WorldWideScience

Sample records for ubiquitous gel particles

  1. Performance of Magnetic Filter for Separation of Magnetic Gel Particles

    OpenAIRE

    栗延, 俊太郎; 尾崎, 博明; 渡辺, 恒雄; クリノブ, シュンタロウ; オザキ, ヒロアキ; ワタナベ, ツネオ; Shuntaro, KURINOBU; Hiroaki, OZAKI; Tuneo, WATANABE

    2003-01-01

    We have developed a new wastewater treatment process using magnetic gel particles containing immobilized microorganisms and magnetic particles. The performance of magnetic gel particles using a magnetic filter is very important to control the process. In this study, the performance of a magnetic filter was studied for magnetic gel, particles. Agar particles containing magnetite particles were used as gel particles. The recovery and the relative retention area of magnetic gel particles on the ...

  2. Ageing of uranyl gel spherical particles

    International Nuclear Information System (INIS)

    Benadik, A.; Urbanek, V.; Vosecek, V.; Skvor, V.

    1978-01-01

    The structure and chemical composition of U(VI) gel are described and the course of crystal growth in ageing process at 22+-2 degC was found. Store conditions of probes had no influence on crystal growth rate. However, the way of probe storage influenced the quality and appearance of the xerogel obtained by drying via azeotropic distillation. The gel particles stored under trichloroethylene had a good appearance also after storing for 44 hours long. Particles stored in air saturated with H 2 O and NH 3 showed a worse appearance already after 20 hours. After 70 hours particles of spiny form were found. The worst particles were those stored under a trichloroethylene-ethylalcohol mixture. For storing purposes trichloroethylene was recommended as the most appropriate medium of gel protection. (author)

  3. Deformation and fracture behavior of simulated particle gels

    NARCIS (Netherlands)

    Rzepiela, A.A.

    2003-01-01

    In this PhD project rheological properties of model particle gels are investigated using Brownian Dynamics (BD) simulations. Particle gels are systems of colloidal particles that form weakly bonded percolating networks interpenetrated by a suspending fluid. They are characterized as

  4. Internal structure analysis of particle-double network gels used in a gel organ replica

    Science.gov (United States)

    Abe, Mei; Arai, Masanori; Saito, Azusa; Sakai, Kazuyuki; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    In recent years, the fabrication of patient organ replicas using 3D printers has been attracting a great deal of attention in medical fields. However, the cost of these organ replicas is very high as it is necessary to employ very expensive 3D printers and printing materials. Here we present a new gel organ replica, of human kidney, fabricated with a conventional molding technique, using a particle-double network hydrogel (P-DN gel). The replica is transparent and has the feel of a real kidney. It is expected that gel organ replicas produced this way will be a useful tool for the education of trainee surgeons and clinical ultrasonography technologists. In addition to developing a gel organ replica, the internal structure of the P-DN gel used is also discussed. Because the P-DN gel has a complex structure comprised of two different types of network, it has not been possible to investigate them internally in detail. Gels have an inhomogeneous network structure. If it is able to get a more uniform structure, it is considered that this would lead to higher strength in the gel. In the present study we investigate the structure of P-DN gel, using the gel organ replica. We investigated the internal structure of P-DN gel using Scanning Microscopic Light Scattering (SMILS), a non-contacting and non-destructive.

  5. Washing of gel particles in wet chemical manufacture of reactor fuel particles

    International Nuclear Information System (INIS)

    Ringel, H.

    1980-07-01

    In the manufacture of HTR fuel particles and particles of fertile material by wet chemical methods, the ammonium nitrate formed during the precipitation reaction must be washed out of the gel particles. This washing process has been investigated theoretically and experimentally. A counter-current washer has been developed which in particular takes account of the aspects of refabrication - such as compact construction and minimum waste. A counter-current washing column of 17 mm internal diameter and 640 mm length gives to gel particle throughput of 0.65 1/h. The volume ratio of wash water to gel particles is 5, and the residual nitrate concentration in the particles is 7 x 10 -3 mols of NO - 3 /1. (orig.) [de

  6. The structure of particle gels as studied with confocal microscopy and computer simulations

    NARCIS (Netherlands)

    Bos, M.T.A.

    1997-01-01

    This thesis contains the results of a PhD-study on the structure of particle gels. Part of it is directed at a quantification of this structure from measured data, part of it at modelling the aggregation processes that lead to particle gels. Chapter 1 of this thesis is a general

  7. Categorization of rheological scaling models for particle gels applied to casein gels

    NARCIS (Netherlands)

    Mellema, M.; Opheusden, van J.H.J.; Vliet, van T.

    2002-01-01

    Rennet-induced casein gels made from skim milk were studied rheologically. A scaling model or framework for describing the rheological behavior of gels is discussed and used for classification of the structure of casein gels. There are two main parameters in the model that describe the number of

  8. Ubiquitous positioning

    CERN Document Server

    Mannings, Robin

    2008-01-01

    This groundbreaking resource offers a practical, in-depth understanding of Ubiquitous Positioning - positioning systems that identify the location and position of people, vehicles and objects in time and space in the digitized networked economy. The future and growth of ubiquitous positioning will be fueled by the convergence of many other areas of technology, from mobile telematics, Internet technology, and location systems, to sensing systems, geographic information systems, and the semantic web. This first-of-its-kind volume explores ubiquitous positioning from a convergence perspective, of

  9. Nano- and microsized cubic gel particles from cyclodextrin metal-organic frameworks.

    Science.gov (United States)

    Furukawa, Yuki; Ishiwata, Takumi; Sugikawa, Kouta; Kokado, Kenta; Sada, Kazuki

    2012-10-15

    Sweet cube o' mine: Bottom-up control of gel particles has been regarded as a great challenge. By employing internal cross-linking of cyclodextrin metal-organic frameworks, cubic sugar gels were formed with sharp edges that reflect the shape of the crystals. This enabled the fabrication of shape- and size-controlled polymer gels from porous crystals (see picture). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Large shear deformation of particle gels studied by Brownian Dynamics simulations

    NARCIS (Netherlands)

    Rzepiela, A.A.; Opheusden, van J.H.J.; Vliet, van T.

    2002-01-01

    This paper focuses on shear deformation of particle gels. Two different methods of shear deformation are discussed, namely affine and non-affine deformation, the second being novel in simulation studies of gels. Non-affine deformation resulted in a slower increase of the stress at small deformation.

  11. Glutenin macropolymer: A gel formed by glutenin particles

    NARCIS (Netherlands)

    Don, C.; Lichtendonk, W.; Plijter, J.J.; Hamer, R.J.

    2003-01-01

    The quality of wheat-based foods and the processing properties of wheat flour dough are strongly related to the presence and properties of very large glutenin protein aggregates. These very large aggregates are insoluble in 1.5% (w/v) SDS and can be recovered after ultracentrifugation as a gel, the

  12. Glutenin Macropolymer: a Gel Formed by Glutenin Particles

    NARCIS (Netherlands)

    Don, C.; Lichtendonk, W.J.; Plijter, J.J.; Hamer, R.J.

    2003-01-01

    The quality of wheat-based foods and the processing properties of wheat flour dough are strongly related to the presence and properties of very large glutenin protein aggregates. These very large aggregates are insoluble in 1.5% (w/v) SDS and can be recovered after ultracentrifugation as a gel, the

  13. Fractal aggregation in relation to formation and properties of particle gels

    NARCIS (Netherlands)

    Bremer, L.G.B.

    1992-01-01

    The purpose of this study is to gain insight into the conditions determining whether small particles in a liquid are able to jointly occupy the total volume thus forming a gel network. In order to build a network the colloidal particles have to be 'sticky', unstable. In the unassociated

  14. Large shear deformation of particle gels studied by Brownian Dynamics simulations

    NARCIS (Netherlands)

    Rzepiela, A.A.; Opheusden, van J.H.J.; Vliet, van T.

    2004-01-01

    Brownian Dynamics (BD) simulations have been performed to study structure and rheology of particle gels under large shear deformation. The model incorporates soft spherical particles, and reversible flexible bond formation. Two different methods of shear deformation are discussed, namely affine and

  15. On gel electrophoresis of dielectric charged particles with hydrophobic surface: A combined theoretical and numerical study.

    Science.gov (United States)

    Majee, Partha Sarathi; Bhattacharyya, Somnath; Gopmandal, Partha Pratim; Ohshima, Hiroyuki

    2018-03-01

    A theoretical study on the gel electrophoresis of a charged particle incorporating the effects of dielectric polarization and surface hydrophobicity at the particle-liquid interface is made. A simplified model based on the weak applied field and low charge density assumption is also presented and compared with the full numerical model for a nonpolarizable particle to elucidate the nonlinear effects such as double layer polarization and relaxation as well as surface conduction. The main motivation of this study is to analyze the electrophoresis of the surface functionalized nanoparticle with tunable hydrophobicity or charged fluid drop in gel medium by considering the electrokinetic effects and hydrodynamic interactions between the particle and the gel medium. An effective medium approach, in which the transport in the electrolyte-saturated hydrogel medium is governed by the Brinkman equation, is adopted in the present analysis. The governing electrokinetic equations based on the conservation principles are solved numerically. The Navier-slip boundary condition along with the continuity condition of dielectric displacement are imposed on the surface of the hydrophobic polarizable particle. The impact of the slip length on the electrophoresis is profound for a thinner Debye layer, however, surface conduction effect also becomes significant for a hydrophobic particle. Impact of hydrophobicity and relaxation effects are higher for a larger particle. Dielectric polarization creates a reduction in its electrophoretic propulsion and has negligible impact at the thinner Debye length as well as lower gel screening length. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Steady shear rheology of dilute polystyrene particle gels

    NARCIS (Netherlands)

    Folkersma, R.; Diemen, van A.J.G.; Laven, J.; Stein, H.N.

    1999-01-01

    This paper describes an experimental study on dispersions of monodisperse polystyrene (PS) spheres with a typical radius of 1 µm, dispersed in an electrolyte at high ionic strength, screening the electrostatic repulsion. These suspensions gelate at rest even at low volume fractions of PS particles.

  17. Preparation of UO2 dense spherical particles by sol-gel technique

    International Nuclear Information System (INIS)

    Urbanek, V.; Dolezal, J.

    1977-01-01

    The results of the basic research and development of processes of preparation of dense UO 2 spherical particles by sol-gel technique are presented. Attention was paid to the study of chemistry of internal gelation step in the uranylnitrate-urea-hexamethylentetramine system. The existence regions of several stable gels with different properties were established in connection with variable ratio of basic gel's components and the appropriate ''Phase diagrams'' were drawn. From these diagrams, two of the most interesting types of uranyl gels were chosen for the subsequent thermal processing which included drying, reduction and sintering. The detailed studies of each step of the whole process enabled preparation of UO 2 dense spheres with well defined microstructure

  18. Exploratory experiments on the feasibility of Th and Pu sol-gel particles

    International Nuclear Information System (INIS)

    Vanhellemont, G.; Beullens, J.; Bairiot, H.

    1965-05-01

    The sol-gel process as developed by the O.E.C.D. Dragon Project has been applied by the Plutonium Project at Mol to determine the feasibility of producing spherical particles containing Th02, Pu02 and C, in the proportions necessary to fabricate thorium-plutonium carbide kernels for irradiation specimens and for fuel cartridges for the Dragon Reactor Experiment. The process has been extended successfully to the preparation of thorium and plutonium gels, having a significant excess of carbon, with the object of evaluating the feasibility of the sol-gel process for the production of Th, C-10 type kernels. Other experiments have been performed to test the feasibility of incorporating U02 powder into the gel spheres. By using this technique, U to Th ratios of up to 9:1 have been obtained. (author)

  19. Scaling relations between structure and rheology of ageing casein particle gels

    NARCIS (Netherlands)

    Mellema, M.

    2000-01-01

    Mellema, M. (Michel), Scaling relations between structure and rheology of ageing casein particle gels , PhD Thesis, Wageningen University, 150 + 10 pages, references by chapter, English and Dutch summaries (2000).

    The relation between (colloidal)

  20. Ubiquitous atom

    International Nuclear Information System (INIS)

    Spruch, G.M.; Spruch, L.

    1974-01-01

    The fundamentals of modern physics, including the basic physics and chemistry of the atom, elementary particles, cosmology, periodicity, and recent advances, are surveyed. The biology and chemistry of the life process is discussed to provide a background for considering the effects of atomic particles on living things. The uses of atomic power in space travel, merchant shipping, food preservation, desalination, and nuclear clocks are explored. (Pollut. Abstr.)

  1. Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties.

    Science.gov (United States)

    Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R

    2014-05-12

    The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

  2. Microneedle assisted micro-particle delivery from gene guns: experiments using skin-mimicking agarose gel.

    Science.gov (United States)

    Zhang, Dongwei; Das, Diganta B; Rielly, Chris D

    2014-02-01

    A set of laboratory experiments has been carried out to determine if micro-needles (MNs) can enhance penetration depths of high-speed micro-particles delivered by a type of gene gun. The micro-particles were fired into a model target material, agarose gel, which was prepared to mimic the viscoelastic properties of porcine skin. The agarose gel was chosen as a model target as it can be prepared as a homogeneous and transparent medium with controllable and reproducible properties allowing accurate determination of penetration depths. Insertions of various MNs into gels have been analysed to show that the length of the holes increases with an increase in the agarose concentration. The penetration depths of micro-particle were analysed in relation to a number of variables, namely the operating pressure, the particle size, the size of a mesh used for particle separation and the MN dimensions. The results suggest that the penetration depths increase with an increase of the mesh pore size, because of the passage of large agglomerates. As these particles seem to damage the target surface, then smaller mesh sizes are recommended; here, a mesh with a pore size of 178 μm was used for the majority of the experiments. The operating pressure provides a positive effect on the penetration depth, that is it increases as pressure is increased. Further, as expected, an application of MNs maximises the micro-particle penetration depth. The maximum penetration depth is found to increase as the lengths of the MNs increase, for example it is found to be 1272 ± 42, 1009 ± 49 and 656 ± 85 μm at 4.5 bar pressure for spherical micro-particles of 18 ± 7 μm diameter when we used MNs of 1500, 1200 and 750 μm length, respectively. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  3. Shear elastic modulus of magnetic gels with random distribution of magnetizable particles

    Science.gov (United States)

    Iskakova, L. Yu; Zubarev, A. Yu

    2017-04-01

    Magnetic gels present new type of composite materials with rich set of uniquie physical properties, which find active applications in many industrial and bio-medical technologies. We present results of mathematically strict theoretical study of elastic modulus of these systems with randomly distributed magnetizable particles in an elastic medium. The results show that an external magnetic field can pronouncedly increase the shear modulus of these composites.

  4. Development of vapor deposited silica sol-gel particles for use as a bioactive materials system.

    Science.gov (United States)

    Snyder, Katherine L; Holmes, Hallie R; VanWagner, Michael J; Hartman, Natalie J; Rajachar, Rupak M

    2013-06-01

    Silica-based sol-gel and bioglass materials are used in a variety of biomedical applications including the surface modification of orthopedic implants and tissue engineering scaffolds. In this work, a simple system for vapor depositing silica sol-gel nano- and micro-particles onto substrates using nebulizer technology has been developed and characterized. Particle morphology, size distribution, and degradation can easily be controlled through key formulation and manufacturing parameters including water:alkoxide molar ratio, pH, deposition time, and substrate character. These particles can be used as a means to rapidly modify substrate surface properties, including surface hydrophobicity (contact angle changes >15°) and roughness (RMS roughness changes of up to 300 nm), creating unique surface topography. Ions (calcium and phosphate) were successfully incorporated into particles, and induced apatitie-like mineral formation upon exposure to simulated body fluid Preosteoblasts (MC3T3) cultured with these particles showed up to twice the adhesivity within 48 h when compared to controls, potentially indicating an increase in cell proliferation, with the effect likely due to both the modified substrate properties as well as the release of silica ions. This novel method has the potential to be used with implants and tissue engineering materials to influence cell behavior including attachment, proliferation, and differentiation via cell-material interactions to promote osteogenesis. Copyright © 2012 Wiley Periodicals, Inc.

  5. Evaluation of particle release from montmorillonite gel by flowing groundwater based on the DLVO theory

    International Nuclear Information System (INIS)

    Kurosawa, Susumu; Nagasaki, Shinya; Tanaka, Satoru

    2007-01-01

    Theoretical study has been performed to clarify the ability of colloid release form the montmorillonite gel by the flowing groundwater. Evaluation of montmorillonite colloidal particles release from the bentonite buffer material is important for the performance assessment of radioactive waste disposal because the colloids may influence the radionuclide transport. In this study, the minimum groundwater flow rate required to tear off montmorillonite particles from surface of bentonite buffer was estimated from the shear stress on the gel front, which was calculated by the DLVO theory. The estimated shear force was converted to corresponding groundwater velocity by using Stoke's equation. The results indicated that groundwater velocity in a range of about 10 -5 to 10 -4 m/s would be necessary to release montmorillonite particles. This range is higher than the groundwater flow velocity found generally in deep geological media in Japan. This study suggests that the effect of montmorillonite particles release from the bentonite buffer on radionuclide transport is likely to be negligible in the performance assessment of high-level radioactive waste geological disposal. (author)

  6. Nuclear molecular halo: the ubiquitous occurrence of van der Waals molecular states near threshold in molecular, nuclear and particle physics

    International Nuclear Information System (INIS)

    Gai, Moshe

    1999-01-01

    The observation of large E1 strength near threshold in the electromagnetic dissociation of 11 Li poses a fundamental question: Is the large E1 strength due to the threshold or is it due to a low lying E1 state? Such molecular cluster states were observed in 18 O and in several nuclei near the drip line. We discuss the nature of the threshold effect as well as review the situation in Molecular (and Particle Physics) where such Molecular States are observed near the dissociation limit. We suggest that the situation in 11 Li is reminiscent of the argon-benzene molecule where the argon atom is loosely bound by a polarization (van der Waals) mechanism and thus leads to a very extended object lying near the dissociation limit. Such states are also suggested to dominate the structure of mesons [α 0 (980), f 0 (975)] and baryons [λ(1405)] with proposed Kaon molecular structure (Dalitz) near threshold. The inspection of such states throughout Physics allows us to gain insight into this phenomenon and suggest that a new collective Molecular Dipole Degree of Freedom plays a major role in the structure of hadrons (halo nuclei, mesons and baryons), and that quantitative tools such as the E1 Molecular Sum Rule are useful for elucidating the nature of the observed low lying E1 strength in halo nuclei. (author)

  7. Preclinical investigations towards the first spacer gel application in prostate cancer treatment during particle therapy at HIT

    International Nuclear Information System (INIS)

    Ruciński, Antoni; Parodi, Katia; Jäkel, Oliver; Haberer, Thomas; Bauer, Julia; Campbell, Patrick; Brons, Stephan; Unholtz, Daniel; Habl, Gregor; Herfarth, Klaus; Debus, Jürgen; Bert, Christoph

    2013-01-01

    The application of spacer gel represents a promising approach to reliably spare the rectal frontal wall during particle therapy (IJROBP 76:1251-1258, 2010). In order to qualify the spacer gel for the clinical use in particle therapy, a variety of measurements were performed in order to ensure the biological compatibility of the gel, its physical stability during and after the irradiation, and a proper definition of the gel in terms of the Hounsfield Unit (HU) values for the treatment planning system. The potential for the use of the spacer gel for particle therapy monitoring with off-line Positron Emission Tomography (PET) was also investigated. The spacer gel implanted to the prostate patient in direct neighbourhood to the clinical target volume does not interfere with the particle therapy treatment planning procedure applied at Heidelberg Ion Beam Therapy Centre (HIT). The performed measurements show that Bragg-peak position of the particles can be properly predicted on the basis of computed tomography imaging with the treatment planning system used at HIT (measured water equivalent path length of 1.011 ±0.011 (2σ), measured Hounsfield Unit of 28.9 ±6.1 (2σ)). The spacer gel samples remain physically unchanged after irradiation with a dose exceeding the therapeutic dose level. The independently measured Bragg-Peak position does not change within the time interval of 10 weeks. As a result of the presented experiments, the first clinical application of spacer gel implant during prostate cancer treatment with carbon ions and protons was possible at HIT in 2012. The reported pre-clinical investigations demonstrate that use of spacer gel is safe in particle therapy in presence of therapy target motion and patient positioning induced particle range variations. The spacer gel injected between prostate and rectum enlarge the distance between both organs, which is expected to clinically significantly decrease the undesirable exposure of the most critical organ at risk

  8. Synthesis and characterization of CdO nano particles by the sol-gel method

    Science.gov (United States)

    Vadgama, V. S.; Vyas, R. P.; Jogiya, B. V.; Joshi, M. J.

    2017-05-01

    Cadmium Oxide (CdO) is an inorganic compound and one of the main precursors to other cadmium compounds. It finds applications in cadmium plating, storage batteries, in transparent conducting film, etc. Here, an attempt is made to synthesize CdO nano particles by sol-gel technique. The gel was prepared using cadmium nitrate tetra hydrate (Cd(NO3)2.4H2O) and aqueous ammonium hydroxide (NH4OH) as a precursor. The synthesized powder is further characterized by techniques like Powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Thermal gravimetric analysis (TGA). Powder XRD analysis suggested the nano-crystalline nature of the sample with the cubic crystal system. Nano scaled particles of spherical morphology with the size ranging from 50-100 nm are observed from TEM images. While, FT-IR study is used to confirm the presence of different functional groups. Thermo-gravimetric analysis suggests the highly thermally stable nature of the samples. The results are discussed.

  9. Impact of temperature on zinc oxide particle size by using sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Keanchuan, E-mail: lee.kc@petronas.com.my; Ching, Dennis Ling Chuan, E-mail: dennis.ling@petronas.com.my [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Saipolbahri, Zulhilmi Akmal bin, E-mail: zulhilmiakmal@gmail.com [Geoscience and Petroleum Engineering Department, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Guan, Beh Hoe, E-mail: beh.hoeguan@petronas.com.my, E-mail: hassan.soleimani@petronas.com.my; Soleimani, Hassan, E-mail: beh.hoeguan@petronas.com.my, E-mail: hassan.soleimani@petronas.com.my

    2014-10-24

    Zinc oxide (ZnO) nanoparticles were prepared and synthesized via sol-gel method, by using citric acid as a precursor. The impact of annealing on the particle size was investigated. Based on the results from the Thermogravimetric Analysis (TGA), three different annealing temperature which is 500, 600 and 700 °C were chosen followed by the characterization of the ZnO nanoparticle by using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM). Results showed that the crystallite size estimated from PXRD increased with the annealing temperature which was hexagonal structure for ZnO. TEM further revealed the same tendency which the Zn NPs size also increased with the annealing temperature.

  10. Impact of temperature on zinc oxide particle size by using sol-gel process

    International Nuclear Information System (INIS)

    Lee, Keanchuan; Ching, Dennis Ling Chuan; Saipolbahri, Zulhilmi Akmal bin; Guan, Beh Hoe; Soleimani, Hassan

    2014-01-01

    Zinc oxide (ZnO) nanoparticles were prepared and synthesized via sol-gel method, by using citric acid as a precursor. The impact of annealing on the particle size was investigated. Based on the results from the Thermogravimetric Analysis (TGA), three different annealing temperature which is 500, 600 and 700 °C were chosen followed by the characterization of the ZnO nanoparticle by using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM). Results showed that the crystallite size estimated from PXRD increased with the annealing temperature which was hexagonal structure for ZnO. TEM further revealed the same tendency which the Zn NPs size also increased with the annealing temperature

  11. Production of TiO_2 particles by sol-gel ultrasound assisted for photocatalytic applications

    International Nuclear Information System (INIS)

    Martinez Rojas, Vanessa; Solis Veliz, Jose; Gomez Leon, Monica; Matejova, Lenka; Lopez, Alcides; Cruz, Gerardo J.

    2015-01-01

    Synthesis of TiO_2 particles was made by sol-gel technique assisted of ultrasonic radiation from an alcoholic solution of titanium isopropoxide. Then was subjected to a heat treatment in air at 350 °C for 1 h. X-ray diffraction and transmission electron microscopy confirmed that the size of the crystalline domains is between 10 and 37 nm. Infrared spectroscopy study confirms the presence of -OH groups on the surface of TiO_2. Modification of the morphology and surface area, due to the influence of exposure time to the ultrasonic radiation, is evidenced by studies of SEM and BET respectively. Properties of TiO_2 obtained were studied by monitoring the degradation of solutions of methyl orange in the presence of UV-A radiation. It was observed that larger the ultrasonic radiation exposure during the TiO_2 synthesis larger the constant velocity for the photocatalytic reaction for the methyl orange. (author)

  12. Gelation of Soy Milk with Hagfish Exudate Creates a Flocculated and Fibrous Emulsion- and Particle Gel.

    Directory of Open Access Journals (Sweden)

    Lukas Böni

    Full Text Available Hagfish slime is an ultra dilute, elastic and cohesive hydrogel that deploys within milliseconds in cold seawater from a glandularly secreted exudate. The slime is made of long keratin-like fibers and mucin-like glycoproteins that span a network which entraps water and acts as a defense mechanism against predators. Unlike other hydrogels, the slime only confines water physically and is very susceptible to mechanical stress, which makes it unsuitable for many processing operations and potential applications. Despite its huge potential, little work has been done to improve and functionalize the properties of this hydrogel. To address this shortcoming, hagfish exudate was mixed with a soy protein isolate suspension (4% w/v and with a soy emulsion (commercial soy milk to form a more stable structure and combine the functionalities of a suspension and emulsion with those of the hydrogel. Hagfish exudate interacted strongly with the soy systems, showing a markedly increased viscoelasticity and water retention. Hagfish mucin was found to induce a depletion and bridging mechanism, which caused the emulsion and suspension to flocculate, making "soy slime", a cohesive and cold-set emulsion- and particle gel. The flocculation network increases viscoelasticity and substantially contributes to liquid retention by entrapping liquid in the additional confinements between aggregated particles and protein fibers. Because the mucin-induced flocculation resembles the salt- or acid-induced flocculation in tofu curd production, the soy slime was cooked for comparison. The cooked soy slime was similar to conventional cooked tofu, but possessed a long-range cohesiveness from the fibers. The fibrous, cold-set, and curd-like structure of the soy slime represents a novel way for a cold coagulation and fiber incorporation into a suspension or emulsion. This mechanism could be used to efficiently gel functionalized emulsions or produce novel tofu-like structured food

  13. Gelation of Soy Milk with Hagfish Exudate Creates a Flocculated and Fibrous Emulsion- and Particle Gel

    Science.gov (United States)

    Böni, Lukas; Rühs, Patrick A.; Windhab, Erich J.; Fischer, Peter; Kuster, Simon

    2016-01-01

    Hagfish slime is an ultra dilute, elastic and cohesive hydrogel that deploys within milliseconds in cold seawater from a glandularly secreted exudate. The slime is made of long keratin-like fibers and mucin-like glycoproteins that span a network which entraps water and acts as a defense mechanism against predators. Unlike other hydrogels, the slime only confines water physically and is very susceptible to mechanical stress, which makes it unsuitable for many processing operations and potential applications. Despite its huge potential, little work has been done to improve and functionalize the properties of this hydrogel. To address this shortcoming, hagfish exudate was mixed with a soy protein isolate suspension (4% w/v) and with a soy emulsion (commercial soy milk) to form a more stable structure and combine the functionalities of a suspension and emulsion with those of the hydrogel. Hagfish exudate interacted strongly with the soy systems, showing a markedly increased viscoelasticity and water retention. Hagfish mucin was found to induce a depletion and bridging mechanism, which caused the emulsion and suspension to flocculate, making “soy slime”, a cohesive and cold-set emulsion- and particle gel. The flocculation network increases viscoelasticity and substantially contributes to liquid retention by entrapping liquid in the additional confinements between aggregated particles and protein fibers. Because the mucin-induced flocculation resembles the salt- or acid-induced flocculation in tofu curd production, the soy slime was cooked for comparison. The cooked soy slime was similar to conventional cooked tofu, but possessed a long-range cohesiveness from the fibers. The fibrous, cold-set, and curd-like structure of the soy slime represents a novel way for a cold coagulation and fiber incorporation into a suspension or emulsion. This mechanism could be used to efficiently gel functionalized emulsions or produce novel tofu-like structured food products. PMID

  14. Highly dispersed spherical Bi3.25La0.75Ti3O12 nanocrystals via topotactic crystallization of aggregation-free gel particles from an effective inverse miniemulsion sol–gel approach

    International Nuclear Information System (INIS)

    Wang, Aijun; Zeng, Yanwei; Han, Longxiang; Ding, Chuan; Cao, Liangliang; Li, Rongjie

    2015-01-01

    Aggregation-free spherical lanthanum-doped bismuth titanate (Bi 3.25 La 0.75 Ti 3 O 12 , BLT) gel particles with an average size of about 150 nm were successfully obtained from an inverse miniemulsion sol–gel process, with Span-80 acting as surfactant, n-butanol as co-surfactant, cyclohexane as continuous phase, and submicro-droplets of aqueous solution containing Bi 3+ , La 3+ and Ti 4+ ions as dispersed phase, and then topotactically transformed into highly dispersed spherical BLT nanocrystals after an in situ crystallization at 600 °C for 8 h. It has been found that the BLT gel particles can be obtained via a moderate sol–gel reaction inside the miniemulsion droplets at 65 °C, but their morphology and aggregation degree are strongly affected by the relative amounts of Span-80 and n-butanol. The perfect spherical BLT gel particles with no aggregation can be achieved only under the condition of 3 wt% n-butanol relative to the mass of cyclohexane, with excessive amount of n-butanol leading to the formation of ill-gelled particles with irregular shapes, while insufficient addition of n-butanol resulting in terrible aggregation of gel particles. To understand the formation of aggregation-free spherical BLT gel particles, a tentative mechanism is proposed and discussed, which reveals that a well-coordinated oil–water interfacial film made up of Span-80 and n-butanol molecules and the appropriately enhanced evaporation of water from such interfaces should be responsible for the formation of aggregation-free spherical BLT gel particles. Graphical Abstract: Aggregation-free spherical BLT (Bi 3.25 La 0.75 Ti 3 O 12 ) gel particles can be prepared from an effective inverse miniemulsion sol–gel process, and subsequently topotactically transformed into spherical BLT nanocrystals through an in situ crystallization

  15. Impact of protein pre-treatment conditions on the iron encapsulation efficiency of whey protein cold-set gel particles

    NARCIS (Netherlands)

    Martin, A.H.; Jong, G.A.H. de

    2012-01-01

    This paper investigates the possibility for iron fortification of food using protein gel particles in which iron is entrapped using cold-set gelation. The aim is to optimize the iron encapsulation efficiency of whey protein by giving the whey protein different heat treatment prior to gelation with

  16. Effects of structural rearrangements on the rheology of rennet-induced casein particle gels

    NARCIS (Netherlands)

    Mellema, M.; Walstra, P.; Opheusden, van J.H.J.; Vliet, van T.

    2002-01-01

    During ageing of casein or skim milk gels, structural changes take place that affect gel parameters, such as pore size and storage modulus. These changes can be explained in terms of rearrangements of the gel network at various length scales. In this paper, rheological experiments on rennet-induced

  17. Preparation of Raspberry-like Superhydrophobic SiO2 Particles by Sol-gel Method and Its Potential Applications

    Directory of Open Access Journals (Sweden)

    Xu Gui-Long

    2011-12-01

    Full Text Available Raspberry‐like SiO2 particles with a nano‐micro‐binary structure were prepared by a simple sol‐gel method using tetraethoxysilane (TEOS and methyltriethoxysilane (MTES as precursors. The chemical components and morphology of the SiO2 particles were characterized by Fourier transform infrared spectroscopy (FT‐IR and a Transmission electron microscope (TEM. The surface topography and wetting behaviour of the raspberry‐like SiO2 surface were observed with a Scanning electron microscope (SEM and studied by the water/oil contact angle (CA, respectively. The thermal stability of the prepared SiO2 particles was characterized by TGA analysis. The results show that the highly dispersed SiO2 particles initially prepared by the sol‐gel method turn into raspberry‐like particles with during the aging process. The raspberry‐like SiO2 particles show superhydrophobicity and superoleophilicity across a wide range of pH values. The SiO2 particles were thermally stable up to 475°C, while above this temperature the hydrophobicity decreases and finally becomes superhydrophobic when the temperature reaches 600°C. The raspberry‐like SiO2 particles which were prepared have potential applications in the fields of superhydrophobic surfaces, water‐oil separation, anti‐corrosion and fluid transportation.

  18. Ubiquitous human computing.

    Science.gov (United States)

    Zittrain, Jonathan

    2008-10-28

    Ubiquitous computing means network connectivity everywhere, linking devices and systems as small as a drawing pin and as large as a worldwide product distribution chain. What could happen when people are so readily networked? This paper explores issues arising from two possible emerging models of ubiquitous human computing: fungible networked brainpower and collective personal vital sign monitoring.

  19. Learning with Ubiquitous Computing

    Science.gov (United States)

    Rosenheck, Louisa

    2008-01-01

    If ubiquitous computing becomes a reality and is widely adopted, it will inevitably have an impact on education. This article reviews the background of ubiquitous computing and current research projects done involving educational "ubicomp." Finally it explores how ubicomp may and may not change education in both formal and informal settings and…

  20. Solid-phase microextraction Ni-Ti fibers coated with functionalised silica particles immobilized in a sol-gel matrix.

    Science.gov (United States)

    Azenha, Manuel; Ornelas, Mariana; Fernando Silva, A

    2009-03-20

    One of the possible approaches for the development of novel solid-phase microextraction (SPME) fibers is the physical deposition of porous materials onto a support using high-temperature epoxy glue. However, a major drawback arises from decomposition of epoxy glue at temperatures below 300 degrees C and instability in some organic solvents. This limitation motivated us to explore the possibility of replacing the epoxy glue with a sol-gel film, thermally more stable and resistant to organic solvents. We found that functionalised silica particles could be successfully attached to a robust Ni-Ti wire by using a UV-curable sol-gel film. The particles were found to be more important than the sol-gel layer during the microextraction process, as shown by competitive extraction trials and by the different extraction profiles observed with differently functionalised particles. If a quality control microscopic-check aiming at the rejection of fibers exhibiting unacceptably low particle load was conducted, acceptable (6-14%) reproducibility of preparation of C(18)-silica fibers was observed, and a strong indication of the durability of the fibers was also obtained. A cyclohexyldiol-silica fiber was used, as a simple example of applicability, for the successful determination of benzaldehyde, acetophenone and dimethylphenol at trace level in spiked tap water. Recoveries: 95-109%; limits of detection: 2-7 microg/L; no competition effects within the studied range (

  1. Highly dispersed spherical Bi3.25La0.75Ti3O12 nanocrystals via topotactic crystallization of aggregation-free gel particles from an effective inverse miniemulsion sol-gel approach

    Science.gov (United States)

    Wang, Aijun; Zeng, Yanwei; Han, Longxiang; Ding, Chuan; Cao, Liangliang; Li, Rongjie

    2015-09-01

    Aggregation-free spherical lanthanum-doped bismuth titanate (Bi3.25La0.75Ti3O12, BLT) gel particles with an average size of about 150 nm were successfully obtained from an inverse miniemulsion sol-gel process, with Span-80 acting as surfactant, n-butanol as co-surfactant, cyclohexane as continuous phase, and submicro-droplets of aqueous solution containing Bi3+, La3+ and Ti4+ ions as dispersed phase, and then topotactically transformed into highly dispersed spherical BLT nanocrystals after an in situ crystallization at 600 °C for 8 h. It has been found that the BLT gel particles can be obtained via a moderate sol-gel reaction inside the miniemulsion droplets at 65 °C, but their morphology and aggregation degree are strongly affected by the relative amounts of Span-80 and n-butanol. The perfect spherical BLT gel particles with no aggregation can be achieved only under the condition of 3 wt% n-butanol relative to the mass of cyclohexane, with excessive amount of n-butanol leading to the formation of ill-gelled particles with irregular shapes, while insufficient addition of n-butanol resulting in terrible aggregation of gel particles. To understand the formation of aggregation-free spherical BLT gel particles, a tentative mechanism is proposed and discussed, which reveals that a well-coordinated oil-water interfacial film made up of Span-80 and n-butanol molecules and the appropriately enhanced evaporation of water from such interfaces should be responsible for the formation of aggregation-free spherical BLT gel particles.

  2. SU-E-T-753: Three-Dimensional Dose Distributions of Incident Proton Particle in the Polymer Gel Dosimeter and the Radiochromic Gel Dosimeter: A Simulation Study with MCNP Code

    International Nuclear Information System (INIS)

    Park, M; Kim, G; Ji, Y; Kim, K; Park, S; Jung, H

    2015-01-01

    Purpose: The purpose of this study is to estimate the three-dimensional dose distributions in the polymer and the radiochromic gel dosimeter, and to identify the detectability of both gel dosimeters by comparing with the water phantom in case of irradiating the proton particles. Methods: The normoxic polymer gel and the LCV micelle radiochromic gel were used in this study. The densities of polymer and the radiochromic gel dosimeter were 1.024 and 1.005 g/cm 3 , respectively. The dose distributions of protons in the polymer and radiochromic gel were simulated using Monte Carlo radiation transport code (MCNPX, Los Alamos National Laboratory). The shape of phantom irradiated by proton particles was a hexahedron with the dimension of 12.4 × 12.4 × 15.0 cm 3 . The energies of proton beam were 50, 80, and 140 MeV energies were directed to top of the surface of phantom. The cross-sectional view of proton dose distribution in both gel dosimeters was estimated with the water phantom and evaluated by the gamma evaluation method. In addition, the absorbed dose(Gy) was also calculated for evaluating the proton detectability. Results: The evaluation results show that dose distributions in both gel dosimeters at intermediated section and Bragg-peak region are similar with that of the water phantom. At entrance section, however, inconsistencies of dose distribution are represented, compared with water. The relative absorbed doses in radiochromic and polymer gel dosimeter were represented to be 0.47 % and 2.26 % difference, respectively. These results show that the radiochromic gel dosimeter was better matched than the water phantom in the absorbed dose evaluation. Conclusion: The polymer and the radiochromic gel dosimeter show similar characteristics in dose distributions for the proton beams at intermediate section and Bragg-peak region. Moreover the calculated absorbed dose in both gel dosimeters represents similar tendency by comparing with that in water phantom

  3. Ubiquitous Annotation Systems

    DEFF Research Database (Denmark)

    Hansen, Frank Allan

    2006-01-01

    Ubiquitous annotation systems allow users to annotate physical places, objects, and persons with digital information. Especially in the field of location based information systems much work has been done to implement adaptive and context-aware systems, but few efforts have focused on the general...... requirements for linking information to objects in both physical and digital space. This paper surveys annotation techniques from open hypermedia systems, Web based annotation systems, and mobile and augmented reality systems to illustrate different approaches to four central challenges ubiquitous annotation...... systems have to deal with: anchoring, structuring, presentation, and authoring. Through a number of examples each challenge is discussed and HyCon, a context-aware hypermedia framework developed at the University of Aarhus, Denmark, is used to illustrate an integrated approach to ubiquitous annotations...

  4. Study of Gel Growth Cobalt (II Oxalate Crystals as Precursor of Co3O4 Nano Particles

    Directory of Open Access Journals (Sweden)

    Yuniar Ponco Prananto

    2013-03-01

    Full Text Available Crystal growth of cobalt (II oxalate in silica gel at room temperature as precursor of Co3O4 nano particles has been studied. Specifically, this project is focusing on the use of two different reaction tube types toward crystallization of cobalt (II oxalate in gel. The gel was prepared at pH 5 by reacting sodium metasilicate solution with dilute nitric acid (for U-tube and oxalic acid (for straight tube, with gelling time of 4 days and crystal growth time of 8 (for straight tube and 12 (for U-tube weeks. Result shows that pink crystalline powder was directly formed using straight tube method. The use of different solvents in straight tube method affects crystallization and could delay direct precipitation of the product. In contrast, bigger and better shape of red block crystal was yielded from U-tube method; however, longer growth time was needed. FTIR studies suggest that both growth method produces identical compound of hydrated cobalt (II oxalate. © 2013 BCREC UNDIP. All rights reservedReceived: 25th October 2012; Revised: 30th November 2012; Accepted: 5th December 2012[How to Cite: Y.P. Prananto, M.M. Khunur, D.T. Wahyuni, R.A. Shobirin, Y.R. Nata, E. Riskah, (2013. Study of Gel Growth Cobalt (II Oxalate Crystals as Precursor of Co3O4 Nano Particles. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (3: 198-204. (doi:10.9767/bcrec.7.3.4066.198-204][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.7.3.4066.198-204 ] View in  |

  5. Fluorescent gel particles in the nanometer range for detection of metabolites in living cells

    DEFF Research Database (Denmark)

    Almdal, K.; Sun, H.; Poulsen, A.K.

    2006-01-01

    micelles in oil microemulsions. Typical sizes of the particles are tens of nanometers. Characterization methods for such particles based on size exclusion chromatography, photon correlation spectroscopy, scanning electron microscopy, and atomic force microscopy have been developed. The stability...

  6. Lattice Constant Dependence on Particle Size for Ceria prepared from a Citrate Sol-Gel

    International Nuclear Information System (INIS)

    Morris, V N; Farrell, R A; Sexton, A M; Morris, M A

    2006-01-01

    High surface area ceria nanoparticles have been prepared using a citrate solgel precipitation method. Changes to the particle size have been made by calcining the ceria powders at different temperatures, and X-ray methods used to determine their lattice parameters. The particle sizes have been assessed using transmission electron microscopy (TEM) and the lattice parameter found to fall with decreasing particle size. The results are discussed in the light of the role played by surface tension effects

  7. A SURVEY ON UBIQUITOUS COMPUTING

    Directory of Open Access Journals (Sweden)

    Vishal Meshram

    2016-01-01

    Full Text Available This work presents a survey of ubiquitous computing research which is the emerging domain that implements communication technologies into day-to-day life activities. This research paper provides a classification of the research areas on the ubiquitous computing paradigm. In this paper, we present common architecture principles of ubiquitous systems and analyze important aspects in context-aware ubiquitous systems. In addition, this research work presents a novel architecture of ubiquitous computing system and a survey of sensors needed for applications in ubiquitous computing. The goals of this research work are three-fold: i serve as a guideline for researchers who are new to ubiquitous computing and want to contribute to this research area, ii provide a novel system architecture for ubiquitous computing system, and iii provides further research directions required into quality-of-service assurance of ubiquitous computing.

  8. Rheological behavior of emulsion gels stabilized by zein/tannic acid complex particles

    NARCIS (Netherlands)

    Zou, Yuan; Yang, Xiaoquan; Scholten, Elke

    2018-01-01

    In this paper, we report the structure formation and rheological properties of Pickering emulsions stabilized with zein/tannic acid complex particles (ZTPs) over a wide range of particle concentration (1-5%, w/v) and oil content (5-60%, v/v). Microscopy shows that the ZTPs provide stabilization

  9. Effect of Chelating Agents on the Stability of Nano-TiO2 Sol Particles for Sol-Gel Coating.

    Science.gov (United States)

    Maeng, Wan Young; Yoo, Mi

    2015-11-01

    Agglomeration of sol particles in a titanium alkoxide (tetrabutyl orthotitanate (TBOT), > 97%) solution during the hydrolysis and condensation steps makes the sol solution difficult to use for synthesizing homogeneous sol-gel coating. Here, we have investigated the effect of stabilizing agents (acetic acid and ethyl acetoacetate (EAcAc)) on the agglomeration of Ti alkoxide particles during hydrolysis and condensation in order to determine the optimized conditions for controlling the precipitation of TiO2 particles. The study was conducted at R(AC) ([acetic acid]/[TBOT]) = 0.1-5 and R(EAcAc)([EAcAc]/[TBOT]) = 0.05-0.65. We also studied the effects of a basic catalyst ethanolamine (ETA), water, and HCl on sol stability. The chelating ligands in the precursor sol were analyzed with FT-IR. The coating properties were examined by focused ion beam. The stabilizing agents (acetic acid and EAcAc) significantly influenced the agglomeration and precipitation of TBOT precursor particles during hydrolysis. As R(AC) and R(EAcAc) increased, the agglomeration remarkably decreased. The stability of the sol with acetic acid and EAcAc arises from the coordination of the chelating ligand to TBOT that hinders hydrolysis and condensation. A uniform fine coating (thickness: 30 nm) on stainless steel was obtained by using an optimized sol with R(AC) = 0.5 and R(EAcAc) = 0.65.

  10. Ubiquitous Computing Systems

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Friday, Adrian

    2009-01-01

    . While such growth is positive, the newest generation of ubicomp practitioners and researchers, isolated to specific tasks, are in danger of losing their sense of history and the broader perspective that has been so essential to the field’s creativity and brilliance. Under the guidance of John Krumm...... applications Privacy protection in systems that connect personal devices and personal information Moving from the graphical to the ubiquitous computing user interface Techniques that are revolutionizing the way we determine a person’s location and understand other sensor measurements While we needn’t become...

  11. Ubiquitous Network Society

    Directory of Open Access Journals (Sweden)

    Cristian USCATU

    2006-01-01

    Full Text Available Technology is evolving faster than ever in the ITC domain. Computing devices become smaller and more powerful by the day (and cheaper than ever. They have started to move away from the classical “computer” towards portable devices like personal digital assistants (PDAs and mobile phones. Even these devices are no longer what they used to be. A phone is no longer a simple voice communication device, but a minicomputer with lots of functions. The addition of wireless communication protocols, like WiFi and Bluetooth, leads to a web of interconnected devices with the final purpose of enabling us to access desired services anywhere, at any time. Adding less complicated devices, as sensors and detectors, located everywhere (clothes, cars, furniture, home appliances etc. but connected to the same global network, we have a technological world aware of itself and aware of us, ready to serve our needs without hindering our lives. “Ubiquitous computing names the third wave in computing, just now beginning. First were mainframes, each shared by lots of people. Now we are in the personal computing era, person and machine staring uneasily at each other across the desktop. Next comes ubiquitous computing, or the age of calm technology, when technology recedes into the background of our lives.” [Weiser, 1995

  12. Effect of the Amount and Particle Size of Wheat Fiber on the Physicochemical Properties and Gel Morphology of Starches.

    Directory of Open Access Journals (Sweden)

    Qingjie Sun

    Full Text Available Effects of added wheat fiber, with different levels and particle sizes, on the physicochemical properties and gel morphology of wheat starch and mung bean starch were investigated, using rapid visco analyzer (RVA, texture analyzer (TPA and scanning electron microscopy (SEM. Each starch was added with wheat fiber at 10, 20, 30 and 40% (weight basis, g/100g, and different sizes of 60, 100 and 180 mesh, respectively. The peak viscosity (PV of starches with wheat fiber were higher than the control. Starches had the highest PV with 40%, 60 mesh wheat fiber. The starches with wheat fiber showed higher hardness when compared to the control. Wheat starch and mung bean starch, with 40%, 60 mesh wheat fiber, had the highest hardnesses of 147.78 and 1032.11 g, respectively. SEM showed that the dense honeycomb structure of starch gel was diminished with increasing wheat fiber. Additionally, the number of internal pores was reduced, and a large lamellar structure was formed.

  13. Localized internal radiotherapy with 90Y particles embedded in a new thermosetting alginate gel: a feasibility study in pigs.

    Science.gov (United States)

    Holte, Oyvind; Skretting, Arne; Bach-Gansmo, Tore; Hol, Per Kristian; Johnsrud, Kjersti; Tønnesen, Hanne Hjorth; Karlsen, Jan

    2006-02-01

    Internal radiotherapy requires the localization of the radionuclide to the site of action. A new injectable alginate gel formulation intended to undergo immediate gelation in tissues and capable of encapsulating radioactive particles containing 90Y was investigated. The formulation was injected intramuscularly, into the bone marrow compartment of the femur and intravenously, respectively, in pigs. The distribution of radioactivity in various tissues was determined. Following intramuscular injection, more than 90% of the radioactivity was found at the site of injection. Following injection into bone marrow, 30-40% of the radioactivity was retained at the site of injection, but a considerable amount of radioactivity was also detected in the lungs (35-45%) and the liver (5-18%). Following intravenous injection, 80-90% of the radioactivity was found in the lungs. The present formulation appears suitable for localized radiotherapy in organs and tissues having low perfusion.

  14. Tailoring MCM-41 mesoporous silica particles through modified sol-gel process for gas separation

    Science.gov (United States)

    Sang, Wong Yean; Ching, Oh Pei

    2017-10-01

    Mobil Composition of Matter-41 (MCM-41) is recognized as a potential filler to enhance permeability of mixed matrix membrane (MMM). However, the required loading for available micron-sized MCM-41 was considerably high in order to achieve desired separation performance. In this work, reduced-size MCM-41 was synthesized to minimize filler loading, improve surface modification and enhance polymer-filler compatibility during membrane fabrication. The effect of reaction condition, stirring rate and type of post-synthesis washing solution used on particle diameter of resultant MCM-41 were investigated. It was found that MCM-41 produced at room temperature condition yield particles with smaller diameter, higher specific surface area and enhanced mesopore structure. Increase of stirring rate up to 500 rpm during synthesis also reduced the particle diameter. In addition, replacing water with methanol as the post-synthesis washing solution to remove bromide ions from the precipitate was able to further reduce the particle size by inhibiting polycondensation reaction.

  15. Effect of TiO2/Al2O3 film coated diamond abrasive particles by sol-gel technique

    Science.gov (United States)

    Hu, Weida; Wan, Long; Liu, Xiaopan; Li, Qiang; Wang, Zhiqi

    2011-04-01

    The diamond abrasive particles were coated with the TiO2/Al2O3 film by the sol-gel technique. Compared with the uncoated diamonds, the TiO2/Al2O3 film was excellent material for the protection of the diamonds. The results showed that the incipient oxidation temperature of the TiO2/Al2O3 film coated diamonds in air atmosphere was 775 °C, which was higher 175 °C than that of the uncoated diamonds. And the coated diamonds also had better the diamond's single particle compressive strength and the impact toughness than that of uncoated diamonds after sintering at 750 °C. For the vitrified bond grinding wheels, replacing the uncoated diamonds with the TiO2/Al2O3 film coated diamonds, the volume expansion of the grinding wheels decreased from 6.2% to 3.4%, the porosity decreased from 35.7% to 25.7%, the hardness increased from 61.2HRC to 66.5HRC and the grinding ratio of the vitrified bond grinding wheels to carbide alloy (YG8) increased from 11.5 to 19.1.

  16. Hierarchical self-assembly of telechelic star polymers: from soft patchy particles to gels and diamond crystals

    International Nuclear Information System (INIS)

    Capone, Barbara; Coluzza, Ivan; Blaak, Ronald; Likos, Christos N; Verso, Federica Lo

    2013-01-01

    The design of self-assembling materials in the nanometer scale focuses on the fabrication of a class of organic and inorganic subcomponents that can be reliably produced on a large scale and tailored according to their vast applications for, e.g. electronics, therapeutic vectors and diagnostic imaging agent carriers, or photonics. In a recent publication (Capone et al 2012 Phys. Rev. Lett. 109 238301), diblock copolymer stars have been shown to be a novel system, which is able to hierarchically self-assemble first into soft patchy particles and thereafter into more complex structures, such as the diamond and cubic crystal. The self-aggregating single star patchy behavior is preserved from extremely low up to high densities. Its main control parameters are related to the architecture of the building blocks, which are the number of arms (functionality) and the fraction of attractive end-monomers. By employing a variety of computational and theoretical tools, ranging from the microscopic to the mesoscopic, coarse-grained level in a systematic fashion, we investigate the crossover between the formation of microstructure versus macroscopic phase separation, as well as the formation of gels and networks in these systems. We finally show that telechelic star polymers can be used as building blocks for the fabrication of open crystal structures, such as the diamond or the simple-cubic lattice, taking advantage of the strong correlation between single-particle patchiness and lattice coordination at finite densities. (paper)

  17. Structural, mechanical, and tribological characterization of sol-gel layers with inbedded anorganic fullerene-like tungsten-disulphide particles

    International Nuclear Information System (INIS)

    Hattermann, Hilke

    2010-01-01

    The preparation of composite coatings consisting of different materials with improved properties has been an intensively studied area of thin film technology in recent years. One method to prepare such composite coatings is the incorporation of nano or micro particles into a matrix of a different material. In this thesis, such composite coatings are investigated which have been prepared via a sol-gel route und contain up to about 30 wt.-% tungsten disulfide particles. These inorganic fullerenes have typical particle sizes of about 100 nm to 200 nm. Two different types of composite coatings with a thickness of up to a few micrometers and with embedded tungsten disulfide particles are prepared: First, coatings with a relatively stiff alumina matrix, and second, coatings with a matrix made of organically modified silica. Different analytical methods are used for the structural characterization of the coatings. The crystal structure and the chemical composition of the coatings are determined via X-ray diffraction and X-ray fluorescence measurements and via energy-dispersive X-ray spectroscopy. Through scanning and transmission electron microscopy the incorporation and the distribution of the tungsten disulfide particles in the respective matrix are analysed. Furthermore, the roughness and the adhesion of the coatings on the substrate are investigated. The influence of the embedded particles and of the temperature of the final heat treatment during the sample preparation on the mechanical properties, like elastic modulus and hardness, of the composite coatings are measured through nanoindentation testing. These experimental results are compared with theoretical values determined via different analytical models for effective materials. Finally, the tribological behavior of the composite coatings is investigated in comparison to pure coatings made of alumina or organically modified silica. With ball-on-disc tests the coefficient of friction of the coatings is measured

  18. Programmable ubiquitous telerobotic devices

    Science.gov (United States)

    Doherty, Michael; Greene, Matthew; Keaton, David; Och, Christian; Seidl, Matthew L.; Waite, William; Zorn, Benjamin G.

    1997-12-01

    We are investigating a field of research that we call ubiquitous telepresence, which involves the design and implementation of low-cost robotic devices that can be programmed and operated from anywhere on the Internet. These devices, which we call ubots, can be used for academic purposes (e.g., a biologist could remote conduct a population survey), commercial purposes (e.g., a house could be shown remotely by a real-estate agent), and for recreation and education (e.g., someone could tour a museum remotely). We anticipate that such devices will become increasingly common due to recent changes in hardware and software technology. In particular, current hardware technology enables such devices to be constructed very cheaply (less than $500), and current software and network technology allows highly portable code to be written and downloaded across the Internet. In this paper, we present our prototype system architecture, and the ubot implementation we have constructed based on it. The hardware technology we use is the handy board, a 6811-based controller board with digital and analog inputs and outputs. Our software includes a network layer based on TCP/IP and software layers written in Java. Our software enables users across the Internet to program the behavior of the vehicle and to receive image feedback from a camera mounted on it.

  19. The Future of Ubiquitous Elearning

    Science.gov (United States)

    Arndt, Timothy

    2014-01-01

    Post-secondary students are increasingly receiving instruction by eLearning. Many or these are part-time students or are working while taking classes. In such circumstances, students may find themselves short of time to study. One mechanism that can be exploited to make the best use of available time is ubiquitous eLearning. Ubiquitous eLearning…

  20. Development of nanostructured porous TiO2 thick film with uniform spherical particles by a new polymeric gel process for dye-sensitized solar cell applications

    International Nuclear Information System (INIS)

    Bakhshayesh, A.M.; Mohammadi, M.R.

    2013-01-01

    A novel simple synthetic procedure for fabrication of high surface area nanostructured TiO 2 electrode with uniform particles for photovoltaic application is reported. Modifying the TiO 2 particulate sol by pH adjustment together with employment of a polymeric agent, so-called polymeric gel process, was developed. The polymeric gel process was used to deposit nanostructured thick electrode by dip coating incorporated in dye-sensitized solar cells (DSSCs). X-ray diffraction (XRD) analysis revealed that deposited film was composed of primary nanoparticles with average crystallite size in the range 21-39 nm. Field emission scanning electron microscope (FE-SEM) images showed that deposited film had nanostructured and porous morphology containing uniform spherical particles with diameter about 2.5 μm. The spherical particles were made of small nanoparticles with average grain size of 60 nm improving light scattering and dye loading of the DSSC. Moreover, atomic force microscope (AFM) analysis verified that the roughness mean square of prepared electrode was low, enhancing electron transport to the counter electrode. Photovoltaic measurements showed that solar cell made of polymeric gel process had higher photovoltaic performance than that made of conventional paste. An enhancement of power conversion efficiency from 4.54%, for conventional paste, to 6.21%, for polymeric gel process, was achieved. Electrochemical impedance spectroscopy (EIS) study showed that the recombination process in solar cell made of polymeric gel process was slower than that in solar cell made of conventional paste. The presented strategy would open up new insight into fabrication of low-cost TiO 2 DSSCs with high power conversion efficiency

  1. Mobile and ubiquitous learning technologies

    NARCIS (Netherlands)

    Specht, Marcus

    2012-01-01

    Specht, M. (2012, 22 November). Mobile and ubiquitous learning technologies. Presentation given at the Workshop "Blended Learning an Hochschulen" at the Fakultätentag Informatik at the Universität Jena, Jena, Germany.

  2. Effects of alcohols on gas holdup and volumetric liquid-phase mass transfer coefficient in gel-particle-suspended bubble column

    Energy Technology Data Exchange (ETDEWEB)

    Salvacion, J.; Murayama, M.; Otaguchi, K.; Koide, K. [Tokyo Institute of Technology, Tokyo (Japan)

    1995-08-20

    The effects of alcohols, column dimensions, gas velocity, physical properties of liquids, and gel particles on the gas holdup e{sub G} and the volumetric liquid-phase mass transfer coefficient k{sub L}a in a gel-particle-suspended bubble column under liquid-solid batch operation were studied experimentally. It was shown that addition of at alcohols to water generally increases e{sub G}. However, k{sub L}a values in aqueous solutions of alcohols became larger or smaller than those in water, according to the kind and concentration of the alcohol added to water. It was also shown that the presence of suspended gel-particles in the bubble column reduces values of e{sub G} and k{sub L}a. Based on these observations, empirical equations for e{sub G} in the transition regime in an ethanol solution, for e{sub G} in the heterogeneous now regime applicable to various alcohol solutions and for k{sub L}a in both now regimes were proposed. 18 refs., 12 figs., 3 tabs.

  3. Study of the influence of gold particles on the absorbed dose in soft tissue using polymer gel dosimetry

    International Nuclear Information System (INIS)

    Afonso, Luciana Caminha

    2011-01-01

    The presence of high-Z material adjacent to soft tissue, when submitted to irradiation, enhances locally the absorbed dose in these soft tissues. Such effect occurs due to the outscattering of photoelectrons from the high-Z material. Polymer gel dosimeters have been used to investigate this effect. Analytic calculations to estimate the dose enhancement and Monte Carlo simulations have been performed. Samples containing polymer gel (PG) with 0.005 gAu/gPG and pure polymer gel have been irradiated using an X-rays beam produced by 150 kV, filtered with 4 mm Al and 5 mm Cu, which resulted in an approximately 20% higher absorbed dose in the samples with gold in comparison to those with pure polymer gel. The analytic calculations and the Monte Carlo simulation resulted in a dose enhancement factor of approximately 30%. (author)

  4. Ubiquitous Computing, Complexity and Culture

    DEFF Research Database (Denmark)

    environments, experience time, and develop identities individually and socially. Interviews with working media artists lend further perspectives on these cultural transformations. Drawing on cultural theory, new media art studies, human-computer interaction theory, and software studies, this cutting-edge book......The ubiquitous nature of mobile and pervasive computing has begun to reshape and complicate our notions of space, time, and identity. In this collection, over thirty internationally recognized contributors reflect on ubiquitous computing’s implications for the ways in which we interact with our...... critically unpacks the complex ubiquity-effects confronting us every day....

  5. Trust Models in Ubiquitous Computing

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Krukow, Karl; Sassone, Vladimiro

    2008-01-01

    We recapture some of the arguments for trust-based technologies in ubiquitous computing, followed by a brief survey of some of the models of trust that have been introduced in this respect. Based on this, we argue for the need of more formal and foundational trust models.......We recapture some of the arguments for trust-based technologies in ubiquitous computing, followed by a brief survey of some of the models of trust that have been introduced in this respect. Based on this, we argue for the need of more formal and foundational trust models....

  6. Ubiquitous media for collocated interaction

    DEFF Research Database (Denmark)

    Morrison, Ann; Jacucci, Giulio; Peltonen, Peter

    2010-01-01

    Has ubiquitous computing entered our lives as anticipated in the early 90s or at the turn of the millennium? In this last decade, the processing of media combined with sensing and communication capabilities has been slowly entering our lives through powerful smartphones, multimodal game consoles,...

  7. International Symposium on Ubiquitous Networking

    CERN Document Server

    Medromi, Hicham; Sadik, Mohamed

    2016-01-01

    This volume publishes new trends and findings in hot topics related to ubiquitous computing/networking. It is the outcome of UNet - ainternational scientific event that took place on September 08-10, 2015, in the fascinating city of Casablanca, Morocco. UNet’15 is technically sponsored by IEEE Morocco Section and IEEE COMSOC Morocco Chapter.

  8. Trust models in ubiquitous computing.

    Science.gov (United States)

    Krukow, Karl; Nielsen, Mogens; Sassone, Vladimiro

    2008-10-28

    We recapture some of the arguments for trust-based technologies in ubiquitous computing, followed by a brief survey of some of the models of trust that have been introduced in this respect. Based on this, we argue for the need of more formal and foundational trust models.

  9. The Status of Ubiquitous Computing.

    Science.gov (United States)

    Brown, David G.; Petitto, Karen R.

    2003-01-01

    Explains the prevalence and rationale of ubiquitous computing on college campuses--teaching with the assumption or expectation that all faculty and students have access to the Internet--and offers lessons learned by pioneering institutions. Lessons learned involve planning, technology, implementation and management, adoption of computer-enhanced…

  10. Ubiquitous emotion-aware computing

    NARCIS (Netherlands)

    van den Broek, Egon

    Emotions are a crucial element for personal and ubiquitous computing. What to sense and how to sense it, however, remain a challenge. This study explores the rare combination of speech, electrocardiogram, and a revised Self-Assessment Mannequin to assess people’s emotions. 40 people watched 30

  11. A Collaborative Model for Ubiquitous Learning Environments

    Science.gov (United States)

    Barbosa, Jorge; Barbosa, Debora; Rabello, Solon

    2016-01-01

    Use of mobile devices and widespread adoption of wireless networks have enabled the emergence of Ubiquitous Computing. Application of this technology to improving education strategies gave rise to Ubiquitous e-Learning, also known as Ubiquitous Learning. There are several approaches to organizing ubiquitous learning environments, but most of them…

  12. Highly Conducting Nanosized Monodispersed Antimony-Doped Tin Oxide Particles Synthesized via Nonaqueous Sol−Gel Procedure

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rasp, M.; Štefanić, G.; Ba, J.; Günther, S.; Rathouský, Jiří; Niederberger, M.; Fattakhova Rohlfing, D.

    2009-01-01

    Roč. 21, č. 21 (2009), s. 5229-5236 ISSN 0897-4756 Institutional research plan: CEZ:AV0Z40400503 Keywords : nanoparticles * nonaqueous Ssl -gel procedure * oxide materials Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.368, year: 2009

  13. Highly dispersed spherical Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12} nanocrystals via topotactic crystallization of aggregation-free gel particles from an effective inverse miniemulsion sol–gel approach

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Aijun; Zeng, Yanwei, E-mail: zengyw-njut@126.com, E-mail: stephen-zeng@njtech.edu.cn, E-mail: stephen-zeng@163.com; Han, Longxiang; Ding, Chuan; Cao, Liangliang; Li, Rongjie [Nanjing Tech University, State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering (China)

    2015-09-15

    Aggregation-free spherical lanthanum-doped bismuth titanate (Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}, BLT) gel particles with an average size of about 150 nm were successfully obtained from an inverse miniemulsion sol–gel process, with Span-80 acting as surfactant, n-butanol as co-surfactant, cyclohexane as continuous phase, and submicro-droplets of aqueous solution containing Bi{sup 3+}, La{sup 3+} and Ti{sup 4+} ions as dispersed phase, and then topotactically transformed into highly dispersed spherical BLT nanocrystals after an in situ crystallization at 600 °C for 8 h. It has been found that the BLT gel particles can be obtained via a moderate sol–gel reaction inside the miniemulsion droplets at 65 °C, but their morphology and aggregation degree are strongly affected by the relative amounts of Span-80 and n-butanol. The perfect spherical BLT gel particles with no aggregation can be achieved only under the condition of 3 wt% n-butanol relative to the mass of cyclohexane, with excessive amount of n-butanol leading to the formation of ill-gelled particles with irregular shapes, while insufficient addition of n-butanol resulting in terrible aggregation of gel particles. To understand the formation of aggregation-free spherical BLT gel particles, a tentative mechanism is proposed and discussed, which reveals that a well-coordinated oil–water interfacial film made up of Span-80 and n-butanol molecules and the appropriately enhanced evaporation of water from such interfaces should be responsible for the formation of aggregation-free spherical BLT gel particles. Graphical Abstract: Aggregation-free spherical BLT (Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}) gel particles can be prepared from an effective inverse miniemulsion sol–gel process, and subsequently topotactically transformed into spherical BLT nanocrystals through an in situ crystallization.

  14. Structural evolution of the SiO2-Ag system prepared by the Sol-gel process with incorporation of Ag particles

    Directory of Open Access Journals (Sweden)

    Garcia-Gonzalez, L.

    2011-02-01

    Full Text Available Structural evolution of Sol-Gel glasses in powder form and coatings with incorporation of Ag particles at the starting solution showed an evolution from SiO2 amorphous matrix to the cristobalite phase with the annealing treatment at around 800 ºC for one hour. This structural evolution was obtained at lower Ag concentration up 0.7 %vol. Two series of samples were studied, A series using HNO3 and B series using HCl as catalytic agent; in both series grenetine was used as a dispersing agent to avoid the precipitation of Ag particles. We found the incorporation of silver in the xerogeles matrix promotes the devitrification process at relatively low temperatures with the presence of partial crystallization in form of cistobalite. This structure was produced by controlling the catalytic agent quoted in the preparation process. The EPR and UV-Vis absorption spectra show the presence of Fe3+ ions as a contaminant in the source of the Ag particles, due to the process to obtain these particles. By means the IR spectra a high (OH- concentration at higher temperatures was observed in this system, until 600 ºC at difference of the sol-gel glasses made with incorporation of Ag particles by nitrates. The color evolution of the coating samples with the annealing temperature varies from a light brown at 100 ºC to yellow at 500 ºC.La evolución estructural de vidrios de Sol-Gel en forma de polvos y recubrimientos preparados con la incorporación de partículas de Ag a partir de la solución precursora muestra la evolución de la matriz amorfa de SiO2 a la fase cristobalita utilizando tratamientos térmicos alrededor de 800 °C por un tiempo de una hora. Dicha evolución estructural fue obtenida en concentraciones bajas a partir de 0.7% de Ag. Dos series de muestras fueron estudiadas, la serie A usando HNO3 y la serie B usando HCl como agente catalítico; en ambas series se uso grenetina como agente dispersante para evitar la precipitación de las part

  15. Ubiquitous Versus One-to-One

    Science.gov (United States)

    McAnear, Anita

    2006-01-01

    When we planned the editorial calendar with the topic ubiquitous computing, we were thinking of ubiquitous computing as the one-to-one ratio of computers to students and teachers and 24/7 access to electronic resources. At the time, we were aware that ubiquitous computing in the computer science field had more to do with wearable computers. Our…

  16. HCI in Mobile and Ubiquitous Computing

    OpenAIRE

    椎尾, 一郎; 安村, 通晃; 福本, 雅明; 伊賀, 聡一郎; 増井, 俊之

    2003-01-01

    This paper provides some perspectives to human computer interaction in mobile and ubiquitous computing. The review covers overview of ubiquitous computing, mobile computing and wearable computing. It also summarizes HCI topics on these field, including real-world oriented interface, multi-modal interface, context awareness and in-visible computers. Finally we discuss killer applications for coming ubiquitous computing era.

  17. Synthesis of sol–gel silica particles in reverse micelles with mixed-solvent polar cores: tailoring nanoreactor structure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Bürglová, Kristýna; Hlaváč, Jan [Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry (Czech Republic); Bartlett, John R., E-mail: jbartlett@usc.edu.au [University of the Sunshine Coast, Faculty of Science, Health, Education and Engineering (Australia)

    2015-07-15

    In this paper, we describe a new approach for producing metal oxide nano- and microparticles via sol–gel processing in confined media (sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles), in which the chemical and physical properties of the polar aqueous core of the reverse micelles are modulated by the inclusion of a second polar co-solvent. The co-solvents were selected for their capacity to solubilise compounds with low water solubility and included dimethylsulfoxide, dimethylformamide, ethylene glycol, n-propanol, dimethylacetamide and N-methylpyrrolidone. A broad range of processing conditions across the sodium bis(2-ethylhexyl)sulfosuccinate/cyclohexane/water phase diagram were identified that are suitable for preparing particles with dimensions <50 to >500 nm. In contrast, only a relatively narrow range of processing conditions were suitable for preparing such particles in the absence of the co-solvents, highlighting the role of the co-solvent in modulating the properties of the polar core of the reverse micelles. A mechanism is proposed that links the interactions between the various reactive sites on the polar head group of the surfactant and the co-solvent to the nucleation and growth of the particles.

  18. Phase and electrical properties of PZT thin films embedded with CuO nano-particles by a hybrid sol-gel route

    Science.gov (United States)

    Sreesattabud, Tharathip; Gibbons, Brady J.; Watcharapasorn, Anucha; Jiansirisomboon, Sukanda

    2013-07-01

    Pb(Zr0.52Ti0.48)O3 or PZT thin films embedded with CuO nano-particles were successfully prepared by a hybrid sol-gel process. In this process, CuO (0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1 wt. %) nanopowder was suspended in an organometallic solution of PZT, and then coated on platinised silicon substrate using a spin-coating technique. The influence of CuO nano-particles' dispersion on the phase of PZT thin films was investigated. XRD results showed a perovskite phase in all films. At the CuO concentration of 0.4-1 wt. %, a second phase was observed. The addition of CuO nano-particles affected the orientation of PZT thin films. The addition was also found to reduce the ferroelectric properties of PZT thin films. However, at 0.2 wt. % CuO concentration, the film exhibited good ferroelectric properties similar to those of PZT films. In addition, the fatigue retention properties of the PZT/CuO system was observed, and it showed 14% fatigue at 108 switching bipolar pulse cycles while the fatigue in PZT thin films was found to be 17% at the same switching bipolar pulse cycles.

  19. Magnetic properties of BaFe11.6-2xCoxTixO19 particles produced by sol-gel and spray-drying

    International Nuclear Information System (INIS)

    Mendoza-Suarez, G.; Corral-Huacuz, J.C.; Contreras-Garcia, M.E.; Juarez-Medina, H.

    2001-01-01

    Ba-ferrite powders of composition BaFe 11.6-2x Co x Ti x O 19 (with x varying from 0 to 1.1) were prepared by the sol-gel and spray-drying techniques. Green powders showed an amorphous structure. They were heat-treated from 850 deg. C to 1000 deg. C to promote crystallisation and to study the dependence of the magnetic properties on the annealing temperature. Unlike the evaporation-dried powders, the spray-dried samples showed a highly homogeneous structure, which consisted of spherical particles with sizes ranging from 0.1 to ∼0.3 μm. As for the magnetic properties, the saturation magnetisation and remanence remained practically constant up to x=0.8 for all heating temperatures, whereas the coercivity fell uniformly as x increased from ∼5.5 to ∼0.1 kOe

  20. New apparatus for direct counting of β particles from two-dimensional gels and an application to changes in protein synthesis due to cell density

    International Nuclear Information System (INIS)

    Anderson, H.L.; Puck, T.T.; Shera, E.B.

    1987-07-01

    A new method is described for scanning two-dimensional gels by the direct counting of β particles instead of autoradiography. The methodology is described; results are compared with autoradiographic results; and data are presented demonstrating changed patterns of protein synthesis accompanying changes in cell density. The method is rapid and permits identification of differences in protein abundance of approximately 10% for a substantial fraction of the more prominent proteins. A modulation effect of more than 5 standard deviations, accompanying contact inhibition of cell growth, is shown to occur for an appreciable number of these proteins. The method promises to be applicable to a variety of biochemical and genetic experiments designed to delineate changes in protein synthesis accompanying changes in genome, molecular environment, history, and state of differentiation of the cell populations studied. 13 refs., 8 figs., 4 tabs

  1. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    Science.gov (United States)

    Ebrahimpour, Omid

    In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the

  2. Swelling and Degradation of Calcium-Pectic Gel Particles Made of Pectins of Silene vulgaris and Lemna minor Сallus Cultures at Different Concentrations of Pectinase in an Artificial Colon Environment

    Directory of Open Access Journals (Sweden)

    Anatoly A. Shubakov

    2018-03-01

    Full Text Available Spherical calcium-pectic gel particles (CaPGPs were obtained from pectins of callus cultures (CC of campion Silene vulgaris (silenan and duckweed Lemna minor (lemnan, as well as from commercial apple and citrus pectins by the method of ionotropic gelation. We studied the morphological characteristics of the obtained gel particles and found that the largest gel particles were formed from citrus pectin (CP, and the densest gel particles were formed from lemnan pectin (LP. The swelling and degradation of CaPGPs were comparatively evaluated by incubation in a simulated gastrointestinal environment. The swelling and degradation of CaPGPs formed from pectins of the silenan and lemnan callus cultures were studied at different concentrations of pectinase (0.4, 0.8 and 1.7 mg/ml in the simulated fluid of the colon. It has been established that the CaPGPs obtained from lemnan are more resistant to degradation in the simulated colon fluid than CaPGP obtained from silenan. It was shown that the concentration of pectinase in the simulated fluid of the colon and the type of pectin affect the degradability of CaPGPs formed on the basis of pectins of callus cultures.

  3. Ubiquitous Multicriteria Clinic Recommendation System.

    Science.gov (United States)

    Chen, Toly

    2016-05-01

    Advancements in information, communication, and sensor technologies have led to new opportunities in medical care and education. Patients in general prefer visiting the nearest clinic, attempt to avoid waiting for treatment, and have unequal preferences for different clinics and doctors. Therefore, to enable patients to compare multiple clinics, this study proposes a ubiquitous multicriteria clinic recommendation system. In this system, patients can send requests through their cell phones to the system server to obtain a clinic recommendation. Once the patient sends this information to the system, the system server first estimates the patient's speed according to the detection results of a global positioning system. It then applies a fuzzy integer nonlinear programming-ordered weighted average approach to assess four criteria and finally recommends a clinic with maximal utility to the patient. The proposed methodology was tested in a field experiment, and the experimental results showed that it is advantageous over two existing methods in elevating the utilities of recommendations. In addition, such an advantage was shown to be statistically significant.

  4. Dashboard for Analyzing Ubiquitous Learning Log

    Science.gov (United States)

    Lkhagvasuren, Erdenesaikhan; Matsuura, Kenji; Mouri, Kousuke; Ogata, Hiroaki

    2016-01-01

    Mobile and ubiquitous technologies have been applied to a wide range of learning fields such as science, social science, history and language learning. Many researchers have been investigating the development of ubiquitous learning environments; nevertheless, to date, there have not been enough research works related to the reflection, analysis…

  5. Multimedia and ubiquitous engineering MUE 2013

    CERN Document Server

    Ng, Joseph; Jeong, Hwa; Waluyo, Borgy

    2013-01-01

    The new multimedia standards (for example, MPEG-21) facilitate the seamless integration of multiple modalities into interoperable multimedia frameworks, transforming the way people work and interact with multimedia data. These key technologies and multimedia solutions interact and collaborate with each other in increasingly effective ways, contributing to the multimedia revolution and having a significant impact across a wide spectrum of consumer, business, healthcare, education, and governmental domains. Multimedia and Ubiquitous Engineering provides an opportunity for academic and industry professionals to discuss recent progress in the area of multimedia and ubiquitous environment including models and systems, new directions, novel applications associated with the utilization and acceptance of ubiquitous computing devices and systems.

  6. Embedding Moodle into Ubiquitous Computing Environments

    NARCIS (Netherlands)

    Glahn, Christian; Specht, Marcus

    2010-01-01

    Glahn, C., & Specht, M. (2010). Embedding Moodle into Ubiquitous Computing Environments. In M. Montebello, et al. (Eds.), 9th World Conference on Mobile and Contextual Learning (MLearn2010) (pp. 100-107). October, 19-22, 2010, Valletta, Malta.

  7. Ubiquitous Information Technologies and Applications CUTE 2012

    CERN Document Server

    Park, Doo-Soon; Jia, Weijia; Yeo, Sang-Soo

    2013-01-01

    This book is for The 7th International Conference on Ubiquitous Information Technologies and Applications (CUTE 2012). Ubiquitous computing will require a new approach to fitting technology to our lives. The advent of new computing devices, and the seamless connectivity between these devices, thanks to diverse wired and wireless networks, are enabling new opportunities for a user to perform his/her operation all the time and everywhere. These seamlessly connected devices are ranging from mobile handset to wearable computers. Also, it is expected that these devices will become so pervasive that they will be embedded in the surrounding physical environment, and transparent and invisible to a user. Such devices, whether carried on by people or embedded into other systems, will constitute a global internetworking infrastructure and likely to provide a new level of openness and dynamics. Ubiquitous computing has as its goal the enhancing computer use by pushing computational services out of conventional desktop in...

  8. Unit and ubiquitous Internet of Things

    CERN Document Server

    Ning, Huansheng

    2013-01-01

    Although the Internet of Things (IoT) will play a key role in the development of next generation information, network, and communication technologies, many are still unclear about what makes IoT different from similar concepts. Answering fundamental questions about IoT architectures and models, Unit and Ubiquitous Internet of Things introduces essential IoT concepts from the perspectives of mapping and interaction between the physical world and the cyber world. It addresses key issues such as strategy and education, particularly around unit and ubiquitous IoT technologies. Supplying a new pers

  9. Attacker Modelling in Ubiquitous Computing Systems

    DEFF Research Database (Denmark)

    Papini, Davide

    in with our everyday life. This future is visible to everyone nowadays: terms like smartphone, cloud, sensor, network etc. are widely known and used in our everyday life. But what about the security of such systems. Ubiquitous computing devices can be limited in terms of energy, computing power and memory...... attacker remain somehow undened and still under extensive investigation. This Thesis explores the nature of the ubiquitous attacker with a focus on how she interacts with the physical world and it denes a model that captures the abilities of the attacker. Furthermore a quantitative implementation...

  10. Learning potentials of the ubiquitous internet

    DEFF Research Database (Denmark)

    Dalsgaard, Christian; Pedersen, Nicholai Friis; Aaen, Janus Holst

    The aim of this paper is to identify the key learning potentials of the ubiquitous internet. Rather than focusing on mobile technology or the mobility of the learner, the paper emphasises the ubiquity of internet access as a paramount catalyst for new learning in the digital age. From...... a sociocultural perspective the paper discusses different ways in which the use of mobile devices can extend and augment the context of the learner. The learning potentials of the ubiquitous internet relate to the opportunities to extend the context of the learner on three levels: 1) personalisation...

  11. Creating ubiquitous intelligent sensing environments (CRUISE)

    DEFF Research Database (Denmark)

    Prasad, Neeli R.; Prasad, Ramjee

    2006-01-01

    The recent developments in the research and the technology have brought attention to the wireless sensor networks as one of the key enabling technologies in the next 10 years. Ubiquitous Intelligent Sensing Environments have promising future in supporting the everyday life of the European citizens...

  12. Ubiquitous Computing in Physico-Spatial Environments

    DEFF Research Database (Denmark)

    Dalsgård, Peter; Eriksson, Eva

    2007-01-01

    Interaction design of pervasive and ubiquitous computing (UC) systems must take into account physico-spatial issues as technology is implemented into our physical surroundings. In this paper we discuss how one conceptual framework for understanding interaction in context, Activity Theory (AT...

  13. Designing for Privacy in Ubiquitous Social Networking

    DEFF Research Database (Denmark)

    Sapuppo, Antonio; Figueiras, Joao

    2015-01-01

    Improving human communication during face–to–face meetings is nowadays possible by transferring online social networking benefits to the physical world. This is enabled by the ubiquitous social networking services that became available by means of wirelessly interconnected smart devices...

  14. Ubiquitous developments of the digital single market

    NARCIS (Netherlands)

    Maciejewski, M.; Porrino, F.; Veenstra, A.F.E. van; Marcus, J.S.; Cave, J.; Huijboom, N.M.; Elixmann, D.; Hillebrand, A.; Schindler, R.; Horvath, V.

    2013-01-01

    Ubiquitous solutions providing access from anywhere at any time are a next step for government and commercial services, and are expected to result in lower costs, increased flexibility, and an enhanced user experience. These solutions, based on modern cloud technologies, may facilitate re-use across

  15. Ubiquitous Retailing Innovative Scenario: From the Fixed Point of Sale to the Flexible Ubiquitous Store

    Directory of Open Access Journals (Sweden)

    Eleonora Pantano

    2013-05-01

    Full Text Available The current advances in information and communications technologies developed new tools for retailers to innovate. In fact, the increasing computing capacity and the advancements in networking systems provided a new ubiquitous scenario that can be adapted for retailing in order to develop innovative shopping environments. The aim of this paper is to deeply understand the emergence of the ubiquitous retailing phenomenon and the possible shift from the physical point of sale to a ubiquitous one, by analysing this radical innovation and the main consequences for frms and market.

  16. Identification of TiO2 clusters present during synthesis of sol-gel derived TiO2 nano-particles

    DEFF Research Database (Denmark)

    Simonsen, Morten Enggrob; Søgaard, Erik Gydesen

    Synthesis of titanium dioxide nanoparticles with controlled size distribution and morphology are of great interest for many applications i.e. photocatalysis and dye sensitized solar cells (DSSC). The sol-gel method has some advantages over other preparation techniques in the many parameters, whic...

  17. Ubiquitous Robotic Technology for Smart Manufacturing System.

    Science.gov (United States)

    Wang, Wenshan; Zhu, Xiaoxiao; Wang, Liyu; Qiu, Qiang; Cao, Qixin

    2016-01-01

    As the manufacturing tasks become more individualized and more flexible, the machines in smart factory are required to do variable tasks collaboratively without reprogramming. This paper for the first time discusses the similarity between smart manufacturing systems and the ubiquitous robotic systems and makes an effort on deploying ubiquitous robotic technology to the smart factory. Specifically, a component based framework is proposed in order to enable the communication and cooperation of the heterogeneous robotic devices. Further, compared to the service robotic domain, the smart manufacturing systems are often in larger size. So a hierarchical planning method was implemented to improve the planning efficiency. A test bed of smart factory is developed. It demonstrates that the proposed framework is suitable for industrial domain, and the hierarchical planning method is able to solve large problems intractable with flat methods.

  18. An Instrumental Paradigm for Ubiquitous Interaction

    DEFF Research Database (Denmark)

    Klokmose, Clemens Nylandsted

    2008-01-01

    will require comprehensive experimental user centred development. Originality/Value -- This research offers a new way of thinking interaction, suited for the dynamism of modern computing. Take away message -- Through a strong foundation in activity theory and ecological psychology a new paradigm for ubiquitous...... shortcomings of some of the restrictive assumptions contemporary graphical user interfaces are built upon. Research approach -- Based on activity theory and ecological psychology a conceptual model for ubiquitous interaction is proposed and iteratively challenged and developed through actual implementation....... Findings/Design -- The project will ultimately shed light on how an understanding of interaction form activity theory and ecological psychology maps to an implementation of a new conceptual model for interaction with technology. Research limitations/Implications -- Implementation of an actual system...

  19. Student Assessment in the Ubiquitously Connected World

    OpenAIRE

    Adams, A. A.

    2017-01-01

    Student cheating on university assessments from entrance exams to finals and from contract cheating on coursework to requesting exam answers using a mobile phone during the exam, has received more and more attention of late. As connection to the Internet becomes ubiquitous and computing and communications technology more embedded in our environment, it is argued that a re-focussing on providing educational opportunities is needed in higher education, rather than chasing the ever-retreating p...

  20. Polymer architecture of magnetic gels: a review

    Science.gov (United States)

    Weeber, Rudolf; Hermes, Melissa; Schmidt, Annette M.; Holm, Christian

    2018-02-01

    In this review article, we provide an introduction to ferrogels, i.e. polymeric gels with embedded magnetic particles. Due to the interplay between magnetic and elastic properties of these materials, they are promising candidates for engineering and biomedical applications such as actuation and controlled drug release. Particular emphasis will be put on the polymer architecture of magnetic gels since it controls the degrees of freedom of the magnetic particles in the gel, and it is important for the particle-polymer coupling determining the mechanisms available for the gel deformation in magnetic fields. We report on the different polymer architectures that have been realized so far, and provide an overview of synthesis strategies and experimental techniques for the characterization of these materials. We further focus on theoretical and simulational studies carried out on magnetic gels, and highlight their contributions towards understanding the influence of the gels’ polymer architecture.

  1. Sol-gel derived sorbents

    Science.gov (United States)

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  2. Structure of the vault, a ubiquitous celular component.

    Science.gov (United States)

    Kong, L B; Siva, A C; Rome, L H; Stewart, P L

    1999-04-15

    The vault is a ubiquitous and highly conserved ribonucleoprotein particle of approximately 13 MDa. This particle has been shown to be upregulated in certain multidrug-resistant cancer cell lines and to share a protein component with the telomerase complex. Determination of the structure of the vault was undertaken to provide a first step towards understanding the role of this cellular component in normal metabolism and perhaps to shed some light on its role in mediating drug resistance. Over 1300 particle images were combined to calculate an approximately 31 A resolution structure of the vault. Rotational power spectra did not yield a clear symmetry peak, either because of the thin, smooth walls or inherent flexibility of the vault. Although cyclic eightfold (C8) symmetry was imposed, the resulting reconstruction may be partially cylindrically averaged about the eightfold axis. Our results reveal the vault to be a hollow, barrel-like structure with two protruding caps and an invaginated waist. Although the normal cellular function of the vault is as yet undetermined, the structure of the vault is consistent with either a role in subcellular transport, as previously suggested, or in sequestering macromolecular assemblies.

  3. A proposal of ubiquitous fuzzy computing for ambient Intelligence

    NARCIS (Netherlands)

    Acampora, G.; Loia, V.

    2008-01-01

    Ambient Intelligence is considered as the composition of three emergent technologies: Ubiquitous Computing, Ubiquitous Communication and Intelligent User Interfaces. The aim of integration of aforesaid technologies is to make wider the interaction between human beings and information technology

  4. Ubiquitous fuzzy computing in open ambient intelligence environments

    NARCIS (Netherlands)

    Acampora, G.; Loia, V.

    2006-01-01

    Ambient intelligence (AmI) is considered as the composition of three emergent technologies: ubiquitous computing, ubiquitous communication and intelligent user interfaces. The aim of integration of aforesaid technologies is to make wider the interaction between human beings and information

  5. CILT2000: Ubiquitous Computing--Spanning the Digital Divide.

    Science.gov (United States)

    Tinker, Robert; Vahey, Philip

    2002-01-01

    Discusses the role of ubiquitous and handheld computers in education. Summarizes the contributions of the Center for Innovative Learning Technologies (CILT) and describes the ubiquitous computing sessions at the CILT2000 Conference. (Author/YDS)

  6. Silica reinforced triblock copolymer gels

    DEFF Research Database (Denmark)

    Theunissen, E.; Overbergh, N.; Reynaers, H.

    2004-01-01

    The effect of silica and polymer coated silica particles as reinforcing agents on the structural and mechanical properties of polystyrene-poly(ethylene/butylene)-polystyrene (PS-PEB-PS) triblock gel has been investigated. Different types of chemically modified silica have been compared in order...

  7. New Trends on Ubiquitous Mobile Multimedia Applications

    Directory of Open Access Journals (Sweden)

    Oliveira Marco

    2010-01-01

    Full Text Available Mobile devices present the opportunity to enhance our fast-growing and globally connected society, improving user-experience through novel approaches for information dissemination through mobile communication. The research community is developing new technologies, services, and applications to enable ubiquitous environments based on mobile technology. This paper tackles several important challenges such as communication cost and device limitations for development of ubiquitous multimedia applications. And we propose a system for news delivery using a set of wireless multimedia applications. For this purpose, we have performed a case study with Apple iPhone's platform, featuring two multimedia application contexts, namely, Web and native applications. The multimedia mobile applications draw on iPhone's assets, enabling context-awareness to distribute news, improving communication efficiency and setting-up viewing optimizations, thus enhancing user-experience. The proposed system is evaluated and validated through a series of real-life experiments on real devices, with online full availability. Moreover, due to the Web application availability, the system is not restrained to Apple's iPhone platform, but can also benefit users with other devices.

  8. Ubiquitous computing in shared-care environments.

    Science.gov (United States)

    Koch, S

    2006-07-01

    In light of future challenges, such as growing numbers of elderly, increase in chronic diseases, insufficient health care budgets and problems with staff recruitment for the health-care sector, information and communication technology (ICT) becomes a possible means to meet these challenges. Organizational changes such as the decentralization of the health-care system lead to a shift from in-hospital to both advanced and basic home health care. Advanced medical technologies provide solutions for distant home care in form of specialist consultations and home monitoring. Furthermore, the shift towards home health care will increase mobile work and the establishment of shared care teams which require ICT-based solutions that support ubiquitous information access and cooperative work. Clinical documentation and decision support systems are the main ICT-based solutions of interest in the context of ubiquitous computing for shared care environments. This paper therefore describes the prerequisites for clinical documentation and decision support at the point of care, the impact of mobility on the documentation process, and how the introduction of ICT-based solutions will influence organizations and people. Furthermore, the role of dentistry in shared-care environments is discussed and illustrated in the form of a future scenario.

  9. Ubiquitous Learning Environments in Higher Education: A Scoping Literature Review

    Science.gov (United States)

    Virtanen, Mari Aulikki; Haavisto, Elina; Liikanen, Eeva; Kääriäinen, Maria

    2018-01-01

    Ubiquitous learning and the use of ubiquitous learning environments heralds a new era in higher education. Ubiquitous learning environments enhance context-aware and seamless learning experiences available from any location at any time. They support smooth interaction between authentic and digital learning resources and provide personalized…

  10. Integrating Collaborative and Decentralized Models to Support Ubiquitous Learning

    Science.gov (United States)

    Barbosa, Jorge Luis Victória; Barbosa, Débora Nice Ferrari; Rigo, Sandro José; de Oliveira, Jezer Machado; Rabello, Solon Andrade, Jr.

    2014-01-01

    The application of ubiquitous technologies in the improvement of education strategies is called Ubiquitous Learning. This article proposes the integration between two models dedicated to support ubiquitous learning environments, called Global and CoolEdu. CoolEdu is a generic collaboration model for decentralized environments. Global is an…

  11. The Construction of an Ontology-Based Ubiquitous Learning Grid

    Science.gov (United States)

    Liao, Ching-Jung; Chou, Chien-Chih; Yang, Jin-Tan David

    2009-01-01

    The purpose of this study is to incorporate adaptive ontology into ubiquitous learning grid to achieve seamless learning environment. Ubiquitous learning grid uses ubiquitous computing environment to infer and determine the most adaptive learning contents and procedures in anytime, any place and with any device. To achieve the goal, an…

  12. Characterization of silica particles prepared via urease-catalyzed urea hydrolysis and activity of urease in sol–gel silica matrix

    International Nuclear Information System (INIS)

    Kato, Katsuya; Nishida, Masakazu; Ito, Kimiyasu; Tomita, Masahiro

    2012-01-01

    Highlights: ► Silica precipitation occurred via urease-catalytic reactions. ► Higher urease activity for silica synthesis enables mesostructure of silica–urease composites. ► Urease encapsulating in silica matrix retained high activity. - Abstract: Urease templated precipitation of silica synthesized by sol–gel chemistry produces a composite material allowing high urease activity. This study investigates the structural properties of the composite material that allow for the retention of the urease hydrolysis activity. Scanning (SEM) and transmission (TEM) electron microscopy reveal that the composite has a mesoporous structure composed of closely packed spherical structures ∼20–50 nm in diameter. Brunauer–Emmett–Teller (BET) analysis revealed that the surface area and pore volume of the composite prepared under the conditions of 50 mM urea and 25 °C is relatively high (324 m 2 /g and 1.0 cm 3 /g). These values are equivalent to those of usual mesoporous silica materials synthesized from the self-assembly of triblock copolymers as organic templates. In addition, after encapsulating in a sol–gel silica matrix, urease retained high activity (∼90% of the activity compared with native urease). Our results suggest a new method for synthesizing mesoporous silica materials with highly tunable pore sizes and shapes under mild conditions.

  13. Silica-gel Particles Loaded with an Ionic Liquid for Separation of Zr(IV Prior to Its Determination by ICP-OES

    Directory of Open Access Journals (Sweden)

    Hadi M. Marwani

    2016-06-01

    Full Text Available A new ionic liquid loaded silica gel amine (SG-APTMS-N,N-EPANTf2 was developed, as an adsorptive material, for selective adsorption and determination of zirconium, Zr(IV, without the need for a chelating intermediate. Based on a selectivity study, the SG-APTMS-N,N-EPANTf2 phase showed a perfect selectivity towards Zr(IV at pH 4 as compared to other metallic ions, including gold [Au(III], copper [Cu(II], cobalt [Co(II], chromium [Cr(III], lead [Pb(II], selenium [Se(IV] and mercury [Hg(II] ions. The influence of pH, Zr(IV concentration, contact time and interfering ions on SG-APTMS-N,N-EPANTf2 uptake for Zr(IV was evaluated. The presence of incorporated donor atoms in newly synthesized SG-APTMS-N,N-EPANTf2 phase played a significant role in enhancing its uptake capacity of Zr(IV by 78.64% in contrast to silica gel (activated. The equilibrium and kinetic information of Zr(IV adsorption onto SG-APTMS-N,N-EPANTf2 were best expressed by Langmuir and pseudo second-order kinetic models, respectively. General co-existing cations did not interfere with the extraction and detection of Zr(IV. Finally, the analytical efficiency of the newly developed method was also confirmed by implementing it for the determination of Zr(IV in several water samples.

  14. Networked Biomedical System for Ubiquitous Health Monitoring

    Directory of Open Access Journals (Sweden)

    Arjan Durresi

    2008-01-01

    Full Text Available We propose a distributed system that enables global and ubiquitous health monitoring of patients. The biomedical data will be collected by wearable health diagnostic devices, which will include various types of sensors and will be transmitted towards the corresponding Health Monitoring Centers. The permanent medical data of patients will be kept in the corresponding Home Data Bases, while the measured biomedical data will be sent to the Visitor Health Monitor Center and Visitor Data Base that serves the area of present location of the patient. By combining the measured biomedical data and the permanent medical data, Health Medical Centers will be able to coordinate the needed actions and help the local medical teams to make quickly the best decisions that could be crucial for the patient health, and that can reduce the cost of health service.

  15. Ubiquitous health in practice: the interreality paradigm.

    Science.gov (United States)

    Gaggioli, Andrea; Raspelli, Simona; Grassi, Alessandra; Pallavicini, Federica; Cipresso, Pietro; Wiederhold, Brenda K; Riva, Giuseppe

    2011-01-01

    In this paper we introduce a new ubiquitous computing paradigm for behavioral health care: "Interreality". Interreality integrates assessment and treatment within a hybrid environment, that creates a bridge between the physical and virtual worlds. Our claim is that bridging virtual experiences (fully controlled by the therapist, used to learn coping skills and emotional regulation) with real experiences (allowing both the identification of any critical stressors and the assessment of what has been learned) using advanced technologies (virtual worlds, advanced sensors and PDA/mobile phones) may improve existing psychological treatment. To illustrate the proposed concept, a clinical scenario is also presented and discussed: Daniela, a 40 years old teacher, with a mother affected by Alzheimer's disease.

  16. Neutron detector using sol-gel absorber

    Science.gov (United States)

    Hiller, John M.; Wallace, Steven A.; Dai, Sheng

    1999-01-01

    An neutron detector composed of fissionable material having ions of lithium, uranium, thorium, plutonium, or neptunium, contained within a glass film fabricated using a sol-gel method combined with a particle detector is disclosed. When the glass film is bombarded with neutrons, the fissionable material emits fission particles and electrons. Prompt emitting activated elements yielding a high energy electron contained within a sol-gel glass film in combination with a particle detector is also disclosed. The emissions resulting from neutron bombardment can then be detected using standard UV and particle detection methods well known in the art, such as microchannel plates, channeltrons, and silicon avalanche photodiodes.

  17. Structural, Morphological and Optical Characterization of Eu3+ and Nd3+ Co-Doped Tio2 Nano Particles by Sol Gel Method

    Directory of Open Access Journals (Sweden)

    P. Sanjay

    2017-06-01

    Full Text Available Semiconductor nano crystals have been widely studied for their fundamental properties. The Eu3+ and Nd3+ doped titanium dioxide nano powder was successfully synthesized by sol-gel method. The morphological and structural properties of as-prepared samples were characterized by X-ray diffraction (XRD, High Resolution Transmission Electron Microscope (HRTEM. The Powder X- ray diffraction is carried out in order to examine the phase formation and substitution of Eu3+ and Nd3+ doped in TiO2 matrix. The UV-Vis spectral analysis was carried out between 200 nm and 1200 nm. The band gap of the Eu3+ and Nd3+ doped Tio2 nanoparticles was calculated. The functional groups of the synthesized compound have been identified by FTIR spectral analysis. The strong PL intensity confirms a blue shift.

  18. A single gene (Eu4) encodes the tissue-ubiquitous urease of soybean.

    Science.gov (United States)

    Torisky, R S; Griffin, J D; Yenofsky, R L; Polacco, J C

    1994-02-01

    We sought to determine the genetic basis of expression of the ubiquitous (metabolic) urease of soybean. This isozyme is termed the metabolic urease because its loss, in eu4/eu4 mutants, leads to accumulation of urea, whereas loss of the embryo-specific urease isozyme does not. The eu4 lesion eliminated the expression of the ubiquitous urease in vegetative and embryonic tissues. RFLP analysis placed urease clone LC4 near, or within, the Eu4 locus. Sequence comparison of urease proteins (ubiquitous and embryo-specific) and clones (LC4 and LS1) indicated that LC4 and LS1 encode ubiquitous and embryo-specific ureases, respectively. That LC4 is transcribed into poly(A)+ RNA in all tissues was indicated by the amplification of its transcript by an LC4-specific PCR primer. (The LS1-specific primer, on the other hand, amplified poly(A)+ RNA only from developing embryos expressing the embryo-specific urease.) These observations are consistent with Eu4 being the ubiquitous urease structural gene contained in the LC4 clone. In agreement with this notion, the mutant phenotype of eu4/eu4 callus was partially corrected by the LC4 urease gene introduced by particle bombardment.

  19. The mechanism and properties of acid-coagulated milk gels

    Directory of Open Access Journals (Sweden)

    Chanokphat Phadungath

    2005-03-01

    Full Text Available Acid-coagulated milk products such as fresh acid-coagulated cheese varieties and yogurt areimportant dairy food products. However, little is known regarding the mechanisms involved in gel formation, physical properties of acid gels, and the effects of processing variables such as heat treatment and gelation temperature on the important physical properties of acid milk gels. This paper reviews the modern concepts of possible mechanisms involved in the formation of particle milk gel aggregation, along with recent developments including the use of techniques such as dynamic low amplitude oscillatory rheology to observe the gel formation process, and confocal laser scanning microscopy to monitor gel microstructure.

  20. Ubiquitous information for ubiquitous computing: expressing clinical data sets with openEHR archetypes.

    Science.gov (United States)

    Garde, Sebastian; Hovenga, Evelyn; Buck, Jasmin; Knaup, Petra

    2006-01-01

    Ubiquitous computing requires ubiquitous access to information and knowledge. With the release of openEHR Version 1.0 there is a common model available to solve some of the problems related to accessing information and knowledge by improving semantic interoperability between clinical systems. Considerable work has been undertaken by various bodies to standardise Clinical Data Sets. Notwithstanding their value, several problems remain unsolved with Clinical Data Sets without the use of a common model underpinning them. This paper outlines these problems like incompatible basic data types and overlapping and incompatible definitions of clinical content. A solution to this based on openEHR archetypes is motivated and an approach to transform existing Clinical Data Sets into archetypes is presented. To avoid significant overlaps and unnecessary effort during archetype development, archetype development needs to be coordinated nationwide and beyond and also across the various health professions in a formalized process.

  1. Ubiquitous Monitoring of Electrical Household Appliances

    Science.gov (United States)

    Lloret, Jaime; Macías, Elsa; Suárez, Alvaro; Lacuesta, Raquel

    2012-01-01

    The number of appliances at home is increasing continuously, mainly because they make our lives easier. Currently, technology is integrated in all objects of our daily life. TCP/IP let us monitor our home in real time and check ubiquitously if something is happening at home. Bearing in mind this idea, we have developed a low-cost system, which can be used in any type of electrical household appliance that takes information from the appliance and posts the information to the Twitter Social network. Several sensors placed in the household appliances gather the sensed data and send them wired or wirelessly, depending on the case, using small and cheap devices to a gateway located in the home. This gateway takes decisions, based on the received data, and sends notifications to Twitter. We have developed a software application that takes the values and decides when to issue an alarm to the registered users (Twitter friends of our smart home). The performance of our system has been measured taking into account the home network (using IEEE 802.3u and IEEE 802.11g) and the data publishing in Twitter. As a result, we have generated an original product and service for any electrical household appliance, regardless of the model and manufacturer, that helps home users improve their quality of life. The paper also shows that there is no system with the same innovative features like the ones presented in this paper. PMID:23202205

  2. Ubiquitous monitoring of electrical household appliances.

    Science.gov (United States)

    Lloret, Jaime; Macías, Elsa; Suárez, Alvaro; Lacuesta, Raquel

    2012-11-07

    The number of appliances at home is increasing continuously, mainly because they make our lives easier. Currently, technology is integrated in all objects of our daily life. TCP/IP let us monitor our home in real time and check ubiquitously if something is happening at home. Bearing in mind this idea, we have developed a low-cost system, which can be used in any type of electrical household appliance that takes information from the appliance and posts the information to the Twitter Social network. Several sensors placed in the household appliances gather the sensed data and send them wired or wirelessly, depending on the case, using small and cheap devices to a gateway located in the home. This gateway takes decisions, based on the received data, and sends notifications to Twitter. We have developed a software application that takes the values and decides when to issue an alarm to the registered users (Twitter friends of our smart home). The performance of our system has been measured taking into account the home network (using IEEE 802.3u and IEEE 802.11g) and the data publishing in Twitter. As a result, we have generated an original product and service for any electrical household appliance, regardless of the model and manufacturer, that helps home users improve their quality of life. The paper also shows that there is no system with the same innovative features like the ones presented in this paper.

  3. Ubiquitous Graphene Electronics on Scotch Tape

    Science.gov (United States)

    Chung, Yoonyoung; Ho Kim, Hyun; Lee, Sangryun; Lee, Eunho; Won Kim, Seong; Ryu, Seunghwa; Cho, Kilwon

    2015-07-01

    We report a novel concept of graphene transistors on Scotch tape for use in ubiquitous electronic systems. Unlike common plastic substrates such as polyimide and polyethylene terephthalate, the Scotch tape substrate is easily attached onto various objects such as banknotes, curved surfaces, and human skin, which implies potential applications wherein electronics can be placed in any desired position. Furthermore, the soft Scotch tape serves as an attractive substrate for flexible/foldable electronics that can be significantly bent, or even crumpled. We found that the adhesive layer of the tape with a relatively low shear modulus relaxes the strain when subjected to bending. The capacitance of the gate dielectric made of oxidized aluminum oxide was 1.5 μF cm-2, so that a supply voltage of only 2.5 V was sufficient to operate the devices. As-fabricated graphene transistors on Scotch tape exhibited high electron mobility of 1326 (±155) cm2 V-1 s-1 the transistors still showed high mobility of 1254 (±478) cm2 V-1 s-1 even after they were crumpled.

  4. UBIQUITOUS POLLUTION FROM HEALTH AND COSMETIC ...

    Science.gov (United States)

    Those chemical pollutants that are regulated under various international, federal, and state programs represent but a small fraction of the universe of chemicals that occur in the environment as a result of both natural processses and human influence. Although this galaxy of targeted chemicals might be miniuscule compared with the universe of both known and yet-to-be identified chemicals, an implicit assumption is that these selective lists of chemicals are responsible for the most significant share of risk with respect to environmental or economic impairment or to human health.Pharmaceuticals and person care products (PPCPs) comprise a particularly large and diverse array of unregulated pollutants that occur in the environment from the combined activities and actions of multitudes of individuals as well as from veterinary and agricultural use. Although the concentration of any individual PPCP are generally less than ppt-ppb), evidence is accumulateing that these trace-level pollutants are ubiquitous, they can have a continuous presence regardless of environment half-lives (especially where sanitary wastewaters enter the environment), and the numbers of distinct and varied chemical entities could be extremely large (given that thousands are in commerical use). The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Locat

  5. Security policies and trust in ubiquitous computing.

    Science.gov (United States)

    Joshi, Anupam; Finin, Tim; Kagal, Lalana; Parker, Jim; Patwardhan, Anand

    2008-10-28

    Ubiquitous environments comprise resource-constrained mobile and wearable devices and computational elements embedded in everyday artefacts. These are connected to each other using both infrastructure-based as well as short-range ad hoc networks. Limited Internet connectivity limits the use of conventional security mechanisms such as public key infrastructures and other forms of server-centric authentication. Under these circumstances, peer-to-peer interactions are well suited for not just information interchange, but also managing security and privacy. However, practical solutions for protecting mobile devices, preserving privacy, evaluating trust and determining the reliability and accuracy of peer-provided data in such interactions are still in their infancy. Our research is directed towards providing stronger assurances of the reliability and trustworthiness of information and services, and the use of declarative policy-driven approaches to handle the open and dynamic nature of such systems. This paper provides an overview of some of the challenges and issues, and points out directions for progress.

  6. Intelligent Multi-Agent Middleware for Ubiquitous Home Networking Environments

    OpenAIRE

    Minwoo Son; Seung-Hun Lee; Dongkyoo Shin; Dongil Shin

    2008-01-01

    The next stage of the home networking environment is supposed to be ubiquitous, where each piece of material is equipped with an RFID (Radio Frequency Identification) tag. To fully support the ubiquitous environment, home networking middleware should be able to recommend home services based on a user-s interests and efficiently manage information on service usage profiles for the users. Therefore, USN (Ubiquitous Sensor Network) technology, which recognizes and manages a ...

  7. Ubiquitous and pervasive commerce new frontiers for electronic business

    CERN Document Server

    Roussos, George

    2006-01-01

    The new capabilities of ubiquitous and pervasive computing imply that products, locations, consumers and employees create rich streams of information about themselves, their immediate environment and their use. This book brings together technological and business aspects of conducting commerce using ubiquitous and pervasive computing techniques and also examines its implications for society at large. Individual chapters examine in detail the core technologies that make ubiquitous computing possible, the business standards that must be established to support the envisioned global infrastructure

  8. Fluorescence metrology of silica sol-gels

    Indian Academy of Sciences (India)

    We have developed a new method for measuring in-situ the growth of the nanometre-size silica particles which lead to the formation of sol-gel glasses. This technique is based on the decay of fluorescence polarisation anisotropy due to Brownian rotation of dye molecules bound to the particles. Results to date give near ...

  9. A ubiquitous reflective e-portfolio architecture.

    Science.gov (United States)

    Forte, Marcos; de Souza, Wanderley L; da Silva, Roseli F; do Prado, Antonio F; Rodrigues, Jose F

    2013-11-01

    In nurse and in medicine courses, the use of reflective portfolios as a pedagogical tool is becoming a common practice; in the last years, this practice has gradually migrated from paper-based to electronic-based portfolios. Current approaches for reflective e-portfolios, however, do not widely operate at outdoor sites, where data networks are limited or nonexistent. Considering that many of the activities related to nurse and medicine courses relate to professional practices conducted in such conditions, these network shortcomings restrict the adoption of e-portfolios. The present study describes the requirements specification, design, implementation, and evaluation of the Ubiquitous Reflective E-Portfolio Architecture, a solution proposed to support the development of systems based on mobile and wired access for both online and offline operation. We have implemented a prototype named Professional Practice Module to evaluate the Ubiquitous Reflective E-Portfolio Architecture; the module was based on requirements observed during the professional practice, the paper-based portfolio in use, and related learning meetings in the Medicine Course of a Brazilian University. The evaluation of the system was carried out with a learning group of 2nd year students of the medicine course, who answered to extensive evaluation questionnaires. The prototype proved to be operational in the activities of the professional practice of the Medicine Course object of the study, including homework tasks, patient care, data sharing, and learning meetings. It also demonstrated to be versatile with respect to the availability of the computer network that, many times, was not accessible. Moreover, the students considered the module useful and easy to use, but pointed out difficulties about the keyboard and the display sizes of the netbook devices, and about their operational system. Lastly, most of the students declared preference for the electronic Professional Practice Module in internal

  10. Food gels filled with emulsion droplets : linking large deformation properties to sensory perception

    NARCIS (Netherlands)

    Sala, G.

    2007-01-01

    Key words: polymer gels, particle gels, emulsion, large deformation, friction, sensory This thesis reports studies on the large deformation and lubrication properties of emulsion-filled gels and the way these properties are related to the sensory perception of the gels. The design of the studies

  11. Ubiquitous Learning Project Using Life-Logging Technology in Japan

    Science.gov (United States)

    Ogata, Hiroaki; Hou, Bin; Li, Mengmeng; Uosaki, Noriko; Mouri, Kosuke; Liu, Songran

    2014-01-01

    A Ubiquitous Learning Log (ULL) is defined as a digital record of what a learner has learned in daily life using ubiquitous computing technologies. In this paper, a project which developed a system called SCROLL (System for Capturing and Reusing Of Learning Log) is presented. The aim of developing SCROLL is to help learners record, organize,…

  12. Implications of Ubiquitous Computing for the Social Studies Curriculum

    Science.gov (United States)

    van Hover, Stephanie D.; Berson, Michael J.; Bolick, Cheryl Mason; Swan, Kathleen Owings

    2004-01-01

    In March 2002, members of the National Technology Leadership Initiative (NTLI) met in Charlottesville, Virginia to discuss the potential effects of ubiquitous computing on the field of education. Ubiquitous computing, or "on-demand availability of task-necessary computing power," involves providing every student with a handheld computer--a…

  13. Ubiquitous Computing: The Universal Use of Computers on College Campuses.

    Science.gov (United States)

    Brown, David G., Ed.

    This book is a collection of vignettes from 13 universities where everyone on campus has his or her own computer. These 13 institutions have instituted "ubiquitous computing" in very different ways at very different costs. The chapters are: (1) "Introduction: The Ubiquitous Computing Movement" (David G. Brown); (2) "Dartmouth College" (Malcolm…

  14. Towards context adaptive privacy decisions in ubiquitous computing

    NARCIS (Netherlands)

    Schaub, Florian; Könings, Bastian; Weber, M.; Kargl, Frank

    2012-01-01

    In ubiquitous systems control of privacy settings will be increasingly difficult due to the pervasive nature of sensing and communication capabilities. We identify challenges for privacy decisions in ubiquitous systems and propose a system for in situ privacy decision support. When context changes

  15. Architecture of personal healthcare information system in ubiquitous healthcare

    NARCIS (Netherlands)

    Bhardwaj, S.; Sain, M.; Lee, H.-J.; Chung, W.Y.; Slezak, D.; et al., xx

    2009-01-01

    Due to recent development in Ubiquitous Healthcare now it’s time to build such application which can work independently and with less interference of Physician. In this paper we are try to build the whole architecture of personal Healthcare information system for ubiquitous healthcare which also

  16. Development of high-throughput and high sensitivity capillary gel electrophoresis platform method for Western, Eastern, and Venezuelan equine encephalitis (WEVEE) virus like particles (VLPs) purity determination and characterization.

    Science.gov (United States)

    Gollapudi, Deepika; Wycuff, Diane L; Schwartz, Richard M; Cooper, Jonathan W; Cheng, K C

    2017-10-01

    In this paper, we describe development of a high-throughput, highly sensitive method based on Lab Chip CGE-SDS platform for purity determination and characterization of virus-like particle (VLP) vaccines. A capillary gel electrophoresis approach requiring about 41 s per sample for analysis and demonstrating sensitivity to protein initial concentrations as low as 20 μg/mL, this method has been used previously to evaluate monoclonal antibodies, but this application for lot release assay of VLPs using this platform is unique. The method was qualified and shown to be accurate for the quantitation of VLP purity. Assay repeatability was confirmed to be less than 2% relative standard deviation of the mean (% RSD) with interday precision less than 2% RSD. The assay can evaluate purified VLPs in a concentration range of 20-249 μg/mL for VEE and 20-250 μg/mL for EEE and WEE VLPs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Removing water from gels

    International Nuclear Information System (INIS)

    Lane, E.S.; Winter, J.A.

    1982-01-01

    Water is removed from a gel material by contacting the gel material with an organic liquid and contacting the organic liquid with a gas such that water is taken up by the gas. The invention, in one embodiment, may be used to dry gel materials whilst maintaining an open porous network therein. In one example, the invention is applied to gel precipitated spheres containing uranium and plutonium. (author)

  18. Socio-technical Issues for Ubiquitous Information Society in 2010

    Science.gov (United States)

    Funabashi, Motohisa; Homma, Koichi; Sasaki, Toshiro; Sato, Yoshinori; Kido, Kunihiko; Fukumoto, Takashi; Yano, Koujin

    Impact of the ubiquitous information technology on our society is so significant that directing technological development and preparing institutional apparatus are quite important and urgent. The present paper elaborates, with the efforts by both humanity and engineering disciplines, to find out the socio-technical issues of ubiquitous information society in 2010 by inspecting social implications of emerging technology as well as social expectations. In order to deliberate the issues, scenarios are developed that describes possible life in ubiquitous information society. The derived issues cover integrating information technology and human body, producing smart sharable environment, protecting individual rights, fostering new service business, and forming community.

  19. USE OF UBIQUITOUS TECHNOLOGIES IN MILITARY LOGISTIC SYSTEM IN IRAN

    Directory of Open Access Journals (Sweden)

    P. Jafari

    2013-09-01

    Full Text Available This study is about integration and evaluation of RFID and ubiquitous technologies in military logistic system management. Firstly, supply chain management and the necessity of a revolution in logistic systems especially in military area, are explained. Secondly RFID and ubiquitous technologies and the advantages of their use in supply chain management are introduced. Lastly a system based on these technologies for controlling and increasing the speed and accuracy in military logistic system in Iran with its unique properties, is presented. The system is based on full control of military logistics (supplies from the time of deployment to replenishment using sensor network, ubiquitous and RFID technologies.

  20. Use of Ubiquitous Technologies in Military Logistic System in Iran

    Science.gov (United States)

    Jafari, P.; Sadeghi-Niaraki, A.

    2013-09-01

    This study is about integration and evaluation of RFID and ubiquitous technologies in military logistic system management. Firstly, supply chain management and the necessity of a revolution in logistic systems especially in military area, are explained. Secondly RFID and ubiquitous technologies and the advantages of their use in supply chain management are introduced. Lastly a system based on these technologies for controlling and increasing the speed and accuracy in military logistic system in Iran with its unique properties, is presented. The system is based on full control of military logistics (supplies) from the time of deployment to replenishment using sensor network, ubiquitous and RFID technologies.

  1. Polymer gels and networks

    National Research Council Canada - National Science Library

    Osada, Yoshihito; Khokhlov, A. R

    2002-01-01

    ... or magnetic field, etc.). It was realized that not only can polymer gels absorb and hold a considerable volume of liquids, but they can also be forced to expel the absorbed liquid in a controlled manner. Of particular interest are hydrogels, i.e., polymer gels, which swell extensively in water. The most common hydrogels are polyelectrolyte gels: ...

  2. Association of triglyceride-rich lipoproteins-related markers and low-density lipoprotein heterogeneity with cardiovascular risk: effectiveness of polyacrylamide-gel electrophoresis as a method of determining low-density lipoprotein particle size.

    Science.gov (United States)

    Tani, Shigemasa; Matsumoto, Michiaki; Nagao, Ken; Hirayama, Atsushi

    2014-01-01

    Despite well-controlled low-density lipoprotein cholesterol (LDL-C), hypertriglyceridemia is an independent predictor of coronary events. We investigated the risk of atherosclerotic cardiovascular disease through examining the relation between triglyceride (TG) metabolism and LDL-heterogeneity as assessed by polyacrylamide-gel electrophoresis (PAGE). Estimated LDL-particle size [relative LDL migration (LDL-Rm value)] measured by PAGE with the LipoPhor system (Joko, Tokyo, Japan) was evaluated in 645 consecutive patients with one additional risk factor for atherosclerotic cardiovascular disease.Multivariate regression analysis after adjustments for traditional risk factors revealed an elevated triglyceride-rich lipoproteins (TRLs)-related markers [TG, remnant-like particle cholesterol (RLP-C), very LDL (VLDL) fraction, apolipoprotein (apo) C-II, and apo C-III] level to be an independent predictor of smaller-size LDL-particle size, both in the overall population, and in a subset of patients with serum LDL-C <100 mg/dL. Even among the patients with LDL-C levels <100 mg/dL, the serum levels of atherogenic lipid markers in those with a LDL-Rm value ≥0.40, suggesting the presence of large amounts of small-dense LDL and upper limit (mean+2 standard deviation) in this population, were significantly higher than in those with a LDL-Rm value <0.40. Moreover, the serum levels of TRLs-related markers showed high accurate area under the receiver-operating characteristic curve (TG, 0.896; RLP-C, 0.875; VLDL fraction, 0.803; apo C-II, 0.778; and apo C-III, 0.804, respectively) in terms of evaluation of the indicators of LDL-Rm value ≥0.40. To further reduce the risk of atherosclerotic cardiovascular disease, it may be of particular importance to pay attention not only to the quantitative change in the serum LDL-C, but also TG-metabolism associated with LDL-heterogeneity. Combined evaluation of TRLs-related markers and LDL-Rm value may be useful for assessing the risk of

  3. Modelling of the inhomogeneous interior of polymer gels

    International Nuclear Information System (INIS)

    Shew, C-Y; Iwaki, Takafumi

    2006-01-01

    A simple model has been investigated to elucidate the mean squared displacement (MSD) of probe molecules in cross-linked polymer gels. In the model, we assume that numerous cavities distribute in the inhomogeneous interior of a gel, and probe molecules are confined within these cavities. The individual probe molecules trapped in a gel are treated as Brownian particles confined to a spherical harmonic potential. The harmonic potential is chosen to model the effective potential experienced by the probe particle in the cavity of a gel. Each field strength is corresponding to the characteristic of one type of effective cavity. Since the statistical distribution of different effective cavity sizes is unknown, several distribution functions are examined. Meanwhile, the calculated averaged MSDs are compared to the experimental data by Nisato et al (2000 Phys. Rev. E 61 2879). We find that the theoretical results of the MSD are sensitive to the shape of the distribution function. For low cross-linked gels, the best fit is obtained when the interior cavities of a gel follow a bimodal distribution. Such a result may be attributed to the presence of at least two distinct classes of cavity in gels. For high cross-linked gels, the cavities in the gel can be depicted by a single-modal uniform distribution function, suggesting that the range of cavity sizes becomes smaller. These results manifest the voids inside a gel, and the shape of distribution functions may provide the insight into the inhomogeneous interior of a gel

  4. New functionalities in abundant element oxides: ubiquitous element strategy

    International Nuclear Information System (INIS)

    Hosono, Hideo; Hayashi, Katsuro; Kamiya, Toshio; Atou, Toshiyuki; Susaki, Tomofumi

    2011-01-01

    While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust), many advanced materials are based on rare elements. A 'rare-element crisis' is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a 'ubiquitous element strategy' for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements. (topical review)

  5. Awareness for Contextualized Digital Contents in Ubiquitous Learning Environments

    NARCIS (Netherlands)

    Börner, Dirk

    2010-01-01

    Börner, D. (2009). Awareness for Contextualized Digital Contents in Ubiquitous Learning Environments. Presented at the Doctoral Consortium of the Fourth European Conference on Technology Enhanced Learning (EC-TEL 2009). September, 29-October, 2, 2009, Nice, France.

  6. Mining the preferences of patients for ubiquitous clinic recommendation.

    Science.gov (United States)

    Chen, Tin-Chih Toly; Chiu, Min-Chi

    2018-03-06

    A challenge facing all ubiquitous clinic recommendation systems is that patients often have difficulty articulating their requirements. To overcome this problem, a ubiquitous clinic recommendation mechanism was designed in this study by mining the clinic preferences of patients. Their preferences were defined using the weights in the ubiquitous clinic recommendation mechanism. An integer nonlinear programming problem was solved to tune the values of the weights on a rolling basis. In addition, since it may take a long time to adjust the values of weights to their asymptotic values, the back propagation network (BPN)-response surface method (RSM) method is applied to estimate the asymptotic values of weights. The proposed methodology was tested in a regional study. Experimental results indicated that the ubiquitous clinic recommendation system outperformed several existing methods in improving the successful recommendation rate.

  7. Disclosure of Personal Data in Ubiquitous Social Networking

    DEFF Research Database (Denmark)

    Sapuppo, Antonio

    users' privacy. Firstly, it updates the current privacy guidelines of ubiquitous computing by proposing four drawbacks to be avoided when designing for privacy in ubiquitous social networking environments. Secondly, this dissertation identifies and investigates the determinants that might influence......Ubiquitous social networking focuses on developing possible advantageous relationships such as friendships, partnerships and business relations in the physical world, by uncovering hidden connections that people share with others nearby. The foundation of these services is based on disclosure...... of personal information, which can provoke numerous accidental invasions of privacy. This dissertation contributes by addressing two problems, related to support of privacy-aware social networking in ubiquitous computing environments that focus on maximizing potential networking benefits while preserving...

  8. Applications of gel dosimetry

    International Nuclear Information System (INIS)

    Ibbott, Geoffrey S

    2004-01-01

    Gel dosimetry has been examined as a clinical dosimeter since the 1950s. During the last two decades, however, a rapid increase in the number of investigators has been seen, and the body of knowledge regarding gel dosimetry has expanded considerably. Gel dosimetry is still considered a research project, and the introduction of this tool into clinical use is proceeding slowly. This paper will review the characteristics of gel dosimetry that make it desirable for clinical use, the postulated and demonstrated applications of gel dosimetry, and some complications, set-backs, and failures that have contributed to the slow introduction into routine clinical use

  9. USE OF UBIQUITOUS TECHNOLOGIES IN MILITARY LOGISTIC SYSTEM IN IRAN

    OpenAIRE

    P. Jafari; A. Sadeghi-Niaraki

    2013-01-01

    This study is about integration and evaluation of RFID and ubiquitous technologies in military logistic system management. Firstly, supply chain management and the necessity of a revolution in logistic systems especially in military area, are explained. Secondly RFID and ubiquitous technologies and the advantages of their use in supply chain management are introduced. Lastly a system based on these technologies for controlling and increasing the speed and accuracy in military logistic system ...

  10. Cluster-based localization and tracking in ubiquitous computing systems

    CERN Document Server

    Martínez-de Dios, José Ramiro; Torres-González, Arturo; Ollero, Anibal

    2017-01-01

    Localization and tracking are key functionalities in ubiquitous computing systems and techniques. In recent years a very high variety of approaches, sensors and techniques for indoor and GPS-denied environments have been developed. This book briefly summarizes the current state of the art in localization and tracking in ubiquitous computing systems focusing on cluster-based schemes. Additionally, existing techniques for measurement integration, node inclusion/exclusion and cluster head selection are also described in this book.

  11. Sol-gel-state of hydrated zirconium dioxide

    International Nuclear Information System (INIS)

    Karakchiev, L.G.; Lyakhov, N.Z.

    1995-01-01

    The change in viscosity and density of a system in the course of sol-gel-xerogel has been traced. The size and molecular mass of particles in sol have been determined. Initial sol is practically a monodisperse system. Gel is a spatial net of similar particles. Reversible character of sol-gel transition with a change in water content in the system suggests instability of the bond between the particles in the structure of the solid state body formed. 11 refs.; 4 figs

  12. Transport Phenomena in Gel

    Directory of Open Access Journals (Sweden)

    Masayuki Tokita

    2016-05-01

    Full Text Available Gel becomes an important class of soft materials since it can be seen in a wide variety of the chemical and the biological systems. The unique properties of gel arise from the structure, namely, the three-dimensional polymer network that is swollen by a huge amount of solvent. Despite the small volume fraction of the polymer network, which is usually only a few percent or less, gel shows the typical properties that belong to solids such as the elasticity. Gel is, therefore, regarded as a dilute solid because its elasticity is much smaller than that of typical solids. Because of the diluted structure, small molecules can pass along the open space of the polymer network. In addition to the viscous resistance of gel fluid, however, the substance experiences resistance due to the polymer network of gel during the transport process. It is, therefore, of importance to study the diffusion of the small molecules in gel as well as the flow of gel fluid itself through the polymer network of gel. It may be natural to assume that the effects of the resistance due to the polymer network of gel depends strongly on the network structure. Therefore, detailed study on the transport processes in and through gel may open a new insight into the relationship between the structure and the transport properties of gel. The two typical transport processes in and through gel, that is, the diffusion of small molecules due to the thermal fluctuations and the flow of gel fluid that is caused by the mechanical pressure gradient will be reviewed.

  13. Sol-Gel Manufactured Energetic Materials

    Science.gov (United States)

    Simpson, Randall L.; Lee, Ronald S.; Tillotson, Thomas M.; Hrubesh, Lawrence W.; Swansiger, Rosalind W.; Fox, Glenn A.

    2005-05-17

    Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

  14. Buckling of paramagnetic chains in soft gels

    Science.gov (United States)

    Huang, Shilin; Pessot, Giorgio; Cremer, Peet; Weeber, Rudolf; Holm, Christian; Nowak, Johannes; Odenbach, Stefan; Menzel, Andreas M.; Auernhammer, Günter K.

    We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under oblique magnetic fields, in particular a pronounced buckling deformation. The details of the resulting morphological shapes depend on the length of the chain, the strength of the external magnetic field, and the modulus of the gel. Based on the observation that the magnetic chains are strongly coupled to the surrounding polymer network, a simplified model is developed to describe their buckling behavior. A coarse-grained molecular dynamics simulation model featuring an increased matrix stiffness on the surfaces of the particles leads to morphologies in agreement with the experimentally observed buckling effects.

  15. Sol-Gel Glasses

    Science.gov (United States)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  16. Trust information-based privacy architecture for ubiquitous health.

    Science.gov (United States)

    Ruotsalainen, Pekka Sakari; Blobel, Bernd; Seppälä, Antto; Nykänen, Pirkko

    2013-10-08

    Ubiquitous health is defined as a dynamic network of interconnected systems that offers health services independent of time and location to a data subject (DS). The network takes place in open and unsecure information space. It is created and managed by the DS who sets rules that regulate the way personal health information is collected and used. Compared to health care, it is impossible in ubiquitous health to assume the existence of a priori trust between the DS and service providers and to produce privacy using static security services. In ubiquitous health features, business goals and regulations systems followed often remain unknown. Furthermore, health care-specific regulations do not rule the ways health data is processed and shared. To be successful, ubiquitous health requires novel privacy architecture. The goal of this study was to develop a privacy management architecture that helps the DS to create and dynamically manage the network and to maintain information privacy. The architecture should enable the DS to dynamically define service and system-specific rules that regulate the way subject data is processed. The architecture should provide to the DS reliable trust information about systems and assist in the formulation of privacy policies. Furthermore, the architecture should give feedback upon how systems follow the policies of DS and offer protection against privacy and trust threats existing in ubiquitous environments. A sequential method that combines methodologies used in system theory, systems engineering, requirement analysis, and system design was used in the study. In the first phase, principles, trust and privacy models, and viewpoints were selected. Thereafter, functional requirements and services were developed on the basis of a careful analysis of existing research published in journals and conference proceedings. Based on principles, models, and requirements, architectural components and their interconnections were developed using system

  17. An improved anonymous authentication scheme for roaming in ubiquitous networks.

    Science.gov (United States)

    Lee, Hakjun; Lee, Donghoon; Moon, Jongho; Jung, Jaewook; Kang, Dongwoo; Kim, Hyoungshick; Won, Dongho

    2018-01-01

    With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people's lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost. In 2017, Chaudhry et al. proposed a password-based authentication scheme for the roaming in ubiquitous networks to enhance the security. Unfortunately, we found that their scheme remains insecure in its protection of the user privacy. In this paper, we prove that Chaudhry et al.'s scheme is vulnerable to the stolen-mobile device and user impersonation attacks, and its drawbacks comprise the absence of the incorrect login-input detection, the incorrectness of the password change phase, and the absence of the revocation provision. Moreover, we suggest a possible way to fix the security flaw in Chaudhry et al's scheme by using the biometric-based authentication for which the bio-hash is applied in the implementation of a three-factor authentication. We prove the security of the proposed scheme with the random oracle model and formally verify its security properties using a tool named ProVerif, and analyze it in terms of the computational and communication cost. The analysis result shows that the proposed scheme is suitable for resource-constrained ubiquitous environments.

  18. Internet messenger based smart virtual class learning using ubiquitous computing

    Science.gov (United States)

    Umam, K.; Mardi, S. N. S.; Hariadi, M.

    2017-06-01

    Internet messenger (IM) has become an important educational technology component in college education, IM makes it possible for students to engage in learning and collaborating at smart virtual class learning (SVCL) using ubiquitous computing. However, the model of IM-based smart virtual class learning using ubiquitous computing and empirical evidence that would favor a broad application to improve engagement and behavior are still limited. In addition, the expectation that IM based SVCL using ubiquitous computing could improve engagement and behavior on smart class cannot be confirmed because the majority of the reviewed studies followed instructions paradigms. This article aims to present the model of IM-based SVCL using ubiquitous computing and showing learners’ experiences in improved engagement and behavior for learner-learner and learner-lecturer interactions. The method applied in this paper includes design process and quantitative analysis techniques, with the purpose of identifying scenarios of ubiquitous computing and realize the impressions of learners and lecturers about engagement and behavior aspect and its contribution to learning

  19. An improved anonymous authentication scheme for roaming in ubiquitous networks.

    Directory of Open Access Journals (Sweden)

    Hakjun Lee

    Full Text Available With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people's lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost. In 2017, Chaudhry et al. proposed a password-based authentication scheme for the roaming in ubiquitous networks to enhance the security. Unfortunately, we found that their scheme remains insecure in its protection of the user privacy. In this paper, we prove that Chaudhry et al.'s scheme is vulnerable to the stolen-mobile device and user impersonation attacks, and its drawbacks comprise the absence of the incorrect login-input detection, the incorrectness of the password change phase, and the absence of the revocation provision. Moreover, we suggest a possible way to fix the security flaw in Chaudhry et al's scheme by using the biometric-based authentication for which the bio-hash is applied in the implementation of a three-factor authentication. We prove the security of the proposed scheme with the random oracle model and formally verify its security properties using a tool named ProVerif, and analyze it in terms of the computational and communication cost. The analysis result shows that the proposed scheme is suitable for resource-constrained ubiquitous environments.

  20. Sol-Gel Derived Hafnia Coatings

    Science.gov (United States)

    Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

    2002-01-01

    Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.

  1. GelTouch

    DEFF Research Database (Denmark)

    Miruchna, Viktor; Walter, Robert; Lindlbauer, David

    2015-01-01

    We present GelTouch, a gel-based layer that can selectively transition between soft and stiff to provide tactile multi-touch feedback. It is flexible, transparent when not activated, and contains no mechanical, electromagnetic, or hydraulic components, resulting in a compact form factor (a 2mm thin...... touchscreen layer for our prototype). The activated areas can be morphed freely and continuously, without being limited to fixed, predefined shapes. GelTouch consists of a poly(N-isopropylacrylamide) gel layer which alters its viscoelasticity when activated by applying heat (>32 C). We present three different...

  2. Thorium inorganic gels

    International Nuclear Information System (INIS)

    Genet, M.; Brandel, V.

    1988-01-01

    The optimum pH and concentration values of thorium salts and oxoacids or oxoacid salts which lead to transparent and stable inorganic gels have been determined. The isotherm drying process of the gel at 50 0 C leads successively to a partly dehydrated gel, then, to the formation of an unusual liquid phase and, finally to a dry amorphous solid phase which is still transparent. This kind of transparent inorganic gels and amorphous phase can be used as matrices for spectroscopic studies [fr

  3. Mobile, ubiquitous, and pervasive learning fundaments, applications, and trends

    CERN Document Server

    2016-01-01

    This book is concerned with the mobile, ubiquitous, and pervasive learning arena. It present a collection of works corresponding to four categories: reviews, studies, conceptual proposals, and approaches. As a result of the submission and revision processes eight manuscripts were accepted and organized into the aforementioned four parts as follows: ·Review: a couple of chapters offer a survey of related works. One concerns with the diversity of mobile, ubiquitous, and pervasive labor, where interested findings are unveiled based on correlations. Other focuses on adaptive and adaptable architectures that are suitable to implement ubiquitous learning sceneries, whose contribution represents a model of a domain specific architecture. ·Studies: two chapters explore issues related to the effect of question styles made through smartphones and tablets, and the disposition of teachers to exploit mobile devices at classroom. ·Conceptual: a pair of chapters offer a given proposal, the first to develop adaptive mobil...

  4. A model for ubiquitous care of noncommunicable diseases.

    Science.gov (United States)

    Vianna, Henrique Damasceno; Barbosa, Jorge Luis Victória

    2014-09-01

    The ubiquitous computing, or ubicomp, is a promising technology to help chronic diseases patients managing activities, offering support to them anytime, anywhere. Hence, ubicomp can aid community and health organizations to continuously communicate with patients and to offer useful resources for their self-management activities. Communication is prioritized in works of ubiquitous health for noncommunicable diseases care, but the management of resources is not commonly employed. We propose the UDuctor, a model for ubiquitous care of noncommunicable diseases. UDuctor focuses the resources offering, without losing self-management and communication supports. We implemented a system and applied it in two practical experiments. First, ten chronic patients tried the system and filled out a questionnaire based on the technology acceptance model. After this initial evaluation, an alpha test was done. The system was used daily for one month and a half by a chronic patient. The results were encouraging and show potential for implementing UDuctor in real-life situations.

  5. Navigation studies based on the ubiquitous positioning technologies

    Science.gov (United States)

    Ye, Lei; Mi, Weijie; Wang, Defeng

    2007-11-01

    This paper summarized the nowadays positioning technologies, such as absolute positioning methods and relative positioning methods, indoor positioning and outdoor positioning, active positioning and passive positioning. Global Navigation Satellite System (GNSS) technologies were introduced as the omnipresent out-door positioning technologies, including GPS, GLONASS, Galileo and BD-1/2. After analysis of the shortcomings of GNSS, indoor positioning technologies were discussed and compared, including A-GPS, Cellular network, Infrared, Electromagnetism, Computer Vision Cognition, Embedded Pressure Sensor, Ultrasonic, RFID (Radio Frequency IDentification), Bluetooth, WLAN etc.. Then the concept and characteristics of Ubiquitous Positioning was proposed. After the ubiquitous positioning technologies contrast and selection followed by system engineering methodology, a navigation system model based on Incorporate Indoor-Outdoor Positioning Solution was proposed. And this model was simulated in the Galileo Demonstration for World Expo Shanghai project. In the conclusion, the prospects of ubiquitous positioning based navigation were shown, especially to satisfy the public location information acquiring requirement.

  6. Integrated Environment for Ubiquitous Healthcare and Mobile IPv6 Networks

    Science.gov (United States)

    Cagalaban, Giovanni; Kim, Seoksoo

    The development of Internet technologies based on the IPv6 protocol will allow real-time monitoring of people with health deficiencies and improve the independence of elderly people. This paper proposed a ubiquitous healthcare system for the personalized healthcare services with the support of mobile IPv6 networks. Specifically, this paper discusses the integration of ubiquitous healthcare and wireless networks and its functional requirements. This allow an integrated environment where heterogeneous devices such a mobile devices and body sensors can continuously monitor patient status and communicate remotely with healthcare servers, physicians, and family members to effectively deliver healthcare services.

  7. Privacy-related context information for ubiquitous health.

    Science.gov (United States)

    Seppälä, Antto; Nykänen, Pirkko; Ruotsalainen, Pekka

    2014-03-11

    Ubiquitous health has been defined as a dynamic network of interconnected systems. A system is composed of one or more information systems, their stakeholders, and the environment. These systems offer health services to individuals and thus implement ubiquitous computing. Privacy is the key challenge for ubiquitous health because of autonomous processing, rich contextual metadata, lack of predefined trust among participants, and the business objectives. Additionally, regulations and policies of stakeholders may be unknown to the individual. Context-sensitive privacy policies are needed to regulate information processing. Our goal was to analyze privacy-related context information and to define the corresponding components and their properties that support privacy management in ubiquitous health. These properties should describe the privacy issues of information processing. With components and their properties, individuals can define context-aware privacy policies and set their privacy preferences that can change in different information-processing situations. Scenarios and user stories are used to analyze typical activities in ubiquitous health to identify main actors, goals, tasks, and stakeholders. Context arises from an activity and, therefore, we can determine different situations, services, and systems to identify properties for privacy-related context information in information-processing situations. Privacy-related context information components are situation, environment, individual, information technology system, service, and stakeholder. Combining our analyses and previously identified characteristics of ubiquitous health, more detailed properties for the components are defined. Properties define explicitly what context information for different components is needed to create context-aware privacy policies that can control, limit, and constrain information processing. With properties, we can define, for example, how data can be processed or how components

  8. A Survey of Service Composition Mechanisms in Ubiquitous Computing

    DEFF Research Database (Denmark)

    Brønsted, Jeppe; Hansen, Klaus Marius; Ingstrup, Mads

    2007-01-01

    Composition of services, i.e., providing new services by combining existing ones, is a pervasive idea in ubiquitous computing. We surveyed the field by looking at what features are actually present in technologies that support service composition in some form. Condensing this into a list...... of features allowed us to discuss the qualitative merits and drawbacks of various approaches to service composition, focusing in particular on usability, adaptability and efficiency. Moreover, we found that further research is needed into quality-of-service assurance of composites and into contingency...... management for composites—one of the concerns differentiating service composition in ubiquitous computing from its counterpart in less dynamic settings....

  9. Privacy-Related Context Information for Ubiquitous Health

    Science.gov (United States)

    Nykänen, Pirkko; Ruotsalainen, Pekka

    2014-01-01

    Background Ubiquitous health has been defined as a dynamic network of interconnected systems. A system is composed of one or more information systems, their stakeholders, and the environment. These systems offer health services to individuals and thus implement ubiquitous computing. Privacy is the key challenge for ubiquitous health because of autonomous processing, rich contextual metadata, lack of predefined trust among participants, and the business objectives. Additionally, regulations and policies of stakeholders may be unknown to the individual. Context-sensitive privacy policies are needed to regulate information processing. Objective Our goal was to analyze privacy-related context information and to define the corresponding components and their properties that support privacy management in ubiquitous health. These properties should describe the privacy issues of information processing. With components and their properties, individuals can define context-aware privacy policies and set their privacy preferences that can change in different information-processing situations. Methods Scenarios and user stories are used to analyze typical activities in ubiquitous health to identify main actors, goals, tasks, and stakeholders. Context arises from an activity and, therefore, we can determine different situations, services, and systems to identify properties for privacy-related context information in information-processing situations. Results Privacy-related context information components are situation, environment, individual, information technology system, service, and stakeholder. Combining our analyses and previously identified characteristics of ubiquitous health, more detailed properties for the components are defined. Properties define explicitly what context information for different components is needed to create context-aware privacy policies that can control, limit, and constrain information processing. With properties, we can define, for example, how

  10. Compatibility between weak gel and microorganisms in weak gel-assisted microbial enhanced oil recovery.

    Science.gov (United States)

    Qi, Yi-Bin; Zheng, Cheng-Gang; Lv, Cheng-Yuan; Lun, Zeng-Min; Ma, Tao

    2018-03-20

    To investigate weak gel-assisted microbial flooding in Block Wang Long Zhuang in the Jiangsu Oilfield, the compatibility of weak gel and microbe was evaluated using laboratory experiments. Bacillus sp. W5 was isolated from the formation water in Block Wang Long Zhuang. The rate of oil degradation reached 178 mg/day, and the rate of viscosity reduction reached 75.3%. Strain W5 could produce lipopeptide with a yield of 1254 mg/L. Emulsified crude oil was dispersed in the microbial degradation system, and the average diameter of the emulsified oil particles was 18.54 μm. Bacillus sp. W5 did not affect the rheological properties of the weak gel, and the presence of the weak gel did not significantly affect bacterial reproduction (as indicated by an unchanged microbial biomass), emulsification (surface tension is 35.56 mN/m and average oil particles size is 21.38 μm), oil degradation (162 mg/day) and oil viscosity reduction (72.7%). Core-flooding experiments indicated oil recovery of 23.6% when both weak gel and Bacillus sp. W5 were injected into the system, 14.76% when only the weak gel was injected, and 9.78% with strain W5 was injected without the weak gel. The results demonstrate good compatibility between strains W5 and the weak gel and highlight the application potential of weak gel-assisted microbial flooding. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Sol-gel preparation of uranium oxide spheres

    International Nuclear Information System (INIS)

    Dolezal, J.; Urbanek, V.

    1978-01-01

    Information is presented on problems of preparing nuclear fuel by the sol-gel method. Basic data on different process types are given. A more detailed description of the method of preparation of spherical particles of uranium oxide gel developed and used at the Nuclear Research Institute at Rez is given. Advantages and disadvantages of sol-gel materials are discussed in comparison with fuel materials prepared by classical precipitation methods. The feasibility of the sol-gel methods for preparing other materials is shortly mentioned and their application outlined. (author)

  12. Cyanocobalamin Nasal Gel

    Science.gov (United States)

    ... to supply extra vitamin B12 to people who need unusually large amounts of this vitamin because they are pregnant or have certain diseases. ... Cyanocobalamin nasal gel will supply you with enough vitamin B12 only as ... it regularly. You may need to use cyanocobalamin nasal gel every week for ...

  13. Sealing wells with gel

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, E C

    1967-10-01

    A new system is being used in Mexico to temporarily plug producing wells. The temporary seal is a gel with a catalyst. The use of this temporary plug allows gas-lift wells to be taken off production in order to carry out emergency repairs. The gel solidifies by the action of the catalyst to a high temperature (70 - 150/sup 0/C). By locating the bottom of the tubing at the top of the production interval, the gel material will go into the permeable formation, and immediately set. When the gel has solidified, it seals off the horizon that must not be stimulated, and leaves the others exposed to the acid action. When the treatment is finished, the gel, by action of the catalyst, is liquefied and removed from the formation, being produced with the oil.

  14. Highly-correlated charges in polyelectrolyte gels

    Science.gov (United States)

    Sing, Charles; Zwanikken, Johannes; Olvera de La Cruz, Monica

    2013-03-01

    Polyelectrolyte gels are ubiquitous in polymer physics due to their attractive combination of structural and chemical features that permit the realization of ``environmentally responsive'' systems. The conventional conceptual picture of the volume response of these systems is based on a competition between osmotic and elastic effects. We elaborate on this fundamental understanding by including ion correlations through the use of liquid-state integral equation theory. This allows for a statistical mechanical representation of the state of the system that not only surpasses traditional Poisson-Boltzmann theories but also renders structural features in a highly accurate fashion. In particular, the local ion structure is elucidated, allowing for detailed articulation of charge inversion and condensation effects in the context of gel swelling. The inclusion of correlations has a number of ramifications that become apparent, with enhanced gel collapse and excluded volume competitions that give rise to novel and ion-dependent reentrant swelling effects. We expect this rigorous theory to prove instructive in understanding any number of gelated structures, such as chromosomes or designed synthetic materials for drug delivery.

  15. Ubiquitous and Seamless Localization: Fusing GNSS Pseudoranges and WLAN Signal Strengths

    Directory of Open Access Journals (Sweden)

    Philipp Richter

    2017-01-01

    Full Text Available Ubiquitous global positioning is not feasible by GNSS alone, as it lacks accurate position fixes in dense urban centres and indoors. Hybrid positioning methods have been developed to aid GNSS in those environments. Fingerprinting localization in wireless local area networks (WLANs is a promising aiding system because of its availability, accuracy, and error mechanisms opposed to that of GNSS. This article presents a low-cost approach to ubiquitous, seamless positioning based on a particle filter integrating GNSS pseudoranges and WLAN received signal strength indicators (RSSIs. To achieve accurate location estimates indoors/outdoors and in the transition zones, appropriate likelihood functions are essential as they determine the influence of each sensor information on the position estimate. We model the spatial RSSI distributions with Gaussian processes and use these models to predict RSSIs at the particle’s positions to obtain point estimates of the RSSI likelihood function. The particle filter’s performance is assessed with real data of two test trajectories in an environment challenging for GNSS and WLAN fingerprinting localization. Outcomes of an extended Kalman filter using pseudoranges and a WLAN position as observation is included as benchmark. The proposed algorithm achieves accurate and robust seamless localization with a median accuracy of five meters.

  16. Ubiquitous Learning Ecologies for a Critical Cyber-Citizenship

    Science.gov (United States)

    Díez-Gutiérrez, Enrique; Díaz-Nafría, José-María

    2018-01-01

    The aim of this research is to identify and analyse the ubiquitous learning acquired through blending education settings devoted to the "lifelong training of trainers" and how these contribute to the development of a conscious, critic and engaged citizenship. Through active exploration of the learning process, the study analyses the…

  17. Multimedia Adaptation in Ubiquitous Environments: Benefits of Structured Multimedia Documents

    NARCIS (Netherlands)

    P.S. Cesar Garcia (Pablo Santiago); I. Vaishnavi (Ishan); R. Kernchen; S. Meissner; M. Boussard; A. Spedalieri; B. Gao (Bo); D.C.A. Bulterman (Dick)

    2008-01-01

    htmlabstractThis paper demonstrates the advantages of using structured multimedia documents for session management and media distribution in ubiquitous environments. We show how document manipulations can be used to perform powerful operations such as content to context adaptation and presentation

  18. Noise and Vibration Risk Prevention Virtual Web for Ubiquitous Training

    Science.gov (United States)

    Redel-Macías, María Dolores; Cubero-Atienza, Antonio J.; Martínez-Valle, José Miguel; Pedrós-Pérez, Gerardo; del Pilar Martínez-Jiménez, María

    2015-01-01

    This paper describes a new Web portal offering experimental labs for ubiquitous training of university engineering students in work-related risk prevention. The Web-accessible computer program simulates the noise and machine vibrations met in the work environment, in a series of virtual laboratories that mimic an actual laboratory and provide the…

  19. Dynamic Service Discovery and Composition for Ubiquitous Networks Applications

    NARCIS (Netherlands)

    Bonino da Silva Santos, L.O.; van Sinderen, Marten J.; Ferreira Pires, Luis

    2006-01-01

    The realization of ubiquitous networks brings new challenges to application development. In this kind of network, services and, more specifically web services, have been used to provide the functionality required by its users and applications. In such environments features like automatic service

  20. A survey on web modeling approaches for ubiquitous web applications

    NARCIS (Netherlands)

    Schwinger, W.; Retschitzegger, W.; Schauerhuber, A.; Kappel, G.; Wimmer, M.; Pröll, B.; Cachero Castro, C.; Casteleyn, S.; De Troyer, O.; Fraternali, P.; Garrigos, I.; Garzotto, F.; Ginige, A.; Houben, G.J.P.M.; Koch, N.; Moreno, N.; Pastor, O.; Paolini, P.; Pelechano Ferragud, V.; Rossi, G.; Schwabe, D.; Tisi, M.; Vallecillo, A.; Sluijs, van der K.A.M.; Zhang, G.

    2008-01-01

    Purpose – Ubiquitous web applications (UWA) are a new type of web applications which are accessed in various contexts, i.e. through different devices, by users with various interests, at anytime from anyplace around the globe. For such full-fledged, complex software systems, a methodologically sound

  1. PERKAM: Personalized Knowledge Awareness Map for Computer Supported Ubiquitous Learning

    Science.gov (United States)

    El-Bishouty, Moushir M.; Ogata, Hiroaki; Yano, Yoneo

    2007-01-01

    This paper introduces a ubiquitous computing environment in order to support the learners while doing tasks; this environment is called PERKAM (PERsonalized Knowledge Awareness Map). PERKAM allows the learners to share knowledge, interact, collaborate, and exchange individual experiences. It utilizes the RFID ubiquities technology to detect the…

  2. Twenty-First Century Learning: Communities, Interaction and Ubiquitous Computing

    Science.gov (United States)

    Leh, Amy S.C.; Kouba, Barbara; Davis, Dirk

    2005-01-01

    Advanced technology makes 21st century learning, communities and interactions unique and leads people to an era of ubiquitous computing. The purpose of this article is to contribute to the discussion of learning in the 21st century. The paper will review literature on learning community, community learning, interaction, 21st century learning and…

  3. Ubiquitous Computing--Are We Crazy? Point/Counterpoint

    Science.gov (United States)

    DeWitt, Scott W.; Horn, Patricia S.

    2005-01-01

    The push for ubiquitous computing (UC) relies on an understandable and well-intentioned belief that teaching and schooling need to be transformed. This view appears credible based on large-scale criteria, such as test scores relative to other countries, drop-out rates, and economic changes. And the use of technology to achieve this goal is…

  4. Commentary: Ubiquitous Computing Revisited--A New Perspective

    Science.gov (United States)

    Bull, Glen; Garofalo, Joe

    2006-01-01

    In 2002, representatives from the teacher educator associations representing the core content areas (science, mathematics, language arts, and social studies) and educational technology met at the National Technology Leadership Retreat (NTLR) to discuss potential implications of ubiquitous computing for K-12 schools. This paper re-examines some of…

  5. Mobile Computing and Ubiquitous Networking: Concepts, Technologies and Challenges.

    Science.gov (United States)

    Pierre, Samuel

    2001-01-01

    Analyzes concepts, technologies and challenges related to mobile computing and networking. Defines basic concepts of cellular systems. Describes the evolution of wireless technologies that constitute the foundations of mobile computing and ubiquitous networking. Presents characterization and issues of mobile computing. Analyzes economical and…

  6. Awareness for Contextualized Digital Contents in Ubiquitous Learning Environments

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2010-01-01

    Börner, D., & Specht, M. (2009). Awareness for Contextualized Digital Contents in Ubiquitous Learning Environments. Proceedings of the Doctoral Consortium of the Fourth European Conference on Technology Enhanced Learning (EC-TEL 2009). September, 29-October, 2, 2009, Nice, France. [unpublished

  7. Privacy context model for dynamic privacy adaptation in ubiquitous computing

    NARCIS (Netherlands)

    Schaub, Florian; Koenings, Bastian; Dietzel, Stefan; Weber, M.; Kargl, Frank

    Ubiquitous computing is characterized by the merger of physical and virtual worlds as physical artifacts gain digital sensing, processing, and communication capabilities. Maintaining an appropriate level of privacy in the face of such complex and often highly dynamic systems is challenging. We argue

  8. Influence of Uranium and Polivinyl Alcohol Concentration in the Feed of Sol Gel Process on the Gel Spherical Product

    International Nuclear Information System (INIS)

    Indra Suryawan; Endang Susiantini

    2007-01-01

    The gel particles have been made at various uranium and polyvinyl alcohol concentration in the sol gel process. The variables of uranium concentration were 0.3; 0.5; 0.7; 0.9; 1.1; 1.3; 1.5; 1.7; 1.9 and 2.1 M The variables of polyvinyl alcohol concentration were 0.3; 0.6; 0.9; 1.2; 1.5; 1.8; 2.1 and 2.4 M After drying the sol gel process products were heated at 300, 500 and 750°C during 4 hours. The gel particles were characterized using an optic microscope to know the shape and condition morphology of gel. From experimental result using uranium concentration of 0.3 until 2.1 M and polyvinyl alcohol of 1.8 until 2.4 M spherical and gel was formed elastic, after heating at 750°C it was unbreakable. At the concentration of polyvinyl alcohol from 0.3 to 0.5 M, the gel product was soft and broken after being dried. At the concentration of polyvinyl alcohol from 0.6 to 0.8 M, the dried gel product was not perfect. At the concentration of polyvinyl alcohol from 0.9 to 1.7 M, the gel product of gelation process was spherical and it was broken after being heated up to 300°C. (author)

  9. An improved anonymous authentication scheme for roaming in ubiquitous networks

    Science.gov (United States)

    Lee, Hakjun; Lee, Donghoon; Moon, Jongho; Jung, Jaewook; Kang, Dongwoo; Kim, Hyoungshick

    2018-01-01

    With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people’s lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost. In 2017, Chaudhry et al. proposed a password-based authentication scheme for the roaming in ubiquitous networks to enhance the security. Unfortunately, we found that their scheme remains insecure in its protection of the user privacy. In this paper, we prove that Chaudhry et al.’s scheme is vulnerable to the stolen-mobile device and user impersonation attacks, and its drawbacks comprise the absence of the incorrect login-input detection, the incorrectness of the password change phase, and the absence of the revocation provision. Moreover, we suggest a possible way to fix the security flaw in Chaudhry et al’s scheme by using the biometric-based authentication for which the bio-hash is applied in the implementation of a three-factor authentication. We prove the security of the proposed scheme with the random oracle model and formally verify its security properties using a tool named ProVerif, and analyze it in terms of the computational and communication cost. The analysis result shows that the proposed scheme is suitable for resource-constrained ubiquitous environments. PMID:29505575

  10. Normal modes of weak colloidal gels

    Science.gov (United States)

    Varga, Zsigmond; Swan, James W.

    2018-01-01

    The normal modes and relaxation rates of weak colloidal gels are investigated in calculations using different models of the hydrodynamic interactions between suspended particles. The relaxation spectrum is computed for freely draining, Rotne-Prager-Yamakawa, and accelerated Stokesian dynamics approximations of the hydrodynamic mobility in a normal mode analysis of a harmonic network representing several colloidal gels. We find that the density of states and spatial structure of the normal modes are fundamentally altered by long-ranged hydrodynamic coupling among the particles. Short-ranged coupling due to hydrodynamic lubrication affects only the relaxation rates of short-wavelength modes. Hydrodynamic models accounting for long-ranged coupling exhibit a microscopic relaxation rate for each normal mode, λ that scales as l-2, where l is the spatial correlation length of the normal mode. For the freely draining approximation, which neglects long-ranged coupling, the microscopic relaxation rate scales as l-γ, where γ varies between three and two with increasing particle volume fraction. A simple phenomenological model of the internal elastic response to normal mode fluctuations is developed, which shows that long-ranged hydrodynamic interactions play a central role in the viscoelasticity of the gel network. Dynamic simulations of hard spheres that gel in response to short-ranged depletion attractions are used to test the applicability of the density of states predictions. For particle concentrations up to 30% by volume, the power law decay of the relaxation modulus in simulations accounting for long-ranged hydrodynamic interactions agrees with predictions generated by the density of states of the corresponding harmonic networks as well as experimental measurements. For higher volume fractions, excluded volume interactions dominate the stress response, and the prediction from the harmonic network density of states fails. Analogous to the Zimm model in polymer

  11. Synthesis of organic/inorganic hybrid gel with acid activated clay after γ-ray radiation.

    Science.gov (United States)

    Kim, Donghyun; Lee, Hoik; Sohn, Daewon

    2014-08-01

    A hybrid gel was prepared from acid activated clay (AA clay) and acrylic acid by gamma ray irradiation. Irradiated inorganic particles which have peroxide groups act as initiator because it generates oxide radicals by increasing temperature. Inorganic nanoparticles which are rigid part in hybrid gel also contribute to increase the mechanical property as a crosslinker. We prepared two hybrid gels to compare the effect of acid activated treatment of clay; one is synthesized with raw clay particles and another is synthesized with AA clay particles. The composition and structure of AA clay particles and raw clay particles were confirmed by X-ray diffraction (XRD), X-ray fluorescence instrument and surface area analyzer. And chemical and physical property of hybrid gel with different ratios of acrylic acid and clay particle was tested by Raman spectroscope and universal testing machine (UTM). The synthesized hydrogel with 76% gel contents can elongated approximately 1000% of its original size.

  12. Sol-gel synthesis of hydroxyapatite

    International Nuclear Information System (INIS)

    Zupanski, M.D.; Lucena, M.P.P.; Bergmann, C.P.

    2010-01-01

    Hydroxyapatite (HAp) has been established as the calcium phosphate based compound with most applications in the biological field. Among the numerous techniques for synthesis of HAp, the sol-gel processing route affords great control over purity and formed phases using low processing temperatures. In addition, the sol-gel approach offers an option for homogeneous HAp coating on metal substrates, as well as the ability to generate nanocrystalline powders. In this work, the sol-gel synthesis of HAp was investigated employing triethyl phosphate and calcium nitrate tetrahydrate as phosphorous and calcium precursors, respectively. The aging effect on phase composition and powder morphology of the final product was studied in terms of temperature and aging time. The powders were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, particle size distribution by laser diffraction and scanning electron microscopy. (author)

  13. Towards ubiquitous access of computer-assisted surgery systems.

    Science.gov (United States)

    Liu, Hui; Lufei, Hanping; Shi, Weishong; Chaudhary, Vipin

    2006-01-01

    Traditional stand-alone computer-assisted surgery (CAS) systems impede the ubiquitous and simultaneous access by multiple users. With advances in computing and networking technologies, ubiquitous access to CAS systems becomes possible and promising. Based on our preliminary work, CASMIL, a stand-alone CAS server developed at Wayne State University, we propose a novel mobile CAS system, UbiCAS, which allows surgeons to retrieve, review and interpret multimodal medical images, and to perform some critical neurosurgical procedures on heterogeneous devices from anywhere at anytime. Furthermore, various optimization techniques, including caching, prefetching, pseudo-streaming-model, and compression, are used to guarantee the QoS of the UbiCAS system. UbiCAS enables doctors at remote locations to actively participate remote surgeries, share patient information in real time before, during, and after the surgery.

  14. Design requirements for ubiquitous computing environments for healthcare professionals.

    Science.gov (United States)

    Bång, Magnus; Larsson, Anders; Eriksson, Henrik

    2004-01-01

    Ubiquitous computing environments can support clinical administrative routines in new ways. The aim of such computing approaches is to enhance routine physical work, thus it is important to identify specific design requirements. We studied healthcare professionals in an emergency room and developed the computer-augmented environment NOSTOS to support teamwork in that setting. NOSTOS uses digital pens and paper-based media as the primary input interface for data capture and as a means of controlling the system. NOSTOS also includes a digital desk, walk-up displays, and sensor technology that allow the system to track documents and activities in the workplace. We propose a set of requirements and discuss the value of tangible user interfaces for healthcare personnel. Our results suggest that the key requirements are flexibility in terms of system usage and seamless integration between digital and physical components. We also discuss how ubiquitous computing approaches like NOSTOS can be beneficial in the medical workplace.

  15. Network architecture test-beds as platforms for ubiquitous computing.

    Science.gov (United States)

    Roscoe, Timothy

    2008-10-28

    Distributed systems research, and in particular ubiquitous computing, has traditionally assumed the Internet as a basic underlying communications substrate. Recently, however, the networking research community has come to question the fundamental design or 'architecture' of the Internet. This has been led by two observations: first, that the Internet as it stands is now almost impossible to evolve to support new functionality; and second, that modern applications of all kinds now use the Internet rather differently, and frequently implement their own 'overlay' networks above it to work around its perceived deficiencies. In this paper, I discuss recent academic projects to allow disruptive change to the Internet architecture, and also outline a radically different view of networking for ubiquitous computing that such proposals might facilitate.

  16. Polymer gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Baldock, C [Institute of Medical Physics, School of Physics, University of Sydney (Australia); De Deene, Y [Radiotherapy and Nuclear Medicine, Ghent University Hospital (Belgium); Doran, S [CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Surrey (United Kingdom); Ibbott, G [Radiation Physics, UT M D Anderson Cancer Center, Houston, TX (United States); Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria, BC (Canada); Lepage, M [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et de radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); McAuley, K B [Department of Chemical Engineering, Queen' s University, Kingston, ON (Canada); Oldham, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Schreiner, L J [Cancer Centre of South Eastern Ontario, Kingston, ON (Canada)], E-mail: c.baldock@physics.usyd.edu.au, E-mail: yves.dedeene@ugent.be

    2010-03-07

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. (topical review)

  17. A Client-Server System for Ubiquitous Video Service

    Directory of Open Access Journals (Sweden)

    Ronit Nossenson

    2012-12-01

    Full Text Available In this work we introduce a simple client-server system architecture and algorithms for ubiquitous live video and VOD service support. The main features of the system are: efficient usage of network resources, emphasis on user personalization, and ease of implementation. The system supports many continuous service requirements such as QoS provision, user mobility between networks and between different communication devices, and simultaneous usage of a device by a number of users.

  18. I WHATSAPP AN IGUANA: AN ATTEMPT TO APPLY UBIQUITOUS LEARNING

    OpenAIRE

    Dwi Haryanti

    2017-01-01

    This paper aims at presenting how Whatsapp provides alternative method to enhance writing skills on personal letter for senior high school student. This method Whatsapps inspired by the concept called ubiquitous learning (U-Learning), which means ―learning supported by ICT resources held anytime, anywhere and fits the context of the learner‖ (de Sousa Monteiro et al., 2014). Participants were 40 11-th grade students in one class in Cirebon High School. A short story in the form of personal le...

  19. Application of ubiquitous computing in personal health monitoring systems.

    Science.gov (United States)

    Kunze, C; Grossmann, U; Stork, W; Müller-Glaser, K D

    2002-01-01

    A possibility to significantly reduce the costs of public health systems is to increasingly use information technology. The Laboratory for Information Processing Technology (ITIV) at the University of Karlsruhe is developing a personal health monitoring system, which should improve health care and at the same time reduce costs by combining micro-technological smart sensors with personalized, mobile computing systems. In this paper we present how ubiquitous computing theory can be applied in the health-care domain.

  20. Development of Wearable Systems for Ubiquitous Healthcare Service Provisioning

    OpenAIRE

    Ogunduyile, O.O.; Olugbara, O.O.; Lall, M.

    2013-01-01

    This paper reports on the development of a wearable system using wireless biomedical sensors for ubiquitous healthcare service provisioning. The prototype system is developed to address current healthcare challenges such as increasing cost of services, inability to access diverse services, low quality services and increasing population of elderly as experienced globally. The biomedical sensors proactively collect physiological data of remote patients to recommend diagnostic services. The prot...

  1. Alexithymia in anorexia and bulimia: Ubiquitous and primary trait?

    Directory of Open Access Journals (Sweden)

    F. Amianto

    2016-05-01

    Full Text Available Background: Alexithymia is associated to Eating Disorders (ED and relevant for their prognosis but it is uncertain if it is ubiquitous, primary and necessary for ED outburst. Methods: 124 ED outpatients and 80 healthy controls were compared with the Toronto Alexithymia Scale, personality and psychopathology measures. Alexithymia and the other features are compared between anorexia nervosa (AN, bulimia nervosa (BN and control groups. Alexithymia-based clusters were explored and compared with controls. Alexithymia traits are correlated with the other features. Results: Difficulty in identifying feelings was ubiquitous in ED subjects. A Non-Alexithymic Cluster (NAC and an Alexithymic Cluster (ALC were found with no difference in AN/BN distribution. ALC displays disordered personality and high psychopathology. Self-directiveness and interoceptive awareness were independently related to alexithymia and to depressive feelings. These two features along with depressive features completely accounted for alexithymia variance. Conclusion: even though the difficulty in identifying feelings is ubiquitous in ED subjects, Alexithymia may not represent a primary trait but a complex dysfunction consequent to co-occurring character immaturity, altered interoceptive awareness, and depressive traits.

  2. Ubiquitous mobile knowledge construction in collaborative learning environments.

    Science.gov (United States)

    Baloian, Nelson; Zurita, Gustavo

    2012-01-01

    Knowledge management is a critical activity for any organization. It has been said to be a differentiating factor and an important source of competitiveness if this knowledge is constructed and shared among its members, thus creating a learning organization. Knowledge construction is critical for any collaborative organizational learning environment. Nowadays workers must perform knowledge creation tasks while in motion, not just in static physical locations; therefore it is also required that knowledge construction activities be performed in ubiquitous scenarios, and supported by mobile and pervasive computational systems. These knowledge creation systems should help people in or outside organizations convert their tacit knowledge into explicit knowledge, thus supporting the knowledge construction process. Therefore in our understanding, we consider highly relevant that undergraduate university students learn about the knowledge construction process supported by mobile and ubiquitous computing. This has been a little explored issue in this field. This paper presents the design, implementation, and an evaluation of a system called MCKC for Mobile Collaborative Knowledge Construction, supporting collaborative face-to-face tacit knowledge construction and sharing in ubiquitous scenarios. The MCKC system can be used by undergraduate students to learn how to construct knowledge, allowing them anytime and anywhere to create, make explicit and share their knowledge with their co-learners, using visual metaphors, gestures and sketches to implement the human-computer interface of mobile devices (PDAs).

  3. Microfluidics of soft granular gels

    Science.gov (United States)

    Nixon, Ryan; Bhattacharjee, Tapomoy; Sawyer, W. Gregory; Angelini, Thomas E.

    Microfluidic methods for encapsulating cells and particles typically involve drop making with two immiscible fluids. The main materials constraint in this approach is surface tension, creating inherent instability between the two fluids. We can eliminate this instability by using miscible inner and outer phases. This is achieved by using granular micro gels which are chemically miscible but physically do not mix. These microgels are yield stress materials, so they flow as solid plugs far from shear gradients, and fluidize where gradients are generated - near an injection nozzle for example. We have found that tuning the yield stress of the material by varying polymer concentration, device performance can be controlled. The solid like behavior of the gel allows us to produces infinitely stable jets that maintain their integrity and configuration over long distances and times. These properties can be combined and manipulated to produce discrete particulate bunches of an inner phase, flowing inside of an outer phase, well enough even to print a Morse code message suspended within flow chambers about a millimeter in diameter moving at millimeters a second.

  4. The Influence of Microgravity on Silica Sol-Gel Formation

    Science.gov (United States)

    Sibille, L.; Smith, D. D.; Cronise, R.; Hunt, A. J.; Wolfe, D. B.; Snow, L. A.; Oldenberg, S.; Halas, N.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    We discuss space-flight experiments involving the growth of silica particles and gels. The effect of microgravity on the growth of silica particles via the sol-gel route is profound. In four different recipes spanning a large range of the parameter space that typically produces silica nanoparticles in unit-gravity, low-density gel structures were instead formed in microgravity. The particles that did form were generally smaller and more polydisperse than those grown on the ground. These observations suggest that microgravity reduces the particle growth rate, allowing unincorporated species to form aggregates and ultimately gel. Hence microgravity favors the formation of more rarefied structures, providing a bias towards diffusion-limited cluster-cluster aggregation. These results further suggest that in unit gravity, fluid flows and sedimentation can significantly perturb sol-gel substructures prior to gelation and these deleterious perturbations may be "frozen" into the resulting microstructure. Hence, sol-gel pores may be expected to be smaller, more uniform, and less rough when formed in microgravity.

  5. Densification and crystallization behaviour of colloidal cordierite-type gels

    Directory of Open Access Journals (Sweden)

    LJILJANA KOSTIC-GVOZDENOVIC

    2001-05-01

    Full Text Available Three cordierite-type gels were prepared from an aqueous solution of Mg(NO32, a boehmite sol and silica sols of very small particle sizes. The effect of varying the silica particle size on the crystallization and densification behaviour was studied. Phase development was examined by thermal analysis and X-ray diffraction, while the densification behaviour was characterized by measuring the linear shrinkage of pellets. The activation energy of densification by viscous flow was determined using the Franckel model for non-isothermal conditions and a constant heating rate. The results show that spinel crystallizes from the colloidal gels prior to cristobalite, and their reaction gives a-cordierite, which is specific for three-phase gels. Decreasing the silica particles size lowers the cristobalite crystallization temperature and the a-cordierite formation temperature. The activation energy of densification by viscous flow is lower and the densification more efficient, the smaller the silica particles are.

  6. Design of Autonomous Gel Actuators

    Directory of Open Access Journals (Sweden)

    Shuji Hashimoto

    2011-01-01

    Full Text Available In this paper, we introduce autonomous gel actuators driven by chemical energy. The polymer gels prepared here have cyclic chemical reaction networks. With a cyclic reaction, the polymer gels generate periodical motion. The periodic motion of the gel is produced by the chemical energy of the oscillatory Belouzov-Zhabotinsky (BZ reaction. We have succeeded in making synthetic polymer gel move autonomously like a living organism. This experimental fact represents the great possibility of the chemical robot.

  7. Review of Fricke gel dosimeters

    International Nuclear Information System (INIS)

    Schreiner, L J

    2004-01-01

    The innovation of adding a gel matrix to the traditional Fricke dosimeter to stabilize geometric information established the field of gel dosimetry for radiation therapy. A discussion of Fricke gels provides an overview of the issues that determine the dose response of all gel dosimeters in general. In this paper we review some of the features of Fricke systems to illustrate these issues and, in addition, to motivate renewed clinical interest in Fricke gels

  8. Aging and nonlinear rheology of thermoreversible colloidal gels

    Science.gov (United States)

    Wagner, Norman; Gordon, Melissa; Kloxin, Christopher

    Colloidal dispersions are found in a wide variety of consumer products such as paint, food and pharmaceuticals. We investigate gel formation and aging in a thermoreverible gel consisting of octadecyl-coated silica nanoparticles suspended in n-tetradecane. In this system, the octadecyl brush can undergo a phase change allowing the attractions between particles to be tuned by temperature (1,2). By probing the system with steady shear and large amplitude oscillatory shear, we have studied the effect of thermal history and shear history on gel formation and gel mechanical properties during aging. Gels were formed by approaching a common temperature from above and below to determine a reference state from which creep tests were conducted. Creep ringing was observed as expected for the viscoelastic gel. The rheological aging is interpreted in terms of the gel microstructure formed with differing thermal and shear histories to determine how processing affects structure. Recently proposed scaling laws for the rheology and structure under flow are explored within the context of gel aging (3). Through rheological and microstructural measurements, we will further the understanding of gel formation and aging in this model system which may be applied to processing conditions in an industrial setting.

  9. 3D MR gel dosimetry with lung equivalent gel

    International Nuclear Information System (INIS)

    Scherer, J.; Solleder, M.; Schiessl, I.; Bogner, L.; Herbst, M.

    1998-01-01

    The MR gel dosimetry is used to verify complex 3D treatment plans. Till now this method served only for dose evaluation in homogeneous phantoms. On the way to build a heterogeneous anthropomorphic gel phantom, a lung equivalent gel with the density 0.4 g/cm 3 was developed. First experiments show a 1.55 times higher dose reponse in the low density gel (LD gel). The comparison of a dose distribution in a gel/LD gel/gel slab phantom with Monte Carlo calculations shows good agreement within 5%. More over the accuray of the measuring device magnetic resonance imager was studied in respect to the now exclusive digital image processing with the software MRD (MR dosimetry). Because of the dimensions of the Fricke gel phantom an artefact correction, based on the data from the unirradiated phantom proved to be essential. (orig.) [de

  10. Structure of mineral gels

    International Nuclear Information System (INIS)

    Miranda Salvado, I.M.; Margaca, F.M.A.; Teixeira, J.

    1999-01-01

    Small Angle Neutron Scattering (SANS) measurements have been performed to investigate the nanoscale structure of materials of the systems xTiO 2 -(1-x)SiO 2 and xZrO 2 -(1-x)SiO 2 with x ≤ 10 mol % at different processing stages. The materials were prepared by sol-gel using the alkoxides method, in strong acidic conditions. Samples were studied as xerogels heat-treated at 120 and 850 deg. C and as wet gels at gel point and after aging. All samples showed identical microstructure at gel point, extended linear chains ∼10 nm long. The aged gel has a mass fractal structure with fractal dimension of 1.7 - 1.9. The 120 deg. C heat-treated xerogels show homogeneous oxide regions with mass fractal structure. For the 850 deg. C heat-treated xerogel the oxide regions average size has reduced and it has densified as compared to 120 deg. C heat-treated sample. (author)

  11. Effect of temperature on internal structure of uranyl gels

    International Nuclear Information System (INIS)

    Landspersky, H.; Urbanek, V.

    1983-01-01

    Tempering freshly prepared uranyl gel serves the homogenization of the volume of the individual spheres and the whole volume of the processed material. Tempering is carried out at a temperature of 90 degC in a special countercurrent through-flow column. The tempered gel particles were analyzed for specific surface and porosity using different methods, subjected to phase analysis, and the crystallite mean size was determined. It was found that the quality of the final gel depends on the residence time in the tempering column. Gel recrystallization probably takes place during tempering leading to stress and cracks which in the final stage lead to the disintegration of the xerogel. Maximum permissible gel residence time in the tempering column is 15 mins. (M.D.)

  12. Magneto-dependent stress relaxation of magnetorheological gels

    KAUST Repository

    Xu, Yangguang; Liu, Taixiang; Liao, G J; Lubineau, Gilles

    2017-01-01

    The stress relaxation behaviors of magnetorheological (MR) gels under stepwise shear loading are systematically investigated. The particle-enhanced effect, the magneto-induced effect, and the temperature-enhanced effect on the stress relaxation of MR gels are discussed. For further analysis of the magneto-induced stress relaxation mechanism in MR gels, a phenomenological model is established to describe the stress relaxation behavior of the matrix and the magnetic particle chains. All characteristic parameters introduced in the model, i.e. relaxation time, instantaneous modulus, and stable modulus, have well-defined physical meanings and are fitted based on the experimental results. The influence of each parameter on the macroscopic response is discussed and it is found that the relaxation stress induced by the magneto-mechanical coupling effect plays an important role in the stress relaxation process of MR gels.

  13. Magneto-dependent stress relaxation of magnetorheological gels

    KAUST Repository

    Xu, Yangguang

    2017-09-01

    The stress relaxation behaviors of magnetorheological (MR) gels under stepwise shear loading are systematically investigated. The particle-enhanced effect, the magneto-induced effect, and the temperature-enhanced effect on the stress relaxation of MR gels are discussed. For further analysis of the magneto-induced stress relaxation mechanism in MR gels, a phenomenological model is established to describe the stress relaxation behavior of the matrix and the magnetic particle chains. All characteristic parameters introduced in the model, i.e. relaxation time, instantaneous modulus, and stable modulus, have well-defined physical meanings and are fitted based on the experimental results. The influence of each parameter on the macroscopic response is discussed and it is found that the relaxation stress induced by the magneto-mechanical coupling effect plays an important role in the stress relaxation process of MR gels.

  14. Gel electrolytes and electrodes

    Science.gov (United States)

    Fleischmann, Sven; Bunte, Christine; Mikhaylik, Yuriy V.; Viner, Veronika G.

    2017-09-05

    Gel electrolytes, especially gel electrolytes for electrochemical cells, are generally described. In some embodiments, the gel electrolyte layers comprise components a) to c). Component a) may be at least one layer of at least one polymer comprising polymerized units of: a1) at least one monomer containing an ethylenically unsaturated unit and an amido group and a2) at least one crosslinker. Component b) may be at least one conducting salt and component c) may be at least one solvent. Electrodes may comprise the components a), d) and e), wherein component a) may be at least one layer of at least one polymer as described herein. Component d) may be at least one electroactive layer and component e) may be at least one ceramic layer. Furthermore, electrochemical cells comprising component a) which may be at least one layer of at least one polymer as described herein, are also provided.

  15. Electroblotting from Polyacrylamide Gels.

    Science.gov (United States)

    Goldman, Aaron; Ursitti, Jeanine A; Mozdzanowski, Jacek; Speicher, David W

    2015-11-02

    Transferring proteins from polyacrylamide gels onto retentive membranes is now primarily used for immunoblotting. A second application that was quite common up to about a decade ago was electroblotting of proteins for N-terminal and internal sequencing using Edman chemistry. This unit contains procedures for electroblotting proteins from polyacrylamide gels onto a variety of membranes, including polyvinylidene difluoride (PVDF) and nitrocellulose. In addition to the commonly used tank or wet transfer system, protocols are provided for electroblotting using semidry and dry systems. This unit also describes procedures for eluting proteins from membranes using detergents or acidic extraction with organic solvents for specialized applications. Copyright © 2015 John Wiley & Sons, Inc.

  16. Some guidelines for the ethical development of ubiquitous computing.

    Science.gov (United States)

    Greenfield, Adam

    2008-10-28

    At a time when both the landscape of everyday life and the choices available to us there are increasingly conditioned by ubiquitous information processing systems, it seems wise to articulate some general principles guiding their ethical design and deployment. I here enunciate five broad guidelines for the designers of such systems, including recommendations that they be devised in such a way as to default to harmlessness, be conservative of time, be conservative of face, be self-disclosing and be deniable. I conclude with some observations about the likelihood of any such principles winning usefully widespread voluntary adherence.

  17. Observations on sustainable and ubiquitous healthcare informatics from Florence Nightingale.

    Science.gov (United States)

    Betts, Helen J; Wright, Graham

    2009-01-01

    As nurses around the world prepare to celebrate the centenary of the death of Florence Nightingale in 2010 this paper reviews her work on using information, especially statistics, to analyze and manage patient care and links that to current developments in informatics. It then examines assistive technologies and how they may impact on nursing practice in the future and links these developments to the writings of Florence Nightingale. The paper concludes by suggesting that in progressing towards sustainable and ubiquitous healthcare informatics we need to study history in order to learn from the lessons of Florence Nightingale and other healthcare pioneers.

  18. Etodolac Containing Topical Niosomal Gel: Formulation Development and Evaluation

    Directory of Open Access Journals (Sweden)

    Gyati Shilakari Asthana

    2016-01-01

    Full Text Available The present study aimed to investigate the delivery potential of Etodolac (ETD containing topical niosomal gel. Niosomal formulations were prepared by thin film hydration method at various ratios of cholesterol and Span 60 and were evaluated with respect to particle size, shape, entrapment efficiency, and in vitro characteristics. Dicetyl phosphate (DCP was also added in the niosomal formulation. Mean particle size of niosomal formulation was found to be in the range of 2 μm to 4 μm. Niosomal formulation N2 (1 : 1 ratio of cholesterol and surfactant displayed good entrapment efficiency (96.72%. TEM analyses showed that niosomal formulation was spherical in shape. Niosomal formulation (N2 displayed high percentage of drug release after 24 h (94.91 at (1 : 1 ratio of cholesterol : surfactant. Further selected niosomal formulation was used to formulate topical gel and was characterized with respect to its various parameters such as pH, viscosity, spreadability, ex vivo study, and in vivo potential permeation. Ex vivo study showed that niosomal gel possessed better skin permeation study than the plain topical gel. Further in vivo study revealed good inhibition of inflammation in case of topical niosomal gel than plain gel and niosomal formulation. The present study suggested that topical niosomal gel formulations provide sustained and prolonged delivery of drug.

  19. A proposal of an open ubiquitous fuzzy computing system for Ambient Intelligence

    NARCIS (Netherlands)

    Acampora, G.; Loia, V.; Lee, R.S.T.; Lioa, V.

    2007-01-01

    Ambient Intelligence (AmI) is considered as the composition of three emergent technologies: Ubiquitous Computing, Ubiquitous Communication and Intelligent User Interfaces. The aim of integration of aforesaid technologies is to make wider the interaction between human beings and information

  20. Datenschutz- und Medizinprodukterecht bei Ubiquitous Computing-Anwendungen im Gesundheitssektor / Data protection and medical product law with respect to medical ubiquitous computing applications

    Directory of Open Access Journals (Sweden)

    Skistims, Hendrik

    2011-01-01

    Full Text Available With respect to ubiquitous computing there is a great potential of application, particularly in medicine and health care. This work deals with the legal problems which ubiquitous computing is facing in these areas. At the beginning, issues with respect to data protection and professional secrecy are treated. Afterwards the problem of applicability of medical product law for medical ubiquitous computing applications as well as the resulting requirements for manufactures, operators and users will be discussed.

  1. CyberPsychological Computation on Social Community of Ubiquitous Learning

    Science.gov (United States)

    Zhou, Xuan; Dai, Genghui; Huang, Shuang; Sun, Xuemin; Hu, Feng; Hu, Hongzhi; Ivanović, Mirjana

    2015-01-01

    Under the modern network environment, ubiquitous learning has been a popular way for people to study knowledge, exchange ideas, and share skills in the cyberspace. Existing research findings indicate that the learners' initiative and community cohesion play vital roles in the social communities of ubiquitous learning, and therefore how to stimulate the learners' interest and participation willingness so as to improve their enjoyable experiences in the learning process should be the primary consideration on this issue. This paper aims to explore an effective method to monitor the learners' psychological reactions based on their behavioral features in cyberspace and therefore provide useful references for adjusting the strategies in the learning process. In doing so, this paper firstly analyzes the psychological assessment of the learners' situations as well as their typical behavioral patterns and then discusses the relationship between the learners' psychological reactions and their observable features in cyberspace. Finally, this paper puts forward a CyberPsychological computation method to estimate the learners' psychological states online. Considering the diversity of learners' habitual behaviors in the reactions to their psychological changes, a BP-GA neural network is proposed for the computation based on their personalized behavioral patterns. PMID:26557846

  2. Distributed user interfaces for clinical ubiquitous computing applications.

    Science.gov (United States)

    Bång, Magnus; Larsson, Anders; Berglund, Erik; Eriksson, Henrik

    2005-08-01

    Ubiquitous computing with multiple interaction devices requires new interface models that support user-specific modifications to applications and facilitate the fast development of active workspaces. We have developed NOSTOS, a computer-augmented work environment for clinical personnel to explore new user interface paradigms for ubiquitous computing. NOSTOS uses several devices such as digital pens, an active desk, and walk-up displays that allow the system to track documents and activities in the workplace. We present the distributed user interface (DUI) model that allows standalone applications to distribute their user interface components to several devices dynamically at run-time. This mechanism permit clinicians to develop their own user interfaces and forms to clinical information systems to match their specific needs. We discuss the underlying technical concepts of DUIs and show how service discovery, component distribution, events and layout management are dealt with in the NOSTOS system. Our results suggest that DUIs--and similar network-based user interfaces--will be a prerequisite of future mobile user interfaces and essential to develop clinical multi-device environments.

  3. Non-Orthogonal Multiple Access for Ubiquitous Wireless Sensor Networks.

    Science.gov (United States)

    Anwar, Asim; Seet, Boon-Chong; Ding, Zhiguo

    2018-02-08

    Ubiquitous wireless sensor networks (UWSNs) have become a critical technology for enabling smart cities and other ubiquitous monitoring applications. Their deployment, however, can be seriously hampered by the spectrum available to the sheer number of sensors for communication. To support the communication needs of UWSNs without requiring more spectrum resources, the power-domain non-orthogonal multiple access (NOMA) technique originally proposed for 5th Generation (5G) cellular networks is investigated for UWSNs for the first time in this paper. However, unlike 5G networks that operate in the licensed spectrum, UWSNs mostly operate in unlicensed spectrum where sensors also experience cross-technology interferences from other devices sharing the same spectrum. In this paper, we model the interferences from various sources at the sensors using stochastic geometry framework. To evaluate the performance, we derive a theorem and present new closed form expression for the outage probability of the sensors in a downlink scenario under interference limited environment. In addition, diversity analysis for the ordered NOMA users is performed. Based on the derived outage probability, we evaluate the average link throughput and energy consumption efficiency of NOMA against conventional orthogonal multiple access (OMA) technique in UWSNs. Further, the required computational complexity for the NOMA users is presented.

  4. Toward ubiquitous healthcare services with a novel efficient cloud platform.

    Science.gov (United States)

    He, Chenguang; Fan, Xiaomao; Li, Ye

    2013-01-01

    Ubiquitous healthcare services are becoming more and more popular, especially under the urgent demand of the global aging issue. Cloud computing owns the pervasive and on-demand service-oriented natures, which can fit the characteristics of healthcare services very well. However, the abilities in dealing with multimodal, heterogeneous, and nonstationary physiological signals to provide persistent personalized services, meanwhile keeping high concurrent online analysis for public, are challenges to the general cloud. In this paper, we proposed a private cloud platform architecture which includes six layers according to the specific requirements. This platform utilizes message queue as a cloud engine, and each layer thereby achieves relative independence by this loosely coupled means of communications with publish/subscribe mechanism. Furthermore, a plug-in algorithm framework is also presented, and massive semistructure or unstructured medical data are accessed adaptively by this cloud architecture. As the testing results showing, this proposed cloud platform, with robust, stable, and efficient features, can satisfy high concurrent requests from ubiquitous healthcare services.

  5. Ubiquitous Supervisory System Based on Social Contexts Using Ontology

    Directory of Open Access Journals (Sweden)

    Satoru Izumi

    2009-01-01

    Full Text Available As described in this paper, we propose a supervisory system that considers actual situations and social aspects of users in a ubiquitous computing environment. To realize gentle and safe supervision while providing efficient supervisory services, the system must recognize the situations of a watched person, such as the person's physical condition. To achieve this, we have proposed a ubiquitous supervisory system "uEyes", which introduces Social Context Awareness: a distinguishing feature for supervision. Using this feature, the system can combine environmental information acquired from sensors in the real world and common-sense knowledge related to human activities in daily life. As described in this paper, we specifically examine design of Social Context Awareness using ontology technologies. Based on this advanced feature, a live video streaming system is configured autonomously depending on the users' circumstances in runtime. We implemented a uEyes prototype for supervising elderly people and performed some experiments based on several scenarios. Based on those experimental results, we confirmed that the social contexts are handled effectively to support the supervision.

  6. gel template method

    Indian Academy of Sciences (India)

    TiO2 nanotubes have been synthesized by sol–gel template method using alumina membrane. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, UV absorption spectrum and X-ray diffraction techniques have been used to investigate the structure, morphology and optical ...

  7. After Installation: Ubiquitous Computing and High School Science in Three Experienced, High-Technology Schools

    Science.gov (United States)

    Drayton, Brian; Falk, Joni K.; Stroud, Rena; Hobbs, Kathryn; Hammerman, James

    2010-01-01

    There are few studies of the impact of ubiquitous computing on high school science, and the majority of studies of ubiquitous computing report only on the early stages of implementation. The present study presents data on 3 high schools with carefully elaborated ubiquitous computing systems that have gone through at least one "obsolescence cycle"…

  8. Sol-gel synthesis of hydroxyapatite; Sintese de hidroxiapatita via sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Zupanski, M.D.; Lucena, M.P.P.; Bergmann, C.P., E-mail: michelledunin@yahoo.com.b [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2010-07-01

    Hydroxyapatite (HAp) has been established as the calcium phosphate based compound with most applications in the biological field. Among the numerous techniques for synthesis of HAp, the sol-gel processing route affords great control over purity and formed phases using low processing temperatures. In addition, the sol-gel approach offers an option for homogeneous HAp coating on metal substrates, as well as the ability to generate nanocrystalline powders. In this work, the sol-gel synthesis of HAp was investigated employing triethyl phosphate and calcium nitrate tetrahydrate as phosphorous and calcium precursors, respectively. The aging effect on phase composition and powder morphology of the final product was studied in terms of temperature and aging time. The powders were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, particle size distribution by laser diffraction and scanning electron microscopy. (author)

  9. Transdermal delivery of paeonol using cubic gel and microemulsion gel

    Science.gov (United States)

    Luo, Maofu; Shen, Qi; Chen, Jinjin

    2011-01-01

    Background The aim of this study was to develop new systems for transdermal delivery of paeonol, in particular microemulsion gel and cubic gel formulations. Methods Various microemulsion vehicles were prepared using isopropyl myristate as an oil phase, polyoxyethylated castor oil (Cremophor® EL) as a surfactant, and polyethylene glycol 400 as a cosurfactant. In the optimum microemulsion gel formulation, carbomer 940 was selected as the gel matrix, and consisted of 1% paeonol, 4% isopropyl myristate, 28% Cremophor EL/polyethylene glycol 400 (1:1), and 67% water. The cubic gel was prepared containing 3% paeonol, 30% water, and 67% glyceryl monooleate. Results A skin permeability test using excised rat skins indicated that both the cubic gel and microemulsion gel formulations had higher permeability than did the paeonol solution. An in vivo pharmacokinetic study done in rats showed that the relative bioavailability of the cubic gel and microemulsion gel was enhanced by about 1.51-fold and 1.28-fold, respectively, compared with orally administered paeonol suspension. Conclusion Both the cubic gel and microemulsion gel formulations are promising delivery systems to enhance the skin permeability of paeonol, in particular the cubic gel. PMID:21904450

  10. The use of static light scattering for the structure analysis of radiosensitive polymer gels: a literature survey

    Energy Technology Data Exchange (ETDEWEB)

    Bussche, E Vanden [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Deene, Y de [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Dubruel, P [Polymer Material Research Group, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Vergote, K [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Schacht, E [Polymer Material Research Group, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Wagter, C de [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium)

    2004-01-01

    Static light scattering (SLS) could be a worthy technique to perform a structure analysis of the polymer structures inside radiation sensitive gels. The information obtained with SLS is a static characterization of the particle structures inside the gel. SLS will be combined with NMR relaxometry and NMR diffusion measurements, which deliver a hydrodynamic characterization of the microstructure of the gels.

  11. Disintegration kinetics of food gels during gastric digestion and its role on gastric emptying: an in vitro analysis.

    Science.gov (United States)

    Guo, Qing; Ye, Aiqian; Lad, Mita; Ferrua, Maria; Dalgleish, Douglas; Singh, Harjinder

    2015-03-01

    The understanding of the disintegration and gastric emptying of foods in the stomach is important for designing functional foods. In this study, a dynamic stomach model (human gastric simulator, HGS) was employed to investigate the disintegration and subsequent emptying of two differently structured whey protein emulsion gels (soft and hard gels).The gels were mechanically ground into fragments to reproduce the particle size distribution of an in vivo gel bolus. The simulated gel bolus was prepared by mixing gel fragments and artificial saliva, and exposed to 5 hours of simulated gastric digestion in the presence and absence of pepsin. Results showed that regardless of pepsin, the soft gel always disintegrated faster than the hard gel. The presence of pepsin significantly accelerated the disintegration of both gels. In particular, it enhanced abrasion of the soft gel into fine particles (disintegration kinetics in the HGS. In the presence or absence of pepsin, the larger particles of the soft gel emptied slower than the hard one during the first 120 min of process. However, in the presence of pepsin, the soft gel emptied faster than the hard one after 120 min because of a higher level of disintegration. These findings highlight the role of food structure, bolus properties and biochemical effects on the disintegration and gastric emptying patterns of gels during gastric digestion.

  12. Colloid molecular weight estimation by gel chromatography/acrylamide gel electrophoresis

    International Nuclear Information System (INIS)

    Liberatore, F.A.; Dearborn, C.; Nigam, S.; Poon, C.; Camin, L.; Liteplo, M.

    1984-01-01

    Size or molecular weight (MW) estimation of radiolabeled collides in aqueous solutions has long been a problem. The authors have prepared several minimicroaggregated albumin colloids (mμAA) by heat denaturation of stannous-containing HSA solutions at pH 7.0, 7.5, and 8.5). The resulting colloids were labeled with Tc-99m and compared with Au-198 colloid and Tc-99m-antimony sulfide colloid (Tc-99m-Sb/sub 2/S3) by gel chromatography and gel electrophoresis. Tc-99mm-mμAA aggregated at pH 7.0 and the Au-198 colloid appeared in the external void volume of a BioRad A5.0 agarose column indicating an apparent MW of > 5 x 10/sup 6/ daltons. The pH7.5 Tc-99m-mμAA, migrated within the filtration range of the column as did a small fraction of Tc-99m-Sb/sub 2/S/sub 3/, suggesting that the MW is between 6 x 10/sup 4/ - 5 x 10/sup 6/ daltons. The Tc-99m-mμAA, aggregated at pH 8.5, had an apparent MW on gel filtration similar to that of untreated albumin, MW 6.6 x 10-/sup 4/ daltons. The mobilities of the colloids, on acrylamide disc gel electrophoresis, were consistent with the results on gel chromatography. The largest colloids, Au-198 colloid and pH 7.0 Tc-99m-mμAA, barely entered the separating gel; intermediate sized colloids, a small fraction of Tc-99m-Sb/sub 2/S/sub 3/ and pH 7.5 Tc-99m-mμAA migrated farther into the separating gel; while pH 8.5 Tc-99m-mμAA had mobility approaching that of untreated albumin. Lymphoscintigraphy studies using these colloids in animals showed the predicted, particle size-related differences in migration and clearance. The authors conclude that gel chromatography and gel electrophoresis are useful methods for estimating the apparent size of the colloidal particles

  13. Self-Supporting Nanodiamond Gels: Elucidating Colloidal Interactions Through Rheology_

    Science.gov (United States)

    Adhikari, Prajesh; Tripathi, Anurodh; Vogel, Nancy A.; Rojas, Orlando J.; Raghavan, Sriunivasa R.; Khan, Saad A.

    This work investigates the colloidal interactions and rheological behavior of nanodiamond (ND) dispersions. While ND represents a promising class of nanofiller due to its high surface area, superior mechanical strength, tailorable surface functionality and biocompatibility, much remains unknown about the behavior of ND dispersions. We hypothesize that controlling interactions in ND dispersions will lead to highly functional systems with tunable modulus and shear response. Steady and dynamic rheology techniques are thus employed to systematically investigate nanodiamonds dispersed in model polar and non-polar media. We find that low concentrations of ND form gels almost instantaneously in a non-polar media. In contrast, ND's in polar media show a time-dependent behavior with the modulus increasing with time. We attribute the difference in behavior to variations in inter-particle interactions as well as the interaction of the ND with the media. Large steady and oscillatory strains are applied to ND colloidal gels to investigate the role of shear in gel microstructure breakdown and recovery. For colloidal gels in non-polar medium, the incomplete recovery of elastic modulus at high strain amplitudes indicates dominance of particle-particle interactions; however, in polar media the complete recovery of elastic modulus even at high strain amplitudes indicates dominance of particle-solvent interactions. These results taken together provide a platform to develop self-supporting gels with tunable properties in terms of ND concentration, and solvent type.

  14. Agarose gel electrophoresis and polyacrylamide gel electrophoresis for visualization of simple sequence repeats.

    Science.gov (United States)

    Anderson, James; Wright, Drew; Meksem, Khalid

    2013-01-01

    In the modern age of genetic research there is a constant search for ways to improve the efficiency of plant selection. The most recent technology that can result in a highly efficient means of selection and still be done at a low cost is through plant selection directed by simple sequence repeats (SSRs or microsatellites). The molecular markers are used to select for certain desirable plant traits without relying on ambiguous phenotypic data. The best way to detect these is the use of gel electrophoresis. Gel electrophoresis is a common technique in laboratory settings which is used to separate deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) by size. Loading DNA and RNA onto gels allows for visualization of the size of fragments through the separation of DNA and RNA fragments. This is achieved through the use of the charge in the particles. As the fragments separate, they form into distinct bands at set sizes. We describe the ability to visualize SSRs on slab gels of agarose and polyacrylamide gel electrophoresis.

  15. Decentralized Sensor Fusion for Ubiquitous Networking Robotics in Urban Areas

    Science.gov (United States)

    Sanfeliu, Alberto; Andrade-Cetto, Juan; Barbosa, Marco; Bowden, Richard; Capitán, Jesús; Corominas, Andreu; Gilbert, Andrew; Illingworth, John; Merino, Luis; Mirats, Josep M.; Moreno, Plínio; Ollero, Aníbal; Sequeira, João; Spaan, Matthijs T.J.

    2010-01-01

    In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted. PMID:22294927

  16. Empowering Pre-Service Teachers to Produce Ubiquitous Flipped Classes

    Directory of Open Access Journals (Sweden)

    Soraya García-Sánchez

    2017-01-01

    Full Text Available This work focuses on technological and educational outcomes that resulted from the production of foreign language educational videos by 90 pre-service instructors enrolled in an official Master’s Degree in Secondary Education programme. This teaching practice, conducted during two consecutive years, was set in a ubiquitous learning environment with the intention of effectively linking digital technology with pedagogy by means of producing flipped classroom units. The findings reveal that these pre-service teachers successfully combined instructional dynamics with digital skills to produce flipped classes adapted to the young generation’s needs. The classroom becomes, therefore, a more participatory learner-centred scenario with a variety of interactive and collaborative activities performed by foreign language students.

  17. Unfolding and Refolding Embodiment into the Landscape of Ubiquitous Computing

    DEFF Research Database (Denmark)

    Schick, Lea; Malmborg, Lone

    2009-01-01

    This paper advocates the future of the body as a distributed and shared embodiment; an unfolded body that doesn’t end at one's skin, but emerges as intercorporeality between bodies and the technological environment. Looking at new tendencies within interaction design and ubiquitous computing to see...... how these are to an increasing extent focusing on sociality, context-awareness, relations, affects, connectedness, and collectivity we will examine how these new technological movements can change our perception of embodiment towards a distributed and shared one. By examining interactive textiles...... as part of a future rising landscape of multi-sensory networks we will exemplify how the new technologies can shutter dichotomies and challenge traditional notions of embodiment and the subject. Finally, we show how this ‘new embodiment’ manifests Deleuze’s philosophy of the body as something unstable...

  18. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer.

    Science.gov (United States)

    Chabalko, Matthew J; Shahmohammadi, Mohsen; Sample, Alanson P

    2017-01-01

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power.

  19. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer.

    Directory of Open Access Journals (Sweden)

    Matthew J Chabalko

    Full Text Available Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR, which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power.

  20. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer

    Science.gov (United States)

    Shahmohammadi, Mohsen; Sample, Alanson P.

    2017-01-01

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power. PMID:28199321

  1. Decentralized Sensor Fusion for Ubiquitous Networking Robotics in Urban Areas

    Directory of Open Access Journals (Sweden)

    Aníbal Ollero

    2010-03-01

    Full Text Available In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites, a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted.

  2. A Survey of Software Infrastructures and Frameworks for Ubiquitous Computing

    Directory of Open Access Journals (Sweden)

    Christoph Endres

    2005-01-01

    Full Text Available In this survey, we discuss 29 software infrastructures and frameworks which support the construction of distributed interactive systems. They range from small projects with one implemented prototype to large scale research efforts, and they come from the fields of Augmented Reality (AR, Intelligent Environments, and Distributed Mobile Systems. In their own way, they can all be used to implement various aspects of the ubiquitous computing vision as described by Mark Weiser [60]. This survey is meant as a starting point for new projects, in order to choose an existing infrastructure for reuse, or to get an overview before designing a new one. It tries to provide a systematic, relatively broad (and necessarily not very deep overview, while pointing to relevant literature for in-depth study of the systems discussed.

  3. Mobile-PKI Service Model for Ubiquitous Environment

    Science.gov (United States)

    Jeun, Inkyung; Chun, Kilsoo

    One of the most important things in PKI(Public Key Infrastructure) is the private key management issue. The private key must be deal with safely for secure PKI service. Even though PKI service is usually used for identification and authentication of user in e-commerce, PKI service has many inconvenient factors. Especially, the fact that storage media of private key for PKI service is limited to PC hard disk drive or smart card users must always carry, gives an inconvenience to user and is not suitable in ubiquitous network. This paper suggests the digital signature service using a mobile phone(m-PKI service) which is suitable in future network. A mobile phone is the most widely used for personal communication means and has a characteristic of high movability. We can use the PKI service anytime and anywhere using m-PKI.

  4. Transparency of intentions decreases privacy concerns in ubiquitous surveillance.

    Science.gov (United States)

    Oulasvirta, Antti; Suomalainen, Tiia; Hamari, Juho; Lampinen, Airi; Karvonen, Kristiina

    2014-10-01

    An online experiment (n=1,897) was carried out to understand how data disclosure practices in ubiquitous surveillance affect users' privacy concerns. Information about the identity and intentions of a data collector was manipulated in hypothetical surveillance scenarios. Privacy concerns were found to differ across the scenarios and moderated by knowledge about the collector's identity and intentions. Knowledge about intentions exhibited a stronger effect. When no information about intentions was disclosed, the respondents postulated negative intentions. A positive effect was found for disclosing neutral intentions of an organization or unknown data collector, but not for a private data collector. The findings underline the importance of disclosing intentions of data use to users in an easily understandable manner.

  5. A Comprehensive Ubiquitous Healthcare Solution on an Android™ Mobile Device

    Directory of Open Access Journals (Sweden)

    Pei-Cheng Hii

    2011-06-01

    Full Text Available Provision of ubiquitous healthcare solutions which provide healthcare services at anytime anywhere has become more favorable nowadays due to the emphasis on healthcare awareness and also the growth of mobile wireless technologies. Following this approach, an Android™ smart phone device is proposed as a mobile monitoring terminal to observe and analyze ECG (electrocardiography waveforms from wearable ECG devices in real time under the coverage of a wireless sensor network (WSN. The exploitation of WSN in healthcare is able to substitute the complicated wired technology, moving healthcare away from a fixed location setting. As an extension to the monitoring scheme, medicine care is taken into consideration by utilizing the mobile phone as a barcode decoder, to verify and assist out-patients in the medication administration process, providing a better and more comprehensive healthcare service.

  6. Successful enrichment of the ubiquitous freshwater acI Actinobacteria.

    Science.gov (United States)

    Garcia, Sarahi L; McMahon, Katherine D; Grossart, Hans-Peter; Warnecke, Falk

    2014-02-01

    Actinobacteria of the acI lineage are often the numerically dominant bacterial phylum in surface freshwaters, where they can account for > 50% of total bacteria. Despite their abundance, there are no described isolates. In an effort to obtain enrichment of these ubiquitous freshwater Actinobacteria, diluted freshwater samples from Lake Grosse Fuchskuhle, Germany, were incubated in 96-well culture plates. With this method, a successful enrichment containing high abundances of a member of the lineage acI was established. Phylogenetic classification showed that the acI Actinobacteria of the enrichment belonged to the acI-B2 tribe, which seems to prefer acidic lakes. This enrichment grows to low cell densities and thus the oligotrophic nature of acI-B2 was confirmed. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Modelling of erosion of bentonite gel by gel/sol flow

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Luis; Neretnieks, Ivars; Longcheng Liu (Chemical Engineering and Technology, School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm (Sweden))

    2010-11-15

    Bentonite intrusion into a fracture intersecting the canister deposition hole is modelled. The model describes the expansion of the bentonite within the fracture. It accounts for the repulsive electrostatic double-layer forces, the attractive van der Waals forces and friction forces between the particles and the water. The model also takes into account the diffusion of the colloid particles in the smectite sol. Diffusion of a counterion, sodium, is accounted for as this strongly influences the double layer force and the viscosity of the gel/sol. The gel/sol is considered to be a fluid with a varying viscosity that is strongly dependent on the bentonite volume fraction in the gel and the sodium concentration in the water. Two different geometries were modelled; a rectangular and a cylindrical. The rectangular geometry was used to gain experience with the processes and mechanisms and how they interact since the cylindrical geometry was somewhat less stable numerically and more time consuming. In the rectangular geometry a fracture 1 metre long in the flow direction was modelled. In both geometries the fracture size was selected sufficiently large to ensure that the water velocity, near the distant border was nearly the same as the approaching water velocity and that the smectite concentration there was vanishingly small. It was found that the velocity of the fluid drops considerably where the bentonite volume fraction is larger than 1-2%. This is due to the strong increase in viscosity with increasing bentonite volume fraction. The loss of smectite by the slowly flowing fluid was found to be proportional to the square root of the seeping water velocity for the rectangular geometry. For the cylindrical geometry, the dependence is somewhat lower (exponent about 0.4) since the length of the gel/water interface decreases with increasing water flow rate. The penetration depth of the gel/water interface decreases with increasing water flow rate. For water velocity of the

  8. Modelling of erosion of bentonite gel by gel/sol flow

    International Nuclear Information System (INIS)

    Moreno, Luis; Neretnieks, Ivars; Longcheng Liu

    2010-11-01

    Bentonite intrusion into a fracture intersecting the canister deposition hole is modelled. The model describes the expansion of the bentonite within the fracture. It accounts for the repulsive electrostatic double-layer forces, the attractive van der Waals forces and friction forces between the particles and the water. The model also takes into account the diffusion of the colloid particles in the smectite sol. Diffusion of a counterion, sodium, is accounted for as this strongly influences the double layer force and the viscosity of the gel/sol. The gel/sol is considered to be a fluid with a varying viscosity that is strongly dependent on the bentonite volume fraction in the gel and the sodium concentration in the water. Two different geometries were modelled; a rectangular and a cylindrical. The rectangular geometry was used to gain experience with the processes and mechanisms and how they interact since the cylindrical geometry was somewhat less stable numerically and more time consuming. In the rectangular geometry a fracture 1 metre long in the flow direction was modelled. In both geometries the fracture size was selected sufficiently large to ensure that the water velocity, near the distant border was nearly the same as the approaching water velocity and that the smectite concentration there was vanishingly small. It was found that the velocity of the fluid drops considerably where the bentonite volume fraction is larger than 1-2%. This is due to the strong increase in viscosity with increasing bentonite volume fraction. The loss of smectite by the slowly flowing fluid was found to be proportional to the square root of the seeping water velocity for the rectangular geometry. For the cylindrical geometry, the dependence is somewhat lower (exponent about 0.4) since the length of the gel/water interface decreases with increasing water flow rate. The penetration depth of the gel/water interface decreases with increasing water flow rate. For water velocity of the

  9. The Gel Generator option

    International Nuclear Information System (INIS)

    Boyd, R.E.

    1999-01-01

    The development of a national policy for guaranteeing an ample supply of 99m Tc to nuclear medicine, involves issues which go beyond the means by which radioactivation is achieved. Indeed, in such an exercise the pragmatic dictates of business and the sensitivities of politics must also be taken into account. Furthermore where a preference towards the nuclear reactor or the potential of cyclotrons is being questioned, the debate is incomplete if the only options that are considered are the fission-based 99 Mo generator versus the direct cyclotron production of 99m Tc. There is a third option (also neutron γ-based), an alternative to the fission 99 Mo generator, which ought not be overlooked. The application of low specific activity (n,γ) 99 Mo to a new type of generator, the Gel Generator, has been the focus of much research, particularly in Australia and more recently in China. After the initial concept had been established in the laboratory, the Australian researchers then undertook a comprehensive program of tests on the Gel Generator to assess its potential, either in the clinical laboratory or the centralised radiopharmacy, for supplying 99m Tc suitable for nuclear medicine. The outcome of this program was a clear indication that the Gel Generator innovation had the capability to provide both technical and economic advantages to the nuclear medicine industry. These advantages are described. Since that time the Gel Generator has been selected for routine use in China where it now satisfies more than 30% of the 99m Tc demand. (author)

  10. Caffeine-catalyzed gels.

    Science.gov (United States)

    DiCiccio, Angela M; Lee, Young-Ah Lucy; Glettig, Dean L; Walton, Elizabeth S E; de la Serna, Eva L; Montgomery, Veronica A; Grant, Tyler M; Langer, Robert; Traverso, Giovanni

    2018-07-01

    Covalently cross-linked gels are utilized in a broad range of biomedical applications though their synthesis often compromises easy implementation. Cross-linking reactions commonly utilize catalysts or conditions that can damage biologics and sensitive compounds, producing materials that require extensive post processing to achieve acceptable biocompatibility. As an alternative, we report a batch synthesis platform to produce covalently cross-linked materials appropriate for direct biomedical application enabled by green chemistry and commonly available food grade ingredients. Using caffeine, a mild base, to catalyze anhydrous carboxylate ring-opening of diglycidyl-ether functionalized monomers with citric acid as a tri-functional crosslinking agent we introduce a novel poly(ester-ether) gel synthesis platform. We demonstrate that biocompatible Caffeine Catalyzed Gels (CCGs) exhibit dynamic physical, chemical, and mechanical properties, which can be tailored in shape, surface texture, solvent response, cargo release, shear and tensile strength, among other potential attributes. The demonstrated versatility, low cost and facile synthesis of these CCGs renders them appropriate for a broad range of customized engineering applications including drug delivery constructs, tissue engineering scaffolds, and medical devices. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Chiromagnetic nanoparticles and gels

    Science.gov (United States)

    Yeom, Jihyeon; Santos, Uallisson S.; Chekini, Mahshid; Cha, Minjeong; de Moura, André F.; Kotov, Nicholas A.

    2018-01-01

    Chiral inorganic nanostructures have high circular dichroism, but real-time control of their optical activity has so far been achieved only by irreversible chemical changes. Field modulation is a far more desirable path to chiroptical devices. We hypothesized that magnetic field modulation can be attained for chiral nanostructures with large contributions of the magnetic transition dipole moments to polarization rotation. We found that dispersions and gels of paramagnetic Co3O4 nanoparticles with chiral distortions of the crystal lattices exhibited chiroptical activity in the visible range that was 10 times as strong as that of nonparamagnetic nanoparticles of comparable size. Transparency of the nanoparticle gels to circularly polarized light beams in the ultraviolet range was reversibly modulated by magnetic fields. These phenomena were also observed for other nanoscale metal oxides with lattice distortions from imprinted amino acids and other chiral ligands. The large family of chiral ceramic nanostructures and gels can be pivotal for new technologies and knowledge at the nexus of chirality and magnetism.

  12. Gel Fabrication of Molybdenum “Beads”

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Armstrong, Beth L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Cooley, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-11-01

    Spherical molybdenum particles or “beads” of various diameters are of interest as feedstock materials for the additive manufacture of targets and assemblies used in the production of 99Mo medical isotopes using accelerator technology. Small metallic beads or ball bearings are typically fabricated from wire; however, small molybdenum spheres cannot readily be produced in this manner. Sol-gel processes are often employed to produce small dense microspheres of metal oxides across a broad diameter range that in the case of molybdenum could be reduced and sintered to produce metallic spheres. These Sol-gel type processes were examined for forming molybdenum oxide beads; however, the molybdenum trioxide was chemically incompatible with commonly used gelation materials. As an alternative, an aqueous alginate process being assessed for the fabrication of oxide spheres for catalyst applications was employed to form molybdenum trioxide beads that were successfully reduced and sintered to produce small molybdenum spheres.

  13. Fibril formation from pea protein and subsequent gel formation.

    Science.gov (United States)

    Munialo, Claire Darizu; Martin, Anneke H; van der Linden, Erik; de Jongh, Harmen H J

    2014-03-19

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20 h at pH 2.0. Following heating of pea proteins, it was observed that all of the proteins were hydrolyzed into peptides and that 50% of these peptides were assembled into fibrils. Changes on a structural level in pea proteins were studied using circular dichroism, transmission electron microscopy, and particle size analysis. During the fibril assembly process, an increase in aggregate size was observed, which coincided with an increase in thioflavin T binding, indicating the presence of β-sheet aggregates. Fibrils made using pea proteins were more branched and curly. Gel formation of preformed fibrils was induced by slow acidification from pH 7.0 to a final pH of around pH 5.0. The ability of pea protein-based fibrillar gels to fracture during an amplitude sweep was comparable to those of soy protein and whey protein-based fibrillar gels, although gels prepared from fibrils made using pea protein and soy protein were weaker than those of whey protein. The findings show that fibrils can be prepared from pea protein, which can be incorporated into protein-based fibrillar gels.

  14. Numerical modelling and experimental study of liquid evaporation during gel formation

    Science.gov (United States)

    Pokusaev, B. G.; Khramtsov, D. P.

    2017-11-01

    Gels are promising materials in biotechnology and medicine as a medium for storing cells for bioprinting applications. Gel is a two-phase system consisting of solid medium and liquid phase. Understanding of a gel structure evolution and gel aging during liquid evaporation is a crucial step in developing new additive bioprinting technologies. A numerical and experimental study of liquid evaporation was performed. In experimental study an evaporation process of an agarose gel layer located on Petri dish was observed and mass difference was detected using electronic scales. Numerical model was based on a smoothed particle hydrodynamics method. Gel in a model was represented as a solid-liquid system and liquid evaporation was modelled due to capillary forces and heat transfer. Comparison of experimental data and numerical results demonstrated that model can adequately represent evaporation process in agarose gel.

  15. Effects of Shear Fracture on In-depth Profile Modification of Weak Gels

    Institute of Scientific and Technical Information of China (English)

    Li Xianjie; Song Xinwang; Yue Xiang'an; Hou Jirui; Fang Lichun; Zhang Huazhen

    2007-01-01

    Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the in-depth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs,and the weak gels in these two cases became small gel particles after water flooding. The differences were:the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor (FRR) caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack,which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack,while in the quartz sand pack,the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water,the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.

  16. The role of quench rate in colloidal gels.

    Science.gov (United States)

    Royall, C Patrick; Malins, Alex

    2012-01-01

    Interactions between colloidal particles have hitherto usually been fixed by the suspension composition. Recent experimental developments now enable the control of interactions in situ. Here we use Brownian dynamics simulations to investigate the effect of controlling interactions upon gelation, by "quenching" the system from an equilibrium fluid to a gel. We find that, contrary to the normal case of an instantaneous quench, where the local structure of the gel is highly disordered, controlled quenching results in a gel with a much higher degree of local order. Under sufficiently slow quenching, local crystallisation is found, which is strongly enhanced when a monodisperse system is used. The higher the degree of local order, the smaller the mean squared displacement, indicating an enhancement of gel stability.

  17. Radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Baldock, C.

    2002-01-01

    shapes and sizes while sparing normal tissue. The situation is further complicated if the normal tissues are critical organs or are particularly sensitive to radiation. Radiotherapy techniques employed to obtain a closer conformation of the dose distribution to the tumour volume are referred to as conformal radiotherapy techniques. The clinical implementation of conformal therapy has been delayed by limitations in the verification of conformal dose distributions calculated by treatment planning systems prior to the irradiation of the patient and the verification of complex treatments during its delivery to the patient. There are several aspects of conformal therapy that complicate dose verification. To achieve the dose distributions conforming to complex 3D volumes, high dose gradients arise in the treatment volume. Further, overdose or underdose regions can exist when separate radiation fields are used to deliver additional radiation. These aspects require that practical dose measurement (dosimetry) techniques be able to integrate dose over time and easily measure dose distributions in 3D with high spatial resolution. Traditional dosimeters, such as ion chambers, thermoluminescent dosimeters and radiographic film do not fulfil these requirements. Novel gel dosimetry techniques are being developed in which dose distributions can potentially be determined in vitro in 3D using anthropomorphic phantoms to simulate a clinically irradiated situation. As long ago as the 1950's, radiation-induced colour change in dyes was used to investigate radiation doses in gels. It was subsequently shown that radiation induced changes in nuclear magnetic resonance (NMR) relaxation properties of gels infused with conventional Fricke dosimetry solutions could be measured using magnetic resonance imaging (MRI). In Fricke gels, Fe 2+ ions in ferrous sulphate solutions are usually dispersed throughout a gelatin, agarose or PVA matrix. Radiation-induced changes in the dosimeters are considered to

  18. A seamless ubiquitous emergency medical service for crisis situations.

    Science.gov (United States)

    Lin, Bor-Shing

    2016-04-01

    In crisis situations, a seamless ubiquitous communication is necessary to provide emergency medical service to save people's lives. An excellent prehospital emergency medicine provides immediate medical care to increase the survival rate of patients. On their way to the hospital, ambulance personnel must transmit real-time and uninterrupted patient information to the hospital to apprise the physician of the situation and provide options to the ambulance personnel. In emergency and crisis situations, many communication channels can be unserviceable because of damage to equipment or loss of power. Thus, data transmission over wireless communication to achieve uninterrupted network services is a major obstacle. This study proposes a mobile middleware for cognitive radio (CR) for improving the wireless communication link. CRs can sense their operating environment and optimize the spectrum usage so that the mobile middleware can integrate the existing wireless communication systems with a seamless communication service in heterogeneous network environments. Eventually, the proposed seamless mobile communication middleware was ported into an embedded system, which is compatible with the actual network environment without the need for changing the original system architecture. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Distributing Workflows over a Ubiquitous P2P Network

    Directory of Open Access Journals (Sweden)

    Eddie Al-Shakarchi

    2007-01-01

    Full Text Available This paper discusses issues in the distribution of bundled workflows across ubiquitous peer-to-peer networks for the application of music information retrieval. The underlying motivation for this work is provided by the DART project, which aims to develop a novel music recommendation system by gathering statistical data using collaborative filtering techniques and the analysis of the audio itsel, in order to create a reliable and comprehensive database of the music that people own and which they listen to. To achieve this, the DART scientists creating the algorithms need the ability to distribute the Triana workflows they create, representing the analysis to be performed, across the network on a regular basis (perhaps even daily in order to update the network as a whole with new workflows to be executed for the analysis. DART uses a similar approach to BOINC but differs in that the workers receive input data in the form of a bundled Triana workflow, which is executed in order to process any MP3 files that they own on their machine. Once analysed, the results are returned to DART's distributed database that collects and aggregates the resulting information. DART employs the use of package repositories to decentralise the distribution of such workflow bundles and this approach is validated in this paper through simulations that show that suitable scalability is maintained through the system as the number of participants increases. The results clearly illustrate the effectiveness of the approach.

  20. FCJ-135 Feral Computing: From Ubiquitous Calculation to Wild Interactions

    Directory of Open Access Journals (Sweden)

    Matthew Fuller

    2011-12-01

    Full Text Available In ‘The Coming Age of Calm Technology’, Mark Weiser and John Seely Brown are clear in their assertions, what really ‘matters’ about technology is not technology in itself, rather, its capacity to continuously recreate our relationship with the world at large (Brown and Weiser 1996. Even though they promote such an idea under the banner of ‘calm technology’, what is central to their thesis is the mutational capacities brought into the world by the spillage of computation out from its customary boxes. What their work tends to occlude is that in setting the sinking of technology almost imperceptibly, but deeply into the ‘everyday’ as a target for ubiquitous computing, other possibilities are masked, for instance, those of greater hackability or interrogability of such technologies. Our contention is that making ubicomp seamless (MacColl et al, 2002 tends to obfuscate the potential of computation in reworking computational subjects, including societies, modes of life, and inter-relations with the dynamics of thought and the composition of experience and understanding.

  1. Ubiquitous Monitoring of Electrical Household Appliances 

    Directory of Open Access Journals (Sweden)

    Raquel Lacuesta

    2012-11-01

    Full Text Available The number of appliances at home is increasing continuously, mainly because they make our lives easier. Currently, technology is integrated in all objects of our daily life. TCP/IP let us monitor our home in real time and check ubiquitously if something is happening at home. Bearing in mind this idea, we have developed a low-cost system, which can be used in any type of electrical household appliance that takes information from the appliance and posts the information to the Twitter Social network. Several sensors placed in the household appliances gather the sensed data and send them wired or wirelessly, depending on the case, using small and cheap devices to a gateway located in the home. This gateway takes decisions, based on the received data, and sends notifications to Twitter. We have developed a software application that takes the values and decides when to issue an alarm to the registered users (Twitter friends of our smart home. The performance of our system has been measured taking into account the home network (using IEEE 802.3u and IEEE 802.11g and the data publishing in Twitter. As a result, we have generated an original product and service for any electrical household appliance, regardless of the model and manufacturer, that helps home users improve their quality of life. The paper also shows that there is no system with the same innovative features like the ones presented in this paper.

  2. I WHATSAPP AN IGUANA: AN ATTEMPT TO APPLY UBIQUITOUS LEARNING

    Directory of Open Access Journals (Sweden)

    Dwi Haryanti

    2017-12-01

    Full Text Available This paper aims at presenting how Whatsapp provides alternative method to enhance writing skills on personal letter for senior high school student. This method Whatsapps inspired by the concept called ubiquitous learning (U-Learning, which means ―learning supported by ICT resources held anytime, anywhere and fits the context of the learner‖ (de Sousa Monteiro et al., 2014. Participants were 40 11-th grade students in one class in Cirebon High School. A short story in the form of personal letter entitled I Wanna Iguana by Karen Kaufman Orloff was used as main learning source and the mobile version of the story was sent to the class Whatsapp group along with the reading comprehension questions and the personal letter template. The study was conducted for three weeks in the middle of the second semester year 2017. Contrary to the basic face-to-face teaching and learning, the using of Whatsapp group demonstrates how mobile technology can be fully integrated in an educational context to support students‘ learning beyond the classroom. Another advantages of using Whatsapp group is the fact that learning become the responsibility of learners and may take place through observation, trial and error, asking for help, conversing with others, reading to stories, reflecting on a one‘s personal event, or stimulated by general interests

  3. From computers to ubiquitous computing by 2010: health care.

    Science.gov (United States)

    Aziz, Omer; Lo, Benny; Pansiot, Julien; Atallah, Louis; Yang, Guang-Zhong; Darzi, Ara

    2008-10-28

    Over the past decade, miniaturization and cost reduction in semiconductors have led to computers smaller in size than a pinhead with powerful processing abilities that are affordable enough to be disposable. Similar advances in wireless communication, sensor design and energy storage have meant that the concept of a truly pervasive 'wireless sensor network', used to monitor environments and objects within them, has become a reality. The need for a wireless sensor network designed specifically for human body monitoring has led to the development of wireless 'body sensor network' (BSN) platforms composed of tiny integrated microsensors with on-board processing and wireless data transfer capability. The ubiquitous computing abilities of BSNs offer the prospect of continuous monitoring of human health in any environment, be it home, hospital, outdoors or the workplace. This pervasive technology comes at a time when Western world health care costs have sharply risen, reflected by increasing expenditure on health care as a proportion of gross domestic product over the last 20 years. Drivers of this rise include an ageing post 'baby boom' population, higher incidence of chronic disease and the need for earlier diagnosis. This paper outlines the role of pervasive health care technologies in providing more efficient health care.

  4. Ubiquitous computing in sports: A review and analysis.

    Science.gov (United States)

    Baca, Arnold; Dabnichki, Peter; Heller, Mario; Kornfeind, Philipp

    2009-10-01

    Ubiquitous (pervasive) computing is a term for a synergetic use of sensing, communication and computing. Pervasive use of computing has seen a rapid increase in the current decade. This development has propagated in applied sport science and everyday life. The work presents a survey of recent developments in sport and leisure with emphasis on technology and computational techniques. A detailed analysis on new technological developments is performed. Sensors for position and motion detection, and such for equipment and physiological monitoring are discussed. Aspects of novel trends in communication technologies and data processing are outlined. Computational advancements have started a new trend - development of smart and intelligent systems for a wide range of applications - from model-based posture recognition to context awareness algorithms for nutrition monitoring. Examples particular to coaching and training are discussed. Selected tools for monitoring rules' compliance and automatic decision-making are outlined. Finally, applications in leisure and entertainment are presented, from systems supporting physical activity to systems providing motivation. It is concluded that the emphasis in future will shift from technologies to intelligent systems that allow for enhanced social interaction as efforts need to be made to improve user-friendliness and standardisation of measurement and transmission protocols.

  5. A concept for ubiquitous robotics in industrial environment

    Science.gov (United States)

    Sallinen, Mikko; Heilala, Juhani; Kivikunnas, Sauli

    2007-09-01

    In this paper a concept for industrial ubiquitous robotics is presented. The concept combines two different approaches to manage agile, adaptable production: firstly the human operator is strongly in the production loop and secondly, the robot workcell will be more autonomous and smarter to manage production. This kind of autonomous robot cell can be called production island. Communication to the human operator working in this kind of smart industrial environment can be divided into two levels: body area communication and operator-infrastructure communication including devices, machines and infra. Body area communication can be supportive in two directions: data is recorded by means of measuring physical actions, such as hand movements, body gestures or supportive when it will provide information to user such as guides or manuals for operation. Body area communication can be carried out using short range communication technologies such as NFC (Near Field communication) which is RFID type of communication. In the operator-infrastructure communication, WLAN or Bluetooth -communication can be used. Beyond the current Human Machine interaction HMI systems, the presented system concept is designed to fulfill the requirements for hybrid, knowledge intensive manufacturing in the future, where humans and robots operate in close co-operation.

  6. Ubiquitous Health in Korea: Progress, Barriers, and Prospects

    Science.gov (United States)

    Lee, Yountae

    2012-01-01

    Objectives Korea has one of the most advanced information technology (IT) infrastructures in the world, and the application of IT in health systems is rapidly progressing from computerization to information systems, ubiquitous systems, and smart systems. This study aims to analyze Korean environments in regards to the development of their u-Health industry and propose directions for u-Healthcare services based on this analysis. Methods This paper reviews the background, progress history, and current status of u-Health in Korea, and suggests strategies for the u-Health industry based on an analysis of its barriers and obstacles. Results When u-Health was introduced to Koreans, their policies and approaches focused mainly on environmental factors, yet these efforts have not progressed further to impact the u-Healthcare service industry itself. To develop the u-Healthcare industry, four points need to be considered: the development and support of the practical service model, institutional support, support of core technology and industry, and the institutionalization of health management service. Conclusions Korea is at a strategic point to start building u-Healthcare service delivery models. u-Healthcare is a healthcare service that provides added value through u-Health environments. By identifying critical success factors in u-Healthcare, we can strengthen the u-Health industry and implement policies to coordinate our efforts in the process of value chains to which we belong. PMID:23346474

  7. Sol-gel based oxidation catalyst and coating system using same

    Science.gov (United States)

    Watkins, Anthony N. (Inventor); Leighty, Bradley D. (Inventor); Oglesby, Donald M. (Inventor); Patry, JoAnne L. (Inventor); Schryer, Jacqueline L. (Inventor)

    2010-01-01

    An oxidation catalyst system is formed by particles of an oxidation catalyst dispersed in a porous sol-gel binder. The oxidation catalyst system can be applied by brush or spray painting while the sol-gel binder is in its sol state.

  8. High transparent shape memory gel

    Science.gov (United States)

    Gong, Jin; Arai, Masanori; Kabir, M. H.; Makino, Masato; Furukawa, Hidemitsu

    2014-03-01

    Gels are a new material having three-dimensional network structures of macromolecules. They possess excellent properties as swellability, high permeability and biocompatibility, and have been applied in various fields of daily life, food, medicine, architecture, and chemistry. In this study, we tried to prepare new multi-functional and high-strength gels by using Meso-Decoration (Meso-Deco), one new method of structure design at intermediate mesoscale. High-performance rigid-rod aromatic polymorphic crystals, and the functional groups of thermoreversible Diels-Alder reaction were introduced into soft gels as crosslinkable pendent chains. The functionalization and strengthening of gels can be realized by meso-decorating the gels' structure using high-performance polymorphic crystals and thermoreversible pendent chains. New gels with good mechanical properties, novel optical properties and thermal properties are expected to be developed.

  9. Process of forming a sol-gel/metal hydride composite

    Science.gov (United States)

    Congdon, James W [Aiken, SC

    2009-03-17

    An external gelation process is described which produces granules of metal hydride particles contained within a sol-gel matrix. The resulting granules are dimensionally stable and are useful for applications such as hydrogen separation and hydrogen purification. An additional coating technique for strengthening the granules is also provided.

  10. ARSENIC REMOVAL USING SOL-GEL SYNTHESIZED TITANIUM DIOXIDE NANOPARTICLES

    Science.gov (United States)

    In this study, the effectiveness of TiO2 nanoparticles in arsenic adsorption was examined. TiO2 particles (LS) were synthesized via sol-gel techniques and characterized for their crystallinity, surface area and pore volume. Batch adsorption studies were perf...

  11. Effect of DCCA on synthesis of inorganic mesoporous gels

    International Nuclear Information System (INIS)

    Nemancha, A.R.

    2004-01-01

    Full text.The porous texture of the monolith inorganic gels plays an important role in the utilization of porous material by control of several properties such as gas diffusion, thermal stability, mechanical strength. the sol gel process provides many possibilities to manufacture porous material with extremely low concentration of impurities at low sinter temperature. The serious problem in the production of the monolith gels is fracture and crack formation which may occur in the conversion of the wet gels to dry gels. This phenomenon is probably due to the capillary forces which appear during the drying steps. in order to reduce the effect of capillary forces a number of methods were applied (hyper critic drying, organic DCCAs). The purpose of the present work, is to understand the chemical changes that result from adding formamide as drying control chemical additives DCCA to the colloidal silica sols in the presence of acid catalyst. Fourier Transformed Infrared spectroscopy and Raman spectroscopy were used to investigate the influence of formamide on gel formation. The Nitrogen adsorption-desorption technique is used to investigate the effect of formamide on gel texture. The results show that the gels with formamide are monolith and obtained during a short time of gelling reaction, the silica particles link formation depend strongly on the formamide concentration. the BET and BJH results show that the presence of formamide promotes the creation of meso porous texture depending on formamide/silica molar ratio in the starting sol. The maximum average diameter of the obtained gel reaches a value close to 25 nm with a bulk density equal to 1.1 g/cm 3

  12. Thoria sol-gel processes

    International Nuclear Information System (INIS)

    Matthews, R.B.

    1978-10-01

    Alternate fuel fabrication techniques are being developed at WNRE as part of the thorium fuel cycle program. The sol-gel techniques are attractive and this report assembles and summarizes information relating to thoria sol-gel fuels. Some background information on the behaviour and advantages of sol-gel fuel forms is presented, followed by a review of relevant colloid chemistry and an explanation of the fundamental steps of sol-gel processes. Finally, several variants to the basic process are reviewed and evaluated. (author)

  13. Silver nitrate based gel dosimeter

    International Nuclear Information System (INIS)

    Titus, D; Samuel, E J J; Srinivasan, K; Roopan, S M; Madhu, C S

    2017-01-01

    A new radiochromic gel dosimeter based on silver nitrate and a normoxic gel dosimeter was investigated using UV-Visible spectrophotometry in the clinical dose range. Gamma radiation induced the synthesis of silver nanoparticles in the gel and is confirmed from the UV-Visible spectrum which shows an absorbance peak at around 450 nm. The dose response function of the dosimeter is found to be linear upto12Gy. In addition, the gel samples were found to be stable which were kept under refrigeration. (paper)

  14. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  15. A system for ubiquitous health monitoring in the bedroom via a Bluetooth network and wireless LAN.

    Science.gov (United States)

    Choi, J M; Choi, B H; Seo, J W; Sohn, R H; Ryu, M S; Yi, W; Park, K S

    2004-01-01

    Advances in information technology have enabled ubiquitous health monitoring at home, which is particularly useful for patients, who have to live alone. We have focused on the automatic and unobtrusive measurement of biomedical signals and activities of patients. We have constructed wireless communication networks in order to transfer data. The networks consist of Bluetooth and Wireless Local Area Network (WLAN). In this paper, we present the concept of a ubiquitous-Bedroom (u-Bedroom) which is a part of a ubiquitous-House (u-House) and we present our systems for ubiquitous health monitoring.

  16. Comparative Genomics of the Ubiquitous, Hydrocarbon-degrading Genus Marinobacter

    Science.gov (United States)

    Singer, E.; Webb, E.; Edwards, K. J.

    2012-12-01

    The genus Marinobacter is amongst the most ubiquitous in the global oceans and strains have been isolated from a wide variety of marine environments, including offshore oil-well heads, coastal thermal springs, Antarctic sea water, saline soils and associations with diatoms and dinoflagellates. Many strains have been recognized to be important hydrocarbon degraders in various marine habitats presenting sometimes extreme pH or salinity conditions. Analysis of the genome of M. aquaeolei revealed enormous adaptation versatility with an assortment of strategies for carbon and energy acquisition, sensation, and defense. In an effort to elucidate the ecological and biogeochemical significance of the Marinobacters, seven Marinobacter strains from diverse environments were included in a comparative genomics study. Genomes were screened for metabolic and adaptation potential to elucidate the strategies responsible for the omnipresence of the Marinobacter genus and their remedial action potential in hydrocarbon-polluted waters. The core genome predominantly encodes for key genes involved in hydrocarbon degradation, biofilm-relevant processes, including utilization of external DNA, halotolerance, as well as defense mechanisms against heavy metals, antibiotics, and toxins. All Marinobacter strains were observed to degrade a wide spectrum of hydrocarbon species, including aliphatic, polycyclic aromatic as well as acyclic isoprenoid compounds. Various genes predicted to facilitate hydrocarbon degradation, e.g. alkane 1-monooxygenase, appear to have originated from lateral gene transfer as they are located on gene clusters of 10-20% lower GC-content compared to genome averages and are flanked by transposases. Top ortholog hits are found in other hydrocarbon degrading organisms, e.g. Alcanivorax borkumensis. Strategies for hydrocarbon uptake encoded by various Marinobacter strains include cell surface hydrophobicity adaptation via capsular polysaccharide biosynthesis and attachment

  17. Twelve previously unknown phage genera are ubiquitous in global oceans.

    Science.gov (United States)

    Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh; Corrier, Kristen; Riemann, Lasse; Verberkmoes, Nathan C; Sullivan, Matthew B

    2013-07-30

    Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.

  18. mORCA: ubiquitous access to life science web services.

    Science.gov (United States)

    Diaz-Del-Pino, Sergio; Trelles, Oswaldo; Falgueras, Juan

    2018-01-16

    Technical advances in mobile devices such as smartphones and tablets have produced an extraordinary increase in their use around the world and have become part of our daily lives. The possibility of carrying these devices in a pocket, particularly mobile phones, has enabled ubiquitous access to Internet resources. Furthermore, in the life sciences world there has been a vast proliferation of data types and services that finish as Web Services. This suggests the need for research into mobile clients to deal with life sciences applications for effective usage and exploitation. Analysing the current features in existing bioinformatics applications managing Web Services, we have devised, implemented, and deployed an easy-to-use web-based lightweight mobile client. This client is able to browse, select, compose parameters, invoke, and monitor the execution of Web Services stored in catalogues or central repositories. The client is also able to deal with huge amounts of data between external storage mounts. In addition, we also present a validation use case, which illustrates the usage of the application while executing, monitoring, and exploring the results of a registered workflow. The software its available in the Apple Store and Android Market and the source code is publicly available in Github. Mobile devices are becoming increasingly important in the scientific world due to their strong potential impact on scientific applications. Bioinformatics should not fall behind this trend. We present an original software client that deals with the intrinsic limitations of such devices and propose different guidelines to provide location-independent access to computational resources in bioinformatics and biomedicine. Its modular design makes it easily expandable with the inclusion of new repositories, tools, types of visualization, etc.

  19. Lipid droplets as ubiquitous fat storage organelles in C. elegans

    Directory of Open Access Journals (Sweden)

    Guo Fengli

    2010-12-01

    Full Text Available Abstract Background Lipid droplets are a class of eukaryotic cell organelles for storage of neutral fat such as triacylglycerol (TAG and cholesterol ester (CE. We and others have recently reported that lysosome-related organelles (LROs are not fat storage structures in the nematode C. elegans. We also reported the formation of enlarged lipid droplets in a class of peroxisomal fatty acid β-oxidation mutants. In the present study, we seek to provide further evidence on the organelle nature and biophysical properties of fat storage structures in wild-type and mutant C. elegans. Results In this study, we provide biochemical, histological and ultrastructural evidence of lipid droplets in wild-type and mutant C. elegans that lack lysosome related organelles (LROs. The formation of lipid droplets and the targeting of BODIPY fatty acid analogs to lipid droplets in live animals are not dependent on lysosomal trafficking or peroxisome dysfunction. However, the targeting of Nile Red to lipid droplets in live animals occurs only in mutants with defective peroxisomes. Nile Red labelled-lipid droplets are characterized by a fluorescence emission spectrum distinct from that of Nile Red labelled-LROs. Moreover, we show that the recently developed post-fix Nile Red staining method labels lipid droplets exclusively. Conclusions Our results demonstrate lipid droplets as ubiquitous fat storage organelles and provide a unified explanation for previous studies on fat labelling methods in C. elegans. These results have important applications to the studies of fat storage and lipid droplet regulation in the powerful genetic system, C. elegans.

  20. Soft particles at a fluid interface

    Science.gov (United States)

    Mehrabian, Hadi; Harting, Jens; Snoeijer, Jacco H.

    2015-11-01

    Particles added to a fluid interface can be used as a surface stabilizer in the food, oil and cosmetic industries. As an alternative to rigid particles, it is promising to consider highly deformable particles that can adapt their conformation at the interface. In this study, we compute the shapes of soft elastic particles using molecular dynamics simulations of a cross-linked polymer gel, complemented by continuum calculations based on the linear elasticity. It is shown that the particle shape is not only affected by the Young's modulus of the particle, but also strongly depends on whether the gel is partially or completely wetting the fluid interface. We find that the molecular simulations for the partially wetting case are very accurately described by the continuum theory. By contrast, when the gel is completely wetting the fluid interface the linear theory breaks down and we reveal that molecular details have a strong influence on the equilibrium shape.

  1. Rheology and structure of milk protein gels

    NARCIS (Netherlands)

    Vliet, van T.; Lakemond, C.M.M.; Visschers, R.W.

    2004-01-01

    Recent studies on gel formation and rheology of milk gels are reviewed. A distinction is made between gels formed by aggregated casein, gels of `pure` whey proteins and gels in which both casein and whey proteins contribute to their properties. For casein' whey protein mixtures, it has been shown

  2. Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump

    KAUST Repository

    Agusti, Susana

    2015-07-09

    The role of the ocean as a sink for CO2 is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean requires confirmation. Here we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark ocean. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from a few days to a few weeks, corresponding to sinking rates (124–732 m d−1) comparable to those of fast-sinking aggregates and faecal pellets. These results confirm the expectation that fast-sinking mechanisms inject fresh organic carbon into the deep sea and that this is a prevalent process operating across the global oligotrophic ocean.

  3. Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump

    KAUST Repository

    Agusti, Susana; Gonzá lez-Gordillo, J. I.; Vaqué , D.; Estrada, M.; Cerezo, M. I.; Salazar, G.; Gasol, J. M.; Duarte, Carlos M.

    2015-01-01

    The role of the ocean as a sink for CO2 is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean requires confirmation. Here we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark ocean. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from a few days to a few weeks, corresponding to sinking rates (124–732 m d−1) comparable to those of fast-sinking aggregates and faecal pellets. These results confirm the expectation that fast-sinking mechanisms inject fresh organic carbon into the deep sea and that this is a prevalent process operating across the global oligotrophic ocean.

  4. Pecan drying with silica gel

    Energy Technology Data Exchange (ETDEWEB)

    Ghate, S.R.; Chhinnan, M.S.

    1983-07-01

    High moisture in-shell pecans were dried by keeping them in direct and indirect contact with silica gel to investigate their drying characteristics. In-shell pecans were also dried with ambient air from a controlled environment chamber and with air dehumidified by silica gel. Direct contact and dehumidified air drying seemed feasible approaches.

  5. Nanocrystal/sol-gel nanocomposites

    Science.gov (United States)

    Petruska, Melissa A [Los Alamos, NM; Klimov, Victor L [Los Alamos, NM

    2007-06-05

    The present invention is directed to solid composites including colloidal nanocrystals within a sol-gel host or matrix and to processes of forming such solid composites. The present invention is further directed to alcohol soluble colloidal nanocrystals useful in formation of sol-gel based solid composites.

  6. Dynamic Scaling of Colloidal Gel Formation at Intermediate Concentrations.

    Science.gov (United States)

    Zhang, Qingteng; Bahadur, Divya; Dufresne, Eric M; Grybos, Pawel; Kmon, Piotr; Leheny, Robert L; Maj, Piotr; Narayanan, Suresh; Szczygiel, Robert; Ramakrishnan, Subramanian; Sandy, Alec

    2017-10-27

    We have examined the formation and dissolution of gels composed of intermediate volume-fraction nanoparticles with temperature-dependent short-range attractions using small-angle x-ray scattering, x-ray photon correlation spectroscopy, and rheology to obtain nanoscale and macroscale sensitivity to structure and dynamics. Gel formation after temperature quenches to the vicinity of the rheologically determined gel temperature, T_{gel}, was characterized via the slowdown of dynamics and changes in microstructure observed in the intensity autocorrelation functions and structure factor, respectively, as a function of quench depth (ΔT=T_{quench}-T_{gel}), wave vector, and formation time t_{f}. We find the wave-vector-dependent dynamics, microstructure, and rheology at a particular ΔT and t_{f} map to those at other ΔTs and t_{f}s via an effective scaling temperature, T_{s}. A single T_{s} applies to a broad range of ΔT and t_{f} but does depend on the particle size. The rate of formation implied by the scaling is a far stronger function of ΔT than expected from the attraction strength between colloids. We interpret this strong temperature dependence in terms of cooperative bonding required to form stable gels via energetically favored, local structures.

  7. Energy-Efficient Bioalcohol Recovery by Gel Stripping

    Science.gov (United States)

    Godbole, Rutvik; Ma, Lan; Hedden, Ronald

    2014-03-01

    Design of energy-efficient processes for recovering butanol and ethanol from dilute fermentations is a key challenge facing the biofuels industry due to the high energy consumption of traditional multi-stage distillation processes. Gel stripping is an alternative purification process by which a dilute alcohol is stripped from the fermentation product by passing it through a packed bed containing particles of a selectively absorbent polymeric gel material. The gel must be selective for the alcohol, while swelling to a reasonable degree in dilute alcohol-water mixtures. To accelerate materials optimization, a combinatorial approach is taken to screen a matrix of copolymer gels having orthogonal gradients in crosslinker concentration and hydrophilicity. Using a combination of swelling in pure solvents, the selectivity and distribution coefficients of alcohols in the gels can be predicted based upon multi-component extensions of Flory-Rehner theory. Predictions can be validated by measuring swelling in water/alcohol mixtures and conducting h HPLC analysis of the external liquid. 95% + removal of butanol from dilute aqueous solutions has been demonstrated, and a mathematical model of the unsteady-state gel stripping process has been developed. NSF CMMI Award 1335082.

  8. Characterization of a humic gel synthesized from an activated epoxy silica gel

    International Nuclear Information System (INIS)

    Barbot, C.; Pieri, J.; Durand, J.P.; Goudard, F.; Czerwinski, K.; Vial, M.; Buckau, G.; Kim, J.I.; Moulin, V.

    2002-01-01

    Purified humic acid has been covalently bound on activated epoxy silica gel particles. Determination of physical properties and chemical properties was conducted in order to characterize the material at different stages of the preparation. FTIR spectra and the PEC of the surface bound humic acid is very similar to that of humic acid starting material. This shows that the humic acid was not deteriorated during the surface binding process. This humic gel can be used as an analogue for sediment associated humic acid, with the advantage that covalently bound humic acid does not desorb, and thus allows for simple species separation between non-complexed and humic bound metal ions in batch and column experiments

  9. An Expert System-based Context-Aware Ubiquitous Learning Approach for Conducting Science Learning Activities

    Science.gov (United States)

    Wu, Po-Han; Hwang, Gwo-Jen; Tsai, Wen-Hung

    2013-01-01

    Context-aware ubiquitous learning has been recognized as being a promising approach that enables students to interact with real-world learning targets with supports from the digital world. Several researchers have indicated the importance of providing learning guidance or hints to individual students during the context-aware ubiquitous learning…

  10. Evaluation of a ubiquitous learning system in a design engineering environment

    NARCIS (Netherlands)

    Vroom, R.W.; Horvath, I.; Rusak, Z.; De Smit, A.; Opiyo, E.Z.

    2012-01-01

    Ubiquitous computing is computing power that is integrated in devices and environments in such a way that they offer optimal support to human daily life activities. For industrial design engineering students, applying ubiquitous technologies offer a great opportunity and challenge for innovating

  11. Conjoint Analysis for Mobile Devices for Ubiquitous Learning in Higher Education: The Korean Case

    Science.gov (United States)

    Lee, Hyeongjik

    2013-01-01

    Despite the increasing importance of mobile devices in education, the essential features of these devices for ubiquitous learning have not been empirically addressed. This study empirically investigated the necessary conditions for using mobile devices as an educational tool for ubiquitous learning in higher education by a conjoint method. The…

  12. The Influential Factors for the Variation of Data Sensitivity in Ubiquitous Social Networking

    DEFF Research Database (Denmark)

    Sapuppo, Antonio

    2013-01-01

    Ubiquitous social networking services offer new opportunities for developing advantageous relationships by uncovering hidden connections that people share with others nearby. As sharing of personal information is an intrinsic part of ubiquitous social networking, these services are subject......, mood, location familiarity, number of previous encounters and mutual friends, were also discovered to influence participants' data disclosure, but as factors of secondary importance....

  13. Ambient Learning Displays - Distributed Mixed Reality Information Mash-ups to support Ubiquitous Learning

    NARCIS (Netherlands)

    Börner, Dirk

    2012-01-01

    Börner, D. (2012). Ambient Learning Displays - Distributed Mixed Reality Information Mash-ups to support Ubiquitous Learning. 2012 IEEE Seventh International Conference on Wireless, Mobile and Ubiquitous Technology in Education (pp. 337-338). March, 27-30, 2012, Takamatsu, Japan: IEEE Computer

  14. Self-Assembly of Molecular Threads into Reversible Gels

    Science.gov (United States)

    Sayar, Mehmet; Stupp, Samuel I.

    2001-03-01

    Reversible gels formed by low concentrations of molecular gelators that self-assemble into fibers with molecular width and extremely long length have been studied via Monte Carlo simulations. The gelators of interest have two kinds of interactions, one governs self-assembly into fibers and the other provides inter-fiber connectivity to drive the formation of a network. The off-lattice Monte Carlo simulation presented here is based on a point particle representation of gelators. In this model each particle can form only two strong bonds, that enable linear fiber formation, but a variable number of weak bonds which provide inter-fiber connectivity. The gel formation has been studied as a function of concentration of monomers, the strength of interactions, number of bonding sites per particle for weak interactions, and the stiffness of the fibers. The simulation results are compared with two experimental systems synthesized in our group in order to understand gelation mechanisms.

  15. Neutron detector based on lithiated sol-gel glass

    CERN Document Server

    Wallace, S; Miller, L F; Dai, S

    2002-01-01

    A neutron detector technology is demonstrated based on sup 6 Li/ sup 1 sup 0 B doped sol-gel glass. The detector is a sol-gel glass film coated silicon surface barrier detector (SBD). The ionized charged particles from (n, alpha) reactions in the sol-gel film enter the SBD and are counted. Data showing that gamma-ray pulse amplitudes interfere with identifying charged particles that exit the film layer with energies below the gamma-ray energy is presented. Experiments were performed showing the effect of sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co gamma rays on the SBD detector. The reaction product energies of the triton and alpha particles from sup 6 Li are significantly greater than the energies of the Compton electrons from high-energy gamma rays, allowing the measurement of neutrons in a high gamma background. The sol-gel radiation detection technology may be applicable to the characterization of transuranic waste, spent nuclear fuel and to the monitoring of stored plutonium.

  16. Rheology of Emulsion-Filled Gels Applied to the Development of Food Materials

    Directory of Open Access Journals (Sweden)

    Ivana M. Geremias-Andrade

    2016-08-01

    Full Text Available Emulsion-filled gels are classified as soft solid materials and are complex colloids formed by matrices of polymeric gels into which emulsion droplets are incorporated. Several structural aspects of these gels have been studied in the past few years, including their applications in food, which is the focus of this review. Knowledge of the rheological behavior of emulsion-filled gels is extremely important because it can measure interferences promoted by droplets or particle inclusion on the textural properties of the gelled systems. Dynamic oscillatory tests, more specifically, small amplitude oscillatory shear, creep-recovery tests, and large deformation experiments, are discussed in this review as techniques present in the literature to characterize rheological behavior of emulsion-filled gels. Moreover, the correlation of mechanical properties with sensory aspects of emulsion-filled gels appearing in recent studies is discussed, demonstrating the applicability of these parameters in understanding mastication processes.

  17. Kinetics Study of Gas Pollutant Adsorption and Thermal Desorption on Silica Gel

    Directory of Open Access Journals (Sweden)

    Rong A

    2017-06-01

    Full Text Available Silica gel is a typical porous desiccant material. Its adsorption performance for gaseous air pollutants was investigated to determine its potential contribution to reducing such pollutants. Three gaseous air pollutants, toluene, carbon dioxide, and methane, were investigated in this paper. A thermogravimetric analyzer was used to obtain the equilibrium adsorption capacity of gases on single silica gel particles. The silica gel adsorption capacity for toluene is much higher than that for carbon dioxide and methane. To understand gas pollutant thermal desorption from silica gel, the thermogravimetric analysis of toluene desorption was conducted with 609 ppm toluene vapor at 313 K, 323 K, and 333 K. The overall regeneration rate of silica gel was strongly dependent on temperature and the enthalpy of desorption. The gas pollutant adsorption performance and thermal desorption on silica gel material may be used to estimate the operating and design parameters for gas pollutant adsorption by desiccant wheels.

  18. Chemical Gel for Surface Decontamination

    International Nuclear Information System (INIS)

    Jung, Chong Hun; Moon, J. K.; Won, H. J.; Lee, K. W.; Kim, C. K.

    2010-01-01

    Many chemical decontamination processes operate by immersing components in aggressive chemical solutions. In these applications chemical decontamination technique produce large amounts of radioactive liquid waste. Therefore it is necessary to develop processes using chemical gels instead of chemical solutions, to avoid the well-known disadvantages of chemical decontamination techniques while retaining their high efficiency. Chemical gels decontamination process consists of applying the gel by spraying it onto the surface of large area components (floors, walls, etc) to be decontaminated. The gel adheres to any vertical or complex surface due to their thixotropic properties and operates by dissolving the radioactive deposit, along with a thin layer of the gel support, so that the radioactivity trapped at the surface can be removed. Important aspects of the gels are that small quantities can be used and they show thixitropic properties : liquid during spraying, and solid when stationary, allowing for strong adherence to surfaces. This work investigates the decontamination behaviors of organic-based chemical gel for SS 304 metallic surfaces contaminated with radioactive materials

  19. Denaturing gradient gel electrophoresis

    International Nuclear Information System (INIS)

    Kocherginskaya, S.A.; Cann, I.K.O.; Mackie, R.I.

    2005-01-01

    It is worthwhile considering that only some 30 species make up the bulk of the bacterial population in human faeces at any one time based on the classical cultivation-based approach. The situation in the rumen is similar. Thus, it is practical to focus on specific groups of interest within the complex community. These may be the predominant or the most active species, specific physiological groups or readily identifiable (genetic) clusters of phylogenetically related organisms. Several 16S rDNA fingerprinting techniques can be invaluable for selecting and monitoring sequences or phylogenetic groups of interest and are described below. Over the past few decades, considerable attention was focussed on the identification of pure cultures of microbes on the basis of genetic polymorphisms of DNA encoding rRNA such as ribotyping, amplified fragment length polymorphism and randomly amplified polymorphic DNA. However, many of these methods require prior cultivation and are less suitable for use in analysis of complex mixed populations although important in describing cultivated microbial diversity in molecular terms. Much less attention was given to molecular characterization of complex communities. In particular, research into diversity and community structure over time has been revolutionized by the advent of molecular fingerprinting techniques for complex communities. Denaturing or temperature gradient gel electrophoresis (DGGE/TGGE) methods have been successfully applied to the analysis of human, pig, cattle, dog and rodent intestinal populations

  20. Method of using triaxial magnetic fields for making particle structures

    Science.gov (United States)

    Martin, James E.; Anderson, Robert A.; Williamson, Rodney L.

    2005-01-18

    A method of producing three-dimensional particle structures with enhanced magnetic susceptibility in three dimensions by applying a triaxial energetic field to a magnetic particle suspension and subsequently stabilizing said particle structure. Combinations of direct current and alternating current fields in three dimensions produce particle gel structures, honeycomb structures, and foam-like structures.

  1. Ubi-RKE: A Rhythm Key Based Encryption Scheme for Ubiquitous Devices

    Directory of Open Access Journals (Sweden)

    Jae Dong Lee

    2014-01-01

    Full Text Available As intelligent ubiquitous devices become more popular, security threats targeting them are increasing; security is seen as one of the major challenges of the ubiquitous computing. Now a days, applying ubiquitous computing in number of fields for human safety and convenience was immensely increased in recent years. The popularity of the technology is rising day by day, and hence the security is becoming the main focused point with the advent and rising popularity of the applications. In particular, the number of wireless networks based on ubiquitous devices has increased rapidly; these devices support transmission for many types of data traffic. The convenient portability of ubiquitous devices makes them vulnerable to security threats, such as loss, theft, data modification, and wiretapping. Developers and users should seriously consider employing data encryption to protect data from such vulnerabilities. In this paper, we propose a Rhythm Key based Encryption scheme for ubiquitous devices (Ubi-RKE. The concept of Rhythm Key based Encryption has been applied to numerous real world applications in different domains. It provides key memorability and secure encryption through user touching rhythm on ubiquitous devices. Our proposed scheme is more efficient for users than existing schemes, by providing a strong cipher.

  2. SU-E-T-243: MonteCarlo Simulation Study of Polymer and Radiochromic Gel for Three-Dimensional Proton Dose Distribution

    International Nuclear Information System (INIS)

    Park, M; Jung, H; Kim, G; Ji, Y; Kim, K; Park, S

    2014-01-01

    Purpose: To estimate the three dimensional dose distributions in a polymer gel and a radiochromic gel by comparing with the virtual water phantom exposed to proton beams by applying Monte Carlo simulation. Methods: The polymer gel dosimeter is the compositeness material of gelatin, methacrylic acid, hydroquinone, tetrakis, and distilled water. The radiochromic gel is PRESAGE product. The densities of polymer and radiochromic gel were 1.040 and 1.0005 g/cm3, respectively. The shape of water phantom was a hexahedron with the size of 13 × 13 × 15 cm3. The proton beam energies of 72 and 116 MeV were used in the simulation. Proton beam was directed to the top of the phantom with Z-axis and the shape of beam was quadrangle with 10 × 10 cm2 dimension. The Percent depth dose and the dose distribution were evaluated for estimating the dose distribution of proton particle in two gel dosimeters, and compared with the virtual water phantom. Results: The Bragg-peak for proton particles in two gel dosimeters was similar to the virtual water phantom. Bragg-peak regions of polymer gel, radiochromic gel, and virtual water phantom were represented in the identical region (4.3 cm) for 72 MeV proton beam. For 116 MeV proton beam, the Bragg-peak regions of polymer gel, radiochromic gel, and virtual water phantom were represented in 9.9, 9.9 and 9.7 cm, respectively. The dose distribution of proton particles in polymer gel, radiochromic gel, and virtual water phantom was approximately identical in the case of 72 and 116 MeV energies. The errors for the simulation were under 10%. Conclusion: This work indicates the evaluation of three dimensional dose distributions by exposing proton particles to polymer and radiochromic gel dosimeter by comparing with the water phantom. The polymer gel and the radiochromic gel dosimeter show similar dose distributions for the proton beams

  3. Multiple dark matter scenarios from ubiquitous stringy throats

    DEFF Research Database (Denmark)

    Chialva, D.; Dev, P.S.B.; Mazumdar, A.

    2013-01-01

    We discuss the possibility of having multiple Kaluza-Klein dark matter candidates which arise naturally in generic type-IIB string theory compactification scenarios. These dark matter candidates reside in various throats of the Calabi-Yau manifold. In principle, they can come with a varied range......, we find that the mass scales allowed for the Kaluza-Klein dark matter particles in various throats can vary between 0.1 eV and 10 TeV, depending upon the throat geometry. Thus, there could be simultaneously more than one kind of cold (and possibly warm and hot) dark matter components residing...... in the Universe. This multiple dark matter scenario could weaken the bound on a conventional supersymmetric dark matter candidate and could also account for extra relativistic degrees of freedom in our Universe....

  4. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  5. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  6. Multimodal and ubiquitous computing systems: supporting independent-living older users.

    Science.gov (United States)

    Perry, Mark; Dowdall, Alan; Lines, Lorna; Hone, Kate

    2004-09-01

    We document the rationale and design of a multimodal interface to a pervasive/ubiquitous computing system that supports independent living by older people in their own homes. The Millennium Home system involves fitting a resident's home with sensors--these sensors can be used to trigger sequences of interaction with the resident to warn them about dangerous events, or to check if they need external help. We draw lessons from the design process and conclude the paper with implications for the design of multimodal interfaces to ubiquitous systems developed for the elderly and in healthcare, as well as for more general ubiquitous computing applications.

  7. FTRA 4th International Conference on Mobile, Ubiquitous, and Intelligent Computing

    CERN Document Server

    Adeli, Hojjat; Park, Namje; Woungang, Isaac

    2014-01-01

    MUSIC 2013 will be the most comprehensive text focused on the various aspects of Mobile, Ubiquitous and Intelligent computing. MUSIC 2013 provides an opportunity for academic and industry professionals to discuss the latest issues and progress in the area of intelligent technologies in mobile and ubiquitous computing environment. MUSIC 2013 is the next edition of the 3rd International Conference on Mobile, Ubiquitous, and Intelligent Computing (MUSIC-12, Vancouver, Canada, 2012) which was the next event in a series of highly successful International Workshop on Multimedia, Communication and Convergence technologies MCC-11 (Crete, Greece, June 2011), MCC-10 (Cebu, Philippines, August 2010).

  8. Gel electrophoresis of inorganic cations

    International Nuclear Information System (INIS)

    Schoenhofer, F.; Grass, F.

    1978-01-01

    In order to be able to separate the largest possible amounts of substance, polyacryl amide gel (PAA) and silica gel are used as carrier for the electrophoresis. Milligramme quantities can easily be separated on PAA gel plates. Electrophoretic ion focussing considerably improves it. Separations of Sr/Y and lanthanoids were carried out. The behaviour of the readily soluble complexing agent acids on silica gel thin layers was minutely investigated and an interpretation of the focussing effect was derived. The conditions for separating radionuclides were optimized. A further improved separation can be achieved by a time sequence combination of normal electrophoresis and ion focussing. Selective isolation methods are advantageous to determine radionuclide traces in environmental samples. The selective adsorption on preformed deposits was transferred to electrophoresis. After pre-investigations on silica gel layers, strontium and barium could also be retained on PAA gel and radium on strontium sulphate in PAA, whereas the disturbing calcium can easily pass through. Cesium can also be retained by prussian blue in the electrophoresis. (orig.) [de

  9. NMR mechanisms in gel dosimetry

    International Nuclear Information System (INIS)

    Schreiner, L J

    2009-01-01

    Nuclear magnetic resonance was critical to the development of gel dosimetry, as it established the potential for three dimensional dosimetry with chemical dosimeter systems through magnetic resonance imaging [1]. In the last two decades MRI has served as the gold standard for imaging, while NMR relaxometry has played an important role in the development and understanding of the behaviour of new gel dosimetry systems. Therefore, an appreciation of the relaxation mechanisms determining the NMR behaviour of irradiated gel dosimeters is important for a full comprehension of a considerable component of the literature on gel dosimetry. A number of excellent papers have presented this important theory, this brief review will highlight some of the salient points made previously [1-5]. The spin relaxation of gel dosimeters (which determines the dose dependence in most conventional MR imaging) is determined principally by the protons on water molecules in the system. These water protons exist in different environments, or groups (see Figure 1): on bulk water, on water hydrating the chemical species that are being modified under irradiation, and on water hydrating the gel matrix used to spatially stabilize the dosimeter (e.g., gelatin, agarose, etc). The spin relaxation depends on the inherent relaxation rate of each spin group, that is, on the relaxation rate which would be observed for the specific group if it were isolated. Also, the different water environments are not isolated from each other, and the observed relaxation rate also depends on the rate of exchange of magnetization between the groups, and on the fraction of protons in each group. In fact, the water exchanges quickly between the environments, so that relaxation is in what is usually termed the fast exchange regime. In the limit of fast exchange, the relaxation of the water protons is well characterized by a single exponential and hence by a single apparent relaxation rate. In irradiated gel dosimeters this

  10. Influence of Ubiquitous Electron Acceptors on In Situ Anaerobic Biotransformation of RDX in Groundwater

    National Research Council Canada - National Science Library

    Wani, Altaf

    2003-01-01

    A series of column studies, with aquifer material from the former Nebraska Ordnance Plant, were performed to explore the phenomenon of electron competition from ubiquitous inorganic electron acceptors (nitrate and sulfate...

  11. Ambient Learning Displays - Distributed Mixed Reality Information Mash-ups to support Ubiquitous Learning

    NARCIS (Netherlands)

    Börner, Dirk

    2010-01-01

    Börner, D. (2010, 19-21 March). Ambient Learning Displays Distributed Mixed Reality Information Mash-ups to support Ubiquitous Learning. Presented at the IADIS International Conference Mobile Learning 2010, Porto, Portugal.

  12. The Synergy of Paper-Based and Digital Material for Ubiquitous Foreign Language Learners

    Directory of Open Access Journals (Sweden)

    Sabrina Leone

    2011-09-01

    Full Text Available In recent years, the development of digital information transfer, storage and communication methods has allowed for access to ubiquitous global connections and to a large number of resources available to foreign language students at all age and levels of schooling. Further, the combination of traditional paper-based learning material with digital one in a ubiquitous learning environment may offer great innovation in the delivery of education, to foster a student-centred approach, and to accommodate the needs of ubiquitous learners’ personal lifestyles. In this direction, research has increasingly emphasised the importance of a technology-enhanced rather than technology-driven learning approach. This paper aims to evaluate the effectiveness of the integration of paper-based and digital material through Quick Response (QR code for ubiquitous English language learners in three different scenarios. Results show that, despite some difficulties, flexibility and personalisation of learning have been perceived as an asset.

  13. System architecture for ubiquitous live video streaming in university network environment

    CSIR Research Space (South Africa)

    Dludla, AG

    2013-09-01

    Full Text Available an architecture which supports ubiquitous live streaming for university or campus networks using a modified bluetooth inquiry mechanism with extended ID, integrated end-user device usage and adaptation to heterogeneous networks. Riding on that architecture...

  14. Gel combustion synthesis of yttria stabilized zirconia

    International Nuclear Information System (INIS)

    Vijay, Soja K.; Chandramouli, V.; Anthonysamy, S.

    2013-01-01

    Nano - crystalline 8 mol% yttria stabilized zirconia (YSZ) powders were synthesized by gel combustion technique employing both microwave heating as well as conventional heating method. Three different fuels - citric acid, urea and glycine were used for the synthesis with fuel to oxidant ratio as 1:1. The effect of fuel on the crystal structure, particle size, specific surface area, morphology and sintering density was studied. X-ray powder diffraction (XRD), BET gas adsorption technique, dynamic light scattering, transmission and scanning electron microscopy (TEM and SEM) and micro-Raman spectroscopy were used to characterize the powders. The results obtained for powders obtained using both methods - microwave assisted and hotplate - were compared. The specific surface area of powders in all cases are comparable except in the case of urea as fuel where microwave assisted synthesis yielded powders with lower surface area. The particle size distribution of all samples obtained using microwave method was unimodal, whereas the particle size distribution of samples prepared using hot plate method using urea fuel showed bimodal distribution. The compacts obtained using powders with citric acid and glycine as fuel showed more than 94% theoretical density, whereas the samples obtained using urea showed density below 90% of theoretical density. (author)

  15. Smart Geographic object: Toward a new understanding of GIS Technology in Ubiquitous Computing

    OpenAIRE

    Zakaria, Sakyoud; Rey, Gaëtan; Mohamed, Eladnani; Lavirotte, Stéphane; Abdelaziz, El Fazziki; Tigli, Jean-Yves

    2015-01-01

    International audience; One of the fundamental aspects of ubiquitous computing is the instrumentation of the real world by smart devices. This instrumentation constitutes an opportunity to rethink the interactions between human beings and their environment on the one hand, and between the components of this environment on the other. In this paper we discuss what this understanding of ubiquitous computing can bring to geographic science and particularly to GIS technology. Our main idea is the ...

  16. Interactive Spaces: Towards Collaborative structuring and Ubiquitous Presentation in Domestic Environment

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Grønbæk, Kaj

    2004-01-01

    collaborative structuring and ubiquitous presentation of materials in private homes. With DoHM we propose establishing new relationship between digital and physical hyperspaces, folding hyperspaces into the physical space of the household. Thus we strive to combine the qualities of physical domestic materials...... and spaces with the flexibility and dynamics of digital hyperspaces. We propose a variety of new ubiquitous home appliances called MediaWall, MediaTable, MediaTray and MediaPort, which address these issues....

  17. Interactive Spaces: Towards Collaborative Structuring and Ubiquitous Presentation in Domestic Environments

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Grønbæk, Kaj

    2004-01-01

    collaborative structuring and ubiquitous presentation of materials in private homes. With DoHM we propose establishing new relationship between digital and physical hyperspaces, folding hyperspaces into the physical space of the household. Thus we strive to combine the qualities of physical domestic materials...... and spaces with the flexibility and dynamics of digital hyperspaces. We propose a variety of new ubiquitous home appliances called MediaWall, MediaTable, MediaTray and MediaPort, which address these issues....

  18. Thixotropic gel for vadose zone remediation

    Science.gov (United States)

    Rhia, Brian D [Augusta, GA

    2011-03-01

    A thixotropic gel suitable for use in subsurface bioremediation is provided along with a process of using the gel. The thixotropic gel provides a non-migrating injectable substrate that can provide below ground barrier properties. In addition, the gel components provide for a favorable environment in which certain contaminants are preferentially sequestered in the gel and subsequently remediated by either indigenous or introduced microorganisms.

  19. Recovery of Filtered Graphene Oxide Residue Using Elastic Gel Packed in a Column by Cross Flow

    Directory of Open Access Journals (Sweden)

    Yuji Takaoka

    2018-04-01

    Full Text Available To recover the filtered residues on a gel layer in a column, the method using the elasticity of the gel layer and flowing water in a cross-flow manner is proposed. Polymerized spherical gel (40 μm was packed in a column to a set height of 0.7 cm. The suspensions of graphene oxide at various sizes and shapes were injected on the top of the gel layer and then water was flowed at a flow rate of 1000 mL·h−1 until 0.10 MPa. By releasing the applied pressure, the elastic gel layer rose up, and the filtered graphene oxide also rose above the layer. This rise of the gel layer is due to the difference of pressure between the gel layer, including the filtered graphene oxide, and the open bottom of the column, using the flow of water. The cross flow of water through the column carried away the larger-sized filtered graphene oxide floating above the gel layer. The elasticity of the gel layer and cross flow through the column has the potential to recover the filtered particles.

  20. Active nematic gels as active relaxing solids

    Science.gov (United States)

    Turzi, Stefano S.

    2017-11-01

    I propose a continuum theory for active nematic gels, defined as fluids or suspensions of orientable rodlike objects endowed with active dynamics, that is based on symmetry arguments and compatibility with thermodynamics. The starting point is our recent theory that models (passive) nematic liquid crystals as relaxing nematic elastomers. The interplay between viscoelastic response and active dynamics of the microscopic constituents is naturally taken into account. By contrast with standard theories, activity is not introduced as an additional term of the stress tensor, but it is added as an external remodeling force that competes with the passive relaxation dynamics and drags the system out of equilibrium. In a simple one-dimensional channel geometry, we show that the interaction between nonuniform nematic order and activity results in either a spontaneous flow of particles or a self-organization into subchannels flowing in opposite directions.

  1. THERMALLY STABLE NANOCRYSTALLINE TIO2 PHOTOCATALYSTS SYNTHESIZED VIA SOL-GEL METHODS MODIFIED WITH IONIC LIQUID AND SURFACTANT MOLECULES

    Science.gov (United States)

    Recently, sol-gel methods employing ionic liquids (ILs) have shown significant implications for the synthesis of well-defined nanostructured inorganic materials. Herein, we synthesized nanocrystalline TiO2 particles via an alkoxide sol-gel method employing a water-immi...

  2. Surface grafted chitosan gels. Part II. Gel formation and characterization

    DEFF Research Database (Denmark)

    Liu, Chao; Thormann, Esben; Claesson, Per M.

    2014-01-01

    Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After...... cross-linking the chitosan present in the polyelectrolyte multilayer, poly(acrylic acid) is partly removed by exposing the multilayer structure to a concentrated carbonate buffer solution at a high pH, leaving a surface-grafted cross-linked gel. Chemical cross-linking enhances the gel stability against...... detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross...

  3. From Many-to-One to One-to-Many: The Evolution of Ubiquitous Computing in Education

    Science.gov (United States)

    Chen, Wenli; Lim, Carolyn; Tan, Ashley

    2011-01-01

    Personal, Internet-connected technologies are becoming ubiquitous in the lives of students, and ubiquitous computing initiatives are already expanding in educational contexts. Historically in the field of education, the terms one-to-one (1:1) computing and ubiquitous computing have been interpreted in a number of ways and have at times been used…

  4. Alpha/beta separation in liquid scintillation gel samples

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    1994-01-01

    The pulse shape analysis commonly used in liquid scintillation alpha/beta separations is satisfactory for moderate quench levels. However, for gel samples, the alpha particle counting efficiency is never greater than 10%, and an optimum separation of the alpha component cannot be achieved when beta to alpha counting rate ratios are greater than 100. In such cases, it is better to use a spectrum analysis method for alpha/beta separation. ((orig.))

  5. Host Tissue Interaction, Fate, and Risks of Degradable and Nondegradable Gel Fillers

    DEFF Research Database (Denmark)

    Christensen, Lise

    2009-01-01

    BACKGROUND A constantly increasing number of gel fillers for aesthetic and reconstructive purposes have been introduced during the last 20 years. Most of the new ones are modified versions of the original collagen and hyaluronic acid gels. They have been reconstructed, often by adding cross......-bindings to the polymer in order to obtain a more dense molecular structure, which will prolong degradation and filling effect of the gel. Other gel fillers contain particles of organic (poly-lactic acid) or inorganic (calcium hydroxylapatite) material, which have been used in human tissue for other purposes (degradable...... are based on experimental and clinical observations coupled with a search of the literature. RESULTS AND CONCLUSION Complications following homogenous hydrogels are caused by infection with bacteria, which have been inserted into the gel during injection. If not treated with relevant antibiotics (but...

  6. Fundamentals of Polymer Gel Dosimeters

    Science.gov (United States)

    McAuley, Kim B.

    2006-12-01

    The recent literature on polymer gel dosimetry contains application papers and basic experimental studies involving polymethacrylic-acid-based and polyacrylamide-based gel dosimeters. The basic studies assess the relative merits of these two most commonly used dosimeters, and explore the effects of tetrakis hydroxymethyl phosphonium chloride (THPC) antioxidant on dosimeter performance. Polymer gel dosimeters that contain THPC or other oxygen scavengers are called normoxic dosimeters, because they can be prepared under normal atmospheric conditions, rather than in a glove box that excludes oxygen. In this review, an effort is made to explain some of the underlying chemical phenomena that affect dosimeter performance using THPC, and that lead to differences in behaviour between dosimeters made using the two types of monomer systems. Progress on the development of new more effective and less toxic dosimeters is also reported.

  7. Fast and facile preparation of CTAB based gels and their applications in Au and Ag nanoparticles synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ravi Kant, E-mail: rkupadhyay85@gmail.com [Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India); Soin, Navneet, E-mail: n.soin@bolton.ac.uk [Knowledge Centre for Materials Chemistry (KCMC), Institute for Materials Research and Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom); Saha, Susmita, E-mail: ssaha@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Barman, Anjan, E-mail: abarman@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Sinha Roy, Susanta, E-mail: susanta.roy@snu.edu.in [Department of Physics, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India)

    2015-04-15

    We have demonstrated that the gel-like mesophase of Cetyltrimethylammonium bromide (CTAB) can be synthesized by judicial adjustment of water to surfactant molar ratio (W{sub 0}), without using any additional salts, gelating agents or co-surfactants. Gel formation was found to be highly dependent on the water to surfactant molar ratio (W{sub 0}), with the lowest value of W{sub 0} (41.5) resulting in rapid gel formation. Environmental scanning electron microscope (ESEM) analysis revealed that the gel was comprised of interconnected cylindrical structures. The presence of hydrogen bonding in the gel-like mesophase was confirmed by Fourier Transform Infrared spectroscopy (FTIR) analysis. Rheology measurements revealed that all the gel samples were highly viscoelastic in nature. Furthermore, Au and Ag containing CTAB gels were explored as precursors for the preparation of spherical Gold (Au) and Silver (Ag) nanoparticles using Sodium borohydride (NaBH{sub 4}) as reducing agent. The effects of NaBH{sub 4} concentration on the particle size and morphology of the Au and Ag nanoparticles have also been studied. - Highlights: • A facile synthesis of CTAB based gel-like mesophase is reported. • CTAB gels were obtained by adjusting water to surfactant molar ratio (W{sub 0}). • FTIR analysis revealed that hydrogen bonding plays a key role in gel formation. • Au, Ag nanoparticles were synthesized by using CTAB gel and NaBH{sub 4}.

  8. AUP1 (Ancient Ubiquitous Protein 1) Is a Key Determinant of Hepatic Very-Low-Density Lipoprotein Assembly and Secretion.

    Science.gov (United States)

    Zhang, Jing; Zamani, Mostafa; Thiele, Christoph; Taher, Jennifer; Amir Alipour, Mohsen; Yao, Zemin; Adeli, Khosrow

    2017-04-01

    AUP1 (ancient ubiquitous protein 1) is an endoplasmic reticulum-associated protein that also localizes to the surface of lipid droplets (LDs), with dual role in protein quality control and LD regulation. Here, we investigated the role of AUP1 in hepatic lipid mobilization and demonstrate critical roles in intracellular biogenesis of apoB100 (apolipoprotein B-100), LD mobilization, and very-low-density lipoprotein (VLDL) assembly and secretion. APPROACH AND RESULTS: siRNA (short/small interfering RNA) knockdown of AUP1 significantly increased secretion of VLDL-sized apoB100-containing particles from HepG2 cells, correcting a key metabolic defect in these cells that normally do not secrete much VLDL. Secreted particles contained higher levels of metabolically labeled triglyceride, and AUP1-deficient cells displayed a larger average size of LDs, suggesting a role for AUP1 in lipid mobilization. Importantly, AUP1 was also found to directly interact with apoB100, and this interaction was enhanced with proteasomal inhibition. Knockdown of AUP1 reduced apoB100 ubiquitination, decreased intracellular degradation of newly synthesized apoB100, and enhanced extracellular apoB100 secretion. Interestingly, the stimulatory effect of AUP1 knockdown on VLDL assembly was reminiscent of the effect previously observed after MEK-ERK (mitogen-activated protein kinase kinase-extracellular signal-regulated kinase) inhibition; however, further studies indicated that the AUP1 effect was independent of MEK-ERK signaling. In summary, our findings reveal an important role for AUP1 as a regulator of apoB100 stability, hepatic LD metabolism, and intracellular lipidation of VLDL particles. AUP1 may be a crucial factor in apoB100 quality control, determining the rate at which apoB100 is degraded or lipidated to enable VLDL particle assembly and secretion. © 2017 American Heart Association, Inc.

  9. Ultrasound-assisted sol-gel synthesis of ZrO2.

    Science.gov (United States)

    Guel, Marlene Lariza Andrade; Jiménez, Lourdes Díaz; Hernández, Dora Alicia Cortés

    2017-03-01

    Synthesis of tetragonal ZrO 2 by both conventional sol-gel and ultrasound-assisted sol-gel methods and using a non-ionic surfactant Tween-20, was performed. A porous microstructure composed of nanometric particles was observed. Tetragonal ZrO 2 was obtained using a low heat treatment temperature of powders, 500°C by both methods. A higher crystallinity and a shorter reaction time were observed when ultrasound was used in the sol-gel method due to the cavitation phenomenon. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. SOL-Gel microspheres and nanospheres for controlled release applications

    International Nuclear Information System (INIS)

    Barbe, C.; Beyer, R.; Kong, L.; Blackford, M.; Trautman, R.; Bartlett, J.

    2002-01-01

    We present a novel approach to the synthesis of inorganic sol-gel microspheres for encapsulating organic and bioactive molecules, and controlling their subsequent release kinetics. The bioactive species are incorporated, at ambient temperature, into the inorganic particles using an emulsion gelation process. Independent control of the release rate (by adapting the nanostructure of the internal pore network to the physico-chemical properties of the bioactive molecules) and particle size (by tailoring the emulsion chemistry) is demonstrated. Sol-gel chemistry has been shown to be a flexible technique for producing inorganic silica matrices with tailored microstructures, which can be used for the encapsulation and controlled release of organic and bioactive molecules. The present paper extends this concept by combining sol-gel chemistry with an emulsion approach for producing inorganic particles with controlled dimensions, and demonstrates how the particle size and microstructure can be independently controlled. Sol-Gel Chemistry and Encapsulation of Model Compounds. A stock solution of 4-(2-hydroxy-l-naphthylazo) benzene sulfonic acid (Orange II) was produced by dissolving Orange II in water (0.1 wt%), and adjusting the pH to the required value. Sol-gel solutions were subsequently prepared by mixing the aqueous solution with tetramethylorthosilicate (TMOS) and methanol (MeOH), to achieve H 2 O:TMOS (W] and MeOH:TMOS mole ratios (D) of four. The resulting solution was stirred and left to age at ambient temperature for one day. A transparent emulsion was prepared by mixing selected surfactants and organic solvents. The surfactants used included sorbitan monooleate, sorbitan monolaurate and bis-2-ethylhexylsulfo-succinate (AOT), while the organic phase was typically chosen from the group consisting of kerosene, hexane, heptane, octane, decane, dodecane and cyclohexane. The sol-gel solution was added to the emulsion, and the resulting mixture was stirred at 500 rpm for

  11. Ubiquitous testing using tablets: its impact on medical student perceptions of and engagement in learning.

    Science.gov (United States)

    Kim, Kyong-Jee; Hwang, Jee-Young

    2016-03-01

    Ubiquitous testing has the potential to affect medical education by enhancing the authenticity of the assessment using multimedia items. This study explored medical students' experience with ubiquitous testing and its impact on student learning. A cohort (n=48) of third-year students at a medical school in South Korea participated in this study. The students were divided into two groups and were given different versions of 10 content-matched items: one in text version (the text group) and the other in multimedia version (the multimedia group). Multimedia items were delivered using tablets. Item response analyses were performed to compare item characteristics between the two versions. Additionally, focus group interviews were held to investigate the students' experiences of ubiquitous testing. The mean test score was significantly higher in the text group. Item difficulty and discrimination did not differ between text and multimedia items. The participants generally showed positive responses on ubiquitous testing. Still, they felt that the lectures that they had taken in preclinical years did not prepare them enough for this type of assessment and clinical encounters during clerkships were more helpful. To be better prepared, the participants felt that they needed to engage more actively in learning in clinical clerkships and have more access to multimedia learning resources. Ubiquitous testing can positively affect student learning by reinforcing the importance of being able to understand and apply knowledge in clinical contexts, which drives students to engage more actively in learning in clinical settings.

  12. A novel fibrin gel derived from hyaluronic acid-grafted fibrinogen

    International Nuclear Information System (INIS)

    Yang, Chiung L; Chen, Hui W; Wang, Tzu C; Wang, Yng J

    2011-01-01

    Fibrinogen is a major plasma protein that forms a three-dimensional fibrin gel upon being activated by thrombin. In this study, we report the synthesis and potential applications of hybrid molecules composed of fibrinogen coupled to the reducing ends of short-chain hyaluronic acids (sHAs) by reductive amination. The grafting of sHAs to fibrinogen was verified by analyzing particle size, zeta potential and gel-electrophoretic mobility of the hybrid molecules. The sHA-fibrinogen hybrid molecules with graft ratios (sHA/fibrinogen) of up to 6.5 retained the ability to form gels in response to thrombin activation. The sHA-fibrin gels were transparent in appearance and exhibited high water content, which were characteristics distinct from those of gels formed by mixtures of sHAs and fibrinogen. The potential applications of the sHA-fibrin gels were evaluated. The sHA-fibrinogen gel with a graft ratio of 3.6 (S3.6F) was examined for its ability to encapsulate and support the differentiation of ATDC5 chondrocyte-like cells. Compared with the fibrinogen-formed gel, cells cultured in the S3.6F gel exhibited increased lacunae formation; moreover, the abundance of cartilaginous extracellular matrix molecules and the expression of chondrocyte marker genes, such as aggrecan, collagen II and Sox9, were also significantly increased. Our data suggest that the three-dimensional gel formed by the sHA-fibrinogen hybrid is a better support than the fibrin gel for chondrogenesis induction.

  13. A novel fibrin gel derived from hyaluronic acid-grafted fibrinogen

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chiung L; Chen, Hui W; Wang, Tzu C; Wang, Yng J, E-mail: wang@ym.edu.tw [Institute of Biomedical Engineering, National Yang Ming University, No. 155, Sec. 2, Li-Nung St., Shih-Pai, Taipei, Taiwan 112 (China)

    2011-04-15

    Fibrinogen is a major plasma protein that forms a three-dimensional fibrin gel upon being activated by thrombin. In this study, we report the synthesis and potential applications of hybrid molecules composed of fibrinogen coupled to the reducing ends of short-chain hyaluronic acids (sHAs) by reductive amination. The grafting of sHAs to fibrinogen was verified by analyzing particle size, zeta potential and gel-electrophoretic mobility of the hybrid molecules. The sHA-fibrinogen hybrid molecules with graft ratios (sHA/fibrinogen) of up to 6.5 retained the ability to form gels in response to thrombin activation. The sHA-fibrin gels were transparent in appearance and exhibited high water content, which were characteristics distinct from those of gels formed by mixtures of sHAs and fibrinogen. The potential applications of the sHA-fibrin gels were evaluated. The sHA-fibrinogen gel with a graft ratio of 3.6 (S3.6F) was examined for its ability to encapsulate and support the differentiation of ATDC5 chondrocyte-like cells. Compared with the fibrinogen-formed gel, cells cultured in the S3.6F gel exhibited increased lacunae formation; moreover, the abundance of cartilaginous extracellular matrix molecules and the expression of chondrocyte marker genes, such as aggrecan, collagen II and Sox9, were also significantly increased. Our data suggest that the three-dimensional gel formed by the sHA-fibrinogen hybrid is a better support than the fibrin gel for chondrogenesis induction.

  14. Functional Nanofibers and Colloidal Gels: Key Elements to Enhance Functionality

    Science.gov (United States)

    Vogel, Nancy Amanda

    material so that prolonged release can be readily achieved from highly water soluble nanofibers. The final research theme focuses on gaining a fundamental understanding of a new class of materials, nanodiamond, so that a desired microstructure can be achieved via functionalization or manipulating processing parameters. In particular, we utilize both steady and dynamic rheology techniques to systematically investigate systems of nanodiamonds dispersed in model nonpolar (mineral oil) and polar (glycerol) media. In both cases, selfsupporting colloidal gels form at relatively low nanodiamond content; however, the gel behavior is highly dependent on the type of media used. Nanodiamonds dispersed in mineral oil exhibit characteristic colloidal gel behavior, with a rheological response that is independent of both frequency and time. However, nanodiamonds dispersed in glycerol exhibit a time dependent response, with the strength of the colloidal gels increasing several orders of magnitude. We attribute these rheological differences to changes in solvent complexity, where new particle-solvent and particle-particle interactions have the potential to delay optimal gel formation. In addition to colloidal gel formation, we use large oscillatory strains to probe the effect of processing parameters on microstructure disruption and recovery. The results indicate that the formation and rearrangement of the nanodiamond microstructures are concentration dependent for both media types; however, the recovery after breakdown is different for each system. Recovery of the nanodiamond/mineral oil gels is incomplete, with the strength of the recovered gel being significantly reduced. In contrast, the original strength of the nanodiamond/glycerol gels is recoverable as the system restructures with time. The practical implications of these results are significant as it suggest that shear history and solvent polarity play a dominant role in nanodiamond processing.

  15. Ubiquitous Computing Services Discovery and Execution Using a Novel Intelligent Web Services Algorithm

    Science.gov (United States)

    Choi, Okkyung; Han, SangYong

    2007-01-01

    Ubiquitous Computing makes it possible to determine in real time the location and situations of service requesters in a web service environment as it enables access to computers at any time and in any place. Though research on various aspects of ubiquitous commerce is progressing at enterprises and research centers, both domestically and overseas, analysis of a customer's personal preferences based on semantic web and rule based services using semantics is not currently being conducted. This paper proposes a Ubiquitous Computing Services System that enables a rule based search as well as semantics based search to support the fact that the electronic space and the physical space can be combined into one and the real time search for web services and the construction of efficient web services thus become possible.

  16. 21 CFR 866.4900 - Support gel.

    Science.gov (United States)

    2010-04-01

    ... IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866.4900 Support gel. (a) Identification. A support gel for clinical use is a device that consists of an agar or agarose preparation that...

  17. Yield stress determination of a physical gel

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2013-01-01

    Pluronic F127 solutions form gels in water with high elastic moduli. Pluronic gels can, however, only withstand small deformations and stresses. Different steady shear and oscillatory methods traditionally used to determine yield stress values are compared. The results show that the yield stresses...... values of these gels depend on test type and measurement time, and no absolute yield stress value can be determined for these physical gels....

  18. RECON: Capturing Mobile and Ubiquitous Interaction in Real Contexts

    DEFF Research Database (Denmark)

    Jensen, Kasper Løvborg

    2009-01-01

    for studying the user experience of such applications in the field tend to be cumbersome and expensive with regard to time and manpower, and they generally do not scale well with number of users and duration of studies. RECON addresses these challenges and provides an addition to the methodological...... to conduct large scale remote studies of mobile and ubiquitous applications in real contexts.......Evaluating the user experience of mobile and ubiquitous applications is a challenging task. They are becoming increasingly complex and tightly interwoven into the fabric of everyday life and thus cannot easily be taken out of context and evaluated in controlled experimental environments. Methods...

  19. [Facing the challenges of ubiquitous computing in the health care sector].

    Science.gov (United States)

    Georgieff, Peter; Friedewald, Michael

    2010-01-01

    The steady progress of microelectronics, communications and information technology will enable the realisation of the vision for "ubiquitous computing" where the Internet extends into the real world embracing everyday objects. The necessary technical basis is already in place. Due to their diminishing size, constantly falling price and declining energy consumption, processors, communications modules and sensors are being increasingly integrated into everyday objects today. This development is opening up huge opportunities for both the economy and individuals. In the present paper we discuss possible applications, but also technical, social and economic barriers to a wide-spread use of ubiquitous computing in the health care sector. .

  20. Particle Trapping and Banding in Rapid Colloidal Solidification

    KAUST Repository

    Elliott, J. A. W.; Peppin, S. S. L.

    2011-01-01

    We derive an expression for the nonequilibrium segregation coefficient of colloidal particles near a moving solid-liquid interface. The resulting kinetic phase diagram has applications for the rapid solidification of clay soils, gels, and related

  1. Physical Properties of Silicone Gel Breast Implants.

    Science.gov (United States)

    Jewell, Mark L; Bengtson, Bradley P; Smither, Kate; Nuti, Gina; Perry, TracyAnn

    2018-04-28

    Surgical applications using breast implants are individualized operations to fill and shape the breast. Physical properties beyond shape, size, and surface texture are important considerations during implant selection. Compare form stability, gel material properties, and shell thickness of textured shaped, textured round, and smooth round breast implants from 4 manufacturers: Allergan, Mentor, Sientra, and Establishment Labs through bench testing. Using a mandrel height gauge, form stability was measured by retention of dimensions on device movement from a horizontal to vertical supported orientation. Dynamic response of gel material (gel cohesivity, resistance to gel deformation, energy absorption) was measured using a synchronized target laser following application of graded negative pressure. Shell thickness was measured using digital thickness gauge calipers. Form stability, gel material properties, and shell thickness differed across breast implants. Of textured shaped devices, Allergan Natrelle 410 exhibited greater form stability than Mentor MemoryShape and Sientra Shaped implants. Allergan Inspira round implants containing TruForm 3 gel had greater form stability, higher gel cohesivity, greater resistance to gel deformation, and lower energy absorption than those containing TruForm 2 gel and in turn, implants containing TruForm 1 gel. Shell thickness was greater for textured versus smooth devices, and differed across styles. Gel cohesivity, resistance to gel deformation, and energy absorption are directly related to form stability, which in turn determines shape retention. These characteristics provide information to aid surgeons choosing an implant based on surgical application, patient tissue characteristics, and desired outcome.

  2. Synthesis of cadmium tungstate films via sol-gel processing

    Energy Technology Data Exchange (ETDEWEB)

    Lennstrom, Kirk; Limmer, Steven J.; Cao Guozhong

    2003-06-23

    Cadmium tungstate is a scintillator material with excellent intrinsic photoluminescent properties. It is highly resistant to gamma radiation, has an almost non-existent afterglow and is highly efficient. Cadmium tungstate is also non-hydroscopic, unlike the more prevalent thallium-doped alkali halide scintillators. In order to create thin films of cadmium tungstate with precise stoichiometric control, a sol-gel processing technique has been applied to produce this material for the first time. In addition to lower processing temperatures, sol-gel-derived cadmium tungstate is cheaper and easier than other technologies, particularly for thin films. Furthermore, it has the potential to produce nanostructured materials with good optical quality. X-Ray diffraction results of sol-gel-derived materials fired at various temperatures imply crystallization of cadmium tungstate without the intermediate formation of either tungsten oxide or cadmium oxide. Scanning electron microscopy analysis shows the formation of nano-sized particles prior to heat treatment, which form meso-sized particles after the heat treatment. Photoluminesce analysis indicates emission of derived films at 480 nm, which agrees with other published data. Finally, the efficiency of derived films was approximately 6%{+-}1.8%.

  3. Development and Characterization of Titanium Dioxide Gel with Encapsulated Bacteriorhodopsin for Hydrogen Production.

    Science.gov (United States)

    Johnson, Kaitlin E; Gakhar, Sukriti; Risbud, Subhash H; Longo, Marjorie L

    2018-06-06

    We study bacteriorhodopsin (BR) in its native purple membrane encapsulated within amorphous titanium dioxide, or titania, gels and in the presence of titania sol-particles to explore this system for hydrogen production. Förster resonance energy transfer between BR and titanium dioxide sol particles was used to conclude that there is nanometer-scale proximity of bacteriorhodopsin to the titanium dioxide. The detection of BR-titania sol aggregates by fluorescence anisotropy and particle sizing indicated the affinity amorphous titania has for BR without the use of additional cross-linkers. UV-Visible spectroscopy of BR-titania gels show that methanol addition did not denature BR at a 25 mM concentration presence as a sacrificial electron donor. Additionally, confinement of BR in the gels significantly limited protein denaturation at higher concentration of added methanol or ethanol. Subsequently, titania gels fabricated through the sol-gel process using a titanium ethoxide precursor, water and the addition of 25 mM methanol were used to encapsulate BR and a platinum reduction catalyst for the production of hydrogen gas under white light irradiation. The inclusion of 5 µM bacteriorhodopsin resulted in a hydrogen production rate of about 3.8 µmole hydrogen mL -1 hr -1 , an increase of 52% compared to gels containing no protein. Electron transfer and proton pumping by BR in close proximity to the titania gel surface are feasible explanations for the enhanced production of hydrogen without the need to crosslink BR to the titania gel. This work sets the stage for further developments of amorphous, rather than crystalline, titania-encapsulated bacteriorhodopsin for solar-driven hydrogen production through water-splitting.

  4. Evolution of heterogeneity accompanying sol-gel transitions in a supramolecular hydrogel.

    Science.gov (United States)

    Matsumoto, Yuji; Shundo, Atsuomi; Ohno, Masashi; Tsuruzoe, Nobutomo; Goto, Masahiro; Tanaka, Keiji

    2017-10-18

    When a peptide amphiphile is dispersed in water, it self-assembles into a fibrous network, leading to a supramolecular hydrogel. When the gel is physically disrupted by shaking, it transforms into a sol state. After aging at room temperature for a while, it spontaneously returns to the gel state, called sol-gel transition. However, repeating the sol-gel transition often causes a change in the rheological properties of the gel. To gain a better understanding of the sol-gel transition and its reversibility, we herein examined the thermal motion of probe particles at different locations in a supramolecular hydrogel. The sol obtained by shaking the gel was heterogeneous in terms of the rheological properties and the extent decreased with increasing aging time. This time course of heterogeneity, or homogeneity, which corresponded to the sol-to-gel transition, was observed for the 1st cycle. However, this was not the case for the 2nd and 3rd cycles; the heterogeneity was preserved even after aging. Fourier-transform infrared spectroscopy, small-angle X-ray scattering, and atomic force and confocal laser scanning microscopies revealed that, although the molecular aggregation states of amphiphiles both in the gel and sol remained unchanged with the cycles, the fibril density diversified to high and low density regions even after aging. The tracking of particles with different sizes indicated that the partial mesh size in the high density region and the characteristic length scale of the density fluctuation were smaller than 50 nm and 6 μm, respectively.

  5. The gel electrophoresis markup language (GelML) from the Proteomics Standards Initiative.

    Science.gov (United States)

    Gibson, Frank; Hoogland, Christine; Martinez-Bartolomé, Salvador; Medina-Aunon, J Alberto; Albar, Juan Pablo; Babnigg, Gyorgy; Wipat, Anil; Hermjakob, Henning; Almeida, Jonas S; Stanislaus, Romesh; Paton, Norman W; Jones, Andrew R

    2010-09-01

    The Human Proteome Organisation's Proteomics Standards Initiative has developed the GelML (gel electrophoresis markup language) data exchange format for representing gel electrophoresis experiments performed in proteomics investigations. The format closely follows the reporting guidelines for gel electrophoresis, which are part of the Minimum Information About a Proteomics Experiment (MIAPE) set of modules. GelML supports the capture of metadata (such as experimental protocols) and data (such as gel images) resulting from gel electrophoresis so that laboratories can be compliant with the MIAPE Gel Electrophoresis guidelines, while allowing such data sets to be exchanged or downloaded from public repositories. The format is sufficiently flexible to capture data from a broad range of experimental processes, and complements other PSI formats for MS data and the results of protein and peptide identifications to capture entire gel-based proteome workflows. GelML has resulted from the open standardisation process of PSI consisting of both public consultation and anonymous review of the specifications.

  6. Weak and Strong Gels and the Emergence of the Amorphous Solid State

    Directory of Open Access Journals (Sweden)

    Jack F. Douglas

    2018-02-01

    Full Text Available Gels are amorphous solids whose macroscopic viscoelastic response derives from constraints in the material that serve to localize the constituent molecules or particles about their average positions in space. These constraints may either be local in nature, as in chemical cross-linking and direct physical associations, or non-local, as in case of topological “entanglement” interactions between highly extended fiber or sheet structures in the fluid. Either of these interactions, or both combined, can lead to “gelation” or “amorphous solidification”. While gels are often considered to be inherently non-equilibrium materials, and correspondingly termed “soft glassy matter”, this is not generally the case. For example, the formation of vulcanized rubbers by cross-linking macromolecules can be exactly described as a second order phase transition from an equilibrium fluid to an equilibrium solid state, and amorphous solidification also arises in diverse physical gels in which molecular and particle localization occurs predominantly through transient molecuar associations, or even topological interactions. As equilibrium, or near equilibrium systems, such gels can be expected to exhibit universal linear and non-linear viscoelastic properties, especially near the “critical” conditions at which the gel state first emerges. In particular, a power-law viscoelastic response is frequently observed in gel materials near their “gelation” or “amorphous solidification” transition. Another basic property of physical gels of both theoretical and practical interest is their response to large stresses at constant shear rate or under a fixed macrocopic strain. In particular, these materials are often quite sensitive to applied stresses that can cause the self-assembled structure to progressively break down under flow or deformation. This disintegration of gel structure can lead to “yield” of the gel material, i.e., a fluidization

  7. Gel dosimetry for conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Gambarini, G [Department of Physics of the University and INFN, Milan (Italy)

    2005-07-01

    With the continuum development of conformal radio therapies, aimed at delivering high dose to tumor tissue and low dose to the healthy tissue around, the necessities has appeared of suitable improvement of dosimetry techniques giving the possibility of obtaining dose images to be compared with diagnostic images. Also if wide software has been developed for calculating dose distributions in the fields of various radiotherapy units, experimental verifications are necessary, in particular in the case of complex geometries in conformal radiotherapy. Gel dosimetry is a promising method for imaging the absorbed dose in tissue-equivalent phantoms, with the possibility of 3D reconstruction of the spatial dose distribution, with milli metric resolution. Optical imaging of gel dosimeters, based on visible light absorbance analysis, has shown to be a reliable technique for achieving dose distributions. (Author)

  8. Effect of Sol Concentration, Aging and Drying Process on Cerium Stabilization Zirconium Gel Produced by External Gelation

    Science.gov (United States)

    Sukarsono, R.; Rachmawati, M.; Susilowati, S. R.; Husnurrofiq, D.; Nurwidyaningrum, K.; Dewi, A. K.

    2018-02-01

    to release the decomposition of the material during heating. Larger the concentration of nitric metal in sol solution, yields a gel with a larger diameter of gels. This research allows us to plan the diameter of the sintered particles to be made.

  9. Osteoconducting bioglass synthesis via sol-gel process; Biovidro osteocondutor sintetizado pelo processo sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, R.V.; Aragones, A.; Barra, G.O.M.; Salmoria, G.V.; Fredel, M.C., E-mail: rafaelavpereira@gmail.com [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    The presence of bioglasses in scaffolds has been studied as they promote the osteoconduction in bones. The scaffolds are developed in order to induce the repair and regeneration in bone tissue. An absorbable bioglass from SiO2-CaO-P2O5 system was synthesized by sol-gel process with the intent of producing these scaffolds. Bioglass 58S was define for these work once it presents ions (Ca and P) which assist at the carbonated apatite layer formation when released. The apatite layer presents an important role at the bone regeneration and metabolism, being involved at grow and mineralization of bones. FTIR was realized to characterize the synthesized bioglass on its chemical composition, XRD to analyze the crystalline structure, solubility test to observe the weight variance and SEM to observe the particles morphology. The obtained results confirmed the production of a bioglass with the desired composition to produce osteoconducting scaffolds. (author)

  10. Study on the Context-Aware Middleware for Ubiquitous Greenhouses Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jeonghwang Hwang

    2011-04-01

    Full Text Available Wireless Sensor Network (WSN technology is one of the important technologies to implement the ubiquitous society, and it could increase productivity of agricultural and livestock products, and secure transparency of distribution channels if such a WSN technology were successfully applied to the agricultural sector. Middleware, which can connect WSN hardware, applications, and enterprise systems, is required to construct ubiquitous agriculture environment combining WSN technology with agricultural sector applications, but there have been insufficient studies in the field of WSN middleware in the agricultural environment, compared to other industries. This paper proposes a context-aware middleware to efficiently process data collected from ubiquitous greenhouses by applying WSN technology and used to implement combined services through organic connectivity of data. The proposed middleware abstracts heterogeneous sensor nodes to integrate different forms of data, and provides intelligent context-aware, event service, and filtering functions to maximize operability and scalability of the middleware. To evaluate the performance of the middleware, an integrated management system for ubiquitous greenhouses was implemented by applying the proposed middleware to an existing greenhouse, and it was tested by measuring the level of load through CPU usage and the response time for users’ requests when the system is working.

  11. Undergraduate Students' Opinions with Regard to Ubiquitous MOOC for Enhancing Cross-Cultural Competence

    Science.gov (United States)

    Plangsorn, Boonrat; Na-Songkhla, Jaitip; Luetkehans, Lara M.

    2016-01-01

    The purpose of this study was to study undergraduate students' opinions with regard to the ubiquitous massive open online course (MOOC) for enhancing cross-cultural competence. This descriptive research applied a survey method. The survey data were collected by using survey questionnaires and online questionnaires from 410 undergraduate students…

  12. Pervasion of what? : techno–human ecologies and their ubiquitous spirits.

    NARCIS (Netherlands)

    Coeckelbergh, Mark

    2012-01-01

    Are the robots coming? Is the singularity near? Will we be dominated by technology? The usual response to ethical issues raised by pervasive and ubiquitous technologies assumes a philosophical anthropology centered on existential autonomy and agency, a dualistic ontology separating humans from

  13. A Socio-technical study of an Ubiquitous CPOE-system in Local Use

    DEFF Research Database (Denmark)

    Wentzer, Helle; Böttger, Ulrich; Boye, Niels

    2006-01-01

    , transformation in competencies, and less time spent at the bedside for nurses and doctors, as a system - constructed for ubiquitous drug-order entries and handling - was implemented for local use. This study throws light on problems of patient continuity, patient-related and IT-system-related error...

  14. 2nd FTRA International Conference on Ubiquitous Computing Application and Wireless Sensor Network

    CERN Document Server

    Pan, Yi; Chao, Han-Chieh; Yi, Gangman

    2015-01-01

    IT changes everyday’s life, especially in education and medicine. The goal of ITME 2014 is to further explore the theoretical and practical issues of Ubiquitous Computing Application and Wireless Sensor Network. It also aims to foster new ideas and collaboration between researchers and practitioners. The organizing committee is soliciting unpublished papers for the main conference and its special tracks.

  15. Ubiquitous Accessibility for People with Visual Impairments: Are We There Yet?

    Science.gov (United States)

    Billah, Syed Masum; Ashok, Vikas; Porter, Donald E; Ramakrishnan, I V

    2017-05-01

    Ubiquitous access is an increasingly common vision of computing, wherein users can interact with any computing device or service from anywhere, at any time. In the era of personal computing, users with visual impairments required special-purpose, assistive technologies, such as screen readers, to interact with computers. This paper investigates whether technologies like screen readers have kept pace with, or have created a barrier to, the trend toward ubiquitous access, with a specific focus on desktop computing as this is still the primary way computers are used in education and employment. Towards that, the paper presents a user study with 21 visually-impaired participants, specifically involving the switching of screen readers within and across different computing platforms, and the use of screen readers in remote access scenarios. Among the findings, the study shows that, even for remote desktop access-an early forerunner of true ubiquitous access-screen readers are too limited, if not unusable. The study also identifies several accessibility needs, such as uniformity of navigational experience across devices, and recommends potential solutions. In summary, assistive technologies have not made the jump into the era of ubiquitous access, and multiple, inconsistent screen readers create new practical problems for users with visual impairments.

  16. Radar sensor technology developments as CSIR DPSS in support of persistent, ubiquitous surveillance systems

    CSIR Research Space (South Africa)

    Anderson, F

    2008-11-01

    Full Text Available of an S&T capability based on international technology trends in persistent, ubiquitous surveillance. The ultimate aim of this programme is to develop and produce a series of South African innovations that can be used by departments and agencies...

  17. Bringing Mohamed to the Mountain: Situated Professional Development in a Ubiquitous Computing Classroom

    Science.gov (United States)

    Swan, Karen; Kratcoski, Annette; Mazzer, Pat; Schenker, Jason

    2005-01-01

    This article describes an ongoing situated professional development program in which teachers bring their intact classes for an extended stay in a ubiquitous computing environment equipped with a variety of state-of-the-art computing devices. The experience is unique in that it not only situates teacher learning about technology integration in…

  18. Ubiquitous Computing and Changing Pedagogical Possibilities: Representations, Conceptualizations and Uses of Knowledge

    Science.gov (United States)

    Swan, Karen; Van 'T Hooft, Mark; Kratcoski, Annette; Schenker, Jason

    2007-01-01

    This article reports on preliminary findings from an ongoing study of teaching and learning in a ubiquitous computing classroom. The research employed mixed methods and multiple measures to document changes in teaching and learning that result when teachers and students have access to a variety of digital devices wherever and whenever they need…

  19. Conditions for Ubiquitous Computing: What Can Be Learned from a Longitudinal Study

    Science.gov (United States)

    Lei, Jing

    2010-01-01

    Based on survey data and interview data collected over four academic years, this longitudinal study examined how a ubiquitous computing project evolved along with the changes in teachers, students, the human infrastructure, and technology infrastructure in the school. This study also investigated what conditions were necessary for successful…

  20. Evaluating Ubiquitous Media Usability Challenges: Content Transfer and Channel Switching Delays

    DEFF Research Database (Denmark)

    Fleury, Alexandre; Pedersen, Jakob Schou; Larsen, Lars Bo

    2011-01-01

    As ubiquitous media is developing rapidly, new HCI challenges emerge. In this paper, we address usability issues related to the transfer of content between fixed and mobile devices, as well as channel switching delays on mobile devices. We first provide an extensive review of the field. We...

  1. Introducing Laptops to Children: An Examination of Ubiquitous Computing in Grade 3 Reading, Language, and Mathematics

    Science.gov (United States)

    Bernard, Robert M.; Bethel, Edward Clement; Abrami, Philip C.; Wade, C. Anne

    2007-01-01

    This study examines the achievement outcomes accompanying the implementation of a Grade 3 laptop or so-­called "ubiquitous computing" program in a Quebec school district. CAT­3 reading, language, and mathematics batteries were administered at the end of Grade 2 and again at the end of Grade 3, after the first year of computer…

  2. Ubiquitous Knowledge Construction: Mobile Learning Re-Defined and a Conceptual Framework

    Science.gov (United States)

    Peng, Hsinyi; Su, Yi-Ju; Chou, Chien; Tsai, Chin-Chung

    2009-01-01

    Emerging from recent mobile technologies, mobile learning, or m-learning, is beginning to offer "stunning new technical capabilities" in education (DiGiano et al., 2003). This new genre of learning is viewed as a revolutionary stage in educational technology. However, ubiquitous computing technologies have given rise to several issues. This…

  3. Four Stages of Research on the Educational Use of Ubiquitous Computing

    Science.gov (United States)

    Laru, Jari; Naykki, Piia; Järvelä, Sanna

    2015-01-01

    In this paper, the Gartner Group's hype cycle is used as the basis for categorizing and analyzing research on the educational use of ubiquitous computing. There are five phases of the hype cycle: the technology trigger, the peak of inflated expectations, the trough of disillusionment, the slope of enlightenment, and the plateau of productivity.…

  4. Ubiquitous and Ambient Intelligence Assisted Learning Environment Infrastructures Development--A Review

    Science.gov (United States)

    Kanagarajan, Sujith; Ramakrishnan, Sivakumar

    2018-01-01

    Ubiquitous Learning Environment (ULE) has been becoming a mobile and sensor based technology equipped environment that suits the modern world education discipline requirements for the past few years. Ambient Intelligence (AmI) makes much smarter the ULE by the support of optimization and intelligent techniques. Various efforts have been so far…

  5. Refining the ethics of computer-made decisions : A classification of moral mediation by ubiquitous machines

    NARCIS (Netherlands)

    Van der Voort, M.; Pieters, W.; Consoli, L.

    2015-01-01

    In the past decades, computers have become more and more involved in society by the rise of ubiquitous systems, increasing the number of interactions between humans and IT systems. At the same time, the technology itself is getting more complex, enabling devices to act in a way that previously only

  6. Using TinyOS Components for the Design of an Adaptive Ubiquitous System

    NARCIS (Netherlands)

    Kaya, O.S.; Durmaz, O.; Dulman, S.O.; Gemesi, R.; Jansen, P.G.; Havinga, Paul J.M.

    2005-01-01

    This work is an initiative attempt toward component-based software engineering in ubiquitous computing systems. Software components cooperate in a distributed manner to meet a demand, and adapt their software bindings during run-time depending on the context information. There are two main research

  7. Using TinyOS Components for the Design of an Adaptive Ubiquitous System

    NARCIS (Netherlands)

    Kaya, O.S.; Durmaz, O.; Dulman, S.O.; Gemesi, R.; Jansen, P.G.; Havinga, Paul J.M.

    This work is an initiative attempt toward component-based software engineering in ubiquitous computing systems. Software components cooperate in a distributed manner to meet a demand, and adapt their software bindings during run-time depending on the context information. There are two main research

  8. Structure and amphoteric properties of titanium dioxide gels

    International Nuclear Information System (INIS)

    Kertesz, C.

    1991-01-01

    Mechanisms responsible for the in-solution ion retention by titanium dioxide are studied. Mineral oxide gel formation and structure are described and various titanium dioxide gel synthesis modes are presented. A two-phase model, taking into account the porous nature of the solid and allowing for the application of the mass action law, is adopted. The oxide amphoteric properties are studied with the potentiometric titration technique. Hysteresis loops are imputed to the slowness of the acid-basic neutralization reaction. The main characteristics are determined: isoelectric point, cation and anion retention capacity. Depending on the suspension agitation, the speed limiting factor may be the diffusion in the film or the diffusion in the particle. 60 fig., 128 ref

  9. Water equivalence of polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sellakumar, P.; James Jebaseelan Samuel, E.; Supe, Sanjay S.

    2007-01-01

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z eff ), electron density (ρ e ), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μ en /ρ) and total stopping power (S/ρ) tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close ( en /ρ for all polymer gels were in close agreement ( tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

  10. Ubiquitous Total Station Development using Smartphone, RSSI and Laser Sensor providing service to Ubi-GIS

    Directory of Open Access Journals (Sweden)

    M. A. Shoushtari

    2014-10-01

    Full Text Available The growing trend in technological advances and Micro Electro Mechanical Systems (MEMS has targeted for intelligent human lives. Accordingly, Ubiquitous Computing Approach was proposed by Mark Weiser. This paper proposes an ubiquitous surveying solution in Geometrics and surveying field. Ubiquitous Surveying provides cost-effective, smart and available surveying techniques while traditional surveying equipment are so expensive and have small availability specially in indoor and daily surveying jobs. In order to have a smart surveying instrument, different information technology methods and tools like Triangle method, Received Signal Strength Indicator (RSSI method and laser sensor are used. These new ways in combine with surveying equations introduces a modern surveying equipment called Ubi-Total Station that also employed different sensors embedded in smartphone and mobile stand. RSSI-based localization and Triangle method technique are easy and well known methods to predict the position of an unknown node in indoor environments whereas additional measures are required for a sufficient accuracy. In this paper the main goal is to introduce the Ubiquitous Total Station as a development in smart and ubiquitous GIS. In order to public use of the surveying equipment, design and implementation of this instrument has been done. Conceptual model of Smartphone-based system is designed for this study and based on this model, an Android application as a first sample is developed. Finally the evaluations shows that absolute errors in X and Y calculation are 0.028 and 0.057 meter respectively. Also RMSE of 0.26 was calculated in RSSI method for distance measurement. The high price of traditional equipment and their requirement for professional surveyors has given way to intelligent surveying. In the suggested system, smartphones can be used as tools for positioning and coordinating geometric information of objects.

  11. Colloidal probe dynamics in gelatin solution during the sol-gel transition.

    Science.gov (United States)

    Hong, Wei; Xu, Guozhi; Ou, Xiaogang; Sun, Weixiang; Wang, Tao; Tong, Zhen

    2018-05-16

    The dynamics of the colloidal probes in a gelatin solution during the time-dependent sol-gel transition was investigated by multi-particle tracking. The relationship between the relaxation of the medium at the critical gel point and the mean square displacement of the probes was elucidated. Based on this understanding, the critical gel point of gelatin and the corresponding critical exponent n were unambiguously determined by the loss angle criterion and the time-cure superposition. The shift factors of the latter are further used to estimate the time/length-scale evolution of the gelatin during the sol-gel transition. The growth of the medium length scale crossed with the two measuring length scales successively at the pre-gel regime. Coinciding with the length-scale crossovers, the probability density function (PDF) of the probe displacements displayed two transient peaks of non-Gaussianity. In the post-gel regime, the third peak of Gaussianity suggested inhomogeneity in the gel network. The non-Gaussianity results from the bifurcation of diffusivity. The present work showed that the non-Gaussian dynamics of the probes are not the direct equivalence of that of the medium, but an effect of length-scale coupling.

  12. Development of hydroxyapatite-chitosan gel sunscreen combating clinical multidrug-resistant bacteria

    Science.gov (United States)

    Morsy, Reda; Ali, Sameh S.; El-Shetehy, Mohamed

    2017-09-01

    The several harmful effects on infected human skin resulting from exposure to the sun's UV radiation generate an interest in the development of a multifunctional hydroxyapatite-chitosan (HAp-chitosan) gel that works as an antibacterial sunscreen agent for skin care. In this work, HAp-chitosan gel was synthesized via coprecipitation method by dissolving chitosan in phosphoric acid and adding HAp. The characteristics of HAp-chitosan composite were investigated by conventional techniques, such as XRD, FTIR, and SEM techniques, while its sunscreen property was investigated by UV-spectroscopy. In addition to the influence of the gel on bacterial cell morphology, the antibacterial activity of HAp-chitosan gel against clinical multidrug resistant skin pathogens, such as Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa has been studied. The results revealed the formation of HAp-chitosan gel having nanosized particles, which confers protection against UV-radiation. The antibacterial activity records showed that chitosan-HAp gel exhibits a significant effect on the growth and ultrastructure of multi-drug resistant bacterial activities. Therefore, the chitosan-HAp gel is promising for skin health care as an antibacterial sunscreen.

  13. Preparation and evaluation of chitosan-based nanogels/gels for oral delivery of myricetin.

    Science.gov (United States)

    Yao, Yashu; Xia, Mengxin; Wang, Huizhen; Li, Guowen; Shen, Hongyi; Ji, Guang; Meng, Qianchao; Xie, Yan

    2016-08-25

    A novel nanogel/gel based on chitosan (CS) for the oral delivery of myricetin (Myr) was developed and evaluated comprehensively. The particle size of the obtained Myr-loaded CS/β-glycerol phosphate (β-GP) nanogels was in the range of 100-300nm. The rheological tests showed that the sol-gel transition happened when the nanogels were exposed to physiological temperatures, and 3D network structures of the gelatinized nanogels (gels) were confirmed by Scanning Electron Microscopy. Myr was released from CS/β-GP nanogel/gel in acidic buffers via a Fickian mechanism, and this release was simultaneously accompanied by swelling and erosion. Moreover, the nanogel/gel exhibited no cytotoxicity by MTT assay, and the oral bioavailability of Myr in rats was improved with an accelerated absorption rate after Myr was loaded into CS/β-GP nanogel/gel. In summary, all of the above showed that CS/β-GP nanogel/gel was an excellent system for orally delivering Myr. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Control size of silver nanoparticles in sol-gel glasses

    Science.gov (United States)

    Renteria, Victor M.; Celis, Antonio C.; Garcia-Macedo, Jorge A.

    2000-10-01

    By the sol-gel processing, silver ions in presence of stabilizing function (3-thiocyanatopropyl)triethoxysilane are reduced by heating gels at 180 C for several times in air atmosphere. The spectroscopic Uv-Vis observations, confirm silver nanoparticles presence with peak maximum around 350 nm. The optical properties of the metallic particles are observed at room temperature as function of time, and the absorption spectra practically do not change, which indicated they are trapped and stabilized within the fine porous silica cage. Mie theory calculations, considering the mean free path effect of the conduction electrons, are compatible with experimental spectra, indicating homogeneity in size and form of the metallic nanoparticles. Smithard correlation curve, between half width height (W1/2) of the optical absorption and the particle diameter 2r, predict silver particles size between 4 and 10 nm, during composite heating. Activation energy was measured and compared with previous data on similar systems and the probable reduction process are discussed.

  15. Metal-silica sol-gel materials

    Science.gov (United States)

    Stiegman, Albert E. (Inventor)

    2002-01-01

    The present invention relates to a single phase metal-silica sol-gel glass formed by the co-condensation of a transition metal with silicon atoms where the metal atoms are uniformly distributed within the sol-gel glass as individual metal centers. Any transition metal may be used in the sol-gel glasses. The present invention also relates to sensor materials where the sensor material is formed using the single phase metal-silica sol-gel glasses. The sensor materials may be in the form of a thin film or may be attached to an optical fiber. The present invention also relates to a method of sensing chemicals using the chemical sensors by monitoring the chromatic change of the metal-silica sol-gel glass when the chemical binds to the sensor. The present invention also relates to oxidation catalysts where a metal-silica sol-gel glass catalyzes the reaction. The present invention also relates to a method of performing oxidation reactions using the metal-silica sol-gel glasses. The present invention also relates to organopolymer metal-silica sol-gel composites where the pores of the metal-silica sol-gel glasses are filled with an organic polymer polymerized by the sol-gel glass.

  16. Rare particles

    International Nuclear Information System (INIS)

    Kutschera, W.

    1984-01-01

    The use of Accelerator Mass Spectrometry (AMS) to search for hypothetical particles and known particles of rare processes is discussed. The hypothetical particles considered include fractionally charged particles, anomalously heavy isotopes, and superheavy elements. The known particles produced in rare processes discussed include doubly-charged negative ions, counting neutrino-produced atoms in detectors for solar neutrino detection, and the spontaneous emission of 14 C from 223 Ra. 35 references

  17. Ubiquitous geospatial concept in evolution of the macro and micro spatial planning

    International Nuclear Information System (INIS)

    Sabri, S; Ludin, A N M; Majid, M R

    2014-01-01

    There are many examples of GIS application in planning such as urban land-use planning, cultural heritage conservation, coastal zone management, and the design of structure plans for sustainable economic development. All these applications are dealing with systems in which natural and human factors are interconnected. But an issue that should be addressed is to what extent the current information technology is able to connect all these parts together? Contemporary improvement in information technology made the computer so imbedded in our everyday practices that we use it without having to think about it. Thus, computing is becoming truly ubiquitous and is available anywhere anytime. Advances in the internet facilities and devices, such as high speed wireless networks, mobile middleware, and smart technologies, has pushed the concept of ubiquitous computing to the forefront of GIS research and development. There are developments in this regards, these are such as GeoWeb 2.0, voluntarily geographic Information (VGI), and Mashups, whereby the application of cloud computing was possible in visualizing urban air pollution and emergency responses to ensure the safety and security. These advancements therefore, have changed the conventional facet of macro and micro spatial planning. Every possible information system such as residential, medical, business, environmental, governmental, and the like can be linked through ubiquitous computing technologies and acts as a virtually one system which works for society. However, the journey to achieve a true ubiquitous GIS is not without challenges. Despite the current potentials there are many issues and obstacles need to be addressed before GIS can to be truly ubiquitous in planning context. Perhaps four criteria as explained by Goodchild et al (1997) can be applied to ubiquitous GIS in planning very well: the system must be distributed (data storage, processing and user interaction can occur at locations that are potentially

  18. Ubiquitous geospatial concept in evolution of the macro and micro spatial planning

    Science.gov (United States)

    Sabri, S.; Ludin, A. N. M.; Majid, M. R.

    2014-02-01

    There are many examples of GIS application in planning such as urban land-use planning, cultural heritage conservation, coastal zone management, and the design of structure plans for sustainable economic development. All these applications are dealing with systems in which natural and human factors are interconnected. But an issue that should be addressed is to what extent the current information technology is able to connect all these parts together? Contemporary improvement in information technology made the computer so imbedded in our everyday practices that we use it without having to think about it. Thus, computing is becoming truly ubiquitous and is available anywhere anytime. Advances in the internet facilities and devices, such as high speed wireless networks, mobile middleware, and smart technologies, has pushed the concept of ubiquitous computing to the forefront of GIS research and development. There are developments in this regards, these are such as GeoWeb 2.0, voluntarily geographic Information (VGI), and Mashups, whereby the application of cloud computing was possible in visualizing urban air pollution and emergency responses to ensure the safety and security. These advancements therefore, have changed the conventional facet of macro and micro spatial planning. Every possible information system such as residential, medical, business, environmental, governmental, and the like can be linked through ubiquitous computing technologies and acts as a virtually one system which works for society. However, the journey to achieve a true ubiquitous GIS is not without challenges. Despite the current potentials there are many issues and obstacles need to be addressed before GIS can to be truly ubiquitous in planning context. Perhaps four criteria as explained by Goodchild et al (1997) can be applied to ubiquitous GIS in planning very well: the system must be distributed (data storage, processing and user interaction can occur at locations that are potentially

  19. Preparation and characterization of silk/silica hybrid biomaterials by sol-gel crosslinking process

    Energy Technology Data Exchange (ETDEWEB)

    Hou Aiqin, E-mail: aiqinhou@dhu.edu.c [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, 3H, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China); Chen Huawei [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, 3H, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China)

    2010-03-15

    The silk/silica hybrid biomaterials are synthesized by sol-gel crosslinking process. The chemical and morphological structures of silk/silica hybrids are investigated with micro-FT-IR spectra, X-ray diffraction, SEM, AFM, and DSC. The results show that the crosslinking reactions among inorganic nano-particles, fibroin and 2,4,6-tri[(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) take place during sol-gel process. The silk/silica hybrids form new molecular structures containing not only organic fibroin but also inorganic nano-silica particles. The inorganic particles are bounded to the fibroin through covalent bonds. The silk/silica hybrids can form excellent film with very even nanometer particles. The thermal properties of organic/inorganic hybrid are improved.

  20. Preparation and characterization of silk/silica hybrid biomaterials by sol-gel crosslinking process

    International Nuclear Information System (INIS)

    Hou Aiqin; Chen Huawei

    2010-01-01

    The silk/silica hybrid biomaterials are synthesized by sol-gel crosslinking process. The chemical and morphological structures of silk/silica hybrids are investigated with micro-FT-IR spectra, X-ray diffraction, SEM, AFM, and DSC. The results show that the crosslinking reactions among inorganic nano-particles, fibroin and 2,4,6-tri[(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) take place during sol-gel process. The silk/silica hybrids form new molecular structures containing not only organic fibroin but also inorganic nano-silica particles. The inorganic particles are bounded to the fibroin through covalent bonds. The silk/silica hybrids can form excellent film with very even nanometer particles. The thermal properties of organic/inorganic hybrid are improved.

  1. Tracer diffusion in a polymer gel: simulations of static and dynamic 3D networks using spherical boundary conditions

    International Nuclear Information System (INIS)

    Kamerlin, Natasha; Elvingson, Christer

    2016-01-01

    We have investigated an alternative to the standard periodic boundary conditions for simulating the diffusion of tracer particles in a polymer gel by performing Brownian dynamics simulations using spherical boundary conditions. The gel network is constructed by randomly distributing tetravalent cross-linking nodes and connecting nearest pairs. The final gel structure is characterised by the radial distribution functions, chain lengths and end-to-end distances, and the pore size distribution. We have looked at the diffusion of tracer particles with a wide range of sizes, diffusing in both static and dynamic networks of two different volume fractions. It is quantitatively shown that the dynamical effect of the network becomes more important in facilitating the diffusional transport for larger particle sizes, and that one obtains a finite diffusion also for particle sizes well above the maximum in the pore size distribution. (paper)

  2. Preparation and characterization of bismuth ruthenate pyrochlore via solid state reaction and sol-gel methods

    Directory of Open Access Journals (Sweden)

    Mayuree Sansernnivet

    2010-01-01

    Full Text Available Bismuth ruthenate pyrochlores, potential cathode materials for intermediate temperature solid oxide fuel cells(ITSOFCs, were prepared via solid-state and sol-gel method. Effects of the preparation routes and conditions on the phase and microstructures of the materials were investigated in this study using XRD and SEM. The study showed that the preparation method and the adding sequence of the starting meterials have a significant effect on the crystal phase and the particle size obtained. Sol-gel synthesis could yield a material with only pyrochlore structure, i.e. Bi2Ru2O7, while the solid state method yielded powder with a small amount of the secondary RuO2 phase. The sol-gel synthesis resulted in materialswith a finer particle size (~0.3-1.0 μm compared to powder synthesized via the solid state reaction method.

  3. Ubiquitous Performance-Support System as Mindtool: A Case Study of Instructional Decision Making and Learning Assistant

    Science.gov (United States)

    Peng, Hsinyi; Chuang, Po-Ya; Hwang, Gwo-Jen; Chu, Hui-Chun; Wu, Ting-Ting; Huang, Shu-Xian

    2009-01-01

    Researchers have conducted various studies on applying wireless communication and ubiquitous computing technologies to education, so that the technologies can provide learners and educators with more active and adaptive support. This study proposes a Ubiquitous Performance-support System (UPSS) that can facilitate the seamless use of powerful new…

  4. Researching the Ethical Dimensions of Mobile, Ubiquitous and Immersive Technology Enhanced Learning (MUITEL): A Thematic Review and Dialogue

    Science.gov (United States)

    Lally, Vic; Sharples, Mike; Tracy, Frances; Bertram, Neil; Masters, Sherriden

    2012-01-01

    In this article, we examine the ethical dimensions of researching the mobile, ubiquitous and immersive technology enhanced learning (MUITEL), with a particular focus on learning in informal settings. We begin with an analysis of the interactions between mobile, ubiquitous and immersive technologies and the wider context of the digital economy. In…

  5. Research on pre-staining gel electrophoresis

    International Nuclear Information System (INIS)

    Zhong Ruibo; Liu Yushuang; Zhang Ping; Liu Jingran; Zhao Guofen; Zhang Feng

    2014-01-01

    Background: Gel electrophoresis is a powerful biochemical separation technique. Most biological molecules are completely transparent in the visible region of light, so it is necessary to use staining to show the results after gel electrophoresis, and the general steps of conventional staining methods are time-consuming. Purpose: We try to develop a novel approach to simplify the gel electrophoresis: Pre-Staining Gel Electrophoresis (PSGE), which can make the gel electrophoresis results monitored in real time. Methods: Pre-stain the protein samples with Coomassie Brilliant Blue (CBB) for 30 min before loading the sample into the gel well. Results and Conclusion: PSGE can be successfully used to analyze the binding efficiency of Bovine Serum Albumin (BSA) and amphiphilic polymer via chemical coupling and physical absorption, and the double PSGE also shows a great potential in bio-analytical chemistry. (authors)

  6. Human Pacman: A Mobile Augmented Reality Entertainment System Based on Physical, Social, and Ubiquitous Computing

    Science.gov (United States)

    Cheok, Adrian David

    This chapter details the Human Pacman system to illuminate entertainment computing which ventures to embed the natural physical world seamlessly with a fantasy virtual playground by capitalizing on infrastructure provided by mobile computing, wireless LAN, and ubiquitous computing. With Human Pacman, we have a physical role-playing computer fantasy together with real human-social and mobile-gaming that emphasizes on collaboration and competition between players in a wide outdoor physical area that allows natural wide-area human-physical movements. Pacmen and Ghosts are now real human players in the real world experiencing mixed computer graphics fantasy-reality provided by using the wearable computers on them. Virtual cookies and actual tangible physical objects are incorporated into the game play to provide novel experiences of seamless transitions between the real and virtual worlds. This is an example of a new form of gaming that anchors on physicality, mobility, social interaction, and ubiquitous computing.

  7. NOVEL APPLICATIONS FOR EMERGING MARKETS USING TELEVISION AS A UBIQUITOUS DEVICE

    DEFF Research Database (Denmark)

    Pal, Arpan

    2013-01-01

    – personal computer (including laptop and tablet), television and mobile (including smart phone). For emerging market countries like India, personal computers are not yet affordable to masses and most of the people are not savvy or skilled enough to operate a personal computer. Mobile phones, though being...... connected to the internet-world in a low-cost manner, it has the potential of becoming the ―Ubiquitous Computing Screen‖ for the home. The emerging markets are characterized by some unique issues like low bandwidth / low Quality-of-Service (QoS) of the available wireless networks, extreme cost...... solutions for seamlessly blending Internet with broadcasting content. To this end, in this thesis a novel application development framework is proposed first on top of a low-cost over-the-top box that uses television as a ubiquitous device with a focus on emerging markets. Then an end-to-end solution...

  8. Ubiquitous health monitoring and real-time cardiac arrhythmias detection: a case study.

    Science.gov (United States)

    Li, Jian; Zhou, Haiying; Zuo, Decheng; Hou, Kun-Mean; De Vaulx, Christophe

    2014-01-01

    As the symptoms and signs of heart diseases that cause sudden cardiac death, cardiac arrhythmia has attracted great attention. Due to limitations in time and space, traditional approaches to cardiac arrhythmias detection fail to provide a real-time continuous monitoring and testing service applicable in different environmental conditions. Integrated with the latest technologies in ECG (electrocardiograph) analysis and medical care, the pervasive computing technology makes possible the ubiquitous cardiac care services, and thus brings about new technical challenges, especially in the formation of cardiac care architecture and realization of the real-time automatic ECG detection algorithm dedicated to care devices. In this paper, a ubiquitous cardiac care prototype system is presented with its architecture framework well elaborated. This prototype system has been tested and evaluated in all the clinical-/home-/outdoor-care modes with a satisfactory performance in providing real-time continuous cardiac arrhythmias monitoring service unlimitedly adaptable in time and space.

  9. Real-time long term measurement using integrated framework for ubiquitous smart monitoring

    Science.gov (United States)

    Heo, Gwanghee; Lee, Giu; Lee, Woosang; Jeon, Joonryong; Kim, Pil-Joong

    2007-04-01

    Ubiquitous monitoring combining internet technologies and wireless communication is one of the most promising technologies of infrastructure health monitoring against the natural of man-made hazards. In this paper, an integrated framework of the ubiquitous monitoring is developed for real-time long term measurement in internet environment. This framework develops a wireless sensor system based on Bluetooth technology and sends measured acceleration data to the host computer through TCP/IP protocol. And it is also designed to respond to the request of web user on real time basis. In order to verify this system, real time monitoring tests are carried out on a prototype self-anchored suspension bridge. Also, wireless measurement system is analyzed to estimate its sensing capacity and evaluate its performance for monitoring purpose. Based on the evaluation, this paper proposes the effective strategies for integrated framework in order to detect structural deficiencies and to design an early warning system.

  10. Gel-combustion-synthesized ZnO nanoparticles for visible light ...

    Indian Academy of Sciences (India)

    Zinc oxide nanoparticles (ZnO NPs) synthesized by the gel combustion technique using a bio-fuel, cassava starch (root tubers of Manihot esculenta), have been characterized by various techniques. The X-ray diffractionpattern reveals hexagonal wurtzite structure. The particle size averaged around 45nm with an excellent ...

  11. Transient gels in colloid-polymer mixtures studied with fluorescence confocal scanning laser microscopy

    NARCIS (Netherlands)

    Verhaegh, N.A.M.; Asnaghi, D.; Lekkerkerker, H.N.W.

    1999-01-01

    We study the structure and the time evolution of transient gels formed in colloid-polymer mixtures, by means of uorescence Confocal Scanning Laser Microscopy (CSLM). This technique is used in conjunction with novel colloidal silica particles containing a uorescent core. The confocal micrographs

  12. Functional coatings: the sol-gel approach

    International Nuclear Information System (INIS)

    Belleville, Ph.

    2010-01-01

    CEA's sol-gel laboratory is specialized in the development of innovative sol-gel optical coatings and has extended its application field to membrane materials and coatings for energy conversion, to electric coatings for microelectronics devices and to thin films for gas sensing. This article describes, by way of examples, the laboratory's research on sol-gel functional coatings, including nano-material synthesis, organic-inorganic hybrid-based solution preparation as well as deposition process development and prototyping. (author)

  13. Dosimetry Evolution in Teletherapy: Polimer Gel

    Science.gov (United States)

    Hamann, J. H.; Peixoto, J. G. P.

    2018-03-01

    Polymer gels evolution and chemical composition used in dosimetry. Type Composition First gels Folin’s Phenol or Gallic Acid Polymer Gel Agarose and N,N’-methylene-bis-acrylamide BANANA Bis, acrylamide, nitrous oxide and agarose BANG-1TM Bis, acrylamide, nitrogen and gelatin BANG-2TM Bis, acrylic acid, sodium hydroxide, nitrogen and gelatin BANG-3TM Bis, methacrylate acid, sodium hydroxide, nitrogen and gelatin MAGIC Methacrylate acid, ascorbic acid, gelatin and copper sulphate

  14. Stabilized aqueous gels and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, B.L.

    1978-08-29

    New improved aqueous gels, and methods of using same in contacting subterranean formations, are provided. The gels are prepared by gelling an aqueous brine having incorporated therein a water-soluble cellulose ether such as a carboxymethylcellulose (CMC), and are rendered more stable to decomposition by incorporating a sulfoalkylated tannin stabilizing agent, such as a sulfomethylated quebracho (SMQ), in the gel during the preparation thereof.

  15. Ubiquitous Wireless Sensor Networks and future “Internet of Things""

    OpenAIRE

    Vermesan, Ovidiu

    2009-01-01

    Overview of heterogeneous networks of embedded devices that can range from RFID, to smart identifiable systems with sensing and actuating capabilitie. Presentation of wireless sensor networks protocols and Internet of Things future technology. Bridging the real, virtual and digital worlds by using wireless connectivity. Application examples in automotive, aeronautics, healthcare, building, oil and gas industries. Ubiquitous Wireless Sensor Networks and future “Internet ...

  16. Expressing clinical data sets with openEHR archetypes: a solid basis for ubiquitous computing.

    Science.gov (United States)

    Garde, Sebastian; Hovenga, Evelyn; Buck, Jasmin; Knaup, Petra

    2007-12-01

    The purpose of this paper is to analyse the feasibility and usefulness of expressing clinical data sets (CDSs) as openEHR archetypes. For this, we present an approach to transform CDS into archetypes, and outline typical problems with CDS and analyse whether some of these problems can be overcome by the use of archetypes. Literature review and analysis of a selection of existing Australian, German, other European and international CDSs; transfer of a CDS for Paediatric Oncology into openEHR archetypes; implementation of CDSs in application systems. To explore the feasibility of expressing CDS as archetypes an approach to transform existing CDSs into archetypes is presented in this paper. In case of the Paediatric Oncology CDS (which consists of 260 data items) this lead to the definition of 48 openEHR archetypes. To analyse the usefulness of expressing CDS as archetypes, we identified nine problems with CDS that currently remain unsolved without a common model underpinning the CDS. Typical problems include incompatible basic data types and overlapping and incompatible definitions of clinical content. A solution to most of these problems based on openEHR archetypes is motivated. With regard to integrity constraints, further research is required. While openEHR cannot overcome all barriers to Ubiquitous Computing, it can provide the common basis for ubiquitous presence of meaningful and computer-processable knowledge and information, which we believe is a basic requirement for Ubiquitous Computing. Expressing CDSs as openEHR archetypes is feasible and advantageous as it fosters semantic interoperability, supports ubiquitous computing, and helps to develop archetypes that are arguably of better quality than the original CDS.

  17. SiC: An Agent Based Architecture for Preventing and Detecting Attacks to Ubiquitous Databases

    OpenAIRE

    Pinzón, Cristian; de Paz Santana, Yanira; Bajo Pérez, Javier; Abraham, Ajith P.; Corchado Rodríguez, Juan M.

    2009-01-01

    One of the main attacks to ubiquitous databases is the structure query language (SQL) injection attack, which causes severe damages both in the commercial aspect and in the user’s confidence. This chapter proposes the SiC architecture as a solution to the SQL injection attack problem. This is a hierarchical distributed multiagent architecture, which involves an entirely new approach with respect to existing architectures for the prevention and detection of SQL injections. SiC incorporates a k...

  18. The new transparency: police violence in the context of ubiquitous surveillance

    OpenAIRE

    Brucato, Ben

    2015-01-01

    Media and surveillance scholars often comment on the purported empowering quality of transparency, which they expect participatory media to promote. From its Enlightenment origins, transparency is related to accountability and legitimacy: its increase is believed to promote these. It has earned a position as an unassailed, prime normative value in contemporary liberal and social democracies. Though still valued, transparency is undergoing change in an era of ubiquitous surveillance. Publics s...

  19. Particulate morphology mathematics applied to particle assemblies

    CERN Document Server

    Gotoh, Keishi

    2012-01-01

    Encompassing over fifty years of research, Professor Gotoh addresses the correlation function of spatial structures and the statistical geometry of random particle assemblies. In this book morphological study is formed into random particle assemblies to which various mathematics are applied such as correlation function, radial distribution function and statistical geometry. This leads to the general comparison between the thermodynamic state such as gases and liquids and the random particle assemblies. Although structures of molecular configurations change at every moment due to thermal vibration, liquids can be regarded as random packing of particles. Similarly, gaseous states correspond to particle dispersion. If physical and chemical properties are taken away from the subject, the remainder is the structure itself. Hence, the structural study is ubiquitous and of fundamental importance. This book will prove useful to chemical engineers working on powder technology as well as mathematicians interested in le...

  20. Design and Implementation of Ubiquitous Health System U-Health Using Smart-Watches Sensors

    Science.gov (United States)

    Razavi Termeh, V.; Sadeghi Niaraki, A.

    2015-12-01

    Today as diseases grow rapidly, the responsibilities of the health clinics in giving services to patients increase and patients have to be more monitored and controlled. Remote systems of monitoring patients result in reducing cost, ease of movement, and also persistent control of patients by their doctors, so that patient can be monitored without need to go to the clinic. Recent advances in the field of ubiquitous sciences as well as using smartphones have resulted in increasingly use of this devices in remote monitoring of patients. The aim of this paper is to design and implement a ubiquitous health system using smartphones and sensors of smart-watches. This is accomplished through the information sent to the smartphone from the sensors of the watch, e.g. heart beat measurement sensor and ultraviolet ray. Then, this information is analyzed in the smartphone and some information based on the position of the patient and the path of him/her using GIS analyses as well as the information about the health level of the patient is sent to the doctor via SMS or phone call. Unnatural heart beats can be resulted in diseases such as Heart Failure and Arterial Fibrillation. With the approach adopted in this study, the patient or the doctor could be aware of these diseases at any time. The proposed approach is a low cost, without need to complex and resilient equipment, system in ubiquitous health that does not limit the movement of the patient.

  1. Developing Ubiquitous Sensor Network Platform Using Internet of Things: Application in Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Francisco Javier Ferrández-Pastor

    2016-07-01

    Full Text Available The application of Information Technologies into Precision Agriculture methods has clear benefits. Precision Agriculture optimises production efficiency, increases quality, minimises environmental impact and reduces the use of resources (energy, water; however, there are different barriers that have delayed its wide development. Some of these main barriers are expensive equipment, the difficulty to operate and maintain and the standard for sensor networks are still under development. Nowadays, new technological development in embedded devices (hardware and communication protocols, the evolution of Internet technologies (Internet of Things and ubiquitous computing (Ubiquitous Sensor Networks allow developing less expensive systems, easier to control, install and maintain, using standard protocols with low-power consumption. This work develops and test a low-cost sensor/actuator network platform, based in Internet of Things, integrating machine-to-machine and human-machine-interface protocols. Edge computing uses this multi-protocol approach to develop control processes on Precision Agriculture scenarios. A greenhouse with hydroponic crop production was developed and tested using Ubiquitous Sensor Network monitoring and edge control on Internet of Things paradigm. The experimental results showed that the Internet technologies and Smart Object Communication Patterns can be combined to encourage development of Precision Agriculture. They demonstrated added benefits (cost, energy, smart developing, acceptance by agricultural specialists when a project is launched.

  2. Automatic, Global and Dynamic Student Modeling in a Ubiquitous Learning Environment

    Directory of Open Access Journals (Sweden)

    Sabine Graf

    2009-03-01

    Full Text Available Ubiquitous learning allows students to learn at any time and any place. Adaptivity plays an important role in ubiquitous learning, aiming at providing students with adaptive and personalized learning material, activities, and information at the right place and the right time. However, for providing rich adaptivity, the student model needs to be able to gather a variety of information about the students. In this paper, an automatic, global, and dynamic student modeling approach is introduced, which aims at identifying and frequently updating information about students’ progress, learning styles, interests and knowledge level, problem solving abilities, preferences for using the system, social connectivity, and current location. This information is gathered in an automatic way, using students’ behavior and actions in different learning situations provided by different components/services of the ubiquitous learning environment. By providing a comprehensive student model, students can be supported by rich adaptivity in every component/service of the learning environment. Furthermore, the information in the student model can help in giving teachers a better understanding about the students’ learning process.

  3. Developing Ubiquitous Sensor Network Platform Using Internet of Things: Application in Precision Agriculture.

    Science.gov (United States)

    Ferrández-Pastor, Francisco Javier; García-Chamizo, Juan Manuel; Nieto-Hidalgo, Mario; Mora-Pascual, Jerónimo; Mora-Martínez, José

    2016-07-22

    The application of Information Technologies into Precision Agriculture methods has clear benefits. Precision Agriculture optimises production efficiency, increases quality, minimises environmental impact and reduces the use of resources (energy, water); however, there are different barriers that have delayed its wide development. Some of these main barriers are expensive equipment, the difficulty to operate and maintain and the standard for sensor networks are still under development. Nowadays, new technological development in embedded devices (hardware and communication protocols), the evolution of Internet technologies (Internet of Things) and ubiquitous computing (Ubiquitous Sensor Networks) allow developing less expensive systems, easier to control, install and maintain, using standard protocols with low-power consumption. This work develops and test a low-cost sensor/actuator network platform, based in Internet of Things, integrating machine-to-machine and human-machine-interface protocols. Edge computing uses this multi-protocol approach to develop control processes on Precision Agriculture scenarios. A greenhouse with hydroponic crop production was developed and tested using Ubiquitous Sensor Network monitoring and edge control on Internet of Things paradigm. The experimental results showed that the Internet technologies and Smart Object Communication Patterns can be combined to encourage development of Precision Agriculture. They demonstrated added benefits (cost, energy, smart developing, acceptance by agricultural specialists) when a project is launched.

  4. Conducting polymer electrodes for gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Katarina Bengtsson

    Full Text Available In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene (PEDOT can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  5. Ionic liquid based multifunctional double network gel

    Science.gov (United States)

    Ahmed, Kumkum; Higashihara, Tomoya; Arafune, Hiroyuki; Kamijo, Toshio; Morinaga, Takashi; Sato, Takaya; Furukawa, Hidemitsu

    2015-04-01

    Gels are a promising class of soft and wet materials with diverse application in tissue engineering and bio-medical purpose. In order to accelerate the development of gels, it is required to synthesize multi-functional gels of high mechanical strength, ultra low surface friction and suitable elastic modulus with a variety of methods and new materials. Among many types of gel ionic gel made from ionic liquids (ILs) could be used for diverse applications in electrochemical devices and in the field of tribology. IL, a promising materials for lubrication, is a salt with a melting point lower than 100 °C. As a lubricant, ILs are characterized by an extremely low vapor pressure, high thermal stability and high ion conductivity. In this work a novel approach of making double network DN ionic gel using IL has been made utilizing photo polymerization process. A hydrophobic monomer Methyl methacrylate (MMA) has been used as a first network and a hydrophobic IL monomer, N,N-diethyl-N-(2-mthacryloylethyl)-N-methylammonium bistrifluoromethylsulfonyl)imide (DEMM-TFSI) has been used as a second network using photo initiator benzophenon and crosslinker triethylene glycol dimethacrylate (TEGDMA). The resulting DN ionic gel shows transparency, flexibility, high thermal stability, good mechanical toughness and low friction coefficient value which can be a potential candidate as a gel slider in different mechanical devices and can open a new area in the field of gel tribology.

  6. Gel nano-particulates against radioactivity

    International Nuclear Information System (INIS)

    Deroin, Ph.

    2004-01-01

    The Argonne research center (USA) has developed a 'super-gel' compound, a polymer close to those used in baby's diapers, which can reach a 90% efficiency in the radioactive decontamination of porous materials, like bricks or concrete. The contaminated materials are sprayed with a mixture of polymer gel and wetting agent with nano-particulates in suspension. Under the action of the wetting agent, radioactivity migrates from the pores to the gel and is trapped by the nano-particulates. The drying and recycling of the gel allows to reduce the volume of radioactive wastes. Short paper. (J.S.)

  7. Conducting polymer electrodes for gel electrophoresis.

    Science.gov (United States)

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  8. Comparison effect of azithromycin gel 2% with clindamycin gel 1% in patients with acne

    Directory of Open Access Journals (Sweden)

    Fatemeh Mokhtari

    2016-01-01

    Conclusion: Azithromycin gel has medical impact at least similar to Clindamycin Gel in treatment of mild to moderate acne vulgaris, and it may be consider as suitable drug for resistant acne to conventional topical therapy.

  9. Smectic liquid crystals in anisotropic colloidal silica gels

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Dennis [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Borthwick, Matthew A [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Leheny, Robert L [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2004-05-19

    We report x-ray scattering studies of the smectic liquid crystal octylcyano-biphenol (8CB) confined by strained colloidal silica gels. The gels, comprised of aerosil particles, possess an anisotropic structure that stabilizes long-range nematic order in the liquid crystal while introducing random field effects that disrupt the smectic transition. The short-range smectic correlations that form within this environment are inconsistent with the presence of a topologically ordered state predicted for 3D random field XY systems and are quantitatively like the correlations of smectics confined by isotropic gels. Detailed analysis reveals that the quenched disorder suppresses the anisotropic scaling of the smectic correlation lengths observed in the pure liquid crystal. These results and additional measurements of the smectic-A to smectic-C transition in 4-n-pentylphenylthiol-4'-n-octyloxybenzoate (8barS5) indicate that the observed smectic behaviour is dictated by random fields coupling directly to the smectic order while fields coupling to the nematic director play a subordinate role.

  10. Nanoscale dynamics and aging of fibrous peptide-based gels

    Energy Technology Data Exchange (ETDEWEB)

    Dudukovic, Nikola A., E-mail: dudukov1@illinois.edu [Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Zukoski, Charles F. [Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, New York 14222 (United States)

    2014-10-28

    Solutions of the aromatic dipeptide derivative molecule fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) in dimethyl sulfoxide produce fibrous gels when mixed with water. We study the evolution of density fluctuations of this three-component system using X-ray photon correlation spectroscopy (XPCS) and compare these results to the macroscopic rheology of the gels and optical observations of the microstructure evolution. At the investigated scattering angles, the intensity autocorrelation functions do not follow behavior expected for simple diffusion of individual Fmoc-FF molecules localized within cages of nearest neighbors. Instead, the dynamics are associated with density fluctuations on length scales of ∼10–100 nm arising from disaggregation and reformation of fibers, leading to an increasingly uniform network. This process is correlated with the growth of the elastic modulus, which saturates at long times. Autocorrelation functions and relaxation times acquired from XPCS measurements are consistent with relaxation rates of structures at dynamic equilibrium. This study provides further support to the concept of exploring peptide-based gelators as valence-limited patchy particles capable of forming equilibrium gels.

  11. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  12. Modified thermoresponsive Poloxamer 407 and chitosan sol-gels as potential sustained-release vaccine delivery systems

    DEFF Research Database (Denmark)

    Kojarunchitt, Thunjiradasiree; Baldursdottir, Stefania; Dong, Yao-Da

    2015-01-01

    Thermoresponsive, particle-loaded, Poloxamer 407 (P407)-Pluronic-R® (25R4) or chitosan-methyl cellulose (MC) formulations were developed as single-dose, sustained release vaccines. The sol-gels, loaded either with a particulate vaccine (cubosomes) or soluble antigen (ovalbumin) and adjuvants (Quil...... the chitosan-MC sol-gels sustained the release of antigen up to at least 14 days after administration. The chitosan-MC sol-gels stimulated both cellular and humoral responses. The inclusion of cubosomes in the sol-gels did not provide a definitive beneficial effect. Further analysis of the formulations...... with small-angle X-ray scattering (SAXS) revealed that while cubosomes were stable in chitosan-MC gels they were not stable in P407-25R4 formulations. The reason for the mixed response to cubosome-loaded vehicles requires more investigation, however it appears that the cubosomes did not facilitate...

  13. Effectiveness of silica based Sol-gel microencapsulation Method for odorants and flavours leading to sustainable Environment

    Directory of Open Access Journals (Sweden)

    Muhammad Aqeel eAshraf

    2015-08-01

    Full Text Available Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol–gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol–gel SiO2 is non-toxic and safe, whereas the sol–gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped actives, thereby broadening the practical utilization of chemically unstable essential oils. Reviewing progress in the fabrication of diverse odorant and flavoured sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  14. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits. PMID:26322304

  15. Method and apparatus for producing microspherical particles

    International Nuclear Information System (INIS)

    Egli, W.; Bailey, W.H.; Leary, D.F.; Lansley, R.J.

    1979-01-01

    This invention relates generally to a method and apparatus for producing microspherical particles and more particularly to a method and apparatus which are particularly useful in connection with the sol-gel process for the production of nuclear fuel kernels. (U.K.)

  16. Functional characterization of recombinant chloroplast signal recognition particle

    NARCIS (Netherlands)

    Groves, M R; Mant, A; Kuhn, A; Koch, J; Dübel, S; Robinson, C; Sinning, I

    2001-01-01

    The signal recognition particle (SRP) is a ubiquitous system for the targeting of membrane and secreted proteins. The chloroplast SRP (cpSRP) is unique among SRPs in that it possesses no RNA and is functional in post-translational as well as co-translational targeting. We have expressed and purified

  17. Stacking gels: A method for maximising output for pulsed-field gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Heng See

    2009-01-01

    Full Text Available Pulsed field gel electrophoresis (PFGE, the gold standard of molecular typing methods, has a major disadvantage of an unusually long electrophoretic time. From the original protocol of 6 days, it was modified to 3 days and subsequently to a single day. We describe the procedure of stacking five to six gels one on top of another in order to increase and maximize the output in a shorter time without compromising the resolution and reproducibility. All the variables that affect pulsed field gels during electrophoresis were taken into consideration. We firstly optimized the parameters to be used and secondly determined whether stacking of five to six gels had any effect on the molecular separation during electrophoresis in comparison with a single gel run. DNA preparation, restriction, electrophoresis, staining and gel documentation was carried out based on previously published methods. Gels were analysed using BioNumerics and dice coefficient and unweighted pair group methods were used to generate dendrograms based on 1.5% tolerance values. Identical band profiles and band resolution-separation were seen in the PFGE patterns with single gel and multiple stacking gels. Cluster analysis further strengthened the fact that results from stacking gels were reproducible and comparable with a single gel run. This method of stacking gels saves time and maximizes the output at the same time. The run time for a single gel was about 28 hours, but with six stacked gels the run time was 54 hours compared with 28 x 6 = 168 hours if they were run separately as single gels thus saving time of 67.86%. Beside the big factor of saving time, stacking gels save resources (electricity, reagents, water, chemicals and working time by increasing the sample throughput in a shorter time without compromising on quality of data. But optimization of working parameters is vital depending on the PFGE system used.

  18. Particle detection

    International Nuclear Information System (INIS)

    Charpak, G.

    2000-01-01

    In this article G.Charpak presents the principles on which particle detection is based. Particle accelerators are becoming more and more powerful and require new detectors able to track the right particle in a huge flux of particles. The gigantic size of detectors in high energy physics is often due to the necessity of getting a long enough trajectory in a magnetic field in order to deduce from the curvature an accurate account of impulses in the reaction. (A.C.)

  19. Strange particles

    International Nuclear Information System (INIS)

    Chinowsky, W.

    1989-01-01

    Work done in the mid 1950s at Brookhaven National Laboratory on strange particles is described. Experiments were done on the Cosmotron. The author describes his own and others' work on neutral kaons, lambda and theta particles and points out the theoretical gap between predictions and experimental findings. By the end of the decade, the theory of strange particles was better understood. (UK)

  20. Ophthalmic gels: Past, present and future.

    Science.gov (United States)

    Al-Kinani, Ali A; Zidan, Ghada; Elsaid, Naba; Seyfoddin, Ali; Alani, Adam W G; Alany, Raid G

    2018-02-15

    Aqueous gels formulated using hydrophilic polymers (hydrogels) along with those based on stimuli responsive polymers (in situ gelling or gel forming systems) continue to attract increasing interest for various eye health-related applications. They allow the incorporation of a variety of ophthalmic pharmaceuticals to achieve therapeutic levels of drugs and bioactives at target ocular sites. The integration of sophisticated drug delivery technologies such as nanotechnology-based ones with intelligent and environment responsive systems can extend current treatment duration to provide more clinically relevant time courses (weeks and months instead of hours and days) which will inevitably reduce dose frequency, increase patient compliance and improve clinical outcomes. Novel applications and design of contact lenses and intracanalicular delivery devices along with the move towards integrating gels into various drug delivery devices like intraocular pumps, injections and implants has the potential to reduce comorbidities caused by glaucoma, corneal keratopathy, cataract, diabetic retinopathies and age-related macular degeneration. This review describes ophthalmic gelling systems with emphasis on mechanism of gel formation and application in ophthalmology. It provides a critical appraisal of the techniques and methods used in the characterization of ophthalmic preformed gels and in situ gelling systems along with a thorough insight into the safety and biocompatibility of these systems. Newly developed ophthalmic gels, hydrogels, preformed gels and in situ gelling systems including the latest in the area of stimuli responsive gels, molecularly imprinted gels, nanogels, 3D printed hydrogels; 3D printed devices comprising ophthalmic gels are covered. Finally, new applications of gels in the production of artificial corneas, corneal wound healing and hydrogel contact lenses are described. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Magnetically tunable elasticity for magnetic hydrogels consisting of carrageenan and carbonyl iron particles.

    Science.gov (United States)

    Mitsumata, Tetsu; Honda, Atomu; Kanazawa, Hiroki; Kawai, Mika

    2012-10-11

    A new class of magnetoelastic gel that demonstrates drastic and reversible changes in storage modulus without using strong magnetic fields was obtained. The magnetic gel consists of carrageenan and carbonyl iron particles. The magnetic gel with a volume fraction of magnetic particles of 0.30 exhibited a reversible increase by a factor of 1400 of the storage modulus upon a magnetic field of 500 mT, which is the highest value in the past for magnetorheological soft materials. It is considered that the giant magnetoelastic behavior is caused by both high dispersibility and high mobility of magnetic particles in the carrageenan gel. The off-field storage modulus of the magnetic gel at volume fractions below 0.30 obeyed the Krieger-Dougherty equation, indicating random dispersion of magnetic particles. At 500 mT, the storage modulus was higher than 4.0 MPa, which is equal to that of magnetic fluids, indicating that the magnetic particles move and form a chain structure by magnetic fields. Morphological study revealed the evidence that the magnetic particles embedded in the gel were aligned in the direction of magnetic fields, accompanied by stretching of the gel network. We conclude that the giant magnetoelastic phenomenon originates from the chain structure consisting of magnetic particles similar to magnetic fluids.

  2. Radiation Synthesis of PEGDA and Acrylated Palm Oil Nanosized Gel for Bioactives Immobilization

    International Nuclear Information System (INIS)

    Hamzah, M.Y.; Tajau, R.; Dahlan, K.Z. Mohd; Mahmood, M.H.; Hashim, K.

    2010-01-01

    The use of microemulsion in the development of nanosized gel based on polyethylene glycol diacrylate (PEGDA) and acrylated palm oil (APO) is demonstrated. PEGDA was solubilized in n-heptane with use of AOT at 0.15M concentration to form reverse micelles, while APO was solubilized with SDS in water to form direct micelles. Both of these systems were depicted by means of ternary phase diagram. These micelles were than irradiated at 1,3,5,10,15 and 30kGy using gamma irradiation or EB to crosslink the entrapped polymer in the micelles. Ionizing radiation was imparted to the emulsions to generate crosslinking reactions in the micelles formed. The nanosized gel was evaluated in terms of particle diameter using dynamic light scattering and the images of the nanosized gel were studied using transmission electron microscopy (TEM). Results show that the size, charge and shape of the particles are influenced by concentration of surfactants and radiation dose. This study showed that this method can be utilized to produce nanosized gel. Future work include the attachment of functional group to the nano sized gel, loading of drug such as curcumin and further characterization using dynamic light scattering. (author)

  3. Radiation Synthesis of PEGDA and Acrylated Palm Oil Nanosized Gel for Bioactives Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, M. Y.; Tajau, R.; Dahlan, K.Z. Mohd; Mahmood, M. H.; Hashim, K., E-mail: m_yusof@nuclearmalaysia.gov.my [Makmal Nanoteknologi, Blok 64, BTS, Jafan Denghil, Agensi Nuklear Malaysia, Bangi 43000 Kajang, Selangor (Malaysia)

    2010-07-01

    The use of microemulsion in the development of nanosized gel based on polyethylene glycol diacrylate (PEGDA) and acrylated palm oil (APO) is demonstrated. PEGDA was solubilized in n-heptane with use of AOT at 0.15M concentration to form reverse micelles, while APO was solubilized with SDS in water to form direct micelles. Both of these systems were depicted by means of ternary phase diagram. These micelles were than irradiated at 1,3,5,10,15 and 30kGy using gamma irradiation or EB to crosslink the entrapped polymer in the micelles. Ionizing radiation was imparted to the emulsions to generate crosslinking reactions in the micelles formed. The nanosized gel was evaluated in terms of particle diameter using dynamic light scattering and the images of the nanosized gel were studied using transmission electron microscopy (TEM). Results show that the size, charge and shape of the particles are influenced by concentration of surfactants and radiation dose. This study showed that this method can be utilized to produce nanosized gel. Future work include the attachment of functional group to the nano sized gel, loading of drug such as curcumin and further characterization using dynamic light scattering. (author)

  4. Radiation sensitive polymer gel dosimeters

    International Nuclear Information System (INIS)

    Lepage, M.; Back, S.A.J.; Baldock, C.; Whittaker, A.K.; Rintoul, L.

    2000-01-01

    Full text: Radiation sensitive gels are studied for their potential to retain a permanent 3D dose distribution for applications in radiotherapy. Co-monomers dissolved in a tissue-equivalent hydrogel undergo a polymerization reaction upon absorption of ionizing radiation. The polymer formed influences the local spin-spin relaxation time (T 2 ) of the dosimeter that can be determined using magnetic resonance imaging (MRI). The relationship between T2 and the absorbed dose was studied for different initial chemical compositions. The aim was to find a model linking the changes in T 2 with absorbed dose to the initial composition of the dosimeter. It is believed this will help designing new gel dosimeters having desired properties to minimize the uncertainty in the determination of the dose distribution. 1 H, 13 C nuclear magnetic resonance spectroscopy and FT-Raman spectroscopy were used to quantify the amount of monomers still remaining after the absorption of a given dose of radiation. This data is used to model the changes of T2 as a function of the absorbed dose. A model of fast exchange of magnetization between three proton pools was used, where the fraction of protons (f x H ) in the x th pool is obtained from the chemical composition of the dosimeter and the apparent T2 of each pool is determined for a given composition. Initially, the protons are contained in two pools; a mobile (mob), which contains the water protons and the monomers protons, and a gelatin (gela) proton pool. The mobile pool is partially depleted as polymer is formed, the protons are transferred into the polymer (pol) pool. In the figure, the experimental data along with the calculated values are plotted for three different monomer concentrations, with the gelatin concentration fixed. The model is seen to provide a good fit to the experimental data

  5. Silica gel matrix immobilized Chlorophyta hydrodictyon africanum ...

    African Journals Online (AJOL)

    Chlorophyta hydrodictyon africanum was immobilized on a silica gel matrix to improve its mechanical properties. The algae-silica gel adsorbent was used for batch sorption studies of a cationic dye, methylene blue (MB). Optimum adsorption was obtained with a dosage of 0.8 g bio sorbent. Results from sorption studies ...

  6. Contaminant containment using polymer gel barriers

    NARCIS (Netherlands)

    Darwish, M.I.M.; Rowe, R.K.; Maarel, van der J.R.C.; Pel, L.; Huinink, H.P.; Zitha, P.L.J.

    2004-01-01

    Polymer gels are well known in the oil industry, but their potential for use as barriers to contaminant transport has not previously received significant study. As a first step, this paper examines the potential for a polyelectrolyte gel to serve as a barrier to the migration of sodium chloride. Two

  7. Serum release boosts sweetness intensity in gels

    NARCIS (Netherlands)

    Sala, G.; Stieger, M.A.; Velde, van de F.

    2010-01-01

    This paper describes the effect of serum release on sweetness intensity in mixed whey protein isolate/gellan gum gels. The impact of gellan gum and sugar concentration on microstructure, permeability, serum release and large deformation properties of the gels was determined. With increasing gellan

  8. Fast Processing of Sol-Gel TCO

    NARCIS (Netherlands)

    Deelen, J. van; Rem, M.; Arfsten, N.; Buskens, P.P.

    2016-01-01

    TCOs are usually deposited using sputtering or chemical vapor deposition, which have a yield of typically 50-75%. The sol gel method does not need low pressure and can be done with a high precursor yield in the range of 90 – 100%. Sol gel enables also the TCO function as a planarization or

  9. Sol – Gel synthesis and characterization of magnesium peroxide nanoparticles

    International Nuclear Information System (INIS)

    Jaison, J; Chan, Y S; Ashok raja, C; Balakumar, S

    2015-01-01

    Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO 2 ) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO 2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles. (paper)

  10. Nanostructured energetic materials derived from sol-gel chemistry

    International Nuclear Information System (INIS)

    Simpson, R L; Tillotson, T M; Hrubesh, L W; Gash, A E

    2000-01-01

    Initiation and detonation properties are dramatically affected by an energetic material's microstructural properties. Sol-gel chemistry allows intimacy of mixing to be controlled and dramatically improved over existing methodologies. One material goal is to create very high power energetic materials which also have high energy densities. Using sol-gel chemistry we have made a nanostructured composite energetic material. Here a solid skeleton of fuel, based on resorcinol-formaldehyde, has nanocrystalline ammonium perchlorate, the oxidizer, trapped within its pores. At optimum stoichiometry it has approximately the energy density of HMX. Transmission electron microscopy indicated no ammonium perchlorate crystallites larger than 20 nm while near-edge soft x-ray absorption microscopy showed that nitrogen was uniformly distributed, at least on the scale of less than 80 nm. Small-angle neutron scattering studies were conducted on the material. Those results were consistent with historical ones for this class of nanostructured materials. The average skeletal primary particle size was on the order of 2.7 nm, while the nanocomposite showed the growth of small 1 nm size crystals of ammonium perchlorate with some clustering to form particles greater than 10 nm

  11. Gel compression considerations for chromatography scale-up for protein C purification.

    Science.gov (United States)

    He, W; Bruley, D F; Drohan, W N

    1998-01-01

    This work is to establish theoretical and experimental relationships for the scale-up of Immobilized Metal Affinity Chromatography (IMAC) and Immuno Affinity Chromatography for the low cost production of large quantities of Protein C. The external customer requirements for this project have been established for Protein C deficient people with the goal of providing prophylactic patient treatment. Deep vein thrombosis is the major symptom for protein C deficiency creating the potential problem of embolism transport to important organs, such as, lung and brain. Gel matrices for protein C separation are being analyzed to determine the relationship between the material properties of the gel and the column collapse characteristics. The fluid flow rate and pressure drop is being examined to see how they influence column stability. Gel packing analysis includes two considerations; one is bulk compression due to flow rate, and the second is gel particle deformation due to fluid flow and pressure drop. Based on the assumption of creeping flow, Darcy's law is being applied to characterize the flow through the gel particles. Biot's mathematical description of three-dimensional consolidation in porous media is being used to develop a set of system equations. Finite difference methods are being utilized to obtain the equation solutions. In addition, special programs such as finite element approaches, ABAQUS, will be studied to determine their application to this particular problem. Experimental studies are being performed to determine flow rate and pressure drop correlation for the chromatographic columns with appropriate gels. Void fraction is being measured using pulse testing to allow Reynolds number calculations. Experimental yield stress is being measured to compare with the theoretical calculations. Total Quality Management (TQM) tools have been utilized to optimize this work. For instance, the "Scatter Diagram" has been used to evaluate and select the appropriate gels and

  12. Meso-Decorated Switching-Knot Gels

    Science.gov (United States)

    Gong, Jin; Sawamura, Kensuke; Makino, Masato; Kabir, M. H.; Furukawa, Hidemitsu

    Gels are a new material having three-dimensional network structures of macromolecules. They possess excellent properties as swellability, high permeability and biocompatibility, and have been applied in various fields of daily life, food, medicine, architecture, and chemistry .In this study, we tried to prepare new multi-functional and high-strength gels by using Meso-Decoration (Meso-Deco), one new method of structure design at intermediate mesoscale. High-performance rigid-rod aromatic polymorphic crystals. The strengthening of gels can be realized by meso-decorating the gels' structure using high-performance polymorphic crystals. New gels with good mechanical properties, novel optical properties and thermal properties are expected to be developed.

  13. On shear rheology of gel propellants

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Shai; Peretz, Arie [RAFAEL, MANOR Propulsion and Explosive Systems Division, Haifa (Israel); Natan, Benveniste [Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2007-04-15

    Selected fuel, oxidizer and simulant gels were prepared and rheologically characterized using a rotational rheometer. For fuel gelation both organic and inorganic gellants were utilized, whereas oxidizers and simulants were gelled with addition of silica and polysaccharides, respectively. The generalized Herschel-Bulkley constitutive model was found to most adequately represent the gels studied. Hydrazine-based fuels, gelled with polysaccharides, were characterized as shear-thinning pseudoplastic fluids with low shear yield stress, whereas inhibited red-fuming nitric acid (IRFNA) and hydrogen peroxide oxidizers, gelled with silica, were characterized as yield thixotropic fluids with significant shear yield stress. Creep tests were conducted on two rheological types of gels with different gellant content and the results were fitted by Burgers-Kelvin viscoelastic constitutive model. The effect of temperature on the rheological properties of gel propellant simulants was also investigated. A general rheological classification of gel propellants and simulants is proposed. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  14. Structural and optical studies of nano-structure silica gel doped with different rare earth elements, prepared by two different sol -gel techniques

    International Nuclear Information System (INIS)

    Battisha, I.K.; El Beyally, A.; Seliman, S.I.; El Nahrawi, A.S.

    2005-01-01

    Structural and optical characteristics of pure silica gel (silica-xerogel, SiO 2 ) and doped with different concentrations ranging from 1 up to 6% of some rare earth (REEs) ions such as, praseodymium Pr +3 ,and Europium Eu +3 , Erbium Er +3 and Holmium Ho +3 , ions, in the form of thin film and monolith materials were prepared by sol - gel technique, Using tetra-ethoxysilane as precursor materials, which are of particular interest for sol-gel integrated optics applications. Some structural and optical features of sol-gel derived monolith and thin films are analyzed and compared, namely the structure of nano-particle monolith and thin film silica-gel samples, based on X-ray diffraction (XRD). The types of structural information obtainable are compared in detail. It is show that the XRD spectra of a-cristobalite are obtained for the two type materials and even by doping with the four REEs ions. Optical measurements of monolith and thin films were also studied and compared, the normal transmission and specular reflection were measured. The refractive index were calculated and discussed

  15. Electrophoresis of DNA in agarose gels, polyacrylamide gels and in free solution

    Science.gov (United States)

    Stellwagen, Nancy C.

    2009-01-01

    This review describes the electrophoresis of curved and normal DNA molecules in agarose gels, polyacrylamide gels and in free solution. These studies were undertaken to clarify why curved DNA molecules migrate anomalously slowly in polyacrylamide gels but not in agarose gels. Two milestone papers are cited, in which Ferguson plots were used to estimate the effective pore size of agarose and polyacrylamide gels. Subsequent studies on the effect of the electric field on agarose and polyacrylamide gel matrices, DNA interactions with the two gel matrices, and the effect of curvature on the free solution mobility of DNA are also described. The combined results suggest that the anomalously slow mobilities observed for curved DNA molecules in polyacrylamide gels are due primarily to preferential interactions of curved DNAs with the polyacrylamide gel matrix; the restrictive pore size of the matrix is of lesser importance. In free solution, DNA mobilities increase with increasing molecular mass until leveling off at a plateau value of (3.17 ± 0.01) × 10-4 cm2/Vs in 40 mM Tris-acetate-EDTA buffer at 20°C. Curved DNA molecules migrate anomalously slowly in free solution as well as in polyacrylamide gels, explaining why the Ferguson plots of curved and normal DNAs containing the same number of base pairs extrapolate to different mobilities at zero gel concentration. PMID:19517510

  16. Nanostructured sol-gel coatings doped with cerium nitrate as pre-treatments for AA2024-T3

    International Nuclear Information System (INIS)

    Zheludkevich, M.L.; Serra, R.; Montemor, M.F.; Yasakau, K.A.; Salvado, I.M. Miranda; Ferreira, M.G.S.

    2005-01-01

    Nanostructured hybrid sol-gel coatings doped with cerium ions were investigated in the present work as pre-treatments for the AA2024-T3 alloy. The sol-gel films have been synthesized from tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) precursors. Additionally the hybrid sol was doped with zirconia nanoparticles prepared from hydrolyzed tetra-n-propoxyzirconium (TPOZ). Cerium nitrate, as corrosion inhibitor, was added into the hybrid matrix or into the oxide nanoparticles. The chemical composition and the structure of the hybrid sol-gel films were studied by XPS (X-ray photoelectron spectroscopy) and AFM (atomic force microscopy), respectively. The evolution of the corrosion protection properties of the sol-gel films was studied by EIS (electrochemical impedance spectroscopy), which can provide quantitative information on the role of the different pre-treatments. Different equivalent circuits, for different stages of the corrosion processes, were used in order to model the coating degradation. The models were supported by SEM (scanning electron microscopy) measurements. The results show that the sol-gel films containing zirconia nanoparticles present improved barrier properties. Doping the hybrid nanostructured sol-gel coatings with cerium nitrate leads to additional improvement of the corrosion protection. The zirconia particles present in the sol-gel matrix seem to act as nanoreservoirs providing a prolonged release of cerium ions. The nanostructured sol-gel films doped with cerium nitrate can be proposed as a potential candidate for substitution of the chromate pre-treatments for AA2024-T3

  17. One-day pulsed-field gel electrophoresis protocol for rapid determination of emetic Bacillus cereus isolates.

    Science.gov (United States)

    Kaminska, Paulina S; Fiedoruk, Krzysztof; Jankowska, Dominika; Mahillon, Jacques; Nowosad, Karol; Drewicka, Ewa; Zambrzycka, Monika; Swiecicka, Izabela

    2015-04-01

    Bacillus cereus, the Gram-positive and spore-forming ubiquitous bacterium, may cause emesis as the result of food intoxication with cereulide, a heat-stable emetic toxin. Rapid determination of cereulide-positive B. cereus isolates is of highest importance due to consequences of this intoxication for human health and life. Here we present a 1-day pulsed-field gel electrophoresis for emetic B. cereus isolates, which allows rapid and efficient determination of their genomic relatedness and helps determining the source of intoxication in case of outbreaks caused by these bacilli. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Stability of bentonite gels in crystalline rock

    International Nuclear Information System (INIS)

    Pusch, R.

    1983-02-01

    The present, extended study comprises a derivation of a simple rock model as a basis for calculation of the penetration rate of bentonite and of the groundwater flow rate, which is a determinant of the erodibility of the protruding clay film. This model, which is representative of a gross permeability of about 10 -8 - 10 -9 m/s, implies a spectrum of slot-shaped joints with apertures ranging between 0.1 and 0.5 mm. It is concluded that less than 2percent of the highly compacted bentonite will be lost into traversing joints in 10 6 years. A closer analysis, in which also Poiseuille retardation and short-term experiments were taken into account, even suggests that the penetration into the considered joints will be less than that. The penetration rate is expected to be 1 decimeter in a few hundred years. The risk of erosion by flowing groundwater was estimated by comparing clay particle bond strength, evaluated from viscometer tests, and theoretically derived drag forces, the conclusion being that the maximum expected water flow rate in the widest joints of the rock model (4 times 10 -4 m/s) is not sufficient to disrupt the gel front or the large individual clay flocs that may exist at this front. The experiments support the conclusion that erosion will not be a source of bentonite loss. A worst case scenario with a shear zone being developed across deposition holes is finally considered and in addition to this, the conditions in the fracture-rich tunnel floor at the upper end of the deposition holes are also analysed. This study shows that even if the rock is much more fractured than normal conditions would imply, the bentonite loss is expected to be very moderate and without substantial effect on the barrier functions of the remaining clay cores in the deposition holes. (author)

  19. An abundance of ubiquitously expressed genes revealed by tissue transcriptome sequence data.

    Directory of Open Access Journals (Sweden)

    Daniel Ramsköld

    2009-12-01

    Full Text Available The parts of the genome transcribed by a cell or tissue reflect the biological processes and functions it carries out. We characterized the features of mammalian tissue transcriptomes at the gene level through analysis of RNA deep sequencing (RNA-Seq data across human and mouse tissues and cell lines. We observed that roughly 8,000 protein-coding genes were ubiquitously expressed, contributing to around 75% of all mRNAs by message copy number in most tissues. These mRNAs encoded proteins that were often intracellular, and tended to be involved in metabolism, transcription, RNA processing or translation. In contrast, genes for secreted or plasma membrane proteins were generally expressed in only a subset of tissues. The distribution of expression levels was broad but fairly continuous: no support was found for the concept of distinct expression classes of genes. Expression estimates that included reads mapping to coding exons only correlated better with qRT-PCR data than estimates which also included 3' untranslated regions (UTRs. Muscle and liver had the least complex transcriptomes, in that they expressed predominantly ubiquitous genes and a large fraction of the transcripts came from a few highly expressed genes, whereas brain, kidney and testis expressed more complex transcriptomes with the vast majority of genes expressed and relatively small contributions from the most expressed genes. mRNAs expressed in brain had unusually long 3'UTRs, and mean 3'UTR length was higher for genes involved in development, morphogenesis and signal transduction, suggesting added complexity of UTR-based regulation for these genes. Our results support a model in which variable exterior components feed into a large, densely connected core composed of ubiquitously expressed intracellular proteins.

  20. Heterogeneous nuclear ribonucleoproteins H, H', and F are members of a ubiquitously expressed subfamily of related but distinct proteins encoded by genes mapping to different chromosomes

    DEFF Research Database (Denmark)

    Honoré, B; Rasmussen, H H; Vorum, H

    1995-01-01

    Molecular cDNA cloning, two-dimensional gel immunoblotting, and amino acid microsequencing identified three sequence-unique and distinct proteins that constitute a subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins corresponding to hnRNPs H, H', and F. These proteins share...... epitopes and sequence identity with two other proteins, isoelectric focusing sample spot numbers 2222 (37.6 kDa; pI 6.5) and 2326 (39.5 kDa; pI 6.6), indicating that the subfamily may contain additional members. The identity between hnRNPs H and H' is 96%, between H and F 78%, and between H' and F 75......%, respectively. The three proteins contain three repeats, which we denote quasi-RRMs (qRRMs) since they have a remote similarity to the RNA recognition motif (RRM). The three qRRMs of hnRNP H, with a few additional NH2-terminal amino acids, were constructed by polymerase chain reaction amplification and used...

  1. Organic influences on inorganic patterns of diffusion-controlled precipitation in gels

    Science.gov (United States)

    Barge, Laura M.; Nealson, Kenneth H.; Petruska, John

    2010-06-01

    The well-known AgNO 3/K 2CrO 4 reaction-diffusion system produces periodic bands of silver chromate precipitate in gelatin, but only randomly oriented crystals in agarose gel. We show that comparable bands can be produced in agarose gel by adding small amounts of simple organic acids (e.g., acetic acid, N-acetyl glycine, and N-acetyl alanine) that suppress crystal growth and promote formation of rounded particles of precipitate. These results indicate that α-carboxyl groups of amino acids or short peptides in gelatin under mildly acidic conditions can induce periodic band patterns in diffusion-controlled silver chromate precipitates.

  2. Revisiting Frequency Reuse towards Supporting Ultra-Reliable Ubiquitous-Rate Communication

    DEFF Research Database (Denmark)

    Park, Jihong; Kim, Dong Min; Popovski, Petar

    2017-01-01

    One of the goals of 5G wireless systems stated by the NGMN alliance is to provide moderate rates (50+ Mbps) everywhere and with very high reliability. We term this service Ultra-Reliable Ubiquitous-Rate Communication (UR2C). This paper investigates the role of frequency reuse in supporting UR2C...... in the downlink. To this end, two frequency reuse schemes are considered: user-specific frequency reuse (FRu) and BS-specific frequency reuse (FRb). For a given unit frequency channel, FRu reduces the number of serving user equipments (UEs), whereas FRb directly decreases the number of interfering base stations...

  3. Processing models for conflicting user requests in ubiquitous corporate smart spaces

    Directory of Open Access Journals (Sweden)

    Levonevskiy Dmitriy

    2018-01-01

    Full Text Available This paper considers processing of conflicting user requests in ubiquitous corporate smart spaces. The formulated problem consists in the contradiction between the limitation of available smart space resources to perform the conflicting user requests and necessity to provide the proper quality of service in corporate smart spaces. The principles of constructing the simulation model are described. The experiments were carried out basing on a model of the SPIIRAS digital signage service. Several task management strategies are discussed, an assessment of their effectiveness is given. The research is aimed at improving the quality of service and user experience in human-computer interaction within the corporate smart spaces.

  4. Handling membership dynamicity in service composition for ubiquitous computing

    DEFF Research Database (Denmark)

    Brønsted, Jeppe

    2007-01-01

    In ubiquitous computing, as more and more devices are introduced into the environment, new applications are made possible that exploit device capabilities in new ways. Currently, however, there is a mismatch between the effort involved in implementing these applications and the benefit they provide...... to specify which nodes partake in the composite and how they interact. In this paper we introduce mechanisms for handling membership dynamicity in service composition specifications. We demonstrate how an application scenario developed in cooperation with users can be implemented using the mechanisms...

  5. A cloud-based X73 ubiquitous mobile healthcare system: design and implementation.

    Science.gov (United States)

    Ji, Zhanlin; Ganchev, Ivan; O'Droma, Máirtín; Zhang, Xin; Zhang, Xueji

    2014-01-01

    Based on the user-centric paradigm for next generation networks, this paper describes a ubiquitous mobile healthcare (uHealth) system based on the ISO/IEEE 11073 personal health data (PHD) standards (X73) and cloud computing techniques. A number of design issues associated with the system implementation are outlined. The system includes a middleware on the user side, providing a plug-and-play environment for heterogeneous wireless sensors and mobile terminals utilizing different communication protocols and a distributed "big data" processing subsystem in the cloud. The design and implementation of this system are envisaged as an efficient solution for the next generation of uHealth systems.

  6. Reference model of future ubiquitous convergent network and context-aware telecommunication service platform

    Institute of Scientific and Technical Information of China (English)

    QIAO Xiu-quan; LI Xiao-feng; LIANG Shou-qing

    2006-01-01

    A reference model for future ubiquitous convergent network is analyzed. To provide user-centric, intelligent,personalized service, this article presents a context-aware telecommunication service platform (CaTSP) to adapt to dynamically changing context. This article focuses on the new design method of context-aware telecommunication service platform and its architecture. Through the use of model-driven architecture (MDA) and semantic web technologies, CaTSP can enable context reasoning and service personalization adaption.This article explores a new approach for service intelligence,personalization, and adaptability in the semantic web service computing era.

  7. Ubiquitous computing in the workplace what ethical issues? : an interdisciplinary perspective

    CERN Document Server

    Nihan, Céline

    2015-01-01

    This book provides an interdisciplinary collection of views on the ethical challenges and opportunities of workplaces in the Internet of things. Current developments within Ubiquitous computing (ubicomp) systems designed for the workplace are introduced and philosophical, organizational and socio-ethical considerations of ubicomp in workplaces are provided. Suggestions regarding the rules that should be respected in order to favor an adequate implementation of ubicomp in the workplace are offered, considering both intra-organizational but also wider societal concerns. The interdisciplinary collection of contributions invites the reader to engage in the discussion of ubicomp in everyday working environments.      

  8. Particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.

    1993-09-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics.

  9. Particle therapy

    International Nuclear Information System (INIS)

    Raju, M.R.

    1993-01-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics

  10. Ionic liquid gel materials: applications in green and sustainable chemistry

    OpenAIRE

    Marr, Patricia C.; Marr, Andrew C.

    2016-01-01

    Ionic liquid gel materials offer a way to further utilise ionic liquids in technological applications. Combining the controlled and directed assembly of gels, with the diverse applications of ionic liquids, enables the design of a heady combination of functional tailored materials, leading to the development of task specific / functional ionic liquid gels. This review introduces gels and gel classification, focusing on ionic liquid gels and their potential roles in a more sustainable future. ...

  11. Particle cosmology

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The understanding of the Universe at the largest and smallest scales traditionally has been the subject of cosmology and particle physics, respectively. Studying the evolution of the Universe connects today's large scales with the tiny scales in the very early Universe and provides the link between the physics of particles and of the cosmos. This series of five lectures aims at a modern and critical presentation of the basic ideas, methods, models and observations in today's particle cosmology.

  12. Sol-gel technology for biomedical engineering

    International Nuclear Information System (INIS)

    Podbielska, H.; Ulatowska-Jarza, A.

    2005-01-01

    Sol-gel derived silica possess many promising features, including low-temperature preparation procedure, porosity, chemical and physical stability. Applications exploiting porous materials to encapsulate sensor molecules, enzymes and many other compounds, are developing rapidly. In this paper some potential applications, with emphasis on biomedical and environmental ones, are reviewed. The material preparation procedure is described and practical remarks on silica-based sol-gels are included. It is reported that sol-gels with entrapped various molecules may be used in construction of implants and coatings with bioactive properties. It is shown how to exploit the sol-gel production route for construction of sol-gel coated fiberoptic applicators for laser therapy. The applications of bioactive materials are discussed, as well. It is demonstrated that it is possible to immobilize photosensitive compounds in sol-gel matrix without loosing their photoactivity. Some examples of sol-gel based biosensors are demonstrated, as well, showing their potential for detecting various gases, toxic substances, acidity, humidity, enzymes and biologically active agents. (authors)

  13. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Short, K.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Sol-gel bonds have been produced between smooth, clean silicon substrates by spin-coating solutions containing partially hydrolysed silicon alkoxides. The two coated substrates were assembled and the resulting sandwich fired at temperatures ranging from 60 to 600 deg. C. The sol-gel coatings were characterised using attenuated total reflectance Fourier transform infrared spectroscopy, ellipsometry, and atomic force microscopy, while the corresponding bonded specimens were investigated using scanning electron microscopy and cross-sectional transmission electron microscopy. Mechanical properties were characterised using both microindentation and tensile testing. Bonding of silicon wafers has been successfully achieved at temperatures as low as 60 deg. C. At 300 deg. C, the interfacial fracture energy was 1.55 J/m 2 . At 600 deg. C, sol-gel bonding provided superior interfacial fracture energy over classical hydrophilic bonding (3.4 J/m 2 vs. 1.5 J/m 2 ). The increase in the interfacial fracture energy is related to the increase in film density due to the sintering of the sol-gel interface with increasing temperature. The superior interfacial fracture energy obtained by sol-gel bonding at low temperature is due to the formation of an interfacial layer, which chemically bonds the two sol-gel coatings on each wafer. Application of a tensile stress on the resulting bond leads to fracture of the samples at the silicon/sol-gel interface

  14. Particle physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  15. Magnetic particles

    Science.gov (United States)

    Chang, Manchium (Inventor); Colvin, Michael S. (Inventor)

    1989-01-01

    Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.

  16. The chemistry of plutonium in sol-gel processes

    International Nuclear Information System (INIS)

    Lloyd, M.H.; Haire, R.G.

    1978-01-01

    Studies of plutonium chemical behavior conducted in conjunction with plutonia sol-gel process development at ORNL are described. The colloidal solutions produced consist of 'Pu(IV) polymer,' and this is therefore the study of polymeric plutonium behavior. Spectrophotometric, electron diffraction, and electron microscopy studies, in addition to specific studies that were concerned with the colloidal behavior of Pu(IV) polymer, indicate several characteristics of polymer that are not generally recognized. The particle nature of Pu(IV) polymer indicated by electron microscopy, the amorphous-crystalline characteristics of primary polymer particles demonstrated by electron diffraction, and the reversible and irreversible aggregation of the primary particles shown by spectrophotometric techniques present a useful view of the nature of Pu(IV) polymer that has been helpful in solving or understanding various types of processing problems involving plutonium hydrolytic behavior. The colloidal characteristics of Pu(IV) polymer and crystallite growth of primary polymer particles by thermal denitration are also described. (orig.) [de

  17. Polymer gel dosimeter with AQUAJOINT® as hydrogel matrix

    Science.gov (United States)

    Maeyama, Takuya; Ishida, Yasuhiro; Kudo, Yoshihiro; Fukasaku, Kazuaki; Ishikawa, Kenichi L.; Fukunishi, Nobuhisa

    2018-05-01

    We report a polymer gel dosimeter based on a new gel matrix (AQUAJOINT®) that is a thermo-irreversible hydrogel formed by mixing two types of water-based liquids at room temperature. Normoxic N-vinylpyrrolidone-based polymer gels were prepared with AQUAJOINT® instead of gelatin. This AQUAJOINT®-based gel dosimeter exhibits a 2.5-fold increase in sensitivity over a gelatin-based gel dosimeter and a linear dose-response in the dose range of 0-8 Gy. This gel has heat resistance in a jar and controlled gel properties such as viscoelastic and mechanical characters, which may be useful for deformable polymer gel dosimetry.

  18. A Wireless Sensor Network-Based Ubiquitous Paprika Growth Management System

    Directory of Open Access Journals (Sweden)

    Jeonghwan Hwang

    2010-12-01

    Full Text Available Wireless Sensor Network (WSN technology can facilitate advances in productivity, safety and human quality of life through its applications in various industries. In particular, the application of WSN technology to the agricultural area, which is labor-intensive compared to other industries, and in addition is typically lacking in IT technology applications, adds value and can increase the agricultural productivity. This study attempts to establish a ubiquitous agricultural environment and improve the productivity of farms that grow paprika by suggesting a ‘Ubiquitous Paprika Greenhouse Management System’ using WSN technology. The proposed system can collect and monitor information related to the growth environment of crops outside and inside paprika greenhouses by installing WSN sensors and monitoring images captured by CCTV cameras. In addition, the system provides a paprika greenhouse environment control facility for manual and automatic control from a distance, improves the convenience and productivity of users, and facilitates an optimized environment to grow paprika based on the growth environment data acquired by operating the system.

  19. A Wireless Sensor Network-Based Ubiquitous Paprika Growth Management System

    Science.gov (United States)

    Hwang, Jeonghwan; Shin, Changsun; Yoe, Hyun

    2010-01-01

    Wireless Sensor Network (WSN) technology can facilitate advances in productivity, safety and human quality of life through its applications in various industries. In particular, the application of WSN technology to the agricultural area, which is labor-intensive compared to other industries, and in addition is typically lacking in IT technology applications, adds value and can increase the agricultural productivity. This study attempts to establish a ubiquitous agricultural environment and improve the productivity of farms that grow paprika by suggesting a ‘Ubiquitous Paprika Greenhouse Management System’ using WSN technology. The proposed system can collect and monitor information related to the growth environment of crops outside and inside paprika greenhouses by installing WSN sensors and monitoring images captured by CCTV cameras. In addition, the system provides a paprika greenhouse environment control facility for manual and automatic control from a distance, improves the convenience and productivity of users, and facilitates an optimized environment to grow paprika based on the growth environment data acquired by operating the system. PMID:22163543

  20. Automated Construction of Node Software Using Attributes in a Ubiquitous Sensor Network Environment

    Science.gov (United States)

    Lee, Woojin; Kim, Juil; Kang, JangMook

    2010-01-01

    In sensor networks, nodes must often operate in a demanding environment facing restrictions such as restricted computing resources, unreliable wireless communication and power shortages. Such factors make the development of ubiquitous sensor network (USN) applications challenging. To help developers construct a large amount of node software for sensor network applications easily and rapidly, this paper proposes an approach to the automated construction of node software for USN applications using attributes. In the proposed technique, application construction proceeds by first developing a model for the sensor network and then designing node software by setting the values of the predefined attributes. After that, the sensor network model and the design of node software are verified. The final source codes of the node software are automatically generated from the sensor network model. We illustrate the efficiency of the proposed technique by using a gas/light monitoring application through a case study of a Gas and Light Monitoring System based on the Nano-Qplus operating system. We evaluate the technique using a quantitative metric—the memory size of execution code for node software. Using the proposed approach, developers are able to easily construct sensor network applications and rapidly generate a large number of node softwares at a time in a ubiquitous sensor network environment. PMID:22163678

  1. Analysis of energy efficient routing protocols for implementation of a ubiquitous health system

    Science.gov (United States)

    Kwon, Jongwon; Park, Yongman; Koo, Sangjun; Ayurzana, Odgeral; Kim, Hiesik

    2007-12-01

    The innovative Ubiquitous-Health was born through convergence of medical service, with development of up to date information technologies and ubiquitous IT. The U-Health can be applied to a variety of special situations for managing functions of each medical center efficiently. This paper focuses on estimation of various routing protocols for implementation of U-health monitoring system. In order to facilitate wireless communication over the network, a routing protocol on the network layer is used to establish precise and efficient route between sensor nodes so that information acquired from sensors may be delivered in a timely manner. A route establishment should be considered to minimize overhead, data loss and power consumption because wireless networks for U-health are organized by a large number of sensor nodes which are small in size and have limited processing power, memory and battery life. In this paper a overview of wireless sensor network technologies commonly known is described as well as evaluation of three multi hop routing protocols which are flooding, gossiping and modified low energy adaptive clustering hierarchy(LEACH) for use with these networks using TOSSIM simulator. As a result of evaluation the integrated wireless sensor board was developed in particular. The board is embedded device based on AVR128 porting TinyOS. Also it employs bio sensor measures blood pressure, pulse frequency and ZigBee module for wireless communication. This paper accelerates the digital convergence age through continual research and development of technologies related the U-Health.

  2. The Characteristics of Ubiquitous and Unique Leptospira Strains from the Collection of Russian Centre for Leptospirosis

    Science.gov (United States)

    Voronina, Olga L.; Kunda, Marina S.; Aksenova, Ekaterina I.; Ryzhova, Natalia N.; Semenov, Andrey N.; Petrov, Evgeny M.; Didenko, Lubov V.; Lunin, Vladimir G.; Ananyina, Yuliya V.; Gintsburg, Alexandr L.

    2014-01-01

    Background and Aim. Leptospira, the causal agent of leptospirosis, has been isolated from the environment, patients, and wide spectrum of animals in Russia. However, the genetic diversity of Leptospira in natural and anthropurgic foci was not clearly defined. Methods. The recent MLST scheme was used for the analysis of seven pathogenic species. 454 pyrosequencing technology was the base of the whole genome sequencing (WGS). Results. The most wide spread and prevalent Leptospira species in Russia were L. interrogans, L. kirschneri, and L. borgpetersenii. Five STs, common for Russian strains: 37, 17, 199, 110, and 146, were identified as having a longtime and ubiquitous distribution in various geographic areas. Unexpected properties were revealed for the environmental Leptospira strain Bairam-Ali. WGS of this strain genome suggested that it combined the features of the pathogenic and nonpathogenic strains and may be a reservoir of the natural resistance genes. Results of the comparative analysis of rrs and rpoB genes and MLST loci for different Leptospira species strains and phenotypic and serological properties of the strain Bairam-Ali suggested that it represented separate Leptospira species. Conclusions. Thus, the natural and anthropurgic foci supported ubiquitous Leptospira species and the pool of genes important for bacterial adaptivity to various conditions. PMID:25276806

  3. Ubiquitous Monitoring Solution for Wireless Sensor Networks with Push Notifications and End-to-End Connectivity

    Directory of Open Access Journals (Sweden)

    Luis M. L. Oliveira

    2014-01-01

    Full Text Available Wireless Sensor Networks (WSNs belongs to a new trend in technology in which tiny and resource constrained devices are wirelessly interconnected and are able to interact with the surrounding environment by collecting data such as temperature and humidity. Recently, due to the huge growth in the use of mobile devices with Internet connection, smartphones are becoming the center of future ubiquitous wireless networks. Interconnecting WSNs with smartphones and the Internet is a big challenge and new architectures are required due to the heterogeneity of these devices. Taking into account that people are using smartphones with Internet connection, there is a good opportunity to propose a new architecture for wireless sensors monitoring using push notifications and smartphones. Then, this paper proposes a ubiquitous approach for WSN monitoring based on a REST Web Service, a relational database, and an Android mobile application. Real-time data sensed by WSNs are sent directly to a smartphone or stored in a database and requested by the mobile application using a well-defined RESTful interface. A push notification system was created in order to alert mobile users when a sensor parameter overcomes a given threshold. The proposed architecture and mobile application were evaluated and validated using a laboratory WSN testbed and are ready for use.

  4. A Framework for Real-Time Collection, Analysis, and Classification of Ubiquitous Infrasound Data

    Science.gov (United States)

    Christe, A.; Garces, M. A.; Magana-Zook, S. A.; Schnurr, J. M.

    2015-12-01

    Traditional infrasound arrays are generally expensive to install and maintain. There are ~10^3 infrasound channels on Earth today. The amount of data currently provided by legacy architectures can be processed on a modest server. However, the growing availability of low-cost, ubiquitous, and dense infrasonic sensor networks presents a substantial increase in the volume, velocity, and variety of data flow. Initial data from a prototype ubiquitous global infrasound network is already pushing the boundaries of traditional research server and communication systems, in particular when serving data products over heterogeneous, international network topologies. We present a scalable, cloud-based approach for capturing and analyzing large amounts of dense infrasonic data (>10^6 channels). We utilize Akka actors with WebSockets to maintain data connections with infrasound sensors. Apache Spark provides streaming, batch, machine learning, and graph processing libraries which will permit signature classification, cross-correlation, and other analytics in near real time. This new framework and approach provide significant advantages in scalability and cost.

  5. The ubiquitous presence of exopolygalacturonase in maize suggests a fundamental cellular function for this enzyme.

    Science.gov (United States)

    Dubald, M; Barakate, A; Mandaron, P; Mache, R

    1993-11-01

    Exopolygalacturonase (exoPG) is a pectin-degrading enzyme abundant in maize pollen. Using immunochemistry and in situ hybridization it is shown that in addition to its presence in pollen, exoPG is also present in sporophytic tissues, such as the tapetum and mesophyll cells. The enzyme is located in the cytoplasm of pollen and of some mesophyll cells. In other mesophyll cells, the tapetum and the pollen tube, exoPG is located in the cell wall. The measurement of enzyme activity shows that exoPG is ubiquitous in the vegetative organs. These results suggest a general function for exoPG in cell wall edification or degradation. ExoPG is encoded by a closely related multigene family. The regulation of the expression of one of the exoPG genes was analyzed in transgenic tobacco. Reporter GUS activity was detected in anthers, seeds and stems but not in leaves or roots of transgenic plants. This strongly suggests that the ubiquitous presence of exoPG in maize is the result of the expression of different exoPG genes.

  6. Automated Construction of Node Software Using Attributes in a Ubiquitous Sensor Network Environment

    Directory of Open Access Journals (Sweden)

    JangMook Kang

    2010-09-01

    Full Text Available In sensor networks, nodes must often operate in a demanding environment facing restrictions such as restricted computing resources, unreliable wireless communication and power shortages. Such factors make the development of ubiquitous sensor network (USN applications challenging. To help developers construct a large amount of node software for sensor network applications easily and rapidly, this paper proposes an approach to the automated construction of node software for USN applications using attributes. In the proposed technique, application construction proceeds by first developing a model for the sensor network and then designing node software by setting the values of the predefined attributes. After that, the sensor network model and the design of node software are verified. The final source codes of the node software are automatically generated from the sensor network model. We illustrate the efficiency of the proposed technique by using a gas/light monitoring application through a case study of a Gas and Light Monitoring System based on the Nano-Qplus operating system. We evaluate the technique using a quantitative metric—the memory size of execution code for node software. Using the proposed approach, developers are able to easily construct sensor network applications and rapidly generate a large number of node softwares at a time in a ubiquitous sensor network environment.

  7. Clinical decision support systems in hospital care using ubiquitous devices: Current issues and challenges.

    Science.gov (United States)

    Baig, Mirza Mansoor; GholamHosseini, Hamid; Moqeem, Aasia A; Mirza, Farhaan; Lindén, Maria

    2017-11-01

    Supporting clinicians in decision making using advanced technologies has been an active research area in biomedical engineering during the past years. Among a wide range of ubiquitous systems, smartphone applications have been increasingly developed in healthcare settings to help clinicians as well as patients. Today, many smartphone applications, from basic data analysis to advanced patient monitoring, are available to clinicians and patients. Such applications are now increasingly integrating into healthcare for clinical decision support, and therefore, concerns around accuracy, stability, and dependency of these applications are rising. In addition, lack of attention to the clinicians' acceptability, as well as the low impact on the medical professionals' decision making, are posing more serious issues on the acceptability of smartphone applications. This article reviews smartphone-based decision support applications, focusing on hospital care settings and their overall impact of these applications on the wider clinical workflow. Additionally, key challenges and barriers of the current ubiquitous device-based healthcare applications are identified. Finally, this article addresses current challenges, future directions, and the adoption of mobile healthcare applications.

  8. HSDPA (3.5G)-based ubiquitous integrated biotelemetry system for emergency care.

    Science.gov (United States)

    Kang, Jaemin; Shin, Il Hyung; Koo, Yoonseo; Jung, Min Yang; Suh, Gil Joon; Kim, Hee Chan

    2007-01-01

    We have developed the second prototype system of Ubiquitous Integrated Biotelemetry System for Emergency Care(UIBSEC) using a HSDPA(High Speed Downlink Packet Access) modem to be used by emergency rescuers to get directions from medical doctors in providing emergency medical services for patients in ambulance. Five vital bio-signal instrumentation modules have been implemented, which include noninvasive arterial blood pressure (NIBP), arterial oxygen saturation (SaO2), 6-channel electro-cardiogram(ECG), blood glucose level, and body temperature and real-time motion picture of the patient and GPS information are also taken. Measured patient data, captured motion picture and GPS information are then transferred to a doctor's PC through the HSDPA and TCP/IP networks using stand-alone HSDPA modem. Most prominent feature of the developed system is that it is based on the HSDPA backbone networks available in Korea now, through which we will be able to establish a ubiquitous emergency healthcare service system.

  9. Automated construction of node software using attributes in a ubiquitous sensor network environment.

    Science.gov (United States)

    Lee, Woojin; Kim, Juil; Kang, JangMook

    2010-01-01

    In sensor networks, nodes must often operate in a demanding environment facing restrictions such as restricted computing resources, unreliable wireless communication and power shortages. Such factors make the development of ubiquitous sensor network (USN) applications challenging. To help developers construct a large amount of node software for sensor network applications easily and rapidly, this paper proposes an approach to the automated construction of node software for USN applications using attributes. In the proposed technique, application construction proceeds by first developing a model for the sensor network and then designing node software by setting the values of the predefined attributes. After that, the sensor network model and the design of node software are verified. The final source codes of the node software are automatically generated from the sensor network model. We illustrate the efficiency of the proposed technique by using a gas/light monitoring application through a case study of a Gas and Light Monitoring System based on the Nano-Qplus operating system. We evaluate the technique using a quantitative metric-the memory size of execution code for node software. Using the proposed approach, developers are able to easily construct sensor network applications and rapidly generate a large number of node softwares at a time in a ubiquitous sensor network environment.

  10. A pervasive health monitoring service system based on ubiquitous network technology.

    Science.gov (United States)

    Lin, Chung-Chih; Lee, Ren-Guey; Hsiao, Chun-Chieh

    2008-07-01

    The phenomenon of aging society has derived problems such as shortage of medical resources and reduction of quality in healthcare services. This paper presents a system infrastructure for pervasive and long-term healthcare applications, i.e. a ubiquitous network composed of wireless local area network (WLAN) and cable television (CATV) network serving as a platform for monitoring physiological signals. Users can record vital signs including heart rate, blood pressure, and body temperature anytime either at home or at frequently visited public places in order to create a personal health file. The whole system was formally implemented in December 2004. Analysis of 2000 questionnaires indicates that 85% of users were satisfied with the provided community-wide healthcare services. Among the services provided by our system, health consultation services offered by family doctors was rated the most important service by 17.9% of respondents, and was followed by control of one's own health condition (16.4% of respondents). Convenience of data access was rated most important by roughly 14.3% of respondents. We proposed and implemented a long-term healthcare system integrating WLAN and CATV networks in the form of a ubiquitous network providing a service platform for physiological monitoring. This system can classify the health levels of the resident according to the variation tendency of his or her physiological signal for important reference of health management.

  11. A SURVEY OF SMART ELECTRICAL BOARDS IN UBIQUITOUS SENSOR NETWORKS FOR GEOMATICS APPLICATIONS

    Directory of Open Access Journals (Sweden)

    S. M. R. Moosavi

    2015-12-01

    Full Text Available Nowadays more advanced sensor networks in various fields are developed. There are lots of online sensors spreading around the world. Sensor networks have been used in Geospatial Information Systems (GIS since sensor networks have expanded. Health monitoring, environmental monitoring, traffic monitoring, etc, are the examples of its applications in Geomatics. Sensor network is an infrastructure comprised of sensing (measuring, computing, and communication elements that gives an administrator the ability to instrument, observe, and react to events and phenomena in a specified environment. This paper describes about development boards which can be used in sensor networks and their applications in Geomatics and their role in wireless sensor networks and also a comparison between various types of boards. Boards that are discussed in this paper are Arduino, Raspberry Pi, Beagle board, Cubieboard. The Boards because of their great potential are also known as single board computers. This paper is organized in four phases: First, Reviewing on ubiquitous computing and sensor networks. Second, introducing of some electrical boards. Then, defining some criterions for comparison. Finally, comparing the Ubiquitous boards.

  12. Acoustic evaluation of polymer gel dosimeters

    International Nuclear Information System (INIS)

    Mather, M.L.; De Deene, Y.; Baldock, C.; Whittaker, A.K.

    2002-01-01

    Advances in radiotherapy treatment techniques such as intensity modulated radiotherapy are placing increasing demands on radiation dosimetry for verification of dose distributions in 3D. In response, polymer gel dosimeters that are capable of recording dose distributions in 3D are currently being developed. Recently, a new technique for evaluation of absorbed dose distributions in these dosimeters using ultrasound was introduced. The current work aims to demonstrate the potential of ultrasound as an evaluation technique for polymer gel dosimeters and to investigate the ultrasound properties of two different dosimeter formulations, PAG and MAGIC gels

  13. Pulsed field gel electrophoresis a practical guide

    CERN Document Server

    Birren, Bruce

    1993-01-01

    Pulsed Field Gel Electrophoresis: A Practical Guide is the first laboratory manual to describe the theory and practice of this technique. Based on the authors' experience developing pulsed field gel instruments and teaching procedures, this book provides everything a researcher or student needs to know in order to understand and carry out pulsed field gel experiments. Clear, well-tested protocols assume only that users have a basic familiarity with molecular biology. Thorough coverage of useful data, theory, and applications ensures that this book is also a lasting resource for more adv

  14. Applications of sol gel ceramic coatings

    International Nuclear Information System (INIS)

    Barrow, D.

    1996-01-01

    The sol gel method is a chemical technique in which polycrystalline ceramic films are fabricated from a solution of organometallic precursors. The technique is attractive for many industrial applications because it is a simple (films are processed in air), flexible (can be used to coat complex geometries) and cost effective (does not require expensive equipment) process. In addition, dense, high quality coatings can be achieved at much lower temperatures than is generally required for sintering bulk ceramics. In this paper the conventional sol gel method and the new datec process are reviewed and potential applications of sol gel coatings in automotive, aerospace, petrochemical, nuclear and electronic industries are discussed. (orig.)

  15. Variables of synthesis in obtaining nanosilicas with sol-gel

    International Nuclear Information System (INIS)

    Elia, A; Martin-Aispuro, P; Musante, L; Martin-Martinez, J.M; Vazquez, P

    2008-01-01

    Amorphous silica materials and polycrystalline are now being developed for different applications as optic components, superconductors, nano-particles used as charges in adhesives and paints, among others. Some methods of obtaining these materials involve complex techniques and high costs. Generally, the materials constituents are fused, for example, using the pyrogenic silica technique, widely used industrially. Meanwhile, the sol-gel meted is based on a mixture of liquid reagents at the molecular level, to easily obtain amorphous and polycrystalline materials, even at room temperature. Therefore, the sol-gel way is a promising option for producing new materials, due to its cost advantages compared to the traditional methods. The sol-gel technique consists of the simultaneous reaction of the hydrolysis and the condensation. In this process the precursor solution, the TEOS in our case, becomes a polymeric gel network polymer. The partial hydrolysis of the orthosilicate takes place when it is mixed with water and ethanol (EtOH), the reaction that occurs is: S i(OEt) 4 + H 2 O S i(OEt) 3 (OH) + EtOH. The condensation takes place between two OH groups or between an OH group and an ethoxy to form an oxygen bridge plus water or ethanol. S i(OEt) 4 + H 2 O + S i(OEt) 3 (OH)(EtO) 3 Si-O-Si(OEt) 3 (OH) + H 2 O S i-OH + HO-Si S i-O-Si + H 2 O. The addition of a base or of an acid catalyzes the process and changes the pH of the solution influencing the condensation process and size of the final particle. This work focuses on finding different conditions by varying the pH, using HCI, with and without agitation during the addition of the HCI, and washing the solid obtained with ethanol in order to study its effect. The nanosilicas were characterized by TEM-EDX, DTA-TGA, S BET , FT-IR, DRX, DRS, SEM and pH measurements. The morphology of the nanosilicas was characterized with SEM and TEM. Using these techniques a partial conclusion showed that the samples synthesized with HCI

  16. Particle accelerator

    International Nuclear Information System (INIS)

    Ress, R.I.

    1976-01-01

    Charged particles are entrained in a predetermined direction, independent of their polarity, in a circular orbit by a magnetic field rotating at high speed about an axis in a closed cylindrical or toroidal vessel. The field may be generated by a cylindrical laser structure, whose beam is polygonally reflected from the walls of an excited cavity centered on the axis, or by high-frequency energization of a set of electromagnets perpendicular to the axis. In the latter case, a separate magnetostatic axial field limits the orbital radius of the particles. These rotating and stationary magnetic fields may be generated centrally or by individual magnets peripherally spaced along its circular orbit. Chemical or nuclear reactions can be induced by collisions between the orbiting particles and an injected reactant, or by diverting high-speed particles from one doughnut into the path of counterrotating particles in an adjoining doughnut

  17. Sol-gel synthesis of lithium metatitanate as tritium breeding material under different sintering conditions

    Science.gov (United States)

    Lu, Wei; Wang, Jing; Pu, Wenjing; Li, Kaiping; Ma, Shubing; Wang, Weihua

    2018-04-01

    Lithium metatitanate (Li2TiO3) is a promising tritium breeding material candidate for solid blanket of D-T fusion reactors, due to its high mechanical strength, chemical stability, and tritium release rate. In this paper, Li2TiO3 powder with homogeneous crystal structure is synthesized by sol-gel method. The chemical reactions in gel thermal cracking and sintering process are studied by thermo gravimetric/differential scanning calorimetry (TG-DSC). The relationship between the sintering condition and the particle/grain size is characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that below 673 K the gel precursor is completely decomposed and Li2TiO3 phase initially forms. The LiTiO2 by-product formed under the reductive atmosphere in muffle furnace, could be oxidized continually to Li2TiO3 at higher sintering temperature (≥1273 K) for longer sintering time (≥10 h). Both grain and particle sizes rely on a linear growth with the increase of sintering time at 1273 K. Over 1473 K, significant agglomerations exist among particles. The optimal sintering condition is selected as 1273 K for 10 h, for the purer Li2TiO3 phase (>99%), smaller grain and particle size.

  18. Sodium Dedecyl Suphate Polyacrilamide Gel Electrophosis of ...

    African Journals Online (AJOL)

    polyacrilamide gel electrophoresis (SDS-PAGE). The isolates were obtained from the faeces of diarrhoeic children with the age range of 0 t 36 months attending paediatric clinic at the Lagos University Teaching Hospital (LUTH) and Obafemi Awolowo ...

  19. Preparation of zirconium molybdate gel generator

    International Nuclear Information System (INIS)

    Charoen, S.; Aungurarat, G.; Laohawilai, S.; Sukontpradit, W.; Jingjit, S.

    1994-01-01

    A procedure for preparation of 99mTc generator based on conversion to zirconium molybdate gel of 99Mo produced by neutron activation was reported. The gel was prepared from zirconium oxychloride solution pH 1.6, ammonium molybdate solution pH 3-5 and mole ratio of Zr:Mo 1:1 which had water content about 7-8%. Small generators containing 1-1.5 g of gel were eluted with average efficiencies of 77% and the activity peak in the first 3 ml of 10 ml of saline solution. The amount of Mo and Zr in eluates were below the acceptance limit. The gel generators of activity about 100 mCi were prepared and had the good performance in elutability and stability

  20. K-Basin gel formation studies

    International Nuclear Information System (INIS)

    Beck, M.A.

    1998-01-01

    A key part of the proposed waste treatment for K Basin sludge is the elimination of reactive uranium metal by dissolution in nitric acid (Fkirnent, 1998). It has been found (Delegard, 1998a) that upon nitric acid dissolution of the sludge, a gel sometimes forms. Gels are known to sometimes impair solid/liquid separation and/or material transfer. The purpose of the work reported here is to determine the cause(s) of the gel formation and to determine operating parameters for the sludge dissolution that avoid formation of gel. This work and related work were planned in (Fkunent, 1998), (Jewett, 1998) and (Beck, 1998a). This report describes the results of the tests in (Beck, 1998a) with non-radioactive surrogates

  1. Formulation of Bioadhesive Carbomer Gel Incorporating Drug ...

    African Journals Online (AJOL)

    incorporated into carbomer gel and evaluated for drug release. Results: ... localized delivery system for the treatment inflammation and infection in periodontal pockets. ..... loaded with diclofenac sodium for intra- articular administration. J Drug ...

  2. Structure of gels layers with cells

    Science.gov (United States)

    Pokusaev, B. G.; Karlov, S. P.; Vyazmin, A. V.; Nekrasov, D. A.; Zakharov, N. S.; Khramtsov, D. P.; Skladnev, D. A.; Tyupa, D. V.

    2017-11-01

    The structure of two-layer agarose gels containing yeast cells is investigated experimentally by spectrometry, to shed a light on the theoretical foundations for the development of bioreactors by the method of 3D bioprinting. Due to division, cells overcome the layer of the dispersion phase separating successively applied layers of the agarose gel. However a gel layer of 100 μm thick with a high concentration of silver nanoparticles completely excludes the infiltration of yeast cells through it. A special sort of agarose is suggested where the concentration of silver nanoparticles formed by cells from salt of silver can serve as an indicator of the state of the yeast cells in the volume of the gel.

  3. Thixotropic corrosive gels for nuclear decontamination

    International Nuclear Information System (INIS)

    Bargues, St.

    1998-01-01

    The aim of this thesis was the development of corrosive gels for metallic surface decontamination. These gels formulation, based on a powerful oxidant (the cerium IV), the nitric acid, a mineral charge (silica) and a non ionic surface-active, has been developed according to the specific constraints of the nuclear industry. The objective was to prepare thixotropic gels becoming liquid after shacking to allow an easy pulverization and coming again solid to permit a perfect adhesion on the metallic surface. This rheological study of the gels has been completed by an evaluation of their corrosive properties. The last part of the work presents an industrial utilization during two years. (A.L.B.)

  4. Sol-gel antireflective coating on plastics

    Science.gov (United States)

    Ashley, Carol S.; Reed, Scott T.

    1990-01-01

    An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

  5. Coordination Polymer Gels by Electron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Ha; Cho, Young Je; Jung, Jong Hwa [Gyeongsang National Univ., Jinju (Korea, Republic of)

    2011-07-01

    Hydrogenation of a pyridine derivative possessing tetrazole moieties as end groups, without long alkyl chain groups, results in the formation of a Mg(NO{sub 3}){sub 2} coordination polymer gel. The polymer exhibits a strong fluorescence enhancement upon gel formation. 1 can also be gloated with a variety of magnesium anions such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Cl{sup -}, Br{sup -} and I{sup -}, indicating that the coordination polymer gel formation of 1 does not strongly depends on anions. The Seam and ABM images of Mg{sup 2+} coordination polymer gel 1 display a flabbier network with several micrometers long, widths in the range 60-70 nm and thicknesses of about 3 nm. In addition, photophysical studies show that the hydrogel exhibits a typical {pi}-{pi} transition and gives rise to high fluorescence behavior. The coordination polymer hydrogel exhibits viscoelastic behavior as evidenced from the rheological studies.

  6. Maize Arabinoxylan Gels as Protein Delivery Matrices

    Directory of Open Access Journals (Sweden)

    Ana Luisa Martínez-López

    2009-04-01

    Full Text Available The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v in the presence of insulin or β-lactoglobulin at 0.1% (w/v was investigated. Insulin and β-lacto-globulin did not modify either the gel elasticity (9 Pa or the cross-links content (0.03 and 0.015 mg di- and triferulic acids/mg arabinoxylan, respectively. The protein release capability of the gel was also investigated. The rate of protein release from gels was dependent on the protein molecular weight. The apparent diffusion coefficient was 0.99 × 10-7 and 0.79 × 10-7 cm2/s for insulin (5 kDa and β-lactoglobulin (18 kDa, respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins.

  7. Oxygen-17 relaxation in aqueous agarose gels

    International Nuclear Information System (INIS)

    Ablett, S.; Lillford, P.J.

    1977-01-01

    Nuclear magnetic relaxation of oxygen-17 in H 2 17 O enriched agarose gels shows that existing explanations of water behaviour are oversimplified. Satisfactory models must include at least three proton phases, two of which involve water molecules. (Auth.)

  8. Fricke xylenol gel energy dependence

    International Nuclear Information System (INIS)

    Costa, Rosangela T.; Moreira, Marcos V.; Almeida, Adelaide de

    2009-01-01

    The advancement of technology has increasingly use the of ionizing radiation mainly in the areas of medicine, industry and research. The development of instruments and methods for an effective performance for detection and measurement of each radiation area was crucial. The literature have demonstrated the effectiveness of the Fricke Xylenol Gel (FXG) as an adequate chemical sensor to be used for dosimetry, once its effective atomic number and density are near to those of the soft tissue. The use of photon beams for therapeutic purpose requires knowledge of their characteristics that can vary for each equipment. Therefore, is important to know all parameters involved for the patient irradiation as the total geometry involved, type of radiation, target material composition and beam energy, that have to be taken into account in the beam dosimetry for the treatment success being the energy parameter is one of the most important. This work was developed to study the energetic dependence of the FXG dosimeter. This chemical solution is made with gelatine 300 Bloom, ferrous ammonium sulfate, xylenol orange, sulfuric acid and Milli-Q water and is based on the Fe +2 oxidation to Fe +3 , due to the ionizing radiation leading to the xylenol orange - ferric complex formation, that is linear depend on the absorbed dose. The FXG samples were irradiated with photons of different energies and the absorbance measurements were done with the spectrophotometric technique at the 585 nm, FXG highest absorption peak. The energetic dependence results presented a stronger dependence for low energies and almost independence for high energies, as expected by the interaction of radiation with matter. (author)

  9. Polymer gel dosimeters with enhanced sensitivity for use in x-ray CT polymer gel dosimetry

    International Nuclear Information System (INIS)

    Jirasek, A; Hilts, M; McAuley, K B

    2010-01-01

    A primary limitation of current x-ray CT polymer gel dosimetry is the low contrast, and hence poor dose resolution, of dose images produced by the system. The low contrast is largely due to the low-dose sensitivity of current formulations of polymer gel for x-ray CT imaging. This study reports on the investigation of new dosimeter formulations with improved dose sensitivity for x-ray CT polymer gel dosimetry. We incorporate an isopropanol co-solvent into an N-isopropylacrylamide-based gel formulation in order to increase the total monomer/crosslinker concentration (%T) within the formulation. It is shown that gels of high %T exhibit enhanced dose sensitivity and dose resolutions over traditional formulations. The gels are shown to be temporally stable and reproducible. A single formulation (16%T) is used to demonstrate the capabilities of the x-ray CT polymer gel dosimetry system in measuring known dose distributions. A 1 L gel volume is exposed to three separate irradiations: a single-field percent depth dose, a two-field 'cross' and a three-field 'test case'. The first two irradiations are used to generate a dose calibration curve by which images are calibrated. The calibrated images are compared with treatment planning predictions and it is shown that the x-ray CT polymer gel dosimetry system is capable of capturing spatial and dose information accurately. The proposed new gel formulation is shown to be sensitive, stable and to improve the dose resolution over current formulations so as to provide a feasible gel for clinical applications of x-ray CT polymer gel dosimetry.

  10. Polymer gel dosimeters with enhanced sensitivity for use in x-ray CT polymer gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6 (Canada); Hilts, M [Medical Physics, BC Cancer Agency-Vancouver Island Centre, Victoria BC V6R 2B6 (Canada); McAuley, K B, E-mail: jirasek@uvic.c [Department of Chemical Engineering, Queens University, Kingston, ON K7 L 3N6 (Canada)

    2010-09-21

    A primary limitation of current x-ray CT polymer gel dosimetry is the low contrast, and hence poor dose resolution, of dose images produced by the system. The low contrast is largely due to the low-dose sensitivity of current formulations of polymer gel for x-ray CT imaging. This study reports on the investigation of new dosimeter formulations with improved dose sensitivity for x-ray CT polymer gel dosimetry. We incorporate an isopropanol co-solvent into an N-isopropylacrylamide-based gel formulation in order to increase the total monomer/crosslinker concentration (%T) within the formulation. It is shown that gels of high %T exhibit enhanced dose sensitivity and dose resolutions over traditional formulations. The gels are shown to be temporally stable and reproducible. A single formulation (16%T) is used to demonstrate the capabilities of the x-ray CT polymer gel dosimetry system in measuring known dose distributions. A 1 L gel volume is exposed to three separate irradiations: a single-field percent depth dose, a two-field 'cross' and a three-field 'test case'. The first two irradiations are used to generate a dose calibration curve by which images are calibrated. The calibrated images are compared with treatment planning predictions and it is shown that the x-ray CT polymer gel dosimetry system is capable of capturing spatial and dose information accurately. The proposed new gel formulation is shown to be sensitive, stable and to improve the dose resolution over current formulations so as to provide a feasible gel for clinical applications of x-ray CT polymer gel dosimetry.

  11. A Practical Use for FXG Gel Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Olding, T; Salomons, G; Darko, J; Schreiner, L J, E-mail: Tim.Olding@krcc.on.c

    2010-11-01

    In-phantom Fricke-xylenol orange-gelatin (FXG) gel dosimetry yields three dimensional (3D) dose data for intensity modulated radiation therapy (IMRT) treatment plan verification within 18-24 hours from the point of request. The information obtained from a 3% dose difference, 3 mm distance-to-agreement gamma function comparison between treatment plan dose and gel-measured dose then provides a useful secondary 3D quality assurance check of the treatment plan prior to delivery.

  12. Conducting Polymer Electrodes for Gel Electrophoresis

    OpenAIRE

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that p-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel ...

  13. A theory for fracture of polymeric gels

    Science.gov (United States)

    Mao, Yunwei; Anand, Lallit

    2018-06-01

    A polymeric gel is a cross-linked polymer network swollen with a solvent. If the concentration of the solvent or the deformation is increased to substantial levels, especially in the presence of flaws, then the gel may rupture. Although various theoretical aspects of coupling of fluid permeation with large deformation of polymeric gels are reasonably well-understood and modeled in the literature, the understanding and modeling of the effects of fluid diffusion on the damage and fracture of polymeric gels is still in its infancy. In this paper we formulate a thermodynamically-consistent theory for fracture of polymeric gels - a theory which accounts for the coupled effects of fluid diffusion, large deformations, damage, and also the gradient effects of damage. The particular constitutive equations for fracture of a gel proposed in our paper, contain two essential new ingredients: (i) Our constitutive equation for the change in free energy of a polymer network accounts for not only changes in the entropy, but also changes in the internal energy due the stretching of the Kuhn segments of the polymer chains in the network. (ii) The damage and failure of the polymer network is taken to occur by chain-scission, a process which is driven by the changes in the internal energy of the stretched polymer chains in the network, and not directly by changes in the configurational entropy of the polymer chains. The theory developed in this paper is numerically implemented in an open-source finite element code MOOSE, by writing our own application. Using this simulation capability we report on our study of the fracture of a polymeric gel, and some interesting phenomena which show the importance of the diffusion of the fluid on fracture response of the gel are highlighted.

  14. Improving calibration accuracy in gel dosimetry

    International Nuclear Information System (INIS)

    Oldham, M.; McJury, M.; Webb, S.; Baustert, I.B.; Leach, M.O.

    1998-01-01

    A new method of calibrating gel dosimeters (applicable to both Fricke and polyacrylamide gels) is presented which has intrinsically higher accuracy than current methods, and requires less gel. Two test-tubes of gel (inner diameter 2.5 cm, length 20 cm) are irradiated separately with a 10x10cm 2 field end-on in a water bath, such that the characteristic depth-dose curve is recorded in the gel. The calibration is then determined by fitting the depth-dose measured in water, against the measured change in relaxivity with depth in the gel. Increased accuracy is achieved in this simple depth-dose geometry by averaging the relaxivity at each depth. A large number of calibration data points, each with relatively high accuracy, are obtained. Calibration data over the full range of dose (1.6-10 Gy) is obtained by irradiating one test-tube to 10 Gy at dose maximum (D max ), and the other to 4.5 Gy at D max . The new calibration method is compared with a 'standard method' where five identical test-tubes of gel were irradiated to different known doses between 2 and 10 Gy. The percentage uncertainties in the slope and intercept of the calibration fit are found to be lower with the new method by a factor of about 4 and 10 respectively, when compared with the standard method and with published values. The gel was found to respond linearly within the error bars up to doses of 7 Gy, with a slope of 0.233±0.001 s -1 Gy -1 and an intercept of 1.106±0.005 Gy. For higher doses, nonlinear behaviour was observed. (author)

  15. White-light-emitting supramolecular gels.

    Science.gov (United States)

    Praveen, Vakayil K; Ranjith, Choorikkat; Armaroli, Nicola

    2014-01-07

    Let there be light, let it be white: Recent developments in the use of chromophore-based gels as scaffolds for the assembly of white-light-emitting soft materials have been significant. The main advantage of this approach lies in the facile accommodation of selected luminescent components within the gel. Excitation-energy-transfer processes between these components ultimately generate the desired light output. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Yield of reversible colloidal gels during flow start-up: release from kinetic arrest.

    Science.gov (United States)

    Johnson, Lilian C; Landrum, Benjamin J; Zia, Roseanna N

    2018-06-05

    Yield of colloidal gels during start-up of shear flow is characterized by an overshoot in shear stress that accompanies changes in network structure. Prior studies of yield of reversible colloidal gels undergoing strong flow model the overshoot as the point at which network rupture permits fluidization. However, yield under weak flow, which is of interest in many biological and industrial fluids shows no such disintegration. The mechanics of reversible gels are influenced by bond strength and durability, where ongoing rupture and re-formation impart aging that deepens kinetic arrest [Zia et al., J. Rheol., 2014, 58, 1121], suggesting that yield be viewed as release from kinetic arrest. To explore this idea, we study reversible colloidal gels during start-up of shear flow via dynamic simulation, connecting rheological yield to detailed measurements of structure, bond dynamics, and potential energy. We find that pre-yield stress grows temporally with the changing roles of microscopic transport processes: early time behavior is set by Brownian diffusion; later, advective displacements permit relative particle motion that stretches bonds and stores energy. Stress accumulates in stretched, oriented bonds until yield, which is a tipping point to energy release, and is passed with a fully intact network, where the loss of very few bonds enables relaxation of many, easing glassy arrest. This is immediately followed by a reversal to growth in potential energy during bulk plastic deformation and condensation into larger particle domains, supporting the view that yield is an activated release from kinetic arrest. The continued condensation of dense domains and shrinkage of network surfaces, along with a decrease in the potential energy, permit the gel to evolve toward more complete phase separation, supporting our view that yield of weakly sheared gels is a 'non-equilibrium phase transition'. Our findings may be particularly useful for industrial or other coatings, where weak

  17. Instrumental texture profile analysis of gelatin gel extracted from grouper skin and commercial (bovine and porcine) gelatin gels.

    Science.gov (United States)

    Rahman, Mohammad Shafiur; Al-Mahrouqi, Abdullah Issa

    2009-01-01

    Mechanical compression was used to study the gelling characteristics of gelatin gels. Texture profile analysis (TPA) showed that the hardness of fish and mammalian gelatin increased significantly as the concentrations of gels increased. TPA attributes of 10% fish skin gel showed significant differences from those obtained from 20% and 30% gels. In bovine and porcine cases, such generic trends were not observed. Mechanical characteristics of 10% gels of gelatin from fish skin, determined from one cycle compression, were significantly lower than other sources of gelatin gels, while bovine and porcine gels did not show any significant differences. In the case of TPA, hardness of bovine gelatin gel was highest at 41 N for 10% gel, followed by porcine (30 N) then fish skin (5 N) gelatin gels. The gels prepared from different sources did not show any generic trends when all other mechanical attributes were considered.

  18. Study of nuclear glasses alteration gel and synthesis of some model gels; Etude du gel d`alteration des verres nucleaires et synthese de gels modeles

    Energy Technology Data Exchange (ETDEWEB)

    Ricol, S

    1995-10-05

    This work deals with the general problem of alteration of the reference nuclear glass R7T7. Attention is paid particularly to the altered layer formed at the glass surface during alteration process. In opposition to previous works, related essentially to glass dissolution kinetics based on chemical analyses of lixiviated elements, this thesis deals with alteration problems through structural studies of the reference glass and derived gel. This approach allows the determination of mechanisms for the gel formation and a better understanding of the behaviour of glasses towards lixiviation. Both approaches appeared complementary. Based on several spectroscopic techniques, this work showed the particular role of cations such as calcium, zirconium and iron. Studies of silica-based synthetic gels showed the synergic effect of formers cation and of one highly coordinated cation. The variation of the wavenumber related to Si-O-Si asymmetric stretching vibration can be correlated to O/Si ratio for ternary systems Si/Na/Zr. On the contrary, the Si losses of the materials depend on the number of non-bridging oxygen atoms. In the perspective of long-term behaviour, the alteration gel presents better characteristics than initial glass. It is therefore a highly stable material in static conditions. In the same way, synthetic gels are materials with very low solubilities (much lower than the alteration gel) and could be used as confining matrices. (authors). refs., 71 figs., 37 tabs.

  19. Actuator device utilizing a conductive polymer gel

    Science.gov (United States)

    Chinn, Douglas A.; Irvin, David J.

    2004-02-03

    A valve actuator based on a conductive polymer gel is disclosed. A nonconductive housing is provided having two separate chambers separated by a porous frit. The conductive polymer is held in one chamber and an electrolyte solution, used as a source of charged ions, is held in the second chamber. The ends of the housing a sealed with a flexible elastomer. The polymer gel is further provide with electrodes with which to apply an electrical potential across the gel in order to initiate an oxidation reaction which in turn drives anions across the porous frit and into the polymer gel, swelling the volume of the gel and simultaneously contracting the volume of the electrolyte solution. Because the two end chambers are sealed the flexible elastomer expands or contracts with the chamber volume change. By manipulating the potential across the gel the motion of the elastomer can be controlled to act as a "gate" to open or close a fluid channel and thereby control flow through that channel.

  20. Basic investigations on LCV micelle gel

    International Nuclear Information System (INIS)

    Ebenezer, S B; Rafic, M K; Ravindran, P B

    2013-01-01

    The aim of this study was to investigate the feasibility of using Leuco Crystal Violet (LCV) based micelle gel dosimeter as a quality assurance tool in radiotherapy applications. Basic properties such as absorption coefficient and diffusion of LCV gel phantom over time were evaluated. The gel formulation consisted of 25 mM Trichloroacetic acid, 1mM LCV, 4 mM Triton X-100, 4% gelatin by mass and distilled water. The advantages of using this gel are its tissue equivalence, easy and less preparation time, lower diffusion rate and it can be read with an optical scanner. We were able to reproduce some of the results of Babic et al. The peak absorption was found to be at 600 nm and hence a matrix of yellow LEDs was used as light source. The profiles obtained from projection images confirmed the diffusion of LCV gel after 6 hours of irradiation. Hence the LCV gel phantom should be read before 6 hours post irradiation to get accurate dose information as suggested previously.