WorldWideScience

Sample records for surface-associated multilayer reservoir

  1. Hydrocarbon accumulation characteristics and enrichment laws of multi-layered reservoirs in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2017-03-01

    Full Text Available The Sichuan Basin represents the earliest area where natural gas is explored, developed and comprehensively utilized in China. After over 50 years of oil and gas exploration, oil and gas reservoirs have been discovered in 24 gas-dominant layers in this basin. For the purpose of predicting natural gas exploration direction and target of each layer in the Sichuan Basin, the sedimentary characteristics of marine and continental strata in this basin were summarized and the forms of multi-cycled tectonic movement and their controlling effect on sedimentation, diagenesis and hydrocarbon accumulation were analyzed. Based on the analysis, the following characteristics were identified. First, the Sichuan Basin has experienced the transformation from marine sedimentation to continental sedimentation since the Sinian with the former being dominant. Second, multiple source–reservoir assemblages are formed based on multi-rhythmed deposition, and multi-layered reservoir hydrocarbon accumulation characteristics are vertically presented. And third, multi-cycled tectonic movement appears in many forms and has a significant controlling effect on sedimentation, diagenesis and hydrocarbon accumulation. Then, oil and gas reservoir characteristics and enrichment laws were investigated. It is indicated that the Sichuan Basin is characterized by coexistence of conventional and unconventional oil and gas reservoirs, multi-layered reservoir hydrocarbon supply, multiple reservoir types, multiple trap types, multi-staged hydrocarbon accumulation and multiple hydrocarbon accumulation models. Besides, its natural gas enrichment is affected by hydrocarbon source intensity, large paleo-uplift, favorable sedimentary facies belt, sedimentary–structural discontinuity plane and structural fracture development. Finally, the natural gas exploration and research targets of each layer in the Sichuan Basin were predicted according to the basic petroleum geologic conditions

  2. Cross-flow analysis of injection wells in a multilayered reservoir

    Directory of Open Access Journals (Sweden)

    Mohammadreza Jalali

    2016-09-01

    Natural and forced cross-flow is modeled for some injection wells in an oil reservoir located at North Sea. The solution uses a transient implicit finite difference approach for multiple sand layers with different permeabilities separated by impermeable shale layers. Natural and forced cross-flow rates for each reservoir layer during shut-in are calculated and compared with different production logging tool (PLT measurements. It appears that forced cross-flow is usually more prolonged and subject to a higher flow rate when compared with natural cross-flow, and is thus worthy of more detailed analysis.

  3. Application of Bayesian Inversion for Multilayer Reservoir Mapping while Drilling Measurements

    Science.gov (United States)

    Wang, J.; Chen, H.; Wang, X.

    2017-12-01

    Real-time geosteering technology plays a key role in horizontal well development, which keeps the wellbore trajectories within target zones to maximize reservoir contact. The new generation logging while drilling (LWD) resistivity tools have longer spacing and deeper investigation depth, but meanwhile bring a new challenge to inversion of logging data that is formation model not be restricted to few possible numbers of layer such as typical three layers model. If the inappropriate starting models of deterministic and gradient-based methods are adopted may mislead geophysicists in interpretation of subsurface structure. For this purpose, to take advantage of richness of the measurements and deep depth of investigation across multiple formation boundaries, a trans-dimensional Markov chain Monte Carlo(MCMC) inversion algorithm has been developed that combines phase and attenuation measurements at various frequencies and spacings. Unlike conventional gradient-based inversion approaches, MCMC algorithm does not introduce bias from prior information and require any subjective choice of regularization parameter. A synthetic three layers model example demonstrates how the algorithm can be used to image the subsurface using the LWD data. When the tool is far from top boundary, the inversion clearly resolves the boundary position; that is where the boundary histogram shows a large peak. But the measurements cannot resolve the bottom boundary; the large spread between quantiles reflects the uncertainty associated with the bed resolution. As the tool moves closer to the top boundary, the middle layer and bottom layer are resolved and retained models are more similar, the uncertainty associated with these two beds decreases. From the spread observed between models, we can evaluate actual depth of investigation, uncertainty, and sensitivity, which is more useful then just a single best model.

  4. Feasibility study of the in-situ combustion in shallow, thin, and multi-layered heavy oil reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, L. [Society of Petroleum Engineers, Kuala Lumpur (Malaysia)]|[Daqing Petroleum Inst., Beijing (China); Yu, D. [Daqing Petroleum Inst., Beijing (China); Gong, Y. [China National Petroleum Corp., Beijing (China). Liaohe Oilfield; Wang, P.; Zhang, L. [China National Petroleum Corp., Beijing (China). Huabei Oilfield; Liu, C. [China National Petroleum Corp., Beijing (China). JiLin Oilfield

    2008-10-15

    In situ combustion is a process where oxygen is injected into oil reservoirs in order to oxidize the heavier components of crude oil. The oil is driven towards the production wells by the combustion gases and steam generated by the combustion processes. This paper investigated dry and wet forward in situ combustion processes designed for an oil reservoir with thin sand layers. Laboratory and numerical simulations were conducted to demonstrate the feasibility of the processes in a shallow, thin, heterogenous heavy oil reservoir in China. Combustion tube experiments were conducted in order to determine fuel consumption rates. A numerical geological model was constructed to represent the reservoir conditions. Gas, water, oil and solid phases were modelled. Four processes were considered: cracking; pyrolysis of heavy fractions; the combustion of light and heavy fractions; and the combustion of coke. Oil recovery rates were calculated for a period of 10 years. Reactor experiments were conducted to investigate igniting temperatures and air injection rates using an apparatus comprised of an electric heater, oil sand pack tube and a computerized control system. Experiments were performed at different temperature and injection rates. The experiments demonstrated that ignition times and air volumes decreased when air temperature was increased. Results of the study showed that a 20 per cent increase in oil recovery using the in situ combustion processes. It was concluded that adequate air injection rates are needed to ensure effective combustion front movement. 4 refs., 6 tabs., 4 figs.

  5. The Performance of Surfactant-Polymer Flooding in Horizontal Wells Consisting of Multilayers in a Reservoir System

    Directory of Open Access Journals (Sweden)

    Si Le Van

    2016-03-01

    Full Text Available Surfactant-polymer (SP flooding has been demonstrated to be an effective method to recover oil in the enhanced oil recovery (EOR stage when water flooding is no longer relevant. Theoretically, adding surfactant causes the reduction of the interfacial tension between oil and water in pores, therefore reducing the residual oil saturation, whereas the sweep efficiency will be significantly improved by the polymer injection as a result of proper mobility control. With regard to the well patterns, water flooding has demonstrated a high productivity in horizontal wells. Recently, other EOR processes have been increasingly applied to the horizontal wells in various well patterns. In this study, the efficiency of SP flooding applied to horizontal wells in various well configurations is investigated in order to select the best EOR performance in terms of either a technical or economical point of view. Furthermore, the reservoir is assumed to be anisotropic with four different layers that have same porosity but different permeability between each layer. The study figures out that, the utilization of a horizontal injector and producer always gives a higher oil production in comparison with the reference case of a conventional vertical injector and producer; however, the best EOR performances that demonstrate the higher oil recovery and lower fluid injected volume than those of the reference case are achieved when the production well is located in bottom layers and parallel with the injection well at a distance. While the location of producer decides oil productivity, the location of injector yet affects the uniformity of fluids propagation in the reservoir. A predefined feasibility factor is also taken into consideration in order to reject the infeasible cases that might give a high oil production but require a higher injected volume than the reference case. This factor is used as an economic parameter to evaluate the success of the EOR performance. The

  6. Trade-off analysis of discharge-desiltation-turbidity and ANN analysis on sedimentation of a combined reservoir-reach system under multi-phase and multi-layer conjunctive releasing operation

    Science.gov (United States)

    Huang, Chien-Lin; Hsu, Nien-Sheng; Wei, Chih-Chiang; Yao, Chun-Hao

    2017-10-01

    Multi-objective reservoir operation considering the trade-off of discharge-desiltation-turbidity during typhoons and sediment concentration (SC) simulation modeling are the vital components for sustainable reservoir management. The purposes of this study were (1) to analyze the multi-layer release trade-offs between reservoir desiltation and intake turbidity of downstream purification plants and thus propose a superior conjunctive operation strategy and (2) to develop ANFIS-based (adaptive network-based fuzzy inference system) and RTRLNN-based (real-time recurrent learning neural networks) substitute SC simulation models. To this end, this study proposed a methodology to develop (1) a series of multi-phase and multi-layer sediment-flood conjunctive release modes and (2) a specialized SC numerical model for a combined reservoir-reach system. The conjunctive release modes involve (1) an optimization model where the decision variables are multi-phase reduction/scaling ratios and the timings to generate a superior total release hydrograph for flood control (Phase I: phase prior to flood arrival, Phase II/III: phase prior to/subsequent to peak flow) and (2) a combination method with physical limitations regarding separation of the singular hydrograph into multi-layer release hydrographs for sediment control. This study employed the featured signals obtained from statistical quartiles/sediment duration curve in mesh segmentation, and an iterative optimization model with a sediment unit response matrix and corresponding geophysical-based acceleration factors, for efficient parameter calibration. This research applied the developed methodology to the Shihmen Reservoir basin in Taiwan. The trade-off analytical results using Typhoons Sinlaku and Jangmi as case examples revealed that owing to gravity current and re-suspension effects, Phase I + II can de-silt safely without violating the intake's turbidity limitation before reservoir discharge reaches 2238 m3/s; however

  7. Geological Characterisation of Depleted Oil and Gas Reservoirs for ...

    African Journals Online (AJOL)

    Dr Tse

    The reservoir formation consists of multilayered alternating beds of sandstone and shale cap rocks ... In the oil sector, Nigeria is one of the highest emitters ... Industrial emission and flaring .... integration of the 3D seismic data and wireline logs.

  8. Magnetic multilayer structure

    Science.gov (United States)

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  9. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neural reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers, geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  10. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  11. Fabrication of multilayer nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Jasveer, E-mail: kaurjasveer89@gmail.com; Singh, Avtar; Kumar, Davinder [Department of Physics, Punjabi University Patiala, 147002, Punjab (India); Thakur, Anup; Kaur, Raminder, E-mail: raminder-k-saini@yahoo.com [Department of Basic and Applied Sciences, Punjabi University Patiala, 147002, Punjab (India)

    2016-05-06

    Multilayer nanowires were fabricated by potentiostate ectrodeposition template synthesis method into the pores of polycarbonate membrane. In present work layer by layer deposition of two different metals Ni and Cu in polycarbonate membrane having pore size of 600 nm were carried out. It is found that the growth of nanowires is not constant, it varies with deposition time. Scanning electron microscopy (SEM) is used to study the morphology of fabricated multilayer nanowires. An energy dispersive X-ray spectroscopy (EDS) results confirm the composition of multilayer nanowires. The result shows that multilayer nanowires formed is dense.

  12. Fabrication of multilayer nanowires

    International Nuclear Information System (INIS)

    Kaur, Jasveer; Singh, Avtar; Kumar, Davinder; Thakur, Anup; Kaur, Raminder

    2016-01-01

    Multilayer nanowires were fabricated by potentiostate ectrodeposition template synthesis method into the pores of polycarbonate membrane. In present work layer by layer deposition of two different metals Ni and Cu in polycarbonate membrane having pore size of 600 nm were carried out. It is found that the growth of nanowires is not constant, it varies with deposition time. Scanning electron microscopy (SEM) is used to study the morphology of fabricated multilayer nanowires. An energy dispersive X-ray spectroscopy (EDS) results confirm the composition of multilayer nanowires. The result shows that multilayer nanowires formed is dense.

  13. Multilayer Brain Networks

    Science.gov (United States)

    Vaiana, Michael; Muldoon, Sarah Feldt

    2018-01-01

    The field of neuroscience is facing an unprecedented expanse in the volume and diversity of available data. Traditionally, network models have provided key insights into the structure and function of the brain. With the advent of big data in neuroscience, both more sophisticated models capable of characterizing the increasing complexity of the data and novel methods of quantitative analysis are needed. Recently, multilayer networks, a mathematical extension of traditional networks, have gained increasing popularity in neuroscience due to their ability to capture the full information of multi-model, multi-scale, spatiotemporal data sets. Here, we review multilayer networks and their applications in neuroscience, showing how incorporating the multilayer framework into network neuroscience analysis has uncovered previously hidden features of brain networks. We specifically highlight the use of multilayer networks to model disease, structure-function relationships, network evolution, and link multi-scale data. Finally, we close with a discussion of promising new directions of multilayer network neuroscience research and propose a modified definition of multilayer networks designed to unite and clarify the use of the multilayer formalism in describing real-world systems.

  14. Interfacial effects in multilayers

    International Nuclear Information System (INIS)

    Barbee, T.W. Jr.

    1998-01-01

    Interfacial structure and the atomic interactions between atoms at interfaces in multilayers or nano-laminates have significant impact on the physical properties of these materials. A technique for the experimental evaluation of interfacial structure and interfacial structure effects is presented and compared to experiment. In this paper the impact of interfacial structure on the performance of x-ray, soft x-ray and extreme ultra-violet multilayer optic structures is emphasized. The paper is concluded with summary of these results and an assessment of their implications relative to multilayer development and the study of buried interfaces in solids in general

  15. Wedged multilayer Laue lens

    International Nuclear Information System (INIS)

    Conley, Ray; Liu Chian; Qian Jun; Kewish, Cameron M.; Macrander, Albert T.; Yan Hanfei; Maser, Joerg; Kang, Hyon Chol; Stephenson, G. Brian

    2008-01-01

    A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures

  16. Controlling light with plasmonic multilayers

    DEFF Research Database (Denmark)

    Orlov, Alexey A.; Zhukovsky, Sergei; Iorsh, Ivan V.

    2014-01-01

    metamaterials and describe their use for light manipulation at the nanoscale. While demonstrating the recently emphasized hallmark effect of hyperbolic dispersion, we put special emphasis to the comparison between multilayered hyperbolic metamaterials and more broadly defined plasmonic-multilayer metamaterials...

  17. Porous germanium multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Garralaga Rojas, Enrique; Hensen, Jan; Brendel, Rolf [Institut fuer Solarenergieforschung Hameln (ISFH), Emmerthal (Germany); Carstensen, Juergen; Foell, Helmut [Chair for General Materials Science, Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany)

    2011-06-15

    We present the reproducible fabrication of porous germanium (PGe) single- and multilayers. Mesoporous layers form on heavily doped 4'' p-type Ge wafers by electrochemical etching in highly concentrated HF-based electrolytes with concentrations in a range of 30-50 wt.%. Direct PGe formation is accompanied by a constant dissolution of the already-formed porous layer at the electrolyte/PGe interface, hence yielding a thinner substrate after etching. This effect inhibits multilayer formation as the starting layer is etched while forming the second layer. We avoid dissolution of the porous layer by alternating the etching bias from anodic to cathodic. PGe formation occurs during anodic etching whereas the cathodic step passivates pore walls with H-atoms and avoids electropolishing. The passivation lasts a limited time depending on the etching current density and electrolyte concentration, necessitating a repetition of the cathodic step at suitable intervals. With optimized alternating bias mesoporous multilayer production is possible. We control the porosity of each single layer by varying the etching current density and the electrolyte (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1. Introduction. Sediment ... rendered water storage structures useless in less than 25 years. ... reservoir, thus reducing the space available for water storage and ...

  19. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  20. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  1. Digital multilayer tomography

    International Nuclear Information System (INIS)

    Dueber, C.; Klose, K.J.; Thelen, M.

    1991-01-01

    With digital multilayer tomography a sequence of projection images is recorded by an image intensifier television system and stored as digital data during a linear run of a layer sequence. Using this data record, tomograms of the examined body region can be computed for any layer thickness by shifts and superimposition of the single projections later at a digital workstation. The qualities of digital and conventional tomograms are basically comparable. A drawback of digital tomography is its lower local resolution (512 x 512 image matrix), advantages are a lower radiation exposure, a shorter patient examination time, and the facilities of digital image processing (later processing, archive setup, transmission). (orig.) [de

  2. Interfacial behaviour of biopolymer multilayers

    NARCIS (Netherlands)

    Corstens, Meinou N.; Osorio Caltenco, Lilia A.; Vries, de Renko; Schroën, Karin; Berton-Carabin, Claire C.

    2017-01-01

    Although multilayered emulsions have been related to reduced lipolysis, the involved interfacial phenomena have never been studied directly. In this work, we systematically built multilayers of whey protein and pectin, which we further subjected to digestive conditions, using two different

  3. Compositionally Graded Multilayer Ceramic Capacitors.

    Science.gov (United States)

    Song, Hyun-Cheol; Zhou, Jie E; Maurya, Deepam; Yan, Yongke; Wang, Yu U; Priya, Shashank

    2017-09-27

    Multilayer ceramic capacitors (MLCC) are widely used in consumer electronics. Here, we provide a transformative method for achieving high dielectric response and tunability over a wide temperature range through design of compositionally graded multilayer (CGML) architecture. Compositionally graded MLCCs were found to exhibit enhanced dielectric tunability (70%) along with small dielectric losses (filters and power converters.

  4. Experimental survey of the potential energy surfaces associated with fission

    International Nuclear Information System (INIS)

    Britt, H.C.

    1980-01-01

    Progress in the experimental determination of the properties of the potential energy surface associated with fission is reviewed. The importance of nuclear symmetry effects on the calculation of fission widths is demonstrated. Evidence is presented for the fragmentation of the mass-asymmetric second barrier in the thorium region and the axial asymmetric first barrier in the californium region. Detailed analyses of experimental data suggest the presence of two parallel second barriers; the normal mass-asymmetric, axial-symmetric barrier and a slightly higher mass-symmetric, axial-asymmetric barrier. Experimental barrier parameters are determined systematically and compared with calculations from various theoretical models. Techniques for expanding fission probability measurements to higher energies are discussed. (author)

  5. Ultrahard Multilayer Coatings

    International Nuclear Information System (INIS)

    Chrzan, D.C.; Dugger, M.; Follstaedt, D.M.; Friedman, Lawrence H.; Friedmann, T.A.; Knapp, J.A.; McCarty, K.F.; Medlin, D.L.; Mirkarimi, P.B.; Missert, N.; Newcomer, P.P.; Sullivan, J.P.; Tallant, D.R.

    1999-01-01

    We have developed a new multilayer a-tC material that is thick stress-free, adherent, low friction, and with hardness and stiffness near that of diamond. The new a-tC material is deposited by J pulsed-laser deposition (PLD) at room temperature, and fully stress-relieved by a short thermal anneal at 600 ampersand deg;C. A thick multilayer is built up by repeated deposition and annealing steps. We measured 88 GPa hardness, 1100 GPa Young's modulus, and 0.1 friction coefficient (under high load). Significantly, these results are all well within the range reported for crystalline diamond. In fact, this material, if considered separate from crystalline diamond, is the 2nd hardest material known to man. Stress-free a-tC also has important advantages over thin film diamond; namely, it is smooth, processed at lower temperature, and can be grown on a much broader range of substrates. This breakthrough will enable a host of applications that we are actively pursuing in MEMs, sensors, LIGA, etc

  6. Magnetic metallic multilayers

    International Nuclear Information System (INIS)

    Hood, R.Q.

    1994-04-01

    Utilizing self-consistent Hartree-Fock calculations, several aspects of multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field induced transitions. Magnetoresistance of ferromagnetic-normal-metal multilayers is found by solving the Boltzmann equation. Results explain the giant negative magnetoresistance encountered in these systems when an initial antiparallel arrangement is changed into a parallel configuration by an external magnetic field. The calculation depends on (1) geometric parameters (thicknesses of layers), (2) intrinsic metal parameters (number of conduction electrons, magnetization, and effective masses in layers), (3) bulk sample properties (conductivity relaxation times), (4) interface scattering properties (diffuse scattering versus potential scattering at the interfaces, and (5) outer surface scattering properties (specular versus diffuse surface scattering). It is found that a large negative magnetoresistance requires considerable asymmetry in interface scattering for the two spin orientations. Features of the interfaces that may produce an asymmetrical spin-dependent scattering are studied: varying interfacial geometric random roughness with no lateral coherence, correlated (quasi-periodic) roughness, and varying chemical composition of the interfaces. The interplay between these aspects of the interfaces may enhance or suppress the magnetoresistance, depending on whether it increases or decreases the asymmetry in the spin-dependent scattering of the conduction electrons

  7. Wrapped Multilayer Insulation

    Science.gov (United States)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  8. Fortescue reservoir development and reservoir studies

    Energy Technology Data Exchange (ETDEWEB)

    Henzell, S.T.; Hicks, G.J.; Horden, M.J.; Irrgang, H.R.; Janssen, E.J.; Kable, C.W.; Mitchell, R.A.H.; Morrell, N.W.; Palmer, I.D.; Seage, N.W.

    1985-03-01

    The Fortescue field in the Gippsland Basin, offshore southeastern Australia is being developed from two platforms (Fortescue A and Cobia A) by Esso Australia Ltd. (operator) and BHP Petroleum. The Fortescue reservoir is a stratigraphic trap at the top of the Latrobe Group of sediments. It overlies the western flank of the Halibut and Cobia fields and is separated from them by a non-net sequence of shales and coals which form a hydraulic barrier between the two systems. Development drilling into the Fortescue reservoir commenced in April 1983 with production coming onstream in May 1983. Fortescue, with booked reserves of 44 stock tank gigalitres (280 million stock tank barrels) of 43/sup 0/ API oil, is the seventh major oil reservoir to be developed in the offshore Gippsland Basin by Esso/BHP. In mid-1984, after drilling a total of 20 exploration and development wells, and after approximately one year of production, a detailed three-dimensional, two-phase reservoir simulation study was performed to examine the recovery efficiency, drainage patterns, pressure performance and production rate potential of the reservoir. The model was validated by history matching an extensive suite of Repeat Formation Test (RFT) pressure data. The results confirmed the reserves basis, and demonstrated that the ultimate oil recovery from the reservoir is not sensitive to production rate. This result is consistent with studies on other high quality Latrobe Group reservoirs in the Gippsland Basin which contain undersaturated crudes and receive very strong water drive from the Basin-wide aquifer system. With the development of the simulation model during the development phase, it has been possible to more accurately define the optimal well pattern for the remainder of the development.

  9. Neutron optics with multilayer monochromators

    International Nuclear Information System (INIS)

    Saxena, A.M.; Majkrzak, C.F.

    1984-01-01

    A multilayer monochromator is made by depositing thin films of two materials in an alternating sequence on a glass substrate. This makes a multilayer periodic in a direction perpendicular to the plane of the films, with a d-spacing equal to the thickness of one bilayer. Neutrons of wavelength λ incident on a multilayer will be reflected at an angle phi given by the Bragg relation nλ = 2d sinphi, where n is the order of reflection. The use of thin-film multilayers for monochromating neutrons is discussed. Because of the low flux of neutrons, the samples have to be large, and the width of the incident beam can be as much as 2 cm. Multilayers made earlier were fabricated by resistive heating of the materials in a vacuum chamber. Because of geometrical constraints imposed by the size of the vacuum chamber, limits on the amount of material that can be loaded in a boat, and finite life of the boats, this method of preparation limits the length of a multilayer to ∼ 15 cm and the total number of bilayers in a multilayer to about 200. This paper discusses a thin-film deposition system using RF sputtering for depositing films

  10. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...... dispersion equation in modeling the transport and the deposition of reservoir fines. It successfully predicts the unsymmetrical concentration profiles and the hyperexponential deposition in experiments....

  11. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  12. Integrated Multilayer Insulation

    Science.gov (United States)

    Dye, Scott

    2009-01-01

    Integrated multilayer insulation (IMLI) is being developed as an improved alternative to conventional multilayer insulation (MLI), which is more than 50 years old. A typical conventional MLI blanket comprises between 10 and 120 metallized polymer films separated by polyester nets. MLI is the best thermal- insulation material for use in a vacuum, and is the insulation material of choice for spacecraft and cryogenic systems. However, conventional MLI has several disadvantages: It is difficult or impossible to maintain the desired value of gap distance between the film layers (and consequently, it is difficult or impossible to ensure consistent performance), and fabrication and installation are labor-intensive and difficult. The development of IMLI is intended to overcome these disadvantages to some extent and to offer some additional advantages over conventional MLI. The main difference between IMLI and conventional MLI lies in the method of maintaining the gaps between the film layers. In IMLI, the film layers are separated by what its developers call a micro-molded discrete matrix, which can be loosely characterized as consisting of arrays of highly engineered, small, lightweight, polymer (typically, thermoplastic) frames attached to, and placed between, the film layers. The term "micro-molded" refers to both the smallness of the frames and the fact that they are fabricated in a process that forms precise small features, described below, that are essential to attainment of the desired properties. The term "discrete" refers to the nature of the matrix as consisting of separate frames, in contradistinction to a unitary frame spanning entire volume of an insulation blanket.

  13. Development of Novel Drugs from Marine Surface Associated Microorganisms

    Directory of Open Access Journals (Sweden)

    Suhelen Egan

    2010-03-01

    Full Text Available While the oceans cover more than 70% of the Earth’s surface, marine derived microbial natural products have been largely unexplored. The marine environment is a habitat for many unique microorganisms, which produce biologically active compounds (“bioactives” to adapt to particular environmental conditions. For example, marine surface associated microorganisms have proven to be a rich source for novel bioactives because of the necessity to evolve allelochemicals capable of protecting the producer from the fierce competition that exists between microorganisms on the surfaces of marine eukaryotes. Chemically driven interactions are also important for the establishment of cross-relationships between microbes and their eukaryotic hosts, in which organisms producing antimicrobial compounds (“antimicrobials”, may protect the host surface against over colonisation in return for a nutrient rich environment. As is the case for bioactive discovery in general, progress in the detection and characterization of marine microbial bioactives has been limited by a number of obstacles, such as unsuitable culture conditions, laborious purification processes, and a lack of de-replication. However many of these limitations are now being overcome due to improved microbial cultivation techniques, microbial (meta- genomic analysis and novel sensitive analytical tools for structural elucidation. Here we discuss how these technical advances, together with a better understanding of microbial and chemical ecology, will inevitably translate into an increase in the discovery and development of novel drugs from marine microbial sources in the future.

  14. Soliton surfaces associated with sigma models: differential and algebraic aspects

    International Nuclear Information System (INIS)

    Goldstein, P P; Grundland, A M; Post, S

    2012-01-01

    In this paper, we consider both differential and algebraic properties of surfaces associated with sigma models. It is shown that surfaces defined by the generalized Weierstrass formula for immersion for solutions of the CP N-1 sigma model with finite action, defined in the Riemann sphere, are themselves solutions of the Euler–Lagrange equations for sigma models. On the other hand, we show that the Euler–Lagrange equations for surfaces immersed in the Lie algebra su(N), with conformal coordinates, that are extremals of the area functional, subject to a fixed polynomial identity, are exactly the Euler–Lagrange equations for sigma models. In addition to these differential constraints, the algebraic constraints, in the form of eigenvalues of the immersion functions, are systematically treated. The spectrum of the immersion functions, for different dimensions of the model, as well as its symmetry properties and its transformation under the action of the ladder operators are discussed. Another approach to the dynamics is given, i.e. description in terms of the unitary matrix which diagonalizes both the immersion functions and the projectors constituting the model. (paper)

  15. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  16. Multilayer graphene rubber nanocomposites

    Science.gov (United States)

    Schartel, Bernhard; Frasca, Daniele; Schulze, Dietmar; Wachtendorf, Volker; Krafft, Bernd; Morys, Michael; Böhning, Martin; Rybak, Thomas

    2016-05-01

    Multilayer Graphene (MLG), a nanoparticle with a specific surface of BET = 250 m2/g and thus made of only approximately 10 graphene sheets, is proposed as a nanofiller for rubbers. When homogenously dispersed, it works at low loadings enabling the replacement of carbon black (CB), increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young's modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The later shown by the reduction in heat release rate in the cone calorimeter. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as a multifunctional nanofiller and seems to be quite ready for rubber development.

  17. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  18. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    Anvendelse af optimeringsteknik til drift af reservoirer er blevet et væsentligt element i vandressource-planlægning og -forvaltning. Traditionelt har reservoirer været styret af heuristiske procedurer for udtag af vand, suppleret i en vis udstrækning af subjektive beslutninger. Udnyttelse af...... reservoirer involverer en lang række interessenter med meget forskellige formål (f.eks. kunstig vanding, vandkraft, vandforsyning mv.), og optimeringsteknik kan langt bedre lede frem til afbalancerede løsninger af de ofte modstridende interesser. Afhandlingen foreslår en række tiltag, hvormed traditionelle...

  19. Sectioning of multilayers to make a multilayer Laue lens

    International Nuclear Information System (INIS)

    Kang, Hyon Chol; Stephenson, G. Brian; Liu Chian; Conley, Ray; Khachatryan, Ruben; Wieczorek, Michael; Macrander, Albert T.; Yan Hanfei; Maser, Joerg; Hiller, Jon; Koritala, Rachel

    2007-01-01

    We report a process to fabricate multilayer Laue lenses (MLL's) by sectioning and thinning multilayer films. This method can produce a linear zone plate structure with a very large ratio of zone depth to width (e.g., >1000), orders of magnitude larger than can be attained with photolithography. Consequently, MLL's are advantageous for efficient nanofocusing of hard x rays. MLL structures prepared by the technique reported here have been tested at an x-ray energy of 19.5 keV, and a diffraction-limited performance was observed. The present article reports the fabrication techniques that were used to make the MLL's

  20. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  1. Design and fabrication of heat resistant multilayers

    International Nuclear Information System (INIS)

    Thorne, J.M.; Knight, L.V.; Peterson, B.G.; Perkins, R.T.; Gray, K.J.

    1986-01-01

    Many promising applications of multilayer x-ray optical elements subject them to intense radiation. This paper discusses the selection of optimal pairs of materials to resist heat damage and presents simulations of multilayer performance under extreme heat loadings

  2. Transfer matrices for multilayer structures

    International Nuclear Information System (INIS)

    Baquero, R.

    1988-08-01

    We consider four of the transfer matrices defined to deal with multilayer structures. We deduce algorithms to calculate them numerically, in a simple and neat way. We illustrate their application to semi-infinite systems using SGFM formulae. These algorithms are of fast convergence and allow a calculation of bulk-, surface- and inner-layers band structure in good agreement with much more sophisticated calculations. Supermatrices, interfaces and multilayer structures can be calculated in this way with a small computational effort. (author). 10 refs

  3. Inflow forecasting using Artificial Neural Networks for reservoir operation

    Directory of Open Access Journals (Sweden)

    C. Chiamsathit

    2016-05-01

    Full Text Available In this study, multi-layer perceptron (MLP artificial neural networks have been applied to forecast one-month-ahead inflow for the Ubonratana reservoir, Thailand. To assess how well the forecast inflows have performed in the operation of the reservoir, simulations were carried out guided by the systems rule curves. As basis of comparison, four inflow situations were considered: (1 inflow known and assumed to be the historic (Type A; (2 inflow known and assumed to be the forecast (Type F; (3 inflow known and assumed to be the historic mean for month (Type M; and (4 inflow is unknown with release decision only conditioned on the starting reservoir storage (Type N. Reservoir performance was summarised in terms of reliability, resilience, vulnerability and sustainability. It was found that Type F inflow situation produced the best performance while Type N was the worst performing. This clearly demonstrates the importance of good inflow information for effective reservoir operation.

  4. A hybrid framework for reservoir characterization using fuzzy ranking and an artificial neural network

    Science.gov (United States)

    Wang, Baijie; Wang, Xin; Chen, Zhangxin

    2013-08-01

    Reservoir characterization refers to the process of quantitatively assigning reservoir properties using all available field data. Artificial neural networks (ANN) have recently been introduced to solve reservoir characterization problems dealing with the complex underlying relationships inherent in well log data. Despite the utility of ANNs, the current limitation is that most existing applications simply focus on directly implementing existing ANN models instead of improving/customizing them to fit the specific reservoir characterization tasks at hand. In this paper, we propose a novel intelligent framework that integrates fuzzy ranking (FR) and multilayer perceptron (MLP) neural networks for reservoir characterization. FR can automatically identify a minimum subset of well log data as neural inputs, and the MLP is trained to learn the complex correlations from the selected well log data to a target reservoir property. FR guarantees the selection of the optimal subset of representative data from the overall well log data set for the characterization of a specific reservoir property; and, this implicitly improves the modeling and predication accuracy of the MLP. In addition, a growing number of industrial agencies are implementing geographic information systems (GIS) in field data management; and, we have designed the GFAR solution (GIS-based FR ANN Reservoir characterization solution) system, which integrates the proposed framework into a GIS system that provides an efficient characterization solution. Three separate petroleum wells from southwestern Alberta, Canada, were used in the presented case study of reservoir porosity characterization. Our experiments demonstrate that our method can generate reliable results.

  5. Multilayer Controller for Outdoor Vehicle

    DEFF Research Database (Denmark)

    Reske-Nielsen, Anders; Mejnertsen, Asbjørn; Andersen, Nils Axel

    2006-01-01

    A full software and hardware solution has been designed, implemented and tested for control of a small agricultural automatic tractor. The objective was to realise a user-friendly, multi-layer controller architecture for an outdoor platform. The collaborative research work was done as a part of a...

  6. New developments in Ni/Ti multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I; Hoghoj, P [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    It is now 20 years since super-mirrors were first used as a neutron optical element. Since then the field of multilayer neutron-optics has matured with multilayers finding their way to application in many neutron scattering instruments. However, there is still room for progress in terms of multilayer quality, performance and application. Along with work on multilayers for neutron polarisation Ni/Ti super-mirrors have been optimised. The state-of-the-art Ni/Ti super-mirror performance and the results obtained in two neutron-optics applications of Ni/Ti multilayers are presented. (author).

  7. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  8. EUV multilayer mirror, optical system including a multilayer mirror and method of manufacturing a multilayer mirror

    NARCIS (Netherlands)

    Huang, Qiushi; Louis, Eric; Bijkerk, Frederik; de Boer, Meint J.; von Blanckenhagen, G.

    2016-01-01

    A multilayer mirror (M) reflecting extreme ultraviolet (EUV) radiation from a first wave-length range in a EUV spectral region comprises a substrate (SUB) and a stack of layers (SL) on the substrate, the stack of layers comprising layers comprising a low index material and a high index material, the

  9. Nagylengyel: an interesting reservoir. [Yugoslovia

    Energy Technology Data Exchange (ETDEWEB)

    Dedinszky, J

    1971-04-01

    The Nagylengyel oil field, discovered in 1951, has oil-producing formations mostly in the Upper-Triassic dolomites, in the Norian-Ractian transition formations, in the Upper-Cretaceous limestones and shales, and in the Miocene. The formation of the reservoir space occurred in many stages. A porous, cavernous fractured reservoir is developed in the Norian principal dolomite. A cavernous fractured reservoir exists in the Cretaceous limestone and in the Cretaceous shale and porous fractured reservoir is developed in the Miocene. The derivation of the model of the reservoir, and the conservative evaluation of the volume of the reservoir made it possible to use secondary recovery.

  10. Parallel reservoir simulator computations

    International Nuclear Information System (INIS)

    Hemanth-Kumar, K.; Young, L.C.

    1995-01-01

    The adaptation of a reservoir simulator for parallel computations is described. The simulator was originally designed for vector processors. It performs approximately 99% of its calculations in vector/parallel mode and relative to scalar calculations it achieves speedups of 65 and 81 for black oil and EOS simulations, respectively on the CRAY C-90

  11. unconventional natural gas reservoirs

    International Nuclear Information System (INIS)

    Correa G, Tomas F; Osorio, Nelson; Restrepo R, Dora P

    2009-01-01

    This work is an exploration about different unconventional gas reservoirs worldwide: coal bed methane, tight gas, shale gas and gas hydrate? describing aspects such as definition, reserves, production methods, environmental issues and economics. The overview also mentioned preliminary studies about these sources in Colombia.

  12. Thermally induced delamination of multilayers

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Sarraute, S.; Jørgensen, O.

    1998-01-01

    Steady-state delamination of multilayered structures, caused by stresses arising during processing due to thermal expansion mismatch, is analyzed by a fracture mechanics model based on laminate theory. It is found that inserting just a few interlayers with intermediate thermal expansion coefficie...... coefficients may be an effective way of reducing the delamination energy release rate. Uneven layer thickness and increasing elastic mismatch are shown to raise the energy release rate. Experimental work confirms important trends of the model.......Steady-state delamination of multilayered structures, caused by stresses arising during processing due to thermal expansion mismatch, is analyzed by a fracture mechanics model based on laminate theory. It is found that inserting just a few interlayers with intermediate thermal expansion...

  13. Anomalous magnetoresistance in Fibonacci multilayers.

    Energy Technology Data Exchange (ETDEWEB)

    Machado, L. D.; Bezerra, C. G.; Correa, M. A.; Chesman, C.; Pearson, J. E.; Hoffmann, A. (Materials Science Division); (Universidade Federal do Rio Grande do Norte)

    2012-01-01

    We theoretically investigated magnetoresistance curves in quasiperiodic magnetic multilayers for two different growth directions, namely, [110] and [100]. We considered identical ferromagnetic layers separated by nonmagnetic layers with two different thicknesses chosen based on the Fibonacci sequence. Using parameters for Fe/Cr multilayers, four terms were included in our description of the magnetic energy: Zeeman, cubic anisotropy, bilinear coupling, and biquadratic coupling. The minimum energy was determined by the gradient method and the equilibrium magnetization directions found were used to calculate magnetoresistance curves. By choosing spacers with a thickness such that biquadratic coupling is stronger than bilinear coupling, unusual behaviors for the magnetoresistance were observed: (i) for the [110] case, there is a different behavior for structures based on even and odd Fibonacci generations, and, more interesting, (ii) for the [100] case, we found magnetic field ranges for which the magnetoresistance increases with magnetic field.

  14. Mathematical Formulation of Multilayer Networks

    Science.gov (United States)

    De Domenico, Manlio; Solé-Ribalta, Albert; Cozzo, Emanuele; Kivelä, Mikko; Moreno, Yamir; Porter, Mason A.; Gómez, Sergio; Arenas, Alex

    2013-10-01

    A network representation is useful for describing the structure of a large variety of complex systems. However, most real and engineered systems have multiple subsystems and layers of connectivity, and the data produced by such systems are very rich. Achieving a deep understanding of such systems necessitates generalizing “traditional” network theory, and the newfound deluge of data now makes it possible to test increasingly general frameworks for the study of networks. In particular, although adjacency matrices are useful to describe traditional single-layer networks, such a representation is insufficient for the analysis and description of multiplex and time-dependent networks. One must therefore develop a more general mathematical framework to cope with the challenges posed by multilayer complex systems. In this paper, we introduce a tensorial framework to study multilayer networks, and we discuss the generalization of several important network descriptors and dynamical processes—including degree centrality, clustering coefficients, eigenvector centrality, modularity, von Neumann entropy, and diffusion—for this framework. We examine the impact of different choices in constructing these generalizations, and we illustrate how to obtain known results for the special cases of single-layer and multiplex networks. Our tensorial approach will be helpful for tackling pressing problems in multilayer complex systems, such as inferring who is influencing whom (and by which media) in multichannel social networks and developing routing techniques for multimodal transportation systems.

  15. APPLICATION OF INTEGRATED RESERVOIR MANAGEMENT AND RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jack Bergeron; Tom Blasingame; Louis Doublet; Mohan Kelkar; George Freeman; Jeff Callard; David Moore; David Davies; Richard Vessell; Brian Pregger; Bill Dixon; Bryce Bezant

    2000-03-01

    Reservoir performance and characterization are vital parameters during the development phase of a project. Infill drilling of wells on a uniform spacing, without regard to characterization does not optimize development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, especially carbonate reservoirs. These reservoirs are typically characterized by: (1) large, discontinuous pay intervals; (2) vertical and lateral changes in reservoir properties; (3) low reservoir energy; (4) high residual oil saturation; and (5) low recovery efficiency. The operational problems they encounter in these types of reservoirs include: (1) poor or inadequate completions and stimulations; (2) early water breakthrough; (3) poor reservoir sweep efficiency in contacting oil throughout the reservoir as well as in the nearby well regions; (4) channeling of injected fluids due to preferential fracturing caused by excessive injection rates; and (5) limited data availability and poor data quality. Infill drilling operations only need target areas of the reservoir which will be economically successful. If the most productive areas of a reservoir can be accurately identified by combining the results of geological, petrophysical, reservoir performance, and pressure transient analyses, then this ''integrated'' approach can be used to optimize reservoir performance during secondary and tertiary recovery operations without resorting to ''blanket'' infill drilling methods. New and emerging technologies such as geostatistical modeling, rock typing, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can then be used to develop a 3-D simulation model for prediction of infill locations. The application of reservoir surveillance techniques to identify additional reservoir ''pay'' zones

  16. An Analytical Model for Multilayer Well Production Evaluation to Overcome Cross-Flow Problem

    KAUST Repository

    Hakiki, Farizal; Wibowo, Aris T.; Rahmawati, Silvya D.; Yasutra, Amega; Sukarno, Pudjo

    2017-01-01

    One of the major concerns in a multi-layer system is that interlayer cross-flow may occur if reservoir fluids are produced from commingled layers that have unequal initial pressures. Reservoir would commonly have bigger average reservoir pressure (pore fluid pressure) as it goes deeper. The phenomenon is, however, not followed by the reservoir productivity or injectivity. The existence of reservoir with quite low average-pressure and high injectivity would tend experiencing the cross-flow problem. It is a phenomenon of fluid from bottom layer flowing into upper layer. It would strict upper-layer fluid to flow into wellbore. It is as if there is an injection treatment from bottom layer. The study deploys productivity index an approach parameter taking into account of cross-flow problem instead of injectivity index since it is a production well. The analytical study is to model the reservoir multilayer by addressing to avoid cross-flow problem. The analytical model employed hypothetical and real field data to test it. The scope of this study are: (a) Develop mathematical-based solution to determine the production rate from each layer; (b) Assess different scenarios to optimize production rate, those are: pump setting depth and performance of in-situ choke (ISC) installation. The ISC is acting as an inflow control device (ICD) alike that help to reduce cross-flow occurrence. This study employed macro program to write the code and develop the interface. Fast iterative procedure happens on solving the analytical model. Comparison results recognized that the mathematical-based solution shows a good agreement with the commercial software derived results.

  17. An Analytical Model for Multilayer Well Production Evaluation to Overcome Cross-Flow Problem

    KAUST Repository

    Hakiki, Farizal

    2017-10-17

    One of the major concerns in a multi-layer system is that interlayer cross-flow may occur if reservoir fluids are produced from commingled layers that have unequal initial pressures. Reservoir would commonly have bigger average reservoir pressure (pore fluid pressure) as it goes deeper. The phenomenon is, however, not followed by the reservoir productivity or injectivity. The existence of reservoir with quite low average-pressure and high injectivity would tend experiencing the cross-flow problem. It is a phenomenon of fluid from bottom layer flowing into upper layer. It would strict upper-layer fluid to flow into wellbore. It is as if there is an injection treatment from bottom layer. The study deploys productivity index an approach parameter taking into account of cross-flow problem instead of injectivity index since it is a production well. The analytical study is to model the reservoir multilayer by addressing to avoid cross-flow problem. The analytical model employed hypothetical and real field data to test it. The scope of this study are: (a) Develop mathematical-based solution to determine the production rate from each layer; (b) Assess different scenarios to optimize production rate, those are: pump setting depth and performance of in-situ choke (ISC) installation. The ISC is acting as an inflow control device (ICD) alike that help to reduce cross-flow occurrence. This study employed macro program to write the code and develop the interface. Fast iterative procedure happens on solving the analytical model. Comparison results recognized that the mathematical-based solution shows a good agreement with the commercial software derived results.

  18. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    , and the best reservoir properties are typically found in mudstone intervals. Chalk mudstones vary a lot though. The best mudstones are purely calcitic, well sorted and may have been redeposited by traction currents. Other mudstones are rich in very fine grained silica, which takes up pore space and thus...... basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... have hardly any stylolites and can have porosity above 40% or even 50% and thus also have relatively high permeability. Such intervals have the problem though, that increasing effective stress caused by hydrocarbon production results in mechanical compaction and overall subsidence. Most other chalk...

  19. Magnetoresistive multilayers deposited on the AAO membranes

    International Nuclear Information System (INIS)

    Malkinski, Leszek M.; Chalastaras, Athanasios; Vovk, Andriy; Jung, Jin-Seung; Kim, Eun-Mee; Jun, Jong-Ho; Ventrice, Carl A.

    2005-01-01

    Silicon and GaAs wafers are the most commonly used substrates for deposition of giant magnetoresistive (GMR) multilayers. We explored a new type of a substrate, prepared electrochemically by anodization of aluminum sheets, for deposition of GMR multilayers. The surface of this AAO substrate consists of nanosized hemispheres organized in a regular hexagonal array. The current applied along the substrate surface intersects many magnetic layers in the multilayered structure, which results in enhancement of giant magnetoresistance effect. The GMR effect in uncoupled Co/Cu multilayers was significantly larger than the magnetoresistance of similar structures deposited on Si

  20. Work reservoirs in thermodynamics

    International Nuclear Information System (INIS)

    Anacleto, Joaquim

    2010-01-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  1. Work reservoirs in thermodynamics

    Science.gov (United States)

    Anacleto, Joaquim

    2010-05-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  2. Advantageous Reservoir Characterization Technology in Extra Low Permeability Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yutian Luo

    2017-01-01

    Full Text Available This paper took extra low permeability reservoirs in Dagang Liujianfang Oilfield as an example and analyzed different types of microscopic pore structures by SEM, casting thin sections fluorescence microscope, and so on. With adoption of rate-controlled mercury penetration, NMR, and some other advanced techniques, based on evaluation parameters, namely, throat radius, volume percentage of mobile fluid, start-up pressure gradient, and clay content, the classification and assessment method of extra low permeability reservoirs was improved and the parameter boundaries of the advantageous reservoirs were established. The physical properties of reservoirs with different depth are different. Clay mineral variation range is 7.0%, and throat radius variation range is 1.81 μm, and start pressure gradient range is 0.23 MPa/m, and movable fluid percentage change range is 17.4%. The class IV reservoirs account for 9.56%, class II reservoirs account for 12.16%, and class III reservoirs account for 78.29%. According to the comparison of different development methods, class II reservoir is most suitable for waterflooding development, and class IV reservoir is most suitable for gas injection development. Taking into account the gas injection in the upper section of the reservoir, the next section of water injection development will achieve the best results.

  3. Bioinspired design of dental multilayers.

    Science.gov (United States)

    Huang, M; Wang, R; Thompson, V; Rekow, D; Soboyejo, W O

    2007-01-01

    This paper considers the use of bioinspired functionally graded structures in the design of dental multi-layers that are more resistant to sub-surface crack nucleation. Unlike existing dental crown restorations that give rise to high stress concentration, the functionally graded layers (between crown materials and the joins that attach them to dentin) are shown to promote significant reductions in stress and improvements in the critical crack size. Special inspiration is drawn from the low stress concentrations associated with the graded distributions in the dentin-enamel-junction (DEJ). The implications of such functionally graded structures are also discussed for the design of dental restorations.

  4. Multi-Layer Traffic Steering

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Gimenez, Lucas Chavarria

    2013-01-01

    This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle...... periods are not significantly long. Finally, better alignment between the RRC Connected and Idle mobility procedures is observed, guarantying significant decrease of handovers/reselections and potential battery life savings by minimizing the Inter-Frequency (IF) measurement rate in the RRC Idle....

  5. Robust giant magnetoresistive effect type multilayer sensor

    NARCIS (Netherlands)

    Lenssen, K.M.H.; Kuiper, A.E.T.; Roozeboom, F.

    2002-01-01

    A robust Giant Magneto Resistive effect type multilayer sensor comprising a free and a pinned ferromagnetic layer, which can withstand high temperatures and strong magnetic fields as required in automotive applications. The GMR multi-layer has an asymmetric magneto-resistive curve and enables

  6. Multi-Layer E-Textile Circuits

    Science.gov (United States)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  7. Multilayer Graphene for Waveguide Terahertz Modulator

    DEFF Research Database (Denmark)

    Khromova, I.; Andryieuski, Andrei; Lavrinenko, Andrei

    2014-01-01

    We study terahertz to infrared electromagnetic properties of multilayer graphene/dielectric artificial medium and present a novel concept of terahertz modulation at midinfrared wavelengths. This approach allows the realization of high-speed electrically controllable terahertz modulators based...... on hollow waveguide sections filled with multilayer graphene....

  8. Figure correction of multilayer coated optics

    Science.gov (United States)

    Chapman; Henry N. , Taylor; John S.

    2010-02-16

    A process is provided for producing near-perfect optical surfaces, for EUV and soft-x-ray optics. The method involves polishing or otherwise figuring the multilayer coating that has been deposited on an optical substrate, in order to correct for errors in the figure of the substrate and coating. A method such as ion-beam milling is used to remove material from the multilayer coating by an amount that varies in a specified way across the substrate. The phase of the EUV light that is reflected from the multilayer will be affected by the amount of multilayer material removed, but this effect will be reduced by a factor of 1-n as compared with height variations of the substrate, where n is the average refractive index of the multilayer.

  9. Multilayer Nanoporous Graphene Membranes for Water Desalination.

    Science.gov (United States)

    Cohen-Tanugi, David; Lin, Li-Chiang; Grossman, Jeffrey C

    2016-02-10

    While single-layer nanoporous graphene (NPG) has shown promise as a reverse osmosis (RO) desalination membrane, multilayer graphene membranes can be synthesized more economically than the single-layer material. In this work, we build upon the knowledge gained to date toward single-layer graphene to explore how multilayer NPG might serve as a RO membrane in water desalination using classical molecular dynamic simulations. We show that, while multilayer NPG exhibits similarly promising desalination properties to single-layer membranes, their separation performance can be designed by manipulating various configurational variables in the multilayer case. This work establishes an atomic-level understanding of the effects of additional NPG layers, layer separation, and pore alignment on desalination performance, providing useful guidelines for the design of multilayer NPG membranes.

  10. Advances in photonic reservoir computing

    Science.gov (United States)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  11. Dynamical diffraction in periodic multilayers

    CERN Document Server

    Sears, V F

    1997-01-01

    Exact reflectivity curves are calculated numerically for various periodic multilayers using the optical matrix method in order to test the dynamical theory of diffraction. The theory is generally valid for values of the bilayer thickness d up to about 100 A. For somewhat larger values of d, where the theory begins to break down, the initial discrepancy is in the phase of the oscillations in the wings of the peaks. For very large values of d, where the first-order Bragg peak approaches the edge of the mirror reflection, two general types of multilayers can be distinguished. In the first (typified in the present work by Ni/Ti), there is a large (30% or more) reduction in the actual value of the critical wave vector for total reflection while, in the second (typified here by Fe/Ge), there is very little reduction (3 % or so). The origin of these two very different types of behavior is explained. It is also shown that, within the dynamical theory of diffraction, the change in the position of the center of the Dar...

  12. Encapsulated microsensors for reservoir interrogation

    Science.gov (United States)

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  13. All-optical reservoir computing.

    Science.gov (United States)

    Duport, François; Schneider, Bendix; Smerieri, Anteo; Haelterman, Marc; Massar, Serge

    2012-09-24

    Reservoir Computing is a novel computing paradigm that uses a nonlinear recurrent dynamical system to carry out information processing. Recent electronic and optoelectronic Reservoir Computers based on an architecture with a single nonlinear node and a delay loop have shown performance on standardized tasks comparable to state-of-the-art digital implementations. Here we report an all-optical implementation of a Reservoir Computer, made of off-the-shelf components for optical telecommunications. It uses the saturation of a semiconductor optical amplifier as nonlinearity. The present work shows that, within the Reservoir Computing paradigm, all-optical computing with state-of-the-art performance is possible.

  14. Algae as reservoirs for coral pathogens.

    Directory of Open Access Journals (Sweden)

    Michael J Sweet

    Full Text Available Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS in the Indo-Pacific and Yellow Band Disease (YBD in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively. Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is

  15. Cesium reservoir and interconnective components

    International Nuclear Information System (INIS)

    1994-03-01

    The program objective is to demonstrate the technology readiness of a TFE (thermionic fuel element) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW range. A thermionic converter must be supplied with cesium vapor for two reasons. Cesium atoms adsorbed on the surface of the emitter cause a reduction of the emitter work function to permit high current densities without excessive heating of the emitter. The second purpose of the cesium vapor is to provide space-charge neutralization in the emitter-collector gap so that the high current densities may flow across the gap unattenuated. The function of the cesium reservoir is to provide a source of cesium atoms, and to provide a reserve in the event that cesium is lost from the plasma by any mechanism. This can be done with a liquid cesium metal reservoir in which case it is heated to the desired temperature with auxiliary heaters. In a TFE, however, it is desirable to have the reservoir passively heated by the nuclear fuel. In this case, the reservoir must operate at a temperature intermediate between the emitter and the collector, ruling out the use of liquid reservoirs. Integral reservoirs contained within the TFE will produce cesium vapor pressures in the desired range at typical electrode temperatures. The reservoir material that appears to be the best able to meet requirements is graphite. Cesium intercalates easily into graphite, and the cesium pressure is insensitive to loading for a given intercalation stage. The goals of the cesium reservoir test program were to verify the performance of Cs-graphite reservoirs in the temperature-pressure range of interest to TFE operation, and to test the operation of these reservoirs after exposure to a fast neutron fluence corresponding to seven year mission lifetime. In addition, other materials were evaluated for possible use in the integral reservoir

  16. Daily reservoir inflow forecasting combining QPF into ANNs model

    Science.gov (United States)

    Zhang, Jun; Cheng, Chun-Tian; Liao, Sheng-Li; Wu, Xin-Yu; Shen, Jian-Jian

    2009-01-01

    Daily reservoir inflow predictions with lead-times of several days are essential to the operational planning and scheduling of hydroelectric power system. The demand for quantitative precipitation forecasting (QPF) is increasing in hydropower operation with the dramatic advances in the numerical weather prediction (NWP) models. This paper presents a simple and an effective algorithm for daily reservoir inflow predictions which solicits the observed precipitation, forecasted precipitation from QPF as predictors and discharges in following 1 to 6 days as predicted targets for multilayer perceptron artificial neural networks (MLP-ANNs) modeling. An improved error back-propagation algorithm with self-adaptive learning rate and self-adaptive momentum coefficient is used to make the supervised training procedure more efficient in both time saving and search optimization. Several commonly used error measures are employed to evaluate the performance of the proposed model and the results, compared with that of ARIMA model, show that the proposed model is capable of obtaining satisfactory forecasting not only in goodness of fit but also in generalization. Furthermore, the presented algorithm is integrated into a practical software system which has been severed for daily inflow predictions with lead-times varying from 1 to 6 days of more than twenty reservoirs operated by the Fujian Province Grid Company, China.

  17. Magnetic-plasmonic multilayered nanorods

    Science.gov (United States)

    Thumthan, Orathai

    Multilayered nanorods which consist of alternating magnetic layers separated by Au layers combine two distinctive properties, magnetic properties and surface plasmonic resonance (SPR) properties into one nano-entity. Their magnetic properties are tunable by changing the layer thickness, varying from single domain to superparamagnetic state. Superparamagnetic is a key requirement for magnetic nanoparticles for bioapplications. Superparamagnetic nanoparticles exhibit high magnetic moments at low applied magnetic field while retain no magnetic moments when magnetic field is removed preventing them from aggregation due to magnetic attraction. Au layers in the nanorods provide anchorage sites for functional group attachment. Also, Au nanodisks exhibit SPR properties. The SPR peak can be tuned from 540 nm to 820 nm by controlling the thickness of magnetic segments while keeping Au thickness constant. In this research, there are three types of multilayered nanorod have been fabricated: Au/NiFe nanorods, Au/Fe nanorods, and Au/Co nanorods. These magnetic nanorods were fabricated by templated electrodeposition into the channels in Anodic Aluminum Oxide (AAO) membrane. The setup for AAO fabrication was developed as a part of this research. Our fabricated AAO membrane has channels with a diameter ranging from 40nm to 80 nm and a thickness of 10um to 12um. Magnetic properties of nanorods such as saturation field, saturation moment, coercivity and remanence are able to manipulate through their shape anisotropy. The magnetization will be easier in long axis rather than short axis of particle. In addition, Au nanodisks in the nanorod structure are not only serving as anchorage sites for functional groups but also provide SPR properties. Under irradiation of light Au nanodisks strongly absorb light at SPR frequency which ranging from 540 nm to 820 nm by controlling the thickness of magnetic segments while keeping Au thickness constant. The SPR tunability of nanorods in near

  18. Multilayer Insulation Ascent Venting Model

    Science.gov (United States)

    Tramel, R. W.; Sutherlin, S. G.; Johnson, W. L.

    2017-01-01

    The thermal and venting transient experienced by tank-applied multilayer insulation (MLI) in the Earth-to-orbit environment is very dynamic and not well characterized. This new predictive code is a first principles-based engineering model which tracks the time history of the mass and temperature (internal energy) of the gas in each MLI layer. A continuum-based model is used for early portions of the trajectory while a kinetic theory-based model is used for the later portions of the trajectory, and the models are blended based on a reference mean free path. This new capability should improve understanding of the Earth-to-orbit transient and enable better insulation system designs for in-space cryogenic propellant systems.

  19. Thermal transfer in multilayer materials

    Energy Technology Data Exchange (ETDEWEB)

    Bouayad, H.; Mokhtari, A.; Martin, C.; Fauchais, P. [Laboratoire de Materiaux Ceramiques et Traitements de Surface, 87 - Limoges (France)

    1993-12-31

    It is easier to measure the thermal diffusivity (a) of material rather than its thermal conductivity (k), a simple relationship (k=a cp) allowing to calculate k provided and cp are measured. However this relationship applies only if the considered material is homogenous. For composite materials, especially for multilayers ones, we have developed an analytical model and a numerical one. The first one allows to determine the thermal diffusivity and conductivity of a two-layer material. The second one allows to determine the thermal diffusivity of one of the layers provided the values of (a) are known for the two other layers (for a two or three-layer material). The use of the two models to calculate the apparent diffusivity of a two layer material results in values in fairly good agreement. (Authors). 4 refs., 3 figs., 3 tabs.

  20. Reservoir engineering and hydrogeology

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Summaries are included which show advances in the following areas: fractured porous media, flow in single fractures or networks of fractures, hydrothermal flow, hydromechanical effects, hydrochemical processes, unsaturated-saturated systems, and multiphase multicomponent flows. The main thrust of these efforts is to understand the movement of mass and energy through rocks. This has involved treating fracture rock masses in which the flow phenomena within both the fractures and the matrix must be investigated. Studies also address the complex coupling between aspects of thermal, hydraulic, and mechanical processes associated with a nuclear waste repository in a fractured rock medium. In all these projects, both numerical modeling and simulation, as well as field studies, were employed. In the theoretical area, a basic understanding of multiphase flow, nonisothermal unsaturated behavior, and new numerical methods have been developed. The field work has involved reservoir testing, data analysis, and case histories at a number of geothermal projects

  1. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  2. Superconductivity in multilayer perovskite. Weak coupling analysis

    International Nuclear Information System (INIS)

    Koikegami, Shigeru; Yanagisawa, Takashi

    2006-01-01

    We investigate the superconductivity of a three-dimensional d-p model with a multilayer perovskite structure on the basis of the second-order perturbation theory within the weak coupling framework. Our model has been designed with multilayer high-T c superconducting cuprates in mind. In our model, multiple Fermi surfaces appear, and the component of a superconducting gap function develops on each band. We have found that the multilayer structure can stabilize the superconductivity in a wide doping range. (author)

  3. Nondestructive diagnosis of multilayer electronic plates

    International Nuclear Information System (INIS)

    Matvienko, A.N.; Savin, D.O.; Yas'ko, A.V.

    1992-01-01

    Methods of non-destructive tomographic investigation into multilayer printed plates using x radiation are described. Mathematic problem setting is given, experimental facility and methods for source data ecquisition are described. A special attention is paid to the consideration of the main factors differing the actual problem setting from the idealized one. Methods for accounting and correction of these factors are described. The efficiency of the approach proposed is demonstrated using the actual problems of reducing separate layers of multilayer printed plate metallization. The method developed is useful when exersizing control over multilayer printed plate production

  4. Reservoir sedimentation; a literature survey

    NARCIS (Netherlands)

    Sloff, C.J.

    1991-01-01

    A survey of literature is made on reservoir sedimentation, one of the most threatening processes for world-wide reservoir performance. The sedimentation processes, their impacts, and their controlling factors are assessed from a hydraulic engineering point of view with special emphasis on

  5. Advances in photonic reservoir computing

    Directory of Open Access Journals (Sweden)

    Van der Sande Guy

    2017-05-01

    Full Text Available We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir’s complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  6. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim (University of Texas at Austin, Austin, TX); Gilbert, Bob (University of Texas at Austin, Austin, TX); Lake, Larry W. (University of Texas at Austin, Austin, TX); Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett (University of Texas at Austin, Austin, TX); Thomas, Sunil G. (University of Texas at Austin, Austin, TX); Rightley, Michael J.; Rodriguez, Adolfo (University of Texas at Austin, Austin, TX); Klie, Hector (University of Texas at Austin, Austin, TX); Banchs, Rafael (University of Texas at Austin, Austin, TX); Nunez, Emilio J. (University of Texas at Austin, Austin, TX); Jablonowski, Chris (University of Texas at Austin, Austin, TX)

    2006-11-01

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  7. Soft X-ray multilayers and filters

    CERN Document Server

    Wang Zhan Shan; Tang Wei Xing; Qin Shuji; Zhou Bing; Chen Ling Ya

    2002-01-01

    The periodic and non-periodic multilayers were designed by using a random number to change each layer and a suitable merit function. Ion beam sputtering and magnetron sputtering were used to fabricate various multilayers and beam splitters in soft X-ray range. The characterization of multilayers by small angle X-ray diffraction, Auger electron spectroscopy, Rutherford back scattering spectroscopy and reflectivity illustrated the multilayers had good structures and smooth interlayers. The reflectivity and transmission of a beam splitter is about 5%. The fabrication and transmission properties of Ag, Zr were studied. The Rutherford back scattering spectroscopy and auger electron spectroscopy were used to investigate the contents and distributions of impurities and influence on qualities of filters. The attenuation coefficients were corrected by the data obtained by measurements

  8. Lamellar multilayer hexadecylaniline-modified gold nanoparticle ...

    Indian Academy of Sciences (India)

    standard Wilhelmy plate was used for surface pressure sensing. Multilayer ... carried out on a JEOL model 1200EX instrument operated at an accelerating voltage of ... the gold nanoparticles within domains (and reorganization of the domains ...

  9. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon

  10. Irradiated multilayer film for primal meat packaging

    International Nuclear Information System (INIS)

    Lustig, S.; Schuetz, J.M.; Vicik, S.J.

    1987-01-01

    This patent deals with a heat-shrinkable, multilayer film suitable for use in fabricating bags for packaging primal and sub-primal meat cuts and processed meats. The multilayer film has a first outer layer of a first ethylene-vinyl acetate copolymer, a core layer of a polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride as a barrier film, and a second outer layer of a second ethylene-vinyl acetate copolymer. The multilayer film is preferably made by co-extrusion of the layers, and then it is biaxially stretched. After biaxial stretching, the entire multilayer film is substantially uniformly irradiated to a dosage level of between about 2 megarads and about 3 megarads and heat-sealed in the form of a bag. The film is not significantly discoloured by the irradiation and the bag has improved toughness properties and heat-sealing characteristics

  11. Irradiated multilayer film for primal meat packaging

    International Nuclear Information System (INIS)

    Lustig, S.; Schuetz, J.M.; Vicik, S.J.

    1987-01-01

    This patent deals with a heat-shrinkable, multilayer film suitable for use in fabricating bags for packaging primal and sub-primal meat cuts and processed meats. The multilayer film has a first outer layer of an ethylene-vinyl acetate copolymer, a core layer of a barrier film comprising vinylidene chloride-methyl acrylate copolymer, and a second outer layer of an ethylene-vinyl acetate copolymer. The multilayer film is preferably made by co-extrusion of the layers, and then it is biaxially stretched. After biaxial stretching, the multilayer film is irradiated to a dosage level of between 1 megarad and 5 megarads and heat-sealed in the form of a bag. The bag has improved storage stability characteristics

  12. Tc dependence on the number of CuO2 planes in multilayered Ba2Can-1CunO2n(O, F)2 superconductors

    International Nuclear Information System (INIS)

    Iyo, A; Tanaka, Y; Kodama, Y; Kito, H; Tokiwa, K; Watanabe, T

    2006-01-01

    Multilayered cuprates of Ba 2 Ca n-1 Cu n O 2n (O, F) 2 (F-02(n-1)n) with n = 5 - 9 have been synthesized by using high pressure synthesis method in order to investigate the variation of T c . The temperature dependence of susceptibility showed that the T c (about 80 K) does not depend on n for n 5 - 9. This result can be explained using the carrier imbalance model in multilayered cuprates. Charge reservoir layers supply most of the carriers to adjacent CuO 2 planes (OP) and the OP keeps the T c constant even for large n

  13. Ordered organic-organic multilayer growth

    Science.gov (United States)

    Forrest, Stephen R; Lunt, Richard R

    2015-01-13

    An ordered multilayer crystalline organic thin film structure is formed by depositing at least two layers of thin film crystalline organic materials successively wherein the at least two thin film layers are selected to have their surface energies within .+-.50% of each other, and preferably within .+-.15% of each other, whereby every thin film layer within the multilayer crystalline organic thin film structure exhibit a quasi-epitaxial relationship with the adjacent crystalline organic thin film.

  14. Finding overlapping communities in multilayer networks.

    Science.gov (United States)

    Liu, Weiyi; Suzumura, Toyotaro; Ji, Hongyu; Hu, Guangmin

    2018-01-01

    Finding communities in multilayer networks is a vital step in understanding the structure and dynamics of these layers, where each layer represents a particular type of relationship between nodes in the natural world. However, most community discovery methods for multilayer networks may ignore the interplay between layers or the unique topological structure in a layer. Moreover, most of them can only detect non-overlapping communities. In this paper, we propose a new community discovery method for multilayer networks, which leverages the interplay between layers and the unique topology in a layer to reveal overlapping communities. Through a comprehensive analysis of edge behaviors within and across layers, we first calculate the similarities for edges from the same layer and the cross layers. Then, by leveraging these similarities, we can construct a dendrogram for the multilayer networks that takes both the unique topological structure and the important interplay into consideration. Finally, by introducing a new community density metric for multilayer networks, we can cut the dendrogram to get the overlapping communities for these layers. By applying our method on both synthetic and real-world datasets, we demonstrate that our method has an accurate performance in discovering overlapping communities in multilayer networks.

  15. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf; Saad, Bilal; Negara, Ardiansyah; Sun, Shuyu

    2017-01-01

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically

  16. Exploring the Plant–Microbe Interface by Profiling the Surface-Associated Proteins of Barley Grains

    DEFF Research Database (Denmark)

    Sultan, Abida; Andersen, Birgit; Svensson, Birte

    2016-01-01

    Cereal grains are colonized by a microbial community that actively interacts with the plant via secretion of various enzymes, hormones, and metabolites. Microorganisms decompose plant tissues by a collection of depolymerizing enzymes, including β-1,4-xylanases, that are in turn inhibited by plant...... xylanase inhibitors. To gain insight into the importance of the microbial consortia and their interaction with barley grains, we used a combined gel-based (2-DE coupled to MALDI-TOF-TOF MS) and gel-free (LC–MS/MS) proteomics approach complemented with enzyme activity assays to profile the surface......-associated proteins and xylanolytic activities of two barley cultivars. The surface-associated proteome was dominated by plant proteins with roles in defense and stress-responses, while the relatively less abundant microbial (bacterial and fungal) proteins were involved in cell-wall and polysaccharide degradation...

  17. Antibacterial activity of the sponge Ircinia ramosa: Importance of its surface-associated bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Thakur, N.L.; Anil, A.C.

    , and concentrated under reduced pressure in a rotary evap- orator. A flow chart of extraction of sponge and its associated bacteria and anti- bacterial bioassays is given in Figure 1. Fractionation of Crude Extracts. The crude methanol extracts collected during... activity, and (3) whether there is a role for sponge surface-associated bacteria in antibacterial activity of the host? ANTIBACTERIAL ACTIVITY OF SPONGE 59 METHODS AND MATERIALS Specimen Collection and Preparation of Crude Extracts. Specimens of Ircinia...

  18. Proteomic analysis of cell surface-associated proteins from probiotic Lactobacillus plantarum

    DEFF Research Database (Denmark)

    Beck, Hans Christian; Madsen, Søren M; Glenting, Jacob

    2009-01-01

    In the present study, we used a proteomic approach to identify surface-associated proteins from the probiotic bacterium Lactobacillus plantarum 299v. Proteins were extracted from the cell surface using a mild wash in phosphate buffer and analysed by sodium dodecyl sulphate-polyacrylamide gel...... of probiotics in the gastrointestinal tract. The results provide the basis for future studies on the molecular mechanisms of probiotics....

  19. Multilayer Piezoelectric Stack Actuator Characterization

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  20. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-12-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  1. Multilayer heterostructures and their manufacture

    Science.gov (United States)

    Hammond, Scott R; Reese, Matthew; Rupert, Benjamin; Miedaner, Alexander; Curtis, Clavin; Olson, Dana; Ginley, David S

    2015-11-04

    A method of synthesizing multilayer heterostructures including an inorganic oxide layer residing on a solid substrate is described. Exemplary embodiments include producing an inorganic oxide layer on a solid substrate by a liquid coating process under relatively mild conditions. The relatively mild conditions include temperatures below 225.degree. C. and pressures above 9.4 mb. In an exemplary embodiment, a solution of diethyl aluminum ethoxide in anhydrous diglyme is applied to a flexible solid substrate by slot-die coating at ambient atmospheric pressure, and the diglyme removed by evaporation. An AlO.sub.x layer is formed by subjecting material remaining on the solid substrate to a relatively mild oven temperature of approximately 150.degree. C. The resulting AlO.sub.x layer exhibits relatively high light transmittance and relatively low vapor transmission rates for water. An exemplary embodiment of a flexible solid substrate is polyethylene napthalate (PEN). The PEN is not substantially adversely affected by exposure to 150.degree. C

  2. Design Techniques and Reservoir Simulation

    Directory of Open Access Journals (Sweden)

    Ahad Fereidooni

    2012-11-01

    Full Text Available Enhanced oil recovery using nitrogen injection is a commonly applied method for pressure maintenance in conventional reservoirs. Numerical simulations can be practiced for the prediction of a reservoir performance in the course of injection process; however, a detailed simulation might take up enormous computer processing time. In such cases, a simple statistical model may be a good approach to the preliminary prediction of the process without any application of numerical simulation. In the current work, seven rock/fluid reservoir properties are considered as screening parameters and those parameters having the most considerable effect on the process are determined using the combination of experimental design techniques and reservoir simulations. Therefore, the statistical significance of the main effects and interactions of screening parameters are analyzed utilizing statistical inference approaches. Finally, the influential parameters are employed to create a simple statistical model which allows the preliminary prediction of nitrogen injection in terms of a recovery factor without resorting to numerical simulations.

  3. The Characteristics of Spanish Reservoirs

    National Research Council Canada - National Science Library

    Armengol, J; Merce, R

    2003-01-01

    Sau Reservoir was first filled in 1963 in a middle stretch of the Ter River, as part of a multi-use scheme, including hydroelectric power, agricultural irrigation, domestic and industrial water supply...

  4. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  5. EUV multilayer mirrors with enhanced stability

    Science.gov (United States)

    Benoit, Nicolas; Yulin, Sergiy; Feigl, Torsten; Kaiser, Norbert

    2006-08-01

    The application of multilayer optics in EUV lithography requires not only the highest possible normal-incidence reflectivity but also a long-term thermal and radiation stability at operating temperatures. This requirement is most important in the case of the collector mirror of the illumination system close to the EUV source where a short-time decrease in reflectivity is most likely. Mo/Si multilayer mirrors, designed for high normal reflectivity at the wavelength of 13.5 nm and deposited by dc magnetron sputtering, were directly exposed to EUV radiation without mitigation system. They presented a loss of reflectivity of more than 18% after only 8 hours of irradiation by a Xe-discharge source. Another problem of Mo/Si multilayers is the instability of reflectivity and peak wavelength under high heat load. It becomes especially critical at temperatures above 200°C, where interdiffusion between the molybdenum and the silicon layers is observed. The development of high-temperature multilayers was focused on two alternative Si-based systems: MoSi II/Si and interface engineered Mo/C/Si/C multilayer mirrors. The multilayer designs as well as the deposition parameters of all systems were optimized in terms of high peak reflectivity (>= 60 %) at a wavelength of 13.5 nm and high thermal stability. Small thermally induced changes of the MoSi II/Si multilayer properties were found but they were independent of the annealing time at all temperatures examined. A wavelength shift of -1.7% and a reflectivity drop of 1.0% have been found after annealing at 500°C for 100 hours. The total degradation of optical properties above 650°C can be explained by a recrystallization process of MoSi II layers.

  6. Chickamauga reservoir embayment study - 1990

    Energy Technology Data Exchange (ETDEWEB)

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.

    1992-12-01

    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  7. A rationale for reservoir management economics

    International Nuclear Information System (INIS)

    Hickman, T.S.

    1995-01-01

    Significant economic benefits can be derived from the application f reservoir management. The key elements in economical reservoir management are the efficient use of available resources and optimization of reservoir exploitation through a multidisciplined approach. This paper describes various aspects of and approaches to reservoir management and provides case histories that support the findings

  8. Refractive index contrast in porous silicon multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Nava, R.; Mora, M.B. de la; Tagueena-Martinez, J. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Temixco, Morelos (Mexico); Rio, J.A. del [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Temixco, Morelos (Mexico); Centro Morelense de Innovacion y Transferencia Tecnologica, Consejo de Ciencia y Tecnologia del Estado de Morelos (Mexico)

    2009-07-15

    Two of the most important properties of a porous silicon multilayer for photonic applications are flat interfaces and a relative large refractive index contrast between layers in the optical wavelength range. In this work, we studied the effect of the current density and HF electrolyte concentration on the refractive index of porous silicon. With the purpose of increasing the refractive index contrast in a multilayer, the refractive index of porous silicon produced at low current was studied in detail. The current density applied to produce the low porosity layers was limited in order to keep the electrolyte flow through the multilayer structure and to avoid deformation of layer interfaces. We found that an electrolyte composed of hydrofluoric acid, ethanol and glycerin in a ratio of 3:7:1 gives a refractive index contrast around 1.3/2.8 at 600 nm. Several multilayer structures with this refractive index contrast were fabricated, such as dielectric Bragg mirrors and microcavities. Reflectance spectra of the structures show the photonic quality of porous silicon multilayers produced under these electrochemical conditions. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Base Metal Co-Fired Multilayer Piezoelectrics

    Directory of Open Access Journals (Sweden)

    Lisheng Gao

    2016-03-01

    Full Text Available Piezoelectrics have been widely used in different kinds of applications, from the automobile industry to consumer electronics. The novel multilayer piezoelectrics, which are inspired by multilayer ceramic capacitors, not only minimize the size of the functional parts, but also maximize energy efficiency. Development of multilayer piezoelectric devices is at a significant crossroads on the way to achieving low costs, high efficiency, and excellent reliability. Concerning the costs of manufacturing multilayer piezoelectrics, the trend is to replace the costly noble metal internal electrodes with base metal materials. This paper discusses the materials development of metal co-firing and the progress of integrating current base metal chemistries. There are some significant considerations in metal co-firing multilayer piezoelectrics: retaining stoichiometry with volatile Pb and alkaline elements in ceramics, the selection of appropriate sintering agents to lower the sintering temperature with minimum impact on piezoelectric performance, and designing effective binder formulation for low pO2 burnout to prevent oxidation of Ni and Cu base metal.

  10. Corrugated grating on organic multilayer Bragg reflector

    Science.gov (United States)

    Jaquet, Sylvain; Scharf, Toralf; Herzig, Hans Peter

    2007-08-01

    Polymeric multilayer Bragg structures are combined with diffractive gratings to produce artificial visual color effects. A particular effect is expected due to the angular reflection dependence of the multilayer Bragg structure and the dispersion caused by the grating. The combined effects can also be used to design particular filter functions and various resonant structures. The multilayer Bragg structure is fabricated by spin-coating of two different low-cost polymer materials in solution on a cleaned glass substrate. These polymers have a refractive index difference of about 0.15 and permit multilayer coatings without interlayer problems. Master gratings of different periods are realized by laser beam interference and replicated gratings are superimposed on the multilayer structure by soft embossing in a UV curing glue. The fabrication process requires only polymer materials. The obtained devices are stable and robust. Angular dependent reflection spectrums for the visible are measured. These results show that it is possible to obtain unexpected reflection effects. A rich variety of color spectra can be generated, which is not possible with a single grating. This can be explained by the coupling of transmission of grating orders and the Bragg reflection band. A simple model permits to explain some of the spectral vs angular dependence of reflected light.

  11. Magnetic surfaces, thin films, and multilayers

    International Nuclear Information System (INIS)

    Parkin, S.S.P.; Renard, J.P.; Shinjo, T.; Zinn, W.

    1992-01-01

    This paper details recent developments in the magnetism of surfaces, thin films and multilayers. More than 20 invited contributions and more than 60 contributed papers attest to the great interest and vitality of this subject. In recent years the study of magnetic surfaces, thin films and multilayers has undergone a renaissance, partly motivated by the development of new growth and characterization techniques, but perhaps more so by the discovery of many exciting new properties, some quite unanticipated. These include, most recently, the discovery of enormous values of magnetoresistance in magnetic multilayers far exceeding those found in magnetic single layer films and the discovery of oscillatory interlayer coupling in transition metal multilayers. These experimental studies have motivated much theoretical work. However these developments are to a large extent powered by materials engineering and our ability to control and understand the growth of thin layers just a few atoms thick. The preparation of single crystal thin film layers and multilayers remains important for many studies, in particular, for properties dependent. These studies obviously require engineering not just a layer thicknesses but of lateral dimensions as well. The properties of such structures are already proving to be a great interest

  12. Limonene inhibits streptococcal biofilm formation by targeting surface-associated virulence factors.

    Science.gov (United States)

    Subramenium, Ganapathy Ashwinkumar; Vijayakumar, Karuppiah; Pandian, Shunmugiah Karutha

    2015-08-01

    The present study explores the efficacy of limonene, a cyclic terpene found in the rind of citrus fruits, for antibiofilm potential against species of the genus Streptococcus, which have been deeply studied worldwide owing to their multiple pathogenic efficacy. Limonene showed a concentration-dependent reduction in the biofilm formation of Streptococcus pyogenes (SF370), with minimal biofilm inhibitory concentration (MBIC) of 400 μg ml - 1. Limonene was found to possess about 75-95 % antibiofilm activity against all the pathogens tested, viz. Streptococcus pyogenes (SF370 and 5 clinical isolates), Streptococcus mutans (UA159) and Streptococcus mitis (ATCC 6249) at 400 μg ml - 1 concentration. Microscopic analysis of biofilm architecture revealed a quantitative breach in biofilm formation. Results of a surface-coating assay suggested that the possible mode of action of limonene could be by inhibiting bacterial adhesion to surfaces, thereby preventing the biofilm formation cascade. Susceptibility of limonene-treated Streptococcus pyogenes to healthy human blood goes in unison with gene expression studies in which the mga gene was found to be downregulated. Anti-cariogenic efficacy of limonene against Streptococcus mutans was confirmed, with inhibition of acid production and downregulation of the vicR gene. Downregulation of the covR, mga and vicR genes, which play a critical role in regulating surface-associated proteins in Streptococcus pyogenes and Streptococcus mutans, respectively, is yet further evidence to show that limonene targets surface-associated proteins. The results of physiological assays and gene expression studies clearly show that the surface-associated antagonistic mechanism of limonene also reduces surface-mediated virulence factors.

  13. Description of surfaces associated with Grassmannian sigma models on Minkowski space

    International Nuclear Information System (INIS)

    Grundland, A.M.; Snobl, L.

    2005-01-01

    We construct and investigate smooth orientable surfaces in su(N) algebras. The structural equations of surfaces associated with Grassmannian sigma models on Minkowski space are studied using moving frames adapted to the surfaces. The first and second fundamental forms of these surfaces as well as the relations between them as expressed in the Gauss-Weingarten and Gauss-Codazzi-Ricci equations are found. The scalar curvature and the mean curvature vector expressed in terms of a solution of Grassmanian sigma model are obtained

  14. Multilayer cladding with hyperbolic dispersion for plasmonic waveguides

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi

    2015-01-01

    We study the properties of plasmonic waveguides with a dielectric core and multilayer metal-dielectric claddings that possess hyperbolic dispersion. The waveguides hyperbolic multilayer claddings show better performance in comparison to conventional plasmonic waveguides. © OSA 2015....

  15. Multilayer Integrated Film Bulk Acoustic Resonators

    CERN Document Server

    Zhang, Yafei

    2013-01-01

    Multilayer Integrated Film Bulk Acoustic Resonators mainly introduces the theory, design, fabrication technology and application of a recently developed new type of device, multilayer integrated film bulk acoustic resonators, at the micro and nano scale involving microelectronic devices, integrated circuits, optical devices, sensors and actuators, acoustic resonators, micro-nano manufacturing, multilayer integration, device theory and design principles, etc. These devices can work at very high frequencies by using the newly developed theory, design, and fabrication technology of nano and micro devices. Readers in fields of IC, electronic devices, sensors, materials, and films etc. will benefit from this book by learning the detailed fundamentals and potential applications of these advanced devices. Prof. Yafei Zhang is the director of the Ministry of Education’s Key Laboratory for Thin Films and Microfabrication Technology, PRC; Dr. Da Chen was a PhD student in Prof. Yafei Zhang’s research group.

  16. Exchange interactions in Fe/Y multilayers

    International Nuclear Information System (INIS)

    Elkabil, R.; Elkaidi, I.; Annouar, F.; Lassri, H.; Hamdoun, A.; Bensassi, B.; Berrada, A.; Krishnan, R.

    2005-01-01

    The magnetization of Fe/Y multilayers has been measured as a function of temperature. A bulk-like T 3/2 temperature dependence of the magnetization is observed for all multilayers in the temperature range 5-300 K. The spin-wave constant B is found to decrease inversely with t Fe . A simple theoretical model with exchange interactions only, and with non-interacting magnons, has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction J b , surface exchange interaction J s and the interlayer exchange interaction J I for various Fe layer thicknesses have been obtained

  17. Measure of Node Similarity in Multilayer Networks

    DEFF Research Database (Denmark)

    Møllgaard, Anders; Zettler, Ingo; Dammeyer, Jesper

    2016-01-01

    university.Our analysis is based on data obtained using smartphones equipped with customdata collection software, complemented by questionnaire-based data. The networkof social contacts is represented as a weighted multilayer network constructedfrom different channels of telecommunication as well as data...... might bepresent in one layer of the multilayer network and simultaneously be absent inthe other layers. For a variable such as gender, our measure reveals atransition from similarity between nodes connected with links of relatively lowweight to dis-similarity for the nodes connected by the strongest...

  18. Piezoelectric multilayer actuator life test.

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Jones, Christopher M; Aldrich, Jack B; Blodget, Chad J; Moore, James D; Carson, John W; Goullioud, Renaud

    2011-04-01

    Potential NASA optical missions such as the Space Interferometer Mission require actuators for precision positioning to accuracies of the order of nanometers. Commercially available multilayer piezoelectric stack actuators are being considered for driving these precision mirror positioning mechanisms. These mechanisms have potential mission operational requirements that exceed 5 years for one mission life. To test the feasibility of using these commercial actuators for these applications and to determine their reliability and the redundancy requirements, a life test study was undertaken. The nominal actuator requirements for the most critical actuators on the Space Interferometry Mission (SIM) in terms of number of cycles was estimated from the Modulation Optics Mechanism (MOM) and Pathlength control Optics Mechanism (POM) and these requirements were used to define the study. At a nominal drive frequency of 250 Hz, one mission life is calculated to be 40 billion cycles. In this study, a set of commercial PZT stacks configured in a potential flight actuator configuration (pre-stressed to 18 MPa and bonded in flexures) were tested for up to 100 billion cycles. Each test flexure allowed for two sets of primary and redundant stacks to be mechanically connected in series. The tests were controlled using an automated software control and data acquisition system that set up the test parameters and monitored the waveform of the stack electrical current and voltage. The samples were driven between 0 and 20 V at 2000 Hz to accelerate the life test and mimic the voltage amplitude that is expected to be applied to the stacks during operation. During the life test, 10 primary stacks were driven and 10 redundant stacks, mechanically in series with the driven stacks, were open-circuited. The stroke determined from a strain gauge, the temperature and humidity in the chamber, and the temperature of each individual stack were recorded. Other properties of the stacks, including the

  19. 75 FR 79019 - Multilayered Wood Flooring From China

    Science.gov (United States)

    2010-12-17

    ...)] Multilayered Wood Flooring From China Determinations On the basis of the record \\1\\ developed in the subject... imports from China of multilayered wood flooring, provided for in subheadings 4409.10, 4409.29, 4412.31... multilayered wood flooring. The following companies are members of the CAHP: Anderson Hardwood Floors, LLC...

  20. Cloud computing and Reservoir project

    International Nuclear Information System (INIS)

    Beco, S.; Maraschini, A.; Pacini, F.; Biran, O.

    2009-01-01

    The support for complex services delivery is becoming a key point in current internet technology. Current trends in internet applications are characterized by on demand delivery of ever growing amounts of content. The future internet of services will have to deliver content intensive applications to users with quality of service and security guarantees. This paper describes the Reservoir project and the challenge of a reliable and effective delivery of services as utilities in a commercial scenario. It starts by analyzing the needs of a future infrastructure provider and introducing the key concept of a service oriented architecture that combines virtualisation-aware grid with grid-aware virtualisation, while being driven by business service management. This article will then focus on the benefits and the innovations derived from the Reservoir approach. Eventually, a high level view of Reservoir general architecture is illustrated.

  1. Multilevel techniques for Reservoir Simulation

    DEFF Research Database (Denmark)

    Christensen, Max la Cour

    The subject of this thesis is the development, application and study of novel multilevel methods for the acceleration and improvement of reservoir simulation techniques. The motivation for addressing this topic is a need for more accurate predictions of porous media flow and the ability to carry...... Full Approximation Scheme) • Variational (Galerkin) upscaling • Linear solvers and preconditioners First, a nonlinear multigrid scheme in the form of the Full Approximation Scheme (FAS) is implemented and studied for a 3D three-phase compressible rock/fluids immiscible reservoir simulator...... is extended to include a hybrid strategy, where FAS is combined with Newton’s method to construct a multilevel nonlinear preconditioner. This method demonstrates high efficiency and robustness. Second, an improved IMPES formulated reservoir simulator is implemented using a novel variational upscaling approach...

  2. Reservoir effects in radiocarbon dating

    International Nuclear Information System (INIS)

    Head, M.J.

    1997-01-01

    Full text: The radiocarbon dating technique depends essentially on the assumption that atmospheric carbon dioxide containing the cosmogenic radioisotope 14 C enters into a state of equilibrium with all living material (plants and animals) as part of the terrestrial carbon cycle. Terrestrial reservoir effects occur when the atmospheric 14 C signal is diluted by local effects where systems depleted in 14 C mix with systems that are in equilibrium with the atmosphere. Naturally, this can occur with plant material growing close to an active volcano adding very old CO 2 to the atmosphere (the original 14 C has completely decayed). It can also occur in highly industrialised areas where fossil fuel derived CO 2 dilutes the atmospheric signal. A terrestrial reservoir effect can occur in the case of fresh water shells living in rivers or lakes where there is an input of ground water from springs or a raising of the water table. Soluble bicarbonate derived from the dissolution of very old limestone produces a 14 C dilution effect. Land snail shells and stream carbonate depositions (tufas and travertines) can be affected by a similar mechanism. Alternatively, in specific cases, these reservoir effects may not occur. This means that general interpretations assuming quantitative values for these terrestrial effects are not possible. Each microenvironment associated with samples being analysed needs to be evaluated independently. Similarly, the marine environment produces reservoir effects. With respect to marine shells and corals, the water depth at which carbonate growth occurs can significantly affect quantitative 14 C dilution, especially in areas where very old water is uplifted, mixing with top layers of water that undergo significant exchange with atmospheric CO 2 . Hence, generalisations with respect to the marine reservoir effect also pose problems. These can be exacerbated by the mixing of sea water with either terrestrial water in estuaries, or ground water where

  3. Study on fine geological modelling of the fluvial sandstone reservoir in Daqing oilfield

    Energy Technology Data Exchange (ETDEWEB)

    Zhoa Han-Qing [Daqing Research Institute, Helongjiang (China)

    1997-08-01

    These paper aims at developing a method for fine reservoir description in maturing oilfields by using close spaced well logging data. The main productive reservoirs in Daqing oilfield is a set of large fluvial-deltaic deposits in the Songliao Lake Basin, characterized by multi-layers and serious heterogeneities. Various fluvial channel sandstone reservoirs cover a fairly important proportion of reserves. After a long period of water flooding, most of them have turned into high water cut layers, but there are considerable residual reserves within them, which are difficult to find and tap. Making fine reservoir description and developing sound a geological model is essential for tapping residual oil and enhancing oil recovery. The principal reason for relative lower precision of predicting model developed by using geostatistics is incomplete recognition of complex distribution of fluvial reservoirs and their internal architecture`s. Tasking advantage of limited outcrop data from other regions (suppose no outcrop data available in oilfield) can only provide the knowledge of subtle changing of reservoir parameters and internal architecture. For the specific geometry distribution and internal architecture of subsurface reservoirs (such as in produced regions) can be gained only from continuous infilling logging well data available from studied areas. For developing a geological model, we think the first important thing is to characterize sandbodies geometries and their general architecture`s, which are the framework of models, and then the slight changing of interwell parameters and internal architecture`s, which are the contents and cells of the model. An excellent model should possess both of them, but the geometry is the key to model, because it controls the contents and cells distribution within a model.

  4. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    Energy Technology Data Exchange (ETDEWEB)

    P. K. Pande

    1998-10-29

    Initial drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. These reservoirs are typically characterized by: o Large, discontinuous pay intervals o Vertical and lateral changes in reservoir properties o Low reservoir energy o High residual oil saturation o Low recovery efficiency

  5. Sedimentological and Geomorphological Effects of Reservoir Flushing: The Cachi Reservoir, Costa Rica, 1996

    DEFF Research Database (Denmark)

    Brandt, Anders; Swenning, Joar

    1999-01-01

    Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs......Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs...

  6. Guided wave sensing of polyelectrolyte multilayers

    DEFF Research Database (Denmark)

    Horvath, R.; Pedersen, H.C.; Cuisinier, F.J.G.

    2006-01-01

    A planar optical waveguide configuration is proposed to monitor the buildup of thick polyelectrolyte multilayers on the surface of the waveguide in aqueous solutions. Instead of detecting the layer by the electromagnetic evanescent field the polyelectrolyte layer acts as an additional waveguiding...

  7. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...... to the recently derived plasma resonance phenomena for high T-c superconductors of the BSCCO type is discussed....

  8. Study of thermal conductivity of multilayer insulation

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, D; Sundaram, S; Nath, G K; Sethuram, N P; Chandrasekharan, T; Varadarajan, T G [Heavy Water Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author). 3 refs., 3 figs.

  9. The visco-elastic multilayer program VEROAD

    NARCIS (Netherlands)

    Hopman, P.C.

    1996-01-01

    The mathematical principles and derivation of a linear visco-elastic multilayer computer program are described. The mathematical derivation is based on Fourier Transformation. The program is called VEROAD, which is an acronym for Visco-Elastic ROad Analysis Delft. The program allows calculation of

  10. Transmission fingerprints in quasiperiodic magnonic multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, I.P. [Departamento de Ensino Superior, Instituto Federal de Educacao, Ciencia e Tecnologia do Maranhao, Imperatriz-MA 65919-050 (Brazil); Departamento de Fisica, Universidade Federal do Rio Grande do Norte, Natal-RN 59072-970 (Brazil); Vasconcelos, M.S. [Escola de Ciencias e Tecnologia, Universidade Federal do Rio Grande do Norte, Natal-RN 59072-970 (Brazil); Bezerra, C.G., E-mail: cbezerra@dfte.ufrn.br [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, Natal-RN 59072-970 (Brazil)

    2011-12-15

    In this paper we investigated the influence of mirror symmetry on the transmission spectra of quasiperiodic magnonic multilayers arranged according to Fibonacci, Thue-Morse and double period quasiperiodic sequences. We consider that the multilayers composed of two simple cubic Heisenberg ferromagnets with bulk exchange constants J{sub A} and J{sub B} and spin quantum numbers S{sub A} and S{sub B}, respectively. The multilayer structure is surrounded by two semi-infinite slabs of a third Heisenberg ferromagnetic material with exchange constant J{sub C} and spin quantum number S{sub C}. For simplicity, the lattice constant has the same value a in each material, corresponding to epitaxial growth at the interfaces. The transfer matrix treatment was used for the exchange-dominated regime, taking into account the random phase approximation (RPA). Our numerical results illustrate the effects of mirror symmetry on (i) transmission spectra and (ii) transmission fingerprints. - Highlights: > We model quasiperiodic magnetic multilayers presenting mirror symmetry. > We investigated the allowed and forbidden bands of magnonic transmission. > Transmission return maps show the influence of mirror symmetry. > Mirror symmetry has no effect on the Fibonacci case. > Mirror symmetry does have effect on the Thue-Morse and double period cases.

  11. Transmission fingerprints in quasiperiodic magnonic multilayers

    International Nuclear Information System (INIS)

    Coelho, I.P.; Vasconcelos, M.S.; Bezerra, C.G.

    2011-01-01

    In this paper we investigated the influence of mirror symmetry on the transmission spectra of quasiperiodic magnonic multilayers arranged according to Fibonacci, Thue-Morse and double period quasiperiodic sequences. We consider that the multilayers composed of two simple cubic Heisenberg ferromagnets with bulk exchange constants J A and J B and spin quantum numbers S A and S B , respectively. The multilayer structure is surrounded by two semi-infinite slabs of a third Heisenberg ferromagnetic material with exchange constant J C and spin quantum number S C . For simplicity, the lattice constant has the same value a in each material, corresponding to epitaxial growth at the interfaces. The transfer matrix treatment was used for the exchange-dominated regime, taking into account the random phase approximation (RPA). Our numerical results illustrate the effects of mirror symmetry on (i) transmission spectra and (ii) transmission fingerprints. - Highlights: → We model quasiperiodic magnetic multilayers presenting mirror symmetry. → We investigated the allowed and forbidden bands of magnonic transmission. → Transmission return maps show the influence of mirror symmetry. → Mirror symmetry has no effect on the Fibonacci case. → Mirror symmetry does have effect on the Thue-Morse and double period cases.

  12. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sakai, S

    1998-01-01

    We derive an analytical solution for the Josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low-T-c systems with magnetic coupling between the superconducting layers. but many features of our results are more general, and thus an application...

  13. Multilayer Network Planning - A Practical Perspective

    OpenAIRE

    Autenrieth, Achim

    2018-01-01

    The paper presents a pragmatic and practical multilayer network planning approach based on a candidate lightpath auxiliary graph model. The paper discusses, how this approach can be applied to offline network planning as well as dynamic planning and provisioning of services.

  14. Multilayer scaffolds in orthopaedic tissue engineering.

    Science.gov (United States)

    Atesok, Kivanc; Doral, M Nedim; Karlsson, Jon; Egol, Kenneth A; Jazrawi, Laith M; Coelho, Paulo G; Martinez, Amaury; Matsumoto, Tomoyuki; Owens, Brett D; Ochi, Mitsuo; Hurwitz, Shepard R; Atala, Anthony; Fu, Freddie H; Lu, Helen H; Rodeo, Scott A

    2016-07-01

    The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration. Clinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces. In vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications. Present data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

  15. Study of thermal conductivity of multilayer insulation

    International Nuclear Information System (INIS)

    Dutta, D.; Sundaram, S.; Nath, G.K.; Sethuram, N.P.; Chandrasekharan, T.; Varadarajan, T.G.

    1994-01-01

    This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author)

  16. Optical and structural study of BST multilayers

    Czech Academy of Sciences Publication Activity Database

    Železný, Vladimír; Chvostová, Dagmar; Pajasová, Libuše; Jelínek, Miroslav; Kocourek, Tomáš; Daniš, S.; Valvoda, V.

    2010-01-01

    Roč. 12, č. 3 (2010), 538-541 ISSN 1454-4164 R&D Projects: GA ČR GA202/07/0591 Institutional research plan: CEZ:AV0Z10100522; CEZ:AV0Z10100520 Keywords : ellipsometry * structure * ferroelectric multilayers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

  17. Stimulation and reservoir engineering of geothermal resources. Second annual report, July 1, 1978-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Ramey, H.J. Jr.

    1979-09-01

    Individual projects are grouped under four main areas of study: energy extraction, bench-scale flow experiments, radon tracer techniques, and well test analysis. The energy extraction experiments concern the efficiency with which the in-place heat and fluids can be produced in the most economical manner. The bench-scale flow experiments cover the results of three models used to examine the properties of flow through porous media at elevated temperature and pressures. Random tracer techniques describe accelerated efforts to field test several geothermal reservoirs by both transient and transect test procedures. The well test analysis section describes several new developments: analysis of earth-tide effects, pressure transient analysis of multilayered systems, interference testing with storage and skin effects, determination of steam-water relative permeability from wellhead data, well test analysis for wells produced at constant pressure, the parallelepiped model, slug test DST analysis, and pressure transient behavior in naturally fractured reservoirs. (MHR)

  18. Prevention of Reservoir Interior Discoloration

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, K.F.

    2001-04-03

    Contamination is anathema in reservoir production. Some of the contamination is a result of welding and some appears after welding but existed before. Oxygen was documented to be a major contributor to discoloration in welding. This study demonstrates that it can be controlled and that some of the informal cleaning processes contribute to contamination.

  19. Nonlinear Multigrid for Reservoir Simulation

    DEFF Research Database (Denmark)

    Christensen, Max la Cour; Eskildsen, Klaus Langgren; Engsig-Karup, Allan Peter

    2016-01-01

    efficiency for a black-oil model. Furthermore, the use of the FAS method enables a significant reduction in memory usage compared with conventional techniques, which suggests new possibilities for improved large-scale reservoir simulation and numerical efficiency. Last, nonlinear multilevel preconditioning...

  20. Numerical simulation and experiment on multilayer stagger-split die.

    Science.gov (United States)

    Liu, Zhiwei; Li, Mingzhe; Han, Qigang; Yang, Yunfei; Wang, Bolong; Sui, Zhou

    2013-05-01

    A novel ultra-high pressure device, multilayer stagger-split die, has been constructed based on the principle of "dividing dies before cracking." Multilayer stagger-split die includes an encircling ring and multilayer assemblages, and the mating surfaces of the multilayer assemblages are mutually staggered between adjacent layers. In this paper, we investigated the stressing features of this structure through finite element techniques, and the results were compared with those of the belt type die and single split die. The contrast experiments were also carried out to test the bearing pressure performance of multilayer stagger-split die. It is concluded that the stress distributions are reasonable and the materials are utilized effectively for multilayer stagger-split die. And experiments indicate that the multilayer stagger-split die can bear the greatest pressure.

  1. Oligo-Miocene reservoir sequence characterization and structuring in the Sisseb El Alem-Kalaa Kebira regions (Northeastern Tunisia)

    Science.gov (United States)

    Houatmia, Faten; Khomsi, Sami; Bédir, Mourad

    2015-11-01

    The Sisseb El Alem-Enfidha basin is located in the northeastern Tunisia, It is borded by Nadhour - Saouaf syncline to the north, Kairouan plain to the south, the Mediterranean Sea to the east and Tunisian Atlassic "dorsale" to the west. Oligocene and Miocene deltaic deposits present the main potential deep aquifers in this basin with high porosity (25%-30%). The interpretation of twenty seismic reflection profiles, calibrated by wire line logging data of twelve oil wells, hydraulic wells and geologic field sections highlighted the impact of tectonics on the structuring geometry of Oligo-Miocene sandstones reservoirs and their distribution in raised structures and subsurface depressions. Miocene seismostratigraphy analysis from Ain Ghrab Formation (Langhian) to the Segui Formation (Quaternary) showed five third-order seismic sequence deposits and nine extended lenticular sandy bodies reservoirs limited by toplap and downlap surfaces unconformities, Oligocene deposits presented also five third- order seismic sequences with five extended lenticular sandy bodies reservoirs. The Depth and the thickness maps of these sequence reservoir packages exhibited the structuring of this basin in sub-basins characterized by important lateral and vertical geometric and thichness variations. Petroleum wells wire line logging correlation with clay volume calculation showed an heterogeneous multilayer reservoirs of Oligocene and Miocene formed by the arrangement of fourteen sandstone bodies being able to be good reservoirs, separated by impermeable clay packages and affected by faults. Reservoirs levels correspond mainly to the lower system tract (LST) of sequences. Intensive fracturing by deep seated faults bounding the different sub-basins play a great role for water surface recharge and inter-layer circulations between affected reservoirs. The total pore volume of the Oligo-Miocene reservoir sandy bodies in the study area, is estimated to about 4 × 1012 m3 and equivalent to 4

  2. 49 CFR 236.792 - Reservoir, equalizing.

    Science.gov (United States)

    2010-10-01

    ... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of the equalizing piston chamber of the automatic brake valve, to provide uniform service reductions in brake pipe...

  3. RECENT ADVANCES IN NATURALLY FRACTURED RESERVOIR MODELING

    OpenAIRE

    ORDOÑEZ, A; PEÑUELA, G; IDROBO, E. A; MEDINA, C. E

    2001-01-01

    Large amounts of oil reserves are contained in naturally fractured reservoirs. Most of these hydrocarbon volumes have been left behind because of the poor knowledge and/or description methodology of those reservoirs. This lack of knowledge has lead to the nonexistence of good quantitative models for this complicated type of reservoirs. The complexity of naturally fractured reservoirs causes the need for integration of all existing information at all scales (drilling, well logging, seismic, we...

  4. Reservoir resistivity characterization incorporating flow dynamics

    KAUST Repository

    Arango, Santiago; Sun, Shuyu; Hoteit, Ibrahim; Katterbauer, Klemens

    2016-01-01

    Systems and methods for reservoir resistivity characterization are provided, in various aspects, an integrated framework for the estimation of Archie's parameters for a strongly heterogeneous reservoir utilizing the dynamics of the reservoir are provided. The framework can encompass a Bayesian estimation/inversion method for estimating the reservoir parameters, integrating production and time lapse formation conductivity data to achieve a better understanding of the subsurface rock conductivity properties and hence improve water saturation imaging.

  5. Reservoir resistivity characterization incorporating flow dynamics

    KAUST Repository

    Arango, Santiago

    2016-04-07

    Systems and methods for reservoir resistivity characterization are provided, in various aspects, an integrated framework for the estimation of Archie\\'s parameters for a strongly heterogeneous reservoir utilizing the dynamics of the reservoir are provided. The framework can encompass a Bayesian estimation/inversion method for estimating the reservoir parameters, integrating production and time lapse formation conductivity data to achieve a better understanding of the subsurface rock conductivity properties and hence improve water saturation imaging.

  6. Tenth workshop on geothermal reservoir engineering: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  7. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Nurhandoko, Bagus Endar B., E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4" t" hfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia); Susilowati, E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Rock Fluid Imaging Lab., Bandung (Indonesia)

    2015-04-16

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia.

  8. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    International Nuclear Information System (INIS)

    thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" data-affiliation=" (Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" >Nurhandoko, Bagus Endar B.; Susilowati

    2015-01-01

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia

  9. 4. International reservoir characterization technical conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This volume contains the Proceedings of the Fourth International Reservoir Characterization Technical Conference held March 2-4, 1997 in Houston, Texas. The theme for the conference was Advances in Reservoir Characterization for Effective Reservoir Management. On March 2, 1997, the DOE Class Workshop kicked off with tutorials by Dr. Steve Begg (BP Exploration) and Dr. Ganesh Thakur (Chevron). Tutorial presentations are not included in these Proceedings but may be available from the authors. The conference consisted of the following topics: data acquisition; reservoir modeling; scaling reservoir properties; and managing uncertainty. Selected papers have been processed separately for inclusion in the Energy Science and Technology database.

  10. Measure of Node Similarity in Multilayer Networks

    DEFF Research Database (Denmark)

    Møllgaard, Anders; Zettler, Ingo; Dammeyer, Jesper

    2016-01-01

    The weight of links in a network is often related to the similarity of thenodes. Here, we introduce a simple tunable measure for analysing the similarityof nodes across different link weights. In particular, we use the measure toanalyze homophily in a group of 659 freshman students at a large...... university.Our analysis is based on data obtained using smartphones equipped with customdata collection software, complemented by questionnaire-based data. The networkof social contacts is represented as a weighted multilayer network constructedfrom different channels of telecommunication as well as data...... might bepresent in one layer of the multilayer network and simultaneously be absent inthe other layers. For a variable such as gender, our measure reveals atransition from similarity between nodes connected with links of relatively lowweight to dis-similarity for the nodes connected by the strongest...

  11. Topological edge modes in multilayer graphene systems

    KAUST Repository

    Ge, Lixin

    2015-08-10

    Plasmons can be supported on graphene sheets as the Dirac electrons oscillate collectively. A tight-binding model for graphene plasmons is a good description as the field confinement in the normal direction is strong. With this model, the topological properties of plasmonic bands in multilayer graphene systems are investigated. The Zak phases of periodic graphene sheet arrays are obtained for different configurations. Analogous to Su-Schrieffer-Heeger (SSH) model in electronic systems, topological edge plasmon modes emerge when two periodic graphene sheet arrays with different Zak phases are connected. Interestingly, the dispersion of these topological edge modes is the same as that in the monolayer graphene and is invariant as the geometric parameters of the structure such as the separation and period change. These plasmonic edge states in multilayer graphene systems can be further tuned by electrical gating or chemical doping. © 2015 Optical Society of America.

  12. Nanosecond Surface Microdischarges in Multilayer Structures

    Science.gov (United States)

    Dubinov, A. E.; Lyubimtseva, V. A.

    2018-05-01

    Multilayer structures in which nanosecond surface microdischarges are generated have been developed, fabricated, and investigated. In these structures, layers are made in the form of thin transparent films, and a plasma discharge channel is formed in thin spacings between the layers. Passage of the discharge channel from one layer into the neighboring layer is implemented via pre-fabricated microholes. Images of microdischarges were obtained which confirmed that their plasma channels are formed according to the route assigned by the holes. The route may follow a fairly complex scheme and have self-intersection points and portions in which the electrons are bound to move in opposition to the electric field. In studying the shape of channels in multilayer strictures, the authors have found a new physical effect which lies in the azimuthal self-orientation of the discharge channel as it passes from one microhole to another.

  13. KLASIFIKASI WEBSITE MENGGUNAKAN ALGORITMA MULTILAYER PERCEPTRON

    Directory of Open Access Journals (Sweden)

    Nyoman Purnama

    2014-12-01

    Full Text Available Sistem klasifikasi merupakan proses temu balik informasi yang sangat bergantung dari elemen-elemen penyusunnya.Sistem ini banyak digunakan untuk mengatasi permasalahan segmentasi data. Klasifikasi dapat digunakan pada website sebagaimetode untuk mengelompokkan website. Website merupakan salah satu data yang memiliki informasi yang beraneka-ragam,sehingga pengelompokan data ini penting untuk diteliti. Sistem klasifikasi dimulai dengan melakukan proses pengumpulaninformasi dari halaman website (parsing dan untuk setiap hasil parsing dilakukan proses penghapusan kata henti, stemming,feature selection dengan tf-idf. Hasil dari proses ini berupa fitur yang menjadi inputan algoritma Multilayer Perceptron. Dalamalgoritma ini terjadi proses pembelajaran terhadap pola input masukan dan pembuatan bobot pelatihan. Bobot ini akandigunakan pada proses klasifikasi. Hasil dari penelitian menunjukkan bahwa algoritma Multilayer Perceptron dapatmenghasilkan klasifikasi website dengan akurasi yang bagus. Hal ini dibuktikan dengan beberapa tahapan penelitian yangberbeda dan didapatkan nilai akurasi rata-rata diatas 70%.

  14. MIKROMITSETY- MIGRANTS IN MINGECHEVIR RESERVOIR

    Directory of Open Access Journals (Sweden)

    M. A. Salmanov

    2017-01-01

    Full Text Available Aim. It is hardly possible to predict the continued stability of the watercourse ecosystems without the study of biological characteristics and composition of organisms inhabiting them. In the last 35-40 years, environmental conditions of the Mingachevir reservoir are determined by the stationary anthropogenic pressure. It was found that such components of plankton as algae, bacteria and fungi play a leading role in the transformation and migration of pollutants. The role of the three groups of organisms is very important in maintaining the water quality by elimination of pollutants. Among the organisms inhabiting the Mingachevir Reservoir, micromycetes have not yet been studied. Therefore, the study of the species composition and seasonal dynamics, peculiarities of their growth and development in the environment with the presence of some of the pollutants should be considered to date.Methods. In order to determine the role of micromycetes-migrants in the mineralization of organic substrates, as an active participant of self-purification process, we used water samples from the bottom sediments as well as decaying and skeletonized stalks of cane, reeds, algae, macrophytes, exuvia of insects and fish remains submerged in water.Findings. For the first time, we obtained the data on the quality and quantity of microscopic mycelial fungi in freshwater bodies on the example of the Mingachevir water reservoir; we also studied the possibilities for oxygenating the autochthonous organic matter of allochthonous origin with micromycetes-migrants.Conclusions. It was found that the seasonal development of micromycetes-migrants within the Mingachevir reservoir is characterized by an increase in the number of species in the summer and a gradual reduction in species diversity in the fall. 

  15. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  16. Williston Reservoir raising - environmental overview

    Energy Technology Data Exchange (ETDEWEB)

    1988-07-01

    This preliminary environmental overview report was prepared by B.C. Hydro in June 1987 and revised in July 1988 as an initial assessment of a possible 1.5 m (5 ft.) raise in the Williston Reservoir maximum normal level. The enviromental overview study and the associated engineering and property studies were undertaken to provide information for a decision on whether to initiate more detailed studies. Overview studies are based mainly on available reports, mapping and field data, supplemented by limited site reconnaissance and, in this case, input from key agencies and groups. The lack of adequate mapping of areas which could be affected by reservoir raising did not permit definitive conclusion to be reached. This mapping will be done over the next year to complete the overview assessment. This document covers the impact assessment of socio-economic factors, forestry, reservoir clearing, heritage, recreation, aquatic resources, and wilflife. Further studies in each of these areas are also included. 54 refs., 11 figs., 8 tabs.

  17. Analysis of Fracture Behaviour of Multilayer Pipes

    Czech Academy of Sciences Publication Activity Database

    Nezbedová, E.; Knésl, Zdeněk; Vlach, B.

    2007-01-01

    Roč. 36, č. 5 (2007), s. 207-212 ISSN 1465-8011. [Plastic Pipes /13./. Washington, D. C., 02.10.2006-05.10.2006] R&D Projects: GA ČR GA106/07/1284 Institutional research plan: CEZ:AV0Z20410507 Keywords : multi-layer pipes Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.431, year: 2007

  18. Training trajectories by continuous recurrent multilayer networks.

    Science.gov (United States)

    Leistritz, L; Galicki, M; Witte, H; Kochs, E

    2002-01-01

    This paper addresses the problem of training trajectories by means of continuous recurrent neural networks whose feedforward parts are multilayer perceptrons. Such networks can approximate a general nonlinear dynamic system with arbitrary accuracy. The learning process is transformed into an optimal control framework where the weights are the controls to be determined. A training algorithm based upon a variational formulation of Pontryagin's maximum principle is proposed for such networks. Computer examples demonstrating the efficiency of the given approach are also presented.

  19. Process of obtaining the multilayer structure

    International Nuclear Information System (INIS)

    Buzdugan, A.; Dolghieru, V.; Jitari, V.; Colomeico, E.; Popescu, A.

    1997-01-01

    The invention relates to the multilayer structures of glassy semiconductors with the refractive index abrupt and smooth variation at the bound between the layers and may be used for manufacturing the optical information transmission and recording media. With a view to simplify the technology, compositionally different layers of chalcogenide glassy semiconductors having various refractive indexes from As 2 S 3 , are being by thermal vacuum evaporation, changing the vaporization temperature thereof from 120 to 280 C

  20. Quaternionic Multilayer Perceptron with Local Analyticity

    Directory of Open Access Journals (Sweden)

    Nobuyuki Matsui

    2012-11-01

    Full Text Available A multi-layered perceptron type neural network is presented and analyzed in this paper. All neuronal parameters such as input, output, action potential and connection weight are encoded by quaternions, which are a class of hypercomplex number system. Local analytic condition is imposed on the activation function in updating neurons’ states in order to construct learning algorithm for this network. An error back-propagation algorithm is introduced for modifying the connection weights of the network.

  1. Thermoelastoplastic Deformation of a Multilayer Ball

    Science.gov (United States)

    Murashkin, E. V.; Dats, E. P.

    2017-09-01

    The problem of centrally symmetric deformation of a multilayer elastoplastic ball in the process of successive accretion of preheated layers to its outer surface is considered in the framework of small elastoplastic deformations. The problems of residual stress formation in the elastoplastic ball with an inclusion and a cavity are solved under various mechanical boundary conditions on the inner surface and for prescribed thermal compression distributions. The graphs of residual stress and displacement fields are constructed.

  2. Reservoir floodplains support distinct fish assemblages

    Science.gov (United States)

    Miranda, Leandro E.; Wigen, S. L.; Dagel, Jonah D.

    2014-01-01

    Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  3. The role of reservoir characterization in the reservoir management process (as reflected in the Department of Energy`s reservoir management demonstration program)

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, M.L. [BDM-Petroleum Technologies, Bartlesville, OK (United States); Young, M.A.; Madden, M.P. [BDM-Oklahoma, Bartlesville, OK (United States)] [and others

    1997-08-01

    Optimum reservoir recovery and profitability result from guidance of reservoir practices provided by an effective reservoir management plan. Success in developing the best, most appropriate reservoir management plan requires knowledge and consideration of (1) the reservoir system including rocks, and rock-fluid interactions (i.e., a characterization of the reservoir) as well as wellbores and associated equipment and surface facilities; (2) the technologies available to describe, analyze, and exploit the reservoir; and (3) the business environment under which the plan will be developed and implemented. Reservoir characterization is the essential to gain needed knowledge of the reservoir for reservoir management plan building. Reservoir characterization efforts can be appropriately scaled by considering the reservoir management context under which the plan is being built. Reservoir management plans de-optimize with time as technology and the business environment change or as new reservoir information indicates the reservoir characterization models on which the current plan is based are inadequate. BDM-Oklahoma and the Department of Energy have implemented a program of reservoir management demonstrations to encourage operators with limited resources and experience to learn, implement, and disperse sound reservoir management techniques through cooperative research and development projects whose objectives are to develop reservoir management plans. In each of the three projects currently underway, careful attention to reservoir management context assures a reservoir characterization approach that is sufficient, but not in excess of what is necessary, to devise and implement an effective reservoir management plan.

  4. Conductivity Evolution of Fracture Proppant in Partial Monolayers and Multilayers

    Science.gov (United States)

    Fan, M.; Han, Y.; McClure, J. E.; Chen, C.

    2017-12-01

    Proppant is a granular material, typically sand, coated sand, or man-made ceramic materials, which is widely used in hydraulic fracturing to keep the induced fractures open. Optimization of proppant placement in a hydraulic fracture, as well as its role on the fracture's conductivity, is vital for effective and economical production of petroleum hydrocarbons. In this research, a numerical modeling approach, combining Discrete Element Method (DEM) with lattice Boltzmann (LB) method, was adopted to advance the understanding of fracture conductivity as function of proppant concentration under various effective stresses. DEM was used to simulate effective stress increase and the resultant proppant particle compaction and rearrangement during the process of reservoir depletion due to hydrocarbon extraction. DEM-simulated pore structure was extracted and imported into the LB simulator as boundary conditions to calculate the time-dependent permeability of the proppant pack. We first validated the DEM-LB coupling workflow; the simulated proppant pack permeabilities as functions of effective stress were in good agreement with laboratory measurements. Next, several proppant packs were generated with various proppant concentrations, ranging from partial-monolayer to multilayer structures. Proppant concentration is defined as proppant mass per unit fracture face area. Fracture conductivity as function of proppant concentration was measured in LB simulations. It was found that a partial-monolayer proppant pack with large-diameter particles was optimal in maintaining sufficient conductivity while lowering production costs. Three proppant packs with the same average diameter but different diameter distributions were generated. Specifically, we used the coefficient of variation (COV) of diameter, defined as the ratio of standard deviation of diameter to mean diameter, to characterize the heterogeneity in particle size. We obtained proppant pack porosity, permeability, and fracture

  5. Automation Enhancement of Multilayer Laue Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Lauer K. R.; Conley R.

    2010-12-01

    X-ray optics fabrication at Brookhaven National Laboratory has been facilitated by a new, state of the art magnetron sputtering physical deposition system. With its nine magnetron sputtering cathodes and substrate carrier that moves on a linear rail via a UHV brushless linear servo motor, the system is capable of accurately depositing the many thousands of layers necessary for multilayer Laue lenses. I have engineered a versatile and automated control program from scratch for the base system and many subsystems. Its main features include a custom scripting language, a fully customizable graphical user interface, wireless and remote control, and a terminal-based interface. This control system has already been successfully used in the creation of many types of x-ray optics, including several thousand layer multilayer Laue lenses.Before reaching the point at which a deposition can be run, stencil-like masks for the sputtering cathodes must be created to ensure the proper distribution of sputtered atoms. Quality of multilayer Laue lenses can also be difficult to measure, given the size of the thin film layers. I employ my knowledge of software and algorithms to further ease these previously painstaking processes with custom programs. Additionally, I will give an overview of an x-ray optic simulator package I helped develop during the summer of 2010. In the interest of keeping my software free and open, I have worked mostly with the multiplatform Python and the PyQt application framework, utilizing C and C++ where necessary.

  6. Symmetric scrolled packings of multilayered carbon nanoribbons

    Science.gov (United States)

    Savin, A. V.; Korznikova, E. A.; Lobzenko, I. P.; Baimova, Yu. A.; Dmitriev, S. V.

    2016-06-01

    Scrolled packings of single-layer and multilayer graphene can be used for the creation of supercapacitors, nanopumps, nanofilters, and other nanodevices. The full atomistic simulation of graphene scrolls is restricted to consideration of relatively small systems in small time intervals. To overcome this difficulty, a two-dimensional chain model making possible an efficient calculation of static and dynamic characteristics of nanoribbon scrolls with allowance for the longitudinal and bending stiffness of nanoribbons is proposed. The model is extended to the case of scrolls of multilayer graphene. Possible equilibrium states of symmetric scrolls of multilayer carbon nanotribbons rolled up so that all nanoribbons in the scroll are equivalent are found. Dependences of the number of coils, the inner and outer radii, lowest vibrational eigenfrequencies of rolled packages on the length L of nanoribbons are obtained. It is shown that the lowest vibrational eigenfrequency of a symmetric scroll decreases with a nanoribbon length proportionally to L -1. It is energetically unfavorable for too short nanoribbons to roll up, and their ground state is a stack of plane nanoribbons. With an increasing number k of layers, the nanoribbon length L necessary for creation of symmetric scrolls increases. For a sufficiently small number of layers k and a sufficiently large nanoribbon length L, the scrolled packing has the lowest energy as compared to that of stack of plane nanoribbons and folded structures. The results can be used for development of nanomaterials and nanodevices on the basis of graphene scrolled packings.

  7. Subwavelength resolution from multilayered structure (Conference Presentation)

    Science.gov (United States)

    Cheng, Bo Han; Jen, Yi-Jun; Liu, Wei-Chih; Lin, Shan-wen; Lan, Yung-Chiang; Tsai, Din Ping

    2016-10-01

    Breaking optical diffraction limit is one of the most important issues needed to be overcome for the demand of high-density optoelectronic components. Here, a multilayered structure which consists of alternating semiconductor and dielectric layers for breaking optical diffraction limitation at THz frequency region are proposed and analyzed. We numerically demonstrate that such multilayered structure not only can act as a hyperbolic metamaterial but also a birefringence material via the control of the external temperature (or magnetic field). A practical approach is provided to control all the diffraction signals toward a specific direction by using transfer matrix method and effective medium theory. Numerical calculations and computer simulation (based on finite element method, FEM) are carried out, which agree well with each other. The temperature (or magnetic field) parameter can be tuned to create an effective material with nearly flat isofrequency feature to transfer (project) all the k-space signals excited from the object to be resolved to the image plane. Furthermore, this multilayered structure can resolve subwavelength structures at various incident THz light sources simultaneously. In addition, the resolution power for a fixed operating frequency also can be tuned by only changing the magnitude of external magnetic field. Such a device provides a practical route for multi-functional material, photolithography and real-time super-resolution image.

  8. Multilayer network decoding versatility and trust

    Science.gov (United States)

    Sarkar, Camellia; Yadav, Alok; Jalan, Sarika

    2016-01-01

    In the recent years, the multilayer networks have increasingly been realized as a more realistic framework to understand emergent physical phenomena in complex real-world systems. We analyze massive time-varying social data drawn from the largest film industry of the world under a multilayer network framework. The framework enables us to evaluate the versatility of actors, which turns out to be an intrinsic property of lead actors. Versatility in dimers suggests that working with different types of nodes are more beneficial than with similar ones. However, the triangles yield a different relation between type of co-actor and the success of lead nodes indicating the importance of higher-order motifs in understanding the properties of the underlying system. Furthermore, despite the degree-degree correlations of entire networks being neutral, multilayering picks up different values of correlation indicating positive connotations like trust, in the recent years. The analysis of weak ties of the industry uncovers nodes from a lower-degree regime being important in linking Bollywood clusters. The framework and the tools used herein may be used for unraveling the complexity of other real-world systems.

  9. Multilayer modal actuator-based piezoelectric transformers.

    Science.gov (United States)

    Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung

    2007-02-01

    An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well.

  10. Performance of multilayer coated silicon pore optics

    Science.gov (United States)

    Ackermann, M. D.; Collon, M. J.; Jensen, C. P.; Christensen, F. E.; Krumrey, M.; Cibik, L.; Marggraf, S.; Bavdaz, M.; Lumb, D.; Shortt, B.

    2010-07-01

    The requirements for the IXO (International X-ray Observatory) telescope are very challenging in respect of angular resolution and effective area. Within a clear aperture with 1.7 m > R > 0.25 m that is dictated by the spacecraft envelope, the optics technology must be developed to satisfy simultaneously requirements for effective area of 2.5 m2 at 1.25 keV, 0.65 m2 at 6 keV and 150 cm2 at 30 keV. The reflectivity of the bare mirror substrate materials does not allow these requirements to be met. As such the IXO baseline design contains a coating layout that varies as a function of mirror radius and in accordance with the variation in grazing incidence angle. The higher energy photon response is enhanced through the use of depth-graded multilayer coatings on the inner radii mirror modules. In this paper we report on the first reflectivity measurements of wedged ribbed silicon pore optics mirror plates coated with a depth graded W/Si multilayer. The measurements demonstrate that the deposition and performance of the multilayer coatings is compatible with the SPO production process.

  11. Technique for etching monolayer and multilayer materials

    Science.gov (United States)

    Bouet, Nathalie C. D.; Conley, Raymond P.; Divan, Ralu; Macrander, Albert

    2015-10-06

    A process is disclosed for sectioning by etching of monolayers and multilayers using an RIE technique with fluorine-based chemistry. In one embodiment, the process uses Reactive Ion Etching (RIE) alone or in combination with Inductively Coupled Plasma (ICP) using fluorine-based chemistry alone and using sufficient power to provide high ion energy to increase the etching rate and to obtain deeper anisotropic etching. In a second embodiment, a process is provided for sectioning of WSi.sub.2/Si multilayers using RIE in combination with ICP using a combination of fluorine-based and chlorine-based chemistries and using RF power and ICP power. According to the second embodiment, a high level of vertical anisotropy is achieved by a ratio of three gases; namely, CHF.sub.3, Cl.sub.2, and O.sub.2 with RF and ICP. Additionally, in conjunction with the second embodiment, a passivation layer can be formed on the surface of the multilayer which aids in anisotropic profile generation.

  12. Inkjet-printed Polyvinyl Alcohol Multilayers.

    Science.gov (United States)

    Salaoru, Iulia; Zhou, Zuoxin; Morris, Peter; Gibbons, Gregory J

    2017-05-11

    Inkjet printing is a modern method for polymer processing, and in this work, we demonstrate that this technology is capable of producing polyvinyl alcohol (PVOH) multilayer structures. A polyvinyl alcohol aqueous solution was formulated. The intrinsic properties of the ink, such as surface tension, viscosity, pH, and time stability, were investigated. The PVOH-based ink was a neutral solution (pH 6.7) with a surface tension of 39.3 mN/m and a viscosity of 7.5 cP. The ink displayed pseudoplastic (non-Newtonian shear thinning) behavior at low shear rates, and overall, it demonstrated good time stability. The wettability of the ink on different substrates was investigated, and glass was identified as the most suitable substrate in this particular case. A proprietary 3D inkjet printer was employed to manufacture polymer multilayer structures. The morphology, surface profile, and thickness uniformity of inkjet-printed multilayers were evaluated via optical microscopy.

  13. Evolutionary games on multilayer networks: a colloquium

    Science.gov (United States)

    Wang, Zhen; Wang, Lin; Szolnoki, Attila; Perc, Matjaž

    2015-05-01

    Networks form the backbone of many complex systems, ranging from the Internet to human societies. Accordingly, not only is the range of our interactions limited and thus best described and modeled by networks, it is also a fact that the networks that are an integral part of such models are often interdependent or even interconnected. Networks of networks or multilayer networks are therefore a more apt description of social systems. This colloquium is devoted to evolutionary games on multilayer networks, and in particular to the evolution of cooperation as one of the main pillars of modern human societies. We first give an overview of the most significant conceptual differences between single-layer and multilayer networks, and we provide basic definitions and a classification of the most commonly used terms. Subsequently, we review fascinating and counterintuitive evolutionary outcomes that emerge due to different types of interdependencies between otherwise independent populations. The focus is on coupling through the utilities of players, through the flow of information, as well as through the popularity of different strategies on different network layers. The colloquium highlights the importance of pattern formation and collective behavior for the promotion of cooperation under adverse conditions, as well as the synergies between network science and evolutionary game theory.

  14. Partitioning of functional and taxonomic diversity in surface-associated microbial communities.

    Science.gov (United States)

    Roth-Schulze, Alexandra J; Zozaya-Valdés, Enrique; Steinberg, Peter D; Thomas, Torsten

    2016-12-01

    Surfaces, including those submerged in the marine environment, are subjected to constant interactions and colonisation by surrounding microorganisms. The principles that determine the assembly of those epibiotic communities are however poorly understood. In this study, we employed a hierarchical design to assess the functionality and diversity of microbial communities on different types of host surfaces (e.g. macroalgae, seagrasses). We found that taxonomic diversity was unique to each type of host, but that the majority of functions (> 95%) could be found in any given surface community, suggesting a high degree of functional redundancy. However, some community functions were enriched on certain surfaces and were related to host-specific properties (e.g. the degradation of specific polysaccharides). Together these observations support a model, whereby communities on surfaces are assembled from guilds of microorganisms with a functionality that is partitioned into general properties for a surface-associated life-style, but also specific features that mediate host-specificity. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Staphylococcus saprophyticus surface-associated protein (Ssp) is associated with lifespan reduction in Caenorhabditis elegans.

    Science.gov (United States)

    Szabados, Florian; Mohner, Amelie; Kleine, Britta; Gatermann, Sören G

    2013-10-01

    Staphylococcal lipases have been proposed as pathogenicity factors. In Staphylococcus saprophyticus the surface-associated protein (Ssp) has been previously characterized as a cell wall-associated true lipase. A S. saprophyticus Δssp::ermB mutant has been described as less virulent in an in vivo model of urinary tract infection compared with its wild-type. This is the first report showing that S. saprophyticus induced a lifespan reduction in Caenorhabditis elegans similar to that of S. aureus RN4220. In two S. saprophyticus Δssp::ermB mutants lifespan reduction in C. elegans was partly abolished. In order to attribute virulence to the lipase activity itself and distinguish this phenomenon from the presence of the Ssp-protein, the conserved active site of the lipase was modified by site-directed ligase-independent mutagenesis and lipase activity-deficient mutants were constructed. These results indicate that the Ssp is associated with pathogenicity in C. elegans and one could speculate that the lipase activity itself is responsible for this virulence.

  16. Mechanical properties of highly textured Cu/Ni multilayers

    International Nuclear Information System (INIS)

    Liu, Y.; Bufford, D.; Wang, H.; Sun, C.; Zhang, X.

    2011-01-01

    We report on the synthesis of highly (1 1 1) and (1 0 0) textured Cu/Ni multilayers with individual layer thicknesses, h, varying from 1 to 200 nm. When, h, decreases to 5 nm or less, X-ray diffraction spectra show epitaxial growth of Cu/Ni multilayers. High resolution transmission electron microscopy studies show the coexistence of nanotwins and coherent layer interfaces in highly (1 1 1) textured Cu/Ni multilayers with smaller h. Hardnesses of multilayer films increase with decreasing h, approach a maximum at h of a few nanometers, and show softening thereafter at smaller h. The influence of layer interfaces as well as twin interfaces on strengthening mechanisms of multilayers and the formation of twins in Ni in multilayers are discussed.

  17. Advances in polyelectrolyte multilayer nanofilms as tunable drug delivery systems

    Science.gov (United States)

    Jiang, Bingbing; Barnett, John B; Li, Bingyun

    2009-01-01

    There has been considerable interest in polyelectrolyte multilayer nanofilms, which have a variety of applications ranging from optical and electrochemical materials to biomedical devices. Polyelectrolyte multilayer nanofilms are constructed from aqueous solutions using electrostatic layer-by-layer self-assembly of oppositely-charged polyelectrolytes on a solid substrate. Multifunctional polyelectrolyte multilayer nanofilms have been studied using charged dyes, metal and inorganic nanoparticles, DNA, proteins, and viruses. In the past few years, there has been increasing attention to developing polyelectrolyte multilayer nanofilms as drug delivery vehicles. In this mini-review, we present recent developments in polyelectrolyte multilayer nanofilms with tunable drug delivery properties, with particular emphasis on the strategies in tuning the loading and release of drugs in polyelectrolyte multilayer nanofilms as well as their applications. PMID:24198464

  18. Multiperiodicity in plasmonic multilayers: General description and diversity of topologies

    DEFF Research Database (Denmark)

    Orlov, Alexey A.; Krylova, Anastasia K.; Zhukovsky, Sergei

    2014-01-01

    We introduce multiperiodicity in periodicmetal-dielectric multilayers by stacking more than two types of metal and/or dielectric layers into the unit cell. A simple way to characterize arbitrary multiperiodic multilayers using permutation vectors is suggested and employed. Effects of multiperiodi...... of multiperiodicity up to its fourth order are investigated. We demonstrate that various topologies of multiple-sheet isofrequency and dispersion surfaces exist for such plasmonic multilayers, including a photonic realization of nontrivial isolated Dirac cones....

  19. Neutron diffraction studies of thin film multilayer structures

    International Nuclear Information System (INIS)

    Majkrzak, C.F.

    1985-01-01

    The application of neutron diffraction methods to the study of the microscopic chemical and magnetic structures of thin film multilayers is reviewed. Multilayer diffraction phenomena are described in general and in particular for the case in which one of the materials of a bilayer is ferromagnetic and the neutron beam polarized. Recent neutron diffraction measurements performed on some interesting multilayer systems are discussed. 70 refs., 5 figs

  20. Distinct Element Method modelling of fold-related fractures in a multilayer sequence

    Science.gov (United States)

    Kaserer, Klemens; Schöpfer, Martin P. J.; Grasemann, Bernhard

    2017-04-01

    Natural fractures have a significant impact on the performance of hydrocarbon systems/reservoirs. In a multilayer sequence, both the fracture density within the individual layers and the type of fracture intersection with bedding contacts are key parameters controlling fluid pathways. In the present study the influence of layer stacking and interlayer friction on fracture density and connectivity within a folded sequence is systematically investigated using 2D Distinct Element Method modelling. Our numerical approach permits forward modelling of both fracture nucleation/propagation/arrest and (contemporaneous) frictional slip along bedding planes in a robust and mechanically sound manner. Folding of the multilayer sequence is achieved by enforcing constant curvature folding by means of a velocity boundary condition at the model base, while a constant overburden pressure is maintained at the model top. The modelling reveals that with high bedding plane friction the multilayer stack behaves mechanically as a single layer so that the neutral surface develops in centre of the sequence and fracture spacing is controlled by the total thickness of the folded sequence. In contrast, low bedding plane friction leads to decoupling of the individual layers (flexural slip folding) so that a neutral surface develops in the centre of each layer and fracture spacing is controlled by the thickness of the individual layers. The low interfacial friction models illustrate that stepping of fractures across bedding planes is a common process, which can however have two contrasting origins: The mechanical properties of the interface cause fracture stepping during fracture propagation. Originally through-going fractures are later offset by interfacial slip during folding. A combination of these two different origins may lead to (apparently) inconsistent fracture offsets across bedding planes within a flexural slip fold.

  1. 76 FR 92 - Multilayered Wood Flooring From the People's Republic of China: Postponement of Preliminary...

    Science.gov (United States)

    2011-01-03

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-971] Multilayered Wood Flooring... Department'') initiated an investigation of multilayered wood flooring from the People's Republic of China (``PRC''). See Multilayered Wood Flooring From the People's Republic of China: Initiation of...

  2. Global Carbon Reservoir Oxidative Ratios

    Science.gov (United States)

    Masiello, C. A.; Gallagher, M. E.; Hockaday, W. C.

    2010-12-01

    Photosynthesis and respiration move carbon and oxygen between the atmosphere and the biosphere at a ratio that is characteristic of the biogeochemical processes involved. This ratio is called the oxidative ratio (OR) of photosynthesis and respiration, and is defined as the ratio of moles of O2 per moles of CO2. This O2/CO2 ratio is a characteristic of biosphere-atmosphere gas fluxes, much like the 13C signature of CO2 transferred between the biosphere and the atmosphere has a characteristic signature. OR values vary on a scale of 0 (CO2) to 2 (CH4), with most ecosystem values clustered between 0.9 and 1.2. Just as 13C can be measured for both carbon fluxes and carbon pools, OR can also be measured for fluxes and pools and can provide information about the processes involved in carbon and oxygen cycling. OR values also provide information about reservoir organic geochemistry because pool OR values are proportional to the oxidation state of carbon (Cox) in the reservoir. OR may prove to be a particularly valuable biogeochemical tracer because of its ability to couple information about ecosystem gas fluxes with ecosystem organic geochemistry. We have developed 3 methods to measure the OR of ecosystem carbon reservoirs and intercalibrated them to assure that they yield accurate, intercomparable data. Using these tools we have built a large enough database of biomass and soil OR values that it is now possible to consider the implications of global patterns in ecosystem OR values. Here we present a map of the natural range in ecosystem OR values and begin to consider its implications. One striking pattern is an apparent offset between soil and biospheric OR values: soil OR values are frequently higher than that of their source biomass. We discuss this trend in the context of soil organic geochemistry and gas fluxes.

  3. Are Geotehrmal Reservoirs Stressed Out?

    Science.gov (United States)

    Davatzes, N. C.; Laboso, R. C.; Layland-Bachmann, C. E.; Feigl, K. L.; Foxall, W.; Tabrez, A. R.; Mellors, R. J.; Templeton, D. C.; Akerley, J.

    2017-12-01

    Crustal permeability can be strongly influenced by developing connected networks of open fractures. However, the detailed evolution of a fracture network, its extent, and the persistence of fracture porosity are difficult to analyze. Even in fault-hosted geothermal systems, where heat is brought to the surface from depth along a fault, hydrothermal flow is heterogeneously distributed. This is presumably due to variations in fracture density, connectivity, and attitude, as well as variations in fracture permeability caused by sealing of fractures by precipitated cements or compaction. At the Brady Geothermal field in Nevada, we test the relationship between the modeled local stress state perturbed by dislocations representing fault slip or volume changes in the geothermal reservoir inferred from surface deformation measured by InSAR and the location of successful geothermal wells, hydrothermal activity, and seismicity. We postulate that permeability is favored in volumes that experience positive Coulomb stress changes and reduced compression, which together promote high densities of dilatant fractures. Conversely, permeability can be inhibited in locations where Coulomb stress is reduced, compression promotes compaction, or where the faults are poorly oriented in the stress field and consequently slip infrequently. Over geologic time scales spanning the development of the fault system, these local stress states are strongly influenced by the geometry of the fault network relative to the remote stress driving slip. At shorter time scales, changes in fluid pressure within the fracture network constituting the reservoir cause elastic dilations and contractions. We integrate: (1) direct observations of stress state and fractures in boreholes and the mapped geometry of the fault network; (2) evidence of permeability from surface hydrothermal features, production/injection wells and surface deformations related to pumping history; and (3) seismicity to test the

  4. A reservoir trap for antiprotons

    CERN Document Server

    Smorra, Christian; Franke, Kurt; Nagahama, Hiroki; Schneider, Georg; Higuchi, Takashi; Van Gorp, Simon; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Yamazaki, Yasunori; Ulmer, Stefan

    2015-01-01

    We have developed techniques to extract arbitrary fractions of antiprotons from an accumulated reservoir, and to inject them into a Penning-trap system for high-precision measurements. In our trap-system antiproton storage times > 1.08 years are estimated. The device is fail-safe against power-cuts of up to 10 hours. This makes our planned comparisons of the fundamental properties of protons and antiprotons independent from accelerator cycles, and will enable us to perform experiments during long accelerator shutdown periods when background magnetic noise is low. The demonstrated scheme has the potential to be applied in many other precision Penning trap experiments dealing with exotic particles.

  5. Effect of reservoir heterogeneity on air injection performance in a light oil reservoir

    Directory of Open Access Journals (Sweden)

    Hu Jia

    2018-03-01

    Full Text Available Air injection is a good option to development light oil reservoir. As well-known that, reservoir heterogeneity has great effect for various EOR processes. This also applies to air injection. However, oil recovery mechanisms and physical processes for air injection in heterogeneous reservoir with dip angle are still not well understood. The reported setting of reservoir heterogeneous for physical model or simulation model of air injection only simply uses different-layer permeability of porous media. In practice, reservoir heterogeneity follows the principle of geostatistics. How much of contrast in permeability actually challenges the air injection in light oil reservoir? This should be investigated by using layered porous medial settings of the classical Dykstra-Parsons style. Unfortunately, there has been no work addressing this issue for air injection in light oil reservoir. In this paper, Reservoir heterogeneity is quantified based on the use of different reservoir permeability distribution according to classical Dykstra-Parsons coefficients method. The aim of this work is to investigate the effect of reservoir heterogeneity on physical process and production performance of air injection in light oil reservoir through numerical reservoir simulation approach. The basic model is calibrated based on previous study. Total eleven pseudo compounders are included in this model and ten complexity of reactions are proposed to achieve the reaction scheme. Results show that oil recovery factor is decreased with the increasing of reservoir heterogeneity both for air and N2 injection from updip location, which is against the working behavior of air injection from updip location. Reservoir heterogeneity sometimes can act as positive effect to improve sweep efficiency as well as enhance production performance for air injection. High O2 content air injection can benefit oil recovery factor, also lead to early O2 breakthrough in heterogeneous reservoir. Well

  6. Data Compression of Hydrocarbon Reservoir Simulation Grids

    KAUST Repository

    Chavez, Gustavo Ivan

    2015-05-28

    A dense volumetric grid coming from an oil/gas reservoir simulation output is translated into a compact representation that supports desired features such as interactive visualization, geometric continuity, color mapping and quad representation. A set of four control curves per layer results from processing the grid data, and a complete set of these 3-dimensional surfaces represents the complete volume data and can map reservoir properties of interest to analysts. The processing results yield a representation of reservoir simulation results which has reduced data storage requirements and permits quick performance interaction between reservoir analysts and the simulation data. The degree of reservoir grid compression can be selected according to the quality required, by adjusting for different thresholds, such as approximation error and level of detail. The processions results are of potential benefit in applications such as interactive rendering, data compression, and in-situ visualization of large-scale oil/gas reservoir simulations.

  7. Structural integrity of ceramic multilayer capacitor materials and ceramic multilayer capacitors

    NARCIS (Netherlands)

    With, de G.

    1993-01-01

    An review with 61 refs. is given of the fracture of and stress situation in ceramic capacitor materials and ceramic multilayer capacitors. A brief introduction to the relevant concepts is given first. Next the data for capacitor materials and the data for capacitors are discussed. The materials data

  8. A multilayer approach for turbidity currents

    Science.gov (United States)

    Fernandez-Nieto, Enrique; Castro Díaz, Manuel J.; Morales de Luna, Tomás

    2017-04-01

    When a river that carries sediment in suspension enters into a lake or the ocean it can form a plume that can be classified as hyperpycnal or hypopycnal. Hypopycnal plumes occurs if the combined density of the sediment and interstitial fluid is lower than that of the ambient. Hyperpycnal plumes are a class of sediment-laden gravity current commonly referred to as turbidity currents [7,9]. Some layer-averaged models have been previously developed (see [3, 4, 8] among others). Although this layer-averaged approach gives a fast and valuable information, it has the disadvantage that the vertical distribution of the sediment in suspension is lost. A recent technique based on a multilayer approach [1, 2, 6] has shown to be specially useful to generalize shallow water type models in order to keep track of the vertical components of the averaged variables in the classical shallow water equations. In [5] multilayer model is obtained using a vertical discontinuous Galerkin approach for which the vertical velocity is supposed to be piecewise linear and the horizontal velocity is supposed to be piecewise constant. In this work the technique introduced in [5] is generalized to derive a model for turbidity currents. This model allows to simulate hyperpycnal as well as hypopycnal plumes. Several numerical tests will be presented. References [1] E. Audusse, M. Bristeau, B. Perthame, and J. Sainte-Marie. A multilayer Saint-Venant system with mass exchanges for shallow water flows. derivation and numerical validation. ESAIM: Mathematical Modelling and Numerical Analysis, 45(1):169-200, (2010). [2] E. Audusse, M.-O. Bristeau, M. Pelanti, and J. Sainte-Marie. Approximation of the hydrostatic Navier–Stokes system for density stratified flows by a multilayer model: Kinetic interpretation and numerical solution. Journal of Computational Physics, 230(9):3453-3478, (2011). [3] S. F. Bradford and N. D. Katopodes. Hydrodynamics of turbid underflows. i: Formulation and numerical

  9. Dipole radiation in a multilayer geometry

    International Nuclear Information System (INIS)

    Reed, C.E.; Giergiel, J.; Hemminger, J.C.; Ushioda, S.

    1987-01-01

    There are several kinds of experiments that can be done with multilayer stacks of dielectric media which require an understanding of light emission by sources within the stack for their analysis. These experiments may involve, for example, light-emitting tunnel junctions, Raman scattering in Kretschmann and other multilayered geometries, and Rayleigh scattering by small amounts of surface or interface roughness, either alone or in combination with other processes. A set of electromagnetic Green's functions for a multilayer stack of isotropic dielectric media [D. L. Mills and A. A. Maradudin, Phys. Rev. B 12, 2943 (1975)] gives the electric fields produced everywhere by a point source of current oscillating at a frequency f. These Green's functions can thus be used to solve this type of problem. In this paper we show how these Green's functions can be written in terms of 2 x 2 transfer matrices of the type commonly used to find the fields in a dielectric stack due to an incident plane wave. With this simplification we can easily evaluate the Green's functions for a stack with an arbitrary number of layers. We further show that, when the electric fields generated by a point source within the stack are evaluated far away, they can be written directly in terms of the electric fields that would be generated at the location of the current source by plane waves incident from the direction of the observation point. We show that this follows from the Lorentz reciprocity theorem. Thus, in this case the formalism of Green's functions is not needed

  10. Multilayer models of photosynthetic membranes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brocklehurst, J R; Flanagan, M T

    1982-01-01

    The primary aim of this project has been to build an artificial membrane in which is incorporated, in a functional state, the protein bacteriorhodopsin responsible for generating an electrical potential difference across the membrane of the photosynthetic bacterium, halobacterium halobium, and to investigate the use of this artificial system as the basis of a solar cell. the bacteriorhodopsin has been incorporated into Langmuir-Blodgett multilayers. If ths supporting filter is then illuminated, a potential difference is generated between the two compartments. The lipid in the filter appears to act as a charge carrier for protons, the charge species that forms the electrochemical gradient generated by the bacteriorhodopsin when this molecule absorbs light. The internal resistances of such solar cells were determined and found to be so high that the cells could not be seriously considered as competitors with classical semiconductor cells. Multilayerswere deposited onto filters in which ion carriers that make the filters permeable to sodium ions had been dissolved in the paraffin. The photovoltage obtained indicated that protons transferred from one side of the filter to the other by the action of the bacteriorhodopsin were bing exchanged for sodium ions. A secondary aim of the project has been to examine the possibility of depositing mixed multilayers of a dye and a long chain quinone onto a semiconductor surface. A sensitizing multilayer has been prepared and the mobility of long chain quinones within the layers is high enough to warrant further research. However, it was found that, with the dyes and quinones used, quenched complexes were formed which would not act as sensitizers.

  11. Muon Tomography of Deep Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Bonneville, Alain H.; Kouzes, Richard T.

    2016-12-31

    Imaging subsurface geological formations, oil and gas reservoirs, mineral deposits, cavities or magma chambers under active volcanoes has been for many years a major quest of geophysicists and geologists. Since these objects cannot be observed directly, different indirect geophysical methods have been developed. They are all based on variations of certain physical properties of the subsurface that can be detected from the ground surface or from boreholes. Electrical resistivity, seismic wave’s velocities and density are certainly the most used properties. If we look at density, indirect estimates of density distributions are performed currently by seismic reflection methods - since the velocity of seismic waves depend also on density - but they are expensive and discontinuous in time. Direct estimates of density are performed using gravimetric data looking at variations of the gravity field induced by the density variations at depth but this is not sufficiently accurate. A new imaging technique using cosmic-ray muon detectors has emerged during the last decade and muon tomography - or muography - promises to provide, for the first time, a complete and precise image of the density distribution in the subsurface. Further, this novel approach has the potential to become a direct, real-time, and low-cost method for monitoring fluid displacement in subsurface reservoirs.

  12. Smart waterflooding in carbonate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Zahid, A.

    2012-02-15

    During the last decade, smart waterflooding has been developed into an emerging EOR technology both for carbonate and sandstone reservoirs that does not require toxic or expensive chemicals. Although it is widely accepted that different salinity brines may increase the oil recovery for carbonate reservoirs, understanding of the mechanism of this increase is still developing. To understand this smart waterflooding process, an extensive research has been carried out covering a broad range of disciplines within surface chemistry, thermodynamics of crude oil and brine, as well as their behavior in porous media. The main conclusion of most previous studies was that it is the rock wettability alteration towards more water wetting condition that helps improving the oil recovery. In the first step of this project, we focused on verifying this conclusion. Coreflooding experiments were carried out using Stevens Klint outcrop chalk core plugs with brines without sulfate, as well as brines containing sulfate in different concentrations. The effects of temperature, injection rate, crude oil composition and different sulfate concentrations on the total oil recovery and the recovery rate were investigated. Experimental results clearly indicate improvement of the oil recovery without wettability alteration. At the second step of this project, we studied crude oil/brine interactions under different temperatures, pressures and salinity conditions in order to understand mechanisms behind the high salinity waterflooding. Our results show, in particular that sulfate ions may help decreasing the crude oil viscosity or formation of, seemingly, an emulsion phase between sulfate-enriched brine and oil at high temperature and pressure. Experimental results indicate that crude oils interact differently with the same brine solutions regarding phase behavior and viscosity measurements. This difference is attributed to the difference in composition of the different crude oils. More experiments

  13. Development of gas and gas condensate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    In the study of gas reservoir development, the first year topics are restricted on reservoir characterization. There are two types of reservoir characterization. One is the reservoir formation characterization and the other is the reservoir fluid characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. The results of conditional simulation has higher confidence level than the unconditional simulation because conditional simulation considers the sample location as well as distance correlation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. From the liquid volume fraction with pressure drop, the phase behavior of reservoir fluid can be estimated. The calculation results of fluid recombination, constant composition expansion, and constant volume depletion are matched very well with the experimental data. In swelling test of the reservoir fluid with lean gas, the accuracy of dew point pressure forecast depends on the component characterization. (author). 28 figs., 10 tabs.

  14. Stretch due to Penile Prosthesis Reservoir Migration

    Directory of Open Access Journals (Sweden)

    E. Baten

    2016-03-01

    Full Text Available A 43-year old patient presented to the emergency department with stretch, due to impossible deflation of the penile prosthesis, 4 years after successful implant. A CT-scan showed migration of the reservoir to the left rectus abdominis muscle. Refilling of the reservoir was inhibited by muscular compression, causing stretch. Removal and replacement of the reservoir was performed, after which the prosthesis was well-functioning again. Migration of the penile prosthesis reservoir is extremely rare but can cause several complications, such as stretch.

  15. Magnetic pinning in superconductor-ferromagnet multilayers

    International Nuclear Information System (INIS)

    Bulaevskii, L. N.; Chudnovsky, E. M.; Maley, M. P.

    2000-01-01

    We argue that superconductor/ferromagnet multilayers of nanoscale period should exhibit strong pinning of vortices by the magnetic domain structure in magnetic fields below the coercive field when ferromagnetic layers exhibit strong perpendicular magnetic anisotropy. The estimated maximum magnetic pinning energy for single vortex in such a system is about 100 times larger than the pinning energy by columnar defects. This pinning energy may provide critical currents as high as 10 6 -10 7 A/cm 2 at high temperatures (but not very close to T c ) at least in magnetic fields below 0.1 T. (c) 2000 American Institute of Physics

  16. Magnetic pinning in superconductor-ferromagnet multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Bulaevskii, L. N. [Department of Physics and Astronomy, CUNY Lehman College 250 Bedford Park Boulevard West, Bronx, New York 10468-1589 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Chudnovsky, E. M. [Department of Physics and Astronomy, CUNY Lehman College, 250 Bedford Park Boulevard West, Bronx, New York 10468-1589 (United States); Maley, M. P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2000-05-01

    We argue that superconductor/ferromagnet multilayers of nanoscale period should exhibit strong pinning of vortices by the magnetic domain structure in magnetic fields below the coercive field when ferromagnetic layers exhibit strong perpendicular magnetic anisotropy. The estimated maximum magnetic pinning energy for single vortex in such a system is about 100 times larger than the pinning energy by columnar defects. This pinning energy may provide critical currents as high as 10{sup 6}-10{sup 7} A/cm{sup 2} at high temperatures (but not very close to T{sub c}) at least in magnetic fields below 0.1 T. (c) 2000 American Institute of Physics.

  17. Magnetic anisotropy of Ni/Cr multilayers

    International Nuclear Information System (INIS)

    Kang, S.; Xia, H.

    1997-01-01

    The magnetic anisotropy of Ni/Cr multilayers has been investigated by using vibrating sample magnetometer (VSM) and ferromagnetic resonance techniques (FMR). The FMR spectra are obtained as a function of the orientation of the applied magnetic field from in-plane to out-of-plane. The results are fitted theoretically to determine the magnetic anisotropy. From VSM and FMR, a positive value for Ni/Cr interface anisotropy is obtained, which favours a perpendicular easy axis. The possible mechanism for the perpendicular anisotropy has been discussed and it may be attributed to the magnetostriction, caused by intrinsic stress due to lattice mismatch. (orig.). With 005 figs., 001 tabs

  18. Effective Interactions between Multilayered Ionic Microgels

    Directory of Open Access Journals (Sweden)

    Clemens Hanel

    2014-12-01

    Full Text Available Using a one-component reduction formalism, we calculate the effective interactions and the counterion density profiles for microgels that feature a multilayered shell structure. We follow a strategy that involves second order perturbation theory and obtain analytical expressions for the effective interactions by modeling the layers of the particles as linear superpostion of homogeneously charged spheres. The general method is applied to the important case of core–shell microgels and compared with the well-known results for a microgel that can be approximated by a macroscopic, and homogeneously charged, spherical macroion.

  19. Magnetic properties of Dy/Zr multilayers

    International Nuclear Information System (INIS)

    Luche, M.C.; Boyer, P.

    1992-01-01

    [Dy(xA)/Zr(30A)] n superlattices (x ≤ 30), were evaporated under ultra-high vacuum on Si(100) substrates. Magnetization measurements indicate that the antiferromagnetic transition occurring at 178K in bulk Dy is suppressed in the multilayers. This phenomenon is attributed to magnetoelastic effects induced by strains at Zr/Dy interfaces. A perpendicular magnetic anisotropy takes place for x ≤ 15. However, the magnetic anisotropy is found to depend markedly on the technique used for Dy deposition. (author). 11 refs., 4 figs

  20. Multilayer detector for skin absorbed dose measuring

    International Nuclear Information System (INIS)

    Osanov, D.P.; Panova, V.P.; Shaks, A.I.

    1985-01-01

    A method for skin dosimetry based on utilization of multilayer detectors and permitting to estimate distribution of absorbed dose by skin depth is described. The detector represents a set of thin sensitive elements separated by tissue-equivalent absorbers. Quantitative evaluation and forecasting the degree of radiation injury of skin are determined by the formula based on determination of the probability of the fact that cells are not destroyed and they can divide further on. The given method ensures a possibility of quantitative evaluation of radiobiological effect and forecasting clinical consequences of skin irradiation by results of corresponding measurements of dose by means of the miultilayer detector

  1. Optics and multilayer coatings for EUVL systems

    Energy Technology Data Exchange (ETDEWEB)

    Soufli, R; Bajt, S; Hudyma, R M; Taylor, J S

    2008-03-21

    EUV lithography (EUVL) employs illumination wavelengths around 13.5 nm, and in many aspects it is considered an extension of optical lithography, which is used for the high-volume manufacturing (HVM) of today's microprocessors. The EUV wavelength of illumination dictates the use of reflective optical elements (mirrors) as opposed to the refractive lenses used in conventional lithographic systems. Thus, EUVL tools are based on all-reflective concepts: they use multilayer (ML) coated optics for their illumination and projection systems, and they have a ML-coated reflective mask.

  2. Multilayer Perceptron: Architecture Optimization and Training

    Directory of Open Access Journals (Sweden)

    Hassan Ramchoun

    2016-09-01

    Full Text Available The multilayer perceptron has a large wide of classification and regression applications in many fields: pattern recognition, voice and classification problems. But the architecture choice has a great impact on the convergence of these networks. In the present paper we introduce a new approach to optimize the network architecture, for solving the obtained model we use the genetic algorithm and we train the network with a back-propagation algorithm. The numerical results assess the effectiveness of the theoretical results shown in this paper, and the advantages of the new modeling compared to the previous model in the literature.

  3. Optimization of Perfect Absorbers with Multilayer Structures

    Science.gov (United States)

    Li Voti, Roberto

    2018-02-01

    We study wide-angle and broadband perfect absorbers with compact multilayer structures made of a sequence of ITO and TiN layers deposited onto a silver thick layer. An optimization procedure is introduced for searching the optimal thicknesses of the layers so as to design a perfect broadband absorber from 400 nm to 750 nm, for a wide range of angles of incidence from 0{°} to 50{°}, for both polarizations and with a low emissivity in the mid-infrared. We eventually compare the performances of several optimal structures that can be very promising for solar thermal energy harvesting and collectors.

  4. Fabrication and Properties of Multilayer Structures

    Science.gov (United States)

    1983-09-01

    according to both the high x-ray count and a Read camera pattern which showed only the 111 8 SiC reflection in a tight ± 30 distribution about the substrate...structural rearrangement. X-ray analysis of the deposited films at the composition of Pd2 Si using a Read camera indicated strong texturing. The...Phys. 35, 547 (1964). 11. C.A. Neubauer and J.R. Randen, Proc. IEEE 52, 1234 (1964). 12. W.A. Tiller, "Fabrication and Properties of Multilayer

  5. Improving reservoir history matching of EM heated heavy oil reservoirs via cross-well seismic tomography

    KAUST Repository

    Katterbauer, Klemens; Hoteit, Ibrahim

    2014-01-01

    process. While becoming a promising technology for heavy oil recovery, its effect on overall reservoir production and fluid displacements are poorly understood. Reservoir history matching has become a vital tool for the oil & gas industry to increase

  6. Multi-data reservoir history matching for enhanced reservoir forecasting and uncertainty quantification

    KAUST Repository

    Katterbauer, Klemens; Arango, Santiago; Sun, Shuyu; Hoteit, Ibrahim

    2015-01-01

    Reservoir simulations and history matching are critical for fine-tuning reservoir production strategies, improving understanding of the subsurface formation, and forecasting remaining reserves. Production data have long been incorporated

  7. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, Roy; Clarke, Don; Walker, Scott

    1999-11-09

    The objectives of this quarterly report was to summarize the work conducted under each task during the reporting period April - June 1998 and to report all technical data and findings as specified in the ''Federal Assistance Reporting Checklist''. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology.

  8. Multilayer thin films: sequential assembly of nanocomposite materials

    National Research Council Canada - National Science Library

    Decher, Gero; Schlenoff, Joseph B

    2003-01-01

    ... polymeric or nanoparticulate building blocks, understanding the polymer physical chemistry of multilayers, or characterizing their optical, electrical or biological activities. The reasons for the intense interest in the field are also clearly evident: multilayers bridge the gap between monolayers and spun-on or dip-coated films, ...

  9. Identifying key nodes in multilayer networks based on tensor decomposition.

    Science.gov (United States)

    Wang, Dingjie; Wang, Haitao; Zou, Xiufen

    2017-06-01

    The identification of essential agents in multilayer networks characterized by different types of interactions is a crucial and challenging topic, one that is essential for understanding the topological structure and dynamic processes of multilayer networks. In this paper, we use the fourth-order tensor to represent multilayer networks and propose a novel method to identify essential nodes based on CANDECOMP/PARAFAC (CP) tensor decomposition, referred to as the EDCPTD centrality. This method is based on the perspective of multilayer networked structures, which integrate the information of edges among nodes and links between different layers to quantify the importance of nodes in multilayer networks. Three real-world multilayer biological networks are used to evaluate the performance of the EDCPTD centrality. The bar chart and ROC curves of these multilayer networks indicate that the proposed approach is a good alternative index to identify real important nodes. Meanwhile, by comparing the behavior of both the proposed method and the aggregated single-layer methods, we demonstrate that neglecting the multiple relationships between nodes may lead to incorrect identification of the most versatile nodes. Furthermore, the Gene Ontology functional annotation demonstrates that the identified top nodes based on the proposed approach play a significant role in many vital biological processes. Finally, we have implemented many centrality methods of multilayer networks (including our method and the published methods) and created a visual software based on the MATLAB GUI, called ENMNFinder, which can be used by other researchers.

  10. 75 FR 66126 - Multilayered Wood Flooring From China

    Science.gov (United States)

    2010-10-27

    ...)] Multilayered Wood Flooring From China AGENCY: United States International Trade Commission. ACTION: Institution... flooring, provided for in subheadings 4409.10, 4409.29, 4412.31, 4412.32, 4412.39, 4412.94, 4412.99, 4418... multilayered wood flooring. The following companies are members of the CAHP: Anderson Hardwood Floors, LLC...

  11. 78 FR 30329 - Multilayered Wood Flooring from China

    Science.gov (United States)

    2013-05-22

    ...)] Multilayered Wood Flooring from China AGENCY: United States International Trade Commission. ACTION: Notice of...-1179 (Final) concerning multilayered wood flooring (``MLWF'') from China. For further information... reconsider ``its decision not to investigate domestic producers of hardwood plywood used for flooring'' 2. to...

  12. 76 FR 76435 - Multilayered Wood Flooring From China

    Science.gov (United States)

    2011-12-07

    ...)] Multilayered Wood Flooring From China Determinations On the basis of the record \\1\\ developed in the subject... multilayered wood flooring, provided for in subheadings 4409.10, 4409.29, 4412.31, 4412.32, 4412.39, 4412.94... flooring. The following companies are members of the CAHP: Anderson Hardwood Floors, LLC, Fountain Inn, SC...

  13. Multiple analysis of an unknown optical multilayer coating

    International Nuclear Information System (INIS)

    Dobrowolski, J.A.; Ho, F.C.; Waldorf, A.

    1985-01-01

    Results are given of the analysis at five different laboratories of an unknown optical multilayer coating. In all, eleven different analytical and laboratory techniques were applied to the problem. The multilayer nominally consisted of three dielectric and two metallic layers. It was demonstrated convincingly that with present day techniques it is possible to determine the basic structure of such a coating

  14. Simulation of reflectivity spectrum for non-absorbing multilayer ...

    Indian Academy of Sciences (India)

    Reflectivity simulation is an essential tool for the design and optimization of optical thin ... with the experimental results of the multilayer optical thin films grown by electron-beam evaporation ... beam splitters [4] and various optical filters. ... thickness (QWOT) layer AR coating and multilayer HR coating using electron- beam ...

  15. Stress in tungsten carbide-diamond like carbon multilayer coatings

    NARCIS (Netherlands)

    Pujada, B.R.; Tichelaar, F.D.; Janssen, G.C.A.M.

    2007-01-01

    Tungsten carbide-diamond like carbon (WC-DLC) multilayer coatings have been prepared by sputter deposition from a tungsten-carbide target and periodic switching on and off of the reactive acetylene gas flow. The stress in the resulting WC-DLC multilayers has been studied by substrate curvature.

  16. Heat stability evaluations of Co/SiO2 multilayers

    International Nuclear Information System (INIS)

    Ishino, Masahiko; Koike, Masato; Kanehira, Mika; Satou, Futami; Terauchi, Masami; Sano, Kazuo

    2008-01-01

    The heat stability of Co/SiO 2 multilayers was evaluated. Co/SiO 2 multilayer samples were deposited on Si substrate by means of an ion beam sputtering method, and annealed at temperatures from 100degC to 600degC in a vacuum furnace. For the structural and optical evaluations, small angle x-ray diffraction (XRD) measurements, soft x-ray reflectivity measurements, and transmission electron microscopy (TEM) observations were carried out. As the results, the Co/SiO 2 multilayer samples annealed up to 400degC maintained the initial multilayer structures, and kept almost the same soft x-ray reflectivities as that of the as-deposited Co/SiO 2 multilayer sample. A deterioration of the multilayer structure caused by the growth of Co grains was found on the Co/SiO 2 multilayer samples annealed over 500degC, and the soft x-ray reflectivity dropped in accordance with the deterioration of the multilayer structure. (author)

  17. Multilayer tape cast SOFC – Effect of anode sintering temperature

    DEFF Research Database (Denmark)

    Hauch, Anne; Birkl, Christoph; Brodersen, Karen

    2012-01-01

    Multilayer tape casting (MTC) is considered a promising, cost-efficient, up-scalable shaping process for production of planar anode supported solid oxide fuel cells (SOFC). Multilayer tape casting of the three layers comprising the half cell (anode support/active anode/electrolyte) can potentially...

  18. Phosphorus-based compounds for EUV multilayer optics materials

    NARCIS (Netherlands)

    Medvedev, Viacheslav; Yakshin, Andrey; van de Kruijs, Robbert Wilhelmus Elisabeth; Bijkerk, Frederik

    2015-01-01

    We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were

  19. Characterization of Mo/Si multilayer growth on stepped topographies

    NARCIS (Netherlands)

    van den Boogaard, Toine; Louis, Eric; Zoethout, E.; Goldberg, K.A.; Bijkerk, Frederik

    2011-01-01

    Mo/Si multilayer mirrors with nanoscale bilayer thicknesses have been deposited on stepped substrate topographies, using various deposition angles. The multilayer morphology at the step-edge region was studied by cross section transmission electron microscopy. A transition from a continuous- to

  20. A MULTILAYER BIOCHEMICAL DRY DEPOSITION MODEL 1. MODEL FORMULATION

    Science.gov (United States)

    A multilayer biochemical dry deposition model has been developed based on the NOAA Multilayer Model (MLM) to study gaseous exchanges between the soil, plants, and the atmosphere. Most of the parameterizations and submodels have been updated or replaced. The numerical integration ...

  1. A refined model for characterizing x-ray multilayers

    International Nuclear Information System (INIS)

    Oren, A.L.; Henke, B.L.

    1987-12-01

    The ability to quickly and accurately characterize arbitrary multilayers is very valuable for not only can we use the characterizations to predict the reflectivity of a multilayer for any soft x-ray wavelength, we also can generalize the results to apply to other multilayers of the same type. In addition, we can use the characterizations as a means of evaluating various sputtering environments and refining sputtering techniques to obtain better multilayers. In this report we have obtained improved characterizations for sample molybdenum-silicon and vanadium-silicon multilayers. However, we only examined five crystals overall, so the conclusions that we could draw about the structure of general multilayers is limited. Research involving many multilayers manufactured under the same sputtering conditions is clearly in order. In order to best understand multilayer structures it may be necessary to further refine our model, e.g., adopting a Gaussian form for the interface regions. With such improvements we can expect even better agreement with experimental values and continued concurrence with other characterization techniques. 18 refs., 30 figs., 7 tabs

  2. Estimation of Bank Erosion Due To Reservoir Operation in Cascade (Case Study: Citarum Cascade Reservoir

    Directory of Open Access Journals (Sweden)

    Sri Legowo

    2009-11-01

    Full Text Available Sedimentation is such a crucial issue to be noted once the accumulated sediment begins to fill the reservoir dead storage, this will then influence the long-term reservoir operation. The sediment accumulated requires a serious attention for it may influence the storage capacity and other reservoir management of activities. The continuous inflow of sediment to the reservoir will decrease the capacity of reservoir storage, the reservoir value in use, and the useful age of reservoir. Because of that, the rate of the sediment needs to be delayed as possible. In this research, the delay of the sediment rate is considered based on the rate of flow of landslide of the reservoir slope. The rate of flow of the sliding slope can be minimized by way of each reservoir autonomous efforts. This effort can be performed through; the regulation of fluctuating rate of reservoir surface current that does not cause suddenly drawdown and upraising as well. The research model is compiled using the searching technique of Non Linear Programming (NLP.The rate of bank erosion for the reservoir variates from 0.0009 to 0.0048 MCM/year, which is no sigrificant value to threaten the life time of reservoir.Mean while the rate of watershed sediment has a significant value, i.e: 3,02 MCM/year for Saguling that causes to fullfill the storage capacity in 40 next years (from years 2008.

  3. Multilayered membranes with tuned well arrays to be used as regenerative patches.

    Science.gov (United States)

    Martins, Nádia I; Sousa, Maria P; Custódio, Catarina A; Pinto, Vânia C; Sousa, Paulo J; Minas, Graça; Cleymand, Franck; Mano, João F

    2017-07-15

    Membranes have been explored as patches in tissue repair and regeneration, most of them presenting a flat geometry or a patterned texture at the nano/micrometer scale. Herein, a new concept of a flexible membrane featuring well arrays forming pore-like environments to accommodate cell culture is proposed. The processing of such membranes using polysaccharides is based on the production of multilayers using the layer-by-layer methodology over a patterned PDMS substrate. The detached multilayered membrane exhibits a layer of open pores at one side and a total thickness of 38±2.2µm. The photolithography technology used to produce the molds allows obtaining wells on the final membranes with a tuned shape and micro-scale precision. The influence of post-processing procedures over chitosan/alginate films with 100 double layers, including crosslinking with genipin or fibronectin immobilization, on the adhesion and proliferation of human osteoblast-like cells is also investigated. The results suggest that the presence of patterned wells affects positively cell adhesion, morphology and proliferation. In particular, it is seen that cells colonized preferentially the well regions. The geometrical features with micro to sub-millimeter patterned wells, together with the nano-scale organization of the polymeric components along the thickness of the film will allow to engineer highly versatile multilayered membranes exhibiting a pore-like microstructure in just one of the sides, that could be adaptable in the regeneration of multiple tissues. Flexible multilayered membranes containing multiple micro-reservoirs are found as potential regenerative patches. Layer-by-layer (LbL) methodology over a featured PDMS substrate is used to produce patterned membranes, composed only by natural-based polymers, that can be easily detached from the PDMS substrate. The combination of nano-scale control of the polymeric organization along the thickness of the chitosan/alginate (CHT

  4. An X-ray grazing incidence phase multilayer grating

    CERN Document Server

    Chernov, V A; Mytnichenko, S V

    2001-01-01

    An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating stripes on a Ni/C multilayer and optimized for the hard X-ray range was fabricated. Its diffraction properties were studied at photon energies of 7 and 8 keV. The obtained maximum value of the diffraction efficiency of the +1 grating order was 9% at 7 keV and 6.5% at 8 keV. The data obtained are in a rather good accordance with the theory.

  5. Bonded Multilayer Laue Lens for focusing hard X-rays

    International Nuclear Information System (INIS)

    Liu Chian; Conley, R.; Qian, J.; Kewish, C.M.; Macrander, A.T.; Maser, J.; Kang, H.C.; Yan, H.; Stephenson, G.B.

    2007-01-01

    We have fabricated partial Multilayer Laue Lens (MLL) linear zone plate structures with thousands of alternating WSi 2 and Si layers and various outermost zone widths according to the Fresnel zone plate formula. Using partial MLL structures, we were able to focus hard X-rays to line foci with a width of 30 nm and below. Here, we describe challenges and approaches used to bond these multilayers to achieve line and point focusing. Bonding was done by coating two multilayers with AuSn and heating in a vacuum oven at 280-300 o C. X-ray reflectivity measurements confirmed that there was no change in the multilayers after heating to 350 o C. A bonded MLL was polished to a 5-25 μm wedge without cracking. SEM image analyses found well-positioned multilayers after bonding. These results demonstrate the feasibility of a bonded full MLL for focusing hard X-rays

  6. Effect of boundary conditions on pressure behavior of finite-conductivity fractures in bounded stratified reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Osman, Mohammed E.; Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, Al-Ain (United Arab Emirates)

    1996-08-15

    In this study, a mathematical model was developed to model the pressure behavior of a well located in a bounded multilayer reservoir and crossed by a finite-conductivity vertical fracture. It was found that the dimensionless pressure function and its derivative strongly depend on fracture conductivity and fracture extension during early times. The effect of reservoir heterogeneity on the pressure function is negligible compared to that on the pressure derivative. Both functions exhibit four flow periods: bilinear, formation linear, pseudoradial and pseudosteady-state which are separated by transition periods. One or more of these flow periods may be missing. Data obtained from a long test and which are characterized by a unit slope line indicate that the well is intercepted by deeply extended fractures. It has been found that the fractional production rates of different layers are a good measure of reservoir and fracture characteristics. Flowmeter survey data can be used to eliminate the non-uniqueness problem when using the type curves presented in this study

  7. Load responsive multilayer insulation performance testing

    International Nuclear Information System (INIS)

    Dye, S.; Kopelove, A.; Mills, G. L.

    2014-01-01

    Cryogenic insulation designed to operate at various pressures from one atmosphere to vacuum, with high thermal performance and light weight, is needed for cryogenically fueled space launch vehicles and aircraft. Multilayer insulation (MLI) performs well in a high vacuum, but the required vacuum shell for use in the atmosphere is heavy. Spray-on foam insulation (SOFI) is often used in these systems because of its light weight, but can have a higher heat flux than desired. We report on the continued development of Load Responsive Multilayer Insulation (LRMLI), an advanced thermal insulation system that uses dynamic beam discrete spacers that provide high thermal performance both in atmosphere and vacuum. LRMLI consists of layers of thermal radiation barriers separated and supported by micromolded polymer spacers. The spacers have low thermal conductance, and self-support a thin, lightweight vacuum shell that provides internal high vacuum in the insulation. The dynamic load responsive spacers compress to support the external load of a vacuum shell in one atmosphere, and decompress under reduced atmospheric pressure for lower heat leak. Structural load testing was performed on the spacers with various configurations. LRMLI was installed on a 400 liter tank and boil off testing with liquid nitrogen performed at various chamber pressures from one atmosphere to high vacuum. Testing was also performed with an MLI blanket on the outside of the LRMLI

  8. Measure of Node Similarity in Multilayer Networks.

    Directory of Open Access Journals (Sweden)

    Anders Mollgaard

    Full Text Available The weight of links in a network is often related to the similarity of the nodes. Here, we introduce a simple tunable measure for analysing the similarity of nodes across different link weights. In particular, we use the measure to analyze homophily in a group of 659 freshman students at a large university. Our analysis is based on data obtained using smartphones equipped with custom data collection software, complemented by questionnaire-based data. The network of social contacts is represented as a weighted multilayer network constructed from different channels of telecommunication as well as data on face-to-face contacts. We find that even strongly connected individuals are not more similar with respect to basic personality traits than randomly chosen pairs of individuals. In contrast, several socio-demographics variables have a significant degree of similarity. We further observe that similarity might be present in one layer of the multilayer network and simultaneously be absent in the other layers. For a variable such as gender, our measure reveals a transition from similarity between nodes connected with links of relatively low weight to dis-similarity for the nodes connected by the strongest links. We finally analyze the overlap between layers in the network for different levels of acquaintanceships.

  9. Polymer multilayer tattooing for enhanced DNA vaccination

    Science.gov (United States)

    Demuth, Peter C.; Min, Younjin; Huang, Bonnie; Kramer, Joshua A.; Miller, Andrew D.; Barouch, Dan H.; Hammond, Paula T.; Irvine, Darrell J.

    2013-04-01

    DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These ‘multilayer tattoo’ DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination.

  10. Relaxation dynamics of multilayer triangular Husimi cacti

    Science.gov (United States)

    Galiceanu, Mircea; Jurjiu, Aurel

    2016-09-01

    We focus on the relaxation dynamics of multilayer polymer structures having, as underlying topology, the Husimi cactus. The relaxation dynamics of the multilayer structures is investigated in the framework of generalized Gaussian structures model using both Rouse and Zimm approaches. In the Rouse type-approach, we determine analytically the complete eigenvalues spectrum and based on it we calculate the mechanical relaxation moduli (storage and loss modulus) and the average monomer displacement. First, we monitor these physical quantities for structures with a fixed generation number and we increase the number of layers, such that the linear topology will smoothly come into play. Second, we keep constant the size of the structures, varying simultaneously two parameters: the generation number of the main layer, G, and the number of layers, c. This fact allows us to study in detail the crossover from a pure Husimi cactus behavior to a predominately linear chain behavior. The most interesting situation is found when the two limiting topologies cancel each other. For this case, we encounter in the intermediate frequency/time domain regions of constant slope for different values of the parameter set (G, c) and we show that the number of layers follows an exponential-law of G. In the Zimm-type approach, which includes the hydrodynamic interactions, the quantities that describe the mechanical relaxation dynamics do not show scaling behavior as in the Rouse model, except the limiting case, namely, a very high number of layers and low generation number.

  11. Load responsive multilayer insulation performance testing

    Energy Technology Data Exchange (ETDEWEB)

    Dye, S.; Kopelove, A. [Quest Thermal Group, 6452 Fig Street Suite A, Arvada, CO 80004 (United States); Mills, G. L. [Ball Aerospace and Technologies Corp, 1600 Commerce Street, Boulder, CO 80301 (United States)

    2014-01-29

    Cryogenic insulation designed to operate at various pressures from one atmosphere to vacuum, with high thermal performance and light weight, is needed for cryogenically fueled space launch vehicles and aircraft. Multilayer insulation (MLI) performs well in a high vacuum, but the required vacuum shell for use in the atmosphere is heavy. Spray-on foam insulation (SOFI) is often used in these systems because of its light weight, but can have a higher heat flux than desired. We report on the continued development of Load Responsive Multilayer Insulation (LRMLI), an advanced thermal insulation system that uses dynamic beam discrete spacers that provide high thermal performance both in atmosphere and vacuum. LRMLI consists of layers of thermal radiation barriers separated and supported by micromolded polymer spacers. The spacers have low thermal conductance, and self-support a thin, lightweight vacuum shell that provides internal high vacuum in the insulation. The dynamic load responsive spacers compress to support the external load of a vacuum shell in one atmosphere, and decompress under reduced atmospheric pressure for lower heat leak. Structural load testing was performed on the spacers with various configurations. LRMLI was installed on a 400 liter tank and boil off testing with liquid nitrogen performed at various chamber pressures from one atmosphere to high vacuum. Testing was also performed with an MLI blanket on the outside of the LRMLI.

  12. Superconductivity and vortex properties in various multilayers

    International Nuclear Information System (INIS)

    Koorevaar, P.

    1994-01-01

    In this thesis three qualitatively different type of superconducting multilayers are studied. We discuss the vortex lattice structure in Nb/NbZr multilayers, a system where both type of constituting layers are superconducting. At certain temperatures and for parallel fields close to H c2parallel , the Nb/NbZr system has a strongly modulated order parameter, and in this aspect resembles the high-Tc materials. By lowering the field the modulation decreases, having important consequences for the vortex lattice structure. By studying the transport critical currents we show that in the case of strong modulation the vortex lattice has a kinked structure, but at weaker modulations the vortices are straight, and the change in modulation actually results in a vortex lattice transition. Our study confirms the picture of the existence of kinked vortex lattices, but it is rather surprising that these kinked structures can exist in a system which in itself is not at all that anisotropic. It indicates the relevance of other parameters governing the vortex lattice structure. (orig.)

  13. Multiple leaders on a multilayer social media

    International Nuclear Information System (INIS)

    Borondo, J.; Morales, A.J.; Benito, R.M.; Losada, J.C.

    2015-01-01

    Twitter is a social media platform where users can interact in three different ways: following, mentioning, or retweeting. Accordingly, one can define Twitter as a multilayer social network where each layer represents one of the three interaction mechanisms. First, we review the main findings of our previous work regarding two Twitter political conversations: the 2010 Venezuelan protest and the 2011 Spanish general elections. We found that the structure of the follower layer conditions the retweet layer, as having a low number of followers represents a constrain to effectively propagate information. The collapsed directed multiplex network does not present a rich-club ordering, as politicians presided large communities of regular users in the mention layer; while media accounts were the sources from which people retweeted information. However, when considering reciprocal interactions the rich-club ordering emerges, as elite accounts preferentially interacted among themselves and largely ignored the crowd. Finally, we explore the main relationships between the community structure of the three layers. At the follower level users cluster in large and dense communities holding various hubs, that break into smaller and more segregated ones in the mention and retweet layers. Hence, we argue that to fully understand Twitter we have to analyze it as a multilayer social network, evaluating the three types of interactions

  14. Optimization of multi-layered metallic shield

    International Nuclear Information System (INIS)

    Ben-Dor, G.; Dubinsky, A.; Elperin, T.

    2011-01-01

    Research highlights: → We investigated the problem of optimization of a multi-layered metallic shield. → The maximum ballistic limit velocity is a criterion of optimization. → The sequence of materials and the thicknesses of layers in the shield are varied. → The general problem is reduced to the problem of Geometric Programming. → Analytical solutions are obtained for two- and three-layered shields. - Abstract: We investigate the problem of optimization of multi-layered metallic shield whereby the goal is to determine the sequence of materials and the thicknesses of the layers that provide the maximum ballistic limit velocity of the shield. Optimization is performed under the following constraints: fixed areal density of the shield, the upper bound on the total thickness of the shield and the bounds on the thicknesses of the plates manufactured from every material. The problem is reduced to the problem of Geometric Programming which can be solved numerically using known methods. For the most interesting in practice cases of two-layered and three-layered shields the solution is obtained in the explicit analytical form.

  15. Dry etching technologies for reflective multilayer

    Science.gov (United States)

    Iino, Yoshinori; Karyu, Makoto; Ita, Hirotsugu; Kase, Yoshihisa; Yoshimori, Tomoaki; Muto, Makoto; Nonaka, Mikio; Iwami, Munenori

    2012-11-01

    We have developed a highly integrated methodology for patterning Extreme Ultraviolet (EUV) mask, which has been highlighted for the lithography technique at the 14nm half-pitch generation and beyond. The EUV mask is characterized as a reflective-type mask which is completely different compared with conventional transparent-type of photo mask. And it requires not only patterning of absorber layer without damaging the underlying multi reflective layers (40 Si/Mo layers) but also etching multi reflective layers. In this case, the dry etch process has generally faced technical challenges such as the difficulties in CD control, etch damage to quartz substrate and low selectivity to the mask resist. Shibaura Mechatronics ARESTM mask etch system and its optimized etch process has already achieved the maximal etch performance at patterning two-layered absorber. And in this study, our process technologies of multi reflective layers will be evaluated by means of optimal combination of process gases and our optimized plasma produced by certain source power and bias power. When our ARES™ is used for multilayer etching, the user can choose to etch the absorber layer at the same time or etch only the multilayer.

  16. A Designed Room Temperature Multilayered Magnetic Semiconductor

    Science.gov (United States)

    Bouma, Dinah Simone; Charilaou, Michalis; Bordel, Catherine; Duchin, Ryan; Barriga, Alexander; Farmer, Adam; Hellman, Frances; Materials Science Division, Lawrence Berkeley National Lab Team

    2015-03-01

    A room temperature magnetic semiconductor has been designed and fabricated by using an epitaxial antiferromagnet (NiO) grown in the (111) orientation, which gives surface uncompensated magnetism for an odd number of planes, layered with the lightly doped semiconductor Al-doped ZnO (AZO). Magnetization and Hall effect measurements of multilayers of NiO and AZO are presented for varying thickness of each. The magnetic properties vary as a function of the number of Ni planes in each NiO layer; an odd number of Ni planes yields on each NiO layer an uncompensated moment which is RKKY-coupled to the moments on adjacent NiO layers via the carriers in the AZO. This RKKY coupling oscillates with the AZO layer thickness, and it disappears entirely in samples where the AZO is replaced with undoped ZnO. The anomalous Hall effect data indicate that the carriers in the AZO are spin-polarized according to the direction of the applied field at both low temperature and room temperature. NiO/AZO multilayers are therefore a promising candidate for spintronic applications demanding a room-temperature semiconductor.

  17. Finite element analysis of multilayer coextrusion.

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, Matthew Morgan; Schunk, Peter Randall; Baer, Thomas A. (Proctor & Gamble Company, West Chester, OH); Mrozek, Randy A. (Army Research Laboratory, Adelphi, MD); Lenhart, Joseph Ludlow (Army Research Laboratory, Adelphi, MD); Rao, Rekha Ranjana; Collins, Robert (Oak Ridge National Laboratory); Mondy, Lisa Ann

    2011-09-01

    Multilayer coextrusion has become a popular commercial process for producing complex polymeric products from soda bottles to reflective coatings. A numerical model of a multilayer coextrusion process is developed based on a finite element discretization and two different free-surface methods, an arbitrary-Lagrangian-Eulerian (ALE) moving mesh implementation and an Eulerian level set method, to understand the moving boundary problem associated with the polymer-polymer interface. The goal of this work is to have a numerical capability suitable for optimizing and troubleshooting the coextrusion process, circumventing flow instabilities such as ribbing and barring, and reducing variability in layer thickness. Though these instabilities can be both viscous and elastic in nature, for this work a generalized Newtonian description of the fluid is used. Models of varying degrees of complexity are investigated including stability analysis and direct three-dimensional finite element free surface approaches. The results of this work show how critical modeling can be to reduce build test cycles, improve material choices, and guide mold design.

  18. Polymer multilayer tattooing for enhanced DNA vaccination

    Science.gov (United States)

    DeMuth, Peter C.; Min, Younjin; Huang, Bonnie; Kramer, Joshua A.; Miller, Andrew D.; Barouch, Dan H.; Hammond, Paula T.; Irvine, Darrell J.

    2014-01-01

    DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These “multilayer tattoo” DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination. PMID:23353628

  19. Smart Waterflooding in Carbonate Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel

    brine solutions regarding phase behavior and viscosity measurements. This difference is attributed to the difference in composition of the different crude oils. More experiments are carried out in order to understand mechanisms of the crude oil viscosity reduction and emulsion formation. We observed...... with and without aging. The total oil recovery, recovery rate and interaction mechanisms of ions with rock were studied for different injected fluids under different temperatures and wettability conditions. Experimental results demonstrate that the oil recovery mechanism under high salinity seawater flooding...... phase could be the possible reasons for the observed increase in oil recovery with sulfate ions at high temperature in chalk reservoirs, besides the mechanism of the rock wettability alteration. * Crude oil/brine interaction study suggests that viscosity reduction for crude oil in contact with brine...

  20. Reservoirs talk to pressure recorders

    Energy Technology Data Exchange (ETDEWEB)

    Pamenter, C B

    1968-02-01

    Keeping pace with increased demand for efficiency in secondary recovery schemes is the widening use of downhole tools charged with supplying data before and during the operation of the projects. One of the most important of these is the pressure recorder. This highly sensitive instrument, housed in a tough, slim steel case and lowered by drill pipe or cable, accurately measures the pressure of its downhole environment. This information is instantly available at the surface whenever a pressure reading is required. Typical applications of surface recorders often contribute are: (1) production practices such as checking surface and subsurface equipment, and special lifting problems; (2) well conditions including regular productivity indices, data observations and for interference studies; (3) secondary recovery projects, in both producing and injection wells; and (4) reservoir conditions where oil-water contacts and damaged zones need close attention.

  1. Production Optimization of Oil Reservoirs

    DEFF Research Database (Denmark)

    Völcker, Carsten

    with emphasis on optimal control of water ooding with the use of smartwell technology. We have implemented immiscible ow of water and oil in isothermal reservoirs with isotropic heterogenous permeability elds. We use the method of lines for solution of the partial differential equation (PDE) system that governs...... the uid ow. We discretize the the two-phase ow model spatially using the nite volume method (FVM), and we use the two point ux approximation (TPFA) and the single-point upstream (SPU) scheme for computing the uxes. We propose a new formulation of the differential equation system that arise...... as a consequence of the spatial discretization of the two-phase ow model. Upon discretization in time, the proposed equation system ensures the mass conserving property of the two-phase ow model. For the solution of the spatially discretized two-phase ow model, we develop mass conserving explicit singly diagonally...

  2. Economics of Developing Hot Stratigraphic Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  3. Carbon emission from global hydroelectric reservoirs revisited.

    Science.gov (United States)

    Li, Siyue; Zhang, Quanfa

    2014-12-01

    Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO2)/year and 18.7 Tg methane (CH4)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO2 and 67 % CH4 of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO2/kWh and 5.7 g CH4/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO2eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs.

  4. Zooplankton of the Zaporiz’ke Reservoir

    Directory of Open Access Journals (Sweden)

    T. V. Mykolaichuk

    2006-01-01

    Full Text Available The paper is devoted to zooplankton species composition in the Zaporiz’ke Reservoir. The greatest species diversity was found in the macrophyte communities of the upper reservoir’s littoral, but the least zooplankton diversity – in the pelagic zone of the lower reservoir.

  5. Estimating Western U.S. Reservoir Sedimentation

    Science.gov (United States)

    Bensching, L.; Livneh, B.; Greimann, B. P.

    2017-12-01

    Reservoir sedimentation is a long-term problem for water management across the Western U.S. Observations of sedimentation are limited to reservoir surveys that are costly and infrequent, with many reservoirs having only two or fewer surveys. This work aims to apply a recently developed ensemble of sediment algorithms to estimate reservoir sedimentation over several western U.S. reservoirs. The sediment algorithms include empirical, conceptual, stochastic, and processes based approaches and are coupled with a hydrologic modeling framework. Preliminary results showed that the more complex and processed based algorithms performed better in predicting high sediment flux values and in a basin transferability experiment. However, more testing and validation is required to confirm sediment model skill. This work is carried out in partnership with the Bureau of Reclamation with the goal of evaluating the viability of reservoir sediment yield prediction across the western U.S. using a multi-algorithm approach. Simulations of streamflow and sediment fluxes are validated against observed discharges, as well as a Reservoir Sedimentation Information database that is being developed by the US Army Corps of Engineers. Specific goals of this research include (i) quantifying whether inter-algorithm differences consistently capture observational variability; (ii) identifying whether certain categories of models consistently produce the best results, (iii) assessing the expected sedimentation life-span of several western U.S. reservoirs through long-term simulations.

  6. Ichthyofauna of the reservoirs of Central Vietnam

    Directory of Open Access Journals (Sweden)

    I. A. Stolbunov

    2012-01-01

    Full Text Available Species composition, distribution and abundance of fish in the pelagic and littoral zone of four reservoirs of Central Vietnam (Suoi Chau, Kam Lam, Da Ban and Suoi Dau were studied first. According to the research data the fish community of the reservoirs is represented by 43 species of 19 fish families.

  7. An index of reservoir habitat impairment

    Science.gov (United States)

    Miranda, L.E.; Hunt, K.M.

    2011-01-01

    Fish habitat impairment resulting from natural and anthropogenic watershed and in-lake processes has in many cases reduced the ability of reservoirs to sustain native fish assemblages and fisheries quality. Rehabilitation of impaired reservoirs is hindered by the lack of a method suitable for scoring impairment status. To address this limitation, an index of reservoir habitat impairment (IRHI) was developed by merging 14 metrics descriptive of common impairment sources, with each metric scored from 0 (no impairment) to 5 (high impairment) by fisheries scientists with local knowledge. With a plausible range of 5 to 25, distribution of the IRHI scores ranged from 5 to 23 over 482 randomly selected reservoirs dispersed throughout the USA. The IRHI reflected five impairment factors including siltation, structural habitat, eutrophication, water regime, and aquatic plants. The factors were weakly related to key reservoir characteristics including reservoir area, depth, age, and usetype, suggesting that common reservoir descriptors are poor predictors of fish habitat impairment. The IRHI is rapid and inexpensive to calculate, provides an easily understood measure of the overall habitat impairment, allows comparison of reservoirs and therefore prioritization of restoration activities, and may be used to track restoration progress. The major limitation of the IRHI is its reliance on unstandardized professional judgment rather than standardized empirical measurements. ?? 2010 US Government.

  8. Monitoring programme of water reservoir Grliste

    International Nuclear Information System (INIS)

    Vuckovic, M; Milenkovic, P.; Lukic, D.

    2002-01-01

    The quality of surface waters is a very important problem incorporated in the environment protection, especially in water resources. The Timok border-land hasn't got sufficient underground and surface waters. This is certificated by the International Association for Water Resource. That was reason for building the water reservoir 'Grliste'. Drinking water from water reservoir 'Grliste' supplies Zajecar and the surroundings. (author)

  9. Geothermal reservoir insurance study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-09

    The principal goal of this study was to provide analysis of and recommendations on the need for and feasibility of a geothermal reservoir insurance program. Five major tasks are reported: perception of risk by major market sectors, status of private sector insurance programs, analysis of reservoir risks, alternative government roles, and recommendations.

  10. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    of magnitude and degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants, and animals, shows that age differences of up to 2000 14C years can occur within one river. The freshwater reservoir effect has also implications......The freshwater reservoir effect can result in anomalously old radiocarbon ages of samples from lakes and rivers. This includes the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. Water rich in dissolved ancient calcium carbonates, commonly known...... as hard water, is the most common reason for the freshwater reservoir effect. It is therefore also called hardwater effect. Although it has been known for more than 60 years, it is still less well-recognized by archaeologists than the marine reservoir effect. The aim of this study is to examine the order...

  11. Reservoir model for the Alameda Central waterflood

    Energy Technology Data Exchange (ETDEWEB)

    Randall, T E

    1968-01-01

    The basic approach used in developing the model to characterize the Alameda Central Unit Waterflood assumes continuity of the reservoir mechanics with time. The past performance was analyzed to describe the reservoir and future performance was assumed to follow the established patterns. To develop a mathematical picture of the Alameda Central Unit reservoir, a two-dimensional single-phase steady-state model was used in conjunction with material balance calculations, real-time conversion methods and oil-water interface advance calculations. The model was developed to optimize water injection allocation, determine the configuration of the frontal advance and evaluate the success of the waterflood. The model also provides a basis for continuing review and revision of the basic concepts of reservoir operation. The results of the reservoir study have confirmed the apparent lack of permeability orientation in the pool and indicate that the waterflood is progressing better than originally anticipated.

  12. The Alphabet Soup of HIV Reservoir Markers.

    Science.gov (United States)

    Sharaf, Radwa R; Li, Jonathan Z

    2017-04-01

    Despite the success of antiretroviral therapy in suppressing HIV, life-long therapy is required to avoid HIV reactivation from long-lived viral reservoirs. Currently, there is intense interest in searching for therapeutic interventions that can purge the viral reservoir to achieve complete remission in HIV patients off antiretroviral therapy. The evaluation of such interventions relies on our ability to accurately and precisely measure the true size of the viral reservoir. In this review, we assess the most commonly used HIV reservoir assays, as a clear understanding of the strengths and weaknesses of each is vital for the accurate interpretation of results and for the development of improved assays. The quantification of intracellular or plasma HIV RNA or DNA levels remains the most commonly used tests for the characterization of the viral reservoir. While cost-effective and high-throughput, these assays are not able to differentiate between replication-competent or defective fractions or quantify the number of infected cells. Viral outgrowth assays provide a lower bound for the fraction of cells that can produce infectious virus, but these assays are laborious, expensive and substantially underestimate the potential reservoir of replication-competent provirus. Newer assays are now available that seek to overcome some of these problems, including full-length proviral sequencing, inducible HIV RNA assays, ultrasensitive p24 assays and murine adoptive transfer techniques. The development and evaluation of strategies for HIV remission rely upon our ability to accurately and precisely quantify the size of the remaining viral reservoir. At this time, all current HIV reservoir assays have drawbacks such that combinations of assays are generally needed to gain a more comprehensive view of the viral reservoir. The development of novel, rapid, high-throughput assays that can sensitively quantify the levels of the replication-competent HIV reservoir is still needed.

  13. Reservoir Models for Gas Hydrate Numerical Simulation

    Science.gov (United States)

    Boswell, R.

    2016-12-01

    Scientific and industrial drilling programs have now providing detailed information on gas hydrate systems that will increasingly be the subject of field experiments. The need to carefully plan these programs requires reliable prediction of reservoir response to hydrate dissociation. Currently, a major emphasis in gas hydrate modeling is the integration of thermodynamic/hydrologic phenomena with geomechanical response for both reservoir and bounding strata. However, also critical to the ultimate success of these efforts is the appropriate development of input geologic models, including several emerging issues, including (1) reservoir heterogeneity, (2) understanding of the initial petrophysical characteristics of the system (reservoirs and seals), the dynamic evolution of those characteristics during active dissociation, and the interdependency of petrophysical parameters and (3) the nature of reservoir boundaries. Heterogeneity is ubiquitous aspect of every natural reservoir, and appropriate characterization is vital. However, heterogeneity is not random. Vertical variation can be evaluated with core and well log data; however, core data often are challenged by incomplete recovery. Well logs also provide interpretation challenges, particularly where reservoirs are thinly-bedded due to limitation in vertical resolution. This imprecision will extend to any petrophysical measurements that are derived from evaluation of log data. Extrapolation of log data laterally is also complex, and should be supported by geologic mapping. Key petrophysical parameters include porosity, permeability and it many aspects, and water saturation. Field data collected to date suggest that the degree of hydrate saturation is strongly controlled by/dependant upon reservoir quality and that the ratio of free to bound water in the remaining pore space is likely also controlled by reservoir quality. Further, those parameters will also evolve during dissociation, and not necessary in a simple

  14. Reservoir Identification: Parameter Characterization or Feature Classification

    Science.gov (United States)

    Cao, J.

    2017-12-01

    The ultimate goal of oil and gas exploration is to find the oil or gas reservoirs with industrial mining value. Therefore, the core task of modern oil and gas exploration is to identify oil or gas reservoirs on the seismic profiles. Traditionally, the reservoir is identify by seismic inversion of a series of physical parameters such as porosity, saturation, permeability, formation pressure, and so on. Due to the heterogeneity of the geological medium, the approximation of the inversion model and the incompleteness and noisy of the data, the inversion results are highly uncertain and must be calibrated or corrected with well data. In areas where there are few wells or no well, reservoir identification based on seismic inversion is high-risk. Reservoir identification is essentially a classification issue. In the identification process, the underground rocks are divided into reservoirs with industrial mining value and host rocks with non-industrial mining value. In addition to the traditional physical parameters classification, the classification may be achieved using one or a few comprehensive features. By introducing the concept of seismic-print, we have developed a new reservoir identification method based on seismic-print analysis. Furthermore, we explore the possibility to use deep leaning to discover the seismic-print characteristics of oil and gas reservoirs. Preliminary experiments have shown that the deep learning of seismic data could distinguish gas reservoirs from host rocks. The combination of both seismic-print analysis and seismic deep learning is expected to be a more robust reservoir identification method. The work was supported by NSFC under grant No. 41430323 and No. U1562219, and the National Key Research and Development Program under Grant No. 2016YFC0601

  15. Reservoir management under geological uncertainty using fast model update

    NARCIS (Netherlands)

    Hanea, R.; Evensen, G.; Hustoft, L.; Ek, T.; Chitu, A.; Wilschut, F.

    2015-01-01

    Statoil is implementing "Fast Model Update (FMU)," an integrated and automated workflow for reservoir modeling and characterization. FMU connects all steps and disciplines from seismic depth conversion to prediction and reservoir management taking into account relevant reservoir uncertainty. FMU

  16. Extended asymmetric-cut multilayer X-ray gratings.

    Science.gov (United States)

    Prasciolu, Mauro; Haase, Anton; Scholze, Frank; Chapman, Henry N; Bajt, Saša

    2015-06-15

    The fabrication and characterization of a large-area high-dispersion blazed grating for soft X-rays based on an asymmetric-cut multilayer structure is reported. An asymmetric-cut multilayer structure acts as a perfect blazed grating of high efficiency that exhibits a single diffracted order, as described by dynamical diffraction throughout the depth of the layered structure. The maximum number of grating periods created by cutting a multilayer deposited on a flat substrate is equal to the number of layers deposited, which limits the size of the grating. The size limitation was overcome by depositing the multilayer onto a substrate which itself is a coarse blazed grating and then polish it flat to reveal the uniformly spaced layers of the multilayer. The number of deposited layers required is such that the multilayer thickness exceeds the step height of the substrate structure. The method is demonstrated by fabricating a 27,060 line pairs per mm blazed grating (36.95 nm period) that is repeated every 3,200 periods by the 120-μm period substrate structure. This preparation technique also relaxes the requirements on stress control and interface roughness of the multilayer film. The dispersion and efficiency of the grating is demonstrated for soft X-rays of 13.2 nm wavelength.

  17. Localization of multilayer networks by optimized single-layer rewiring.

    Science.gov (United States)

    Jalan, Sarika; Pradhan, Priodyuti

    2018-04-01

    We study localization properties of principal eigenvectors (PEVs) of multilayer networks (MNs). Starting with a multilayer network corresponding to a delocalized PEV, we rewire the network edges using an optimization technique such that the PEV of the rewired multilayer network becomes more localized. The framework allows us to scrutinize structural and spectral properties of the networks at various localization points during the rewiring process. We show that rewiring only one layer is enough to attain a MN having a highly localized PEV. Our investigation reveals that a single edge rewiring of the optimized MN can lead to the complete delocalization of a highly localized PEV. This sensitivity in the localization behavior of PEVs is accompanied with the second largest eigenvalue lying very close to the largest one. This observation opens an avenue to gain a deeper insight into the origin of PEV localization of networks. Furthermore, analysis of multilayer networks constructed using real-world social and biological data shows that the localization properties of these real-world multilayer networks are in good agreement with the simulation results for the model multilayer network. This paper is relevant to applications that require understanding propagation of perturbation in multilayer networks.

  18. Assessment of Climate Change Effects on Shahcheraghi Reservoir Inflow

    Directory of Open Access Journals (Sweden)

    M. E. Banihabib

    2016-10-01

    compared to BPD. The best ANN sub-model has minimum Mean Absolute Relative Error (MARE index (0.27 in test phases and maximum correlation coefficient (ρ (0.82 in test phases. Results and Discussion: The tested climate change scenarios revealed that climate change has more impact on rainfall and temperature than solar radiation. The utmost growth of monthly rainfall occurred in May under all the three tested climate change scenarios. But, rainfall under A1B scenario had the maximum growth (52% whereas the most decrease occurred (–21.5% during January under the A2 climate change scenario. Rainfall dropped over the period of June to October under the three tested climate change scenarios. Furthermore, in all three scenarios, the maximum temperature increased about 2.2 to 2.6°C in May but the lowest increase of temperature occurred in January under A2 and B1 scenarios as 0.3 and 0.5°C, respectively. The maximum temperature usually increased in all months compared to the baseline period. Minimum and maximum temperatures enlarged likewise in all months, with 2.05°C in September under A2 climate change scenario. Conversely, solar radiation change was comparatively low and the most decreases occurred in February under A1B and A2 climate change scenarios as –4.2% and –4.3% , respectively, and in August under the B1 scenario as –4.2%. The greatest increase of solar radiation occurs in April, November, and March by 3.1%, 3.2%, and 4.9% for A1B, A2, and B1 scenarios, respectively. The impact of climate change on rainfall and temperature can origin changes on reservoir inflow and need new strategies to adapt reservoir operation for change inflows. Therefore, first, reservoir inflow in future period (after climate change impact should be anticipated for the adaptation of the reservoir. A Feed-Forward (FF Multilayer-Perceptron (MLP Artificial Neural Network (ANN model was nominated for the seven tested ANN models based on minimization of error function. The selected model had

  19. Multilayer Stochastic Block Models Reveal the Multilayer Structure of Complex Networks

    Directory of Open Access Journals (Sweden)

    Toni Vallès-Català

    2016-03-01

    Full Text Available In complex systems, the network of interactions we observe between systems components is the aggregate of the interactions that occur through different mechanisms or layers. Recent studies reveal that the existence of multiple interaction layers can have a dramatic impact in the dynamical processes occurring on these systems. However, these studies assume that the interactions between systems components in each one of the layers are known, while typically for real-world systems we do not have that information. Here, we address the issue of uncovering the different interaction layers from aggregate data by introducing multilayer stochastic block models (SBMs, a generalization of single-layer SBMs that considers different mechanisms of layer aggregation. First, we find the complete probabilistic solution to the problem of finding the optimal multilayer SBM for a given aggregate-observed network. Because this solution is computationally intractable, we propose an approximation that enables us to verify that multilayer SBMs are more predictive of network structure in real-world complex systems.

  20. Critical currents in multilayered superconducting films

    International Nuclear Information System (INIS)

    Raffy, Helene

    1977-01-01

    The superconducting critical currents Isub(c) were measured as a function of magnetic field H and temperature T, on multilayered films. These films consist of alternating layers of two different superconductors S 1 and S 2 being a weaker superconductor acting as a flux pinning barrier region. A strong anisotropy was observed between the two situations where the magnetic field H is applied parallel or perpendicular to the layers. In the case discussed, there is a peak effect in the curves Isub(c)H well defined at the highest temperatures, and disappearing at low temperatures. The anisotropy of the critical current at constant field presents a maximum at a temperature T* close to the critical temperature Tsub(c 2 ) of S 2 [fr

  1. Plasmon resonance in multilayer graphene nanoribbons

    DEFF Research Database (Denmark)

    Emani, Naresh Kumar; Wang, Di; Chung, Ting Fung

    2015-01-01

    Plasmon resonances in nanopatterned single-layer graphene nanoribbons (SL-GNRs), double-layer graphene nanoribbons (DL-GNRs) and triple-layer graphene nanoribbons (TL-GNRs) are studied experimentally using 'realistic' graphene samples. The existence of electrically tunable plasmons in stacked...... multilayer graphene nanoribbons was first experimentally verified by infrared microscopy. We find that the strength of the plasmonic resonance increases in DL-GNRs when compared to SL-GNRs. However, further increase was not observed in TL-GNRs when compared to DL-GNRs. We carried out systematic full......-wave simulations using a finite-element technique to validate and fit experimental results, and extract the carrier-scattering rate as a fitting parameter. The numerical simulations show remarkable agreement with experiments for an unpatterned SLG sheet, and a qualitative agreement for a patterned graphene sheet...

  2. Multilayer Statistical Intrusion Detection in Wireless Networks

    Science.gov (United States)

    Hamdi, Mohamed; Meddeb-Makhlouf, Amel; Boudriga, Noureddine

    2008-12-01

    The rapid proliferation of mobile applications and services has introduced new vulnerabilities that do not exist in fixed wired networks. Traditional security mechanisms, such as access control and encryption, turn out to be inefficient in modern wireless networks. Given the shortcomings of the protection mechanisms, an important research focuses in intrusion detection systems (IDSs). This paper proposes a multilayer statistical intrusion detection framework for wireless networks. The architecture is adequate to wireless networks because the underlying detection models rely on radio parameters and traffic models. Accurate correlation between radio and traffic anomalies allows enhancing the efficiency of the IDS. A radio signal fingerprinting technique based on the maximal overlap discrete wavelet transform (MODWT) is developed. Moreover, a geometric clustering algorithm is presented. Depending on the characteristics of the fingerprinting technique, the clustering algorithm permits to control the false positive and false negative rates. Finally, simulation experiments have been carried out to validate the proposed IDS.

  3. Optimisation of Multilayer Insulation an Engineering Approach

    CERN Document Server

    Chorowski, M; Parente, C; Riddone, G

    2001-01-01

    A mathematical model has been developed to describe the heat flux through multilayer insulation (MLI). The total heat flux between the layers is the result of three distinct heat transfer modes: radiation, residual gas conduction and solid spacer conduction. The model describes the MLI behaviour considering a layer-to-layer approach and is based on an electrical analogy, in which the three heat transfer modes are treated as parallel thermal impedances. The values of each of the transfer mode vary from layer to layer, although the total heat flux remains constant across the whole MLI blanket. The model enables the optimisation of the insulation with regard to different MLI parameters, such as residual gas pressure, number of layers and boundary temperatures. The model has been tested with experimental measurements carried out at CERN and the results revealed to be in a good agreement, especially for insulation vacuum between 10-5 Pa and 10-3 Pa.

  4. Interface stress in Au/Ni multilayers

    DEFF Research Database (Denmark)

    Schweitz, K.O.; Böttiger, J.; Chevallier, J.

    2000-01-01

    The effect of intermixing on the apparent interface stress is studied in -textured dc-magnetron sputtered Au/Ni multilayers by use of two methods commonly used for determining interface stress. The method using profilometry and in-plane x-ray diffraction does not take intermixing...... into account and yields an apparent interface stress of -8.46 +/- 0.99 J m(-2). However, observed discrepancies between model calculations and measured high-angle x-ray diffractograms indicate intermixing, and by use of the profilometry and sin(2) psi method the real interface stress value of -2.69 +/- 0.43 J...... m(-2) is found. This method also reveals a significant and systematic change of the stress-free lattice parameter of both constituents as a function of modulation period which is shown to account for the difference between the two findings. The method using in-plane diffraction is thus shown...

  5. Properties of multilayer nonuniform holographic structures

    International Nuclear Information System (INIS)

    Pen, E F; Rodionov, Mikhail Yu

    2010-01-01

    Experimental results and analysis of properties of multilayer nonuniform holographic structures formed in photopolymer materials are presented. The theoretical hypotheses is proved that the characteristics of angular selectivity for the considered structures have a set of local maxima, whose number and width are determined by the thicknesses of intermediate layers and deep holograms and that the envelope of the maxima coincides with the selectivity contour of a single holographic array. It is also experimentally shown that hologram nonuniformities substantially distort shapes of selectivity characteristics: they become asymmetric, the local maxima differ in size and the depths of local minima reduce. The modelling results are made similar to experimental data by appropriately choosing the nonuniformity parameters. (imaging and image processing. holography)

  6. A multilayer surface detector for ultracold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui, E-mail: zwang@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hoffbauer, M.A.; Morris, C.L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Callahan, N.B.; Adamek, E.R. [Indiana University, Bloomington, IN 47405 (United States); Bacon, J.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Blatnik, M. [Cleveland State University, Cleveland, OH 44115 (United States); Brandt, A.E. [North Carolina State University, Raleigh, NC 27695 (United States); Broussard, L.J.; Clayton, S.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Cude-Woods, C. [North Carolina State University, Raleigh, NC 27695 (United States); Currie, S. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Dees, E.B. [North Carolina State University, Raleigh, NC 27695 (United States); Ding, X. [Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Gao, J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Gray, F.E. [Regis University, Denver, CO 80221 (United States); Hickerson, K.P. [University of California Los Angeles, Los Angeles, CA 90095 (United States); Holley, A.T. [Tennessee Technological University, Cookeville, TN 38505 (United States); Ito, T.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Liu, C.-Y. [Indiana University, Bloomington, IN 47405 (United States); and others

    2015-10-21

    A multilayer surface detector for ultracold neutrons (UCNs) is described. The top {sup 10}B layer is exposed to vacuum and directly captures UCNs. The ZnS:Ag layer beneath the {sup 10}B layer is a few microns thick, which is sufficient to detect the charged particles from the {sup 10}B(n,α){sup 7}Li neutron-capture reaction, while thin enough that ample light due to α and {sup 7}Li escapes for detection by photomultiplier tubes. A 100-nm thick {sup 10}B layer gives high UCN detection efficiency, as determined by the mean UCN kinetic energy, detector materials, and other parameters. Low background, including negligible sensitivity to ambient neutrons, has also been verified through pulse-shape analysis and comparison with other existing {sup 3}He and {sup 10}B detectors. This type of detector has been configured in different ways for UCN flux monitoring, development of UCN guides and neutron lifetime research.

  7. Multilayer Network Analysis of Nuclear Reactions

    Science.gov (United States)

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-08-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, 4He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart.

  8. Multilayer X-ray imaging systems

    Science.gov (United States)

    Shealy, D. L.; Hoover, R. B.; Gabardi, D. R.

    1986-01-01

    An assessment of the imaging properties of multilayer X-ray imaging systems with spherical surfaces has been made. A ray trace analysis was performed to investigate the effects of using spherical substrates (rather than the conventional paraboloidal/hyperboloidal contours) for doubly reflecting Cassegrain telescopes. These investigations were carried out for mirrors designed to operate at selected soft X-ray/XUV wavelengths that are of significance for studies of the solar corona/transition region from the Stanford/MSFC Rocket X-Ray Telescope. The effects of changes in separation of the primary and secondary elements were also investigated. These theoretical results are presented as well as the results of ray trace studies to establish the resolution and vignetting effects as a function of field angle and system parameters.

  9. The polymorphic, multilayered and networked urbanised territory

    DEFF Research Database (Denmark)

    Nielsen, Tom

    2015-01-01

    The discussion of the network city has in recent years been supplemented by an increasing interest in reconsidering the notion of territory. Looking into both geographical and urban design theories, we find examples of a focus on how the networks of the city not only connect them irreversibly...... with sites and systems without any direct physical relation, but also of how this does not necessarily result in complete fragmentation and dissociation between the parts and the surrounding landscapes, as described in network city theory. By relating examples from this literature to a description...... in theory. The concept of The Polymorphic, Multilayered and Networked Urbanised Territory is introduced to grasp the reality experienced in European regions outside the largest and most potent versions of contemporary cities....

  10. Channel Equalization Using Multilayer Perceptron Networks

    Directory of Open Access Journals (Sweden)

    Saba Baloch

    2012-07-01

    Full Text Available In most digital communication systems, bandwidth limited channel along with multipath propagation causes ISI (Inter Symbol Interference to occur. This phenomenon causes distortion of the given transmitted symbol due to other transmitted symbols. With the help of equalization ISI can be reduced. This paper presents a solution to the ISI problem by performing blind equalization using ANN (Artificial Neural Networks. The simulated network is a multilayer feedforward Perceptron ANN, which has been trained by utilizing the error back-propagation algorithm. The weights of the network are updated in accordance with training of the network. This paper presents a very effective method for blind channel equalization, being more efficient than the pre-existing algorithms. The obtained results show a visible reduction in the noise content.

  11. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    Amin, Muhammad

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon modes that destructively interfere with the dipolar mode and generate electromagnetically induced absorption. (ii) The patterned graphene layers biased at different gate voltages backedup with dielectric substrates are stacked on top of each other. The resulting absorber is polarization dependent but has an ultra-broadband of operation. (iii) Graphene\\'s damping factor is increased by lowering its electron mobility to 1000cm 2=Vs. Indeed, numerical experiments demonstrate that with only three layers, bandwidth of 90% absorption can be extended upto 7THz, which is drastically larger than only few THz of bandwidth that can be achieved with existing metallic/graphene absorbers. © 2013 Optical Society of America.

  12. Integrating gravimetric and interferometric synthetic aperture radar data for enhancing reservoir history matching of carbonate gas and volatile oil reservoirs

    KAUST Repository

    Katterbauer, Klemens; Arango, Santiago; Sun, Shuyu; Hoteit, Ibrahim

    2016-01-01

    Reservoir history matching is assuming a critical role in understanding reservoir characteristics, tracking water fronts, and forecasting production. While production data have been incorporated for matching reservoir production levels

  13. Magnons in ultrahigh vacuum deposited Fe/Ag multilayers

    International Nuclear Information System (INIS)

    El Kiadi, I.; Lassri, H.; Benkirane, K.; Bensassi, B.

    2007-01-01

    We have grown Fe/Ag multilayers with Ag buffer layer, by evaporation under UHV conditions on glass substrates. The magnetic properties of Fe/Ag multilayers are examined as a function of Fe layer thickness t Fe . The temperature dependence of the spontaneous magnetization M(T) is well described by a T 3/2 law in all multilayers. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction J b and surface exchange interaction J s for various Fe layer thicknesses have been obtained

  14. Status and limitations of multilayer X-ray interference structures

    International Nuclear Information System (INIS)

    Kortright, J.B.

    1996-01-01

    Trends in the performance of x-ray multilayer interference structures with periods ranging from 9 to 130 (angstrom) are reviewed. Analysis of near-normal incidence reflectance data vs photon energy reveals that the effective interface with σ in a static Debye-Waller model, describing interdiffusion and roughness, decreases as the multilayer period decreases, and reaches a lower limit of roughly 2 (angstrom). Specular reflectance and diffuse scattering from uncoated and multilayer-coated substrates having different roughness suggest that this lower limit results largely from substrate roughness. The increase in interface width with period thus results from increasing roughness of interdiffusion as the layer thickness increases

  15. Laminated multilayer sheet structure and its utilization

    International Nuclear Information System (INIS)

    Chiba, K.; Itoh, K.; Mitani, Y.; Sobajima, S.; Yonemura, U.

    1980-01-01

    A laminated multilayer sheet structure is described comprising (A) an opaque flexible sheet layer, and (B) a flexible layer laminated on the surface of layer (A) and composed of a transparent thermic ray reflecting layer (B 1 ) bonded to a transparent synthetic resin layer (B 2 ), said layer (B 1 ) being a transparent thermic ray reflecting layer composed of (I) a layer of a metal having a thickness of about 50 to about 600 A, said metal being selected from the group consisting of gold, silver, copper, aluminum and a mixture of alloy of at least two of said metals, and (II) a high refractive substance layer having a thickness of about 50 to about 600 A, of an oxide of titanium derived from a layer of an organic titanium compound of the formula Ti 1 O/sub m/R/sub n/, where R is alkyl of 1-20 carbon atoms, l=1-30, m=4+3(1-1), and n=4+2(1-1), and containing the organic residual moiety of the organic titanium compound, the amount of said organic residual moiety being 0.1 to 30% by weight based on the weight of the high refractive substance layer; or said layer (B 1 ) being a transparent semiconductive layer having a thickness of about 500 to about 5,000 a and being composed of a compound selected from the group consisting of indium oxide, tin oxide, cadmium oxide, antimony oxide, copper iodide, and a mixture of at least two of said compounds. A method is described for heat-insulating a room, which comprises applying to the surface of a floor, wall, ceiling or partition in the room a laminated multilayer sheet structure comprising (A) an opaque flexible sheet layer, and (B) a flexible layer laminated on the surface of layer (A) and composed of a transparent thermic ray reflecting layer (B 1 ) bonded to a transparent synthetic resin layer

  16. Multilayer Approach for Advanced Hybrid Lithium Battery

    KAUST Repository

    Ming, Jun

    2016-06-06

    Conventional intercalated rechargeable batteries have shown their capacity limit, and the development of an alternative battery system with higher capacity is strongly needed for sustainable electrical vehicles and hand-held devices. Herein, we introduce a feasible and scalable multilayer approach to fabricate a promising hybrid lithium battery with superior capacity and multivoltage plateaus. A sulfur-rich electrode (90 wt % S) is covered by a dual layer of graphite/Li4Ti5O12, where the active materials S and Li4Ti5O12 can both take part in redox reactions and thus deliver a high capacity of 572 mAh gcathode -1 (vs the total mass of electrode) or 1866 mAh gs -1 (vs the mass of sulfur) at 0.1C (with the definition of 1C = 1675 mA gs -1). The battery shows unique voltage platforms at 2.35 and 2.1 V, contributed from S, and 1.55 V from Li4Ti5O12. A high rate capability of 566 mAh gcathode -1 at 0.25C and 376 mAh gcathode -1 at 1C with durable cycle ability over 100 cycles can be achieved. Operando Raman and electron microscope analysis confirm that the graphite/Li4Ti5O12 layer slows the dissolution/migration of polysulfides, thereby giving rise to a higher sulfur utilization and a slower capacity decay. This advanced hybrid battery with a multilayer concept for marrying different voltage plateaus from various electrode materials opens a way of providing tunable capacity and multiple voltage platforms for energy device applications. © 2016 American Chemical Society.

  17. Reflection Phenomena in Underground Pumped Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Elena Pummer

    2018-04-01

    Full Text Available Energy storage through hydropower leads to free surface water waves in the connected reservoirs. The reason for this is the movement of water between reservoirs at different elevations, which is necessary for electrical energy storage. Currently, the expansion of renewable energies requires the development of fast and flexible energy storage systems, of which classical pumped storage plants are the only technically proven and cost-effective technology and are the most used. Instead of classical pumped storage plants, where reservoirs are located on the surface, underground pumped storage plants with subsurface reservoirs could be an alternative. They are independent of topography and have a low surface area requirement. This can be a great advantage for energy storage expansion in case of environmental issues, residents’ concerns and an unusable terrain surface. However, the reservoirs of underground pumped storage plants differ in design from classical ones for stability and space reasons. The hydraulic design is essential to ensure their satisfactory hydraulic performance. The paper presents a hybrid model study, which is defined here as a combination of physical and numerical modelling to use the advantages and to compensate for the disadvantages of the respective methods. It shows the analysis of waves in ventilated underground reservoir systems with a great length to height ratio, considering new operational aspects from energy supply systems with a great percentage of renewable energies. The multifaceted and narrow design of the reservoirs leads to complex free surface flows; for example, undular and breaking bores arise. The results show excessive wave heights through wave reflections, caused by the impermeable reservoir boundaries. Hence, their knowledge is essential for a successful operational and constructive design of the reservoirs.

  18. Optimal Operation of Hydropower Reservoirs under Climate Change: The Case of Tekeze Reservoir, Eastern Nile

    Directory of Open Access Journals (Sweden)

    Fikru Fentaw Abera

    2018-03-01

    Full Text Available Optimal operation of reservoirs is very essential for water resource planning and management, but it is very challenging and complicated when dealing with climate change impacts. The objective of this paper was to assess existing and future hydropower operation at the Tekeze reservoir in the face of climate change. In this study, a calibrated and validated Soil and Water Assessment Tool (SWAT was used to model runoff inflow into the Tekeze hydropower reservoir under present and future climate scenarios. Inflow to the reservoir was simulated using hydro-climatic data from an ensemble of downscaled climate data based on the Coordinated Regional climate Downscaling Experiment over African domain (CORDEX-Africa with Coupled Intercomparison Project Phase 5 (CMIP5 simulations under Representative Concentration Pathway (RCP4.5 and RCP8.5 climate scenarios. Observed and projected inflows to Tekeze hydropower reservoir were used as input to the US Army Corps of Engineer’s Reservoir Evaluation System Perspective Reservoir Model (HEC-ResPRM, a reservoir operation model, to optimize hydropower reservoir release, storage and pool level. Results indicated that climate change has a clear impact on reservoir inflow and showed increase in annual and monthly inflow into the reservoir except in dry months from May to June under RCP4.5 and RCP8.5 climate scenarios. HEC-ResPRM optimal operation results showed an increase in Tekeze reservoir power storage potential up to 25% and 30% under RCP4.5 and RCP8.5 climate scenarios, respectively. This implies that Tekeze hydropower production will be affected by climate change. This analysis can be used by water resources planners and mangers to develop reservoir operation techniques considering climate change impact to increase power production.

  19. Improving reservoir history matching of EM heated heavy oil reservoirs via cross-well seismic tomography

    KAUST Repository

    Katterbauer, Klemens

    2014-01-01

    Enhanced recovery methods have become significant in the industry\\'s drive to increase recovery rates from oil and gas reservoirs. For heavy oil reservoirs, the immobility of the oil at reservoir temperatures, caused by its high viscosity, limits the recovery rates and strains the economic viability of these fields. While thermal recovery methods, such as steam injection or THAI, have extensively been applied in the field, their success has so far been limited due to prohibitive heat losses and the difficulty in controlling the combustion process. Electromagnetic (EM) heating via high-frequency EM radiation has attracted attention due to its wide applicability in different environments, its efficiency, and the improved controllability of the heating process. While becoming a promising technology for heavy oil recovery, its effect on overall reservoir production and fluid displacements are poorly understood. Reservoir history matching has become a vital tool for the oil & gas industry to increase recovery rates. Limited research has been undertaken so far to capture the nonlinear reservoir dynamics and significantly varying flow rates for thermally heated heavy oil reservoir that may notably change production rates and render conventional history matching frameworks more challenging. We present a new history matching framework for EM heated heavy oil reservoirs incorporating cross-well seismic imaging. Interfacing an EM heating solver to a reservoir simulator via Andrade’s equation, we couple the system to an ensemble Kalman filter based history matching framework incorporating a cross-well seismic survey module. With increasing power levels and heating applied to the heavy oil reservoirs, reservoir dynamics change considerably and may lead to widely differing production forecasts and increased uncertainty. We have shown that the incorporation of seismic observations into the EnKF framework can significantly enhance reservoir simulations, decrease forecasting

  20. TRANSFER RESERVOIR AS A RAINWATER DRAINAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Robert Malmur

    2016-06-01

    Full Text Available Intensive rainfalls and snow melting often cause floods in protected areas and overflow the existing sewage systems. Such cases are particularly burdensome for the inhabitants and cause considerable physical losses. One of the possible constructional solutions to ensure the effective outflow of stormwater are transfer reservoirs located between the draining system and a receiver set discussed in this paper. If gravity outflow of sewage is impossible, the initial part of sewage volume is accumulated in the transfer reservoir and then it is transferred into the water receiver set. However, gravity discharge of sewage to the water receiver set occurs through transfer chambers in the transfer reservoir.

  1. Non-Markovian reservoir-dependent squeezing

    International Nuclear Information System (INIS)

    Paavola, J

    2010-01-01

    The squeezing dynamics of a damped harmonic oscillator are studied for different types of environment without making the Markovian approximation. The squeezing dynamics of a coherent state depend on the reservoir spectrum in a unique way that can, in the weak coupling approximation, be analysed analytically. Comparison of squeezing dynamics for ohmic, sub-ohmic and super-ohmic environments is done, showing a clear connection between the squeezing-non-squeezing oscillations and reservoir structure. Understanding the effects occurring due to structured reservoirs is important both from a purely theoretical point of view and in connection with evolving experimental techniques and future quantum computing applications.

  2. Multilayer Spectral Graph Clustering via Convex Layer Aggregation: Theory and Algorithms

    OpenAIRE

    Chen, Pin-Yu; Hero, Alfred O.

    2017-01-01

    Multilayer graphs are commonly used for representing different relations between entities and handling heterogeneous data processing tasks. Non-standard multilayer graph clustering methods are needed for assigning clusters to a common multilayer node set and for combining information from each layer. This paper presents a multilayer spectral graph clustering (SGC) framework that performs convex layer aggregation. Under a multilayer signal plus noise model, we provide a phase transition analys...

  3. Improving reservoir conformance using gelled polymer systems. Annual report, September 25, 1994--September 24, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.

    1996-05-01

    The objectives of the research program are to (1) identify and develop polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focused on four types of gel systems -- KUSP1 systems which contain an aqueous polysaccharide designated KUSP1, phenolic-aldehyde systems composed of resorcinol and formaldehyde, colloidal-dispersion systems composed of polyacrylamide and aluminum citrate, and a chromium-based system where polyacrylamide is crosslinked by chromium(III). Gelation behavior of the resorcinol-formaldehyde systems and the KUSP1-borate system was examined. Size distributions of aggregates that form in the polyacrylamide-aluminum colloidal-dispersion gel system were determined. Permeabilities to brine of several rock materials were significantly reduced by gel treatments using the KUSP1 polymer-ester (monoethylphthalate) system, the KUSP1 polymer-boric acid system, and the sulfomethylated resorcinol-formaldehyde system. The KUSP1 polymer-ester system and the sulfomethylated resorcinol-formaldehyde system were also shown to significantly reduce the permeability to super-critical carbon dioxide. A mathematical model was developed to simulate the behavior of a chromium redox-polyacrylamide gel system that is injected through a wellbore into a multi-layer reservoir in which crossflow between layers is allowed. The model describes gelation kinetics and filtration of pre-gel aggregates in the reservoir. Studies using the model demonstrated the effect filtration of gel aggregates has on the placement of gel systems in layered reservoirs.

  4. Improving reservoir conformance using gelled polymer systems. Final report, September 25, 1992--July 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1997-06-01

    The objectives of the research program were to (1) identify and develop polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focused on four types of gel systems--KUSP1 systems that contain an aqueous polysaccharide designated KUSP1, phenolic-aldehyde systems composed of resorcinol and formaldehyde, colloidal-dispersion systems composed of polyacrylamide and aluminum citrate, and a chromium-based system where polyacrylamide is crosslinked by chromium(III). Gelation behavior of the resorcinol-formaldehyde systems and the KUSP1-borate system was examined. Size distributions of aggregates that form in the polyacrylamide-aluminum colloidal-dispersion gel system were determined. Permeabilities to brine of several rock materials were significantly reduced by gel treatments using the KUSP1 polymer-ester (monoethyl phthalate) system, the KUSP1 polymer-boric acid system, and the sulfomethylated resorcinol-formaldehyde system were also shown to significantly reduce the permeability to supercritical carbon dioxide. A mathematical model was developed to simulate the behavior of a chromium redox-polyacrylamide gel system that is injected through a wellbore into a multi-layer reservoir in which crossflow between layers is allowed. The model describes gelation kinetics and filtration of pre-gel aggregates in the reservoir. Studies using the model demonstrated the effect filtration of gel aggregates has on the placement of gel systems in layered reservoirs.

  5. Gasbuggy reservoir evaluation - 1969 report

    International Nuclear Information System (INIS)

    Atkinson, C.H.; Ward, Don C.; Lemon, R.F.

    1970-01-01

    The December 10, 1967, Project Gasbuggy nuclear detonation followed the drilling and testing of two exploratory wells which confirmed reservoir characteristics and suitability of the site. Reentry and gas production testing of the explosive emplacement hole indicated a collapse chimney about 150 feet in diameter extending from the 4,240-foot detonation depth to about 3,900 feet, the top of the 300-foot-thick Pictured Cliffs gas sand. Production tests of the chimney well in the summer of 1968 and during the last 12 months have resulted in a cumulative production of 213 million cubic feet of hydrocarbons, and gas recovery in 20 years is estimated to be 900 million cubic feet, which would be an increase by a factor of at least 5 over estimated recovery from conventional field wells in this low permeability area. At the end of production tests the flow rate was 160,000 cubic feet per day, which is 6 to 7 times that of an average field well in the area. Data from reentry of a pre-shot test well and a new postshot well at distances from the detonation of 300 and 250 feet, respectively, indicate low productivity and consequently low permeability in any fractures at these locations. (author)

  6. Gasbuggy reservoir evaluation - 1969 report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C H; Ward, Don C [Bureau of Mines, U.S. Department of the Interior (United States); Lemon, R F [El Paso Natural Gas Company (United States)

    1970-05-01

    The December 10, 1967, Project Gasbuggy nuclear detonation followed the drilling and testing of two exploratory wells which confirmed reservoir characteristics and suitability of the site. Reentry and gas production testing of the explosive emplacement hole indicated a collapse chimney about 150 feet in diameter extending from the 4,240-foot detonation depth to about 3,900 feet, the top of the 300-foot-thick Pictured Cliffs gas sand. Production tests of the chimney well in the summer of 1968 and during the last 12 months have resulted in a cumulative production of 213 million cubic feet of hydrocarbons, and gas recovery in 20 years is estimated to be 900 million cubic feet, which would be an increase by a factor of at least 5 over estimated recovery from conventional field wells in this low permeability area. At the end of production tests the flow rate was 160,000 cubic feet per day, which is 6 to 7 times that of an average field well in the area. Data from reentry of a pre-shot test well and a new postshot well at distances from the detonation of 300 and 250 feet, respectively, indicate low productivity and consequently low permeability in any fractures at these locations. (author)

  7. Physics and technology development of multilayer EUV reflective optics

    NARCIS (Netherlands)

    Louis, Eric

    2012-01-01

    This thesis describes the development of molybdenum/silicon based multilayer reflective elements for the Extreme UV wavelength range, as motivated by their application in photolithography for semiconductor manufacturing. The thesis reflects the basic thin film physics, technological developments,

  8. Photo-crosslinkable polymers for fabrication of photonic multilayer sensors

    Science.gov (United States)

    Chiappelli, Maria; Hayward, Ryan C.

    2013-03-01

    We have used photo-crosslinkable polymers to fabricate photonic multilayer sensors. Benzophenone is utilized as a covalently incorporated pendent photo-crosslinker, providing a convenient means of fabricating multilayer films by sequential spin-coating and crosslinking processes. Colorimetric temperature sensors were designed from thermally-responsive, low-refractive index poly(N-isopropylacrylamide) (PNIPAM) and high-refractive index poly(para-methyl styrene) (P pMS). Copolymer chemistries and layer thicknesses were selected to provide robust multilayer sensors which show color changes across nearly the full visible spectrum due to changes in temperature of the hydrated film stack. We have characterized the uniformity and interfacial broadening within the multilayers, the kinetics of swelling and de-swelling, and the reversibility over multiple hydration/dehydration cycles. We also describe how the approach can be extended to alternative sensor designs through the ability to tailor each layer independently, as well as to additional stimuli by selecting alternative copolymer chemistries.

  9. Wave transmission prediction of multilayer floating breakwater using neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Patil, S.G.; Hegde, A.V.

    In the present study, an artificial neural network method has been applied for wave transmission prediction of multilayer floating breakwater. Two neural network models are constructed based on the parameters which influence the wave transmission...

  10. SIW based multilayer transition and power divider in LTCC technology

    KAUST Repository

    Abuzaid, Hattan; Doghri, Ali; Wu, Ke; Shamim, Atif

    2013-01-01

    A multilayer transition and balanced power divider are presented for millimeter-wave system-on-package (SoP). These two components operate at Ka-band and exploit the substrate integrate waveguide (SIW) technology with its shielding characteristics

  11. Acoustic transmittance of an aperiodic deterministic multilayer structure

    International Nuclear Information System (INIS)

    Madrigal-Melchor, J; Enciso-Muñoz, A; Contreras-Solorio, D A

    2013-01-01

    We study theoretically the acoustic transmission for a multilayer structure where the characteristic acoustic impedance follows the values generated by the self-similar sequence called the 1 s counting sequence . The transmission spectrum shows clearly self-similarity characteristics.

  12. Multi-layer protective armour for underwater shock wave mitigation

    Directory of Open Access Journals (Sweden)

    Ahmed Hawass

    2015-12-01

    The strain gauge data and displacement sensors results showed that the multi-layer plates have higher level of underwater shock wave mitigation than the triple aluminum plates with strain and deflection of nearly 50%.

  13. Modeling Delamination of Interfacial Corner Cracks in Multilayered Structures

    DEFF Research Database (Denmark)

    Veluri, Badrinath (Badri); Jensen, Henrik Myhre

    2013-01-01

    Multilayered electronic components, typically of heterogeneous materials, delaminate under thermal and mechanical loading. A phenomenological model focused on modeling the shape of such interface cracks close to corners in layered interconnect structures for calculating the critical stress...

  14. Robots for Field Operations with Comprehensive Multilayer Control

    DEFF Research Database (Denmark)

    Jæger, Claes Lund Dühring; Griepentrog, H. W.; Paraforos, D. S.

    2013-01-01

    artificial intelligence. A multilayer controller has successfully been implemented on two outdoor machines with various implements to conduct several agricultural applications in autonomous mode. Future work has to be conducted to achieve a more integrated and flexible implement control....

  15. Optical Properties of Multilayer CdSe/POLYMER Structures

    Science.gov (United States)

    Red'Ko, V. P.; Voitenkov, A. I.; Kovalenko, O. E.

    The effects of preparation condition, concentration and size of particles upon optical and photoelectrical characteristics of multilayer structures CdSe/polyethylene terephthalate obtained by electron-beam evaporation were investigated.

  16. Magnetic and transport properties of sputtered Gd-Y multilayers

    International Nuclear Information System (INIS)

    Freitas, P.P.; From, M.; Melo, L.V.

    1991-01-01

    Gd-Y-Gd multilayers were prepared that show a magnetoresistance enhancement for an Y layer separation of 30 A. This magnetoresistance enhancement is an interface effect and occurs in samples where some degree of antiferromagnetic coupling is present

  17. Tunable drug loading and release from polypeptide multilayer nanofilms

    Science.gov (United States)

    Jiang, Bingbing; Li, Bingyun

    2009-01-01

    Polypeptide multilayer nanofilms were prepared using electrostatic layer-by-layer self-assembly nanotechnology. Small charged drug molecules (eg, cefazolin, gentamicin, and methylene blue) were loaded in polypeptide multilayer nanofilms. Their loading and release were found to be pH-dependent and could also be controlled by changing the number of film layers and drug incubation time, and applying heat-treatment after film formation. Antibioticloaded polypeptide multilayer nanofilms showed controllable antibacterial properties against Staphylococcus aureus. The developed biodegradable polypeptide multilayer nanofilms are capable of loading both positively- and negatively-charged drug molecules and promise to serve as drug delivery systems on biomedical devices for preventing biomedical device-associated infection, which is a significant clinical complication for both civilian and military patients. PMID:19421369

  18. Multi-layer Far-Infrared Component Technology, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR will demonstrate the feasibility of a process to create multi-layer thin-film optics for the far-infrared/sub-millimeter wave spectral region. The...

  19. Assembling evidence for identifying reservoirs of infection.

    Science.gov (United States)

    Viana, Mafalda; Mancy, Rebecca; Biek, Roman; Cleaveland, Sarah; Cross, Paul C; Lloyd-Smith, James O; Haydon, Daniel T

    2014-05-01

    Many pathogens persist in multihost systems, making the identification of infection reservoirs crucial for devising effective interventions. Here, we present a conceptual framework for classifying patterns of incidence and prevalence, and review recent scientific advances that allow us to study and manage reservoirs simultaneously. We argue that interventions can have a crucial role in enriching our mechanistic understanding of how reservoirs function and should be embedded as quasi-experimental studies in adaptive management frameworks. Single approaches to the study of reservoirs are unlikely to generate conclusive insights whereas the formal integration of data and methodologies, involving interventions, pathogen genetics, and contemporary surveillance techniques, promises to open up new opportunities to advance understanding of complex multihost systems. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. NYC Reservoirs Watershed Areas (HUC 12)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This NYC Reservoirs Watershed Areas (HUC 12) GIS layer was derived from the 12-Digit National Watershed Boundary Database (WBD) at 1:24,000 for EPA Region 2 and...

  1. determination of verticality of reservoir engineering structure

    African Journals Online (AJOL)

    user

    applications is 3D survey and management of oil and gas facilities and other engineering structures. This recent .... also affect ground water contamination. 2. VERTICALITY ...... The soil, water and concrete in a Reservoir at the foundation bed ...

  2. Reservoir Greenhouse Gas Emissions at Russian HPP

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, M. P.; Elistratov, V. V.; Maslikov, V. I.; Sidorenko, G. I.; Chusov, A. N.; Atrashenok, V. P.; Molodtsov, D. V. [St. Petersburg State Polytechnic University (Russian Federation); Savvichev, A. S. [Russian Academy of Sciences, S. N. Vinogradskii Institute of Microbiology (Russian Federation); Zinchenko, A. V. [A. I. Voeikov Main Geophysical Observatory (Russian Federation)

    2015-05-15

    Studies of greenhouse-gas emissions from the surfaces of the world’s reservoirs, which has demonstrated ambiguity of assessments of the effect of reservoirs on greenhouse-gas emissions to the atmosphere, is analyzed. It is recommended that greenhouse- gas emissions from various reservoirs be assessed by the procedure “GHG Measurement Guidelines for Fresh Water Reservoirs” (2010) for the purpose of creating a data base with results of standardized measurements. Aprogram for research into greenhouse-gas emissions is being developed at the St. Petersburg Polytechnic University in conformity with the IHA procedure at the reservoirs impounded by the Sayano-Shushenskaya and Mainskaya HPP operated by the RusHydro Co.

  3. Refined reservoir description to maximize oil recovery

    International Nuclear Information System (INIS)

    Flewitt, W.E.

    1975-01-01

    To assure maximized oil recovery from older pools, reservoir description has been advanced by fully integrating original open-hole logs and the recently introduced interpretive techniques made available through cased-hole wireline saturation logs. A refined reservoir description utilizing normalized original wireline porosity logs has been completed in the Judy Creek Beaverhill Lake ''A'' Pool, a reefal carbonate pool with current potential productivity of 100,000 BOPD and 188 active wells. Continuous porosity was documented within a reef rim and cap while discontinuous porous lenses characterized an interior lagoon. With the use of pulsed neutron logs and production data a separate water front and pressure response was recognized within discrete environmental units. The refined reservoir description aided in reservoir simulation model studies and quantifying pool performance. A pattern water flood has now replaced the original peripheral bottom water drive to maximize oil recovery

  4. Zooplankton assemblage of Oyun Reservoir, Offa, Nigeria.

    Science.gov (United States)

    Mustapha, Moshood K

    2009-12-01

    The influence of physico-chemical properties of Oyun Reservoir, Offa, Nigeria (a shallow tropical African reservoir) on its zooplankton composition and abundance were investigated at three stations for two years between January 2002 and December 2003. Diversity is not high: only three groups of zooplankton were found: Rotifera with eight genera; and Cladocera and Copepoda with three genera each. Rotifera dominated numerically (71.02%), followed by Cladocera (16.45%) and Copepoda (12.53%). The zooplankton was more prevalent during the rainy season, and there were variations in the composition and abundance along the reservoir continuum. Factors such as temperature, nutrients, food availability, shape and hydrodynamics of the reservoir, as well as reproductive strategies of the organisms, strongly influence the generic composition and population density of zooplankton. Prevention of ecological deterioration of the water body would greatly should result in a more productive water body, rich in zooplankton and with better fisheries.

  5. Data Compression of Hydrocarbon Reservoir Simulation Grids

    KAUST Repository

    Chavez, Gustavo Ivan; Harbi, Badr M.

    2015-01-01

    A dense volumetric grid coming from an oil/gas reservoir simulation output is translated into a compact representation that supports desired features such as interactive visualization, geometric continuity, color mapping and quad representation. A

  6. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    case studies will show the degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants and animals, shows that age differences of up to 2000 years can occur within one river. In the Limfjord, freshwater influence......The freshwater reservoir effect can result in too high radiocarbon ages of samples from lakes and rivers, including the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. In my talk, I will explain the causes and consequences of this effect. Two...... caused reservoir ages to vary between 250 and 700 years during the period 5400 BC - AD 700. Finally, I will discuss the implications of the freshwater reservoir effect for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany....

  7. Assembling evidence for identifying reservoirs of infection

    Science.gov (United States)

    Mafalda, Viana; Rebecca, Mancy; Roman, Biek; Sarah, Cleaveland; Cross, Paul C.; James O, Lloyd-Smith; Daniel T, Haydon

    2014-01-01

    Many pathogens persist in multihost systems, making the identification of infection reservoirs crucial for devising effective interventions. Here, we present a conceptual framework for classifying patterns of incidence and prevalence, and review recent scientific advances that allow us to study and manage reservoirs simultaneously. We argue that interventions can have a crucial role in enriching our mechanistic understanding of how reservoirs function and should be embedded as quasi-experimental studies in adaptive management frameworks. Single approaches to the study of reservoirs are unlikely to generate conclusive insights whereas the formal integration of data and methodologies, involving interventions, pathogen genetics, and contemporary surveillance techniques, promises to open up new opportunities to advance understanding of complex multihost systems.

  8. Lower Palaeozoic reservoirs of North Africa

    Energy Technology Data Exchange (ETDEWEB)

    Crossley, R.; McDougall, N. [Robertson Research International Ltd., Llandudno, Conwy (United Kingdom)

    1998-12-31

    This paper provides an overview of features considered significant in the exploration and development of Lower Palaeozoic reservoirs of North Africa. Information is derived from a review of literature on the Lower Palaeozoic successions of North Africa, combined with outcrop observations from the Anti Atlas mountains of Morocco. The focus of the exploration-oriented part of the review is on identification of potential traps other than two-way structural dip closure. Stratigraphic elements described include depositional models of reservoir facies, tectonic unconformities and possible eustatic unconformities. Cases of established or potential trapping by post-depositional faulting by diagenesis and by hydrodynamic flow are examined. Development-related topics highlighted include the impact on reservoir matrix quality of burial diagenesis and of palaeo-weathering at the Hercynian unconformity. Other issues discussed which additionally affect producibility from the reservoir matrix include tectonic fracturing, palaeotopography and unloading fracturing at the Hercynian unconformity, and induced fracturing within the present stress regimes. (author)

  9. 49 CFR 393.50 - Reservoirs required.

    Science.gov (United States)

    2010-10-01

    ... using air or vacuum braking must have either reserve capacity, or a reservoir, that would enable the... have a condensate drain valve that can be manually operated. Automatic condensate drain valves may be...

  10. Reference Models for Multi-Layer Tissue Structures

    Science.gov (United States)

    2016-09-01

    function of multi-layer tissues (etiology and management of pressure ulcers ). What was the impact on other disciplines? As part of the project, a data...simplification to develop cost -effective models of surface manipulation of multi-layer tissues. Deliverables. Specimen- (or subject) and region-specific...simplification to develop cost -effective models of surgical manipulation. Deliverables. Specimen-specific surrogate models of upper legs confirmed against data

  11. Multilayer DNA Origami Packed on Hexagonal and Hybrid Lattices

    OpenAIRE

    Ke, Yonggang; Voigt, Niels V.; Gothelf, Kurt V.; Shih, William M.

    2012-01-01

    “Scaffolded DNA origami” has been proven to be a powerful and efficient approach to construct two-dimensional or three-dimensional objects with great complexity. Multilayer DNA origami has been demonstrated with helices packing along either honeycomb-lattice geometry or square-lattice geometry. Here we report successful folding of multilayer DNA origami with helices arranged on a close-packed hexagonal lattice. This arrangement yields a higher density of helical packing and therefore higher r...

  12. Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy.

    Science.gov (United States)

    Bogachev, S A; Chkhalo, N I; Kuzin, S V; Pariev, D E; Polkovnikov, V N; Salashchenko, N N; Shestov, S V; Zuev, S Y

    2016-03-20

    We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term stabilities of the proposed multilayer coatings. In the spectral range λ=13  nm, Mo/Be multilayer mirrors were shown to demonstrate a better ratio of reflection efficiency and spectral resolution compared with the commonly used Mo/Si. In the spectral range λ=17-21  nm, a new multilayer structure Al/Si was proposed, which had higher spectral resolution along with comparable reflection efficiency compared with the commonly used Al/Zr multilayer structures. In the spectral range λ=30  nm, the Si/B4C/Mg/Cr multilayer structure turned out to best obey reflection efficiency and long-term stability. The B4C and Cr layers prevented mutual diffusion of the Si and Mg layers. For the spectral range λ=58  nm, a new multilayer Mo/Mg-based structure was developed; its reflection efficiency and long-term stability have been analyzed. We also investigated intrinsic stresses inherent for most of the multilayer structures and proposed possibilities for stress elimination.

  13. Finite-width plasmonic waveguides with hyperbolic multilayer cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi

    2015-01-01

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogeniz......Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any...

  14. Multilayer Relaxation and Surface Energies of Metallic Surfaces

    Science.gov (United States)

    Bozzolo, Guillermo; Rodriguez, Agustin M.; Ferrante, John

    1994-01-01

    The perpendicular and parallel multilayer relaxations of fcc (210) surfaces are studied using equivalent crystal theory (ECT). A comparison with experimental and theoretical results is made for AI(210). The effect of uncertainties in the input parameters on the magnitudes and ordering of surface relaxations for this semiempirical method is estimated. A new measure of surface roughness is proposed. Predictions for the multilayer relaxations and surface energies of the (210) face of Cu and Ni are also included.

  15. Flow of a stream through a reservoir

    International Nuclear Information System (INIS)

    Sauerwein, K.

    1967-01-01

    If a reservoir is fed from a single source, which may not always be pure, the extent to which the inflowing stream mixes with the water in the reservoir is important for the quality of the water supplied by the reservoir. This question was investigated at the Lingese Reservoir, containing between one and two million cubic metres of water, in the Bergisches Land (North Rhine-Westphalia). The investigation was carried out at four different seasons so that the varying effects of the stream-water temperatures could be studied in relation to the temperature of the reservoir water. The stream was radioactively labelled at the point of inflow into the reservoir, and its flow through the reservoir was measured in length and depth from boats, by means of 1-m-long Geiger counters. In two cases the radioactivity of the outflowing water was also measured at fixed points. A considerable variety of intermixing phenomena were observed; these were mainly of limnological interest. The results of four experiments corresponding to the four different seasons are described in detail. They were as follows: (1) The mid-October experiment where the stream, with a temperature of 8.0 deg. C, was a good 5 deg. C colder than the water of the reservoir, whose temperature was almost uniform, ranging from 13.2 deg. C at the bed to 13.6 deg. C at the surface. (2) The spring experiment (second half of March), when the stream temperature was only 0.3 deg. C below that of the reservoir surface (7.8 deg. C), while the temperature of the bed was 5.8 deg. C. (3) The winter experiment (early December) where at first the temperature of the stream was approximately the same as that of the surface so that, once again, the stream at first flowed 1/2 - 1 m below the surface. During the almost wind-free night a sudden fall in temperature occurred, and the air temperature dropped from 0 deg. C to -12 deg. C. (4) The summer experiment (end of July to mid-August) when the stream was nearly 1 deg. C colder than

  16. limnological study of the Guavio Reservoir (Colombia)

    International Nuclear Information System (INIS)

    Roldan, Gabriel; Bohorquez, Amparo; Catano, Ramiro; Ardila, Jorge I

    2000-01-01

    From September to December 1996, a limnological study of el Guavio reservoir from o to 100m deep was undertaken. Samples of plankton were taken and chlorophyll a determined. The study showed a well-mixed column of water. Dissolved oxygen remained 60% saturation at 100m deep. Values of phosphorus and nitrogen, as well chlorophyll was very low. Phytoplankton and zooplankton were diverse. The main problem of the reservoir is sediments coming from very erossionable surroundings

  17. Pollination Reservoirs in Lowbush Blueberry (Ericales: Ericaceae)

    OpenAIRE

    Venturini, E. M.; Drummond, F. A.; Hoshide, A. K.; Dibble, A. C.; Stack, L. B.

    2017-01-01

    Abstract Pollinator-dependent agriculture heavily relies upon a single pollinator?the honey bee. To diversify pollination strategies, growers are turning to alternatives. Densely planted reservoirs of pollen- and nectar-rich flowers (pollination reservoirs, hereafter ?PRs?) may improve pollination services provided by wild bees. Our focal agroecosystem, lowbush blueberry (Vaccinium angustifolium Aiton), exists in a simple landscape uniquely positioned to benefit from PRs. First, we contrast b...

  18. Ecological operation for Three Gorges Reservoir

    Directory of Open Access Journals (Sweden)

    Wen-xian Guo

    2011-06-01

    Full Text Available The traditional operation of the Three Gorges Reservoir has mainly focused on water for flood control, power generation, navigation, water supply, and recreation, and given less attention to the negative impacts of reservoir operation on the river ecosystem. In order to reduce the negative influence of reservoir operation, ecological operation of the reservoir should be studied with a focus on maintaining a healthy river ecosystem. This study considered ecological operation targets, including maintaining the river environmental flow and protecting the spawning and reproduction of the Chinese sturgeon and four major Chinese carps. Using flow data from 1900 to 2006 at the Yichang gauging station as the control station data for the Yangtze River, the minimal and optimal river environmental flows were analyzed, and eco-hydrological targets for the Chinese sturgeon and four major Chinese carps in the Yangtze River were calculated. This paper proposes a reservoir ecological operation model, which comprehensively considers flood control, power generation, navigation, and the ecological environment. Three typical periods, wet, normal, and dry years, were selected, and the particle swarm optimization algorithm was used to analyze the model. The results show that ecological operation modes have different effects on the economic benefit of the hydropower station, and the reservoir ecological operation model can simulate the flood pulse for the requirements of spawning of the Chinese sturgeon and four major Chinese carps. According to the results, by adopting a suitable re-operation scheme, the hydropower benefit of the reservoir will not decrease dramatically while the ecological demand is met. The results provide a reference for designing reasonable operation schemes for the Three Gorges Reservoir.

  19. Analog readout for optical reservoir computers

    OpenAIRE

    Smerieri, Anteo; Duport, François; Paquot, Yvan; Schrauwen, Benjamin; Haelterman, Marc; Massar, Serge

    2012-01-01

    Reservoir computing is a new, powerful and flexible machine learning technique that is easily implemented in hardware. Recently, by using a time-multiplexed architecture, hardware reservoir computers have reached performance comparable to digital implementations. Operating speeds allowing for real time information operation have been reached using optoelectronic systems. At present the main performance bottleneck is the readout layer which uses slow, digital postprocessing. We have designed a...

  20. Geophysical monitoring in a hydrocarbon reservoir

    Science.gov (United States)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

    Extraction of hydrocarbons from reservoirs demands ever-increasing technological effort, and there is need for geophysical monitoring to better understand phenomena occurring within the reservoir. Significant deformation processes happen when man-made stimulation is performed, in combination with effects deriving from the existing natural conditions such as stress regime in situ or pre-existing fracturing. Keeping track of such changes in the reservoir is important, on one hand for improving recovery of hydrocarbons, and on the other hand to assure a safe and proper mode of operation. Monitoring becomes particularly important when hydraulic-fracturing (HF) is used, especially in the form of the much-discussed "fracking". HF is a sophisticated technique that is widely applied in low-porosity geological formations to enhance the production of natural hydrocarbons. In principle, similar HF techniques have been applied in Europe for a long time in conventional reservoirs, and they will probably be intensified in the near future; this suggests an increasing demand in technological development, also for updating and adapting the existing monitoring techniques in applied geophysics. We review currently available geophysical techniques for reservoir monitoring, which appear in the different fields of analysis in reservoirs. First, the properties of the hydrocarbon reservoir are identified; here we consider geophysical monitoring exclusively. The second step is to define the quantities that can be monitored, associated to the properties. We then describe the geophysical monitoring techniques including the oldest ones, namely those in practical usage from 40-50 years ago, and the most recent developments in technology, within distinct groups, according to the application field of analysis in reservoir. This work is performed as part of the FracRisk consortium (www.fracrisk.eu); this project, funded by the Horizon2020 research programme, aims at helping minimize the

  1. Magnetic damping phenomena in ferromagnetic thin-films and multilayers

    Science.gov (United States)

    Azzawi, S.; Hindmarch, A. T.; Atkinson, D.

    2017-11-01

    Damped ferromagnetic precession is an important mechanism underpinning the magnetisation processes in ferromagnetic materials. In thin-film ferromagnets and ferromagnetic/non-magnetic multilayers, the role of precession and damping can be critical for spintronic device functionality and as a consequence there has been significant research activity. This paper presents a review of damping in ferromagnetic thin-films and multilayers and collates the results of many experimental studies to present a coherent synthesis of the field. The terms that are used to define damping are discussed with the aim of providing consistent definitions for damping phenomena. A description of the theoretical basis of damping is presented from early developments to the latest discussions of damping in ferromagnetic thin-films and multilayers. An overview of the time and frequency domain methods used to study precessional magnetisation behaviour and damping in thin-films and multilayers is also presented. Finally, a review of the experimental observations of magnetic damping in ferromagnetic thin-films and multilayers is presented with the most recent explanations. This brings together the results from many studies and includes the effects of ferromagnetic film thickness, the effects of composition on damping in thin-film ferromagnetic alloys, the influence of non-magnetic dopants in ferromagnetic films and the effects of combining thin-film ferromagnets with various non-magnetic layers in multilayered configurations.

  2. Desktop aligner for fabrication of multilayer microfluidic devices.

    Science.gov (United States)

    Li, Xiang; Yu, Zeta Tak For; Geraldo, Dalton; Weng, Shinuo; Alve, Nitesh; Dun, Wu; Kini, Akshay; Patel, Karan; Shu, Roberto; Zhang, Feng; Li, Gang; Jin, Qinghui; Fu, Jianping

    2015-07-01

    Multilayer assembly is a commonly used technique to construct multilayer polydimethylsiloxane (PDMS)-based microfluidic devices with complex 3D architecture and connectivity for large-scale microfluidic integration. Accurate alignment of structure features on different PDMS layers before their permanent bonding is critical in determining the yield and quality of assembled multilayer microfluidic devices. Herein, we report a custom-built desktop aligner capable of both local and global alignments of PDMS layers covering a broad size range. Two digital microscopes were incorporated into the aligner design to allow accurate global alignment of PDMS structures up to 4 in. in diameter. Both local and global alignment accuracies of the desktop aligner were determined to be about 20 μm cm(-1). To demonstrate its utility for fabrication of integrated multilayer PDMS microfluidic devices, we applied the desktop aligner to achieve accurate alignment of different functional PDMS layers in multilayer microfluidics including an organs-on-chips device as well as a microfluidic device integrated with vertical passages connecting channels located in different PDMS layers. Owing to its convenient operation, high accuracy, low cost, light weight, and portability, the desktop aligner is useful for microfluidic researchers to achieve rapid and accurate alignment for generating multilayer PDMS microfluidic devices.

  3. The characterization of multilayers analyzers: Models and measurements

    International Nuclear Information System (INIS)

    Henke, B.L.; Vejio, J.Y.; Tackaberry, R.E.; Yamada, H.T.

    1985-01-01

    A procedure is described for the detailed characterization of multilayer analyzers which can be effectively applied to their design, optimization and application for absolute x-ray spectrometry. An accurate analytical model has been developed that is based upon a simple modification of the dynamical Darwin-Prins theory to extend its application to finite multilayer systems. Its equivalence to the optical E and M solution of the Fresnel equations at each interface is demonstrated by detailed calculation comparisons for the reflectivity of a multilayer throughout the angular range of incidence of 0 to 90 0 . A special spectrograph and experimental method is described for the measurement of the absolute reflectivity characteristics of the multilayer. The experimental measurements at three photon energies in the 100-200 eV region are fit by the analytical modified Darwin-Prins equation (MDP) for I(θ), generating a detailed characterization of two ''state of the art'' multilayers, a sputtered tungsten-carbon of 2d ≅ 70 A and a molecular lead separate of 2d ≅ 100 A. The fitting parameters that are determined in this procedure are applied to help establish the structural characteristics of the particular multilayer

  4. Clustering network layers with the strata multilayer stochastic block model.

    Science.gov (United States)

    Stanley, Natalie; Shai, Saray; Taylor, Dane; Mucha, Peter J

    2016-01-01

    Multilayer networks are a useful data structure for simultaneously capturing multiple types of relationships between a set of nodes. In such networks, each relational definition gives rise to a layer. While each layer provides its own set of information, community structure across layers can be collectively utilized to discover and quantify underlying relational patterns between nodes. To concisely extract information from a multilayer network, we propose to identify and combine sets of layers with meaningful similarities in community structure. In this paper, we describe the "strata multilayer stochastic block model" (sMLSBM), a probabilistic model for multilayer community structure. The central extension of the model is that there exist groups of layers, called "strata", which are defined such that all layers in a given stratum have community structure described by a common stochastic block model (SBM). That is, layers in a stratum exhibit similar node-to-community assignments and SBM probability parameters. Fitting the sMLSBM to a multilayer network provides a joint clustering that yields node-to-community and layer-to-stratum assignments, which cooperatively aid one another during inference. We describe an algorithm for separating layers into their appropriate strata and an inference technique for estimating the SBM parameters for each stratum. We demonstrate our method using synthetic networks and a multilayer network inferred from data collected in the Human Microbiome Project.

  5. Oromucosal multilayer films for tailor-made, controlled drug delivery.

    Science.gov (United States)

    Lindert, Sandra; Breitkreutz, Jörg

    2017-11-01

    The oral mucosa has recently become increasingly important as an alternative administration route for tailor-made, controlled drug delivery. Oromucosal multilayer films, assigned to the monograph oromucosal preparations in the Ph.Eur. may be a promising dosage form to overcome the requirements related to this drug delivery site. Areas covered: We provide an overview of multilayer films as drug delivery tools, and discuss manufacturing processes and characterization methods. We focus on the suitability of characterization methods for particular requirements of multilayer films. A classification was performed covering indication areas and APIs incorporated in multilayer film systems for oromucosal use in order to provide a summary of data published in this field. Expert opinion: The shift in drug development to high molecular weight drugs will influence the field of pharmaceutical development and delivery technologies. For a high number of indication areas, such as hormonal disorders, cardiovascular diseases or local treatment of infections, the flexible layer design of oromucosal multilayer films provides a promising option for tailor-made, controlled delivery of APIs to or through defined surfaces in the oral cavity. However, there is a lack of discriminating or standardized testing methods to assess the quality of multilayer films in a reliable way.

  6. Asynchronous cracking with dissimilar paths in multilayer graphene.

    Science.gov (United States)

    Jang, Bongkyun; Kim, Byungwoon; Kim, Jae-Hyun; Lee, Hak-Joo; Sumigawa, Takashi; Kitamura, Takayuki

    2017-11-16

    Multilayer graphene consists of a stack of single-atomic-thick monolayer graphene sheets bound with π-π interactions and is a fascinating model material opening up a new field of fracture mechanics. In this study, fracture behavior of single-crystalline multilayer graphene was investigated using an in situ mode I fracture test under a scanning electron microscope, and abnormal crack propagation in multilayer graphene was identified for the first time. The fracture toughness of graphene was determined from the measured load-displacement curves and the realistic finite element modelling of specimen geometries. Nonlinear fracture behavior of the multilayer graphene is discussed based on nonlinear elastic fracture mechanics. In situ scanning electron microscope images obtained during the fracture test showed asynchronous crack propagation along independent paths, causing interlayer shear stress and slippages. We also found that energy dissipation by interlayer slippages between the graphene layers is the reason for the enhanced fracture toughness of multilayer graphene. The asynchronous cracking with independent paths is a unique cracking and toughening mechanism for single-crystalline multilayer graphene, which is not observed for the monolayer graphene. This could provide a useful insight for the design and development of graphene-based composite materials for structural applications.

  7. Recycling of Polymer-Based Multilayer Packaging: A Review

    Directory of Open Access Journals (Sweden)

    Katharina Kaiser

    2017-12-01

    Full Text Available Polymer-based multilayer packaging materials are commonly used in order to combine the respective performance of different polymers. By this approach, the tailored functionality of packaging concepts is created to sufficiently protect sensitive food products and thus obtain extended shelf life. However, because of their poor recyclability, most multilayers are usually incinerated or landfilled, counteracting the efforts towards a circular economy and crude oil independency. This review depicts the current state of the European multilayer packaging market and sketches the current end-of-life situation of postconsumer multilayer packaging waste in Germany. In the main section, a general overview of the state of research about material recycling of different multilayer packaging systems is provided. It is divided into two subsections, whereby one describes methods to achieve a separation of the different components, either by delamination or the selective dissolution–reprecipitation technique, and the other describes methods to achieve recycling by compatibilization of nonmiscible polymer types. While compatibilization methods and the technique of dissolution–reprecipitation are already extensively studied, the delamination of packaging has not been investigated systematically. All the presented options are able to recycle multilayer packaging, but also have drawbacks like a limited scope or a high expenditure of energy.

  8. Polymerization of vinyl stearate multilayers by electron beam irradiation

    International Nuclear Information System (INIS)

    Nishii, Masanobu; Hatada, Motoyoshi

    1975-01-01

    Studies on the radiation-induced polymerization of vinyl stearate (VST) multilayers were carried out. The VST multilayers built-up on an aluminum plated glass plate by Langmuir-Blodgett technique were irradiated with electron beams from a Van de Graaff electron accelerator in nitrogen atmosphere. The structure of the multilayers and the effects of irradiation were investigated by X-ray diffractometry, contact angle measurement, multireflection infrared spectroscopy, and scanning electron microscopy. The VST multilayers became insoluble to methanol by the irradiation, and the multi-reflection infrared spectrum of the VST multilayers turned into that of poly (VST) with increasing dosage. The polymerization proceeded during the irradiation at the temperature range between -10 0 and 10 0 C, and the conversion attained to 90% within 2.5 minutes (total dose, 5.6 Mrads). The multilayers irradiated above 13 Mrads turned into the polymer film insoluble to benzene, indicating that the polymer chains were cross-linked by the irradiation. Stearic acid which was formed by the irradiation of VST at nitrogen-water interface as a hydrolysis product was not detected in this system. (auth.)

  9. Multilayer composition coatings for cutting tools: formation and performance properties

    Science.gov (United States)

    Tabakov, Vladimir P.; Vereschaka, Anatoly S.; Vereschaka, Alexey A.

    2018-03-01

    The paper considers the concept of a multi-layer architecture of the coating in which each layer has a predetermined functionality. Latest generation of coatings with multi-layered architecture for cutting tools secure a dual nature of the coating, in which coatings should not only improve the mechanical and physical characteristics of the cutting tool material, but also reduce the thermo-mechanical effect on the cutting tool determining wear intensity. Here are presented the results of the development of combined methods of forming multi-layer coatings with improved properties. Combined method of forming coatings using a pulsed laser allowed reducing excessively high levels of compressive residual stress and increasing micro hardness of the multilayered coatings. The results in testing coated HSS tools showed that the use of additional pulse of laser processing increases tool life up to 3 times. Using filtered cathodic vacuum arc deposition for the generation of multilayer coatings based on TiAlN compound has increased the wear-resistance of carbide tools by 2 fold compared with tool life of cutting tool with commercial TiN coatings. The aim of this study was to develop an innovative methodological approach to the deposition of multilayer coatings for cutting tools with functional architectural selection, properties and parameters of the coating based on sound knowledge of coating failure in machining process.

  10. Evaluation of an Empirical Reservoir Shape Function to Define Sediment Distributions in Small Reservoirs

    Directory of Open Access Journals (Sweden)

    Bogusław Michalec

    2015-08-01

    Full Text Available Understanding and defining the spatial distribution of sediment deposited in reservoirs is essential not only at the design stage but also during the operation. The majority of research concerns the distribution of sediment deposition in medium and large water reservoirs. Most empirical methods do not provide satisfactory results when applied to the determination of sediment deposition in small reservoirs. Small reservoir’s volumes do not exceed 5 × 106 m3 and their capacity-inflow ratio is less than 10%. Long-term silting measurements of three small reservoirs were used to evaluate the method described by Rahmanian and Banihashemi for predicting sediment distributions in small reservoirs. Rahmanian and Banihashemi stated that their model of distribution of sediment deposition in water reservoir works well for a long duration operation. In the presented study, the silting rate was used in order to determine the long duration operation. Silting rate is a quotient of volume of the sediment deposited in the reservoir and its original volume. It was stated that when the silting rate had reached 50%, the sediment deposition in the reservoir may be described by an empirical reservoir depth shape function (RDSF.

  11. Water in chalk reservoirs: 'friend or foe?'

    International Nuclear Information System (INIS)

    Hjuler, Morten Leth

    2004-01-01

    Most of the petroleum fields in the Norwegian sector of the North Sea are sandstone reservoirs; the oil and gas are trapped in different species of sandstone. But the Ekofisk Field is a chalk reservoir, which really challenges the operator companies. When oil is produced from chalk reservoirs, water usually gets in and the reservoir subsides. The subsidence may be expensive for the oil companies or be used to advantage by increasing the recovery rate. Since 60 per cent of the world's petroleum reserves are located in carbonate reservoirs, it is important to understand what happens as oil and gas are pumped out. Comprehensive studies at the Department of Petroleum Technology and Applied Geophysics at Stavanger University College in Norway show that the mechanical properties of chalk are considerably altered when the pores in the rock become saturated with oil/gas or water under different stress conditions. The processes are extremely complex. The article also maintains that the effects of injecting carbon dioxide from gas power plants into petroleum reservoirs should be carefully studied before this is done extensively

  12. The pollution of the 'iron gate' reservoir

    International Nuclear Information System (INIS)

    Babic-Mladenovic, M.; Varga, S; Popovic, L.; Damjanovic, M.

    2002-01-01

    The paper presents the characteristics of the Iron Gate I (the Djerdap) Water Power and Navigational System, one of the largest in Europe (completed in 1972 by joint efforts of Yugoslavia and Romania). In this paper the attention is devoted to review of the sediment monitoring program and impacts of reservoir sedimentation, as well as to the investigations of water and sediment quality. Special consideration is paid to the issue of sediment pollution research needs. Namely, the hot spot of the 'Iron Gate' sedimentation represents a scarcely known pollution of sediment deposits. The present pollution probably is considerable, since the 'Iron Gate' reservoir drains about 577000 km 2 , with over 80 million inhabitants, and developed municipal and industrial infrastructure. Therefore, in the thirty-year reservoir life various types of sediment-bound pollutants entered and deposited within it. Especially severe incidents happened during 1999 (as a result of NATO bombing campaign) and 2000 (two accidental pollutions in the Tisza river catchment). The study of the 'Iron Gate' reservoir pollution should be prepared in order to enlighten the present state of reservoir sedimentation and pollution. The main objectives of the study are to enhance the government and public awareness of the present environmental state of the 'Iron Gate' reservoir and to serve as a baseline for all future actions. (author)

  13. Electron density profile in multilayer systems

    International Nuclear Information System (INIS)

    Toekesi, K.

    2004-01-01

    Complete text of publication follows. Electron energy loss spectroscopy (EELS) has been used extensively to study the multilayer systems, where the thickness of layers are in the nanometer range. These studies has received considerable attention because of its technological interest, for example in the nanotechnology. On the most fundamental level, its importance is derived from the basic physics that is involved. One key quantities of interest is the response of a many-body system to an external perturbation: How act and how modify the interface between the solid-solid or solid-vacuum the excitations in the solid and in the vicinity of the interfaces. In this work, as a starting point of such investigations we calculated the electron density profile for multilayer systems. Our approach employs the time-dependent density functional theory (TDDFT), that is, the solution of a time-dependent Schroedinger equation in which the potential and forces are determined selfconsistently from the dynamics governed by the Schroedinger equation. We treat the problem in TDDFT at the level of the local-density approximation (LDA). Later, the comparison of experimentally obtained loss functions and the theory, based on our TDDFT calculations can provide deeper understanding of surface physics. We performed the calculations for half-infinite samples characterized by r s =1.642 and r s =1.997. We also performed the calculations for double layer systems. The substrate was characterized by r s =1.997 and the coverage by r s =1.642. Fig. 1. shows the obtained electron density profile in LDA approximation. Because of the sharp cutoff of electronic wave vectors at the Fermi surface, the densities in the interior exhibit slowly decaying Friedel oscillations. To highlight the Friedel oscillation we enlarged the electron density profile in Fig. 1a. and Fig. 1b. The work was supported by the Hungarian Scientific Research Found: OTKA No. T038016, the grant 'Bolyai' from the Hungarian Academy of

  14. Massachusetts reservoir simulation tool—User’s manual

    Science.gov (United States)

    Levin, Sara B.

    2016-10-06

    IntroductionThe U.S. Geological Survey developed the Massachusetts Reservoir Simulation Tool to examine the effects of reservoirs on natural streamflows in Massachusetts by simulating the daily water balance of reservoirs. The simulation tool was developed to assist environmental managers to better manage water withdrawals in reservoirs and to preserve downstream aquatic habitats.

  15. An environmental data base for all Hydro-Quebec reservoirs

    International Nuclear Information System (INIS)

    Demers, C.

    1988-01-01

    Hydro-Quebec has created two management positions specifically for reservoirs, namely Reservoir Ecology Advisor and Reservoir Management Advisor. To assist management decisions, a means was required of bringing together all existing environmental information for each reservoir operated by Hydro-Quebec, including storage reservoirs, auxiliary reservoirs and forebays. A relational database using Reflex software was developed on a network of Macintosh computers. The database contains five blocks of information: general information, and physical, physiochemical, biologic and socioeconomic characteristics for each reservoir. Data will be collected on over 100 sites, and the tool will form the basis for developing a medium-range study program on reservoir ecology. The program must take into account the physical, biological and socioeconomic aspects of the environment, as well as the concerns of management personnel operating the reservoirs, the local population, reservoir users, and various government departments. 2 figs

  16. Organizing Books and Authors by Multilayer SOM.

    Science.gov (United States)

    Zhang, Haijun; Chow, Tommy W S; Wu, Q M Jonathan

    2016-12-01

    This paper introduces a new framework for the organization of electronic books (e-books) and their corresponding authors using a multilayer self-organizing map (MLSOM). An author is modeled by a rich tree-structured representation, and an MLSOM-based system is used as an efficient solution to the organizational problem of structured data. The tree-structured representation formulates author features in a hierarchy of author biography, books, pages, and paragraphs. To efficiently tackle the tree-structured representation, we used an MLSOM algorithm that serves as a clustering technique to handle e-books and their corresponding authors. A book and author recommender system is then implemented using the proposed framework. The effectiveness of our approach was examined in a large-scale data set containing 3868 authors along with the 10500 e-books that they wrote. We also provided visualization results of MLSOM for revealing the relevance patterns hidden from presented author clusters. The experimental results corroborate that the proposed method outperforms other content-based models (e.g., rate adapting poisson, latent Dirichlet allocation, probabilistic latent semantic indexing, and so on) and offers a promising solution to book recommendation, author recommendation, and visualization.

  17. Progress at the ESRF multilayer facility

    International Nuclear Information System (INIS)

    Morawe, Ch; Peffen, J Ch; Friedrich, K; Osterhoff, M

    2013-01-01

    The ESRF multilayer (ML) deposition facility is fully operational since 2009. By the end of 2011, almost 50 ML projects were completed using the new machine, bringing the total number to 143 since 1998. Thanks to the new equipment and its improved performance the throughput could be significantly increased. The ESRF upgrade project caused strong demands for new ML optics, in particular dynamically bent KB focusing devices requiring very precise and steeply graded ML coatings. Thanks to this technology, the ESRF nano-imaging end-station ID22NI now provides the users with spot sizes of the order of 50×50 nm 2 at a photon flux of 10 12 ph/s. Among various in-house research and development activities the study of stress evolution during thin film and ML growth will be highlighted. Additional projects involving a PhD student and a PostDoc fellow cover the fields of wave optical simulations using curved MLs and the exposure of ML based monochromators to the white beam.

  18. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, Sara

    2015-05-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

  19. Pentacene Multilayers On Ag(111) Surface

    International Nuclear Information System (INIS)

    Mete, E.

    2010-01-01

    The structural profiles and electronic properties of pentacene (C 2 2H 1 4) multilayers on Ag(111) surface has been studied within the density functional theory (DFT) framework. We have performed first-principle total energy calculations based on the projector augmented wave (PAW) method to investigate the initial growth patterns of pentacene (Pn) on Ag(111) surface. In its bulk phase, pentacene crystallizes with a triclinic symmetry while a thin film phase having an orthorhombic unit cell is energetically less favorable by 0.12 eV/cell. Pentacene prefers to stay planar on Ag(111) surface and aligns perfectly along lattice vector (1,-1,0) without any molecular deformation at a height of 3.9 angstroms. At one monolayer (ML) coverage the separation between the molecular layer and the surface plane extends to 4.1 angstroms due to intermolecular interactions weakening surface-pentacene attraction. While the first ML remains flat, the molecules on a second full pentacene layer deposited on the surface rearrange so that they become skewed with respect to each other. This adsorption mode is energetically more preferable than the one for which the molecules form a flat pentacene layer by an energy difference similar to that obtained for bulk and thin film phases. Moreover, as new layers added, pentacenes assemble to maintain this skewness for 3 and 4 ML similar to its bulk phase while the first ML always remains flat. Therefore, our calculations indicate bulk-like initial stages for the growth pattern.

  20. Multilayer optics for x-ray analysis: design - fabrication - application

    International Nuclear Information System (INIS)

    Dietsch, R.; Holz, Th.; Bruegemann, L.

    2002-01-01

    Full text: The use of multilayer optics induced a decisive extension of opportunities in laboratory based X-ray analysis. With the growing number of different applications, more and more dedicated X-ray optics are required, optimized for the spectral range they are intended to be used for. Both the characteristic of the used X-ray source and the design of the multilayer optics finally define the performance of the conditioned incident beam for the application. In any case, qualified spacer and absorber materials have to be selected for the deposition of the multilayer in respect to the designated X-ray wavelength. X-ray optical devices based on uniform multilayers have the advantage of a wide acceptance angle but show chromatic aberrations. This effect can be avoided by synthesizing a multilayer with a lateral thickness gradient. The gradient ensures that any beam of a certain wavelength emitted from an infinite narrow X-ray source impinging the multilayer optics fulfills the Bragg condition. Three different types of curvature of laterally graded multilayer mirrors are used for X-ray analysis experiments: parabolic, elliptic and planar, which result in parallel, focusing and divergent beam conditions, respectively. Furthermore, the X-ray beam characteristics: intensity, monochromasy, divergence, beam width and brilliance can be additionally conditioned by combining one multilayer optics with either a different optic and/or with a crystal monochromator. The deposition of nanometer-multilayers, used as X-ray optical components, result in extraordinary requirements of the deposition process concerning precision, reproducibility and long term stability. Across a stack of more than 150 individual layers with thicknesses in the range between 1 to 10 nm, a variation of single layer thickness considerably lower than σ D = 0.1 nm and an interface roughness below σ R = 0.25 nm have to be achieved. Thickness homogeneity Δd/d -8 have to be guaranteed across macroscopic

  1. Surface association and the MreB cytoskeleton regulate pilus production, localization and function in Pseudomonas aeruginosa.

    Science.gov (United States)

    Cowles, Kimberly N; Gitai, Zemer

    2010-06-01

    Spatial organization of bacterial proteins influences many cellular processes, including division, chromosome segregation and motility. Virulence-associated proteins also localize to specific destinations within bacterial cells. However, the functions and mechanisms of virulence factor localization remain largely unknown. In this work, we demonstrate that polar assembly of the Pseudomonas aeruginosa PAO1 type IV pilus is regulated by surface association in a manner that affects gene transcription, protein levels and protein localization. We also uncover one mechanism for this regulation that acts through the actin homologue MreB. Inactivation of MreB leads to mislocalization of the pilus retraction ATPase PilT, mislocalization of the pili themselves and a reduction in motility. Furthermore, the role of MreB in polar localization of PilT is modulated by surface association, corroborating our results that environmental factors influence the regulation of pilus production. Specifically, MreB mediates both the initiation and maintenance of PilT localization when cells are grown in suspension but only affects the initiation of localization when cells are grown on a surface. Together, these results suggest that the bacterial cytoskeleton provides a mechanism for the polar localization of P. aeruginosa pili and demonstrate that protein localization may represent an important aspect of virulence factor regulation in bacterial pathogens.

  2. Analysis and application of classification methods of complex carbonate reservoirs

    Science.gov (United States)

    Li, Xiongyan; Qin, Ruibao; Ping, Haitao; Wei, Dan; Liu, Xiaomei

    2018-06-01

    There are abundant carbonate reservoirs from the Cenozoic to Mesozoic era in the Middle East. Due to variation in sedimentary environment and diagenetic process of carbonate reservoirs, several porosity types coexist in carbonate reservoirs. As a result, because of the complex lithologies and pore types as well as the impact of microfractures, the pore structure is very complicated. Therefore, it is difficult to accurately calculate the reservoir parameters. In order to accurately evaluate carbonate reservoirs, based on the pore structure evaluation of carbonate reservoirs, the classification methods of carbonate reservoirs are analyzed based on capillary pressure curves and flow units. Based on the capillary pressure curves, although the carbonate reservoirs can be classified, the relationship between porosity and permeability after classification is not ideal. On the basis of the flow units, the high-precision functional relationship between porosity and permeability after classification can be established. Therefore, the carbonate reservoirs can be quantitatively evaluated based on the classification of flow units. In the dolomite reservoirs, the average absolute error of calculated permeability decreases from 15.13 to 7.44 mD. Similarly, the average absolute error of calculated permeability of limestone reservoirs is reduced from 20.33 to 7.37 mD. Only by accurately characterizing pore structures and classifying reservoir types, reservoir parameters could be calculated accurately. Therefore, characterizing pore structures and classifying reservoir types are very important to accurate evaluation of complex carbonate reservoirs in the Middle East.

  3. Upper Hiwassee River Basin reservoirs 1989 water quality assessment

    International Nuclear Information System (INIS)

    Fehring, J.P.

    1991-08-01

    The water in the Upper Hiwassee River Basin is slightly acidic and low in conductivity. The four major reservoirs in the Upper Hiwassee River Basin (Apalachia, Hiwassee, Chatuge, and Nottely) are not threatened by acidity, although Nottely Reservoir has more sulfates than the other reservoirs. Nottely also has the highest organic and nutrient concentrations of the four reservoirs. This results in Nottely having the poorest water clarity and the most algal productivity, although clarity as measured by color and secchi depths does not indicate any problem with most water use. However, chlorophyll concentrations indicate taste and odor problems would be likely if the upstream end of Nottely Reservoir were used for domestic water supply. Hiwassee Reservoir is clearer and has less organic and nutrient loading than either of the two upstream reservoirs. All four reservoirs have sufficient algal activity to produce supersaturated dissolved oxygen conditions and relatively high pH values at the surface. All four reservoirs are thermally stratified during the summer, and all but Apalachia have bottom waters depleted in oxygen. The very short residence time of Apalachia Reservoir, less than ten days as compared to over 100 days for the other three reservoirs, results in it being more riverine than the other three reservoirs. Hiwassee Reservoir actually develops three distinct water temperature strata due to the location of the turbine intake. The water quality of all of the reservoirs supports designated uses, but water quality complaints are being received regarding both Chatuge and Nottely Reservoirs and their tailwaters

  4. Reservoir architecture and tough gas reservoir potential of fluvial crevasse-splay deposits

    NARCIS (Netherlands)

    Van Toorenenburg, K.A.; Donselaar, M.E.; Weltje, G.J.

    2015-01-01

    Unconventional tough gas reservoirs in low-net-to-gross fluvial stratigraphic intervals may constitute a secondary source of fossil energy to prolong the gas supply in the future. To date, however, production from these thin-bedded, fine-grained reservoirs has been hampered by the economic risks

  5. Multi-data reservoir history matching for enhanced reservoir forecasting and uncertainty quantification

    KAUST Repository

    Katterbauer, Klemens

    2015-04-01

    Reservoir simulations and history matching are critical for fine-tuning reservoir production strategies, improving understanding of the subsurface formation, and forecasting remaining reserves. Production data have long been incorporated for adjusting reservoir parameters. However, the sparse spatial sampling of this data set has posed a significant challenge for efficiently reducing uncertainty of reservoir parameters. Seismic, electromagnetic, gravity and InSAR techniques have found widespread applications in enhancing exploration for oil and gas and monitoring reservoirs. These data have however been interpreted and analyzed mostly separately, rarely exploiting the synergy effects that could result from combining them. We present a multi-data ensemble Kalman filter-based history matching framework for the simultaneous incorporation of various reservoir data such as seismic, electromagnetics, gravimetry and InSAR for best possible characterization of the reservoir formation. We apply an ensemble-based sensitivity method to evaluate the impact of each observation on the estimated reservoir parameters. Numerical experiments for different test cases demonstrate considerable matching enhancements when integrating all data sets in the history matching process. Results from the sensitivity analysis further suggest that electromagnetic data exhibit the strongest impact on the matching enhancements due to their strong differentiation between water fronts and hydrocarbons in the test cases.

  6. PLANET TOPERS: Planets, Tracing the Transfer, Origin, Preservation, and Evolution of their ReservoirS.

    Science.gov (United States)

    Dehant, V; Asael, D; Baland, R M; Baludikay, B K; Beghin, J; Belza, J; Beuthe, M; Breuer, D; Chernonozhkin, S; Claeys, Ph; Cornet, Y; Cornet, L; Coyette, A; Debaille, V; Delvigne, C; Deproost, M H; De WInter, N; Duchemin, C; El Atrassi, F; François, C; De Keyser, J; Gillmann, C; Gloesener, E; Goderis, S; Hidaka, Y; Höning, D; Huber, M; Hublet, G; Javaux, E J; Karatekin, Ö; Kodolanyi, J; Revilla, L Lobo; Maes, L; Maggiolo, R; Mattielli, N; Maurice, M; McKibbin, S; Morschhauser, A; Neumann, W; Noack, L; Pham, L B S; Pittarello, L; Plesa, A C; Rivoldini, A; Robert, S; Rosenblatt, P; Spohn, T; Storme, J -Y; Tosi, N; Trinh, A; Valdes, M; Vandaele, A C; Vanhaecke, F; Van Hoolst, T; Van Roosbroek, N; Wilquet, V; Yseboodt, M

    2016-11-01

    The Interuniversity Attraction Pole (IAP) 'PLANET TOPERS' (Planets: Tracing the Transfer, Origin, Preservation, and Evolution of their Reservoirs) addresses the fundamental understanding of the thermal and compositional evolution of the different reservoirs of planetary bodies (core, mantle, crust, atmosphere, hydrosphere, cryosphere, and space) considering interactions and feedback mechanisms. Here we present the first results after 2 years of project work.

  7. Application of integrated reservoir management and reservoir characterization to optimize infill drilling, Class II

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, Jack; Blasingame, Tom; Doublet, Louis; Kelkar, Mohan; Freeman, George; Callard, Jeff; Moore, David; Davies, David; Vessell, Richard; Pregger, Brian; Dixon, Bill; Bezant, Bryce

    2000-03-16

    The major purpose of this project was to demonstrate the use of cost effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability carbonate reservoirs such as the North Robertson (Clearfork) Unit.

  8. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Frauk; Hughes, Richard G.

    2001-08-15

    Research continues on characterizing and modeling the behavior of naturally fractured reservoir systems. Work has progressed on developing techniques for estimating fracture properties from seismic and well log data, developing naturally fractured wellbore models, and developing a model to characterize the transfer of fluid from the matrix to the fracture system for use in the naturally fractured reservoir simulator.

  9. Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Cole, E.L.; Fowler, M.L.; Jackson, S.R.; Madden, M.P.; Raw-Schatzinger, V.; Salamy, S.P.; Sarathi, P.; Young, M.A.

    1999-04-28

    The Department of Energy's (DOE's) Oil Recovery Field Demonstration Program was initiated in 1992 to maximize the economically and environmentally sound recovery of oil from known domestic reservoirs and to preserve access to this resource. Cost-shared field demonstration projects are being initiated in geology defined reservoir classes which have been prioritized by their potential for incremental recovery and their risk of abandonment. This document defines the characteristics of the fifth geological reservoir class in the series, fluvial/alluvial reservoirs. The reservoirs of Class 5 include deposits of alluvial fans, braided streams, and meandering streams. Deposit morphologies vary as a complex function of climate and tectonics and are characterized by a high degree of heterogeneity to fluid flow as a result of extreme variations in water energy as the deposits formed.

  10. Development Optimization and Uncertainty Analysis Methods for Oil and Gas Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ettehadtavakkol, Amin, E-mail: amin.ettehadtavakkol@ttu.edu [Texas Tech University (United States); Jablonowski, Christopher [Shell Exploration and Production Company (United States); Lake, Larry [University of Texas at Austin (United States)

    2017-04-15

    Uncertainty complicates the development optimization of oil and gas exploration and production projects, but methods have been devised to analyze uncertainty and its impact on optimal decision-making. This paper compares two methods for development optimization and uncertainty analysis: Monte Carlo (MC) simulation and stochastic programming. Two example problems for a gas field development and an oilfield development are solved and discussed to elaborate the advantages and disadvantages of each method. Development optimization involves decisions regarding the configuration of initial capital investment and subsequent operational decisions. Uncertainty analysis involves the quantification of the impact of uncertain parameters on the optimum design concept. The gas field development problem is designed to highlight the differences in the implementation of the two methods and to show that both methods yield the exact same optimum design. The results show that both MC optimization and stochastic programming provide unique benefits, and that the choice of method depends on the goal of the analysis. While the MC method generates more useful information, along with the optimum design configuration, the stochastic programming method is more computationally efficient in determining the optimal solution. Reservoirs comprise multiple compartments and layers with multiphase flow of oil, water, and gas. We present a workflow for development optimization under uncertainty for these reservoirs, and solve an example on the design optimization of a multicompartment, multilayer oilfield development.

  11. Development Optimization and Uncertainty Analysis Methods for Oil and Gas Reservoirs

    International Nuclear Information System (INIS)

    Ettehadtavakkol, Amin; Jablonowski, Christopher; Lake, Larry

    2017-01-01

    Uncertainty complicates the development optimization of oil and gas exploration and production projects, but methods have been devised to analyze uncertainty and its impact on optimal decision-making. This paper compares two methods for development optimization and uncertainty analysis: Monte Carlo (MC) simulation and stochastic programming. Two example problems for a gas field development and an oilfield development are solved and discussed to elaborate the advantages and disadvantages of each method. Development optimization involves decisions regarding the configuration of initial capital investment and subsequent operational decisions. Uncertainty analysis involves the quantification of the impact of uncertain parameters on the optimum design concept. The gas field development problem is designed to highlight the differences in the implementation of the two methods and to show that both methods yield the exact same optimum design. The results show that both MC optimization and stochastic programming provide unique benefits, and that the choice of method depends on the goal of the analysis. While the MC method generates more useful information, along with the optimum design configuration, the stochastic programming method is more computationally efficient in determining the optimal solution. Reservoirs comprise multiple compartments and layers with multiphase flow of oil, water, and gas. We present a workflow for development optimization under uncertainty for these reservoirs, and solve an example on the design optimization of a multicompartment, multilayer oilfield development.

  12. Mercury and methylmercury in reservoirs in Indiana

    Science.gov (United States)

    Risch, Martin R.; Fredericksen, Amanda L.

    2015-01-01

    Mercury (Hg) is an element that occurs naturally, but evidence suggests that human activities have resulted in increased amounts being released to the atmosphere and land surface. When Hg is converted to methylmercury (MeHg) in aquatic ecosystems, MeHg accumulates and increases in the food web so that some fish contain levels which pose a health risk to humans and wildlife that consume these fish. Reservoirs unlike natural lakes, are a part of river systems that are managed for flood control. Data compiled and interpreted for six flood-control reservoirs in Indiana showed a relation between Hg transport, MeHg formation in water, and MeHg in fish that was influenced by physical, chemical, and biological differences among the reservoirs. Existing information precludes a uniform comparison of Hg and MeHg in all reservoirs in the State, but factors and conditions were identified that can indicate where and when Hg and MeHg levels in reservoirs could be highest.

  13. Tracing fluid flow in geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rose, P.E.; Adams, M.C. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    A family of fluorescent compounds, the polycyclic aromatic sulfonates, were evaluated for application in intermediate- and high-temperature geothermal reservoirs. Whereas the naphthalene sulfonates were found to be very thermally stable and reasonably detectable, the amino-substituted naphthalene sulfonates were found to be somewhat less thermally stable, but much more detectable. A tracer test was conducted at the Dixie Valley, Nevada, geothermal reservoir using one of the substituted naphthalene sulfonates, amino G, and fluorescein. Four of 9 production wells showed tracer breakthrough during the first 200 days of the test. Reconstructed tracer return curves are presented that correct for the thermal decay of tracer assuming an average reservoir temperature of 227{degrees}C. In order to examine the feasibility of using numerical simulation to model tracer flow, we developed simple, two-dimensional models of the geothermal reservoir using the numerical simulation programs TETRAD and TOUGH2. By fitting model outputs to measured return curves, we show that numerical reservoir simulations can be calibrated with the tracer data. Both models predict the same order of elution, approximate tracer concentrations, and return curve shapes. Using these results, we propose a method for using numerical models to design a tracer test.

  14. Application of integrated reservoir management and reservoir characterization to optimize infill drilling. Quarterly progress report, June 13, 1995--September 12, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pande, P.K.

    1995-09-12

    At this stage of the reservoir characterization research, the main emphasis is on the geostatistics and reservoir simulation. Progress is reported on geological analysis, reservoir simulation, and reservoir management.

  15. Spectral tailoring of nanoscale EUV and soft x-ray multilayer optics

    Science.gov (United States)

    Huang, Qiushi; Medvedev, Viacheslav; van de Kruijs, Robbert; Yakshin, Andrey; Louis, Eric; Bijkerk, Fred

    2017-03-01

    Extreme ultraviolet and soft X-ray (XUV) multilayer optics have experienced significant development over the past few years, particularly on controlling the spectral characteristics of light for advanced applications like EUV photolithography, space observation, and accelerator- or lab-based XUV experiments. Both planar and three dimensional multilayer structures have been developed to tailor the spectral response in a wide wavelength range. For the planar multilayer optics, different layered schemes are explored. Stacks of periodic multilayers and capping layers are demonstrated to achieve multi-channel reflection or suppression of the reflective properties. Aperiodic multilayer structures enable broadband reflection both in angles and wavelengths, with the possibility of polarization control. The broad wavelength band multilayer is also used to shape attosecond pulses for the study of ultrafast phenomena. Narrowband multilayer monochromators are delivered to bridge the resolution gap between crystals and regular multilayers. High spectral purity multilayers with innovated anti-reflection structures are shown to select spectrally clean XUV radiation from broadband X-ray sources, especially the plasma sources for EUV lithography. Significant progress is also made in the three dimensional multilayer optics, i.e., combining micro- and nanostructures with multilayers, in order to provide new freedom to tune the spectral response. Several kinds of multilayer gratings, including multilayer coated gratings, sliced multilayer gratings, and lamellar multilayer gratings are being pursued for high resolution and high efficiency XUV spectrometers/monochromators, with their advantages and disadvantages, respectively. Multilayer diffraction optics are also developed for spectral purity enhancement. New structures like gratings, zone plates, and pyramids that obtain full suppression of the unwanted radiation and high XUV reflectance are reviewed. Based on the present achievement

  16. Multilayer porous UHMWPE scaffolds for bone defects replacement

    Energy Technology Data Exchange (ETDEWEB)

    Maksimkin, A.V. [National University of Science and Technology “MISIS”, Moscow (Russian Federation); Senatov, F.S., E-mail: senatov@misis.ru [National University of Science and Technology “MISIS”, Moscow (Russian Federation); Anisimova, N.Yu.; Kiselevskiy, M.V. [National University of Science and Technology “MISIS”, Moscow (Russian Federation); N.N. Blokhin Russian Cancer Research Center, Moscow (Russian Federation); Zalepugin, D.Yu.; Chernyshova, I.V.; Tilkunova, N.A. [State Plant of Medicinal Drugs, Moscow (Russian Federation); Kaloshkin, S.D. [National University of Science and Technology “MISIS”, Moscow (Russian Federation)

    2017-04-01

    Reconstruction of the structural integrity of the damaged bone tissue is an urgent problem. UHMWPE may be potentially used for the manufacture of porous implants simulating as closely as possible the porous cancellous bone tissue. But the extremely high molecular weight of the polymer does not allow using traditional methods of foaming. Porous and multilayer UHMWPE scaffolds with nonporous bulk layer and porous layer that mimics cancellous bone architecture were obtained by solid-state mixing, thermopressing and washing in subcritical water. Structural and mechanical properties of the samples were studied. Porous UHMWPE samples were also studied in vitro and in vivo. The pores of UHMWPE scaffold are open and interconnected. Volume porosity of the obtained samples was 79 ± 2%; the pore size range was 80–700 μm. Strong connection of the two layers in multilayer UHMWPE scaffolds was observed with decreased number of fusion defects. Functionality of implants based on multilayer UHMWPE scaffolds is provided by the fixation of scaffolds in the bone defect through ingrowths of the connective tissue into the pores, which ensures the maintenance of the animals' mobility - Highlights: • Porous UHMWPE scaffold mimics cancellous bone architecture, maintaining its flexibility. • Multilayer UHMWPE scaffold is able to simulate different types of bone tissue. • Fixation of scaffolds in the bone provides through ingrowths of the connective tissue into pores. • Multilayer UHMWPE scaffolds can be used for the formation of bone implants.

  17. Multilayer porous UHMWPE scaffolds for bone defects replacement

    International Nuclear Information System (INIS)

    Maksimkin, A.V.; Senatov, F.S.; Anisimova, N.Yu.; Kiselevskiy, M.V.; Zalepugin, D.Yu.; Chernyshova, I.V.; Tilkunova, N.A.; Kaloshkin, S.D.

    2017-01-01

    Reconstruction of the structural integrity of the damaged bone tissue is an urgent problem. UHMWPE may be potentially used for the manufacture of porous implants simulating as closely as possible the porous cancellous bone tissue. But the extremely high molecular weight of the polymer does not allow using traditional methods of foaming. Porous and multilayer UHMWPE scaffolds with nonporous bulk layer and porous layer that mimics cancellous bone architecture were obtained by solid-state mixing, thermopressing and washing in subcritical water. Structural and mechanical properties of the samples were studied. Porous UHMWPE samples were also studied in vitro and in vivo. The pores of UHMWPE scaffold are open and interconnected. Volume porosity of the obtained samples was 79 ± 2%; the pore size range was 80–700 μm. Strong connection of the two layers in multilayer UHMWPE scaffolds was observed with decreased number of fusion defects. Functionality of implants based on multilayer UHMWPE scaffolds is provided by the fixation of scaffolds in the bone defect through ingrowths of the connective tissue into the pores, which ensures the maintenance of the animals' mobility - Highlights: • Porous UHMWPE scaffold mimics cancellous bone architecture, maintaining its flexibility. • Multilayer UHMWPE scaffold is able to simulate different types of bone tissue. • Fixation of scaffolds in the bone provides through ingrowths of the connective tissue into pores. • Multilayer UHMWPE scaffolds can be used for the formation of bone implants.

  18. Elastic properties of suspended multilayer WSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rui, E-mail: rui.zhang@ed.ac.uk; Cheung, Rebecca [Scottish Microelectronics Centre, Alexander Crum Brown Road, The University of Edinburgh, King' s Buildings, Edinburgh EH9 3FF (United Kingdom); Koutsos, Vasileios [Institute for Materials and Processes, School of Engineering, The University of Edinburgh, King' s Buildings, Edinburgh EH9 3FB (United Kingdom)

    2016-01-25

    We report the experimental determination of the elastic properties of suspended multilayer WSe{sub 2}, a promising two-dimensional (2D) semiconducting material combined with high optical quality. The suspended WSe{sub 2} membranes have been fabricated by mechanical exfoliation of bulk WSe{sub 2} and transfer of the exfoliated multilayer WSe{sub 2} flakes onto SiO{sub 2}/Si substrates pre-patterned with hole arrays. Then, indentation experiments have been performed on these membranes with an atomic force microscope. The results show that the 2D elastic modulus of the multilayer WSe{sub 2} membranes increases linearly while the prestress decreases linearly as the number of layers increases. The interlayer interaction in WSe{sub 2} has been observed to be strong enough to prevent the interlayer sliding during the indentation experiments. The Young's modulus of multilayer WSe{sub 2} (167.3 ± 6.7 GPa) is statistically independent of the thickness of the membranes, whose value is about two thirds of other most investigated 2D semiconducting transition metal dichalcogenides, namely, MoS{sub 2} and WS{sub 2}. Moreover, the multilayer WSe{sub 2} can endure ∼12.4 GPa stress and ∼7.3% strain without fracture or mechanical degradation. The 2D WSe{sub 2} can be an attractive semiconducting material for application in flexible optoelectronic devices and nano-electromechanical systems.

  19. Self-Propagating Reactive Fronts in Compacts of Multilayered Particles

    International Nuclear Information System (INIS)

    Sraj, I.; Vohra, M.; Alawieh, L.; Weihs, T.P.; Knio, O.M.

    2013-01-01

    Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self-propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011) to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self-sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self-propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two-dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.

  20. Docetaxel-loaded multilayer nanoparticles with nanodroplets for cancer therapy.

    Science.gov (United States)

    Oh, Keun Sang; Kim, Kyungim; Yoon, Byeong Deok; Lee, Hye Jin; Park, Dal Yong; Kim, Eun-Yeong; Lee, Kiho; Seo, Jae Hong; Yuk, Soon Hong

    2016-01-01

    A mixture of docetaxel (DTX) and Solutol(®) HS 15 (Solutol) transiently formed nanodroplets when it was suspended in an aqueous medium. However, nanodroplets that comprised DTX and Solutol showed a rapid precipitation of DTX because of their unstable characteristics in the aqueous medium. The incorporation of nanodroplets that comprised DTX and Solutol through vesicle fusion and subsequent stabilization was designed to prepare multilayer nanoparticles (NPs) with a DTX-loaded Solutol nanodroplet (as template NPs) core for an efficient delivery of DTX as a chemotherapeutic drug. As a result, the DTX-loaded Solutol nanodroplets (~11.7 nm) were observed to have an increased average diameter (from 11.7 nm to 156.1 nm) and a good stability of the hydrated NPs without precipitation of DTX by vesicle fusion and multilayered structure, respectively. Also, a long circulation of the multilayer NPs was observed, and this was due to the presence of Pluronic F-68 on the surface of the multilayer NPs. This led to an improved antitumor efficacy based on the enhanced permeation and retention effect. Therefore, this study indicated that the multilayer NPs have a considerable potential as a drug delivery system with an enhanced therapeutic efficacy by blood circulation and with low side effects.

  1. Self-Propagating Reactive Fronts in Compacts of Multilayered Particles

    Directory of Open Access Journals (Sweden)

    Ihab Sraj

    2013-01-01

    Full Text Available Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self-propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011 to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self-sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self-propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two-dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.

  2. Tidal heating in multilayered terrestrial exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Henning, Wade G.; Hurford, Terry, E-mail: wade.g.henning@nasa.gov [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

    2014-07-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  3. Tidal Heating in Multilayered Terrestrial Exoplanets

    Science.gov (United States)

    Henning, Wade G.; Hurford, Terry

    2014-01-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R(sub E) is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  4. Tidal heating in multilayered terrestrial exoplanets

    International Nuclear Information System (INIS)

    Henning, Wade G.; Hurford, Terry

    2014-01-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R E is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  5. Photoluminescence properties of perovskite multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Leilane Roberta; Longo, Elson, E-mail: leilanemacario@gmail.com [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil); Mazzo, Tatiana Martelli [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil); Bouquet, Valerie; Deputier, Stephanie; Ollivier, Sophie; Guilloux-Viry, Maryline [Universite de Rennes (France)

    2016-07-01

    Full text: The knowledge of the optical properties of thin films is important in many scientific, technological and industrial applications of thin films such as photoconductivity, solar energy, photography, and numerous other applications [1]. In this study, perovskite type oxides were grown by pulsed laser deposition [2] in order to obtain thin films with applicable optical properties. The LaNiO{sub 3} (LN), BaTiO{sub 3} (BT) and KNbO{sub 3} (KNb) targets were prepared by solid-state reaction. The X-ray Diffraction revealed the presence of the desired phases, containing the elements of interest in the targets and in the thin films that were produced. The LN, BT and KNb thin films were polycrystalline and the corresponding diffraction peaks were indexed in the with JCPDS cards n. 00-033-0711, n. 00-005-0626, and n. 00-009-0156, respectively. The multilayers films were polycrystalline. The majority of the micrographs obtained by scanning electron microscopy presented films with a thickness from 100 to 400 nm. The photoluminescent (PL) emission spectra of thin films show different broad bands that occupies large region of the visible spectrum, ranging from about 300-350 to 600-650 nm of the electromagnetic spectrum. The PL emission is associated with the order-disorder structural, even small structural changes can modify the interactions between electronic states. The structural disorder results in formation of new energy levels in the forbidden region. The proximity or distance of these new energy levels formed in relation to valence band and to the conduction band results in PL spectra located at higher or lower energies. These interactions change the electronic states which can be influenced by defects, particularly the interface defects between the layers of the thin films. The presence of defects results in changes in the broad band matrix intensity and in displacement of the PL emission maximum. (author)

  6. Wind speed estimation using multilayer perceptron

    International Nuclear Information System (INIS)

    Velo, Ramón; López, Paz; Maseda, Francisco

    2014-01-01

    Highlights: • We present a method for determining the average wind speed using neural networks. • We use data from that site in the short term and data from other nearby stations. • The inputs used in the ANN were wind speed and direction data from a station. • The method allows knowing the wind speed without topographical data. - Abstract: Wind speed knowledge is prerequisite in the siting of wind turbines. In consequence the wind energy use requires meticulous and specified knowledge of the wind characteristics at a location. This paper presents a method for determining the annual average wind speed at a complex terrain site by using neural networks, when only short term data are available for that site. This information is useful for preliminary calculations of the wind resource at a remote area having only a short time period of wind measurements measurement in a site. Artificial neural networks are useful for implementing non-linear process variables over time, and therefore are a useful tool for estimating the wind speed. The neural network used is multilayer perceptron with three layers and the supervised learning algorithm used is backpropagation. The inputs used in the neural network were wind speed and direction data from a single station, and the training patterns used correspond to sixty days data. The results obtained by simulating the annual average wind speed at the selected site based on data from nearby stations with correlation coefficients above 0.5 were satisfactory, compared with actual values. Reliable estimations were obtained, with errors below 6%

  7. Operational trade-offs in reservoir control

    Science.gov (United States)

    Georgakakos, Aris P.

    1993-11-01

    Reservoir operation decisions require constant reevaluation in the face of conflicting objectives, varying hydrologic conditions, and frequent operational policy changes. Optimality is a relative concept very much dependent on the circumstances under which a decision is made. More than anything else, reservoir management authorities need the means to assess the impacts of various operational options. It is their responsibility to define what is desirable after a thorough evaluation of the existing circumstances. This article presents a model designed to generate operational trade-offs common among reservoir systems. The model avoids an all-encompassing problem formulation and distinguishes three operational modes (levels) corresponding to normal, drought, and flood operations. Each level addresses only relevant system elements and uses a static and a dynamic control module to optimize turbine performance within each planning period and temporally. The model is used for planning the operation of the Savannah River System.

  8. Prediction of reservoir compaction and surface subsidence

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, J.A.; Smits, R.M.M.

    1988-06-01

    A new loading-rate-dependent compaction model for unconsolidated clastic reservoirs is presented that considerably improves the accuracy of predicting reservoir rock compaction and surface subsidence resulting from pressure depletion in oil and gas fields. The model has been developed on the basis of extensive laboratory studies and can be derived from a theory relating compaction to time-dependent intergranular friction. The procedure for calculating reservoir compaction from laboratory measurements with the new model is outlined. Both field and laboratory compaction behaviors appear to be described by one single normalized, nonlinear compaction curve. With the new model, the large discrepancies usually observed between predictions based on linear compaction models and actual (nonlinear) field behavior can be explained.

  9. Reservoir Sedimentation: Impact, Extent, and Mitigation

    Science.gov (United States)

    Hadley, Richard F.

    Storage reservoirs play an important role in water resources development throughout the world. The one problem with reservoirs that is universal is the continual reduction in usable capacity caused by siltation. This book reviews the world picture of erosion and sediment yield, the large variations that exist, and the physical phenomena related to reservoir siltation. The book is in the Technical Paper series of The World Bank (Technical Paper 71) and is not a formal publication. Rather, it is intended to be circulated to encourage discussion and comment and to communicate results quickly. The book is reproduced from typescript, but this does not detract from the value of the contents as a useful text for hydrologrsts, engineers, and soil conservationists in developing countries.

  10. Greenhouse gas emissions from hydroelectric reservoirs

    International Nuclear Information System (INIS)

    Rosa, L.P.; Schaeffer, R.

    1994-01-01

    In a recent paper, Rudd et al. have suggested that, per unit of electrical energy produced, greenhouse-gas emissions from some hydroelectric reservoirs in northern Canada may be comparable to emissions from fossil-fuelled power plants. The purpose of this comment is to elaborate these issues further so as to understand the potential contribution of hydroelectric reservoirs to the greenhouse effect. More than focusing on the total budget of carbon emissions (be they in the form of CH 4 or be they in the form of CO 2 ), this requires an evaluation of the accumulated greenhouse effect of gas emissions from hydroelectric reservoirs and fossil-fuelled power plants. Two issues will be considered: (a) global warming potential (GWP) for CH 4 ; and (b) how greenhouse-gas emissions from hydroelectric power plants stand against emissions from fossil-fuelled power plants with respect to global warming

  11. Frameworks for amending reservoir water management

    Science.gov (United States)

    Mower, Ethan; Miranda, Leandro E.

    2013-01-01

    Managing water storage and withdrawals in many reservoirs requires establishing seasonal targets for water levels (i.e., rule curves) that are influenced by regional precipitation and diverse water demands. Rule curves are established as an attempt to balance various water needs such as flood control, irrigation, and environmental benefits such as fish and wildlife management. The processes and challenges associated with amending rule curves to balance multiuse needs are complicated and mostly unfamiliar to non-US Army Corps of Engineers (USACE) natural resource managers and to the public. To inform natural resource managers and the public we describe the policies and process involved in amending rule curves in USACE reservoirs, including 3 frameworks: a general investigation, a continuing authority program, and the water control plan. Our review suggests that water management in reservoirs can be amended, but generally a multitude of constraints and competing demands must be addressed before such a change can be realized.

  12. Oil Reservoir Production Optimization using Optimal Control

    DEFF Research Database (Denmark)

    Völcker, Carsten; Jørgensen, John Bagterp; Stenby, Erling Halfdan

    2011-01-01

    Practical oil reservoir management involves solution of large-scale constrained optimal control problems. In this paper we present a numerical method for solution of large-scale constrained optimal control problems. The method is a single-shooting method that computes the gradients using the adjo...... reservoir using water ooding and smart well technology. Compared to the uncontrolled case, the optimal operation increases the Net Present Value of the oil field by 10%.......Practical oil reservoir management involves solution of large-scale constrained optimal control problems. In this paper we present a numerical method for solution of large-scale constrained optimal control problems. The method is a single-shooting method that computes the gradients using...

  13. Characterization of oil and gas reservoir heterogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, N.; Barton, M.D.; Bebout, D.G.; Fisher, R.S.; Grigsby, J.D.; Guevara, E.; Holtz, M.; Kerans, C.; Nance, H.S.; Levey, R.A.

    1992-10-01

    Research described In this report addresses the internal architecture of two specific reservoir types: restricted-platform carbonates and fluvial-deltaic sandstones. Together, these two reservoir types contain more than two-thirds of the unrecovered mobile oil remaining ill Texas. The approach followed in this study was to develop a strong understanding of the styles of heterogeneity of these reservoir types based on a detailed outcrop description and a translation of these findings into optimized recovery strategies in select subsurface analogs. Research targeted Grayburg Formation restricted-platform carbonate outcrops along the Algerita Escarpment and In Stone Canyon In southeastern New Mexico and Ferron deltaic sandstones in central Utah as analogs for the North Foster (Grayburg) and Lake Creek (Wilcox) units, respectively. In both settings, sequence-stratigraphic style profoundly influenced between-well architectural fabric and permeability structure. It is concluded that reservoirs of different depositional origins can therefore be categorized Into a heterogeneity matrix'' based on varying intensity of vertical and lateral heterogeneity. The utility of the matrix is that it allows prediction of the nature and location of remaining mobile oil. Highly stratified reservoirs such as the Grayburg, for example, will contain a large proportion of vertically bypassed oil; thus, an appropriate recovery strategy will be waterflood optimization and profile modification. Laterally heterogeneous reservoirs such as deltaic distributary systems would benefit from targeted infill drilling (possibly with horizontal wells) and improved areal sweep efficiency. Potential for advanced recovery of remaining mobile oil through heterogeneity-based advanced secondary recovery strategies In Texas is projected to be an Incremental 16 Bbbl. In the Lower 48 States this target may be as much as 45 Bbbl at low to moderate oil prices over the near- to mid-term.

  14. Controls on Cementation in a Chalk Reservoir

    DEFF Research Database (Denmark)

    Meireles, Leonardo Teixeira Pinto; Hussein, A.; Welch, M.J.

    In this study, we identify different controls on cementation in a chalk reservoir. Biot’s coefficient, a measure of cementation, stiffness and strength in porous rocks, is calculated from logging data (bulk density and sonic Pwave velocity). We show that Biot’s coefficient is correlated...... to the water saturation of the Kraka reservoir and is partly controlled by its stratigraphic sub-units. While the direct causal relationship between Biot’s coefficient and water saturation cannot be extended for Biot’s coefficient and porosity, a correlation is also identified between the two, implying...

  15. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, B.; Heinemeier, J.

    2013-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14C dating of f...... that can also be expected for the past. This knowledge will be applied to the dating of food crusts on pottery from the Mesolithic sites Kayhude at the Alster River and Schlamersdorf at the Trave River, both in Schleswig-Holstein, northern Germany....

  16. HIV-1 Reservoir Association with Immune Activation

    Directory of Open Access Journals (Sweden)

    Alejandro Vallejo

    2015-09-01

    Full Text Available In this issue of EBioMedicine, Ruggiero and colleagues describe immune activation biomarkers associated with the size of the HIV reservoir in a carefully designed cross-sectional study. The cohort consists of a homogeneous sample of HIV-1-infected patients with long-term plasma HIV-1 RNA suppression under antiretroviral treatment (ART. It is crucial to explore the potential utility of biomarkers that are easier (less labor intensive, less expensive to measure than integrated HIV DNA load, in order to quickly and accurately quantify cellular reservoirs of HIV.

  17. Nonlinearities in reservoir engineering: Enhancing quantum correlations

    Science.gov (United States)

    Hu, Xiangming; Hu, Qingping; Li, Lingchao; Huang, Chen; Rao, Shi

    2017-12-01

    There are two decisive factors for quantum correlations in reservoir engineering, but they are strongly reversely dependent on the atom-field nonlinearities. One is the squeezing parameter for the Bogoliubov modes-mediated collective interactions, while the other is the dissipative rates for the engineered collective dissipations. Exemplifying two-level atomic ensembles, we show that the moderate nonlinearities can compromise these two factors and thus enhance remarkably two-mode squeezing and entanglement of different spin atomic ensembles or different optical fields. This suggests that the moderate nonlinearities of the two-level systems are more advantageous for applications in quantum networks associated with reservoir engineering.

  18. Characterization of oil and gas reservoir heterogeneity

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The objective of the cooperative research program is to characterize Alaskan reservoirs in terms of their reserves, physical and chemical properties, geologic configuration and structure, and the development potential. The tasks completed during this period include: (1) geologic reservoir description of Endicott Field; (2) petrographic characterization of core samples taken from selected stratigraphic horizons of the West Sak and Ugnu (Brookian) wells; (3) development of a polydispersed thermodynamic model for predicting asphaltene equilibria and asphaltene precipitation from crude oil-solvent mixtures, and (4) preliminary geologic description of the Milne Point Unit.

  19. Writing nanopatterns with electrochemical oxidation on redox responsive organometallic multilayers by AFM

    NARCIS (Netherlands)

    Song, Jing; Hempenius, Mark A.; Chung, H.J.; Vancso, Gyula J.

    2015-01-01

    Nanoelectrochemical patterning of redox responsive organometallic poly(ferrocenylsilane) (PFS) multilayers is demonstrated by electrochemical dip pen lithography (EDPN). Local electrochemical oxidation and Joule heating of PFS multilayers from the tip are considered as relevant mechanisms related to

  20. Zone compensated multilayer laue lens and apparatus and method of fabricating the same

    Science.gov (United States)

    Conley, Raymond P.; Liu, Chian Qian; Macrander, Albert T.; Yan, Hanfei; Maser, Jorg; Kang, Hyon Chol; Stephenson, Gregory Brian

    2015-07-14

    A multilayer Laue Lens includes a compensation layer formed in between a first multilayer section and a second multilayer section. Each of the first and second multilayer sections includes a plurality of alternating layers made of a pair of different materials. Also, the thickness of layers of the first multilayer section is monotonically increased so that a layer adjacent the substrate has a minimum thickness, and the thickness of layers of the second multilayer section is monotonically decreased so that a layer adjacent the compensation layer has a maximum thickness. In particular, the compensation layer of the multilayer Laue lens has an in-plane thickness gradient laterally offset by 90.degree. as compared to other layers in the first and second multilayer sections, thereby eliminating the strict requirement of the placement error.

  1. Neutron spin quantum precession using multilayer spin splitters and a phase-spin echo interferometer

    International Nuclear Information System (INIS)

    Ebisawa, Toru; Tasaki, Seiji; Kawai, Takeshi; Hino, Masahiro; Akiyoshi, Tsunekazu; Achiwa, Norio; Otake, Yoshie; Funahashi, Haruhiko.

    1996-01-01

    Neutron spin quantum precession by multilayer spin splitter has been demonstrated using a new spin interferometer. The multilayer spin splitter consists of a magnetic multilayer mirror on top, followed by a gap layer and a non magnetic multilayer mirror which are evaporated on a silicon substrate. Using the multilayer spin splitter, a polarized neutron wave in a magnetic field perpendicular to the polarization is split into two spin eigenstates with a phase shift in the direction of the magnetic field. The spin quantum precession is equal to the phase shift, which depends on the effective thickness of the gap layer. The demonstration experiments verify the multilayer spin splitter as a neutron spin precession device as well as the coherent superposition principle of the two spin eigenstates. We have developed a new phase-spin echo interferometer using the multilayer spin splitters. We present successful performance tests of the multilayer spin splitter and the phase-spin echo interferometer. (author)

  2. A New Method for Fracturing Wells Reservoir Evaluation in Fractured Gas Reservoir

    Directory of Open Access Journals (Sweden)

    Jianchun Guo

    2014-01-01

    Full Text Available Natural fracture is a geological phenomenon widely distributed in tight formation, and fractured gas reservoir stimulation effect mainly depends on the communication of natural fractures. Therefore it is necessary to carry out the evaluation of this reservoir and to find out the optimal natural fractures development wells. By analyzing the interactions and nonlinear relationships of the parameters, it establishes three-level index system of reservoir evaluation and proposes a new method for gas well reservoir evaluation model in fractured gas reservoir on the basis of fuzzy logic theory and multilevel gray correlation. For this method, the Gaussian membership functions to quantify the degree of every factor in the decision-making system and the multilevel gray relation to determine the weight of each parameter on stimulation effect. Finally through fuzzy arithmetic operator between multilevel weights and fuzzy evaluation matrix, score, rank, the reservoir quality, and predicted production will be gotten. Result of this new method shows that the evaluation of the production coincidence rate reaches 80%, which provides a new way for fractured gas reservoir evaluation.

  3. Simulation of Reservoir Sediment Flushing of the Three Gorges Reservoir Using an Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Xueying Li

    2016-05-01

    Full Text Available Reservoir sedimentation and its effect on the environment are the most serious world-wide problems in water resources development and utilization today. As one of the largest water conservancy projects, the Three Gorges Reservoir (TGR has been controversial since its demonstration period, and sedimentation is the major concern. Due to the complex physical mechanisms of water and sediment transport, this study adopts the Error Back Propagation Training Artificial Neural Network (BP-ANN to analyze the relationship between the sediment flushing efficiency of the TGR and its influencing factors. The factors are determined by the analysis on 1D unsteady flow and sediment mathematical model, mainly including reservoir inflow, incoming sediment concentration, reservoir water level, and reservoir release. Considering the distinguishing features of reservoir sediment delivery in different seasons, the monthly average data from 2003, when the TGR was put into operation, to 2011 are used to train, validate, and test the BP-ANN model. The results indicate that, although the sample space is quite limited, the whole sediment delivery process can be schematized by the established BP-ANN model, which can be used to help sediment flushing and thus decrease the reservoir sedimentation.

  4. Multilayer mirrors as power filters in insertion device beamlines

    International Nuclear Information System (INIS)

    Kortright, J.B.; DiGennaro, R.S.

    1988-08-01

    The power-filtering capabilities of multilayer band-pass x-ray mirrors relative to total reflection low-pass mirrors is presented. Results are based on calculations assuming proposed wiggler sources on the upcoming generation of low energy (1.5 GeV) and high energy (7.0 GeV) synchrotron radiation sources. Results show that multilayers out-perform total reflection mirrors in terms of reduction in reflected power by roughly an order of magnitude, with relatively small increases in total absorbed power and power density over total reflection mirrors, and with comparable reflected flux values. Various aspects of this potential application of multilayer x-ray optics are discussed. 13 refs., 3 figs., 1 tab

  5. Young’s modulus of multi-layer microcantilevers

    Directory of Open Access Journals (Sweden)

    Zhikang Deng

    2017-12-01

    Full Text Available A theoretical model for calculating the Young’s modulus of multi-layer microcantilevers with a coating is proposed, and validated by a three-dimensional (3D finite element (FE model using ANSYS parametric design language (APDL and atomic force microscopy (AFM characterization. Compared with typical theoretical models (Rayleigh-Ritz model, Euler-Bernoulli (E-B beam model and spring mass model, the proposed theoretical model can obtain Young’s modulus of multi-layer microcantilevers more precisely. Also, the influences of coating’s geometric dimensions on Young’s modulus and resonant frequency of microcantilevers are discussed. The thickness of coating has a great influence on Young’s modulus and resonant frequency of multi-layer microcantilevers, and the coating should be considered to calculate Young’s modulus more precisely, especially when fairly thicker coating is employed.

  6. Anomalously Weak Scattering in Metal-Semiconductor Multilayer Hyperbolic Metamaterials

    Directory of Open Access Journals (Sweden)

    Hao Shen

    2015-05-01

    Full Text Available In contrast to strong plasmonic scattering from metal particles or structures in metal films, we show that patterns of arbitrary shape fabricated out of multilayer hyperbolic metamaterials become invisible within a chosen band of optical frequencies. This is due to anomalously weak scattering when the in-plane permittivity of the multilayer hyperbolic metamaterials is tuned to match with the surrounding medium. This new phenomenon is described theoretically and demonstrated experimentally by optical characterization of various patterns in Au-Si multilayer hyperbolic metamaterials. This anomalously weak scattering is insensitive to pattern sizes, shapes, and incident angles, and has potential applications in scattering cross-section engineering, optical encryption, low-observable conductive probes, and optoelectric devices.

  7. Multilayer Photonic Crystal for Spectral Narrowing of Emission

    Directory of Open Access Journals (Sweden)

    Zhanfang LIU

    2017-08-01

    Full Text Available Multilayer colloidal crystal has been prepared by the layer-by-layer deposition of silica microspheres on a glass slide. Each layer is a slab consisting of a fcc close-packed colloidal arrays. By properly choosing the sizes of spheres, the whole spectral feature of multilayer colloidal crystal can be tuned. Here, we engineered a multilayer superlattice structure with an effective passband between two stop bands. This gives a strong narrowing effect on emission spectrum. With the stop bands at the shortwave and longwave edges of emission spectrum, the passband in the central wavelength region can be regarded as a strong decrease of suppression effect and enhancement of a narrow wavelength region of emission. The spectral narrowing modification effect of suitably engineered colloidal crystals shows up their importance in potential application as optical filters and lasing devices.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16320

  8. Nanolaminated TiN/Mo2N hard multilayer coatings

    International Nuclear Information System (INIS)

    Martev, I N; Dechev, D A; Ivanov, N P; Uzunov, T S D; Kashchieva, E P

    2010-01-01

    The paper presents results on the synthesis of hard multilayer coatings consisting of titanium nitride and molybdenum nitride thin films with thickness of several nm. The TiN and Mo 2 N films were successively deposited by reactive DC magnetron sputtering. These multilayer structures were investigated by Auger electron spectroscopy (AES), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), cross-section scanning electron microscopy (CSSEM) and cross-section electron probe microanalysis (CSEPMA). The mechanical properties of the multilayer coatings, namely, hardness, Young's modulus and the coefficient of plastic deformation were measured. The adhesion was evaluated by the Rockwell-C-impact test. Coatings with different total thickness were examined with respect to adhesion to substrates of tool materials.

  9. Biocolloids with ordered urease multilayer shells as enzymatic reactors.

    Science.gov (United States)

    Lvov, Y; Caruso, F

    2001-09-01

    The preparation of biocolloids with organized enzyme-containing multilayer shells for exploitation as colloidal enzymatic nanoreactors is described. Urease multilayers were assembled onto submicrometer-sized polystyrene spheres by the sequential adsorption of urease and polyelectrolyte, in a predetermined order, utilizing electrostatic interactions for layer growth. The catalytic activity of the biocolloids increased proportionally with the number of urease layers deposited on the particles, demonstrating that biocolloid particles with tailored enzymatic activities can be produced. It was further found that precoating the latex spheres with nanoparticles (40-nm silica or 12-nm magnetite) enhanced both the stability (with respect to adsorption) and enzymatic activity of the urease multilayers. The presence of the magnetite nanoparticle coating also provided a magnetic function that allowed the biocolloids to be easily and rapidly separated with a permanent magnet. The fabrication of such colloids opens new avenues for the application of bioparticles and represents a promising route for the creation of complex catalytic particles.

  10. The NSLS-II Multilayer Laue Lens Deposition System

    International Nuclear Information System (INIS)

    Conley, R.; Bouet, N.; Biancarosa, J.; Shen, Q.; Boas, L.; Feraca, J.; Rosenbaum, L.

    2009-01-01

    The NSLS-II(1) program has a requirement for an unprecedented level of x-ray nanofocusing and has selected the wedged multilayer Laue lens(2,3) (MLL) as the optic of choice to meet this goal. In order to fabricate the MLL a deposition system is required that is capable of depositing depth-graded and laterally-graded multilayers with precise thickness control over many thousands of layers, with total film growth in one run up to 100 m thick or greater. This machine design expounds on the positive features of a rotary deposition system(4) constructed previously for MLLs and will contain multiple stationary, horizontally-oriented magnetron sources where a transport will move a substrate back and forth in a linear fashion over shaped apertures at well-defined velocities to affect a multilayer coating.

  11. Multilayer DNA Origami Packed on Hexagonal and Hybrid Lattices

    DEFF Research Database (Denmark)

    Ke, Yonggang; Voigt, Niels Vinther; Shih, William M.

    2012-01-01

    “Scaffolded DNA origami” has been proven to be a powerful and efficient approach to construct two-dimensional or three-dimensional objects with great complexity. Multilayer DNA origami has been demonstrated with helices packing along either honeycomb-lattice geometry or square-lattice geometry....... Here we report successful folding of multilayer DNA origami with helices arranged on a close-packed hexagonal lattice. This arrangement yields a higher density of helical packing and therefore higher resolution of spatial addressing than has been shown previously. We also demonstrate hybrid multilayer...... DNA origami with honeycomb-lattice, square-lattice, and hexagonal-lattice packing of helices all in one design. The availability of hexagonal close-packing of helices extends our ability to build complex structures using DNA nanotechnology....

  12. Multilayer DNA origami packed on hexagonal and hybrid lattices.

    Science.gov (United States)

    Ke, Yonggang; Voigt, Niels V; Gothelf, Kurt V; Shih, William M

    2012-01-25

    "Scaffolded DNA origami" has been proven to be a powerful and efficient approach to construct two-dimensional or three-dimensional objects with great complexity. Multilayer DNA origami has been demonstrated with helices packing along either honeycomb-lattice geometry or square-lattice geometry. Here we report successful folding of multilayer DNA origami with helices arranged on a close-packed hexagonal lattice. This arrangement yields a higher density of helical packing and therefore higher resolution of spatial addressing than has been shown previously. We also demonstrate hybrid multilayer DNA origami with honeycomb-lattice, square-lattice, and hexagonal-lattice packing of helices all in one design. The availability of hexagonal close-packing of helices extends our ability to build complex structures using DNA nanotechnology. © 2011 American Chemical Society

  13. Surface modification of multilayer graphene using Ga ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Shao, Ying; Ge, Daohan; Ren, Naifei [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yang, Qizhi [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State key laboratory of Robotics, Chinese Academy of Sciences, Shengyang 110000 (China)

    2015-04-28

    The effect of Ga ion irradiation intensity on the surface of multilayer graphene was examined. Using Raman spectroscopy, we determined that the irradiation caused defects in the crystal structure of graphene. The density of defects increased with the increase in dwell times. Furthermore, the strain induced by the irradiation changed the crystallite size and the distance between defects. These defects had the effect of doping the multilayer graphene and increasing its work function. The increase in work function was determined using contact potential difference measurements. The surface morphology of the multilayer graphene changed following irradiation as determined by atomic force microscopy. Additionally, the adhesion between the atomic force microscopy tip and sample increased further indicating that the irradiation had caused surface modification, important for devices that incorporate graphene.

  14. Enhancement of the spin Peltier effect in multilayers

    Science.gov (United States)

    Uchida, K.; Iguchi, R.; Daimon, S.; Ramos, R.; Anadón, A.; Lucas, I.; Algarabel, P. A.; Morellón, L.; Aguirre, M. H.; Ibarra, M. R.; Saitoh, E.

    2017-05-01

    The spin Peltier effect (SPE), heat-current generation as a result of spin-current injection, has been investigated in alternately stacked Pt/Fe3O4 multilayer films. The temperature modulation induced by the SPE in the [Pt/Fe3O4]×n films was found to be significantly enhanced with increasing the number of Pt/Fe3O4 bilayers n . This SPE enhancement is much greater than that expected for a simple stack of independent Pt/Fe3O4 bilayers. The observed n dependence of the SPE can be explained by introducing spin-current redistribution in the multilayer films in the thickness direction, in a manner similar to the enhancement of the spin Seebeck effect in multilayers.

  15. Processing and characterization of multilayers for energy device fabrication (invited)

    DEFF Research Database (Denmark)

    Kaiser, Andreas; Kiebach, Wolff-Ragnar; Gurauskis, Jonas

    SOFC and tubular OTM, we present selected challenges in ceramic processing such asymmetric multilayer structures. By optimizing different steps in the ceramic processing, we improved the mechanical properties and gas permeability of porous supports and the (electrochemical) performance of electrodes......The performance of asymmetric multilayer structures in solid oxide fuel cells (SOFC)/solid oxide electrolysis cells (SOEC), tubular oxygen transport membranes (OTM) and similar high temperature energy devices is often determined by the ceramic fabrication (for given materials and design). A good...... understanding and control of different processing steps (from powder/materials selection, through shaping and sintering) is of crucial importance to achieve a defect-free multilayer microstructure with the desired properties and performance. Based on the experiences at DTU Energy with the fabrication of planar...

  16. Electron with arbitrary pseudo-spins in multilayer graphene

    International Nuclear Information System (INIS)

    Prarokijjak Worasak; Soodchomshom Bumned

    2015-01-01

    Using the low-energy effective Hamiltonian of the ABC-stacked multilayer graphene, the pseudo-spin coupling to real orbital angular momentum of electrons in multilayer graphene is investigated. We show that the electron wave function in N-layer graphene mimics the behavior of a particle with a spin of N × (ħ/2), where N = {1, 2, 3,…}. It is said that for N > 1 the low-energy effective Hamiltonian for ABC-stacked graphene cannot be used to describe pseudo-spin-1/2 particles. The wave function of electrons in multilayer graphene may behave like fermionic (or bosonic) particle for N being odd (or even). In this paper, we propose a theory of graphene serving as a host material of electrons with arbitrary pseudo-spins tunable by changing the number of graphene layers. (paper)

  17. Electron with arbitrary pseudo-spins in multilayer graphene

    Institute of Scientific and Technical Information of China (English)

    Worasak Prarokijjak; Bumned Soodchomshom

    2015-01-01

    Using the low-energy effective Hamiltonian of the ABC-stacked multilayer graphene, the pseudo-spin coupling to real orbital angular momentum of electrons in multilayer graphene is investigated. We show that the electron wave function in N-layer graphene mimics the behavior of a particle with a spin of N × (}/2), where N={1, 2, 3, . . .}. It is said that for N>1 the low-energy effective Hamiltonian for ABC-stacked graphene cannot be used to describe pseudo-spin-1/2 particles. The wave function of electrons in multilayer graphene may behave like fermionic (or bosonic) particle for N being odd (or even). In this paper, we propose a theory of graphene serving as a host material of electrons with arbitrary pseudo-spins tunable by changing the number of graphene layers.

  18. Tunable Multilayer Graphene Metamaterials for Terahertz/Infrared Waveguide Modulators

    DEFF Research Database (Denmark)

    Khromova, Irina; Andryieuski, Andrei; Lavrinenko, Andrei

    regimes of multilayer graphene-dielectric artificial metamaterials. The interplay between interband and intraband transitions in graphene allows converting the structure into a transparent and/or electromagnetically dense artificial medium. The gate voltage can be used to electrically control...... the concentration of carriers in the graphene sheets and, thus, efficiently change the dispersion of the whole structure. Placed inside a hollow waveguide, a multilayer graphene/dielectric metamaterial provides high-speed modulation and tunable bandpass filtering. The absence of scattered radiation enables dense...... the latter to shift its central frequency by 1:25% per every meV graphene Fermi energy change. We believe that graphene-dielectric multilayer metamaterials will constitute the functional platform for THz-IR waveguide-integrated devices....

  19. Design considerations for energy efficient, resilient, multi-layer networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Hansen, Line Pyndt; Ruepp, Sarah Renée

    2016-01-01

    measures. In this complex problem, considerations such as client traffic granularity, applied grooming policies and multi-layer resiliency add even more complexity. A commercially available network planning tool is used to investigate the interplay between different methods for resilient capacity planning......This work investigates different network design considerations with respect to energy-efficiency, under green-field resilient multi-layer network deployment. The problem of energy efficient, reliable multi-layer network design is known to result in different trade-offs between key performance....... Switching off low-utilized transport links has been investigated via a pro-active re-routing applied during the network planning. Our analysis shows that design factors such as the applied survivability strategy and the applied planning method have higher impact on the key performance indicators compared...

  20. Interface alloying in multilayer thin films using polarized neutron reflectometry

    International Nuclear Information System (INIS)

    Basu, Saibal

    2013-01-01

    Polarized Neutron Reflectometry (PNR) is an excellent tool to probe magnetic depth profile in multilayer thin film samples. In case of multilayer films with alternating magnetic and non-magnetic layers, PNR can provide magnetic depth profile at the interfaces with better than nanometer resolution. Using PNR and Xray Reflectometry (XRR) together one can obtain chemical composition and magnetic structure, viz. magnetic moment density at interfaces in multilayer films. We have used these two techniques to obtain kinetics of alloy formation at the interfaces and the magnetic nature of the alloy at the interfaces in several important thin films with magnetic/non-magnetic bilayers. These include Ni/Ti, Ni/Al and Si/Ni pairs. Results obtained from these studies will be presented in this talk. (author)

  1. Radiography simulation based on exposure buildup factors for multilayer structures

    International Nuclear Information System (INIS)

    Marinkovic, Predrag; Pesic, Milan

    2009-01-01

    Monte Carlo techniques were usually used to study the effect of scattered photons on a radiographic X-ray image. Such approach is accurate, but computer time consuming. On the other hand, the exposure buildup factors can be used as approximate and efficient assessment to account for the scattering of X-rays. This method uses the known radiography parameters to find the resulting detector exposure due to both scattered and un-collided photons. A model for radiography simulation, based on X-ray dose buildup factor, is proposed. This model includes non-uniform attenuation in voxelized object of imaging (patient body tissue). Composition of patient body is considered as a multi-layer structure. Various empirical formulas exist for multi-layer structure calculations and they all calculate multi-layer buildup factors by combining single-layer buildup factors. The proposed model is convenient in cases when more exact techniques (like Monte Carlo) are not economical. (author)

  2. SIW based multilayer transition and power divider in LTCC technology

    KAUST Repository

    Abuzaid, Hattan

    2013-06-01

    A multilayer transition and balanced power divider are presented for millimeter-wave system-on-package (SoP). These two components operate at Ka-band and exploit the substrate integrate waveguide (SIW) technology with its shielding characteristics and the Low-temperature co-fired ceramics (LTCC) technology for its high density integration. A coupling slot has been used to perform vertical integration, which can be easily optimized through its length. The measured input return loss within the bandwidth of interest (32 GHz-38 GHz) is less than -15 dB and -18 dB for the multilayer transition and the power divider, respectively. The lateral dimensions of a multilayer system, such as a feed network of an array, can be greatly reduced by employing these 3D slot-coupled components. © 2013 IEEE.

  3. Research on the Multilayer Free Damping Structure Design

    Directory of Open Access Journals (Sweden)

    Jie Meng

    2018-01-01

    Full Text Available The aim of this paper is to put forward a design model for multilayer free damping structures. It sets up a mathematical model and deduces the formula for its structural loss factor η and analyzes the change rules of η along with the change rate of the elastic modulus ratio q1, the change rate of the loss factors of damping materials q2, and the change rate of the layer thickness ratio q3 under the condition with the layer thickness ratio h2=1,3,5,10 by software MATLAB. Based on three specific damping structures, the mathematical model is verified through ABAQUS. With the given structural loss factor (η≥2 and the layer number (n=3,4,5,6, 34 kinds of multilayer free damping structures are then presented. The study is meant to provide a more flexible and more diverse design solution for multilayer free damping structures.

  4. Anisotropic in-plane thermal conductivity in multilayer silicene

    Science.gov (United States)

    Zhou, Yang; Guo, Zhi-Xin; Chen, Shi-You; Xiang, Hong-Jun; Gong, Xin-Gao

    2018-06-01

    We systematically study thermal conductivity of multilayer silicene by means of Boltzmann Transportation Equation (BTE) method. We find that their thermal conductivity strongly depends on the surface structures. Thermal conductivity of bilayer silicene varies from 3.31 W/mK to 57.9 W/mK with different surface structures. Also, the 2 × 1 surface reconstruction induces unusual large thermal conductivity anisotropy, which reaches 70% in a four-layer silicene. We also find that the anisotropy decreases with silicene thickness increasing, owing to the significant reduction of thermal conductivity in the zigzag direction and its slight increment in the armchair direction. Finally, we find that both the phonon-lifetime anisotropy and the phonon-group-velocity anisotropy contribute to the thermal conductivity anisotropy of multilayer silicene. These findings could be helpful in the field of heat management, thermoelectric applications involving silicene and other multilayer nanomaterials with surface reconstructions in the future.

  5. Modeling Macroscopic Shape Distortions during Sintering of Multi-layers

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye

    as to help achieve defect free multi-layer components. The initial thickness ratio between the layers making the multi-layer has also significant effect on the extent of camber evolution depending on the material systems. During sintering of tubular bi-layer structures, tangential (hoop) stresses are very...... large compared to radial stresses. The maximum value of hoop stress, which can generate processing defects such as cracks and coating peel-offs, occurs at the beginning of the sintering cycle. Unlike most of the models defining material properties based on porosity and grain size only, the multi...... (firing). However, unintended features like shape instabilities of samples, cracks or delamination of layers may arise during sintering of multi-layer composites. Among these defects, macroscopic shape distortions in the samples can cause problems in the assembly or performance of the final component...

  6. Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings

    Science.gov (United States)

    Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan

    2016-12-01

    Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

  7. INCREASING WATERFLOOD RESERVES IN THE WILMINGTON OIL FIELD THROUGH IMPROVED RESERVOIR CHARACTERIZATION AND RESERVOIR MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Scott Walker; Chris Phillips; Roy Koerner; Don Clarke; Dan Moos; Kwasi Tagbor

    2002-02-28

    This project increased recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs. Transferring technology so that it can be applied in other sections of the Wilmington Field and by operators in other slope and basin reservoirs is a primary component of the project. This project used advanced reservoir characterization tools, including the pulsed acoustic cased-hole logging tool, geologic three-dimensional (3-D) modeling software, and commercially available reservoir management software to identify sands with remaining high oil saturation following waterflood. Production from the identified high oil saturated sands was stimulated by recompleting existing production and injection wells in these sands using conventional means as well as a short radius redrill candidate. Although these reservoirs have been waterflooded over 40 years, researchers have found areas of remaining oil saturation. Areas such as the top sand in the Upper Terminal Zone Fault Block V, the western fault slivers of Upper Terminal Zone Fault Block V, the bottom sands of the Tar Zone Fault Block V, and the eastern edge of Fault Block IV in both the Upper Terminal and Lower Terminal Zones all show significant remaining oil saturation. Each area of interest was uncovered emphasizing a different type of reservoir characterization technique or practice. This was not the original strategy but was necessitated by the different levels of progress in each of the project activities.

  8. Improved characterization of reservoir behavior by integration of reservoir performances data and rock type distributions

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D.K.; Vessell, R.K. [David K. Davies & Associates, Kingwood, TX (United States); Doublet, L.E. [Texas A& M Univ., College Station, TX (United States)] [and others

    1997-08-01

    An integrated geological/petrophysical and reservoir engineering study was performed for a large, mature waterflood project (>250 wells, {approximately}80% water cut) at the North Robertson (Clear Fork) Unit, Gaines County, Texas. The primary goal of the study was to develop an integrated reservoir description for {open_quotes}targeted{close_quotes} (economic) 10-acre (4-hectare) infill drilling and future recovery operations in a low permeability, carbonate (dolomite) reservoir. Integration of the results from geological/petrophysical studies and reservoir performance analyses provide a rapid and effective method for developing a comprehensive reservoir description. This reservoir description can be used for reservoir flow simulation, performance prediction, infill targeting, waterflood management, and for optimizing well developments (patterns, completions, and stimulations). The following analyses were performed as part of this study: (1) Geological/petrophysical analyses: (core and well log data) - {open_quotes}Rock typing{close_quotes} based on qualitative and quantitative visualization of pore-scale features. Reservoir layering based on {open_quotes}rock typing {close_quotes} and hydraulic flow units. Development of a {open_quotes}core-log{close_quotes} model to estimate permeability using porosity and other properties derived from well logs. The core-log model is based on {open_quotes}rock types.{close_quotes} (2) Engineering analyses: (production and injection history, well tests) Material balance decline type curve analyses to estimate total reservoir volume, formation flow characteristics (flow capacity, skin factor, and fracture half-length), and indications of well/boundary interference. Estimated ultimate recovery analyses to yield movable oil (or injectable water) volumes, as well as indications of well and boundary interference.

  9. Sensitivity Analysis of Methane Hydrate Reservoirs: Effects of Reservoir Parameters on Gas Productivity and Economics

    Science.gov (United States)

    Anderson, B. J.; Gaddipati, M.; Nyayapathi, L.

    2008-12-01

    This paper presents a parametric study on production rates of natural gas from gas hydrates by the method of depressurization, using CMG STARS. Seven factors/parameters were considered as perturbations from a base-case hydrate reservoir description based on Problem 7 of the International Methane Hydrate Reservoir Simulator Code Comparison Study led by the Department of Energy and the USGS. This reservoir is modeled after the inferred properties of the hydrate deposit at the Prudhoe Bay L-106 site. The included sensitivity variables were hydrate saturation, pressure (depth), temperature, bottom-hole pressure of the production well, free water saturation, intrinsic rock permeability, and porosity. A two-level (L=2) Plackett-Burman experimental design was used to study the relative effects of these factors. The measured variable was the discounted cumulative gas production. The discount rate chosen was 15%, resulting in the gas contribution to the net present value of a reservoir. Eight different designs were developed for conducting sensitivity analysis and the effects of the parameters on the real and discounted production rates will be discussed. The breakeven price in various cases and the dependence of the breakeven price on the production parameters is given in the paper. As expected, initial reservoir temperature has the strongest positive effect on the productivity of a hydrate deposit and the bottom-hole pressure in the production well has the strongest negative dependence. Also resulting in a positive correlation is the intrinsic permeability and the initial free water of the formation. Negative effects were found for initial hydrate saturation (at saturations greater than 50% of the pore space) and the reservoir porosity. These negative effects are related to the available sensible heat of the reservoir, with decreasing productivity due to decreasing available sensible heat. Finally, we conclude that for the base case reservoir, the break-even price (BEP

  10. Docetaxel-loaded multilayer nanoparticles with nanodroplets for cancer therapy

    Directory of Open Access Journals (Sweden)

    Oh KS

    2016-03-01

    Full Text Available Keun Sang Oh,1,* Kyungim Kim,1,* Byeong Deok Yoon,1 Hye Jin Lee,1 Dal Yong Park,1 Eun-yeong Kim,1 Kiho Lee,1 Jae Hong Seo,2 Soon Hong Yuk1,2 1College of Pharmacy, Korea University, Sejong, 2Biomedical Research Center, Korea University Guro Hospital, Guro-gu, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: A mixture of docetaxel (DTX and Solutol® HS 15 (Solutol transiently formed nanodroplets when it was suspended in an aqueous medium. However, nanodroplets that comprised DTX and Solutol showed a rapid precipitation of DTX because of their unstable characteristics in the aqueous medium. The incorporation of nanodroplets that comprised DTX and Solutol through vesicle fusion and subsequent stabilization was designed to prepare multilayer nanoparticles (NPs with a DTX-loaded Solutol nanodroplet (as template NPs core for an efficient delivery of DTX as a chemotherapeutic drug. As a result, the DTX-loaded Solutol nanodroplets (~11.7 nm were observed to have an increased average diameter (from 11.7 nm to 156.1 nm and a good stability of the hydrated NPs without precipitation of DTX by vesicle fusion and multilayered structure, respectively. Also, a long circulation of the multilayer NPs was observed, and this was due to the presence of Pluronic F-68 on the surface of the multilayer NPs. This led to an improved antitumor efficacy based on the enhanced permeation and retention effect. Therefore, this study indicated that the multilayer NPs have a considerable potential as a drug delivery system with an enhanced therapeutic efficacy by blood circulation and with low side effects. Keywords: multilayer nanoparticles, Solutol, Pluronic F-68, docetaxel, cancer therapy

  11. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for

  12. Magnetothermoelectric figure of merit of Co/Cu multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Hu, X. K., E-mail: xiukun.hu@ptb.de; Krzysteczko, P.; Liebing, N.; Schumacher, H. W. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig (Germany); Serrano-Guisan, S. [International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, 4715-330 Braga (Portugal); Rott, K.; Reiss, G. [Fakultät für Physik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld (Germany); Kimling, J.; Böhnert, T.; Nielsch, K. [Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, D-20355 Hamburg (Germany)

    2014-03-03

    The switching of the magnetic configuration of giant magnetoresistance multilayers not only changes the electrical and thermal conductivities but also the thermopower. We study the magnetotransport and the magnetothermoelectric properties of Co/Cu multilayer devices in a lateral thermal gradient. The Seebeck coefficient reaches values up to −18 μV/K at room temperature and shows a magnetic field dependence up to 28.6% upon spin reversal. In combination with thermal conductivity data of the same Co/Cu stack, we find a magnetothermoelectric figure of merit of up to 65%. Furthermore, a magneto-power factor of up to 110% is derived.

  13. Self organized formation of Ge nanocrystals in multilayers

    OpenAIRE

    Zschintzsch-Dias, Manuel

    2012-01-01

    The aim of this work is to create a process which allows the tailored growth of Ge nanocrystals for use in photovoltic applications. The multilayer systems used here provide a reliable method to control the Ge nanocrystal size after phase separation. In this thesis, the deposition of GeOx/SiO2 and Ge:SiOx~ 2/SiO2 multilayers via reactive dc magnetron sputtering and the self-ordered Ge nanocrystal formation within the GeOx and Ge:SiOx~ 2 sublayers during subsequent annealing is investigated...

  14. 24 h stability of thick multilayer silicene in air

    International Nuclear Information System (INIS)

    De Padova, Paola; Ottaviani, Carlo; Quaresima, Claudio; Generosi, Amanda; Paci, Barbara; Le Lay, Guy; Olivieri, Bruno; Imperatori, Patrizia; Salomon, Eric; Angot, Thierry; Quagliano, Lucia; Romano, Claudia; Vona, Alessandro; Muniz-Miranda, Maurizio

    2014-01-01

    Thick epitaxial multilayer silicene films with a √3 × √3R(30°) surface structure show only mild surface oxidation after 24 h in air, as measured by Auger electron spectroscopy. X-ray diffraction and Raman spectroscopy measurements performed in air without any protective capping, as well as, for comparison, with a thin Al 2 O 3 cap, showed the (002) reflection and the G, D and 2D Raman structures, which are unique fingerprints of thick multilayer silicene. (letter)

  15. Soft Magnetic Multilayered Thin Films for HF Applications

    Science.gov (United States)

    Loizos, George; Giannopoulos, George; Serletis, Christos; Maity, Tuhin; Roy, Saibal; Lupu, Nicoleta; Kijima, Hanae; Yamaguchi, Masahiro; Niarchos, Dimitris

    Multilayered thin films from various soft magnetic materials were successfully prepared by magnetron sputtering in Ar atmosphere. The magnetic properties and microstructure were investigated. It is found that the films show good soft magnetic properties: magnetic coercivity of 1-10 Oe and saturation magnetization higher than 1T. The initial permeability of the films is greater than 300 and flattens up to 600 MHz. The multilayer thin film properties in combination with their easy, fast and reproducible fabrication indicate that they are potential candidates for high frequency applications.

  16. X-ray grazing incidence diffraction from multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

  17. Negative Refraction Using Frequency-Tuned Oxide Multilayer Structure

    Directory of Open Access Journals (Sweden)

    Yalin Lu

    2008-01-01

    Full Text Available An oxide-based multilayer structure was proposed to realize negative refraction. The multilayer composes of alternative layers having negative permittivity and negative permeability, respectively. In order to realize negative refraction, their dielectric and magnetic resonances of layers will be tuned to the frequency as close as possibly via changing their temperature, composition, structure, and so forth. Such oxide-based NIMs are attractive for their potential applications as optical super lenses, imagers, optical cloaking, sensors, and so forth, those are required with low-loss, low-cost, and good fabrication flexibility.

  18. Atomic hydrogen cleaning of EUV multilayer optics

    Science.gov (United States)

    Graham, Samuel, Jr.; Steinhaus, Charles A.; Clift, W. Miles; Klebanoff, Leonard E.; Bajt, Sasa

    2003-06-01

    Recent studies have been conducted to investigate the use of atomic hydrogen as an in-situ contamination removal method for EUV optics. In these experiments, a commercial source was used to produce atomic hydrogen by thermal dissociation of molecular hydrogen using a hot filament. Samples for these experiments consisted of silicon wafers coated with sputtered carbon, Mo/Si optics with EUV-induced carbon, and bare Si-capped and Ru-B4C-capped Mo/Si optics. Samples were exposed to an atomic hydrogen source at a distance of 200 - 500 mm downstream and angles between 0-90° with respect to the source. Carbon removal rates and optic oxidation rates were measured using Auger electron spectroscopy depth profiling. In addition, at-wavelength peak reflectance (13.4 nm) was measured using the EUV reflectometer at the Advanced Light Source. Data from these experiments show carbon removal rates up to 20 Å/hr for sputtered carbon and 40 Å/hr for EUV deposited carbon at a distance of 200 mm downstream. The cleaning rate was also observed to be a strong function of distance and angular position. Experiments have also shown that the carbon etch rate can be increased by a factor of 4 by channeling atomic hydrogen through quartz tubes in order to direct the atomic hydrogen to the optic surface. Atomic hydrogen exposures of bare optic samples show a small risk in reflectivity degradation after extended periods. Extended exposures (up to 20 hours) of bare Si-capped Mo/Si optics show a 1.2% loss (absolute) in reflectivity while the Ru-B4C-capped Mo/Si optics show a loss on the order of 0.5%. In order to investigate the source of this reflectivity degradation, optic samples were exposed to atomic deuterium and analyzed using low energy ion scattering direct recoil spectroscopy to determine any reactions of the hydrogen with the multilayer stack. Overall, the results show that the risk of over-etching with atomic hydrogen is much less than previous studies using RF discharge cleaning

  19. High-reflectance La/B-based multilayer mirror for 6.x  nm wavelength

    NARCIS (Netherlands)

    Kuznetsov, Dmitry; Yakshin, Andrey; Sturm, Jacobus Marinus; van de Kruijs, Robbert Wilhelmus Elisabeth; Louis, Eric; Bijkerk, Frederik

    2015-01-01

    We report a hybrid thin-film deposition procedure to significantly enhance the reflectivity of La/B-based multilayer structures. This is of relevance for applications of multilayer optics at 6.7-nm wavelength and beyond. Such multilayers showed a reflectance of 64.1% at 6.65 nm measured at

  20. Highly efficient blazed grating with multilayer coating for tender X-ray energies

    NARCIS (Netherlands)

    Senf, F.; Bijkerk, Frederik; Eggenstein, F.; Gwalt, G.; Huang, Qiushi; van de Kruijs, Robbert Wilhelmus Elisabeth; Kutz, O.; Lemke, S.; Louis, Eric; Mertin, M.; Packe, I.; Rudolph, I.; Schafers, F.; Siewert, F.; Sokolov, A.; Sturm, Jacobus Marinus; Waberski, C.; Wang, Z.; Wolf, J.; Zeschke, T.; Erko, A.

    2016-01-01

    For photon energies of 1 – 5 keV, blazed gratings with multilayer coating are ideally suited for the suppression of stray and higher orders light in grating monochromators. We developed and characterized a blazed 2000 lines/mm grating coated with a 20 period Cr/C- multilayer. The multilayer

  1. 77 FR 5484 - Multilayered Wood Flooring From the People's Republic of China: Amended Antidumping and...

    Science.gov (United States)

    2012-02-03

    ..., tongue-and-groove construction or locking joints). All multilayered wood flooring is included within the... DEPARTMENT OF COMMERCE International Trade Administration [A-570-970, C-570-971] Multilayered Wood... (``CVD'') orders on multilayered wood flooring from the People's Republic of China (``PRC'') to remove an...

  2. 76 FR 76693 - Multilayered Wood Flooring From the People's Republic of China: Countervailing Duty Order

    Science.gov (United States)

    2011-12-08

    ..., tongue-and-groove construction or locking joints). All multilayered wood flooring is included within the... DEPARTMENT OF COMMERCE International Trade Administration [C-570-971] Multilayered Wood Flooring...''), the Department is issuing a countervailing duty (``CVD'') order on multilayered wood flooring from the...

  3. 76 FR 76690 - Multilayered Wood Flooring From the People's Republic of China: Amended Final Determination of...

    Science.gov (United States)

    2011-12-08

    ... construction or locking joints). All multilayered wood flooring is included within the definition of the... DEPARTMENT OF COMMERCE International Trade Administration [A-570-970] Multilayered Wood Flooring... is issuing an antidumping duty order on multilayered wood flooring (``wood flooring'') from the...

  4. 77 FR 45336 - Multilayered Wood Flooring From the People's Republic of China: Initiation of Antidumping Duty...

    Science.gov (United States)

    2012-07-31

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-970] Multilayered Wood Flooring... on multilayered wood flooring from the People's Republic of China (``PRC'') meets the statutory and... announcing the antidumping duty order on multilayered wood flooring from the PRC was published in the Federal...

  5. 78 FR 46318 - Multilayered Wood Flooring From the People's Republic of China: Initiation of Antidumping Duty...

    Science.gov (United States)

    2013-07-31

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-970] Multilayered Wood Flooring... antidumping duty order on multilayered wood flooring from the People's Republic of China (``PRC'') meet the...: Background The Department published the antidumping duty order on multilayered wood flooring from the PRC on...

  6. Fifteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The Fifteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23--25, 1990. Major topics included: DOE's geothermal research and development program, well testing, field studies, geosciences, geysers, reinjection, tracers, geochemistry, and modeling.

  7. Dissolved methane in Indian freshwater reservoirs

    Digital Repository Service at National Institute of Oceanography (India)

    Narvenkar, G.; Naqvi, S.W.A.; Kurian, S.; Shenoy, D.M.; Pratihary, A.K.; Naik, H.; Patil, S.; Sarkar, A.; Gauns, M.

    of the central part of the Indo- Gangetic Plain just north of the Tropic of Cancer. The eighth – the Bhakra-Nangal Dam is built over the Sutlej River at the foothills of the Himalayas. The reservoirs of these dams vary greatly in size from very small systems...

  8. Do cyanobacterial picoplankton exist in eutrophic reservoirs?

    Czech Academy of Sciences Publication Activity Database

    Komárková, Jaroslava

    2002-01-01

    Roč. 28, - (2002), s. 497-500 ISSN 0368-0770 R&D Projects: GA AV ČR IBS6017004; GA AV ČR IAA6017803; GA AV ČR KSK2005601 Keywords : reservoir * colonial picocynobacteria Subject RIV: DA - Hydrology ; Limnology

  9. Accounting for Greenhouse Gas Emissions from Reservoirs ...

    Science.gov (United States)

    Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used as a ‘basis for future methodological development’ due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. In the U.S., research approaches include: 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane em

  10. Landscape runoff, precipitation variation and reservoir limnology

    OpenAIRE

    Geraldes, Ana Maria

    2010-01-01

    Landscape runoff potential impact on reservoir limnology was indirectly evaluated by assessing the effect of precipitation variation on several water quality parameters, on Anabaena (Cyanophyta) and crustacean zooplankton abundances. The obtained results showed that total phosphorus increased with strong precipitation events whereas water transparency presented an opposite trend. Wet periods followed by long dry periods favored Anabaena dominance, which induced a...

  11. Fourteenth workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

    1989-01-01

    The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

  12. Probing magma reservoirs to improve volcano forecasts

    Science.gov (United States)

    Lowenstern, Jacob B.; Sisson, Thomas W.; Hurwitz, Shaul

    2017-01-01

    When it comes to forecasting eruptions, volcano observatories rely mostly on real-time signals from earthquakes, ground deformation, and gas discharge, combined with probabilistic assessments based on past behavior [Sparks and Cashman, 2017]. There is comparatively less reliance on geophysical and petrological understanding of subsurface magma reservoirs.

  13. Accouting for Greenhouse Gas Emissions from Reservoirs

    Science.gov (United States)

    Beaulieu, J. J.; Deemer, B. R.; Harrison, J. A.; Nietch, C. T.; Waldo, S.

    2016-12-01

    Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used as a `basis for future methodological development' due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. In the U.S., research approaches include: 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane emissions linked to the National Lakes Assessment.

  14. Fourteenth workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

    1989-12-31

    The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

  15. Novel Synechococcus genomes reconstructed from freshwater reservoirs

    Czech Academy of Sciences Publication Activity Database

    Cabello-Yeves, P.J.; Haro-Moreno, J.M.; Martin-Cuadrado, A.B.; Ghai, Rohit; Picazo, A.; Camacho, A.; Rodriguez-Valera, F.

    2017-01-01

    Roč. 8, June (2017), č. článku 1151. ISSN 1664-302X R&D Projects: GA ČR(CZ) GA17-04828S Institutional support: RVO:60077344 Keywords : Synechococcus * picocyanobacteria * freshwater reservoirs * metagenomics * abundance Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

  16. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    Kayhude at the river Alster and Schlamersdorf at the river Trave, both in Schleswig-Holstein, Northern Germany. Measurements on modern materials from these rivers may not give a single reservoir age correction that can be applied to archaeological samples, but they will show the order of magnitude...

  17. Adsorption of hydrocarbons in chalk reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  18. Exponential rate of convergence in current reservoirs

    OpenAIRE

    De Masi, Anna; Presutti, Errico; Tsagkarogiannis, Dimitrios; Vares, Maria Eulalia

    2015-01-01

    In this paper, we consider a family of interacting particle systems on $[-N,N]$ that arises as a natural model for current reservoirs and Fick's law. We study the exponential rate of convergence to the stationary measure, which we prove to be of the order $N^{-2}$.

  19. The glaciogenic reservoir analogue studies project (GRASP)

    DEFF Research Database (Denmark)

    Moscariello, A.; Moreau, Julien; Vegt, P. van der

    in Quaternary glaciated areas and their nature and sediment composition is critical to drive a sustainable production strategy and assess their vulnerability. Seismic resolution however, often limits the understanding of channel valleys morphology, 3D geometry and internal reservoir distribution, thus...

  20. Parallel Numerical Simulations of Water Reservoirs

    Science.gov (United States)

    Torres, Pedro; Mangiavacchi, Norberto

    2010-11-01

    The study of the water flow and scalar transport in water reservoirs is important for the determination of the water quality during the initial stages of the reservoir filling and during the life of the reservoir. For this scope, a parallel 2D finite element code for solving the incompressible Navier-Stokes equations coupled with scalar transport was implemented using the message-passing programming model, in order to perform simulations of hidropower water reservoirs in a computer cluster environment. The spatial discretization is based on the MINI element that satisfies the Babuska-Brezzi (BB) condition, which provides sufficient conditions for a stable mixed formulation. All the distributed data structures needed in the different stages of the code, such as preprocessing, solving and post processing, were implemented using the PETSc library. The resulting linear systems for the velocity and the pressure fields were solved using the projection method, implemented by an approximate block LU factorization. In order to increase the parallel performance in the solution of the linear systems, we employ the static condensation method for solving the intermediate velocity at vertex and centroid nodes separately. We compare performance results of the static condensation method with the approach of solving the complete system. In our tests the static condensation method shows better performance for large problems, at the cost of an increased memory usage. Performance results for other intensive parts of the code in a computer cluster are also presented.

  1. Studies of Reservoir Hosts for Marburg virus

    DEFF Research Database (Denmark)

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E

    2007-01-01

    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of...

  2. Analysis of Sedimentation in Wonogiri Reservoir

    Directory of Open Access Journals (Sweden)

    Tri Joko Inti Budi Santosa

    2016-01-01

    Full Text Available The Wonogiri reservoir which has 730 million cubic meters of total storage, 90 square kilometers of water area, and 1260 square kilometers of catchment area, is located in the Wonogiri Regency, Central Java Province. It was first established in 1981 and began its operation in 1982 with the expectation that it would last for about 100 years. Today (2002 the reservoir has got a serious problem of sedimentation. The sedimentation is so large that it would decrease the capacity storage of the reservoir and would shorten the length of operation. Therefore, it is necessary to predict the sediment that comes into the reservoir. This research would be based on the total sediment calculation of the sedimentation, through some methods, such as echo sounding measured data, land erosion (USLE, the calculation of the sediment in rivers. This research calculates the sediment capacities based on the water flow data and the sediment rating curves in rivers of Keduang, Tirtomoyo, Temon, upstream reach of Bengawan Solo, Alang, and Wuryantoro. The suspended load was calculated based on the sediment rating curves, whereas the bed load was computed as the percentage of the suspended load. The sum of both calculation results would be the total sediment. The calculation result showed that the total sediment which has come into the reservoir is 6.68 million cubic meters per year. As a comparison, the writer noted that the former researcher using echo sounding method done by the Faculty of Geography of the Universitas Gadjah Mada in 1985, it found that the total sediment capacity which came into the reservoir was 6.60 million cubic meters per year or 5.40 mm per year of sheet erosion. The other research using echo sounding method done by JICA in 2000 found that the total sediment which had come into the reservoir was 4.50 million cubic meters per year or 3.50 mm per year of sheet erosion. By knowing the results of calculation of the total sediment, we can learn that

  3. Reservoir pressure evolution model during exploration drilling

    Directory of Open Access Journals (Sweden)

    Korotaev B. A.

    2017-03-01

    Full Text Available Based on the analysis of laboratory studies and literature data the method for estimating reservoir pressure in exploratory drilling has been proposed, it allows identify zones of abnormal reservoir pressure in the presence of seismic data on reservoir location depths. This method of assessment is based on developed at the end of the XX century methods using d- and σ-exponentials taking into account the mechanical drilling speed, rotor speed, bit load and its diameter, lithological constant and degree of rocks' compaction, mud density and "regional density". It is known that in exploratory drilling pulsation of pressure at the wellhead is observed. Such pulsation is a consequence of transferring reservoir pressure through clay. In the paper the mechanism for transferring pressure to the bottomhole as well as the behaviour of the clay layer during transmission of excess pressure has been described. A laboratory installation has been built, it has been used for modelling pressure propagation to the bottomhole of the well through a layer of clay. The bulge of the clay layer is established for 215.9 mm bottomhole diameter. Functional correlation of pressure propagation through the layer of clay has been determined and a reaction of the top clay layer has been shown to have bulge with a height of 25 mm. A pressure distribution scheme (balance has been developed, which takes into account the distance from layers with abnormal pressure to the bottomhole. A balance equation for reservoir pressure evaluation has been derived including well depth, distance from bottomhole to the top of the formation with abnormal pressure and density of clay.

  4. Reservoir Cathode for Electric Space Propulsion, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a hollow reservoir cathode to improve performance in ion and Hall thrusters. We will adapt our existing reservoir cathode technology to this purpose....

  5. Evaluation of Gaussian approximations for data assimilation in reservoir models

    KAUST Repository

    Iglesias, Marco A.; Law, Kody J H; Stuart, Andrew M.

    2013-01-01

    is fundamental for the optimal management of reservoirs. Unfortunately, due to the large-scale highly nonlinear properties of standard reservoir models, characterizing the posterior is computationally prohibitive. Instead, more affordable ad hoc techniques, based

  6. Performance Analysis of Depleted Oil Reservoirs for Underground Gas Storage

    Directory of Open Access Journals (Sweden)

    Dr. C.I.C. Anyadiegwu

    2014-02-01

    Full Text Available The performance of underground gas storage in depleted oil reservoir was analysed with reservoir Y-19, a depleted oil reservoir in Southern region of the Niger Delta. Information on the geologic and production history of the reservoir were obtained from the available field data of the reservoir. The verification of inventory was done to establish the storage capacity of the reservoir. The plot of the well flowing pressure (Pwf against the flow rate (Q, gives the deliverability of the reservoir at various pressures. Results of the estimated properties signified that reservoir Y-19 is a good candidate due to its storage capacity and its flow rate (Q of 287.61 MMscf/d at a flowing pressure of 3900 psig

  7. AUTOMATED TECHNIQUE FOR FLOW MEASUREMENTS FROM MARIOTTE RESERVOIRS.

    Science.gov (United States)

    Constantz, Jim; Murphy, Fred

    1987-01-01

    The mariotte reservoir supplies water at a constant hydraulic pressure by self-regulation of its internal gas pressure. Automated outflow measurements from mariotte reservoirs are generally difficult because of the reservoir's self-regulation mechanism. This paper describes an automated flow meter specifically designed for use with mariotte reservoirs. The flow meter monitors changes in the mariotte reservoir's gas pressure during outflow to determine changes in the reservoir's water level. The flow measurement is performed by attaching a pressure transducer to the top of a mariotte reservoir and monitoring gas pressure changes during outflow with a programmable data logger. The advantages of the new automated flow measurement techniques include: (i) the ability to rapidly record a large range of fluxes without restricting outflow, and (ii) the ability to accurately average the pulsing flow, which commonly occurs during outflow from the mariotte reservoir.

  8. Increasing Waterflood Reserves in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, D.; Koerner, R.; Moos D.; Nguyen, J.; Phillips, C.; Tagbor, K.; Walker, S.

    1999-04-05

    This project used advanced reservoir characterization tools, including the pulsed acoustic cased-hole logging tool, geologic three-dimensional (3-D) modeling software, and commercially available reservoir management software to identify sands with remaining high oil saturation following waterflood. Production from the identified high oil saturated sands was stimulated by recompleting existing production and injection wells in these sands using conventional means as well as a short radius redrill candidate.

  9. State of the art of reservoir sedimentation management in Spain

    OpenAIRE

    Avendaño Salas, Cándido; Sanz Montero, Esther; Cobo Rayán, Rafael

    2000-01-01

    Part of the total reservoir storage capacity in Spain (56 km3) is lost due to sedimentation processes taking place. Surveys carried out in 121 reservoirs indicate that 6% of them have undergone a capacity reduction of over 50%. However, most of them (81%) are characterised by a reservoir capacity loss below 20%. The most frequent methods used to control reservoir sedimentation in Spain fall into one of the following groups: reduction of sediment yield through basin management and removal of t...

  10. First assessment of the ecological status of Karaoun reservoir, Lebanon

    International Nuclear Information System (INIS)

    Fadel, A.; Lemaire, B.; Vinc on Leite, B.; Tassin, B.; Amacha, N.; Slim, K.; Atoui, A.

    2014-01-01

    Many reservoirs have been constructed throughout the world during the 20th century, with many also suffering from eutrophication. The resulting increased phytoplankton biomass in reservoirs impairs their use. Except for Lake Kinneret, the environmental status of lakes and reservoirs in the Middle East is poorly documented. Karaoun reservoir, also known as Qaroun, Qaraoun or Qarun, is the largest water body in Lebanon, having been constructed for irrigation and hydropower production. This present study reviews Karaoun reservoir, including its characteristics, uses, water quality and phytoplankton succession, to assess the environmental status of the reservoir on the basis of the few existing previous publications about the reservoir. Since 2004, which is 39 years after its construction, the reservoir is considered to be hypereutrophic, with low phytoplankton biodiversity and regular blooms of toxic cyanobacteria. The nutrient and trace metal concentrations would not prevent use of the reservoir for a drinking water supply for Beirut, as is currently being planned, although not all the micropollutants in the lake were documented. Karaoun reservoir is compared to other monitored lakes and reservoirs around the Mediterranean Sea. They share annual toxic cyanobacteria blooms of Aphanizomenon ovalisporum and of Microcystis aeruginosa. The phytoplankton composition and succession of Karaoun reservoir is more similar to El Gergal reservoir (Spain) than nearby natural lakes such as Lake Kinneret (Israel) and Lake Trichonis (Greece). Phytoplankton diversity in Karaoun reservoir was the lowest, due to higher nutrient concentrations and a larger decrease in water level in the dry season. Karaoun reservoir represents an interesting example of the potential response of the phytoplankton community in other lakes and reservoirs during the drought periods expected to occur as a result of global climate change. (author)

  11. Reservoir management under consideration of stratification and hydraulic phenomena

    OpenAIRE

    Nandalal, K.D.W.

    1995-01-01


    Reservoirs are the most important components in a water resources system. They are used to store water to extend its temporal availability. The physical, chemical and biological characteristics of water change when impounded in reservoirs. This implies the possibility of using reservoirs for the control of the quality of water besides merely satisfying the quantity requirement. This study presents several techniques formulated to manage a reservoir when both quantity and quality of...

  12. Sudden water pollution accidents and reservoir emergency operations: impact analysis at Danjiangkou Reservoir.

    Science.gov (United States)

    Zheng, Hezhen; Lei, Xiaohui; Shang, Yizi; Duan, Yang; Kong, Lingzhong; Jiang, Yunzhong; Wang, Hao

    2018-03-01

    Danjiangkou Reservoir is the source reservoir of the Middle Route of the South-to-North Water Diversion Project (MRP). Any sudden water pollution accident in the reservoir would threaten the water supply of the MRP. We established a 3-D hydrodynamic and water quality model for the Danjiangkou Reservoir, and proposed scientific suggestions on the prevention and emergency management for sudden water pollution accidents based on simulated results. Simulations were performed on 20 hypothetical pollutant discharge locations and 3 assumed amounts, in order to model the effect of pollutant spreading under different reservoir operation types. The results showed that both the location and mass of pollution affected water quality; however, different reservoir operation types had little effect. Five joint regulation scenarios, which altered the hydrodynamic processes of water conveyance for the Danjiangkou and Taocha dams, were considered for controlling pollution dispersion. The results showed that the spread of a pollutant could be effectively controlled through the joint regulation of the two dams and that the collaborative operation of the Danjiangkou and Taocha dams is critical for ensuring the security of water quality along the MRP.

  13. Analysis of the Pseudoalteromonas tunicata genome reveals properties of a surface-associated life style in the marine environment.

    Directory of Open Access Journals (Sweden)

    Torsten Thomas

    Full Text Available BACKGROUND: Colonisation of sessile eukaryotic host surfaces (e.g. invertebrates and seaweeds by bacteria is common in the marine environment and is expected to create significant inter-species competition and other interactions. The bacterium Pseudoalteromonas tunicata is a successful competitor on marine surfaces owing primarily to its ability to produce a number of inhibitory molecules. As such P. tunicata has become a model organism for the studies into processes of surface colonisation and eukaryotic host-bacteria interactions. METHODOLOGY/PRINCIPAL FINDINGS: To gain a broader understanding into the adaptation to a surface-associated life-style, we have sequenced and analysed the genome of P. tunicata and compared it to the genomes of closely related strains. We found that the P. tunicata genome contains several genes and gene clusters that are involved in the production of inhibitory compounds against surface competitors and secondary colonisers. Features of P. tunicata's oxidative stress response, iron scavenging and nutrient acquisition show that the organism is well adapted to high-density communities on surfaces. Variation of the P. tunicata genome is suggested by several landmarks of genetic rearrangements and mobile genetic elements (e.g. transposons, CRISPRs, phage. Surface attachment is likely to be mediated by curli, novel pili, a number of extracellular polymers and potentially other unexpected cell surface proteins. The P. tunicata genome also shows a utilisation pattern of extracellular polymers that would avoid a degradation of its recognised hosts, while potentially causing detrimental effects on other host types. In addition, the prevalence of recognised virulence genes suggests that P. tunicata has the potential for pathogenic interactions. CONCLUSIONS/SIGNIFICANCE: The genome analysis has revealed several physiological features that would provide P. tunciata with competitive advantage against other members of the surface-associated

  14. Analysis of the Pseudoalteromonas tunicata genome reveals properties of a surface-associated life style in the marine environment.

    Science.gov (United States)

    Thomas, Torsten; Evans, Flavia F; Schleheck, David; Mai-Prochnow, Anne; Burke, Catherine; Penesyan, Anahit; Dalisay, Doralyn S; Stelzer-Braid, Sacha; Saunders, Neil; Johnson, Justin; Ferriera, Steve; Kjelleberg, Staffan; Egan, Suhelen

    2008-09-24

    Colonisation of sessile eukaryotic host surfaces (e.g. invertebrates and seaweeds) by bacteria is common in the marine environment and is expected to create significant inter-species competition and other interactions. The bacterium Pseudoalteromonas tunicata is a successful competitor on marine surfaces owing primarily to its ability to produce a number of inhibitory molecules. As such P. tunicata has become a model organism for the studies into processes of surface colonisation and eukaryotic host-bacteria interactions. To gain a broader understanding into the adaptation to a surface-associated life-style, we have sequenced and analysed the genome of P. tunicata and compared it to the genomes of closely related strains. We found that the P. tunicata genome contains several genes and gene clusters that are involved in the production of inhibitory compounds against surface competitors and secondary colonisers. Features of P. tunicata's oxidative stress response, iron scavenging and nutrient acquisition show that the organism is well adapted to high-density communities on surfaces. Variation of the P. tunicata genome is suggested by several landmarks of genetic rearrangements and mobile genetic elements (e.g. transposons, CRISPRs, phage). Surface attachment is likely to be mediated by curli, novel pili, a number of extracellular polymers and potentially other unexpected cell surface proteins. The P. tunicata genome also shows a utilisation pattern of extracellular polymers that would avoid a degradation of its recognised hosts, while potentially causing detrimental effects on other host types. In addition, the prevalence of recognised virulence genes suggests that P. tunicata has the potential for pathogenic interactions. The genome analysis has revealed several physiological features that would provide P. tunciata with competitive advantage against other members of the surface-associated community. We have also identified properties that could mediate interactions

  15. Tunable photonic multilayer sensors from photo-crosslinkable polymers

    Science.gov (United States)

    Chiappelli, Maria; Hayward, Ryan

    2014-03-01

    The fabrication of tunable photonic multilayer sensors from stimuli-responsive, photo-crosslinkable polymers will be described. Benzophenone is covalently incorporated as a pendent photo-crosslinker, allowing for facile preparation of multilayer films by sequential spin-coating and crosslinking processes. Copolymer chemistries and layer thicknesses are selected to provide robust multilayer sensors which can show color changes across nearly the full visible spectrum due to the specific stimulus-responsive nature of the hydrated film stack. We will describe how this approach is extended to alternative sensor designs by tailoring the thickness and chemistry of each layer independently, allowing for the preparation of sensors which depend not only on the shift in wavelength of a reflectance peak, but also on the transition between Bragg mirrors and filters. Device design is optimized by photo-patterning sensor arrays on a single substrate, providing more efficient fabrication time as well as multi-functional sensors. Finally, radiation-sensitive multilayers, designed by choosing polymers which will preferentially degrade or crosslink under ionizing radiation, will also be described.

  16. Fabrication of dye-sensitized solar cells with multilayer photoanodes

    Indian Academy of Sciences (India)

    Volume 39 Issue 6 October 2016 pp 1403-1410 ... Keywords. Dye-sensitized solar cells; hydrothermal method; TiO 2 nanocrystals; multilayer photoanodes; energy conversion efficiency. ... Higher energy conversion efficiencies were also attainable using two transparent sub-layers of hydrothermally grown TiO 2 NCs.

  17. Hot-rolled Process of Multilayered Composite Metal Plate

    Directory of Open Access Journals (Sweden)

    YU Wei

    2017-02-01

    Full Text Available For multi-layer plate, it is a difficult problem to increase product yield rate and improve bonding interface quality. A high yield hot-rolled method of multilayered plate was proposed. The raw strips and plate were fixed by argon arc welding. The combined billet was put into a metal box and vacuum pumped, and then heated and rolled by multi passes at the temperature of 1000-1200℃. The 67 layered plate with the thickness of 2.5mm was successfully produced. The interfacial microstructures and diffusion behavior were investigated and analyzed by optical microscopy and scan electronic microscopy. The tensile and shear strength were tested,and the shear fractures were analyzed. The results show that the multilayered plate yield rate is more than 90% by two steps billet combination method and rolling process optimization. The good bonding interface quality is obtained, the shear strength of multilayered plate reaches 241 MPa. Nickel interlayer between 9Cr18 and 1Cr17 can not only prevent the diffusion of carbon, but also improve the microstructure characteristics.

  18. Oblique roughness replication in strained SiGe/Si multilayers

    NARCIS (Netherlands)

    Holy, V.; Darhuber, A.A.; Stangl, J.; Bauer, G.; Nützel, J.-F.; Abstreiter, G.

    1998-01-01

    The replication of the interface roughness in SiGe/Si multilayers grown on miscut Si(001) substrates has been studied by means of x-ray reflectivity reciprocal space mapping. The interface profiles were found to be highly correlated and the direction of the maximal replication was inclined with

  19. Origin of perpendicular magnetic anisotropy in Co/Ni multilayers

    Science.gov (United States)

    Arora, M.; Hübner, R.; Suess, D.; Heinrich, B.; Girt, E.

    2017-07-01

    We studied the variation in perpendicular magnetic anisotropy of (111) textured Au /N ×[Co /Ni ]/Au films as a function of the number of bilayer repeats N . The ferromagnetic resonance and superconducting quantum interference device magnetometer measurements show that the perpendicular magnetic anisotropy of Co/Ni multilayers first increases with N for N ≤10 and then moderately decreases for N >10 . The model we propose reveals that the decrease of the anisotropy for N reduction in the magnetoelastic and magnetocrystalline anisotropies. A moderate decrease in the perpendicular magnetic anisotropy for N >10 is due to the reduction in the magnetocrystalline and the surface anisotropies. To calculate the contribution of magnetoelastic anisotropy in the Co/Ni multilayers, in-plane and out-of-plane x-ray diffraction measurements are performed to determine the spacing between Co/Ni (111) and (220) planes. The magnetocrystalline bulk anisotropy is estimated from the difference in the perpendicular and parallel g factors of Co/Ni multilayers that are measured using the in-plane and out-of-plane ferromagnetic resonance measurements. Transmission electron microscopy has been used to estimate the multilayer film roughness. These values are used to calculate the roughness-induced surface and magnetocrystalline anisotropy coefficients as a function of N .

  20. Cross-linked polyelectrolyte multilayers for marine antifouling applications

    NARCIS (Netherlands)

    Zhu, X.; Janczewski, D.; Lee, S.S.C.; Teo, S.L-M.; Vancso, Gyula J.

    2013-01-01

    A polyionic multilayer film was fabricated by layer-by-layer (LbL) sequential deposition followed by cross-linking under mild conditions on a substrate surface to inhibit marine fouling. A novel polyanion, featuring methyl ester groups for an easy cross-linking was used as a generic solution for

  1. High-resolution X-ray diffraction studies of multilayers

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Schnopper, H. W.

    1988-01-01

    High-resolution X-ray diffraction studies of the perfection of state-of-the-art multilayers are presented. Data were obtained using a triple-axis perfect-crystal X-ray diffractometer. Measurements reveal large-scale figure errors in the substrate. A high-resolution triple-axis set up is required...

  2. Thermal-Insulation Properties of Multilayer Textile Packages

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2014-12-01

    Full Text Available Thermal-insulation properties of textile materials play a significant role in material engineering of protective clothing. Thermal-insulation properties are very important from the point of view of thermal comfort of the clothing user as well as the protective efficiency against low or high temperature. Thermal protective clothing usually is a multilayer construction. Its thermal insulation is a resultant of a number of layers and their order, as well as the thermalinsulation properties of a single textile material creating particular layers. The aim of the presented work was to investigate the relationships between the thermal-insulation properties of single materials and multilayer textile packages composed of these materials. Measurement of the thermal-insulation properties of single and multilayer textile materials has been performed with the Alambeta. The following properties have been investigated: thermal conductivity, resistance and absorptivity. Investigated textile packages were composed of two, three and four layers made of woven and knitted fabrics, as well as nonwovens. On the basis of the obtained results an analysis has been carried out in order to assess the dependency of the resultant values of the thermal-insulation properties of multilayer packages on the appropriate values of particular components.

  3. Multilayer composite material and method for evaporative cooling

    Science.gov (United States)

    Buckley, Theresa M. (Inventor)

    2002-01-01

    A multilayer composite material and method for evaporative cooling of a person employs an evaporative cooling liquid that changes phase from a liquid to a gaseous state to absorb thermal energy. The evaporative cooling liquid is absorbed into a superabsorbent material enclosed within the multilayer composite material. The multilayer composite material has a high percentage of the evaporative cooling liquid in the matrix. The cooling effect can be sustained for an extended period of time because of the high percentage of phase change liquid that can be absorbed into the superabsorbent. Such a composite can be used for cooling febrile patients by evaporative cooling as the evaporative cooling liquid in the matrix changes from a liquid to a gaseous state to absorb thermal energy. The composite can be made with a perforated barrier material around the outside to regulate the evaporation rate of the phase change liquid. Alternatively, the composite can be made with an imperveous barrier material or semipermeable membrane on one side to prevent the liquid from contacting the person's skin. The evaporative cooling liquid in the matrix can be recharged by soaking the material in the liquid. The multilayer composite material can be fashioned into blankets, garments and other articles.

  4. Overview of the CERES Edition-4 Multilayer Cloud Property Datasets

    Science.gov (United States)

    Chang, F. L.; Minnis, P.; Sun-Mack, S.; Chen, Y.; Smith, R. A.; Brown, R. R.

    2014-12-01

    Knowledge of the cloud vertical distribution is important for understanding the role of clouds on earth's radiation budget and climate change. Since high-level cirrus clouds with low emission temperatures and small optical depths can provide a positive feedback to a climate system and low-level stratus clouds with high emission temperatures and large optical depths can provide a negative feedback effect, the retrieval of multilayer cloud properties using satellite observations, like Terra and Aqua MODIS, is critically important for a variety of cloud and climate applications. For the objective of the Clouds and the Earth's Radiant Energy System (CERES), new algorithms have been developed using Terra and Aqua MODIS data to allow separate retrievals of cirrus and stratus cloud properties when the two dominant cloud types are simultaneously present in a multilayer system. In this paper, we will present an overview of the new CERES Edition-4 multilayer cloud property datasets derived from Terra as well as Aqua. Assessment of the new CERES multilayer cloud datasets will include high-level cirrus and low-level stratus cloud heights, pressures, and temperatures as well as their optical depths, emissivities, and microphysical properties.

  5. Pencil beam proton radiography using a multilayer ionization chamber

    NARCIS (Netherlands)

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-01-01

    A pencil beam proton radiography (PR) method, using a commercial multilayer ionization chamber (MLIC) integrated with a treatment planning system (TPS) was developed. A Giraffe (IBA Dosimetry) MLIC (+/- 0.5 mm accuracy) was used to obtain pencil beam PR by delivering spots uniformly positioned at a

  6. Magnetic-field inversion in vortices in multilayers

    International Nuclear Information System (INIS)

    Theodorakis, S.; Leontidis, E.

    1997-01-01

    We present a description of very dense vortex lattices in highly anisotropic multilayers, for high fields parallel to the layers. We show that a magnetic-field inversion can occur away from the center of a vortex, provided the layers are sufficiently far apart. copyright 1997 The American Physical Society

  7. Charge equilibration and potential steps in organic semiconductor multilayers

    NARCIS (Netherlands)

    Brocks, G.; Cakir, Deniz; Bokdam, Menno; de Jong, Machiel Pieter; Fahlman, M.

    2012-01-01

    Substantial potential steps ∼0.5 eV are frequently observed in organic multilayers of donor and acceptor molecules. Often such potential steps depend on the order in which the individual layers are deposited, or on which substrate they are deposited. In this paper we outline a model for these

  8. Resonant diffuse X-ray scattering from magnetic multilayers

    International Nuclear Information System (INIS)

    Spezzani, Carlo; Torelli, Piero; Delaunay, Renaud; Hague, C.F.; Petroff, Frederic; Scholl, Andreas; Gullikson, E.M.; Sacchi, Maurizio

    2004-01-01

    We have measured field-dependent resonant diffuse scattering from a magnetoresistive Co/Cu multilayer. We have observed that the magnetic domain size in zero field depends on the magnetic history of the sample. The results of the X-ray scattering analysis have been compared to PEEM images of the magnetic domains

  9. Magnetic studies in evaporated Ni/Pd multilayers

    International Nuclear Information System (INIS)

    Chafai, K.; Salhi, H.; Lassri, H.; Yamkane, Z.; Lassri, M.; Abid, M.; Hlil, E.K.; Krishnan, R.

    2011-01-01

    The magnetic properties of Ni/Pd multilayers, prepared by sequential evaporation in ultrahigh vacuum, have been studied. The Ni thickness dependence of the magnetization and magnetic anisotropy is discussed. The temperature dependence of the spontaneous magnetization is well described by a T 3/2 law in all multilayers. A spin-wave theory has been used to explain the temperature dependence of the spontaneous magnetization, and the approximate values for the exchange interactions for various Ni layer thicknesses have been obtained. - Research highlights: → The magnetic properties of Ni/Pd multilayers, prepared by sequential evaporation in ultrahigh vacuum, have been studied. → The temperature dependence of the spontaneous magnetization is well described by a T 3/2 law in Ni/Pd multilayers. → The spin-wave constant B was observed to depend on t Ni nonmonotonically. → A spin-wave theory has been used to explain the temperature dependence of the spontaneous magnetization. → The approximate values for the exchange interactions for various Ni layer thicknesses have been obtained.

  10. Multilayered antifriction nanostraction covering for lubrication in the tribocoupling

    Directory of Open Access Journals (Sweden)

    Vladimir KOLESNIKOV

    2010-01-01

    Full Text Available In article principles of creation of a new way of the lubrication a wheel-rail tribosystem by drawing on a lateral side of a rail head of a multilayered antifriction nanostructurial covering possessing property of blocking negative segregation phenomena in metals of a wheel and a rail are considered.

  11. Off-axis electron holography of ferromagnetic multilayer nanowires

    DEFF Research Database (Denmark)

    Akhtari-Zavareh, Azadeh; Carignan, L. P.; Yelon, A.

    2014-01-01

    with respect to the axis of the wires. In thinner Cu/CoFeB ((multilayer, magnetic field vortices were detected, associated with opposing magnetization in neighbouring layers. The measured crystallinity, compositions, and layer thicknesses of individual NWs were found to be significantly different...

  12. Multilayer control for inverters in parallel operation without signal interconnection

    DEFF Research Database (Denmark)

    Hua, Ming; Hu, Haibing; Xing, Yan

    2011-01-01

    A multilayer control is proposed for inverters with wireless parallel operation in this paper. The control is embedded in every inverter respectively and consists of three layers. The first layer is based on an improved droop method, which shares the active and reactive power in each module...

  13. Multilayer Control for Inverters in Parallel Operation without Intercommunications

    DEFF Research Database (Denmark)

    Hua, Ming; Hu, Haibing; Xing, Yan

    2012-01-01

    In this paper, a multilayer control is proposed for inverters able to operate in parallel without intercommunications. The first control layer is an improved droop method that introduces power proportional terms into the conventional droop scheme, letting both active and reactive power to be shared...

  14. Ultrasensitive Terahertz Waveguide Modulators Using Multilayer Graphene Metamaterials

    DEFF Research Database (Denmark)

    Khromova, I.; Andryieuski, Andrei; Lavrinenko, Andrei

    2014-01-01

    We study terahertz-infrared electromagnetic properties of multilayer graphene- dielectric metamaterial and present novel waveguide-based devices: modulators with high mod- ulation depth ( > 38 dB at 0 : 07 eV graphene’s Fermi energy change) or extreme sensitivity (mod- ulation depth of > 13 : 2 d...

  15. Exciton ionization in multilayer transition-metal dichalcogenides

    DEFF Research Database (Denmark)

    Pedersen, Thomas Garm; Latini, Simone; Thygesen, Kristian Sommer

    2016-01-01

    Photodetectors and solar cells based on materials with strongly bound excitons rely crucially on field-assisted exciton ionization. We study the ionization process in multilayer transition-metal dichalcogenides (TMDs) within the Mott-Wannier model incorporating fully the pronounced anisotropy...

  16. Multilayer Slab Waveguide Distributed Feedback Dye Laser Sensors

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Smith, Cameron; Leung, M.

    2013-01-01

    of DFB lasers. Here, we present a simple yet precise model for calculating the emission wavelength of multilayer DFB lasers. We ¯nd that experimental and calculated wavelength values are in compelling agreement for hybrid nanoimprinted Ormocomp-TiO2 (doped with Pyrromethene 597) ¯rst order DFB lasers [2...

  17. Simulated SAM A-scans on multilayer MEMS components

    DEFF Research Database (Denmark)

    Janting, Jakob; Petersen, Dirch Hjorth; Greisen, Christoffer

    2002-01-01

    A spreadsheet program for simulation of Scanning Acoustic Microscopy (SAM) A-scans on multilayer structures has been developed. Using this program, structure variations in samples can be analysed better. Further samples can be prepared to get optimal signal for enhanced failure and materials...

  18. A MULTILAYER BIOCHEMICAL DRY DEPOSITION MODEL 2. MODEL EVALUATION

    Science.gov (United States)

    The multilayer biochemical dry deposition model (MLBC) described in the accompanying paper was tested against half-hourly eddy correlation data from six field sites under a wide range of climate conditions with various plant types. Modeled CO2, O3, SO2<...

  19. Long term physical and chemical stability of polyelectrolyte multilayer membranes

    NARCIS (Netherlands)

    de Grooth, Joris; Haakmeester, Brian; Wever, Carlos; Potreck, Jens; de Vos, Wiebe Matthijs; Nijmeijer, Dorothea C.

    2015-01-01

    This work presents a detailed investigation into the long term stability of polyelectrolyte multilayer (PEM) modified membranes, a key factor for the application of these membranes in water purification processes. Although PEM modified membranes have been frequently investigated, their long term

  20. Multilayered tori in a system of two coupled logistic maps

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai; Mosekilde, Erik

    2009-01-01

    of two coupled logistic maps through period-doubling or pitchfork bifurcations of the saddle cycle on an ordinary resonance torus. We hereafter present two different scenarios by which a multilayered torus can be destructed. One scenario involves a cascade of period-doubling bifurcations of both...

  1. Second-Order Learning Methods for a Multilayer Perceptron

    International Nuclear Information System (INIS)

    Ivanov, V.V.; Purehvdorzh, B.; Puzynin, I.V.

    1994-01-01

    First- and second-order learning methods for feed-forward multilayer neural networks are studied. Newton-type and quasi-Newton algorithms are considered and compared with commonly used back-propagation algorithm. It is shown that, although second-order algorithms require enhanced computer facilities, they provide better convergence and simplicity in usage. 13 refs., 2 figs., 2 tabs

  2. Electromechanical field effect transistors based on multilayer phosphorene nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Z.T., E-mail: jiangzhaotan@hotmail.com; Lv, Z.T.; Zhang, X.D.

    2017-06-21

    Based on the tight-binding Hamiltonian approach, we demonstrate that the electromechanical field effect transistors (FETs) can be realized by using the multilayer phosphorene nanoribbons (PNRs). The synergistic combination of the electric field and the external strains can establish the on–off switching since the electric field can shift or split the energy band, and the mechanical strains can widen or narrow the band widths. This kind of multilayer PNR FETs, much solider than the monolayer PNR one and more easily biased by different electric fields, has more transport channels consequently leading to the higher on–off current ratio or the higher sensitivity to the electric fields. Meanwhile, the strain-induced band-flattening will be beneficial for improving the flexibility in designing the electromechanical FETs. In addition, such electromechanical FETs can act as strain-controlled FETs or mechanical detectors for detecting the strains, indicating their potential applications in nano- and micro-electromechanical fields. - Highlights: • Electromechanical transistors are designed with multilayer phosphorene nanoribbons. • Electromechanical synergistic effect can establish the on–off switching more flexibly. • Multilayer transistors, solider and more easily biased, has more transport channels. • Electromechanical transistors can act as strain-controlled transistors or mechanical detectors.

  3. Diversity of multilayer networks and its impact on collaborating epidemics

    Science.gov (United States)

    Min, Yong; Hu, Jiaren; Wang, Weihong; Ge, Ying; Chang, Jie; Jin, Xiaogang

    2014-12-01

    Interacting epidemics on diverse multilayer networks are increasingly important in modeling and analyzing the diffusion processes of real complex systems. A viral agent spreading on one layer of a multilayer network can interact with its counterparts by promoting (cooperative interaction), suppressing (competitive interaction), or inducing (collaborating interaction) its diffusion on other layers. Collaborating interaction displays different patterns: (i) random collaboration, where intralayer or interlayer induction has the same probability; (ii) concentrating collaboration, where consecutive intralayer induction is guaranteed with a probability of 1; and (iii) cascading collaboration, where consecutive intralayer induction is banned with a probability of 0. In this paper, we develop a top-bottom framework that uses only two distributions, the overlaid degree distribution and edge-type distribution, to model collaborating epidemics on multilayer networks. We then state the response of three collaborating patterns to structural diversity (evenness and difference of network layers). For viral agents with small transmissibility, we find that random collaboration is more effective in networks with higher diversity (high evenness and difference), while the concentrating pattern is more suitable in uneven networks. Interestingly, the cascading pattern requires a network with moderate difference and high evenness, and the moderately uneven coupling of multiple network layers can effectively increase robustness to resist cascading failure. With large transmissibility, however, we find that all collaborating patterns are more effective in high-diversity networks. Our work provides a systemic analysis of collaborating epidemics on multilayer networks. The results enhance our understanding of biotic and informative diffusion through multiple vectors.

  4. Modelling of multilayer piezoelectric transducers for echographic applications Equivalent circuits

    International Nuclear Information System (INIS)

    Ramos, A.; Riera, E.; San Emeterio, J.L.; Sanz, P.T.

    1988-01-01

    In this paper, the main equivalent circuits of pulse-echo, single element, multilayer piezoelectric transducers, are analysed. The analogy of matching layers with lossless transmission lines is described. Finally, using the KLM model, the effects of backing and matching layers on the bandwidth and impulse response is analysed. (Author)

  5. Infrared diffractive filtering for extreme ultraviolet multilayer Bragg reflectors

    NARCIS (Netherlands)

    Medvedev, Viacheslav; van den Boogaard, Toine; van der Meer, R.; Yakshin, Andrey; Louis, Eric; Krivtsun, V.M.; Bijkerk, Frederik

    2013-01-01

    Abstract: We report on the development of a hybrid mirror realized by integrating an EUV-reflecting multilayer coating with a lamellar grating substrate. This hybrid irror acts as an efficient Bragg reflector for extreme ultraviolet (EUV) radiation at a given wavelength while simultaneously

  6. Residual stresses in multilayer ceramic capacitors: measurement and computation

    NARCIS (Netherlands)

    Toonder, den J.M.J.; Rademaker, C.W.; Hu, C.L.

    2003-01-01

    In this paper, we present a combined experimental and computational study of the thermomechanical reliability of multilayer ceramic capacitors (MLCC's). We focus on residual stresses introduced into the components during the cooling down step of the sintering process. The technique of

  7. Highly stable thin film transistors using multilayer channel structure

    KAUST Repository

    Nayak, Pradipta K.; Wang, Zhenwei; Anjum, Dalaver H.; Hedhili, Mohamed N.; Alshareef, Husam N.

    2015-01-01

    We report highly stable gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured

  8. Mathematical and field analysis of longitudinal reservoir infill

    Science.gov (United States)

    Ke, W. T.; Capart, H.

    2016-12-01

    In reservoirs, severe problems are caused by infilled sediment deposits. In long term, the sediment accumulation reduces the capacity of reservoir storage and flood control benefits. In the short term, the sediment deposits influence the intakes of water-supply and hydroelectricity generation. For the management of reservoir, it is important to understand the deposition process and then to predict the sedimentation in reservoir. To investigate the behaviors of sediment deposits, we propose a one-dimensional simplified theory derived by the Exner equation to predict the longitudinal sedimentation distribution in idealized reservoirs. The theory models the reservoir infill geomorphic actions for three scenarios: delta progradation, near-dam bottom deposition, and final infill. These yield three kinds of self-similar analytical solutions for the reservoir bed profiles, under different boundary conditions. Three analytical solutions are composed by error function, complementary error function, and imaginary error function, respectively. The theory is also computed by finite volume method to test the analytical solutions. The theoretical and numerical predictions are in good agreement with one-dimensional small-scale laboratory experiment. As the theory is simple to apply with analytical solutions and numerical computation, we propose some applications to simulate the long-profile evolution of field reservoirs and focus on the infill sediment deposit volume resulting the uplift of near-dam bottom elevation. These field reservoirs introduced here are Wushe Reservoir, Tsengwen Reservoir, Mudan Reservoir in Taiwan, Lago Dos Bocas in Puerto Rico, and Sakuma Dam in Japan.

  9. 33 CFR 110.77 - Amistad Reservoir, Tex.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Amistad Reservoir, Tex. 110.77... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.77 Amistad Reservoir, Tex. (a) Diablo East, Tex. That portion of the Amistad Reservoir enclosed by a line connecting the following points, excluding a 300-foot...

  10. Analysis of Fluvial Sediment Discharges into Kubanni Reservoir ...

    African Journals Online (AJOL)

    The sediment discharges into the Kubanni Reservoir (KR) has been measured and analysed in this study. The predominant sandy-clay sediment in the reservoir has an estimated total sediment load of 20,387,000 kg/year. The depth and area coverage of the reservoir was surveyed using a defined distributed grid line ...

  11. Reservoir site evaluation through routing | Ogunlela | Journal of ...

    African Journals Online (AJOL)

    ... m3/s, and a relative attenuation of 41.10%. Also; the reservoir would not be overtopped since the 99.54 m water elevation for the 25-yr, 24-hr storm was below the reservoir embankment top elevation. Keywords:Reservoir routing. Journal of Modeling, Design and Management of Engineering Systems Vol. 3 (1) 2005: pp.

  12. Reservoir management under consideration of stratification and hydraulic phenomena

    NARCIS (Netherlands)

    Nandalal, K.D.W.

    1995-01-01


    Reservoirs are the most important components in a water resources system. They are used to store water to extend its temporal availability. The physical, chemical and biological characteristics of water change when impounded in reservoirs. This implies the possibility of using reservoirs

  13. High-frequency characteristics of glass/ceramic composite and alumina multilayer structures

    International Nuclear Information System (INIS)

    Niwa, K.; Suzuki, H.; Yokoyama, H.; Kamechara, N.; Tsubone, K.; Tanisawa, H.; Sugiki, H.

    1990-01-01

    This paper reports the transmission characteristics of glass/ceramic composite (borosilicate glass/alumina) and alumina multilayer structures examined. The triplate stripline formed in the glass/ceramic multilayer shows low conductor and dielectric loss. Alumina multilayer, however, has twice the transmission loss at 10 GHz, because the resistivity of W in the alumina multilayer is higher than the Cu in the glass/ceramic multilayer. Crosstalk between striplines in the glass/ceramics is less than -80 dB up to 11 GHz and 9 GHz for alumina

  14. Third workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P. (eds.)

    1977-12-15

    The Third Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 14, 1977, with 104 attendees from six nations. In keeping with the recommendations expressed by the participants at the Second Workshop, the format of the Workshop was retained, with three days of technical sessions devoted to reservoir physics, well and reservoir testing, field development, and mathematical modeling of geothermal reservoirs. The program presented 33 technical papers, summaries of which are included in these Proceedings. Although the format of the Workshop has remained constant, it is clear from a perusal of the Table of Contents that considerable advances have occurred in all phases of geothermal reservoir engineering over the past three years. Greater understanding of reservoir physics and mathematical representations of vapor-dominated and liquid-dominated reservoirs are evident; new techniques for their analysis are being developed, and significant field data from a number of newer reservoirs are analyzed. The objectives of these workshops have been to bring together researchers active in the various physical and mathematical disciplines comprising the field of geothermal reservoir engineering, to give the participants a forum for review of progress and exchange of new ideas in this rapidly developing field, and to summarize the effective state of the art of geothermal reservoir engineering in a form readily useful to the many government and private agencies involved in the development of geothermal energy. To these objectives, the Third Workshop and these Proceedings have been successfully directed. Several important events in this field have occurred since the Second Workshop in December 1976. The first among these was the incorporation of the Energy Research and Development Administration (ERDA) into the newly formed Department of Energy (DOE) which continues as the leading Federal agency in geothermal reservoir engineering research. The Third

  15. Design and application of multilayer monolithic microwave integrated circuit transformers

    Energy Technology Data Exchange (ETDEWEB)

    Economides, S.B

    1999-07-01

    The design and performance of planar spiral transformers, using multilayer GaAs and silicon MMIC technology, are presented. This multilayer technology gives new opportunities for improving the performance of planar transformers, couplers and baluns. Planar transformers have high parasitic resistance and capacitance and low levels of coupling. Using multilayer technology these problems are overcome by applying a multilayer structure of three metal layers separated by two polyimide dielectric layers. The improvements gained by placing the conductors on different metal layers, and using conductors raised on polyimide layers for low capacitance, have been investigated. The circuits were fabricated using a novel experimental fabrication process, which uses entirely standard materials and techniques and is compatible with BJT's and silicon-germanium HBT's. The transformers were all characterised up to 20 GHz using RF-on-wafer measurements. They demonstrated good performance, considering the experimental nature of in-house multilayer technology and the difficulties in simulating these three-dimensional new geometries. With high resistivity substrates, the silicon components achieved virtually the same performance as their gallium arsenide counterparts. The transformers were then used in simulations of transformer-coupled HBT amplifier circuits, to demonstrate their capabilities. It was shown that these circuits present good performance compared to standard off-the shelf component circuits and are very promising for use in most multilayer MMIC applications. The structures were further used in coupling configurations, and applied in balun circuits and pushpull amplifiers. The spiral transformer coupler can operate at low frequencies without using up much chip area. In a balun configuration, the balun can compensate for coupling and phase imbalance and operates over 5 to 15 GHz. The spiral coupler does not always need multilayer processing, so the balun may be

  16. An Intelligent Systems Approach to Reservoir Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Shahab D. Mohaghegh; Jaime Toro; Thomas H. Wilson; Emre Artun; Alejandro Sanchez; Sandeep Pyakurel

    2005-08-01

    Today, the major challenge in reservoir characterization is integrating data coming from different sources in varying scales, in order to obtain an accurate and high-resolution reservoir model. The role of seismic data in this integration is often limited to providing a structural model for the reservoir. Its relatively low resolution usually limits its further use. However, its areal coverage and availability suggest that it has the potential of providing valuable data for more detailed reservoir characterization studies through the process of seismic inversion. In this paper, a novel intelligent seismic inversion methodology is presented to achieve a desirable correlation between relatively low-frequency seismic signals, and the much higher frequency wireline-log data. Vertical seismic profile (VSP) is used as an intermediate step between the well logs and the surface seismic. A synthetic seismic model is developed by using real data and seismic interpretation. In the example presented here, the model represents the Atoka and Morrow formations, and the overlying Pennsylvanian sequence of the Buffalo Valley Field in New Mexico. Generalized regression neural network (GRNN) is used to build two independent correlation models between; (1) Surface seismic and VSP, (2) VSP and well logs. After generating virtual VSP's from the surface seismic, well logs are predicted by using the correlation between VSP and well logs. The values of the density log, which is a surrogate for reservoir porosity, are predicted for each seismic trace through the seismic line with a classification approach having a correlation coefficient of 0.81. The same methodology is then applied to real data taken from the Buffalo Valley Field, to predict inter-well gamma ray and neutron porosity logs through the seismic line of interest. The same procedure can be applied to a complete 3D seismic block to obtain 3D distributions of reservoir properties with less uncertainty than the geostatistical

  17. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf Carbonate Reservoir

    International Nuclear Information System (INIS)

    Hickman, Scott T.; Justice James L.; Taylor, Archie R.

    1999-01-01

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs

  18. Modeling Reservoir-River Networks in Support of Optimizing Seasonal-Scale Reservoir Operations

    Science.gov (United States)

    Villa, D. L.; Lowry, T. S.; Bier, A.; Barco, J.; Sun, A.

    2011-12-01

    HydroSCOPE (Hydropower Seasonal Concurrent Optimization of Power and the Environment) is a seasonal time-scale tool for scenario analysis and optimization of reservoir-river networks. Developed in MATLAB, HydroSCOPE is an object-oriented model that simulates basin-scale dynamics with an objective of optimizing reservoir operations to maximize revenue from power generation, reliability in the water supply, environmental performance, and flood control. HydroSCOPE is part of a larger toolset that is being developed through a Department of Energy multi-laboratory project. This project's goal is to provide conventional hydropower decision makers with better information to execute their day-ahead and seasonal operations and planning activities by integrating water balance and operational dynamics across a wide range of spatial and temporal scales. This presentation details the modeling approach and functionality of HydroSCOPE. HydroSCOPE consists of a river-reservoir network model and an optimization routine. The river-reservoir network model simulates the heat and water balance of river-reservoir networks for time-scales up to one year. The optimization routine software, DAKOTA (Design Analysis Kit for Optimization and Terascale Applications - dakota.sandia.gov), is seamlessly linked to the network model and is used to optimize daily volumetric releases from the reservoirs to best meet a set of user-defined constraints, such as maximizing revenue while minimizing environmental violations. The network model uses 1-D approximations for both the reservoirs and river reaches and is able to account for surface and sediment heat exchange as well as ice dynamics for both models. The reservoir model also accounts for inflow, density, and withdrawal zone mixing, and diffusive heat exchange. Routing for the river reaches is accomplished using a modified Muskingum-Cunge approach that automatically calculates the internal timestep and sub-reach lengths to match the conditions of

  19. A chemically stable PVD multilayer encapsulation for lithium microbatteries

    International Nuclear Information System (INIS)

    Ribeiro, J F; Sousa, R; Cunha, D J; Vieira, E M F; Goncalves, L M; Silva, M M; Dupont, L

    2015-01-01

    A multilayer physical vapour deposition (PVD) thin-film encapsulation method for lithium microbatteries is presented. Lithium microbatteries with a lithium cobalt oxide (LiCoO 2 ) cathode, a lithium phosphorous oxynitride (LiPON) electrolyte and a metallic lithium anode are under development, using PVD deposition techniques. Metallic lithium film is still the most common anode on this battery technology; however, it presents a huge challenge in terms of material encapsulation (lithium reacts with almost any materials deposited on top and almost instantly begins oxidizing in contact with atmosphere). To prove the encapsulation concept and perform all the experiments, lithium films were deposited by thermal evaporation technique on top of a glass substrate, with previously patterned Al/Ti contacts. Three distinct materials, in a multilayer combination, were tested to prevent lithium from reacting with protection materials and atmosphere. These multilayer films were deposited by RF sputtering and were composed of lithium phosphorous oxide (LiPO), LiPON and silicon nitride (Si 3 N 4 ). To complete the long-term encapsulation after breaking the vacuum, an epoxy was applied on top of the PVD multilayer. In order to evaluate oxidation state of lithium films, the lithium resistance was measured in a four probe setup (cancelling wires/contact resistances) and resistivity calculated, considering physical dimensions. A lithium resistivity of 0.16 Ω μm was maintained for more than a week. This PVD multilayer exonerates the use of chemical vapour deposition (CVD), glove-box chambers and sample manipulation between them, significantly reducing the fabrication cost, since battery and its encapsulation are fabricated in the same PVD chamber. (paper)

  20. A chemically stable PVD multilayer encapsulation for lithium microbatteries

    Science.gov (United States)

    Ribeiro, J. F.; Sousa, R.; Cunha, D. J.; Vieira, E. M. F.; Silva, M. M.; Dupont, L.; Goncalves, L. M.

    2015-10-01

    A multilayer physical vapour deposition (PVD) thin-film encapsulation method for lithium microbatteries is presented. Lithium microbatteries with a lithium cobalt oxide (LiCoO2) cathode, a lithium phosphorous oxynitride (LiPON) electrolyte and a metallic lithium anode are under development, using PVD deposition techniques. Metallic lithium film is still the most common anode on this battery technology; however, it presents a huge challenge in terms of material encapsulation (lithium reacts with almost any materials deposited on top and almost instantly begins oxidizing in contact with atmosphere). To prove the encapsulation concept and perform all the experiments, lithium films were deposited by thermal evaporation technique on top of a glass substrate, with previously patterned Al/Ti contacts. Three distinct materials, in a multilayer combination, were tested to prevent lithium from reacting with protection materials and atmosphere. These multilayer films were deposited by RF sputtering and were composed of lithium phosphorous oxide (LiPO), LiPON and silicon nitride (Si3N4). To complete the long-term encapsulation after breaking the vacuum, an epoxy was applied on top of the PVD multilayer. In order to evaluate oxidation state of lithium films, the lithium resistance was measured in a four probe setup (cancelling wires/contact resistances) and resistivity calculated, considering physical dimensions. A lithium resistivity of 0.16 Ω μm was maintained for more than a week. This PVD multilayer exonerates the use of chemical vapour deposition (CVD), glove-box chambers and sample manipulation between them, significantly reducing the fabrication cost, since battery and its encapsulation are fabricated in the same PVD chamber.