760 research outputs found

    Three-Dimensional Bioprinting Materials with Potential Application in Preprosthetic Surgery

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    Current methods in handling maxillofacial defects are not robust and are highly dependent on the surgeon’s skills and the inherent potential in the patients’ bodies for regenerating lost tissues. Employing custom-designed 3D printed scaffolds that securely and effectively reconstruct the defects by using tissue engineering and regenerative medicine techniques can revolutionize preprosthetic surgeries. Various polymers, ceramics, natural and synthetic bioplastics, proteins, biomolecules, living cells, and growth factors as well as their hybrid structures can be used in 3D printing of scaffolds, which are still under development by scientists. These scaffolds not only are beneficial due to their patient-specific design, but also may be able to prevent micromobility, make tension free soft tissue closure, and improve vascularity. In this manuscript, a review of materials employed in 3D bioprinting including bioceramics, biopolymers, composites, and metals is conducted. A discussion of the relevance of 3D bioprinting using these materials for craniofacial interventions is included as well as their potential to create analogs to craniofacial tissues, their benefits, limitations, and their application

    Introduction to the special issue: Applications of internet of things

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    © 2018 by the authors. This editorial introduces the special issue, entitled "Applications of Internet of Things", of Symmetry. The topics covered in this issue fall under four main parts: (I) communication techniques and applications, (II) data science techniques and applications, (III) smart transportation, and (IV) smart homes. Four papers on sensing techniques and applications are included as follows: (1) "Reliability of improved cooperative communication over wireless sensor networks", by Chen et al.; (2) "User classification in crowdsourcing-based cooperative spectrum sensing", by Zhai andWang; (3) "IoT's tiny steps towards 5G: Telco's perspective", by Cero et al.; and (4) "An Internet of things area coverage analyzer (ITHACA) for complex topographical scenarios", by Parada et al. One paper on data science techniques and applications is as follows: "Internet of things: a scientometric review", by Ruiz-Rosero et al. Two papers on smart transportation are as follows: (1) "An Internet of things approach for extracting featured data using an AIS database: an application based on the viewpoint of connected ships", by He et al.; and (2) "The development of key technologies in applications of vessels connected to the Internet", by Tian et al. Two papers on smart home are as follows: (1) "A novel approach based on time cluster for activity recognition of daily living in smart homes", by Liu et al.; and (2) "IoT-based image recognition system for smart home-delivered meal services", by Tseng et al

    OPTIMIZATION PERFORMANCE OF BIOLOGICAL CATHODIC PROTECTION SYSTEM USING ORGANIC WASTE

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    In this study, the concept of Microbial Fuel Cells (MFCs) is applied in the biological cathodic protection (CP) system. MFCs are a promising technology for electricity production from a variety of materials. Impressed current cathodic protection (ICCP) was the tradition method used in corrosion control method. Biological CP uses the microbiological presence in wastewater to generate the electrons. The focus of this study is on the effect of organic waste towards the biological CP system. The selected organic wastes are orange peel and pineapple peel. The presence of starch and sugar in the organic waste are promote the microbial growth and increase the performance of biological CP system. The method used to prepare the substrate was based on the previous studies and the CP system was a single chamber system. Current and power density was calculated from the experimental data of the specific weight of substrates and the results was discussed in this study. The weight of substrate are manipulated for each experiment. The statistical analysis was done on the voltage potential output for the selected optimum substrate’s weight and the result was varies for each of organic waste used. The highest voltage potential output by the CP system was 920 mV (20 grams of orange peel) and 1046 mV (40 grams of pineapple peel)

    Aging in Dense Colloids as Diffusion in the Logarithm of Time

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    The far-from-equilibrium dynamics of glassy systems share important phenomenological traits. A transition is generally observed from a time-homogeneous dynamical regime to an aging regime where physical changes occur intermittently and, on average, at a decreasing rate. It has been suggested that a global change of the independent time variable to its logarithm may render the aging dynamics homogeneous: for colloids, this entails diffusion but on a logarithmic time scale. Our novel analysis of experimental colloid data confirms that the mean square displacement grows linearly in time at low densities and shows that it grows linearly in the logarithm of time at high densities. Correspondingly, pairs of particles initially in close contact survive as pairs with a probability which decays exponentially in either time or its logarithm. The form of the Probability Density Function of the displacements shows that long-ranged spatial correlations are very long-lived in dense colloids. A phenomenological stochastic model is then introduced which relies on the growth and collapse of strongly correlated clusters ("dynamic heterogeneity"), and which reproduces the full spectrum of observed colloidal behaviors depending on the form assumed for the probability that a cluster collapses during a Monte Carlo update. In the limit where large clusters dominate, the collapse rate is ~1/t, implying a homogeneous, log-Poissonian process that qualitatively reproduces the experimental results for dense colloids. Finally an analytical toy-model is discussed to elucidate the strong dependence of the simulation results on the integrability (or lack thereof) of the cluster collapse probability function.Comment: 6 pages, extensively revised, final version; for related work, see http://www.physics.emory.edu/faculty/boettcher/ or http://www.fysik.sdu.dk/staff/staff-vip/pas-personal.htm

    The Physics of the Colloidal Glass Transition

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    As one increases the concentration of a colloidal suspension, the system exhibits a dramatic increase in viscosity. Structurally, the system resembles a liquid, yet motions within the suspension are slow enough that it can be considered essentially frozen. This kinetic arrest is the colloidal glass transition. For several decades, colloids have served as a valuable model system for understanding the glass transition in molecular systems. The spatial and temporal scales involved allow these systems to be studied by a wide variety of experimental techniques. The focus of this review is the current state of understanding of the colloidal glass transition. A brief introduction is given to important experimental techniques used to study the glass transition in colloids. We describe features of colloidal systems near and in glassy states, including tremendous increases in viscosity and relaxation times, dynamical heterogeneity, and ageing, among others. We also compare and contrast the glass transition in colloids to that in molecular liquids. Other glassy systems are briefly discussed, as well as recently developed synthesis techniques that will keep these systems rich with interesting physics for years to come.Comment: 56 pages, 18 figures, Revie

    Adaptive service binding with lightweight semantic web services

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    [About the book]: Service-oriented systems are increasingly challenging traditional software engineering approaches including distribution, componentization, composition, requirements, specification, verification, and evolution. Continuous mutual impact between service-oriented computing and software engineering has been seen in the last decade, and can increasingly be witnessed. The book aims to introduce the state-of-the-art service engineering methods and on-going research efforts from the perspective of research results elaborated in European research projects. Essential problems such as service specification and service composition are addressed by innovative approaches. Emerging requirements of adaptive service and pervasive service are met with new infrastructures. The book provides an integrated vision of the most important research directions in service engineering. This book is intended for scientists to be inspired with new ideas, for researchers new to the exciting field of service engineering and provides a consolidated overview on service engineering, thus supporting practitioners to facilitate their service-oriented architectures

    Evidence of Critical Behavior in the Disassembly of Nuclei with A ~ 36

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    A wide variety of observables indicate that maximal fluctuations in the disassembly of hot nuclei with A ~ 36 occur at an excitation energy of 5.6 +- 0.5 MeV/u and temperature of 8.3 +- 0.5 MeV. Associated with this point of maximal fluctuations are a number of quantitative indicators of apparent critical behavior. The associated caloric curve does not appear to show a flattening such as that seen for heavier systems. This suggests that, in contrast to similar signals seen for liquid-gas transitions in heavier nuclei, the observed behavior in these very light nuclei is associated with a transition much closer to the critical point.Comment: v2: Major changes, new model calculations, new figure

    Critical Behavior in Light Nuclear Systems: Experimental Aspects

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    An extensive experimental survey of the features of the disassembly of a small quasi-projectile system with AA \sim 36, produced in the reactions of 47 MeV/nucleon 40^{40}Ar + 27^{27}Al, 48^{48}Ti and 58^{58}Ni, has been carried out. Nuclei in the excitation energy range of 1-9 MeV/u have been investigated employing a new method to reconstruct the quasi-projectile source. At an excitation energy \sim 5.6 MeV/nucleon many observables indicate the presence of maximal fluctuations in the de-excitation processes. The fragment topological structure shows that the rank sorted fragments obey Zipf's law at the point of largest fluctuations providing another indication of a liquid gas phase transition. The caloric curve for this system shows a monotonic increase of temperature with excitation energy and no apparent plateau. The temperature at the point of maximal fluctuations is 8.3±0.58.3 \pm 0.5 MeV. Taking this temperature as the critical temperature and employing the caloric curve information we have extracted the critical exponents β\beta, γ\gamma and σ\sigma from the data. Their values are also consistent with the values of the universality class of the liquid gas phase transition. Taken together, this body of evidence strongly suggests a phase change in an equilibrated mesoscopic system at, or extremely close to, the critical point.Comment: Physical Review C, in press; some discussions about the validity of excitation energy in peripheral collisions have been added; 24 pages and 32 figures; longer abstract in the preprin
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