersion of the fiber can be tailored by adjusting the structural parameters....

  4. Phase space distributions tailored for dispersive media.

    Science.gov (United States)

    Petruccelli, Jonathan C; Alonso, Miguel A

    2010-05-01

    New phase space distributions are proposed for describing pulse propagation in dispersive media for one spatial dimension. These distributions depend on time, position, and velocity, so that the pulse's spatial propagation or temporal evolution is described by a free-particle-like transformation followed by integration over velocity. Examples are considered for approximate Lorentz-model dielectrics and metallic waveguides. PMID:20448787

  5. Group delay and dispersion tailoring in nonadiabatic tapered fibers

    Science.gov (United States)

    Mas, Sara; Palací, Jesús; Martí, Javier

    2016-09-01

    The dispersion profile of a nonadiabatic tapered singlemode fiber is characterized and dynamically tuned. Its group delay and dispersion parameters are measured and compared to those of a standard singlemode fiber. The dispersion profile can be tuned by introducing a phase shift through mechanical stretching. Coarse tuning is also obtained by varying the surrounding medium of the tapered fiber. Dispersion values up to 700 ps/nm·km in nonadiabatic tapered fibers are obtained for the first time. Dynamic tuning exposed here can be very useful in applications such as nonlinearities or soliton generation.

  6. Tailoring chromatic dispersion in chalcogenide-tellurite microstructured optical fiber

    Science.gov (United States)

    Kohoutek, Tomas; Duan, Zhongchao; Kawashima, Hiroyasu; Cheng, Tonglei; Suzuki, Takenobu; Matsumoto, Morio; Misumi, Takashi; Ohishi, Yasutake

    2014-08-01

    We report fabrication of a highly nonlinear hybrid microstructured optical fiber composed of chalcogenide glass core and tellurite glass cladding. The flattened chromatic dispersion can be achieved in such an optical fiber with near zero dispersion wavelength at telecommunication wavelengths λ = 1.35-1.7 μm, which cannot be achieved in chalcogenide glass optical fibers due to their high refractive index, i.e. n > 2.1. We demonstrate a hybrid 4-air hole chalcogenide-tellurite optical fiber (Δn = 0.25) with flattened chromatic dispersion around λ = 1.55 μm. In optimized 12-air hole optical fiber composed of the same glasses, the chromatic dispersion values were achieved between -20 and 32 ps/nm/km in a broad wavelength range of 1.5-3.8 μm providing the fiber with extremely high nonlinear coefficient 86,000 km-1W-1. Hybrid chalcogenide/tellurite fibers pumped with the near infrared lasers give good promise for broadband optical amplification, wavelength conversion, and supercontinuum generation in the near- to mid-infrared region.

  7. Polymer Clad Silica Fibers for Tailoring Modal Area and Dispersion

    Science.gov (United States)

    Rishøj, Lars; Jones, Maxwell; Demas, Jeffrey; Gregg, Patrick; Prabhakar, Gautam; Yan, Lu; Hawkins, Thomas; Ballato, John; Ramachandran, Siddharth

    2016-01-01

    We demonstrate higher-order-mode (Aeff up to ~2000 μm2) propagation in a 100 μm outer diameter pure-silica fiber with a low-index polymer jacket commonly used for fiber-laser pump-guidance. This simple structure obviates the need for complex designs deemed necessary for realizing large-mode-area fibers. Modes ranging from HE1,12 to HE1,22 were found to propagate stably over 15 m in this fiber. The index step is approximately 4 times larger than that obtained with fluorine down doping, thus the fiber supports even higher order modes, which may have implications for building rare earth doped fiber lasers or achieving enhanced dispersion tunability for high-energy fiber nonlinear phenomena. PMID:27472625

  8. An efficient method for supercontinuum generation in dispersion-tailored Lead-silicate fiber taper

    Science.gov (United States)

    Chen, Z.; Ma, S.; Dutta, N. K.

    2010-08-01

    In this paper we theoretically study the broadband mid-IR supercontinuum generation (SCG) in a lead-silicate microstructured fiber (the glass for simulation is SF57). The total dispersion of the fiber can be tailored by changing the core diameter of the fiber so that dispersion profiles with two zero dispersion wavelengths (ZDWs) can be obtained. Numerical simulations of the SCG process in a 4 cm long SF57 fiber/fiber taper seeded by femto-second pulses at telecommunications wavelength of 1.55 µm are presented. The results show that a fiber taper features a continuous shift of the longer zero dispersion wavelength. This extends the generated continuum to a longer wavelength region compared to fibers with fixed ZDWs. The phase-matching condition (PMC) is continuously modified in the fiber taper and the bandwidth of the generated dispersive waves (DWs) is significantly broadened.

  9. TAILORING OF FLATTENED DISPERSION IN TRIANGULAR-LATTICE PHOTONIC CRYSTAL FIBER

    Directory of Open Access Journals (Sweden)

    Sandhir Kumar Singh

    2011-12-01

    Full Text Available The interest of researchers and engineers in several laboratories, since the1980s, has been attracted by the ability to structure materials on the scale of the optical wavelength, a fraction of micrometers or less, in order to develop new optical medium, known as photonic crystals . Photonic crystals rely on a regular morphological microstructure of air-holes, incorporated into the material, which radically alters its optical properties. In Photonic Crystal Fiber (PCF it is possible to realize flat dispersion over a wide wavelength range that cannot be realized with a conventional single-mode fiber. In PCFs, the dispersion can be controlled and tailored with unprecedented freedom. In fact, due to the high refractive index difference between silica and air, and to the flexibility of changing air-hole sizes and patterns, the waveguide contribution to the dispersion parameter can be significantly changed, thus obtaining unusual position of the zero dispersion wavelength, as well as particular values of the dispersion curve slope. In particular, by manipulating the air- hole radius or the lattice period of the micro structured cladding, it is possible to control the zero-dispersion wavelength, which can be tuned over a very wide range, or the dispersion curves, which can be engineered to be ultra flattened. In this paper the geometric parameters of triangular PCF have been properly changed to optimize the dispersion compensation over a wide wavelength range.

  10. Supercontinuum generation in dispersion-tailored lead-silicate fiber taper

    Science.gov (United States)

    Hu, Hongyu; Li, Wenbo; Ma, Shaozhen; Dutta, Niloy K.

    2013-01-01

    In this paper we numerically study the coherence properties of the supercontinuum generated in a lead-silicate microstructured fiber taper, with an increasing core radius along the propagation distance which tailors the dispersion property. Simulations are conducted by adding quantum noise into the input pulse at 1.55 μm, and the complex degree of first-order coherence function and the overall spectral coherence degree are both calculated. Although the spectral broadening is comparable, the coherence degree is shown to vary with different pumping conditions. It decreases with higher peak power and longer duration due to the significant competition between the soliton-fission process and the noise-seeded modulation instability. By controlling the input pulse parameters, it is possible to generate perfectly coherent supercontinuum with a flat broadened spectrum extending to ~5μm in this fiber taper.

  11. Coherence Properties of Supercontinuum Generated in Dispersion-Tailored Lead-Silicate Microstructured Fiber Taper

    Science.gov (United States)

    Hu, Hongyu; Li, Wenbo; Ma, Shaozhen; Dutta, Niloy K.

    2013-05-01

    This article details the numerically studied coherence properties of the supercontinuum generated in a lead-silicate microstructured fiber taper, with an increasing core radius along the propagation distance that tailors the dispersion property. Simulations are conducted by adding quantum noise into the input pulse at 1.55 μm, and the complex degree of first-order coherence function and the overall spectral coherence degree are both calculated. Although the spectral broadening is comparable, the coherence degree is shown to vary with different pumping conditions. It decreases with higher peak power and longer duration due to the significant competition between the soliton-fission process and the noise-seeded modulation instability. By controlling the input pulse parameters, it is possible to generate a perfectly coherent supercontinuum with a flat broadened spectrum extending from ~1 μm to ~5μm in this fiber taper.

  12. Control of millimeter wave propagation by tailoring the dispersive properties of the medium

    International Nuclear Information System (INIS)

    Full Text:We have developed a space - frequency model for the propagation of a high frequency signal A an arbitrary dispersive medium. The model can be solved analytically under certain conditions for a Gaussian pulse, revealing the conditions under which pulse compression or expansion occurs. It can also be shown that under appropriate conditions the delay time of the pulse can be stretched almost indefinitely. By studying a Gaussian pulse propagating in air described by the standard dispersion model of Liebe we were able to shoe, that even in a substance as trivial as standard atmospheric air some of the effects that we predict are pronounced especially for carrier frequencies in the vicinity of the 60 GHz O2 absorption line. In this case the calculations were carried both analytically and numerically. We further discuss how materials and wave-guides might be tailored for a certain pulse characteristics in order to achieve an a priori-defined amount of compression and delay

  13. Tailoring alphabetical metamaterials in optical frequency: plasmonic coupling, dispersion, and sensing.

    Science.gov (United States)

    Zhang, Jun; Cao, Cuong; Xu, Xinlong; Liow, Chihao; Li, Shuzhou; Tan, Pingheng; Xiong, Qihua

    2014-04-22

    Tailoring optical properties of artificial metamaterials, whose optical properties go beyond the limitations of conventional and naturally occurring materials, is of importance in fundamental research and has led to many important applications such as security imaging, invisible cloak, negative refraction, ultrasensitive sensing, and transformable and switchable optics. Herein, by precisely controlling the size, symmetry, and topology of alphabetical metamaterials with U, S, Y, H, U-bar, and V shapes, we have obtained highly tunable optical response covering visible-to-infrared (vis-NIR) optical frequency. In addition, we show a detailed study on the physical origin of resonance modes, plasmonic coupling, the dispersion of resonance modes, and the possibility of negative refraction. We have found that all the electronic and magnetic modes follow the dispersion of surface plasmon polaritons; thus, essentially they are electronic- and magnetic-surface-plasmon-polaritons-like (ESPP-like and MSPP-like) modes resulted from diffraction coupling between localized surface plasmon and freely propagating light. On the basis of the fill factor and formula of magnetism permeability, we predict that the alphabetical metamaterials should show the negative refraction capability in visible optical frequency. Furthermore, we have demonstrated the specific ultrasensitive surface enhanced Raman spectroscopy (SERS) sensing of monolayer molecules and femtomolar food contaminants by tuning their resonance to match the laser wavelength, or by tuning the laser wavelength to match the plasmon resonance of metamaterials. Our tunable alphabetical metamaterials provide a generic platform to study the electromagnetic properties of metamaterials and explore the novel applications in optical frequency.

  14. Efficacy of tailored-print interventions to promote physical activity: a systematic review of randomised trials

    OpenAIRE

    Plotnikoff Ronald C; James Erica L; Short Camille E; Girgis Afaf

    2011-01-01

    Abstract Objective Computer-tailored physical activity interventions are becoming increasingly popular. Recent reviews have comprehensively synthesised published research on computer-tailored interventions delivered via interactive technology (e.g. web-based programs) but there is a paucity of synthesis for interventions delivered via traditional print-based media in the physical activity domain (i.e. tailored-print interventions). The current study provides a systematic review of the tailore...

  15. Dispersion-tailored, low-loss photonic crystal fibers for the THz range

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Rasmussen, Henrik K.; Adam, Aurèle J.L.;

    2009-01-01

    We have fabricated a new type of photonic crystal fibers based on a cyclic olefin copolymer, transparent in the THz range. We characterize the propagation loss, dispersion, and spatial beam profile in fibers designed for low and high dispersion.......We have fabricated a new type of photonic crystal fibers based on a cyclic olefin copolymer, transparent in the THz range. We characterize the propagation loss, dispersion, and spatial beam profile in fibers designed for low and high dispersion....

  16. Active coatings technologies for tailorable military coating systems

    Science.gov (United States)

    Zunino, J. L., III

    2007-04-01

    The main objective of the U.S. Army's Active Coatings Technologies Program is to develop technologies that can be used in combination to tailor coatings for utilization on Army Materiel. The Active Coatings Technologies Program, ACT, is divided into several thrusts, including the Smart Coatings Materiel Program, Munitions Coatings Technologies, Active Sensor packages, Systems Health Monitoring, Novel Technology Development, as well as other advanced technologies. The goal of the ACT Program is to conduct research leading to the development of multiple coatings systems for use on various military platforms, incorporating unique properties such as self repair, selective removal, corrosion resistance, sensing, ability to modify coatings' physical properties, colorizing, and alerting logistics staff when tanks or weaponry require more extensive repair. A partnership between the U.S. Army Corrosion Office at Picatinny Arsenal, NJ along with researchers at the New Jersey Institute of Technology, NJ, Clemson University, SC, University of New Hampshire, NH, and University of Massachusetts (Lowell), MA, are developing the next generation of Smart Coatings Materiel via novel technologies such as nanotechnology, Micro-electromechanical Systems (MEMS), meta-materials, flexible electronics, electrochromics, electroluminescence, etc. This paper will provide the reader with an overview of the Active Coatings Technologies Program, including an update of the on-going Smart Coatings Materiel Program, its progress thus far, description of the prototype Smart Coatings Systems and research tasks as well as future nanotechnology concepts, and applications for the Department of Defense.

  17. Tailoring Graphene Nanosheets for Highly Improved Dispersion Stability and Quantitative Assessment in Nonaqueous Solvent.

    Science.gov (United States)

    Park, Minju; Song, Kyonghwa; Lee, Taemin; Cha, JinHyeok; Lyo, InWoong; Kim, Byeong-Su

    2016-08-24

    Aggregation is a critical limitation for the practical application of graphene-based materials. Herein, we report that graphene oxide (GO) nanosheets chemically modified with ethanolamine (EA), ethylene glycol (EG), and sulfanilic acid (SA) demonstrate superior dispersion stability in organic solvents, specifically EG, based on the differences in their covalent chemistries. Functionalized GO was successfully dispersed in EG at a concentration of 9.0 mg mL(-1) (0.50 vol %), the highest dispersion concentration reported to date. Moreover, our study introduces a unique analytical method for the assessment of dispersion stability and successfully quantifies the instability index based on transmission profiles under centrifugation cycles. Interestingly, GO-EG and GO-EA exhibited highly improved dispersion stabilities approximately 96 and 48 times greater than that of GO in EG solvent, respectively. This finding highlights the critical role of surface functional groups in the enhancement of chemical affinity and miscibility in the surrounding media. We anticipate that the novel structural designs and unique tools presented in this study will further the understanding and application of chemically functionalized carbon materials.

  18. Photonic crystal waveguides with semi-slow light and tailored dispersion properties

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Lavrinenko, Andrei; Fage-Pedersen, Jacob;

    2006-01-01

    waveguide with either vanishing, positive, or negative group velocity dispersion and semi-slow light. We realize experimentally a silicon-on-insulator photonic crystal waveguide having nearly constant group velocity [similar to]c$-0$//34 in an 11-nm bandwidth below the silica-line. $CPY@2006 Optical Society...

  19. Tellurite Composite Microstructured Optical Fibers with Tailored Chromatic Dispersion for Nonlinear Applications

    Science.gov (United States)

    Duan, Zhongchao; Liao, Meisong; Yan, Xin; Kito, Chihiro; Suzuki, Takenobu; Ohishi, Yasutake

    2011-07-01

    We report the fabrication of tellurite composite microstructured optical fibers (CMOFs) which consist of a TeO2-Li2O-WO3-MoO3-Nb2O5 (TLWMN) tellurite glass core and TeO2-ZnO-Na2O-La2O3 (TZNL) tellurite glass cladding. Flattened chromatic dispersion and tunable zero dispersion wavelength (ZDW) were realized in the small core diameter (˜1.5 µm) fiber with six surrounding air holes. The optical loss was measured to be about 4.0 dB/m in the spectral range of 1510-1640 nm. Supercontinuum (SC) generation was demonstrated by a femtosecond laser pumping at 1.55 µm. The threshold pump power for this novel tellurite CMOF was the lowest among tellurite microstructured optical fibers (MOFs).

  20. Topology-optimized and dispersion-tailored photonic crystal slow-light devices

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Lavrinenko, Andrei; Borel, Peter Ingo;

    2007-01-01

    Within the last few years, photonic crystal waveguides (PhCWs) with low propagation losses and exotic dispersion properties have been realized and, presently, there is a strong movement towards the deployment of such structures in integrated circuits. Effective passive components such as bends...... on an Edisonian design approach combining physical arguments and experimental/numerical verifications. Further optimizations are typically done in an iterative trial-and-error procedure in order to improve a chosen performance measure of the PhCW component. Such an approach is very time-consuming and does...... distribution for the target mode and through a simple structural tuning of the waveguide geometry [3]. In this way, it is possible to realize a silicon-on-insulator PhCW with semi-slow light having a group velocity in the range ~(c0/15 – c0/100); vanishing, positive, or negative group velocity dispersion (GVD...

  1. Applications of highly nonlinear dispersion tailored lead silicate fibres for high speed optical communications

    OpenAIRE

    Parmigiani F.; Camerlingo A.; Feng X; Poletti F.; Ponzo G.M.; Slavik R.; Horak P.; Petrovich M.N.; Loh W.H.; Petropoulos P.

    2010-01-01

    Recent advances in optical fibre technology, most notably in the area of microstructured optical fibres (MOFs), offer a host of new opportunities within future high speed communication systems. Herein we review how our recent progress on the implementation of lead silicate fibre designs, allowing both flexible dispersion control and a high effective nonlinearity, can be integrated into various all-optical signal processing devices for high speed optical communication systems. Highly nonlinear...

  2. Computer-tailored physical activity behavior change interventions targeting adults: a systematic review

    Directory of Open Access Journals (Sweden)

    Neville Leonie

    2009-06-01

    Full Text Available Abstract Background Increasing physical activity is important in the promotion of better health. Computer-tailored behavior change programs have shown promise in changing lifestyle risk factors. Purpose To provide a narrative systematic review describing the range of evidence on 'second' and 'third' generation computer-tailored primary prevention interventions for physical activity, to determine their effectiveness and key characteristics of success. Unlike previous reviews, this review used specific criteria to measure the external validity of studies, was exclusive to primary prevention interventions in which tailoring was generated through an expert system, and excluded first generation computer-tailored interventions. Methods Computer-tailored intervention studies published from January 1996–2008 were identified through a search of five databases: Medline; Embase; PsycINFO; CINAHL; and All EBM Reviews and by examining reference lists of relevant articles. Results Seventeen articles were included, describing the evaluation of 16 interventions, ten of which found significant positive effects of the computer-tailored interventions on physical activity or weight reduction outcomes. Conclusion The evidence of effectiveness for computer-tailored physical activity interventions is inconclusive. They have potential to reach large groups of people however there is uncertainty whether reported effects are generalizable and sustained.

  3. The working mechanisms of an environmentally tailored physical activity intervention for older adults: a randomized controlled trial

    OpenAIRE

    Mudde Aart N; de Vries Hein; van Stralen Maartje M; Bolman Catherine; Lechner Lilian

    2009-01-01

    Abstract Background The aim of this study was to explore the working mechanisms of a computer tailored physical activity intervention for older adults with environmental information compared to a basic tailored intervention without environmental information. Method A clustered randomized controlled trial with two computer tailored interventions and a no-intervention control group was conducted among 1971 adults aged ≥ 50. The two tailored interventions were developed using Intervention Mappin...

  4. The working mechanisms of an environmentally tailored physical activity intervention for older adults: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Mudde Aart N

    2009-12-01

    Full Text Available Abstract Background The aim of this study was to explore the working mechanisms of a computer tailored physical activity intervention for older adults with environmental information compared to a basic tailored intervention without environmental information. Method A clustered randomized controlled trial with two computer tailored interventions and a no-intervention control group was conducted among 1971 adults aged ≥ 50. The two tailored interventions were developed using Intervention Mapping and consisted of three tailored letters delivered over a four-month period. The basic tailored intervention targeted psychosocial determinants alone, while the environmentally tailored intervention additionally targeted environmental determinants, by providing tailored environmental information. Study outcomes were collected with questionnaires at baseline, three and six months and comprised total physical activity (days/week, walking (min/week, cycling (min/week, sports (min/week, environmental perceptions and use and appreciation of the interventions. Results Mediation analyses showed that changes in cycling, sports and total physical activity behaviour induced by the environmentally tailored intervention were mediated by changes in environmental perceptions. Changes in environmental perceptions did not mediate the effect of the basic tailored intervention on behaviour. Compared with the basic tailored intervention, the environmentally tailored intervention significantly improved cycling behaviour (τ = 30.2. Additionally, the tailored letters of the environmentally tailored intervention were better appreciated and used, although these differences did not mediate the intervention effect. Discussion This study gave some first indications of the relevance of environmental perceptions as a determinant of changing physical activity behaviours and the potential effectiveness of providing environmental information as an intervention strategy aimed at

  5. Smart tailoring of real-time physical activity coaching systems

    OpenAIRE

    Akker, op den, Harm

    2014-01-01

    The lack of physical activity in the general population is recognized internationally as an important societal issue. For apparently healthy adults, inactivity leads to overweight, and increased risk of numerous chronic and acute diseases including coronary heart disease, type 2 diabetes, as well as breast and colon cancers. This Thesis deals with the promotion of daily life physical activity — walking, cycling, gardening, or housework — all the activities regularly performed in everyday life...

  6. Smart tailoring of real-time physical activity coaching systems

    NARCIS (Netherlands)

    Akker, op den Harm

    2014-01-01

    The lack of physical activity in the general population is recognized internationally as an important societal issue. For apparently healthy adults, inactivity leads to overweight, and increased risk of numerous chronic and acute diseases including coronary heart disease, type 2 diabetes, as well as

  7. Feasibility of Using Computer-Tailored and Internet-Based Interventions to Promote Physical Activity in Underserved Populations

    OpenAIRE

    Pekmezi, Dorothy W.; Williams, David M.; Dunsiger, Shira; Jennings, Ernestine G.; Lewis, Beth A.; Jakicic, John M.; Marcus, Bess H

    2010-01-01

    Objective: Computer-tailored and Internet-based interventions to promote physical activity behavior have shown some promise, but only few have been tested among African Americans. We examined the feasibility and efficacy of three 1-year, multiple contact physical activity interventions (Tailored Internet, Tailored Print, Standard Internet) in a subsample of African American participants (n = 38) enrolled in a randomized controlled trial. Materials and Methods: Participants randomly assigned t...

  8. Effectiveness of an online computer-tailored physical activity intervention in a real-life setting

    NARCIS (Netherlands)

    H. Spittaels (Heleen); I. Bourdeaudhuij, de (Ilse); J. Brug (Hans); C. Vandelanotte

    2007-01-01

    textabstractThe aim of this study was to evaluate the effectiveness of a computer-tailored physical activity intervention delivered through the Internet in a real-life setting. Healthy adults (n = 526), recruited in six worksites, between 25 and 55 years of age were randomized to one of three condit

  9. Fibrinogen patterns and activity on substrates with tailored hydroxy density.

    Science.gov (United States)

    Rodríguez Hernández, José Carlos; Rico, Patricia; Moratal, David; Monleón Pradas, Manuel; Salmerón-Sánchez, Manuel

    2009-08-11

    The influence of the surface fraction of OH groups on fibrinogen (FG) adsorption is investigated in copolymers of ethyl acrylate and hydroxy ethylacrylate. The amount of adsorbed FG, quantified by western-blotting combined with image analysis of the corresponding bands, decreases as the hydrophilicity of the substrate increases. The influence of substrate wettability on FG conformation and distribution is observed by atomic force microscopy (AFM). The most hydrophobic substrate promotes FG fibrillogenesis, which leads to a fibrin-like appearance in the absence of any thrombin. The degree of FG interconnection was quantified by calculating the fractal dimension of the adsorbed protein from image analysis of the AFM results. The biological activity of the adsorbed FG is correlated to cell adhesion on FG-coated substrates.

  10. A systematic review of randomized trials on the effectiveness of computer-tailored education on physical activity and dietary behaviors

    NARCIS (Netherlands)

    Kroeze, W.; Werkman, A.M.; Brug, J.

    2006-01-01

    Although computer-tailored promotion of dietary change and physical activity has been identified as a promising intervention strategy, there is a need for a more systematic evaluation of the evidence. Purpose: This study systematically reviews the scientific literature on computer-tailored physical

  11. SOFT MALLEABLE VESICLES TAILORED FOR ENHANCED DELIVERY OF ACTIVE AGENTS THROUGH THE SKIN: AN UPDATE

    OpenAIRE

    Sandeep Kumar Parihar*, Mithun Bhowmick, Rajeev Kumar and Balkrishna Dubey

    2013-01-01

    Ethosomes are noninvasive delivery carriers that enable drugs to reach the deep skin layers and/or the systemic circulation. These are soft, malleable vesicles tailored for enhanced delivery of active agents. They are composed mainly of phospholipids, high concentration of ethanol and water. The high concentration of ethanol makes the ethosomes unique, as ethanol is known for its disturbance of skin lipid bilayer organization; therefore, when integrated into ...

  12. Dispersion relations and sum rules for natural optical activity

    International Nuclear Information System (INIS)

    Dispersion relations and sum rules are derived for the complex rotatory power of an arbitrary linear (nonmagnetic) isotropic medium showing natural optical activity. Both previously known dispersion relations and sum rules as well as new ones are obtained. It is shown that the Rosenfeld-Condon dispersion formula is inconsistent with the expected asymptotic behavior at high frequencies. A new dispersion formula based on quantum eletro-dynamics removes this inconsistency; however, it still requires modification in the low-frequency limit. (Author)

  13. Towards self-similar propagation in a dispersion tailored and highly nonlinear segmented bandgap fiber at 2.8 micron

    CERN Document Server

    Biswas, Piyali; Biswas, Abhijit; Pal, Bishnu P

    2016-01-01

    We numerically demonstrate self-similar propagation of parabolic optical pulses through a highly nonlinear and passive specialty photonic bandgap fiber at 2.8 micron. In this context, we have proposed a scheme endowed with a rapidly varying, but of nearly-mean-zero longitudinal dispersion and modulated nonlinear profile in order to achieve self-similarity of the formed parabolic pulse propagating over longer distances. To implement the proposed scheme, we have designed a segmented bandgap fiber with suitably tapered counterparts to realize such customized dispersion with chalchogenide glass materials. A self-similar parabolic pulse with full-width-at-half-maxima of 4.12 ps and energy of ~ 39 pJ as been achieved at the output. Along with a linear chirp spanning over the entire pulse duration, 3dB spectral broadening of about 38 nm at the output has been reported.

  14. Tailoring the chemical composition and dispersion behavior of fluorinated graphene oxide via CF{sub 4} plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Baoming; Qian, Xiaoming; Li, Mingming; Ma, Jilan; Liu, Liangsen, E-mail: 83019163@163.com; Hu, Chuansheng; Xu, Zhiwei; Jiao, Xiaoning [Tianjin Polytechnic University, Key Laboratory of Advanced Braided Composites, Ministry of Education, School of Textiles (China)

    2015-03-15

    Grafting fluorine onto graphene oxide (GO) by CF{sub 4} plasma treatment was investigated in this study. An easy, low-cost, and effective synthesis of the high-dispersive fluorinated GO (FGO) with tunable atomic ratio of F/O (R{sub F/O}) has been realized and the R{sub F/O} can be readily manipulated just by adjusting the reaction time. The influence of plasma treatment time on the microstructure, morphology, and dispersion of graphene nanosheets was systematically analyzed. X-ray photoelectron spectroscopy analysis confirmed that fluorine has been grafted onto graphene, and the R{sub F/O} was gradually increased to 3.54 for the FGO treated for 20 min. Morphology investigation indicated that etching on the edge of GO occurred during the fluorination. The dispersion performance of FGO in water reduced continuously, which in N,N-dimethylacetamide (DMAc) increased firstly and then decreased with the increase in plasma time. The zeta potentials of FGO in DMAc reached the lowest at −28.6 mV when GO was treated for 10 min. The dispersion of FGO in water should be attributed to the decrease of C–O group, while there was a same variation trend of FGO zeta potential in DMAc as the value of C–F content, regardless of R{sub F/O}, CF{sub 2} group content and CF{sub 3} group content. The GO film was super-hydrophilic and the film of FGO treated for 20 min was found to be neither hydrophilic nor hydrophobic.

  15. Generation and Stability Analysis of Self Similar Pulses Through Dispersion Tailored Passive Microstructured Optical Fibers in Mid Infrared Regime

    CERN Document Server

    Biswas, Piyali; Biswas, Abhijit; Ghosh, Somnath

    2015-01-01

    We report a numerical study on generation and stability of a parabolic pulse during its propagation through a highly nonlinear specialty optical fiber. Here, we have generated a parabolic pulse at 2.1 $\\mu$m wavelength from a Gaussian input pulse with 1.9 ps FWHM and 75 W peak power after travelling through only 20 cm length of a chalcogenide glass based microstructured optical fiber (MOF). The stability of such a parabolic pulse has been analyzed by introducing a variable loss profile within the loss window of the MOF. Moreover, three different dispersion regimes of propagation have been considered to achieve most stable propagation of the pulse.

  16. Return dispersion, stock market liquidity and aggregate economic activity

    OpenAIRE

    Stavros Degiannakis; Andreas Andrikopoulos; Timotheos Angelidis; Christos Floros

    2013-01-01

    This paper examines the effect of return dispersion on the dynamics of stock market liquidity, risk and return. Moreover, the importance of return dispersion in forecasting aggregate economic activity is rediscovered in the context of a regime switching model that accounts for stock market fluctuations and their association with the state of the economy. We find that there is a bidirectional, Granger-causal association between illiquidity and return dispersion in the U.S. stock market. The em...

  17. Tailoring ultrafine grained and dispersion-strengthened Ti$_2$AlC/TiAl composite via a new fabrication route

    Indian Academy of Sciences (India)

    TAOTAO AI; QI YU; WENHU LI; XIANGYU ZOU; ZHIFENG DENG; XINQIANG YUAN

    2016-09-01

    In situ Ti$_2$AlC/TiAl composite was fabricated by hot-pressing method via the reaction system of Ti$_3$AlC$_2$ and Ti-Al pre-alloyed powders at low temperature of 1150$^{\\circ}$C. The composite mainly consisted of TiAl, Ti$_3$Al and Ti$_2$AlC phases. Fine Ti$_2$AlC particles were homogeneously distributed and dispersed in the matrix. Ti$_2$AlC played the significant role of deflecting and blunting the cracks and contributed to improve the mechanical properties of the composite. The Vickers hardness, flexural strength and fracture toughness were 6.2 GPa, $993.9\\pm 50.8$ MPa and $6.7\\pm 0.3$ MPa m$^{1/2}$, respectively.

  18. Particle size tailoring of ursolic acid nanosuspensions for improved anticancer activity by controlled antisolvent precipitation.

    Science.gov (United States)

    Wang, Yancai; Song, Ju; Chow, Shing Fung; Chow, Albert H L; Zheng, Ying

    2015-10-15

    The present study was aimed at tailoring the particle size of ursolic acid (UA) nanosuspension for improved anticancer activity. UA nanosuspensions were prepared by antisolvent precipitation using a four-stream multi-inlet vortex mixer (MIVM) under defined conditions of varying solvent composition, drug feeding concentration or stream flow rate. The resulting products were characterized for particle size and polydispersity. Two of the UA nanosuspensions with mean particle sizes of 100 and 300 nm were further assessed for their in-vitro activity against MCF-7 breast cancer cells using fluorescence microscopy with 4',6-diamidino-2-phenylindole (DAPI) staining, as well as flow cytometry with propidium (PI) staining and with double staining by fluorescein isothiocyanate. It was revealed that the solvent composition, drug feeding concentration and stream flow rate were critical parameters for particle size control of the UA nanosuspensions generated with the MIVM. Specifically, decreasing the UA feeding concentration or increasing the stream flow rate or ethanol content resulted in a reduction of particle size. Excellent reproducibility for nanosuspension production was demonstrated for the 100 and 300 nm UA preparations with a deviation of not more than 5% in particle size from the mean value of three independent batches. Fluorescence microscopy and flow cytometry revealed that these two different sized UA nanosuspensions, particularly the 300 nm sample, exhibited a higher anti-proliferation activity against the MCF-7 cells and afforded a larger population of these cells in both early and late apoptotic phases. In conclusion, MIVM is a robust and pragmatic tool for tailoring the particle size of the UA nanosuspension. Particle size appears to be a critical determinant of the anticancer activity of the UA nanoparticles.

  19. Open Rabi model with ultrastrong coupling plus large dispersive-type nonlinearity: Nonclassical light via a tailored degeneracy

    Science.gov (United States)

    Grimsmo, Arne L.; Parkins, Scott

    2014-03-01

    We consider a generalized version of the Rabi model that includes a nonlinear, dispersive-type atom-field interaction in addition to the usual linear dipole coupling, as well as cavity dissipation. An effective system of this sort arises, for example, in a quantum simulation of the Rabi model based upon Raman transitions in an optical cavity QED setting [A. L. Grimsmo and S. Parkins, Phys. Rev. A 87, 033814 (2013), 10.1103/PhysRevA.87.033814]. For a range of the nonlinear interaction strength about a special value, degeneracies or near degeneracies of the states in the cavity-mode vacuum and single-photon subspaces, in combination with cavity loss, gives rise to an essentially closed cycle of excitations and photon emissions within these subspaces. Consequently, the cavity output field is strongly antibunched, while over this range of nonlinear strengths the atomic population undergoes an abrupt inversion. We develop a quantum-trajectory-based description of the system that models its key properties very well, and use a simple dressed-state picture to explain the novel structure of the cavity fluorescence spectrum. We also present numerical results for a potential realization of the system using a rubidium atom coupled strongly to a high-finesse optical cavity mode.

  20. Efficacy of 'Tailored Physical Activity' on reducing sickness absence among health care workers

    DEFF Research Database (Denmark)

    Andersen, Lotte Nygaard; Juul-Kristensen, Birgit; Roessler, Kirsten Kaya;

    2015-01-01

    AIM: The aim was to evaluate efficacy of "Tailored Physical Activity" (TPA) versus a reference group (REF) in reducing the number of self-reported days of sickness absence for health care workers in the Sonderborg Municipality. METHODS: In this randomised controlled trial, all participants (n = 54...... intervention is a promising initiative for health care workers since participants achieved a substantial effect on their experience of pain, on their work ability and on their fear of physical movement relating to pain. Moreover, a difference in aerobic capacity was apparent between the sample groups. TPA......) received health guidance for 1.5 h and were randomised to TPA or REF. The primary aim was to make a comparison of participants' self-reported sickness absence due to musculoskeletal troubles measured three months after baseline. Secondary outcomes included anthropometric, health-related and physical...

  1. SOFT MALLEABLE VESICLES TAILORED FOR ENHANCED DELIVERY OF ACTIVE AGENTS THROUGH THE SKIN: AN UPDATE

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar Parihar*, Mithun Bhowmick, Rajeev Kumar and Balkrishna Dubey

    2013-01-01

    Full Text Available Ethosomes are noninvasive delivery carriers that enable drugs to reach the deep skin layers and/or the systemic circulation. These are soft, malleable vesicles tailored for enhanced delivery of active agents. They are composed mainly of phospholipids, high concentration of ethanol and water. The high concentration of ethanol makes the ethosomes unique, as ethanol is known for its disturbance of skin lipid bilayer organization; therefore, when integrated into a vesicle membrane, it gives that vesicle the ability to penetrate the stratum corneum. Also, because of their high ethanol concentration, the lipid membrane is packed less tightly than conventional vesicles but has equivalent stability, allowing a more malleable structure and improves drug distribution ability in stratum corneum lipids. The Ethosomes were found to be suitable for various applications within the pharmaceutical, biotechnology, veterinary, cosmetic, and nutraceutical markets. These “soft vesicles” represents novel vesicular carrier for enhanced delivery to/through skin.

  2. A Systematic Review of Randomized Controlled Trials on the Effectiveness of Computer-Tailored Physical Activity and Dietary Behavior Promotion Programs: an Update

    OpenAIRE

    Broekhuizen, Karen; Kroeze, Willemieke; van Poppel, Mireille NM; Oenema, Anke; Brug, Johannes

    2012-01-01

    Background A review update is necessary to document evidence regarding the effectiveness of computer-tailored physical activity and nutrition education. Purpose The purpose of this study was to summarize the latest evidence on the effectiveness of computer-tailored physical activity and nutrition education, and to compare the results to the 2006 review. Methods Databases were searched for randomized controlled trials evaluating computer-tailored physical activity and nutrition education aimed...

  3. Qualitative and quantitative research into the development and feasibility of a video-tailored physical activity intervention

    Directory of Open Access Journals (Sweden)

    Mummery W Kerry

    2011-07-01

    Full Text Available Abstract Background Continued low adherence to physical activity recommendations illustrates the need to refine intervention strategies and increase their effectiveness. The purpose of this study was to conduct formative research related to the development of a next generation of computer-tailored interventions that use online tailored video-messages to increase physical activity. Methods Five focus groups (n = 30, aimed at males and females, aged between 35 and 60 years, that do not meet the physical activity recommendation, were conducted to allow in-depth discussion of various elements related to the development of an online video-tailored intervention. In addition, a series of questions were delivered to a random sample (n = 1261 of Australians, using CATI survey technology, to gain more information and add a quantitative assessment of feasibility related to the development of the intervention. Focus group data was transcribed, and summarised using Nvivo software. Descriptive and frequency data of the survey was obtained using SPSS 18.0. Results Nearly all of the focus group participants supported the concept of a video-tailored intervention and 35.8% of survey participants indicated that they would prefer a video-based over a text-based intervention. Participants with a slow internet-connection displayed a lower preference for video-based advice (31.9%; however less than 20% of the survey sample indicated that downloading videos would be slow. The majority of focus group and survey participants did not support the idea of using mobile phones to receive this kind of intervention and indicated that video-tailored messages should be shorter than 5 minutes. Video-delivery of content is very rich in information, which increases the challenge to appropriately tailor content to participant characteristics; focus-group outcomes indicated a large diversity in participant preferences. 52.4% of survey participants indicated that the videos should be

  4. Correlates of the intention to implement a tailored physical activity intervention: perceptions of intermediaries.

    Science.gov (United States)

    Peels, Denise; Mudde, Aart; Bolman, Catherine; Golsteijn, Rianne; de Vries, Hein; Lechner, Lilian

    2014-02-01

    The public health impact of health behaviour interventions is highly dependent on large-scale implementation. Intermediaries-intervention providers-determine to a large extent whether an intervention reaches the target population, and hence its impact on public health. A cross-sectional study was performed to identify the correlates of intermediaries' intention to implement a computer-tailored physical activity intervention. According to theory, potential correlates are intervention characteristics, organisational characteristics, socio-political characteristics and intermediary characteristics. This study investigated whether intermediary characteristics mediated the association between the intervention, organisational and socio-political characteristics and intention to implement the intervention. Results showed that intervention characteristics (i.e., observability (B = 0.53; p = 0.006); relative advantage (B = 0.79; p = 0.020); complexity (B = 0.80; p responsibility (B = 0.66; p ≤ 0.001); capacity (B = 0.83; p social support received by intermediary organisations (B = 0.81; p strategy. Since self-efficacy and social norms perceived by the intermediary organisations partially mediated the effects of other variables on intention to implement the intervention (varying between 29% and 84%), these factors should be targeted to optimise the effectiveness of the implementation strategy. PMID:24518647

  5. Correlates of the intention to implement a tailored physical activity intervention: perceptions of intermediaries.

    Science.gov (United States)

    Peels, Denise; Mudde, Aart; Bolman, Catherine; Golsteijn, Rianne; de Vries, Hein; Lechner, Lilian

    2014-02-10

    The public health impact of health behaviour interventions is highly dependent on large-scale implementation. Intermediaries-intervention providers-determine to a large extent whether an intervention reaches the target population, and hence its impact on public health. A cross-sectional study was performed to identify the correlates of intermediaries' intention to implement a computer-tailored physical activity intervention. According to theory, potential correlates are intervention characteristics, organisational characteristics, socio-political characteristics and intermediary characteristics. This study investigated whether intermediary characteristics mediated the association between the intervention, organisational and socio-political characteristics and intention to implement the intervention. Results showed that intervention characteristics (i.e., observability (B = 0.53; p = 0.006); relative advantage (B = 0.79; p = 0.020); complexity (B = 0.80; p organisational characteristics (i.e., type of organization (B = 0.38; p = 0.002); perceived task responsibility (B = 0.66; p ≤ 0.001); capacity (B = 0.83; p organisations (B = 0.81; p strategy. Since self-efficacy and social norms perceived by the intermediary organisations partially mediated the effects of other variables on intention to implement the intervention (varying between 29% and 84%), these factors should be targeted to optimise the effectiveness of the implementation strategy.

  6. Correlates of the Intention to Implement a Tailored Physical Activity Intervention: Perceptions of Intermediaries

    Directory of Open Access Journals (Sweden)

    Denise Peels

    2014-02-01

    Full Text Available The public health impact of health behaviour interventions is highly dependent on large-scale implementation. Intermediaries—intervention providers—determine to a large extent whether an intervention reaches the target population, and hence its impact on public health. A cross-sectional study was performed to identify the correlates of intermediaries’ intention to implement a computer-tailored physical activity intervention. According to theory, potential correlates are intervention characteristics, organisational characteristics, socio-political characteristics and intermediary characteristics. This study investigated whether intermediary characteristics mediated the association between the intervention, organisational and socio-political characteristics and intention to implement the intervention. Results showed that intervention characteristics (i.e., observability (B = 0.53; p = 0.006; relative advantage (B = 0.79; p = 0.020; complexity (B = 0.80; p < 0.001; compatibility (B = 0.70; p < 0.001, organisational characteristics (i.e., type of organization (B = 0.38; p = 0.002; perceived task responsibility (B = 0.66; p ≤ 0.001; capacity (B = 0.83; p < 0.001, and the social support received by intermediary organisations (B = 0.81; p < 0.001 were associated with intention to implement the intervention. These factors should thus be targeted by an implementation strategy. Since self-efficacy and social norms perceived by the intermediary organisations partially mediated the effects of other variables on intention to implement the intervention (varying between 29% and 84%, these factors should be targeted to optimise the effectiveness of the implementation strategy.

  7. Effects of individually tailored physical and daily activities in nursing home residents on activities of daily living, physical performance and physical activity level

    DEFF Research Database (Denmark)

    Andresen, Mette; Frändin, Kerstin; Bergland, Astrid;

    2012-01-01

    participants in the IG and CG on measures of balance, physical activity and transfers. The CG significantly improved walking/wheelchair speed and functional leg muscle strength. The CG had significantly deteriorated in ADL, balance and transfers. Persons who had taken part in the intervention for more than 150...... min/week significantly improved their balance and physical activity level. Participation in more than 10 weeks of intervention significantly improved physical activity and walking/wheelchair speed, while a deterioration was seen in those who had participated less. Conclusion: Individually tailored...

  8. Elucidating the role of phenolic compounds in the effectiveness of DOM adsorption on novel tailored activated carbon.

    Science.gov (United States)

    Yan, Liang; Fitzgerald, Martha; Khov, Cindy; Schafermeyer, Amy; Kupferle, Margaret J; Sorial, George A

    2013-11-15

    Two novel tailored activated carbons (BC-41-OG and BC-41-MnN) with favorable physicochemical characteristics were successfully prepared for adsorption of dissolved natural organic matter (DOM) by applying systematically chemical and thermal treatment. This research was conducted to investigate the impact of the presence of phenolics on the adsorption capacity of DOM. Isotherm tests were performed for both humic acid (HA) and phenolics on both novel tailored activated carbons and commercial activated carbon F400. The presence of phenolics display a significant effect on hindering the adsorption of HA, however; the physicochemical characteristics of novel activated carbons (surface metal oxides and mesoporosity) can play an important role in alleviating this effect. In contrast, F400, with a relatively lower mesoporosity and surface basicity as compared to the developed adsorbents, was severely impacted by the oligomerization of phenolic compounds. The adsorption capacity of DOM in presence of phenolics was further studied in a continuous flow microcolumn system. The column results showed that both BC-41-OG and BC-41-MnN have not only higher HA adsorption capacity but also better selective adsorption ability than F400.

  9. Syntheses, characterizations, and catalytic activities of mesostructured aluminophosphates with tailorable acidity assembled with various preformed zeolite nanoclusters

    KAUST Repository

    Suo, Hongri

    2015-02-25

    © 2015, Springer Science+Business Media New York. A series of ordered hexagonal mesoporous zeolites have been successfully synthesized by the assembly of various preformed aluminosilicates zeolite (MFI, FAU, BEA etc.) with surfactants (cetyltrimethylammonium chloride) under hydrothermal conditions. These unique samples were further characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption, infrared spectroscopy. Characterization results showed that these samples contain primary and secondary structural building units of various zeolites, which may be responsible for their distinguished acidic strength, suggesting that the acidic strength of these mesoporous silicoaluminophosphates could be tailored and controlled. Furthermore, the prepared samples were catalytically active in the cracking of cumene.

  10. Catalyst dispersion and activity under conditions of temperature- staged liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1992-02-01

    The general objectives of this research are (1) to investigate the use of highly dispersed catalysts for the pretreatment of coal by mild hydrogenation, (2) to identify the active forms of catalysts under reaction conditions and (3) to clarify the mechanisms of catalysis. The ultimate objective is to ascertain if mild catalytic hydrogenation resulting in very limited or no coal solubilization is an advantageous pretreatment for the transformation of coal into transportable fuels. The experimental program will focus upon the development of effective methods of impregnating coal with catalysts, evaluating the conditions under which the catalysts are most active and establishing the relative impact of improved impregnation on conversion and product distributions obtained from coal hydrogenation.

  11. Fusion production of solid dispersions containing a heat-sensitive active ingredient by hot melt extrusion and Kinetisol dispersing.

    Science.gov (United States)

    Dinunzio, James C; Brough, Chris; Hughey, Justin R; Miller, Dave A; Williams, Robert O; McGinity, James W

    2010-02-01

    Many techniques for the production of solid dispersions rely on elevated temperatures and prolonged material residence times, which can result in decomposition of temperature-sensitive components. In this study, hydrocortisone was used as a model temperature-sensitive active ingredient to study the effect of formulation and processing techniques as well as to characterize the benefits of KinetiSol Dispersing for the production of solid dispersions. Preformulation studies were conducted using differential scanning calorimetry and hot stage microscopy to identify optimum carriers for the production of amorphous solid dispersions. After identification, solid dispersions were prepared by hot melt extrusion and KinetiSol Dispersing, with material characterized by X-ray diffraction, dissolution and potency testing to evaluate physicochemical properties. Results from the preformulation studies showed that vinylacetate:vinylpyrrolidone (PVPVA) copolymer allowed for hydrocortisone dissolution within the carrier at temperatures as low as 160 degrees C, while hydroxypropyl methylcellulose required temperatures upward of 180 degrees C to facilitate solubilization. Low substituted hydroxypropyl cellulose, a high glass transition temperature control, showed that the material was unable to solubilize hydrocortisone. Manufacturing process control studies using hot melt extruded compositions of hydrocortisone and PVPVA showed that increased temperatures and residence times negatively impacted product potency due to decomposition. Using KinetiSol Dispersing to reduce residence time and to facilitate lower temperature processing, it was possible to produce solid dispersions with improved product potency. This study clearly demonstrated the importance of carrier selection to facilitate lower temperature processing, as well as the effect of residence time on product potency. Furthermore, KinetiSol Dispersing provided significant advantages over hot melt extrusion due to the reduced

  12. Tailoring group velocity by topology optimization

    DEFF Research Database (Denmark)

    Stainko, Roman; Sigmund, Ole

    2007-01-01

    up with slow light, zero group velocity dispersion photonic waveguides or photonic waveguides with tailored dispersion properties for dispersion compensation purposes. An example concerning the design of a wide bandwidth, constant low group velocity waveguide demonstrate the e±ciency of the method....

  13. Additive manufactured polymeric 3D scaffolds with tailored surface topography influence mesenchymal stromal cells activity.

    Science.gov (United States)

    Neves, Sara C; Mota, Carlos; Longoni, Alessia; Barrias, Cristina C; Granja, Pedro L; Moroni, Lorenzo

    2016-06-01

    Additive manufactured three-dimensional (3D) scaffolds with tailored surface topography constitute a clear advantage in tissue regeneration strategies to steer cell behavior. 3D fibrous scaffolds of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer presenting different fiber surface features were successfully fabricated by additive manufacturing combined with wet-spinning, in a single step, without any post-processing. The optimization of the processing parameters, mainly driven by different solvent/non-solvent combinations, led to four distinct scaffold types, with average surface roughness values ranging from 0.071 ± 0.012 μm to 1.950 ± 0.553 μm, average pore sizes in the x- and y-axis between 351.1 ± 33.6 μm and 396.1 ± 32.3 μm, in the z-axis between 36.5 ± 5.3 μm and 70.7 ± 8.8 μm, average fiber diameters between 69.4 ± 6.1 μm and 99.0 ± 9.4 μm, and porosity values ranging from 60.2 ± 0.8% to 71.7 ± 2.6%. Human mesenchymal stromal cells (hMSCs) cultured on these scaffolds adhered, proliferated, and produced endogenous extracellular matrix. The effect of surface roughness and topography on hMSCs differentiation was more evident for cells seeded at lower density, where the percentage of cells in direct contact with the surface was higher compared to more densely seeded scaffolds. Under osteogenic conditions, lower surface roughness values (0.227 ± 0.035 μm) had a synergistic effect on hMSCs behavior, while chondrogenesis was favored on rougher surfaces (1.950 ± 0.553 μm). PMID:27219645

  14. Platinum nanocatalysts loaded on graphene oxide-dispersed carbon nanotubes with greatly enhanced peroxidase-like catalysis and electrocatalysis activities.

    Science.gov (United States)

    Wang, Hua; Li, Shuai; Si, Yanmei; Zhang, Ning; Sun, Zongzhao; Wu, Hong; Lin, Yuehe

    2014-07-21

    A powerful enzymatic mimetic has been fabricated by employing graphene oxide (GO) nanocolloids to disperse conductive carbon supports of hydrophobic carbon nanotubes (CNTs) before and after the loading of Pt nanocatalysts. The resulting GOCNT-Pt nanocomposites could present improved aqueous dispersion stability and Pt spatial distribution. Unexpectedly, they could show greatly enhanced peroxidase-like catalysis and electrocatalysis activities in water, as evidenced in the colorimetric and electrochemical investigations in comparison to some inorganic nanocatalysts commonly used. Moreover, it is found that the new enzyme mimetics could exhibit peroxidase-like catalysis activity comparable to natural enzymes; yet, they might circumvent some of their inherent problems in terms of catalysis efficiency, electron transfer, environmental stability, and cost effectiveness. Also, sandwiched electrochemical immunoassays have been successfully conducted using GOCNT-Pt as enzymatic tags. Such a fabrication avenue of noble metal nanocatalysts loaded on well-dispersed conductive carbon supports should be tailored for the design of different enzyme mimics promising the extensive catalysis applications in environmental, medical, industrial, and particularly aqueous biosensing fields.

  15. Activity pacing for osteoarthritis symptom management: study design and methodology of a randomized trial testing a tailored clinical approach using accelerometers for veterans and non-veterans

    Directory of Open Access Journals (Sweden)

    Geisser Michael E

    2011-08-01

    Full Text Available Abstract Background Osteoarthritis (OA is a prevalent chronic disease and a leading cause of disability in adults. For people with knee and hip OA, symptoms (e.g., pain and fatigue can interfere with mobility and physical activity. Whereas symptom management is a cornerstone of treatment for knee and hip OA, limited evidence exists for behavioral interventions delivered by rehabilitation professionals within the context of clinical care that address how symptoms affect participation in daily activities. Activity pacing, a strategy in which people learn to preplan rest breaks to avoid symptom exacerbations, has been effective as part of multi-component interventions, but hasn't been tested as a stand-alone intervention in OA or as a tailored treatment using accelerometers. In a pilot study, we found that participants who underwent a tailored activity pacing intervention had reduced fatigue interference with daily activities. We are now conducting a full-scale trial. Methods/Design This paper provides a description of our methods and rationale for a trial that evaluates a tailored activity pacing intervention led by occupational therapists for adults with knee and hip OA. The intervention uses a wrist accelerometer worn during the baseline home monitoring period to glean recent symptom and physical activity patterns and to tailor activity pacing instruction based on how symptoms relate to physical activity. At 10 weeks and 6 months post baseline, we will examine the effectiveness of a tailored activity pacing intervention on fatigue, pain, and physical function compared to general activity pacing and usual care groups. We will also evaluate the effect of tailored activity pacing on physical activity (PA. Discussion Managing OA symptoms during daily life activity performance can be challenging to people with knee and hip OA, yet few clinical interventions address this issue. The activity pacing intervention tested in this trial is designed to help

  16. I Move: Systematic development of a web-based computer tailored physical activity intervention, based on motivational interviewing and self-determination theory

    NARCIS (Netherlands)

    Friederichs, S.A.; Oenema, A.; Bolman, C.; Guyaux, J.; Keulen, H.M. van; Lechner, L.

    2014-01-01

    Background: This article describes the systematic development of the I Move intervention: a web-based computer tailored physical activity promotion intervention, aimed at increasing and maintaining physical activity among adults. This intervention is based on the theoretical insights and practical a

  17. Effectiveness of a Computer-Tailored Print-Based Physical Activity Intervention among French Canadians with Type 2 Diabetes in a Real-Life Setting

    Science.gov (United States)

    Boudreau, Francois; Godin, Gaston; Poirier, Paul

    2011-01-01

    The promotion of regular physical activity for people with type 2 diabetes poses a challenge for public health authorities. The purpose of this study was to evaluate the efficiency of a computer-tailoring print-based intervention to promote the adoption of regular physical activity among people with type 2 diabetes. An experimental design was…

  18. Catalyst dispersion and activity under conditions of temperature- staged liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1991-09-01

    The general objectives of this research are (1) to investigate the use of highly dispersed catalysts for the pretreatment of coal by mild hydrogenation, (2) to identify the active forms of the catalysts under reaction conditions and (3) to clarify the mechanisms of catalysis. The ultimate objective is to ascertain if mild catalytic hydrogenation resulting in very limited or no coal solubilization is an advantageous pretreatment for the transformation of coal into transportable fuels. The experimental program will focus upon the development of effective methods of impregnating coal with catalysts, evaluating the conditions under which the catalysts are most active and establishing the relative impact of improved impregnation on conversion and product distributions obtained from coal hydrogenation. Liquefaction experiments of solvent-treated and untreated Blind Canyon (DECS-6) and Texas lignite (DECS-1) have been performed using ammonium tetrathiomolybdate (ATTM) and bis (dicarbonylcyclopentadienyl) iron (CPI) as catalyst precursors using temperature-staged conditions (275{degrees}C, 30 min; 425{degrees}C, 30 min). Solid state {sup 13}C NMR analysis was carried out for each coal and for selected residues. 12 refs., 14 figs., 9 tabs.

  19. Activated Carbon Nanochains with Tailored Micro-Meso Pore Structures and Their Application for Supercapacitors

    DEFF Research Database (Denmark)

    Zhang, Miao; He, Chunnian; Liu, Enzuo;

    2015-01-01

    Carbon nanochains (CNCs) were synthesized by a facile chemical vapor deposition process consisting of a 1D chain of interconnected carbon nano-onions for potential application in supercapacitors. In this study, the CNCs were further activated by a chemical method using potassium hydroxide (KOH...... that CNCs with a hierarchical pore structure and high SSA could be achieved using an activation process with a KOH-to-CNC ratio of 2 at 900 degrees C for 20 h. The mechanism is also discussed. The activation temperature and duration affect the promotion of the carbon graphitization and exaggeration...... of the carbon etching. The CNCs activated using the optimal parameters exhibited a high capacitance performance of 112.7 F g(-1) at 50 mV s(-1) with excellent stability in 6 M KOH electrolyte, which was due to the improved surface and micromesoporosity without sacrificing their electronic transmission...

  20. Tailored ceramics

    International Nuclear Information System (INIS)

    In polyphase tailored ceramic forms two distinct modes of radionuclide immobilization occur. At high waste loadings the radionuclides are distributed through most of the ceramic phases in dilute solid solution, as indicated schematically in this paper. However, in the case of low waste loadings, or a high loading of a waste with low radionuclide content, the ceramic can be designed with only selected phases containing the radionuclides. The remaining material forms nonradioactive phases which provide a degree of physical microstructural isolation. The research and development work with polyphase ceramic nuclear waste forms over the past ten years is discussed. It has demonstrated the critical attributes which suggest them as a waste form for future HLW disposal. From a safety standpoint, the crystalline phases in the ceramic waste forms offer the potential for demonstrable chemical durability in immobilizing the long-lived radionuclides in a geologic environment. With continued experimental research on pure phases, analysis of mineral analogue behavior in geochemical environments, and the study of radiation effects, realistic predictive models for waste form behavior over geologic time scales are feasible. The ceramic forms extend the degree of freedom for the economic optimization of the waste disposal system

  1. Room-temperature synthesis of BiOI with tailorable (001) facets and enhanced photocatalytic activity.

    Science.gov (United States)

    He, Rongan; Zhang, Jinfeng; Yu, Jiaguo; Cao, Shaowen

    2016-09-15

    The photocatalytic activity of bismuth oxyhalides largely depends on their morphologies and microstructures. In this work, hierarchically structured bismuth oxyiodide (BiOI) with tunable ratios of (110) and (001) facets are fabricated through a facile route combining solid-state reaction with subsequent hydrolysis at room temperature. The hierarchical structures endow BiOI with excellent visible-light photocatalytic performance for phenol degradation. Besides, the optimal ratio of (001) and (110) surfaces also plays an important role in enhancing the photocatalytic activity of BiOI. DFT calculation demonstrates that a surface heterojunction formed between (001) and (110) surfaces can improve the separation of electrons and holes on different surfaces and thus enhance the photocatalytic activity. PMID:27295322

  2. Tailoring Cytotoxicity of Antimicrobial Peptidomimetics with High Activity against Multidrug-Resistant Escherichia coli

    DEFF Research Database (Denmark)

    Jahnsen, Rasmus D; Sandberg-Schaal, Anne; Vissing, Karina Juul;

    2014-01-01

    Infections with multidrug-resistant pathogens are an increasing concern for public health. Recently, subtypes of peptide-peptoid hybrids were demonstrated to display potent activity against multidrug-resistant Gram-negative bacteria. Here, structural variation of these antibacterial peptidomimetics...... cells. Thus, lead compounds with a high selectivity toward killing of clinically important multidrug-resistant E. coli were identified....

  3. Tailoring real-time physical activity coaching systems: a literature survey and model

    NARCIS (Netherlands)

    Akker, op den Harm; Jones, Valerie M.; Hermens, Hermie J.

    2014-01-01

    Technology mediated healthcare services designed to stimulate patients’ self-efficacy are widely regarded as a promising paradigm to reduce the burden on the healthcare system. The promotion of healthy, active living is a topic of growing interest in research and business. Recent advances in wireles

  4. Investigating message-framing effects in the context of a tailored intervention promoting physical activity.

    NARCIS (Netherlands)

    Riet, van 't J.P.; Ruiter, R.A.C.; Werrij, M.Q.; Vries, de H.

    2010-01-01

    Health-promoting messages can be framed in terms of the gains associated with healthy behaviour or the losses associated with unhealthy behaviour. It has been argued that gain-framed messages promoting physical activity (PA) are more effective than loss-framed messages, but empirical findings are in

  5. Discrimination of differentially inhibited cysteine proteases by activity-based profiling using cystatin variants with tailored specificities.

    Science.gov (United States)

    Sainsbury, Frank; Rhéaume, Ann-Julie; Goulet, Marie-Claire; Vorster, Juan; Michaud, Dominique

    2012-12-01

    Recent research has shown the possibility of tailoring the inhibitory specificity of plant cystatins toward cysteine (Cys) proteases by single mutations at positively selected amino acid sites. Here we devised a cystatin activity-based profiling approach to assess the impact of such mutations at the proteome scale using single variants of tomato cystatin SlCYS8 and digestive Cys proteases of the herbivorous insect, Colorado potato beetle, as a model. Biotinylated forms of SlCYS8 and SlCYS8 variants were used to capture susceptible Cys proteases in insect midgut protein extracts by biotin immobilization on avidin-embedded beads. A quantitative LC-MS/MS analysis of the captured proteins was performed to compare the inhibitory profile of different SlCYS8 variants. The approach confirmed the relevance of phylogenetic inferences categorizing the insect digestive Cys proteases into six functionally distinct families. It also revealed significant variation in protease family profiles captured with N-terminal variants of SlCYS8, in line with in silico structural models for Cys protease-SlCYS8 interactions suggesting a functional role for the N-terminal region. Our data confirm overall the usefulness of cystatin activity-based protease profiling for the monitoring of Cys protease-inhibitor interactions in complex biological systems. They also illustrate the potential of biotinylated cystatins to identify recombinant cystatin candidates for the inactivation of specific Cys protease targets.

  6. Tailoring activated carbon by surface chemical modification with O, S, and N containing molecules

    Directory of Open Access Journals (Sweden)

    Rachel RibeiroVieira Azzi Rios

    2003-06-01

    Full Text Available In this work the surface of activated carbon was chemically modified in order to introduce O, S and N containing groups. The activated carbon surface was selectively oxidized with concentrated HNO3 under controlled conditions. Characterization by thermogravimetric analyses, infrared spectroscopy and NaOH titration suggested the formation of mainly -COOH and small amounts of -OH groups, with concentration of approximately 4.10(21 groups/g of carbon. These -COOH functionalized carbons showed high adsorption capacity for metal cations in aqueous solution in the following order: Pb+2>Cu+2>Ni+2 >Cd+2~Co+2>Ca+2 , suggesting a cation exchange mechanism via a surface complex [COO-M+2]. These -COOHsurf groups can be reacted with SOCl2 to produce a surface acylchloride group, -COCl. This surface -COCl group proved to be a very reactive and versatile intermediate for the grafting of different S and N containing molecules onto the carbon surface, such as 1,2-ethaneditiol (EDT-, HSCH2CH2SH 1,7-dimercapto-4-thioheptane (DMTH-HSCH2CH2CH2SCH2CH 2CH2SH or 1,2-ethylenediamine (EDA- NH2CH2CH2NH2 and triethyltetraamine, TEA (H2NCH2CH2NHCH2CH 2NHCH2CH2 NH2. The characterization of these materials was carried out by TG, IR and TPDMS (Temperature Programmed Decomposition Mass Spectrometry experiments suggesting the formation of thioesther and amide surface groups, i.e. -COSR and -CONHR, with yields of approximately 50 and 75% for the reaction with DME and EDA, respectively. Preliminary adsorption experiments showed that these materials can efficiently remove metals such as Pb+2, Cu+2 and Ni+2 from aqueous medium.

  7. Tailored spectroscopic and optical properties in rare earth-activated glass-ceramics planar waveguides

    Science.gov (United States)

    Ristic, Davor; Van Tran, Thi Thanh; Dieudonné, Belto; Cristina, Armellini; Berneschi, Simone; Chiappini, Andrea; Chiasera, Alessandro; Varas, Stefano; Carpentiero, Alessandro; Mazzola, Maurizio; Nunzi Conti, Gualtiero; Pelli, Stefano; Speranza, Giorgio; Feron, Patrice; Duverger Arfuso, Claire; Cibiel, Gilles; Turrell, Sylvia; Tran Ngoc, Khiem; Boulard, Brigitte; Righini, Giancarlo C.; Ferrari, Maurizio

    2013-03-01

    Glass ceramic activated by rare earth ions are nanocomposite systems that exhibit specific morphologic, structural and spectroscopic properties allowing to develop interesting new physical concepts, for instance the mechanism related to the transparency, as well as novel photonic devices based on the enhancement of the luminescence. At the state of art the fabrication techniques based on bottom-up and top-down approaches appear to be viable although a specific effort is required to achieve the necessary reliability and reproducibility of the preparation protocols. In particular, the dependence of the final product on the specific parent glass and on the employed synthesis still remain an important task of the research in material science. Glass-ceramic waveguides overcome some of the efficiency problems experienced with conventional waveguides. These two-phase materials are composed of nanocrystals embedded in an amorphous matrix. The respective volume fractions of the crystalline and amorphous phases determine the properties of the glass ceramic. They also represent a valid alternative to widely used glass hosts such as silica as an effective optical medium for light propagation and luminescence enhancement. Looking to application, the enhanced spectroscopic properties typical of glass ceramic in respect to those of the amorphous structures constitute an important point for the development of integrated optics devices, including optical amplifiers, monolithic waveguide laser, novel sensors, coating of spherical microresonators, and up and down converters for solar energy exploitation.

  8. Tailoring fly ash activated with bentonite as adsorbent for complex wastewater treatment

    International Nuclear Information System (INIS)

    Highlights: ► The spent adsorbent annealed at 500 °C can be a suggestion for padding in stone blocks. ► The cations can be adsorbent by the silanol group (Si-OH) of the layers from bentonite ► Copper has a higher affinity for the active sites on adsorbent FAw + B than cadmium. ► This substrate can be recommended for simultaneous removal of heavy metals and MB. ► FAw + B is recommended for wastewater treatment resulted in the dyes finishing industry. - Abstract: Used as adsorbent, alkali fly ash represents a low cost solution for advanced wastewater treatment. The alkali treatment raises sustainability issues therefore, in this research we aim to replace alkali fly ash with washed fly ash (FAw). For improving the adsorption capacity of washed fly ash, bentonite powder (B) was added, as a natural adsorbent with a composition almost identical to the fly ash. The new adsorbent was characterized by AFM, XRD, FTIR, SEM, EDS and the surface energy was evaluated by contact angle measurements. For understanding the complex adsorption process on this mixed substrate, preliminary tests were developed on synthetic wastewaters containing a single pollutant system (heavy metal), binary (two-heavy metals) and ternary (dye and two heavy metals) systems. Experiments were done on synthetic wastewaters containing methylene blue, cadmium and copper, using FAw, B and their powder mixtures. The pseudo-second order kinetics could well model all the processes, indicating a good adsorbent material which can be used for the pollutants removal from wastewater. After adsorption the substrates loaded with pollutants, annealed at 500 °C can be reused for padding in stone blocks.

  9. Tailoring fly ash activated with bentonite as adsorbent for complex wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Visa, Maria, E-mail: maria.visa@unitbv.ro [Transilvania University of Brasov, Department Renewable Energy Systems and Recycling, Eroilor 29, 500036 Brasov (Romania)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The spent adsorbent annealed at 500 Degree-Sign C can be a suggestion for padding in stone blocks. Black-Right-Pointing-Pointer The cations can be adsorbent by the silanol group (Si-OH) of the layers from bentonite Black-Right-Pointing-Pointer Copper has a higher affinity for the active sites on adsorbent FAw + B than cadmium. Black-Right-Pointing-Pointer This substrate can be recommended for simultaneous removal of heavy metals and MB. Black-Right-Pointing-Pointer FAw + B is recommended for wastewater treatment resulted in the dyes finishing industry. - Abstract: Used as adsorbent, alkali fly ash represents a low cost solution for advanced wastewater treatment. The alkali treatment raises sustainability issues therefore, in this research we aim to replace alkali fly ash with washed fly ash (FAw). For improving the adsorption capacity of washed fly ash, bentonite powder (B) was added, as a natural adsorbent with a composition almost identical to the fly ash. The new adsorbent was characterized by AFM, XRD, FTIR, SEM, EDS and the surface energy was evaluated by contact angle measurements. For understanding the complex adsorption process on this mixed substrate, preliminary tests were developed on synthetic wastewaters containing a single pollutant system (heavy metal), binary (two-heavy metals) and ternary (dye and two heavy metals) systems. Experiments were done on synthetic wastewaters containing methylene blue, cadmium and copper, using FAw, B and their powder mixtures. The pseudo-second order kinetics could well model all the processes, indicating a good adsorbent material which can be used for the pollutants removal from wastewater. After adsorption the substrates loaded with pollutants, annealed at 500 Degree-Sign C can be reused for padding in stone blocks.

  10. Emerging Methods for Producing Monodisperse Graphene Dispersions

    OpenAIRE

    Green, Alexander A.; Hersam, Mark C.

    2010-01-01

    With the recent burst of activity surrounding solution phase production of graphene, comparatively little progress has been made towards the generation of graphene dispersions with tailored thickness, lateral area, and shape. The polydispersity of graphene dispersions, however, can lead to unpredictable or non-ideal behavior once they are incorporated into devices, since the properties of graphene vary as a function of its structural parameters. In this brief perspective, we overview the prob...

  11. I Move: Systematic development of a web-based computer tailored physical activity intervention, based on motivational interviewing and self-determination theory

    OpenAIRE

    Friederichs, S.A.; Oenema, A.; Bolman, C.; Guyaux, J.; Keulen, H.M. van; Lechner, L.

    2014-01-01

    Background: This article describes the systematic development of the I Move intervention: a web-based computer tailored physical activity promotion intervention, aimed at increasing and maintaining physical activity among adults. This intervention is based on the theoretical insights and practical applications of self-determination theory and motivational interviewing. Methods/design. Since developing interventions in a systemically planned way increases the likelihood of effectiveness, we us...

  12. Systematic Development of the YouRAction program, a computer-tailored Physical Activity promotion intervention for Dutch adolescents, targeting personal motivations and environmental opportunities

    OpenAIRE

    Prins Richard G; van Empelen Pepijn; Beenackers Marielle A; Brug Johannes; Oenema Anke

    2010-01-01

    Abstract Background Increasing physical activity (PA) among adolescents is an important health promotion goal. PA has numerous positive health effects, but the majority of Dutch adolescents do not meet PA requirements. The present paper describes the systematic development of a theory-based computer-tailored intervention, YouRAction, which targets individual and environmental factors determining PA among adolescents. Design The intervention development was guided by the Intervention Mapping p...

  13. ACTION OF HIGH-DISPERSED SILICA ON BLOOD COAGULATION FACTORS ACTIVATION

    Directory of Open Access Journals (Sweden)

    T. M. Chernyshenko

    2013-02-01

    Full Text Available Using of high-dispersed silica based sorbents is a new and prospective method of bleeding arrest. Studies of high-dispersed silica haemostatic action during superficial wounds were promising for its surgery usage. However the mechanisms of haemostatic effects of high-dispersed silica are still unknown. Our investigations were focused on high-dispersed silica action on activation of some blood coagulation factors and clearing of its blood arresting mechanisms. Activation of individual coagulation factors was measured using specific chromogenic substrates. It was shown that high-dispersed silica increases the activation of intrinsic and extrinsic blood coagulation pathway factors which was initiated by «Activated partial thromboplastin time» and thromboplastin. Blood coagulation factor X was determined as a target of high-dispersed silica using highspecific activators from the snake venoms. Observed increasing of factor X activation could be the consequence of the adsorption of the intrinsic blood coagulation pathway factors on sorbent surface. Obtained results give a possibility to speculate about high-dispersed silica effects on blood coagulation increasing.

  14. The positive effect on determinants of physical activity of a tailored, general practice-based physical activity intervention

    NARCIS (Netherlands)

    Sluijs, van E.M.F.; Poppel-Bruinvels, van M.N.M.; Twisk, J.W.R.; Brug, J.; Mechelen, van W.

    2005-01-01

    PACE (Physician-based Assessment and Counseling for Exercise) is an individualized theory-based minimal intervention strategy aimed at the enhancement of regular physical activity. The aim of this study was to evaluate the effectiveness of a PACE intervention applied by general practitioners (GPs) o

  15. Biomolecular structure manipulation using tailored electromagnetic radiation: a proof of concept on a simplified model of the active site of bacterial DNA topoisomerase.

    Science.gov (United States)

    Jarukanont, Daungruthai; Coimbra, João T S; Bauerhenne, Bernd; Fernandes, Pedro A; Patel, Shekhar; Ramos, Maria J; Garcia, Martin E

    2014-10-21

    We report on the viability of breaking selected bonds in biological systems using tailored electromagnetic radiation. We first demonstrate, by performing large-scale simulations, that pulsed electric fields cannot produce selective bond breaking. Then, we present a theoretical framework for describing selective energy concentration on particular bonds of biomolecules upon application of tailored electromagnetic radiation. The theory is based on the mapping of biomolecules to a set of coupled harmonic oscillators and on optimal control schemes to describe optimization of temporal shape, the phase and polarization of the external radiation. We have applied this theory to demonstrate the possibility of selective bond breaking in the active site of bacterial DNA topoisomerase. For this purpose, we have focused on a model that was built based on a case study. Results are given as a proof of concept.

  16. Carbon nanotubes-dispersed TiO{sub 2} nanoparticles with their enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bo; Xu, Youfeng; Cui, Jing [Department of Materials Engineering, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Wang, Sheng, E-mail: wangsheng571@hotmail.com [Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Department of Materials Engineering, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Wang, Tao, E-mail: Taotao571@hotmail.com [Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Department of Materials Engineering, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2014-11-15

    Graphical abstract: Carbon nanotubes-dispersed TiO{sub 2} nanoparticles with their enhanced photocatalytic activity. - Abstract: A novel carbon nanotubes (CNTs)-dispersed route is used to prepare high-activity titanium dioxide nanoparticles (TiO{sub 2}). Field-emission scanning electron microscopy and transmission electron microscopy reveals that the irregular TiO{sub 2} nanoparticles with diameters of 10–20 nm are highly dispersed. X-ray diffraction and specific surface area measurement show that high-activity anatase crystal is formed and the specific surface area of TiO{sub 2} nanoparticles is 147.36 m{sup 2}/g. The photoactivity of TiO{sub 2} was tested by photodegradation of Rhodamine B. The result shows that the photocatalytic activity of TiO{sub 2} nanoparticles prepared by the CNTs-dispersed route is three times higher than that by conventional hydrothermal treatment.

  17. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

    Directory of Open Access Journals (Sweden)

    Crittenden Elizabeth L

    2004-07-01

    Full Text Available Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. Results The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Conclusions Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

  18. Controlling Spatiotemporal Chaos in Active Dissipative-Dispersive Nonlinear Systems

    Science.gov (United States)

    Gomes, Susana; Pradas, Marc; Kalliadasis, Serafim; Papageorgiou, Demetrios; Pavliotis, Grigorios

    2015-11-01

    We present a novel generic methodology for the stabilization and control of infinite-dimensional dynamical systems exhibiting low-dimensional spatiotemporal chaos. The methodology is exemplified with the generalized Kuramoto-Sivashinsky equation, the simplest possible prototype that retains that fundamental elements of any nonlinear process involving wave evolution. The equation is applicable on a wide variety of systems including falling liquid films and plasma waves with dispersion due to finite banana width. We show that applying the appropriate choice of time-dependent feedback controls via blowing and suction, we are able to stabilize and/or control all stable or unstable solutions, including steady solutions, travelling waves and spatiotemporal chaos, but also use the controls obtained to stabilize the solutions to more general long wave models. We acknowledge financial support from Imperial College through a Roth PhD studentship, Engineering and Physical Sciences Research Council of the UK through Grants No. EP/H034587, EP/J009636, EP/K041134, EP/L020564 and EP/L024926 and European Research Council via Advanced Grant No. 247031.

  19. Optimized dispersion of ZnO nanoparticles and antimicrobial activity against foodborne pathogens and spoilage microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Perez Espitia, Paula Judith; Ferreira Soares, Nilda de Fatima, E-mail: nfsoares1@gmail.com [Department of Food Technology, Federal University of Vicosa (Brazil); Teofilo, Reinaldo F. [Federal University of Vicosa, Department of Chemistry (Brazil); Vitor, Debora M.; Reis Coimbra, Jane Selia dos; Andrade, Nelio Jose de [Department of Food Technology, Federal University of Vicosa (Brazil); Sousa, Frederico B. de; Sinisterra, Ruben D. [Federal University of Minas Gerais, Department of Chemistry (Brazil); Medeiros, Eber Antonio Alves [Department of Food Technology, Federal University of Vicosa (Brazil)

    2013-01-15

    Single primary nanoparticles of zinc oxide (nanoZnO) tend to form particle collectives, resulting in loss of antimicrobial activity. This work studied the effects of probe sonication conditions: power, time, and the presence of a dispersing agent (Na{sub 4}P{sub 2}O{sub 7}), on the size of nanoZnO particles. NanoZnO dispersion was optimized by response surface methodology (RSM) and characterized by the zeta potential (ZP) technique. NanoZnO antimicrobial activity was investigated at different concentrations (1, 5, and 10 % w/w) against four foodborne pathogens and four spoilage microorganisms. The presence of the dispersing agent had a significant effect on the size of dispersed nanoZnO. Minimum size after sonication was 238 nm. An optimal dispersion condition was achieved at 200 W for 45 min of sonication in the presence of the dispersing agent. ZP analysis indicated that the ZnO nanoparticle surface charge was altered by the addition of the dispersing agent and changes in pH. At tested concentrations and optimal dispersion, nanoZnO had no antimicrobial activity against Pseudomonas aeruginosa, Lactobacillus plantarum, and Listeria monocytogenes. However, it did have antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger. Based on the exhibited antimicrobial activity of optimized nanoZnO against some foodborne pathogens and spoilage microorganisms, nanoZnO is a promising antimicrobial for food preservation with potential application for incorporation in polymers intended as food-contact surfaces.

  20. pH-Sensitive Microparticles with Matrix-Dispersed Active Agent

    Science.gov (United States)

    Li, Wenyan (Inventor); Buhrow, Jerry W. (Inventor); Jolley, Scott T. (Inventor); Calle, Luz M. (Inventor)

    2014-01-01

    Methods to produce pH-sensitive microparticles that have an active agent dispersed in a polymer matrix have certain advantages over microcapsules with an active agent encapsulated in an interior compartment/core inside of a polymer wall. The current invention relates to pH-sensitive microparticles that have a corrosion-detecting or corrosion-inhibiting active agent or active agents dispersed within a polymer matrix of the microparticles. The pH-sensitive microparticles can be used in various coating compositions on metal objects for corrosion detecting and/or inhibiting.

  1. Research on giving antibacteria activity of tailored dental materials; Gin ion ni yoru shikayo zairyo no kokinsei fuyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The secondary dental caries easily occur by breeding of bacteria in cavities between living body and composite resin, false tooth or root of tailored tooth as tooth repairing materials. The antibacteria activity of tailored dental materials was thus studied by implanting Ag ion. The antibacteria effect with time after culture of caries bacteria was studied by implanting Ag ion into SiO2 powder, PMMA samples and Ti alloy samples at 20 and 200keV in energy of ion. In addition, the antibacteria activity of SiO2 powder as composite material was found at 25keV which was previously effective for the antibacteria activity. This SiO2 filler (Ag{sup +} filler) showed the antibacteria activity on every bacteria sample after 2h, and in particular, could kill all of 3 kinds of bacteria obtained from a composite resin surface after 12h. The number of living S. salivarius was reduced by half after 12h. The application of the composite resin filler implanted with Ag{sup +} is significant to prevent recurrence of caries. 5 refs., 27 figs., 7 tabs.

  2. Efficacy of Tailored Physical Activity or Chronic Pain Self-Management Programme on return to work for sick-listed citizens

    DEFF Research Database (Denmark)

    Andersen, Lotte Nygaard; Juul-Kristensen, Birgit; Sørensen, Thomas Lund;

    2015-01-01

    OBJECTIVES: The aim was to evaluate the efficacy of 'Tailored Physical Activity' (TPA) and a 'Chronic Pain Self-management Programme' (CPSMP) compared with a reference group (REF) on return to work after 3 months as sick-listed citizens with pain related to the back or the upper body. METHODS....... In contrast, no benefit of TPA and CPSMP was evident regarding work ability, kinesiophobia or physical capacity after 3 months of follow-up. CONCLUSIONS: The results suggest that TPA is a promising intervention to facilitate return to work and reduce pain among sick-listed citizens with pain related...

  3. Influence of nano-dispersive modified additive on cement activity

    Energy Technology Data Exchange (ETDEWEB)

    Sazonova, Natalya, E-mail: n.a.sazonova@mail.ru; Badenikov, Artem, E-mail: rector@agta.ru; Ivanova, Elizaveta, E-mail: lisik-iva@mail.ru [Angarsk State Technical University, 60, Tchaykovsky St., 665835, Angarsk (Russian Federation); Skripnikova, Nelli, E-mail: nks2003@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation)

    2016-01-15

    In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4–6.3 fold relatively to the reference samples and may reach 179.6 MPa. It may intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C{sub 3}S and β-C{sub 2}S.

  4. Influence of nano-dispersive modified additive on cement activity

    Science.gov (United States)

    Sazonova, Natalya; Badenikov, Artem; Skripnikova, Nelli; Ivanova, Elizaveta

    2016-01-01

    In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4-6.3 fold relatively to the reference samples and may reach 179.6 MPa. It may intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C3S and β-C2S.

  5. The role of the catalysts with highly dispersed and isolated active sites in the selective oxidation of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    WANG Hongxuan; ZHAO Zhen

    2005-01-01

    This review summarizes the role of catalysts with highly dispersed and isolated active sites (active sites: supported atoms f≤0.5 % ) in the selective oxidation of light hydrocarbons, such as methane, ethane and propane, into oxygenatesand the epoxidation of olefins. The plausible structures of the highly dispersed and isolated active species, as well as their effects on the catalytic performances are discussed. The special physico-chemical properties and the functional mechanism of the catalysts with highly dispersed and isolated active sites, as well as the preparation, characterization of the catalysts with highly dispersed and isolated active sites and their applications in other types of reactions of lower hydrocarbons are summarized.

  6. Structural features of bionanocomposite derived from novel designed poly(ester-imide) based on natural amino acids with hydroxyl segments tailored for better dispersion of TiO2 nanofiller

    Indian Academy of Sciences (India)

    Shadpour Mallakpour; Parvin Asadi

    2013-04-01

    Deliberately inorganic nanoparticles (NP)s in polymer matrices significantly affect their characteristics and therefore their applications, but key factor to achieve the expected efficiency is well dispersion of the NPs in polymer matrix. The work presented here deals with the polymerization of amino acid-based monomer to synthesize optically active poly(ester-imide) (PEI) with hydroxyl terminated groups, using tosyl chloride/pyridine/,-dimethylformamide system as a condensing agent. The synthesized polymer was used for the preparation of bionanocomposite (BNC) containing modified titanium dioxide (TiO2) NPs using ultrasonic irradiation. With the aim of -amidopropyl-triethoxylsilicane as a coupling agent, the surface of nanoscale TiO2 was modified to decrease aggregation of the NPs in polymer matrix. The obtained PEI/TiO2 BNCs were characterized with fourier transfer infrared (FT–IR), thermogravimetric analysis, field emission scanning electron microscopy (FE–SEM), X-ray diffraction and transmission electron microscopy (TEM) techniques. Morphology study of resulting PEI/TiO2 BNCs by FE–SEM and TEM analyses demonstrated that the hydroxyl-terminated polymer chains reduced aggregation of the NPs and thus lead to better dispersion of the NPs in the polymer matrix.

  7. Microparticles Containing Curcumin Solid Dispersion: Stability, Bioavailability and Anti-Inflammatory Activity.

    Science.gov (United States)

    Teixeira, C C C; Mendonça, L M; Bergamaschi, M M; Queiroz, R H C; Souza, G E P; Antunes, L M G; Freitas, L A P

    2016-04-01

    This work aimed at improving the solubility of curcumin by the preparation of spray-dried ternary solid dispersions containing Gelucire®50/13-Aerosil® and quantifying the resulting in vivo oral bioavailability and anti-inflammatory activity. The solid dispersion containing 40% of curcumin was characterised by calorimetry, infrared spectroscopy and X-ray powder diffraction. The solubility and dissolution rate of curcumin in aqueous HCl or phosphate buffer improved up to 3600- and 7.3-fold, respectively. Accelerated stability test demonstrated that the solid dispersion was stable for 9 months. The pharmacokinetic study showed a 5.5-fold increase in curcumin in rat blood plasma when compared to unprocessed curcumin. The solid dispersion also provided enhanced anti-inflammatory activity in rat paw oedema. Finally, the solid dispersion proposed here is a promising way to enhance curcumin bioavailability at an industrial pharmaceutical perspective, since its preparation applies the spray drying, which is an easy to scale up technique. The findings herein stimulate further in vivo evaluations and clinical tests as a cancer and Alzheimer chemoprevention agent.

  8. The (cost-effectiveness of an individually tailored long-term worksite health promotion programme on physical activity and nutrition: design of a pragmatic cluster randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Burdorf Alex

    2007-09-01

    Full Text Available Abstract Background Cardiovascular disease is the leading cause of disability and mortality in most Western countries. The prevalence of several risk factors, most notably low physical activity and poor nutrition, is very high. Therefore, lifestyle behaviour changes are of great importance. The worksite offers an efficient structure to reach large groups and to make use of a natural social network. This study investigates a worksite health promotion programme with individually tailored advice in physical activity and nutrition and individual counselling to increase compliance with lifestyle recommendations and sustainability of a healthy lifestyle. Methods/Design The study is a pragmatic cluster randomised controlled trial with the worksite as the unit of randomisation. All workers will receive a standard worksite health promotion program. Additionally, the intervention group will receive access to an individual Health Portal consisting of four critical features: a computer-tailored advice, a monitoring function, a personal coach, and opportunities to contact professionals at request. Participants are employees working for companies in the Netherlands, being literate enough to read and understand simple Internet-based messages in the Dutch language. A questionnaire to assess primary outcomes (compliance with national recommendations on physical activity and on fruit and vegetable intake will take place at baseline and after 12 and 24 months. This questionnaire also assesses secondary outcomes including fat intake, self-efficacy and self-perceived barriers on physical activity and fruit and vegetable intake. Other secondary outcomes, including a cardiovascular risk profile and physical fitness, will be measured at baseline and after 24 months. Apart from the effect evaluation, a process evaluation will be carried out to gain insight into participation and adherence to the worksite health promotion programme. A cost-effectiveness analysis and

  9. Nanocapsular Dispersion of Cinnamaldehyde for Enhanced Inhibitory Activity against Aflatoxin Production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Hongbo Li

    2015-04-01

    Full Text Available Cinnamaldehyde (CA is marginally soluble in water, making it challenging to evenly disperse it in foods, and resulting in lowered anti-A. flavus efficacy. In the present study, nano-dispersed CA (nano-CA was prepared to increase its aqueous solubility. Free and nano-dispersed CA were compared in terms of their inhibitory activity against fungal growth and aflatoxin production of A. flavus both in Sabouraud Dextrose (SD culture and in peanut butter. Our results indicated that free CA inhibited the mycelia growth and aflatoxin production of A. flavus with a minimal inhibitory concentration (MIC value of 1.0 mM, but promoted the aflatoxin production at some concentrations lower than the MIC. Nano-CA had a lower MIC value of 0.8 mM against A. flavus, and also showed improved activity against aflatoxin production without the promotion at lower dose. The solidity of peanut butter had an adverse impact on the antifungal activity of free CA, whereas nano-dispersed CA showed more than 2-fold improved activity against the growth of A. flavus. Free CA still promoted AFB1 production at the concentration of 0.25 mM, whereas nano-CA showed more efficient inhibition of AFB1 production in the butter.

  10. Effect of sodium dodecyl sulfate on flow and electrokinetic properties of Na-activated bentonite dispersions

    Indian Academy of Sciences (India)

    E Günıster; S İşçı; A Alemdar; N Güngör

    2004-06-01

    The present study reports the effect of anionic surfactant sodium dodecyl sulfate (SDS, C12H25 OSO3Na) upon the electrokinetic (electrophoretic mobility, zeta potential) and rheological (viscosity, yield value) properties of the Ca-bentonitic clay found in Turkey and its Na-activated form. The SDS dispersant was added in different concentrations in the range of 1 × 10-5-5 × 10-2 mol/l. The results show that the viscosity and zeta potential values of bentonite dispersion are affected by the addition of anionic surfactant. The obtained data are analysed by considering the kind of exchangeable cations. Thixotropic property effect was observed in bentonite dispersions.

  11. Tailored Porous Materials

    Energy Technology Data Exchange (ETDEWEB)

    BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

    1999-11-09

    Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

  12. Effectiveness of a Web-Based, Computer-Tailored, Pedometer-Based Physical Activity Intervention for Adults: A Cluster Randomized Controlled Trial

    Science.gov (United States)

    Vandelanotte, Corneel; Cardon, Greet; De Bourdeaudhuij, Ilse; De Cocker, Katrien

    2015-01-01

    Background Computer-tailored physical activity (PA) interventions delivered through the Internet represent a promising and appealing method to promote PA at a population level. However, personalized advice is mostly provided based on subjectively measured PA, which is not very accurate and might result in the delivery of advice that is not credible or effective. Therefore, an innovative computer-tailored PA advice was developed, based on objectively pedometer-measured PA. Objective The study aim was to evaluate the effectiveness of a computer-tailored, pedometer-based PA intervention in working adults. Methods Participants (≥18 years) were recruited between May and December 2012 from eight Flemish workplaces. These workplaces were allocated randomly to an intervention or control group. Intervention group participants (n=137) received (1) a booklet with information on how to increase their steps, (2) a non-blinded pedometer, and (3) an Internet link to request computer-tailored step advice. Control group participants (n=137) did not receive any of the intervention components. Self-reported and pedometer-based PA were assessed at baseline (T0), and 1 month (T1) and 3 months (T2) months post baseline. Repeated measures analyses of covariance were used to examine intervention effects for both the total sample and the at-risk sample (ie, adults not reaching 10,000 steps a day at baseline). Results The recruitment process resulted in 274 respondents (response rate of 15.1%) who agreed to participate, of whom 190 (69.3%) belonged to the at-risk sample. Between T0 and T1 (1-month post baseline), significant intervention effects were found for participants’ daily step counts in both the total sample (P=.004) and the at-risk sample (P=.001). In the at-risk sample, the intervention effects showed a daily step count increase of 1056 steps in the intervention group, compared to a decrease of 258 steps in the control group. Comparison of participants’ self-reported PA

  13. WATER DISPERSIBLE METAL OXIDE NANOBIOCOMPOSITE AS A POTENTIATOR OF THE ANTIMICROBIAL ACTIVITY OF KANAMYCIN

    Directory of Open Access Journals (Sweden)

    Coralia Bleotu

    2012-12-01

    Full Text Available This study reports the evaluation of a water dispersible metal oxide nanobiocomposite based CS and magnetite as a potential drug delivery system and its cytotoxicity. The results proved that loading kanamycin sulfate into the water dispersible metal oxide nanobiocomposite improve the delivery of this drug in active form reducing minimum inhibitory concentration of kanamycin by two (in case of S. aureus to four folds (in case of E. coli, as compared with the kanamycin control. Furthermore, cytotoxicity test revealed that the nanobiocomposite has a very low toxic effect on eukaryotic cells. Our data suggest that water soluble metal oxide nanobiocomposite derivative is a good candidate for developing alternative strategies for enhancing the activity of antimicrobial drugs, without increasing the amount of the loaded active compound.

  14. Effect of Activated Carbon as a Support on Metal Dispersion and Activity of Ruthenium Catalyst for Ammonia Synthesis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ten kinds of activated carbon from different raw materials were used as supports to prepare ruthenium catalysts. N2 physisorption and CO chemisorption were carried out to investigate the pore size distribution and the ruthenium dispersion of the catalysts. It was found that the Ru dispersion of the catalyst was closely related to not only the texture of carbon support but also the purity of activated carbon. The activities of a series of the carbon-supported barium-promoted Ru catalysts for ammonia synthesis were measured at 425 ℃, 10.0 MPa and 10 000 h-1. The result shows that the same raw material activated carbon, with a high purity, high surface area, large pore volume and reasonable pore size distribution might disperse ruthenium and promoter sufficiently, which activated carbon as support, could be used to manufacture ruthenium catalyst with a high activity for ammonia synthesis. The different raw material activated carbon as the support would greatly influence the catalytic properties of the ruthenium catalyst for ammonia synthesis. For example, with coconut shell carbon(AC1) as the support, the ammonia concentration in the effluent was 13.17% over 4%Ru-BaO/AC1 catalyst, while with the desulfurized coal carbon(AC10) as the support, that in the effluent was only 1.37% over 4%Ru-BaO/AC10 catalyst.

  15. Impact of ultrasonic dispersion on the photocatalytic activity of titania aggregates

    Directory of Open Access Journals (Sweden)

    Hoai Nga Le

    2015-12-01

    Full Text Available The effectiveness of photocatalytic materials increases with the specific surface area, thus nanoscale photocatalyst particles are preferred. However, such nanomaterials are frequently found in an aggregated state, which may reduce the photocatalytic activity due to internal obscuration and the extended diffusion path of the molecules to be treated. This paper investigates the effect of aggregate size on the photocatalytic activity of pyrogenic titania (Aeroxide® P25, Evonik, which is widely used in fundamental photocatalysis research. Well-defined and reproducible aggregate sizes were achieved by ultrasonic dispersion. The photocatalytic activity was examined by the color removal of methylene blue (MB with a laboratory-scale setup based on a plug flow reactor (PFR and planar UV illumination. The process parameters such as flow regime, optical path length and UV intensity are well-defined and can be varied. Our results firstly show that a complete dispersion of the P25 aggregates is not practical. Secondly, the photocatalytic activity is not further increased beyond a certain degree of dispersion, which probably corresponds to a critical size for which UV irradiation can penetrate the aggregate without significant obscuration.

  16. Efficacy and use of an internet-delivered computer-tailored lifestyle intervention, targeting saturated fat intake, physical activity and smoking cessation : A randomized controlled trial

    NARCIS (Netherlands)

    Oenema, Anke; Brug, Johannes; Dijkstra, Arie; de Weerdt, Inge; de Vries, Hein

    2008-01-01

    Background Although experts claim that computer-tailored interventions provided over the Internet have great potential to promote health behavior change, few studies have tested the efficacy of computer-tailored lifestyle interventions online-delivered over the Internet. Purpose To evaluate the shor

  17. Antimicrobial activity of clove oil dispersed in a concentrated sugar solution.

    Science.gov (United States)

    Briozzo, J; Núñez, L; Chirife, J; Herszage, L; D'Aquino, M

    1989-01-01

    Essential oil of clove, dispersed (0.4% v/v) in a concentrated sugar solution, had a marked germicidal effect against various bacteria and Candida albicans. Staphylococcus aureus (five strains), Klebsiella pneumoniae, Pseudomonas aeruginosa, Clostridium perfringens, and Escherichia coli inoculated at a level of 10(7) cfu/ml, and C. albicans (inoculum 4.0 x 10(5) cfu/ml) were killed (greater than 99.999%) after 2-7 min in a laboratory broth supplemented with 63% (v/w) of sugar, and containing 0.4% (v/w) of essential oil of clove. Added organic matter (i.e. human or bovine serum) did not impair its antimicrobial activity. Sugar was not necessary for the antimicrobial activity of clove oil, but the concentrated sugar solution provided a good vehicle for obtaining an oil dispersion that is relatively stable for certain practical applications. PMID:2542213

  18. Disperse Dyes Based on Thiazole, Their Dyeing Application on Polyester Fiber and Their Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    S. K. Zadafiya

    2013-01-01

    Full Text Available Various diazotized aryl amines were coupled with N-(4-nitrophenyl-2-[(4-phenyl-1,3-thiazol-2-ylamino]acetamide to give the corresponding various azo disperse dyes (D1-D13. These dyes were applied to polyester fiber by HTHP method and their fastness properties were evaluated. Dyes were characterized by IR, elemental analysis, and NMR spectral studies. These dyes showed very good antibacterial and antifungal activities.

  19. Disperse Dyes Based on Thiazole, Their Dyeing Application on Polyester Fiber and Their Antimicrobial Activity

    OpenAIRE

    Zadafiya, S. K.; J. H. Tailor; Malik, G. M.

    2013-01-01

    Various diazotized aryl amines were coupled with N-(4-nitrophenyl)-2-[(4-phenyl-1,3-thiazol-2-yl)amino]acetamide to give the corresponding various azo disperse dyes (D1-D13). These dyes were applied to polyester fiber by HTHP method and their fastness properties were evaluated. Dyes were characterized by IR, elemental analysis, and NMR spectral studies. These dyes showed very good antibacterial and antifungal activities.

  20. Concentration and Dispersion in Global Industries: Remote Electronic Access and the Location of Economic Activities

    OpenAIRE

    Srilata Zaheer; Shalini Manrakhan

    2001-01-01

    We explore how the possibility of remote electronic access to markets, resources and knowledge, enabled by the new information and communication technologies (ICTs), might change the motivations of firms to locate activities internationally, and in turn affect worldwide dispersion and concentration in an industry. Preliminary results from an exploratory analysis of the spatial distribution of firms in financial services suggest that the introduction of a business-to-business (B2B) trading net...

  1. Systematic Development of the YouRAction program, a computer-tailored Physical Activity promotion intervention for Dutch adolescents, targeting personal motivations and environmental opportunities

    Directory of Open Access Journals (Sweden)

    Prins Richard G

    2010-08-01

    Full Text Available Abstract Background Increasing physical activity (PA among adolescents is an important health promotion goal. PA has numerous positive health effects, but the majority of Dutch adolescents do not meet PA requirements. The present paper describes the systematic development of a theory-based computer-tailored intervention, YouRAction, which targets individual and environmental factors determining PA among adolescents. Design The intervention development was guided by the Intervention Mapping protocol, in order to define clear program objectives, theoretical methods and practical strategies, ensure systematic program planning and pilot-testing, and anticipate on implementation and evaluation. Two versions of YouRAction were developed: one that targets individual determinants and an extended version that also provides feedback on opportunities to be active in the neighbourhood. Key determinants that were targeted included: knowledge and awareness, attitudes, self-efficacy and subjective norms. The extended version also addressed perceived availability of neighbourhood PA facilities. Both versions aimed to increase levels of moderate-to-vigorous PA among adolescents. The intervention structure was based on self-regulation theory, comprising of five steps in the process of successful goal pursuit. Monitoring of PA behaviour and behavioural and normative feedback were used to increase awareness of PA behaviour; motivation was enhanced by targeting self-efficacy and attitudes, by means of various interactive strategies, such as web movies; the perceived environment was targeted by visualizing opportunities to be active in an interactive geographical map of the home environment; in the goal setting phase, the adolescents were guided in setting a goal and developing an action plan to achieve this goal; in the phase of active goal pursuit adolescents try to achieve their goal and in the evaluation phase the achievements are evaluated. Based on the results

  2. Dexamethasone-Mediated Activation of Fibronectin Matrix Assembly Reduces Dispersal of Primary Human Glioblastoma Cells.

    Directory of Open Access Journals (Sweden)

    Stephen Shannon

    Full Text Available Despite resection and adjuvant therapy, the 5-year survival for patients with Glioblastoma multiforme (GBM is less than 10%. This poor outcome is largely attributed to rapid tumor growth and early dispersal of cells, factors that contribute to a high recurrence rate and poor prognosis. An understanding of the cellular and molecular machinery that drive growth and dispersal is essential if we are to impact long-term survival. Our previous studies utilizing a series of immortalized GBM cell lines established a functional causation between activation of fibronectin matrix assembly (FNMA, increased tumor cohesion, and decreased dispersal. Activation of FNMA was accomplished by treatment with Dexamethasone (Dex, a drug routinely used to treat brain tumor related edema. Here, we utilize a broad range of qualitative and quantitative assays and the use of a human GBM tissue microarray and freshly-isolated primary human GBM cells grown both as conventional 2D cultures and as 3D spheroids to explore the role of Dex and FNMA in modulating various parameters that can significantly influence tumor cell dispersal. We show that the expression and processing of fibronectin in a human GBM tissue-microarray is variable, with 90% of tumors displaying some abnormality or lack in capacity to secrete fibronectin or assemble it into a matrix. We also show that low-passage primary GBM cells vary in their capacity for FNMA and that Dex treatment reactivates this process. Activation of FNMA effectively "glues" cells together and prevents cells from detaching from the primary mass. Dex treatment also significantly increases the strength of cell-ECM adhesion and decreases motility. The combination of increased cohesion and decreased motility discourages in vitro and ex vivo dispersal. By increasing cell-cell cohesion, Dex also decreases growth rate of 3D spheroids. These effects could all be reversed by an inhibitor of FNMA and by the glucocorticoid receptor antagonist, RU

  3. Higher order mode excitation in eccentric active nano-particles for tailoring of the near-field radiation

    DEFF Research Database (Denmark)

    Thorsen, R. O.; Arslanagic, Samel

    2015-01-01

    We examine the excitation of resonant modes inside eccentrically layered cylindrical active nano-particles. The nano-particle is a three-layer structure comprised of a silica core, a free-space middle layer, and an outer shell of silver. It is shown that a concentric configuration, initially desi...... of the gain constant, is shown to be controlled by the direction of the core displacement. The present eccentric active nano-particles may provide alternative strategies for directive near-field radiation relative to the existing designs....

  4. The Differentiated Effectiveness of a Printed versus a Web-Based Tailored Physical Activity Intervention among Adults Aged over 50

    Science.gov (United States)

    Peels, D. A.; van Stralen, M. M.; Bolman, C.; Golsteijn, R. H. J.; de Vries, H.; Mudde, A. N.; Lechner, L.

    2014-01-01

    This study provides insight in the effectiveness of a print-delivered and a Web-based physical activity (PA) intervention (with or without additional environmental information on local PA possibilities) among people aged over 50. Intervention groups (print-delivered basic [PB; n = 439], print-delivered environmental [PE; n = 435], Web-based basic…

  5. Can a Website-Delivered Computer-Tailored Physical Activity Intervention Be Acceptable, Usable, and Effective for Older People?

    Science.gov (United States)

    Ammann, Rahel; Vandelanotte, Corneel; de Vries, Hein; Mummery, W. Kerry

    2013-01-01

    Despite the numerous health benefits, population physical activity levels are low and declining with age. A continued increase of Internet access allows for website-delivered interventions to be implemented across age-groups, though older people have typically not been considered for this type of intervention. Therefore, the purpose of this study…

  6. Volume 1, 1st Edition, Multiscale Tailoring of Highly Active and Stable Nanocomposite Catalysts, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Veser, Goetz

    2009-08-31

    Nanomaterials have gained much attention as catalysts since the discovery of exceptional CO oxidation activity of nanoscale gold by Haruta. However, many studies avoid testing nanomaterials at the high-temperatures relevant to reactions of interest for the production of clean energy (T > 700°C). The generally poor thermal stability of catalytically active noble metals has thus far prevented significant progress in this area. We have recently overcome the poor thermal stability of nanoparticles by synthesizing a platinum barium-hexaaluminate (Pt-BHA) nanocomposite which combines the high activity of noble metal nanoparticles with the thermal stability of hexaaluminates. This Pt-BHA nanocomposite demonstrates excellent activity, selectivity, and long-term stability in CPOM. Pt-BHA is anchored onto a variety of support structures in order to improve the accessibility, safety, and reactivity of the nanocatalyst. Silica felts prove to be particularly amenable to this supporting procedure, with the resulting supported nanocatalyst proving to be as active and stable for CPOM as its unsupported counterpart. Various pre-treatment conditions are evaluated to determine their effectiveness in removing residual surfactant from the active nanoscale platinum particles. The size of these particles is measured across a wide temperature range, and the resulting “plateau” of stability from 600-900°C can be linked to a particle caging effect due to the structure of the supporting ceramic framework. The nanocomposites are used to catalyze the combustion of a dilute methane stream, and the results indicate enhanced activity for both Pt-BHA as well as ceria-doped BHA, as well as an absence of internal mass transfer limitations at the conditions tested. In water-gas shift reaction, nanocomposite Pt-BHA shows stability during prolonged WGS reaction and no signs of deactivation during start-up/shut-down of the reactor. The chemical and thermal stability, low molecular weight, and

  7. Coordination of atmospheric dispersion activities for the real-time decision support system RODOS

    International Nuclear Information System (INIS)

    This projects task has been to coordinate activities among the RODOS Atmospheric Dispersion sub-group A participants, with the overall objective of developing and integrating an atmospheric transport and dispersion module for the joint European Real-time On-line DecisiOn Support system RODOS headed by FZK (formerly KfK), Germany. The project's final goal is the establishment of a fully operational, system-integrated atmospheric transport module for the RODOS system by year 2000, capable of consistent now- and forecasting of radioactive airborne spread over all types of terrain and on all scales of interest, including in particular complex terrain and the different scales of operation, such as the local, the national and the European scale. (au)

  8. Solubility Enhancement of a Poorly Water Soluble Drug by Forming Solid Dispersions using Mechanochemical Activation

    Science.gov (United States)

    Rojas-Oviedo, I.; Retchkiman-Corona, B.; Quirino-Barreda, C. T.; Cárdenas, J.; Schabes-Retchkiman, P. S.

    2012-01-01

    Mechanochemical activation is a practical cogrinding operation used to obtain a solid dispersion of a poorly water soluble drug through changes in the solid state molecular aggregation of drug-carrier mixtures and the formation of noncovalent interactions (hydrogen bonds) between two crystalline solids such as a soluble carrier, lactose, and a poorly soluble drug, indomethacin, in order to improve its solubility and dissolution rate. Samples of indomethacin and a physical mixture with a weight ratio of 1:1 of indomethacin and lactose were ground using a high speed vibrating ball mill. Particle size was determined by electron microscopy, the reduction of crystallinity was determined by calorimetry and transmission electron microscopy, infrared spectroscopy was used to find evidence of any interactions between the drug and the carrier and the determination of apparent solubility allowed for the corroboration of changes in solubility. Before grinding, scanning electron microscopy showed the drug and lactose to have an average particle size of around 50 and 30 μm, respectively. After high speed grinding, indomethacin and the mixture had a reduced average particle size of around 5 and 2 μm, respectively, showing a morphological change. The ground mixture produced a solid dispersion that had a loss of crystallinity that reached 81% after 30 min of grinding while the drug solubility of indomethacin within the solid dispersion increased by 2.76 fold as compared to the pure drug. Drug activation due to hydrogen bonds between the carboxylic group of the drug and the hydroxyl group of lactose as well as the decrease in crystallinity of the solid dispersion and the reduction of the particle size led to a better water solubility of indomethacin. PMID:23798775

  9. The generalized Tailor Problem

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.; Maragos, P; Schafer, RW; Butt, MA

    1996-01-01

    The so-called 'Tailor Problem' concerns putting a number of sets within another set by translation, such that the translated sets do not overlap. In this paper we consider a generalization of this problem in which also rotations of the sets are allowed.

  10. Tailoring of onboard system software

    Institute of Scientific and Technical Information of China (English)

    彭俊杰; 洪炳镕; 魏振华; 乔永强

    2003-01-01

    Tailoring of an operating system and an in embedded real-time operating system in particular is es-sential for both, kernel and operation. But many of current embedded real-time operating systems provide somebasic tailoring at the cost of depleting the flexibility of hardware, which causes the lack of flexibility, and de-grades their tailors. A layered modular tailoring model has been proposed together with some tailoring operationsto improve the flexibility of the systems, and algorithms have been proposed for verification of tailoring opera-tions with the current operating system.

  11. Method and the device for measurement of volume activity of gas and aerosol fractions of radioactive aero disperse systems

    Directory of Open Access Journals (Sweden)

    Tsovianov A.G.

    2013-12-01

    Full Text Available The given article aims a development of the method and the device for the disperse analysis and simultaneous measurement of volume activity of aerosol and gas fractions of radioactive aero disperse systems. Importance of the article is concerned with the fact that for measuring volume activity of sample including gas and aerosol fractions it's necessary to measure an activity of both fractions. Taking into account the volume activity of only one fraction in other case can result to understatement of internal dose estimation induced by radioactive aerosols inhalation. The method includes separation of aerosol fraction from gas by inertial sedimentation on cascade elements of the impactor, the subsequent chemical transformation of a gas component of aero disperse system to a disperse phase by input of reagent vapors in a gas stream and sedimentation of the formed aerosol particles on the filter. The device can be used in the industry for control of radioactive pollution of the air environment.

  12. Active-passive measurements and CFD based modelling for indoor radon dispersion study

    International Nuclear Information System (INIS)

    Computational fluid dynamics (CFD) play a significant role in indoor pollutant dispersion study. Radon is an indoor pollutant which is radioactive and inert gas in nature. The concentration level and spatial distribution of radon may be affected by the dwelling's ventilation conditions. Present work focus at the study of indoor radon gas distribution via measurement and CFD modeling in naturally ventilated living room. The need of the study is the prediction of activity level and to study the effect of natural ventilation on indoor radon. Two measurement techniques (Passive measurement using pin-hole dosimeters and active measurement using continuous radon monitor (SRM)) were used for the validation purpose of CFD results. The CFD simulation results were compared with the measurement results at 15 points, 3 XY planes at different heights along with the volumetric average concentration. The simulation results found to be comparable with the measurement results. The future scope of these CFD codes is to study the effect of varying inflow rate of air on the radon concentration level and dispersion pattern. - Highlights: • The distribution of radon gas in indoor environment was simulated using CFD modelling. • The distribution of radon was found to be more homogenous in open room condition. • The radon concentration level in open room was low as compare to closed room due to enhanced ventilation rate. • Simulation results are in agreement with active and passive measurements results

  13. Synthesis, characterizations and antimicrobial activities of well dispersed ultra-long CdO nanowires

    Directory of Open Access Journals (Sweden)

    Sumeet Kumar

    2013-05-01

    Full Text Available We present a simple, efficient, low cost and template free method for preparation of well dispersed ultra-long (1 μm CdO nanowires. The CdO nanowires were characterized by x-ray diffraction (XRD, Transmission electron microscopy (TEM, UV-visible spectroscopy and Raman measurements. The direct and indirect band gaps were calculated to be 3.5 eV and 2.6 eV, respectively. In the Raman spectra only second order features were observed. The CdO nanowires were used to study antimicrobial activities against B.subtilis and E.coli microbes. It shows antimicrobial activity against B.subtilis and E.coli. However, the antimicrobial activities are better against B.subtilis than that of E.coli.

  14. Nanocomposites of polymers with layered inorganic nanofillers: Antimicrobial activity, thermo-mechanical properties, morphology, and dispersion

    Science.gov (United States)

    Songtipya, Ponusa

    In the first part of the thesis, polyethylene/layered silicate nanocomposites that exhibit an antimicrobial activity were synthesized and studied. Their antimicrobial activity was designed to originate from non-leaching, novel cationic modifiers---amine-based surfactants---used as the organic-modification of the fillers. Specifically, PE/organically-modified montmorillonite ( mmt) nanocomposites were prepared via melt-processing, and simultaneous dispersion and antimicrobial activity was designed by proper choice of the fillers' organic modification. The antimicrobial activity was measured against three micotoxinogen fungal strains (Penicillium roqueforti and claviforme, and Fusarium graminearum ). Various mmt-based organofillers, which only differ in the type or amount of their organic modification, were used to exemplify how these surfactants can be designed to render antifungal activity to the fillers themselves and the respective nanocomposites. A comparative discussion of the growth of fungi on unfilled PE and nanocomposite PE films is used to demonstrate how the antimicrobial efficacy is dictated by the surfactant chemistry and, further, how the nanocomposites' inhibitory activity compares to that of the organo-fillers and the surfactants. An attempt to improve the thermomechanical reinforcement of PE/mmt nanocomposites while maintaining their antimicrobial activity, was also carried out by combining two different organically modified montmorillonites. However, a uniform microscopic dispersion could not be achieved through this approach. In the second part of this thesis, a number of fundamental studies relating to structure-property relations in nanocomposites were carried out, towards unveiling strategies that can concurrently optimize selected properties of polymers by the addition of nanofillers. Specifically, the dispersion-crystallinity-reinforcement relations in HDPE/mmt nanocomposites was investigated. The influence of a functional HDPE compatibilizer

  15. Active dispersal in loggerhead sea turtles (Caretta caretta) during the 'lost years'.

    Science.gov (United States)

    Briscoe, D K; Parker, D M; Balazs, G H; Kurita, M; Saito, T; Okamoto, H; Rice, M; Polovina, J J; Crowder, L B

    2016-06-15

    Highly migratory marine species can travel long distances and across entire ocean basins to reach foraging and breeding grounds, yet gaps persist in our knowledge of oceanic dispersal and habitat use. This is especially true for sea turtles, whose complex life history and lengthy pelagic stage present unique conservation challenges. Few studies have explored how these young at-sea turtles navigate their environment, but advancements in satellite technology and numerical models have shown that active and passive movements are used in relation to open ocean features. Here, we provide the first study, to the best of our knowledge, to simultaneously combine a high-resolution physical forcing ocean circulation model with long-term multi-year tracking data of young, trans-oceanic North Pacific loggerhead sea turtles during their 'lost years' at sea. From 2010 to 2014, we compare simulated trajectories of passive transport with empirical data of 1-3 year old turtles released off Japan (29.7-37.5 straight carapace length cm). After several years, the at-sea distribution of simulated current-driven trajectories significantly differed from that of the observed turtle tracks. These results underscore current theories on active dispersal by young oceanic-stage sea turtles and give further weight to hypotheses of juvenile foraging strategies for this species. Such information can also provide critical geographical information for spatially explicit conservation approaches to this endangered population. PMID:27252021

  16. Catalyst dispersion and activity under conditions of temperature-staged liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1992-02-01

    The general objectives of this research are (1) to investigate the use of highly dispersed catalysts for the pretreatment of coal by mild hydrogenation, (2) to identify the active forms of the catalysts under reaction conditions and (3) to clarify the mechanisms of catalysis. The ultimate objective is to ascertain if mild catalytic hydrogenation resulting in very limited or no coal solubilization is an advantageous pretreatment for the transformation of coal into transportable fuels. The experimental program will focus upon the development of effective methods of impregnating coal with catalysts, evaluating the conditions under which the catalysts are most active and establishing the relative impact of improved impregnation on conversion and product distributions obtained from coal hydrogenation.

  17. Modal amplification in active waveguides with hyperbolic dispersion at telecommunication frequencies.

    Science.gov (United States)

    Smalley, Joseph S T; Vallini, Felipe; Kanté, Boubacar; Fainman, Yeshaiahu

    2014-08-25

    We present a method for studying amplification of electromagnetic modes in active, circularly symmetric waveguides with hyperbolic dispersion. Using this method, we obtain a closed-form expression for the modal threshold condition. We find that modal amplification is possible in a region of the radius-wavelength phase-space with small enough radius so that propagation of the mode is permitted while modal energy and phase counter-propagate. At telecommunication frequencies, such a situation is achievable only when the absolute value of the real metal permittivity exceeds that of the active dielectric. We validate our theoretical conclusions with numerical simulations that explain the threshold condition in terms of an energy balance between the longitudinal and radial components of the electric field.

  18. Cosmic bombardment V: Threat object-dispersing approaches to active planetary defense

    Energy Technology Data Exchange (ETDEWEB)

    Teller, E.; Wood, L. [Stanford Univ., CA (United States). Hoover Institution on War, Revolution and Peace]|[Lawrence Livermore National Lab., CA (United States); Ishikawa, M. [Stanford Univ., CA (United States). Dept. of Aeronautics and Astronautics]|[Lawrence Livermore National Lab., CA (United States); Hyde, R. [Lawrence Livermore National Lab., CA (United States)

    1995-05-24

    Earth-impacting comets and asteroids with diameters {approx}0.03 - 10 km pose the greatest threats to the terrestrial biosphere in terms of impact frequency-weighted impact consequences, and thus are of most concern to designers of active planetary defenses. Specific gravitational binding energies of such objects range from 10{sup -7} to 10{sup -2} J/gm, and are small compared with the specific energies of 1x10{sup 3} to 3x10{sup 3} J/gm required to vaporize objects of typical composition or the specific energies required to pulverize them, which are 10{sup -1} to 10 J/gm. All of these are small compared to the specific kinetic energy of these objects in the Earth- centered frame, which is 2x10{sup 5} to 2x10{sup 6} J/gm. The prospect naturally arises of negating all such threats by deflecting, pulverizing or vaporizing the objects. Pulverization-with-dispersal is an attractive option of reasonable defensive robustness. Examples of such equipments - which employ no explosives of any type - are given. Vaporization is the maximally robust defensive option, and may be invoked to negate threat objects not observed until little time is left until Earth-strike, and pulverization-with-dispersal has proven inadequate. Physically larger threats may be vaporized with nuclear explosives. No contemporary technical means of any kind appear capable of directly dispersing the -100 km diameter scale Charon- class cometary objects recently observed in the outer solar system, although such objects may be deflected to defensively useful extents. Means of implementing defenses of each of these types are proposed for specificity, and areas for optimization noted. Biospheric impacts of threat object debris are briefly considered, for bounding purposes. Experiments are suggested on cometary and asteroidal objects.

  19. PL3 Amidase, a Tailor-made Lysin Constructed by Domain Shuffling with Potent Killing Activity against Pneumococci and Related Species.

    Science.gov (United States)

    Blázquez, Blas; Fresco-Taboada, Alba; Iglesias-Bexiga, Manuel; Menéndez, Margarita; García, Pedro

    2016-01-01

    that the structure/function-based domain shuffling approach is a successful method to construct tailor-made endolysins with higher bactericidal activities than their parental enzymes. PMID:27516758

  20. PL3 Amidase, a Tailor-made Lysin Constructed by Domain Shuffling with Potent Killing Activity against Pneumococci and Related Species

    Science.gov (United States)

    Blázquez, Blas; Fresco-Taboada, Alba; Iglesias-Bexiga, Manuel; Menéndez, Margarita; García, Pedro

    2016-01-01

    that the structure/function-based domain shuffling approach is a successful method to construct tailor-made endolysins with higher bactericidal activities than their parental enzymes. PMID:27516758

  1. Tailored reflectors for illumination.

    Science.gov (United States)

    Jenkins, D; Winston, R

    1996-04-01

    We report on tailored reflector design methods that allow the placement of general illumination patterns onto a target plane. The use of a new integral design method based on the edge-ray principle of nonimaging optics gives much more compact reflector shapes by eliminating the need for a gap between the source and the reflector profile. In addition, the reflectivity of the reflector is incorporated as a design parameter. We show the performance of design for constant irradiance on a distant plane, and we show how a leading-edge-ray method may be used to achieve general illumination patterns on nearby targets. PMID:21085288

  2. Tailor-made Au-Ag core–shell nanoparticle 2D arrays on protein-coated graphene oxide with assembly enhanced antibacterial activity

    International Nuclear Information System (INIS)

    Water-dispersible two-dimensional (2D) assemblies of Au-Ag core–shell nanoparticles are obtained through a highly selective electroless silver deposition on pre-assembled gold nanoparticles on bovine serum albumin (BSA)-coated graphene oxide (BSA-GO). While neither BSA-GO nor AuNP-decorated BSA-GO shows any antibacterial ability, the silver-coated GO-Au nanosheets (namely GO-Au-Ag) exhibit an enhanced antibacterial activity against Gram-negative Escherichia coli (E. coli) bacteria, superior to unassembled Au-Ag nanoparticles and even ionic Ag. Such an improvement may be attributed to the increased local concentration of silver nanoparticles around a bacterium and a polyvalent interaction with the bacterial surface. In addition, the colloidal stability of this novel nano-antimicrobial against the formation of random nanoparticle aggregates guarantees a minimized activity loss of the Au-Ag nanoparticles. The antibacterial efficacy of GO-Au-Ag is less sensitive to the existence of Cl−, in comparison with silver ions, providing another advantage for wound dressing applications. Our research unambiguously reveals a strong and very specific interaction between the GO-Au-Ag nanoassembly and E. coli, which could be an important clue toward a rational design, synthesis and assembly of innovative and highly active antibacterial nanomaterials. (paper)

  3. Catalyst dispersion and activity under conditions of temperature-staged liquefaction. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1993-02-01

    This research program involves the investigation of the use of highly dispersed catalyst precursors for the pretreatment of coals by mild hydrogenation. During the course of this effort solvent preswelling of the coal was evaluated as a means of deeply impregnating catalysts into coal, active phases of catalysts under reaction conditions were studied and the impact of these techniques were evaluated during pretreatment and temperature-staged liquefaction. Two coals, a Texas subbituminous and a Utah high volatile A bituminous, were used to examine the effects of solvent swelling pretreatment and catalyst impregnation on conversion behavior at 275{degrees}C, representative of the first, low-temperature stage in a temperature-staged liquefaction reaction. Ferrous sulfate, iron pentacarbonyl, ammonium tetrathiomolybdate, and molybdenum hexacarbonyl were used as catalyst precursors. Without swelling pretreatment, impregnation of both coals increased conversion, mainly through increased yields of preasphaltenes.

  4. Catalyst dispersion and activity under conditions of temperature-staged liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1993-02-01

    This research program involves the investigation of the use of highly dispersed catalyst precursors for the pretreatment of coals by mild hydrogenation. During the course of this effort solvent preswelling of the coal was evaluated as a means of deeply impregnating catalysts into coal, active phases of catalysts under reaction conditions were studied and the impact of these techniques were evaluated during pretreatment and temperature-staged liquefaction. Two coals, a Texas subbituminous and a Utah high volatile A bituminous, were used to examine the effects of solvent swelling pretreatment and catalyst impregnation on conversion behavior at 275[degrees]C, representative of the first, low-temperature stage in a temperature-staged liquefaction reaction. Ferrous sulfate, iron pentacarbonyl, ammonium tetrathiomolybdate, and molybdenum hexacarbonyl were used as catalyst precursors. Without swelling pretreatment, impregnation of both coals increased conversion, mainly through increased yields of preasphaltenes.

  5. My Activity Coach – Using video-coaching to assist a web-based computer-tailored physical activity intervention: a randomised controlled trial protocol

    OpenAIRE

    Alley, Stephanie; Jennings, Cally; Ronald C Plotnikoff; Vandelanotte, Corneel

    2014-01-01

    Background There is a need for effective population-based physical activity interventions. The internet provides a good platform to deliver physical activity interventions and reach large numbers of people at low cost. Personalised advice in web-based physical activity interventions has shown to improve engagement and behavioural outcomes, though it is unclear if the effectiveness of such interventions may further be improved when providing brief video-based coaching sessions with participant...

  6. Diesel exhaust particulate material expression of in vitro genotoxic activities when dispersed into a phospholipid component of lung surfactant

    International Nuclear Information System (INIS)

    Bacterial mutagenicity and mammalian cell chromosomal and DNA damage in vitro assays were performed on a diesel exhaust particulate material (DPM) standard in two preparations: as an organic solvent extract, and as an aqueous dispersion in a simulated pulmonary surfactant. U.S. National Institute for Standards and Technology DPM SRM 2975 expressed mutagenic activity in the Salmonella reversion assay, and for in vitro genotoxicity to mammalian cells as micronucleus induction and as DNA damage in both preparations: as an acetone extract of the DPM mixed into dimethylsulfoxide, and as a mixture of whole DPM in a dispersion of dipalmitoyl phosphatidyl choline. Dispersion in surfactant was used to model the conditioning of DPM depositing on the deep respiratory airways of the lung. DPM solid residue after acetone extraction was inactive when assayed as a surfactant dispersion in the micronucleus induction assay, as was surfactant dispersion of a respirable particulate carbon black. In general, a given mass of the DPM in surfactant dispersion expressed greater activity than the solvent extract of an equal mass of DPM.

  7. Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

    Science.gov (United States)

    Navaneetha Pandiyaraj, K.; Ram Kumar, M. C.; Arun Kumar, A.; Padmanabhan, P. V. A.; Deshmukh, R. R.; Bah, M.; Ismat Shah, S.; Su, Pi-Guey; Halleluyah, M.; Halim, A. S.

    2016-05-01

    Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as Osbnd Cdbnd O, Cdbnd O, Csbnd N and Ssbnd S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was found that the anti-thrombogenic properties of the PP films are effectively controlled by the CAPP grafting of AAc and PEG followed by immobilization of biomolecules of heparin, chitosan and insulin. The grafting and immobilization was confirmed by FTIR and XPS through the recognition of specific functional groups such as COOH, Csbnd O, Ssbnd S and Csbnd N. on the surface of PP film. Furthermore, the surface morphology and hydrophilic nature of the PP films also tailored

  8. Tailoring the Microstructure of Sol–Gel Derived Hydroxyapatite/Zirconia Nanocrystalline Composites

    Directory of Open Access Journals (Sweden)

    Vasconcelos HC

    2011-01-01

    Full Text Available Abstract In this study, we tailor the microstructure of hydroxyapatite/zirconia nanocrystalline composites by optimizing processing parameters, namely, introducing an atmosphere of water vapor during sintering in order to control the thermal stability of hydroxyapatite, and a modified sol–gel process that yields to an excellent intergranular distribution of zirconia phase dispersed intergranularly within the hydroxyapatite matrix. In terms of mechanical behavior, SEM images of fissure deflection and the presence of monoclinic ZrO2 content on cracked surface indicate that both toughening mechanisms, stress-induced tetragonal to monoclinic phase transformation and deflection, are active for toughness enhancement.

  9. Spatial-mode-interaction-induced dispersive-waves and their active tuning in microresonators

    CERN Document Server

    Yang, Qi-Fan; Yang, Ki Youl; Vahala, Kerry

    2016-01-01

    The nonlinear propagation of optical pulses in dielectric waveguides and resonators provides a laboratory to investigate a wide range of remarkable interactions. Many of the resulting phenomena find applications in optical systems. One example is dispersive wave generation, the optical analog of Cherenkov radiation. These waves have an essential role in fiber spectral broadeners that are routinely used in spectrocopy and metrology. Dispersive waves form when a soliton pulse begins to radiate power as a result of higher-order dispersion. Recently, dispersive wave generation in microcavities has been reported by phase matching the waves to dissipative Kerr cavity (DKC) solitons. Here, it is shown that spatial mode interactions within a microcavity can also be used to induce dispersive waves. These interactions are normally avoided altogether in DKC soliton generation. The soliton self frequency shift is also shown to induce fine tuning control of the dispersive wave frequency. Both this mechanism and spatial mo...

  10. Black howler monkey (Alouatta pigra) activity, foraging and seed dispersal patterns in shaded cocoa plantations versus rainforest in southern Mexico.

    Science.gov (United States)

    Zárate, Diego A; Andresen, Ellen; Estrada, Alejandro; Serio-Silva, Juan Carlos

    2014-09-01

    Recent evidence has shown that primates worldwide use agroecosystems as temporary or permanent habitats. Detailed information on how these primates are using these systems is scant, and yet their role as seed dispersers is often implied. The main objective of this study was to compare the activity, foraging patterns and seed dispersal role of black howler monkeys (Alouatta pigra) inhabiting shaded cocoa plantations and rainforest in southern Chiapas, Mexico. We gathered data on three monkey groups living in shaded cocoa plantations and three groups living in rainforest, using focal sampling, and collecting fecal samples. General activity and foraging patterns were similar in both habitats, with the exception that monkeys in the cocoa habitat spent more time feeding on petioles. Monkeys in shaded cocoa plantations dispersed 51,369 seeds (4% were seeds ≥3 mm width) of 16 plant species. Monkeys in the rainforest dispersed 6,536 seeds (78% were seeds ≥3 mm width) of 13 plant species. Our data suggest that the difference between habitats in the proportion of large versus small seeds dispersed reflects differences in fruit species abundance and availability in cocoa versus forest. Mean seed dispersal distances were statistically similar in both habitats (cocoa = 149 m, forest = 86 m). We conclude that the studied cocoa plantations provide all elements necessary to constitute a long-term permanent habitat for black howler monkeys. In turn, howler monkeys living in these plantations are able to maintain their functional role as seed dispersers for those native tree and liana species present within their areas of activities.

  11. Mycelia promote active transport and spatial dispersion of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Furuno, Shoko; Foss, Susan; Wild, Ed; Jones, Kevin C; Semple, Kirk T; Harms, Hauke; Wick, Lukas Y

    2012-05-15

    To cope with heterogeneous subsurface environments mycelial microorganisms have developed a unique ramified growth form. By extending hyphae, they can obtain nutrients from remote places and transport them even through air gaps and in small pore spaces, repectively. To date, studies have been focusing on the role that networks play in the distribution of nutrients. Here, we investigated the role of mycelia for the translocation of nonessential substances, using polycyclic aromatic hydrocarbons (PAHs) as model compounds. We show that the hyphae of the mycelial soil oomycete Pythium ultimum function as active translocation vectors for a wide range of PAHs. Visualization by two-photon excitation microscopy (TPEM) demonstrated the uptake and accumulation of phenanthrene (PHE) in lipid vesicles and its active transport by cytoplasmic streaming of the hyphae ('hyphal pipelines'). In mycelial networks, contaminants were translocated over larger distances than by diffusion. Given their transport capacity and ubiquity, hyphae may substantially distribute remote hydrophobic contaminants in soil, thereby improving their bioavailability to bacterial degradation. Hyphal contaminant dispersal may provide an untapped potential for future bioremediation approaches. PMID:22559873

  12. Characterization of microstructural and mechanical properties of a reduced activation ferritic oxide dispersion strengthened steel

    Science.gov (United States)

    Eiselt, Ch. Ch.; Klimenkov, M.; Lindau, R.; Möslang, A.

    2011-09-01

    For specific blanket and divertor applications in future fusion power reactors a replacement of presently considered Reduced Activation Ferritic Martensitic (RAFM) steels as structural material by suitable oxide dispersion strengthened (ODS) ferritic martensitic steels would allow a substantial increase of the operating temperature from ˜823 K to about 923 K. Temperatures above 973 K in the He cooled modular divertor concept necessitate the use of Reduced Activation Ferritic (RAF)-ODS-steels, which are not limited by a phase transition. The development concentrates on the ferritic ODS-steel Fe-13Cr-1W-0.3Ti-0.3Y 2O 3. The microstructures of a mechanically alloyed powder particle are observed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ageing experiments for 1000 h and 3000 h at 1123.5 K and 1223.5 K of compacted Fe-13Cr-1W-0.3Ti-0.3Y 2O 3 were executed. The impact especially on the oxide particles in terms of segregation and decomposition effects were monitored by electron energy loss spectroscopy (EELS). Long term vacuum creep experiments have been performed with rolled Fe-13Cr-1W-0.3Ti-0.3Y 2O 3 at 923.5 K and 1023.5 K, which will be compared to reference alloys.

  13. USE OF PLUME DISPERSION MODELLING FOR VIABLE AEROSOLS FROM AN ACTIVATED SLUDGE SEWAGE TREATMENT PLANT

    Science.gov (United States)

    Predictions of the emissions of airborne total viable particle (TVP) concentrations from sewage are of concern due to possible adverse human health effects. Two types of modelling approaches were explored: dispersion modelling such as the Gaussian plume dispersion model and stati...

  14. Effect of polydimethylsiloxane viscosity on the electrorheological activity of dispersions based on it

    Science.gov (United States)

    Davydova, O. I.; Kraev, A. S.; Redozubov, A. A.; Trusova, T. A.; Agafonov, A. V.

    2016-06-01

    The effect the viscosity of a dispersion medium of a polymethylsiloxane fluid (PMS) with a kinematic viscosity over a wide range of values from 5 to 300 cSt has on the electrorheological properties of suspensions based on nanosized titanium dioxide obtained via the sol-gel method is investigated. The investigations are conducted in a wide range of concentrations of suspensions: from 30 to 60 wt % (from 15 to 38 vol %) of the dispersed phase. The role the dispersion medium in two-phase disperse systems plays in the formation of structures of dispersed phase in the presence of an electric field is determined from the dependence of yield points of TiO2 in PMS with different viscosities on the applied electric field strength.

  15. Metal dispersion resulting from mining activities in coastal environments: a pathways approach

    Science.gov (United States)

    Koski, Randolph A.

    2012-01-01

    Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

  16. Multiwavelength Dispersion-Tuned Actively Mode-Locked Erbium-Doped Fibre Ring Laser with Gain Competition Suppression

    Institute of Scientific and Technical Information of China (English)

    PAN Shi-Long; LOU Cai-Yun

    2006-01-01

    Multiwavelength dispersion-tuned actively mode-locked erbium-doped fibre ring laser is demonstrated by incorporating a section of highly nonlinear fibre (HNLF) in the laser cavity. The HNLF and the time gate element (modulator) in the fibre laser successfully suppress the gain competition in the erbium-doped fibre, and thus enable multiwavelength operation. Simultaneous generation of 10 GHz pulses up to eight different wavelengths is achieved. Wavelength, spacing and modes number tuning are investigated by changing fibre cavity length, dispersion, and erbium-doped fibre amplifier power, respectively.

  17. Synthesis of Some Novel 2-Amino-5-arylazothiazole Disperse Dyes for Dyeing Polyester Fabrics and Their Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Hatem E. Gaffer

    2016-01-01

    Full Text Available The present work describes the synthesis of a series of four novel biologically active 2-amino-5-arylazothiazole disperse dyes containing the sulfa drug nucleus. The structures of the synthesized thiazole derivatives are confirmed using UV-spectrophotometry, infrared and nuclear magnetic resonance techniques and elemental analysis. The synthesized dyes are applied to polyester fabrics as disperse dyes and their fastness properties to washing, perspiration, rubbing, sublimation, and light are evaluated. The synthesized compounds exhibit promising biological efficiency against selected Gram-positive and Gram-negative pathogenic bacteria as well as fungi.

  18. Influence of Physical and Chemical Modification on the Optical Rotatory Dispersion and Biological Activity of Chitosan Films

    Directory of Open Access Journals (Sweden)

    A. B. Shipovskaya

    2013-01-01

    Full Text Available The optical and bactericidal properties of acetic and basic chitosan films were studied. By the ORD technique, we found that these films differed in the values of their specific optical rotation and of their rotary and dispersive constants. A sign inversion of was observed when the acetic chitosan films were heat-treated. The bactericidal activity of the initial and dehydrated acetic films was analyzed, and their moisture content and optical and biological activities were compared.

  19. Entrapment of curcumin into monoolein-based liquid crystalline nanoparticle dispersion for enhancement of stability and anticancer activity

    Directory of Open Access Journals (Sweden)

    Baskaran R

    2014-06-01

    Full Text Available Rengarajan Baskaran,1 Thiagarajan Madheswaran,2 Pasupathi Sundaramoorthy,1 Hwan Mook Kim,1 Bong Kyu Yoo1 1College of Pharmacy, Gachon University, Incheon, South Korea; 2College of Pharmacy Yeungnam University, Gyeongsan, South Korea Abstract: Despite the promising anticancer potential of curcumin, its therapeutic application has been limited, owing to its poor solubility, bioavailability, and chemical fragility. Therefore, various formulation approaches have been attempted to address these problems. In this study, we entrapped curcumin into monoolein (MO-based liquid crystalline nanoparticles (LCNs and evaluated the physicochemical properties and anticancer activity of the LCN dispersion. The results revealed that particles in the curcumin-loaded LCN dispersion were discrete and monodispersed, and that the entrapment efficiency was almost 100%. The stability of curcumin in the dispersion was surprisingly enhanced (about 75% of the curcumin survived after 45 days of storage at 40°C, and the in vitro release of curcumin was sustained (10% or less over 15 days. Fluorescence-activated cell sorting (FACS analysis using a human colon cancer cell line (HCT116 exhibited 99.1% fluorescence gating for 5 µM curcumin-loaded LCN dispersion compared to 1.36% for the same concentration of the drug in dimethyl sulfoxide (DMSO, indicating markedly enhanced cellular uptake. Consistent with the enhanced cellular uptake of curcumin-loaded LCNs, anticancer activity and cell cycle studies demonstrated apoptosis induction when the cells were treated with the LCN dispersion; however, there was neither noticeable cell death nor significant changes in the cell cycle for the same concentration of the drug in DMSO. In conclusion, entrapping curcumin into MO-based LCNs may provide, in the future, a strategy for overcoming the hurdles associated with both the stability and cellular uptake issues of the drug in the treatment of various cancers. Keywords: liquid

  20. Towards tailored radiopeptide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Radojewski, Piotr [University Hospital Bern, Institute of Nuclear Medicine, Bern (Switzerland); Dumont, Rebecca [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); UCLA, Department of Radiology, David Geffen School of Medicine, Los Angeles, CA (United States); Marincek, Nicolas; Walter, Martin A. [University Hospital Bern, Institute of Nuclear Medicine, Bern (Switzerland); University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Brunner, Philippe; Mueller-Brand, Jan [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Briel, Matthias [University Hospital Basel, Basel Institute for Clinical Epidemiology and Biostatistics, Basel (Switzerland)

    2015-07-15

    Somatostatin receptor-targeted radiopeptide therapy is commonly performed using single radioisotopes. We evaluated the benefits and harms of combining radioisotopes in radiopeptide therapy in patients with neuroendocrine tumor. Using multivariable-adjusted survival analyses and competing risk analyses we evaluated outcomes in patients with neuroendocrine tumor receiving {sup 90}Y-DOTATOC, {sup 177}Lu-DOTATOC or their combination. {sup 90}Y-DOTATOC plus {sup 177}Lu-DOTATOC treatment was associated with longer survival than {sup 90}Y-DOTATOC (66.1 vs. 47.5 months; n = 1,358; p < 0.001) or {sup 177}Lu-DOTATOC alone (66.1 vs. 45.5 months; n = 390; p < 0.001). {sup 177}Lu-DOTATOC was associated with longer survival than {sup 90}Y-DOTATOC in patients with solitary lesions (HR 0.3, range 0.1 - 0.7; n = 153; p = 0.005), extrahepatic metastases (HR 0.5, range 0.3 - 0.9; n = 256; p = 0.029) and metastases with low uptake (HR 0.1, range 0.05 - 0.4; n = 113; p = 0.001). {sup 90}Y-DOTATOC induced higher hematotoxicity rates than combined treatment (9.5 % vs. 4.0 %, p = 0.005) or {sup 177}Lu-DOTATOC (9.5 % vs. 1.4 %, p = 0.002). Renal toxicity was similar among the treatments. Using {sup 90}Y and {sup 177}Lu might facilitate tailoring radiopeptide therapy and improve survival in patients with neuroendocrine tumors. (orig.)

  1. Synthesis of water-dispersible zinc oxide quantum dots with antibacterial activity and low cytotoxicity for cell labeling

    International Nuclear Information System (INIS)

    Typical photoluminescent semiconductor nanoparticles, called quantum dots (QDs), have potential applications in biological labeling. When used to label stem cells, QDs may impair the differentiation capacity of the stem cells. In this study, we synthesized zinc oxide (ZnO) QDs in methanol with an average size of ∼2 nm. We then employed two different types of polyethylene glycol (PEG) molecules (SH-PEG-NH2 and NH2-PEG-NH2) to conjugate ZnO QDs and made them water-dispersible. Fourier transform infrared spectroscopy spectra indicated the attachment of PEG molecules on ZnO QDs. No obvious size alteration was observed for ZnO QDs after PEG conjugation. The water-dispersible ZnO QDs still retained the antibacterial activity and fluorescence intensity. The cytotoxicity evaluation revealed that ZnO QDs at higher concentrations decreased cell viability but were generally safe at 30 ppm or below. Cell lines of hepatocytes (HepG2), osteoblasts (MC3T3-E1) and mesenchymal stem cells (MSCs) were successfully labeled by the water-dispersible ZnO QDs at 30 ppm. The ZnO QD-labeled MSCs maintained their stemness and differentiation capacity. Therefore, we conclude that the water-dispersible ZnO QDs developed in this study have antibacterial activity, low cytotoxicity, and proper labeling efficiency, and can be used to label a variety of cells including stem cells. (paper)

  2. Synthesis of water-dispersible zinc oxide quantum dots with antibacterial activity and low cytotoxicity for cell labeling

    Science.gov (United States)

    Hsu, Shan-hui; Lin, Ying Yi; Huang, Sherry; Lem, Kwok Wai; Huong Nguyen, Dinh; Lee, Dai Soo

    2013-11-01

    Typical photoluminescent semiconductor nanoparticles, called quantum dots (QDs), have potential applications in biological labeling. When used to label stem cells, QDs may impair the differentiation capacity of the stem cells. In this study, we synthesized zinc oxide (ZnO) QDs in methanol with an average size of ∼2 nm. We then employed two different types of polyethylene glycol (PEG) molecules (SH-PEG-NH2 and NH2-PEG-NH2) to conjugate ZnO QDs and made them water-dispersible. Fourier transform infrared spectroscopy spectra indicated the attachment of PEG molecules on ZnO QDs. No obvious size alteration was observed for ZnO QDs after PEG conjugation. The water-dispersible ZnO QDs still retained the antibacterial activity and fluorescence intensity. The cytotoxicity evaluation revealed that ZnO QDs at higher concentrations decreased cell viability but were generally safe at 30 ppm or below. Cell lines of hepatocytes (HepG2), osteoblasts (MC3T3-E1) and mesenchymal stem cells (MSCs) were successfully labeled by the water-dispersible ZnO QDs at 30 ppm. The ZnO QD-labeled MSCs maintained their stemness and differentiation capacity. Therefore, we conclude that the water-dispersible ZnO QDs developed in this study have antibacterial activity, low cytotoxicity, and proper labeling efficiency, and can be used to label a variety of cells including stem cells.

  3. The effect of dispersed Petrobaltic oil droplet size on photosynthetically active radiation in marine environment.

    Science.gov (United States)

    Haule, Kamila; Freda, Włodzimierz

    2016-04-01

    Oil pollution in seawater, primarily visible on sea surface, becomes dispersed as an effect of wave mixing as well as chemical dispersant treatment, and forms spherical oil droplets. In this study, we examined the influence of oil droplet size of highly dispersed Petrobaltic crude on the underwater visible light flux and the inherent optical properties (IOPs) of seawater, including absorption, scattering, backscattering and attenuation coefficients. On the basis of measured data and Mie theory, we calculated the IOPs of dispersed Petrobaltic crude oil in constant concentration, but different log-normal size distributions. We also performed a radiative transfer analysis, in order to evaluate the influence on the downwelling irradiance Ed, remote sensing reflectance Rrs and diffuse reflectance R, using in situ data from the Baltic Sea. We found that during dispersion, there occurs a boundary size distribution characterized by a peak diameter d0  = 0.3 μm causing a maximum E d increase of 40% within 0.5-m depth, and the maximum Ed decrease of 100% at depths below 5 m. Moreover, we showed that the impact of size distribution on the "blue to green" ratios of Rrs and R varies from 24% increase to 27% decrease at the same crude oil concentration.

  4. Highly dispersive nano-TiO{sub 2} in situ growing on functional graphene with high photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gonggang; Wang, Ruimeng; Liu, Hui, E-mail: liuhui@csu.edu.cn; Han, Kai; Cui, Huanqing; Ye, Hongqi [Central South University, Department of Chemistry and Chemical Engineering (China)

    2016-01-15

    We present a novel approach to prepare highly dispersive nano-TiO{sub 2} by in situ growth on functional graphene (FG) via impregnation-hydrothermal method. The functional graphene was obtained by means of triethanolamine to modify graphene oxide. The characterization results collected by Fourier-transform infrared spectra, transmission electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy showed that nano-TiO{sub 2} particles with anatase phase and a narrow size distribution (the average particle size is 5 nm) were dispersed on the surface of FG uniformly. Then, the photocatalytic activity of as-prepared catalyst under UV light was evaluated, and the results showed that it possessed better photocatalytic activity than pure TiO{sub 2} and TiO{sub 2} on GO prepared by similar method. In addition, the as-prepared photocatalyst revealed considerable photocatalytic ability under visible light.

  5. Relation between the structure and catalytic activity for automotive emissions. Use of x-ray anomalous dispersion effect

    CERN Document Server

    Mizuki, J; Tanaka, H

    2003-01-01

    The employment of the X-ray anomalous dispersion effect allows us to detect the change in structure of catalytic converters with the environment exposed. Here we show that palladium atoms in a perovskite crystal move into and out of the crystal by anomalous X-ray diffraction and absorption techniques. This movement of the precious metal plays an important role to keep the catalytic activity long-lived. (author)

  6. Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the Black Hole Mass-Velocity Dispersion Relationship for Active Galactic Nuclei

    DEFF Research Database (Denmark)

    Onken, Christopher A.; Ferrarese, Laura; Merritt, David;

    2004-01-01

    We calibrate reverberation-based black hole masses in active galactic nuclei (AGNs) by using the correlation between black hole mass, M, and bulge/spheroid stellar velocity dispersion, sigma. We use new measurements of sigma for 6 AGNs and published velocity dispersions for 10 others......, in conjunction with improved reverberation mapping results, to determine the scaling factor required to bring reverberation-based black hole masses into agreement with the quiescent galaxy M-sigma relationship. The scatter in the AGN black hole masses is found to be less than a factor of 3. The current...

  7. Ultrasound assisted dispersal of a copper nanopowder for electroless copper activation.

    Science.gov (United States)

    Graves, John E; Sugden, Mark; Litchfield, Robert E; Hutt, David A; Mason, Timothy J; Cobley, Andrew J

    2016-03-01

    This paper describes the ultrasound assisted dispersal of a low wt./vol.% copper nanopowder mixture and determines the optimum conditions for de-agglomeration. A commercially available powder was added to propan-2-ol and dispersed using a magnetic stirrer, a high frequency 850 kHz ultrasonic cell, a standard 40 kHz bath and a 20 kHz ultrasonic probe. The particle size of the powder was characterized using dynamic light scattering (DLS). Z-Average diameters (mean cluster size based on the intensity of scattered light) and intensity, volume and number size distributions were monitored as a function of time and energy input. Low frequency ultrasound was found to be more effective than high frequency ultrasound at de-agglomerating the powder and dispersion with a 20 kHz ultrasonic probe was found to be very effective at breaking apart large agglomerates containing weakly bound clusters of nanoparticles. In general, the breakage of nanoclusters was found to be a factor of ultrasonic intensity, the higher the intensity the greater the de-agglomeration and typically micron sized clusters were reduced to sub 100 nm particles in less than 30 min using optimum conditions. However, there came a point at which the forces generated by ultrasonic cavitation were either insufficient to overcome the cohesive bonds between smaller aggregates or at very high intensities decoupling between the tip and solution occurred. Absorption spectroscopy indicated a copper core structure with a thin oxide shell and the catalytic performance of this dispersion was demonstrated by drop coating onto substrates and subsequent electroless copper metallization. This relatively inexpensive catalytic suspension has the potential to replace precious metal based colloids used in electronics manufacturing. PMID:26585024

  8. Improving the biogas production performance of municipal waste activated sludge via disperser induced microwave disintegration.

    Science.gov (United States)

    Kavitha, S; Rajesh Banu, J; Vinoth Kumar, J; Rajkumar, M

    2016-10-01

    In this study, the influence of disperser induced microwave pretreatment was investigated to analyze the proficiency of floc disruption on subsequent disintegration and biodegradability process. Initially, the flocs in the sludge was disrupted through disperser at a specific energy input of 25.3kJ/kgTS. The upshot of the microwave disintegration presents that the solids reduction and solubilization of floc disrupted (disperser induced microwave pretreated) sludge was found to be 17.33% and 22% relatively greater than that achieved in microwave pretreated (9.3% and 16%) sludge alone. The biodegradability analysis, affords an evaluation of parameter confidence and correlation determination. The eventual biodegradability of microwave pretreated, and floc disrupted sludges were computed to be 0.15(gCOD/gCOD) and 0.28(gCOD/gCOD), respectively. An economic assessment of this study offers a positive net profit of about 104.8USD/ton of sludge in floc disrupted sample. PMID:26897472

  9. A family based tailored counselling to increase non-exercise physical activity in adults with a sedentary job and physical activity in their young children: design and methods of a year-long randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Finni Taija

    2011-12-01

    Full Text Available Abstract Background Epidemiological evidence suggests that decrease in sedentary behaviour is beneficial for health. This family based randomized controlled trial examines whether face-to-face delivered counselling is effective in reducing sedentary time and improving health in adults and increasing moderate-to-vigorous activities in children. Methods The families are randomized after balancing socioeconomic and environmental factors in the Jyväskylä region, Finland. Inclusion criteria are: healthy men and women with children 3-8 years old, and having an occupation where they self-reportedly sit more than 50% of their work time and children in all-day day-care in kindergarten or in the first grade in primary school. Exclusion criteria are: body mass index > 35 kg/m2, self-reported chronic, long-term diseases, families with pregnant mother at baseline and children with disorders delaying motor development. From both adults and children accelerometer data is collected five times a year in one week periods. In addition, fasting blood samples for whole blood count and serum metabonomics, and diurnal heart rate variability for 3 days are assessed at baseline, 3, 6, 9, and 12 months follow-up from adults. Quadriceps and hamstring muscle activities providing detailed information on muscle inactivity will be used to realize the maximum potential effect of the intervention. Fundamental motor skills from children and body composition from adults will be measured at baseline, and at 6 and 12 months follow-up. Questionnaires of family-influence-model, health and physical activity, and dietary records are assessed. After the baseline measurements the intervention group will receive tailored counselling targeted to decrease sitting time by focusing on commute and work time. The counselling regarding leisure time is especially targeted to encourage toward family physical activities such as visiting playgrounds and non-built environments, where children can

  10. Direct generation of titanium dioxide nanoparticles dispersion under supercritical conditions for photocatalytic active thermoplastic surfaces for microbiological inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Zydziak, Nicolas, E-mail: nicolas.zydziak@kit.edu [Polymer Engineering Department, Fraunhofer Institute of Chemical Technology, Joseph-von-Fraunhofer-Str. 7, 76327 Pfinztal (Germany); Zanin, Maria-Helena Ambrosio [Laboratory of Chemical Processes and Particle Technology Bionanomanufacturing, Institute for Technological Research of the State of São Paulo – IPT, Av. Prof. Almeida Prado 532, Cidade Universitária, CEP 05508-901 São Paulo, SP (Brazil); Trick, Iris [Environmental Biotechnology and Bioprocess Engineering Department, Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstrasse 12, 70569 Stuttgart (Germany); Hübner, Christof [Polymer Engineering Department, Fraunhofer Institute of Chemical Technology, Joseph-von-Fraunhofer-Str. 7, 76327 Pfinztal (Germany)

    2015-03-01

    Thermoplastic poly(propylene) (PP) and acrylonitrile-butadiene-styrene (ABS) surfaces were coated with silica based films via the sol–gel process, containing titanium dioxide (TiO{sub 2}) as photocatalyst. TiO{sub 2} was previously synthesized via sol–gel and treated under supercritical conditions in water dispersions. The characterization of the TiO{sub 2} dispersions was performed via disc centrifuge to determine the particle size and via Raman spectroscopy and X-Ray Diffraction (XRD) to characterize the crystallinity of TiO{sub 2}. The synthesized TiO{sub 2} dispersions and commercially available TiO{sub 2} particles were incorporated in silica based films which were synthesized under acidic or basic conditions, leading to dense or porous films respectively. The morphology of the films was characterized via Scanning Electron Microscopy (SEM). The incorporation of synthesized TiO{sub 2} in the coating led to photocatalytically more active thermoplastic surfaces than films formulated with commercially available TiO{sub 2} as determined via dye discoloration test. A microbiological test performed with Sarcina lutea confirmed this result and showed an inactivation factor of 6 (99.9999%) after 24 h UV irradiation, for synthesized TiO{sub 2} incorporated in acidic formulated silica layer on ABS surfaces. - Highlights: • We report about photocatalytic layers formulated on thermoplastic surfaces. • We synthesized silica layer and TiO{sub 2} via sol–gel and supercritical treatment. • Amorphous, crystalline and commercial dispersions were generated and characterized. • The morphology of dense and porous photocatalytic layers is observed via SEM. • Discoloration and microbiological tests correlate activity and surface morphology.

  11. Direct generation of titanium dioxide nanoparticles dispersion under supercritical conditions for photocatalytic active thermoplastic surfaces for microbiological inactivation

    International Nuclear Information System (INIS)

    Thermoplastic poly(propylene) (PP) and acrylonitrile-butadiene-styrene (ABS) surfaces were coated with silica based films via the sol–gel process, containing titanium dioxide (TiO2) as photocatalyst. TiO2 was previously synthesized via sol–gel and treated under supercritical conditions in water dispersions. The characterization of the TiO2 dispersions was performed via disc centrifuge to determine the particle size and via Raman spectroscopy and X-Ray Diffraction (XRD) to characterize the crystallinity of TiO2. The synthesized TiO2 dispersions and commercially available TiO2 particles were incorporated in silica based films which were synthesized under acidic or basic conditions, leading to dense or porous films respectively. The morphology of the films was characterized via Scanning Electron Microscopy (SEM). The incorporation of synthesized TiO2 in the coating led to photocatalytically more active thermoplastic surfaces than films formulated with commercially available TiO2 as determined via dye discoloration test. A microbiological test performed with Sarcina lutea confirmed this result and showed an inactivation factor of 6 (99.9999%) after 24 h UV irradiation, for synthesized TiO2 incorporated in acidic formulated silica layer on ABS surfaces. - Highlights: • We report about photocatalytic layers formulated on thermoplastic surfaces. • We synthesized silica layer and TiO2 via sol–gel and supercritical treatment. • Amorphous, crystalline and commercial dispersions were generated and characterized. • The morphology of dense and porous photocatalytic layers is observed via SEM. • Discoloration and microbiological tests correlate activity and surface morphology

  12. Direct evidence of swimming demonstrates active dispersal in the sea turtle "lost years".

    Science.gov (United States)

    Putman, Nathan F; Mansfield, Katherine L

    2015-05-01

    Although oceanic dispersal in larval and juvenile marine animals is widely studied, the relative contributions of swimming behavior and ocean currents to movements and distribution are poorly understood [1-4]. The sea turtle "lost years" [5] (often referred to as the surface-pelagic [6] or oceanic [7] stage) are a classic example. Upon hatching, young turtles migrate offshore and are rarely observed until they return to coastal waters as larger juveniles [5]. Sightings of small turtles downcurrent of nesting beaches and in association with drifting organisms (e.g., Sargassum algae) led to this stage being described as a "passive migration" during which turtles' movements are dictated by ocean currents [5-10]. However, laboratory and modeling studies suggest that dispersal trajectories might also be shaped by oriented swimming [11-15]. Here, we use an experimental approach designed to directly test the passive-migration hypothesis by deploying pairs of surface drifters alongside small green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) wild-caught turtles, tracking their movements via satellite telemetry. We conclusively demonstrate that these turtles do not behave as passive drifters. In nearly all cases, drifter trajectories were uncharacteristic of turtle trajectories. Species-specific and location-dependent oriented swimming behavior, inferred by subtracting track velocity from modeled ocean velocity, contributed substantially to individual movement and distribution. These findings highlight the importance of in situ observations for depicting the dispersal of weakly swimming animals. Such observations, paired with information on the mechanisms of orientation, will likely allow for more accurate predictions of the ecological and evolutionary processes shaped by animal movement. PMID:25866396

  13. Bactericidal Activity of Aqueous Acrylic Paint Dispersion for Wooden Substrates Based on TiO2 Nanoparticles Activated by Fluorescent Light

    Directory of Open Access Journals (Sweden)

    Diana Di Gioia

    2013-08-01

    Full Text Available The photocatalytic effect of TiO2 has great potential for the disinfection of surfaces. Most studies reported in the literature use UV activation of TiO2, while visible light has been used only in a few applications. In these studies, high concentrations of TiO2, which can compromise surface properties, have been used. In this work, we have developed an acrylic-water paint dispersion containing low TiO2 content (2 vol % for the inactivation of microorganisms involved in hospital-acquired infections. The nanoparticles and the coating have been characterized using spectroscopic techniques and transmission electron microscopy, showing their homogenous dispersion in the acrylic urethane coating. A common fluorescent light source was used to activate the photocatalytic activity of TiO2. The paint dispersion showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The coating containing the TiO2 nanoparticles maintained good UV stability, strong adhesion to the substrate and high hardness. Therefore, the approach used is feasible for paint formulation aimed at disinfection of healthcare surfaces.

  14. Removal of bacteria from coastal seawater by foam separation using dispersed bubbles and surface-active substances.

    Science.gov (United States)

    Suzuki, Yoshihiro; Hanagasaki, Nobuaki; Furukawa, Takashi; Yoshida, Terutoyo

    2008-04-01

    The removal of bacteria from rearing water and washing water in aquaculture systems, aquariums and fishing port facilities is the most important means of diminishing the risk of fish diseases, improving public health and ensuring high food quality. However, there are few methods of bacterial elimination, e.g., disinfection. Thus, it is necessary to develop a technology for bacterial removal from coastal seawater. In this study, the removal efficiency for several groups of bacteria by foam separation using dispersed bubbles and surface-active substances was determined using both batch equipment and a continuous-flow unit. By batch processing with only 1 mg/l milk casein added as a surface-active substance and by supplying bubbles, viable bacteria, enterococci, Vibrio, and Salmonella-like bacteria were removed effectively at removal efficiencies of 80% or greater. In addition, suspended solids were also removed from coastal seawater. However, fecal coliforms were difficult to remove by foam separation. The removal efficiency for viable bacteria was greater than 70% using a continuous system. Bacteria were concentrated in a very small amount of generated foam and removed from the water. The foam separation using dispersed bubbles and surface-active substances is a feasible convenient technology for seawater purification as a treatment prior to membrane filtration or ultraviolet irradiation.

  15. The Coach2Move approach : Development and acceptability of an individually tailored physical therapy strategy to increase activity levels in older adults with mobility problems

    NARCIS (Netherlands)

    Vries, Nienke M. de; Ravensberg, C. Dorine van; Hobbelen, Johannes S.M.; Wees, Philip J. van der; Olde Rikkert, Marcel G.M.; Staal, J. Bart; Nijhuis-van der Sanden, Maria W.G.

    2015-01-01

    Background and Purpose: Despite the positive effects of physical activity on numerous aspects of health, many older adults remain sedentary even after participating in physical activity interventions. Standardized exercise programs do not necessarily bring about the behavioral change that is neces

  16. The Coach2Move Approach: Development and Acceptability of an Individually Tailored Physical Therapy Strategy to Increase Activity Levels in Older Adults With Mobility Problems

    NARCIS (Netherlands)

    Vries, N.M. de; Ravensberg, C.D. van; Hobbelen, J.S.; Wees, P.J. van der; Olde Rikkert, M.G.M.; Staal, J.B.; Nijhuis-Van der Sanden, M.W.G.

    2015-01-01

    BACKGROUND AND PURPOSE: Despite the positive effects of physical activity on numerous aspects of health, many older adults remain sedentary even after participating in physical activity interventions. Standardized exercise programs do not necessarily bring about the behavioral change that is necessa

  17. Tailoring the Spacer Arm for Covalent Immobilization of Candida antarctica Lipase B-Thermal Stabilization by Bisepoxide-Activated Aminoalkyl Resins in Continuous-Flow Reactors.

    Science.gov (United States)

    Abaházi, Emese; Lestál, Dávid; Boros, Zoltán; Poppe, László

    2016-01-01

    An efficient and easy-to-perform method was developed for immobilization of CaLB on mesoporous aminoalkyl polymer supports by bisepoxide activation. Polyacrylate resins (100-300 µm; ~50 nm pores) with different aminoalkyl functional groups (ethylamine: EA and hexylamine: HA) were modified with bisepoxides differing in the length, rigidity and hydrophobicity of the units linking the two epoxy functions. After immobilization, the different CaLB preparations were evaluated using the lipase-catalyzed kinetic resolution (KR) of racemic 1-phenylethanol (rac-1) in batch mode and in a continuous-flow reactor as well. Catalytic activity, enantiomer selectivity, recyclability, and the mechanical and long-term stability of CaLB immobilized on the various supports were tested. The most active CaLB preparation (on HA-resin activated with 1,6-hexanediol diglycidyl ether-HDGE) retained 90% of its initial activity after 13 consecutive reaction cycles or after 12 month of storage at 4 °C. The specific rate (rflow), enantiomer selectivity (E) and enantiomeric excess (ee) achievable with the best immobilized CaLB preparations were studied as a function of temperature in kinetic resolution of rac-1 performed in continuous-flow packed-bed bioreactors. The optimum temperature of the most active HA-HDGE CaLB in continuous-flow mode was 60 °C. Although CaLB immobilized on the glycerol diglycidyl ether (GDGE)-activated EA-resin was less active and less selective, a much higher optimum temperature (80 °C) was observed with this form in continuous-flow mode KR of rac-1. PMID:27304947

  18. Catalyst dispersion and activity under conditions of temperature-staged liquefaction. Technical progress report, October--December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1992-02-01

    The general objectives of this research are (1) to investigate the use of highly dispersed catalysts for the pretreatment of coal by mild hydrogenation, (2) to identify the active forms of the catalysts under reaction conditions and (3) to clarify the mechanisms of catalysis. The ultimate objective is to ascertain if mild catalytic hydrogenation resulting in very limited or no coal solubilization is an advantageous pretreatment for the transformation of coal into transportable fuels. The experimental program will focus upon the development of effective methods of impregnating coal with catalysts, evaluating the conditions under which the catalysts are most active and establishing the relative impact of improved impregnation on conversion and product distributions obtained from coal hydrogenation.

  19. Catalyst dispersion and activity under conditions of temperature- staged liquefaction. Technical progress report, July--September 1991

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

    1992-02-01

    The general objectives of this research are (1) to investigate the use of highly dispersed catalysts for the pretreatment of coal by mild hydrogenation, (2) to identify the active forms of catalysts under reaction conditions and (3) to clarify the mechanisms of catalysis. The ultimate objective is to ascertain if mild catalytic hydrogenation resulting in very limited or no coal solubilization is an advantageous pretreatment for the transformation of coal into transportable fuels. The experimental program will focus upon the development of effective methods of impregnating coal with catalysts, evaluating the conditions under which the catalysts are most active and establishing the relative impact of improved impregnation on conversion and product distributions obtained from coal hydrogenation.

  20. Tailored Ceramics for Laser Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, Joel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2007-12-10

    Transparent ceramics match or exceed the performance of single-crystal materials in laser applications, with a more-robust fabrication process. Controlling the distribution of optical dopants in transparent ceramics would allow qualitative improvements in amplifier slab design by allowing gain and loss to be varied within the material. My work aims to achieve a controlled pattern or gradient of dopant prior to sintering, in order to produce tailored ceramics.

  1. Deep drawing simulation of Tailored Blanks

    NARCIS (Netherlands)

    Berg, van den A.; Meinders, V.T.; Stokman, B.

    1998-01-01

    Tailored blanks are increasingly used in the automotive industry. A tailored blank consists of different metal parts, which are joined by a welding process. These metal parts usually have different material properties. Hence, the main advantage of using a tailored blank is to provide the right mater

  2. Using a Toolbox of Tailored Educational Lessons to Improve Fruit, Vegetable, and Physical Activity Behaviors among African American Women in California

    Science.gov (United States)

    Backman, Desiree; Scruggs, Valarie; Atiedu, Akpene Ama; Bowie, Shene; Bye, Larry; Dennis, Angela; Hall, Melanie; Ossa, Alexandra; Wertlieb, Stacy; Foerster, Susan B.

    2011-01-01

    Objective: Evaluate the effectiveness of the "Fruit, Vegetable, and Physical Activity Toolbox for Community Educators" ("Toolbox"), an intervention originally designed for Spanish- and English-speaking audiences, in changing knowledge, attitudes, and behavior among low-income African American women. Design: Quasi-experimental design with treatment…

  3. Systematic development of the YouRAction program, a computer-tailored physical activity promotion intervention for Dutch adolescents, targeting personal motivations and environmental opportunities

    NARCIS (Netherlands)

    R.G. Prins (Richard); P. van Empelen (Pepijn); M.A. Beenackers (Marielle); J. Brug (Hans); A. Oenema (Anke)

    2010-01-01

    textabstractBackground. Increasing physical activity (PA) among adolescents is an important health promotion goal. PA has numerous positive health effects, but the majority of Dutch adolescents do not meet PA requirements. The present paper describes the systematic development of a theory-based comp

  4. P2Y2 nucleotide receptor activation enhances the aggregation and self-organization of dispersed salivary epithelial cells.

    Science.gov (United States)

    El-Sayed, Farid G; Camden, Jean M; Woods, Lucas T; Khalafalla, Mahmoud G; Petris, Michael J; Erb, Laurie; Weisman, Gary A

    2014-07-01

    Hyposalivation resulting from salivary gland dysfunction leads to poor oral health and greatly reduces the quality of life of patients. Current treatments for hyposalivation are limited. However, regenerative medicine to replace dysfunctional salivary glands represents a revolutionary approach. The ability of dispersed salivary epithelial cells or salivary gland-derived progenitor cells to self-organize into acinar-like spheres or branching structures that mimic the native tissue holds promise for cell-based reconstitution of a functional salivary gland. However, the mechanisms involved in salivary epithelial cell aggregation and tissue reconstitution are not fully understood. This study investigated the role of the P2Y2 nucleotide receptor (P2Y2R), a G protein-coupled receptor that is upregulated following salivary gland damage and disease, in salivary gland reconstitution. In vitro results with the rat parotid acinar Par-C10 cell line indicate that P2Y2R activation with the selective agonist UTP enhances the self-organization of dispersed salivary epithelial cells into acinar-like spheres. Other results indicate that the P2Y2R-mediated response is dependent on epidermal growth factor receptor activation via the metalloproteases ADAM10/ADAM17 or the α5β1 integrin/Cdc42 signaling pathway, which leads to activation of the MAPKs JNK and ERK1/2. Ex vivo data using primary submandibular gland cells from wild-type and P2Y2R(-/-) mice confirmed that UTP-induced migratory responses required for acinar cell self-organization are mediated by the P2Y2R. Overall, this study suggests that the P2Y2R is a promising target for salivary gland reconstitution and identifies the involvement of two novel components of the P2Y2R signaling cascade in salivary epithelial cells, the α5β1 integrin and the Rho GTPase Cdc42.

  5. Citrem Modulates Internal Nanostructure of Glyceryl Monooleate Dispersions and Bypasses Complement Activation

    DEFF Research Database (Denmark)

    Wibroe, Peter P; Mat Azmi, Intan Diana Binti; Nilsson, Christa;

    2015-01-01

    Lyotropic non-lamellar liquid crystalline (LLC) aqueous nanodispersions hold a great promise in drug solubilization and delivery, but these nanosystems often induce severe hemolysis and complement activation, which limit their applications for safe intravenous administration. Here, we engineer...

  6. Reducing neuropsychiatric symptoms in persons with dementia and associated burden in family caregivers using tailored activities: Design and methods of a randomized clinical trial.

    Science.gov (United States)

    Gitlin, Laura N; Piersol, Catherine Verrier; Hodgson, Nancy; Marx, Katherine; Roth, David L; Johnston, Deidre; Samus, Quincy; Pizzi, Laura; Jutkowitz, Eric; Lyketsos, Constantine G

    2016-07-01

    Among over 5million people in the USA with dementia, neuropsychiatric symptoms (NPS) are almost universal, occurring across disease etiology and stage. If untreated, NPS can lead to significant morbidity and mortality including increased cost, distress, depression, and faster disease progression, as well as heightened burden on families. With few pharmacological solutions, identifying nonpharmacologic strategies is critical. We describe a randomized clinical trial, the Dementia Behavior Study, to test the efficacy of an activity program to reduce significant existing NPS and associated caregiver burden at 3 and 6months compared to a control group intervention. Occupational therapists deliver 8 in-home sessions over 3months to assess capabilities and interests of persons with dementia, home environments, and caregiver knowledge, and readiness from which activities are developed and families trained in their use. Families learn to modify activities for future declines and use strategies to address care challenges. The comparison group controls for time and attention and involves 8 in-home sessions delivered by health educators who provide dementia education, home safety recommendations, and advanced care planning. We are randomizing 250 racially diverse families (person with dementia and primary caregiver dyads) recruited from community-based social services, conferences and media announcements. The primary outcome is change in agitation/aggression at 3 and 6months. Secondary outcomes assess quality of life of persons with dementia, other behaviors, burden and confidence of caregivers, and cost and cost effectiveness. If benefits are supported, this activity intervention will provide a clinically meaningful approach to prevent, reduce, and manage NPS. PMID:27339865

  7. Steps toward high specific activity labeling of biomolecules for therapeutic application: preparation of precursor [(188)Re(H(2)O)(3)(CO)(3)](+) and synthesis of tailor-made bifunctional ligand systems.

    Science.gov (United States)

    Schibli, Roger; Schwarzbach, Rolf; Alberto, Roger; Ortner, Kirstin; Schmalle, Helmut; Dumas, Cécile; Egli, André; Schubiger, P August

    2002-01-01

    Two kit preparations of the organometallic precursor [(188)Re(H(2)O)(3)(CO)(3)](+) in aqueous media are presented. Method A uses gaseous carbon monoxide and amine borane (BH(3).NH(3)) as the reducing agent. In method B CO(g) is replaced by K(2)[H(3)BCO(2)] that releases carbon monoxide during hydrolysis. Both procedures afford the desired precursor in yields >85% after 10 min at 60 degrees C. HPLC and TLC analyses revealed 7 +/- 3% of unreacted (188)ReO(4)(-) and 95% with [(188)Re(H(2)O)(3)(CO)(3)](+) under mild reaction conditions (PBS buffer, 60 degrees C, 60 min) at ligand concentrations between 5 x 10(-4) M and 5 x 10(-5) M. Thus, specific activities of 22-220 GBq pe micromol of ligand could be achieved. Incubation of the corresponding Re-188 complexes in human serum at 37 degrees C revealed stabilities between 80 +/- 4% and 45 +/- 10% at 24 h, respectively, and 63 +/- 3% and 34 +/- 3% at 48 h postincubation in human serum depending on the chelating system. Decomposition product was mainly (188)ReO(4)(-). The routine kit-preparation of the precursor [(188)Re(H(2)O)(3)(CO)(3)](+) in combination with tailor-made ligand systems enables the organometallic labeling of biomolecules with unprecedented high specific activities. PMID:12121130

  8. Superdiffusion in dispersions of active colloids driven by an external field and their sedimentation equilibrium

    Science.gov (United States)

    Chen, Yen-Fu; Wei, Hsien-Hung; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2016-04-01

    The diffusive behaviors of active colloids with run-and-tumble movement are explored by dissipative particle dynamics simulations for self-propelled particles (force dipole) and external field-driven particles (point force). The self-diffusion of tracers (solvent) is investigated as well. The influences of the active force, run time, and concentration associated with active particles are studied. For the system of self-propelled particles, the normal diffusion is observed for both active particles and tracers. The diffusivity of the former is significantly greater than that of the latter. For the system of field-driven particles, the superdiffusion is seen for both active particles and tracers. In contrast, it is found that the anomalous diffusion exponent of the former is slightly less than that of the latter. The anomalous diffusion is caused by the many-body, long-range hydrodynamic interactions. In spite of the superdiffusion, the sedimentation equilibrium of field-driven particles can be acquired and the density profile is still exponentially decayed. The sedimentation length of field-driven particles is always greater than that of self-propelled particles.

  9. Deep Drawing of High-Strength Tailored Blanks by Using Tailored Tools

    OpenAIRE

    Thomas Mennecart; Hamad ul Hassan; Alper Güner; Noomane Ben Khalifa; Mohamad Hosseini

    2016-01-01

    In most forming processes based on tailored blanks, the tool material remains the same as that of sheet metal blanks without tailored properties. A novel concept of lightweight construction for deep drawing tools is presented in this work to improve the forming behavior of tailored blanks. The investigations presented here deal with the forming of tailored blanks of dissimilar strengths using tailored dies made of two different materials. In the area of the steel blank with higher strength, t...

  10. Thermally-activated deformation in dispersion-hardened polycrystalline iron at room temperature

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Cotteril, P.

    1970-01-01

    The activation volume and dislocation velocity exponent have been obtained for polycrystalline iron in the extruded, extruded and annealed, and cold-rolled and annealed condition containing various amounts of alumina or zirconia particles, using the strain rate-change technique. It is found...... that the activation volume decreases and the dislocation velocity exponent increases, respectively, with decreasing interparticle spacing. The activation volume and dislocation velocity exponent have been examined on the basis of the various theories relating these parameters to the dislocation obstacles responsible...... for the lattice friction stress in b.c.c. iron. It is concluded that the basic dislocation-lattice interaction in iron is modified by the presence of particles; the presence of particles is considered to alter (directly or indirectly) the dislocation segment lengths and their critical bulge-size giving rise...

  11. A Switchable and Tunable Dual-Wavelength Actively Mode-Locked Fiber Laser Based on Dispersion Tuning

    International Nuclear Information System (INIS)

    A switchable and tunable dual-wavelength actively mode-locked fiber laser based on a dispersion tuning technique is proposed and demonstrated. Synchronous wavelength tuning of dual-wavelength operation with wavelength spacing of 22.9 nm can be achieved up to 23.2 nm by changing the modulation frequency. The proposed laser can operate in dual-wavelength or single-wavelength by simple adjustment of the polarization controller. Moreover, wavelength spacing can also be varied from 22 to 45 nm at the cost of a reduced tuning range by changing the harmonic order, which is determined by the modulation frequency. These experimental observations agree well with the theoretical analysis

  12. Highly stable and re-dispersible nano Cu hydrosols with sensitively size-dependent catalytic and antibacterial activities

    Science.gov (United States)

    Zhang, Yu; Zhu, Pengli; Li, Gang; Wang, Wenzhao; Chen, Liang; Lu, Daoqiang Daniel; Sun, Rong; Zhou, Feng; Wong, Chingping

    2015-08-01

    Highly stable monodispersed nano Cu hydrosols were facilely prepared by an aqueous chemical reduction method through selecting copper hydroxide (Cu(OH)2) as the copper precursor, poly(acrylic acid) (PAA) and ethanol amine (EA) as the complexing agents, and hydrazine hydrate as the reducing agent. The size of the obtained Cu colloidal nanoparticles was controlled from 0.96 to 26.26 nm by adjusting the dosage of the copper precursor. Moreover, the highly stable nano Cu hydrosols could be easily concentrated and re-dispersed in water meanwhile maintaining good dispersibility. A model catalytic reaction of reducing p-nitrophenol with NaBH4 in the presence of nano Cu hydrosols with different sizes was performed to set up the relationship between the apparent kinetic rate constant (kapp) and the particle size of Cu catalysts. The experimental results indicate that the corresponding kapp showed an obvious size-dependency. Calculations revealed that kapp was directly proportional to the surface area of Cu catalyst nanoparticles, and also proportional to the reciprocal of the particle size based on the same mass of Cu catalysts. This relationship might be a universal principle for predicting and assessing the catalytic efficiency of Cu nanoparticles. The activation energy (Ea) of this catalytic reaction when using 0.96 nm Cu hydrosol as a catalyst was calculated to be 9.37 kJ mol-1, which is considered an extremely low potential barrier. In addition, the synthesized nano Cu hydrosols showed size-dependent antibacterial activities against Pseudomonas aeruginosa (P. aeruginosa) and the minimal inhibitory concentration of the optimal sample was lower than 5.82 μg L-1.Highly stable monodispersed nano Cu hydrosols were facilely prepared by an aqueous chemical reduction method through selecting copper hydroxide (Cu(OH)2) as the copper precursor, poly(acrylic acid) (PAA) and ethanol amine (EA) as the complexing agents, and hydrazine hydrate as the reducing agent. The size of the

  13. Visualizing Dispersion Interactions

    Science.gov (United States)

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  14. Time Series with Tailored Nonlinearities

    CERN Document Server

    Raeth, C

    2015-01-01

    It is demonstrated how to generate time series with tailored nonlinearities by inducing well- defined constraints on the Fourier phases. Correlations between the phase information of adjacent phases and (static and dynamic) measures of nonlinearities are established and their origin is explained. By applying a set of simple constraints on the phases of an originally linear and uncor- related Gaussian time series, the observed scaling behavior of the intensity distribution of empirical time series can be reproduced. The power law character of the intensity distributions being typical for e.g. turbulence and financial data can thus be explained in terms of phase correlations.

  15. Serrulatane Diterpenoid from Eremophila neglecta Exhibits Bacterial Biofilm Dispersion and Inhibits Release of Pro-inflammatory Cytokines from Activated Macrophages.

    Science.gov (United States)

    Mon, Htwe H; Christo, Susan N; Ndi, Chi P; Jasieniak, Marek; Rickard, Heather; Hayball, John D; Griesser, Hans J; Semple, Susan J

    2015-12-24

    The purpose of this study was to assess the biofilm-removing efficacy and inflammatory activity of a serrulatane diterpenoid, 8-hydroxyserrulat-14-en-19-oic acid (1), isolated from the Australian medicinal plant Eremophila neglecta. Biofilm breakup activity of compound 1 on established Staphylococcus epidermidis and Staphylococcus aureus biofilms was compared to the antiseptic chlorhexidine and antibiotic levofloxacin. In a time-course study, 1 was deposited onto polypropylene mesh to mimic a wound dressing and tested for biofilm removal. The ex-vivo cytotoxicity and effect on lipopolysaccharide-induced pro-inflammatory cytokine release were studied in mouse primary bone-marrow-derived macrophage (BMDM) cells. Compound 1 was effective in dispersing 12 h pre-established biofilms with a 7 log10 reduction of viable bacterial cell counts, but was less active against 24 h biofilms (approximately 2 log10 reduction). Compound-loaded mesh showed dosage-dependent biofilm-removing capability. In addition, compound 1 displayed a significant inhibitory effect on tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) secretion from BMDM cells, but interleukin-1 beta (IL-1β) secretion was not significant. The compound was not cytotoxic to BMDM cells at concentrations effective in removing biofilm and lowering cytokine release. These findings highlight the potential of this serrulatane diterpenoid to be further developed for applications in wound management. PMID:26636180

  16. Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting: functional display of the mouse interleukin-2 and myelin oligodendrocyte glycoprotein

    Directory of Open Access Journals (Sweden)

    Brockelbank Jane A

    2007-01-01

    Full Text Available Abstract Background Fluorescence activated cell sorting (FACS is a powerful technique for the qualitative and quantitative detection of biomolecules used widely in both basic research and clinical diagnostic applications. Beads displaying a specific antigen are used to bind antibodies which are then fluorescently labelled using secondary antibodies. As the individual suspension bead passes through the sensing region of the FACS machine, fluorescent signals are acquired and analysed. Currently, antigens are tediously purified and chemically cross-linked to preformed beads. Purification and coupling of proteins often renders them inactive and they will not be displayed in its native configuration. As an alternative, we genetically engineered Escherichia coli to produce biopolyester (polyhdroxyalkanoate=PHA granules displaying diagnostically relevant antigens in their native conformation and suitable for FACS analysis. Results Hybrid genes were constructed, which encode either the mouse interleukin-2 (IL2 or the myelin oligodendrocyte glycoprotein (MOG fused via an enterokinase site providing linker region to the C terminus of the PHA granule associated protein PhaP, respectively. The hybrid genes were expressed in PHA-accumulating recombinant E. coli. MOG and IL2 fusion proteins were abundantly attached to PHA granules and were identified by MALDI-TOF/MS analysis and N terminal sequencing. A more abundant second fusion protein of either MOG or IL2 resulted from an additional N terminal fusion, which did surprisingly not interfere with attachment to PHA granule. PHA granules displaying either IL2 or MOG were used for FACS using monoclonal anti-IL2 or anti-MOG antibodies conjugated to a fluorescent dye. FACS analysis showed significant and specific binding of respective antibodies. Enterokinase treatment of IL2 displaying PHA granules enabled removal of IL2 as monitored by FACS analysis. Mice were immunized with either MOG or OVA (ovalbumin and the

  17. Tailoring supercontinuum generation using highly nonlinear photonic crystal fiber

    Science.gov (United States)

    Hossain, M. A.; Namihira, Y.; Islam, M. A.; Razzak, S. M. A.; Hirako, Y.; Miyagi, K.; Kaijage, S. F.; Higa, H.

    2012-09-01

    This paper discusses about the tailoring supercontinuum (SC) generation based on a highly nonlinear germanium (Ge) doped photonic crystal fiber (HNL-GePCF) with all normal group velocity dispersion (GVD). Using finite element method (FEM) with a circular perfectly matched boundary layer (PML), it is shown through simulations that how simply the center wavelength can be shifted from one center point to another after optimizing at a particular wavelength using the proposed HNL-GePCF. Moreover, SC spectra at 1.06, 1.31 and 1.55 μm have been generated using picosecond optical pulses produced from relatively less expensive laser sources.

  18. Characterization of solid polymer dispersions of active pharmaceutical ingredients by 19F MAS NMR and factor analysis

    Science.gov (United States)

    Urbanova, Martina; Brus, Jiri; Sedenkova, Ivana; Policianova, Olivia; Kobera, Libor

    In this contribution the ability of 19F MAS NMR spectroscopy to probe structural variability of poorly water-soluble drugs formulated as solid dispersions in polymer matrices is discussed. The application potentiality of the proposed approach is demonstrated on a moderately sized active pharmaceutical ingredient (API, Atorvastatin) exhibiting extensive polymorphism. In this respect, a range of model systems with the API incorporated in the matrix of polvinylpyrrolidone (PVP) was prepared. The extent of mixing of both components was determined by T1(1H) and T1ρ(1H) relaxation experiments, and it was found that the API forms nanosized domains. Subsequently it was found out that the polymer matrix induces two kinds of changes in 19F MAS NMR spectra. At first, this is a high-frequency shift reaching 2-3 ppm which is independent on molecular structure of the API and which results from the long-range polarization of the electron cloud around 19F nucleus induced by electrostatic fields of the polymer matrix. At second, this is broadening of the signals and formation of shoulders reflecting changes in molecular arrangement of the API. To avoid misleading in the interpretation of the recorded 19F MAS NMR spectra, because both the contributions act simultaneously, we applied chemometric approach based on multivariate analysis. It is demonstrated that factor analysis of the recorded spectra can separate both these spectral contributions, and the subtle structural differences in the molecular arrangement of the API in the nanosized domains can be traced. In this way 19F MAS NMR spectra of both pure APIs and APIs in solid dispersions can be directly compared. The proposed strategy thus provides a powerful tool for the analysis of new formulations of fluorinated pharmaceutical substances in polymer matrices.

  19. Effect of active zinc oxide dispersion on reduced graphite oxide for hydrogen sulfide adsorption at mid-temperature

    International Nuclear Information System (INIS)

    Composites of Zinc oxide (ZnO) with reduced graphite oxide (rGO) were synthesized and used as adsorbents for hydrogen sulfide (H2S) at 300 °C. Various characterization methods (TGA, XRD, FT-IR, TEM and XPS) were performed in order to link their H2S adsorption performance to the properties of the adsorbent's surface. Microwave-assisted reduction process of graphite oxide (GO) provided mild reduction environment, allowing oxygen-containing functional groups to remain on the rGO surface. It was confirmed that for the ZnO/rGO synthesize using the microwave-assisted reduction method, the ZnO particle size and the degree of ZnO dispersion remained stable over time at 300 °C, which was not the case for only the ZnO particles themselves. This stable highly dispersed feature allows for sustained high surface area over time. This was confirmed through breakthrough experiments for H2S adsorption where it was found that the ZnO/rGO composite showed almost four times higher ZnO utilization efficiency than ZnO itself. The effect of the H2 and CO2 on H2S adsorption was also investigated. The presence of hydrogen in the H2S stream had a positive effect on the removal of H2S since it allows a reducing environment for Zn-O and Zn-S bonds, leading to more active sites (Zn2+) to sulfur molecules. On the other hand, the presence of carbon dioxide (CO2) showed the opposite trend, likely due to the oxidation environment and also due to possible competitive adsorption between H2S and CO2.

  20. Tailorable Trimethyl chitosans as adjuvant for intranasal immunization

    NARCIS (Netherlands)

    Verheul, R.J.

    2010-01-01

    Tailorable Trimethyl Chitosans as Adjuvant for Intranasal Immunization Active vaccination has proven to be the most (cost) effective tool in the fight against infectious diseases. Nowadays, most vaccines are administered via parenteral injection. However, the risk of contaminated needles and need fo

  1. Mercury speciation and dispersion from an active gold mine at the West Wits area, South Africa.

    Science.gov (United States)

    Lusilao-Makiese, J G; Tessier, E; Amouroux, D; Tutu, H; Chimuka, L; Weiersbye, I; Cukrowska, E M

    2016-01-01

    Total mercury (HgTOT), inorganic mercury (IHg), and methylmercury (MHg) were determined in dry season waters, sediments, and tailings from an active mine which has long history of gold exploitation. Although HgTOT in waters was generally low (0.03 to 19.60 ng L(-1)), the majority of the samples had proportions of MHg of at least 90 % of HgTOT which denotes a substantial methylation potential of the mine watersheds. Mercury was relatively high in tailing materials (up to 867 μg kg(-1)) and also in the mine sediments (up to 837 μg kg(-1)) especially in samples collected near tailing storage facilities and within a receiving water dam. Sediment profiles revealed mercury enrichment and enhanced methylation rate at deeper layers. The presence of IHg and decaying plants (organic matter) in the watersheds as well as the anoxic conditions of bulk sediments are believed to be some of the key factors favoring the mercury methylation at the site.

  2. Mercury speciation and dispersion from an active gold mine at the West Wits area, South Africa.

    Science.gov (United States)

    Lusilao-Makiese, J G; Tessier, E; Amouroux, D; Tutu, H; Chimuka, L; Weiersbye, I; Cukrowska, E M

    2016-01-01

    Total mercury (HgTOT), inorganic mercury (IHg), and methylmercury (MHg) were determined in dry season waters, sediments, and tailings from an active mine which has long history of gold exploitation. Although HgTOT in waters was generally low (0.03 to 19.60 ng L(-1)), the majority of the samples had proportions of MHg of at least 90 % of HgTOT which denotes a substantial methylation potential of the mine watersheds. Mercury was relatively high in tailing materials (up to 867 μg kg(-1)) and also in the mine sediments (up to 837 μg kg(-1)) especially in samples collected near tailing storage facilities and within a receiving water dam. Sediment profiles revealed mercury enrichment and enhanced methylation rate at deeper layers. The presence of IHg and decaying plants (organic matter) in the watersheds as well as the anoxic conditions of bulk sediments are believed to be some of the key factors favoring the mercury methylation at the site. PMID:26687090

  3. Energetic materials and methods of tailoring electrostatic discharge sensitivity of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Michael A.; Heaps, Ronald J.; Wallace, Ronald S.; Pantoya, Michelle L.; Collins, Eric S.

    2016-11-01

    An energetic material comprising an elemental fuel, an oxidizer or other element, and a carbon nanofiller or carbon fiber rods, where the carbon nanofiller or carbon fiber rods are substantially homogeneously dispersed in the energetic material. Methods of tailoring the electrostatic discharge sensitivity of an energetic material are also disclosed.

  4. Targeted therapy: tailoring cancer treatment

    Institute of Scientific and Technical Information of China (English)

    Min Yan; Quentin Qiang Liu

    2013-01-01

    Targeted therapies include small-molecule inhibitors and monoclonal antibodies,have made treatment more tumor-specific and less toxic,and have opened new possibilities for tailoring cancer treatment.Nevertheless,there remain several challenges to targeted therapies,including molecular identification,drug resistance,and exploring reliable biomarkers.Here,we present several selected signaling pathways and molecular targets involved in human cancers including Aurora kinases,PI3K/mTOR signaling,FOXO-FOXM1 axis,and MDM2/MDM4-p53 interaction.Understanding the molecular mechanisms for tumorigenesis and development of drug resistance will provide new insights into drug discovery and design of therapeutic strategies for targeted therapies.

  5. Molecular tailoring of solid surfaces

    CERN Document Server

    Evenson, S A

    1997-01-01

    The overall performance of a material can be dramatically improved by tailoring its surface at the molecular level. The aim of this project was to develop a universal technique for attaching dendrimers (well-defined, nanoscale, functional polymers) and Jeffamines (high molecular weight polymer chains) to the surface of any shaped solid substrate. This desire for controlled functionalization is ultimately driven by the need to improve material compatibility in various biomedical applications. Atomic force microscopy (AFM) was used initially to study the packing and structure of Langmuir-Blodgett films on surfaces, and subsequently resulted in the first visualization of individual, spherically shaped, nanoscopic polyamidoamine dendrimers. The next goal was to develop a methodology for attaching such macromolecules to inert surfaces. Thin copolymer films were deposited onto solid substrates to produce materials with a fixed concentration of surface anhydride groups. Vapor-phase functionalization reactions were t...

  6. Tailored logistics: the next advantage.

    Science.gov (United States)

    Fuller, J B; O'Conor, J; Rawlinson, R

    1993-01-01

    How many top executives have ever visited with managers who move materials from the factory to the store? How many still reduce the costs of logistics to the rent of warehouses and the fees charged by common carriers? To judge by hours of senior management attention, logistics problems do not rank high. But logistics have the potential to become the next governing element of strategy. Whether they know it or not, senior managers of every retail store and diversified manufacturing company compete in logistically distinct businesses. Customer needs vary, and companies can tailor their logistics systems to serve their customers better and more profitably. Companies do not create value for customers and sustainable advantage for themselves merely by offering varieties of goods. Rather, they offer goods in distinct ways. A particular can of Coca-Cola, for example, might be a can of Coca-Cola going to a vending machine, or a can of Coca-Cola that comes with billing services. There is a fortune buried in this distinction. The goal of logistics strategy is building distinct approaches to distinct groups of customers. The first step is organizing a cross-functional team to proceed through the following steps: segmenting customers according to purchase criteria, establishing different standards of service for different customer segments, tailoring logistics pipelines to support each segment, and creating economics of scale to determine which assets can be shared among various pipelines. The goal of establishing logistically distinct businesses is familiar: improved knowledge of customers and improved means of satisfying them. PMID:10126157

  7. A New Class of Highly Dispersed VOx Catalysts on Mesoporous Silica: Synthesis, Characterization, and Catalytic Activity in the Partial Oxidation of Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ja Hun; Herrera, Jose E.; Hu, Jian Zhi; Wang, Yong; Peden, Charles HF

    2006-01-26

    The morphology of vanadium oxide supported on a titania-modified mesoporous silica (MCM-41), obtained by means of a careful grafting process through atomic layer deposition, was studied using a variety of characterization techniques. The XRD together with TEM, 51V-NMR, Raman, FTIR and DRS-UV-Vis results showed that the vanadia species are extremely well dispersed onto the surface of the mesoporous support; the dispersion being stable upon thermal treatments up to 400 °C. Studies of the catalytic activity of these materials were performed using the partial oxidation of ethanol as a probe reaction. The results indicate an intrinsic relationship between dispersion, the presence of a TiO2-VOx phase, and catalytic activity for oxidation and dehydration.

  8. Surface-active derivative of inulin (Inutec® SP1) is a superior carrier for solid dispersions with a high drug load

    NARCIS (Netherlands)

    Srinarong, Parinda; Hämäläinen, Suvi; Visser, Marinella R.; Hinrichs, Wouter L.J; Ketolainen, Jarkko; Frijlink, Henderik W.

    2011-01-01

    The aim of this study was to compare the applicability of inulin, its surface-active derivative (Inutec® SP1), and polyvinylpyrrolidone (PVP) as carriers in high drug load solid dispersions (SDs) for improving the dissolution rate of a range of lipophilic drugs (diazepam, fenofibrate, ritonavir, and

  9. Impact of salinity and dispersed oil on adsorption of dissolved aromatic hydrocarbons by activated carbon and organoclay.

    Science.gov (United States)

    Younker, Jessica M; Walsh, Margaret E

    2015-12-15

    Adsorption capacity of phenol and naphthalene by powdered activated carbon (PAC), a commercial organoclay (OC) and a lab synthesized organoclay (BTMA) was studied using batch adsorption experiments under variable feed water quality conditions including single- and multi- solute conditions, fresh water, saline water and oily-and-saline water. Increasing salinity levels was found to reduce adsorption capacity of OC, likely due to destabilization, aggregation and subsequent removal of organoclay from the water column, but did not negatively impact adsorption capacity of PAC or BTMA. Increased dispersed oil concentrations were found to reduce the surface area of all adsorbents. This decreased the adsorption capacity of PAC for both phenol and naphthalene, and reduced BTMA adsorption of phenol, but did not negatively affect naphthalene removals by either organoclay. The presence of naphthalene as a co-solute significantly reduced phenol adsorption by PAC, but had no impact on organoclay adsorption. These results indicated that adsorption by PAC occurred via a surface adsorption mechanism, while organoclay adsorption occurred by hydrophobic or pi electron interactions. In general, PAC was more sensitive to changes in water quality than either of the organoclays evaluated in this study. However, PAC exhibited a higher adsorption capacity for phenol and naphthalene compared to both organoclays even in adverse water quality conditions. PMID:26259095

  10. Facile synthesis of well-dispersed Bi2S3 nanoparticles on reduced graphene oxide and enhanced photocatalytic activity

    Science.gov (United States)

    Chen, Yajie; Tian, Guohui; Mao, Guijie; Li, Rong; Xiao, Yuting; Han, Taoran

    2016-08-01

    Here we present a facile method for the synthesis of highly dispersed Bi2S3 nanoparticles (Bi2S3 NPs) with an average diameter of ca. 25 ± 3 nm on the surface of reduced graphene oxide (RGO) via a poly(sodium-p-styrenesul-fonate) (PSS) asisted hydrothermal process. Such synthetic strategy can avoid excess aggregates of Bi2S3 nanoparticles, meanwhile from effective interfacial contact between Bi2S3 nanoparticles and RGO nanosheets, and inhibit the recombination of photogenerated charges. The enhanced charge transfer properties were proved by photoluminescence (PL) measurement. The obtained Bi2S3 NPs/RGO composites showed more significant visible light photoactivity for the degradation of 2,4-dichlorophenol and Rhodamine B than that pure Bi2S3 and the control sample prepared in the absence of PSS. The enhanced photocatalytic performance could be attributed to the synergistic effect of efficient separation of photogenerated electron-hole pairs, increased catalytic active sites and visible light utilization.

  11. Dispersal from Microbial Biofilms.

    Science.gov (United States)

    Barraud, Nicolas; Kjelleberg, Staffan; Rice, Scott A

    2015-12-01

    One common feature of biofilm development is the active dispersal of cells from the mature biofilm, which completes the biofilm life cycle and allows for the subsequent colonization of new habitats. Dispersal is likely to be critical for species survival and appears to be a precisely regulated process that involves a complex network of genes and signal transduction systems. Sophisticated molecular mechanisms control the transition of sessile biofilm cells into dispersal cells and their coordinated detachment and release in the bulk liquid. Dispersal cells appear to be specialized and exhibit a unique phenotype different from biofilm or planktonic bacteria. Further, the dispersal population is characterized by a high level of heterogeneity, reminiscent of, but distinct from, that in the biofilm, which could potentially allow for improved colonization under various environmental conditions. Here we review recent advances in characterizing the molecular mechanisms that regulate biofilm dispersal events and the impact of dispersal in a broader ecological context. Several strategies that exploit the mechanisms controlling biofilm dispersal to develop as applications for biofilm control are also presented. PMID:27337281

  12. Formability of stainless steel tailored blanks

    DEFF Research Database (Denmark)

    Bagger, Claus; Gong, Hui; Olsen, Flemming Ove

    2004-01-01

    In a number of systematic tests, the formability of tailored blanks consisting of even and different combinations of AISI304 and AISI316 in thickness of 0.8 mm and 1.5 mm have been investigated. In order to analyse the formability of tailored blanks with different sheet thickness, a method based ...

  13. 纳米TiO2的分散及光催化活性%Dispersion and photocatalytic activity of titanium dioxide nanoparticles

    Institute of Scientific and Technical Information of China (English)

    张小强; 尹立红; 浦跃朴

    2011-01-01

    To investigate the dispersion state and photocatalytic activity of TiO2nanoparticles under ultraviolet irradiation, a variety of approaches for suspension of TiO2 nanoparticles were conducted with different dispersion stabilizers, dosage, pH value and various working parameter of ultrasound vibration. The average size of dispersed TiO2 nanoparticles was measured by dynamic light scattering device. The photocatalytic activity for degradation of methylene blue was determined by detecting the absorbance with the help of UV-visible spectrophotometry. The results show that the optimum dispersion stabilizer is 100% fetal bovine serum (FBS) which can provide TiO2 nanoparticles dispersion with the smallest particle size and the highest photocatalytic activity. The TiO2 nanoparticles dispersion prepared by 100% FBS is well-dispersed at the concentration of 0.50 mg/mL (1:100) or 1. 0 mg/mL (1:50). In our experiments the dispersion state and photocatalytic activity of TiO2 nanoparticles are not influenced by different pH values. The dispersion state and photocatalytic activity of TiO2 nanoparticles are promoted sufficiently with ultrasound energy of 33 W for 5 min. It is shown that the photocatalytic activity of titanium dioxide nanoparticles is promoted by the well-dispersed state.%为了研究纳米TiO2的分散及其紫外光催化活性,采用不同的分散剂、用量、pH条件及不同的超声波工作参数制备纳米TiO2分散体系.采用动态光散射法分析纳米颗粒的分散状态,采用分光光度法分析不同分散体系的纳米TiO2在紫外光照射下对亚甲基蓝降解率.采用100%FBS作为分散剂可以获得最小粒径的TiO2分散体系且有最大的光催化活性,使用时以制备终质量浓度为0.50 mg/mL(1∶100)或1.0 mg/mL (1∶50)的TiO2分散体系为最佳使用量.在该实验条件下不同pH值对纳米TiO2分散水平和光催化活性均未产生显著性影响.超声波33 W振荡5min即可明显提高纳米TiO2分散

  14. Effects of Crude Oil/Dispersant Mixture and Dispersant Components on PPARγ Activity in Vitro and in Vivo: Identification of Dioctyl Sodium Sulfosuccinate (DOSS; CAS #577-11-7) as a Probable Obesogen

    Science.gov (United States)

    Temkin, Alexis M.; Bowers, Robert R.; Magaletta, Margaret E.; Holshouser, Steven; Maggi, Adriana; Ciana, Paolo; Guillette, Louis J.; Bowden, John A.; Kucklick, John R.; Baatz, John E.; Spyropoulos, Demetri D.

    2015-01-01

    Background The obesity pandemic is associated with multiple major health concerns. In addition to diet and lifestyle, there is increasing evidence that environmental exposures to chemicals known as obesogens also may promote obesity. Objectives We investigated the massive environmental contamination resulting from the Deepwater Horizon (DWH) oil spill, including the use of the oil dispersant COREXIT in remediation efforts, to determine whether obesogens were released into the environment during this incident. We also sought to improve the sensitivity of obesogen detection methods in order to guide post-toxicological chemical assessments. Methods Peroxisome proliferator–activated receptor gamma (PPARγ) transactivation assays were used to identify putative obesogens. Solid-phase extraction (SPE) was used to sub-fractionate the water-accommodated fraction generated by mixing COREXIT, cell culture media, and DWH oil (CWAF). Liquid chromatography–mass spectrometry (LC-MS) was used to identify components of fractionated CWAF. PPAR response element (PPRE) activity was measured in PPRE-luciferase transgenic mice. Ligand-binding assays were used to quantitate ligand affinity. Murine 3T3-L1 preadipocytes were used to assess adipogenic induction. Results Serum-free conditions greatly enhanced the sensitivity of PPARγ transactivation assays. CWAF and COREXIT had significant dose-dependent PPARγ transactivation activities. From SPE, the 50:50 water:ethanol volume fraction of CWAF contained this activity, and LC-MS indicated that major components of COREXIT contribute to PPARγ transactivation in the CWAF. Molecular modeling predicted several components of COREXIT might be PPARγ ligands. We classified dioctyl sodium sulfosuccinate (DOSS), a major component of COREXIT, as a probable obesogen by PPARγ transactivation assays, PPAR-driven luciferase induction in vivo, PPARγ binding assays (affinity comparable to pioglitazone and arachidonic acid), and in vitro murine

  15. An experimental indoor phasing system based on active optics using dispersed Hartmann sensing technology in the visible waveband

    International Nuclear Information System (INIS)

    A telescope with a larger primary mirror can collect much more light and resolve objects much better than one with a smaller mirror, and so the larger version is always pursued by astronomers and astronomical technicians. Instead of using a monolithic primary mirror, more and more large telescopes, which are currently being planned or in construction, have adopted a segmented primary mirror design. Therefore, how to sense and phase such a primary mirror is a key issue for the future of extremely large optical/infrared telescopes. The Dispersed Fringe Sensor (DFS), or Dispersed Hartmann Sensor (DHS), is a non-contact method using broadband point light sources and it can estimate the piston by the two-directional spectrum formed by the transmissive grating's dispersion and lenslet array. Thus it can implement the combination of co-focusing by Shack-Hartmann technology and phasing by dispersed fringe sensing technologies such as the template-mapping method and the Hartmann method. We introduce the successful design, construction and alignment of our dispersed Hartmann sensor together with its design principles and simulations. We also conduct many successful real phasing tests and phasing corrections in the visible waveband using our existing indoor segmented mirror optics platform. Finally, some conclusions are reached based on the test and correction of experimental results.

  16. An experimental indoor phasing system based on active optics using dispersed Hartmann sensing technology in the visible waveband

    Institute of Scientific and Technical Information of China (English)

    Yong Zhang; Gen-Rong Liu; Yue-Fei Wang; Ye-Ping Li; Ya-Jun Zhang; Liang Zhang; Yi-Zhong Zeng; Jie Zhang

    2011-01-01

    A telescope with a larger primary mirror can collect much more light and resolve objects much better than one with a smaller mirror,and so the larger version is always pursued by astronomers and astronomical technicians.Instead of using a monolithic primary mirror,more and more large telescopes,which are currently being planned or in construction,have adopted a segmented primary mirror design.Therefore,how to sense and phase such a primary mirror is a key issue for the future of extremely large optical/infrared telescopes.The Dispersed Fringe Sensor (DFS),or Dispersed Hartmann Sensor (DHS),is a non-contact method using broadband point light sources and it can estimate the piston by the two-directional spectrum formed by the transmissive grating's dispersion and lenslet array.Thus it can implement the combination of co-focusing by Shack-Hartmann technology and phasing by dispersed fringe sensing technologies such as the template-mapping method and the Hartmann method.We introduce the successful design,construction and alignment of our dispersed Hartmann sensor together with its design principles and simulations.We also conduct many successful real phasing tests and phasing corrections in the visible waveband using our existing indoor segmented mirror optics platform.Finally,some conclusions are reached based on the test and correction of experimental results.

  17. Evaluating the biodegradability and effects of dispersed oil using Arctic test species and conditions : phase 1 activities

    Energy Technology Data Exchange (ETDEWEB)

    McFarlin, K.M.; Perkins, R.A. [Alaska Univ., Fairbanks, AK (United States); Gardiner, G.; Word, J.D [NewFields Northwest, Port Gamble, WA (United States)

    2009-07-01

    Spill prevention techniques and response options are important considerations of exploration and production operations within the Arctic Circle, where much of the world's undiscovered oil and gas is located. In the event of a marine oil spill, response teams must decide on actions such as natural recovery, mechanical recovery, in situ burning or chemical dispersion. A Net Environmental Benefit Analysis (NEBA) involves an examination of various spill response actions and their net environmental effects of key resources and habitats. Performing a NEBA requires information about the sensitivity of relevant species under conditions following various spill response techniques. This paper reported on a research project that investigated the toxic effects and biodegradation rates of dispersed oil under Arctic open water conditions. The 2 key objectives were to determine the toxicity of dispersed Alaska North Slope (ANS) crude oil to indigenous copepods and Arctic cod compared to non-dispersed oil and to compare those results to temperate species; and to determine the biodegradation rates of dispersed oil compared to non-dispersed oil. The data acquired from the study is intended to help optimize response options to minimize negative ecological effects. Natural Arctic conditions were simulated in the laboratory. All water used in this study was fresh seawater collected from the Beaufort and Chukchi Seas. Temperature, dissolved oxygen, salinity, pH and light intensities were measured when collecting indigenous test species for simulation in the laboratory. The research is ongoing and will continue until the summer of 2010, at which time a technical report with results will be prepared. 19 refs.

  18. Tailor made preservation strategies : Food Innovation Concepts

    NARCIS (Netherlands)

    Blankestijn, J.

    2013-01-01

    High quality, long shelf life, clean label, less salt: food must comply with many requirements. From genomics and mild preservation to a ‘Quick Scan’ for process hygiene, TNO helps manufacturers to develop a tailor made preservation strategy.

  19. User-tailored Inter-Widget Communication

    NARCIS (Netherlands)

    Drachsler, Hendrik; Hoisl, Bernhard; Waglecher, Christoph

    2010-01-01

    Drachsler, H., Hoisl, B., & Wagenlecher, C. (2010, 16 September). User-tailored Inter-Widget Communication. Extending the Shared Data Interface for the Apache Wookie Engine, International Conference on Interactive Computer Aided Learning 2010, Hasselt, Belgium.

  20. Aeroelastic Tailoring via Tow Steered Composites

    Science.gov (United States)

    Stanford, Bret K.; Jutte, Christine V.

    2014-01-01

    The use of tow steered composites, where fibers follow prescribed curvilinear paths within a laminate, can improve upon existing capabilities related to aeroelastic tailoring of wing structures, though this tailoring method has received relatively little attention in the literature. This paper demonstrates the technique for both a simple cantilevered plate in low-speed flow, as well as the wing box of a full-scale high aspect ratio transport configuration. Static aeroelastic stresses and dynamic flutter boundaries are obtained for both cases. The impact of various tailoring choices upon the aeroelastic performance is quantified: curvilinear fiber steering versus straight fiber steering, certifiable versus noncertifiable stacking sequences, a single uniform laminate per wing skin versus multiple laminates, and identical upper and lower wing skins structures versus individual tailoring.

  1. Welding of tailored blanks of different materials

    OpenAIRE

    Suban, Marjan; Tušek, Janez; Kampuš, Zlatko

    2015-01-01

    This paper treats welding of tailored blanks made of different materials. In general, fusion welding and welding with pressure, practically without fusion, are described. Fusion welding may be carried out with or without the addition of filler material. In Section 3, general characteristics of tailored blanks are described. In Section 4, MIG welding and laser welding of austenitic stainless steel with ferrite non-stainless steel are described. After welding, hardness of the welded joints was ...

  2. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodeg

  3. Spectrally tailored supercontinuum generation from single-mode-fiber amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Qiang; Guo, Zhengru; Zhang, Qingshan [Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China); Liu, Yang; Li, Wenxue [State Key Laboratory of Precision Spectroscopy, East China Normal University, 3663 Zhongshan North Road, Shanghai 200062 (China); Zeng, Heping, E-mail: hpzeng@phy.ecnu.edu.cn [Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China); State Key Laboratory of Precision Spectroscopy, East China Normal University, 3663 Zhongshan North Road, Shanghai 200062 (China)

    2014-05-19

    Spectral filtering of an all-normal-dispersion Yb-doped fiber laser was demonstrated effective for broadband supercontinuum generation in the picosecond time region. The picosecond pump pulses were tailored in spectrum with 1 nm band-pass filter installed between two single-mode fiber amplifiers. By tuning the spectral filter around 1028 nm, four-wave mixing was initiated in a photonic crystal fiber spliced with single-mode fiber, as manifested by the simultaneous generation of Stokes wave at 1076 nm and anti-Stokes wave at 984 nm. Four-wave mixing took place in cascade with the influence of stimulated Raman scattering and eventually extended the output spectrum more than 900 nm of 10 dB bandwidth. This technique allows smooth octave supercontinuum generation by using simple single-mode fiber amplifiers rather than complicated multistage large-mode-area fiber amplifiers.

  4. Generalized uniform formulae for atmospheric dispersion of activities released from a ventilation stack or from a leaky reactor building

    International Nuclear Information System (INIS)

    Relations are given for the calculation of the atmospheric transport and dispersion of industrial gaseous wastes released from the stacks of factories, power plants and nuclear power plants. Modified formulae are derived for stack disposal from a small stack, also applicable in calculating the gaseous waste release from a leaky reactor. Uniform generalized formulae are presented serving the calculation of both high and short stack disposals as well as of reactor building leakages. (L.O.)

  5. Selective Functionalization of Tailored Nanostructures

    NARCIS (Netherlands)

    Slingenbergh, Winand; Boer, Sanne K. de; Cordes, Thorben; Browne, Wesley R.; Feringa, Ben L.; Hoogenboom, Jacob P.; Hosson, Jeff Th.M. De; Dorp, Willem F. van

    2012-01-01

    The controlled positioning of nanostructures with active molecular components is of importance throughout nanoscience and nanotechnology. We present a novel three-step method to produce nanostructures that are selectively decorated with functional molecules. We use fluorophores and nanoparticles to

  6. Dry particle coating of polymer particles for tailor-made product properties

    OpenAIRE

    Blümel, C.; Schmidt, Jochen; Dielesen, A.; Sachs, Marius; Winzer, B.; Peukert, Wolfgang; Wirth, Karl-Ernst

    2014-01-01

    Disperse polymer powders with tailor-made particle properties are of increasing interest in industrial applications such as Selective Laser Beam Melting processes (SLM). This study focuses on dry particle coating processes to improve the conductivity of the insulating polymer powder in order to assemble conductive devices. Therefore PP particles were coated with Carbon Black nanoparticles in a dry particle coating process. This process was investigated in dependence of process time and mass f...

  7. A family based tailored counselling to increase non-exercise physical activity in adults with a sedentary job and physical activity in their young children: design and methods of a year-long randomized controlled trial

    OpenAIRE

    Finni Taija; Sääkslahti Arja; Laukkanen Arto; Pesola Arto; Sipilä Sarianna

    2011-01-01

    Abstract Background Epidemiological evidence suggests that decrease in sedentary behaviour is beneficial for health. This family based randomized controlled trial examines whether face-to-face delivered counselling is effective in reducing sedentary time and improving health in adults and increasing moderate-to-vigorous activities in children. Methods The families are randomized after balancing socioeconomic and environmental factors in the Jyväskylä region, Finland. Inclusion criteria are: h...

  8. Quantifying the impact of relativity and of dispersion interactions on the activation of molecular oxygen promoted by noble metal nanoparticles

    KAUST Repository

    Kanoun, Mohammed

    2014-06-26

    We compared the mechanism of O2 dissociation catalyzed by Cu38, Ag38, and Au38 nanoparticles. Overall, our results indicate that O2 dissociation is extremely easy on Cu38, with an almost negligible barrier for the O-O breaking step. It presents an energy barrier close to 20 kcal/mol on Ag38, which decreases to slightly more than 10 kcal/mol on Au38. This behavior is analyzed to quantify the impact of relativity and of dispersion interactions through a comparison of nonrelativistic, scalar-relativistic, and dispersioncorrected DFT methods. Nonrelativistic calculations show a clear trend down the triad, with larger in size nanoparticle (NP), weaker O2 adsorption energy, and higher O2 dissociation barrier, which is so high for Au38 to be in sharp contrast with the mild conditions used experimentally. Inclusion of relativity has no impact on the O2 adsorption energy, but it reduces the energy barrier for O2 dissociation on Au38 from 30.1 to 11.4 kcal/mol, making it even lower than that on Ag38 and consistent with the mild conditions used experimentally. Dispersion interactions have a remarkable role in improving the adsorption ability of O2 on the heavier Ag38 and especially Au38 NPs, contributing roughly 50% of the total adsorption energy, while they have much less impact on O2 adsorption on Cu38.

  9. A nano-disperse ferritin-core mimetic that efficiently corrects anemia without luminal iron redox activity.

    Science.gov (United States)

    Powell, Jonathan J; Bruggraber, Sylvaine F A; Faria, Nuno; Poots, Lynsey K; Hondow, Nicole; Pennycook, Timothy J; Latunde-Dada, Gladys O; Simpson, Robert J; Brown, Andy P; Pereira, Dora I A

    2014-10-01

    The 2-5 nm Fe(III) oxo-hydroxide core of ferritin is less ordered and readily bioavailable compared to its pure synthetic analogue, ferrihydrite. We report the facile synthesis of tartrate-modified, nano-disperse ferrihydrite of small primary particle size, but with enlarged or strained lattice structure (~2.7Å for the main Bragg peak versus 2.6Å for synthetic ferrihydrite). Analysis indicated that co-precipitation conditions can be achieved for tartrate inclusion into the developing ferrihydrite particles, retarding both growth and crystallization and favoring stabilization of the cross-linked polymeric structure. In murine models, gastrointestinal uptake was independent of luminal Fe(III) reduction to Fe(II) and, yet, absorption was equivalent to that of ferrous sulphate, efficiently correcting the induced anemia. This process may model dietary Fe(III) absorption and potentially provide a side effect-free form of cheap supplemental iron. From the clinical editor: Small size tartrate-modified, nano-disperse ferrihydrite was used for efficient gastrointestinal delivery of soluble Fe(III) without the risk for free radical generation in murine models. This method may provide a potentially side effect-free form iron supplementation. PMID:24394211

  10. Tailoring the magnetic properties of cobalt-ferrite nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Vega, A. Estrada de la; Garza-Navarro, M. A., E-mail: marco.garzanr@uanl.edu.mx; Durán-Guerrero, J. G.; Moreno Cortez, I. E.; Lucio-Porto, R.; González-González, V. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica (Mexico)

    2016-01-15

    In this contribution, we report on the tuning of magnetic properties of cobalt-ferrite nanoclusters. The cobalt-ferrite nanoclusters were synthesized from a two-step approach that consists of the synthesis of cobalt-ferrite nanoparticles in organic media, followed by their dispersion into aqueous dissolution to form an oil-in-water emulsion. These emulsions were prepared at three different concentrations of the cationic surfactant cetyltrimethylammonium bromide (CTAB), in order to control the size and clustering density of the nanoparticles in the nanoclusters. The synthesized samples were characterized by transmission electron microscopy and their related techniques, such as bright-field and Z-contrast imaging, electron diffraction and energy-dispersive X-ray spectrometry; as well as static magnetic measures. The experimental evidence indicates that the size, morphology, and nanoparticles clustering density in the nanoclusters is highly dependent of the cobalt-ferrite:CTAB molar ratio that is used in their synthesis. In addition, due to the clustering of the nanoparticles into the nanoclusters, their magnetic moments are blocked to relax cooperatively. Hence, the magnetic response of the nanoclusters can be tailored by controlling the size and nanoparticles clustering density.

  11. In vitro activity of the new water-dispersible Fe{sub 3}O{sub 4}@usnic acid nanostructure against planktonic and sessile bacterial cells

    Energy Technology Data Exchange (ETDEWEB)

    Grumezescu, Alexandru Mihai, E-mail: grumezescu@yahoo.com [Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Department of Science and Engineering of Oxidic Materials and Nanomaterials (Romania); Cotar, Ani Ioana [Faculty of Biology, University of Bucharest, Department of Microbiology Immunology (Romania); Andronescu, Ecaterina; Ficai, Anton; Ghitulica, Cristina Daniela; Grumezescu, Valentina; Vasile, Bogdan Stefan [Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Department of Science and Engineering of Oxidic Materials and Nanomaterials (Romania); Chifiriuc, Mariana Carmen [Faculty of Biology, University of Bucharest, Department of Microbiology Immunology (Romania)

    2013-07-15

    A new water-dispersible nanostructure based on magnetite (Fe{sub 3}O{sub 4}) and usnic acid (UA) was prepared in a well-shaped spherical form by a precipitation method. Nanoparticles were well individualized and homogeneous in size. The presence of Fe{sub 3}O{sub 4}@UA was confirmed by transmission electron microscopy, Fourier transform-infrared spectroscopy, and X-ray diffraction. The UA was entrapped in the magnetic nanoparticles during preparation and the amount of entrapped UA was estimated by thermogravimetric analysis. Fabricated nanostructures were tested on planktonic cells growth (minimal inhibitory concentration assay) and biofilm development on Gram-positive Staphylococcusaureus (S.aureus),Enterococcus faecalis (E.faecalis) and Gram-negative Escherichia coli (E.coli),Pseudomonasaeruginosa (P.aeruginosa) reference strains. Concerning the influence of Fe{sub 3}O{sub 4}@UA on the planktonic bacterial cells, the functionalized magnetic nanoparticles exhibited a significantly improved antimicrobial activity against E.faecalis and E.coli, as compared with the Fe{sub 3}O{sub 4} control. The UA incorporated into the magnetic nanoparticles exhibited a very significant inhibitory effect on the biofilm formed by the S.aureus and E.faecalis, on a wide range of concentrations, while in case of the Gram-negative microbial strains, the UA-loaded nanoparticles inhibited the E.coli biofilm development, only at high concentrations, while for P.aeruginosa biofilms, no inhibitory effect was observed. The obtained results demonstrate that the new water-dispersible Fe{sub 3}O{sub 4}@UA nanosystem, combining the advantages of the intrinsic antimicrobial features of the UA with the higher surface to volume ratio provided by the magnetic nanocarrier dispersible in water, exhibits efficient antimicrobial activity against planktonic and adherent cells, especially on Gram-positive strains.

  12. Interactive Multimedia Tailored to Improve Diabetes Self-Management.

    Science.gov (United States)

    Wood, Felecia G; Alley, Elizabeth; Baer, Spencer; Johnson, Rebecca

    2015-09-01

    A pilot program was initiated to improve self-management of type 2 diabetes by rural adults. Using an iOS-based, individually tailored pre-/postintervention to improve diabetes self-management, undergraduate students developed a native mobile application to help participants effectively manage their diabetes. Brief quizzes assessed diabetes knowledge. A diabetes dictionary and physical activity assessment provided additional support to users of the app. On completion of the pilot, data analysis indicated increased diabetes knowledge and self-efficacy, and ease of use of the technology. Native app technology permits ready access to important information for those living with type 2 diabetes. PMID:26333610

  13. Dispersed Indeterminacy

    CERN Document Server

    Fayngold, Moses

    2013-01-01

    A state of a single particle can be represented by a quantum blob in the corresponding phase space, or a patch (granule) in its 2-D subspace. Its area is frequently stated to be no less than, implying that such a granule is an indivisible quantum of the 2-D phase space. But this is generally not true, as is evident, for instance, from representation of some states in the basis of innately discrete observables like angular momentum. Here we consider some dispersed states involving the evanescent waves different from that in the total internal reflection. Such states are represented by a set of separated granules with individual areas, but with the total indeterminacy . An idealized model has a discrete Wigner function and is described by a superposition of eigenstates with eigenvalues and forming an infinite periodic array of dots on the phase plane. The question about the total indeterminacy in such state is discussed. We argue that the eigenstates corresponding to the considered EW cannot be singled out by a...

  14. Tailored Trustworthy Spaces: Solutions for the Smart Grid

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — The NITRD workshop on Tailored Trustworthy Spaces: Solutions for the Smart Grid was conceived by the Federal government to probe deeper into how Tailored...

  15. Dissolution of tailored ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    Dissolution experiments on polyphase, high alumina tailored ceramic nuclear waste forms developed for the chemical immobilization of Savannah River Plant nuclear waste are described. Three forms of leach tests have been adopted; bulk samples conforming to the Materials Characterization Center Static Leach Test (MCC-1), a powdered sample leach test, and a leach test performed on transmission electron microscope thin foil samples. From analysis of these tests the crystalline phases that preferentially dissolve on leaching and the product phases formed are identified and related to the tailoring and processing schemes used in forming the ceramics. The thin foil sample leaching enables the role of intergranular amorphous phases as short-circuit leaching paths in polyphase ceramics to be investigated

  16. All-optical bandwidth-tailorable radar

    CERN Document Server

    Zou, Weiwen; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2015-01-01

    Radar has been widely used in military, security, and rescue. Metamaterial cloak is employed in stealth targets to evade radar detection. Hence modern radar should be reconfigurable at multi-bands for detecting stealth targets, which might be realized based on microwave photonics. Here, we demonstrate an all-optical bandwidth-tailorable radar architecture. It is a coherent system utilizing one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates wideband linearly-chirped radar signal. The working bands can be flexibly tailored with desired bandwidth at user-preferred carrier frequency. After modulated onto the pre-chirped optical pulse, radar echoes are time-stretched and frequency-compressed by several times. The digitization becomes much easier without loss of detection ability. We believe that the demonstration can innovate the radar's architecture with ultra-high range resolution.

  17. Tailored Security and Safety for Pervasive Computing

    Science.gov (United States)

    Blass, Erik-Oliver; Zitterbart, Martina

    Pervasive computing makes high demands on security: devices are seriously resource-restricted, communication takes place spontaneously, and adversaries might control some of the devices. We claim that 1.) today’s research, studying traditional security properties for pervasive computing, leads to inefficient, expensive, and unnecessary strong and unwanted security solutions. Instead, security solutions tailored to the demands of a user, the scenario, or the expected adversary are more promising. 2.) Today’s research for security in pervasive computing makes naive, inefficient, and unrealistic assumptions regarding safety properties, in particular the quality of basic communication. Therefore, future security research has to consider safety characteristics and has to jointly investigate security and safety for efficient, tailored solutions.

  18. A Tailor Made Concrete Solution for Tunneling

    OpenAIRE

    Río, Olga; Arciniegas, Carlos

    2010-01-01

    Thc develoment of tailor made materials by using a performance based approach are attracting research interest in different construction areas due to the advantages of having solutions that should perform according to the specified needs. If focus is put on concrete and on the fitness of Its functional requirements. the rational procedure would be to state the required main structural, durability and executíon indicators (PI) and subindicators (PSI). i.e. mechanical strength al different age ...

  19. A Propulsion System Tailored to Cubesat Applications

    OpenAIRE

    Platt, Donald

    2007-01-01

    Cubesats and other nano- and pico-satellite platforms have traditionally not had the capability of on-board propulsion. A complete propulsion system tailored to cubesat and other nano-picosat applications is presented in this paper. This system has been demonstrated and is ready for use in cubesat missions. A diaphragm positive expulsion tank or integral structure/bladder tank has been developed for propellant storage and feed to the thrusters. Propellant systems available include hydrogen pe...

  20. Different approaches to tailoring chemical pulp fibres

    OpenAIRE

    El-Sharkawy, Khalil

    2008-01-01

    The objective of this thesis work was to examine different approaches to tailor chemical fibres of different raw materials. The focus in searching for new approaches was on pressure screen fractionation, selective treatment of each fraction, mechanical pre-treatment before refining, refiner loadability and its link to fibre properties and filling design, and on-line quality control of fibre properties. The evaluation is based on the impacts on fibre properties, filtration, refining and the re...

  1. Preparation of well-dispersed Mg-doped LaCoO3 nanocrystals with controllable particle size and high visible-light photocatalytic activity.

    Science.gov (United States)

    Sun, Shangmei; Pang, Guangsheng; Huang, Yuliang; Li, Chunguang; Feng, Shouhua

    2010-08-01

    Mg-doped LaCoO3 nanocrystals are prepared by a modified sol-gel method. Excess MgO is used to inhibit the crystal growth and agglomeration during the calcination process. A series of Mg-doped LaCoO3 nanocrystals with average crystallite size varying from 13.4 to 31.6 nm can be obtained by changing the molar ratio of Mg:La from 4:1 to 1:10 in the reaction mixture. The largest BET surface area observed is 64.5 m2/g if the molar ratio of Mg:La is 4:1. The product can be well dispersed in water and a very stable colloid formed without any stabilizer. The photocatalytic performance of Mg-doped LaCoO3 nanocrystals is evaluated by the degradation of Reactive Brilliant Red X-3B solution. The well-dispersed Mg-doped LaCoO3 nanocrystals exhibit high visible-light photocatalytic activity.

  2. Advance in Active Biofilm Dispersal Mechanism%生物被膜主动分散机制研究进展

    Institute of Scientific and Technical Information of China (English)

    高宗良; 谷元兴; 赵峰; 刘永生

    2012-01-01

    细菌生物被膜(bacterial biofilm,BBF)为微生物栖息提供了所需要的保护屏障和生长微环境.生物被膜对抗菌药物的耐受性使得它在医学治疗等领域产生了严重的危害.因此如何分散被膜显得意义重大.综述了生物被膜主动分散的几种主要机制,包括降解酶的合成、运动力的恢复、表面活性剂的产生和细胞死亡.%Microbial biofilms are composed of a hydrated matrix of biopolymers including polypeptides, polysaccharides and nucleic acids and act as a protective barrier and microenvironment for the inhabiting microbes. The resistantce of biofilms to antimicrobial agents leads to a range of problems, including medical treatment, which highlights the significance of biofilm dispersal. The mechanisms that result in active dispersal of bacteria from biofilm, which include the synthesis of enzymes, the return of motility, surfactant production and cell lysis were reviewed.

  3. FT-IR, dispersive Raman, NMR, DFT and antimicrobial activity studies on 2-(Thiophen-2-yl)-1H-benzo[d]imidazole

    Science.gov (United States)

    Ünal, Arslan; Eren, Bilge

    2013-10-01

    2-(Thiophen-2-yl)-1H-benzo[d]imidazole (TBI) was synthesized under microwave conditions and was characterized by FT-IR, dispersive Raman, 1H-, 13C-, DEPT-, HETCOR-NMR spectroscopies and density functional theory (DFT) computations. The FT-IR and dispersive Raman spectra of TBI were recorded in the regions 4000-400 cm-1 and 4000-100 cm-1. The experimental vibrational spectra were interpreted with the help of normal coordinate analysis based on DFT/B3LYP/6-311++G(d,p) theory level for the more stable tautomeric form (Tautomer 1). The complete vibrational assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. A satisfactory consistency between the experimental and theoretical findings was obtained. The frontier molecular orbitals (FMOs), atomic charges and NMR shifts of the two stable tautomeric forms were also obtained at the same theory level without any symmetry restrictions. In addition, the title compound was screened for its antimicrobial activity and was found to be exhibit antifungal and antibacterial effects.

  4. Rational and combinatorial tailoring of bioactive cyclic dipeptides

    Directory of Open Access Journals (Sweden)

    Tobias Wolfgang Giessen

    2015-07-01

    Full Text Available Modified cyclic dipeptides represent a diverse family of microbial secondary metabolites. They display a broad variety of biological and pharmacological activities and have long been recognized as privileged structures with the ability to bind to a wide range of receptors. This is due to their conformationally constrained 2, 5-diketopiperazine (DKP scaffold and the diverse set of DKP tailoring enzymes present in nature. After initial DKP assembly through different biosynthetic systems modifying enzymes are responsible for installing functional groups crucial for the biological activities of the resulting modified DKPs. They represent a vast and largely untapped enzyme repository very useful for synthetic biology approaches aiming at introducing structural variations into DKP scaffolds. In this review we focus on these DKP modification enzymes found in various microbial secondary metabolite gene clusters. We will give a brief overview of their distribution and highlight a select number of characterized DKP tailoring enzymes before turning to their application potential in combinatorial biosynthesis with the aim of producing molecules with improved or entirely new biological and medicinally relevant properties.

  5. Rational and combinatorial tailoring of bioactive cyclic dipeptides.

    Science.gov (United States)

    Giessen, Tobias W; Marahiel, Mohamed A

    2015-01-01

    Modified cyclic dipeptides represent a diverse family of microbial secondary metabolites. They display a broad variety of biological and pharmacological activities and have long been recognized as privileged structures with the ability to bind to a wide range of receptors. This is due to their conformationally constrained 2, 5-diketopiperazine (DKP) scaffold and the diverse set of DKP tailoring enzymes present in nature. After initial DKP assembly through different biosynthetic systems modifying enzymes are responsible for installing functional groups crucial for the biological activities of the resulting modified DKPs. They represent a vast and largely untapped enzyme repository very useful for synthetic biology approaches aiming at introducing structural variations into DKP scaffolds. In this review we focus on these DKP modification enzymes found in various microbial secondary metabolite gene clusters. We will give a brief overview of their distribution and highlight a select number of characterized DKP tailoring enzymes before turning to their application potential in combinatorial biosynthesis with the aim of producing molecules with improved or entirely new biological and medicinally relevant properties. PMID:26284060

  6. Testing a Dutch web-based tailored lifestyle programme among adults: a study protocol

    Directory of Open Access Journals (Sweden)

    van Osch Liesbeth ADM

    2011-02-01

    Full Text Available Abstract Background Smoking, high alcohol consumption, unhealthy eating habits and physical inactivity often lead to (chronic diseases, such as cardiovascular diseases and cancer. Tailored online interventions have been proven to be effective in changing health behaviours. The aim of this study is to test and compare the effectiveness of two different tailoring strategies for changing lifestyle compared to a control group using a multiple health behaviour web-based approach. Methods In our Internet-based tailored programme, the five lifestyle behaviours of smoking, alcohol intake, fruit consumption, vegetable consumption, and physical activity are addressed. This randomized controlled trial, conducted among Dutch adults, includes two experimental groups (i.e., a sequential behaviour tailoring condition and a simultaneous behaviour tailoring condition and a control group. People in the sequential behaviour tailoring condition obtain feedback on whether their lifestyle behaviours meet the Dutch recommendations. Using a step-by-step approach, they are stimulated to continue with a computer tailored module to change only one unhealthy behaviour first. In the course of the study, they can proceed to change a second behaviour. People in the simultaneous behaviour tailoring condition receive computer tailored feedback about all their unhealthy behaviours during their first visit as a stimulation to change all unhealthy behaviours. The experimental groups can re-visit the website and can then receive ipsative feedback (i.e., current scores are compared to previous scores in order to give feedback about potential changes. The (difference in effectiveness of the different versions of the programme will be tested and compared to a control group, in which respondents only receive a short health risk appraisal. Programme evaluations will assess satisfaction with and appreciation and personal relevance of the intervention among the respondents. Finally

  7. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    International Nuclear Information System (INIS)

    A successive anchoring of Ti(NMe2)4, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, 13C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, 13C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated

  8. Vacuum template synthesis of multifunctional nanotubes with tailored nanostructured walls.

    Science.gov (United States)

    Filippin, A Nicolas; Macias-Montero, Manuel; Saghi, Zineb; Idígoras, Jesús; Burdet, Pierre; Barranco, Angel; Midgley, Paul; Anta, Juan A; Borras, Ana

    2016-01-01

    A three-step vacuum procedure for the fabrication of vertical TiO2 and ZnO nanotubes with three dimensional walls is presented. The method combines physical vapor deposition of small-molecules, plasma enhanced chemical vapor deposition of inorganic functional thin films and layers and a post-annealing process in vacuum in order to remove the organic template. As a result, an ample variety of inorganic nanotubes are made with tunable length, hole dimensions and shapes and tailored wall composition, microstructure, porosity and structure. The fabrication of multishell nanotubes combining different semiconducting oxides and metal nanoparticles is as well explored. This method provides a feasible and reproducible route for the fabrication of high density arrays of vertically alligned nanotubes on processable substrates. The emptying mechanism and microstructure of the nanotubes have been elucidated through SEM, STEM, HAADF-STEM tomography and energy dispersive X-ray spectroscopy. In this article, as a proof of concept, it is presented the straightforward integration of ZnO nanotubes as photoanode in a photovoltaic cell and as a photonic oxygen gas sensor. PMID:26860367

  9. Vacuum template synthesis of multifunctional nanotubes with tailored nanostructured walls

    Science.gov (United States)

    Filippin, A. Nicolas; Macias-Montero, Manuel; Saghi, Zineb; Idígoras, Jesús; Burdet, Pierre; Barranco, Angel; Midgley, Paul; Anta, Juan A.; Borras, Ana

    2016-02-01

    A three-step vacuum procedure for the fabrication of vertical TiO2 and ZnO nanotubes with three dimensional walls is presented. The method combines physical vapor deposition of small-molecules, plasma enhanced chemical vapor deposition of inorganic functional thin films and layers and a post-annealing process in vacuum in order to remove the organic template. As a result, an ample variety of inorganic nanotubes are made with tunable length, hole dimensions and shapes and tailored wall composition, microstructure, porosity and structure. The fabrication of multishell nanotubes combining different semiconducting oxides and metal nanoparticles is as well explored. This method provides a feasible and reproducible route for the fabrication of high density arrays of vertically alligned nanotubes on processable substrates. The emptying mechanism and microstructure of the nanotubes have been elucidated through SEM, STEM, HAADF-STEM tomography and energy dispersive X-ray spectroscopy. In this article, as a proof of concept, it is presented the straightforward integration of ZnO nanotubes as photoanode in a photovoltaic cell and as a photonic oxygen gas sensor.

  10. Tailored antireflective biomimetic nanostructures for UV applications

    Energy Technology Data Exchange (ETDEWEB)

    Morhard, Christoph; Pacholski, Claudia; Spatz, Joachim P [Department of New Materials and Biosystems, Max Planck Institute for Metals Research, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Lehr, Dennis; Brunner, Robert; Helgert, Michael [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Promenade 10, D-07745 Jena (Germany); Sundermann, Michael, E-mail: Pacholski@mf.mpg.de [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Strasse 56, D-73447 Oberkochen (Germany)

    2010-10-22

    Antireflective surfaces composed of biomimetic sub-wavelength structures that employ the 'moth eye principle' for reflectance reduction are highly desirable in many optical applications such as solar cells, photodetectors and laser optics. We report an efficient approach for the fabrication of antireflective surfaces based on a two-step process consisting of gold nanoparticle mask generation by micellar block copolymer nanolithography and a multi-step reactive ion etching process. Depending on the RIE process parameters nanostructured surfaces with tailored antireflective properties can easily be fabricated that show optimum performance for specific applications.

  11. Investigation of catalytic activity towards oxygen reduction reaction of Pt dispersed on boron doped graphene in acid medium.

    Science.gov (United States)

    Pullamsetty, Ashok; Sundara, Ramaprabhu

    2016-10-01

    Boron doped graphene was prepared by a facile method and platinum (Pt) decoration over boron doped graphene was done in various chemical reduction methods such as sodium borohydride (NaBH4), polyol and modified polyol. X-ray diffraction analysis indicates that the synthesized catalyst particles are present in a nanocrystalline structure and transmission and scanning electron microscopy were employed to investigate the morphology and particle distribution. The electrochemical properties were investigated with the help of the rotating disk electrode (RDE) technique and cyclic voltammetry. The results show that the oxygen reduction reaction (ORR) takes place by a four-electron process. The kinetics of the ORR was evaluated using K-L and Tafel plots. The electrocatalyst obtained in modified polyol reduction method has shown the better catalytic activity compared to other two electrocatalysts. PMID:27393888

  12. In-syringe magnetic stirring-assisted dispersive liquid-liquid microextraction for automation and downscaling of methylene blue active substances assay.

    Science.gov (United States)

    Suárez, Ruth; Horstkotte, Burkhard; Cerdà, Victor

    2014-12-01

    A simple and rapid method for the determination of the methylene blue active substances assay based on in-syringe automation of magnetic stirring-assisted dispersive liquid-liquid microextraction was developed. The proposed method proved to be valid for the determination of anionic surfactant in waste, pond, well, tap, and drinking water samples. Sample mixing with reagents, extraction and phase separation were performed within the syringe of an automated syringe pump containing a magnetic stirring bar for homogenization and solvent dispersion. The syringe module was used upside-down to enable the use of chloroform as an extraction solvent of higher density than water. The calibration was found to be linear up to 0.3mg/L using only 200 µL of solvent and 4 mL of sample. The limits of detection (3σ) and quantification (10σ) were 7.0 µg/L and 22 µg/L, respectively. The relative standard deviation for 10 replicate determinations of 0.1mg/L SBDS was below 3%. Concentrations of anionic surfactants in natural water samples were in the range of 0.032-0.213 mg/L and no significant differences towards the standard method were found. Standard additions gave analyte recoveries between 95% and 106% proving the general applicability and adequateness of the system to MBSA index determination. Compared to the tedious standard method requiring up to 50 mL of chloroform, the entire procedure took only 345 s using 250-times less solvent.

  13. Surface engineering of SPIONs: role of phosphonate ligand multivalency in tailoring their efficacy

    Science.gov (United States)

    Lam, Tina; Avti, Pramod K.; Pouliot, Philippe; Tardif, Jean-Claude; Rhéaume, Éric; Lesage, Frederic; Kakkar, Ashok

    2016-10-01

    We report the design of scaffolds containing mono-, bis-, and tris-phosphonate coordinating groups, and a polyethylene glycol chain, for stabilizing superparamagnetic iron oxide nanoparticles (SPIONs), using simple and versatile chemistry. We demonstrate that the number of anchoring phosphonate sites on the ligand influence the colloidal stability, magnetic and biological properties of SPIONs, and the latter do not solely depend on attaching moieties that can enhance their aqueous dispersion. These parameters can be tailored by the number of conjugation sites on the ligand, as evidenced from dynamic light scattering at various salt concentrations, magnetic relaxivities and cell viability studies.

  14. Tailoring assembly of reduced graphene oxide nanosheets to control gas barrier properties of natural rubber nanocomposites.

    Science.gov (United States)

    Scherillo, Giuseppe; Lavorgna, Marino; Buonocore, Giovanna G; Zhan, Yanhu H; Xia, Hesheng S; Mensitieri, Giuseppe; Ambrosio, Luigi

    2014-02-26

    Self-assembling of reduced graphene oxide platelets, as a tailored interconnected network within a natural rubber matrix, is proposed as a mean for obtaining nanocomposites with improved gas barrier, as compared to neat natural rubber. Interestingly, this nanocomposite structure results to be much more effective than homogeneous dispersion of graphene platelike particles, even at low graphene loadings. Such behavior is interpreted on the grounds of a theoretical model describing permeability of heterogeneous systems specifically accounting for self-segregated graphene morphology. PMID:24490910

  15. Edaphics, active tectonics and animal movements in the Kenyan Rift - implications for early human evolution and dispersal

    Science.gov (United States)

    Kübler, Simon; Owenga, Peter; Rucina, Stephen; King, Geoffrey C. P.

    2014-05-01

    The quality of soils (edaphics) and the associated vegetation strongly controls the health of grazing animals. Until now, this has hardly been appreciated by paleo-anthropologists who only take into account the availability of water and vegetation in landscape reconstruction attempts. A lack of understanding the importance of the edaphics of a region greatly limits interpretations of the relation between our ancestors and animals over the last few million years. If a region lacks vital trace elements then wild grazing and browsing animals will avoid it and go to considerable length and take major risks to seek out better pasture. As a consequence animals must move around the landscape at different times of the year. In complex landscapes, such as tectonically active rifts, hominins can use advanced group behaviour to gain strategic advantage for hunting. Our study in the southern Kenya rift in the Lake Magadi region shows that the edaphics and active rift structures play a key role in present day animal movements as well as the for the location of an early hominin site at Mt. Olorgesailie. We carried out field analysis based on studying the relationship between the geology and soil development as well as the tectonic geomorphology to identify 'good' and 'bad' regions both in terms of edaphics and accessibility for grazing animals. We further sampled different soils that developed on the volcanic bedrock and sediment sources of the region and interviewed the local Maasai shepherds to learn about present-day good and bad grazing sites. At the Olorgesailie site the rift valley floor is covered with flood trachytes; basalts only occur at Mt. Olorgesailie and farther east up the rift flank. The hominin site is located in lacustrine sediments at the southern edge of a playa that extends north and northwest of Mt. Olorgesailie. The lakebeds are now tilted and eroded by motion on two north-south striking faults. The lake was trapped by basalt flows from Mt. Olorgesailie

  16. Effect of Gold Dispersion on the Photocatalytic Activity of Mesoporous Titania for the Vapor-Phase Oxidation of Acetone

    Directory of Open Access Journals (Sweden)

    S. V. Awate

    2008-01-01

    Full Text Available Mesostructured titanium dioxide photocatalyst, having uniform crystallite size (6–12 nm and average pore diameter of ∼4.2 nm, was synthesized by using a low-temperature nonsurfactant hydrothermal route, employing tartaric acid as a templating agent. Gold additions from 0.5 to 2 wt% were incorporated, either during the hydrothermal process or by postsynthesis wet impregnation. Compared to the impregnation-prepared samples, the samples synthesized hydrothermally contained smaller-size (≤1 nm gold clusters occluded in the pores of the host matrix. Whereas CO2 and H2O were the main reaction products in UV-assisted vapor-phase oxidation of acetone using these catalysts, C2H6 and HCO2CH3 were also produced for higher acetone concentrations in air. The conversion of acetone was found to increase with decrease in the size of both TiO2 and gold particles. In situ IR spectroscopy revealed that titania and gold particles serve as independent adsorption and reaction sites for acetone and oxygen molecules. Acetone molecules adsorb exclusively at TiO2 surface, giving rise to a strongly adsorbed (condensed state as well as to the formation of formate- and methyl formate-type surface species. Hydroxyl groups at titania surface participate directly in these adsorption steps. Nanosize gold particles, on the other hand, were primarily responsible for the adsorption and activation of oxygen molecules. Mechanistic aspects of the photochemical processes are discussed on the basis of these observations.

  17. Quantum optical rotatory dispersion

    Science.gov (United States)

    Tischler, Nora; Krenn, Mario; Fickler, Robert; Vidal, Xavier; Zeilinger, Anton; Molina-Terriza, Gabriel

    2016-01-01

    The phenomenon of molecular optical activity manifests itself as the rotation of the plane of linear polarization when light passes through chiral media. Measurements of optical activity and its wavelength dependence, that is, optical rotatory dispersion, can reveal information about intricate properties of molecules, such as the three-dimensional arrangement of atoms comprising a molecule. Given a limited probe power, quantum metrology offers the possibility of outperforming classical measurements. This has particular appeal when samples may be damaged by high power, which is a potential concern for chiroptical studies. We present the first experiment in which multiwavelength polarization-entangled photon pairs are used to measure the optical activity and optical rotatory dispersion exhibited by a solution of chiral molecules. Our work paves the way for quantum-enhanced measurements of chirality, with potential applications in chemistry, biology, materials science, and the pharmaceutical industry. The scheme that we use for probing wavelength dependence not only allows one to surpass the information extracted per photon in a classical measurement but also can be used for more general differential measurements. PMID:27713928

  18. Deep Drawing of High-Strength Tailored Blanks by Using Tailored Tools

    Directory of Open Access Journals (Sweden)

    Thomas Mennecart

    2016-01-01

    Full Text Available In most forming processes based on tailored blanks, the tool material remains the same as that of sheet metal blanks without tailored properties. A novel concept of lightweight construction for deep drawing tools is presented in this work to improve the forming behavior of tailored blanks. The investigations presented here deal with the forming of tailored blanks of dissimilar strengths using tailored dies made of two different materials. In the area of the steel blank with higher strength, typical tool steel is used. In the area of the low-strength steel, a hybrid tool made out of a polymer and a fiber-reinforced surface replaces the steel half. Cylindrical cups of DP600/HX300LAD are formed and analyzed regarding their formability. The use of two different halves of tool materials shows improved blank thickness distribution, weld-line movement and pressure distribution compared to the use of two steel halves. An improvement in strain distribution is also observed by the inclusion of springs in the polymer side of tools, which is implemented to control the material flow in the die. Furthermore, a reduction in tool weight of approximately 75% can be achieved by using this technique. An accurate finite element modeling strategy is developed to analyze the problem numerically and is verified experimentally for the cylindrical cup. This strategy is then applied to investigate the thickness distribution and weld-line movement for a complex geometry, and its transferability is validated. The inclusion of springs in the hybrid tool leads to better material flow, which results in reduction of weld-line movement by around 60%, leading to more uniform thickness distribution.

  19. Tailor-Made Ruthenium-Triphos Catalysts for the Selective Homogeneous Hydrogenation of Lactams.

    Science.gov (United States)

    Meuresch, Markus; Westhues, Stefan; Leitner, Walter; Klankermayer, Jürgen

    2016-01-22

    The development of a tailored tridentate ligand enabled the synthesis of a molecular ruthenium-triphos catalyst, eliminating dimerization as the major deactivation pathway. The novel catalyst design showed strongly increased performance and facilitated the hydrogenation of highly challenging lactam substrates with unprecedented activity and selectivity. PMID:26661531

  20. An Online Tailored Self-Management Program for Patients With Rheumatoid Arthritis: A Developmental Study

    NARCIS (Netherlands)

    Zuidema, R.M.; Gaal, B.G. van; Dulmen, S. van; Repping-Wuts, H.; Schoonhoven, L.

    2015-01-01

    BACKGROUND: Every day rheumatoid arthritis (RA) patients make many decisions about managing their disease. An online, computer-tailored, self-management program can support this decision making, but development of such a program requires the active participation of patients. OBJECTIVE: To develop an

  1. An online tailored self-management program for patients with rheumatoid arthritis: a developmental study.

    NARCIS (Netherlands)

    Zuidema, R.M.; Gaal, B.G.I.; Dulmen, S. van; Repping-Wuts, H.; Schoonhoven, L.

    2015-01-01

    Background: Every day rheumatoid arthritis (RA) patients make many decisions about managing their disease. An online, computer-tailored, self-management program can support this decision making, but development of such a program requires the active participation of patients. Objective: To develop an

  2. Gridcole: A Tailorable Grid Service Based System that Supports Scripted Collaborative Learning

    Science.gov (United States)

    Bote-Lorenzo, Miguel L.; Gomez-Sanchez, Eduardo; Vega-Gorgojo, Guillermo; Dimitriadis, Yannis A.; Asensio-Perez, Juan I.; Jorrin-Abellan, Ivan M.

    2008-01-01

    This paper introduces Gridcole, a new system that can be easily tailored by educators in order to support the realization of scripted collaborative learning situations. To do so, educators can provide a script specifying the sequence of activities to be performed by learners as well as the tools and documents required to support them. Gridcole can…

  3. Photoswitchable molecular dipole antennas with tailored coherent coupling in glassy composite

    DEFF Research Database (Denmark)

    Elbahri, Mady; Zillohu, Ahnaf Usman; Gothe, Bastian;

    2015-01-01

    . We also introduce the concept of 'tailored molecular photonic coupling' while highlighting the role of interferences for the design of optically active media by adjusting the photonic response of the medium with the real and imaginary refractive index of photoswitchable molecules in the 'ON' state...

  4. First-year dam removal activities in the Elwha River - dam removal, sediment dispersal, and fish relocations

    Science.gov (United States)

    Duda, J. J.; McMillan, J. R.; Moses, R.; McHenry, M.; Pess, G. R.; Brenkman, S.; Peters, R.; Zimmerman, M.; Warrick, J. A.; Curran, C. A.; Magirl, C. S.; Beirne, M.; Rubin, S.

    2012-12-01

    After years of anticipation, volumes of Environmental Impact Statements, unprecedented mitigation projects, and the multifaceted collection of pre-dam removal data, the deconstruction phase of the Elwha River restoration project officially began on September 17th, 2011. With their simultaneous decommissioning, the removal of the 64 m tall Glines Canyon Dam and 33 m tall Elwha Dam represents one of the largest such projects of its kind in North America. The nearly 19 million m3 of sediment residing in the dammed reservoirs is being eroded by the river in one of the largest controlled releases of sediment into a river and marine waters in recorded history. The release of sediment and the halting of deconstruction and reservoir draw down activities during "fish windows" are largely determining a deconstruction schedule expected to last about 2 years. High suspended sediment concentrations, modeled to exceed 10,000 mg/L during the highest flows and to exceed 500 mg/L for 39% of the time in year 4 of the project (15% is the recorded background level entering the upper reservoir), could last for up to 3-5 years following dam removal depending on hydrological conditions. Anadromous fish, including three federally listed species (Puget Sound Chinook salmon, steelhead, and bull trout), reside in the river downstream of the Elwha dam for part of their life cycle. All five species of Pacific salmon and steelhead, either locally extirpated (sockeye) or persisting below the impassable Elwha Dam in degraded spawning and rearing habitat, are expected to recolonize the watershed to degrees that will vary spatially and temporally due to life history characteristics and levels of human intervention. During the first year of dam removal, adult coho salmon and steelhead were relocated from areas of high turbidity downstream of the Elwha Dam site to two tributaries upstream, where some of them successfully spawned. Additionally, steelhead were observed to naturally migrate past the

  5. Site-Selective Acylations with Tailor-Made Catalysts.

    Science.gov (United States)

    Huber, Florian; Kirsch, Stefan F

    2016-04-18

    The acylation of alcohols catalyzed by N,N-dimethylamino pyridine (DMAP) is, despite its widespread use, sometimes confronted with substrate-specific problems: For example, target compounds with multiple hydroxy groups may show insufficient selectivity for one hydroxyl, and the resulting product mixtures are hardly separable. Here we describe a concept that aims at tailor-made catalysts for the site-specific acylation. To this end, we introduce a catalyst library where each entry is constructed by connecting a variable and readily tuned peptide scaffold with a catalytically active unit based on DMAP. For selected examples, we demonstrate how library screening leads to the identification of optimized catalysts, and the substrates of interest can be converted with a markedly enhanced site-selectivity compared with only DMAP. Furthermore, substrate-optimized catalysts of this type can be used to selectively convert "their" substrate in the presence of structurally similar compounds, an important requisite for reactions with mixtures of substances. PMID:26970553

  6. Multiscale-tailored bioelectrode surfaces for optimized catalytic conversion efficiency.

    Science.gov (United States)

    Bon Saint Côme, Yémima; Lalo, Hélène; Wang, Zhijie; Etienne, Mathieu; Gajdzik, Janine; Kohring, Gert-Wieland; Walcarius, Alain; Hempelmann, Rolf; Kuhn, Alexander

    2011-10-18

    We describe the elaboration of a multiscale-tailored bioelectrocatalytic system. The combination of two enzymes, D-sorbitol dehydrogenase and diaphorase, is studied with respect to the oxidation of D-sorbitol as a model system. The biomolecules are immobilized in an electrodeposited paint (EDP) layer. Reproducible and efficient catalysis of D-sorbitol oxidation is recorded when this system is immobilized on a gold electrode modified by a self-assembled monolayer of 4-carboxy-(2,5,7-trinitro-9-fluorenylidene)malonitrile used as a mediator. The insertion of mediator-modified gold nanoparticles into the EDP film increases significantly the active surface area for the catalytic reaction, which can be further enhanced when the whole system is immobilized in macroporous gold electrodes. This multiscale architecture finally leads to a catalytic device with optimized efficiency for potential use in biosensors, bioelectrosynthesis, and biofuel cells.

  7. Long-term health outcomes and cost-effectiveness of a computer-tailored physical activity intervention among people aged over fifty : modelling the results of a randomized controlled trial

    NARCIS (Netherlands)

    Peels, Denise A.; Hoogenveen, Rudolf R.; Feenstra, Talitha L.; Golsteijn, Rianne H. J.; Bolman, Catherine; Mudde, Aart N.; Wendel-Vos, Gerrie C. W.; de Vries, Hein; Lechner, Lilian

    2014-01-01

    Background: Physical inactivity is a significant predictor of several chronic diseases, becoming more prevalent as people age. Since the aging population increases demands on healthcare budgets, effectively stimulating physical activity (PA) against acceptable costs is of major relevance. This study

  8. Tailored Patient Information Some Issues and Questions

    CERN Document Server

    Reiter, E R; Reiter, Ehud; Osman, Liesl

    1997-01-01

    Tailored patient information (TPI) systems are computer programs which produce personalised heath-information material for patients. TPI systems are of growing interest to the natural-language generation (NLG) community; many TPI systems have also been developed in the medical community, usually with mail-merge technology. No matter what technology is used, experience shows that it is not easy to field a TPI system, even if it is shown to be effective in clinical trials. In this paper we discuss some of the difficulties in fielding TPI systems. This is based on our experiences with 2 TPI systems, one for generating asthma-information booklets and one for generating smoking-cessation letters.

  9. Betatron radiation from density tailored plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ta Phuoc, Kim; Esarey, E.; Leurent, V.; Cormier-Michel, E.; Geddes, C.G.R.; Schroeder, C.B.; Rousse, A.; Leemans, W.P.

    2009-04-11

    In laser wakefield accelerators, electron motion is driven by intense forces that depend on the plasma density. Transverse oscillations in the accelerated electron orbits produce betatron radiation. The electron motion and the resulting betatron radiation spectrum can therefore be controlled by shaping the plasma density along the orbit of the electrons. Here, a method based on the use of a plasma with a longitudinal density variation (density depression or step) is proposed to increase the transverse oscillation amplitude and the energy of the electrons accelerated in a wakefield cavity. For fixed laser parameters, by appropriately tailoring the plasma profile, the betatron radiation emitted by these electrons is significantly increased in both flux and energy.

  10. Tailored vacuum chambers for ac magnets

    International Nuclear Information System (INIS)

    The proposed LAMPF-II accelerator has a 60-Hz booster synchrotron and a 3-Hz main ring. To provide a vacuum enclosure inside the magnets with low eddy-current losses and minimal field distortion, yet capable of carrying rf image currents and providing beam stabilization, we propose an innovative combination pipe. Structurally, the enclosure is high-purity alumina ceramic, which is strong, radiation resistant, and has good vacuum properties. Applied to the chamber are thin, spaced, silver conductors using adapted thick-film technology. The conductor design can be tailored to the stabilization requirements, for example, longitudinal conductors for image currents, circumferential for transverse stabilization. The inside of the chamber has a thin, resistive coating to avoid charge build-up. The overall 60-Hz power loss is less than 100 W/m

  11. Tailoring superradiance to design artificial quantum systems

    Science.gov (United States)

    Longo, Paolo; Keitel, Christoph H.; Evers, Jörg

    2016-03-01

    Cooperative phenomena arising due to the coupling of individual atoms via the radiation field are a cornerstone of modern quantum and optical physics. Recent experiments on x-ray quantum optics added a new twist to this line of research by exploiting superradiance in order to construct artificial quantum systems. However, so far, systematic approaches to deliberately design superradiance properties are lacking, impeding the desired implementation of more advanced quantum optical schemes. Here, we develop an analytical framework for the engineering of single-photon superradiance in extended media applicable across the entire electromagnetic spectrum, and show how it can be used to tailor the properties of an artificial quantum system. This “reverse engineering” of superradiance not only provides an avenue towards non-linear and quantum mechanical phenomena at x-ray energies, but also leads to a unified view on and a better understanding of superradiance across different physical systems.

  12. Tailoring superradiance to design artificial quantum systems.

    Science.gov (United States)

    Longo, Paolo; Keitel, Christoph H; Evers, Jörg

    2016-03-24

    Cooperative phenomena arising due to the coupling of individual atoms via the radiation field are a cornerstone of modern quantum and optical physics. Recent experiments on x-ray quantum optics added a new twist to this line of research by exploiting superradiance in order to construct artificial quantum systems. However, so far, systematic approaches to deliberately design superradiance properties are lacking, impeding the desired implementation of more advanced quantum optical schemes. Here, we develop an analytical framework for the engineering of single-photon superradiance in extended media applicable across the entire electromagnetic spectrum, and show how it can be used to tailor the properties of an artificial quantum system. This "reverse engineering" of superradiance not only provides an avenue towards non-linear and quantum mechanical phenomena at x-ray energies, but also leads to a unified view on and a better understanding of superradiance across different physical systems.

  13. Tailoring Accelerating Beams in Phase Space

    CERN Document Server

    Wen, Yuanhui; Zhang, Yanfeng; Chen, Hui; Yu, Siyuan

    2016-01-01

    An appropriate design of wavefront will enable light fields propagating along arbitrary trajectories thus forming accelerating beams in free space. Previous ways of designing such accelerating beams mainly rely on caustic methods, which start from diffraction integrals and only deal with two-dimensional fields. Here we introduce a new perspective to construct accelerating beams in phase space by designing the corresponding Wigner distribution function (WDF). We find such a WDF-based method is capable of providing both the initial field distribution and the angular spectrum in need by projecting the WDF into the real space and the Fourier space respectively. Moreover, this approach applies to the construction of both two- and three-dimensional fields, greatly generalizing previous caustic methods. It may therefore open up a new route to construct highly-tailored accelerating beams and facilitate applications ranging from particle manipulation and trapping to optical routing as well as material processing.

  14. Development of patient-centric linguistically tailored psychoeducational messages to support nutrition and medication self-management in type 2 diabetes: a feasibility study

    Science.gov (United States)

    Ellis, Rebecca J Bartlett; Connor, Ulla; Marshall, James

    2014-01-01

    with the ultimate goal to design intervention studies to investigate if linguistically tailoring communication within the context of patient education influences patient knowledge, motivation, and activation toward making healthy behavior changes in T2DM self-management. PMID:25336928

  15. White light emitting diodes realized by using an active packaging method with CdSe/ZnS quantum dots dispersed in photosensitive epoxy resins

    Science.gov (United States)

    Wang, Hao; Lee, Kyu-Seung; Ryu, Jae-Hyoung; Hong, Chang-Hee; Cho, Yong-Hoon

    2008-04-01

    White light emitting diodes (LEDs) have been realized using the active packaging (AP) method. The starting materials were bare InGaN LED chips and CdSe/ZnS core-shell quantum dots (QDs) dispersed in photosensitive epoxy resins. Such hybrid LED devices were fabricated using QD mixtures with one ('single'), two ('dual') or four ('multi') emission wavelengths. The AP method allows for convenient adjustment of multiple parameters such as the CIE-1931 coordinate (x, y), color temperature, and color rending index (CRI). All samples show good white balance, and under a 20 mA working current the luminous efficacies of the single, dual, and multi hybrid devices were 8.1 lm W-1, 5.1 lm W-1, and 6.4 lm W-1, respectively. The corresponding quantum efficiencies were 4.1%, 3.1%, and 3.1%; the CRIs were 21.46, 43.76, and 66.20; and the color temperatures were 12 000, 8190, and 7740 K. This shows that the CRI of the samples can be enhanced by broadening the QD emission band, as is exemplified by the 21.46 CRI of the single hybrid LED compared to the 66.20 value for the multi hybrid LED. In addition, we were able to increase the CRI of the single hybrid LED from 15.31 to 32.50 by increasing the working currents from 1 to 50 mA.

  16. The remarkable activity and stability of a highly dispersive beta-brass Cu-Zn catalyst for the production of ethylene glycol

    Science.gov (United States)

    Li, Molly Meng-Jung; Zheng, Jianwei; Qu, Jin; Liao, Fenglin; Raine, Elizabeth; Kuo, Winson C. H.; Su, Shei Sia; Po, Pang; Yuan, Youzhu; Tsang, Shik Chi Edman

    2016-02-01

    Incorporation of Zn atoms into a nanosize Cu lattice is known to alter the electronic properties of Cu, improving catalytic performance in a number of industrially important reactions. However the structural influence of Zn on the Cu phase is not well studied. Here, we show that Cu nano-clusters modified with increasing concentration of Zn, derived from ZnO support doped with Ga3+, can dramatically enhance their stability against metal sintering. As a result, the hydrogenation of dimethyl oxalate (DMO) to ethylene glycol, an important reaction well known for deactivation from copper nanoparticle sintering, can show greatly enhanced activity and stability with the CuZn alloy catalysts due to no noticeable sintering. HRTEM, nano-diffraction and EXAFS characterization reveal the presence of a small beta-brass CuZn alloy phase (body-centred cubic, bcc) which appears to greatly stabilise Cu atoms from aggregation in accelerated deactivation tests. DFT calculations also indicate that the small bcc CuZn phase is more stable against Cu adatom migration than the fcc CuZn phase with the ability to maintain a higher Cu dispersion on its surface.

  17. The remarkable activity and stability of a highly dispersive beta-brass Cu-Zn catalyst for the production of ethylene glycol

    Science.gov (United States)

    Li, Molly Meng-Jung; Zheng, Jianwei; Qu, Jin; Liao, Fenglin; Raine, Elizabeth; Kuo, Winson C. H.; Su, Shei Sia; Po, Pang; Yuan, Youzhu; Tsang, Shik Chi Edman

    2016-01-01

    Incorporation of Zn atoms into a nanosize Cu lattice is known to alter the electronic properties of Cu, improving catalytic performance in a number of industrially important reactions. However the structural influence of Zn on the Cu phase is not well studied. Here, we show that Cu nano-clusters modified with increasing concentration of Zn, derived from ZnO support doped with Ga3+, can dramatically enhance their stability against metal sintering. As a result, the hydrogenation of dimethyl oxalate (DMO) to ethylene glycol, an important reaction well known for deactivation from copper nanoparticle sintering, can show greatly enhanced activity and stability with the CuZn alloy catalysts due to no noticeable sintering. HRTEM, nano-diffraction and EXAFS characterization reveal the presence of a small beta-brass CuZn alloy phase (body-centred cubic, bcc) which appears to greatly stabilise Cu atoms from aggregation in accelerated deactivation tests. DFT calculations also indicate that the small bcc CuZn phase is more stable against Cu adatom migration than the fcc CuZn phase with the ability to maintain a higher Cu dispersion on its surface. PMID:26856760

  18. Physical parameters of late M-type members of Chamaleon I and TW Hydrae Association: Dust settling, age dispersion and activity

    CERN Document Server

    Bayo, A; Allard, F; Henning, T; Comeron, F; Morales-Calderon, M; Rajpurohit, A S; Ramırez, K Pena; Beamın, J C

    2016-01-01

    Although mid-to-late type M dwarfs are the most common stars in our stellar neighborhood, our knowledge of these objects is still limited. Open questions include the evolution of their angular momentum, internal structures, dust settling in their atmospheres, age dispersion within populations. In addition, at young ages, late-type Ms have masses below the hydrogen burning limit and therefore are key objects in the debate on the brown dwarf mechanism of formation. In this work we determine and study in detail the physical parameters of two samples of young, late M-type sources belonging to either the Chamaeleon I Dark Cloud or the TW Hydrae Association and compare them with the results obtained in the literature for other young clusters and also for older, field, dwarfs. We used multi-wavelength photometry to construct and analyze SEDs to determine general properties of the photosphere and disk presence. We also used low resolution optical and near-infrared spectroscopy to study activity, accretion, gravity an...

  19. Tailoring buckybowls for fullerene recognition. A dispersion-corrected DFT study.

    Science.gov (United States)

    Josa, Daniela; González-Veloso, Iván; Rodríguez-Otero, Jesús; Cabaleiro-Lago, Enrique M

    2015-03-01

    A series of buckybowls with different sizes and structures have been tested as potential receptors of fullerenes C60, C70 and C40. Among these bowls are corannulene (C20H10), sumanene (C21H12), pinakene (C28H14), hemifullerene (C30H12), circumtrindene (C36H12), pentaindenocorannulene (C50H20) and bowl-shaped hexabenzocoronene derivatives. An exhaustive study, taking into account different orientations of fullerenes, was performed in order to obtain the most favourable arrangement for interacting with the bowls. Complexes were optimised at the SCC-DFTB-D level and interaction energies were obtained at the B97-D2/TZVP level including BSSE corrections. Comparison with the full B97-D2/TZVP results (optimisation plus interaction energies) suggests that the B97-D2/TZVP//SCC-DFTB-D approach may be a useful screening tool for designing fullerene receptors. Regarding the "catching" ability of the different buckybowls, it can be concluded that the shape of a buckybowl plays a crucial role in its success. Thus, it seems that the addition of flaps at the bowl rim by benzannelation is an effective strategy for enhancing the interaction with fullerenes, providing enough flexibility to extend the contact surface with the fullerene moiety. Accordingly, a bowl-shaped hexabenzocoronene derivative (C72H24) showed the best ability among the buckybowls evaluated for catching the fullerenes C60, C70 and C40; it is noteworthy that, when interacting with C60, the interaction energy is three times that corresponding to the prototypical buckybowl, corannulene. On the contrary, the more rigid and compact is the structure of a buckybowl, the smaller its ability to interact with fullerenes.

  20. Dispersal of the Japanese pine sawyer, Monochamus alternatus (Coleoptera: Cerambycidae), in mainland China as inferred from molecular data and associations to indices of human activity.

    Science.gov (United States)

    Hu, Shao-ji; Ning, Tiao; Fu, Da-ying; Haack, Robert A; Zhang, Zhen; Chen, De-dao; Ma, Xue-yu; Ye, Hui

    2013-01-01

    The Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae), is an important forest pest as well as the principal vector of the pinewood nematode (PWN), Bursaphelenchus xylophilus (Steiner et Buhrer), in mainland China. Despite the economic importance of this insect-disease complex, only a few studies are available on the population genetic structure of M. alternatus and the relationship between its historic dispersal pattern and various human activities. The aim of the present study was to further explore aspects of human activity on the population genetic structure of M. alternatus in mainland China. The molecular data based on the combined mitochondrial cox1 and cox2 gene fragments from 140 individuals representing 14 Chinese populations yielded 54 haplotypes. Overall, a historical (natural) expansion that originated from China's eastern coast to the western interior was revealed by the haplotype network, as well as several recent, long-distant population exchanges. Correlation analysis suggested that regional economic status and proximity to marine ports significantly influenced the population genetic structure of M. alternatus as indicated by both the ratio of shared haplotypes and the haplotype diversity, however, the PWN distribution in China was significantly correlated with only the ratio of shared haplotypes. Our results suggested that the modern logistical network (i.e., the transportation system) in China is a key medium by which humans have brought about population exchange of M. alternatus in mainland China, likely through inadvertent movement of infested wood packaging material associated with trade, and that this genetic exchange was primarily from the economically well-developed east coast of China, westward, to the less-developed interior. In addition, this study demonstrated the existence of non-local M. alternatus in new PWN-infested localities in China, but not all sites with non-local M. alternatus were infested with PWN

  1. Dispersal of the Japanese pine sawyer, Monochamus alternatus (Coleoptera: Cerambycidae, in mainland China as inferred from molecular data and associations to indices of human activity.

    Directory of Open Access Journals (Sweden)

    Shao-ji Hu

    Full Text Available The Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae, is an important forest pest as well as the principal vector of the pinewood nematode (PWN, Bursaphelenchus xylophilus (Steiner et Buhrer, in mainland China. Despite the economic importance of this insect-disease complex, only a few studies are available on the population genetic structure of M. alternatus and the relationship between its historic dispersal pattern and various human activities. The aim of the present study was to further explore aspects of human activity on the population genetic structure of M. alternatus in mainland China. The molecular data based on the combined mitochondrial cox1 and cox2 gene fragments from 140 individuals representing 14 Chinese populations yielded 54 haplotypes. Overall, a historical (natural expansion that originated from China's eastern coast to the western interior was revealed by the haplotype network, as well as several recent, long-distant population exchanges. Correlation analysis suggested that regional economic status and proximity to marine ports significantly influenced the population genetic structure of M. alternatus as indicated by both the ratio of shared haplotypes and the haplotype diversity, however, the PWN distribution in China was significantly correlated with only the ratio of shared haplotypes. Our results suggested that the modern logistical network (i.e., the transportation system in China is a key medium by which humans have brought about population exchange of M. alternatus in mainland China, likely through inadvertent movement of infested wood packaging material associated with trade, and that this genetic exchange was primarily from the economically well-developed east coast of China, westward, to the less-developed interior. In addition, this study demonstrated the existence of non-local M. alternatus in new PWN-infested localities in China, but not all sites with non-local M. alternatus were

  2. What’s in a Surname? Physique, Aptitude, and Sports Type Comparisons between Tailors and Smiths

    Science.gov (United States)

    Voracek, Martin; Rieder, Stephan; Stieger, Stefan; Swami, Viren

    2015-01-01

    Combined heredity of surnames and physique, coupled with past marriage patterns and trade-specific physical aptitude and selection factors, may have led to differential assortment of bodily characteristics among present-day men with specific trade-reflecting surnames (Tailor vs. Smith). Two studies reported here were partially consistent with this genetic-social hypothesis, first proposed by Bäumler (1980). Study 1 (N = 224) indicated significantly higher self-rated physical aptitude for prototypically strength-related activities (professions, sports, hobbies) in a random sample of Smiths. The counterpart effect (higher aptitude for dexterity-related activities among Tailors) was directionally correct, but not significant, and Tailor-Smith differences in basic physique variables were nil. Study 2 examined two large total-population-of-interest datasets (Austria/Germany combined, and UK: N = 7001 and 20532) of men’s national high-score lists for track-and-field events requiring different physiques. In both datasets, proportions of Smiths significantly increased from light-stature over medium-stature to heavy-stature sports categories. The predicted counterpart effect (decreasing prevalences of Tailors along these categories) was not supported. Related prior findings, the viability of possible alternative interpretations of the evidence (differential positive selection for trades and occupations, differential endogamy and assortative mating patterns, implicit egotism effects), and directions for further inquiry are discussed in conclusion. PMID:26161803

  3. Tailorable software architectures in the accelerator control system environment

    Science.gov (United States)

    Mejuev, Igor; Kumagai, Akira; Kadokura, Eiichi

    2001-08-01

    Tailoring is further evolution of an application after deployment in order to adapt it to requirements that were not accounted for in the original design. End-user tailorability has been extensively researched in applied computer science from HCl and software engineering perspectives. Tailorability allows coping with flexibility requirements, decreasing maintenance and development costs of software products. In general, dynamic or diverse software requirements constitute the need for implementing end-user tailorability in computer systems. In accelerator physics research the factor of dynamic requirements is especially important, due to frequent software and hardware modifications resulting in correspondingly high upgrade and maintenance costs. In this work we introduce the results of feasibility study on implementing end-user tailorability in the software for accelerator control system, considering the design and implementation of distributed monitoring application for 12 GeV KEK Proton Synchrotron as an example. The software prototypes used in this work are based on a generic tailoring platform (VEDICI), which allows decoupling of tailoring interfaces and runtime components. While representing a reusable application-independent framework, VEDICI can be potentially applied for tailoring of arbitrary compositional Web-based applications.

  4. Tailored cognitive-behavioral therapy for fibromyalgia: two case studies.

    NARCIS (Netherlands)

    Koulil, S. van; Lankveld, W. van; Kraaimaat, F.W.; Helmond, T. van; Vedder, A.; Hoorn, H. van; Cats, H.; Riel, P.L.C.M. van; Evers, A.W.

    2008-01-01

    OBJECTIVE: To illustrate a multidisciplinary group treatment for patients with fibromyalgia (FM) tailored to the patient's cognitive-behavioral pattern. METHOD: In a case-study design the tailored treatment approaches of two FM patients were described. One patient characterized by avoidance behavior

  5. Building Tailorable Hypermedia Systems: The embedded-interpreter approach

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Malhotra, Jawahar

    1994-01-01

    This paper discusses an approach for developing dynamically tailorable hypermedia systems in an object-oriented environment. The approach is aimed at making applications developed in compiled languages like Beta and C++ tailorable at run-time. The approach is based on use of: 1) a hypermedia appl...

  6. Dispersing powders in liquids

    CERN Document Server

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  7. Influences of urea–glycerol mixtures as mixed mesopore-controlling agents on tailoring physicochemical properties and photocatalytic H{sub 2} production activity of sol–gel-derived mesoporous-assembled TiO{sub 2} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Sreethawong, Thammanoon, E-mail: sreethawongt@imre.a-star.edu.sg [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); Ngamsinlapasathian, Supachai, E-mail: wonone@hotmail.com [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan); Yoshikawa, Susumu [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2013-01-15

    Graphical abstract: Display Omitted Highlights: ► Mesoporous-assembled TiO{sub 2} nanocrystals were synthesized by modified sol–gel process. ► Urea–glycerol mixtures were applied as mixed mesopore-controlling agents. ► Urea and glycerol contents affected physicochemical properties of synthesized TiO{sub 2}. ► Photocatalytic H{sub 2} production activity also depended on urea and glycerol contents. ► 75 mol% urea and 25 mol% glycerol yielded the most photocatalytically active TiO{sub 2}. -- Abstract: In this work, the mesoporous-assembled TiO{sub 2} nanocrystal photocatalysts were successfully synthesized by a sol–gel process with the aid of urea–glycerol mixtures used as mixed mesopore-controlling agents. The photocatalytic activity of the synthesized mesoporous-assembled TiO{sub 2} nanocrystal photocatalysts was investigated for hydrogen production from the water splitting reaction using methanol as a hole scavenger under UV light irradiation. The synthesized TiO{sub 2} nanocrystal photocatalysts were systematically characterized by TG–DTA, N{sub 2} adsorption–desorption, SEM, high resolution TEM, and XRD analyses. The characterization results showed that the well-controlled contents of urea and glycerol in a urea–glycerol mixture at 75 mol% urea and 25 mol% glycerol resulted in not only the most highly porous network (i.e. the highest specific surface area and total pore volume, and the smallest mean mesopore diameter), but also the smallest crystallite size of the synthesized TiO{sub 2} nanocrystal photocatalyst. The photocatalytic reaction results, hence, revealed a much superior photocatalytic hydrogen production activity of the mesoporous-assembled TiO{sub 2} nanocrystal synthesized with 75 mol% urea and 25 mol% glycerol to the other synthesized TiO{sub 2} nanocrystals, also being much higher than those of the commercially available P-25 TiO{sub 2} and ST-01 TiO{sub 2} powders.

  8. Dispersion y dinamica poblacional

    Science.gov (United States)

    Dispersal behavior of fruit flies is appetitive. Measures of dispersion involve two different parameter: the maximum distance and the standard distance. Standard distance is a parameter that describes the probalility of dispersion and is mathematically equivalent to the standard deviation around ...

  9. Toward Tailored All-Spin Molecular Devices.

    Science.gov (United States)

    Bazarnik, Maciej; Bugenhagen, Bernhard; Elsebach, Micha; Sierda, Emil; Frank, Annika; Prosenc, Marc H; Wiesendanger, Roland

    2016-01-13

    Molecular based spintronic devices offer great potential for future energy-efficient information technology as they combine ultimately small size, high-speed operation, and low-power consumption. Recent developments in combining atom-by-atom assembly with spin-sensitive imaging and characterization at the atomic level have led to a first prototype of an all-spin atomic-scale logic device, but the very low working temperature limits its application. Here, we show that a more stable spintronic device could be achieved using tailored Co-Salophene based molecular building blocks, combined with in situ electrospray deposition under ultrahigh vacuum conditions as well as control of the surface-confined molecular assembly at the nanometer scale. In particular, we describe the tools to build a molecular, strongly bonded device structure from paramagnetic molecular building blocks including spin-wires, gates, and tails. Such molecular device concepts offer the advantage of inherent parallel fabrication based on molecular self-assembly as well as an order of magnitude higher operation temperatures due to enhanced energy scales of covalent through-bond linkage of basic molecular units compared to substrate-mediated coupling schemes employing indirect exchange coupling between individual adsorbed magnetic atoms on surfaces. PMID:26704349

  10. Facile Preparation of Optically Tailored Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Susana Fernández de Ávila

    2014-01-01

    Full Text Available Lead sulfide nanoparticles (PbS NPs have been synthesized directly in poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV semiconducting polymer by a simple low temperature method. Hybrid solutions with different concentrations of PbS with respect to the polymer have been prepared and characterized first in solution and then as thin film nanocomposites deposited on quartz substrates by spin coating. Quenching of photoluminescence emission is observed both in solutions and thin films when the ratio of PbS NPs increases with respect to the polymer, suggesting the occurrence of Dexter energy transfer from the polymer to the PbS NPs. Optical absorption is markedly increased for hybrid solutions compared to pure polymer. In thin nanocomposite films an enhancement of absorbance is observed with increasing PbS NPs concentration, which is more pronounced below 400 nm. The reported results could lead to the development of a method for tailoring the optical response of devices based on PbS NP-polymer nanocomposite by controlling the PbS NP concentration inside the polymer matrix.

  11. Does tailoring really make a difference? : the development and evaluation of tailored interventions aimed at benzodiazepine cessation

    NARCIS (Netherlands)

    Wolde, Geeske Brecht ten

    2008-01-01

    Because of the problems associated with chronic benzodiazepine use, there is impetus to prevent and reduce chronic benzodiazepine use. The overall aim was to develop a 'tailor-made' intervention in order to reduce chronic use. Before developing tailored patient education, it is first of all importan

  12. Effectiveness of activated carbon disk for the analysis of iodine in water samples using wavelength dispersive X-ray fluorescence spectrometry.

    Science.gov (United States)

    Lee, Junseok; An, Jinsung; Kim, Joo-Ae; Yoon, Hye-On

    2016-01-01

    A novel approach using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry combined with an activated carbon (AC) disk was developed for the determination of total iodine concentrations in water samples. Dissolved iodine species (i.e., I(-) and IO3(-)) in water samples were preconcentrated on the AC disk and directly analyzed by WDXRF spectrometry. The adsorption behavior of I(-) and IO3(-) on the AC disk was assessed at varying pH levels (4, 6, and 8). The AC disks completely retained the I(-) and IO3(-) for all the pH levels tested. The calibration curve obtained from the iodine concentrations (i.e., 0, 20, 200, and 400 μg) of AC disks and the measured X-ray intensity from the WDXRF analysis showed a good linearity (R(2)=0.9960), with a relatively low limit of detection (0.575 μg). The durability of the AC disk for repeatable measurements was also assessed to validate the sustainability of the proposed method and consequently the measured X-ray intensity for the AC disks was constant until 8d of analysis time. The accuracy of the proposed AC-WDXRF method was confirmed by measuring iodine concentration spiked in drinking water using inductively coupled plasma-mass spectrometry (ICP-MS). The proposed method is simple, rapid, efficient, and environmental friendly for iodine analysis in water samples. As a precursor of disinfection by products (DBPs), it is important to determine the total iodine concentrations in raw water.

  13. Dispersion-induced nonlinearities in semiconductors

    DEFF Research Database (Denmark)

    Mørk, Jesper; Mecozzi, A.

    2002-01-01

    A dispersive and saturable medium is shown, under very general conditions, to possess ultrafast dynamic behaviour due to non-adiabatic polarisation dynamics. Simple analytical expressions relating the effect to the refractive index dispersion of a semiconductor ire derived and the magnitude of the...... equivalent Kerr coefficient is shown to be in qualitative agreement with measurements on active semiconductor waveguides....

  14. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang, E-mail: gfzhang@snnu.edu.cn; Gao, Ziwei, E-mail: zwgao@snnu.edu.cn

    2015-01-15

    A successive anchoring of Ti(NMe{sub 2}){sub 4}, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, {sup 13}C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, {sup 13}C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated.

  15. Thin tailored composite wing for civil tiltrotor

    Science.gov (United States)

    Rais-Rohani, Masoud

    1994-01-01

    The tiltrotor aircraft is a flight vehicle which combines the efficient low speed (i.e., take-off, landing, and hover) characteristics of a helicopter with the efficient cruise speed of a turboprop airplane. A well-known example of such vehicle is the Bell-Boeing V-22 Osprey. The high cruise speed and range constraints placed on the civil tiltrotor require a relatively thin wing to increase the drag-divergence Mach number which translates into lower compressibility drag. It is required to reduce the wing maximum thickness-to-chord ratio t/c from 23% (i.e., V-22 wing) to 18%. While a reduction in wing thickness results in improved aerodynamic efficiency, it has an adverse effect on the wing structure and it tends to reduce structural stiffness. If ignored, the reduction in wing stiffness leads to susceptibility to aeroelastic and dynamic instabilities which may consequently cause a catastrophic failure. By taking advantage of the directional stiffness characteristics of composite materials the wing structure may be tailored to have the necessary stiffness, at a lower thickness, while keeping the weight low. The goal of this study is to design a wing structure for minimum weight subject to structural, dynamic and aeroelastic constraints. The structural constraints are in terms of strength and buckling allowables. The dynamic constraints are in terms of wing natural frequencies in vertical and horizontal bending and torsion. The aeroelastic constraints are in terms of frequency placement of the wing structure relative to those of the rotor system. The wing-rotor-pylon aeroelastic and dynamic interactions are limited in this design study by holding the cruise speed, rotor-pylon system, and wing geometric attributes fixed. To assure that the wing-rotor stability margins are maintained a more rigorous analysis based on a detailed model of the rotor system will need to ensue following the design study. The skin-stringer-rib type architecture is used for the wing

  16. Tailoring electronic structure of polyazomethines thin films

    Directory of Open Access Journals (Sweden)

    J. Weszka

    2010-09-01

    Full Text Available Purpose: The aim of this work is to show how electronic properties of polyazomethine thin films deposited by chemical vapor deposition method (CVD can be tailored by manipulating technological parameters of pristine films preparation as well as modifying them while the as-prepared films put into iodine atmosphere.Design/methodology/approach: The recent achievements in the field of designing and preparation methods to be used while preparing polymer photovoltaic solar cells or optoelectronic devices.Findings: The method used allow for pure pristine polymer thin films to be prtepared without any unintentional doping taking place during prepoaration methods. This is a method based on polycondensation process, where polymer chain developing is running directly due to chemical reaction between molecules of bifunctional monomers. The method applied to prepare thin films of polyazomethines takes advantage of monomer transporting by mreans of neutral transport agent as pure argon is.Research limitations/implications: The main disadvantage of alternately conjugated polymers seems to be quite low mobility of charge carrier that is expected to be a consequence of their backbone being built up of sp2 hybridized carbon and nitrogen atoms. Varying technological conditions towards increasing reagents mass transport to the substrate is expected to give such polyazomethine thin films organization that phenylene rin stacking can result in special π electron systems rather than linear ones as it is the case.Originality/value: Our results supply with original possibilities which can be useful in ooking for good polymer materials for optoelectronic and photovoltaic applications. These results have been gained on polyazomethine thin films but their being isoelectronic counterpart to widely used poly p-phenylene vinylene may be very convenient to develop high efficiency polymer solar cells

  17. Comparing tailored and untailored text messages for smoking cessation

    DEFF Research Database (Denmark)

    Skov-Ettrup, Lise; Ringgaard, L W; Dalum, Peter;

    2014-01-01

    The aim was to compare the effectiveness of untailored text messages for smoking cessation to tailored text messages delivered at a higher frequency. From February 2007 to August 2009, 2030 users of an internet-based smoking cessation program with optional text message support aged 15-25 years were...... consecutively randomized to versions of the program that offered either tailored or untailored text messages. Thirty-day point abstinence from smoking was measured self-reportedly at 12-months follow-up. Response rates were 36.3% and 38.1% in the tailored and untailored group, respectively. We analyzed...

  18. Engineering Property Prediction Tools for Tailored Polymer Composite Structures

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Foss, Peter; Wyzgoski, Michael; Trantina, Gerry; Kunc, Vlastimil; Schutte, Carol; Smith, Mark T.

    2009-12-23

    This report summarizes our FY 2009 research activities for the project titled:"Engineering Property Prediction Tools for Tailored Polymer Composite Structures." These activities include (i) the completion of the development of a fiber length attrition model for injection-molded long-fiber thermoplastics (LFTs), (ii) development of the a fatigue damage model for LFTs and its implementation in ABAQUS, (iii) development of an impact damage model for LFTs and its implementation in ABAQUS, (iv) development of characterization methods for fatigue testing, (v) characterization of creep and fatigue responses of glass-fiber/polyamide (PA6,6) and glass-fiber/polypropylene (PP), (vi) characterization of fiber length distribution along the flow length of glass/PA6,6 and glass-fiber/PP, and (vii) characterization of impact responses of glass-fiber/PA6,6. The fiber length attrition model accurately captures the fiber length distribution along the flow length of the studied glass-fiber/PP material. The fatigue damage model is able to predict the S-N and stiffness reduction data which are valuable to the fatigue design of LFTs. The impact damage model correctly captures damage accumulation observed in experiments of glass-fiber/PA6,6 plaques.Further work includes validations of these models for representative LFT materials and a complex LFT part.

  19. Milk protein tailoring to improve functional and biological properties

    Directory of Open Access Journals (Sweden)

    JEAN-MARC CHOBERT

    2012-01-01

    Full Text Available Proteins are involved in every aspects of life: structure, motion, catalysis, recognition and regulation. Today's highly sophisticated science of the modifications of proteins has ancient roots. The tailoring of proteins for food and medical uses precedes the beginning of what is called biochemistry. Chemical modification of proteins was pursued early in the twentieth century as an analytical procedure for side-chain amino acids. Later, methods were developed for specific inactivation of biologically active proteins and titration of their essential groups. Enzymatic modifications were mainly developed in the seventies when many more enzymes became economically available. Protein engineering has become a valuable tool for creating or improving proteins for practical use and has provided new insights into protein structure and function. The actual and potential use of milk proteins as food ingredients has been a popular topic for research over the past 40 years. With today's sophisticated analytical, biochemical and biological research tools, the presence of compounds with biological activity has been demonstrated. Improvements in separation techniques and enzyme technology have enabled efficient and economic isolation and modification of milk proteins, which has made possible their use as functional foods, dietary supplements, nutraceuticals and medical foods. In this review, some chemical and enzymatic modifications of milk proteins are described, with particular focus on their functional and biological properties.

  20. Determination of nine sensitizing disperse dyes in activated sludge by ultrasound-assisted liquid-liquid extraction-ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Linjun; Shi, Lili; Liu, Jining; Lv, Fenglan; Xu, Yanhua

    2016-01-01

    A method was developed on the basis of ultrasound-assisted liquid-liquid extraction ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (ULLE-UPLC-ESI-MS/MS) to determine nine sensitizing disperse dyes in activated sludge. The samples were extracted using ULLE and separated through UPLC on an ACQUITY UPLCTM BEH C18 column with a gradient elution program of acetonitrile and acidified water (containing 2% acetonitrile, 0.2% formic acid, and 0.005 mol/L ammonium; pH 2.7) as the mobile phase. The samples were then identified and quantified through UPLC-ESI-MS/MS in a positive mode and multiple reaction monitoring. Results showed good linearity (10-1000 μg/L, 0.9934-0.9998), detection limit (0.08-2.17 μg/L), and quantification limit (0.27-7.38 μg/L) for the nine sensitizing disperse dyes, with recoveries ranging from 65.0 to 111.3%. The proposed method was applied to detect and determine the concentration of sensitizing disperse dyes in sludge samples obtained from various sewage treatment plants (six dyeing enterprises and one dye manufacturer). Three sensitizing disperse dyes were identified, and the lowest concentration detected was 10 μg/kg. PMID:26521175

  1. Past, present, and future of computer-tailored nutrition education

    NARCIS (Netherlands)

    J. Brug (Hans); A. Oenema (Anke); M.K. Campbell (Marci)

    2003-01-01

    textabstractComputer-tailored nutrition education is an innovative and promising tool to motivate people to make healthy dietary changes. It provides respondents with individualized feedback about their dietary behaviors, motivations, attitudes, norms, and skills and mimics the pro

  2. Tailored Materials for High Efficiency CIDI Engines

    Energy Technology Data Exchange (ETDEWEB)

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  3. Semiconductor quantum optics with tailored photonic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Laucht, Arne

    2011-06-15

    single photon emission into the waveguide. The results obtained during the course of this thesis contribute significantly to the understanding of coupling phenomena between excitons in self-assembled quantum dots and optical modes of tailored photonic nanostructures realized on the basis of two-dimensional photonic crystals. While we highlight the potential for advanced applications in the direction of quantum optics and quantum computation, we also identify some of the challenges which will need to be overcome on the way. (orig.)

  4. Semiconductor quantum optics with tailored photonic nanostructures

    International Nuclear Information System (INIS)

    the understanding of coupling phenomena between excitons in self-assembled quantum dots and optical modes of tailored photonic nanostructures realized on the basis of two-dimensional photonic crystals. While we highlight the potential for advanced applications in the direction of quantum optics and quantum computation, we also identify some of the challenges which will need to be overcome on the way. (orig.)

  5. Dispersant field monitoring procedures

    Energy Technology Data Exchange (ETDEWEB)

    Hillman, S. O.; Hood, S. D. [Alyeska Pipeline Service Co. (United States); Bronson, M. T.; Shufelt, G. [EMCON, Alaska,Inc., Anchorage, AK (United States)

    1997-10-01

    Alyeska Pipeline Service Company`s (APSC) dispersant response capability in the Port of Valdez, Prince William Sound, and in the Gulf of Alaska was described. APSC provides dispersal equipment, aerial spray delivery systems, helibucket delivery systems, vessel delivery systems, along with a minimum of 600,000 gallon stockpile of the dispersant Corexit 9527. Effectiveness and effects are monitored by visual observation. In addition, fluorometer and water sample analysis are also used to provide field analytical data indicative of the environmental effects of dispersant applications. The field monitoring plan was field tested in December 1996. Details of the monitoring procedures are outlined in this paper. 18 refs., 5 tabs.

  6. A Brief Culturally Tailored Intervention for Puerto Ricans with Type 2 Diabetes

    OpenAIRE

    Osborn, Chandra Y; Amico, K Rivet; Cruz, Noemi; O’Connell, Ann A.; Perez-Escamilla, Rafael; Kalichman, Seth C.; Wolf, Scott A.; Fisher, Jeffrey D.

    2010-01-01

    The Information-Motivation-Behavioral Skills (IMB) model of health behavior change informed the design of a brief, culturally-tailored diabetes self-care intervention for Puerto Ricans with Type 2 diabetes. Participants (n = 118) were recruited from an outpatient, primary care clinic at an urban hospital in the northeast U.S. ANCOVA models evaluated intervention effects on food label reading, diet adherence, physical activity, and glycemic control (HbA1c). At follow-up, the intervention group...

  7. Insights in the Efficacy of Computer-tailored Nutrition Education

    OpenAIRE

    Kroeze, Willemieke

    2008-01-01

    textabstractSaturated fat intake is an important risk factor for cardiovascular diseases, one of the main burdens of disease worldwide. Therefore it is important to use population-wide health promotion efforts to target this risk behavior. Computer-tailored nutrition education has been found to be a very promising health education strategy that can be applied in population health promotion. However, several questions remained unanswered on why, where and for whom computer-tailored (nutrition)...

  8. Multiscale Surface-Attached Hydrogel Thin Films with Tailored Architecture.

    Science.gov (United States)

    Chollet, Benjamin; Li, Mengxing; Martwong, Ekkachai; Bresson, Bruno; Fretigny, Christian; Tabeling, Patrick; Tran, Yvette

    2016-05-11

    A facile route for the fabrication of surface-attached hydrogel thin films with well-controlled chemistry and tailored architecture on wide range of thickness from nanometers to micrometers is reported. The synthesis, which consists in cross-linking and grafting the preformed and ene-reactive polymer chains through thiol-ene click chemistry, has the main advantage of being well-controlled without the addition of initiators. As thiol-ene click reaction can be selectively activated by UV-irradiation (in addition to thermal heating), micropatterned hydrogel films are easily synthesized. The versatility of our approach is illustrated by the possibility to fabricate various chemical polymer networks, like stimuli-responsive hydrogels, on various solid substrates, such as silicon wafers, glass, and gold surfaces. Another attractive feature is the development of new complex hydrogel films with targeted architecture. The fabrication of various architectures for polymer films is demonstrated: multilayer hydrogel films in which single-networks are stacked one onto the other, interpenetrating networks films with mixture of two networks in the same layer, and nanocomposite hydrogel films where nanoparticles are stably trapped inside the mesh of the network. Thanks to its simplicity and its versatility this novel approach to surface-attached hydrogel films should have a strong impact in the area of polymer coatings. PMID:27008162

  9. Dispersive mudslide-induced tsunamis

    Directory of Open Access Journals (Sweden)

    A. Rubino

    1998-01-01

    Full Text Available A nonlinear nested model for mudslide-induced tsunamis is proposed in which three phases of the life of the wave, i.e. the generation, far-field propagation and costal run-up are described by means of different mathematical models, that are coupled through appropriate matching procedures. The generation and run-up dynamics are simulated through a nonlinear shallow-water model with movable lateral boundaries: in the generation region two active layers are present, the lower one describing the slide descending on a sloping topography. For the intermediate phase, representing wave propagation far from the generation region, the hydrostatic assumption is not assumed as appropriate in general and, therefore, a nonlinear model allowing for weak phase dispersion, namely a Kadomtsev-Petviashvili equation, is used. This choice is made in order to assess the relevance of dispersive features such as solitary waves and dispersive tails. It is shown that in some realistic circumstances dispersive mudslide-induced tsunami waves can be produced over relatively short, distances. In such cases the use of a hydrostatic model throughout the whole tsunami history turns out to give erroneous results. In particular, when solitary waves are generated during the tsunami propagation in the open sea, the resulting run-up process yields peculiar wave forms leading to amplified coastal inundations with respect to a mere hydrostatic context.

  10. Optical tailoring of xFEL beams

    Energy Technology Data Exchange (ETDEWEB)

    West, Gavin [SLAC National Accelerator Lab., Menlo Park, CA (United States); Coffee, R. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    There is an inherent exibility unique to free electron lasers (FELs) that lends well to experimental approaches normally too difficult for other light sources to accomplish. This includes the ability to optically shape the electron bunch prior to final its acceleration for the final FEL process. Optical pulse shaping of the electron bunch can enable both femtosecond and attosecond level FEL pulse control. Pulse shaping is currently implemented, not optically but mechanically, in LCLS-I with an adjustable foil slit that physically spoils the momentum phase of the electron bunch. This selectively suppresses the downstream FEL process ofspoiled electrons. Such a mechanical spoiling method fails for both the soft x-ray regime as well as the high repetition rates that are planned in LCLS-II. Our proposed optical spoiling method circumvents this limitation by making use of the existing ultrafast laser beam that is typically used for adjusting the energy spread for the initial electron bunch. Using Fourier domain shaping we can nearly arbitrarily shape the laser pulses to affect the electron bunch. This can selectively spoil electrons within each bunch. Here we demonstrate the viability of this approach with a programmable acousto-optic dispersive filter. This method is not only well suited for LCLS-II but also has several advantages over mechanical spoiling, including lack of radiation concerns, experiment specific FEL pulse shapes, and real-time adjustment for applications that require high duty-cycle variation such as lock-in amplification of small signals.

  11. Evolution of dispersal distance.

    Science.gov (United States)

    Durrett, Rick; Remenik, Daniel

    2012-03-01

    The problem of how often to disperse in a randomly fluctuating environment has long been investigated, primarily using patch models with uniform dispersal. Here, we consider the problem of choice of seed size for plants in a stable environment when there is a trade off between survivability and dispersal range. Ezoe (J Theor Biol 190:287-293, 1998) and Levin and Muller-Landau (Evol Ecol Res 2:409-435, 2000) approached this problem using models that were essentially deterministic, and used calculus to find optimal dispersal parameters. Here we follow Hiebeler (Theor Pop Biol 66:205-218, 2004) and use a stochastic spatial model to study the competition of different dispersal strategies. Most work on such systems is done by simulation or nonrigorous methods such as pair approximation. Here, we use machinery developed by Cox et al. (Voter model perturbations and reaction diffusion equations 2011) to rigorously and explicitly compute evolutionarily stable strategies.

  12. Perfect Dispersive Medium

    CERN Document Server

    Gupta, Shulabh

    2015-01-01

    Dispersion is at the heart of all ultrafast real-time signal processing systems across the entire electromagnetic spectrum ranging from radio-frequencies to optics. However, following Kramer-Kronig relations, these signal processing systems have been plagued with the parasitic amplitude distortions due to frequency dependent, and non-flat amplitude transmission of naturally dispersive media. This issue puts a serious limitation on the applicability and performance of these signal processing systems. To solve the above mentioned issue, a perfect dispersive medium is proposed in this work, which artificially violates the Kramer-Kronig relations, while satisfying all causality requirements. The proposed dispersive metamaterial is based on loss-gain metasurface pairs and exhibit a perfectly flat transmission response along with arbitrary dispersion in a broad bandwidth, thereby solving a seemingly unavoidable issue in all ultrafast signal processing systems. Such a metamaterial is further shown using sub-waveleng...

  13. Molecular tailoring of interfaces for thin film on substrate systems

    Science.gov (United States)

    Grady, Martha Elizabeth

    Thin film on substrate systems appear most prevalently within the microelectronics industry, which demands that devices operate in smaller and smaller packages with greater reliability. The reliability of these multilayer film systems is strongly influenced by the adhesion of each of the bimaterial interfaces. During use, microelectronic components undergo thermo-mechanical cycling, which induces interfacial delaminations leading to failure of the overall device. The ability to tailor interfacial properties at the molecular level provides a mechanism to improve thin film adhesion, reliability and performance. This dissertation presents the investigation of molecular level control of interface properties in three thin film-substrate systems: photodefinable polyimide films on passivated silicon substrates, self-assembled monolayers at the interface of Au films and dielectric substrates, and mechanochemically active materials on rigid substrates. For all three materials systems, the effect of interfacial modifications on adhesion is assessed using a laser-spallation technique. Laser-induced stress waves are chosen because they dynamically load the thin film interface in a precise, noncontacting manner at high strain rates and are suitable for both weak and strong interfaces. Photodefinable polyimide films are used as dielectrics in flip chip integrated circuit packages to reduce the stress between silicon passivation layers and mold compound. The influence of processing parameters on adhesion is examined for photodefinable polyimide films on silicon (Si) substrates with three different passivation layers: silicon nitride (SiNx), silicon oxynitride (SiOxNy), and the native silicon oxide (SiO2). Interfacial strength increases when films are processed with an exposure step as well as a longer cure cycle. Additionally, the interfacial fracture energy is assessed using a dynamic delamination protocol. The high toughness of this interface (ca. 100 J/m2) makes it difficult

  14. Dispersion of Active Au Nanoparticles on Mesoporous SBA-15 Materials%活性纳米金颗料在介孔分子筛SBA-15上的分散

    Institute of Scientific and Technical Information of China (English)

    周丽绘; 胡军; 谢颂海; 刘洪来

    2007-01-01

    Chemical modification (CM) and deposition-precipitation (DP) methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work. XRD, TEM, N2 adsorption isotherms and UV-Vis absorption spectra were used to characterize in detail Au-SBA-15 materials prepared by the two methods.The analysis results showed that high loading (1.7%, by mass) and uniform Au nanoparticles (approximately 3 nm)were dispersed in the channels of mesoporous SBA-15 by the CM method. While for the DP method, most of Au nanoparticles with the size of 10-15 nm were aggregated outside of the channels of SBA-15 and the actual loading of Au was only 0.38% (by mass).

  15. Tailoring of ZnO with selected group-II elements for LED materials

    Science.gov (United States)

    Saleem, Murtaza; Manzoor, Adnan; Zaffar, Mohammed; Hussain, Syed Zajif; Anwar, M. Sabieh

    2016-06-01

    The semiconductor ZnO is a promising candidate for its applications in light-emitting diodes. In this study ZnO nanostructures tailored with selected group-II elements were synthesized using sol-gel-based fuel-agent-assistive chemical technique. Structural studies from X-ray diffraction analysis revealed the presence of wurtzite hexagonal crystal structure in all compositions confirming the stability of the Mg-doped structure while indicating presence of some traces of un-reacted and oxides of Sr and Ba in other compositions. Lattice parameters, crystallite size, lattice strain, density, and cell volume were extracted from X-ray diffraction data. Morphology and elemental composition analysis showed exact correlation with structural arrangements. The size of particles was also observed with dynamic light-scattering measurements. Absorbance and electrical transport studies were performed using UV-Vis spectrophotometry and four-probe measurements, respectively; the former was used to estimate the band gap of nanostructures. Energy-dispersive X-ray analysis was employed for confirming the substitution of Mg, Sr, and Ba atoms at Zn and O sites. Band gap values show strong dependence upon the tailored ZnO compositions.

  16. Dispersion Synthesis with Multi-Ordered Metatronic Filters

    CERN Document Server

    Li, Yue; Engheta, Nader

    2016-01-01

    We propose the synthesis of frequency dispersion of layered structures based on the design of multi-ordered optical filters using nanocircuit concepts. Following the well known insertion loss method commonly employed in the design of electronic and microwave filters, here we theoretically show how we can tailor optical dispersion as we carry out the design of several low-pass, high-pass, band-pass and band-stop filters of different order with a (maximally flat) Butterworth response. We numerically demonstrate that these filters can be designed by combining metasurfaces made of one or two materials acting as optical lumped elements, and, hence, leading to simple, easy to apply, design rules. The theoretical results based on this circuital approach are validated with full-wave numerical simulations. The results presented here can be extended to virtually any frequency dispersion synthesis, filter design procedure and/or functionality, thus opening up exciting possibilities in the design of composite materials w...

  17. Chemisorption Techniques for the Determination of Metal Dispersion

    International Nuclear Information System (INIS)

    Chemisorption is an effective and un expensive analytical technique for characterizing and titrating active centers of the catalyst surface and for evaluating its activity with good approximation. The paper describes experimental procedures and the nature of information that can be obtained about active metal dispersion and area, diameter of active particles and isosteric heat of dispersion

  18. Shape-tailored polymer colloids on the road to become structural motifs for hierarchically organized materials.

    Science.gov (United States)

    Plüisch, Claudia Simone; Wittemann, Alexander

    2013-12-01

    Anisometric polymer colloids are likely to behave differently when compared with centrosymmetric particles. Their study may not only shine new light on the organization of matter; they may also serve as building units with specific symmetries and complexity to build new materials from them. Polymer colloids of well-defined complex geometries can be obtained by packing a limited number of spherical polymer particles into clusters with defined configurations. Such supracolloidal architectures can be fabricated at larger scales using narrowly dispersed emulsion droplets as templates. Assemblies built from at least two different types of particles as elementary building units open perspectives in selective targeting of colloids with specific properties, aiming for mesoscale building blocks with tailor-made morphologies and multifunctionality. Polymer colloids with defined geometries are also ideal to study shape-dependent properties such as the diffusion of complex particles. PMID:24327380

  19. Coupled cluster method with single and double excitations tailored by matrix product state wave functions

    CERN Document Server

    Veis, Libor; Neese, Frank; Legeza, Örs; Pittner, Jiří

    2016-01-01

    We present an alternative method for accurate treatment of strongly correlated systems which combines the coupled cluster (CC) theory with the density matrix renormalization group method (DMRG). The connection is done in the spirit of the tailored CC method [T. Kinoshita, O. Hino, and R. J. Bartlett, \\textit{J. Chem. Phys.} {\\bf 123} (2005) 074106]. In the first step, the configuration interaction (CI) coefficients corresponding to single and double excitations within the DMRG active space are computed by contraction of the matrix product state (MPS) matrices. These coefficients are subsequently transformed into CC amplitudes. In the second step, the CC amplitudes are used to define a "tailored" single reference CCSD wavefunction. As a result, the DMRG method is responsible for the proper description of non-dynamic correlation, whereas the dynamic correlation is incorporated through the framework of the CC theory. We illustrate the potential of this method on prominent multireference model systems like N$_2$ ...

  20. Engineering chromatic dispersion and effective nonlinearity in a dual-slot waveguide.

    Science.gov (United States)

    Liu, Yan; Yan, Jing; Han, Genquan

    2014-09-20

    In this paper, we propose a new dual slot based on rib-like structure, which exhibits a flat and near-zero dispersion over a 198 nm wide wavelength range. Chromatic dispersion of dual-slot silicon (Si) waveguide is mainly determined by waveguide dispersion due to the manipulating mode effective area rather than by the material dispersion. Moreover, the nonlinear coefficient and effective mode area of the waveguide are also explored in detail. A nonlinear coefficient of 1460/m/W at 1550 nm is achieved, which is 10 times larger than that of the Si rib waveguide. By changing different waveguide variables, both the dispersion and nonlinear coefficient can be tailored, thus enabling the potential for a highly nonlinear waveguide with uniform dispersion over a wide wavelength range, which could benefit the performance of broadband optical signal systems.

  1. Dispersive hydrodynamics: Preface

    Science.gov (United States)

    Biondini, G.; El, G. A.; Hoefer, M. A.; Miller, P. D.

    2016-10-01

    This Special Issue on Dispersive Hydrodynamics is dedicated to the memory and work of G.B. Whitham who was one of the pioneers in this field of physical applied mathematics. Some of the papers appearing here are related to work reported on at the workshop "Dispersive Hydrodynamics: The Mathematics of Dispersive Shock Waves and Applications" held in May 2015 at the Banff International Research Station. This Preface provides a broad overview of the field and summaries of the various contributions to the Special Issue, placing them in a unified context.

  2. Shape-Tailored Features and their Application to Texture Segmentation

    KAUST Repository

    Khan, Naeemullah

    2014-04-01

    Texture Segmentation is one of the most challenging areas of computer vision. One reason for this difficulty is the huge variety and variability of textures occurring in real world, making it very difficult to quantitatively study textures. One of the key tools used for texture segmentation is local invariant descriptors. Texture consists of textons, the basic building block of textures, that may vary by small nuisances like illumination variation, deformations, and noise. Local invariant descriptors are robust to these nuisances making them beneficial for texture segmentation. However, grouping dense descriptors directly for segmentation presents a problem: existing descriptors aggregate data from neighborhoods that may contain different textured regions, making descriptors from these neighborhoods difficult to group, leading to significant errors in segmentation. This work addresses this issue by proposing dense local descriptors, called Shape-Tailored Features, which are tailored to an arbitrarily shaped region, aggregating data only within the region of interest. Since the segmentation, i.e., the regions, are not known a-priori, we propose a joint problem for Shape-Tailored Features and the regions. We present a framework based on variational methods. Extensive experiments on a new large texture dataset, which we introduce, show that the joint approach with Shape-Tailored Features leads to better segmentations over the non-joint non Shape-Tailored approach, and the method out-performs existing state-of-the-art.

  3. Tailoring surface topographies of polymers by using ion beam: Recent advances and the potential applications in biomedical and tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hasebe, Terumitsu, E-mail: teru_hasebe@sakura.med.toho-u.ac.jp [Department of Radiology, Toho University, Sakura Medical Center, 564-1 Shimoshizu, Sakura, Chiba 285-8741 (Japan); Center for Science of Environment, Resources and Energy, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Nagashima, So; Yoshimoto, Yukihiro; Hotta, Atsushi; Suzuki, Tetsuya [Center for Science of Environment, Resources and Energy, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan)

    2012-07-01

    Ion beam technique has recently been actively employed to create various patterns on the surface of polymers. In this paper, we highlight some of the recent advances in tailoring surface topographies of polymers by using ion beam and present a brief discussion on the potential applications in biomedical and tissue engineering.

  4. Tailored print communication and telephone motivational interviewing are equally successful in improving multiple lifestyle behaviors in a randomized controlled trial

    NARCIS (Netherlands)

    Keulen, H.M. van; Mesters, I.; Ausems, M.; Breukelen, G. van; Campbell, M.; Resnicow, K.; Brug, J.; Vries, H. de

    2011-01-01

    Background: Computer tailoring and motivational interviewing show promise in promoting lifestyle change, despite few head-to-head comparative studies. Purpose: Vitalum is a randomized controlled trial in which the efficacy of these methods was compared in changing physical activity and fruit and veg

  5. Tailoring information to enhance quitting in smokers with low motivation to quit: three basic efficacy questions.

    Science.gov (United States)

    Dijkstra, A; De Vries, H; Roijackers, J; van Breukelen, G

    1998-11-01

    Tailoring information to a target individual's features is a promising line of development in self-help interventions. In this article, 752 smokers with explicit low intention to quit were randomly assigned to 1 of 5 conditions: (a) multiple tailored letters with self-help guide, (b) multiple tailored letters only, (c) a single tailored letter with a self-help guide, (d) a single tailored letter only, or (e) a nontailored intervention. Follow-up assessment took place 4 months after the intervention. Results indicated that the single tailored intervention only had no surplus value compared with a nontailored look-alike intervention. The addition of a self-help guide to a tailored intervention was only useful in highly dependent smokers, and multiple tailoring was more effective than single tailoring. It remains important to elucidate why and for whom certain tailored interventions are more effective. PMID:9848801

  6. Monolayer dispersion thresholds and threshold effect displayed by supported catalysts

    Institute of Scientific and Technical Information of China (English)

    Cun DENG

    2008-01-01

    The principle of spontaneous monolayer dis-persion holds that active components of many supported catalysts will disperse spontaneously onto the surface of the carrier. The monolayer dispersion threshold of the active component on the surface of the carrier can be measured by X-ray diffraction phase-quantitative extra-polation method, etc. By measuring the monolayer disper-sion threshold, beneficial information on the surface structure and dispersion of supported catalysts can be obtained, and the optimal preparative processing condi-tions of the catalysts can be chosen. The proportion of the active component of many supported catalysts can be optimized while its monolayer dispersion threshold is observed. Mutation values of many physicochemical properties of supported catalysts are related to monolayer dispersion thresholds; the threshold effect on catalysts is apparent, and the proposal regarding the threshold effect provides instruction for the research on catalysts.

  7. Goal Model Integration for Tailoring Product Line Development Processes

    Directory of Open Access Journals (Sweden)

    Arfan Mansoor

    2016-07-01

    Full Text Available Many companies rely on the promised benefits of product lines, targeting systems between fully custom made software and mass products. Such customized mass products account for a large number of applications automatically derived from a product line. This results in the special importance of product lines for companies with a large part of their product portfolio based on their product line. The success of product line development efforts is highly dependent on tailoring the development process. This paper presents an integrative model of influence factors to tailor product line development processes according to different project needs, organizational goals, individual goals of the developers or constraints of the environment. This model integrates goal models, SPEM models and requirements to tailor development processes.

  8. Tailorable Stimulated Brillouin Scattering in Nanoscale Silicon Waveguides

    CERN Document Server

    Shin, Heedeuk; Jarecki, Robert; Cox, Jonathan A; Olsson, Roy H; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T

    2013-01-01

    While nanoscale modal confinement radically enhances a variety of nonlinear light-matter interactions within silicon waveguides, traveling-wave stimulated Brillouin scattering nonlinearities have never been observed in silicon nanophotonics. Through a new class of hybrid photonic-phononic waveguides, we demonstrate tailorable traveling-wave forward stimulated Brillouin scattering in nanophotonic silicon waveguides for the first time, yielding 3000 times stronger forward SBS responses than any previous waveguide system. Simulations reveal that a coherent combination of electrostrictive forces and radiation pressures are responsible for greatly enhanced photon-phonon coupling at nano-scales. Highly tailorable Brillouin nonlinearities are produced by engineering the structure of a membrane-suspended waveguide to yield Brillouin resonances from 1 to 18 GHz through high quality-factor (>1000) phonon modes. Such wideband and tailorable stimulated Brillouin scattering in silicon photonics could enable practical real...

  9. Tailoring the energy distribution and loss of 2D plasmons

    CERN Document Server

    Lin, Xiao; López, Josué J; Kaminer, Ido; Chen, Hongsheng; Soljačić, Marin

    2016-01-01

    The ability to tailor the energy distribution of plasmons at the nanoscale has many applications in nanophotonics, such as designing plasmon lasers, spasers, and quantum emitters. To this end, we analytically study the energy distribution and the proper field quantization of 2D plasmons with specific examples for graphene plasmons. We find that the portion of the plasmon energy contained inside graphene (energy confinement factor) can exceed 50%, despite graphene being infinitely thin. In fact, this very high energy confinement can make it challenging to tailor the energy distribution of graphene plasmons just by modifying the surrounding dielectric environment or the geometry, such as changing the separation distance between two coupled graphene layers. However, by adopting concepts of parity-time symmetry breaking, we show that tuning the loss in one of the two coupled graphene layers can simultaneously tailor the energy confinement factor and propagation characteristics, causing the phenomenon of loss-indu...

  10. Perfect Dispersive Medium

    OpenAIRE

    Gupta, Shulabh; Caloz, Christophe

    2015-01-01

    Dispersion lies at the heart of real-time signal processing systems across the entire electromagnetic spectrum from radio to optics. However, the performance and applicability of such systems have been severely plagued by distortions due to the frequency dependent nature of the amplitude response of the dispersive media used for processing. This frequency dependence is a fundamental consequence of the causality constraint, incarnated by Kramers-Kronig relations or, equivalently, by the Bode r...

  11. Acoustic dispersive prism

    OpenAIRE

    Hussein Esfahlani; Sami Karkar; Herve Lissek; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic ...

  12. Fickian dispersion is anomalous

    Science.gov (United States)

    Cushman, John H.; O'Malley, Dan

    2015-12-01

    The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

  13. Validation of Design and Analysis Techniques of Tailored Composite Structures

    Science.gov (United States)

    Jegley, Dawn C. (Technical Monitor); Wijayratne, Dulnath D.

    2004-01-01

    Aeroelasticity is the relationship between the elasticity of an aircraft structure and its aerodynamics. This relationship can cause instabilities such as flutter in a wing. Engineers have long studied aeroelasticity to ensure such instabilities do not become a problem within normal operating conditions. In recent decades structural tailoring has been used to take advantage of aeroelasticity. It is possible to tailor an aircraft structure to respond favorably to multiple different flight regimes such as takeoff, landing, cruise, 2-g pull up, etc. Structures can be designed so that these responses provide an aerodynamic advantage. This research investigates the ability to design and analyze tailored structures made from filamentary composites. Specifically the accuracy of tailored composite analysis must be verified if this design technique is to become feasible. To pursue this idea, a validation experiment has been performed on a small-scale filamentary composite wing box. The box is tailored such that its cover panels induce a global bend-twist coupling under an applied load. Two types of analysis were chosen for the experiment. The first is a closed form analysis based on a theoretical model of a single cell tailored box beam and the second is a finite element analysis. The predicted results are compared with the measured data to validate the analyses. The comparison of results show that the finite element analysis is capable of predicting displacements and strains to within 10% on the small-scale structure. The closed form code is consistently able to predict the wing box bending to 25% of the measured value. This error is expected due to simplifying assumptions in the closed form analysis. Differences between the closed form code representation and the wing box specimen caused large errors in the twist prediction. The closed form analysis prediction of twist has not been validated from this test.

  14. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler

    2015-03-01

    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

  15. Design and evaluation protocol of "FATaintPHAT", a computer-tailored intervention to prevent excessive weight gain in adolescents

    Directory of Open Access Journals (Sweden)

    van de Looij-Jansen Petra M

    2007-11-01

    Full Text Available Abstract Background Computer tailoring may be a promising technique for prevention of overweight in adolescents. However, very few well-developed, evidence-based computer-tailored interventions are available for this target group. We developed and evaluated a computer-tailored intervention for adolescents targeting energy balance-related behaviours: i.e. consumption of snacks, sugar-sweetened beverages, fruit, vegetables, and fibre, physical activity, and sedentary behaviours. This paper describes the planned development of a school-based computer-tailored intervention aimed at improving energy balance-related behaviours in order to prevent excessive weight gain in adolescents, and the protocol for evaluating this intervention. Methods/design Intervention development: Informed by the Precaution Adoption Process Model and the Theory of Planned Behaviour, the computer-tailored intervention provided feedback on personal behaviour and suggestions on how to modify it. The intervention (VETisnietVET translated as 'FATaintPHAT' has been developed for use in the first year of secondary school during eight lessons. Evaluation design: The intervention will be evaluated in a cluster-randomised trial including 20 schools with a 4-months and a 2-years follow-up. Outcome measures are BMI, waist circumference, energy balance-related behaviours, and potential determinants of these behaviours. Process measures are appreciation of and satisfaction with the program, exposure to the program's content, and implementation facilitators and barriers measured among students and teachers. Discussion This project resulted in a theory and evidence-based intervention that can be implemented in a school setting. A large-scale randomised controlled trial with a short and long-term follow-up will provide sound statements about the effectiveness of this computer-tailored intervention in adolescents. Trial Registration ISRCTN15743786

  16. When is dispersal for dispersal? Unifying marine and terrestrial perspectives.

    Science.gov (United States)

    Burgess, Scott C; Baskett, Marissa L; Grosberg, Richard K; Morgan, Steven G; Strathmann, Richard R

    2016-08-01

    Recent syntheses on the evolutionary causes of dispersal have focused on dispersal as a direct adaptation, but many traits that influence dispersal have other functions, raising the question: when is dispersal 'for' dispersal? We review and critically evaluate the ecological causes of selection on traits that give rise to dispersal in marine and terrestrial organisms. In the sea, passive dispersal is relatively easy and specific morphological, behavioural, and physiological adaptations for dispersal are rare. Instead, there may often be selection to limit dispersal. On land, dispersal is relatively difficult without specific adaptations, which are relatively common. Although selection for dispersal is expected in both systems and traits leading to dispersal are often linked to fitness, systems may differ in the extent to which dispersal in nature arises from direct selection for dispersal or as a by-product of selection on traits with other functions. Our analysis highlights incompleteness of theories that assume a simple and direct relationship between dispersal and fitness, not just insofar as they ignore a vast array of taxa in the marine realm, but also because they may be missing critically important effects of traits influencing dispersal in all realms. PMID:26118564

  17. Development of patient-centric linguistically tailored psychoeducational messages to support nutrition and medication self-management in type 2 diabetes: a feasibility study

    Directory of Open Access Journals (Sweden)

    Ellis RJB

    2014-10-01

    . The messages developed in this study should be tested in a larger more representative sample. The present study did not explore whether tailored messages were better understood. This research will serve as preliminary evidence to develop future studies with the ultimate goal to design intervention studies to investigate if linguistically tailoring communication within the context of patient education influences patient knowledge, motivation, and activation toward making healthy behavior changes in T2DM self-management. Keywords: health communication, applied linguistics, patient preference, medication management, chronic disease

  18. Aeroelastic tailoring in wind-turbine blade applications

    Energy Technology Data Exchange (ETDEWEB)

    Veers, P.; Lobitz, D. [Sandia National Labs., Albuquerque, NM (United States); Bir, G. [National Renewable Energy Lab., Golden, CO (United States). National Wind Technology Center

    1998-04-01

    This paper reviews issues related to the use of aeroelastic tailoring as a cost-effective, passive means to shape the power curve and reduce loads. Wind turbine blades bend and twist during operation, effectively altering the angle of attack, which in turn affects loads and energy production. There are blades now in use that have significant aeroelastic couplings, either on purpose or because of flexible and light-weight designs. Since aeroelastic effects are almost unavoidable in flexible blade designs, it may be desirable to tailor these effects to the authors advantage. Efforts have been directed at adding flexible devices to a blade, or blade tip, to passively regulate power (or speed) in high winds. It is also possible to build a small amount of desirable twisting into the load response of a blade with proper asymmetric fiber lay up in the blade skin. (Such coupling is akin to distributed {delta}{sub 3} without mechanical hinges.) The tailored twisting can create an aeroelastic effect that has payoff in either better power production or in vibration alleviation, or both. Several research efforts have addressed different parts of this issue. Research and development in the use of aeroelastic tailoring on helicopter rotors is reviewed. Potential energy gains as a function of twist coupling are reviewed. The effects of such coupling on rotor stability have been studied and are presented here. The ability to design in twist coupling with either stretching or bending loads is examined also.

  19. Towards tailored and targeted adherence assessment to optimise asthma management

    NARCIS (Netherlands)

    van Boven, Job F. M.; Trappenburg, Jaap C. A.; van der Molen, Thys; Chavannes, Niels H.

    2015-01-01

    In this paper, we aim to emphasise the need for a more comprehensive and tailored approach to manage the broad nature of non-adherence, to personalise current asthma management. Although currently several methods are available to measure the extent of asthma patients' adherence, the vast majority do

  20. Dynamic groupware services : modular design of tailorable groupware

    NARCIS (Netherlands)

    Slagter, Robert-Jasper Jurriaan

    2004-01-01

    The main research question dealt with in this dissertation is: How can groupware be designed in order to achieve tailorability of groupware services? This question is relevant since the state of the art exploration reveals that the groupware landscape is fragmented: there exists no standard to desig

  1. Insights in the Efficacy of Computer-tailored Nutrition Education

    NARCIS (Netherlands)

    W. Kroeze (Willemieke)

    2008-01-01

    textabstractSaturated fat intake is an important risk factor for cardiovascular diseases, one of the main burdens of disease worldwide. Therefore it is important to use population-wide health promotion efforts to target this risk behavior. Computer-tailored nutrition education has been found to be a

  2. Tailor-made blanks for the aircraft industry

    NARCIS (Netherlands)

    Zad Poor, A.A.

    2010-01-01

    Tailor-Made Blanks (TMBs) are hybrid assemblies made of sheet metals with different materials and/or thicknesses that are joined together prior to forming. Alternatively, a monolithic sheet can be machined to create required thickness variations (machined TMBs). The possibility of having several thi

  3. Tailoring Small IT Projects in the Project Planning Phase

    Science.gov (United States)

    Mulhearn, Michael F.

    2011-01-01

    Project management (PM) and systems engineering (SE) are essential skills in information technology (IT). There is an abundance of information available detailing the comprehensive bodies of knowledge, standards, and best practices. Despite the volume of information, there is surprisingly little information about how to tailor PM and SE tasks for…

  4. Genomic markers to tailor treatments: waiting or initiating?

    NARCIS (Netherlands)

    P. Tajik; P.M. Bossuyt

    2011-01-01

    The decade since the publication of the Human Genome Project draft has ended with the discovery of hundreds of genomic markers related to diseases and phenotypes. However, the project has not yet delivered on its promise to tailor treatments for individuals. The number of genomic markers in clinical

  5. Ethoxyresorufin-O-deethylase activity and fixed wavelength fluorescence detection of PAHs metabolites in bile in turbot (Scophthalmus maximus L.) exposed to a dispersed topped crude oil in a continuous flow system

    Energy Technology Data Exchange (ETDEWEB)

    Camus, L. [Elf Petroleum Norge AS, Randaberg (Norway); Aas, E. [RF-Rogaland Research, Stavanger (Norway); Borseth, J.F. [RF-Rogaland Research, Randaberg (Norway)

    1998-07-01

    Long term effects of sublethal concentrations of oil on the marine environment have become of general concern. Cytochrome P4501A activity (EROD) in liver and fixed wavelength fluorescence detection of PAHs metabolites (FF) have in this study been used as biomarkers for dispersed oil exposure on a long term period of juvenile turbot (Scophthalmus maximus L.). A Continuous Flow System was used to carry out the study. The fish were continuously exposed to 0.125, 0.5 or 2.0 mg litre{sup -1} dispersed topped crude oil for 6, 15, 24h 4 and 21 days followed by a 9 day recovery period in clean seawater. No induction of the cytochrome P4501A was measured. A maximum level in bile metabolites (4- to 5-fold) was recorded after 24h of exposure revealing thereby a detoxification process, but a decline occurred from day 4 to day 21. This study demonstrated that FF detection of PAHs metabolites in bile could be a more sensitive biomarker than EROD activity in a long term exposure to sublethal concentration of oil. (author)

  6. SOLID DISPERSIONS: A REVIEW

    Directory of Open Access Journals (Sweden)

    D. Praveen Kumar

    2012-06-01

    Full Text Available The solubility behaviour of drugs remains one of the most challenging aspects in formulation development. Currently only 8% of the new drug molecules have high solubility and permeability. The solubility behaviour of a drug is key determinant to its oral bioavailability and it is the rate limiting step to absorption of drugs from the gastrointestinal tract. This results in important products not reaching the market or not achieving their full potential. Solid dispersions have attracted considerable interest as an efficient means of improving the dissolution rate and bioavailability of a range of hydrophobic drugs. This article reviews the various preparation techniques for solid dispersion, types of solid dispersions based on molecular arrangement and other aspects such as selection of carriers and methods of characterization and their applications have been discussed.

  7. About measuring velocity dispersions

    Science.gov (United States)

    Fellhauer, M.

    A lot of our knowledge about the dynamics and total masses of pressure dominated stellar systems relies on measuring the internal velocity disper- sion of the system. We assume virial equilibrium and that we are able to measure only the bound stars of the system without any contamination. This article shows how likely it is to measure the correct velocity dispersion in reality. It will show that as long as we have small samples of velocity mea- surements the distribution of possible outcomes can be very large and as soon as we have a source of error the velocity dispersion can wrong by several standard deviations especially in large samples.

  8. Coping with power dispersion?

    DEFF Research Database (Denmark)

    2014-01-01

    how the actors involved cope with the new configurations. In this introduction, we discuss the conceptualization of power dispersion and highlight the ways in which the contributions add to this research agenda. We then outline some general conclusions and end by indicating future avenues of research....... Taken together, the collection contributes some answers to the challenge of defining and measuring – in a comparative way – the control and co-ordination mechanisms which power dispersion generates. It also explores the tension between political actors' quest for autonomy and the acknowledgement of...

  9. Immobilization of Polymer-Decorated Liquid Crystal Droplets on Chemically Tailored Surfaces

    Science.gov (United States)

    Kinsinger, Michael I.; Buck, Maren E.; Abbott, Nicholas L.; Lynn, David M.

    2010-01-01

    We demonstrate that the assembly of an amphiphilic polyamine on the interfaces of micrometer-sized droplets of a thermotropic liquid crystal (LC) dispersed in aqueous solutions can be used to facilitate the immobilization of LC droplets on chemically functionalized surfaces. Polymer 1 was designed to contain both hydrophobic (alkyl-functionalized) and hydrophilic (primary and tertiary amine-functionalized) side chain functionality. The assembly of this polymer at the interfaces of aqueous dispersions of LC droplets was achieved by spontaneous adsorption of polymer from aqueous solution. Polymer adsorption triggered transitions in the orientational ordering of the LCs, as observed by polarized light and bright-field microscopy. We demonstrate that the presence of polymer 1 on the interfaces of these droplets can be exploited to immobilize LC droplets on planar solid surfaces through covalent bond formation (e.g., for surfaces coated with polymer multilayers containing reactive azlactone functionality) or through electrostatic interactions (e.g., for surfaces coated with multilayers containing hydrolyzed azlactone functionality). Characterization of immobilized LC droplets by polarized, fluorescence, and laser scanning confocal microscopy revealed the general spherical shape of the polymer-coated LC droplets to be maintained after immobilization, and that immobilization led to additional ordering transitions within the droplets that was dependent on the nature of the surfaces with which they were in contact. Polymer 1-functionalized LC droplets were not immobilized on polymer multilayers treated with poly(ethylene imine) (PEI). We demonstrate that the ability to design surfaces that promote or prevent the immobilization of polymer-functionalized LC droplets can exploited to pattern the immobilization of LC droplets on surfaces. The results of this investigation provide the basis of an approach that could be used to tailor the properties of dispersed LC emulsions and

  10. Interspecific nematode signals regulate dispersal behavior.

    Directory of Open Access Journals (Sweden)

    Fatma Kaplan

    Full Text Available BACKGROUND: Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2 of plant parasitic Meloidogyne spp. and infective juveniles (IJs of entomopathogenic nematodes (EPN, e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs. METHODOLOGY/PRINCIPAL FINDINGS: Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9. A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9 and C. elegans (ascr#2 dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers. CONCLUSIONS/SIGNIFICANCE: Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes.

  11. Modeling 137CS dispersion from a radiological dispersion device

    International Nuclear Information System (INIS)

    This analysis reveals that, if terrorists detonate a RDD containing a relatively small amount of 137Cs (approximately 12-35g), the resulting dispersion can contaminate a relatively large area. The actual magnitude of a terrorist incident involving the release of radioactive material by a dirty bomb depends on the dimensions of the contaminated area and the accompanying contamination density (i.e., radioactivity) distributed within that area. Applying a semiempirical model indicates that the spatial extent of the contaminated area and the level of activity within that area are dependent primarily on local scale meteorological conditions, especially whether rainfall occurs, as well particle size and effective release height. As a result, the magnitude of the consequences of terrorists acquiring non-weapons grade nuclear materials and releasing those materials with a dirty bomb is contingent on a number of factors beyond the scope of active countermeasures, especially the RDD's design elements and local-scale meteorological conditions. Modeling the dispersion of radioactive aerosols throughout an urban landscape, especially with accurate 3-D representation of its complex geometry and meteorology, is indispensable for assessing the potential consequences of a terrorist incident and implementing effective emergency response, health services, and decontamination decisions. (orig.)

  12. Human-mediated dispersal of seeds over long distances

    Science.gov (United States)

    Wichmann, Matthias C.; Alexander, Matt J.; Soons, Merel B.; Galsworthy, Stephen; Dunne, Laura; Gould, Robert; Fairfax, Christina; Niggemann, Marc; Hails, Rosie S.; Bullock, James M.

    2008-01-01

    Human activities have fundamental impacts on the distribution of species through altered land use, but also directly by dispersal of propagules. Rare long-distance dispersal events have a disproportionate importance for the spread of species including invasions. While it is widely accepted that humans may act as vectors of long-distance dispersal, there are few studies that quantify this process. We studied in detail a mechanism of human-mediated dispersal (HMD). For two plant species we measured, over a wide range of distances, how many seeds are carried by humans on shoes. While over half of the seeds fell off within 5 m, seeds were regularly still attached to shoes after 5 km. Semi-mechanistic models were fitted, and these suggested that long-distance dispersal on shoes is facilitated by decreasing seed detachment probability with distance. Mechanistic modelling showed that the primary vector, wind, was less important as an agent of long-distance dispersal, dispersing seeds less than 250 m. Full dispersal kernels were derived by combining the models for primary dispersal by wind and secondary dispersal by humans. These suggest that walking humans can disperse seeds to very long distances, up to at least 10 km, and provide some of the first quantified dispersal kernels for HMD. PMID:18826932

  13. Effect of gelation of inner dispersed phase on stability of (w1/o/w2) multiple emulsions

    NARCIS (Netherlands)

    Oppermann, A.K.L.; Renssen, M.; Schuch, A.; Stieger, M.A.; Scholten, E.

    2015-01-01

    The use of water-in-oil-in-water (w1/o/w2) multiple emulsions offers a method for the reduction of oil in foods. In this study we investigated the influence of osmotic pressure tailoring and gelation of the inner dispersed w1 water droplets on the stability and yield of multiple emulsions. Yield is

  14. Octave spanning wedge dispersive mirrors with low dispersion oscillations.

    Science.gov (United States)

    Habel, Florian; Shirvanyan, Vage; Trubetskov, Michael; Burger, Christian; Sommer, Annkatrin; Kling, Matthias F; Schultze, Martin; Pervak, Vladimir

    2016-05-01

    A novel concept for octave spanning dispersive mirrors with low spectral dispersion oscillations is presented. The key element of the so-called wedge dispersive mirror is a slightly wedged layer which is coated on a specially optimized dispersive multilayer stack by a common sputter coating process. The group delay dispersion (GDD) of a pulse reflected on a wedge dispersive mirror is nearly free of oscillations. Fabricated mirrors with negative GDD demonstrate the compression of a pulse down to 3.8 fs as good as double angled mirrors optimized for the same bandwidth. PMID:27137538

  15. Tailor-Made Distribution of Nanoparticles in Blend Structure toward Outstanding Electromagnetic Interference Shielding.

    Science.gov (United States)

    Biswas, Sourav; Kar, Goutam Prasanna; Bose, Suryasarathi

    2015-11-18

    Engineering blend structure with tailor-made distribution of nanoparticles is the prime requisite to obtain materials with extraordinary properties. Herein, a unique strategy of distributing nanoparticles in different phases of a blend structure has resulted in >99% blocking of incoming electromagnetic (EM) radiation. This is accomplished by designing a ternary polymer blend structure using polycarbonate (PC), poly(vinylidene fluoride) (PVDF), and poly(methyl methacrylate) (PMMA) to simultaneously improve the structural, electrical, and electromagnetic interference shielding (EMI). The blend structure was made conducting by preferentially localizing the multi-wall nanotubes (MWNTs) in the PVDF phase. By taking advantage of "π-π stacking" MWNTs was noncovalently modified with an imidazolium based ionic liquid (IL). Interestingly, the enhanced dispersion of IL-MWNTs in PVDF improved the electrical conductivity of the blends significantly. While one key requisite to attenuate EM radiation (i.e., electrical conductivity) was achieved using MWNTs, the magnetic properties of the blend structure was tuned by introducing barium ferrite (BaFe) nanoparticles, which can interact with the incoming EM radiation. By suitably modifying the surface of BaFe nanoparticles, we can tailor their localization under the macroscopic processing condition. The precise localization of BaFe nanoparticles in the PC phase, due to nucleophilic substitution reaction, and the MWNTs in the PVDF phase not only improved the conductivity but also facilitated in absorption of the incoming microwave radiation due to synergetic effect from MWNT and BaFe. The shielding effectiveness (SE) was measured in X and Ku band, and an enhanced SE of -37 dB was noted at 18 GHz frequency. PMMA, which acted as an interfacial modifier in PC/PVDF blends further, resulting in a significant enhancement in the mechanical properties besides retaining high SE. This study opens a new avenue in designing mechanically strong

  16. Tailoring of composite wing structures for elastically produced camber deformations

    Science.gov (United States)

    Rehfield, Lawrence W.; Chang, Stephen; Zischka, Peter J.; Pickings, Richard D.; Holl, Michael W.

    1991-01-01

    Structural concepts have been created which produce chordwise camber deformation that results in enhanced lift. A wing box can be tailored to utilize these concepts with composites. In attempting to optimize the aerodynamic benefits, it is found that there are two optimum designs that are of interest. There is a 'weight' optimum which corresponds to the maximum lift per unit structural weight. There is also a 'lift' optimum that corresponds to maximum absolute lift. Experience indicates that a large weight penalty accompanies the transition from weight to lift optimum designs. New structural models, the basic deformation mechanisms that are utilized and typical analytical results are presented. It appears that lift enhancements of sufficient magnitude can be produced to render this type of wing tailoring of practical interest.

  17. PULSED MODE LASER CUTTING OF SHEETS FOR TAILORED BLANKS

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    1999-01-01

    This paper describes how the laser cutting process can be optimised in such a way that the cut sheets can subsequently be used to laser weld tailored blanks. In a number of systematic laboratory experiments the effect of cutting speed, assist gas pressure, average laser power and pulse energy...... was analysed. For quality assessment the squareness, roughness and dross attachment of laser cut blanks were measured. In all tests, the medium strength steel GA 260 with a thickness of 1.8 mm was used. In this work it has been successfully demonstrated that the squareness of a cut can be used as a quality...... item for parameter optimisation of laser cut sheets used for tailored blanks. It was concluded that high quality cut edges with a squareness as small as 0.015 mm may be obtained. Such edges are well suited for subsequent laser welding....

  18. The effect of laser pulse tailored welding of Inconel 718

    Science.gov (United States)

    Mccay, T. Dwayne; Mccay, Mary Helen; Sharp, C. Michael; Womack, Michael G.

    1990-01-01

    Pulse tailored laser welding has been applied to wrought, wrought grain grown, and cast Inconel 718 using a CO2 laser. Prior to welding, the material was characterized metallographically and the solid state transformation regions were identified using Differential Scanning Calorimetry and high temperature x-ray diffraction. Bead on plate welds (restrained and unrestrained) were then produced using a matrix of pulse duty cycles and pulsed average power. Subsequent characterization included heat affected zone width, penetration and underbead width, the presence of cracks, microfissures and porosity, fusion zone curvature, and precipitation and liquated region width. Pedigree welding on three selected processing conditions was shown by microstructural and dye penetrant analysis to produce no microfissures, a result which strongly indicates the viability of pulse tailored welding for microfissure free IN 718.

  19. FSW of Aluminum Tailor Welded Blanks across Machine Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Hovanski, Yuri; Upadhyay, Piyush; Carlson, Blair; Szymanski, Robert; Luzanski, Tom; Marshall, Dustin

    2015-02-16

    Development and characterization of friction stir welded aluminum tailor welded blanks was successfully carried out on three separate machine platforms. Each was a commercially available, gantry style, multi-axis machine designed specifically for friction stir welding. Weld parameters were developed to support high volume production of dissimilar thickness aluminum tailor welded blanks at speeds of 3 m/min and greater. Parameters originally developed on an ultra-high stiffness servo driven machine where first transferred to a high stiffness servo-hydraulic friction stir welding machine, and subsequently transferred to a purpose built machine designed to accommodate thin sheet aluminum welding. The inherent beam stiffness, bearing compliance, and control system for each machine were distinctly unique, which posed specific challenges in transferring welding parameters across machine platforms. This work documents the challenges imposed by successfully transferring weld parameters from machine to machine, produced from different manufacturers and with unique control systems and interfaces.

  20. Tailored fiber lasers and their use in nonlinear optics

    OpenAIRE

    Zeil, Peter

    2015-01-01

    The objective of this thesis work was to develop tailored fiber lasers, which meet the pump requirement for efficient continuous-wave (cw) frequency conversion to the visible and the mid-infrared wavelength regimes: a stable, high-power, wavelength-tunable, narrow-linewidth output in a single polarization. As a first step, the prospect of tuning ytterbium fiber lasers over an unprecedented wavelength range, from 980nm to 1100nm, was investigated. The results further substantiate the enormous ...

  1. Microbes in the tailoring of barley malt properties

    OpenAIRE

    Laitila, Arja

    2007-01-01

    Microbes have a decisive role in the barley-malt-beer chain. A major goal of this thesis was to study the relationships between microbial communities and germinating grains during malting. Furthermore, the study provided a basis for tailoring of malt properties with natural, malt-derived microbes. The malting ecosystem is a dynamic process, exhibiting continous change. The first hours of steeping and kilning were the most important steps in the process with regard to microbiological qual...

  2. Tailored Magnetic Nanoparticles for Optimizing Magnetic Fluid Hyperthermia

    OpenAIRE

    Khandhar, Amit; Ferguson, R. Matthew; Simon, Julian A.; Krishnan, Kannan M

    2011-01-01

    Magnetic Fluid Hyperthermia (MFH) is a promising approach towards adjuvant cancer therapy that is based on the localized heating of tumors using the relaxation losses of iron oxide magnetic nanoparticles (MNPs) in alternating magnetic fields (AMF). In this study, we demonstrate optimization of MFH by tailoring MNP size to an applied AMF frequency. Unlike conventional aqueous synthesis routes, we use organic synthesis routes that offer precise control over MNP size (diameter ~ 10–25 nm), size ...

  3. Magnetic Particle Imaging with Tailored Iron Oxide Nanoparticle Tracers

    OpenAIRE

    Ferguson, R. Matthew; Khandhar, Amit P.; Kemp, Scott J.; Arami, Hamed; Saritas, Emine U.; Croft, Laura R.; Konkle, Justin; Goodwill, Patrick W.; Halkola, Aleksi; Rahmer, Jürgen; Borgert, Jörn; Steven M. Conolly; Krishnan, Kannan M

    2014-01-01

    Magnetic Particle Imaging (MPI) shows promise for medical imaging, particularly in angiography of patients with chronic kidney disease. As the first biomedical imaging technique that truly depends on nanoscale materials properties, MPI requires highly optimized magnetic nanoparticle tracers to generate quality images. Until now, researchers have relied on tracers optimized for MRI T2*-weighted imaging that are suboptimal for MPI. Here, we describe new tracers tailored to MPI's unique physics,...

  4. Tailor-made blanks for the aircraft industry

    OpenAIRE

    Zad Poor, A.A.

    2010-01-01

    Tailor-Made Blanks (TMBs) are hybrid assemblies made of sheet metals with different materials and/or thicknesses that are joined together prior to forming. Alternatively, a monolithic sheet can be machined to create required thickness variations (machined TMBs). The possibility of having several thicknesses and/or materials in one single structure facilitates optimal material distribution and helps us make ground and air vehicles lighter, more cost-effective, fuel-efficient, and environment-f...

  5. Tailoring Carbon Nanostructure for High Frequency Supercapacitor Operation

    OpenAIRE

    Pritesh Hiralal; Gemma Rius; Piers Andrew; Masamichi Yoshimura; Amaratunga, Gehan A. J.

    2014-01-01

    The possibility of enhancing the frequency performance of electrochemical capacitors by tailoring the nanostructure of the carbon electrode to increase electrolyte permeability is demonstrated. Highly porous, vertically oriented carbon electrodes which are in direct electrical contact with the metallic current collector are produced via MPECVD growth on metal foils. The resulting structure has a capacitance and frequency performance between that of an electrolytic capacitor and an electrochem...

  6. Facilitating Physicians’ Access to Information via Tailored Text Summarization

    OpenAIRE

    Elhadad, Noemie; McKeown, Kathleen; Kaufman, David; Jordan, Desmond

    2005-01-01

    We have developed a summarization system, TAS (Technical Article Summarizer), which, when provided with a patient record and journal articles returned by a search, automatically generates a summary that is tailored to the patient characteristics. We hypothesize that a personalized summary will allow a physician to more quickly find information relevant to patient care. In this paper, we present a user study in which subjects carried out a task under three different condition...

  7. Tailoring dynamic ontology-driven web documents by demonstration

    OpenAIRE

    Macías, José A.; Castells, Pablo

    2002-01-01

    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. J. A. Macías, and P. Castells, "Tailoring dynamic ontology-driven web documents by demonstration", in Sixth International Conf...

  8. Tailoring self-assembled monolayers at the electrochemical interface

    Indian Academy of Sciences (India)

    S Varatharajan; Sheela Berchmans; V Yegnaraman

    2009-09-01

    The main focus of this review is to illustrate the amenability of self-assembled monolayers (SAMs) for functionalisation with different receptors, catalytic materials, biomolecules, enzymes, antigen-antibody, etc for various applications. The review discusses initially about the preparation and characterization of SAMs and tailoring of SAMs by incorporation of suitable recognition elements. A description of how the molecular recognition is achieved through forces like electrostatic, covalent and host-guest interactions is included in the review.

  9. Tailoring polarization entanglement in anisotropy-compensated SPDC

    OpenAIRE

    Brida, Giorgio; Genovese, Marco; Chekhova, Maria V.; Krivitsky, Leonid A.

    2007-01-01

    We show that the angular spectrum of type-II SPDC contains a continuum of maximally entangled states. For the realization of a bright source of entangled two-photon states, a standard technique is to compensate for the transverse walk-off in the production crystal. We demonstrate that polarization entangled states can be effectively engineered by generalizing this approach. Our method allows to considerably enrich the set of generated entangled states with a controlled tailoring them.

  10. Humans as long-distance dispersers of rural plant communities.

    Directory of Open Access Journals (Sweden)

    Alistair G Auffret

    Full Text Available Humans are known for their capacity to disperse organisms long distances. Long-distance dispersal can be important for species threatened by habitat destruction, but research into human-mediated dispersal is often focused upon few and/or invasive species. Here we use citizen science to identify the capacity for humans to disperse seeds on their clothes and footwear from a known species pool in a valuable habitat, allowing for an assessment of the fraction and types of species dispersed by humans in an alternative context. We collected material from volunteers cutting 48 species-rich meadows throughout Sweden. We counted 24,354 seeds of 197 species, representing 34% of the available species pool, including several rare and protected species. However, 71 species (36% are considered invasive elsewhere in the world. Trait analysis showed that seeds with hooks or other appendages were more likely to be dispersed by humans, as well as those with a persistent seed bank. More activity in a meadow resulted in more dispersal, both in terms of species and representation of the source communities. Average potential dispersal distances were measured at 13 km. We consider humans capable seed dispersers, transporting a significant proportion of the plant communities in which they are active, just like more traditional vectors such as livestock. When rural populations were larger, people might have been regular and effective seed dispersers, and the net rural-urban migration resulting in a reduction in humans in the landscape may have exacerbated the dispersal failure evident in declining plant populations today. With the fragmentation of habitat and changes in land use resulting from agricultural change, and the increased mobility of humans worldwide, the dispersal role of humans may have shifted from providers of regular local and landscape dispersal to providers of much rarer long-distance and regional dispersal, and international invasion.

  11. Tailor cutting of crystalline solar cells by laser micro jet

    Science.gov (United States)

    Bruckert, F.; Pilat, E.; Piron, P.; Torres, P.; Carron, B.; Richerzhagen, B.; Pirot, M.; Monna, R.

    2012-03-01

    Coupling a laser into a hair thin water micro jet (Laser Micro Jet, LMJ) for cutting applications offers a wide range of processes that are quite unique. As the laser beam is guided by internal reflections inside of a liquid cylinder, the cuts are naturally straight and do not reflect any divergence as otherwise occurs with an unguided laser beam. Furthermore, having a liquid media at the point of contact ensures a fast removal of heat and eventual debris ensuring clean cuts, which are free of any burrs. Many applications have indeed been developed for a large variety of materials, which are as different as e.g. diamond, silicon, aluminum, ceramic and hard metals. The photovoltaic industry has enjoyed in the last decades tremendous growth rates, which are still projected into the future. We focus here on the segment of Building Integrated PV (BIPV), which requests tailored solutions to actual buildings and not-one-fits-it-all standardized modules. Having the option to tailor cut solar cells opens a new field of BIPV applications. For the first time, finished crystalline solar cells have been LMJ cut into predetermined shapes. First results show that the cut is clean and neat. Preliminary solar performance measurements are positive. This opens a new avenue of tailored made modules instead of having to rely on the one-fits-alloy approach used so far.

  12. Dispersion in Alluvial River

    OpenAIRE

    Ferdousi, Amena

    2014-01-01

    River pollution is the contamination of river water by pollutant being discharged directly or indirectly on it. Depending on the degree of pollutant concentration, subsequent negative environmental effects such as oxygen depletion and severe reductions in water quality may occur which affect the whole environment. River pollution can then cause a serious threat for fresh water and as well as the entire living creatures. Dispersion in natural stream is the ability of a stream to dilute soluble...

  13. SOLID DISPERSIONS: A REVIEW

    OpenAIRE

    D. Praveen Kumar; Arora Vandana

    2012-01-01

    The solubility behaviour of drugs remains one of the most challenging aspects in formulation development. Currently only 8% of the new drug molecules have high solubility and permeability. The solubility behaviour of a drug is key determinant to its oral bioavailability and it is the rate limiting step to absorption of drugs from the gastrointestinal tract. This results in important products not reaching the market or not achieving their full potential. Solid dispersions have attracted consid...

  14. Disabling Radiological Dispersal Terror

    Energy Technology Data Exchange (ETDEWEB)

    Hart, M

    2002-11-08

    Terror resulting from the use of a radiological dispersal device (RDD) relies upon an individual's lack of knowledge and understanding regarding its significance. Disabling this terror will depend upon realistic reviews of the current conservative radiation protection regulatory standards. It will also depend upon individuals being able to make their own informed decisions merging perceived risks with reality. Preparation in these areas will reduce the effectiveness of the RDD and may even reduce the possibility of its use.

  15. Synthesis of Some Novel Biologically Active Disperse Dyes Derived from 4-Methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydro-pyridine-3-carbonitrile as Coupling Component and Their Colour Assessment on Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed H. Elnagdi

    2012-07-01

    Full Text Available A series of novel azo-disperse dyes containing alkylhydrazonopyridinone structures were synthesized. 4-Methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydropyridine-3-carbonitrile (8 is synthesized by one-pot synthesis using ethyl cyanoacetate, propylamine, and ethyl acetoacetate. Compound 8 is then coupled with aromatic and heteroaromatic diazonium salts to afford the corresponding aryl- and heteroaryl-4-methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydropyridine-3-carbonitriles 12a,b and 13a–c. Structural assignments to the dyes were made using NMR spectroscopic methods. A high temperature dyeing method was employed to apply these dyes to polyester fabrics. Most of the dyed fabrics tested displayed very good light fastness levels and good wash fastness. Finally, the biological activity of the prepared dyes against Gram positive bacteria and Gram negative bacteria were evaluated.

  16. Toxicity of dispersant application: Biomarkers responses in gills of juvenile golden grey mullet (Liza aurata)

    International Nuclear Information System (INIS)

    Dispersant use in nearshore areas is likely to increase the exposure of aquatic organisms to petroleum. To measure the toxicity of this controversial response technique, golden grey mullets (Liza aurata) were exposed to mechanically dispersed oil, chemically dispersed oil, dispersant alone in seawater, water-soluble fraction of oil and to seawater as a control treatment. Several biomarkers were assessed in the gills (enzymatic antioxidant activities, glutathione content, lipid peroxidation) and in the gallbladder (polycylic aromatic hydrocarbons metabolites). The significant differences between chemically dispersed oil and water soluble fraction of oil highlight the environmental risk to disperse an oil slick when containment and recovery can be conducted. The lack of significance between chemically and mechanically dispersed oil suggests that dispersant application is no more toxic than the natural dispersion of the oil slick. The results of this study are of interest in order to establish dispersant use policies in nearshore areas. - Highlights: → This study simulates and evaluates the toxicity of dispersant use in nearshore area. → Dispersant use toxicity is assessed through biomarkers measurement in a fish species. → Chemical dispersion of an oil slick increases the petroleum toxicity. → Dispersant use does not enhance the toxicity of a mechanically dispersed oil slick. → This work leads to conclusions concerning dispersant use policies in nearshore area. - When the meteorological conditions induce the dispersion of the oil slick (e.g. wave), the application of dispersant does not increase the toxicity of petroleum.

  17. Activation and dissociation of CO2 on the (001), (011), and (111) surfaces of mackinawite (FeS): A dispersion-corrected DFT study

    NARCIS (Netherlands)

    Dzade, N.Y.; Roldan, Alberto; de Leeuw, N.H.

    2015-01-01

    Iron sulfide minerals, including mackinawite (FeS), are relevant in origin of life theories, due to their potential catalytic activity towards the reduction and conversion of carbon dioxide (CO2) to organic molecules, which may be applicable to the production of liquid fuels and commodity chemicals.

  18. Tailored tempering. Customized material properties for hot-stamped parts; Tailored Tempering. Massgeschneiderte Werkstoffeigenschaften fuer waermeumgeformte Bauteile

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, Sascha; Banik, Janko; Graff, Stephane; Laurenz, Robert; Lenze, Franz-Josef [ThyssenKrupp Steel Europe AG, Dortmund (Germany). FuE

    2012-07-01

    The requirements placed on vehicle crash performance and fuel consumption have increased consistently in recent years. Technologies such as the press hardening of manganese-boron steels can help reduce car body weight while optimizing service properties. ThyssenKrupp Steel Europe has developed an enhanced press hardening process called 'tailored tempering' that makes it possible to exploit the full range of strength levels offered by steel through precise control of the cooling process in the forming die. (orig.)

  19. Tailoring science outreach through E-matching using a community-based participatory approach.

    Directory of Open Access Journals (Sweden)

    Bernice B Rumala

    2011-03-01

    Full Text Available In an effort to increase science exposure for pre-college (K-12 students and as part of the science education reform agenda, many biomedical research institutions have established university-community partnerships. Typically, these science outreach programs consist of pre-structured, generic exposure for students, with little community engagement. However, the use of a medium that is accessible to both teachers and scientists, electronic web-based matchmaking (E-matching provides an opportunity for tailored outreach utilizing a community-based participatory approach (CBPA, which involves all stakeholders in the planning and implementation of the science outreach based on the interests of teachers/students and scientists. E-matching is a timely and urgent endeavor that provides a rapid connection for science engagement between teachers/students and experts in an effort to fill the science outreach gap. National Lab Network (formerly National Lab Day, an ongoing initiative to increase science equity and literacy, provides a model for engaging the public in science via an E-matching and hands-on learning approach. We argue that science outreach should be a dynamic endeavor that changes according to the needs of a target school. We will describe a case study of a tailored science outreach activity in which a public school that serves mostly under-represented minority students from disadvantaged backgrounds were E-matched with a university, and subsequently became equal partners in the development of the science outreach plan. In addition, we will show how global science outreach endeavors may utilize a CBPA, like E-matching, to support a pipeline to science among under-represented minority students and students from disadvantaged backgrounds. By merging the CBPA concept with a practical case example, we hope to inform science outreach practices via the lens of a tailored E-matching approach.

  20. Optical micromanipulation using dispersion-compensated and phase-shaped ultrashort pulsed lasers

    OpenAIRE

    Shane, Janelle

    2009-01-01

    Ultrashort pulsed lasers offer high peak powers at low average powers, making them ideal for maximising the efficiency of nonlinear excitation. Their broad bandwidths make it possible to tailor the pulse's temporal profile for advanced control of multiphoton excitation, techniques known as pulse shaping. This thesis represents the first combination of ultrashort pulse shaping with optical trapping and axicon dispersion compensation. We construct an optical trapping system which incorpora...

  1. Dynamic configuration of reduced graphene oxide in aqueous dispersion and its effect on thin film properties.

    Science.gov (United States)

    Wang, Yufei; Zhang, Xuehua; Li, Dan

    2015-12-28

    The dynamic configuration of reduced graphene oxide (rGO) in an aqueous dispersion is revealed by several characterization methods, showing a spontaneous and seemingly irreversible configuration transition from flat to highly corrugated sheets over time. Such dynamic behaviour of rGO leads to a tailored porous structure of graphene-based thin films. This affects their permeation and electrochemical properties, as well as future industry adoption of graphene. PMID:26498678

  2. Ultra-dispersive adaptive prism

    OpenAIRE

    Sautenkov, Vladimir A.; Li, Hebin; Rostovtsev, Yuri V.; Scully, Marlan O.

    2007-01-01

    We have experimentally demonstrated an ultra-dispersive optical prism made from coherently driven Rb atomic vapor. The prism possesses spectral angular dispersion that is six orders of magnitude higher than that of a prism made of optical glass; it is the highest spectral angular dispersion that has ever been shown (such angular dispersion allows one to spatially resolve light beams with different frequencies separated by a few kHz). The prism operates near the resonant frequency of atomic va...

  3. Validity condition of separating dispersion of PCFs into material dispersion and geometrical dispersion

    Institute of Scientific and Technical Information of China (English)

    Wei Wang; Lantian Hou; Zhaolun Liu; Guiyao Zhou

    2009-01-01

    When using normalized dispersion method for the dispersion design of photonic crystal fibers(PCFs),it is vital that the group velocity dispersion of PCF can be seen as the sum of geometrical dispersion and material dispersion.However,the error induced by this way of calculation will deteriorate the final results.Taking 5 ps/(km·nm)and 5% as absolute error and relative error limits,respectively,the structure parameter boundaries of PCFs about when separating total dispersion into geometrical and material components is valid are provided for wavelength shorter than 1700 nm.By using these two criteria together,it is adequate to evaluate the simulatcd dispersion of PCFs when normalized dispersion method is employed.

  4. Synthesis, biological activity and dyeing performance of some novel azo disperse dyes incorporating pyrazolo[1,5-a]pyrimidines for dyeing of polyester fabrics

    Science.gov (United States)

    Sayed, Ahmed Z.; Aboul-Fetouh, Mahmoud S.; Nassar, Hesham S.

    2012-02-01

    Several novel pyrazolopyrimidine azo compounds were achieved from diazotization of 4-aminoacetanilide and coupling with malononitrile and then refluxed with hydrazine hydrate to furnish 3,5-diamino-4-(4-acetamidophenylazo)-1H-pyrazole. The later compound was diazotized and coupled with substituted α-cyanocinnamate, α-cyanocinnamonitrile, 2-cyano-3-ethoxyacrylic acid ethyl ester, chalcones and ethylacetoacetate to produce novel dyestuffs. Structures of the dyes were fully characterized by using FT-IR, 1H NMR, mass spectroscopy and elemental analysis. The dyes were applied to polyester fiber, affording satisfactory results and showed biological activity towards various microorganisms.

  5. Developing a dispersant spraying capability

    Energy Technology Data Exchange (ETDEWEB)

    Gill, S.D.

    1979-01-01

    In developing a national dispersant spraying capability, the Canadian Coast Guard (CCG) has undertaken a modification program to enable the conventional offshore spraying gear to be mounted on almost any vessel of convenience. Smaller, more versatile inshore spraying vessels and pumps have been designed and built. With the popularization of concentrated dispersants, the inshore pumping equipment can be used aboard hovercraft for special application situations. A program of acquiring mobile dispersant storage tanks has been undertaken with auxiliary equipment that will facilitate the shipment of dispersants in bulk by air freight. Work also has commenced on extending the dispersant application program to include the CCG fleet of helicopters.

  6. Spurious dispersion effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Prat, Eduard

    2009-07-15

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  7. Spurious dispersion effects at FLASH

    International Nuclear Information System (INIS)

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  8. Tailored magnetic nanoparticles for optimizing magnetic fluid hyperthermia.

    Science.gov (United States)

    Khandhar, Amit P; Ferguson, R Matthew; Simon, Julian A; Krishnan, Kannan M

    2012-03-01

    Magnetic Fluid Hyperthermia (MFH) is a promising approach towards adjuvant cancer therapy that is based on the localized heating of tumors using the relaxation losses of iron oxide magnetic nanoparticles (MNPs) in alternating magnetic fields (AMF). In this study, we demonstrate optimization of MFH by tailoring MNP size to an applied AMF frequency. Unlike conventional aqueous synthesis routes, we use organic synthesis routes that offer precise control over MNP size (diameter ∼10 to 25 nm), size distribution, and phase purity. Furthermore, the particles are successfully transferred to the aqueous phase using a biocompatible amphiphilic polymer, and demonstrate long-term shelf life. A rigorous characterization protocol ensures that the water-stable MNPs meet all the critical requirements: (1) uniform shape and monodispersity, (2) phase purity, (3) stable magnetic properties approaching that of the bulk, (4) colloidal stability, (5) substantial shelf life, and (6) pose no significant in vitro toxicity. Using a dedicated hyperthermia system, we then identified that 16 nm monodisperse MNPs (σ-0.175) respond optimally to our chosen AMF conditions (f = 373 kHz, H₀ = 14 kA/m); however, with a broader size distribution (σ-0.284) the Specific Loss Power (SLP) decreases by 30%. Finally, we show that these tailored MNPs demonstrate maximum hyperthermia efficiency by reducing viability of Jurkat cells in vitro, suggesting our optimization translates truthfully to cell populations. In summary, we present a way to intrinsically optimize MFH by tailoring the MNPs to any applied AMF, a required precursor to optimize dose and time of treatment. PMID:22213652

  9. Tailor-made force fields for crystal-structure prediction.

    Science.gov (United States)

    Neumann, Marcus A

    2008-08-14

    A general procedure is presented to derive a complete set of force-field parameters for flexible molecules in the crystalline state on a case-by-case basis. The force-field parameters are fitted to the electrostatic potential as well as to accurate energies and forces generated by means of a hybrid method that combines solid-state density functional theory (DFT) calculations with an empirical van der Waals correction. All DFT calculations are carried out with the VASP program. The mathematical structure of the force field, the generation of reference data, the choice of the figure of merit, the optimization algorithm, and the parameter-refinement strategy are discussed in detail. The approach is applied to cyclohexane-1,4-dione, a small flexible ring. The tailor-made force field obtained for cyclohexane-1,4-dione is used to search for low-energy crystal packings in all 230 space groups with one molecule per asymmetric unit, and the most stable crystal structures are reoptimized in a second step with the hybrid method. The experimental crystal structure is found as the most stable predicted crystal structure both with the tailor-made force field and the hybrid method. The same methodology has also been applied successfully to the four compounds of the fourth CCDC blind test on crystal-structure prediction. For the five aforementioned compounds, the root-mean-square deviations between lattice energies calculated with the tailor-made force fields and the hybrid method range from 0.024 to 0.053 kcal/mol per atom around an average value of 0.034 kcal/mol per atom.

  10. Tailor-made force fields for crystal-structure prediction.

    Science.gov (United States)

    Neumann, Marcus A

    2008-08-14

    A general procedure is presented to derive a complete set of force-field parameters for flexible molecules in the crystalline state on a case-by-case basis. The force-field parameters are fitted to the electrostatic potential as well as to accurate energies and forces generated by means of a hybrid method that combines solid-state density functional theory (DFT) calculations with an empirical van der Waals correction. All DFT calculations are carried out with the VASP program. The mathematical structure of the force field, the generation of reference data, the choice of the figure of merit, the optimization algorithm, and the parameter-refinement strategy are discussed in detail. The approach is applied to cyclohexane-1,4-dione, a small flexible ring. The tailor-made force field obtained for cyclohexane-1,4-dione is used to search for low-energy crystal packings in all 230 space groups with one molecule per asymmetric unit, and the most stable crystal structures are reoptimized in a second step with the hybrid method. The experimental crystal structure is found as the most stable predicted crystal structure both with the tailor-made force field and the hybrid method. The same methodology has also been applied successfully to the four compounds of the fourth CCDC blind test on crystal-structure prediction. For the five aforementioned compounds, the root-mean-square deviations between lattice energies calculated with the tailor-made force fields and the hybrid method range from 0.024 to 0.053 kcal/mol per atom around an average value of 0.034 kcal/mol per atom. PMID:18642947

  11. Net shape manufacturing of ceramic micro parts with tailored graded layers

    International Nuclear Information System (INIS)

    Presented in this paper is a novel net shape manufacturing technology for making three-dimensional micro parts with functionally graded layers. Alumina/zirconia micro parts with either core–shell or top–bottom functionally graded material (FGM) profiles have been successfully fabricated by altering both the surface characteristics of polydimethylsiloxane (PDMS) micro moulds and ceramic suspensions composition. PDMS surface modifications were performed to achieve moulds with hydrophilic surfaces, which were used to form core/shell FGM green layers. On the other hand, moulds with hydrophobic surfaces were used to form top–bottom green layers. Cracks have been found between consecutive layers in both the green and sintered micro parts. It was found that, at dispersant concentration of about 9.0 mg g−1, the differences in the drying shrinkage between layers is less than 0.5%. In addition, layers of composition of 100% Al2O3–0% YSZ, 20% Al2O3–80% YSZ and 40% Al2O3–60% YSZ were found to produce less shrinkage difference during sintering. After optimization of both green and sintering layers, crack free core/shell and top–bottom alumina/zirconia FGM micro parts were successfully obtained. The proposed process enables the production of micro patterns tailored with functionally graded microstructures to locally enhance properties and performance. (paper)

  12. Dry particle coating of polymer particles for tailor-made product properties

    International Nuclear Information System (INIS)

    Disperse polymer powders with tailor-made particle properties are of increasing interest in industrial applications such as Selective Laser Beam Melting processes (SLM). This study focuses on dry particle coating processes to improve the conductivity of the insulating polymer powder in order to assemble conductive devices. Therefore PP particles were coated with Carbon Black nanoparticles in a dry particle coating process. This process was investigated in dependence of process time and mass fraction of Carbon Black. The conductivity of the functionalized powders was measured by impedance spectroscopy. It was found that there is a dependence of process time, respectively coating ratio and conductivity. The powder shows higher conductivities with increasing number of guest particles per host particle surface area, i.e. there is a correlation between surface functionalization density and conductivity. The assembled composite particles open new possibilities for processing distinct polymers such as PP in SLM process. The fundamentals of the dry particle coating process of PP host particles with Carbon Black guest particles as well as the influence on the electrical conductivity will be discussed

  13. Tailoring the emissive properties of photocathodes through materials engineering: Ultra-thin multilayers

    Science.gov (United States)

    Velázquez, Daniel; Seibert, Rachel; Ganegoda, Hasitha; Olive, Daniel; Rice, Amy; Logan, Kevin; Yusof, Zikri; Spentzouris, Linda; Terry, Jeff

    2016-01-01

    We report on an experimental verification that emission properties of photocathodes can be manipulated through the engineering of the surface electronic structure. Ultrathin multilayered MgO/Ag(0 0 1)/MgO films were grown by pulsed laser deposition, tuning the thickness n of the flanking MgO layers to 0, 2, 3, and 4 monolayers. We observed an increase in quantum efficiency and simultaneous decrease in work function with layer thickness. The scale and trend direction of measurements are in good but not excellent agreement with theory. Angle resolved photoemission data for the multilayered sample n = 3 showed that the emission profile has a metallic-like momentum dispersion. Deviations from theoretical predictions [K. Németh et al., PRL 104, 046801 (2010)] are attributed to imperfections of real surfaces in contrast with the ideal surfaces of the calculation. Photoemissive properties of cathodes are critical for electron beam applications such as photoinjectors for Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). An ideal photoemitter has a high quantum efficiency, low work function, low intrinsic emittance and long lifetime. It has been demonstrated here that emission properties may be systematically tailored by control of layer thickness in ultrathin multilayered structures. The reproducibility of the emission parameters under specific growth conditions is excellent, even though the interfaces themselves have varying degrees of roughness.

  14. Net shape manufacturing of ceramic micro parts with tailored graded layers

    Science.gov (United States)

    Hassanin, H.; Jiang, K.

    2014-01-01

    Presented in this paper is a novel net shape manufacturing technology for making three-dimensional micro parts with functionally graded layers. Alumina/zirconia micro parts with either core-shell or top-bottom functionally graded material (FGM) profiles have been successfully fabricated by altering both the surface characteristics of polydimethylsiloxane (PDMS) micro moulds and ceramic suspensions composition. PDMS surface modifications were performed to achieve moulds with hydrophilic surfaces, which were used to form core/shell FGM green layers. On the other hand, moulds with hydrophobic surfaces were used to form top-bottom green layers. Cracks have been found between consecutive layers in both the green and sintered micro parts. It was found that, at dispersant concentration of about 9.0 mg g-1, the differences in the drying shrinkage between layers is less than 0.5%. In addition, layers of composition of 100% Al2O3-0% YSZ, 20% Al2O3-80% YSZ and 40% Al2O3-60% YSZ were found to produce less shrinkage difference during sintering. After optimization of both green and sintering layers, crack free core/shell and top-bottom alumina/zirconia FGM micro parts were successfully obtained. The proposed process enables the production of micro patterns tailored with functionally graded microstructures to locally enhance properties and performance.

  15. Structural and magnetic properties of "thick" microwires produced by the modernized Ulitovsky-Tailor method

    Science.gov (United States)

    Shalygina, E. E.; Kharlamova, A. M.; Shalygin, A. N.; Molokanov, V. V.; Umnov, P. P.; Umnova, N. V.; Chueva, T. R.

    2016-10-01

    In this article the results on the detailed investigation of the structural, elastic and magnetic properties of the "thick" Fe73,5Si13,5B9Nb3Cu1 and Fe31Co34Ni10(SiB)25 amorphous microwires with the glass shell, produced by the modernized Ulitovsky-Tailor method, are presented. The diameter of the metallic core of microwires was varied from 50 to 200 μm. It was found that the core has the stable geometric parameters along the microwire length and the smooth (almost without defects) surface. The studied samples are characterized by the weak dispersion of magnetic anisotropy of the near-surface layers and the high homogeneity of the near-surface local magnetic properties. Furthermore, the microwires exhibit the high plasticity and strength. They are not destroyed even after their full tightening into a knot. The strong influence of tensile stress and torsion on the magnetic properties of the microwires was discovered. The comparison of magneto-field behavior of the studied samples was performed.

  16. Tailoring the mechanical properties of SU-8/clay nanocomposites: polymer microcantilever fabrication perspective

    Science.gov (United States)

    Chen, Hao; Ojijo, Vincent; Cele, Hastings; Joubert, Trudi; Suprakas, Sinha Ray; Land, Kevin

    2014-06-01

    SU-8/Clay nanocomposite is considered as a candidate material for microcantilever sensor fabrication. Organically modified montmorillonite clay nanoparticles are dispersed in the universally used negative photoresist polymer SU-8, for a low cost material, which is also biocompatible. If varying the clay loading of the composite material yields a variation of the Young's modulus, the tailored material stiffness presents an opportunity for fabrication of microcantilevers with tunable sensor sensitivity. With this microcantilever application perspective, mechanical and thermal properties of the material were investigated. SU-8/Clay nanocomposite samples were prepared with clay loadings from 1wt% - 10wt%. Tensile test results show a general trend of increase in composite modulus with an increase in the clay loading up to 7wt%, followed by a small drop at 10wt%. The composite material indeed yields moderate variation of the Young's modulus. It was also found that the thermal degradation peak of the material occurred at 300°C, which is beyond the operating temperature of typical microcantilever sensor applications. The fabrication of a custom designed microcantilever array chip with the SU-8/Clay nanocomposite material was achieved in a class 100 cleanroom, using spin-coating and photolithography microfabrication techniques. The optimization of the process for fabricating microcantilever with the SU-8/Clay nanocomposite material is discussed in this paper. The results of this research are promising for cheaper mass production of low cost disposable, yet sensitive, microcantilever sensor elements, including biosensor applications.

  17. Dry particle coating of polymer particles for tailor-made product properties

    Science.gov (United States)

    Blümel, C.; Schmidt, J.; Dielesen, A.; Sachs, M.; Winzer, B.; Peukert, W.; Wirth, K.-E.

    2014-05-01

    Disperse polymer powders with tailor-made particle properties are of increasing interest in industrial applications such as Selective Laser Beam Melting processes (SLM). This study focuses on dry particle coating processes to improve the conductivity of the insulating polymer powder in order to assemble conductive devices. Therefore PP particles were coated with Carbon Black nanoparticles in a dry particle coating process. This process was investigated in dependence of process time and mass fraction of Carbon Black. The conductivity of the functionalized powders was measured by impedance spectroscopy. It was found that there is a dependence of process time, respectively coating ratio and conductivity. The powder shows higher conductivities with increasing number of guest particles per host particle surface area, i.e. there is a correlation between surface functionalization density and conductivity. The assembled composite particles open new possibilities for processing distinct polymers such as PP in SLM process. The fundamentals of the dry particle coating process of PP host particles with Carbon Black guest particles as well as the influence on the electrical conductivity will be discussed.

  18. Dry particle coating of polymer particles for tailor-made product properties

    Energy Technology Data Exchange (ETDEWEB)

    Blümel, C., E-mail: karl-ernst.wirth@fau.de; Schmidt, J., E-mail: karl-ernst.wirth@fau.de; Dielesen, A., E-mail: karl-ernst.wirth@fau.de; Sachs, M., E-mail: karl-ernst.wirth@fau.de; Winzer, B., E-mail: karl-ernst.wirth@fau.de; Peukert, W., E-mail: karl-ernst.wirth@fau.de; Wirth, K.-E., E-mail: karl-ernst.wirth@fau.de [Institute of Particle Technology, University of Erlangen-Nuremberg (Germany)

    2014-05-15

    Disperse polymer powders with tailor-made particle properties are of increasing interest in industrial applications such as Selective Laser Beam Melting processes (SLM). This study focuses on dry particle coating processes to improve the conductivity of the insulating polymer powder in order to assemble conductive devices. Therefore PP particles were coated with Carbon Black nanoparticles in a dry particle coating process. This process was investigated in dependence of process time and mass fraction of Carbon Black. The conductivity of the functionalized powders was measured by impedance spectroscopy. It was found that there is a dependence of process time, respectively coating ratio and conductivity. The powder shows higher conductivities with increasing number of guest particles per host particle surface area, i.e. there is a correlation between surface functionalization density and conductivity. The assembled composite particles open new possibilities for processing distinct polymers such as PP in SLM process. The fundamentals of the dry particle coating process of PP host particles with Carbon Black guest particles as well as the influence on the electrical conductivity will be discussed.

  19. Effects of chemical dispersants on oil physical properties and dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Khelifa, A.; Fingas, M.; Hollebone, B.P.; Brown, C.E. [Environment Canada, Ottawa, ON (Canada). ; Pjontek, D. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering

    2007-07-01

    Laboratory and field testing have shown that the dispersion of oil spilled in water is influenced by chemical dispersants via the modification of the interfacial properties of the oil, such as oil-brine interfacial tension (IFT). This study focused on new laboratory experiments that measured the effects on the physical properties and dispersion of oil, with particular reference to the effects of chemical dispersants on IFT and oil viscosity and the subsequent effects on oil droplet formation. Experiments were conducted at 15 degrees C using Arabian Medium, Alaska North Slope and South Louisiana crude and Corexit 9500 and Corexit 9527 chemical dispersants. The dispersants were denser than the 3 oils. The effect of IFT reduction on oil dispersion was measured and showed substantial reduction in the size and enhancement of the concentration of oil droplets in the water column. It was shown that the brine-oil IFT associated with the 3 crudes reduced to less than 3.6 mN/m with the application of the chemical dispersants, even at a low dispersant-to-oil ratio (DOR) value of 1:200. The use of chemical dispersants increased the viscosity of the dispersant-oil mixture up to 40 per cent over the neat crude oil. It was shown that for each mixing condition, an optimum value of DOR exists that provides for maximal dispersant effectiveness. The IFT reaches maximum reduction at optimum DOR. It was suggested that oil spill modelling can be improved with further study of IFT reduction with DOR and variations of critical micelle concentration with the type and solubility of chemical dispersant, oil type and oil to water ratio. 13 refs., 3 tabs., 7 figs.

  20. Avoiding a knowledge gap in a multiethnic statewide social marketing campaign: is cultural tailoring sufficient?

    Science.gov (United States)

    Buchthal, O Vanessa; Doff, Amy L; Hsu, Laura A; Silbanuz, Alice; Heinrich, Katie M; Maddock, Jay E

    2011-03-01

    In 2007, the State of Hawaii, Healthy Hawaii Initiative conducted a statewide social-marketing campaign promoting increased physical activity and nutrition. The campaign included substantial formative research to develop messages tailored for Hawaii's multiethnic Asian and Pacific Islander populations. The authors conducted a statewide random digital dialing telephone survey to assess the campaign's comparative reach among individuals with different ethnicities and different levels of education and income. This analysis suggests that the intervention was successful in reaching its target ethnic audiences. However, a knowledge gap related to the campaign appeared among individuals with incomes less than 130% of the poverty level and those with less than a high school education. These results varied significantly by message and the communication channel used. Recall of supermarket-based messages was significantly higher among individuals below 130% of the poverty level and those between 18 and 35 years of age, 2 groups that showed consistently lower recall of messages in other channels. Results suggest that cultural tailoring for ethnic audiences, although important, is insufficient for reaching low-income populations, and that broad-based social marketing campaigns should consider addressing socioeconomic status-related channel preferences in formative research and campaign design.

  1. Avoiding a knowledge gap in a multiethnic statewide social marketing campaign: is cultural tailoring sufficient?

    Science.gov (United States)

    Buchthal, O Vanessa; Doff, Amy L; Hsu, Laura A; Silbanuz, Alice; Heinrich, Katie M; Maddock, Jay E

    2011-03-01

    In 2007, the State of Hawaii, Healthy Hawaii Initiative conducted a statewide social-marketing campaign promoting increased physical activity and nutrition. The campaign included substantial formative research to develop messages tailored for Hawaii's multiethnic Asian and Pacific Islander populations. The authors conducted a statewide random digital dialing telephone survey to assess the campaign's comparative reach among individuals with different ethnicities and different levels of education and income. This analysis suggests that the intervention was successful in reaching its target ethnic audiences. However, a knowledge gap related to the campaign appeared among individuals with incomes less than 130% of the poverty level and those with less than a high school education. These results varied significantly by message and the communication channel used. Recall of supermarket-based messages was significantly higher among individuals below 130% of the poverty level and those between 18 and 35 years of age, 2 groups that showed consistently lower recall of messages in other channels. Results suggest that cultural tailoring for ethnic audiences, although important, is insufficient for reaching low-income populations, and that broad-based social marketing campaigns should consider addressing socioeconomic status-related channel preferences in formative research and campaign design. PMID:21298585

  2. Improvement of interaction between pre-dispersed multi-walled carbon nanotubes and unsaturated polyester resin

    Energy Technology Data Exchange (ETDEWEB)

    Beg, M. D. H., E-mail: dhbeg@yahoo.com; Moshiul Alam, A. K. M., E-mail: akmmalam@gmail.com; Yunus, R. M. [Universiti Malaysia Pahang, Faculty of Chemical and Natural Resources Engineering (Malaysia); Mina, M. F. [Bangladesh University of Engineering and Technology, Department of Physics (Bangladesh)

    2015-01-15

    Efforts are being given to the development of well-dispersed nanoparticle-reinforced polymer nanocomposites in order to tailor the material properties. In this perspective, well dispersion of multi-walled carbon nanotubes (MWCNTs) in unsaturated polyester resin (UPR) was prepared using pre-dispersed MWCNTs in tetrahydrofuran solvent with ultrasonication method. Then the well-dispersed MWCNTs reinforced UPR nanocomposites were fabricated through solvent evaporation. Fourier-transform infrared spectroscopy indicates a good interaction between matrix and MWCNTs. This along with homogeneous dispersion of nanotubes in matrix has been confirmed by the field emission scanning electron microscopy. At low shear rate, the value of viscosity of UPR is 8,593 mPa s and that of pre-dispersed MWCNT–UPR suspension is 43,491 mPa s, showing implicitly a good dispersion of nanotubes. A notable improvement in the crystallinity of UPR from 14 to 21 % after MWCNTs inclusion was observed by X-ray diffractometry. The mechanical properties, such as tensile strength, tensile modulus, impact strength, and elongation-at-break, of nanocomposite were found to be increased to 22, 20, 28, and 87 %, respectively. The estimated melting enthalpy per gram for composites as analyzed by differential scanning calorimetry is higher than that of UPR. The onset temperature of thermal decomposition in the nanocomposites as monitored by thermogravimetric analysis is found higher than that of UPR. Correlations among MWCNTs dispersion, nucleation, fracture morphology, and various properties were measured and reported.

  3. Improvement of interaction between pre-dispersed multi-walled carbon nanotubes and unsaturated polyester resin

    International Nuclear Information System (INIS)

    Efforts are being given to the development of well-dispersed nanoparticle-reinforced polymer nanocomposites in order to tailor the material properties. In this perspective, well dispersion of multi-walled carbon nanotubes (MWCNTs) in unsaturated polyester resin (UPR) was prepared using pre-dispersed MWCNTs in tetrahydrofuran solvent with ultrasonication method. Then the well-dispersed MWCNTs reinforced UPR nanocomposites were fabricated through solvent evaporation. Fourier-transform infrared spectroscopy indicates a good interaction between matrix and MWCNTs. This along with homogeneous dispersion of nanotubes in matrix has been confirmed by the field emission scanning electron microscopy. At low shear rate, the value of viscosity of UPR is 8,593 mPa s and that of pre-dispersed MWCNT–UPR suspension is 43,491 mPa s, showing implicitly a good dispersion of nanotubes. A notable improvement in the crystallinity of UPR from 14 to 21 % after MWCNTs inclusion was observed by X-ray diffractometry. The mechanical properties, such as tensile strength, tensile modulus, impact strength, and elongation-at-break, of nanocomposite were found to be increased to 22, 20, 28, and 87 %, respectively. The estimated melting enthalpy per gram for composites as analyzed by differential scanning calorimetry is higher than that of UPR. The onset temperature of thermal decomposition in the nanocomposites as monitored by thermogravimetric analysis is found higher than that of UPR. Correlations among MWCNTs dispersion, nucleation, fracture morphology, and various properties were measured and reported

  4. Optimal Path Planning for Mobile Robot Using Tailored Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Dong Xiao Xian

    2013-07-01

    Full Text Available During routine inspecting, mobile robot may be requested to visit multiple locations to execute special tasks occasionally. This study aims at optimal path planning for multiple goals visiting task based on tailored genetic algorithm. The proposed algorithm will generate an optimal path that has the least idle time, which is proven to be more effective on evaluating a path in our previous work. In proposed algorithm, customized chromosome representing a path and genetic operators including repair and cut are developed and implemented. Afterwards, simulations are carried out to verify the effectiveness and applicability. Finally, analysis of simulation results is conducted and future work is addressed.

  5. Tailoring spin-orbit torque in diluted magnetic semiconductors

    KAUST Repository

    Li, Hang

    2013-05-16

    We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory, and we report here: (1) a strong correlation exists between the angular dependence of the torque and the anisotropy of the Fermi surface; (2) the spin orbit torque depends nonlinearly on the exchange coupling. Our findings suggest the possibility to tailor the spin orbit torque magnitude and angular dependence by structural design.

  6. [Multidisciplinary tailoring of therapy of metastatic colon cancer].

    Science.gov (United States)

    Österlund, Pia; Isoniemi, Helena; Scheinin, Tom; Ristimäki, Ari; Lantto, Eila

    2016-01-01

    Treatment of colon cancer requires multidisciplinary team work. The multitude of therapies in metastatic colon cancer have led to longer overall survival with fewer symptoms. Median survival has increased from 5 months with the best supportive care to 30-40 months in randomized studies, even with curative treatment in some patients. Tailoring of the treatment is best done by a multidisciplinary team considering radiotherapy and operation of the primary tumor, resection of liver, lung and peritoneal metastases, medical treatment alternatives, palliative care, ablative methods etc. Without skillful surgeons, oncologists, pathologists, geneticists, radiologists etc. the best treatment opportunities may be missed. PMID:27483635

  7. Design and Implementation of Company Tailored Automated Material Handling

    DEFF Research Database (Denmark)

    Langer, Gilad; Bilberg, Arne

    1996-01-01

    This article focuses on the problems of analysing automation of material handling systems in order to develop an efficient automated solution that is specifically tailored to the company. The research has resulted in development of new methods for evaluating factory automation from design...... for their application with computer aided information processing tools. The framework is named the "Automated Material Handling (AMH) Preference GuideLine". The research has been carried out in close co-operation with Danish and European industry, where implementations of automation can be referred to. It is our...

  8. Vacuum template synthesis of multifunctional nanotubes with tailored nanostructured walls

    OpenAIRE

    A. Nicolas Filippin; Manuel Macias-Montero; Zineb Saghi; Jesús Idígoras; Pierre Burdet; Angel Barranco; Paul Midgley; Juan A. Anta; Ana Borras

    2016-01-01

    A three-step vacuum procedure for the fabrication of vertical TiO2 and ZnO nanotubes with three dimensional walls is presented. The method combines physical vapor deposition of small-molecules, plasma enhanced chemical vapor deposition of inorganic functional thin films and layers and a post-annealing process in vacuum in order to remove the organic template. As a result, an ample variety of inorganic nanotubes are made with tunable length, hole dimensions and shapes and tailored wall composi...

  9. Improving changeover time: a tailored SMED approach for welding cells

    OpenAIRE

    Guzmán, Ferradás P; Salonitis, Konstantinos

    2013-01-01

    Short changeover times have always been critical in manufacturing business. Set-up duration reduction initiatives have been associated with Shingós ‘Single Minute Exchange of Die' (SMED) method. Although a great number of companies have initiated SMED, some failed on implementation. The main reason is that strict application of Shingós SMED methodology is not the most efficient way to reduce set-up times in all situations. In the present study a tailored methodology is presented that has been...

  10. Tailored solar optics for maximal optical tolerance and concentration

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Alex [Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus (Israel); Gordon, Jeffrey M. [Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus (Israel); The Pearlstone Center for Aeronautical Engineering Studies, Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beersheva (Israel)

    2011-02-15

    Recently identified fundamental classes of dual-mirror double-tailored nonimaging optics have the potential to satisfy the pragmatic exigencies of concentrator photovoltaics. Via a comprehensive survey of their parameter space, including raytrace verification, we identify champion high-concentration high-efficiency designs that offer unprecedented optical tolerance (i.e., sensitivity to off-axis orientation) - a pivotal figure-of-merit with a basic bound that depends on concentration, exit angle, and effective solar angular radius. For comparison, results for the best corresponding dual-mirror aplanatic concentrators are also presented. (author)

  11. Dispersion and current measurements

    International Nuclear Information System (INIS)

    A model for the simulation of particle movements in water should incorporate the mutual distance dependent correlation. As long as reliable data are given accessible a model can be created of the dispersion in a given area from a statistical description of turbulence. Current measurements have been performed in an area north of the Swedish nuclear power plant Barsebaeck, and statistical time series analysis have made it possible to estimate multivariate autoregressive moving-average (ARMA) models for these data using the Box-Jenkins method. The correlation structure for the area has been investigated in detail. Transport and dispersion models for the marine environment are used in estimating doses to the population from the aquatic food chain. Some of these models are described with special emphasis on the time and length scales they cover. Furthermore, to illustrate the background of the simulation model, short introductuions are given to health physics, time series analysis, and turbulence theory. Analysis of the simulation model shows the relative importance of the different parameters. The model can be expanded to conditional simulation, where the current measurements are used directly to simulate the movement of one of the particles. Results from the model are also compared to results from a sampling of bioindicators (Fucus vesiculosus) along the Danish coast. The reliability of bioindicators in this kind of experiment is discussed. (author)

  12. Preparing mono-dispersed liquid core PDMS microcapsules from thiol–ene–epoxy-tailored flow-focusing microfluidic devices

    DEFF Research Database (Denmark)

    Mazurek, Piotr Stanislaw; Daugaard, Anders Egede; Skolimowski, Maciej;

    2015-01-01

    An applied dual-cure system based on thiol–ene and thiol–epoxy “click chemistry” reactions was proved to be an extremely effective and easy to use tool for preparing microfluidic chips, thereby allowing for precise control over material properties and providing the possibility of covalently bonding...... of compositions in relation to high hydrophilicity and hydrophobicity. An obtained microfluidic device was subsequently used in order to produce PDMS microcapsules of very narrow size distribution and which contained various common liquids, such as water and ethanol, as well as an ionic liquid 2...

  13. Bioassay-tracked temperature-stress-induced chemical degradation of bio-active wound healing antibacterial extract of Dissotis theifolia stem dispersed in a pharmaceutical cream and ointment

    Directory of Open Access Journals (Sweden)

    D C Odimegwu

    2011-03-01

    Full Text Available Summary: Owing to the present upsurge in the utilization of medicinal herbal preparations, routine quality control assessment for their continued efficacy and safety is essential if the products are to continue to maintain their pharmacological usefulness under harsh use and storage temperature normally experienced, particularly in the tropics. As herbal medicinal products are complex mixtures which originate from biological sources and are therefore very variable and difficult to characterize, great efforts are necessary to guarantee a constant and adequate quality of potency and safety through selection of an appropriate analytical method for the monitoring of the active ingredient content of such products. Dissotis theifolia is a commonly used plant in traditional herbal medicine for the treatment of several medical ailments, including topical bacterial infections, among several communities in Nigeria. In this present study, the quality control monitoring of the content of active ingredient of pharmaceutical cream and ointment containing the methanol extract of the stem exposed to variegated temperatures was established using a specific microbiological assay method. Results showed reduction of potency of the formulated extracts due to chemical degradation through the first order reaction pathway. The ointment formulation demonstrated a longer half-life and shelf-life being more stable than the cream.   Industrial relevance: Herbal medicine, a form of complimentary and alternative medicine, is becoming increasingly popular in both developing and developed countries. However, there appear to be limited data on their temperature-induce chemical stability/instability profile which correspondingly impinges on their efficacy and safety. In view of this study involving stem extract of D. theifolia formulated as cream and ointment, appropriate bioassay-based techniques can be employed in monitoring the potency of herbal preparations and can serve as

  14. Uniformly dispersed CdS nanoparticles sensitized TiO2 nanotube arrays with enhanced visible-light photocatalytic activity and stability

    International Nuclear Information System (INIS)

    In this study, TiO2 nanotube arrays (TiO2-NTs) with various intertube spaces were fabricated in the electrolyte with different water contents and the CdS nanoparticles (CdS NPs) were further deposited onto the TiO2-NTs as a sensitizer via a sequential chemical bath deposition (S-CBD) method. The FE-SEM, TEM, XRD and XPS results demonstrated that the CdS NPs were uniformly deposited onto the surface of TiO2-NTs. It was found that higher water content in electrolyte was in favor of large intertube space and pore size and the uniform deposition of CdS NPs. The photocatalytic degradation of methyl orange was tested with the as-prepared CdS/TiO2-NTs under visible light (λ>400 nm). It was found that the photodegradation rate reached as high as 96.7% under visible irradiation for 180 min. In addition, a reasonable degradation rate of 75.8% was achieved even after 5 cycles, suggesting a good photocatalytic stability of the as-prepared CdS/TiO2-NTs. - Graphical abstract: The whole sheet of CdS NPs sensitized TiO2-NTs with the Ti subtract was used for degradation of methyl orange under visible light (λ>400 nm) on a XPA-7 photochemical reactor. - Highlights: • Intertube space, pore size were controlled by changing water content in electrolyte. • CdS nanoparticles were uniformly deposited onto the surface of TiO2 nanotubes. • The catalyst with Ti substrate used as a whole was very convenient for recycling. • Visible-light photocatalytic activity and stability were highly enhanced

  15. Toxicity of dispersant application: Biomarkers responses in gills of juvenile golden grey mullet (Liza aurata).

    Science.gov (United States)

    Milinkovitch, Thomas; Godefroy, Joachim; Théron, Michaël; Thomas-Guyon, Hélène

    2011-10-01

    Dispersant use in nearshore areas is likely to increase the exposure of aquatic organisms to petroleum. To measure the toxicity of this controversial response technique, golden grey mullets (Liza aurata) were exposed to mechanically dispersed oil, chemically dispersed oil, dispersant alone in seawater, water-soluble fraction of oil and to seawater as a control treatment. Several biomarkers were assessed in the gills (enzymatic antioxidant activities, glutathione content, lipid peroxidation) and in the gallbladder (polycylic aromatic hydrocarbons metabolites). The significant differences between chemically dispersed oil and water soluble fraction of oil highlight the environmental risk to disperse an oil slick when containment and recovery can be conducted. The lack of significance between chemically and mechanically dispersed oil suggests that dispersant application is no more toxic than the natural dispersion of the oil slick. The results of this study are of interest in order to establish dispersant use policies in nearshore areas. PMID:21592637

  16. SMED - Sulphur MEditerranean Dispersion

    Science.gov (United States)

    Salerno, Giuseppe G.; Sellitto, Pasquale; Corradini, Stefano; Di Sarra, Alcide Giorgio; Merucci, Luca; Caltabiano, Tommaso; La Spina, Alessandro

    2016-04-01

    Emissions of volcanic gases and particles can have profound impacts on terrestrial environment, atmospheric composition, climate forcing, and then on human health at various temporal and spatial scales. Volcanic emissions have been identified as one of the largest sources of uncertainty in our understanding of recent climate change trends. In particular, a primary role is acted by sulphur dioxide emission due to its conversion to volcanic sulphate aerosol via atmospheric oxidation. Aerosols may play a key role in the radiative budget and then in photochemistry and tropospheric composition. Mt. Etna is one of the most prodigious and persistent emitters of gasses and particles on Earth, accounting for about 10% of global average volcanic emission of CO2 and SO2. Its sulphur emissions stand for 0.7 × 106 t S/yr9 and then about 10 times bigger than anthropogenic sulphur emissions in the Mediterranean area. Centrepiece of the SMED project is to advance the understanding of volcanogenic sulphur dioxide and sulphate aerosol particles dispersion and radiative impact on the downwind Mediterranean region by an integrated approach between ground- and space-based observations and modelling. Research is addressed by exploring the potential relationship between proximal SO2 flux and aerosol measured remotely in the volcanic plume of Mt. Etna between 2000 and 2014 and distal aerosol ground-based measurements in Lampedusa, Greece, and Malta from AERONET network. Ground data are combined with satellite multispectral polar and geostationary imagers able to detect and retrieve volcanic ash and SO2. The high repetition time of SEVIRI (15 minutes) will ensure the potential opportunity to follow the entire evolution of the volcanic cloud, while, the higher spatial resolution of MODIS (1x1 km2), are exploited for investigating the probability to retrieve volcanic SO2 abundances from passive degassing. Ground and space observations are complemented with atmospheric Lagrangian model

  17. Dispersive transport across interfaces

    Science.gov (United States)

    Berkowitz, Brian; Adler, Pierre

    2015-04-01

    Experiments demonstrating asymmetrical dispersive transport of a conservative tracer across interfaces between different porous materials have recently been performed. Here, this phenomenon is studied numerically on the pore scale. The flow field is derived by solving the Stokes equation. The dispersive transport is simulated by a large number of particles undergoing random walks under the simultaneous action of convection and diffusion. Two main two-dimensional configurations are studied; each consists of two segments (called coarse and fine) with the same structure, porosity, and length along the main flow, but different characteristic solid/pore sizes. One structure consists of two channels containing cavities of different sizes, and the second of square "grains" of different sizes. At time t=0, a large number of particles is injected (as a pulse) around a given cross-section. The corresponding breakthrough curves (BTCs) are registered as functions of time at six different cross sections. Calculations are made twice; in the first case (CtoF), particles are injected in the coarse side and are transported towards the fine one; in the second one (FtoC), the opposite case is studied. These calculations are performed for various Péclet numbers (Pe). Comparison of the resulting BTCs shows features that are similar to experimental observations, but with qualitative and quantitative differences. The influences of the medium, of the injection and observation planes, and of Pe are detailed and discussed. A BTC for pulse injection can be characterized by its maximum M(t_M) and the time tM at which it occurs. The observed differences for channels bounded by cavities are very small. However for the granular structures, M(t_M) is always larger for FtoC than for CtoF ; tM depends on all the parameters, namely Pe, the size ratio between the large and small grains, the injection and the observation planes. The numerical results are systematically compared with solutions of one

  18. Broadband energy harvesting using acoustic black hole structural tailoring

    Science.gov (United States)

    Zhao, Liuxian; Conlon, Stephen C.; Semperlotti, Fabio

    2014-06-01

    This paper explores the concept of an acoustic black hole (ABH) as a main design framework for performing dynamic structural tailoring of mechanical systems for vibration energy harvesting applications. The ABH is an integral feature embedded in the host structure that allows for a smooth reduction of the phase velocity, theoretically approaching zero, while minimizing the reflected energy. This mechanism results in structural areas with high energy density that can be effectively exploited to develop enhanced vibration-based energy harvesting. Fully coupled electro-mechanical models of an ABH tapered structure with surface mounted piezo-transducers are developed to numerically simulate the response of the system to both steady state and transient excitations. The design performances are numerically evaluated using structural intensity data as well as the instantaneous voltage/power and energy output produced by the piezo-transducer network. Results show that the dynamically tailored structural design enables a drastic increase in the harvested energy as compared to traditional structures, both under steady state and transient excitation conditions.

  19. Models to Tailor Brain Stimulation Therapies in Stroke

    Directory of Open Access Journals (Sweden)

    E. B. Plow

    2016-01-01

    Full Text Available A great challenge facing stroke rehabilitation is the lack of information on how to derive targeted therapies. As such, techniques once considered promising, such as brain stimulation, have demonstrated mixed efficacy across heterogeneous samples in clinical studies. Here, we explain reasons, citing its one-type-suits-all approach as the primary cause of variable efficacy. We present evidence supporting the role of alternate substrates, which can be targeted instead in patients with greater damage and deficit. Building on this groundwork, this review will also discuss different frameworks on how to tailor brain stimulation therapies. To the best of our knowledge, our report is the first instance that enumerates and compares across theoretical models from upper limb recovery and conditions like aphasia and depression. Here, we explain how different models capture heterogeneity across patients and how they can be used to predict which patients would best respond to what treatments to develop targeted, individualized brain stimulation therapies. Our intent is to weigh pros and cons of testing each type of model so brain stimulation is successfully tailored to maximize upper limb recovery in stroke.

  20. Sasang Constitutional Medicine as a Holistic Tailored Medicine

    Directory of Open Access Journals (Sweden)

    Jong Yeol Kim

    2009-01-01

    Full Text Available Sasang constitutional medicine (SCM is a unique traditional Korean therapeutic alternative form of medicine. Based on the Yin and Yang theory and on Confucianism, humans are classified into four constitutions. These differ in terms of (i sensitivity to certain groups of herbs and medicines, (ii equilibrium among internal organic functions, (iii physical features and (iv psychological characteristics. We propose that two main axes in the physiopathology of SCM (food intake/waste discharge and consuming/storing Qi and body fluids are equivalent to the process of internal–external exchange and catabolism/anabolism in modern physiology, respectively. We then used this hypothesis to discuss the physiological and pathological principles of SCM. Constitution-based medicine is based on the theory that some medicinal herbs and remedies are only appropriate for certain constitutions and can cause adverse effects in others. The constitutional approach of SCM share the same vision as tailored medicine; an individualized therapy that can minimize the risk of adverse reaction while increasing the efficacy and an individualized self-regulation that can help prevent specific susceptible chronic disease and live healthily. There is still a long way to this goal for both SCM and tailored medicine, but we may benefit from systems approaches such as systems biology. We suggest that constitutional perspective of SCM and our hypothesis of two main processes may provide a novel insight for further studies.

  1. Sasang constitutional medicine as a holistic tailored medicine.

    Science.gov (United States)

    Kim, Jong Yeol; Pham, Duong Duc

    2009-09-01

    Sasang constitutional medicine (SCM) is a unique traditional Korean therapeutic alternative form of medicine. Based on the Yin and Yang theory and on Confucianism, humans are classified into four constitutions. These differ in terms of (i) sensitivity to certain groups of herbs and medicines, (ii) equilibrium among internal organic functions, (iii) physical features and (iv) psychological characteristics. We propose that two main axes in the physiopathology of SCM (food intake/waste discharge and consuming/storing Qi and body fluids) are equivalent to the process of internal-external exchange and catabolism/anabolism in modern physiology, respectively. We then used this hypothesis to discuss the physiological and pathological principles of SCM. Constitution-based medicine is based on the theory that some medicinal herbs and remedies are only appropriate for certain constitutions and can cause adverse effects in others. The constitutional approach of SCM share the same vision as tailored medicine; an individualized therapy that can minimize the risk of adverse reaction while increasing the efficacy and an individualized self-regulation that can help prevent specific susceptible chronic disease and live healthily. There is still a long way to this goal for both SCM and tailored medicine, but we may benefit from systems approaches such as systems biology. We suggest that constitutional perspective of SCM and our hypothesis of two main processes may provide a novel insight for further studies. PMID:19745007

  2. Tailoring Hydrogel Viscoelasticity with Physical and Chemical Crosslinking

    Directory of Open Access Journals (Sweden)

    Michal Bartnikowski

    2015-12-01

    Full Text Available Biological tissues are viscoelastic, demonstrating a mixture of fluid and solid responses to mechanical strain. Whilst viscoelasticity is critical for native tissue function, it is rarely used as a design criterion in biomaterials science or tissue engineering. We propose that viscoelasticity may be tailored to specific levels through manipulation of the hydrogel type, or more specifically the proportion of physical and chemical crosslinks present in a construct. This theory was assessed by comparing the mechanical properties of various hydrogel blends, comprising elastic, equilibrium, storage and loss moduli, as well as the loss tangent. These properties were also assessed in human articular cartilage explants. It was found that whilst very low in elastic modulus, the physical crosslinks found in gellan gum-only provided the closest approximation of loss tangent levels found in cartilage. Blends of physical and chemical crosslinks (gelatin methacrylamide (GelMA combined with gellan gum gave highest values for elastic response. However, a greater proportion of gellan gum to GelMA than investigated may be required to achieve native cartilage viscoelasticity in this case. Human articular chondrocytes encapsulated in hydrogels remained viable over one week of culture. Overall, it was shown that viscoelasticity may be tailored similarly to other mechanical properties and may prove a new criterion to be included in the design of biomaterial structures for tissue engineering.

  3. Directly tailoring photon-electron coupling for sensitive photoconductance

    Science.gov (United States)

    Huang, Zhiming; Zhou, Wei; Huang, Jingguo; Wu, Jing; Gao, Yanqing; Qu, Yue; Chu, Junhao

    2016-03-01

    The coupling between photons and electrons is at the heart of many fundamental phenomena in nature. Despite tremendous advances in controlling electrons by photons in engineered energy-band systems, control over their coupling is still widely lacking. Here we demonstrate an unprecedented ability to couple photon-electron interactions in real space, in which the incident electromagnetic wave directly tailors energy bands of solid to generate carriers for sensitive photoconductance. By spatially coherent manipulation of metal-wrapped material system through anti-symmetric electric field of the irradiated electromagnetic wave, electrons in the metals are injected and accumulated in the induced potential well (EIW) produced in the solid. Respective positive and negative electric conductances are easily observed in n-type and p-type semiconductors into which electrons flow down from the two metallic sides under light irradiation. The photoconductivity is further confirmed by sweeping the injected electrons out of the semiconductor before recombination applied by sufficiently strong electric fields. Our work opens up new perspectives for tailoring energy bands of solids and is especially relevant to develop high effective photon detection, spin injection, and energy harvesting in optoelectronics and electronics.

  4. Design and Manufacture of Elastically Tailored Tow Placed Plates

    Science.gov (United States)

    Tatting, Brain F.; Guerdal, Zafer; Jegley, Dawn (Technical Monitor)

    2002-01-01

    Elastic stiffness tailoring of laminated composite panels by allowing the fibers to curve within the plane of the laminate is a relatively novel design concept that has been demonstrated to be both beneficial and practical. In particular, for structures with highly non-uniform stress states, such as the case of a flat panel with a central hole subjected to in-plane loading, the concept is likely to provide substantial improvements in load carrying capability. The objective of the present study is to determine the effectiveness of stiffness tailoring through the use of curvilinear fibers to reduce stress concentrations around the hole and improve the load carrying capability of panels with holes. In this study software was created that translates standard finite element models with traditional laminate definitions into ones that possess stacking sequences with curvilinear fiber paths that are directly manufacturable using an advanced tow placement machine. Preliminary designs for the manufacturing and testing phase were determined through rudimentary design studies for flat plates without holes under axial compression. These candidate designs were then analyzed using finite element models that accurately reflect the test conditions and geometries in order to select final designs for testing. A total of six large panels, measuring three feet by six feet, each of which are used to produce four specimens with or without holes, were fabricated and delivered to NASA for machining and testing.

  5. Process Design of Aluminum Tailor Heat Treated Blanks

    Directory of Open Access Journals (Sweden)

    Alexander Kahrimanidis

    2015-12-01

    Full Text Available In many industrials field, especially in the automotive sector, there is a trend toward lightweight constructions in order to reduce the weight and thereby the CO2 and NOx emissions of the products. An auspicious approach within this context is the substitution of conventional deep drawing steel by precipitation hardenable aluminum alloys. However, based on the low formability, the application for complex stamping parts is challenging. Therefore, at the Institute of Manufacturing Technology, an innovative technology to enhance the forming limit of these lightweight materials was invented. The key idea of the so-called Tailor Heat Treated Blanks (THTB is optimization of the mechanical properties by local heat treatment before the forming operation. An accurate description of material properties is crucial to predict the forming behavior of tailor heat treated blanks by simulation. Therefore, within in this research project, a holistic approach for the design of the THTB process in dependency of the main influencing parameters is presented and discussed in detail. The capability of the approach for the process development of complex forming operations is demonstrated by a comparison of local blank thickness of a tailgate with the corresponding results from simulation.

  6. Tailor-made polyamide membranes for water desalination.

    Science.gov (United States)

    Choi, Wansuk; Gu, Joung-Eun; Park, Sang-Hee; Kim, Seyong; Bang, Joona; Baek, Kyung-Youl; Park, Byoungnam; Lee, Jong Suk; Chan, Edwin P; Lee, Jung-Hyun

    2015-01-27

    Independent control of the extrinsic and intrinsic properties of the polyamide (PA) selective layer is essential for designing thin-film composite (TFC) membranes with performance characteristics required for water purification applications besides seawater desalination. Current commercial TFC membranes fabricated via the well-established interfacial polymerization (IP) approach yield materials that are far from ideal because their layer thickness, surface roughness, polymer chemistry, and network structure cannot be separately tailored. In this work, tailor-made PA-based desalination membranes based on molecular layer-by-layer (mLbL) assembly are presented. The mLbL technique enables the construction of an ultrathin and highly cross-linked PA selective layer in a precisely and independently controlled manner. The mLbL-assembled TFC membranes exhibit significant enhancements in performance compared to their IP-assembled counterparts. A maximum sodium chloride rejection of 98.2% is achieved along with over 2.5 times higher water flux than the IP-assembled counterpart. More importantly, this work demonstrates the broad applicability of mLbL in fabricating a variety of PA-based TFC membranes with nanoscale control of the selective layer thickness and roughness independent of the specific polyamide chemistry. PMID:25548959

  7. Directly tailoring photon-electron coupling for sensitive photoconductance.

    Science.gov (United States)

    Huang, Zhiming; Zhou, Wei; Huang, Jingguo; Wu, Jing; Gao, Yanqing; Qu, Yue; Chu, Junhao

    2016-01-01

    The coupling between photons and electrons is at the heart of many fundamental phenomena in nature. Despite tremendous advances in controlling electrons by photons in engineered energy-band systems, control over their coupling is still widely lacking. Here we demonstrate an unprecedented ability to couple photon-electron interactions in real space, in which the incident electromagnetic wave directly tailors energy bands of solid to generate carriers for sensitive photoconductance. By spatially coherent manipulation of metal-wrapped material system through anti-symmetric electric field of the irradiated electromagnetic wave, electrons in the metals are injected and accumulated in the induced potential well (EIW) produced in the solid. Respective positive and negative electric conductances are easily observed in n-type and p-type semiconductors into which electrons flow down from the two metallic sides under light irradiation. The photoconductivity is further confirmed by sweeping the injected electrons out of the semiconductor before recombination applied by sufficiently strong electric fields. Our work opens up new perspectives for tailoring energy bands of solids and is especially relevant to develop high effective photon detection, spin injection, and energy harvesting in optoelectronics and electronics. PMID:26964883

  8. Supporting Multiple Cognitive Processing Styles Using Tailored Support Systems

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Q. Tran; Karen M. Feigh; Amy R. Pritchett

    2007-08-01

    According to theories of cognitive processing style or cognitive control mode, human performance is more effective when an individual’s cognitive state (e.g., intuition/scramble vs. deliberate/strategic) matches his/her ecological constraints or context (e.g., utilize intuition to strive for a "good-enough" response instead of deliberating for the "best" response under high time pressure). Ill-mapping between cognitive state and ecological constraints are believed to lead to degraded task performance. Consequently, incorporating support systems which are designed to specifically address multiple cognitive and functional states e.g., high workload, stress, boredom, and initiate appropriate mitigation strategies (e.g., reduce information load) is essential to reduce plant risk. Utilizing the concept of Cognitive Control Models, this paper will discuss the importance of tailoring support systems to match an operator's cognitive state, and will further discuss the importance of these ecological constraints in selecting and implementing mitigation strategies for safe and effective system performance. An example from the nuclear power plant industry illustrating how a support system might be tailored to support different cognitive states is included.

  9. Understanding the Adsorption Interface of Polyelectrolyte Coating on Redox Active Nanoparticles Using Soft Particle Electrokinetics and Its Biological Activity

    Science.gov (United States)

    2015-01-01

    The application of cerium oxide nanoparticles (CNPs) for therapeutic purposes requires a stable dispersion of nanoparticles in a biological environment. The objective of this study is to tailor the properties of polyelectrolyte coated CNPs as a function of molecular weight to achieve a stable and catalytic active dispersion. The coating of CNPs with polyacrylic acid (PAA) has increased the dispersion stability of CNPs and enhanced the catalytic ability. The stability of PAA coating was analyzed using the change in the Gibbs free energy computed by the Langmuir adsorption model. The adsorption isotherms were determined using soft particle electrokinetics which overcomes the challenges presented by other techniques. The change in Gibbs free energy was highest for CNPs coated with PAA of 250 kg/mol indicating the most stable coating. The change in free energy for PAA of 100 kg/mol coated CNPs was 85% lower than the PAA of 250 kg/mol coated CNPs. This significant difference is caused by the strong adsorption of PAA of 100 kg/mol on CNPs. Catalytic activity of PAA-CNPs is assessed by the catalase enzymatic mimetic activity of nanoparticles. The catalase activity was higher for PAA coated CNPs as compared to bare CNPs which indicated preferential adsorption of hydrogen peroxide induced by coating. This indicates that the catalase activity is also affected by the structure of the coating layer. PMID:24673655

  10. Sol-gel as a method to tailor the magnetic properties of Co1+yAl2-yO4

    OpenAIRE

    Milivojević D.; Babić-Stojić B.; Jokanović V.; Jagličić Z.; Branković D.; Jović N.; Čolović B.; Čupić S.; Kojić D.

    2013-01-01

    The magnetic properties of mesoscopic materials are modified by size and surface effects. We present a sol-gel method used to tailor these effects, and illustrate it on Co1+yAl2-yO4 spinel. Nanocomposites made of spinel oxide Co1+yAl2-yO4 particles dispersed in an amorphous SiO2 matrix were synthesized. Samples with various mass fractions -x of Co1+yAl2-yO4 in composite, ranging from predominantly SiO2 (x = 10 wt%) to predominantly spinel (x = 95 wt%), and with various Co concentrations...

  11. EXAFS in dispersive mode

    International Nuclear Information System (INIS)

    The new method of collecting EXAFS data in dispersive mode will be recalled. Polychromatic radiation is used so that data over the entire EXAFS spectrum can be recorded simultaneously. The improved efficiency in data collection opens up the possibility of kinetic studies in material science, chemistry and biophysics. The first data obtained with a self-scanned photodiode array manufactured by EGandG Reticon (RC 256 EC/17) working at room temperature show that XANES study at a few ms time-scale can be expected since only 1.3 ms were required to collect the XANES plot of elemental Ni, the D.C.I. storage ring running at a 1.72 GeV, 250 mA positron energy and current. (orig.)

  12. Amplified Dispersive Optical Tomography

    CERN Document Server

    Goda, Keisuke; Jalali, Bahram

    2008-01-01

    Optical coherence tomography (OCT) has proven to be a powerful technique for studying tissue morphology in ophthalmology, cardiology, and endomicroscopy. Its performance is limited by the fundamental trade-off between the imaging sensitivity and acquisition speed -- a predicament common in virtually all imaging systems. In this paper, we circumvent this limit by using distributed Raman post-amplification of the reflection from the sample. We combine the amplification with simultaneously performed dispersive Fourier transformation, a process that maps the optical spectrum into an easily measured time-domain waveform. The Raman amplification enables measurement of weak signals which are otherwise buried in noise. It extends the depth range without sacrificing the acquisition speed or causing damage to the sample. As proof of concept, single-shot imaging with 15 dB improvement in sensitivity at an axial scan rate of 36.6 MHz is demonstrated.

  13. Polarization Mode Dispersion

    CERN Document Server

    Galtarossa, Andrea

    2005-01-01

    This book contains a series of tutorial essays on polarization mode dispersion (PMD) by the leading experts in the field. It starts with an introductory review of the basic concepts and continues with more advanced topics, including a thorough review of PMD mitigation techniques. Topics covered include mathematical representation of PMD, how to properly model PMD in numerical simulations, how to accurately measure PMD and other related polarization effects, and how to infer fiber properties from polarization measurements. It includes discussions of other polarization effects such as polarization-dependent loss and the interaction of PMD with fiber nonlinearity. It additionally covers systems issues like the impact of PMD on wavelength division multiplexed systems. This book is intended for research scientists or engineers who wish to become familiar with PMD and its system impacts.

  14. Origin of conical dispersion relations

    OpenAIRE

    Hojman, Sergio A.

    2013-01-01

    A mechanism that produces conical dispersion relations is presented. A Kronig Penney one dimensional array with two different strengths delta function potentials gives rise to both the gap closure and the dispersion relation observed in graphene and other materials. The Schr\\''odinger eigenvalue problem is locally invariant under the infinite dimensional Virasoro algebra near conical dispersion points in reciprocal space, thus suggesting a possible relation to string theory.

  15. Acoustic Rectification in Dispersive Media

    Science.gov (United States)

    Cantrell, John H.

    2008-01-01

    It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

  16. Statistical Thermodynamics of Disperse Systems

    DEFF Research Database (Denmark)

    Shapiro, Alexander

    1996-01-01

    Principles of statistical physics are applied for the description of thermodynamic equilibrium in disperse systems. The cells of disperse systems are shown to possess a number of non-standard thermodynamic parameters. A random distribution of these parameters in the system is determined....... On the basis of this distribution, it is established that the disperse system has an additional degree of freedom called the macro-entropy. A large set of bounded ideal disperse systems allows exact evaluation of thermodynamic characteristics. The theory developed is applied to the description of equilibrium...

  17. Weather explains high annual variation in butterfly dispersal.

    Science.gov (United States)

    Kuussaari, Mikko; Rytteri, Susu; Heikkinen, Risto K; Heliölä, Janne; von Bagh, Peter

    2016-07-27

    Weather conditions fundamentally affect the activity of short-lived insects. Annual variation in weather is therefore likely to be an important determinant of their between-year variation in dispersal, but conclusive empirical studies are lacking. We studied whether the annual variation of dispersal can be explained by the flight season's weather conditions in a Clouded Apollo (Parnassius mnemosyne) metapopulation. This metapopulation was monitored using the mark-release-recapture method for 12 years. Dispersal was quantified for each monitoring year using three complementary measures: emigration rate (fraction of individuals moving between habitat patches), average residence time in the natal patch, and average distance moved. There was much variation both in dispersal and average weather conditions among the years. Weather variables significantly affected the three measures of dispersal and together with adjusting variables explained 79-91% of the variation observed in dispersal. Different weather variables became selected in the models explaining variation in three dispersal measures apparently because of the notable intercorrelations. In general, dispersal rate increased with increasing temperature, solar radiation, proportion of especially warm days, and butterfly density, and decreased with increasing cloudiness, rainfall, and wind speed. These results help to understand and model annually varying dispersal dynamics of species affected by global warming. PMID:27440662

  18. Design, Characterization, and Aerosol Dispersion Performance Modeling of Advanced Spray-Dried Microparticulate/Nanoparticulate Mannitol Powders for Targeted Pulmonary Delivery as Dry Powder Inhalers

    OpenAIRE

    Li, Xiaojian; Vogt, Frederick G; Hayes, Don; Mansour, Heidi M

    2014-01-01

    Background: The purpose was to design and characterize inhalable microparticulate/nanoparticulate dry powders of mannitol with essential particle properties for targeted dry powder delivery for cystic fibrosis mucolytic treatment by dilute organic solution spray drying, and, in addition, to tailor and correlate aerosol dispersion performance delivered as dry powder inhalers based on spray-drying conditions and solid-state physicochemical properties.

  19. Vitalum study design: RCT evaluating the efficacy of tailored print communication and telephone motivational interviewing on multiple health behaviors

    Directory of Open Access Journals (Sweden)

    Severens Johan L

    2008-06-01

    Full Text Available Abstract Background A large proportion of adults fail to meet public health guidelines for physical activity as well as fruit, vegetable and fat intake. Interventions are needed to improve these health behaviors. Both computer tailoring and motivational interviewing have shown themselves to be promising techniques for health behavior change. The Vitalum project aims to compare the efficacy of these techniques in improving the health behaviors of adults aged 45–70. This paper describes the design of the Vitalum study. Methods/Design Dutch general medical practices (N = 23 were recruited via a registration network or by personal invitation. The participants were then enrolled through these general practices using an invitational letter. They (n = 2,881 received a written baseline questionnaire to assess health behaviors, and potential psychosocial and socio-demographic behavioral determinants. A power analysis indicated that 1,600 participants who were failing to meet the guidelines for physical activity and either fruit or vegetable consumption were needed. Eligible participants were stratified based on hypertension status and randomized into one of four intervention groups: tailored print communication, telephone motivational interviewing, combined, and control. The first two groups either received four letters or took part in four interviews, whereas the combined group received two letters and took part in two interviews in turns at 5, 13, 30 and 43 weeks after returning the baseline questionnaire. Each letter and interview focused on physical activity or nutrition behavior. The participants also took part in a telephone survey 25 weeks after baseline to gather new information for tailoring. There were two follow-up questionnaires, at 47 and 73 weeks after baseline, to measure short- and long-term effects. The control group received a tailored letter after the last posttest. The process, efficacy and cost-effectiveness of the interventions

  20. INFLUENCE OF CHROMATIC DISPERSION, DISPERSION SLOPE, DISPERSION CURVATURE ON MICROWAVE GENERATION USING TWO CASCADE MODULATORS

    Directory of Open Access Journals (Sweden)

    Mandeep Singh

    2013-03-01

    Full Text Available This work presents a theoretical study of harmonic generation of microwave signals after detection of a modulated optical carrier in cascaded two electro-optic modulators. Dispersion is one of the major limiting factors for microwave generation in microwave photonics. In this paper, we analyze influence of chromatic dispersion, dispersion slope, dispersion curvature on microwave generation using two cascaded MZMs and it has been found that output intensity of photodetector reduces when dispersion term up to fifth order are added. We have used the two cascaded Mach-Zehnder Modulators for our proposed model and tried to show the dispersion effect with the help of modulation depth factor of MZM, which have been not discussed earlier.

  1. Tailor-made TALEN system for highly efficient targeted gene replacement in the rice blast fungus.

    Science.gov (United States)

    Arazoe, Takayuki; Ogawa, Tetsuo; Miyoshi, Kennosuke; Yamato, Tohru; Ohsato, Shuichi; Sakuma, Tetsushi; Yamamoto, Takashi; Arie, Tsutomu; Kuwata, Shigeru

    2015-07-01

    Genetic manipulation is key to unraveling gene functions and creating genetically modified strains of microbial organisms. Recently, engineered nucleases that can generate DNA double-strand breaks (DSBs) at a specific site in the desired locus within genome are utilized in a rapidly developing genome editing technology via DSBs repair. However, the use of engineered nucleases in filamentous fungi has not been validated. In this study, we demonstrated that tailor-made transcriptional activator-like effector nucleases (TALENs) system, Platinum-Fungal TALENs (PtFg TALENs), could improve the efficiency of homologous recombination-mediated targeted gene replacement by up to 100% in the rice blast fungus Pyricularia oryzae. This high-efficiency PtFg TALEN has great potential for basic and applied biological applications in filamentous fungi. PMID:25683503

  2. Nuclear data needs for neutron spectrum tailoring at International Fusion Materials Irradiation Facility (IFMIF)

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    International Fusion Materials Irradiation Facility (IFMIF) is a proposal of D-Li intense neutron source to cover all aspects of the fusion materials development in the framework of IEA collaboration. The new activity has been started to qualifying the important technical issues called Key Element technology Phase since 2000. Although the neutron spectrum can be adjusted by changing the incident beam energy, it is favorable to be carried out many irradiation tasks at the same time under the unique beam condition. For designing the tailored neutron spectrum, neutron nuclear data for the moderator-reflector materials up to 50 MeV are required. The data for estimating the induced radioactivity is also required to keep the radiation level low enough at maintenance time. The candidate materials and the required accuracy of nuclear data are summarized. (author)

  3. Enhanced magnetic energy harvesting properties of magneto-mechano-electric generator by tailored geometry

    Science.gov (United States)

    Annapureddy, Venkateswarlu; Lee, Ha Young; Yoon, Woon-Ha; Woo, Hyun-Jae; Lee, Ji-Hye; Palneedi, Haribabu; Kim, Hwee-Jong; Choi, Jong-Jin; Jeong, Dae-Yong; Yi, Sam Nyung; Ryu, Jungho

    2016-08-01

    By tailoring the truncated shape of a cantilever structured magneto-mechano-electric (MME) generator that is composed of a piezoelectric single crystal fiber composite and a magnetostrictive Ni plate, a superior output harvesting power density of over 680% was obtained as compared to a typical rectangular shaped generator. The effect of the MME generator's shape on the strain distribution induced by magnetostriction and vibration characteristics and harvesting properties were simulated by finite element analysis modeling and confirmed experimentally, respectively. The truncated shape was effective for not only utilizing a more uniform in-plane strain distribution in the active piezoelectric area but also magnifying the flexural vibration amplitude, which in turn can make the generator more powerful under tiny magnetic oscillations.

  4. Facile synthesis of well-dispersed silver nanoparticles on hierarchical flower-like Ni3Si2O5(OH)4 with a high catalytic activity towards 4-nitrophenol reduction.

    Science.gov (United States)

    Jin, Renxi; Xing, Yan; Yu, Xiaodan; Sun, Shaolin; Yu, Donghui; Wang, Fangfang; Wu, Wenbin; Song, Shuyan

    2012-12-01

    Layered nickel silicate nanoflowers (NSFs) with a hierarchical nanostructure have been successfully fabricated by a template-free solvothermal method. The as-prepared nanoflowers were composed of many interconnected edge-curving lamellae with a thickness of about 15 nm and had a high specific surface area (279 m(2)  g(-1)) and large pore volume (0.67 cm(3)  g(-1)). The highly dispersed small silver nanoparticles (AgNPs) were immobilized on the surface of NSFs through the in situ reduction of Ag(+) by Sn(2+). The AgNP/NSF nanocomposites showed a high performance in the catalytic reduction of 4-nitrophenol. In particular, there was no visible decrease in the catalytic activity of the reused catalysts even after being recycled four times. The as-prepared AgNP/NSF nanocomposites might be an excellent catalyst owing to their availability, formability, chemical and thermal stability, and high specific surface area. PMID:23042713

  5. Evaluation of a Culturally Tailored Skills Intervention for Latinos with Persistent Psychotic Disorders.

    Science.gov (United States)

    Mausbach, Brent T; Bucardo, Jesus; Cardenas, Veronica; McKibbin, Christine L; Barrio, Concepcion; Goldman, Sherrill R; Jeste, Dilip V; Patterson, Thomas L

    2008-01-01

    Fifty-nine Latino participants diagnosed with persistent psychotic disorders were assigned to either a culturally tailored skills-training intervention (n = 21), an equivalent non-tailored intervention (n = 15), or a community-based support group (n = 23). Participants completed a number of skills-based performance assessments (e.g., UCSD performance-based skills assessment; UPSA) and a well-being measure prior to and immediately post-treatment. Compared to those in the non-tailored intervention, participants receiving the tailored intervention showed significant improvement in several outcomes. These results indicate that Latino individuals with persistent psychotic disorders benefit from interventions which consider cultural values and mores.

  6. A Tailorable Structural Composite for GCR and Albedo Neutron Protection on the Lunar Surface Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A tailorable structural composite that will provide protection from the lunar radiation environment, including GCR and albedo neutrons will be developed. This...

  7. Effectiveness of a web-based health risk assessment with individually-tailored feedback on lifestyle behaviour: study protocol

    Directory of Open Access Journals (Sweden)

    Laan Eva K

    2012-03-01

    Full Text Available Abstract Background Physical inactivity, unhealthy dietary habits, smoking and high alcohol consumption are recognized risk factors for cardiovascular disease and cancer. Web-based health risk assessments with tailored feedback seem promising in promoting a healthy lifestyle. This study evaluates the effectiveness of a web-based health risk assessment with individually-tailored feedback on lifestyle behaviour, conducted in a worksite setting. Methods/Design The web-based health risk assessment starts with a questionnaire covering socio-demographic variables, family and personal medical history, lifestyle behaviour and psychological variables. Prognostic models are used to estimate individual cardiovascular risks. In case of high risk further biometric and laboratory evaluation is advised. All participants receive individually-tailored feedback on their responses to the health risk assessment questionnaire. The study uses a quasi-experimental design with a waiting list control group. Data are collected at baseline (T0 and after six months (T1. Within each company, clusters of employees are allocated to either the intervention or the control group. Primary outcome is lifestyle behaviour, expressed as the sum of five indicators namely physical activity, nutrition, smoking behaviour, alcohol consumption, and symptoms of burnout. Multilevel regression analysis will be used to answer the main research question and to correct for clustering effects. Baseline differences between the intervention and control group in the distribution of characteristics with a potential effect on lifestyle change will be taken into account in further analyses using propensity scores. Discussion This study will increase insight into the effectiveness of health risk assessments with tailored feedback and into conditions that may modify the effectiveness. This information can be used to design effective interventions for lifestyle behaviour change among employees. Trial

  8. Nanocrystalline-graphene-tailored hexagonal boron nitride thin films.

    Science.gov (United States)

    Lee, Kang Hyuck; Shin, Hyeon-Jin; Kumar, Brijesh; Kim, Han Sol; Lee, Jinyeong; Bhatia, Ravi; Kim, Sang-Hyeob; Lee, In-Yeal; Lee, Hyo Sug; Kim, Gil-Ho; Yoo, Ji-Beom; Choi, Jae-Young; Kim, Sang-Woo

    2014-10-20

    Unintentionally formed nanocrystalline graphene (nc-G) can act as a useful seed for the large-area synthesis of a hexagonal boron nitride (h-BN) thin film with an atomically flat surface that is comparable to that of exfoliated single-crystal h-BN. A wafer-scale dielectric h-BN thin film was successfully synthesized on a bare sapphire substrate by assistance of nc-G, which prevented structural deformations in a chemical vapor deposition process. The growth mechanism of this nc-G-tailored h-BN thin film was systematically analyzed. This approach provides a novel method for preparing high-quality two-dimensional materials on a large surface. PMID:25204810

  9. Unraveling Spurious Properties of Interaction Networks with Tailored Random Networks

    CERN Document Server

    Bialonski, Stephan; Lehnertz, Klaus; 10.1371/journal.pone.0022826

    2012-01-01

    We investigate interaction networks that we derive from multivariate time series with methods frequently employed in diverse scientific fields such as biology, quantitative finance, physics, earth and climate sciences, and the neurosciences. Mimicking experimental situations, we generate time series with finite length and varying frequency content but from independent stochastic processes. Using the correlation coefficient and the maximum cross-correlation, we estimate interdependencies between these time series. With clustering coefficient and average shortest path length, we observe unweighted interaction networks, derived via thresholding the values of interdependence, to possess non-trivial topologies as compared to Erd\\H{o}s-R\\'{e}nyi networks, which would indicate small-world characteristics. These topologies reflect the mostly unavoidable finiteness of the data, which limits the reliability of typically used estimators of signal interdependence. We propose random networks that are tailored to the way i...

  10. Hacking commercial quantum cryptography systems by tailored bright illumination

    Science.gov (United States)

    Lydersen, Lars; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Makarov, Vadim

    2010-10-01

    The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built from off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.

  11. Au-Ag-Cu nano-alloys: tailoring of permittivity

    Science.gov (United States)

    Hashimoto, Yoshikazu; Seniutinas, Gediminas; Balčytis, Armandas; Juodkazis, Saulius; Nishijima, Yoshiaki

    2016-04-01

    Precious metal alloys enables new possibilities to tailor materials for specific optical functions. Here we present a systematic study of the effects of a nanoscale alloying on the permittivity of Au-Ag-Cu metals at 38 different atomic mixing ratios. The permittivity was measured and analyzed numerically by applying the Drude model. X-ray diffraction (XRD) revealed the face centered cubic lattice of the alloys. Both, optical spectra and XRD results point towards an equivalent composition-dependent electron scattering behavior. Correlation between the fundamental structural parameters of alloys and the resulting optical properties is elucidated. Plasmonic properties of the Au-Ag-Cu alloy nanoparticles were investigated by numerical simulations. Guidelines for designing plasmonic response of nano- structures and their patterns are presented from the material science perspective.

  12. A SYSTEM DESIGN PROCESS TAILORED FOR REVERSE ENGINEERING AND REENGINEERING

    Directory of Open Access Journals (Sweden)

    Tae-Hun Yoon

    2010-10-01

    Full Text Available This paper discusses a system design process using a reverse engineering. The Reverse Engineering Approach, if possible, is a cost-effective and easy approach to be used in a system design. All industries use this approach consciously or unconsciously to reduce system development risks. It can be a part of formal process, simple requirement reuse, or adoption of industry standards. The reverse engineering approach can be considered as an effective system design method in immature system engineering environments. This paper proposes a system design process using reverse engineering which can be tailored for large complex system development projects. The proposed process composed of two stages to produce system specification generation. The reverse engineering stage is performed to define functional and physical architecture of legacy system used as reference model when they are not available. The reengineering stage takes outputs of the reverse engineering stage to define the rest of logical and physical solutions.

  13. Tailoring the properties of polymers via formation of a mesophase

    Energy Technology Data Exchange (ETDEWEB)

    Di Girolamo, Rocco, E-mail: rocco.digirolamo@unina.it; Auriemma, Finizia; De Rosa, Claudio; Malafronte, Anna [Dipartimento di Scienze Chimiche, Università Degli Studi di Napoli “Federico II,” Complesso Monte S. Angelo, Via Cintia,80126 Napoli (Italy)

    2015-12-17

    The combination of the control of the concentration of stereodefects in isotactic polypropylene using metallocene catalysts and the crystallization via the mesophase is a strategy to tailor the mechanical properties. Stiff materials, flexible materials, and thermoplastic elastomers can be produced depending only on the concentration of rr stereodefects. We show that in the case of isotactic polypropylene (iPP) the material properties can be finely tuned at molecular level via formation of a solid mesophase, characterized by an intermediate degree of order between amorphous and crystalline state. The effect of different degree of stereoregularity on the mesophase formation, thermal stability, morphology, is analyzed at different length scales, using different technique including wide angle X-ray scattering, atomic and optical microscopy. Different morphologies are observed depending on the stereoregularity and conditions of crystallization. In contrast to the lamellar morphology of crystals normally obtained from the melt, the solid mesophase show a nodular morphology.

  14. Targeting the Fanconi Anemia Pathway to Identify Tailored Anticancer Therapeutics

    Directory of Open Access Journals (Sweden)

    Chelsea Jenkins

    2012-01-01

    Full Text Available The Fanconi Anemia (FA pathway consists of proteins involved in repairing DNA damage, including interstrand cross-links (ICLs. The pathway contains an upstream multiprotein core complex that mediates the monoubiquitylation of the FANCD2 and FANCI heterodimer, and a downstream pathway that converges with a larger network of proteins with roles in homologous recombination and other DNA repair pathways. Selective killing of cancer cells with an intact FA pathway but deficient in certain other DNA repair pathways is an emerging approach to tailored cancer therapy. Inhibiting the FA pathway becomes selectively lethal when certain repair genes are defective, such as the checkpoint kinase ATM. Inhibiting the FA pathway in ATM deficient cells can be achieved with small molecule inhibitors, suggesting that new cancer therapeutics could be developed by identifying FA pathway inhibitors to treat cancers that contain defects that are synthetic lethal with FA.

  15. Tailoring the slow light behavior in terahertz metasurfaces

    Energy Technology Data Exchange (ETDEWEB)

    Manjappa, Manukumara; Cong, Longqing; Singh, Ranjan, E-mail: ranjans@ntu.edu.sg [Center for Disruptive Photonic Technologies, Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore); Chiam, Sher-Yi [NUS High School of Math and Science, 20 Clementi Avenue 1, Singapore, Singapore 129957 (Singapore); Bettiol, Andrew A. [Department of Physics, National University of Singapore, Science Drive 3, Singapore, Singapore 117542 (Singapore); Zhang, Weili [School of Electrical and Computer Engineering, Oklahoma State University, 202 Engineering South, Stillwater, Oklahoma 74078 (United States)

    2015-05-04

    We experimentally study the effect of near field coupling on the transmission of light in terahertz metasurfaces. Our results show that tailoring the coupling between the resonators modulates the amplitude of resulting electromagnetically induced transmission, probed under different types of asymmetries in the coupled system. Observed change in the transmission amplitude is attributed to the change in the amount of destructive interference between the resonators in the vicinity of strong near field coupling. We employ a two-particle model to theoretically study the influence of the coupling between bright and quasi-dark modes on the transmission properties of the system and we find an excellent agreement with our observed results. Adding to the enhanced transmission characteristics, our results provide a deeper insight into the metamaterial analogues of atomic electromagnetically induced transparency and offer an approach to engineer slow light devices, broadband filters, and attenuators at terahertz frequencies.

  16. Fragmentation and constitutive response of tailored mesostructured aluminum compacts

    Science.gov (United States)

    Marquez, Andrew M.; Braithwaite, Christopher H.; Weihs, Timothy P.; Krywopusk, Nicholas M.; Gibbins, David J.; Vecchio, Kenneth S.; Meyers, Marc A.

    2016-04-01

    The fragmentation and constitutive response of aluminum-based compacts were examined under dynamic conditions using mesostructured powder compacts in which the interfaces between the powders (sizes of 40, 100, and 400 μm) were tailored during the swaging fabrication process. Fragmentation was induced in ring samples of this material through explosive loading and was examined through high speed photography, laser interferometry, and soft capture of fragments. Fragment velocities of around 100 m/s were recorded. The fragment mass distributions obtained correlated in general with the interfacial strength of the compacts as well as with the powder size. Experimental results are compared with fragmentation theories to characterize the behavior of reactive powders based on the material's mesostructure by introducing the fracture toughness of the compacts. The mean fragment size is calculated using a modified form of Mott's theory and successfully compared with experimental results.

  17. Macroporous hydrogels with tailored morphology and mechanical properties

    Science.gov (United States)

    Bignotti, Fabio; Agnelli, Silvia; Baldi, Francesco; Sartore, Luciana; Peroni, Isabella

    2016-05-01

    In this work it is shown that hydroxyethylcellulose (HEC) can be employed for preparing macroporous polyacrylamide (PAAm) hydrogels with tailored morphology and mechanical properties. By changing the HEC content in the reaction mixture hydrogels with different pore sizes and degrees of interconnectivity can be synthesized. The equilibrium swelling ratio in 0.1 M NaCl increases with the amount of HEC employed. Tensile tests run on equilibrated hydrogels show that these materials behave as rubber-like materials. Their mechanical stiffness decreases regularly as the amount of HEC, and therefore their porosity, is increased. A more complex trend is observed for elongation and stress at break, which display a maximum at intermediate contents of HEC.

  18. Tailored quantum statistics from broadband states of light

    CERN Document Server

    Hartmann, S; Molitor, A; Reichert, M; Elsäßer, W; Walser, R

    2014-01-01

    We analyze the statistics of photons originating from amplified spontaneous emission generated by a quantum dot superluminescent diode. Experimentally detectable emission properties are taken into account by parametrizing the corresponding quantum state as a multi-mode phase-randomized Gaussian density operator. The validity of this model is proven in two subsequent experiments using fast two-photon-absorption detection observing second order equal-time- as well as second order fully time-resolved intensity correlations on femtosecond timescales. In the first experiment, we study the photon statistics when the number of contributing longitudinal modes is systematically reduced by applying well-controlled optical feedback. In a second experiment, we add coherent light from a single-mode laserdiode to quantum dot superluminescent diode broadband radiation. Tuning the power ratio, we realize tailored second order correlations ranging from Gaussian to Poissonian statistics. Both experiments are very well matched ...

  19. Tailoring dielectric properties of ferroelectric-dielectric multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Kesim, M. T.; Zhang, J. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Cole, M. W. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Maryland 21005 (United States); Misirlioglu, I. B. [Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı/Tuzla, 34956 Istanbul (Turkey); Alpay, S. P., E-mail: p.alpay@ims.uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2014-01-13

    We develop a nonlinear thermodynamic model for multilayer ferroelectric heterostructures that takes into account electrostatic and electromechanical interactions between layers. We concentrate on the effect of relative layer fractions and in-plane thermal stresses on dielectric properties of Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}-, BaTiO{sub 3}-, and PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} (PZT)-SrTiO{sub 3} (STO) multilayers on Si and c-sapphire. We show that dielectric properties of such multilayers can be significantly enhanced by tailoring the growth/processing temperature and the STO layer fraction. Our computations show that large tunabilities (∼90% at 400 kV/cm) are possible in carefully designed barium strontium titanate-STO and PZT-STO even on Si for which there exist substantially large in-plane strains.

  20. Patterned graphene edges for tailored reflection of plasmonic modes.

    Science.gov (United States)

    Rosolen, Gilles; Maes, Bjorn

    2015-06-15

    Combining graphene with plasmonics is expected to lead to new nanoscale applications such as sensors, photodetectors, and optical circuits, since graphene plasmons in the infrared have relatively low losses and are easily tunable. It was shown that the edges of a graphene sheet completely reflect these plasmons with negligible radiation losses. Here, however, we examine structured graphene edges, which provide the ability to tailor and even completely cancel the reflection. These properties depend on the suitable dimensions of the edge grating. We explain the reflection modulation via the appearance of longitudinal Fabry-Perot type modes. Interesting phase changes and resonances appear when the longitudinal modes interact with lateral modes mediated by edge plasmons.

  1. Press formability YAG laser welded TRIP/DP tailored blanks

    Science.gov (United States)

    Nagasaka, A.; Sugimoto, K. I.; Kobayashi, M.; Makii, K.; Ikeda, S.

    2004-06-01

    In the present work, to improve the press formability of the combination of the TRIP steel and ferrite-martensite dual-phase (DP) steel, the mechanical properties and press formability (stretch-formability) of YAG laser welded TRIP/DP tailored blanks were investigated. An as-cold-rolled sheet steel with the chemical composition of (0.1 0.3)C 1.5Si 1.5Mn (mass%) was used in this study. For comparison, 0.14C 0.22Si 1.78Mn (mass%) DP steel was also prepared. The quenched DP steel is called MDP0, and the tempered MDP0 steel is called MDP4. For butt welding, the blank obtained after the heat treatment was cut using a fine cutter, and YAG laser processing equipment was used. The press formability was evaluated from the maximum stretch-height (Hmax). Tensile tests and stretch forming tests have been conducted for laser butt welded joints obtained from the combination of the different steel. The Hmax value of the MDP0 steel was not controlled at the strength level of the DP steel, and was not different from the Hmax value of the MDP4 steel. It is thought that this was assisted to TRIP of the TDP steel because the tensile strength of the TDP steel is consequentially lower than that of the MDP0 steel. High ductility and the high stretch-formability were able to be secured by the high strength TRIP/DP tailored blanks.

  2. Review on Formability of Tailor-Welded Blanks

    Directory of Open Access Journals (Sweden)

    B.C. Patel

    2012-06-01

    Full Text Available In this paper, an overall review of the different parameter affecting on formability of tailor-welded blanks process is presented so that other researchers can concentrate on same to further critical investigations in this area. Tailor-welded blanks has been widely used in automobile and aerospace application now-a-days. It is the combination of more than or equal to two sheets having different material, thickness and coatings. Efforts have been put for determining the formability of TWB by various authors. Authors have been compared various test data for formability tests of TWB analytically with the help of various software. They have compared analytical data with practical data which were carried out in early 90’s for formability test when various software were not available. The testing of data and analyzing them by generating Forming Limit Diagram (FLD for various tests parameters carried out by Limit Dome Height (LDH test has been being much simpler analytically rather than conducting them practically. The efforts have also been put to conduct data and to verifying them analytically for deep drawing process of formability for TWB sheets with the help of various available software codes. Future scope may include to conduct data practically and to analyzed them by varying various test parameters for deep drawing process of a cylindrical cups on a new software HYPERWORKS which is now-a-days immerging as a powerful tool for software applications due to its some key features of being more efficient and accurate than other available software codes. The analyzing process is very fast, reliable and accurate compare to other finite element code available in the market.

  3. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the

  4. Pigment dispersion syndrome

    Directory of Open Access Journals (Sweden)

    C.S. Sandhya

    2013-10-01

    Full Text Available We report of the rare occurrence of pigment dispersion syndrome (PDS with posterior subcapsular cataract in both eyes in a young male patient. The patient presented with complaints of progressive decrease in vision of one year duration. The patient also had high myopia with mild iridodonesis, phacodonesis and anterior insertion of zonules. Classical signs of PDS like Krukenberg's spindle on the posterior corneal surface were evident on slit lamp examination; transillumination defects in the iris could not be elicited by retroillumination as the iris was heavily pigmented. Gonioscopy revealed heavy and uniform pigmentation of trabecular meshwork. Evidence of a characteristic iris configuration on optical coherence tomography (OCT, namely, posterior bowing of iris in the mid periphery suggested the diagnosis of PDS. This case highlights the importance of OCT in identifying the iris configuration characteristically seen in PDS even in the absence of transillumination defects in the iris and reiterates the need to look for subtle signs like phacodonesis which are important when surgical intervention is planned.

  5. Progress in urban dispersion studies

    DEFF Research Database (Denmark)

    Batchvarova, E.; Gryning, Sven-Erik

    2006-01-01

    The present Study addresses recent achievements in better representation Of the urban area structure in meteorology and dispersion parameterisations. The setup and Main Outcome of several recent dispersion experiments in Urban areas and their use in model validation are discussed. The maximum con...

  6. Gold/Iron Carbonyl Clusters for Tailored Au/FeOx Supported Catalysts

    Directory of Open Access Journals (Sweden)

    Stefania Albonetti

    2011-12-01

    Full Text Available A novel preparation method was developed for the preparation of gold/iron oxide supported catalysts using the bimetallic carbonyl cluster salts [NEt4]4[Au4Fe4(CO16] and [NEt4][AuFe4(CO16] as precursors of highly dispersed nanoparticles over different supports. A series of catalysts with different metal loadings were prepared and tested in the complete oxidation of dichlorobenzene, toluene, methanol and in the preferential oxidation of CO in the presence of H2 (PROX as model reactions. The characterization by BET, XRD, TEM, H2-TPR, ICP-AES and XPS point out the way the nature of the precursors and the thermal treatment conditions affected the dispersion of the active phase and their catalytic activity in the studied reactions.

  7. Systematic tailoring for the implementation of guideline recommendations for anxiety and depressive disorders in general practice: perceived usefulness of tailored interventions

    NARCIS (Netherlands)

    Sinnema, H.; Terluin, B.; Wensing, M.; Volker, D.; Franx, G.; Balkom, A. van; Lange, J.

    2013-01-01

    BACKGROUND: The uptake of guideline recommendations in general practice can potentially be improved by designing implementation interventions that are tailored to prospectively identify barriers. However, there is insufficient evidence regarding the most effective and efficient approaches to tailori

  8. Communicating about microbicides with women in mind: tailoring messages for specific audiences

    Directory of Open Access Journals (Sweden)

    Sekou Sidibe

    2014-09-01

    Full Text Available Introduction: Current HIV prevention options are unrealistic for most women; however, HIV prevention research has made important strides, including on-going development of antiretroviral-based vaginal microbicide gels. Nevertheless, social-behavioural research suggests that women's ability to access and use new HIV prevention technologies will be strongly influenced by a range of socio-cultural, gender and structural factors which should be addressed by communications and marketing strategies, so that these products can be positioned in ways that women can use them. Methods: Based on an extensive literature review and in-country policy consultation, consisting of approximately 43 stakeholders, we describe barriers and facilitators to HIV prevention, including potential microbicide use, for four priority audiences of Kenyan women (female sex workers [FSWs], women in stable and discordant relationships, and sexually active single young women. We then describe how messages that position microbicides might be tailored for each audience of women. Results: We reviewed 103 peer-reviewed articles and reports. In Kenya, structural factors and gender inequality greatly influence HIV prevention for women. HIV risk perception and the ability to consistently use condoms and other prevention products often vary by partner type. Women in stable relationships find condom use challenging because they connote a lack of trust. However, women in other contexts are often able to negotiate condom use, though they may face challenges with consistent use. These women include FSWs who regularly use condoms with their casual clients, young women in the initial stages of a sexual relationship and discordant couples. Thus, we consider two approaches to framing messages aimed at increasing general awareness of microbicides – messages that focus strictly on HIV prevention and ones that focus on other benefits of microbicides such as increased pleasure, intimacy or sexual

  9. Strain Sensors with Adjustable Sensitivity by Tailoring the Microstructure of Graphene Aerogel/PDMS Nanocomposites.

    Science.gov (United States)

    Wu, Shuying; Ladani, Raj B; Zhang, Jin; Ghorbani, Kamran; Zhang, Xuehua; Mouritz, Adrian P; Kinloch, Anthony J; Wang, Chun H

    2016-09-21

    Strain sensors with high elastic limit and high sensitivity are required to meet the rising demand for wearable electronics. Here, we present the fabrication of highly sensitive strain sensors based on nanocomposites consisting of graphene aerogel (GA) and polydimethylsiloxane (PDMS), with the primary focus being to tune the sensitivity of the sensors by tailoring the cellular microstructure through controlling the manufacturing processes. The resultant nanocomposite sensors exhibit a high sensitivity with a gauge factor of up to approximately 61.3. Of significant importance is that the sensitivity of the strain sensors can be readily altered by changing the concentration of the precursor (i.e., an aqueous dispersion of graphene oxide) and the freezing temperature used to process the GA. The results reveal that these two parameters control the cell size and cell-wall thickness of the resultant GA, which may be correlated to the observed variations in the sensitivities of the strain sensors. The higher is the concentration of graphene oxide, then the lower is the sensitivity of the resultant nanocomposite strain sensor. Upon increasing the freezing temperature from -196 to -20 °C, the sensitivity increases and reaches a maximum value of 61.3 at -50 °C and then decreases with a further increase in freezing temperature to -20 °C. Furthermore, the strain sensors offer excellent durability and stability, with their piezoresistivities remaining virtually unchanged even after 10 000 cycles of high-strain loading-unloading. These novel findings pave the way to custom design strain sensors with a desirable piezoresistive behavior.

  10. Trace dispersant detection and removal

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, D.; Volchek, K.; Cathum, S.J.; Peng, H. [SAIC Canada Ltd., Ottawa, ON (Canada); Lane, J. [U.S. Minerals Management Service, Herndon, VA (United States)

    2003-07-01

    A series of tests have been conducted at the OHMSETT facility to determine the performance of different dispersants used to treat oil spills. The testing was complicated by the fact that even trace amounts of dispersants left in the test tank could alter the performance of subsequent dispersants tested in the same test tank. For that reason, an inexpensive membrane based process was developed to remove trace quantities of dispersant from a water source and purify the tank water after each test. Membrane processes have been used to remove surfactants and oil from various types of aqueous streams such as industrial wastewaters, where surfactants and oils can be found in either dissolved or dispersed forms. Several membrane types were tested to determine key operating and separation parameters. The objective was to find a selective membrane with a high flux. Nanofiltration membranes, ultrafiltration membranes, and micro filtration membranes were the three types of membranes considered for this study. Corexit 9500 and Corexit 9527, the two most commonly stocked dispersants in North America, were used to study the relationship between surface tension and dispersant concentration in different solutions. Preliminary results indicate that membrane technology is a viable method to separate surfactants from water. Pilot scale testing was recommended to obtain more accurate estimates and to validate cost estimates. 5 refs., 5 tabs., 9 figs.

  11. Tailoring the size and distribution of Ag nanoparticles in silica glass by defects

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yitao, E-mail: yangyt@impcas.ac.cn [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Chonghong; Song, Yin; Gou, Jie; Zhang, Liqing [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Hengqing; Liu, Juan; Xian, Yongqiang [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Yizhun [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-02-15

    The composites embedded with metallic nanoparticles show large nonlinear optical susceptibility and strong surface plasmon resonance absorption, which enable potential application in opto-electronics. Ion implantation has been proven to be a powerful technique of synthesis of metallic nanoparticles due to its versatility and compatibility. However, the synthesis of nanoparticles by ion implantation inevitably leads to a broad size distribution due to Ostwald ripening process. The broad size distribution has a negative effect on improving the figure of merits for nonlinear optics. In this paper, we tried to introduce defects in silica glass to act as pre-nucleation centers to mediate the size and distribution of Ag nanoparticles. In experiment, the silica glass samples were pre-irradiated by 200 keV Ar ions to fluences of 0.8, 2.0 and 5.0 × 10{sup 16} ions/cm{sup 2}, and then 200 keV Ag ions were implanted into the pre-irradiated samples to fluence of 2.0 × 10{sup 16} ions/cm{sup 2}. UV–VIS results show that the absorbance intensity of Ag SPR peak initially increases and then decreases with pre-irradiation fluence, which implies the change in size and density of Ag nanoparticles in samples. TEM results verify that Ag nanoparticles in the sample pre-irradiated to the fluence of 0.8 × 10{sup 16} ions/cm{sup 2} grow bigger and distribute in a relatively narrow region comparing with that without pre-irradiation. With further increase of pre-irradiation fluence, the size of Ag nanoparticles shows a depth dependent distribution. A boundary can be clear seen at the depth of 110 nm, larger Ag nanoparticles disperse in region shallower than 110 nm, and smaller Ag nanoparticles disperse in the region deeper than 110 nm. The average size of Ag nanoparticles initially increases and then decreases with pre-irradiation fluence. Therefore, the introduction of defects by pre-irradiation could be an effective way to tailor the size and distribution of metallic nanoparticles in

  12. Developing Strategies for Waste Reduction by Means of Tailored Interventions in Santiago De Cuba

    Science.gov (United States)

    Tobias, Robert; Brugger, Adrian; Mosler, Hans-Joachim

    2009-01-01

    This article introduces an approach to tailoring behavior-change campaigns to target populations using the example of solid waste reduction in Santiago de Cuba. Tailoring is performed in the following steps: (1) Psychological constructs are selected to detect problems in performing the target behavior, and data are gathered on these constructs.…

  13. Coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures

    Science.gov (United States)

    Mcknight, R. L.; Huang, H.; Hartle, M.

    1992-01-01

    Accomplishments are described for the fourth years effort of a 5-year program to develop a methodology for coupled structural/thermal/electromagnetic analysis/tailoring of graded component structures. These accomplishments include: (1) demonstration of coupled solution capability; (2) alternate CSTEM electromagnetic technology; (3) CSTEM acoustic capability; (4) CSTEM tailoring; (5) CSTEM composite micromechanics using ICAN; and (6) multiple layer elements in CSTEM.

  14. Native American Indian Adolescents: Response to a Culturally Tailored, School-Based Substance Abuse Intervention

    Science.gov (United States)

    Patchell, Beverly A.

    2011-01-01

    Native American Indian adolescent substance abuse has been a longstanding health concern. There are few culturally tailored interventions for mild to moderate substance users. The purpose of this study was to measure the response of Native American Indian adolescents from the Plains tribal groups to a school-based culturally tailored substance…

  15. A systematic methodology for design of tailor-made blended products

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza Binti; Gernaey, Krist; Woodley, John;

    2014-01-01

    A systematic methodology for design of tailor-made blended products has been developed. In tailor-made blended products, one identifies the product needs and matches them by blending different chemicals. The systematic methodology has four main tasks. First, the design problem is defined: the pro...... methodology is highlighted through two case studies involving gasoline blends and lubricant base oils....

  16. Dispersant effectiveness testing in cold water and brash ice

    Energy Technology Data Exchange (ETDEWEB)

    Owens, C.K. [ExxonMobil Upstream Research Co., Houston, TX (United States); Belore, R.S. [S.L. Ross Environmental Research Ltd., Ottawa, ON (Canada)

    2004-07-01

    This paper presents the results of a wave tank test conducted at OHMSETT to determine the effectiveness of chemical dispersants on oil spilled in brash ice. In particular, Alaska North Slope, Hibernia and Chayvo crude oils were tested and the factors affecting the dispersion process were examined. The dispersant, Corexit 9527 was tested on both fresh and weathered oils under cold water and icy conditions. Dispersion was observed for waves with 17 cm average height and a 5.5 second period, as well as with waves of 33 cm average height and 4 second period. The energy level in the tank was much lower than typically found in open waters. The presence of ice enhanced the dispersion processes compared to what would occur in similar open water conditions. Higher wave energy levels were needed to disperse oil in rings containing a 4/10 ice cover than in rings containing a 8/10 ice cover. This result is likely due to the the higher surface activity observed in the 8/10 covered rings. More than 90 per cent dispersion was achieved in all tests with fresh crude oil in ice. For weathered crudes, the dispersion was less effective but still significant. 11 refs., 4 tabs., 12 figs.

  17. Development and Implementation of Culturally Tailored Offline Mobile Health Surveys

    Science.gov (United States)

    2016-01-01

    Background In low and middle income countries (LMICs), and other areas with low resources and unreliable access to the Internet, understanding the emerging best practices for the implementation of new mobile health (mHealth) technologies is needed for efficient and secure data management and for informing public health researchers. Innovations in mHealth technology can improve on previous methods, and dissemination of project development details and lessons learned during implementation are needed to provide lessons learned to stakeholders in both the United States and LMIC settings. Objective The aims of this paper are to share implementation strategies and lessons learned from the development and implementation stages of two survey research projects using offline mobile technology, and to inform and prepare public health researchers and practitioners to implement new mobile technologies in survey research projects in LMICs. Methods In 2015, two survey research projects were developed and piloted in Puerto Rico and pre-tested in Costa Rica to collect face-to-face data, get formative evaluation feedback, and to test the feasibility of an offline mobile data collection process. Fieldwork in each setting involved survey development, back translation with cultural tailoring, ethical review and approvals, data collector training, and piloting survey implementation on mobile tablets. Results Critical processes and workflows for survey research projects in low resource settings were identified and implemented. This included developing a secure mobile data platform tailored to each survey, establishing user accessibility, and training and eliciting feedback from data collectors and on-site LMIC project partners. Conclusions Formative and process evaluation strategies are necessary and useful for the development and implementation of survey research projects using emerging mHealth technologies in LMICs and other low resource settings. Lessons learned include: (1) plan

  18. Tailored sequential drug release from bilayered calcium sulfate composites

    International Nuclear Information System (INIS)

    The current standard for treating infected bony defects, such as those caused by periodontal disease, requires multiple time-consuming steps and often multiple procedures to fight the infection and recover lost tissue. Releasing an antibiotic followed by an osteogenic agent from a synthetic bone graft substitute could allow for a streamlined treatment, reducing the need for multiple surgeries and thereby shortening recovery time. Tailorable bilayered calcium sulfate (CS) bone graft substitutes were developed with the ability to sequentially release multiple therapeutic agents. Bilayered composite samples having a shell and core geometry were fabricated with varying amounts (1 or 10 wt.%) of metronidazole-loaded poly(lactic-co-glycolic acid) (PLGA) particles embedded in the shell and simvastatin directly loaded into either the shell, core, or both. Microcomputed tomography showed the overall layered geometry as well as the uniform distribution of PLGA within the shells. Dissolution studies demonstrated that the amount of PLGA particles (i.e., 1 vs. 10 wt.%) had a small but significant effect on the erosion rate (3% vs. 3.4%/d). Mechanical testing determined that introducing a layered geometry had a significant effect on the compressive strength, with an average reduction of 35%, but properties were comparable to those of mandibular trabecular bone. Sustained release of simvastatin directly loaded into CS demonstrated that changing the shell to core volume ratio dictates the duration of drug release from each layer. When loaded together in the shell or in separate layers, sequential release of metronidazole and simvastatin was achieved. By introducing a tunable, layered geometry capable of releasing multiple drugs, CS-based bone graft substitutes could be tailored in order to help streamline the multiple steps needed to regenerate tissue in infected defects. - Highlights: • Bilayered CS composites were fabricated as potential bone graft substitutes. • The shell

  19. Tailored sequential drug release from bilayered calcium sulfate composites

    Energy Technology Data Exchange (ETDEWEB)

    Orellana, Bryan R.; Puleo, David A., E-mail: puleo@uky.edu

    2014-10-01

    The current standard for treating infected bony defects, such as those caused by periodontal disease, requires multiple time-consuming steps and often multiple procedures to fight the infection and recover lost tissue. Releasing an antibiotic followed by an osteogenic agent from a synthetic bone graft substitute could allow for a streamlined treatment, reducing the need for multiple surgeries and thereby shortening recovery time. Tailorable bilayered calcium sulfate (CS) bone graft substitutes were developed with the ability to sequentially release multiple therapeutic agents. Bilayered composite samples having a shell and core geometry were fabricated with varying amounts (1 or 10 wt.%) of metronidazole-loaded poly(lactic-co-glycolic acid) (PLGA) particles embedded in the shell and simvastatin directly loaded into either the shell, core, or both. Microcomputed tomography showed the overall layered geometry as well as the uniform distribution of PLGA within the shells. Dissolution studies demonstrated that the amount of PLGA particles (i.e., 1 vs. 10 wt.%) had a small but significant effect on the erosion rate (3% vs. 3.4%/d). Mechanical testing determined that introducing a layered geometry had a significant effect on the compressive strength, with an average reduction of 35%, but properties were comparable to those of mandibular trabecular bone. Sustained release of simvastatin directly loaded into CS demonstrated that changing the shell to core volume ratio dictates the duration of drug release from each layer. When loaded together in the shell or in separate layers, sequential release of metronidazole and simvastatin was achieved. By introducing a tunable, layered geometry capable of releasing multiple drugs, CS-based bone graft substitutes could be tailored in order to help streamline the multiple steps needed to regenerate tissue in infected defects. - Highlights: • Bilayered CS composites were fabricated as potential bone graft substitutes. • The shell

  20. Dispersal of invasive species by drifting

    Institute of Scientific and Technical Information of China (English)

    M.C. VAN RIEL; G. VAN DER VELDE; A. BIJ DE VAATE

    2011-01-01

    Drifting can be an effective way for aquatic organisms to disperse and colonise new areas.Increasing connectivity between European large rivers facilitates invasion by drifting aquatic macroinvertebrates.The present study shows that high abundances of invasive species drift in the headstream of the river Rhine.Dikerogammarus villosus and Chelicorophium curvispinum represented up to 90% of the total of drifting macroinvertebrates.Drift activity shows seasonal and diel patterns.Most species started drifting in spring and were most abundant in the water column during the summer period.Drift activity was very low during the winter period.Diel patterns were apparent; most species,including D.villosus,drifted during the night.Drifting macroinvertebrates colonised stony substrate directly from the water column.D.villosus generally colonised the substrate at night,while higher numbers of C.curvispinum colonised the substrate during the day.It is very likely that drifting functions as a dispersal mechanism for crustacean invaders.Once waterways are connected,these species are no longer necessarily dependent on dispersal vectors other than drift for extending their distribution range [Current Zoology 57 (6):818-827,2011].

  1. Techniques and Protocols for Dispersing Nanoparticle Powders in Aqueous Media—is there a Rationale for Harmonization?

    DEFF Research Database (Denmark)

    Hartmann, Nanna B.; Jensen, Keld Alstrup; Baun, Anders;

    2015-01-01

    preparation process. Such harmonization and standardization will also enhance comparability among tests, labs, and studies on different types of ENP. The scope of this review was to critically discuss the essential parameters in dispersion protocols for ENP. The parameters are identified from individual...... scientific studies and from consensus reached in larger scale research projects and international organizations. A step-wise approach is proposed to develop tailored dispersion protocols for ecotoxicological and mammalian toxicological testing of ENP. The recommendations of this analysis may serve as a guide...

  2. Morphomechanical Innovation Drives Explosive Seed Dispersal.

    Science.gov (United States)

    Hofhuis, Hugo; Moulton, Derek; Lessinnes, Thomas; Routier-Kierzkowska, Anne-Lise; Bomphrey, Richard J; Mosca, Gabriella; Reinhardt, Hagen; Sarchet, Penny; Gan, Xiangchao; Tsiantis, Miltos; Ventikos, Yiannis; Walker, Simon; Goriely, Alain; Smith, Richard; Hay, Angela

    2016-06-30

    How mechanical and biological processes are coordinated across cells, tissues, and organs to produce complex traits is a key question in biology. Cardamine hirsuta, a relative of Arabidopsis thaliana, uses an explosive mechanism to disperse its seeds. We show that this trait evolved through morphomechanical innovations at different spatial scales. At the organ scale, tension within the fruit wall generates the elastic energy required for explosion. This tension is produced by differential contraction of fruit wall tissues through an active mechanism involving turgor pressure, cell geometry, and wall properties of the epidermis. Explosive release of this tension is controlled at the cellular scale by asymmetric lignin deposition within endocarp b cells-a striking pattern that is strictly associated with explosive pod shatter across the Brassicaceae plant family. By bridging these different scales, we present an integrated mechanism for explosive seed dispersal that links evolutionary novelty with complex trait innovation. VIDEO ABSTRACT.

  3. High performance dispersion model PHYSIC

    Energy Technology Data Exchange (ETDEWEB)

    Yamazawa, Hiromi (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

    1992-07-01

    The description and usage of the dispersion calculation model PHYSIC were summarized. The model was developed in the study of developing high performance SPEEDI with the purpose of introducing meteorological forecast function into the environmental emergency response system. PHYSIC consists of two parts, the three-dimensional meteorological model and the dispersion model. The former comprises primitive equations with Boussinesq approximation, which are solved by a finite difference method. The latter employs a particle dispersion method. PHYSIC can be used to evaluate the meteorological condition as well as the dispersion from a point source located in a complex terrain. The spatial and temporal scales of the model are 10 to 1000 km horizontally, 1 to 10 km vertically and 1 hour to 1 day, respectively. (author).

  4. Preventing the radiological dispersal device

    International Nuclear Information System (INIS)

    The paper discusses the IAEA plan of action to protect against nuclear terrorism, the nature of the threat of a radiological dispersal device, international instruments for the prevention of nuclear terrorism, recent progress and perspectives for future action. (author)

  5. Tailoring the chiral magnetic interaction between two individual atoms

    Science.gov (United States)

    Wiebe, J.; Khajetoorians, A. A.; Steinbrecher, M.; Ternes, M.; Bouhassoune, M.; Dos Santos Dias, M.; Lounis, S.; Wiesendanger, R.

    Chiral magnets are a promising route toward dense magnetic storage technology due to their inherent nano-scale dimensions and energy efficient properties. Engineering chiral magnets requires atomic-level control of the magnetic exchange interactions, including the Dzyaloshinskii-Moriya interaction, which defines a rotational sense for the magnetization of two coupled magnetic moments. Here we show that the indirect conduction electron mediated Dzyaloshinskii-Moriya interaction between two individual magnetic atoms on a metallic surface can be manipulated by changing the interatomic distance with the tip of a scanning tunneling microscope. We quantify this interaction by comparing our measurements to a quantum magnetic model and ab-initio calculations yielding a map of the chiral ground states of pairs of atoms depending on the interatomic separation. The map enables tailoring the chirality of the magnetization in dilute atomic-scale magnets. Acknowledgements: SFB668, GrK1286, SFB767, LO 1659 5-1, Emmy Noether Program of the DFG, FOM of NWO, VH-NG-717.

  6. Tailored ramp wave generation in gas gun experiments

    Directory of Open Access Journals (Sweden)

    Cotton Matthew

    2015-01-01

    Full Text Available Gas guns are traditionally used as platforms to introduce a planar shock wave to a material using plate impact methods, generating states on the Hugoniot. The ability to deliver a ramp wave to a target during a gas gun experiment enables access to different regions of the equation-of-state surface, making it a valuable technique for characterising material behaviour. Previous techniques have relied on the use of multi-material impactors to generate a density gradient, which can be complex to manufacture. In this paper we describe the use of an additively manufactured steel component consisting of an array of tapered spikes which can deliver a ramp wave over ∼ 2 μs. The ability to tailor the input wave by varying the component design is discussed, an approach which makes use of the design freedom offered by additive manufacturing techniques to rapidly iterate the spike profile. Results from gas gun experiments are presented to evaluate the technique, and compared with 3D hydrodynamic simulations.

  7. Tailoring approach for obtaining molecular orbitals of large systems

    Indian Academy of Sciences (India)

    Anuja P Rahalkar; Shridhar R Gadre

    2012-01-01

    Molecular orbitals (MO’s) within Hartree-Fock (HF) theory are of vital importance as they provide preliminary information of bonding and features such as electron localization and chemical reactivity. The contemporary literature treats the Kohn-Sham orbitals within density functional theory (DFT) equivalently to the MO's obtained within HF framework. The high scaling order of ab initio methods is the main hurdle in obtaining the MO's for large molecular systems. With this view, an attempt is made in the present work to employ molecular tailoring approach (MTA) for obtaining the complete set of MO's including occupied and virtual orbitals, for large molecules at HF and B3LYP levels of theory. The energies of highest occupied and lowest unoccupied molecular orbitals, and hence the band gaps, are accurately estimated by MTA for most of the test cases benchmarked in this study, which include -conjugated molecules. Typically, the root mean square errors of valence MO's are in range of 0.001 to 0.010 a.u. for all the test cases examined. MTA shows a time advantage factor of 2 to 3 over the corresponding actual calculation, for many of the systems reported.

  8. Bioprinting of hybrid tissue constructs with tailorable mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Schuurman, W; Khristov, V; Pot, M W; Dhert, W J A; Malda, J [Department of Orthopaedics, University Medical Center Utrecht (Netherlands); Van Weeren, P R, E-mail: j.malda@umcutrecht.nl [Faculty of Veterinary Sciences, Department of Equine Sciences, Utrecht University (Netherlands)

    2011-06-15

    Tissue/organ printing aims to recapitulate the intrinsic complexity of native tissues. For a number of tissues, in particular those of musculoskeletal origin, adequate mechanical characteristics are an important prerequisite for their initial handling and stability, as well as long-lasting functioning. Hence, organized implants, possessing mechanical characteristics similar to the native tissue, may result in improved clinical outcomes of regenerative approaches. Using a bioprinter, grafts were constructed by alternate deposition of thermoplastic fibers and (cell-laden) hydrogels. Constructs of different shapes and sizes were manufactured and mechanical properties, as well as cell viability, were assessed. This approach yields novel organized viable hybrid constructs, which possess favorable mechanical characteristics, within the same range as those of native tissues. Moreover, the approach allows the use of multiple hydrogels and can thus produce constructs containing multiple cell types or bioactive factors. Furthermore, since the hydrogel is supported by the thermoplastic material, a broader range of hydrogel types can be used compared to bioprinting of hydrogels alone. In conclusion, we present an innovative and versatile approach for bioprinting, yielding constructs of which the mechanical stiffness provided by thermoplastic polymers can potentially be tailored, and combined specific cell placement patterns of multiple cell types embedded in a wide range of hydrogels. (communication)

  9. Tailoring optical forces for nanoparticle manipulation on layered substrates

    Science.gov (United States)

    Salary, Mohammad M.; Mosallaei, Hossein

    2016-07-01

    Optical forces can be used to manipulate small particles through various mechanisms. In this paper, we present a comprehensive analysis of optical forces acting on the nanoparticles located over a substrate using different manipulation techniques, as well as the conditions of the optimization of these forces. In particular, we study optical trapping, acceleration, and binding. Calculations are carried out using the exact multipole expansion method combined with Maxwell stress tensor formalism, providing a general framework to study optical forces on particles for arbitrary incident fields using closed-form expressions. The method takes into account multiple scattering between the particles and substrate and allows clear predictive abilities well beyond the dipole model. We consider the interaction of dielectric and metallic nanoparticles with various substrates. The presence of substrate is shown to have a significant impact on the nanoparticles' resonances and provides an additional degree of freedom in tailoring the optical forces. We explore different physical processes contributing to the optical force and their interplay on the mobility of the particle. It is established that engineering layered substrates can broaden the scope of trapping and acceleration and enhance the binding forces. It can also provide a high tunability of the acceleration direction. The analysis presented in this paper provides key physical insights to identify optimum setup for nanoparticles manipulation in various applications.

  10. Tailoring and Scaling Energetic Aluminum Clusters into Cluster Assembled Materials

    Science.gov (United States)

    Smith, Jordan Cesar

    As matter decreases in size the importance of a single atom increases exponentially. The properties of clusters, molecules with less than 100 atoms, will change drastically with the addition or removal of a single atom. Clusters have been shown to have properties that mimic other elements and properties that are completely unique. Cluster assemblies could enable the tailoring of precise properties in materials, providing cheap replacements for expensive elements, or novel materials for new applications. Aluminum clusters show great potential use in many applications including energy and catalysis. This work is focused on gaining a better understanding of how geometry and electronic structure affect aluminum cluster reactivity and how useful clusters might be successfully assembled into materials. The effects of doping aluminum cluster ions with boron atoms are reported and show that the addition of a single boron atom usually stabilizes the cluster while adding more boron atoms results in a breaking of symmetry and destabilization. A new analytical technique, matrix isolation cavity ring-down spectroscopy (MICRDS) was developed to help bridge the gap between gas phase cluster studies and condensed phase cluster materials. Molecules are trapped in an inert matrix and studied using cavity ring-down spectroscopy. MICRDS has the potential to also combine clusters into small stable units that would maintain their advantageous gas phase properties.

  11. Tailoring of Interventional Procedures for HCC Patients-Review Article

    Directory of Open Access Journals (Sweden)

    H Ghanaati

    2010-11-01

    Full Text Available One of the most frequent primary malignant tumors in the world is hepatocellular carcinoma (HCC."nCurrently, the optimal treatment methods for HCC are hepatic resection and liver transplantation."nUnfortunately, surgical therapies are suitable for 20% of patients and those who are not eligible"nfor surgery should undergo interventional therapies. In the past decade, a variety of interventional"nprocedures have been employed for local control of hepatocellular carcinoma (HCC including"ntranscatheter arterial chemoembolization (TACE and many tumor ablation techniques, such as"npercutaneous ethanol injection (PEI, radio-frequency ablation (RFA, percutaneous microwave"ncoagulation therapy (PMC, laser-induced interstitial thermotherapy (LITT, cryoablation, and"nacetic acid injection. By development of new technologies in imaging and drug delivery, it is likely"nthat in the future patients with HCC will be treated by combination therapies to improve patient"nsurvival. Computed tomography (CT and magnetic resonance imaging (MRI have a crucial role in"ndiagnosis and also follow-up of HCC patients treated by interventional procedures, by which the"ntreatment efficacy, recurrence of disease and certain complications are evaluated."nIn this review article, we discuss the imaging modalities and also tailoring of interventional"nprocedures for HCC patients.

  12. Tailored ceramic consolidation forms for ICPP waste compositions

    International Nuclear Information System (INIS)

    This paper reports a polyphase tailored ceramic developed for the consolidation of simulated ICPP (Idaho Chemical Processing Plant)-type high Zr content high-level waste (HLW) calcines. The ceramic is specifically designed to provide chemically stable host phases for each species present in the HLW and to maximize waste volume reduction through high loadings and form density. The ceramic is designed for a 73 wt% waste loading with a density of 3.35 ± 0.05 (g/cm3). The major phase in the ceramic is a high-silica glass, which contains the neutron poison boron as well as the majority of the nonrefractory species in the waste. The primary crystalline phases are calcium fluoride, calcium-yttrium stabilized cubic zirconia, a hexagonal apatite type silicate containing the plutonium simulant Ce, and a Cd metal phase. Minor phases include zircon, zirconolite, and a sphene-type. Leaching testing and microscopic analysis shows the ceramic form to be chemically durable, with only the glass phase showing any detectable dissolution in deionized water at 90 degrees C

  13. Dynamic control of droplet jumping by tailoring nanoparticle concentrations

    Science.gov (United States)

    Hao, Chonglei; Zhou, Yang; Zhou, Xiaofeng; Che, Lufeng; Chu, Baojin; Wang, Zuankai

    2016-07-01

    The dynamic impact behavior of droplets from solid surfaces has attracted increasing interest, especially propelled by the advances in the bio-inspired interfacial materials. In this work, we investigate the impact and bouncing dynamics of ethylene glycol droplets containing silica nanoparticles on superhydrophobic surfaces (SHS). We find that the rebounding of droplets from SHS is highly dependent on the impact velocity and suspension concentrations. By increasing the impact velocity or suspension concentrations, the probability of droplet bouncing from SHS is greatly reduced. The presence of nanoparticles can significantly increase the viscous energy dissipation inside the liquid droplets, therefore suppressing the jumping from surfaces. Based on the energy dissipation characterization, we also find the critical concentration to determine the manifestation of the viscous effect, above which the liquid suspensions exhibit non-Newtonian fluid properties. Our study provides an efficient approach to dynamically control the liquid jumping behaviors on SHS by tailoring the suspension concentrations. The insights learned from this study can be very useful in many industrial applications.

  14. A Tailored Concept of Operations for NASA LSP Integrated Operations

    Science.gov (United States)

    Owens, Clark V.

    2016-01-01

    An integral part of the Systems Engineering process is the creation of a Concept of Operations (ConOps) for a given system, with the ConOps initially established early in the system design process and evolved as the system definition and design matures. As Integration Engineers in NASA's Launch Services Program (LSP) at Kennedy Space Center (KSC), our job is to manage the interface requirements for all the robotic space missions that come to our Program for a Launch Service. LSP procures and manages a launch service from one of our many commercial Launch Vehicle Contractors (LVCs) and these commercial companies are then responsible for developing the Interface Control Document (ICD), the verification of the requirements in that document, and all the services pertaining to integrating the spacecraft and launching it into orbit. However, one of the systems engineering tools that have not been employed within LSP to date is a Concept of Operations. The goal of this project is to research the format and content that goes into these various aerospace industry ConOps and tailor the format and content into template form, so the template may be used as an engineering tool for spacecraft integration with future LSP procured launch services.

  15. Tailoring optical complex fields with nano-metallic surfaces

    Directory of Open Access Journals (Sweden)

    Rui Guanghao

    2015-04-01

    Full Text Available Recently there is an increasing interest in complex optical fields with spatially inhomogeneous state of polarizations and optical singularities. Novel effects and phenomena have been predicted and observed for light beams with these unconventional states. Nanostructured metallic thin film offers unique opportunities to generate, manipulate and detect these novel fields. Strong interactions between nano-metallic surfaces and complex optical fields enable the development of highly compact and versatile functional devices and systems. In this review, we first briefly summarize the recent developments in complex optical fields. Various nano-metallic surface designs that can produce and manipulate complex optical fields with tailored characteristics in the optical far field will be presented. Nano-metallic surfaces are also proven to be very effective for receiving and detection of complex optical fields in the near field. Advances made in this nascent field may enable the design of novel photonic devices and systems for a variety of applications such as quantum optical information processing and integrated photonic circuits.

  16. Tailored work hardening descriptions in simulation of sheet metal forming

    Science.gov (United States)

    Vegter, Henk; Mulder, Hans.; van Liempt, Peter; Heijne, Jan

    2013-12-01

    In the previous decades much attention has been given on an accurate material description, especially for simulations at the design stage of new models in the automotive industry. Improvements lead to shorter design times and a better tailored use of material. It also contributed to the design and optimization of new materials. The current description of plastic material behaviour in simulation models of sheet metal forming is covered by a hardening curve and a yield surface. In this paper the focus will be on modelling of work hardening for advanced high strength steels considering the requirements of present applications. Nowadays work hardening models need to include the effect of hard phases in a soft matrix and the effect of strain rate and temperature on work hardening. Most material tests to characterize work hardening are only applicable to low strains whereas many practical applications require hardening data at relatively high strains. Therefore, physically based hardening descriptions are needed allowing reliable extensions to high strain values.

  17. Tailoring Patterns of Surface-Attached Multiresponsive Polymer Networks.

    Science.gov (United States)

    Chollet, Benjamin; D'Eramo, Loïc; Martwong, Ekkachai; Li, Mengxing; Macron, Jennifer; Mai, Thuy Quyen; Tabeling, Patrick; Tran, Yvette

    2016-09-21

    A new strategy for the fabrication of micropatterns of surface-attached hydrogels with well-controlled chemistry is reported. The "grafting onto" approach is preferred to the "grafting from" approach. It consists of cross-linking and grafting preformed and functionalized polymer chains through thiol-ene click chemistry. The advantage is a very good control without adding initiators. A powerful consequence of thiol-ene click reaction by UV irradiation is the facile fabrication of micropatterned hydrogel thin films by photolithography. It is achieved either with photomasks using common UV lamp or without photomasks by direct drawing due to laser technology. Our versatile approach allows the fabrication of various chemical polymer networks on various solid substrates. It is demonstrated here with silicon wafers, glass and gold surfaces as substrates, and two responsive hydrogels, poly(N-isopropylacrylamide) for its responsiveness to temperature and poly(acrylic acid) for its pH-sensitivity. We also demonstrate the fabrication of stable hydrogel multilayers (or stacked layers) in which each elementary layer height can widely range from a few nanometers to several micrometers, providing an additional degree of freedom to the internal architecture of hydrogel patterns. This facile route for the synthesis of micrometer-resolute hydrogel patterns with tailored architecture and multiresponsive properties should have a strong impact. PMID:27560306

  18. Dispersion engineering for integrated nanophotonics

    CERN Document Server

    Vanbésien, Olivier

    2014-01-01

    This book shows how dispersion engineering in two dimensional dielectric photonic crystals can provide new effects for the precise control of light propagation for integrated nanophotonics.Dispersion engineering in regular and graded photonic crystals to promote anomalous refraction effects is studied from the concepts to experimental demonstration via nanofabrication considerations. Self collimation, ultra and negative refraction, second harmonic generation, mirage and invisibility effects which lead to an unprecedented control of light propagation at the (sub-)wavelength scale for the

  19. Global dispersal reduces local diversity.

    OpenAIRE

    Hastings, A; Gavrilets, S.

    1999-01-01

    Metapopulation models and stepping-stone models in genetics are based on very different underlying dispersal structures, yet it can be difficult to distinguish the behaviour of the two kinds of models. We demonstrate a striking qualitative difference in the equilibrium behaviour possible with these two kinds of dispersal. If, in a local patch, there are multiple stable equilibria (and consequently an unstable equilibrium), we demonstrate that, for the spatial system with a metapopulation stru...

  20. Recent results from dispersant testing

    Energy Technology Data Exchange (ETDEWEB)

    Fingas, M.; Fieldhouse, B.; Wang, Z.; Sigouin, L.; Landriault, M. [Environment Canada, Ottawa, ON (Canada). Emergencies Science Div; Mullin, J.V. [Department of the Interior, Herndon, VA (United States). Minerals Management Service

    2000-07-01

    A number of small studies were conducted at Environment Canada on the topic of dispersants and their effectiveness. Dispersant analytical procedures were reviewed and modified when necessary. Testing of new products was also performed along with the testing of long-term stored dispersants. A comparative evaluation of Corexit 9500 and 9527 dispersant formulations showed major modifications to the quantity of dispersed oil, although the Swirling Flask Test did not undergo major modifications. This method used to rely on colorimetric analysis, but was upgraded to gas chromatographic analysis. This move from one method to the other brought on additional changes that had not been considered when the initial change in method was made. Some aspects of the analysis were then improved and corrected to rectify small deficiencies. The authors reported on the results concerning the testing of several new dispersants products. The comparative study between the formulations of Corexit 9500 and 9527 indicated that the effectiveness of 9500 was greater than 9527, but showed no relation to the amount of effectiveness. In terms of statistics, 9527 proved to be more effective than 9500, 25 per cent of the time. The test series conducted on Corexit 9527, stored 20 years in the tank of a truck, varied in effectiveness, toxicity, and colour but did not affect significantly the overall effectiveness of the product in the field. 10 refs., 4 tabs., 2 figs., 1 append.

  1. Organic tailored batteries materials using stable open-shell molecules with degenerate frontier orbitals

    Science.gov (United States)

    Morita, Yasushi; Nishida, Shinsuke; Murata, Tsuyoshi; Moriguchi, Miki; Ueda, Akira; Satoh, Masaharu; Arifuku, Kazunori; Sato, Kazunobu; Takui, Takeji

    2011-12-01

    Secondary batteries using organic electrode-active materials promise to surpass present Li-ion batteries in terms of safety and resource price. The use of organic polymers for cathode-active materials has already achieved a high voltage and cycle performance comparable to those of Li-ion batteries. It is therefore timely to develop approaches for high-capacity organic materials-based battery applications. Here we demonstrate organic tailored batteries with high capacity by using organic molecules with degenerate molecular orbitals (MOs) as electrode-active materials. Trioxotriangulene (TOT), an organic open-shell molecule, with a singly occupied MO (SOMO) and two degenerate lowest-unoccupied MOs (LUMOs) was investigated. A tri-tert-butylated derivative ((t-Bu)3TOT)exhibited a high discharge capacity of more than 300 A h kg-1, exceeding those delivered by Li-ion batteries. A tribrominated derivative (Br3TOT) was also shown to increase the output voltage and cycle performance up to 85% after 100 cycles of the charge-discharge processes.

  2. Energy Conversion and Dispersion Characteristics of“96·7”Central Asian Vortex Persistent Activity%“96·7”中亚低涡持续活动能量转换和频散特征

    Institute of Scientific and Technical Information of China (English)

    杨莲梅; 李曼

    2015-01-01

    —乌拉尔山地区不再出现向中亚地区的能量频散。%Using the NCEP/NCAR reanalysis daily datasets, dynamic and thermal three-dimensional structure, energy cycle and Rossby wave energy dispersion of Central Asian vortex (CAV) persistent activity from July 11 to July 22 in 1996 are studied. The Results show that the vortex developed at the middle-upper ifrstly and extended upward and downward with time, which had an obvious cold core structure down 300 hPa and a warm core structure over 300 hPa along with maximal positive vorticity at the middle-upper troposphere. During its development - mature - weakened process, maximal positive vorticity moved eastward from westside of vortex center. At the same time its upper-level strong divergence, lower-level convergence and upward motion area moved eastward. Eddy kinetic energy (KE) variation can quantitatively manifest intensiifcation change and developing stages of vortex; in the meantimeKE is quite strong at the middle and upper tropospheres. Energy conversion within vortex and energy transportation with environment mostly take place over 700 hPa. The conversion term from eddy available potential energy (AE) toKEand eddy kinetic energy inlfow from open atmospheric region boundaries act as main sources of theKE, and they play an equivalent role which bring about a rapid development of vortex. It keeps weak energy conversions within vortex during its mature stage, and the source and sink ofKE is respectively eddy available potential energy import from environment and eddy kinetic energy outlfow. For middle-range process of this vortex, the anti-cyclone anomaly center over Northeast Atlantic is the fountain of Rossby wave energy dispersion with Rossby wave propagating from Northeast Atlantic to East Europe—Urals (EAU). So the positive height anomaly circulation over EAU acts as “relay station” of energy dispersion for Central Asia. The Rossby wave emanates again from EAU and propagates to Central Asia

  3. Melanocortin systems on pigment dispersion in fish chromatophores

    OpenAIRE

    AkiyoshiTakahashi; YumikoSaito

    2012-01-01

    Alpha-Melanocyte-stimulating hormone (alpha-MSH) is responsible for pigment dispersion in the chromatophores of fish and other tetrapods such as amphibians and reptiles. Recently, we discovered that alpha-MSH did not always stimulate pigment dispersion because this hormonal peptide exerted no effects on the melanophores of flounders. We assumed that the reduction of alpha-MSH activity was related to the co-expression of different alpha-MSH receptor subtypes—termed melanocortin receptors (MC...

  4. Predation risk increases dispersal distance in prey

    Science.gov (United States)

    Otsuki, Hatsune; Yano, Shuichi

    2014-06-01

    Understanding the ecological factors that affect dispersal distances allows us to predict the consequences of dispersal. Although predator avoidance is an important cause of prey dispersal, its effects on dispersal distance have not been investigated. We used simple experimental setups to test dispersal distances of the ambulatory dispersing spider mite ( Tetranychus kanzawai) in the presence or absence of a predator ( Neoseiulus womersleyi). In the absence of predators, most spider mites settled in adjacent patches, whereas the majority of those dispersing in the presence of predators passed through adjacent patches and settled in distant ones. This is the first study to experimentally demonstrate that predators induce greater dispersal distance in prey.

  5. Second-harmonic generation using tailored whispering gallery modes

    International Nuclear Information System (INIS)

    It has been shown that whispering gallery modes can be used to obtain a combination of modal and geometrical quasi-phase-matching in second-harmonic generation. This could be achieved in isotropic, nonferroelectric, strongly dispersive and highly nonlinear materials such as III-V semiconductors. Unfortunately the poor overlap between the second-harmonic field and second order nonlinear polarization limits the conversion efficiency. In this paper we show that by engineering the refractive index it is possible to increase field overlap and to enhance effective second order nonlinear polarization of semiconductor microdisks

  6. Initiation of health-behaviour change among employees participating in a web-based health risk assessment with tailored feedback

    Directory of Open Access Journals (Sweden)

    Kraaijenhagen Roderik A

    2011-03-01

    Full Text Available Abstract Background Primary prevention programs at the worksite can improve employee health and reduce the burden of cardiovascular disease. Programs that include a web-based health risk assessment (HRA with tailored feedback hold the advantage of simultaneously increasing awareness of risk and enhancing initiation of health-behaviour change. In this study we evaluated initial health-behaviour change among employees who voluntarily participated in such a HRA program. Methods We conducted a questionnaire survey among 2289 employees who voluntarily participated in a HRA program at seven Dutch worksites between 2007 and 2009. The HRA included a web-based questionnaire, biometric measurements, laboratory evaluation, and tailored feedback. The survey questionnaire assessed initial self-reported health-behaviour change and satisfaction with the web-based HRA, and was e-mailed four weeks after employees completed the HRA. Results Response was received from 638 (28% employees. Of all, 86% rated the program as positive, 74% recommended it to others, and 58% reported to have initiated overall health-behaviour change. Compared with employees at low CVD risk, those at high risk more often reported to have increased physical activity (OR 3.36, 95% CI 1.52-7.45. Obese employees more frequently reported to have increased physical activity (OR 3.35, 95% CI 1.72-6.54 and improved diet (OR 3.38, 95% CI 1.50-7.60. Being satisfied with the HRA program in general was associated with more frequent self-reported initiation of overall health-behaviour change (OR 2.77, 95% CI 1.73-4.44, increased physical activity (OR 1.89, 95% CI 1.06-3.39, and improved diet (OR 2.89, 95% CI 1.61-5.17. Conclusions More than half of the employees who voluntarily participated in a web-based HRA with tailored feedback, reported to have initiated health-behaviour change. Self-reported initiation of health-behaviour change was more frequent among those at high CVD risk and BMI levels. In

  7. EDITORIAL: Colloidal dispersions in external fields Colloidal dispersions in external fields

    Science.gov (United States)

    Löwen, Hartmut

    2012-11-01

    Colloidal dispersions have long been proven as pivotal model systems for equilibrium phase transition such as crystallization, melting and liquid-gas phase transition. The last decades have revealed that this is also true for nonequilibrium phenomena. In fact, the fascinating possibility to track the individual trajectories of colloidal particles has greatly advanced our understanding of collective behaviour in classical many-body systems and has helped to reveal the underlying physical principles of glass transition, crystal nucleation, and interfacial dynamics (to name just a few typical nonequilibrium effects). External fields can be used to bring colloids out of equilibrium in a controlled way. Different kinds of external fields can be applied to colloidal dispersions, namely shear flow, electric, magnetic and laser-optical fields, and confinement. Typical research areas can be sketched with the by now traditional complexity diagram (figure 1). The complexity of the colloidal system itself as embodied in statistical degrees of freedom is shown on the x-axis while the complexity of the problem posed, namely bulk, an inhomogeneity in equilibrium, steady state nonequilibrium and full time-dependent nonequilibrium are shown on the y-axis. The different external fields which can be imposed are indicated by the different hatched areas. figure1 Figure 1. Diagram of complexity for colloidal dispersions in external fields: while the x-axis shows the complexity of the system, the y-axis shows the complexity of the problem. Regions which can be accessed by different kinds of external fields are indicated. The arrows indicate recent research directions. Active particles are also indicated with a special complexity of internal degrees of freedom [1]. This collection of papers reflects the scientific programme of the International Conference on Colloidal Dispersions in External Fields III (CODEF III) which took place in Bonn-Bad Godesberg from 20-23 March 2012. This was the

  8. Techniques and Protocols for Dispersing Nanoparticle Powders in Aqueous Media-Is there a Rationale for Harmonization?

    Science.gov (United States)

    Hartmann, Nanna B; Jensen, Keld Alstrup; Baun, Anders; Rasmussen, Kirsten; Rauscher, Hubert; Tantra, Ratna; Cupi, Denisa; Gilliland, Douglas; Pianella, Francesca; Riego Sintes, Juan M

    2015-01-01

    Selecting appropriate ways of bringing engineered nanoparticles (ENP) into aqueous dispersion is a main obstacle for testing, and thus for understanding and evaluating, their potential adverse effects to the environment and human health. Using different methods to prepare (stock) dispersions of the same ENP may be a source of variation in the toxicity measured. Harmonization and standardization of dispersion methods applied in mammalian and ecotoxicity testing are needed to ensure a comparable data quality and to minimize test artifacts produced by modifications of ENP during the dispersion preparation process. Such harmonization and standardization will also enhance comparability among tests, labs, and studies on different types of ENP. The scope of this review was to critically discuss the essential parameters in dispersion protocols for ENP. The parameters are identified from individual scientific studies and from consensus reached in larger scale research projects and international organizations. A step-wise approach is proposed to develop tailored dispersion protocols for ecotoxicological and mammalian toxicological testing of ENP. The recommendations of this analysis may serve as a guide to researchers, companies, and regulators when selecting, developing, and evaluating the appropriateness of dispersion methods applied in mammalian and ecotoxicity testing. However, additional experimentation is needed to further document the protocol parameters and investigate to what extent different stock dispersion methods affect ecotoxicological and mammalian toxicological responses of ENP. PMID:26397955

  9. UFOMOD - atmospheric dispersion and deposition

    International Nuclear Information System (INIS)

    The report gives an introduction into the modelling of atmospheric dispersion and deposition which has been implemented in the new program system UFOMOD for assessing the consequences after nuclear accidents. According to the new structure of UFOMOD, different trajectory models with ranges of validity near to the site and at far distances are applied. Emphasis is laid on the description of the segmented plume model MUSEMET and its affilated submodels, being the removal of activity from the cloud by dry and wet deposition, and special effects like plume rise and the behaviour of plumes released into building wakes. In addition, the evaluation of γ-dose correction factors to take account of the finite extent of the radioactive plume in the near range (up to about 20 km) are described. Only brief introductions are given into the principles of the other models available: the puff model RIMPUFF, the long-range puff model MESOS, and the special straight-line Gaussian model ISOLA which are used if low-level long-duration releases are considered. To define starting times of weather sequences and the probabilities of occurrence of these sequences, it is convenient to perform stratified sampling. Therefore, the preprocessing program package METSAM has been developed to perform for generic ACAs a random sampling of weather sequences out off a population of classified weather conditions. The sampling procedure and a detailed input/output (I/O) description is presented and an additional appendix, respectively. A general overview on the I/O structure of MUSEMET as well as a brief user guide to run the KfK version of the MESOS code are also given in the appendix. (orig.)

  10. Indigenous message tailoring increases consumption of fresh vegetables by clients of community pantries.

    Science.gov (United States)

    Clarke, Peter; Evans, Susan H; Hovy, Eduard H

    2011-09-01

    This study tested whether message tailoring of recipes and food-use tips for low-income households is superior to providing a generic version of the material. The field experiment was conducted in the busy conditions found at community food pantries, and included 10 food distributions at each of six sites. We analyzed the consumption of fresh vegetables 6 days following distributions, and retention of print materials 6 weeks later. Self-determination and reactance theories guided the development of tailoring in an indigenous fashion, allowing each pantry client to choose recipes and food tips thought personally useful. This contrasted against paternalistic tailoring, common in health communication, where a motivational theory is used to regulate the health messages given to recipients. Results demonstrated benefits of tailoring over both generic and control conditions and uncovered the degree of tailoring that produced the largest effects. As suggested by construal level theory, the intervention addressed recipients' immediate and concrete decisions about healthy eating, instead of distant or abstract goals like prevention of illnesses. We documented per-client costs of tailored information. Results also suggested that benefits from social capital at sites offering a health outreach may exceed the impact of message tailoring on outcomes of interest.

  11. Critical review of studies on atmospheric dispersion in coastal regions

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, D.L.; Kaleel, R.J.

    1982-09-01

    This study effort was required as a preliminary step prior to initiation of field measurements of atmospheric dispersion in coastal regions. The Nuclear Regulatory Commission (NRC) is in the process of planning an extensive field measurement program to generate data which will serve as improved data bases for licensing decisions, confirmation of regulations, standards, and guides, and for site characterizations. The study being reported here is an effort directed to obtaining as much information as is possible from existing studies that is relevant toward NRC's objectives. For this study, reports covering research and meteorological measurements conducted for industrial purposes, utility needs, military objectives, and academic studies were obtained and critically reviewed in light of NRC's current data needs. This report provides an interpretation of the extent of existing usable information, an indication of the potential for tailoring existing research toward current NRC information needs, and recommendations for several follow-on studies which could provide valuable additional information through reanalysis of the data. Recommendations are also offered regarding new measurement programs. Emphasis is placed on the identification and acquisition of data from atmospheric tracer studies conducted in coastal regions. A total of 225 references were identified which deal with the coastal atmosphere, including meteorological and tracer measurement programs, theoretical descriptions of the relevant processes, and dispersion models.

  12. Tailoring complex optical fields via anisotropic microstructures (Presentation Recording)

    Science.gov (United States)

    Lu, Yan-Qing; Hu, Wei; Cui, Guo-Xin

    2015-10-01

    In recent years, complex optical fields with spatially inhomogeneous phases, polarizations and optical singularities have drawn many research interests. Many novel effects have been predicted and demonstrated for light beams with these unconventional states in both linear and nonlinear optics regimes. Although local optical phase could be controlled directly or through hologram structures in isotropic materials such as glasses, optical anisotropy is still required for manipulating polarization states and wavelengths. The anisotropy could be either intrinsic such as in crystals/liquid crystals (LCs) or the induced birefringence from dielectric or metallic structures. In this talk, we will briefly review some of our attempts in tailoring complex optical fields via anisotropic microstructures. We developed a micro-photo-patterning system that could generate complex micro-images then further guides the arbitrary local LC directors. Due to the electro-optically (EO) tunable anisotropy of LC, various reconfigurable complex optical fields such as optical vortices (OVs), multiplexed OVs, OV array, Airy beams and vector beams are obtained. Different LC modes such as homogeneous alignment nematic, hybrid alignment nematic and even blue phase LCs are adopted to optimize the static and dynamic beam characteristics depending on application circumstances. We are also trying to extend our approaches to new wavelength bands, such as mid-infrared and even THz ranges. Some preliminary results are obtained. In addition, based on our recently developed local poling techniques for ferroelectric crystals, we will also discuss and demonstrate the nonlinear complex optical field conversion in Lithium Niobate wafers with patterned ferroelectric domain structures.

  13. Tailoring the Matrix in Ultra-Nanocrystalline Diamond Films

    Science.gov (United States)

    Buck, Volker; Woehrl, Nicolas

    2008-10-01

    By depositing films in argon-rich plasmas it is possible to produce ultra-nanocrystalline diamond (UNCD) films with grain sizes of 5-100 nm. By reducing the grain size, these films feature rather distinctive combinations of properties making them potential materials for emerging technological developments such as nano/micro-electro-mechanical systems (N/MEMS), optical coatings, bioelectronics, surface acoustic wave (SAW) filters, and tribological applications. The majority of works dealing with nanocrystalline diamond (NCD) up to now have concentrated on diamond grains (e.g., grain size, texture). In doing so the surrounding crystal matrix has been neglected and its effect on the substrate properties has been dismissed as a grain boundary effect. This view does not accord with its relevance to film properties. Because the matrix consists of amorphous carbon structures, approved methods for the characterization of this appropriate special class of materials were used here such as Raman and Fourier transform infrared spectroscopy (FTIR). The use of an amorphous matrix for nanocrystalline diamond grains has lead to an enormous field of new materials, because a whole class of carbon-based materials (diamondlike carbon, DLC) can be used as a matrix that may contain only carbon (a-C) or carbon and hydrogen (a-C:H) as well as other components such as metals (Me-C:H); additionally, other dopants such as silicon, oxygen, halogens, or nitrogen may be included. As an example, it is shown how the mechanical stress in films can be adjusted by tailoring the matrix.

  14. Tailoring of Vibration Test Specifications for a Flight Vehicle

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2002-01-01

    Full Text Available Most equipment are subjected to vibration environment during their useful life. It is seen that nearly half of the failures observed during the flights of. satellite launch vehicles or missiles are due to mechanical vibration and shock. Thus, these stresses must be carefully considered while defining the specifications. Specifications are established for a system for use during a simulation test to show that a product meets the requirements concerning resistance to the environment. If the equipment operates smoothly during a test, there should be a very strong probability that it will perform its intended task correctly in the real environment and vice versa. Hence, the specification must be at least as severe as the real environment and also representative of the real environment. It is also required that no other item of the equipment built according to the same design should fail in operation. Specifications should take care of this and thus the envelop of data obtained during the real world environment should be considered. Generally at the design stage and the initial development stage, existing standards like the Military Specifications or Joint Service Specifications are used as guidelines for formulating the specifications. This causes either an overtest or an undertest with regards to the overall spectrum or in specific frequency bands for any given structure. To overcome this, it is essential to develop a correct specification using the telemetry data acquired for a few flights and a method is required to be formulated for deriving the specifications out of the telemetry data so obtained. This paper discusses the formulation of a specification methodology, and algorithm in general. The above method is applied to a series of flight data obtained for a particular flight vehicle to derive a specification representative of the real world environmental conditions (tailoring.

  15. Nonlinear burn condition control in tokamaks using isotopic fuel tailoring

    Science.gov (United States)

    Boyer, Mark D.; Schuster, Eugenio

    2015-08-01

    One of the fundamental problems in tokamak fusion reactors is how to control the plasma density and temperature in order to regulate the amount of fusion power produced by the device. Control of these parameters will be critical to the success of burning plasma experiments like ITER. The most previous burn condition control efforts use either non-model based control designs or techniques based on models linearized around particular operating points. Such strategies limit the potential operational space and must be carefully retuned or redesigned to accommodate changes in operating points or plasma parameters. In this work, a nonlinear dynamic model of the spatial averages of energy and ion species densities is used to synthesize a nonlinear feedback controller for stabilizing the burn condition. The nonlinear model-based control strategy guarantees a much larger operational space than previous linear controllers. Because it is not designed around a particular operating point, the controller can be used to move from one burn condition to another. The proposed scheme first attempts to use regulation of the auxiliary heating power to reject temperature perturbations, then, if necessary, uses isotopic fuel tailoring as a way to reduce fusion heating during positive temperature perturbations. A global model of hydrogen recycling is incorporated into the model used for design and simulation, and the proposed control scheme is tested for a range of recycling model parameters. As we find the possibility of changing the isotopic mix can be limited for certain unfavorable recycling conditions, we also consider impurity injection as a back-up method for controlling the system. A simple supervisory control strategy is proposed to switch between the primary and back-up control schemes based on stability and performance criteria. A zero-dimensional simulation study is used to study the performance of the control scheme for several scenarios and model parameters. Finally, a one

  16. A novel molluscicide, corrosion inhibitor, and dispersant

    Energy Technology Data Exchange (ETDEWEB)

    Kreuser, R.T. [RTK Technologies, Inc., Baton Rouge, LA (United States); Vanlaer, A. [Mexel S.A.R.L., Haubourdin (France); Damour, A. [Pacific Arra Co., Kowloon (Hong Kong)

    1997-12-01

    The efficacy of filming amines as corrosion inhibitors and dispersants in steam systems is well-documented. A novel formulation retains these functions of traditional filming amines and adds molluscicide capability for controlling macrofouling in fresh water and sea water. Criteria for this development included low toxicity to mammals and to non-target aquatic species, rapid biodegradation, and multifunctionality. Low mammalian toxicity and lack of other hazards exempt it from reporting requirements under SARA Title 3. Toxicity (LC{sub 50}) levels for rainbow trout and fathead minnow are higher than typical dosage rates. Biodegradation is rapid; half life is 22 hours in river water. By effectively dispersing slimes (along with biofilm, scale, and tubercles), it controls slimes without toxicity to biofilm organisms. As corrosion inhibitor, it reduces the open cell potential of metal surfaces by 50--200 millivolts and retards pitting and crevice corrosion. Its molluscicide activity gradually kills and disperses mussels, clams, and barnacles. The protective film, renewed by dosage for a brief period of time each day, proactively prevents scale and slime deposits and repels settling and adhesion by macrofouling species. Refinement of established technology has produced a multi-functional formulation that is safe to handle and has minimal impact on the environment.

  17. Probing Microsecond Time Scale Dynamics in Proteins by Methyl H-1 Carr-Purcell-Meiboom-Gill Relaxation Dispersion NMR Measurements. Application to Activation of the Signaling Protein NtrC(r)

    NARCIS (Netherlands)

    Otten, Renee; Villali, Janice; Kern, Dorothee; Mulder, Frans A. A.

    2010-01-01

    To study microsecond processes by relaxation dispersion NMR spectroscopy, low power deposition and short pulses are crucial and encourage the development of experiments that employ H-1 Carr-Purcell-Meiboom-Gill (CPMG) pulse trains. Herein, a method is described for the comprehensive study of microse

  18. Understanding the impact of graphene sheet tailoring on the conductance of GNRFETs

    Indian Academy of Sciences (India)

    Devendra Upadhyay; Sudhanshu Choudhary

    2015-12-01

    The effect of tailoring the graphene sheets used as channel in a graphene nanoribbon field effect transistor (GNRFET) was investigated. The study was performed using self-consistent solution of Poisson's and Schrodinger's equation in combination with non-equilibrium Green's function (NEGF) formalism. Graphene sheet channel was tailored into different shapes and found that with the introduction of edge roughness along the border of GNR sheet the bandgap of GNRFET channel increases. Tailoring the channel decreases mobility and transmission probability to a great extent and thus the performance of I–V characteristics of GNRFET degrades.

  19. Double-tailored nonimaging reflector optics for maximum-performance solar concentration.

    Science.gov (United States)

    Goldstein, Alex; Gordon, Jeffrey M

    2010-09-01

    A nonimaging strategy that tailors two mirror contours for concentration near the étendue limit is explored, prompted by solar applications where a sizable gap between the optic and absorber is required. Subtle limitations of this simultaneous multiple surface method approach are derived, rooted in the manner in which phase space boundaries can be tailored according to the edge-ray principle. The fundamental categories of double-tailored reflective optics are identified, only a minority of which can pragmatically offer maximum concentration at high collection efficiency. Illustrative examples confirm that acceptance half-angles as large as 30 mrad can be realized at a flux concentration of approximately 1000. PMID:20808405

  20. Dispersal networks for enhancing bacterial degradation in heterogeneous environments

    Energy Technology Data Exchange (ETDEWEB)

    Banitz, Thomas, E-mail: thomas.banitz@ufz.de [Department of Ecological Modelling, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Wick, Lukas Y.; Fetzer, Ingo [Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Frank, Karin [Department of Ecological Modelling, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Harms, Hauke [Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Johst, Karin [Department of Ecological Modelling, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany)

    2011-10-15

    Successful biodegradation of organic soil pollutants depends on their bioavailability to catabolically active microorganisms. In particular, environmental heterogeneities often limit bacterial access to pollutants. Experimental and modelling studies revealed that fungal networks can facilitate bacterial dispersal and may thereby improve pollutant bioavailability. Here, we investigate the influence of such bacterial dispersal networks on biodegradation performance under spatially heterogeneous abiotic conditions using a process-based simulation model. To match typical situations in polluted soils, two types of abiotic conditions are studied: heterogeneous bacterial dispersal conditions and heterogeneous initial resource distributions. The model predicts that networks facilitating bacterial dispersal can enhance biodegradation performance for a wide range of these conditions. Additionally, the time horizon over which this performance is assessed and the network's spatial configuration are key factors determining the degree of biodegradation improvement. Our results support the idea of stimulating the establishment of fungal mycelia for enhanced bioremediation of polluted soils. - Highlights: > Bacterial dispersal networks can considerably improve biodegradation performance. > They facilitate bacterial access to dispersal-limited areas and remote resources. > Abiotic conditions, time horizon and network structure govern the improvements. > Stimulating the establishment of fungal mycelia promises enhanced soil remediation. - Simulation modelling demonstrates that fungus-mediated bacterial dispersal can considerably improve the bioavailability of organic pollutants under spatially heterogeneous abiotic conditions typical for water-unsaturated soils.