588 research outputs found

    Design and analysis of contour bell nozzle and comparison with dual bell nozzle

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    The performance and the thrust delivery of the engine such as nozzles are in renovation for the greater performance. Modern combustion expansion system like in rocket nozzles will be updated with respect to the application. Bell and Dual bell nozzle is the One of such development. Four different types of Bell nozzle one duel bell nozzle is selected and studied using computational fluid dynamics (CFD) in the present paper. The project mainly focuses on design and analysis of contoured convergent divergent bell nozzle. For the simulation, consider  a 2D , parabolic contoured thrust optimized axisymmetric nozzle. The priority is  given to design a bell nozzle with negligible shock wave. The temperature effects are not taken into this study, the flow is purely cold flow (303K). A full length Bell nozzle created using Gambit software. The meshing and analysis of the Bell model were done using FLUENT software. Air is taken as working medium for the nozzle and also for the ambience. Only one half of the nozzle is simulated due to symmetry reasons, and symmetry boundary conditions are used at the corresponding planes. The nozzle walls were set as adiabatic and assumed to be hydraulically smooth. A control volume was constructed around the nozzle to take the interaction with the ambience. The behavior of flow along the bell nozzle is thus obtained

    Barriers to Attracting Private Sector Investment in Public Road Infrastructure Projects in the Developing Country of Iran

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    Abstract Private sector investment, the mainstream financing method for procuring public road transport development projects, has encountered several profound difficulties and risks during execution, particularly in developing countries. However, there needs to be more extensive investigations on the major barriers facing road transport infrastructure projects in these countries. In this vein, the present study aims to identify and assess the perceived barriers inhibiting private sector investment in delivering public road transport infrastructure projects in the developing country of Iran. The research method adopted is based on a descriptive survey with a three-round Delphi technique with 35 experts from both the private and public sector in Iran. According to the research study results, four main groups of legal and organizational, political, economic, and operational barriers have been found to significantly impact the attraction of private sector investment in such projects. The three most significant obstacles for public road transport infrastructure projects in developing countries include: (i) a lack of financial and investment safety; (ii) a lack of proficient managers and policies of public organizations in order to facilitate the process of privatization; and (iii) corruption in the privatization process. The survey findings can help the government and policymakers to eliminate or alleviate the potential barriers towards private sector participation in future public road infrastructure projects, particularly in those developing countries such as Iran

    Mineralogical and geochemical study of rodingites and associated serpentinized peridotite, Eastern Desert of Egypt, Arabian-Nubian Shield

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    We studied rodingite and rodingite-like rocks within a serpentinized ultramafic sequence and ophiolitic mélange at Um Rashid, in the Eastern Desert of Egypt. The Um Rashid ophiolite is strongly deformed, metamorphosed, and altered by serpentinization, carbonatization, listvenitization, rodingitization and silicification. The textures, whole-rock chemistry, and composition of fresh primary mineral relics show that the serpentinite protoliths were strongly melt-depleted harzburgite and minor dunite, typical of a supra-subduction zone fore-arc setting. The light-colored rocks replacing gabbro are divided on the basis of field relations, mineral assemblages and geochemical characteristics into typical rodingite and rodingite-like rock. Typical rodingite, found as blocks with chloritite blackwall rims within ophiolitic mélange, contains garnet, vesuvianite, diopside and chlorite with minor prehnite and opaque minerals. Rodingite-like rock, found as dykes in serpentinite, consists of hercynite, preiswerkite, margarite, corundum, prehnite, ferropargasite, albite, andesine, clinozoisite and diaspore. Some rodingite-like rock samples preserve relict gabbroic minerals and texture, whereas typical rodingite is fully replaced. Rodingite is highly enriched in CaO, Fe₂O₃, MgO, and compatible trace elements, whereas rodingite-like rock is strongly enriched in Al₂O₃ and incompatible trace elements. Based on geochemistry and petrographic evidence, both types of rodingitic rocks likely developed from mafic protoliths in immediate proximity to serpentinite but were affected by interaction with different fluids, most likely at different times. Typical rodingite development likely accompanied serpentinization and shows mineral assemblages characteristic of low-Si, high-Ca fluid infiltration at about 300 °C. Rodingite-like rock, on the other hand, likely developed from seawater infiltration

    Mineralogical and geochemical study of rodingites and associated serpentinized peridotite, Eastern Desert of Egypt, Arabian-Nubian Shield

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    We studied rodingite and rodingite-like rocks within a serpentinized ultramafic sequence and ophiolitic mélange at Um Rashid, in the Eastern Desert of Egypt. The Um Rashid ophiolite is strongly deformed, metamorphosed, and altered by serpentinization, carbonatization, listvenitization, rodingitization and silicification. The textures, whole-rock chemistry, and composition of fresh primary mineral relics show that the serpentinite protoliths were strongly melt-depleted harzburgite and minor dunite, typical of a supra-subduction zone fore-arc setting. The light-colored rocks replacing gabbro are divided on the basis of field relations, mineral assemblages and geochemical characteristics into typical rodingite and rodingite-like rock. Typical rodingite, found as blocks with chloritite blackwall rims within ophiolitic mélange, contains garnet, vesuvianite, diopside and chlorite with minor prehnite and opaque minerals. Rodingite-like rock, found as dykes in serpentinite, consists of hercynite, preiswerkite, margarite, corundum, prehnite, ferropargasite, albite, andesine, clinozoisite and diaspore. Some rodingite-like rock samples preserve relict gabbroic minerals and texture, whereas typical rodingite is fully replaced. Rodingite is highly enriched in CaO, Fe₂O₃, MgO, and compatible trace elements, whereas rodingite-like rock is strongly enriched in Al₂O₃ and incompatible trace elements. Based on geochemistry and petrographic evidence, both types of rodingitic rocks likely developed from mafic protoliths in immediate proximity to serpentinite but were affected by interaction with different fluids, most likely at different times. Typical rodingite development likely accompanied serpentinization and shows mineral assemblages characteristic of low-Si, high-Ca fluid infiltration at about 300 °C. Rodingite-like rock, on the other hand, likely developed from seawater infiltration

    Fuzzy Logic Based Self-Adaptive Handover Algorithm for MobileWiMAX.

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    It is well known that WiMAX is a broadband technology that is capable of delivering triple play (voice, data, and video) services. However, mobility in WiMAX system is still a main issue when the mobile station (MS) moves across the base station (BS) coverage and be handed over between BSs. Among the challenging issues in mobile WiMAX handover are unnecessary handover, handover failure and handover delay, which may affect real-time applications. The conventional handover decision algorithm in mobile WiMAX is based on a single criterion, which usually uses the received signal strength indicator (RSSI) as an indicator, with the other fixed handover parameters such as handover threshold and handover margin. In this paper, a fuzzy logic based self-adaptive handover (FuzSAHO) algorithm is introduced. The proposed algorithm is derived from the self-adaptive handover parameters to overcome the mobile WiMAX ping-pong handover and handover delay issues. Hence, the proposed FuzSAHO is initiated to check whether a handover is necessary or not which depends on its fuzzy logic stage. The proposed FuzSAHO algorithm will first self-adapt the handover parameters based on a set of multiple criteria, which includes the RSSI and MS velocity. Then the handover decision will be executed according to the handover parameter values. Simulation results show that the proposed FuzSAHO algorithm reduces the number of ping-pong handover and its delay. When compared with RSSI based handover algorithm and mobility improved handover (MIHO) algorithm, respectively, FuzSAHO reduces the number of handovers by 12.5 and 7.5 %, respectively, when the MS velocity is <17 m/s. In term of handover delay, the proposed FuzSAHO algorithm shows an improvement of 27.8 and 8 % as compared to both conventional and MIHO algorithms, respectively. Thus, the proposed multi-criteria with fuzzy logic based self-adaptive handover algorithm called FuzSAHO, outperforms both conventional and MIHO handover algorithms

    Synthesis of heterocyclic bromacetylene alcohols and their acryl -, methacryl ethers

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    The article presents a method for obtaining heterocyclic bromoacetylenic alcohols by the action of sodium hypobromide on cyclic and heterocyclic acetylene alcohols, as well as their acrylic and methacrylic esters using lithium aluminum complexes. The composition and structure of the obtained products were confirmed by the data of elemental analysis, IR and PMR spectra. As a result of the study, it was found that in the presence of lithium aluminum hydride, the product yield in all cases is higher than 80 %

    E-cigarettes Perceptions and Use among Jordanian Medical Students

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    Purpose: Medical students are the cornerstone for future public health awareness; this study aimed to assess e-cigarettes perceptions and use among medical students.Methods: This is a cross-sectional, questionnaire-based national study. The study included all five medical schools in the country and addressed students in their clinical years. Data were collected through a self-administered and structured paper-based questionnaire between Dec 1, 2018, and Mar 30, 2019. Data obtained were analyzed using IBM SPSS Statistics for Windows and univariate inferential tests were employed to examine differences between groups.Results: A total sample of 1819 (97.4%) students returned their questionnaires; with a declaration of their smoking habits from the five medical schools, 47% are males, and 53% are females. Only 13 students 0.7% of all students or 2.1% of all smokers used e-cigarettes solely, but 177 students 9.5% of all students or 29% of all smokers used e-cigarettes combined with other types of smoking. Most medical students (86%) were aware of e-cigarettes. The main motive behind using e-cigarettes was the rare and different flavors provided by these cigarettes. The general perception among smokers and non-smokers is that e-cigarettes are less harmful and helpful in quitting smoking.Conclusion: Most medical students are aware of e-cigarettes. While their use as the only form of smoking is rare, e-cigarettes are frequently used in combination with other types of smoking

    Computational Fluid Dynamics Simulation on Particulate Distribution in Gyro Casting for the Manufacture of Al/SiC Particulate Metal Matrix Composite

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    The enhanced specific strength of SiC Particulate Metal Matrix Composites (PMMC) has been the major contributing factor which helps to find applications in the aerospace and automotive industries. Uniform distribution of the particulates in PMMC controls the attainment of better mechanical properties. The most accepted method for producing such a composite is stir casting in which the homogeneity of particulate reinforcement is a significant challenge. This research work proposes a new method for mixing the particulate reinforcement with the liquid and semi-solid aluminium matrix to ensure a uniform mix of the particulates using a gyro shaker. Gyro shaker is a dual rotation mixer commonly used for mixing high viscous fluids. It rotates about two mutually perpendicular axes which help in thoroughly mixing of the ingredients. Developed Computational Fluid Dynamics (CFD) simulation model of the mixing device in finding the mixing performance while mixing SiC particulates with glycerol. The results of the simulation were also validated by experimentation. Analogue fluid simulation of gyro casting was carried out using water and glycerol/water mixture which are having a closer value of viscosity as that of liquid aluminium and semi-solid aluminium. The mixing time obtained in the water system at gyration speeds of 29.63 rpm, 58.18 rpm, 72.73 rpm and 87.27 rpm was 61.84 sec, 43.44 sec, 26.85 sec and 27.24 sec respectively. The mixing time obtained in glycerol/water system at gyration speeds of 58.18 rpm, 87.27 rpm, 116.36 rpm and 145.45 rpm was 26.34 sec, 15.97 sec, 9.8 sec and 6.26 sec respectively. The distribution of the SiC particulates obtained from simulation was compared with stir casting simulations. The homogeneous distribution of particulates was observed in the gyro casting simulation

    Nernst-Planck model of photo-triggered, pH-tunable ionic transport through nanopores functionalized with "caged" lysine chains

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    We describe the fabrication of asymmetric nanopores sensitive to ultraviolet (UV) light, and give a detailed account of the divalent ionic transport through these pores using a theoretical model based on the Nernst-Planck equations. The pore surface is decorated with lysine chains having pH-sensitive (amine and carboxylic acid) moieties that are caged with photo-labile 4,5-dimethoxy- 2-nitrobenzyl (NVOC) groups. The uncharged hydrophobic NVOC groups are removed using UV irradiation, leading to the generation of hydrophilic “uncaged” amphoteric groups on the pore surface. We demonstrate experimentally that polymer membranes containing single pore and arrays of asymmetric nanopores can be employed for the pH-controlled transport of ionic and molecular analytes. Comparison between theory and experiment allows for understanding the individual properties of the phototriggered nanopores, and provides also useful clues for the design and fabrication of multipore membranes to be used in practical applications. © 2013 American Institute of Physics.The authors would like to thank Miguel Ferrandez and Juan Pablo Arranz for assistance in the preparation of the artwork. P. R. and S. M. acknowledge financial support from the Ministerio de Economia y Competitividad (Projects Nos. MAT2009-07747 and MAT2012-32084), the Generalitat Valenciana (Project No. PROMETEO/GV/0069), and FEDER. S.N., M. A., and W. E. gratefully acknowledge financial support by the Beilstein-Institut, Frankfurt/Main, Germany, within the research collaboration NanoBiC, and L. F. and I. A. DFG-CFN Excellence Initiative Project A5.7. The authors thank Dr. Christina Trautmann from GSI (Materials research group) for support with the heavy ion irradiation experiments, and Dr. M. N. Tahir (Mainz University) for fruitful discussions and help in performing the UV light irradiation experiments.Nasir, S.; Ramirez Hoyos, P.; Ali, M.; Ahmed, I.; Fruk, L.; Mafé, S.; Ensinger, W. (2013). Nernst-Planck model of photo-triggered, pH-tunable ionic transport through nanopores functionalized with "caged" lysine chains. Journal of Chemical Physics. 138(3):034709-1-034709-11. doi:10.1063/1.4775811S034709-1034709-111383Healy, K. (2007). Nanopore-based single-molecule DNA analysis. Nanomedicine, 2(4), 459-481. doi:10.2217/17435889.2.4.459Griffiths, J. (2008). The Realm of the Nanopore. Analytical Chemistry, 80(1), 23-27. doi:10.1021/ac085995zJovanovic-Talisman, T., Tetenbaum-Novatt, J., McKenney, A. S., Zilman, A., Peters, R., Rout, M. P., & Chait, B. T. (2008). Artificial nanopores that mimic the transport selectivity of the nuclear pore complex. Nature, 457(7232), 1023-1027. doi:10.1038/nature07600Schoch, R. B., Han, J., & Renaud, P. (2008). Transport phenomena in nanofluidics. Reviews of Modern Physics, 80(3), 839-883. doi:10.1103/revmodphys.80.839Nam, S.-W., Rooks, M. J., Kim, K.-B., & Rossnagel, S. M. (2009). Ionic Field Effect Transistors with Sub-10 nm Multiple Nanopores. Nano Letters, 9(5), 2044-2048. doi:10.1021/nl900309sPerry, J. M., Zhou, K., Harms, Z. D., & Jacobson, S. C. (2010). Ion Transport in Nanofluidic Funnels. ACS Nano, 4(7), 3897-3902. doi:10.1021/nn100692zGuan, W., Fan, R., & Reed, M. A. (2011). Field-effect reconfigurable nanofluidic ionic diodes. Nature Communications, 2(1). doi:10.1038/ncomms1514Striemer, C. C., Gaborski, T. R., McGrath, J. L., & Fauchet, P. M. (2007). Charge- and size-based separation of macromolecules using ultrathin silicon membranes. Nature, 445(7129), 749-753. doi:10.1038/nature05532Van den Berg, A., & Wessling, M. (2007). Silicon for the perfect membrane. Nature, 445(7129), 726-726. doi:10.1038/445726aDekker, C. (2007). Solid-state nanopores. Nature Nanotechnology, 2(4), 209-215. doi:10.1038/nnano.2007.27Mager, M. D., & Melosh, N. A. (2008). Nanopore-Spanning Lipid Bilayers for Controlled Chemical Release. Advanced Materials, 20(23), 4423-4427. doi:10.1002/adma.200800969Apel, P. Y., Korchev, Y. ., Siwy, Z., Spohr, R., & Yoshida, M. (2001). Diode-like single-ion track membrane prepared by electro-stopping. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 184(3), 337-346. doi:10.1016/s0168-583x(01)00722-4Siwy, Z., & Fuliński, A. (2002). Fabrication of a Synthetic Nanopore Ion Pump. Physical Review Letters, 89(19). doi:10.1103/physrevlett.89.198103Ramírez, P., Mafé, S., Aguilella, V. M., & Alcaraz, A. (2003). Synthetic nanopores with fixed charges: An electrodiffusion model for ionic transport. Physical Review E, 68(1). doi:10.1103/physreve.68.011910Siwy, Z., & Fuliński, A. (2004). A nanodevice for rectification and pumping ions. American Journal of Physics, 72(5), 567-574. doi:10.1119/1.1648328Siwy, Z., Kosińska, I. D., Fuliński, A., & Martin, C. R. (2005). Asymmetric Diffusion through Synthetic Nanopores. Physical Review Letters, 94(4). doi:10.1103/physrevlett.94.048102Powell, M. R., Sullivan, M., Vlassiouk, I., Constantin, D., Sudre, O., Martens, C. C., … Siwy, Z. S. (2007). Nanoprecipitation-assisted ion current oscillations. Nature Nanotechnology, 3(1), 51-57. doi:10.1038/nnano.2007.420García-Giménez, E., Alcaraz, A., Aguilella, V. M., & Ramírez, P. (2009). Directional ion selectivity in a biological nanopore with bipolar structure. Journal of Membrane Science, 331(1-2), 137-142. doi:10.1016/j.memsci.2009.01.026Hou, X., Zhang, H., & Jiang, L. (2012). Building Bio-Inspired Artificial Functional Nanochannels: From Symmetric to Asymmetric Modification. Angewandte Chemie International Edition, 51(22), 5296-5307. doi:10.1002/anie.201104904Harrell, C. C., Siwy, Z. S., & Martin, C. R. (2006). Conical Nanopore Membranes: Controlling the Nanopore Shape. Small, 2(2), 194-198. doi:10.1002/smll.200500196Apel, P. Y., Blonskaya, I. V., Dmitriev, S. N., Orelovitch, O. L., Presz, A., & Sartowska, B. A. (2007). Fabrication of nanopores in polymer foils with surfactant-controlled longitudinal profiles. Nanotechnology, 18(30), 305302. doi:10.1088/0957-4484/18/30/305302Apel, P. Y., Blonskaya, I. V., Orelovitch, O. L., Ramirez, P., & Sartowska, B. A. (2011). Effect of nanopore geometry on ion current rectification. Nanotechnology, 22(17), 175302. doi:10.1088/0957-4484/22/17/175302Ali, M., Ramirez, P., Nguyen, H. Q., Nasir, S., Cervera, J., Mafe, S., & Ensinger, W. (2012). Single Cigar-Shaped Nanopores Functionalized with Amphoteric Amino Acid Chains: Experimental and Theoretical Characterization. ACS Nano, 6(4), 3631-3640. doi:10.1021/nn3010119Kalman, E. B., Sudre, O., Vlassiouk, I., & Siwy, Z. S. (2008). Control of ionic transport through gated single conical nanopores. Analytical and Bioanalytical Chemistry, 394(2), 413-419. doi:10.1007/s00216-008-2545-3Mafe, S., Manzanares, J. A., & Ramirez, P. (2010). Gating of Nanopores: Modeling and Implementation of Logic Gates. The Journal of Physical Chemistry C, 114(49), 21287-21290. doi:10.1021/jp1087114Nasir, S., Ali, M., & Ensinger, W. (2012). Thermally controlled permeation of ionic molecules through synthetic nanopores functionalized with amine-terminated polymer brushes. Nanotechnology, 23(22), 225502. doi:10.1088/0957-4484/23/22/225502Guo, W., Xia, H., Cao, L., Xia, F., Wang, S., Zhang, G., … Zhu, D. (2010). Integrating Ionic Gate and Rectifier Within One Solid-State Nanopore via Modification with Dual-Responsive Copolymer Brushes. Advanced Functional Materials, 20(20), 3561-3567. doi:10.1002/adfm.201000989Ali, M., Ramirez, P., Mafé, S., Neumann, R., & Ensinger, W. (2009). A pH-Tunable Nanofluidic Diode with a Broad Range of Rectifying Properties. ACS Nano, 3(3), 603-608. doi:10.1021/nn900039fAli, M., Mafe, S., Ramirez, P., Neumann, R., & Ensinger, W. (2009). Logic Gates Using Nanofluidic Diodes Based on Conical Nanopores Functionalized with Polyprotic Acid Chains. Langmuir, 25(20), 11993-11997. doi:10.1021/la902792fHou, X., Liu, Y., Dong, H., Yang, F., Li, L., & Jiang, L. (2010). A pH-Gating Ionic Transport Nanodevice: Asymmetric Chemical Modification of Single Nanochannels. Advanced Materials, 22(22), 2440-2443. doi:10.1002/adma.200904268Hou, X., Guo, W., Xia, F., Nie, F.-Q., Dong, H., Tian, Y., … Jiang, L. (2009). A Biomimetic Potassium Responsive Nanochannel: G-Quadruplex DNA Conformational Switching in a Synthetic Nanopore. Journal of the American Chemical Society, 131(22), 7800-7805. doi:10.1021/ja901574cHe, Y., Gillespie, D., Boda, D., Vlassiouk, I., Eisenberg, R. S., & Siwy, Z. S. (2009). Tuning Transport Properties of Nanofluidic Devices with Local Charge Inversion. Journal of the American Chemical Society, 131(14), 5194-5202. doi:10.1021/ja808717uAli, M., Neumann, R., & Ensinger, W. (2010). Sequence-Specific Recognition of DNA Oligomer Using Peptide Nucleic Acid (PNA)-Modified Synthetic Ion Channels: PNA/DNA Hybridization in Nanoconfined Environment. ACS Nano, 4(12), 7267-7274. doi:10.1021/nn102119qAli, M., Tahir, M. N., Siwy, Z., Neumann, R., Tremel, W., & Ensinger, W. (2011). Hydrogen Peroxide Sensing with Horseradish Peroxidase-Modified Polymer Single Conical Nanochannels. Analytical Chemistry, 83(5), 1673-1680. doi:10.1021/ac102795aVlassiouk, I., & Siwy, Z. S. (2007). Nanofluidic Diode. Nano Letters, 7(3), 552-556. doi:10.1021/nl062924bKalman, E. B., Vlassiouk, I., & Siwy, Z. S. (2008). Nanofluidic Bipolar Transistors. Advanced Materials, 20(2), 293-297. doi:10.1002/adma.200701867Ali, M., Ramirez, P., Tahir, M. N., Mafe, S., Siwy, Z., Neumann, R., … Ensinger, W. (2011). Biomolecular conjugation inside synthetic polymer nanopores via glycoprotein–lectin interactions. Nanoscale, 3(4), 1894. doi:10.1039/c1nr00003aHou, X., Yang, F., Li, L., Song, Y., Jiang, L., & Zhu, D. (2010). A Biomimetic Asymmetric Responsive Single Nanochannel. Journal of the American Chemical Society, 132(33), 11736-11742. doi:10.1021/ja1045082Healy, K., Schiedt, B., & Morrison, A. P. (2007). Solid-state nanopore technologies for nanopore-based DNA analysis. Nanomedicine, 2(6), 875-897. doi:10.2217/17435889.2.6.875Martin, C. R., & Siwy, Z. S. (2007). CHEMISTRY: Learning Nature’s Way: Biosensing with Synthetic Nanopores. Science, 317(5836), 331-332. doi:10.1126/science.1146126Guo, W., Cao, L., Xia, J., Nie, F.-Q., Ma, W., Xue, J., … Jiang, L. (2010). Energy Harvesting with Single-Ion-Selective Nanopores: A Concentration-Gradient-Driven Nanofluidic Power Source. Advanced Functional Materials, 20(8), 1339-1344. doi:10.1002/adfm.200902312Cervera, J., Ramirez, P., Mafe, S., & Stroeve, P. (2011). Asymmetric nanopore rectification for ion pumping, electrical power generation, and information processing applications. Electrochimica Acta, 56(12), 4504-4511. doi:10.1016/j.electacta.2011.02.056Ramirez, P., Ali, M., Ensinger, W., & Mafe, S. (2012). Information processing with a single multifunctional nanofluidic diode. Applied Physics Letters, 101(13), 133108. doi:10.1063/1.4754845Jiang, Y., Liu, N., Guo, W., Xia, F., & Jiang, L. (2012). Highly-Efficient Gating of Solid-State Nanochannels by DNA Supersandwich Structure Containing ATP Aptamers: A Nanofluidic IMPLICATION Logic Device. Journal of the American Chemical Society, 134(37), 15395-15401. doi:10.1021/ja3053333Ali, M., Nasir, S., Ramirez, P., Ahmed, I., Nguyen, Q. H., Fruk, L., … Ensinger, W. (2011). Optical Gating of Photosensitive Synthetic Ion Channels. Advanced Functional Materials, 22(2), 390-396. doi:10.1002/adfm.201102146Zhang, M., Hou, X., Wang, J., Tian, Y., Fan, X., Zhai, J., & Jiang, L. (2012). Light and pH Cooperative Nanofluidic Diode Using a Spiropyran-Functionalized Single Nanochannel. Advanced Materials, 24(18), 2424-2428. doi:10.1002/adma.201104536Ramírez, P., Apel, P. Y., Cervera, J., & Mafé, S. (2008). Pore structure and function of synthetic nanopores with fixed charges: tip shape and rectification properties. Nanotechnology, 19(31), 315707. doi:10.1088/0957-4484/19/31/315707Ali, M., Yameen, B., Cervera, J., Ramírez, P., Neumann, R., Ensinger, W., … Azzaroni, O. (2010). Layer-by-Layer Assembly of Polyelectrolytes into Ionic Current Rectifying Solid-State Nanopores: Insights from Theory and Experiment. Journal of the American Chemical Society, 132(24), 8338-8348. doi:10.1021/ja101014yYu Apel, P., Blonskaya, I. V., Orelovitch, O. L., Sartowska, B. A., & Spohr, R. (2012). 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    Inflationary cosmology with scalar field and radiation

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    We present a simple, exact and self-consistent cosmology with a phenomenological model of quantum creation of radiation due to decay of the scalar field. The decay drives a non-isentropic inflationary epoch, which exits smoothly to the radiation era, without reheating. The initial vacuum for radiation is a regular Minkowski vacuum. The created radiation obeys standard thermodynamic laws, and the total entropy produced is consistent with the accepted value. We analyze the difference between the present model and a model with decaying cosmological constant previously considered.Comment: 13 pages Latex; to appear Gen. Rel. Gra
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