A Study on Elastic Guided Wave Modal Characteristics in Multi-Layered Structures

International Nuclear Information System (INIS)

Cho, Youn Ho; Lee, Chong Myoung

2008-01-01

In this study, we have developed a program which can calculate phase and group velocities, attenuation and wave structures of each mode in multi-layered plates. The wave structures of each mode are obtained, varying material properties and number of layers. The key in the success of guided wave NDE is how to optimize the mode selection scheme by minimizing energy loss when a structure is in contact with liquid. In this study, the normalized out-of-plane displacements at the surface of a free plate are used to predict the variation of modal attenuation and verily the correlation between attenuation and wave structure. It turns out that the guided wave attenuation can be efficiently obtain from the out-of-plane displacement variation of a free wave guide alleviating such mathematical difficulties in extracting complex roots for the eigenvalue problem of a liquid loaded wave guide. Through this study, the concert to optimize guided wave mode selection is accomplished to enhance sensitivity and efficiency in nondestructive evaluation for multi-layered structures.

Reverse-mode PSLC multi-plane optical see-through display for AR applications.

Science.gov (United States)

Liu, Shuxin; Li, Yan; Zhou, Pengcheng; Chen, Quanming; Su, Yikai

2018-02-05

In this paper we propose an optical see-through multi-plane display with reverse-mode polymer-stabilized liquid crystal (PSLC). Our design solves the problem of accommodation-vergence conflict with correct focus cues. In the reverse mode PSLC system, power consumption could be reduced to ~1/(N-1) of that in a normal mode system if N planes are displayed. The PSLC films fabricated in our experiment exhibit a low saturation voltage ~20 V rms , a high transparent-state transmittance (92%), and a fast switching time within 2 ms and polarization insensitivity. A proof-of-concept two-plane color display prototype and a four-plane monocolor display prototype were implemented.

Oscillating dipole layer facing a conducting plane: a classical analogue of the dynamical Casimir effect

Energy Technology Data Exchange (ETDEWEB)

Fosco, César D. [Centro Atómico Bariloche, Instituto Balseiro, Comisión Nacional de Energía Atómica, R8402AGP, Bariloche (Argentina); Lombardo, Fernando C., E-mail: lombardo@df.uba.ar [Departamento de Física Juan José Giambiagi, FCEyN UBA and IFIBA CONICET-UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina)

2015-12-17

We study the properties of the classical electromagnetic radiation produced by two physically different yet closely related systems, which may be regarded as classical analogues of the dynamical Casimir effect. They correspond to two flat, infinite, parallel planes, one of them static and imposing perfect-conductor boundary conditions, while the other performs a rigid oscillatory motion. The systems differ just in the electrical properties of the oscillating plane: one of them is just a planar dipole layer (representing, for instance, a small-width electret). The other, instead, has a dipole layer on the side which faces the static plane, but behaves as a conductor on the other side: this can be used as a representation of a conductor endowed with patch potentials (on the side which faces the conducting plane). We evaluate, in both cases, the dissipative flux of energy between the system and its environment, showing that, at least for small mechanical oscillation amplitudes, it can be written in terms of the dipole layer autocorrelation function. We show that there are resonances as a function of the frequency of the mechanical oscillation.

Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments

KAUST Repository

Al-Ghadhban, Samir

2014-01-01

© 2014, Springer Science+Business Media New York. Multi-layered space-time block coded systems (MLSTBC) strike a balance between spatial multiplexing and transmit diversity. In this paper, we analyze the block error rate performance of MLSTBC

Dynamic clustering scheme based on the coordination of management and control in multi-layer and multi-region intelligent optical network

Science.gov (United States)

Niu, Xiaoliang; Yuan, Fen; Huang, Shanguo; Guo, Bingli; Gu, Wanyi

2011-12-01

A Dynamic clustering scheme based on coordination of management and control is proposed to reduce network congestion rate and improve the blocking performance of hierarchical routing in Multi-layer and Multi-region intelligent optical network. Its implement relies on mobile agent (MA) technology, which has the advantages of efficiency, flexibility, functional and scalability. The paper's major contribution is to adjust dynamically domain when the performance of working network isn't in ideal status. And the incorporation of centralized NMS and distributed MA control technology migrate computing process to control plane node which releases the burden of NMS and improves process efficiently. Experiments are conducted on Multi-layer and multi-region Simulation Platform for Optical Network (MSPON) to assess the performance of the scheme.

Oscillating dipole layer facing a conducting plane: a classical analogue of the dynamical Casimir effect

Energy Technology Data Exchange (ETDEWEB)

Fosco, Cesar D. [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, Instituto Balseiro, Bariloche (Argentina); Lombardo, Fernando C. [Ciudad Universitaria, Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA y IFIBA CONICET-UBA, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

2015-12-15

We study the properties of the classical electromagnetic radiation produced by two physically different yet closely related systems, which may be regarded as classical analogues of the dynamical Casimir effect. They correspond to two flat, infinite, parallel planes, one of them static and imposing perfect-conductor boundary conditions, while the other performs a rigid oscillatory motion. The systems differ just in the electrical properties of the oscillating plane: one of them is just a planar dipole layer (representing, for instance, a small-width electret). The other, instead, has a dipole layer on the side which faces the static plane, but behaves as a conductor on the other side: this can be used as a representation of a conductor endowed with patch potentials (on the side which faces the conducting plane). We evaluate, in both cases, the dissipative flux of energy between the system and its environment, showing that, at least for small mechanical oscillation amplitudes, it can be written in terms of the dipole layer autocorrelation function. We show that there are resonances as a function of the frequency of the mechanical oscillation. (orig.)

Oscillating dipole layer facing a conducting plane: a classical analogue of the dynamical Casimir effect

International Nuclear Information System (INIS)

Fosco, Cesar D.; Lombardo, Fernando C.

2015-01-01

We study the properties of the classical electromagnetic radiation produced by two physically different yet closely related systems, which may be regarded as classical analogues of the dynamical Casimir effect. They correspond to two flat, infinite, parallel planes, one of them static and imposing perfect-conductor boundary conditions, while the other performs a rigid oscillatory motion. The systems differ just in the electrical properties of the oscillating plane: one of them is just a planar dipole layer (representing, for instance, a small-width electret). The other, instead, has a dipole layer on the side which faces the static plane, but behaves as a conductor on the other side: this can be used as a representation of a conductor endowed with patch potentials (on the side which faces the conducting plane). We evaluate, in both cases, the dissipative flux of energy between the system and its environment, showing that, at least for small mechanical oscillation amplitudes, it can be written in terms of the dipole layer autocorrelation function. We show that there are resonances as a function of the frequency of the mechanical oscillation. (orig.)

Heterogeneous flow in multi-layer joint networks and its influence on incipient karst generation

Science.gov (United States)

Wang, X.; Jourde, H.

2017-12-01

Various dissolution types (e.g. pipe, stripe and sheet karstic features) have been observed in fractured layered limestones. Yet, due to a large range of structural and hydraulic parameters play a role in the karstification process, the dissolution mechanism, occurring either along fractures or bedding planes, is difficult to quantify. In this study, we use numerical models to investigate the influence of these parameters on the generation of different types of incipient karst. Specifically, we focus on two parameters: the fracture intensity contrast between adjacent layers and the aperture ratio between bedding planes and joints (abed/ajoint). The DFN models were generated using a pseudo-genetic code that considers the stress shadow zone. Flow simulations were performed using a combined finite-volume finite-element simulator under practical boundary conditions. The flow channeling within the fracture networks was characterized by applying a multi-fractal technique. The rock block equivalent permeability (keff) was also calculated to quantify the change in bulk hydraulic properties when changing the selected structural and hydraulic parameters. The flow simulation results show that the abed/ajoint ratio has a first-order control on the heterogeneous distribution of flow in the multi-layer system and on the magnitude of equivalent permeability. When abed/ajoint 0.1, the bedding plane has more control and flow becomes more pervasive and uniform, and the keff is accordingly high. A simple model, accounting for the calculation of the heterogeneous distributions of Damköhler number associated with different aperture ratios, is proposed to predict what type of incipient karst tends to develop under the studied flow conditions.

Multi-layered breathing architectural envelope

DEFF Research Database (Denmark)

Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

2014-01-01

A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

Predictive control for stochastic systems based on multi-layer probabilistic sets

Directory of Open Access Journals (Sweden)

Huaqing LIANG

2016-04-01

Full Text Available Aiming at a class of discrete-time stochastic systems with Markov jump features, the state-feedback predictive control problem under probabilistic constraints of input variables is researched. On the basis of the concept and method of the multi-layer probabilistic sets, the predictive controller design algorithm with the soft constraints of different probabilities is presented. Under the control of the multi-step feedback laws, the system state moves to different ellipses with specified probabilities. The stability of the system is guaranteed, the feasible region of the control problem is enlarged, and the system performance is improved. Finally, a simulation example is given to prove the effectiveness of the proposed method.

Study of the in-plane magnetic structure of a layered system using polarized neutron scattering under grazing incidence geometry

Energy Technology Data Exchange (ETDEWEB)

Maruyama, R., E-mail: ryuji.maruyama@j-parc.jp [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195 (Japan); Bigault, T.; Wildes, A.R.; Dewhurst, C.D. [Institut Laue Langevin, 71 avenue des Martyrs, 38042 Grenoble (France); Soyama, K. [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195 (Japan); Courtois, P. [Institut Laue Langevin, 71 avenue des Martyrs, 38042 Grenoble (France)

2016-05-21

The in-plane magnetic structure of a layered system with a polycrystalline grain size less than the ferromagnetic exchange length was investigated using polarized neutron off-specular scattering and grazing incidence small angle scattering measurements to gain insight into the mechanism that controls the magnetic properties which are different from the bulk. These complementary measurements with different length scales and the data analysis based on the distorted wave Born approximation revealed the lateral correlation on a length scale of sub- μm due to the fluctuating orientation of the magnetization in the layer. The obtained in-plane magnetic structure is consistent with the random anisotropy model, i.e. competition between the exchange interactions between neighboring spins and the local magnetocrystalline anisotropy.

Optimization of sound absorbing performance for gradient multi-layer-assembled sintered fibrous absorbers

Science.gov (United States)

Zhang, Bo; Zhang, Weiyong; Zhu, Jian

2012-04-01

The transfer matrix method, based on plane wave theory, of multi-layer equivalent fluid is employed to evaluate the sound absorbing properties of two-layer-assembled and three-layer-assembled sintered fibrous sheets (generally regarded as a kind of compound absorber or structures). Two objective functions which are more suitable for the optimization of sound absorption properties of multi-layer absorbers within the wider frequency ranges are developed and the optimized results of using two objective functions are also compared with each other. It is found that using the two objective functions, especially the second one, may be more helpful to exert the sound absorbing properties of absorbers at lower frequencies to the best of their abilities. Then the calculation and optimization of sound absorption properties of multi-layer-assembled structures are performed by developing a simulated annealing genetic arithmetic program and using above-mentioned objective functions. Finally, based on the optimization in this work the thoughts of the gradient design over the acoustic parameters- the porosity, the tortuosity, the viscous and thermal characteristic lengths and the thickness of each samples- of porous metals are put forth and thereby some useful design criteria upon the acoustic parameters of each layer of porous fibrous metals are given while applying the multi-layer-assembled compound absorbers in noise control engineering.

Effect of Multi-layer Compression Bandage Systems on Leg Ulcers Associated with Chronic Venous Insufficiency

Directory of Open Access Journals (Sweden)

Hüseyin Kuplay

2013-03-01

Full Text Available Introduction: Venous leg ulcer is a major health problem in terms of high prevalence and high cost for treatment. Multi-layer compression bandage systems for venous leg ulcers are supposed to be the gold standard for the treatment of venous ulcers. The aim of the current study is to investigate the effectiveness of multi-layer compression bandage systems for the treatment of venous leg ulcers.Patients and Methods: Nineteen consecutive patients diagnosed to have leg ulcers were evaluated and four patients were excluded from the study due to the peripheral arterial disease. Fifteen patients, enrolled in the study, were classified according to CEAP classification and belonged to the same class. Betaven® multi-layer compression bandage was applied to patients. Patients were followed-up in terms of wound healing and reduction in wound diameter.Results: Twelve male and three female patients underwent multi-layer bandage system. Mean age of patients was 38.2 ± 4.2 years. Ulcer size was measured planimetrically and baseline ulcer size was 4-10 cm². The location of ulcer was on medial malloelus in seven patients, lateral malleolus in three patients, anterior surface of the leg in four patients and lateral side of the leg in one patient. Patients had chronic venous insuuficiency for a mean of 5.1 ± 2.1 years. CEAP classifications were C6, Ep, As2,3-p18, Pr2,3, 18. Each bandage was changed five days after application along with wound care. Mean duration of treatment was 6 ± 2 weeks. Complete healing of the venous ulcers occurred in all patients except for one. This patient was referred to plastic surgery clinic for reconstruction.Conclusion: Multi-layer compression bandage system is an effective method of treatment for venous leg ulcers associated with chronic venous insufficiency by reducing venous return and increasing intertitial tissue pressure. This effect occurred in the shortrun as well as with a low cost and prevented loss of labor.

Bi-layer graphene structure with non-equivalent planes: Magnetic properties study

Science.gov (United States)

Mhirech, A.; Aouini, S.; Alaoui-Ismaili, A.; Bahmad, L.

2018-05-01

In this paper, we study the magnetic properties of a ferromagnetic bi-layer graphene structure with non-equivalent planes. The geometry of the studied system is formed by two layers (A) and (B) consisting of the spins σ = 1 / 2 and S = 1 . For this purpose, the influence of the coupling exchange interactions, the external magnetic and the crystal fields are investigated and presented as well as the ground state phase diagrams. The Monte Carlo simulations have been used to examine the behavior of the partial and the total magnetizations as a function of the system parameters. These effects on the compensation and critical temperatures behavior are also presented in different phase diagrams, for the studied system.

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...

Signal processing approaches to secure physical layer communications in multi-antenna wireless systems

CERN Document Server

Hong, Y-W Peter; Kuo, C-C Jay

2013-01-01

This book introduces various signal processing approaches to enhance physical layer secrecy in multi-antenna wireless systems. Wireless physical layer secrecy has attracted much attention in recent years due to the broadcast nature of the wireless medium and its inherent vulnerability to eavesdropping. While most articles on physical layer secrecy focus on the information-theoretic aspect, we focus specifically on the signal processing aspects, including beamforming and precoding techniques for data transmission and discriminatory training schemes for channel estimation. The discussions will c

Intercorrelated in-plane and out-of-plane ferroelectricity in ultrathin two-dimensional layered semiconductor In2Se3

KAUST Repository

Cui, Chaojie; Hu, Weijin; Yan, Xingxu; Addiego, Christopher; Gao, Wenpei; Wang, Yao; Wang, Zhe; Li, Linze; Cheng, Yingchun; Li, Peng; Zhang, Xixiang; Alshareef, Husam N.; Wu, Tao; Zhu, Wenguang; Pan, Xiaoqing; Li, Lain-Jong

2018-01-01

Enriching the functionality of ferroelectric materials with visible-light sensitivity and multiaxial switching capability would open up new opportunities for their applications in advanced information storage with diverse signal manipulation functions. We report experimental observations of robust intra-layer ferroelectricity in two-dimensional (2D) van der Waals layered -In2Se3 ultrathin flakes at room temperature. Distinct from other 2D and conventional ferroelectrics, In2Se3 exhibits intrinsically intercorrelated out-of-plane and in-plane polarization, where the reversal of the out-of-plane polarization by a vertical electric field also induces the rotation of the in-plane polarization. Based on the in-plane switchable diode effect and the narrow bandgap (~1.3 eV) of ferroelectric In2Se3, a prototypical non-volatile memory device, which can be manipulated both by electric field and visible light illumination, is demonstrated for advancing data storage technologies.

Intercorrelated in-plane and out-of-plane ferroelectricity in ultrathin two-dimensional layered semiconductor In2Se3

KAUST Repository

Cui, Chaojie

2018-01-30

Enriching the functionality of ferroelectric materials with visible-light sensitivity and multiaxial switching capability would open up new opportunities for their applications in advanced information storage with diverse signal manipulation functions. We report experimental observations of robust intra-layer ferroelectricity in two-dimensional (2D) van der Waals layered -In2Se3 ultrathin flakes at room temperature. Distinct from other 2D and conventional ferroelectrics, In2Se3 exhibits intrinsically intercorrelated out-of-plane and in-plane polarization, where the reversal of the out-of-plane polarization by a vertical electric field also induces the rotation of the in-plane polarization. Based on the in-plane switchable diode effect and the narrow bandgap (~1.3 eV) of ferroelectric In2Se3, a prototypical non-volatile memory device, which can be manipulated both by electric field and visible light illumination, is demonstrated for advancing data storage technologies.

Frictionless contact analysis of a functionally graded piezoelectric layered half-plane

International Nuclear Information System (INIS)

Ke Liaoliang; Yang Jie; Kitipornchai, Sritawat; Wang Yuesheng

2008-01-01

This paper investigates the frictionless contact problem of a layered half-plane made of functionally graded piezoelectric material (FGPM) in the plane strain state under the action of a rigid punch whose shape may be flat, triangular or cylindrical. It is assumed that the punch is a perfect electrical insulator with zero electric charge distribution. The electroelastic properties of the FGPM layer vary exponentially along the thickness direction. By using the Fourier integral transform technique, the problem is reduced to a Cauchy singular integral equation which is then numerically solved to determine the contact pressure, contact region, maximum indentation depth, normal stress, electrical potential and electric displacement fields. The stress intensity factor is also given to quantitatively characterize the singularity behavior of the contact pressure at the ends of a flat and triangular punch. Numerical results show that both the material property gradient of the FGPM layer and the punch geometry have a significant influence on the contact performance of the FGPM layered half-plane

Physics considerations in MV-CBCT multi-layer imager design.

Science.gov (United States)

Hu, Yue-Houng; Fueglistaller, Rony; Myronakis, Marios E; Rottmann, Joerg; Wang, Adam; Shedlock, Daniel; Morf, Daniel; Baturin, Paul; Huber, Pascal; Star-Lack, Josh M; Berbeco, Ross I

2018-05-30

Megavoltage (MV) cone-beam computed tomography (CBCT) using an electronic portal imaging (EPID) offers advantageous features, including 3D mapping, treatment beam registration, high-z artifact suppression, and direct radiation dose calculation. Adoption has been slowed by image quality limitations and concerns about imaging dose. Developments in imager design, including pixelated scintillators, structured phosphors, inexpensive scintillation materials, and multi-layer imager (MLI) architecture have been explored to improve EPID image quality and reduce imaging dose. The present study employs a hybrid Monte Carlo and linear systems model to determine the effect of detector design elements, such as multi-layer architecture and scintillation materials. We follow metrics of image quality including modulation transfer function (MTF) and noise power spectrum (NPS) from projection images to 3D reconstructions to in-plane slices and apply a task based figure-of-merit, the ideal observer signal-to-noise ratio (d') to determine the effect of detector design on object detectability. Generally, detectability was limited by detector noise performance. Deploying an MLI imager with a single scintillation material for all layers yields improvement in noise performance and d' linear with the number of layers. In general, improving x-ray absorption using thicker scintillators results in improved DQE(0). However, if light yield is low, performance will be affected by electronic noise at relatively high doses, resulting in rapid image quality degradation. Maximizing image quality in a heterogenous MLI detector (i.e. multiple different scintillation materials) is most affected by limiting imager noise. However, while a second-order effect, maximizing total spatial resolution of the MLI detector is a balance between the intensity contribution of each layer against its individual MTF. So, while a thinner scintillator may yield a maximal individual-layer MTF, its quantum efficiency will

Multi-Stream Saline-Jet Dissection Using a Simple Irrigation System Defines Difficult Tissue Planes

Science.gov (United States)

Ng, Philip CH

2010-01-01

Introduction: Single-stream hydro-jet dissection is increasingly used in various laparoscopic procedures, but its use requires special equipment. We describe a simple method for using an irrigation system for saline-jet tissue dissection as a useful adjunct prior to adhesiolysis. Material and Methods: Intraabdominal adhesions prolong laparoscopic procedures, because tissue planes are difficult to identify. We performed multi-jet saline dissection (MSSJ) between 2000 and 2009 in more than 500 patients during laparoscopy involving hernias, gallbladders, appendices, and intestinal obstructions. We use a standard suction irrigation probe, which is attached to a 1-liter saline bag with an inflatable cuff around to create a pressure of 250mm Hg to 300mm Hg. In effect, this is the standard setup generally used for irrigation. After using saline dissection, tissue planes can be better defined and the structures can then be separated. Result and Discussion: Using this method, we have successfully identified tissue planes in spite of dense adhesions, and our conversion rates to open have been reduced dramatically. This method is relatively safer than other modalities of tissue dissection, such as diathermy, ultrasonic, blunt or sharp dissection. The disadvantage is that with tissues saturated with saline it becomes more difficult to use diathermy hemostasis. Care has to be exercised in monitoring the temperature and volume of the fluid used. PMID:20529528

Dual-layer electrode-driven liquid crystal lens with electrically tunable focal length and focal plane

Science.gov (United States)

Zhang, Y. A.; Lin, C. F.; Lin, J. P.; Zeng, X. Y.; Yan, Q.; Zhou, X. T.; Guo, T. L.

2018-04-01

Electric-field-driven liquid crystal (ELC) lens with tunable focal length and their depth of field has been extensively applied in 3D display and imaging systems. In this work, a dual-layer electrode-driven liquid crystal (DELC) lens with electrically tunable focal length and controllable focal plane is demonstrated. ITO-SiO2-AZO electrodes with the dual-layer staggered structure on the top substrate are used as driven electrodes within a LC cell, which permits the establishment of an alternative controllability. The focal length of the DELC lens can be adjusted from 1.41 cm to 0.29 cm when the operating voltage changes from 15 V to 40 V. Furthermore, the focal plane of the DELC lens can selectively move by changing the driving method of the applied voltage to the next driven electrodes. This work demonstrates that the DELC lens has potential applications in imaging systems because of electrically tunable focal length and controllable focal plane.

Multi-planed unified switching topologies

Science.gov (United States)

Chen, Dong; Heidelberger, Philip; Sugawara, Yutaka

2017-07-04

An apparatus and method for extending the scalability and improving the partitionability of networks that contain all-to-all links for transporting packet traffic from a source endpoint to a destination endpoint with low per-endpoint (per-server) cost and a small number of hops. An all-to-all wiring in the baseline topology is decomposed into smaller all-to-all components in which each smaller all-to-all connection is replaced with star topology by using global switches. Stacking multiple copies of the star topology baseline network creates a multi-planed switching topology for transporting packet traffic. Point-to-point unified stacking method using global switch wiring methods connects multiple planes of a baseline topology by using the global switches to create a large network size with a low number of hops, i.e., low network latency. Grouped unified stacking method increases the scalability (network size) of a stacked topology.

PLANE: A Platform for Negotiation of Multi-attribute Multimedia Objects

Directory of Open Access Journals (Sweden)

Rharon M. Guedes

2013-12-01

Full Text Available This work proposes the definition of a system to negotiate products in an e-commerce scenario. This negotiation system is defined as PLANE – Platform to Assist Negotiation – and it is carried in a semi-automatic way, using multi-attributes functions, based on attributes of the negotiated content. It also presents an architecture to interconnect the participant through an inter-network in the television broadcasters context. Each participant of the inter-network applies policies for its own contents, and all of them must comply these policies. If a participant needs a content not covered by the policies, it is possible to start a negotiation process for this specific content. Experiments present a simulation scenario where PLANE assists the negotiation between three sellers and one buyer with predefined negotiation profiles. Results demonstrated the success of the system in approximate the negotiator after some few interactions, reducing time and cost.

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.

Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments

KAUST Repository

Al-Ghadhban, Samir

2014-12-23

© 2014, Springer Science+Business Media New York. Multi-layered space-time block coded systems (MLSTBC) strike a balance between spatial multiplexing and transmit diversity. In this paper, we analyze the block error rate performance of MLSTBC. In addition, we propose an adaptive MLSTBC schemes that are capable of accommodating the channel signal-to-noise ratio variation of wireless systems by near instantaneously adapting the uplink transmission configuration. The main results demonstrate that significant effective throughput improvements can be achieved while maintaining a certain target bit error rate.

Simultaneous application of two independent EIT devices for real-time multi-plane imaging.

Science.gov (United States)

Schullcke, B; Krueger-Ziolek, S; Gong, B; Mueller-Lisse, U; Moeller, K

2016-09-01

Diagnosis and treatment of many lung diseases like cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD) could benefit from 3D ventilation information. Applying two EIT systems concurrently is a simple approach without specialized hardware that allows monitoring of regional changes of ventilation distribution inside the thorax at different planes with the high temporal resolution much valued in common single plane EIT. Effects of two simultaneously operated EIT devices on one subject were investigated to monitor rapid processes inside the thorax with a multi-plane approach. Results obtained by simulations with a virtual phantom and measurements with a phantom tank reveal that the distance of electrode planes has an important influence on the signal quality. Band-pass filters adapted according to the distance of the planes, can be used to reduce the crosstalk of the concurrent EIT systems. Besides simulations and phantom tank experiments measurements were also taken from a lung healthy volunteer to demonstrate the operation under realistic conditions. Reconstructed images indicate that it is possible to simultaneously visualize regional ventilation at different planes if settings of the EIT devices are chosen appropriately.

Multi-layer adaptive thin shells for future space telescopes

International Nuclear Information System (INIS)

Bastaits, R; Preumont, A; Rodrigues, G; Jetteur, Ph; Hagedorn, P

2012-01-01

This paper examines the morphing capability of doubly curved elastic shells with various layers of active materials with strain actuation capability. The equivalent piezoelectric loads of an orthotropic multi-layer shell is established and it is demonstrated that a set of four active layers offer independent control of the in-plane forces and bending moments, which guarantees optimum morphing with arbitrary profile. This is illustrated by a numerical example which compares a unimorph configuration (single layer of active material) with a twin-bimorph (two pairs of symmetrical layers of active material with orthotropic properties). Numerical simulations indicate that the optical (Zernike) modes with shapes where the curvatures in orthogonal directions have opposite signs (e.g. astigmatism, trefoil, tetrafoil) are fairly easy to control with both configurations and that substantial amplitudes may be achieved. However, the optical modes with shapes where the curvatures in orthogonal directions have the same sign (e.g. defocus, coma, spherical aberration) are difficult to control with the unimorph configuration, and they lead to the appearance of slope discontinuities at the interface between the independent electrodes. As expected, a much better morphing is achieved with a twin-bimorph configuration. (paper)

Cross-layer shared protection strategy towards data plane in software defined optical networks

Science.gov (United States)

Xiong, Yu; Li, Zhiqiang; Zhou, Bin; Dong, Xiancun

2018-04-01

In order to ensure reliable data transmission on the data plane and minimize resource consumption, a novel protection strategy towards data plane is proposed in software defined optical networks (SDON). Firstly, we establish a SDON architecture with hierarchical structure of data plane, which divides the data plane into four layers for getting fine-grained bandwidth resource. Then, we design the cross-layer routing and resource allocation based on this network architecture. Through jointly considering the bandwidth resource on all the layers, the SDN controller could allocate bandwidth resource to working path and backup path in an economical manner. Next, we construct auxiliary graphs and transform the shared protection problem into the graph vertex coloring problem. Therefore, the resource consumption on backup paths can be reduced further. The simulation results demonstrate that the proposed protection strategy can achieve lower protection overhead and higher resource utilization ratio.

Determination of dynamic characteristics of multi-layer carbon plastic structures of high-resolution scanner

Directory of Open Access Journals (Sweden)

В. Н. Маслей

2017-10-01

Full Text Available The comparative analysis results for the numerical determination of the dynamic characteristics of multi-layer carbon-fiber plates of the space vehicle scanner design by various types of finite element approximation of the physico-mechanical properties of the composite material are presented. Using the topological structure of the construction of reinforcing layers material in the plate package plane, experimental data for the elastic and mass characteristics of homogeneous carbon-fiber fibers, equivalent structural and orthotropic stiffness and elastic characteristics of the material of composite plates are determined.

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

Fast and accurate inductance and coupling calculation for a multi-layer Nb process

International Nuclear Information System (INIS)

Fourie, Coenrad J; Takahashi, Akitomo; Yoshikawa, Nobuyuki

2015-01-01

Currently, fabrication processes for superconductive integrated circuits are moving to multiple wiring and shielding layers, some of which are placed below the main ground plane (GP) and device layers. The Advanced Industrial Science and Technology advanced process (ADP2) was the first such multi-layer Nb process with planarized passive transmission line and GP layers below the junction layer, and is at the time of writing still the most developed. This process allows complex circuit designs, and accurate inductance extraction helps to push the boundaries of the layouts possible. We show that the position of ground connections between ground layers influences the inductance of structures for which these GPs act as return path, and that this needs to be accounted for in modelling. However, due to the number of wiring layers and GPs, full layout modelling of large cells causes long calculation times. In this paper we discuss methods with which to reduce model size, and calibrate InductEx calculations using these methods against measured results. We show that model reduction followed by calibration results in fast calculation times while good accuracy is maintained. We also show that InductEx correctly handles coupling between conductors in a multi-layer layout, and how to model layouts to gauge unwanted coupling between power lines and single flux quantum electronics. (paper)

MLDS: Multi-Layer Defense System for Preventing Advanced Persistent Threats

Directory of Open Access Journals (Sweden)

Daesung Moon

2014-12-01

Full Text Available Here we report on the issue of Advanced Persistent Threats (APT, which use malware for the purpose of leaking the data of large corporations and government agencies. APT attacks target systems continuously by utilizing intelligent and complex technologies. To overthrow the elaborate security network of target systems, it conducts an attack after undergoing a pre-reconnaissance phase. An APT attack causes financial loss, information leakage, etc. They can easily bypass the antivirus system of a target system. In this paper, we propose a Multi-Layer Defense System (MLDS that can defend against APT. This system applies a reinforced defense system by collecting and analyzing log information and various information from devices, by installing the agent on the network appliance, server and end-user. It also discusses how to detect an APT attack when one cannot block the initial intrusion while continuing to conduct other activities. Thus, this system is able to minimize the possibility of initial intrusion and damages of the system by promptly responding through rapid detection of an attack when the target system is attacked.

Studies of low current back-discharge in point-plane geometry with dielectric layer

International Nuclear Information System (INIS)

Jaworek, A.; Rajch, E.; Czech, T.; Lackowski, M

2005-01-01

The paper presents results of spectroscopic investigations of back-discharge generated in the point-plane electrode geometry in air at atmospheric pressure, with the plane covered with fly ash layer. Four forms of the discharges were studied: onset streamers, glow, breakdown streamers and low-current back-arc discharge. Both polarities of the active discharge electrode, positive and negative, were tested. The back discharge is a type of DC electrical discharge, which take place when the passive plane electrode is covered with a dielectric layer. The layer can be made of solid material or a packed bed of dust or powder of low conductivity. The charge produced due to ionisation processes in the vicinity of the active point electrode is accumulated on the dielectric surface, and generates high electric field through this layer. When critical electric field through the layer is attained an electrical breakdown of the layer take place. The point of breakdown becomes a new source of ions of polarity opposite to those generated by the active electrode. The dielectric layer on the passive electrode causes that gaseous discharges such as breakdown streamers or arc start at lower voltages than they could in the case of normal corona discharge. The visual forms of the discharge were recorded and correlated with the current-voltage characteristics and optical emission spectra. Emission spectra of the discharge were measured in the light wavelength range of 200 to 600 nm to get information about excitation and ionisation processes. The light spectra were analysed by monochromator SPM-2 Karl-Zeiss-Jena with diffraction grating of 1302 grooves/mm and photomultiplier R375 (Hamamatsu) and signal preamplifier unit C7319 (Hamamatsu). The spectral analysis showed that the nitrogen molecular bands were dominant, but the emission of negative ions from the dielectric layer material were also detected. The most noticeable light emission in the range from 280 to 490 nm due to second

Optimisation of multi-layer rotationally moulded foamed structures

Science.gov (United States)

Pritchard, A. J.; McCourt, M. P.; Kearns, M. P.; Martin, P. J.; Cunningham, E.

2018-05-01

Multi-layer skin-foam and skin-foam-skin sandwich constructions are of increasing interest in the rotational moulding process for two reasons. Firstly, multi-layer constructions can improve the thermal insulation properties of a part. Secondly, foamed polyethylene sandwiched between solid polyethylene skins can increase the mechanical properties of rotationally moulded structural components, in particular increasing flexural properties and impact strength (IS). The processing of multiple layers of polyethylene and polyethylene foam presents unique challenges such as the control of chemical blowing agent decomposition temperature, and the optimisation of cooling rates to prevent destruction of the foam core; therefore, precise temperature control is paramount to success. Long cooling cycle times are associated with the creation of multi-layer foam parts due to their insulative nature; consequently, often making the costs of production prohibitive. Devices such as Rotocooler®, a rapid internal mould water spray cooling system, have been shown to have the potential to significantly decrease cooling times in rotational moulding. It is essential to monitor and control such devices to minimise the warpage associated with the rapid cooling of a moulding from only one side. The work presented here demonstrates the use of threaded thermocouples to monitor the polymer melt in multi-layer sandwich constructions, in order to analyse the cooling cycle of multi-layer foamed structures. A series of polyethylene skin-foam test mouldings were produced, and the effect of cooling medium on foam characteristics, mechanical properties, and process cycle time were investigated. Cooling cycle time reductions of 45%, 26%, and 29% were found for increasing (1%, 2%, and 3%) chemical blowing agent (CBA) amount when using internal water cooling technology from ˜123°C compared with forced air cooling (FAC). Subsequently, a reduction of IS for the same skin-foam parts was found to be 1%, 4

Multi-bits memory cell using degenerated magnetic states in a synthetic antiferromagnetic reference layer

International Nuclear Information System (INIS)

Fukushima, Akio; Yakushiji, Kay; Konoto, Makoto; Kubota, Hitoshi; Imamura, Hiroshi; Yuasa, Shinji

2016-01-01

We newly developed a magnetic memory cell having multi-bit function. The memory cell composed of a perpendicularly magnetized magnetic tunnel junction (MB-pMTJ) and a synthetic antiferromagnetic reference layer. The multi-bit function is realized by combining the freedom of states of the magnetic free layer and that in the antiferromagnetically coupled reference layer. The structure of the reference layer is (FeB/Ta/[Co/Pt]_3)/Ru/([Co/Pt]_6); the top and the bottom layers are coupled through Ru layer where the reference layer has two degrees of freedom of a head-to-head and a bottom-to-bottom magnetic configuration. A four-state memory cell is realized by combination of both degrees of freedom. The states in the reference layer however is hardly detected by the total resistance of MB-pMTJ, because the magnetoresistance effect in the reference layer is negligibly small. That implies that the resistance values for the different states in the reference layer are degenerated. On the other hand, the two different states in the reference layer bring different stray fields to the free layer, which generate two different minor loop with different switching fields. Therefore, the magnetic states in the reference layer can be differentiated by the two-step reading, before and after applying the appropriately pulsed magnetic field which can identify the initial state in the reference layer. This method is similar to distinguishing different magnetic states in an in-plane magnetized spin-valve element. We demonstrated that four different states in the MB-pMTJ can be distinguished by the two-step read-out. The important feature of the two-step reading is a practically large operation margins (large resistance change in reading) which is equal to that of a single MTJ. Even though the two-step reading is a destructive method by which 50% of the magnetic state is changed, this MB-pMTJ is promising for high density non-volatile memory cell with a minor cost of operation speed

Reflection and Transmission of Plane Electromagnetic Waves by a Geologic Layer.

Energy Technology Data Exchange (ETDEWEB)

Aldridge, David F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-04-01

Electric field and magnetic field reflection and transmission responses generated by a plane wave normally incident onto a finite - thickness geologic layer are mathematically derived and numerically evaluated. A thin layer with enhanced electric current conductivity and/or magnetic permeability is a reasonable geophysical representation of a hydraulic fracture inject ed with a high - contrast proppant pack. Both theory and numerics indicate that backward - and forward - scattered electromagnetic wavefields are potentially observable in a field experiment, despite the extreme thinness of a fracture compared to a typical low - frequency electromagnetic wavelength. The First Born Approximation (FBA) representation of layer scattering, significant for inversion studies, is shown to be accurate for a thin layer with mild medium parameter (i.e., conductivity, permeability, and per mittivity) contrasts with the surrounding homogeneous wholespace. However, FBA scattering theory breaks down for thick layers and strong parameter contrasts. ACKNOWLEDGEMENTS Sandia National Laboratories is a multi - mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. This research is conducted under the auspices of CRADA (Cooperative Research and Development Agreement) SC11/01780.00 between Carbo Ceramics Inc. and Sandia National Laboratories. The author acknowledges former Carbo R&D Vic e - President Mr. Chad Cannan and former SNL Geophysics Department manage r Ms. Amy Halloran for their interest i n and support of this work. Technical discussions with Project Manager and Principal Investigator Dr. Chester J. Weiss of the SNL Geophysics Department greatly benefited this work. Dr. Lewis C. Bartel, formerly with S NL and presently a consultant to Carbo Ceramics, provided many useful and intuitive insights, and

T-L Plane Abstraction-Based Energy-Efficient Real-Time Scheduling for Multi-Core Wireless Sensors

Directory of Open Access Journals (Sweden)

Youngmin Kim

2016-07-01

Full Text Available Energy efficiency is considered as a critical requirement for wireless sensor networks. As more wireless sensor nodes are equipped with multi-cores, there are emerging needs for energy-efficient real-time scheduling algorithms. The T-L plane-based scheme is known to be an optimal global scheduling technique for periodic real-time tasks on multi-cores. Unfortunately, there has been a scarcity of studies on extending T-L plane-based scheduling algorithms to exploit energy-saving techniques. In this paper, we propose a new T-L plane-based algorithm enabling energy-efficient real-time scheduling on multi-core sensor nodes with dynamic power management (DPM. Our approach addresses the overhead of processor mode transitions and reduces fragmentations of the idle time, which are inherent in T-L plane-based algorithms. Our experimental results show the effectiveness of the proposed algorithm compared to other energy-aware scheduling methods on T-L plane abstraction.

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.

Parallel Multi-Focusing Using Plane Wave Decomposition

DEFF Research Database (Denmark)

Misaridis, Thanassis; Munk, Peter; Jensen, Jørgen Arendt

2003-01-01

of desired 2-D sensitivity functions is specified, for multi-focusing in a number of directions. The field along these directions is decomposed to a sufficiently large (for accurate specification) number of plane waves, which are then back-propagated to all transducer elements. The contributions of all plane...... waves result in one time function per element. The numerical solution is presented and discussed. It contains pulses with a variation in central frequency and time-varying apodization across the aperture (dynamic apodization). The RMS difference between the transmitted field using the calculated pulse...... of the transmitted pulses is based on the directivity spectrum method, a generalization of the angular spectrum method, a generalization of the angular spectrum method, containing no evanescent waves. The underlying theory is based on the Fourier slice theorem, and field reconstruction from projections. First a set...

Coordinated Multi-layer Multi-domain Optical Network (COMMON) for Large-Scale Science Applications (COMMON)

Energy Technology Data Exchange (ETDEWEB)

Vokkarane, Vinod [University of Massachusetts

2013-09-01

We intend to implement a Coordinated Multi-layer Multi-domain Optical Network (COMMON) Framework for Large-scale Science Applications. In the COMMON project, specific problems to be addressed include 1) anycast/multicast/manycast request provisioning, 2) deployable OSCARS enhancements, 3) multi-layer, multi-domain quality of service (QoS), and 4) multi-layer, multidomain path survivability. In what follows, we outline the progress in the above categories (Year 1, 2, and 3 deliverables).

Intercorrelated In-Plane and Out-of-Plane Ferroelectricity in Ultrathin Two-Dimensional Layered Semiconductor In2Se3.

Science.gov (United States)

Cui, Chaojie; Hu, Wei-Jin; Yan, Xingxu; Addiego, Christopher; Gao, Wenpei; Wang, Yao; Wang, Zhe; Li, Linze; Cheng, Yingchun; Li, Peng; Zhang, Xixiang; Alshareef, Husam N; Wu, Tom; Zhu, Wenguang; Pan, Xiaoqing; Li, Lain-Jong

2018-02-14

Enriching the functionality of ferroelectric materials with visible-light sensitivity and multiaxial switching capability would open up new opportunities for their applications in advanced information storage with diverse signal manipulation functions. We report experimental observations of robust intralayer ferroelectricity in two-dimensional (2D) van der Waals layered α-In 2 Se 3 ultrathin flakes at room temperature. Distinct from other 2D and conventional ferroelectrics, In 2 Se 3 exhibits intrinsically intercorrelated out-of-plane and in-plane polarization, where the reversal of the out-of-plane polarization by a vertical electric field also induces the rotation of the in-plane polarization. On the basis of the in-plane switchable diode effect and the narrow bandgap (∼1.3 eV) of ferroelectric In 2 Se 3 , a prototypical nonvolatile memory device, which can be manipulated both by electric field and visible light illumination, is demonstrated for advancing data storage technologies.

Plasmon analysis and homogenization in plane layered photonic crystals and hyperbolic metamaterials

Energy Technology Data Exchange (ETDEWEB)

Davidovich, M. V., E-mail: davidovichmv@info.sgu.ru [Saratov State University (Russian Federation)

2016-12-15

Dispersion equations are obtained and analysis and homogenization are carried out in periodic and quasiperiodic plane layered structures consisting of alternating dielectric layers, metal and dielectric layers, as well as graphene sheets and dielectric (SiO{sub 2}) layers. Situations are considered when these structures acquire the properties of hyperbolic metamaterials (HMMs), i.e., materials the real parts of whose effective permittivity tensor have opposite signs. It is shown that the application of solely dielectric layers is more promising in the context of reducing losses.

How does the canine paw pad attenuate ground impacts? A multi-layer cushion system

Directory of Open Access Journals (Sweden)

Huaibin Miao

2017-12-01

Full Text Available Macroscopic mechanical properties of digitigrade paw pads, such as non-linear elastic and variable stiffness, have been investigated in previous studies; however, little is known about the micro-scale structural characteristics of digitigrade paw pads, or the relationship between these characteristics and the exceptional cushioning of the pads. The digitigrade paw pad consists of a multi-layered structure, which is mainly comprised of a stratified epithelium layer, a dermis layer and a subcutaneous layer. The stratified epithelium layer and dermal papillae constitute the epidermis layer. Finite element analyses were carried out and showed that the epidermis layer effectively attenuated the ground impact across impact velocities of 0.05–0.4 m/s, and that the von Mises stresses were uniformly distributed in this layer. The dermis layer encompassing the subcutaneous layer can be viewed as a hydrostatic system, which can store, release and dissipate impact energy. All three layers in the paw pad work as a whole to meet the biomechanical requirements of animal locomotion. These findings provide insights into the biomechanical functioning of digitigrade paw pads and could be used to facilitate bio-inspired, ground-contacting component development for robots and machines, as well as contribute to footwear design.

How does the canine paw pad attenuate ground impacts? A multi-layer cushion system.

Science.gov (United States)

Miao, Huaibin; Fu, Jun; Qian, Zhihui; Ren, Luquan; Ren, Lei

2017-12-15

Macroscopic mechanical properties of digitigrade paw pads, such as non-linear elastic and variable stiffness, have been investigated in previous studies; however, little is known about the micro-scale structural characteristics of digitigrade paw pads, or the relationship between these characteristics and the exceptional cushioning of the pads. The digitigrade paw pad consists of a multi-layered structure, which is mainly comprised of a stratified epithelium layer, a dermis layer and a subcutaneous layer. The stratified epithelium layer and dermal papillae constitute the epidermis layer. Finite element analyses were carried out and showed that the epidermis layer effectively attenuated the ground impact across impact velocities of 0.05-0.4 m/s, and that the von Mises stresses were uniformly distributed in this layer. The dermis layer encompassing the subcutaneous layer can be viewed as a hydrostatic system, which can store, release and dissipate impact energy. All three layers in the paw pad work as a whole to meet the biomechanical requirements of animal locomotion. These findings provide insights into the biomechanical functioning of digitigrade paw pads and could be used to facilitate bio-inspired, ground-contacting component development for robots and machines, as well as contribute to footwear design. © 2017. Published by The Company of Biologists Ltd.

A NEXT GENERATION MULTI-BEAM FOCAL PLANE ARRAY RECEIVER OF TRAO FOR 86-115 GHZ BAND

Directory of Open Access Journals (Sweden)

Moon-Hee Chung

2006-03-01

Full Text Available The noise temperature of existing millimeter-wave receivers is already within two or three times quantum noise limit. One of practical ways to increase the observation speed of single dish radio telescope without longer integration time is use of multi-beam focal plane array receiver as demonstrated in several large single dish radio telescopes. In this context the TRAO (Taeduk Radio Astronomy Observatory, which operates a 143n Cassegrain radio telescope, is planning to develop a 4 x 4 beams focal plane array SIS receiver system for 86-115 GHz band. Even though millimeter-wave HEMT LNA-based receivers approach the noise temperature comparable to the SIS receiver at W-band, it is believed that the receiver based on SIS mixer seems to offer a bit more advantages. The critical part of the multi-beam array receiver will be sideband separating SIS mixers. Employing such a type of SIS mixer makes it possible to simplify the quasi-optics of receiver. Otherwise, an SSB filter should be used in front of the mixer or some sophisticated post-processing of observation data is needed. In this paper we will present a preliminary design concept and components needed for the development of a new 3 mm band multi-beam focal plane array receiver.

A manufacturing method for multi-layer polysilicon surface-micromachining technology

Energy Technology Data Exchange (ETDEWEB)

Sniegowski, J.J.; Rodgers, M.S.

1998-01-01

An advanced manufacturing technology which provides multi-layered polysilicon surface micromachining technology for advanced weapon systems is presented. Specifically, the addition of another design layer to a 4 levels process to create a 5 levels process allows consideration of fundamentally new architecture in designs for weapon advanced surety components.

Efficiency of a multi-soil-layering system on wastewater treatment using environment-friendly filter materials.

Science.gov (United States)

Ho, Chia-Chun; Wang, Pei-Hao

2015-03-23

The multi-soil-layering (MSL) system primarily comprises two parts, specifically, the soil mixture layer (SML) and the permeable layer (PL). In Japan, zeolite is typically used as the permeable layer material. In the present study, zeolite was substituted with comparatively cheaper and more environmentally friendly materials, such as expanded clay aggregates, oyster shells, and already-used granular activated carbon collected from water purification plants. A series of indoor tests indicated that the suspended solid (SS) removal efficiency of granular activated carbon was between 76.2% and 94.6%; zeolite and expanded clay aggregates achieved similar efficiencies that were between 53.7% and 87.4%, and oyster shells presented the lowest efficiency that was between 29.8% and 61.8%. Further results show that the oyster shell system required an increase of wastewater retention time by 2 to 4 times that of the zeolite system to maintain similar chemical oxygen demand (COD) removal efficiency. Among the four MSL samples, the zeolite system and granular activated carbon system demonstrated a stable NH3-N removal performance at 92.3%-99.8%. The expanded clay aggregate system present lower removal performance because of its low adsorption capacity and excessively large pores, causing NO3--N to be leached away under high hydraulic loading rate conditions. The total phosphorous (TP) removal efficiency of the MSL systems demonstrated no direct correlation with the permeable layer material. Therefore, all MSL samples achieved a TP efficiency of between 92.1% and 99.2%.

Interferential multi-layer mirrors for X-UV radiation: fabrication, characterization and applications

International Nuclear Information System (INIS)

Youn Ki Byoung

1987-01-01

This research thesis reports the fabrication of W/C, Ni/C and Mo/C interferential multi-layer mirrors which can be used in the X-UV domain. They have been manufactured by cathodic pulverisation by using a new system for the in-situ control of the thickness of deposited layers, based on the measurement, sampling and real time integration of the ionic current which goes through the target during the coating process. Different methods (X ray diffraction at different wavelengths, electron microscopy and diffraction, in situ electronic resistivity measurement) have been used to study the main parameters which govern the multi-layer reflectivity: structure, substrate and interface roughness, minimum thickness to be deposited to obtain a continuous layer, number of bi-layers, stacking evenness, rate of absorbent element thickness to the period. Absolute reflectivity measurements have been performed by using short wavelength synchrotron radiation and the S component of polarised soft X rays obtained after double reflection on two parallel multi-layer mirrors oriented according to the Brewster angle. Ferromagnetic properties of Ni/C multi-layers have been studied to investigate fundamental magnetic properties, and to obtain additional information on interface structure [fr

Calculation of inter-plane thermal resistance of few-layer graphene from equilibrium molecular dynamics simulations

International Nuclear Information System (INIS)

Ni, Y; Chalopin, Y; Volz, S

2012-01-01

Inter-plane thermal resistance in 5-layer graphene is calculated from equilibrium molecular dynamics (EMD) by calculating the autocorrelation function of temperature difference. Our simulated inter-plane resistance for 5-layer graphene is 4.83 × 10 −9 m 2 K/W. This data is in the same order of magnitude with the reported values from NEMD simulations and Debye model calculations, and the possible reasons for the slight differences are discussed in details. The inter-plane resistance is not dependent on temperature, according to the results of the EMD simulation. Phonon density of states (DOSs) were plotted to better understand the mechanism behind the obtained values. These results provide a better insight in the heat transfer across a few layer graphene and yield useful information on the design of graphene based thermal materials.

Cross-Dependency Inference in Multi-Layered Networks: A Collaborative Filtering Perspective.

Science.gov (United States)

Chen, Chen; Tong, Hanghang; Xie, Lei; Ying, Lei; He, Qing

2017-08-01

The increasingly connected world has catalyzed the fusion of networks from different domains, which facilitates the emergence of a new network model-multi-layered networks. Examples of such kind of network systems include critical infrastructure networks, biological systems, organization-level collaborations, cross-platform e-commerce, and so forth. One crucial structure that distances multi-layered network from other network models is its cross-layer dependency, which describes the associations between the nodes from different layers. Needless to say, the cross-layer dependency in the network plays an essential role in many data mining applications like system robustness analysis and complex network control. However, it remains a daunting task to know the exact dependency relationships due to noise, limited accessibility, and so forth. In this article, we tackle the cross-layer dependency inference problem by modeling it as a collective collaborative filtering problem. Based on this idea, we propose an effective algorithm Fascinate that can reveal unobserved dependencies with linear complexity. Moreover, we derive Fascinate-ZERO, an online variant of Fascinate that can respond to a newly added node timely by checking its neighborhood dependencies. We perform extensive evaluations on real datasets to substantiate the superiority of our proposed approaches.

An optimized microstructure to minimizing in-plane and through-plane pressure drops of fibrous materials: Counter-intuitive reduction of gas diffusion layer permeability with porosity

Science.gov (United States)

Sadeghifar, Hamidreza

2018-05-01

The present study experimentally investigates the realistic functionality of in-plane and through-plane pressure drops of layered fibrous media with porosity, fiber diameter, fiber spacing, fiber-fiber angles and fiber-flow angles. The study also reveals that pressure drop may increase with porosity and fiber diameter under specific circumstances. This counter-intuitive point narrows down the validity range of widely-used permeability-porosity-diameter models or correlations. It is found that, for fibrous materials, the most important parameter that impacts the in-plane pressure drop is not their porosities but the number of fibers extended in the flow direction. It is also concluded that in-plane pressure drop is highly dependent upon the flow direction (fiber-flow angles), especially at lower porosities. Contrary to in-plane pressure drop, through-plane pressure drop is a weak function of fiber-fiber angles but is strongly impacted by fiber spacing, especially at lower porosities. At a given porosity, low through-plane pressure drops occur if fiber spacing does not change practically from one layer to another. Through-plane pressure drop also, insignificantly, increases with the intersecting angles between fibers. An optimized microstructure of fibrous media resulting in minimal in-plane and through-plane pressure drops is also offered for the first time in this work.

Linearly polarized photoluminescence of anisotropically strained c-plane GaN layers on stripe-shaped cavity-engineered sapphire substrate

Science.gov (United States)

Kim, Jongmyeong; Moon, Daeyoung; Lee, Seungmin; Lee, Donghyun; Yang, Duyoung; Jang, Jeonghwan; Park, Yongjo; Yoon, Euijoon

2018-05-01

Anisotropic in-plane strain and resultant linearly polarized photoluminescence (PL) of c-plane GaN layers were realized by using a stripe-shaped cavity-engineered sapphire substrate (SCES). High resolution X-ray reciprocal space mapping measurements revealed that the GaN layers on the SCES were under significant anisotropic in-plane strain of -0.0140% and -0.1351% along the directions perpendicular and parallel to the stripe pattern, respectively. The anisotropic in-plane strain in the GaN layers was attributed to the anisotropic strain relaxation due to the anisotropic arrangement of cavity-incorporated membranes. Linearly polarized PL behavior such as the observed angle-dependent shift in PL peak position and intensity comparable with the calculated value based on k.p perturbation theory. It was found that the polarized PL behavior was attributed to the modification of valence band structures induced by anisotropic in-plane strain in the GaN layers on the SCES.

Multi-layer micro/nanofluid devices with bio-nanovalves

Science.gov (United States)

Li, Hao; Ocola, Leonidas E.; Auciello, Orlando H.; Firestone, Millicent A.

2013-01-01

A user-friendly multi-layer micro/nanofluidic flow device and micro/nano fabrication process are provided for numerous uses. The multi-layer micro/nanofluidic flow device can comprise: a substrate, such as indium tin oxide coated glass (ITO glass); a conductive layer of ferroelectric material, preferably comprising a PZT layer of lead zirconate titanate (PZT) positioned on the substrate; electrodes connected to the conductive layer; a nanofluidics layer positioned on the conductive layer and defining nanochannels; a microfluidics layer positioned upon the nanofluidics layer and defining microchannels; and biomolecular nanovalves providing bio-nanovalves which are moveable from a closed position to an open position to control fluid flow at a nanoscale.

Basal-plane thermal conductivity of few-layer molybdenum disulfide

International Nuclear Information System (INIS)

Jo, Insun; Ou, Eric; Shi, Li; Pettes, Michael Thompson; Wu, Wei

2014-01-01

We report the in-plane thermal conductivity of suspended exfoliated few-layer molybdenum disulfide (MoS 2 ) samples that were measured by suspended micro-devices with integrated resistance thermometers. The obtained room-temperature thermal conductivity values are (44–50) and (48–52) W m −1 K −1 for two samples that are 4 and 7 layers thick, respectively. For both samples, the peak thermal conductivity occurs at a temperature close to 120 K, above which the thermal conductivity is dominated by intrinsic phonon-phonon scattering although phonon scattering by surface disorders can still play an important role in these samples especially at low temperatures

Multi-chamber and multi-layer thiol-ene microchip for cell culture

DEFF Research Database (Denmark)

Tan, H. Y.; Hemmingsen, Mette; Lafleur, Josiane P.

2014-01-01

We present a multi-layer and multi-chamber microfluidic chip fabricated using two different thiol-ene mixtures. Sandwiched between the thiol-ene chip layers is a commercially available membrane whose morphology has been altered with coatings of thiol-ene mixtures. Experiments have been conducted ...... with the microchip and shown that the fabricated microchip is suitable for long term cell culture....

Boundary-layer interactions in the plane-parallel incompressible flows

International Nuclear Information System (INIS)

Nguyen, Toan T; Sueur, Franck

2012-01-01

We study the inviscid limit problem of incompressible flows in the presence of both impermeable regular boundaries and a hypersurface transversal to the boundary across which the inviscid flow has a discontinuity jump. In the former case, boundary layers have been introduced by Prandtl as correctors near the boundary between the inviscid and viscous flows. In the latter case, the viscosity smoothes out the discontinuity jump by creating a transition layer which has the same amplitude and thickness as the Prandtl layer. In the neighbourhood of the intersection of the impermeable boundary and of the hypersurface, interactions between the boundary and the transition layers must then be considered. In this paper, we initiate a mathematical study of this interaction and carry out a strong convergence in the inviscid limit for the case of the plane-parallel flows introduced by Di Perna and Majda (1987 Commun. Math. Phys. 108 667–89). (paper)

Efficiency of a Multi-Soil-Layering System on Wastewater Treatment Using Environment-Friendly Filter Materials

Directory of Open Access Journals (Sweden)

Chia-Chun Ho

2015-03-01

Full Text Available The multi-soil-layering (MSL system primarily comprises two parts, specifically, the soil mixture layer (SML and the permeable layer (PL. In Japan, zeolite is typically used as the permeable layer material. In the present study, zeolite was substituted with comparatively cheaper and more environmentally friendly materials, such as expanded clay aggregates, oyster shells, and already-used granular activated carbon collected from water purification plants. A series of indoor tests indicated that the suspended solid (SS removal efficiency of granular activated carbon was between 76.2% and 94.6%; zeolite and expanded clay aggregates achieved similar efficiencies that were between 53.7% and 87.4%, and oyster shells presented the lowest efficiency that was between 29.8% and 61.8%. Further results show that the oyster shell system required an increase of wastewater retention time by 2 to 4 times that of the zeolite system to maintain similar chemical oxygen demand (COD removal efficiency. Among the four MSL samples, the zeolite system and granular activated carbon system demonstrated a stable NH3-N removal performance at 92.3%–99.8%. The expanded clay aggregate system present lower removal performance because of its low adsorption capacity and excessively large pores, causing NO3−-N to be leached away under high hydraulic loading rate conditions. The total phosphorous (TP removal efficiency of the MSL systems demonstrated no direct correlation with the permeable layer material. Therefore, all MSL samples achieved a TP efficiency of between 92.1% and 99.2%.

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.

The edge- and basal-plane-specific electrochemistry of a single-layer graphene sheet

Science.gov (United States)

Yuan, Wenjing; Zhou, Yu; Li, Yingru; Li, Chun; Peng, Hailin; Zhang, Jin; Liu, Zhongfan; Dai, Liming; Shi, Gaoquan

2013-01-01

Graphene has a unique atom-thick two-dimensional structure and excellent properties, making it attractive for a variety of electrochemical applications, including electrosynthesis, electrochemical sensors or electrocatalysis, and energy conversion and storage. However, the electrochemistry of single-layer graphene has not yet been well understood, possibly due to the technical difficulties in handling individual graphene sheet. Here, we report the electrochemical behavior at single-layer graphene-based electrodes, comparing the basal plane of graphene to its edge. The graphene edge showed 4 orders of magnitude higher specific capacitance, much faster electron transfer rate and stronger electrocatalytic activity than those of graphene basal plane. A convergent diffusion effect was observed at the sub-nanometer thick graphene edge-electrode to accelerate the electrochemical reactions. Coupling with the high conductivity of a high-quality graphene basal plane, graphene edge is an ideal electrode for electrocatalysis and for the storage of capacitive charges. PMID:23896697

Multi-layer service function chaining scheduling based on auxiliary graph in IP over optical network

Science.gov (United States)

Li, Yixuan; Li, Hui; Liu, Yuze; Ji, Yuefeng

2017-10-01

Software Defined Optical Network (SDON) can be considered as extension of Software Defined Network (SDN) in optical networks. SDON offers a unified control plane and makes optical network an intelligent transport network with dynamic flexibility and service adaptability. For this reason, a comprehensive optical transmission service, able to achieve service differentiation all the way down to the optical transport layer, can be provided to service function chaining (SFC). IP over optical network, as a promising networking architecture to interconnect data centers, is the most widely used scenarios of SFC. In this paper, we offer a flexible and dynamic resource allocation method for diverse SFC service requests in the IP over optical network. To do so, we firstly propose the concept of optical service function (OSF) and a multi-layer SFC model. OSF represents the comprehensive optical transmission service (e.g., multicast, low latency, quality of service, etc.), which can be achieved in multi-layer SFC model. OSF can also be considered as a special SF. Secondly, we design a resource allocation algorithm, which we call OSF-oriented optical service scheduling algorithm. It is able to address multi-layer SFC optical service scheduling and provide comprehensive optical transmission service, while meeting multiple optical transmission requirements (e.g., bandwidth, latency, availability). Moreover, the algorithm exploits the concept of Auxiliary Graph. Finally, we compare our algorithm with the Baseline algorithm in simulation. And simulation results show that our algorithm achieves superior performance than Baseline algorithm in low traffic load condition.

Generation of tunable terahertz out-of-plane radiation using Josephson vortices in modulated layered superconductors

International Nuclear Information System (INIS)

Savel'ev, Sergey; Yampol'skii, Valery; Rakhmanov, Alexander; Nori, Franco

2005-01-01

We show that a moving Josephson vortex in spatially modulated layered superconductors generates out-of-plane THz radiation. Remarkably, the magnetic and in-plane electric fields radiated are of the same order, which is very unusual for any good-conducting medium. Therefore, the out-of-plane radiation can be emitted to the vacuum without the standard impedance mismatch problem. Thus, the proposed tunable THz emitter for out-of-plane radiation can be more efficient than the standard one which radiates only along the ab-plane

Traveling Wave Modes of a Plane Layered Anelastic Earth

Science.gov (United States)

2016-05-20

grant, “Coupled Modes in Elastic Bottoms” (1) is the publication “Traveling wave modes of a plane layered anelastic earth ” accepted for...anelastic earth Robert I. Odom Applied Physics Laboratory and Department of Earth and Space Sciences University of Washington, 1013 NE 40th St., Seattle...contrast to a similar standing wave problem for the earth free oscillations (Tromp and Dahlen, 1990). Attenuation is commonly incorporated into synthetic

Iontophoretic transdermal drug delivery: a multi-layered approach.

Science.gov (United States)

Pontrelli, Giuseppe; Lauricella, Marco; Ferreira, José A; Pena, Gonçalo

2017-12-11

We present a multi-layer mathematical model to describe the transdermal drug release from an iontophoretic system. The Nernst-Planck equation describes the basic convection-diffusion process, with the electric potential obtained by solving the Laplace's equation. These equations are complemented with suitable interface and boundary conditions in a multi-domain. The stability of the mathematical problem is discussed in different scenarios and a finite-difference method is used to solve the coupled system. Numerical experiments are included to illustrate the drug dynamics under different conditions. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Toward Transparent Data Management in Multi-layer Storage Hierarchy for HPC Systems

Energy Technology Data Exchange (ETDEWEB)

Wadhwa, Bharti [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Computer Science; Byna, Suren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Butt, Ali R. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Computer Science

2018-04-17

Upcoming exascale high performance computing (HPC) systems are expected to comprise multi-tier storage hierarchy, and thus will necessitate innovative storage and I/O mechanisms. Traditional disk and block-based interfaces and file systems face severe challenges in utilizing capabilities of storage hierarchies due to the lack of hierarchy support and semantic interfaces. Object-based and semantically-rich data abstractions for scientific data management on large scale systems offer a sustainable solution to these challenges. Such data abstractions can also simplify users involvement in data movement. Here, we take the first steps of realizing such an object abstraction and explore storage mechanisms for these objects to enhance I/O performance, especially for scientific applications. We explore how an object-based interface can facilitate next generation scalable computing systems by presenting the mapping of data I/O from two real world HPC scientific use cases: a plasma physics simulation code (VPIC) and a cosmology simulation code (HACC). Our storage model stores data objects in different physical organizations to support data movement across layers of memory/storage hierarchy. Our implementation sclaes well to 16K parallel processes, and compared to the state of the art, such as MPI-IO and HDF5, our object-based data abstractions and data placement strategy in multi-level storage hierarchy achieves up to 7 X I/O performance improvement for scientific data.

Multi-layered satisficing decision making in oil and gas production platforms

DEFF Research Database (Denmark)

Lindegaard Mikkelsen, Lars; Demazeau, Yves; Jørgensen, B. N.

2013-01-01

From a control perspective, offshore oil and gas production is very challenging due to the many and potentially conflicting production objectives that arise from the intrinsic complexity of the oil and gas domain. In this paper, we show how a multi-layered multi-agent system can be used to implem...

Homoepitaxial growth of a-plane GaN layers by reaction between Ga2O vapor and NH3 gas

International Nuclear Information System (INIS)

Sumi, Tomoaki; Taniyama, Yuuki; Takatsu, Hiroaki; Juta, Masami; Kitamoto, Akira; Imade, Mamoru; Yoshimura, Masashi; Mori, Yusuke; Isemura, Masashi

2015-01-01

Growth of high-quality a-plane GaN layers was performed by reaction between Ga 2 O vapor and NH 3 gas at a high temperature. Smooth a-plane GaN epitaxial layers were obtained on a-plane GaN seed substrates sliced from thick c-plane GaN crystals. Growth rate increased with increasing Ga 2 O partial pressure. An a-plane GaN layer with a growth rate of 48 μm/h was obtained. The X-ray rocking curve (XRC) measurement showed that the full widths at half maximum (FWHMs) of GaN(112-bar0) with the incident beam parallel and perpendicular to the [0001] direction were 29–43 and 29–42 arcsec, respectively. Secondary ion mass spectrometry (SIMS) measurement revealed that oxygen concentration decreased at a high temperature. These results suggest that growth of a-GaN layers using Ga 2 O vapor and NH 3 gas at a high temperature enables the generation of high-quality crystals. (author)

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

Improvement of the surface morphology of a-plane InN using low-temperature InN buffer layers

International Nuclear Information System (INIS)

Shikata, G.; Hirano, S.; Inoue, T.; Hijikata, Y.; Orihara, M.; Yaguchi, H.; Yoshida, S.

2008-01-01

We report on the improvement of the surface morphology of a-plane InN films grown by RF molecular beam epitaxy. By using low-temperature (LT) InN buffer layers, we could successfully obtain InN films with a smooth surface. The full width at half maximum values of the X-ray diffraction (11-20) rocking curve along the [0001]InN direction were 2870 arcsec and 3410 arcsec for a-plane InN samples grown at 500 C with and without LT-InN buffer layers, respectively. Thus, we could improve also the crystalline quality of a-plane InN films by using LT-InN buffer layers. We observed strong polarization anisotropy in the photoluminescence spectra of a-plane InN, which is typical of nonpolar wurtzite III-nitride films. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The investigation of a two-layer fluid soliton pair using phase plane analysis

International Nuclear Information System (INIS)

Momeni, M.; Moslehi-Fard, M.; Alinejad, H.; Mahmoodi, J.

2004-01-01

Nonlinear long waves theory in a two-layer fluid system has been studied. The dynamical equations according to the normalized heights in first order are obtained using the reductive perturbation method and the equations of shallow water in each fluid and taking boundary conditions appropriate into account. Conserve energy form by definition a independent variable is found. By definition a Lyapunov function, the condition for stability are shown. A new technique was used to prove stability as well as existence of soliton pair using phase plane analysis. (author)

Quantifying hidden defect in multi-layered structures by using eddy current system combined with a scanner

International Nuclear Information System (INIS)

Huang Pingjie; Zhou Zekui; Wu Zhaotong

2005-01-01

The eddy current testing forward model of scanning inspection of multi-layered structures is introduced and simulation work is carried out to reveal the interaction between the scanning coil and defects with different geometric properties. A multi-frequency ECT experimental instrument combined with a scanner is established and scanning inspections are performed to detect the artificial etched flaws with different geometric parameters in the multi-layered structures. The predicted signals by the forward model are compared with the measured signals and the defects are characterized

Experimental analysis on stress wave in inhomogeneous multi-layered structures

International Nuclear Information System (INIS)

Cho, Yun Ho; Ham, Hyo Sick

1998-01-01

The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angle and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

Basic examination of in-plane spatial resolution in multi-slice CT

International Nuclear Information System (INIS)

Hara, Takanori; Kato, Hideki; Akiyama, Mitsutoshi; Murata, Katsutoshi

2002-01-01

In computed tomography (single-slice spiral CT, conventional CT), in-plane (x-y plane) spatial resolution is consistently identified as depending on the detector density of the in-plane (x-y plane). However, we considered that the in-plane (x-y plane) spatial resolution of multi-slice CT (MSCT) was influenced by an error in the detector's sensitivity to the Z-axis and by the frequency of use of direct row data and complementary row data when the image of spiral pitches (SP) was reconstructed. Our goal in this experiment was to analyze the relationship of the in-plane (x-y plane) spatial resolution of an asymmetric-type detector in MSCT to SP, tube current, and rotation time. By employing a tungsten wire phantom of 0.2 mm in diameter, we examined modulation transfer functions (MTF) by point-spread functions (PSF) of CT-images. Next, using the mean-square-root bandwidth theory, we analyzed the MTF of wire phantoms. The analysis of in-plane (x-y plane) spatial resolution revealed that various tube currents had no effect on the value of the mean-square-root bandwidth. However, rotation time and high spiral pitch did have an effect on mean-square-root bandwidth. Considering the results mentioned above, spiral pitch (z-axis reconstruction algorithm) had a slight effect on in-plane (x-y plane) spatial resolution of asymmetric-type detectors in MSCT. Accordingly, we proposed a new general view of VDDz (view/mm) in MSCT that considered view data density on the Z-axis according to spiral pitch (mm/rotation), rotation time (view/rotation), and slice collimation. (author)

Bounds on poloidal kinetic energy in plane layer convection

Science.gov (United States)

Tilgner, A.

2017-12-01

A numerical method is presented that conveniently computes upper bounds on heat transport and poloidal energy in plane layer convection for infinite and finite Prandtl numbers. The bounds obtained for the heat transport coincide with earlier results. These bounds imply upper bounds for the poloidal energy, which follow directly from the definitions of dissipation and energy. The same constraints used for computing upper bounds on the heat transport lead to improved bounds for the poloidal energy.

A Multi-layer, Hierarchical Information Management System for the Smart Grid

Energy Technology Data Exchange (ETDEWEB)

Lu, Ning; Du, Pengwei; Paulson, Patrick R.; Greitzer, Frank L.; Guo, Xinxin; Hadley, Mark D.

2011-10-10

This paper presents the modeling approach, methodologies, and initial results of setting up a multi-layer, hierarchical information management system (IMS) for the smart grid. The IMS allows its users to analyze the data collected by multiple control and communication networks to characterize the states of the smart grid. Abnormal, corrupted, or erroneous measurement data and outliers are detected and analyzed to identify whether they are caused by random equipment failures, unintentional human errors, or deliberate tempering attempts. Data collected from different information networks are crosschecked for data integrity based on redundancy, dependency, correlation, or cross-correlations, which reveal the interdependency between data sets. A hierarchically structured reasoning mechanism is used to rank possible causes of an event to aid the system operators to proactively respond or provide mitigation recommendations to remove or neutralize the threats. The model provides satisfactory performance on identifying the cause of an event and significantly reduces the need of processing myriads of data collected.

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.

Demonstrating multi-layered MAS in control of offshore oil and gas production

DEFF Research Database (Denmark)

Lindegaard Mikkelsen, Lars; Næumann, J. R.; Demazeau, Y.

2013-01-01

From a control perspective, offshore oil and gas production is very challenging due to the many and potentially conflicting production objectives that arise from the intrinsic complexity of the oil and gas domain. In this paper, we demonstrate how a multi-layered multi-agent system can be used in...

m-plane GaN layers grown by rf-plasma assisted molecular beam epitaxy with varying Ga/N flux ratios on m-plane 4H-SiC substrates

International Nuclear Information System (INIS)

Armitage, R.; Horita, M.; Suda, J.; Kimoto, T.

2007-01-01

A series of m-plane GaN layers with the Ga beam-equivalent pressure (BEP) as the only varied parameter was grown by rf-plasma assisted molecular beam epitaxy on m-plane 4H-SiC substrates using AlN buffer layers. The smoothest growth surfaces and most complete film coalescence were found for the highest Ga BEP corresponding to the Ga droplet accumulation regime. However, better structural quality as assessed by x-ray rocking curves was observed for growth at a lower Ga BEP value below the droplet limit. The variation of rocking curve widths for planes inclined with respect to the epilayer c axis followed a different trend with Ga BEP than those of reflections parallel to the c axis. The GaN layers were found to exhibit a large residual compressive strain along the a axis

MATERIAL DEPENDENCE OF TEMPERATURE DISTRIBUTION IN MULTI-LAYER MULTI-METAL COOKWARE

Directory of Open Access Journals (Sweden)

MOHAMMADREZA SEDIGH

2017-09-01

Full Text Available Laminated structure is becoming more popular in cookware markets; however, there seems to be a lack of enough scientific studies to evaluate its pros and cons, and to show that how it functions. A numerical model using a finite element method with temperature-dependent material properties has been performed to investigate material and layer dependence of temperature distribution in multi-layer multi-metal plate exposed to irregular heating. Behavior of two parameters including mean temperature value and uniformity on the inner surface of plate under variations of thermal properties and geometrical conditions have been studied. The results indicate that conductive metals used as first layer in bi-layer plates have better thermal performance than those used in the second layer. In addition, since cookware manufacturers increasingly prefer to use all-clad aluminium plate, recently, this structure is analysed in the present study as well. The results show all-clad copper and aluminum plate possesses lower temperature gradient compared with single layer aluminum and all-clad aluminum core plates.

Elastic Buckling Behaviour of General Multi-Layered Graphene Sheets

Directory of Open Access Journals (Sweden)

Rong Ming Lin

2015-04-01

Full Text Available Elastic buckling behaviour of multi-layered graphene sheets is rigorously investigated. Van der Waals forces are modelled, to a first order approximation, as linear physical springs which connect the nodes between the layers. Critical buckling loads and their associated modes are established and analyzed under different boundary conditions, aspect ratios and compressive loading ratios in the case of graphene sheets compressed in two perpendicular directions. Various practically possible loading configurations are examined and their effect on buckling characteristics is assessed. To model more accurately the buckling behaviour of multi-layered graphene sheets, a physically more representative and realistic mixed boundary support concept is proposed and applied. For the fundamental buckling mode under mixed boundary support, the layers with different boundary supports deform similarly but non-identically, leading to resultant van der Waals bonding forces between the layers which in turn affect critical buckling load. Results are compared with existing known solutions to illustrate the excellent numerical accuracy of the proposed modelling approach. The buckling characteristics of graphene sheets presented in this paper form a comprehensive and wholesome study which can be used as potential structural design guideline when graphene sheets are employed for nano-scale sensing and actuation applications such as nano-electro-mechanical systems.

The Impedance of Multi-layer Vacuum Chambers

CERN Document Server

Vos, L

2003-01-01

Many components of the LHC vacuum chamber have multi-layered walls : the copper coated cold beam screen, the titanium coated ceramic chamber of the dump kickers, the ceramic chamber of the injection kickers coated with copper stripes, only to name a few. Theories and computer programs are available for some time already to evaluate the impedance of these elements. Nevertheless, the algorithm developed in this paper is more convenient in its application and has been used extensively in the design phase of multi-layer LHC vacuum chamber elements. It is based on classical transmission line theory. Closed expressions are derived for simple layer configurations, while beam pipes involving many layers demand a chain calculation. The algorithm has been tested with a number of published examples and was verified with experimental data as well.

Investigation of aperiodic W/C multi-layer mirror for X-ray optics

International Nuclear Information System (INIS)

Wang Zhanshan; Cheng Xinbin; Zhu Jingtao; Huang Qiushi; Zhang Zhong; Chen Lingyan

2011-01-01

Design, fabrication and characterization of aperiodic tungsten/carbon (W/C) multi-layer mirror were studied. W/C multi-layer was designed as a broad-angle reflective supermirror for Cu-Kα line (λ = 0.154 nm) in the grazing incident angular range (0.9-1.1 deg.) using simulated annealing algorithm. To deposit the W/C depth-graded multi-layer mirror accurately, we introduce an effective layer growth rate as a function of layer thickness. This method greatly improves the reflectivity curve compared to the conventional multi-layer mirror prepared with constant growth rate. The deposited multi-layer mirror exhibits an average reflectivity of 19% over the grazing incident angle range of 0.88-1.08 deg. which mainly coincides with the designed value. Furthermore, the physical mechanisms were discussed and the re-sputtering process of light-atom layers is accounted for the modification of layer thicknesses which leads to the effective growth rates. Using this calibration method, the aperiodic multi-layer mirrors can be better fabricated for X-ray optics.

Multi-layer hierarchical array fabricated with diatom frustules for highly sensitive bio-detection applications

International Nuclear Information System (INIS)

Li, Aobo; Cai, Jun; Pan, Junfeng; Wang, Yu; Yue, Yue; Zhang, Deyuan

2014-01-01

Diatoms have delicate porous structures which are very beneficial in improving the absorbing ability in the bio-detection field. In this study, multi-layered hierarchical arrays were fabricated by packing Nitzschia soratensis (N. soratensis) frustules into Cosinodiscus argus (C. argus) frustules to achieve advanced sensitivity in bio-detection chips. Photolithographic patterning was used to obtain N. soratensis frustule arrays, and the floating behavior of C. argus frustules was employed to control their postures for packing N. soratensis frustule array spots. The morphology of the multi-layer C. argus–N. soratensis package array was investigated by scanning electron microscopy, demonstrating that the overall and sub-structures of the diatom frustules were retained. The signal enhancing effect of multi-layer C. argus–N. soratensis packages was demonstrated by fluorescent antibody test results. The mechanism of the enhancement was also analyzed, indicating that both complex hierarchical frustule structures and optimized posture of C. argus frustules were important for improving bio-detection sensitivities. The technique for fabricating multi-layer diatom frustules arrays is also useful for making multi-functional biochips and controllable drug delivery systems. (paper)

In-plane and cross-plane thermal conductivities of molybdenum disulfide

International Nuclear Information System (INIS)

Ding, Zhiwei; Pei, Qing-Xiang; Zhang, Yong-Wei; Jiang, Jin-Wu

2015-01-01

We investigate the in-plane and cross-plane thermal conductivities of molybdenum disulfide (MoS 2 ) using non-equilibrium molecular dynamics simulations. We find that the in-plane thermal conductivity of monolayer MoS 2 is about 19.76 W mK −1 . Interestingly, the in-plane thermal conductivity of multilayer MoS 2 is insensitive to the number of layers, which is in strong contrast to the in-plane thermal conductivity of graphene where the interlayer interaction strongly affects the in-plane thermal conductivity. This layer number insensitivity is attributable to the finite energy gap in the phonon spectrum of MoS 2 , which makes the phonon–phonon scattering channel almost unchanged with increasing layer number. For the cross-plane thermal transport, we find that the cross-plane thermal conductivity of multilayer MoS 2 can be effectively tuned by applying cross-plane strain. More specifically, a 10% cross-plane compressive strain can enhance the thermal conductivity by a factor of 10, while a 5% cross-plane tensile strain can reduce the thermal conductivity by 90%. Our findings are important for thermal management in MoS 2 based nanodevices and for thermoelectric applications of MoS 2 . (paper)

Efficient Exciton Diffusion and Resonance-Energy Transfer in Multi-Layered Organic Epitaxial Nanofibers

DEFF Research Database (Denmark)

Tavares, Luciana; Cadelano, Michele; Quochi, Francesco

2015-01-01

Multi-layered epitaxial nanofibers are exemplary model systems for the study of exciton dynamics and lasing in organic materials due to their well-defined morphology, high luminescence efficiencies, and color tunability. We resort to temperature-dependent cw and picosecond photoluminescence (PL......) spectroscopy to quantify exciton diffusion and resonance-energy transfer (RET) processes in multi-layered nanofibers consisting of alternating layers of para-hexaphenyl (p6P) and α-sexithiophene (6T), serving as exciton donor and acceptor material, respectively. The high probability for RET processes...... is confirmed by Quantum Chemical calculations. The activation energy for exciton diffusion in p6P is determined to be as low as 19 meV, proving p6P epitaxial layers also as a very suitable donor material system. The small activation energy for exciton diffusion of the p6P donor material, the inferred high p6P...

A novel approach for quantifying the zero-plane displacement of rough-wall boundary layers

Science.gov (United States)

Ferreira, Manuel; Rodriguez-Lopez, Eduardo; Ganapathisubramani, Bharath; Aerodynamics; Flight Mechanics Team

2017-11-01

Indirect methods of wall shear stress (WSS) estimation are frequently used to characterise rough wall boundary-layer flows. The zero-plane displacement, hypothesised to be the vertical location where it acts, is often treated as a fitting parameter. However, it would be preferrable to measure both these quantities directly, especially for surfaces with large roughness elements where established scaling and similarity laws may not hold. In this talk we present a novel floating element balance that is able to measure not only the WSS but also the wall normal location at which it acts. While allowing compensation for mild static pressure gradients by means of a first-order analytical model. Its architecture is based on a parallel-shift linkage and it's fitted with custom built force transducers and a data acquisition system especially designed to achieve high Signal-to-Noise Ratios (SNR). The smooth-wall boundary-layer flow is used as benchmark to assess the accuracy of this balance. The values of skin friction coefficient show an agreement with hot-wire anemometry to within 2 % at a local Reynolds number Reθ = 4 ×103 up to 104. A rough surface of regularly distributed large elements is used to investigate the ability to infer the zero-plane displacement.

Effects of layer interface slip on the response and performance of elastic multi-layered flexible airport pavement systems

CSIR Research Space (South Africa)

Maina, JW

2007-08-01

Full Text Available in this study. The new AASHTO pavement design guide for flexible pavements is shifting from an experience (or purely empirical) based design method to a mechanistic-empirical (M-E) design method. The latter approach requires an elastic multi-layered analysis...

Spacer layer effect and microstructure on multi-layer [NdFeB/Nb]n films

International Nuclear Information System (INIS)

Tsai, J.-L.; Yao, Y.-D.; Chin, T.-S.; Kronmueller, H.

2002-01-01

Spacer layer effect on multi-layer [NdFeB/Nb] n films has been investigated from the variation of magnetic properties and microstructure of the films. From a HRTEM cross-section view observation, the average grain size of [NdFeB/Nb] n multi-layers was controlled by both annealing temperature and thickness of NdFeB layer. Selected area diffraction pattern indicated that the structure of Nb spacer layer was amorphous. The grain size and coercivity of [NdFeB x /Nb] n films change from 50 nm and 16.7 kOe to 167 nm and 9 kOe for films with x=40 nm, n=10 and x=200 nm, n=2, respectively

Corrosion behaviour in saline environments of single-layer titanium and aluminium coatings, and of Ti/Al alternated multi-layers elaborated by a multi-beam PVD technique

International Nuclear Information System (INIS)

Merati, Abdenacer

1994-01-01

This research thesis reports the characterization of anti-corrosion titanium and aluminium coatings deposited on a 35CD4 steel under the form of mono-metallic layers or alternated Ti/Al multi-layers, and obtained by a multibeam PVD technique. The influence of different parameters is studied: single-layer thickness (5, 15 or 30 micro-metres), multi-layer distribution (5 to 6) and substrate (smooth or threaded). Layer nature and microstructure are studied by optical microscopy and scanning electron microscopy (SEM), as well as corrosion toughness in aqueous saline environments. Coated threaded samples have been studied after tightening tests. It appears that titanium layers are denser and more uniform than aluminium layers, and that multi-layer coatings provide a better protection than single-layer coatings. The best behaviour is obtained when titanium is in contact with steel, and aluminium is the outer layer in contact with the corroding environment [fr

Interoperability In Multi-Layered Active Defense:The Need For Commonality And Robustness Between Active Defense Weapon Systems

Science.gov (United States)

2016-02-16

into areas where there is no access to maritime platforms. Sea-based interceptor platforms have the ability to intercept targets at each stage of the...argues that the most efficient concept for integrating active defense weapon systems is a multi- layered architecture with redundant intercept ...faster data transfer and will prevent data loss. The need for almost 100% interception successes is increasing as the threat becomes more

Redundancy scheme for multi-layered accelerator control system

International Nuclear Information System (INIS)

Chauhan, Amit; Fatnani, Pravin

2009-01-01

The control system for SRS Indus-2 has three-layered architecture. There are VMEbus based stations at the lower two layers that are controlled by their respective CPU board. The 'Profibus' fieldbus standard is used for communication between these VME stations distributed in the field. There is a Profibus controller board at each station to implement the communication protocol. The mode of communication is master-slave (command-response) type. This paper proposes a scheme to implement redundancy at the lower two layers namely Layer-2 (Supervisory Layer / Profibus-master) and Layer-3 (Equipment Unit Interface Layer / Profibus-slave). The redundancy is for both the CPU and the communication board. The scheme uses two CPU boards and two Profi controller boards at each L-3 station. This helps in decreasing any downtime resulting either from CPU faults or communication board faults that are placed in the field area. Redundancy of Profi boards provides two active communication channels between the stations that can be used in different ways thereby increasing the availability on a communication link. Redundancy of CPU boards provides certain level of auto fault-recovery as one CPU remains active and the other CPU remains in standby mode, which takes over the control of VMEbus in case of any fault in the main CPU. (author)

Quasi-effective medium theory for multi-layered magneto-dielectric structures

International Nuclear Information System (INIS)

Genov, Dentcho A; Mundru, Pattabhiraju C

2014-01-01

We present a quasi-effective medium theory that determines the optical properties of multi-layered composites beyond the quasi-static limit. The proposed theory exactly reproduces the far field scattering/extinction cross sections through an iterative process in which mode-dependent quasi-effective impedances of the composite system are introduced. In the large wavelength limit our theory is consistent with the Maxwell–Garnett formalism. Possible applications in determining the hybridization particle resonances of multi-shell structures and electromagnetic cloaking are identified. (paper)

Usefulness of multi-plane dynamic subtraction CT (MPDS-CT) for intracranial high density lesions

Energy Technology Data Exchange (ETDEWEB)

Takagi, Ryo; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan)

1996-02-01

We present a new CT technique using the high speed CT scanner in detection and evaluation of temporal and spatial contrast enhancement of intracranial high density lesions. A multi-plane dynamic subtraction CT (MPDS-CT) was performed in 21 patients with intracranial high density lesions. These lesions consisted of 10 brain tumors, 7 intracerebral hemorrhages and 4 vascular malformations (2 untreated, 2 post-embolization). Baseline study was first performed, and 5 sequential planes of covering total high density lesions were selected. After obtaining the 5 sequential CT images as mask images, three series of multi-plane dynamic CT were performed for the same 5 planes with an intravenous bolus injection of contrast medium. MPDS-CT images were reconstructed by subtracting dynamic CT images from the mask ones. MPDS-CT were compared with conventional contrast-enhanced CT. MPDS-CT images showed the definite contrast enhancement of high density brain tumors and vascular malformations which were not clearly identified on conventional contrast-enhanced CT images because of calcified or hemorrhagic lesions and embolic materials, enabling us to eliminate enhanced abnormalities with non-enhanced areas such as unusual intracerebral hemorrhages. MPDS-CT will provide us further accurate and objective information and will be greatly helpful for interpreting pathophysiologic condition. (author).

Optimal distance of multi-plane sensor in three-dimensional electrical impedance tomography.

Science.gov (United States)

Hao, Zhenhua; Yue, Shihong; Sun, Benyuan; Wang, Huaxiang

2017-12-01

Electrical impedance tomography (EIT) is a visual imaging technique for obtaining the conductivity and permittivity distributions in the domain of interest. As an advanced technique, EIT has the potential to be a valuable tool for continuously bedside monitoring of pulmonary function. The EIT applications in any three-dimensional (3 D) field are very limited to the 3 D effects, i.e. the distribution of electric field spreads far beyond the electrode plane. The 3 D effects can result in measurement errors and image distortion. An important way to overcome the 3 D effect is to use the multiple groups of sensors. The aim of this paper is to find the best space resolution of EIT image over various electrode planes and select an optimal plane spacing in a 3 D EIT sensor, and provide guidance for 3 D EIT electrodes placement in monitoring lung function. In simulation and experiment, several typical conductivity distribution models, such as one rod (central, midway and edge), two rods and three rods, are set at different plane spacings between the two electrode planes. A Tikhonov regularization algorithm is utilized for reconstructing the images; the relative error and the correlation coefficient are utilized for evaluating the image quality. Based on numerical simulation and experimental results, the image performance at different spacing conditions is evaluated. The results demonstrate that there exists an optimal plane spacing between the two electrode planes for 3 D EIT sensor. And then the selection of the optimal plane spacing between the electrode planes is suggested for the electrodes placement of multi-plane EIT sensor.

Characterization of the morphology of co-extruded, thermoplastic/rubber multi-layer tapes

International Nuclear Information System (INIS)

L'Abee, R.M.A.; Vissers, A.M.J.T.; Goossens, J.G.P.; Spoelstra, A.B.; Duin, M. van

2009-01-01

Tapes with alternating semi-crystalline thermoplastic/rubber layers with thicknesses varying from 100 nm up to several μm were prepared by multi-layer co-extrusion. The variation in layer thickness was obtained by varying the thermoplastic/rubber feed ratio. A systematic study on the use of various microscopy techniques to visualize the morphology of the layered systems is presented. The relatively large length scales and the sample preparation make optical microscopy (OM) unsuitable to study the morphology of the multi-layer tapes. Although excellent contrast between the thermoplastic and rubber layers can be obtained, the usually applied, relatively large magnifications limit the use of transmission electron microscopy (TEM) and atomic force microscopy (AFM) to small sample areas. The large range of applicable magnifications makes scanning electron microscopy (SEM) the most suitable technique to study the morphology of the multi-layer tapes. The sample preparation for SEM with a secondary electron (SE) detector is often based on the removal of one of the components, which may induce changes in the morphology. SEM with a back-scattered electron (BSE) detector is a very convenient method to study the morphology over a wide range of length scales, where the contrast between the different layers can be enhanced by chemical staining. Finally, the nucleation behavior (homogeneous versus heterogeneous) of the semi-crystalline layers, as probed by differential scanning calorimetry (DSC), provides valuable information on the layered morphology. The use of relatively straightforward DSC measurements shows a clear advantage with respect to the discussed microscopy techniques, since no sample preparation is required and relatively large samples can be studied, which are more representative for the bulk.

Heat transfer control in a plane magnetic fluid layer with a free surface

International Nuclear Information System (INIS)

Bashtovoi, V.G.; Pogirnitskaya, S.G.; Reks, A.G.

1993-01-01

The heat transfer mechanisms that are specific to a magnetic liquid have been already investigated extensively. The high sensitivity of the free magnetic liquid surface to the external magnetic field introduces a new feature into the heat transfer process. In the present work, the authors have investigated the possibility of controlling the heat transfer through the phenomenon of magnetic liquid surface instability in a uniform magnetic field. The conditions for heat transfer through a chamber, partially filled with a magnetic liquid, are governed by the characteristics of the free liquid surface and by its stability and development in the supercritical magnetic fields. The authors consider a model two-dimensional problem of heat transfer through a two-layer medium consisting of horizontally situated immiscible layers of magnetic and nonmagnetic liquids with given thermal conductivities. In the absence of an external magnetic field, the interface of the liquids represents a plane surface. In fields which exceed the critical magnitude, the interface is deformed along the wave. As the field intensity is increased, the amplitude of interface distortion becomes larger. The two-dimensional shape of the free magnetic liquid surface may be realized experimentally using two plane layers of magnetic and nonmagnetic liquids in a uniform magnetic field tangent to the interface of the component layers. 7 refs., 9 figs

Improved crystal quality of a-plane GaN with high- temperature 3-dimensional GaN buffer layers deposited by using metal-organic chemical vapor deposition

International Nuclear Information System (INIS)

Park, Sung Hyun; Moon, Dae Young; Kim, Bum Ho; Kim, Dong Uk; Chang, Ho Jun; Jeon, Heon Su; Yoon, Eui Joon; Joo, Ki Su; You, Duck Jae; Nanishi, Yasushi

2012-01-01

a-plane GaN on r-plane sapphire substrates suffers from high density defects and rough surfaces. To obtain pit-free a-plane GaN by metal-organic chemical vapor deposition, we intentionally grew high-temperature (HT) 3-dimensional (3D) GaN buffer layers on a GaN nucleation layer. The effects of the HT 3D GaN buffer layers on crystal quality and the surface morphology of a-plane GaN were studied. The insertion of a 3D GaN buffer layer with an optimum thickness was found to be an effective method to obtain pit-free a-plane GaN with improved crystalline quality on r-plane sapphire substrates. An a-plane GaN light emitting diode (LED) at an emission wavelength around 480 nm with negligible peak shift was successfully fabricated.

The cell engineering construction and function evaluation of multi-layer biochip dialyzer.

Science.gov (United States)

Zhu, Wen; Li, Jiwei; Liu, Jianfeng

2013-10-01

We report the fabrication and function evaluation of multi-layer biochip dialyzer. Such device may potentially be applied to the wearable hemodialysis systems. By merging the advantages of microfluidic chip technology with cell engineering, both functions of glomerular filtration and renal tubule physiological activity are integrated in the same device. This device is designed into a laminated structure, in which the chip number of the superimposed layer can be arbitrarily tailored in accordance with the requirements of dialysis capacity. We propose that such structure can overcome the obstacles of large size and detached structure of the traditional hollow fiber dialyzer. To construct this multilayer biochips dialyzer, two types of dialyzer device with two-layered and six-layered chips are assembled, respectively. Cell adhesion and proliferation on three different dialysis membrane materials under static and dynamic conditions are investigated and compared. The filtration capability, re-absorption function and excrete ammonia function of the resulting multi-layer biochip dialyzer are evaluated. The results reveal that the constructed device can perform higher filtration efficiency and also play a role of renal tubule. This methodology may be useful in developing "scaling down" artificial kidneys that can act as wearable or even implantable hemodialysis systems.

Anisotropic spin motive force in multi-layered Dirac fermion system, α-(BEDT-TTF)2I3

International Nuclear Information System (INIS)

Kubo, K; Morinari, T

2015-01-01

We investigate the anisotropic spin motive force in α-(BEDT-TTF) 2 I 3 , which is a multi-layered massless Dirac fermion system under pressure. Assuming the interlayer antiferromagnetic interaction and the interlayer anisotropic ferromagnetic interaction, we numerically examine the spin ordered state of the ground state using the steepest descent method. The anisotropic interaction leads to the anisotropic spin ordered state. We calculate the spin motive force produced by the anisotropic spin texture. The result quantitatively agrees with the experiment. (paper)

Metallic few-layered VS2 ultrathin nanosheets: high two-dimensional conductivity for in-plane supercapacitors.

Science.gov (United States)

Feng, Jun; Sun, Xu; Wu, Changzheng; Peng, Lele; Lin, Chenwen; Hu, Shuanglin; Yang, Jinlong; Xie, Yi

2011-11-09

With the rapid development of portable electronics, such as e-paper and other flexible devices, practical power sources with ultrathin geometries become an important prerequisite, in which supercapacitors with in-plane configurations are recently emerging as a favorable and competitive candidate. As is known, electrode materials with two-dimensional (2D) permeable channels, high-conductivity structural scaffolds, and high specific surface areas are the indispensible requirements for the development of in-plane supercapacitors with superior performance, while it is difficult for the presently available inorganic materials to make the best in all aspects. In this sense, vanadium disulfide (VS(2)) presents an ideal material platform due to its synergic properties of metallic nature and exfoliative characteristic brought by the conducting S-V-S layers stacked up by weak van der Waals interlayer interactions, offering great potential as high-performance in-plane supercapacitor electrodes. Herein, we developed a unique ammonia-assisted strategy to exfoliate bulk VS(2) flakes into ultrathin VS(2) nanosheets stacked with less than five S-V-S single layers, representing a brand new two-dimensional material having metallic behavior aside from graphene. Moreover, highly conductive VS(2) thin films were successfully assembled for constructing the electrodes of in-plane supercapacitors. As is expected, a specific capacitance of 4760 μF/cm(2) was realized here in a 150 nm in-plane configuration, of which no obvious degradation was observed even after 1000 charge/discharge cycles, offering as a new in-plane supercapacitor with high performance based on quasi-two-dimensional materials.

Multi-Layer Self-Nanoemulsifying Pellets: an Innovative Drug Delivery System for the Poorly Water-Soluble Drug Cinnarizine.

Science.gov (United States)

Shahba, Ahmad Abdul-Wahhab; Ahmed, Abid Riaz; Alanazi, Fars Kaed; Mohsin, Kazi; Abdel-Rahman, Sayed Ibrahim

2018-04-25

Beside their solubility limitations, some poorly water-soluble drugs undergo extensive degradation in aqueous and/or lipid-based formulations. Multi-layer self-nanoemulsifying pellets (ML-SNEP) introduce an innovative delivery system based on isolating the drug from the self-nanoemulsifying layer to enhance drug aqueous solubility and minimize degradation. In the current study, various batches of cinnarizine (CN) ML-SNEP were prepared using fluid bed coating and involved a drug-free self-nanoemulsifying layer, protective layer, drug layer, moisture-sealing layer, and/or an anti-adherent layer. Each layer was optimized based on coating outcomes such as coating recovery and mono-pellets%. The optimized ML-SNEP were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), in vitro dissolution, and stability studies. The optimized ML-SNEP were free-flowing, well separated with high coating recovery. SEM showed multiple well-defined coating layers. The acidic polyvinylpyrrolidone:CN (4:1) solution presented excellent drug-layering outcomes. DSC and XRD confirmed CN transformation into amorphous state within the drug layer. The isolation between CN and self-nanoemulsifying layer did not adversely affect drug dissolution. CN was able to spontaneously migrate into the micelles arising from the drug-free self-nanoemulsifying layer. ML-SNEP showed superior dissolution compared to Stugeron® tablets at pH 1.2 and 6.8. Particularly, on shifting to pH 6.8, ML-SNEP maintained > 84% CN in solution while Stugeron® tablets showed significant CN precipitation leaving only 7% CN in solution. Furthermore, ML-SNEP (comprising Kollicoat® Smartseal 30D) showed robust stability and maintained > 97% intact CN within the accelerated storage conditions. Accordingly, ML-SNEP offer a novel delivery system that combines both enhanced solubilization and stabilization of unstable poorly soluble drugs.

Non-equilibrium quantum dynamics of ultra-cold atomic mixtures: the multi-layer multi-configuration time-dependent Hartree method for bosons

International Nuclear Information System (INIS)

Krönke, Sven; Cao, Lushuai; Schmelcher, Peter; Vendrell, Oriol

2013-01-01

We develop and apply the multi-layer multi-configuration time-dependent Hartree method for bosons, which represents an ab initio method for investigating the non-equilibrium quantum dynamics of multi-species bosonic systems. Its multi-layer feature allows for tailoring the wave function ansatz to describe intra- and inter-species correlations accurately and efficiently. To demonstrate the beneficial scaling and efficiency of the method, we explored the correlated tunneling dynamics of two species with repulsive intra- and inter-species interactions, to which a third species with vanishing intra-species interaction was weakly coupled. The population imbalances of the first two species can feature a temporal equilibration and their time evolution significantly depends on the coupling to the third species. Bosons of the first and second species exhibit a bunching tendency, whose strength can be influenced by their coupling to the third species. (paper)

Improvement of in-plane alignment for surface oxidized NiO layer on textured Ni substrate by two-step heat-treatment

International Nuclear Information System (INIS)

Hasegawa, Katsuya; Izumi, Toru; Izumi, Teruo; Shiohara, Yuh; Maeda, Toshihiko

2004-01-01

Epitaxial growth of NiO on a textured Ni substrate as a template for an REBa 2 Cu 3 O y coated conductor was investigated. Highly in-plane aligned NiO layers were successfully fabricated using a new process of a two-step heat-treatment for oxidation. In the first-step, a highly in-plane aligned thin NiO layer was formed on a textured Ni substrate under a low driving force of oxidation. Then, in the second-step, a thick NiO layer was grown at a higher rate with maintaining its high in-plane grain alignment, as if the first NiO layer acts as a seed crystal layer. Further, growth rates and microstructures of the NiO layers were studied comparatively in the cases with and without the first layer. It was found that the oxidation rate in the case with the first layer was lower than that without the first layer. The microstructure observation revealed that the NiO without the first layer was poly-crystalline with many grain-boundaries. On the other hand, in the case with the first layer, grain-boundaries of the NiO were hardly observed. Hence, the reason for this difference of the growth rate and the microstructure of the NiO layers were discussed in view of a diffusivity path

Contact Problem for an Elastic Layer on an Elastic Half Plane Loaded by Means of Three Rigid Flat Punches

Directory of Open Access Journals (Sweden)

T. S. Ozsahin

2013-01-01

Full Text Available The frictionless contact problem for an elastic layer resting on an elastic half plane is considered. The problem is solved by using the theory of elasticity and integral transformation technique. The compressive loads P and Q (per unit thickness in direction are applied to the layer through three rigid flat punches. The elastic layer is also subjected to uniform vertical body force due to effect of gravity. The contact along the interface between elastic layer and half plane is continuous, if the value of the load factor, λ, is less than a critical value, . In this case, initial separation loads, and initial separation points, are determined. Also the required distance between the punches to avoid any separation between the punches and the elastic layer is studied and the limit distance between punches that ends interaction of punches is investigated for various dimensionless quantities. However, if tensile tractions are not allowed on the interface, for the layer separates from the interface along a certain finite region. Numerical results for distance determining the separation area, vertical displacement in the separation zone, contact stress distribution along the interface between elastic layer and half plane are given for this discontinuous contact case.

Renormalization group study of the multi-layer sine-gordon model

International Nuclear Information System (INIS)

Nandori, I.

2005-01-01

Complete text of publication follows. We analyze the phase structure of the system of coupled sine-Gordon (SG) type field theoric models. The 'pure,' SG model is periodic in the internal space spanned by the field variable. The central subjects of investigation is the multi-layer sine-Gordon (LSG) model, where the periodicity is broken partially by the coupling terms between the layers each of which is described by a scalar field, where the second term on the r.h.s. describes the interaction of the layers. Here, we dis- cuss the generalization of the results obtained for the two-layer sine-Gordon model found in the previous study. Besides the obvious field theoretical interest, the LSG model has been used to describe the vortex properties of high transition temperature superconductors, and the extension of the previous analysis to a general N-layer model is necessary for a description of the critical behaviour of vortices in realistic multi-layer systems. The couplings between the layers can be considered as mass terms. Since the periodicity of the LSG model has been broken only partially, the N-layer model has always a single zero mass eigenvalue. The presence of this single zero mass eigenvalue is found to be decisive with respect to the phase structure of the N-layer models. By a suitable rotation of the field variables, we identify the periodic mode (which corresponds to the zero mass eigenvalue) and N - 1 non-periodic modes (with explicit mass terms). The N - 1 non-periodic modes have a trivial IR scaling which holds independently of β which has been proven consistently using (i) the non-perturbative renormalization group study of the rotated model, (ii) the Gaussian integration about the vanishing-field saddle point. Due to the presence of the periodic mode the model undergoes a Kosterlitz-Thouless type phase transition which occurs at a coupling parameter β c 2 = 8Nπ, where N is the number of layers. The critical value β c 2 corresponds to the critical

Nonlinear acoustic wave propagating in one-dimensional layered system

International Nuclear Information System (INIS)

Yun, Y.; Miao, G.Q.; Zhang, P.; Huang, K.; Wei, R.J.

2005-01-01

The propagation of finite-amplitude plane sound in one-dimensional layered media is studied by the extended method of transfer matrix formalism. For the periodic layered system consisting of two alternate types of liquid, the energy distribution and the phase vectors of the interface vibration are computed and analyzed. It is found that in the pass-band, the second harmonic of sound wave can propagate with the characteristic modulation

Multi-area layered multicast scheme for MPLS networks

Science.gov (United States)

Ma, Yajie; Yang, Zongkai; Wang, Yuming; Chen, Jingwen

2005-02-01

Multi-protocol label switching (MPLS) is multiprotocols both at layer 2 and layer 3. It is suggested to overcome the shortcomings of performing complex longest prefix matching in layer 3 routing by using short, fixed length labels. The MPLS community has put more effort into the label switching of unicast IP traffic, but less in the MPLS multicast mechanism. The reasons are the higher label consumption, the dynamical mapping of L3 multicast tree to L2 LSPs and the 20-bit shim header which is much fewer than the IPv4 IP header. On the other hand, heterogeneity of node capability degrades total performance of a multicast group. In order to achieve the scalability as well as the heterogeneity in MPLS networks, a novel scheme of MPLS-based Multi-area Layered Multicast Scheme (MALM) is proposed. Unlike the existing schemes which focus on aggregating the multicast stream, we construct the multicast tree based on the virtual topology aggregation. The MPLS area is divided into different sub-areas to form the hierarchical virtual topology and the multicast group is reconstructed into multiple layers according to the node capability. At the same time, the label stack is used to save the label space. For stability of the MALM protocol, a multi-layer protection scheme is also discussed. The experiment results show that the proposed scheme saves label space and decrease the Multicast Forwarding Table in much degree.

Electrohydrodynamic direct—writing of conductor—insulator-conductor multi-layer interconnection

International Nuclear Information System (INIS)

Zheng Gao-Feng; Pei Yan-Bo; Wang Xiang; Zheng Jian-Yi; Sun Dao-Heng

2014-01-01

A multi-layer interconnection structure is a basic component of electronic devices, and printing of the multi-layer interconnection structure is the key process in printed electronics. In this work, electrohydrodynamic direct-writing (EDW) is utilized to print the conductor—insulator—conductor multi-layer interconnection structure. Silver ink is chosen to print the conductor pattern, and a polyvinylpyrrolidone (PVP) solution is utilized to fabricate the insulator layer between the bottom and top conductor patterns. The influences of EDW process parameters on the line width of the printed conductor and insulator patterns are studied systematically. The obtained results show that the line width of the printed structure increases with the increase of the flow rate, but decreases with the increase of applied voltage and PVP content in the solution. The average resistivity values of the bottom and top silver conductor tracks are determined to be 1.34 × 10 −7 Ω·m and 1.39 × 10 −7 Ω·m, respectively. The printed PVP layer between the two conductor tracks is well insulated, which can meet the insulation requirement of the electronic devices. This study offers an alternative, fast, and cost-effective method of fabricating conductor—insulator—conductor multi-layer interconnections in the electronic industry

Insights into the growth rate of spatially evolving plane turbulent free-shear layers from 2D vortex-gas simulations

Science.gov (United States)

Suryanarayanan, Saikishan; Narasimha, Roddam

2017-02-01

Although the free-shear or mixing layer has been a subject of extensive research over nearly a century, there are certain fundamental issues that remain controversial. These include the influence of initial and downstream conditions on the flow, the effect of velocity ratio across the layer, and the nature of any possible coupling between small scale dynamics and the large scale evolution of layer thickness. In the spirit of the temporal vortex-gas simulations of Suryanarayanan et al. ["Free turbulent shear layer in a point vortex gas as a problem in nonequilibrium statistical mechanics," Phys. Rev. E 89, 013009 (2014)], we revisit the simple 2D inviscid vortex-gas model with extensive computations and detailed analysis, in order to gain insights into some of the above issues. Simulations of the spatially evolving vortex-gas shear layer are carried out at different velocity ratios using a computational model based on the work of Basu et al. ["Vortex sheet simulation of a plane canonical mixing layer," Comput. Fluids 21, 1-30 (1992) and "Modelling plane mixing layers using vortex points and sheets," Appl. Math. Modell. 19, 66-75 (1995)], but with a crucial improvement that ensures conservation of global circulation. The simulations show that the conditions imposed at the origin of the free shear layer and at the exit to the computational domain can affect flow evolution in their respective downstream and upstream neighbourhoods, the latter being particularly strong in the single stream limit. In between these neighbourhoods at the ends is a regime of universal self-preserving growth rate given by a universal function of velocity ratio. The computed growth rates are generally located within the scatter of experimental data on plane mixing layers and closely agree with recent high Reynolds number experiments and 3D large eddy simulation studies. These findings support the view that observed free-shear layer growth can be largely explained by the 2D vortex dynamics of

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...

Out-of-plane superfluid density of a layered organic superconductor: The coherent Josephson tunneling

International Nuclear Information System (INIS)

Tomic, S.; Prester, M.; Drobac, D.; Milat, O.; Maki, K.; Schweitzer, D.

1999-01-01

Measurements of AC magnetic susceptibility in κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br show that the b-axis penetration depth below T c exhibits behaviour different from that observed in the ac plane, which exhibits the T-linear dependence. In agreement with earlier measurements, a leading quadratic temperature dependence is found at low temperatures. The temperature dependence of the out-of-plane superfluid density is shown to best agree with a model of d-wave superconducting layers coupled by coherent Josephson tunneling. (orig.)

High energy PIXE: A tool to characterize multi-layer thick samples

Science.gov (United States)

Subercaze, A.; Koumeir, C.; Métivier, V.; Servagent, N.; Guertin, A.; Haddad, F.

2018-02-01

High energy PIXE is a useful and non-destructive tool to characterize multi-layer thick samples such as cultural heritage objects. In a previous work, we demonstrated the possibility to perform quantitative analysis of simple multi-layer samples using high energy PIXE, without any assumption on their composition. In this work an in-depth study of the parameters involved in the method previously published is proposed. Its extension to more complex samples with a repeated layer is also presented. Experiments have been performed at the ARRONAX cyclotron using 68 MeV protons. The thicknesses and sequences of a multi-layer sample including two different layers of the same element have been determined. Performances and limits of this method are presented and discussed.

Packer Detection for Multi-Layer Executables Using Entropy Analysis

Directory of Open Access Journals (Sweden)

Munkhbayar Bat-Erdene

2017-03-01

Full Text Available Packing algorithms are broadly used to avoid anti-malware systems, and the proportion of packed malware has been growing rapidly. However, just a few studies have been conducted on detection various types of packing algorithms in a systemic way. Following this understanding, we elaborate a method to classify packing algorithms of a given executable into three categories: single-layer packing, re-packing, or multi-layer packing. We convert entropy values of the executable file loaded into memory into symbolic representations, for which we used SAX (Symbolic Aggregate Approximation. Based on experiments of 2196 programs and 19 packing algorithms, we identify that precision (97.7%, accuracy (97.5%, and recall ( 96.8% of our method are respectively high to confirm that entropy analysis is applicable in identifying packing algorithms.

The acoustic field of a point source in a uniform boundary layer over an impedance plane

Science.gov (United States)

Zorumski, W. E.; Willshire, W. L., Jr.

1986-01-01

The acoustic field of a point source in a boundary layer above an impedance plane is investigated anatytically using Obukhov quasi-potential functions, extending the normal-mode theory of Chunchuzov (1984) to account for the effects of finite ground-plane impedance and source height. The solution is found to be asymptotic to the surface-wave term studies by Wenzel (1974) in the limit of vanishing wind speed, suggesting that normal-mode theory can be used to model the effects of an atmospheric boundary layer on infrasonic sound radiation. Model predictions are derived for noise-generation data obtained by Willshire (1985) at the Medicine Bow wind-turbine facility. Long-range downwind propagation is found to behave as a cylindrical wave, with attention proportional to the wind speed, the boundary-layer displacement thickness, the real part of the ground admittance, and the square of the frequency.

Layered Multi-mode Optimal Control Strategy for Multi-MW Wind Turbine

Institute of Scientific and Technical Information of China (English)

KONG Yi-gang; WANG Zhi-xin

2008-01-01

The control strategy is one of the most important renewable technology, and an increasing number of multi-MW wind turbines are being developed with a variable speed-variable pitch (VS-VP) technology. The main objective of adopting a VS-VP technology is to improve the fast response speed and capture maximum energy. But the power generated by wind turbine changes rapidly because of the centinuous fluctuation of wind speed and direction. At the same time, wind energy conversion systems are of high order, time delays and strong nonlinear characteristics because of many uncertain factors. Based on analyzing the all dynamic processes of wind turbine, a kind of layered multi-mode optimal control strategy is presented which is that three control strategies: bang-bang, fuzzy and adaptive proportienai integral derivative (PID) are adopted according to different stages and expected performance of wind turbine to capture optimum wind power, compensate the nonlinearity and improve the wind turbine performance at low, rated and high wind speed.

Thermoelectric characteristics of Pt-silicide/silicon multi-layer structured p-type silicon

International Nuclear Information System (INIS)

Choi, Wonchul; Jun, Dongseok; Kim, Soojung; Shin, Mincheol; Jang, Moongyu

2015-01-01

Electric and thermoelectric properties of silicide/silicon multi-layer structured devices were investigated with the variation of silicide/silicon heterojunction numbers from 3 to 12 layers. For the fabrication of silicide/silicon multi-layered structure, platinum and silicon layers are repeatedly sputtered on the (100) silicon bulk substrate and rapid thermal annealing is carried out for the silicidation. The manufactured devices show ohmic current–voltage (I–V) characteristics. The Seebeck coefficient of bulk Si is evaluated as 195.8 ± 15.3 μV/K at 300 K, whereas the 12 layered silicide/silicon multi-layer structured device is evaluated as 201.8 ± 9.1 μV/K. As the temperature increases to 400 K, the Seebeck coefficient increases to 237.2 ± 4.7 μV/K and 277.0 ± 1.1 μV/K for bulk and 12 layered devices, respectively. The increase of Seebeck coefficient in multi-layered structure is mainly attributed to the electron filtering effect due to the Schottky barrier at Pt-silicide/silicon interface. At 400 K, the thermal conductivity is reduced by about half of magnitude compared to bulk in multi-layered device which shows the efficient suppression of phonon propagation by using Pt-silicide/silicon hetero-junctions. - Highlights: • Silicide/silicon multi-layer structured is proposed for thermoelectric devices. • Electric and thermoelectric properties with the number of layer are investigated. • An increase of Seebeck coefficient is mainly attributed the Schottky barrier. • Phonon propagation is suppressed with the existence of Schottky barrier. • Thermal conductivity is reduced due to the suppression of phonon propagation

Numerical simulation of the subsolar magnetopause current layer in the sun-earth meridian plane

Science.gov (United States)

Okuda, H.

1993-01-01

The formation and stability of the magnetopause current layer near the subsolar point in the sun-earth meridian plane are examined using a 2D electromagnetic particle simulation. For the case of zero IMF, the simulation results show that the current layer remains stable and is essentially the same as in the 1D simulation. The width of the current layer is given by the electron-ion hybrid gyroradius which is much smaller than the ion gyroradius. The current layer is found to remain stable for the northward IMF as well. As in the 1D simulation, the jump of the magnetic field at the current layer for the northward IMF remains small. For the southward IMF, collisionless magnetic reconnection is found to develop, leading to the formation of magnetic islands and density peaking within the current layer.

Reliably counting atomic planes of few-layer graphene (n > 4).

Science.gov (United States)

Koh, Yee Kan; Bae, Myung-Ho; Cahill, David G; Pop, Eric

2011-01-25

We demonstrate a reliable technique for counting atomic planes (n) of few-layer graphene (FLG) on SiO(2)/Si substrates by Raman spectroscopy. Our approach is based on measuring the ratio of the integrated intensity of the G graphene peak and the optical phonon peak of Si, I(G)/I(Si), and is particularly useful in the range n > 4 where few methods exist. We compare our results with atomic force microscopy (AFM) measurements and Fresnel equation calculations. Then, we apply our method to unambiguously identify n of FLG devices on SiO(2) and find that the mobility (μ ≈ 2000 cm(2) V(-1) s(-1)) is independent of layer thickness for n > 4. Our findings suggest that electrical transport in gated FLG devices is dominated by carriers near the FLG/SiO(2) interface and is thus limited by the environment, even for n > 4.

Basic conception of simultaneous multi-layer hybrid type ECT apparatus 'HEADTOME-2'

International Nuclear Information System (INIS)

Nakanishi, Shigemasa

1981-01-01

Following on the one-slice hybrid type ECT (emission computer tomography) apparatus HEADTOME-1 for the measurement of local cerebral blood stream by single-photon measurement and the measurement of local cerebral metabolism by positron measurement, the development of the simultaneous multi-layer hybrid type ECT apparatus HEADTOME-2 was started for the simultaneous measurement of whole brains. Being designed also for obtaining single-photon simultaneous multi-layer tomography, a peculiar mode of collimator structure was employed, thereby the defect in HEADTOME-1 was eliminated. The design of the detector section is as follows: detector array diameter 42 cm, effective vision-field diameter 21 cm, patient tunnel diameter 25 cm, detector rings 3, slice interval 35 cm, and NaI (Tl) crystals 64 per layer. The basic conception of HEADTOME-2, such as the detectors, collimator, the number of slices, specifications, and data processing system, is described. (J.P.N.)

Dualband MW/LW Strained Layer Superlattice Focal Plane Arrays For Satellite-Based Wildfire Detection, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Dualband focal plane arrays (FPAs) based on gallium-free Type-II strained layer superlattice (SLS) photodiodes have recently experienced significant advances. We...

Size distribution of carbon layer planes in biochar from different plant type of feedstock with different heating temperatures.

Science.gov (United States)

Lu, Guan-Yang; Ikeya, Kosuke; Watanabe, Akira

2016-11-01

Biochar application to soil is a strategy to decelerate the increase in the atmospheric carbon concentration. The composition of condensed aromatic clusters appears to be an important determinant of the degradation rate of char in soil. The objective of the present study was to determine the size distribution of carbon layer planes in biochars produced from different types of feedstock (a broadleaf and a coniferous tree and two herbs) using different heating treatment temperatures (HTT; 400 °C-800 °C) using X-ray diffraction 11 band profile analysis. (13)C nuclear magnetic resonance with the phase-adjusted spinning side bands of the chars indicated different spectral features depending on the HTT and similar carbon composition among the plant types at each HTT. Both the content and composition of carbon layer planes in biochar produced using the same HTT were also similar among the plant types. The carbon layer plane size in the 400 °C and 600 °C chars was distributed from 0.24 to 1.68 or 1.92 nm (corresponding to 37 or 52 rings) with the mean size of 0.79-0.92 and 0.80-1.14 nm, respectively. The carbon layer planes in the 800 °C chars ranged from 0.72-0.96 nm (7-14 rings) to 2.64-3.60 nm (91-169 rings) and the mean values were 1.47-1.89 nm. The relative carbon layer plane content in the 600 °C and 800 °C chars was typically 2 and 3 times that in the 400 °C chars. These results indicate the progression of the formation and/or the size development of graphite-like structures, suggesting that a char produced at a higher HTT would have better carbon sequestrating characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Damping Oriented Design of Thin-Walled Mechanical Components by Means of Multi-Layer Coating Technology

Directory of Open Access Journals (Sweden)

Giuseppe Catania

2018-02-01

Full Text Available The damping behaviour of multi-layer composite mechanical components, shown by recent research and application papers, is analyzed. A local dissipation mechanism, acting at the interface between any two different layers of the composite component, is taken into account, and a beam model, to be used for validating the known experimental results, is proposed. Multi-layer prismatic beams, consisting of a metal substrate and of some thin coated layers exhibiting variable stiffness and adherence properties, are considered in order to make it possible to study and validate this assumption. A dynamical model, based on a simple beam geometry but taking into account the previously introduced local dissipation mechanism and distributed visco-elastic constraints, is proposed. Some different application examples of specific multi-layer beams are considered, and some numerical examples concerning the beam free and forced response are described. The influence of the multilayer system parameters on the damping behaviour of the free and forced response of the composite beam is investigated by means of the definition of some damping estimators. Some effective multi-coating configurations, giving a relevant increase of the damping estimators of the coated structure with respect to the same uncoated structure, are obtained from the model simulation, and the results are critically discussed.

Systems considerations in mosaic focal planes

Science.gov (United States)

White, K. P., III

1983-08-01

Two key reasons for pursuing the development of mosaic focal planes are reviewed and it is shown that rapid frame repetition rate is the only requirement that can be solved no other way than through mosaic focal planes. With the view that spaceborne mosaic focal plane sensors are necessarily 'smart sensors' requiring a lot of onboard processing just to function, it is pointed out that various artificial intelligence techniques may be the most appropriate to incorporate in the data processing. Finally, a novel mosaic focal plane design is proposed, termed a virtual mosaic focal plane, in response to other system constraints.

Preparation of a large-scale and multi-layer molybdenum crystal and its characteristics

International Nuclear Information System (INIS)

Fujii, Tadayuki

1989-01-01

In the present work, the secondary recrystallization method was applied to obtain a large-scale and multi-layer crystal from a hot-rolled multi-laminated molybdenum sheet doped and stacked alternately with different amounts of dopant. It was found that the time and/or temperature at which secondary recrystallization commence from the multi- layer sheet is strongly dependent on the amounts of dopants. Therefore the potential nucleus of the secondary grain from layers with different amounts of dopant occurred first at the layer with a small amount of dopant and then grew into the layer with a large amount of dopant after an anneal at 1800 0 C-2000 0 C. Consequently a large -scale and multi-layer molybdenum crystal can easily be obtained. 12 refs., 9 figs., 2 tabs. (Author)

Dualband MW/LW Strained Layer Superlattice Focal Plane Arrays for Satellite-Based Wildfire Detection, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Infrared focal plane arrays (FPAs) based on Type-II strained layer superlattice (SLS) photodiodes have recently experienced significant advances. In Phase I we...

Prolonged reorganization of thiol-capped Au nanoparticles layered structures

Directory of Open Access Journals (Sweden)

Sarathi Kundu

2013-09-01

Full Text Available Prolonged reorganization behaviour of mono-, di-, tri- and multi-layer films of Au nanoparticles prepared by Langmuir-Blodgett method on hydrophobic Si(001 substrates have been studied by using X-ray scattering techniques. Out-of-plane study shows that although at the initial stage the reorganization occurs through the compaction of the films keeping the layered structure unchanged but finally all layered structures modify to monolayer structure. Due to this reorganization the Au density increases within the nanometer thick films. In-plane study shows that inside the reorganized films Au nanoparticles are distributed randomly and the particle size modifies as the metallic core of Au nanoparticles coalesces.

Measurement of in-plane elasticity of live cell layers using a pressure sensor embedded microfluidic device

Science.gov (United States)

Lin, Chien-Han; Wang, Chien-Kai; Chen, Yu-An; Peng, Chien-Chung; Liao, Wei-Hao; Tung, Yi-Chung

2016-11-01

In various physiological activities, cells experience stresses along their in-plane direction when facing substrate deformation. Capability of continuous monitoring elasticity of live cell layers during a period is highly desired to investigate cell property variation during various transformations under normal or disease states. This paper reports time-lapsed measurement of live cell layer in-plane elasticity using a pressure sensor embedded microfluidic device. The sensor converts pressure-induced deformation of a flexible membrane to electrical signals. When cells are cultured on top of the membrane, flexural rigidity of the composite membrane increases and further changes the output electrical signals. In the experiments, human embryonic lung fibroblast (MRC-5) cells are cultured and analyzed to estimate the in-plane elasticity. In addition, the cells are treated with a growth factor to simulate lung fibrosis to study the effects of cell transformation on the elasticity variation. For comparison, elasticity measurement on the cells by atomic force microscopy (AFM) is also performed. The experimental results confirm highly anisotropic configuration and material properties of cells. Furthermore, the in-plane elasticity can be monitored during the cell transformation after the growth factor stimulation. Consequently, the developed microfluidic device provides a powerful tool to study physical properties of cells for fundamental biophysics and biomedical researches.

Non-reciprocality of waves in inhomogeneous gyrotropic media and multi layer systems with gyrotropic layers

International Nuclear Information System (INIS)

Gevorgyan, A.A.

2002-01-01

There has been considered the dispersion of electromagnetic waves in natural gyrotropic, inhomogeneous media. There has been discovered a new mechanism of waves non-reciprocality conditioned by simultaneous presence of one of the media gradients and natural gyrotropy. The non- reciprocality of waves in multilayer systems with gydrotropic layers has been investigated. It was considered a simple multilayer system glass (1)- cholesteric liquid crystal- glass(2) and demonstrated that non-reciprocality of waves in multilayer system offers good challenges for establishing simple systems with greater reciprocality. It has been shown that the multilayer systems with cholesteric liquid crystal layer can be used as optic diodes

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

A multi-layered safety perspective on the tsunami disaster in Tohoku, Japan

NARCIS (Netherlands)

Tsimopoulou, V.; Jonkman, S.N.; Kolen, B.; Maaskant, B.; Mori, N.; Yasuda, T.

2012-01-01

This paper presents an assessment of the multi-layered safety system in Tohoku, Japan based on the tsunami disaster of March 2011. The performed analysis has been based on data provided by local researchers and field observations. First an overview of the tsunami behaviour along the affected

Estimation of thermal insulation performance in multi-layer insulator for liquid helium pipe

International Nuclear Information System (INIS)

Shibanuma, Kiyoshi; Kuriyama, Masaaki; Shibata, Takemasa

1991-01-01

For a multi-layer insulator around the liquid helium pipes for cryopumps of JT-60 NBI, a multi-layer insulator composed of 10 layers, which can be wound around the pipe at the same time and in which the respective layers are in concentric circles by shifting them in arrangement, has been developed and tested. As the result, it was shown that the newly developed multi-layer insulator has better thermal insulation performance than the existing one, i.e. the heat load of the newly developed insulator composed of 10 layers was reduced to 1/3 the heat load of the existing insulator, and the heat leak at the joint of the insulator in longitudinal direction of the pipe was negligible. In order to clarify thermal characteristics of the multi-layer insulator, the heat transfer through the insulator has been analyzed considering the radiation heat transfer by the netting spacer between the reflectors, and the temperature dependence on the emissivities and the heat transmission coefficients of these two components of the insulator. The analytical results were in good agreements with the experimental ones, so that the analytical method was shown to be valid. Concerning the influence of the number of layers and the layer density on the insulation performance of the insulator, analytical results showed that the multi-layer insulator with the number of layer about N = 20 and the layer density below 2.0 layer/mm was the most effective for the liquid helium pipe of a JT-60 cryopump. (author)

Residual stress analysis of a multi-layer thin film structure by destructive (curvature) and non-destructive (x-ray) methods

International Nuclear Information System (INIS)

Chen, P.C.; Oshida, Y.

1989-01-01

Multi-layer thin film which has structure of Cu/Cr/K/Cr/Cu prepared by sputtering process was analyzed for interfacial stresses for as-deposited conditions. This structure was also annealed at 150 degrees C, and 350 degrees C for around 15 min. in a vacuum and cooled slowly down for stress analyses. Equations for residual stress estimations for homogeneous material system using layer removal technique (stress relief) is now applied for inhomogeneous system (multi-layer structure). The results are compared with the data obtained from x-ray diffraction technique by using sin 2 Ψ - 2 θ method, for Cu layer. From the present analyses, the data obtained using layer removal seem to be qualitatively consistent with but not quantitatively in agreement with x-ray method

Investigation of the in-plane and out-of-plane electrical properties of metallic nanoparticles in dielectric matrix thin films elaborated by atomic layer deposition

Science.gov (United States)

Thomas, D.; Puyoo, E.; Le Berre, M.; Militaru, L.; Koneti, S.; Malchère, A.; Epicier, T.; Roiban, L.; Albertini, D.; Sabac, A.; Calmon, F.

2017-11-01

Pt nanoparticles in a Al2O3 dielectric matrix thin films are elaborated by means of atomic layer deposition. These nanostructured thin films are integrated in vertical and planar test structures in order to assess both their in-plane and out-of-plane electrical properties. A shadow edge evaporation process is used to develop planar devices with electrode separation distances in the range of 30 nm. Both vertical and planar test structures show a Poole-Frenkel conduction mechanism. Low trap energy levels (<0.1 eV) are identified for the two test structures which indicates that the Pt islands themselves are not acting as traps in the PF mechanism. Furthermore, a more than three order of magnitude current density difference is observed between the two geometries. This electrical anisotropy is attributed to a large electron mobility difference in the in-plane and out-of-plane directions which can be related to different trap distributions in both directions.

APT analyses of deuterium-loaded Fe/V multi-layered films

KAUST Repository

Gemma, R.

2009-04-01

Interaction of hydrogen with metallic multi-layered thin films remains as a hot topic in recent days Detailed knowledge on such chemically modulated systems is required if they are desired for application in hydrogen energy system as storage media. In this study, the deuterium concentration profile of Fe/V multi-layer was investigated by atom probe tomography (APT) at 60 and 30 K. It is firstly shown that deuterium-loaded sample can easily react with oxygen at the Pd capping layer on Fe/V and therefore, it is highly desired to avoid any oxygen exposure after D(2) loading before APT analysis. The analysis temperature also has an impact on D concentration profile. The result taken at 60 K shows clear traces of surface segregation of D atoms towards analysis surface. The observed diffusion profile of D allows us to estimate an apparent diffusion coefficient D. The calculated D at 60 K is in the order of 10(-17) cm(2)/s, deviating 6 orders of magnitude from an extrapolated value. This was interpreted with alloying, D-trapping at defects and effects of the large extension to which the extrapolation was done. A D concentration profile taken at 30 K shows nosegregation anymore and a homogeneous distribution at C(D) = 0.05(2) D/Me, which is in good accordance with that measured in the corresponding pressure-composition isotherm. (C) 2008 Elsevier B.V. All rights reserved.

APT analyses of deuterium-loaded Fe/V multi-layered films

KAUST Repository

Gemma, R.; Al-Kassab, Talaat; Kirchheim, R.; Pundt, A.

2009-01-01

Interaction of hydrogen with metallic multi-layered thin films remains as a hot topic in recent days Detailed knowledge on such chemically modulated systems is required if they are desired for application in hydrogen energy system as storage media. In this study, the deuterium concentration profile of Fe/V multi-layer was investigated by atom probe tomography (APT) at 60 and 30 K. It is firstly shown that deuterium-loaded sample can easily react with oxygen at the Pd capping layer on Fe/V and therefore, it is highly desired to avoid any oxygen exposure after D(2) loading before APT analysis. The analysis temperature also has an impact on D concentration profile. The result taken at 60 K shows clear traces of surface segregation of D atoms towards analysis surface. The observed diffusion profile of D allows us to estimate an apparent diffusion coefficient D. The calculated D at 60 K is in the order of 10(-17) cm(2)/s, deviating 6 orders of magnitude from an extrapolated value. This was interpreted with alloying, D-trapping at defects and effects of the large extension to which the extrapolation was done. A D concentration profile taken at 30 K shows nosegregation anymore and a homogeneous distribution at C(D) = 0.05(2) D/Me, which is in good accordance with that measured in the corresponding pressure-composition isotherm. (C) 2008 Elsevier B.V. All rights reserved.

Multi-Layer Visualization of Mobile Mapping Data

Directory of Open Access Journals (Sweden)

D. Eggert

2013-10-01

Full Text Available application various different visualization schemes are conceivable. This paper presents a multi-layer based visualization method, enabling fast data browsing of mobile mapping data. In contrast to systems like Google Street View the proposed visualization does not base on 360° panoramas, but on colored point clouds projected on partially translucent images. Those images are rendered as overlapping textures, preserving the depth of the recorded data and still enabling fast rendering on any kind of platform. Furthermore the proposed visualization allows the user to inspect the mobile mapping data in a panoramic fashion with an immersive depth illusion using the parallax scrolling technic.

Performance Test of the Microwave Ion Source with the Multi-layer DC Break

International Nuclear Information System (INIS)

Kim, Dae Il; Kwon, Hyeok Jung; Kim, Han Sung; Seol, Kyung Tae; Cho, Yong Sub

2012-01-01

A microwave proton source has been developed as a proton injector for the 100-MeV proton linac of the PEFP (Proton Engineering Frontier Project). On microwave ion source, the high voltage for the beam extraction is applied to the plasma chamber, also to the microwave components such as a 2.45GHz magnetron, a 3-stub tuner, waveguides. If microwave components can be installed on ground side, the microwave ion source can be operated and maintained easily. For the purpose, the multi-layer DC break has been developed. A multi-layer insulation has the arrangement of conductors and insulators as shown in the Fig. 1. For the purpose of stable operation as the multi-layer DC break, we checked the radiation of the insulator depending on materials and high voltage test of a fabricated multi-layer insulation. In this report, the details of performance test of the multi-layer DC break will be presented

Structure reconstruction of TiO2-based multi-wall nanotubes: first-principles calculations.

Science.gov (United States)

Bandura, A V; Evarestov, R A; Lukyanov, S I

2014-07-28

A new method of theoretical modelling of polyhedral single-walled nanotubes based on the consolidation of walls in the rolled-up multi-walled nanotubes is proposed. Molecular mechanics and ab initio quantum mechanics methods are applied to investigate the merging of walls in nanotubes constructed from the different phases of titania. The combination of two methods allows us to simulate the structures which are difficult to find only by ab initio calculations. For nanotube folding we have used (1) the 3-plane fluorite TiO2 layer; (2) the anatase (101) 6-plane layer; (3) the rutile (110) 6-plane layer; and (4) the 6-plane layer with lepidocrocite morphology. The symmetry of the resulting single-walled nanotubes is significantly lower than the symmetry of initial coaxial cylindrical double- or triple-walled nanotubes. These merged nanotubes acquire higher stability in comparison with the initial multi-walled nanotubes. The wall thickness of the merged nanotubes exceeds 1 nm and approaches the corresponding parameter of the experimental patterns. The present investigation demonstrates that the merged nanotubes can integrate the two different crystalline phases in one and the same wall structure.

Design, simulation and testing of a novel radial multi-pole multi-layer magnetorheological brake

Science.gov (United States)

Wu, Jie; Li, Hua; Jiang, Xuezheng; Yao, Jin

2018-02-01

This paper deals with design, simulation and experimental testing of a novel radial multi-pole multi-layer magnetorheological (MR) brake. This MR brake has an innovative structural design with superposition principle of two magnetic fields generated by the inner coils and the outer coils. The MR brake has several media layers of magnetorheological (MR) fluid located between the inner coils and the outer coils, and it can provide higher torque and higher torque density than conventional single-disk or multi-disk or multi-pole single-layer MR brakes can. In this paper, a brief introduction to the structure of the proposed MR brake was given first. Then, theoretical analysis of the magnetic circuit and the braking torque was conducted. In addition, a 3D electromagnetic model of the MR brake was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. A prototype of the brake was fabricated and several tests were carried out to validate its torque capacity. The results show that the proposed MR brake can produce a maximum braking torque of 133 N m and achieve a high torque density of 25.0 kN m-2, a high torque range of 42 and a high torque-to-power ratio of 0.95 N m W-1.

Heat conduction analysis of multi-layered FGMs considering the finite heat wave speed

International Nuclear Information System (INIS)

Rahideh, H.; Malekzadeh, P.; Golbahar Haghighi, M.R.

2012-01-01

Highlights: ► Using a layerwise-incremental differential quadrature for heat transfer of FGMs. ► Superior accuracy with fewer degrees of freedom of the method with respect to FEM. ► Considering multi-layered functionally graded materials. ► Hyperbolic heat transfer analysis of thermal system with heat generation. ► Showing the effect of heat wave speed on thermal characteristic of the system. - Abstract: In this work, the heat conduction with finite wave heat speed of multi-layered domain made of functionally graded materials (FGMs) subjected to heat generation is simulated. For this purpose, the domain is divided into a set of mathematical layers, the number of which can be equal or greater than those of the physical layers. Then, in each mathematical layer, the non-Fourier heat transfer equations are employed. Since, the governing equations have variable coefficients due to FGM properties, as an efficient and accurate method the differential quadrature method (DQM) is adopted to discretize both spatial and temporal domains in each layer. This results in superior accuracy with fewer degrees of freedom than conventional finite element method (FEM). To verify this advantages through some comparison studies, a finite element solution are also obtained. After demonstrating the convergence and accuracy of the method, the effects of heat wave speed for two different set of boundary conditions on the temperature distribution and heat flux of the domain are studied.

Elasticity Theory Solution of the Problem on Plane Bending of a Narrow Layered Cantilever Beam by Loads at Its Free End

Science.gov (United States)

Goryk, A. V.; Koval'chuk, S. B.

2018-05-01

An exact elasticity theory solution for the problem on plane bending of a narrow layered composite cantilever beam by tangential and normal loads distributed on its free end is presented. Components of the stress-strain state are found for the whole layers package by directly integrating differential equations of the plane elasticity theory problem by using an analytic representation of piecewise constant functions of the mechanical characteristics of layer materials. The continuous solution obtained is realized for a four-layer beam with account of kinematic boundary conditions simulating the rigid fixation of its one end. The solution obtained allows one to predict the strength and stiffness of composite cantilever beams and to construct applied analytical solutions for various problems on the elastic bending of layered beams.

Quantum-Well Infrared Photodetector (QWIP) Focal Plane Assembly

Science.gov (United States)

Jhabvala, Murzy; Jhabvala, Christine A.; Ewin, Audrey J.; Hess, Larry A.; Hartmann, Thomas M.; La, Anh T.

2012-01-01

A paper describes the Thermal Infrared Sensor (TIRS), a QWIP-based instrument intended to supplement the Operational Land Imager (OLI) for the Landsat Data Continuity Mission (LDCM). The TIRS instrument is a far-infrared imager operating in the pushbroom mode with two IR channels: 10.8 and 12 microns. The focal plane will contain three 640x512 QWIP arrays mounted on a silicon substrate. The silicon substrate is a custom-fabricated carrier board with a single layer of aluminum interconnects. The general fabrication process starts with a 4-in. (approx.10-cm) diameter silicon wafer. The wafer is oxidized, a single substrate contact is etched, and aluminum is deposited, patterned, and alloyed. This technology development is aimed at incorporating three large-format infrared detecting arrays based on GaAs QWIP technology onto a common focal plane with precision alignment of all three arrays. This focal plane must survive the rigors of flight qualification and operate at a temperature of 43 K (-230 C) for five years while orbiting the Earth. The challenges presented include ensuring thermal compatibility among all the components, designing and building a compact, somewhat modular system and ensuring alignment to very tight levels. The multi-array focal plane integrated onto a single silicon substrate is a new application of both QWIP array development and silicon wafer scale integration. The Invar-based assembly has been tested to ensure thermal reliability.

Five-dimensional Lattice Gauge Theory as Multi-Layer World

OpenAIRE

Murata, Michika; So, Hiroto

2003-01-01

A five-dimensional lattice space can be decomposed into a number of four-dimens ional lattices called as layers. The five-dimensional gauge theory on the lattice can be interpreted as four-dimensional gauge theories on the multi-layer with interactions between neighboring layers. In the theory, there exist two independent coupling constants; $\\beta_4$ controls the dynamics inside a layer and $\\beta_5$ does the strength of the inter-layer interaction.We propose the new possibility to realize t...

Memory characteristics of hysteresis and creep in multi-layer piezoelectric actuators: An experimental analysis

Energy Technology Data Exchange (ETDEWEB)

Biggio, Matteo [Department of Electrical, Electronic, Telecommunications Engineering and Naval Architecture, University of Genoa, Via Opera Pia 11a, Genova (Italy); Butcher, Mark [Engineering Department, CERN (Switzerland); Giustiniani, Alessandro; Masi, Alessandro [Engineering Department, CERN (Switzerland); Department of Engineering, University of Sannio, Piazza Roma, 21, I-82100 Benevento (Italy); Storace, Marco, E-mail: marco.storace@unige.it [Department of Electrical, Electronic, Telecommunications Engineering and Naval Architecture, University of Genoa, Via Opera Pia 11a, Genova (Italy)

2014-02-15

In this paper we provide an experimental characterization of creep and hysteresis in a multi-layer piezoelectric actuator (PEA), taking into account their relationships in terms of memory structure. We fit the well-known log-t model to the response of the PEA when driven by piecewise-constant signals, and find that both the instantaneous and the delayed response of the PEA display hysteretic dependence on the voltage level. We investigate experimentally the dependence of the creep coefficient on the input history, by driving the PEA along first-order reversal curves and congruent minor loops, and find that it displays peculiar features like strict congruence of the minor loops and discontinuities. We finally explain the observed experimental behaviors in terms of a slow relaxation of the staircase interface line in the Preisach plane.

Memory characteristics of hysteresis and creep in multi-layer piezoelectric actuators: An experimental analysis

CERN Document Server

Biggio, Matteo; Giustiniani, Alessandro; Masi, Alessandro; Storace, Marco

2014-01-01

In this paper we provide an experimental characterization of creep and hysteresis in a multi layer piezoelectric actuator (PEA), taking into account their relationships in terms of memory structure. We fit the well-known log-t model to the response of the PEA when driven by piecewise-constant signals, and find that both the instantaneous and the delayed response of the PEA display hysteretic dependence on the voltage level. We investigate experimentally the dependence of the creep coefficient on the input history, by driving the PEA along first order reversal curves and congruent minor loops, and find that it displays peculiar features like strict congruence of the minor loops and discontinuities. We finally explain the observed experimental behaviors in terms of a slow relaxation of the staircase interface line in the Preisach plane.

Measurement Verification of Plane Wave Synthesis Technique Based on Multi-probe MIMO-OTA Setup

DEFF Research Database (Denmark)

Fan, Wei; Carreño, Xavier; Nielsen, Jesper Ødum

2012-01-01

Standardization work for MIMO OTA testing methods is currently ongoing, where a multi-probe anechoic chamber based solution is an important candidate. In this paper, the probes located on an OTA ring are used to synthesize a plane wave field in the center of the OTA ring. This paper investigates...

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 115; Issue 6 ... Is the outcrop topology of dolerite dikes of the Precambrian Singhbhum Craton fractal? ... Plane strain deformation of a multi-layered poroelastic half-space by surface ...

The plane mixing layer between parallel streams of different velocities and different densities

International Nuclear Information System (INIS)

Fiedler, H.E.; Lummer, M.; Nottmeyer, K.

1990-01-01

The problem investigated is often encountered in technical applications. For its most basic configuration, the plane turbulent mixing layer, we use the notation as sketched in fig. 1. The influence of density inhomogeneities is twofold: (a) via buoyancy effects and (b) via inertia effects. The investigation described were aimed at studying the latter, while the former -- by appropriate choice of parameters - was essentially suppressed. (authors)

Treatment of turtle aquaculture effluent by an improved multi-soil-layer system.

Science.gov (United States)

Song, Ying; Huang, Yu-ting; Ji, Hong-fang; Nie, Xin-jun; Zhang, Zhi-yuan; Ge, Chuan; Luo, An-cheng; Chen, Xin

2015-02-01

Concentrated turtle aquaculture effluent poses an environmental threat to water bodies, and therefore needs to be treated prior to disposal. This study was conducted to assess the effect of multi-soil-layer (MSL) systems treating turtle aquaculture effluent with adding different amounts of sludge. Four MSL systems were constructed with dry weight ratios of sludge with 0%, 5%, 10%, and 20% (MSL 1, MSL 2, MSL 3, and MSL 4, respectively). The turtle aquaculture effluent had an average chemical oxygen demand (COD), ammonia nitrogen (NH4(+)-N) and total nitrogen (TN) concentration of 288.4, 213.4, and 252.0 mg/L, respectively. The COD/TN (C/N) ratio was 1.2. The results showed that the four MSL systems could effectively treat the COD, NH4(+)-N, and TN, and MSL 4 showed significantly improved NH4(+)-N removal efficiency, suggesting the potential of sludge addition to improve the turtle aquaculture effluent treatment. The average COD, TN, and NH4(+)-N removal efficiencies of MSL 4 were 70.3%, 66.5%, and 72.7%, respectively. To further interpret the contribution of microorganisms to the removal, the microbial community compositions and diversities of the four MSL systems were measured. Comparisons of the denaturing gradient gel electrophoresis (DGGE) profiles revealed that the amount of nitrifying bacteria and diversity in MSL 4 were higher than those in the other three systems. We concluded that adding 20% of sludge improved the NH4(+)-N removal and stability of the system for nitrification, due to the enrichment of the nitrifying bacteria in MSL 4.

SU-F-J-41: Experimental Validation of a Cascaded Linear System Model for MVCBCT with a Multi-Layer EPID

Energy Technology Data Exchange (ETDEWEB)

Hu, Y; Rottmann, J; Myronakis, M; Berbeco, R [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana Farber Cancer Institute and Harvard Medical School, Boston, MA. (United States); Fueglistaller, R; Morf, D [Varian Medical Systems, Dattwil, Aargau (Switzerland); Wang, A; Shedlock, D; Star-Lack, J [Varian Medical Systems, Palo Alto, CA (United States)

2016-06-15

Purpose: The purpose of this study was to validate the use of a cascaded linear system model for MV cone-beam CT (CBCT) using a multi-layer (MLI) electronic portal imaging device (EPID) and provide experimental insight into image formation. A validated 3D model provides insight into salient factors affecting reconstructed image quality, allowing potential for optimizing detector design for CBCT applications. Methods: A cascaded linear system model was developed to investigate the potential improvement in reconstructed image quality for MV CBCT using an MLI EPID. Inputs to the three-dimensional (3D) model include projection space MTF and NPS. Experimental validation was performed on a prototype MLI detector installed on the portal imaging arm of a Varian TrueBeam radiotherapy system. CBCT scans of up to 898 projections over 360 degrees were acquired at exposures of 16 and 64 MU. Image volumes were reconstructed using a Feldkamp-type (FDK) filtered backprojection (FBP) algorithm. Flat field images and scans of a Catphan model 604 phantom were acquired. The effect of 2×2 and 4×4 detector binning was also examined. Results: Using projection flat fields as an input, examination of the modeled and measured NPS in the axial plane exhibits good agreement. Binning projection images was shown to improve axial slice SDNR by a factor of approximately 1.4. This improvement is largely driven by a decrease in image noise of roughly 20%. However, this effect is accompanied by a subsequent loss in image resolution. Conclusion: The measured axial NPS shows good agreement with the theoretical calculation using a linear system model. Binning of projection images improves SNR of large objects on the Catphan phantom by decreasing noise. Specific imaging tasks will dictate the implementation image binning to two-dimensional projection images. The project was partially supported by a grant from Varian Medical Systems, Inc. and grant No. R01CA188446-01 from the National Cancer Institute.

An MILP-Based Cross-Layer Optimization for a Multi-Reader Arbitration in the UHF RFID System

Science.gov (United States)

Choi, Jinchul; Lee, Chaewoo

2011-01-01

In RFID systems, the performance of each reader such as interrogation range and tag recognition rate may suffer from interferences from other readers. Since the reader interference can be mitigated by output signal power control, spectral and/or temporal separation among readers, the system performance depends on how to adapt the various reader arbitration metrics such as time, frequency, and output power to the system environment. However, complexity and difficulty of the optimization problem increase with respect to the variety of the arbitration metrics. Thus, most proposals in previous study have been suggested to primarily prevent the reader collision with consideration of one or two arbitration metrics. In this paper, we propose a novel cross-layer optimization design based on the concept of combining time division, frequency division, and power control not only to solve the reader interference problem, but also to achieve the multiple objectives such as minimum interrogation delay, maximum reader utilization, and energy efficiency. Based on the priority of the multiple objectives, our cross-layer design optimizes the system sequentially by means of the mixed-integer linear programming. In spite of the multi-stage optimization, the optimization design is formulated as a concise single mathematical form by properly assigning a weight to each objective. Numerical results demonstrate the effectiveness of the proposed optimization design. PMID:22163743

An MILP-Based Cross-Layer Optimization for a Multi-Reader Arbitration in the UHF RFID System

Directory of Open Access Journals (Sweden)

Chaewoo Lee

2011-02-01

Full Text Available In RFID systems, the performance of each reader such as interrogation range and tag recognition rate may suffer from interferences from other readers. Since the reader interference can be mitigated by output signal power control, spectral and/or temporal separation among readers, the system performance depends on how to adapt the various reader arbitration metrics such as time, frequency, and output power to the system environment. However, complexity and difficulty of the optimization problem increase with respect to the variety of the arbitration metrics. Thus, most proposals in previous study have been suggested to primarily prevent the reader collision with consideration of one or two arbitration metrics. In this paper, we propose a novel cross-layer optimization design based on the concept of combining time division, frequency division, and power control not only to solve the reader interference problem, but also to achieve the multiple objectives such as minimum interrogation delay, maximum reader utilization, and energy efficiency. Based on the priority of the multiple objectives, our cross-layer design optimizes the system sequentially by means of the mixed-integer linear programming. In spite of the multi-stage optimization, the optimization design is formulated as a concise single mathematical form by properly assigning a weight to each objective. Numerical results demonstrate the effectiveness of the proposed optimization design.

Development of a low activation concrete shielding wall by multi-layered structure for a fusion reactor

International Nuclear Information System (INIS)

Sato, Satoshi; Maegawa, Toshio; Yoshimatsu, Kenji; Sato, Koichi; Nonaka, Akira; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara

2011-01-01

A multi-layered concrete structure has been developed to reduce induced activity in the shielding for neutron generating facilities such as a fusion reactor. The multi-layered concrete structure is composed of: (1) an inner low activation concrete, (2) a boron-doped low activation concrete as the second layer, and (3) ordinary concrete as the outer layer of the neutron shield. With the multi-layered concrete structure the volume of boron is drastically decreased compared to a monolithic boron-doped concrete. A 14 MeV neutron shielding experiment with multi-layered concrete structure mockups was performed at FNS and several reaction rates and induced activity in the mockups were measured. This demonstrated that the multi-layered concrete effectively reduced low energy neutrons and induced activity.

Evaluation of polyethylenimine/carrageenan multi-layer for antibacterial activity of pathogenic bacteria

International Nuclear Information System (INIS)

Briones, Annabelle V.; Bigol, Urcila G.; Sato, Toshinori

2012-01-01

The purpose of this study is to investigate the antibacterial activity of multi-layer of polyethylenimine (PEI) and carrageenan (κ,ι, λ) for potential use as coating on biomaterial surface. The multi-layer of PEI/carrageenan was formed using the layer-by-layer assembly absorption technique and was monitored by atomic force microscopy (AFM) and bio molecular interaction analysis. All samples were prepared in phosphate buffer solution and applied to mica disk alternately. The micrographs showed the formation of bi-layer of polyethylenimine and carrageenan (κ, ι, λ) as observed in the change of height of the layer and surface morphology. The bimolecular binding of carrageenan with polyethylenimine was also investigated using a biosensor. The sensorgram showed that PEI interacted molecularly with carrageenan. Results were: 1,916.08 pg/nm 2 for kappa type; 1,844.1 pg/nm 2 for iota type and 6,074.24 pg/nm 2 for lambda type. The multi-layer showed antibacterial activity against Enterobacter cloaceae, Staphylococcus aureus and Enterococcal strains (Enterococcus faecalis (EF) 29212 and 29505). (author)

Flexible Multi-Numerology Systems for 5G New Radio

OpenAIRE

Yazar, Ahmet; Peköz, Berker; Arslan, Hüseyin

2018-01-01

The physical layer of 5G cellular communications systems is designed to achieve better flexibility in an effort to support diverse services and user requirements. OFDM waveform parameters are enriched with flexible multi-numerology structures. This paper describes the differences between Long Term Evolution (LTE) systems and new radio (NR) from the flexibility perspective. Research opportunities for multi-numerology systems are presented in a structured manner. Finally, inter-numerology inter...

Onboard autonomous mission re-planning for multi-satellite system

Science.gov (United States)

Zheng, Zixuan; Guo, Jian; Gill, Eberhard

2018-04-01

This paper presents an onboard autonomous mission re-planning system for Multi-Satellites System (MSS) to perform onboard re-planing in disruptive situations. The proposed re-planning system can deal with different potential emergency situations. This paper uses Multi-Objective Hybrid Dynamic Mutation Genetic Algorithm (MO-HDM GA) combined with re-planning techniques as the core algorithm. The Cyclically Re-planning Method (CRM) and the Near Real-time Re-planning Method (NRRM) are developed to meet different mission requirements. Simulations results show that both methods can provide feasible re-planning sequences under unforeseen situations. The comparisons illustrate that using the CRM is average 20% faster than the NRRM on computation time. However, by using the NRRM more raw data can be observed and transmitted than using the CRM within the same period. The usability of this onboard re-planning system is not limited to multi-satellite system. Other mission planning and re-planning problems related to autonomous multiple vehicles with similar demands are also applicable.

Few-layered MnO2/SWCNT hybrid in-plane supercapacitor with high energy density

Science.gov (United States)

Dutta, Shibsankar; Pal, Shreyasi; De, Sukanta

2018-05-01

In this present work we have synthesized few layered MnO2 nanosheets by mixed solvent exfoliation process for the application as electrode material of in-plane supercapacitor. The Structure and surface morphology of the as prepared samples are characterized by Raman, Transmission electron microscopy and Scanning electron microscopy. The patterns of the hybrids were directly fabricated by (50: 50 wt %) mixture of MnO2 and SWCNT dispersions with the help of a customized mask, and directly transferred onto a flexible PET substrate. Remarkably, the prepared in-plane supercapacitors deliver high energy density of 2.62mWh/cm2. Furthermore, our supercapacitors shows exceptional flexibility and stable performance under bending conditions

Nonlinear digital out-of-plane waveguide coupler based on nonlinear scattering of a single graphene layer

Science.gov (United States)

Asadi, Reza; Ouyang, Zhengbiao

2018-03-01

A new mechanism for out-of-plane coupling into a waveguide is presented and numerically studied based on nonlinear scattering of a single nano-scale Graphene layer inside the waveguide. In this mechanism, the refractive index nonlinearity of Graphene and nonhomogeneous light intensity distribution occurred due to the interference between the out-of-plane incident pump light and the waveguide mode provide a virtual grating inside the waveguide, coupling the out-of-plane pump light into the waveguide. It has been shown that the coupling efficiency has two distinct values with high contrast around a threshold pump intensity, providing suitable condition for digital optical applications. The structure operates at a resonance mode due to band edge effect, which enhances the nonlinearity and decreases the required threshold intensity.

Fermi system with planes and charge reservoir: Anisotropic in-plane resistivity

International Nuclear Information System (INIS)

Levin, G.A.; Quader, K.F.

1992-01-01

The authors explore the normal state in-plane resistivity of a model Fermi system with two planes and a charge reservoir. When the Fermi energy lies near the top of one of the resulting sub-bands, the system can be described by two types of quasiparticle excitations with different energy spectra and relaxation times. They show that for certain stoichiometry, ρ ab is linear in temperature with positive or negative intercepts. A relation between the slopes and intercepts of resistivities in the a and b directions in untwinned crystals is derived. The results are in good agreement with experimental data on YBCO. 7 refs., 1 tab

Multi-filamentary REBCO tapes fabricated by scratching a buffer layer along the tape longitudinal direction

Energy Technology Data Exchange (ETDEWEB)

Kurihara, Chihaya, E-mail: chihaya.kurihara@jp.fujikura.com [Fujikura Ltd., 1440, Mutsuzaki, Sakura, Chiba 285-8550 (Japan); Fujita, Shinji; Nakamura, Naonori; Igarashi, Mitsunori; Iijima, Yasuhiro [Fujikura Ltd., 1440, Mutsuzaki, Sakura, Chiba 285-8550 (Japan); Higashikawa, Kohei; Uetsuhara, Dai; Kiss, Takanobu; Iwakuma, Masataka [Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka 819-0395 (Japan)

2016-11-15

Highlights: • We developed new method of slitting tape between buffer layer processes for multi-filamentary tape. • By scratching buffer layer along the tape longitudinal direction, we find that REBCO layer is divided easily without damaging it. • We have developed 100 m class multi-filamentary REBCO tapes which are suitable for superconducting coils. - Abstract: A method for making multi-filamentary REBCO tapes by only scratching buffer layer was developed for coil application which requires accurate magnetic fields. By continuous I{sub c} measurement, we found that our new multi-filamentary tape could provide almost equal I{sub c} compared to conventional tapes. Then, using EBSD and RTR-SHPM methods, a divided structure of REBCO layer was surely confirmed. AC loss was also decreased. Furthermore, the result of delamination test of our new multi-filamentary tape showed enough mechanical property. As a result, we have succeeded in developing 100 m class multi-filamentary tape for superconducting coil.

Multi-filamentary REBCO tapes fabricated by scratching a buffer layer along the tape longitudinal direction

International Nuclear Information System (INIS)

Kurihara, Chihaya; Fujita, Shinji; Nakamura, Naonori; Igarashi, Mitsunori; Iijima, Yasuhiro; Higashikawa, Kohei; Uetsuhara, Dai; Kiss, Takanobu; Iwakuma, Masataka

2016-01-01

Highlights: • We developed new method of slitting tape between buffer layer processes for multi-filamentary tape. • By scratching buffer layer along the tape longitudinal direction, we find that REBCO layer is divided easily without damaging it. • We have developed 100 m class multi-filamentary REBCO tapes which are suitable for superconducting coils. - Abstract: A method for making multi-filamentary REBCO tapes by only scratching buffer layer was developed for coil application which requires accurate magnetic fields. By continuous I_c measurement, we found that our new multi-filamentary tape could provide almost equal I_c compared to conventional tapes. Then, using EBSD and RTR-SHPM methods, a divided structure of REBCO layer was surely confirmed. AC loss was also decreased. Furthermore, the result of delamination test of our new multi-filamentary tape showed enough mechanical property. As a result, we have succeeded in developing 100 m class multi-filamentary tape for superconducting coil.

Injection of multi-azimuth permeable planes in weakly cemented formations for enhanced heavy-oil recovery

Energy Technology Data Exchange (ETDEWEB)

Hocking, G. [Society of Petroleum Engineers, Richardson, TX (United States)]|[GeoSierra LLC, Norcross, GA (United States); Cavender, T.; Schultz, R.L. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Halliburton Energy Services, Calgary, AB (Canada)

2008-10-15

Weakly cemented formations have minimal strength without fracture toughness. As such, the well stimulation process must be different from the fracturing process that occurs in hard rocks. This paper presented field injection experiments of multi-azimuth, injected, vertical planar geometries in several weakly cemented formations. The application of the method to shallow petroleum soft rock reservoirs was described, with particular reference to the thermal and solvent recovery of heavy oil. This study showed that in weakly cemented formations, a well-initiation device can control the azimuth of injected vertical planes, thereby controlling the rate of injection and the viscosity of the injected fluid. The concept of using the multi-azimuth, vertical permeable planes has strong potential in soft-rock formations for enhanced production in both shallow gas and shallow heavy-oil reservoirs. The method can be applied in a single well injector-producer for the continuous injection of steam and the continuous extraction of oil, similar to steam assisted gravity drainage (SAGD) and may be more efficient than a confined horizontal well pair typically used in SAGD. However, the authors noted that the effectiveness of the multi-azimuth process has yet to be proven for oil sand formations. 13 refs., 1 tab., 13 figs.

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...

Design of a Multi-layer Lane-Level Map for Vehicle Route Planning

Directory of Open Access Journals (Sweden)

Liu Chaoran

2017-01-01

Full Text Available With the development of intelligent transportation system, there occurs further demand for high precision localization and route planning, and simultaneously the traditional road-level map fails to meet with this requirement, by which this paper is motivated. In this paper, t he three-layer lane-level map architecture for vehicle path guidance is established, and the mathematical models of road-level layer, intermediate layer and lane-level layer are designed considering efficiency and precision. The geometric model of the lane-level layer of the map is characterized by Cubic Hermite Spline for continuity. A method of generating the lane geometry with fixed and variable control points is proposed, which can effectively ensure the accuracy with limited num ber of control points. In experimental part, a multi-layer map of an intersection is built to validate the map model, and an example of a local map was generated with the lane-level geometry.

The transmission of finite amplitude sound beam in multi-layered biological media

Science.gov (United States)

Liu, Xiaozhou; Li, Junlun; Yin, Chang; Gong, Xiufen; Zhang, Dong; Xue, Honghui

2007-02-01

Based on the Khokhlov Zabolotskaya Kuznetsov (KZK) equation, a model in the frequency domain is given to describe the transmission of finite amplitude sound beam in multi-layered biological media. Favorable agreement between the theoretical analyses and the measured results shows this approach could effectively describe the transmission of finite amplitude sound wave in multi-layered biological media.

The transmission of finite amplitude sound beam in multi-layered biological media

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaozhou [Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093 (China)]. E-mail: xzliu@nju.edu.cn; Li, Junlun [Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093 (China); Yin, Chang [Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093 (China); Gong, Xiufen [Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093 (China); Zhang, Dong [Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093 (China); Xue, Honghui [Key Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093 (China)

2007-02-19

Based on the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, a model in the frequency domain is given to describe the transmission of finite amplitude sound beam in multi-layered biological media. Favorable agreement between the theoretical analyses and the measured results shows this approach could effectively describe the transmission of finite amplitude sound wave in multi-layered biological media.

The transmission of finite amplitude sound beam in multi-layered biological media

International Nuclear Information System (INIS)

Liu, Xiaozhou; Li, Junlun; Yin, Chang; Gong, Xiufen; Zhang, Dong; Xue, Honghui

2007-01-01

Based on the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, a model in the frequency domain is given to describe the transmission of finite amplitude sound beam in multi-layered biological media. Favorable agreement between the theoretical analyses and the measured results shows this approach could effectively describe the transmission of finite amplitude sound wave in multi-layered biological media

Optical Properties of Plasmon Resonances with Ag/SiO2/Ag Multi-Layer Composite Nanoparticles

International Nuclear Information System (INIS)

Ye-Wan, Ma; Li-Hua, Zhang; Zhao-Wang, Wu; Jie, Zhang

2010-01-01

Optical properties of plasmon resonance with Ag/SiO 2 /Ag multi-layer nanoparticles are studied by numerical simulation based on Green's function theory. The results show that compared with single-layer Ag nanoparticles, the multi-layer nanoparticles exhibit several distinctive optical properties, e.g. with increasing the numbers of the multi-layer nanoparticles, the scattering efficiency red shifts, and the intensity of scattering enhances accordingly. It is interesting to find out that slicing an Ag-layer into multi-layers leads to stronger scattering intensity and more 'hot spots' or regions of stronger field enhancement. This property of plasmon resonance of surface Raman scattering has greatly broadened the application scope of Raman spectroscopy. The study of metal surface plasmon resonance characteristics is critical to the further understanding of surface enhanced Raman scattering as well as its applications. (fundamental areas of phenomenology (including applications))

Steady flow in a porous layer subjected to a stream uniformly injecting from a plane; Ichiyo ni men kara fukidasu nagare ni sarasareta takoshitsu sonai no teijo nagare

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, E; Horiguchi, Y; Kitazawa, K [Keio University, Tokyo (Japan). Faculty of Science and Technology

1997-08-25

A steady flow in an non-deformable porous layer subjected to a fluid stream is studied analytically and numerically. One side of the layer of sponge is bounded by a solid wall and the other by a layer of fluid. The fluid is injected uniformly from a plane, through which the fluid can pass, set up parallel to the sponge layer. The flow in the sponge layer is assumed to be governed by Darcy`s law. The problem considered is solved in terms of a similarity solution. The equations governing the fluid flows in both the porous layer and the fluid layer are reduced to a system of the ordinary differential equations. These equations are solved analytically for three cases ideal fluid flow, low Reynolds number flow and high Reynolds number flow. On the other hand, these equations are solved numerically for the general case by using the finite difference method. The distributions of the velocity and the pressure in both layers are found for various parameters. In particular, the speed which the fluid intrudes into the sponge layer due to the injection of the stream from the plane is found to be a function of dimensionless parameters. To find this speed is essential to the understanding of porous material. 15 refs., 9 figs.

Nonpolar a-plane GaN grown on r-plane sapphire using multilayer AlN buffer by metalorganic chemical vapor deposition

International Nuclear Information System (INIS)

Chiang, C.H.; Chen, K.M.; Wu, Y.H.; Yeh, Y.S.; Lee, W.I.; Chen, J.F.; Lin, K.L.; Hsiao, Y.L.; Huang, W.C.; Chang, E.Y.

2011-01-01

Mirror-like and pit-free non-polar a-plane (1 1 -2 0) GaN films are grown on r-plane (1 -1 0 2) sapphire substrates using metalorganic chemical vapor deposition (MOCVD) with multilayer high-low-high temperature AlN buffer layers. The buffer layer structure and film quality are essential to the growth of a flat, crack-free and pit-free a-plane GaN film. The multilayer AlN buffer structure includes a thin low-temperature-deposited AlN (LT-AlN) layer inserted into the high-temperature-deposited AlN (HT-AlN) layer. The results demonstrate that the multilayer AlN buffer structure can improve the surface morphology of the upper a-plane GaN film. The grown multilayer AlN buffer structure reduced the tensile stress on the AlN buffer layers and increased the compressive stress on the a-plane GaN film. The multilayer AlN buffer structure markedly improves the surface morphology of the a-plane GaN film, as revealed by scanning electron microscopy. The effects of various growth V/III ratios was investigated to obtain a-plane GaN films with better surface morphology. The mean roughness of the surface was 1.02 nm, as revealed by atomic force microscopy. Accordingly, the multilayer AlN buffer structure improves the surface morphology and facilitates the complete coalescence of the a-plane GaN layer.

Characterization of a compliant multi-layer system for tactile sensing with enhanced sensitivity and range

Science.gov (United States)

Chen, Ying; Yu, Miao; Bruck, Hugh A.; Smela, Elisabeth

2018-06-01

To allow robots to interact with humans via touch, new sensing concepts are needed that can detect a wide range of potential interactions and cover the body of a robot. In this paper, a skin-inspired multi-layer tactile sensing architecture is presented and characterized. The structure consists of stretchable piezoresistive strain-sensing layers over foam layers of different stiffness, allowing for both sufficient sensitivity and pressure range for human contacts. Strip-shaped sensors were used in this architecture to produce a deformation response proportional to pressure. The roles of the foam layers were elucidated by changing their stiffness and thickness, allowing the development of a geometric model to account for indenter interactions with the structure. The advantage of this architecture over other approaches is the ability to easily tune performance by adjusting the stiffness or thickness of the foams to tailor the response for different applications. Since viscoelastic materials were used, the temporal effects were also investigated.

Physical Layer Multi-Core Prototyping A Dataflow-Based Approach for LTE eNodeB

CERN Document Server

Pelcat, Maxime; Piat, Jonathan; Nezan, Jean-François

2013-01-01

Base stations developed according to the 3GPP Long Term Evolution (LTE) standard require unprecedented processing power. 3GPP LTE enables data rates beyond hundreds of Mbits/s by using advanced technologies, necessitating a highly complex LTE physical layer. The operating power of base stations is a significant cost for operators, and is currently optimized using state-of-the-art hardware solutions, such as heterogeneous distributed systems. The traditional system design method of porting algorithms to heterogeneous distributed systems based on test-and-refine methods is a manual, thus time-expensive, task.   Physical Layer Multi-Core Prototyping: A Dataflow-Based Approach for LTE eNodeB provides a clear introduction to the 3GPP LTE physical layer and to dataflow-based prototyping and programming. The difficulties in the process of 3GPP LTE physical layer porting are outlined, with particular focus on automatic partitioning and scheduling, load balancing and computation latency reduction, specifically in sys...

Fatigue crack growth monitoring in multi-layered structures using guided ultrasonic waves

International Nuclear Information System (INIS)

Kostson, E; Fromme, P

2009-01-01

This contribution investigates the application of low frequency guided ultrasonic waves for monitoring fatigue crack growth at fastener holes in the 2nd layer of multi-layered plate structures, a common problem in aerospace industry. The model multi-layered structure investigated consists of two aluminum plate-strips adhesively bonded using a structural paste adhesive. Guided ultrasonic waves were excited using multiple piezoelectric discs bonded to the surface of the multi-layered structure. The wave propagation in the tensile specimen was measured using a laser interferometer and compared to numerical simulations. Thickness and width mode shapes of the excited flexural waves were identified from Semi-Analytical Finite Element (SAFE) calculations. Experiments and 3D Finite Element (FE) simulations show a change in the scattered field around fastener holes caused by a defect in the 2nd layer. The amplitude of the guided ultrasonic wave was monitored during fatigue experiments at a single point. The measured changes in the amplitude of the ultrasonic signal due to fatigue crack growth agree well with FE simulations.

On efficiently computing multigroup multi-layer neutron reflection and transmission conditions

International Nuclear Information System (INIS)

Abreu, Marcos P. de

2007-01-01

In this article, we present an algorithm for efficient computation of multigroup discrete ordinates neutron reflection and transmission conditions, which replace a multi-layered boundary region in neutron multiplication eigenvalue computations with no spatial truncation error. In contrast to the independent layer-by-layer algorithm considered thus far in our computations, the algorithm here is based on an inductive approach developed by the present author for deriving neutron reflection and transmission conditions for a nonactive boundary region with an arbitrary number of arbitrarily thick layers. With this new algorithm, we were able to increase significantly the computational efficiency of our spectral diamond-spectral Green's function method for solving multigroup neutron multiplication eigenvalue problems with multi-layered boundary regions. We provide comparative results for a two-group reactor core model to illustrate the increased efficiency of our spectral method, and we conclude this article with a number of general remarks. (author)

Bloch Surface Waves Using Graphene Layers: An Approach toward In-Plane Photodetectors

Directory of Open Access Journals (Sweden)

Richa Dubey

2018-03-01

Full Text Available A dielectric multilayer platform was investigated as a foundation for two-dimensional optics. In this paper, we present, to the best of our knowledge, the first experimental demonstration of absorption of Bloch surface waves in the presence of graphene layers. Graphene is initially grown on a Cu foil via Chemical Vapor Deposition and transferred layer by layer by a wet-transfer method using poly(methyl methacrylate, (PMMA. We exploit total internal reflection configuration and multi-heterodyne scanning near-field optical microscopy as a far-field coupling method and near-field characterization tool, respectively. The absorption is quantified in terms of propagation lengths of Bloch surface waves. A significant drop in the propagation length of the BSWs is observed in the presence of graphene layers. The propagation length of BSWs in bare multilayer is reduced to 17 times shorter in presence of graphene monolayer, and 23 times shorter for graphene bilayer.

A Unified NET-MAC-PHY Cross-layer Framework for Performance Evaluation of Multi-hop Ad hoc WLANs

Directory of Open Access Journals (Sweden)

Rachid El-Azouzi

2014-09-01

Full Text Available Most of the existing works have been evaluated the performance of 802.11 multihop networks by considering the MAC layer or network layer separately. Knowing the nature of the multi-hop ad hoc networks, many factors in different layers are crucial for study the performance of MANET. In this paper we present a new analytic model for evaluating average end-to-end throughput in IEEE 802.11e multihop wireless networks. In particular, we investigate an intricate interaction among PHY, MAC and Network layers. For instance, we incorporate carrier sense threshold, transmission power, contention window size, retransmissions retry limit, multi rates, routing protocols and network topology together. We build a general cross-layered framework to represent multi-hop ad hoc networks with asymmetric topology and asymmetric traffic. We develop an analytical model to predict throughput of each connection as well as stability of forwarding queues at intermediate nodes in saturated networks. To the best of our knowledge, it seems that our work is the first wherein general topology and asymmetric parameters setup are considered in PHY/MAC/Network layers. Performance of such a system is also evaluated through simulation. We show that performance measures of the MAC layer are affected by the traffic intensity of flows to be forwarded. More precisely, attempt rate and collision probability are dependent on traffic flows, topology and routing.

Preparation of multi-layer film consisting of hydrogen-free DLC and nitrogen-containing DLC for conductive hard coating

Science.gov (United States)

Iijima, Yushi; Harigai, Toru; Isono, Ryo; Degai, Satoshi; Tanimoto, Tsuyoshi; Suda, Yoshiyuki; Takikawa, Hirofumi; Yasui, Haruyuki; Kaneko, Satoru; Kunitsugu, Shinsuke; Kamiya, Masao; Taki, Makoto

2018-01-01

Conductive hard-coating films have potential application as protective films for contact pins used in the electrical inspection process for integrated circuit chips. In this study, multi-layer diamond-like carbon (DLC) films were prepared as conductive hard-coating films. The multi-layer DLC films consisting of DLC and nitrogen-containing DLC (N-DLC) film were prepared using a T-shape filtered arc deposition method. Periodic DLC/N-DLC four-layer and eight-layer films had the same film thickness by changing the thickness of each layer. In the ball-on-disk test, the N-DLC mono-layer film showed the highest wear resistance; however, in the spherical polishing method, the eight-layer film showed the highest polishing resistance. The wear and polishing resistance and the aggressiveness against an opponent material of the multi-layer DLC films improved by reducing the thickness of a layer. In multi-layer films, the soft N-DLC layer between hard DLC layers is believed to function as a cushion. Thus, the tribological properties of the DLC films were improved by a multi-layered structure. The electrical resistivity of multi-layer DLC films was approximately half that of the DLC mono-layer film. Therefore, the periodic DLC/N-DLC eight-layer film is a good conductive hard-coating film.

Comparative Study on Acoustic Behavior Between Light Multi-layered and Traditional Façades

Directory of Open Access Journals (Sweden)

Ruiz, L.

2012-09-01

Full Text Available Light multi-layered facade systems in general have been acoustically little studied. The data available suggests they do not usually fulfil the sound insulation values required in the Technical Building Code (CTE in particularly in noisy environments. Therefore the main objectives of this study, is to obtain light multi-layered façade systems with a high degree of acoustic insulation that can be used in noisy environments. While in turn showing excellent thermal characteristics, without neglecting important aspects such as the sustainability of materials, industrialization, costs, among others. This article will explain the process that has been followed to carry out an investigation on the acoustic behaviour of light multi-layered facades. For this purpose acoustic behaviour and sound intensimetry measurement methods have been used. After obtaining these results, a comparison between light multi-layered and traditional facades was made.Los sistemas de fachadas multicapas ligeras acústicamente, en general han sido poco estudiados. Los primeros datos que se tienen es que no suelen alcanzar los valores de aislamiento acústico requeridos en el Código Técnico de la Edificación (CTE en entornos especialmente ruidosos. Los objetivos principales de esta investigación son obtener fachadas multicapas ligeras con un alto grado de aislamiento acústico, que puedan ser empleados en entornos ruidosos. Al mismo tiempo que presenten excelentes características térmicas, sin descuidar aspectos tan importantes como la sostenibilidad, industrialización, costes, etc. En este artículo se explicará el proceso que se ha llevado a cabo para realizar una investigación relacionada con el comportamiento acústico de fachadas multicapas ligeras. Para ello se han empleado los métodos de medida del comportamiento acústico a ruido aéreo e intensimetría sonora. Una vez obtenidos estos resultados se realiza una comparativa entre las fachadas multicapas ligeras

Multi-type particle layer improved light trapping for photovoltaic applications

DEFF Research Database (Denmark)

David, Christin

2016-01-01

. The absorbance was enhanced compared to the bare Si wafer and I demonstrated on mixing particles a broadband boost in the absorbance within the homogeneous wafer region, excluding parasitic absorption in the particle layer. I studied the efficiency enhancement for varying geometries. Multi-type layers made of Si...

Multi-layered fabrication of large area PDMS flexible optical light guide sheets

Science.gov (United States)

Green, Robert; Knopf, George K.; Bordatchev, Evgueni V.

2017-02-01

Large area polydimethylsiloxane (PDMS) flexible optical light guide sheets can be used to create a variety of passive light harvesting and illumination systems for wearable technology, advanced indoor lighting, non-planar solar light collectors, customized signature lighting, and enhanced safety illumination for motorized vehicles. These thin optically transparent micro-patterned polymer sheets can be draped over a flat or arbitrarily curved surface. The light guiding behavior of the optical light guides depends on the geometry and spatial distribution of micro-optical structures, thickness and shape of the flexible sheet, refractive indices of the constituent layers, and the wavelength of the incident light. A scalable fabrication method that combines soft-lithography, closed thin cavity molding, partial curing, and centrifugal casting is described in this paper for building thin large area multi-layered PDMS optical light guide sheets. The proposed fabrication methodology enables the of internal micro-optical structures (MOSs) in the monolithic PDMS light guide by building the optical system layer-by-layer. Each PDMS layer in the optical light guide can have the similar, or a slightly different, indices of refraction that permit total internal reflection within the optical sheet. The individual molded layers may also be defect free or micro-patterned with microlens or reflecting micro-features. In addition, the bond between adjacent layers is ensured because each layer is only partially cured before the next functional layer is added. To illustrate the scalable build-by-layers fabrication method a three-layer mechanically flexible illuminator with an embedded LED strip is constructed and demonstrated.

Application of Multi-Layered Polyurethane Foams for Flat-Walled Anechoic Linings

DEFF Research Database (Denmark)

Xu, J. F.; Buchholz, Jörg; Fricke, Fergus R.

2006-01-01

of the application of multi-layered polyurethane foams as the flat-walled anechoic lining. The investigation includes aspects such as the efficacy of a single layer of material, the minimum number of layers of linings to achieve the minimum overall thickness for low (100Hz), mid (250Hz) and high (500Hz) cut...

Misfit Layer Compounds and Ferecrystals: Model Systems for Thermoelectric Nanocomposites

Directory of Open Access Journals (Sweden)

Devin R. Merrill

2015-04-01

Full Text Available A basic summary of thermoelectric principles is presented in a historical context, following the evolution of the field from initial discovery to modern day high-zT materials. A specific focus is placed on nanocomposite materials as a means to solve the challenges presented by the contradictory material requirements necessary for efficient thermal energy harvest. Misfit layer compounds are highlighted as an example of a highly ordered anisotropic nanocomposite system. Their layered structure provides the opportunity to use multiple constituents for improved thermoelectric performance, through both enhanced phonon scattering at interfaces and through electronic interactions between the constituents. Recently, a class of metastable, turbostratically-disordered misfit layer compounds has been synthesized using a kinetically controlled approach with low reaction temperatures. The kinetically stabilized structures can be prepared with a variety of constituent ratios and layering schemes, providing an avenue to systematically understand structure-function relationships not possible in the thermodynamic compounds. We summarize the work that has been done to date on these materials. The observed turbostratic disorder has been shown to result in extremely low cross plane thermal conductivity and in plane thermal conductivities that are also very small, suggesting the structural motif could be attractive as thermoelectric materials if the power factor could be improved. The first 10 compounds in the [(PbSe1+δ]m(TiSe2n family (m, n ≤ 3 are reported as a case study. As n increases, the magnitude of the Seebeck coefficient is significantly increased without a simultaneous decrease in the in-plane electrical conductivity, resulting in an improved thermoelectric power factor.

Detector system of the first focal plane of the spectrometer SMART at RIKEN

International Nuclear Information System (INIS)

Okamura, H.; Izshida, S.; Sakamoto, N.; Otsu, H.; Uesaka, T.; Wakasa, T.; Satou, Y.; Sakai, H.; Ichihara, T.

1998-01-01

A detector system of the first focal plane of SMART, the 135 MeV/u high-resolution spectrometer at RIKEN accelerator research facility, is described. It consists of a pair of multi-wire drift chambers and a trigger scintillator hodoscope contained in a He-filled detector box. A major subject using this system is the measurement of the (d, 2 He) reaction making the most of its large angular and momentum acceptances. Without seriously sacrificing the detection efficiency, reasonably good energy and angular resolutions for 2 He, 460 keV and 9 mrad (FWHM), respectively, have been achieved after optimizing the optics property of the spectrometer. (orig.)

Non-localized deformation in Cu−Zr multi-layer amorphous films under tension

Energy Technology Data Exchange (ETDEWEB)

Zhong, C. [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, H. [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9 (Canada); Cao, Q.P.; Wang, X.D. [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, D.X. [State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027 (China); Hu, J.W. [Hangzhou Workers Amateur University, Hangzhou 310027 (China); Liaw, P.K. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Jiang, J.Z., E-mail: jiangjz@zju.edu.cn [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

2016-09-05

In metallic glasses (MGs), plastic deformation at room temperature is dominated by highly localized shear bands. Here we report the non-localized deformation under tension in Cu−Zr multi-layer MGs with a pure amorphous structure using large-scale atomistic simulations. It is demonstrated that amorphous samples with high layer numbers, composed of Cu{sub 64}Zr{sub 36} and Cu{sub 40}Zr{sub 60}, or Cu{sub 64}Zr{sub 36} and Cu{sub 50}Zr{sub 50}, present obviously non-localized deformation behavior. We reveal that the deformation behavior of the multi-layer-structured MG films is related but not determined by the deformation behavior of the composed individual layers. The criterion for the deformation mode change for MGs with a pure amorphous structure, in generally, was suggested, i.e., the competition between the elastic-energy density stored and the energy density needed for forming one mature shear band in MGs. Our results provide a promising strategy for designing tensile ductile MGs with a pure amorphous structure at room temperature. - Highlights: • Tensile deformation behaviors in multi-layer MG films. • Films with high layer numbers confirmed with a non-localized deformation behavior. • The deformation mode is reasonably controlled by whether U{sub p} larger than U{sub SB.}.

High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

Science.gov (United States)

Yao, Rihui; Zhang, Hongke; Fang, Zhiqiang; Ning, Honglong; Zheng, Zeke; Li, Xiaoqing; Zhang, Xiaochen; Cai, Wei; Lu, Xubing; Peng, Junbiao

2018-02-01

In this study, high conductivity and transparent multi-layer (AZO/Al/AZO-/Al/AZO) source/drain (S/D) electrodes for thin film transistors were fabricated via conventional physical vapor deposition approaches, without toxic elements or further thermal annealing process. The 68 nm-thick multi-layer films with excellent optical properties (transparency: 82.64%), good electrical properties (resistivity: 6.64  ×  10-5 Ω m, work function: 3.95 eV), and superior surface roughness (R q   =  0.757 nm with scanning area of 5  ×  5 µm2) were fabricated as the S/D electrodes. Significantly, comprehensive performances of AZO films are enhanced by the insertion of ultra-thin Al layers. The optimal transparent TFT with this multi-layer S/D electrodes exhibited a decent electrical performance with a saturation mobility (µ sat) of 3.2 cm2 V-1 s-1, an I on/I off ratio of 1.59  ×  106, a subthreshold swing of 1.05 V/decade. The contact resistance of AZO/Al/AZO/Al/AZO multi-layer electrodes is as low as 0.29 MΩ. Moreover, the average visible light transmittance of the unpatterned multi-layers constituting a whole transparent TFT could reach 72.5%. The high conductivity and transparent multi-layer S/D electrodes for transparent TFTs possessed great potential for the applications of the green and transparent displays industry.

A fracture mechanics assessment of surface cracks existing in protective layers of multi-layer composite pipes

Czech Academy of Sciences Publication Activity Database

Hutař, Pavel; Náhlík, Luboš; Šestáková, Lucie; Ševčík, Martin; Knésl, Zdeněk; Nezbedová, E.

2010-01-01

Roč. 92, č. 5 (2010), s. 1120-1125 ISSN 0263-8223 R&D Projects: GA ČR GA106/09/0279 Institutional research plan: CEZ:AV0Z20410507 Keywords : Protective layers * Multi-layer pipes damage * Fracture mechanics * Bi-material interface * Generalized stress intensity factor Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.028, year: 2010

Multi-layer enhancement to polysilicon surface-micromachining technology

Energy Technology Data Exchange (ETDEWEB)

Sniegowski, J.J.; Rodgers, M.S. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Micromachine Dept.

1997-10-01

A multi-level polysilicon surface-micromachining technology consisting of 5 layers of polysilicon is presented. Surface topography and film mechanical stress are the major impediments encountered in the development of a multilayer surface-micromachining process. However, excellent mechanical film characteristics have been obtained through the use of chemical-mechanical polishing for planarization of topography and by proper sequencing of film deposition with thermal anneals. Examples of operating microactuators, geared power-transfer mechanisms, and optical elements demonstrate the mechanical advantages of construction with 5 polysilicon layers.

Controlling the formation of wrinkles in a single layer graphene sheet subjected to in-plane shear

KAUST Repository

Duan, Wen Hui

2011-08-01

The initiation and development of wrinkles in a single layer graphene sheet subjected to in-plane shear displacements are investigated. The dependence of the wavelength and amplitude of wrinkles on the applied shear displacements is explicitly obtained with molecular mechanics simulations. A continuum model is developed for the characteristics of the wrinkles which show that the wrinkle wavelength decreases with an increase in shear loading, while the amplitude of the wrinkles is found to initially increase and then become stable. The propagation and growth process of the wrinkles in the sheet is elucidated. It is expected that the research could promote applications of graphenes in the transportation of biological systems, separation science, and the development of the fluidic electronics. © 2011 Elsevier Ltd. All rights reserved.

Calibration of a multi-beam Laser System by using a TLS-generated Reference

Directory of Open Access Journals (Sweden)

M. Gordon

2013-10-01

Full Text Available Rotating multi-beam LIDARs mounted on moving platforms have become very successful for many applications such as autonomous navigation, obstacle avoidance or mobile mapping. To obtain accurate point coordinates, a precise calibration of such a LIDAR system is required. For the determination of the corresponding parameters we propose a calibration scheme which exploits the information of 3D reference point clouds captured by a terrestrial laser scanning (TLS device. It is assumed that the accuracy of this point clouds is considerably higher than that from the multi-beam LIDAR and that the data represent faces of man-made objects at different distances. After extracting planes in the reference data sets, the point-plane-incidences of the measured points and the reference planes are used to formulate the implicit constraints. We inspect the Velodyne HDL-64E S2 system as the best-known representative for this kind of sensor system. The usability and feasibility of the calibration procedure is demonstrated with real data sets representing building faces (walls, roof planes and ground. Beside the improvement of the point accuracy by considering the calibration results, we test the significance of the parameters related to the sensor model and consider the uncertainty of measurements w.r.t. the measured distances. The Velodyne returns two kinds of measurements – distances and encoder angles. To account for this, we perform a variance component estimation to obtain realistic standard deviations for the observations.

Burnout in a high heat flux boiling system with forced supply of liquid through a plane jet

International Nuclear Information System (INIS)

Katto, Yoshiro; Ishii, Kazunori.

1978-01-01

As for pool boiling, the non-dimensional formula for the burnout heat flux of a simple, basic boiling system has been obtained. On the other hand, in forced convection boiling, the studies on the burnout in forced flow boiling in a channel have been continued, but the derivation of a non-dimensional formula applicable generally is far away from the realization because the phenomena are too complex. Accordingly, in this study, the result of the experiment on the burnout of a boiling system to which liquid is supplied by the plane jet flowing out of a thin rectangular nozzle installed near the front edge of a rectangular heating surface is reported. The experimental apparatus is described, and the experiment was carried out in the ranges of two jet thicknesses at the nozzle outlet, two incident angles of jet and from 1.5 to 15 m/s of jet velocity. Burnout occurs under the situation of sufficiently developed nuclear boiling. A part of the liquid supplied from a plane jet is blown apart by the vapor blowing out of the nuclear boiling liquid layer covering the heating surface in the nuclear boiling with sufficiently developed high heat flux. However, the nuclear boiling liquid layer itself continues to exist on the heating surface till burnout occurs. Only the entering velocity of the plane jet affects burnout heat flux. (Kako, I.)

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%.

Effect of antiferromagnetic interfacial coupling on spin-wave resonance frequency of multi-layer film

Energy Technology Data Exchange (ETDEWEB)

Qiu, Rong-ke, E-mail: rkqiu@163.com; Cai, Wei

2017-08-15

Highlights: • A quantum approach is developed to study the SWR of a bicomponent multi-layer films. • The comparison of the SWR in films with FM and AFM interfacial coupling has been made. • The present results show the method to enhance and adjust the SWR frequency of films. - Abstract: We investigate the spin-wave resonance (SWR) frequency in a bicomponent bilayer and triple-layer films with antiferromagnetic or ferromagnetic interfacial couplings, as function of interfacial coupling, surface anisotropy, interface anisotropy, thickness and external magnetic field, using the linear spin-wave approximation and Green’s function technique. The microwave properties for multi-layer magnetic film with antiferromagnetic interfacial coupling is different from those for multi-layer magnetic film with ferromagnetic interfacial coupling. For the bilayer film with antiferromagnetic interfacial couplings, as the lower (upper) surface anisotropy increases, only the SWR frequencies of the odd (even) number modes increase. The lower (upper) surface anisotropy does not affect the SWR frequencies of the even (odd) number modes{sub .} For the multi-layer film with antiferromagnetic interfacial coupling, the SWR frequency of modes m = 1, 3 and 4 decreases while that of mode m = 2 increases with increasing thickness of the film within a proper parameter region. The present results could be useful in enhancing our fundamental understanding and show the method to enhance and adjust the SWR frequency of bicomponent multi-layer magnetic films with antiferromagnetic or ferromagnetic interfacial coupling.

Taxonomy-driven adaptation of multi-layer applications using templates

OpenAIRE

Popescu, Razvan; Staikopoulos, Athanasios; Liu, Peng; Brogi, Antonio; Clarke, Siobh??n

2010-01-01

peer-reviewed Current adaptation approaches mainly work in isolation and cannot be easily integrated to tackle complex adaptation scenarios. The few existing cross-layer adaptation techniques are somewhat inflexible because the adaptation process is predefined and static. In this paper we propose a methodology for the dynamic and flexible adaptation of multi-layer applications. We use events to trigger the process of matching adaptation templates, which expose adaptation logic as BPEL pro...

Study on tribological properties of multi-layer surface texture on Babbitt alloys surface

Science.gov (United States)

Zhang, Dongya; Zhao, Feifei; Li, Yan; Li, Pengyang; Zeng, Qunfeng; Dong, Guangneng

2016-12-01

To improve tribological properties of Babbitt alloys, multi-layer surface texture consisted of the main grooves and secondary micro-dimples are fabricated on the Babbitt substrate through laser pulse ablation. The tribological behaviors of multi-layer surface texture are investigated using a rotating type pin-on-disc tribo-meter under variation sliding speeds, and the film pressure distributions on the textured surfaces are simulated using computational fluid dynamics (CFD) method for elucidating the possible mechanisms. The results suggest that: (i) the multi-layer surface texture can reduce friction coefficient of Babbitt alloy, which has lowest friction coefficient of 0.03, in case of the groove parameter of 300 μm width and 15% of area density; (ii) the improvement effect may be more sensitive to the groove area density and the siding speed, and the textured surface with lower area density has lower friction coefficient under high sliding speed. Based on the reasons of (i) the secondary micro-dimples on Babbitt alloy possesses a hydrophobicity surface and (ii) the CFD analysis indicates that main grooves enhancing hydrodynamic effect, thus the multi-layer surface texture is regarded as dramatically improve the lubricating properties of the Babbitt alloy.

Heating of multi-layered samples by a Nd: YAG pulsed laser

International Nuclear Information System (INIS)

Diniz Neto, O.O.

1998-01-01

In the work we examine the heating of multi-layered samples by a powerful Nd-YAG pulsed laser. The samples are made of two and three layers, conductor-isolator (Al-Al 2 O 3 ). conductor-conductor (Al-Ag: Al-Au) an conductor-conductor-conductor (Al-Au-Ag:Ag-Au-Al). The transient behaviour of the temperature distribution throughout the samples is computed. We carry out three dimensional model calculations for the heating process in which we consider not only the temperature dependence of the sample thermal and optical parameters but also the space and time characteristics of the laser beams as the heating source. We showed the influence of the substrate in the thermal profile, in space and time, and maximum temperature on the multi-layered samples. (Author) 11 refs

Discretization of superintegrable systems on a plane

Science.gov (United States)

Kabát, Z.

2012-02-01

We construct difference analogues of so called Smorodinsky-Winternitz superintegrable systems in the Euclidean plane. Using methods of umbral calculus, we obtain difference equations for generalized isotropic harmonic oscillator on the uniform lattice, and also its solution in terms of power series. In the case of gauge-rotated Hamiltonian, the solution is a polynomial, well-defined in the whole plane.

Absence of effects of an in-plane magnetic field in a quasi-two-dimensional electron system

Science.gov (United States)

Brandt, F. T.; Sánchez-Monroy, J. A.

2018-03-01

The dynamics of a quasi-two-dimensional electron system (q2DES) in the presence of a tilted magnetic field is reconsidered employing the thin-layer method. We derive the effective equations for relativistic and nonrelativistic q2DESs. Through a perturbative expansion, we show that while the magnetic length is much greater than the confinement width, the in-plane magnetic field only affects the particle dynamics through the spin. Therefore, effects due to an in-plane magnetic vector potential reported previously in the literature for 2D quantum rings, 2D quantum dots and graphene are fictitious. In particular, the so-called pseudo chiral magnetic effect recently proposed in graphene is not realistic.

Experimental flame speed in multi-layered nano-energetic materials

Energy Technology Data Exchange (ETDEWEB)

Manesh, Navid Amini; Basu, Saptarshi; Kumar, Ranganathan [Department of Mechanical, Material and Aerospace Engineering, University of Central Florida, Orlando, FL (United States)

2010-03-15

This paper deals with the reaction of dense Metastable Intermolecular Composite (MIC) materials, which have a higher density than conventional energetic materials. The reaction of a multilayer thin film of aluminum and copper oxide has been studied by varying the substrate material and thicknesses. The in-plane speed of propagation of the reaction was experimentally determined using a time of- flight technique. The experiment shows that the reaction is completely quenched for a silicon substrate having an intervening silica layer of less than 200 nm. The speed of reaction seems to be constant at 40 m/s for silica layers with a thickness greater than 1 {mu}m. Different substrate materials such as glass and photoresist were also used. (author)

Multi-layer universal correction magnet

International Nuclear Information System (INIS)

Parzen, G.

1981-08-01

This paper presents an approach for constructing a universal correction magnet in which the return currents play an active role in determining the field. The return currents are not hidden by the iron shield. The coil is wound in many layers, instead of just one layer. Each layer has a particular symmetry, and generates a particular class of field multipoles such that the location of the return current for each independently excited current block is clear. Three layers may be sufficient in many cases. This approach is applied to the ISABELLE storage accelerator correction system

Energy sprawl, land taking and distributed generation: towards a multi-layered density

International Nuclear Information System (INIS)

Moroni, Stefano; Antoniucci, Valentina; Bisello, Adriano

2016-01-01

The transition from fossil fuels to renewable resources is highly desirable to reduce air pollution, and improve energy efficiency and security. Many observers are concerned, however, that the diffusion of systems based on renewable resources may give rise to energy sprawl, i.e. an increasing occupation of available land to build new energy facilities of this kind. These critics foresee a transition from the traditional fossil-fuel systems, towards a renewable resource system likewise based on large power stations and extensive energy grids. A different approach can be taken to reduce the risk of energy sprawl, and this will happen if the focus is as much on renewable sources as on the introduction of distributed renewable energy systems based on micro plants (photovoltaic panels on the roofs of buildings, micro wind turbines, etc.) and on multiple micro-grids. Policy makers could foster local energy enterprises by: introducing new enabling rules; making more room for contractual communities; simplifying the compliance process; proposing monetary incentives and tax cuts. We conclude that the diffusion of innovation in this field will lead not to an energy sprawl but to a new energy system characterized by a multi-layered density: a combination of technology, organization, and physical development. - Highlights: • Energy sprawl is not a necessary consequence of the transition to renewable sources. • A polycentric, distributed renewable energy system reduces land consumption. • This polycentric model is founded on building-related renewable energy production and micro-grids. • Enabling rules, simplified compliance, and tax cuts can foster this result. • The concept of multi-layered density is proposed as a new framework for interpreting this scenario.

Additive Difference Schemes for Filtration Problems in Multilayer Systems

CERN Document Server

Ayrjan, E A; Pavlush, M; Fedorov, A V

2000-01-01

In the present paper difference schemes for solution of the plane filtration problem in multilayer systems are analyzed within the framework of difference schemes general theory. Attention is paid to splitting the schemes on physical processes of filtration along water-carring layers and vertical motion between layers. Some absolutely stable additive difference schemes are obtained the realization of which needs no software modification. Parallel algorithm connected with the solving of the filtration problem in every water-carring layer on a single processor is constructed. Program realization on the multi-processor system SPP2000 at JINR is discussed.

Scattering by a plane-parallel layer with high concentration of optically soft particles

International Nuclear Information System (INIS)

Loiko, Valery A.; Berdnik, Vladimir V.

2009-01-01

A method describing light propagation in a plane-parallel light-scattering layer with large concentration of homogeneous particles is developed. It is based on the radiative transfer equation and the doubling method. The interference approximation is used to take into account collective scattering effects. Spectral dependence of transmitted light for a layer of nonabsorbing optically soft particles with subwavelength-sized particles is investigated. At small volume concentration of the particles the weak spectral dependences of wave exponents for coherently transmitted and diffuse light are observed. It is shown that in a layer with large volume concentration of the subwavelength-sized particles the wave exponent can exceed considerably the value of four, which takes place for the Rayleigh particles. The dependence of wave exponents for coherently transmitted and diffuse light on the refractive index and concentration of particles is investigated in detail. Multiple scattering of light results in the reduction of the exponent. The quantitative results are presented and discussed. It is shown that there is a range of wavelengths where the negative values of the wave exponent at the regime of multiple scattering are implemented.

A Collaborative Digital Pathology System for Multi-Touch Mobile and Desktop Computing Platforms

KAUST Repository

Jeong, W.

2013-06-13

Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server system that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch-enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. We introduce a domain-specific image-stack compression method that leverages real-time hardware decoding on mobile devices. It adaptively encodes image stacks in a decorrelated colour space to achieve extremely low bitrates (0.8 bpp) with very low loss of image quality. We evaluate the image quality of our compression method and the performance of our system for diagnosis with an in-depth user study. Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server systems that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

A Collaborative Digital Pathology System for Multi-Touch Mobile and Desktop Computing Platforms

KAUST Repository

Jeong, W.; Schneider, J.; Hansen, A.; Lee, M.; Turney, S. G.; Faulkner-Jones, B. E.; Hecht, J. L.; Najarian, R.; Yee, E.; Lichtman, J. W.; Pfister, H.

2013-01-01

Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server system that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch-enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. We introduce a domain-specific image-stack compression method that leverages real-time hardware decoding on mobile devices. It adaptively encodes image stacks in a decorrelated colour space to achieve extremely low bitrates (0.8 bpp) with very low loss of image quality. We evaluate the image quality of our compression method and the performance of our system for diagnosis with an in-depth user study. Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server systems that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

Derivation of optimal joint operating rules for multi-purpose multi-reservoir water-supply system

Science.gov (United States)

Tan, Qiao-feng; Wang, Xu; Wang, Hao; Wang, Chao; Lei, Xiao-hui; Xiong, Yi-song; Zhang, Wei

2017-08-01

The derivation of joint operating policy is a challenging task for a multi-purpose multi-reservoir system. This study proposed an aggregation-decomposition model to guide the joint operation of multi-purpose multi-reservoir system, including: (1) an aggregated model based on the improved hedging rule to ensure the long-term water-supply operating benefit; (2) a decomposed model to allocate the limited release to individual reservoirs for the purpose of maximizing the total profit of the facing period; and (3) a double-layer simulation-based optimization model to obtain the optimal time-varying hedging rules using the non-dominated sorting genetic algorithm II, whose objectives were to minimize maximum water deficit and maximize water supply reliability. The water-supply system of Li River in Guangxi Province, China, was selected for the case study. The results show that the operating policy proposed in this study is better than conventional operating rules and aggregated standard operating policy for both water supply and hydropower generation due to the use of hedging mechanism and effective coordination among multiple objectives.

Review of multi-layered magnetoelectric composite materials and devices applications

Science.gov (United States)

Chu, Zhaoqiang; PourhosseiniAsl, MohammadJavad; Dong, Shuxiang

2018-06-01

Multiferroic materials with the coexistence of at least two ferroic orders, such as ferroelectricity, ferromagnetism, or ferroelasticity, have recently attracted ever-increasing attention due to their potential for multifunctional device applications, including magnetic and current sensors, energy harvesters, magnetoelectric (ME) random access memory and logic devices, tunable microwave devices, and ME antenna. In this article, we provide a review of the recent and ongoing research efforts in the field of multi-layered ME composites. After a brief introduction to ME composites and ME coupling mechanisms, we review recent advances in multi-layered ME composites as well as their device applications based on the direct ME effect, magnetic sensors in particular. Finally, some remaining challenges and future perspective of ME composites and their engineering applications will be discussed.

Robust Object Segmentation Using a Multi-Layer Laser Scanner

Science.gov (United States)

Kim, Beomseong; Choi, Baehoon; Yoo, Minkyun; Kim, Hyunju; Kim, Euntai

2014-01-01

The major problem in an advanced driver assistance system (ADAS) is the proper use of sensor measurements and recognition of the surrounding environment. To this end, there are several types of sensors to consider, one of which is the laser scanner. In this paper, we propose a method to segment the measurement of the surrounding environment as obtained by a multi-layer laser scanner. In the segmentation, a full set of measurements is decomposed into several segments, each representing a single object. Sometimes a ghost is detected due to the ground or fog, and the ghost has to be eliminated to ensure the stability of the system. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments show that the proposed method demonstrates good performance in many real-life situations. PMID:25356645

Coastal groundwater salinization: Focus on the vertical variability in a multi-layered aquifer through a multi-isotope fingerprinting (Roussillon Basin, France)

Energy Technology Data Exchange (ETDEWEB)

Petelet-Giraud, Emmanuelle, E-mail: e.petelet@brgm.fr [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France); Négrel, Philippe [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France); Aunay, Bertrand [BRGM, Réunion Agency, 5, rue Sainte-Anne, CS 51016, 97404 Saint Denis Cedex (France); Ladouche, Bernard; Bailly-Comte, Vincent [BRGM Montpellier Agency, 1039, rue de Pinville, 34000 Montpellier (France); Guerrot, Catherine; Flehoc, Christine [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France); Pezard, Philippe; Lofi, Johanna [Géosciences Montpellier, UMR 5243, Université de Montpellier, cc069, Place Eugène Bataillon, 34095 Montpellier Cedex 05 (France); Dörfliger, Nathalie [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France)

2016-10-01

The Roussillon sedimentary Basin (South France) is a complex multi-layered aquifer, close to the Mediterranean Sea facing seasonally increases of water abstraction and salinization issues. We report geochemical and isotopic vertical variability in this aquifer using groundwater sampled with a Westbay System® at two coastal monitoring sites: Barcarès and Canet. The Westbay sampling allows pointing out and explaining the variation of water quality along vertical profiles, both in productive layers and in the less permeable ones where most of the chemical processes are susceptible to take place. The aquifer layers are not equally impacted by salinization, with electrical conductivity ranging from 460 to 43,000 μS·cm{sup −1}. The δ{sup 2}H–δ{sup 18}O signatures show mixing between seawater and freshwater components with long water residence time as evidenced by the lack of contribution from modern water using {sup 3}H, {sup 14}C and CFCs/SF6. S(SO{sub 4}) isotopes also evidence seawater contribution but some signatures can be related to oxidation of pyrite and/or organically bounded S. In the upper layers {sup 87}Sr/{sup 86}Sr ratios are close to that of seawater and then increase with depth, reflecting water–rock interaction with argillaceous formations while punctual low values reflect interaction with carbonate. Boron isotopes highlight secondary processes such as adsorption/desorption onto clays in addition to mixings. At the Barcarès site (120 m deep), the high salinity in some layers appear to be related neither to present day seawater intrusion, nor to Salses-Leucate lagoonwater intrusion. Groundwater chemical composition thus highlights binary mixing between fresh groundwater and inherited salty water together with cation exchange processes, water–rock interactions and, locally, sedimentary organic matter mineralisation probably enhanced by pyrite oxidation. Finally, combining the results of this study and those of Caballero and Ladouche (2015

Competitive dynamics of lexical innovations in multi-layer networks

Science.gov (United States)

Javarone, Marco Alberto

2014-04-01

We study the introduction of lexical innovations into a community of language users. Lexical innovations, i.e. new term added to people's vocabulary, plays an important role in the process of language evolution. Nowadays, information is spread through a variety of networks, including, among others, online and offline social networks and the World Wide Web. The entire system, comprising networks of different nature, can be represented as a multi-layer network. In this context, lexical innovations diffusion occurs in a peculiar fashion. In particular, a lexical innovation can undergo three different processes: its original meaning is accepted; its meaning can be changed or misunderstood (e.g. when not properly explained), hence more than one meaning can emerge in the population. Lastly, in the case of a loan word, it can be translated into the population language (i.e. defining a new lexical innovation or using a synonym) or into a dialect spoken by part of the population. Therefore, lexical innovations cannot be considered simply as information. We develop a model for analyzing this scenario using a multi-layer network comprising a social network and a media network. The latter represents the set of all information systems of a society, e.g. television, the World Wide Web and radio. Furthermore, we identify temporal directed edges between the nodes of these two networks. In particular, at each time-step, nodes of the media network can be connected to randomly chosen nodes of the social network and vice versa. In doing so, information spreads through the whole system and people can share a lexical innovation with their neighbors or, in the event they work as reporters, by using media nodes. Lastly, we use the concept of "linguistic sign" to model lexical innovations, showing its fundamental role in the study of these dynamics. Many numerical simulations have been performed to analyze the proposed model and its outcomes.

Hydro-geochemical paths of multi-layer groundwater system in coal mining regions - Using multivariate statistics and geochemical modeling approaches.

Science.gov (United States)

Liu, Pu; Hoth, Nils; Drebenstedt, Carsten; Sun, Yajun; Xu, Zhimin

2017-12-01

Groundwater is an important drinking water resource that requires protection in North China. Coal mining industry in the area may influence the water quality evolution. To provide primary characterization of the hydrogeochemical processes and paths that control the water quality evolution, a complex multi-layer groundwater system in a coal mining area is investigated. Multivariate statistical methods involving hierarchical cluster analysis (HCA) and principal component analysis (PCA) are applied, 6 zones and 3 new principal components are classified as major reaction zones and reaction factors. By integrating HCA and PCA with hydrogeochemical correlations analysis, potential phases, reactions and connections between various zones are presented. Carbonates minerals, gypsum, clay minerals as well as atmosphere gases - CO 2 , H 2 O and NH 3 are recognized as major reactants. Mixtures, evaporation, dissolution/precipitation of minerals and cation exchange are potential reactions. Inverse modeling is finally used, and it verifies the detailed processes and diverse paths. Consequently, 4 major paths are found controlling the variations of groundwater chemical properties. Shallow and deep groundwater is connected primarily by the flow of deep groundwater up through fractures and faults into the shallow aquifers. Mining does not impact the underlying aquifers that represent the most critical groundwater resource. But controls should be taken to block the mixing processes from highly polluted mine water. The paper highlights the complex hydrogeochemical evolution of a multi-layer groundwater system under mining impact, which could be applied to further groundwater quality management in the study area, as well as most of the other coalfields in North China. Copyright © 2017 Elsevier B.V. All rights reserved.

Multi-Layer Real-Time Support for JVM-based Smart Phone Systems

Directory of Open Access Journals (Sweden)

SEO, E.

2013-08-01

Full Text Available Employing the Java virtual machine (JVM architecture provides smart phone systems stability and security by sandboxing third-party applications and controlling their behavior. However, the JVM layer hinders applications from notifying the operating system scheduler about their timeliness requirements; therefore, applications sometimes fail to respond on time. In order to improve the responsiveness of smart phone applications, this paper proposes two schemes. First, for existing applications that cannot be rebuilt, we modify the kernel scheduler to value task priorities over fairness. Second, we propose cross-layer real-time support APIs to deliver applications' priorities to the kernel scheduler, which will help developers to add real-time scheduling support to their applications. Our prototype demonstrates that the suggested schemes dramatically improve response times and throughputs of prioritized applications.

Penetration of a Small Caliber Projectile into Single and Multi-layered Targets

Directory of Open Access Journals (Sweden)

Riad A.M.

2010-06-01

Full Text Available The normal penetration of armor-piercing projectiles into single and multi-layered steel plates has been investigated. An experimental program has been conducted to study the effect of spaced and in-contact layered targets on their ballistic resistance. Armor piercing projectiles with caliber of 7.62 mm were fired against a series of single and multi-layered steel targets. The projectile impact velocities were ranged from 300-600 m/s, whereas the total thicknesses of the tested single, spaced and in-contact layered steel targets were 3 mm. The penetration process of different tested target configurations has been simulated using Autodayn-2D hydrocode. The experimental measurements of the present work were used to discuss the effect of impact velocity, target configurations and number of layers of different spaced and in-contact layered steel targets on their ballistic resistance. In addition, the post-firing examination of the tested targets over the used impact velocity range showed that the single and each layer of spaced and in-contact laminated steel targets were failed by petalling. Finally, the obtained experimental measurements were compared with the corresponding numerical results of Autodyn-2D hydrocode, good agreement was generally obtained.

Preparation, structures and magnetic properties of Dy/Zr and Ho/Zr two-layers and multi-layers

International Nuclear Information System (INIS)

Luche, M.C.

1993-01-01

The first part of the report is devoted to the description of the ultra-vacuum evaporation equipment, to the sample preparation conditions and to the characterization of the two-layers and multi-layers through reflection and glancing incidence X diffraction and transmission electron microscopy. In the second part, the magnetic properties of the samples are studied and relations between properties and structures are examined. 37 fig., 35 ref

Age and gender estimation using Region-SIFT and multi-layered SVM

Science.gov (United States)

Kim, Hyunduk; Lee, Sang-Heon; Sohn, Myoung-Kyu; Hwang, Byunghun

2018-04-01

In this paper, we propose an age and gender estimation framework using the region-SIFT feature and multi-layered SVM classifier. The suggested framework entails three processes. The first step is landmark based face alignment. The second step is the feature extraction step. In this step, we introduce the region-SIFT feature extraction method based on facial landmarks. First, we define sub-regions of the face. We then extract SIFT features from each sub-region. In order to reduce the dimensions of features we employ a Principal Component Analysis (PCA) and a Linear Discriminant Analysis (LDA). Finally, we classify age and gender using a multi-layered Support Vector Machines (SVM) for efficient classification. Rather than performing gender estimation and age estimation independently, the use of the multi-layered SVM can improve the classification rate by constructing a classifier that estimate the age according to gender. Moreover, we collect a dataset of face images, called by DGIST_C, from the internet. A performance evaluation of proposed method was performed with the FERET database, CACD database, and DGIST_C database. The experimental results demonstrate that the proposed approach classifies age and performs gender estimation very efficiently and accurately.

Incorporating Cyber Layer Failures in Composite Power System Reliability Evaluations

Directory of Open Access Journals (Sweden)

Yuqi Han

2015-08-01

Full Text Available This paper proposes a novel approach to analyze the impacts of cyber layer failures (i.e., protection failures and monitoring failures on the reliability evaluation of composite power systems. The reliability and availability of the cyber layer and its protection and monitoring functions with various topologies are derived based on a reliability block diagram method. The availability of the physical layer components are modified via a multi-state Markov chain model, in which the component protection and monitoring strategies, as well as the cyber layer topology, are simultaneously considered. Reliability indices of composite power systems are calculated through non-sequential Monte-Carlo simulation. Case studies demonstrate that operational reliability downgrades in cyber layer function failure situations. Moreover, protection function failures have more significant impact on the downgraded reliability than monitoring function failures do, and the reliability indices are especially sensitive to the change of the cyber layer function availability in the range from 0.95 to 1.

A methodology for designing flexible multi-generation systems

DEFF Research Database (Denmark)

Lythcke-Jørgensen, Christoffer Ernst; Viana Ensinas, Adriano; Münster, Marie

2016-01-01

An FMG (flexible multi-generation system) consists of integrated and flexibly operated facilities that provide multiple links between the various layers of the energy system. FMGs may facilitate integration and balancing of fluctuating renewable energy sources in the energy system in a cost...... is based on consideration of the following points: Selection, location and dimensioning of processes; systematic heat and mass integration; flexible operation optimization with respect to both short-term market fluctuations and long-term energy system development; global sensitivity and uncertainty...... analysis; biomass supply chains; variable part-load performance; and multi-objective optimization considering economic and environmental performance. Tested in a case study, the methodology is proved effective in screening the solution space for efficient FMG designs, in assessing the importance...

Self-Supporting High Performance Multi-Layer Insulation Technology Development (SSMLI)

Data.gov (United States)

National Aeronautics and Space Administration — A new type of MLI—Integrated Multi-Layer Insulation (IMLI)—uses rigid, low-conductivity polymer spacers instead of netting to keep the radiation barriers separated....

Electrically Tunable and Negative Schottky Barriers in Multi-layered Graphene/MoS2 Heterostructured Transistors

Science.gov (United States)

Qiu, Dongri; Kim, Eun Kyu

2015-09-01

We fabricated multi-layered graphene/MoS2 heterostructured devices by positioning mechanically exfoliated bulk graphite and single-crystalline 2H-MoS2 onto Au metal pads on a SiO2/Si substrate via a contamination-free dry transfer technique. We also studied the electrical transport properties of Au/MoS2 junction devices for systematic comparison. A previous work has demonstrated the existence of a positive Schottky barrier height (SBH) in the metal/MoS2 system. However, analysis of the SBH indicates that the contacts of the multi-layered graphene/MoS2 have tunable negative barriers in the range of 300 to -46 meV as a function of gate voltage. It is hypothesized that this tunable SBH is responsible for the modulation of the work function of the thick graphene in these devices. Despite the large number of graphene layers, it is possible to form ohmic contacts, which will provide new opportunities for the engineering of highly efficient contacts in flexible electronics and photonics.

Electrically Tunable and Negative Schottky Barriers in Multi-layered Graphene/MoS2 Heterostructured Transistors.

Science.gov (United States)

Qiu, Dongri; Kim, Eun Kyu

2015-09-03

We fabricated multi-layered graphene/MoS2 heterostructured devices by positioning mechanically exfoliated bulk graphite and single-crystalline 2H-MoS2 onto Au metal pads on a SiO2/Si substrate via a contamination-free dry transfer technique. We also studied the electrical transport properties of Au/MoS2 junction devices for systematic comparison. A previous work has demonstrated the existence of a positive Schottky barrier height (SBH) in the metal/MoS2 system. However, analysis of the SBH indicates that the contacts of the multi-layered graphene/MoS2 have tunable negative barriers in the range of 300 to -46 meV as a function of gate voltage. It is hypothesized that this tunable SBH is responsible for the modulation of the work function of the thick graphene in these devices. Despite the large number of graphene layers, it is possible to form ohmic contacts, which will provide new opportunities for the engineering of highly efficient contacts in flexible electronics and photonics.

In-plane Tire Deformation Measurement Using a Multi-Laser Sensor System

OpenAIRE

Xiong, Yi

2016-01-01

The interactions between tires and roads are basic mechanisms that alter the dynamic states of vehicles. A fundamental understanding of tire-road interactions is clearly demanded in tire design to achieve performance improvements. The emergence of various tire sensors provides an opportunity to make accurate measurement of the physical quantities that are involved in tire-road interactions.  This thesis aims to measure and analyze the in-plane deformation of rolling tires through its direc...

Analytical modeling of multi-layered printed circuit board using multi-stacked via clusters as component heat spreader

Directory of Open Access Journals (Sweden)

Monier-Vinard Eric

2016-01-01

Full Text Available In order to help the electronic designer to early determine the limits of the power dissipation of electronic component, an analytical model was established to allow a fast insight of relevant design parameters of a multi-layered electronic board constitution. The proposed steady-state approach based on Fourier series method promotes a practical solution to quickly investigate the potential gain of multi-layered thermal via clusters. Generally, it has been shown a good agreement between the results obtained by the proposed analytical model and those given by electronics cooling software widely used in industry. Some results highlight the fact that the conventional practices for Printed Circuit Board modeling can be dramatically underestimate source temperatures, in particular with smaller sources. Moreover, the analytic solution could be applied to optimize the heat spreading in the board structure with a local modification of the effective thermal conductivity layers.

Effects of Mev Si Ions and Thermal Annealing on Thermoelectric and Optical Properties of SiO2/SiO2+Ge Multi-nanolayer thin Films

Science.gov (United States)

Budak, S.; Alim, M. A.; Bhattacharjee, S.; Muntele, C.

Thermoelectric generator devices have been prepared from 200 alternating layers of SiO2/SiO2+Ge superlattice films using DC/RF magnetron sputtering. The 5 MeV Si ionsbombardmenthasbeen performed using the AAMU Pelletron ion beam accelerator to formquantum dots and / or quantum clusters in the multi-layer superlattice thin films to decrease the cross-plane thermal conductivity, increase the cross-plane Seebeck coefficient and increase the cross-plane electrical conductivity to increase the figure of merit, ZT. The fabricated devices have been annealed at the different temperatures to tailor the thermoelectric and optical properties of the superlattice thin film systems. While the temperature increased, the Seebeck coefficient continued to increase and reached the maximum value of -25 μV/K at the fluenceof 5x1013 ions/cm2. The decrease in resistivity has been seen between the fluence of 1x1013 ions/cm2 and 5x1013 ions/cm2. Transport properties like Hall coefficient, density and mobility did not change at all fluences. Impedance spectroscopy has been used to characterize the multi-junction thermoelectric devices. The loci obtained in the C*-plane for these data indicate non-Debye type relaxation displaying the presence of the depression parameter.

Energy management and multi-layer control of networked microgrids

Science.gov (United States)

Zamora, Ramon

Networked microgrids is a group of neighboring microgrids that has ability to interchange power when required in order to increase reliability and resiliency. Networked microgrid can operate in different possible configurations including: islanded microgrid, a grid-connected microgrid without a tie-line converter, a grid-connected microgrid with a tie-line converter, and networked microgrids. These possible configurations and specific characteristics of renewable energy offer challenges in designing control and management algorithms for voltage, frequency and power in all possible operating scenarios. In this work, control algorithm is designed based on large-signal model that enables microgrid to operate in wide range of operating points. A combination between PI controller and feed-forward measured system responses will compensate for the changes in operating points. The control architecture developed in this work has multi-layers and the outer layer is slower than the inner layer in time response. The main responsibility of the designed controls are to regulate voltage magnitude and frequency, as well as output power of the DG(s). These local controls also integrate with a microgrid level energy management system or microgrid central controller (MGCC) for power and energy balance for. the entire microgrid in islanded, grid-connected, or networked microgid mode. The MGCC is responsible to coordinate the lower level controls to have reliable and resilient operation. In case of communication network failure, the decentralized energy management will operate locally and will activate droop control. Simulation results indicate the superiority of designed control algorithms compared to existing ones.

A novel approach to determine the in-plane thermal conductivity of gas diffusion layers in proton exchange membrane fuel cells

Science.gov (United States)

Sadeghi, E.; Djilali, N.; Bahrami, M.

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a proton exchange membrane (PEM) fuel cell. The analysis of this process requires determination of the effective thermal conductivity. This transport property differs significantly in the through-plane and in-plane directions due to the anisotropic micro-structure of the GDL. A novel test bed that allows separation of in-plane effective thermal conductivity and thermal contact resistance in GDLs is described in this paper. Measurements are performed using Toray carbon paper TGP-H-120 samples with varying polytetrafluoroethylene (PTFE) content at a mean temperature of 65-70 °C. The measurements are complemented by a compact analytical model that achieves good agreement with experimental data. The in-plane effective thermal conductivity is found to remain approximately constant, k ≈ 17.5 W m -1 K -1, over a wide range of PTFE content, and its value is about 12 times higher than that for through-plane conductivity.

Feasibility of X-ray analysis of multi-layer thin films at a single beam voltage

International Nuclear Information System (INIS)

Statham, P J

2010-01-01

Multi-layer analysis using electron beam excitation and X-ray spectrometry is a powerful tool for characterising layers down to 1 nm thickness and with typically 1 μm lateral resolution but does not always work. Most published applications have used WDS with many measurements at different beam voltages and considerable experience has been needed to choose lines and voltages particularly for complex multi-layer problems. A new objective mathematical approach is described which demonstrates whether X-ray analysis can obtain reliable results for an arbitrary multi-layer problem. A new algorithm embodied in 'ThinFilmID' software produces a single plot that shows feasibility of achieving results with a single EDS spectrum and suggests the optimal beam voltage. Synthesis of EDS spectra allows the precision in results to be estimated and acquisition conditions modified before wasting valuable instrument time. Thus, practicality of multi-layer thin film analysis at a single beam voltage can now be established without the extensive experimentation that was previously required by a microanalysis expert. Examples are shown where the algorithm discovers viable single-voltage conditions for applications that experts previously thought could only be addressed using measurements at more than one beam voltage.

A layers-overlapping strategy for robotic wire and arc additive manufacturing of multi-layer multi-bead components with homogeneous layers

NARCIS (Netherlands)

Li, Y.; Han, Qinglin; Zhang, Guangjun; Horvath, I.

2018-01-01

Robotic wire and arc additive manufacturing (WAAM) systems are required to provide predictable and efficient operations to fabricate solid metallic parts with high morphological fidelity and geometric accuracy. Since the metallic parts are fabricated based on a layer-by-layer principle, the

Enhancement of electroplex emission by using multi-layer device structure

International Nuclear Information System (INIS)

Wang Yuanmin; Teng Feng; Xu Zheng; Hou Yanbing; Wang Yongsheng; Xu Xurong

2005-01-01

Electroplex emission based on poly(N-vinylcarbazole) (PVK) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) has been improved dramatically by using a multi-layer device structure indium-tin oxide (ITO)/poly(3,4-ethylenedioxythiophene): poly(styrenesulphonic acid) (PEDOT:PSS)/PVK/BCP/PVK/BCP/LiF/Al. Electroplex emission at 595 nm has been improved about 10 times under low voltage and four times under high voltage compared to the double layer device ITO/PVK/BCP/Al. The maximum brightness of the device also has been improved about eight times. Bright white emission via electroplex formation can be obtained with Commission International d'Eclairage (CIE) coordinates (0.336, 0.320) at 26 V with a brightness of 123 cd/m 2 . Based on the analysis of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the materials, we suggest the enhancement is mainly ascribed to the confinement effect of the quantum-well-like multi-layer device structure. Every hole and electron has more possibilities to cross recombination at the PVK/BCP interface

Enhancement of electroplex emission by using multi-layer device structure

Energy Technology Data Exchange (ETDEWEB)

Wang Yuanmin [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Teng Feng [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China) and Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China)]. E-mail: advanced9898@126.com; Xu Zheng [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Hou Yanbing [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Wang Yongsheng [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Xu Xurong [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China)

2005-04-30

Electroplex emission based on poly(N-vinylcarbazole) (PVK) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) has been improved dramatically by using a multi-layer device structure indium-tin oxide (ITO)/poly(3,4-ethylenedioxythiophene): poly(styrenesulphonic acid) (PEDOT:PSS)/PVK/BCP/PVK/BCP/LiF/Al. Electroplex emission at 595 nm has been improved about 10 times under low voltage and four times under high voltage compared to the double layer device ITO/PVK/BCP/Al. The maximum brightness of the device also has been improved about eight times. Bright white emission via electroplex formation can be obtained with Commission International d'Eclairage (CIE) coordinates (0.336, 0.320) at 26 V with a brightness of 123 cd/m{sup 2}. Based on the analysis of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the materials, we suggest the enhancement is mainly ascribed to the confinement effect of the quantum-well-like multi-layer device structure. Every hole and electron has more possibilities to cross recombination at the PVK/BCP interface.

The Advanced Gamma-ray Imaging System (AGIS): Focal Plane Detectors

Science.gov (United States)

Mukherjee, Reshmi; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Horan, D.; Tajima, H.; Wagner, B.; Williams, D.

2008-04-01

Report of the Focal Plane Instrumentation Working Group, AGIS collaboration: The Advanced Gamma-ray Imaging System (AGIS) is a concept for the next generation instrument in ground-based very high energy gamma-ray astronomy. It has the goal of achieving significant improvement in sensitivity over current experiments. One of the main requirements for AGIS will be to achieve higher angular resolution than current imaging atmospheric Cherenkov telescopes (IACTs). Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to 0.05 deg, below that of current IACTs. Reducing the cost per channel and improving reliability and modularity are other important considerations. Here we present several alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs) and summarize results from feasibility testing by various AGIS photodetector group members.

Multi-wing hyperchaotic attractors from coupled Lorenz systems

International Nuclear Information System (INIS)

Grassi, Giuseppe; Severance, Frank L.; Miller, Damon A.

2009-01-01

This paper illustrates an approach to generate multi-wing attractors in coupled Lorenz systems. In particular, novel four-wing (eight-wing) hyperchaotic attractors are generated by coupling two (three) identical Lorenz systems. The paper shows that the equilibria of the proposed systems have certain symmetries with respect to specific coordinate planes and the eigenvalues of the associated Jacobian matrices exhibit the property of similarity. In analogy with the original Lorenz system, where the two-wings of the butterfly attractor are located around the two equilibria with the unstable pair of complex-conjugate eigenvalues, this paper shows that the four-wings (eight-wings) of these attractors are located around the four (eight) equilibria with two (three) pairs of unstable complex-conjugate eigenvalues.

A multi-layer MRI description of Parkinson's disease

Science.gov (United States)

La Rocca, M.; Amoroso, N.; Lella, E.; Bellotti, R.; Tangaro, S.

2017-09-01

Magnetic resonance imaging (MRI) along with complex network is currently one of the most widely adopted techniques for detection of structural changes in neurological diseases, such as Parkinson's Disease (PD). In this paper, we present a digital image processing study, within the multi-layer network framework, combining more classifiers to evaluate the informative power of the MRI features, for the discrimination of normal controls (NC) and PD subjects. We define a network for each MRI scan; the nodes are the sub-volumes (patches) the images are divided into and the links are defined using the Pearson's pairwise correlation between patches. We obtain a multi-layer network whose important network features, obtained with different feature selection methods, are used to feed a supervised multi-level random forest classifier which exploits this base of knowledge for accurate classification. Method evaluation has been carried out using T1 MRI scans of 354 individuals, including 177 PD subjects and 177 NC from the Parkinson's Progression Markers Initiative (PPMI) database. The experimental results demonstrate that the features obtained from multiplex networks are able to accurately describe PD patterns. Besides, also if a privileged scale for studying PD disease exists, exploring the informative content of more scales leads to a significant improvement of the performances in the discrimination between disease and healthy subjects. In particular, this method gives a comprehensive overview of brain regions statistically affected by the disease, an additional value to the presented study.

Detection of Multi-Layer and Vertically-Extended Clouds Using A-Train Sensors

Science.gov (United States)

Joiner, J.; Vasilkov, A. P.; Bhartia, P. K.; Wind, G.; Platnick, S.; Menzel, W. P.

2010-01-01

The detection of mUltiple cloud layers using satellite observations is important for retrieval algorithms as well as climate applications. In this paper, we describe a relatively simple algorithm to detect multiple cloud layers and distinguish them from vertically-extended clouds. The algorithm can be applied to coincident passive sensors that derive both cloud-top pressure from the thermal infrared observations and an estimate of solar photon pathlength from UV, visible, or near-IR measurements. Here, we use data from the A-train afternoon constellation of satellites: cloud-top pressure, cloud optical thickness, the multi-layer flag from the Aqua MODerate-resolution Imaging Spectroradiometer (MODIS) and the optical centroid cloud pressure from the Aura Ozone Monitoring Instrument (OMI). For the first time, we use data from the CloudSat radar to evaluate the results of a multi-layer cloud detection scheme. The cloud classification algorithms applied with different passive sensor configurations compare well with each other as well as with data from CloudSat. We compute monthly mean fractions of pixels containing multi-layer and vertically-extended clouds for January and July 2007 at the OMI spatial resolution (l2kmx24km at nadir) and at the 5kmx5km MODIS resolution used for infrared cloud retrievals. There are seasonal variations in the spatial distribution of the different cloud types. The fraction of cloudy pixels containing distinct multi-layer cloud is a strong function of the pixel size. Globally averaged, these fractions are approximately 20% and 10% for OMI and MODIS, respectively. These fractions may be significantly higher or lower depending upon location. There is a much smaller resolution dependence for fractions of pixels containing vertically-extended clouds (approx.20% for OMI and slightly less for MODIS globally), suggesting larger spatial scales for these clouds. We also find higher fractions of vertically-extended clouds over land as compared with

Global forward-predicting dynamic routing for traffic concurrency space stereo multi-layer scale-free network

International Nuclear Information System (INIS)

Xie Wei-Hao; Zhou Bin; Liu En-Xiao; Lu Wei-Dang; Zhou Ting

2015-01-01

Many real communication networks, such as oceanic monitoring network and land environment observation network, can be described as space stereo multi-layer structure, and the traffic in these networks is concurrent. Understanding how traffic dynamics depend on these real communication networks and finding an effective routing strategy that can fit the circumstance of traffic concurrency and enhance the network performance are necessary. In this light, we propose a traffic model for space stereo multi-layer complex network and introduce two kinds of global forward-predicting dynamic routing strategies, global forward-predicting hybrid minimum queue (HMQ) routing strategy and global forward-predicting hybrid minimum degree and queue (HMDQ) routing strategy, for traffic concurrency space stereo multi-layer scale-free networks. By applying forward-predicting strategy, the proposed routing strategies achieve better performances in traffic concurrency space stereo multi-layer scale-free networks. Compared with the efficient routing strategy and global dynamic routing strategy, HMDQ and HMQ routing strategies can optimize the traffic distribution, alleviate the number of congested packets effectively and reach much higher network capacity. (paper)

2D electron systems viewed through an RF spectrometer

International Nuclear Information System (INIS)

Andrei, E.Y.

1994-01-01

Electrons trapped at the liquid helium-vacuum interface are an almost ideal realization of a 2D electron system. I will describe experiments probing the in-plane as well as the out-of-plane motion of the electrons. The former have emphasized the dynamics and thermodynamics of the electronic motion within the plane to understand the nature of the liquid-solid transition and to outline its phase boundary. The latter have studied the escape out of the electron layer and provided an opportunity to observe tunneling in a clean and well-characterized system as well as to measure the effects of correlations on the tunneling process. More recently experiments in the presence of a magnetic field transverse to the direction of tunneling have revealed several novel phenomena associated with the magnetic coupling between the in-plane and the out-of-plane electronic motions. Together, these experiments helped uncover the multi-faceted physics that can be found in this system. (orig.)

Probing in-plane anisotropy in few-layer ReS2 using low frequency noise measurement

Science.gov (United States)

Mitra, Richa; Jariwala, Bhakti; Bhattacharya, Arnab; Das, Anindya

2018-04-01

ReS2, a layered two-dimensional material popular for its in-plane anisotropic properties, is emerging as one of the potential candidates for flexible electronics and ultrafast optical applications. It is an n-type semiconducting material having a layer independent bandgap of 1.55 eV. In this paper we have characterized the intrinsic electronic noise level of few-layer ReS2 for the first time. Few-layer ReS2 field effect transistor devices show a 1/f nature of noise for frequency ranging over three orders of magnitude. We have also observed that not only the electrical response of the material is anisotropic; the noise level is also dependent on direction. In fact the noise is found to be more sensitive towards the anisotropy. This fact has been explained by evoking the theory where the Hooge parameter is not a constant quantity, but has a distinct power law dependence on mobility along the two-axes direction. The anisotropy in 1/f noise measurement will pave the way to quantify the anisotropic nature of two-dimensional (2D) materials, which will be helpful for the design of low-noise transistors in future.

Some Considerations Regarding Plane to Plane Parallelism Error Effects in Robotic Systems

Directory of Open Access Journals (Sweden)

Stelian Alaci

2015-06-01

Full Text Available The paper shows that by imposing the parallelism constraint between the measured plane and the reference plane, the position of the current plane is not univocal specified and is impossible to specify the way to attain the parallelism errors imposed by accuracy constrains. The parameters involved in the calculus of plane to plane parallelism error can be used to set univocal the relative position between the two planes.

Multi-Directional Environmental Sensors

Science.gov (United States)

Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

2016-01-01

Systems and methods in accordance with embodiments of the invention implement multi-directional environmental sensors. In one embodiment, a multi-directional environmental sensor includes: an inner conductive element that is substantially symmetrical about three orthogonal planes; an outer conductive element that is substantially symmetrical about three orthogonal planes; and a device that measures the electrical characteristics of the multi-directional environmental sensor, the device having a first terminal and a second terminal; where the inner conductive element is substantially enclosed within the outer conductive element; where the inner conductive element is electrically coupled to the first terminal of the device; and where the outer conductive element is electrically coupled to the second terminal of the device.

A heuristic algorithm for a multi-product four-layer capacitated location-routing problem

Directory of Open Access Journals (Sweden)

Mohsen Hamidi

2014-01-01

Full Text Available The purpose of this study is to solve a complex multi-product four-layer capacitated location-routing problem (LRP in which two specific constraints are taken into account: 1 plants have limited production capacity, and 2 central depots have limited capacity for storing and transshipping products. The LRP represents a multi-product four-layer distribution network that consists of plants, central depots, regional depots, and customers. A heuristic algorithm is developed to solve the four-layer LRP. The heuristic uses GRASP (Greedy Randomized Adaptive Search Procedure and two probabilistic tabu search strategies of intensification and diversification to tackle the problem. Results show that the heuristic solves the problem effectively.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

Science.gov (United States)

Li, Na; Chen, Fei; Shen, Qiang; Wang, Chuanbin; Zhang, Lianmeng

2013-03-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

International Nuclear Information System (INIS)

Li Na; Chen Fei; Shen Qiang; Wang Chuanbin; Zhang Lianmeng

2013-01-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

Simulation of Tomographic Reconstruction of Magnetosphere Plasma Distribution By Multi-spacecraft Systems.

Science.gov (United States)

Kunitsyn, V.; Nesterov, I.; Andreeva, E.; Zelenyi, L.; Veselov, M.; Galperin, Y.; Buchner, J.

A satellite radiotomography method for electron density distributions was recently proposed for closely-space multi-spacecraft group of high-altitude satellites to study the physics of reconnection process. The original idea of the ROY project is to use a constellation of spacecrafts (one main and several sub-satellites) in order to carry out closely-spaced multipoint measurements and 2D tomographic reconstruction of elec- tron density in the space between the main satellite and the subsatellites. The distances between the satellites were chosen to vary from dozens to few hundreds of kilometers. The easiest data interpretation is achieved when the subsatellites are placed along the plasma streamline. Then, whenever a plasma density irregularity moves between the main satellite and the subsatellites it will be scanned in different directions and we can get 2D distribution of plasma using these projections. However in general sub- satellites are not placed exactly along the plasma streamline. The method of plasma velocity determination relative to multi-spacecraft systems is considered. Possibilities of 3D tomographic imaging using multi-spacecraft systems are analyzed. The model- ing has shown that efficient scheme for 3D tomographic imaging would be to place spacecrafts in different planes so that the angle between the planes would make not more then ten degrees. Work is supported by INTAS PROJECT 2000-465.

Structural and electronic properties of InN epitaxial layer grown on c-plane sapphire by chemical vapor deposition technique

Energy Technology Data Exchange (ETDEWEB)

Barick, Barun Kumar, E-mail: bkbarick@gmail.com; Prasad, Nivedita; Saroj, Rajendra Kumar; Dhar, Subhabrata [Department of Physics, Indian Institute of Technology, Bombay, Mumbai 400076 (India)

2016-09-15

Growth of InN epilayers on c-plane sapphire substrate by chemical vapor deposition technique using pure indium metal and ammonia as precursors has been systematically explored. It has been found that [0001] oriented indium nitride epitaxial layers with smooth surface morphology can be grown on c-plane sapphire substrates by optimizing the growth conditions. Bandgap of the film is observed to be Burstein–Moss shifted likely to be due to high background electron concentration. It has been found that the concentration of this unintentional doping decreases with the increase in the growth temperature and the ammonia flux. Epitaxial quality on the other hand deteriorates as the growth temperature increases. Moreover, the morphology of the deposited layer has been found to change from flat top islands to faceted mounds as the flow rate of ammonia increases. This phenomenon is expected to be related to the difference in surface termination character at low and high ammonia flow rates.

Linux block IO: introducing multi-queue SSD access on multi-core systems

DEFF Research Database (Denmark)

Bjørling, Matias; Axboe, Jens; Nellans, David

2013-01-01

The IO performance of storage devices has accelerated from hundreds of IOPS five years ago, to hundreds of thousands of IOPS today, and tens of millions of IOPS projected in five years. This sharp evolution is primarily due to the introduc- tion of NAND-flash devices and their data parallel desig...... generation block layer that is capable of handling tens of millions of IOPS on a multi-core system equipped with a single storage device. Our experiments show that our design scales graciously with the number of cores, even on NUMA systems with multiple sockets....

A multi-layered network of the (Colombian) sovereign securities market

NARCIS (Netherlands)

Renneboog, Luc; Leon Rincon, Carlos; Pérez, Jhonatan; Alexandrova-Kabadjova, Bilana; Diehl, Martin; Heuver, Richard; Martinez-Jaramillo, Serafín

2015-01-01

We study the network of Colombian sovereign securities settlements. With data from the settlement market infrastructure we study financial institutions’ transactions from three different trading and registering individual networks that we combine into a multi-layer network. Examining this network of

Surface EMG signals based motion intent recognition using multi-layer ELM

Science.gov (United States)

Wang, Jianhui; Qi, Lin; Wang, Xiao

2017-11-01

The upper-limb rehabilitation robot is regard as a useful tool to help patients with hemiplegic to do repetitive exercise. The surface electromyography (sEMG) contains motion information as the electric signals are generated and related to nerve-muscle motion. These sEMG signals, representing human's intentions of active motions, are introduced into the rehabilitation robot system to recognize upper-limb movements. Traditionally, the feature extraction is an indispensable part of drawing significant information from original signals, which is a tedious task requiring rich and related experience. This paper employs a deep learning scheme to extract the internal features of the sEMG signals using an advanced Extreme Learning Machine based auto-encoder (ELMAE). The mathematical information contained in the multi-layer structure of the ELM-AE is used as the high-level representation of the internal features of the sEMG signals, and thus a simple ELM can post-process the extracted features, formulating the entire multi-layer ELM (ML-ELM) algorithm. The method is employed for the sEMG based neural intentions recognition afterwards. The case studies show the adopted deep learning algorithm (ELM-AE) is capable of yielding higher classification accuracy compared to the Principle Component Analysis (PCA) scheme in 5 different types of upper-limb motions. This indicates the effectiveness and the learning capability of the ML-ELM in such motion intent recognition applications.

Synergy of exchange bias with superconductivity in ferromagnetic-superconducting layered hybrids: the influence of in-plane and out-of-plane magnetic order on superconductivity

International Nuclear Information System (INIS)

Stamopoulos, D; Manios, E; Pissas, M

2007-01-01

It is generally believed that superconductivity and magnetism are two antagonistic long-range phenomena. However, as was preliminarily highlighted in Stamopoulos et al (2007 Phys. Rev. B 75 014501), and extensively studied in this work, under specific circumstances these phenomena instead of being detrimental to each other may even become cooperative so that their synergy may promote the superconducting properties of a hybrid structure. Here, we have studied systematically the magnetic and transport behavior of such exchange biased hybrids that are comprised of ferromagnetic (FM) Ni 80 Fe 20 and low-T c superconducting (SC) Nb for the case where the magnetic field is applied parallel to the specimens. Two structures have been studied: FM-SC-FM trilayers (TLs) and FM-SC bilayers (BLs). Detailed magnetization data on the longitudinal and transverse magnetic components are presented for both the normal and superconducting states. These data are compared to systematic transport measurements including I-V characteristics. The comparison of the exchange biased BLs and TLs that are studied here with the plain ones studied in Stamopoulos et al (2007 Phys. Rev. B 75 184504) enable us to reveal an underlying parameter that may falsify the interpretation of the transport properties of relevant FM-SC-FM TLs and FM-SC BLs investigated in the recent literature: the underlying mechanism motivating the extreme magnetoresistance peaks in the TLs relates to the suppression of superconductivity mainly due to the magnetic coupling of the two FM layers as the out-of-plane rotation of their magnetizations takes place across the coercive field where stray fields emerge in their whole surface owing to the multidomain magnetic state that they acquire. The relative in-plane magnetization configuration of the outer FM layers exerts a secondary contribution on the SC interlayer. Since the exchange bias directly controls the in-plane magnetic order it also controls the out-of-plane rotation of

Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

Directory of Open Access Journals (Sweden)

Zheng-gang Xiao

2014-06-01

Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

A multi-scale and multi-field coupling nonlinear constitutive theory for the layered magnetoelectric composites

Science.gov (United States)

Xu, Hao; Pei, Yongmao; Li, Faxin; Fang, Daining

2018-05-01

The magnetic, electric and mechanical behaviors are strongly coupled in magnetoelectric (ME) materials, making them great promising in the application of functional devices. In this paper, the magneto-electro-mechanical fully coupled constitutive behaviors of ME laminates are systematically studied both theoretically and experimentally. A new probabilistic domain switching function considering the surface ferromagnetic anisotropy and the interface charge-mediated effect is proposed. Then a multi-scale multi-field coupling nonlinear constitutive model for layered ME composites is developed with physical measureable parameters. The experiments were performed to compare the theoretical predictions with the experimental data. The theoretical predictions have a good agreement with experimental results. The proposed constitutive relation can be used to describe the nonlinear multi-field coupling properties of both ME laminates and thin films. Several novel coupling experimental phenomena such as the electric-field control of magnetization, and the magnetic-field tuning of polarization are observed and analyzed. Furthermore, the size-effect of the electric tuning behavior of magnetization is predicted, which demonstrates a competition mechanism between the interface strain-mediated effect and the charge-driven effect. Our study offers deep insight into the coupling microscopic mechanism and macroscopic properties of ME layered composites, which is benefit for the design of electromagnetic functional devices.

Cosmic radiation shielding properties of COLUMBUS and REMSIM multi-layer external shells

Science.gov (United States)

Durante, Marco; Manti, Lorenzo; Rusek, Adam; Belluco, Maurizio; Lobascio, Cesare

The European module COLUMBUS has been recently installed on the International Space Station. Future plans for exploration involve the use of inflatable modules, such as the REMSIM concept proposed in a previous ESA funded study. We studied the radiation shielding properties of COLUMBUS and REMSIM external shell using 1 GeV/n Feor H-ions accelerated at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory (Long Island, NY, USA). COLUMBUS has a 22 mm rigid multi-layer shell with Al, Nextel and Kevlar, as materials of the double bumper for meteoroids and debris protection, MLI for thermal reasons and again Al as pressure shell. Inside the module, astronauts are further protected by secondary structures, including racks, a number of electronic devices and payload equipment. This internal equipment has been simulated using Al and Kevlar, bringing the total thickness to about 15 g/cm2. REMSIM consists of a thermal multi-layer (MLI), four Nextel layers used to provide shock of the impacting micro-meteoroids, a ballistic restraint multi-layer of Kevlar used to absorb debris cloud's kinetic energy, a Kevlar structural restraint to support pressure loads incurred from inflating the module. To contain air inside the module, REMSIM adopts three layers of airtight material separated by two layers of Kevlar (air bladder). A final layer of Nomex provide protection against punctures and fire. In the flight configuration there are also spacer elements (foam) needed to guarantee correct spacing between consecutive bumper layers. These spacers were not included in the tests, making the total thickness about 1.1 cm. The internal equipment in REMSIM was not been defined, but due to its application for exploration missions it was decided to exploit water, valuable resource used for drinking, washing and technical usage, as a radiation shielding. In this test, we have included about 8 cm of water. Measured dose attenuation shows that the Columbus module reduces the

Layer-oriented multigrid wavefront reconstruction algorithms for multi-conjugate adaptive optics

Science.gov (United States)

Gilles, Luc; Ellerbroek, Brent L.; Vogel, Curtis R.

2003-02-01

Multi-conjugate adaptive optics (MCAO) systems with 104-105 degrees of freedom have been proposed for future giant telescopes. Using standard matrix methods to compute, optimize, and implement wavefront control algorithms for these systems is impractical, since the number of calculations required to compute and apply the reconstruction matrix scales respectively with the cube and the square of the number of AO degrees of freedom. In this paper, we develop an iterative sparse matrix implementation of minimum variance wavefront reconstruction for telescope diameters up to 32m with more than 104 actuators. The basic approach is the preconditioned conjugate gradient method, using a multigrid preconditioner incorporating a layer-oriented (block) symmetric Gauss-Seidel iterative smoothing operator. We present open-loop numerical simulation results to illustrate algorithm convergence.

Design optimization of multi-layer Silicon Carbide cladding for light water reactors

Energy Technology Data Exchange (ETDEWEB)

Lee, Youho, E-mail: euo@unm.edu [Department of Nuclear Engineering, University of New Mexico, MSC01 1120 1 University of New Mexico, Albuquerque, NM 87131 (United States); NO, Hee Cheon, E-mail: hcno@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2017-01-15

Highlights: • SiC cladding designs are optimized with a multi-layer structural analysis code. • Layer radial thickness fraction that minimizes cladding fracture probability exists. • The demonstrated procedure is applicable for multi-layer SiC cladding design. • Duplex SiC with the inner composite fraction ∼0.4 is optimal in a reference case. • Increasing composite thermal conductivity markedly decreases SiC cladding stress. - Abstract: A parametric study that demonstrates a methodology for determining the optimum bilayer composition in a duplex SiC cladding is discussed. The structural performance of multi-layer SiC cladding design is significantly affected by radial thickness fraction of each layer. This study shows that there exists an optimal composite/monolith radial thickness fraction that minimizes failure probability for a duplex SiC cladding in steady-state operation. An exemplary reference case study shows that the duplex cladding with the inner composite fraction ∼0.4 and the outer CVD-SiC fraction ∼0.6 is found to be the optimal SiC cladding design for the current PWRs with the reference material choice for CVD-SiC and fiber reinforced composite. A marginal increase in the composite fraction from the presented optimal designs may lead to increase structural integrity by introducing some unquantified merits such as increasing damage tolerance. The major factors that affect the optimum cladding designs are temperature gradients and internal gas pressure. Clad wall thickness, thermal conductivity, and Weibull modulus are among the key design parameters/material properties.

Three-dimensional multi-terminal superconductive integrated circuit inductance extraction

International Nuclear Information System (INIS)

Fourie, Coenrad J; Wetzstein, Olaf; Kunert, Jürgen; Ortlepp, Thomas

2011-01-01

Accurate inductance calculations are critical for the design of both digital and analogue superconductive integrated circuits, and three-dimensional calculations are gaining importance with the advent of inductive biasing, inductive coupling and sky plane shielding for RSFQ cells. InductEx, an extraction programme based on the three-dimensional calculation software FastHenry, was proposed earlier. InductEx uses segmentation techniques designed to accurately model the geometries of superconductive integrated circuit structures. Inductance extraction for complex multi-terminal three-dimensional structures from current distributions calculated by FastHenry is discussed. Results for both a reflection plane modelling an infinite ground plane and a finite segmented ground plane that allows inductive elements to extend over holes in the ground plane are shown. Several SQUIDs were designed for and fabricated with IPHT's 1 kA cm −2 RSFQ1D niobium process. These SQUIDs implement a number of loop structures that span different layers, include vias, inductively coupled control lines and ground plane holes. We measured the loop inductance of these SQUIDs and show how the results are used to calibrate the layer parameters in InductEx and verify the extraction accuracy. We also show that, with proper modelling, FastHenry can be fast enough to be used for the extraction of typical RSFQ cell inductances.

Multi-layer thickness determination using differential-based enhanced Fourier transforms of X-ray reflectivity data

Energy Technology Data Exchange (ETDEWEB)

Poust, Benjamin [Department of Materials Science and Engineering, University of California, Los Angeles, CA (United States); Northrop Grumman Space Technology, Redondo Beach, CA (United States); Sandhu, Rajinder [Northrop Grumman Space Technology, Redondo Beach, CA (United States); Goorsky, Mark [Department of Materials Science and Engineering, University of California, Los Angeles, CA (United States)

2009-08-15

Layer thickness determination of single and multi-layer structures is achieved using a new method for generating Fourier transforms (FTs) of X-ray reflectivity data. This enhanced Fourier analysis is compared to other techniques in the determination of AlN layer thickness deposited on sapphire. In addition to demonstrably improved results, the results also agree with thicknesses determined using simulations and TEM measurements. The effectiveness of the technique is further demonstrated using the more complicated metamorphic epitaxial multi-layer AlSb/InAs structures deposited on GaAs. The approach reported here is based upon differentiating the specular intensity with respect to the vertical reciprocal space coordinate Q{sub Z}. In general, differentiation is far more effective at removing the sloping background present in reflectivity scans than logarithmic compression alone, average subtraction alone, or other methods. When combined with any of the other enhancement techniques, however, differentiation yields distinguishable discrete Fourier transform (DFT) power spectrum peaks for even the weakest and most truncated of sloping oscillations that are present in many reflectivity scans from multi-layer structures. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Multi-Layer Sparse Representation for Weighted LBP-Patches Based Facial Expression Recognition

Directory of Open Access Journals (Sweden)

Qi Jia

2015-03-01

Full Text Available In this paper, a novel facial expression recognition method based on sparse representation is proposed. Most contemporary facial expression recognition systems suffer from limited ability to handle image nuisances such as low resolution and noise. Especially for low intensity expression, most of the existing training methods have quite low recognition rates. Motivated by sparse representation, the problem can be solved by finding sparse coefficients of the test image by the whole training set. Deriving an effective facial representation from original face images is a vital step for successful facial expression recognition. We evaluate facial representation based on weighted local binary patterns, and Fisher separation criterion is used to calculate the weighs of patches. A multi-layer sparse representation framework is proposed for multi-intensity facial expression recognition, especially for low-intensity expressions and noisy expressions in reality, which is a critical problem but seldom addressed in the existing works. To this end, several experiments based on low-resolution and multi-intensity expressions are carried out. Promising results on publicly available databases demonstrate the potential of the proposed approach.

Modelling mass diffusion for a multi-layer sphere immersed in a semi-infinite medium: application to drug delivery.

Science.gov (United States)

Carr, Elliot J; Pontrelli, Giuseppe

2018-04-12

We present a general mechanistic model of mass diffusion for a composite sphere placed in a large ambient medium. The multi-layer problem is described by a system of diffusion equations coupled via interlayer boundary conditions such as those imposing a finite mass resistance at the external surface of the sphere. While the work is applicable to the generic problem of heat or mass transfer in a multi-layer sphere, the analysis and results are presented in the context of drug kinetics for desorbing and absorbing spherical microcapsules. We derive an analytical solution for the concentration in the sphere and in the surrounding medium that avoids any artificial truncation at a finite distance. The closed-form solution in each concentric layer is expressed in terms of a suitably-defined inverse Laplace transform that can be evaluated numerically. Concentration profiles and drug mass curves in the spherical layers and in the external environment are presented and the dependency of the solution on the mass transfer coefficient at the surface of the sphere analyzed. Copyright © 2018 Elsevier Inc. All rights reserved.

Dynamic propagation of a weak-discontinuous interface crack between two dissimilar functionally graded layers under anti-plane shear

International Nuclear Information System (INIS)

Shin, Jeong Woo; Lee, Young Shin

2011-01-01

The dynamic propagation of an interface crack between two functionally graded material (FGM) layers under anti-plane shear is analyzed using the integral transform method. The properties of the FGM layers vary continuously along their thicknesses. The properties of the two FGM layers vary and the two layers are connected weak-discontinuously. A constant velocity Yoffe-type moving crack is considered. The Fourier transform is used to reduce the problem to a dual integral equation, which is then expressed to a Fredholm integral equation of the second kind. Numerical values on the dynamic energy release rate (DERR) are presented for the FGM to show the effect of the gradient of material properties, crack moving velocity, and thickness of FGM layers. The following are helpful to increase resistance to interface crack propagation in FGMs: a) increasing the gradient of material properties, b) an increase of shear modulus and density from the interface to the upper and lower free surface, and c) increasing the thickness of the FGM layer. The DERR increases or decreases with increase of the crack moving velocity

Magnetohydrodynamic Kelvin-Helmholtz instabilities in astrophysics. 1. Relativistic flows-plane boundary layer in vortex sheet approximation

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A; Trussoni, E; Zaninetti, L [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica)

1980-11-01

In this paper some unsolved problems of the linear MHD Kelvin-Helmholtz instability are re-examined, starting from the analysis of relativistic (and non-relativistic) flows in the approximation of a plane vortex sheet, for the contact layer between the fluids in relative motion. Results are discussed for a range of physical parameters in specific connection with application to models of jets in extragalactic radio sources. Other physical aspects of the instability will be considered in forthcoming papers.

Studies of a new multi-layer compression bandage for the treatment of venous ulceration.

Science.gov (United States)

Scriven, J M; Bello, M; Taylor, L E; Wood, A J; London, N J

2000-03-01

This study aimed to develop an alternative graduated compression bandage for the treatment of venous leg ulcers. Alternative bandage components were identified and assessed for optimal performance as a graduated multi-layer compression bandage. Subsequently the physical characteristics and clinical efficacy of the optimal bandage combination was prospectively examined. Ten healthy limbs were used to develop the optimal combination and 20 limbs with venous ulceration to compare the physical properties of the two bandage types. Subsequently 42 consecutive ulcerated limbs were prospectively treated to examine the efficacy of the new bandage combination. The new combination produced graduated median (range) sub-bandage pressures (mmHg) as follows: ankle 59 (42-100), calf 36 (27-67) and knee 35 (16-67). Over a seven-day period this combination maintained a comparable level of compression with the Charing Cross system, and achieved an overall healing rate at one year of 88%. The described combination should be brought to the attention of healthcare professionals treating venous ulcers as a possible alternative to other forms of multi-layer graduated compression bandages pending prospective, randomised clinical trials.

Extended Traffic Crash Modelling through Precision and Response Time Using Fuzzy Clustering Algorithms Compared with Multi-layer Perceptron

Directory of Open Access Journals (Sweden)

Iman Aghayan

2012-11-01

Full Text Available This paper compares two fuzzy clustering algorithms – fuzzy subtractive clustering and fuzzy C-means clustering – to a multi-layer perceptron neural network for their ability to predict the severity of crash injuries and to estimate the response time on the traffic crash data. Four clustering algorithms – hierarchical, K-means, subtractive clustering, and fuzzy C-means clustering – were used to obtain the optimum number of clusters based on the mean silhouette coefficient and R-value before applying the fuzzy clustering algorithms. The best-fit algorithms were selected according to two criteria: precision (root mean square, R-value, mean absolute errors, and sum of square error and response time (t. The highest R-value was obtained for the multi-layer perceptron (0.89, demonstrating that the multi-layer perceptron had a high precision in traffic crash prediction among the prediction models, and that it was stable even in the presence of outliers and overlapping data. Meanwhile, in comparison with other prediction models, fuzzy subtractive clustering provided the lowest value for response time (0.284 second, 9.28 times faster than the time of multi-layer perceptron, meaning that it could lead to developing an on-line system for processing data from detectors and/or a real-time traffic database. The model can be extended through improvements based on additional data through induction procedure.

Anisotropically biaxial strain in non-polar (112-0) plane In x Ga1-x N/GaN layers investigated by X-ray reciprocal space mapping.

Science.gov (United States)

Zhao, Guijuan; Li, Huijie; Wang, Lianshan; Meng, Yulin; Ji, Zesheng; Li, Fangzheng; Wei, Hongyuan; Yang, Shaoyan; Wang, Zhanguo

2017-07-03

In this study, the indium composition x as well as the anisotropically biaxial strain in non-polar a-plane In x Ga 1-x N on GaN is studied by X-ray diffraction (XRD) analysis. In accordance with XRD reciprocal lattice space mapping, with increasing indium composition, the maximum of the In x Ga 1-x N reciprocal lattice points progressively shifts from a fully compressive strained to a fully relaxed position, then to reversed tensile strained. To fully understand the strain in the ternary alloy layers, it is helpful to grow high-quality device structures using a-plane nitrides. As the layer thickness increases, the strain of In x Ga 1-x N layer releases through surface roughening and the 3D growth-mode.

Thermal modeling of multi-shape heating sources on n-layer electronic board

Directory of Open Access Journals (Sweden)

Monier-Vinard Eric

2017-01-01

Full Text Available The present work completes the toolbox of analytical solutions that deal with resolving steady-state temperatures of a multi-layered structure heated by one or many heat sources. The problematic of heating sources having non-rectangular shapes is addressed to enlarge the capability of analytical approaches. Moreover, various heating sources could be located on the external surfaces of the sandwiched layers as well as embedded at interface of its constitutive layers. To demonstrate its relevance, the updated analytical solution has been compared with numerical simulations on the case of a multi-layered electronic board submitted to a set of heating source configurations. The comparison shows a high agreement between analytical and numerical calculations to predict the centroid and average temperatures. The promoted analytical approach establishes a kit of practical expressions, easy to implement, which would be cumulated, using superposition principle, to help electronic designers to early detect component or board temperatures beyond manufacturer limit. The ability to eliminate bad concept candidates with a minimum of set-up, relevant assumptions and low computation time can be easily achieved.

A Comparison of Homogeneous and Multi-layered Berm Breakwaters with Respect to Overtopping and Stability

DEFF Research Database (Denmark)

Andersen, Thomas Lykke; Skals, Kasper; Burcharth, Hans F.

2008-01-01

The paper deals with homogeneous and multi-layer berm breakwaters designed to maximize the utilization of the quarry material. Two wide stone classes are typically used for berm breakwaters with a homogeneous berm.......The paper deals with homogeneous and multi-layer berm breakwaters designed to maximize the utilization of the quarry material. Two wide stone classes are typically used for berm breakwaters with a homogeneous berm....

Support vector regression model for the estimation of γ-ray buildup factors for multi-layer shields

International Nuclear Information System (INIS)

Trontl, Kresimir; Smuc, Tomislav; Pevec, Dubravko

2007-01-01

The accuracy of the point-kernel method, which is a widely used practical tool for γ-ray shielding calculations, strongly depends on the quality and accuracy of buildup factors used in the calculations. Although, buildup factors for single-layer shields comprised of a single material are well known, calculation of buildup factors for stratified shields, each layer comprised of different material or a combination of materials, represent a complex physical problem. Recently, a new compact mathematical model for multi-layer shield buildup factor representation has been suggested for embedding into point-kernel codes thus replacing traditionally generated complex mathematical expressions. The new regression model is based on support vector machines learning technique, which is an extension of Statistical Learning Theory. The paper gives complete description of the novel methodology with results pertaining to realistic engineering multi-layer shielding geometries. The results based on support vector regression machine learning confirm that this approach provides a framework for general, accurate and computationally acceptable multi-layer buildup factor model

Multi-layered silicides coating for vanadium alloys for generation IV reactors

International Nuclear Information System (INIS)

Mathieu, S.; Chaia, N.; Vilasi, M.; Le Flem, M.

2012-01-01

The halide-activated pack-cementation technique was employed to fabricate a diffusion coating that is resistant both to isothermal and to cyclic oxidation in air at 650 degrees C on the surface of the V-4Cr-4Ti vanadium alloy that is a potential core component of future nuclear systems. A thermodynamic assessment determined the deposit conditions in terms of master alloy, activator, filler and temperature. The partial pressures of the main gaseous species (SiCl 4 , SiCl 2 and VCl 2 ) in the pack were calculated with the master alloy Si and the mixture VSi 2 + Si. The VSi 2 + Si master alloy was used to limit vanadium loss from the surface. The obtained coating consisted of multi-layered V x Si y silicides with an outer layer of VSi 2 . This silicide developed a protective layer of silica at 650 degrees C in air and was not susceptible to the pest phenomenon, unlike other refractory silicides (MoSi 2 , NbSi 2 ). We suggest that VSi 2 exhibits no risk of rapid degradation in the gas fast reactor (GFR) conditions. (authors)

Heat transfer characteristics of horizontally oriented multi-layered annular insulation, (1)

International Nuclear Information System (INIS)

Hino, Ryutaro; Simomura, Hiroaki

1985-04-01

A computer code has been developed to analyze the natural convection heat transfer in a horizontal annular insulation layer of a hot gas duct when local gaps and inhomogeneity of filling density of insulation materials exist. This computer code simulates local gaps and inhomogeneity of filling density by a multi-layer model. This report describes an analytical model, a numerical method, an outline of program and some calculation results. (author)

Heteroepitaxial growth of basal plane stacking fault free a-plane GaN

Energy Technology Data Exchange (ETDEWEB)

Wieneke, Matthias; Hempel, Thomas; Noltemeyer, Martin; Witte, Hartmut; Dadgar, Armin; Blaesing, Juergen; Christen, Juergen; Krost, Alois [Otto-von-Guericke Universitaet Magdeburg, FNW/IEP, Magdeburg (Germany)

2010-07-01

Growth of light emitting quantum-wells based on a-plane GaN is a possibility to reduce or even to avoid polarization correlated luminescence red shift and reduction of radiative recombination efficiency. But until now heteroepitaxially grown a-plane GaN films are characterized by a poor crystalline quality expressed by a high density of basal plane stacking faults (BSF) and partial dislocations. We present Si doped a-plane GaN films grown on r-plane sapphire substrates by metal organic vapor phase epitaxy using high temperature AlGaN nucleation layers. FE-SEM images revealed three dimensionally grown GaN crystallites sized up to tenth micrometer in the basal plane and a few tenth micrometers along the c-axes. Though, the full width at half maxima of the X-ray diffraction {omega}-scans of the in-plane GaN(1 anti 100) and GaN(0002) Bragg reflections exhibited a very high crystal quality. Furthermore, luminescence spectra were dominated by near band gap emission, while there was no separated peak of the basal plane stacking fault. In summary we present heteroepitaxially grown a-plane GaN without an evidence of basal plane stacking faults in X-ray diffraction measurements and luminescence spectra.

Optical properties of metallic multi-layer films

International Nuclear Information System (INIS)

Dimmich, R.

1991-09-01

Optical properties of multi-layer films consisting of alternating layers of two different metals are studied on the basis of the Maxwell equations and the Boltzmann transport theory. The influence of free-electron scattering at the film external surface and at the interfaces is taken into account and considered as a function of the electromagnetic field frequency and the structure modulation wavelength. Derived formulas for optical coefficients are valid at low frequencies, where the skin effect is nearly classical, as well as in the near-infrared, visible and ultraviolet spectral ranges, where the skin effect has the anomalous nature. It is shown that the obtained results are apparently dependent on the values of the scattering parameters. What is more, the oscillatory nature of analyzed spectra is observed, where the two oscillation periods may appear on certain conditions. The oscillations result from the electron surface and interface scattering and their amplitudes and periods depend on the boundary conditions for free-electron scattering. Finally, the application of the interference phenomenon in dielectric layers is proposed to obtain the enhancement of the non distinct details which can appear in optical spectra of metallic films. (author). 31 refs, 6 figs

Numerical simulation of multi-layer graphene structures based on quantum-chemical model

International Nuclear Information System (INIS)

Kasper, Y; Tuchin, A; Bokova, A; Bityutskaya, L

2016-01-01

The electronic structure of the multi-layer graphene has been studied using the density functional theory (DFT). The dependence of the average interlayer distance on the number of layers ( n = 2 ÷ 6) has been determined. The analysis of the charge redistribution and the electron density of the bi- and three-layer graphene under the external pressure up to 50 GPa has been performed. The model of the interlayer conductivity of compressed multigraphene was offered (paper)

Study the Z-Plane Strip Capacitance

International Nuclear Information System (INIS)

Parikh, H.; Swain, S.

2005-01-01

The BaBaR detector at the Stanford Linear Accelerator Center is currently undergoing an upgrade to improve its muon and neutral hadron detection system. The Resistive Plate Chambers (RPCs) that had been used till now have deteriorated in performance over the past few years and are being replaced by Limited Streamer Tube (LSTs). Each layer of the system consists of a set of up to 10 streamer tube modules which provide one coordinate (φ coordinate) and a single ''Z-plane'' which provides the Z coordinate of the hit. The large area Z-planes (up to 12m 2 ) are 1mm thick and contain 96 copper strips that detect the induced charge from avalanches created in the streamer tube wires. All the Z-planes needed for the upgrade have already been constructed, but only a third of the planes were installed last summer. After installing the 24 Z-planes last year, it was learned that 0.7% of the strips were dead when put inside the detector. This was mainly due to the delicate solder joint between the read-out cable and the strip, and since it is difficult to access or replace the Z-planes inside the detector, it is very important to perform various tests to make sure that the Z-planes will be efficient and effective in the long term. We measure the capacitance between the copper strips and the ground plane, and compare it to the theoretical value that we expect. Instead of measuring the capacitance channel by channel, which would be a very tedious job, we developed a more effective method of measuring the capacitance. Since all the Z-planes were built at SLAC, we also built a smaller 46 cm by 30 cm Z-plane with 12 strips just to see how they were constructed and to gain a better understanding about the solder joints

Elasto/visco-plastic dynamic response of multi-layered shells of revolution

International Nuclear Information System (INIS)

Takezono, S.; Tao, K.; Taguchi, T.

1989-01-01

Many investigations of the elasto/visco-plastic dynamic response of shells have been conducted. These investigations, however, have been mostly concerned with the case of single-layered shells, and few studies on multi-layered shells have been reported in spite of their importance in engineering. In this paper, the authors study the elasto/visco-plastic dynamic response of the multi-layered shells of revolution subjected to impulsive loads. The equations of motion and the relations between the strains and displacements are derived by extending Sanders' theory for elastic thin shells. As the constitutive relation, Hooke's law is used in the linear elastic range, and the elasto/visco-plastic equations are employed in the plastic range. The criterion for yielding used in the analysis is the von Mises yield theory. In the numerical analysis of the fundamental equations for incremental values an usual finite difference form is employed for the spatial derivatives and the inertia terms are treated with the backward difference formula. The solutions are obtained by summation of the incremental values

Collaborative Multi-Layer Network Coding in Hybrid Cellular Cognitive Radio Networks

KAUST Repository

Moubayed, Abdallah J.; Sorour, Sameh; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

2015-01-01

In this paper, as an extension to [1], we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in hybrid (interweave and underlay) cellular cognitive radio networks. This scheme allows the uncoordinated

Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks

KAUST Repository

Moubayed, Abdallah J.

2014-01-01

In this thesis, as an extension to [1], we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in hybrid (interweave and underlay) cellular cognitive radio networks. This scheme allows the uncoordinated

MEMS mass-spring-damper systems using an out-of-plane suspension scheme

KAUST Repository

Abdel Aziz, Ahmed Kamal Said; Sharaf, Abdel Hameed; Serry, Mohamed Yousef; Sedky, Sherif Salah

2014-01-01

MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

MEMS mass-spring-damper systems using an out-of-plane suspension scheme

KAUST Repository

Abdel Aziz, Ahmed Kamal Said

2014-02-04

MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

Cross-layer optimization of wireless multi-hop networks

OpenAIRE

Soldati, Pablo

2007-01-01

The interest in wireless communications has grown constantly for the past decades, leading to an enormous number of applications and services embraced by billions of users. In order to meet the increasing demand for mobile Internet access, several high data-rate radio networking technologies have been proposed to offer wide area high-speed wireless communications, eventually replacing fixed (wired) networks for many applications. This thesis considers cross-layer optimization of multi-hop rad...

Spectral collocation method with a flexible angular discretization scheme for radiative transfer in multi-layer graded index medium

Science.gov (United States)

Wei, Linyang; Qi, Hong; Sun, Jianping; Ren, Yatao; Ruan, Liming

2017-05-01

The spectral collocation method (SCM) is employed to solve the radiative transfer in multi-layer semitransparent medium with graded index. A new flexible angular discretization scheme is employed to discretize the solid angle domain freely to overcome the limit of the number of discrete radiative direction when adopting traditional SN discrete ordinate scheme. Three radial basis function interpolation approaches, named as multi-quadric (MQ), inverse multi-quadric (IMQ) and inverse quadratic (IQ) interpolation, are employed to couple the radiative intensity at the interface between two adjacent layers and numerical experiments show that MQ interpolation has the highest accuracy and best stability. Variable radiative transfer problems in double-layer semitransparent media with different thermophysical properties are investigated and the influence of these thermophysical properties on the radiative transfer procedure in double-layer semitransparent media is also analyzed. All the simulated results show that the present SCM with the new angular discretization scheme can predict the radiative transfer in multi-layer semitransparent medium with graded index efficiently and accurately.

Multi-Layer Mobility Load Balancing in a Heterogeneous LTE Network

DEFF Research Database (Denmark)

Fotiadis, Panagiotis; Polignano, Michele; Laselva, Daniela

2012-01-01

This paper analyzes the behavior of a distributed Mobility Load Balancing (MLB) scheme in a multi-layer 3GPP (3rd Generation Partnership Project) Long Term Evolution (LTE) deployment with different User Equipment (UE) densities in certain network areas covered with pico cells. Target of the study...

Magnetic resonance of rubidium atoms passing through a multi-layered transmission magnetic grating

International Nuclear Information System (INIS)

Nagata, Y; Kurokawa, S; Hatakeyama, A

2017-01-01

We measured the magnetic resonance of rubidium atoms passing through periodic magnetic fields generated by two types of multi-layered transmission magnetic grating. One of the gratings reported here was assembled by stacking four layers of magnetic films so that the direction of magnetization alternated at each level. The other grating was assembled so that the magnetization at each level was aligned. For both types of grating, the experimental results were in good agreement with our calculations. We studied the feasibility of extending the frequency band of the grating and narrowing its resonance linewidth by performing calculations. For magnetic resonance precision spectroscopy, we conclude that the multi-layered transmission magnetic grating can generate periodic fields with narrower linewidths at higher frequencies when a larger number of layers are assembled at a shorter period length. Moreover, the frequency band of this type of grating can potentially achieve frequencies of up to hundreds of PHz. (paper)

Biologically inspired multi-layered synthetic skin for tactile feedback in prosthetic limbs.

Science.gov (United States)

Osborn, Luke; Nguyen, Harrison; Betthauser, Joseph; Kaliki, Rahul; Thakor, Nitish

2016-08-01

The human body offers a template for many state-of-the-art prosthetic devices and sensors. In this work, we present a novel, sensorized synthetic skin that mimics the natural multi-layered nature of mechanoreceptors found in healthy glabrous skin to provide tactile information. The multi-layered sensor is made up of flexible piezoresistive textiles that act as force sensitive resistors (FSRs) to convey tactile information, which are embedded within a silicone rubber to resemble the compliant nature of human skin. The top layer of the synthetic skin is capable of detecting small loads less than 5 N whereas the bottom sensing layer responds reliably to loads over 7 N. Finite element analysis (FEA) of a simplified human fingertip and the synthetic skin was performed. Results suggest similarities in behavior during loading. A natural tactile event is simulated by loading the synthetic skin on a prosthetic limb. Results show the sensors' ability to detect applied loads as well as the ability to simulate neural spiking activity based on the derivative and temporal differences of the sensor response. During the tactile loading, the top sensing layer responded 0.24 s faster than the bottom sensing layer. A synthetic biologically-inspired skin such as this will be useful for enhancing the functionality of prosthetic limbs through tactile feedback.

MeV Si ion modifications on the thermoelectric generators from Si/Si + Ge superlattice nano-layered films

Science.gov (United States)

Budak, S.; Heidary, K.; Johnson, R. B.; Colon, T.; Muntele, C.; Ila, D.

2014-08-01

The performance of thermoelectric materials and devices is characterized by a dimensionless figure of merit, ZT = S2σT/K, where, S and σ denote, respectively, the Seebeck coefficient and electrical conductivity, T is the absolute temperature in Kelvin and K represents the thermal conductivity. The figure of merit may be improved by means of raising either S or σ or by lowering K. In our laboratory, we have fabricated and characterized the performance of a large variety of thermoelectric generators (TEG). Two TEG groups comprised of 50 and 100 alternating layers of Si/Si + Ge multi-nanolayered superlattice films have been fabricated and thoroughly characterized. Ion beam assisted deposition (IBAD) was utilized to assemble the alternating sandwiched layers, resulting in total thickness of 300 nm and 317 nm for 50 and 100 layer devices, respectively. Rutherford Backscattering Spectroscopy (RBS) was employed in order to monitor the precise quantity of Si and Ge utilized in the construction of specific multilayer thin films. The material layers were subsequently impregnated with quantum dots and/or quantum clusters, in order to concurrently reduce the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and raise the cross plane electrical conductivity. The quantum dots/clusters were implanted via the 5 MeV Si ion bombardment which was performed using a Pelletron high energy ion beam accelerator. We have achieved remarkable results for the thermoelectric and optical properties of the Si/Si + Ge multilayer thin film TEG systems. We have demonstrated that with optimal setting of the 5 MeV Si ion beam bombardment fluences, one can fabricate TEG systems with figures of merits substantially higher than the values previously reported.

MeV Si ion modifications on the thermoelectric generators from Si/Si + Ge superlattice nano-layered films

Energy Technology Data Exchange (ETDEWEB)

Budak, S., E-mail: satilmis.budak@aamu.edu [Department of Electrical Engineering and Computer Science, Alabama A and M University, Huntsville, AL (United States); Heidary, K. [Department of Electrical Engineering and Computer Science, Alabama A and M University, Huntsville, AL (United States); Johnson, R.B.; Colon, T. [Department of Physics, Alabama A and M University, Huntsville, AL (United States); Muntele, C. [Cygnus Scientific Services, Huntsville, AL (United States); Ila, D. [Department of Physics, Fayetteville St. University, Fayetteville, NC (United States)

2014-08-15

The performance of thermoelectric materials and devices is characterized by a dimensionless figure of merit, ZT = S{sup 2}σT/K, where, S and σ denote, respectively, the Seebeck coefficient and electrical conductivity, T is the absolute temperature in Kelvin and K represents the thermal conductivity. The figure of merit may be improved by means of raising either S or σ or by lowering K. In our laboratory, we have fabricated and characterized the performance of a large variety of thermoelectric generators (TEG). Two TEG groups comprised of 50 and 100 alternating layers of Si/Si + Ge multi-nanolayered superlattice films have been fabricated and thoroughly characterized. Ion beam assisted deposition (IBAD) was utilized to assemble the alternating sandwiched layers, resulting in total thickness of 300 nm and 317 nm for 50 and 100 layer devices, respectively. Rutherford Backscattering Spectroscopy (RBS) was employed in order to monitor the precise quantity of Si and Ge utilized in the construction of specific multilayer thin films. The material layers were subsequently impregnated with quantum dots and/or quantum clusters, in order to concurrently reduce the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and raise the cross plane electrical conductivity. The quantum dots/clusters were implanted via the 5 MeV Si ion bombardment which was performed using a Pelletron high energy ion beam accelerator. We have achieved remarkable results for the thermoelectric and optical properties of the Si/Si + Ge multilayer thin film TEG systems. We have demonstrated that with optimal setting of the 5 MeV Si ion beam bombardment fluences, one can fabricate TEG systems with figures of merits substantially higher than the values previously reported.

Multi criteria evaluation for universal soil loss equation based on geographic information system

Science.gov (United States)

Purwaamijaya, I. M.

2018-05-01

The purpose of this research were to produce(l) a conceptual, functional model designed and implementation for universal soil loss equation (usle), (2) standard operational procedure for multi criteria evaluation of universal soil loss equation (usle) using geographic information system, (3) overlay land cover, slope, soil and rain fall layers to gain universal soil loss equation (usle) using multi criteria evaluation, (4) thematic map of universal soil loss equation (usle) in watershed, (5) attribute table of universal soil loss equation (usle) in watershed. Descriptive and formal correlation methods are used for this research. Cikapundung Watershed, Bandung, West Java, Indonesia was study location. This research was conducted on January 2016 to May 2016. A spatial analysis is used to superimposed land cover, slope, soil and rain layers become universal soil loss equation (usle). Multi criteria evaluation for universal soil loss equation (usle) using geographic information system could be used for conservation program.

Initial condition effects on large scale structure in numerical simulations of plane mixing layers

Science.gov (United States)

McMullan, W. A.; Garrett, S. J.

2016-01-01

In this paper, Large Eddy Simulations are performed on the spatially developing plane turbulent mixing layer. The simulated mixing layers originate from initially laminar conditions. The focus of this research is on the effect of the nature of the imposed fluctuations on the large-scale spanwise and streamwise structures in the flow. Two simulations are performed; one with low-level three-dimensional inflow fluctuations obtained from pseudo-random numbers, the other with physically correlated fluctuations of the same magnitude obtained from an inflow generation technique. Where white-noise fluctuations provide the inflow disturbances, no spatially stationary streamwise vortex structure is observed, and the large-scale spanwise turbulent vortical structures grow continuously and linearly. These structures are observed to have a three-dimensional internal geometry with branches and dislocations. Where physically correlated provide the inflow disturbances a "streaky" streamwise structure that is spatially stationary is observed, with the large-scale turbulent vortical structures growing with the square-root of time. These large-scale structures are quasi-two-dimensional, on top of which the secondary structure rides. The simulation results are discussed in the context of the varying interpretations of mixing layer growth that have been postulated. Recommendations are made concerning the data required from experiments in order to produce accurate numerical simulation recreations of real flows.

On the theory of twinning plane superconductivity

International Nuclear Information System (INIS)

Mishonov, T.M.

1988-01-01

The thermodynamic potential of the superconducting layer in the twinning plane (TP) vicinity for the type I superconductors is found. The corrections to the surface tension in powers of the Ginsburg-Landau parameter κ are obtained. The corresponding states law for the supercooling field for the type I twinning plane superconductivity (TPS) is obtained, as well as the critical field law for the type II TPS. A review of experimental and theoretical works on TPS and some similar systems is given. The conditions for the Berezinski-Kosterlitz-Thouless transition for the proximity effect are discussed, as well as the possible mechanisms for the conducting phase transition TPS in Nb and the pinning forces close to the twinning plane. The obtained order parameter distribution can be used for description of the superlattices from normal and superconducting metals as well. 6 figs., 44 refs

Coherent beam control through inhomogeneous media in multi-photon microscopy

Science.gov (United States)

Paudel, Hari Prasad

Multi-photon fluorescence microscopy has become a primary tool for high-resolution deep tissue imaging because of its sensitivity to ballistic excitation photons in comparison to scattered excitation photons. The imaging depth of multi-photon microscopes in tissue imaging is limited primarily by background fluorescence that is generated by scattered light due to the random fluctuations in refractive index inside the media, and by reduced intensity in the ballistic focal volume due to aberrations within the tissue and at its interface. We built two multi-photon adaptive optics (AO) correction systems, one for combating scattering and aberration problems, and another for compensating interface aberrations. For scattering correction a MEMS segmented deformable mirror (SDM) was inserted at a plane conjugate to the objective back-pupil plane. The SDM can pre-compensate for light scattering by coherent combination of the scattered light to make an apparent focus even at a depths where negligible ballistic light remains (i.e. ballistic limit). This problem was approached by investigating the spatial and temporal focusing characteristics of a broad-band light source through strongly scattering media. A new model was developed for coherent focus enhancement through or inside the strongly media based on the initial speckle contrast. A layer of fluorescent beads under a mouse skull was imaged using an iterative coherent beam control method in the prototype two-photon microscope to demonstrate the technique. We also adapted an AO correction system to an existing in three-photon microscope in a collaborator lab at Cornell University. In the second AO correction approach a continuous deformable mirror (CDM) is placed at a plane conjugate to the plane of an interface aberration. We demonstrated that this "Conjugate AO" technique yields a large field-of-view (FOV) advantage in comparison to Pupil AO. Further, we showed that the extended FOV in conjugate AO is maintained over a

Multi-angle lensless digital holography for depth resolved imaging on a chip

Science.gov (United States)

Su, Ting-Wei; Isikman, Serhan O.; Bishara, Waheb; Tseng, Derek; Erlinger, Anthony; Ozcan, Aydogan

2010-01-01

A multi-angle lensfree holographic imaging platform that can accurately characterize both the axial and lateral positions of cells located within multi-layered micro-channels is introduced. In this platform, lensfree digital holograms of the micro-objects on the chip are recorded at different illumination angles using partially coherent illumination. These digital holograms start to shift laterally on the sensor plane as the illumination angle of the source is tilted. Since the exact amount of this lateral shift of each object hologram can be calculated with an accuracy that beats the diffraction limit of light, the height of each cell from the substrate can be determined over a large field of view without the use of any lenses. We demonstrate the proof of concept of this multi-angle lensless imaging platform by using light emitting diodes to characterize various sized microparticles located on a chip with sub-micron axial and lateral localization over ~60 mm2 field of view. Furthermore, we successfully apply this lensless imaging approach to simultaneously characterize blood samples located at multi-layered micro-channels in terms of the counts, individual thicknesses and the volumes of the cells at each layer. Because this platform does not require any lenses, lasers or other bulky optical/mechanical components, it provides a compact and high-throughput alternative to conventional approaches for cytometry and diagnostics applications involving lab on a chip systems. PMID:20588819

Performance of single-pass and by-pass multi-step multi-soil-layering systems for low-(C/N)-ratio polluted river water treatment.

Science.gov (United States)

Wei, Cai-Jie; Wu, Wei-Zhong

2018-09-01

Two kinds of hybrid two-step multi-soil-layering (MSL) systems loaded with different filter medias (zeolite-ceramsite MSL-1 and ceramsite-red clay MSL-2) were set-up for the low-(C/N)-ratio polluted river water treatment. A long-term pollutant removal performance of these two kinds of MSL systems was evaluated for 214 days. By-pass was employed in MSL systems to evaluate its effect on nitrogen removal enhancement. Zeolite-ceramsite single-pass MSL-1 system owns outstanding ammonia removal capability (24 g NH 4 + -Nm -2 d -1 ), 3 times higher than MSL-2 without zeolite under low aeration rate condition (0.8 × 10 4  L m -2 .h -1 ). Aeration rate up to 1.6 × 10 4  L m -2 .h -1 well satisfied the requirement of complete nitrification in first unit of both two MSLs. However, weak denitrification in second unit was commonly observed. By-pass of 50% influent into second unit can improve about 20% TN removal rate for both MSL-1 and MSL-2. Complete nitrification and denitrification was achieved in by-pass MSL systems after addition of carbon source with the resulting C/N ratio up to 2.5. The characters of biofilms distributed in different sections inside MSL-1 system well illustrated the nitrogen removal mechanism inside MSL systems. Two kinds of MSLs are both promising as an appealing nitrifying biofilm reactor. Recirculation can be considered further for by-pass MSL-2 system to ensure a complete ammonia removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

IMRT sequencing for a six-bank multi-leaf system

International Nuclear Information System (INIS)

Topolnjak, R; Heide, U A van der; Lagendijk, J J W

2005-01-01

In this study, we present a sequencer for delivering step-and-shoot IMRT using a six-bank multi-leaf system. Such a system was proposed earlier and combines a high-resolution field-shaping ability with a large field size. It consists of three layers of two opposing leaf banks with 1 cm leaves. The layers are rotated relative to each other at 60 0 . A low-resolution mode of sequencing is achieved by using one layer of leaves as primary MLC, while the other two are used to improve back-up collimation. For high-resolution sequencing, an algorithm is presented that creates segments shaped by all six banks. Compared to a hypothetical mini-MLC with 0.4 cm leaves, a similar performance can be achieved, but a trade-off has to be made between accuracy and the number of segments

Multi-Layer 5G Mobile Phone Antenna for Multi-User MIMO Communications

DEFF Research Database (Denmark)

Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

2015-01-01

for 5G wireless communications. Two identical linear sub arrays can be simultaneously used at different sides of the mobile-phone printed circuit board (PCB) for operation in diversity or multiple-input multiple-output (MIMO) modes. Each sub array contains eight elements of very compact off......-center dipole antennas with dimensions of 5.4×0.67 mm2. The feature of compact design with good beam-steering function makes them well-suited to integrate into the mobile-phone mock-up. The fundamental properties of the proposed antenna have been investigated. Simulations show that the proposed 5G antenna......In this study, a new design of multi-layer phased array antenna for millimeter-wave (mm-Wave) fifth generation (5G) mobile terminals is proposed. The proposed linear phased array antenna is designed on four layers of the Rogers RT5880 substrates to operate at 28 GHz which is under consideration...

Towards single step production of multi-layer inorganic hollow fibers

NARCIS (Netherlands)

de Jong, J.; Benes, Nieck Edwin; Koops, G.H.; Wessling, Matthias

2004-01-01

In this work we propose a generic synthesis route for the single step production of multi-layer inorganic hollow fibers, based on polymer wet spinning combined with a heat treatment. With this new method, membranes with a high surface area per unit volume ratio can be produced, while production time

Multi-layered Chalcogenides with potential for magnetism and superconductivity

Energy Technology Data Exchange (ETDEWEB)

Li, Li, E-mail: lil2@ornl.gov [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Parker, David S. [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Cruz, Clarina R. dela [Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Sefat, Athena S., E-mail: sefata@ornl.gov [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2016-12-15

Highlights: • A comprehensive study on multi-layered thallium copper chalcogenides TlCu{sub 2n}Ch{sub n+1}. • All the TlCu{sub 2n}Ch{sub n+1} exhibit metallic behaviors with no long-range magnetism. • Calculations suggest a lack of Fermi-level spectral weight for magnetic instability. • Our results suggest a likelihood of magnetism for multiple structural layers with Fe. - Abstract: Layered thallium copper chalcogenides can form single, double, or triple layers of Cu–Ch separated by Tl sheets. Here we report on the preparation and properties of Tl-based materials of TlCu{sub 2}Se{sub 2}, TlCu{sub 4}S{sub 3}, TlCu{sub 4}Se{sub 3} and TlCu{sub 6}S{sub 4}. Having no long-range magnetism for these materials is quite surprising considering the possibilities of inter- and intra-layer exchange interactions through Cu 3d, and we measure by magnetic susceptibility and confirm by neutron diffraction. First principles density-functional theory calculations for both the single-layer TlCu{sub 2}Se{sub 2} (isostructural to the ‘122’ iron-based superconductors) and the double-layer TlCu{sub 4}Se{sub 3} suggest a lack of Fermi-level spectral weight that is needed to drive a magnetic or superconducting instability. However, for multiple structural layers with Fe, there is much greater likelihood for magnetism and superconductivity.

Unbiased multi-fidelity estimate of failure probability of a free plane jet

Science.gov (United States)

Marques, Alexandre; Kramer, Boris; Willcox, Karen; Peherstorfer, Benjamin

2017-11-01

Estimating failure probability related to fluid flows is a challenge because it requires a large number of evaluations of expensive models. We address this challenge by leveraging multiple low fidelity models of the flow dynamics to create an optimal unbiased estimator. In particular, we investigate the effects of uncertain inlet conditions in the width of a free plane jet. We classify a condition as failure when the corresponding jet width is below a small threshold, such that failure is a rare event (failure probability is smaller than 0.001). We estimate failure probability by combining the frameworks of multi-fidelity importance sampling and optimal fusion of estimators. Multi-fidelity importance sampling uses a low fidelity model to explore the parameter space and create a biasing distribution. An unbiased estimate is then computed with a relatively small number of evaluations of the high fidelity model. In the presence of multiple low fidelity models, this framework offers multiple competing estimators. Optimal fusion combines all competing estimators into a single estimator with minimal variance. We show that this combined framework can significantly reduce the cost of estimating failure probabilities, and thus can have a large impact in fluid flow applications. This work was funded by DARPA.

Plasma-Assisted Deposition of Au/SiO2 Multi-layers as Surface Plasmon Resonance-Based Red-Colored Coatings

NARCIS (Netherlands)

Beyene, H. T.; Tichelaar, F. D.; Verheijen, M. A.; M. C. M. van de Sanden,; Creatore, M.

2011-01-01

In this work, the expanding thermal plasma chemical vapor deposition in combination with radio frequency magnetron sputtering is used to deposit dielectric/metal multi-layers with controlled size and density of nanoparticles. The multi-layer structure serves the purpose of increasing the

Plasma assisted deposition of Au/SiO2 multi-layers as surface plasmon resonance-based red colored coatings

NARCIS (Netherlands)

Takele Beyene, H.T.; Tichelaar, F.D.; Verheijen, M.A.; Sanden, van de M.C.M.; Creatore, M.

2011-01-01

In this work, the expanding thermal plasma chemical vapor deposition in combination with radio frequency magnetron sputtering is used to deposit dielectric/metal multi-layers with controlled size and density of nanoparticles. The multi-layer structure serves the purpose of increasing the

Correlations in quantum systems and branch points in the complex plane

OpenAIRE

Rotter, I.

2001-01-01

Branch points in the complex plane are responsible for avoided level crossings in closed and open quantum systems. They create not only an exchange of the wave functions but also a mixing of the states of a quantum system at high level density. The influence of branch points in the complex plane on the low-lying states of the system is small.

Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters

Science.gov (United States)

Yu, Woo Jong; Li, Zheng; Zhou, Hailong; Chen, Yu; Wang, Yang; Huang, Yu; Duan, Xiangfeng

2014-01-01

The layered materials such as graphene have attracted considerable interest for future electronics. Here we report the vertical integration of multi-heterostructures of layered materials to enable high current density vertical field-effect transistors (VFETs). An n-channel VFET is created by sandwiching few-layer molybdenum disulfide (MoS2) as the semiconducting channel between a monolayer graphene and a metal thin film. The VFETs exhibit a room temperature on-off ratio >103, while at same time deliver a high current density up to 5,000 A/cm2, sufficient for high performance logic applications. This study offers a general strategy for the vertical integration of various layered materials to obtain both p- and n-channel transistors for complementary logic functions. A complementary inverter with larger than unit voltage gain is demonstrated by vertically stacking the layered materials of graphene, Bi2Sr2Co2O8 (p-channel), graphene, MoS2 (n-channel), and metal thin film in sequence. The ability to simultaneously achieve high on-off ratio, high current density, and logic integration in the vertically stacked multi-heterostructures can open up a new dimension for future electronics to enable three-dimensional integration. PMID:23241535

Quantification of layered patterns with structural anisotropy: a comparison of biological and geological systems

Directory of Open Access Journals (Sweden)

I. Smolyar

2016-03-01

Full Text Available Large-scale patterns evident from satellite images of aeolian landforms on Earth and other planets; those of intermediate scale in marine and terrestrial sand ripples and sediment profiles; and small-scale patterns such as lamellae in the bones of vertebrates and annuli in fish scales are each represented by layers of different thicknesses and lengths. Layered patterns are important because they form a record of the state of internal and external factors that regulate pattern formation in these geological and biological systems. It is therefore potentially possible to recognize trends, periodicities, and events in the history of the formation of these systems among the incremental sequences. Though the structures and sizes of these 2-D patterns are typically scale-free, they are also characteristically anisotropic; that is, the number of layers and their absolute thicknesses vary significantly during formation. The aim of the present work is to quantify the structure of layered patterns and to reveal similarities and differences in the processing and interpretation of layered landforms and biological systems. To reach this goal we used N-partite graph and Boolean functions to quantify the structure of layers and plot charts for “layer thickness vs. layer number” and “layer area vs. layer number”. These charts serve as a source of information about events in the history of formation of layered systems. The concept of synchronization of layer formation across a 2-D plane is introduced to develop the procedure for plotting “layer thickness vs. layer number” and “layer area vs. layer number”, which takes into account the structural anisotropy of layered patterns and increase signal-to-noise ratio in charts. Examples include landforms on Mars and Earth and incremental layers in human and iguana bones.

Geometrical nonlinear free vibration of multi-layered graphene sheets

International Nuclear Information System (INIS)

Wang Jinbao; He Xiaoqiao; Kitipornchai, S; Zhang Hongwu

2011-01-01

A nonlinear continuum model is developed for the nonlinear vibration analysis of multi-layered graphene sheets (MLGSs), in which the nonlinear van der Waals (vdW) interaction between any two layers is formulated explicitly. The nonlinear equations of motion are studied by the harmonic-balance methods. Based on the present model, the nonlinear stiffened amplitude-frequency relations of double-layered graphene sheets (DLGSs) are investigated in the spectral neighbourhood of lower frequencies. The influence of the vdW interaction on the vibration properties of DLGSs is well illustrated by plotting the resulting modes' shapes, in which in-phase and anti-phase vibrations of DLGSs are studied. In particular, the large-amplitude vibration which associates with the anti-phase resonant frequencies, separating DLGS into single-layered GSs, is a promising application that needs to be explored further. In contrast, the vibration modes that are associated with the resonant frequencies are nonidentical and give various vibration patterns, which indicates that MLGSs are highly suited to being used as high-frequency resonators.

On an analytical evaluation of the flux and dominant eigenvalue problem for the steady state multi-group multi-layer neutron diffusion equation

Energy Technology Data Exchange (ETDEWEB)

Ceolin, Celina; Schramm, Marcelo; Bodmann, Bardo Ernst Josef; Vilhena, Marco Tullio Mena Barreto de [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Bogado Leite, Sergio de Queiroz [Comissao Nacional de Energia Nuclear, Rio de Janeiro (Brazil)

2014-11-15

In this work the authors solved the steady state neutron diffusion equation for a multi-layer slab assuming the multi-group energy model. The method to solve the equation system is based on an expansion in Taylor Series resulting in an analytical expression. The results obtained can be used as initial condition for neutron space kinetics problems. The neutron scalar flux was expanded in a power series, and the coefficients were found by using the ordinary differential equation and the boundary and interface conditions. The effective multiplication factor k was evaluated using the power method. We divided the domain into several slabs to guarantee the convergence with a low truncation order. We present the formalism together with some numerical simulations.

Geometric characteristics of aberrations of plane-symmetric optical systems

International Nuclear Information System (INIS)

Lu Lijun; Deng Zhiyong

2009-01-01

The geometric characteristics of aberrations of plane-symmetric optical systems are studied in detail with a wave-aberration theory. It is dealt with as an extension of the Seidel aberrations to realize a consistent aberration theory from axially symmetric to plane-symmetric systems. The aberration distribution is analyzed with the spot diagram of a ray and an aberration curve. Moreover, the root-mean-square value and the centroid of aberration distribution are discussed. The numerical results are obtained with the focusing optics of a toroidal mirror at grazing incidence.

A compact multi-wire-layered secondary winding for Tesla transformer.

Science.gov (United States)

Zhao, Liang; Su, Jian-Cang; Li, Rui; Wu, Xiao-Long; Xu, Xiu-Dong; Qiu, Xu-Dong; Zeng, Bo; Cheng, Jie; Zhang, Yu; Gao, Peng-Cheng

2017-05-01

A compact multi-wire-layered (MWL) secondary winding for a Tesla transformer is put forward. The basic principle of this winding is to wind the metal wire on a polymeric base tube in a multi-layer manner. The tube is tapered and has high electrical strength and high mechanical strength. Concentric-circle grooves perpendicular to the axis of the tube are carved on the surface of the tube to wind the wire. The width of the groove is basically equal to the diameter of the wire so that the metal wire can be fixed in the groove without glue. The depth of the groove is n times of the diameter of the wire to realize the n-layer winding manner. All the concentric-circle grooves are connected via a spiral groove on the surface of the tube to let the wire go through. Compared with the traditional one-wire-layered (OWL) secondary winding for the Tesla transformer, the most conspicuous advantage of the MWL secondary winding is that the latter is compact with only a length of 2/n of the OWL. In addition, the MWL winding has the following advantages: high electrical strength since voids are precluded from the surface of the winding, high mechanical strength because polymer is used as the material of the base tube, and reliable fixation in the Tesla transformer as special mechanical connections are designed. A 2000-turn MWL secondary winding is fabricated with a winding layer of 3 and a total length of 1.0 m. Experiments to test the performance of this winding on a Tesla-type pulse generator are conducted. The results show that this winding can boost the voltage to 1 MV at a repetition rate of 50 Hz reliably for a lifetime longer than 10 4 pulses, which proves the feasibility of the MWL secondary winding.

Multi-layer coatings for bipolar rechargeable batteries with enhanced terminal voltage

Science.gov (United States)

Farmer, Joseph C.; Kaschmitter, James; Pierce, Steve

2017-06-06

A method for producing a multi-layer bipolar coated cell according to one embodiment includes applying a first active cathode material above a substrate to form a first cathode; applying a first solid-phase ionically-conductive electrolyte material above the first cathode to form a first electrode separation layer; applying a first active anode material above the first electrode separation layer to form a first anode; applying an electrically conductive barrier layer above the first anode; applying a second active cathode material above the anode material to form a second cathode; applying a second solid-phase ionically-conductive electrolyte material above the second cathode to form a second electrode separation layer; applying a second active anode material above the second electrode separation layer to form a second anode; and applying a metal material above the second anode to form a metal coating section. In another embodiment, the anode is formed prior to the cathode. Cells are also disclosed.

Multi-strangeness dynamics at PANDA

Energy Technology Data Exchange (ETDEWEB)

Gaitanos, Theodoros; Lenske, Horst; Mosel, Ulrich [Institut fuer Theoretische Physik, Universitaet Giessen (Germany)

2014-07-01

Multi-strange bound hadron systems are excellent candidates for studying in-medium hyperon-hyperon (YY) interactions. A better understanding of the strangeness sector of the hadronic equation of state is crucial for our understanding of astrophysical objects like neutron stars. Furthermore, these studies are being motivated by actual and planed experimental activities on hypernuclear physics (HypHI and PANDA Collaborations). In fact, HypHI has already studied single-strange hypernuclei in heavy-ion collisions, whereas studies on double- and multi-strange nuclear systems are being planed by PANDA. We have reported in the past first studies on single- and double-Λ hypernuclei production in reactions induced by heavy-ions and antiprotons, respectively. The YY-interaction is still little known and many controversial theoretical predictions exist in the literature. We therefore extend our previous works by investigating the influence of various hyperon-hyperon interactions on the production dynamics of multi-Λ hypernuclei in reactions relevant for FAIR. Particular attention is paid to the heavy Ω-baryon (S=-3) and its role to the formation of multi-Λ hypernuclei in reactions induced by antiprotons.

Observations with a mid-plane reciprocating probe in MAST

International Nuclear Information System (INIS)

Yang, Y.; Counsell, G.F.

2003-01-01

A fast reciprocating probe has recently been installed on MAST. It has been used to measure the outboard, mid-plane scrape off layer (SOL) of L-mode plasmas, and to study the intermittent fluctuations in the SOL in L-mode and ELMy H-mode discharges. In this paper, the system and the experiments are introduced

Nonsingular walls in plane cholesteric layers

International Nuclear Information System (INIS)

Belyakov, V A; Osipov, M A; Stewart, I W

2006-01-01

The structure of a straight interface (wall) between regions with differing values of the pitch in planar cholesteric layers with finite strength of the surface anchoring is investigated theoretically. It is found that the shape and strength of the anchoring potential influences essentially the structure of the wall and a motionless wall between thermodynamically stable regions without a singularity in the director distribution in the layer can exist for sufficiently weak anchoring only. More specifically, for the existence of such a wall the dimensionless parameter S d = K 22 /Wd (where W is the depth of the anchoring potential, K 22 is the elastic twist modulus and d is the layer thickness) should exceed its critical value, which is dependent on the shape of the anchoring potential. General equations describing the director distribution in the wall are presented. Detailed analysis of these equations is carried out for the case of infinitely strong anchoring at one surface and finite anchoring strength at the second layer surface. It is shown that the wall width L is directly dependent upon the shape and strength of the anchoring potential and that its estimate ranges from d to (dL p ) 1/2 (where L p = K 22 /W is the penetration length), corresponding to different anchoring strengths and shape potentials. The dependence of the director distribution in the wall upon all three Frank elastic moduli is analytically found for some specific limiting cases of the model anchoring potentials. Motion of the wall is briefly investigated and the corresponding calculations performed under the assumption that the shape of a moving wall is the same as a motionless one. It is noted that experimental investigation of the walls in planar cholesteric layers can be used for the determination of the actual shape of surface anchoring potentials

Rapid fabricating technique for multi-layered human hepatic cell sheets by forceful contraction of the fibroblast monolayer.

Directory of Open Access Journals (Sweden)

Yusuke Sakai

Full Text Available Cell sheet engineering is attracting attention from investigators in various fields, from basic research scientists to clinicians focused on regenerative medicine. However, hepatocytes have a limited proliferation potential in vitro, and it generally takes a several days to form a sheet morphology and multi-layered sheets. We herein report our rapid and efficient technique for generating multi-layered human hepatic cell (HepaRG® cell sheets using pre-cultured fibroblast monolayers derived from human skin (TIG-118 cells as a feeder layer on a temperature-responsive culture dish. Multi-layered TIG-118/HepaRG cell sheets with a thick morphology were harvested on day 4 of culturing HepaRG cells by forceful contraction of the TIG-118 cells, and the resulting sheet could be easily handled. In addition, the human albumin and alpha 1-antitrypsin synthesis activities of TIG-118/HepaRG cells were approximately 1.2 and 1.3 times higher than those of HepaRG cells, respectively. Therefore, this technique is considered to be a promising modality for rapidly fabricating multi-layered human hepatocyte sheets from cells with limited proliferation potential, and the engineered cell sheet could be used for cell transplantation with highly specific functions.

Effective source size, yield and beam profile from multi-layered bremsstrahlung targets

International Nuclear Information System (INIS)

Svensson, R.; Brahme, A.

1996-01-01

Modern conformal radiotherapy benefits from heterogeneous dose delivery using scanned narrow bremsstrahlung beams of high energy in combination with dynamic double focused multi-leaf collimation and purging magnets. When using a purging magnet to remove electrons and positrons the target space is limited and unorthodox thin multi-layered targets are needed. A computational technique has therefore been developed to determine the forward yield and the angular distributions of the bremsstrahlung beam as well as the size and location of the effective and the virtual photon point source for arbitrary multi-layer bremsstrahlung targets. The Gaussian approximation of the diffusion equation for the electrons has been used and convolved with the bremsstrahlung production process. For electrons with arbitrary emittance impinging on targets of any multi-layer and atomic number combination, the model is well applicable, at least for energies in the range 1-100 MeV. The intrinsic bremsstrahlung photon profile has been determined accurately by deconvolving the electron multiple scattering process from thin experimental beryllium target profiles. For electron pencil beams incident on a target of high density and atomic number such as tungsten, the size of the effective photon source stays at around a tenth of a millimetre. The effective photon source for low-Z materials such as Be, C and Al is located at depths from 3-7 mm in the target, decreasing with increasing atomic number. The effective photon source at off-axis positions then moves out considerably from the central axis, which should be considered when aligning collimators. For high-Z materials such as tungsten, the location of the effective photon source is at a few tenths of a millimetre deep. The virtual photon point source is located only a few tenths of a millimetre upstream of the effective photon source both for high- and low-Z materials. For 50 MeV electrons incident on multi-layered full range targets the radial

Assessment of physical server reliability in multi cloud computing system

Science.gov (United States)

Kalyani, B. J. D.; Rao, Kolasani Ramchand H.

2018-04-01

Business organizations nowadays functioning with more than one cloud provider. By spreading cloud deployment across multiple service providers, it creates space for competitive prices that minimize the burden on enterprises spending budget. To assess the software reliability of multi cloud application layered software reliability assessment paradigm is considered with three levels of abstractions application layer, virtualization layer, and server layer. The reliability of each layer is assessed separately and is combined to get the reliability of multi-cloud computing application. In this paper, we focused on how to assess the reliability of server layer with required algorithms and explore the steps in the assessment of server reliability.

Combined multi-plane phase retrieval and super-resolution optical fluctuation imaging for 4D cell microscopy

Science.gov (United States)

Descloux, A.; Grußmayer, K. S.; Bostan, E.; Lukes, T.; Bouwens, A.; Sharipov, A.; Geissbuehler, S.; Mahul-Mellier, A.-L.; Lashuel, H. A.; Leutenegger, M.; Lasser, T.

2018-03-01

Super-resolution fluorescence microscopy provides unprecedented insight into cellular and subcellular structures. However, going `beyond the diffraction barrier' comes at a price, since most far-field super-resolution imaging techniques trade temporal for spatial super-resolution. We propose the combination of a novel label-free white light quantitative phase imaging with fluorescence to provide high-speed imaging and spatial super-resolution. The non-iterative phase retrieval relies on the acquisition of single images at each z-location and thus enables straightforward 3D phase imaging using a classical microscope. We realized multi-plane imaging using a customized prism for the simultaneous acquisition of eight planes. This allowed us to not only image live cells in 3D at up to 200 Hz, but also to integrate fluorescence super-resolution optical fluctuation imaging within the same optical instrument. The 4D microscope platform unifies the sensitivity and high temporal resolution of phase imaging with the specificity and high spatial resolution of fluorescence microscopy.

Anisotropic in-plane thermal conductivity observed in few-layer black phosphorus

Science.gov (United States)

Luo, Zhe; Maassen, Jesse; Deng, Yexin; Du, Yuchen; Garrelts, Richard P.; Lundstrom, Mark S; Ye, Peide D.; Xu, Xianfan

2015-01-01

Black phosphorus has been revisited recently as a new two-dimensional material showing potential applications in electronics and optoelectronics. Here we report the anisotropic in-plane thermal conductivity of suspended few-layer black phosphorus measured by micro-Raman spectroscopy. The armchair and zigzag thermal conductivities are ∼20 and ∼40 W m−1 K−1 for black phosphorus films thicker than 15 nm, respectively, and decrease to ∼10 and ∼20 W m−1 K−1 as the film thickness is reduced, exhibiting significant anisotropy. The thermal conductivity anisotropic ratio is found to be ∼2 for thick black phosphorus films and drops to ∼1.5 for the thinnest 9.5-nm-thick film. Theoretical modelling reveals that the observed anisotropy is primarily related to the anisotropic phonon dispersion, whereas the intrinsic phonon scattering rates are found to be similar along the armchair and zigzag directions. Surface scattering in the black phosphorus films is shown to strongly suppress the contribution of long mean-free-path acoustic phonons. PMID:26472191

Fully Solution-Processable Fabrication of Multi-Layered Circuits on a Flexible Substrate Using Laser Processing

Directory of Open Access Journals (Sweden)

Seok Young Ji

2018-02-01

Full Text Available The development of printing technologies has enabled the realization of electric circuit fabrication on a flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of the laser focal position and intensity. Based on these methods, a flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated to have functional operations.

Fully Solution-Processable Fabrication of Multi-Layered Circuits on a Flexible Substrate Using Laser Processing

Science.gov (United States)

Ji, Seok Young; Choi, Wonsuk; Jeon, Jin-Woo; Chang, Won Seok

2018-01-01

The development of printing technologies has enabled the realization of electric circuit fabrication on a flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of the laser focal position and intensity. Based on these methods, a flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated to have functional operations. PMID:29425144

Target plane imaging system for the Nova laser

International Nuclear Information System (INIS)

Swift, C.D.; Bliss, E.S.; Jones, W.A.; Reeves, R.J.; Seppala, L.G.; Shelton, R.T.; VanArsdall, P.J.

1985-01-01

The Nova laser, in operation since December 1984, is capable of irradiating targets with light at 1.05 μm, 0.53 μm, and 0.35 μm. Correct alignment of these harmonic beams uses a system called a target plane imager (TPI). It is a large microscope (four meters long, weighing one thousand kilograms) that relays images from the target chamber center to a video optics module located on the outside of the chamber. Several modes of operation are possible including: near-field viewing and far-field viewing at three magnifications and three wavelengths. In addition, the entire instrument can be scanned in X,Y,Z to examine various planes near chamber center. Performance of this system and its computer controls will be described

Comparison of the effectiveness of compression stockings and layer compression systems in venous ulceration treatment

Science.gov (United States)

Jawień, Arkadiusz; Cierzniakowska, Katarzyna; Cwajda-Białasik, Justyna; Mościcka, Paulina

2010-01-01

Introduction The aim of the research was to compare the dynamics of venous ulcer healing when treated with the use of compression stockings as well as original two- and four-layer bandage systems. Material and methods A group of 46 patients suffering from venous ulcers was studied. This group consisted of 36 (78.3%) women and 10 (21.70%) men aged between 41 and 88 years (the average age was 66.6 years and the median was 67). Patients were randomized into three groups, for treatment with the ProGuide two-layer system, Profore four-layer compression, and with the use of compression stockings class II. In the case of multi-layer compression, compression ensuring 40 mmHg blood pressure at ankle level was used. Results In all patients, independently of the type of compression therapy, a few significant statistical changes of ulceration area in time were observed (Student’s t test for matched pairs, p ulceration area in each of the successive measurements was observed in patients treated with the four-layer system – on average 0.63 cm2/per week. The smallest loss of ulceration area was observed in patients using compression stockings – on average 0.44 cm2/per week. However, the observed differences were not statistically significant (Kruskal-Wallis test H = 4.45, p > 0.05). Conclusions A systematic compression therapy, applied with preliminary blood pressure of 40 mmHg, is an effective method of conservative treatment of venous ulcers. Compression stockings and prepared systems of multi-layer compression were characterized by similar clinical effectiveness. PMID:22419941

A particle swarm-based algorithm for optimization of multi-layered and graded dental ceramics.

Science.gov (United States)

Askari, Ehsan; Flores, Paulo; Silva, Filipe

2018-01-01

The thermal residual stresses (TRSs) generated owing to the cooling down from the processing temperature in layered ceramic systems can lead to crack formation as well as influence the bending stress distribution and the strength of the structure. The purpose of this study is to minimize the thermal residual and bending stresses in dental ceramics to enhance their strength as well as to prevent the structure failure. Analytical parametric models are developed to evaluate thermal residual stresses in zirconia-porcelain multi-layered and graded discs and to simulate the piston-on-ring test. To identify optimal designs of zirconia-based dental restorations, a particle swarm optimizer is also developed. The thickness of each interlayer and compositional distribution are referred to as design variables. The effect of layers number constituting the interlayer between two based materials on the performance of graded prosthetic systems is also investigated. The developed methodology is validated against results available in literature and a finite element model constructed in the present study. Three different cases are considered to determine the optimal design of graded prosthesis based on minimizing (a) TRSs; (b) bending stresses; and (c) both TRS and bending stresses. It is demonstrated that each layer thickness and composition profile have important contributions into the resulting stress field and magnitude. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

Energy Technology Data Exchange (ETDEWEB)

Grin, A. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

2014-09-01

The goal of this research is to provide durable and long-term water management solutions using exterior insulating sheathing as part of the water management system. It is possible to tape or seal the joints in insulating sheathing to create a drainage plane and even an air control layer. There exists the material durability component of the tape as well as the system durability component being the taped insulating sheathing as the drainage plane. This measure guideline provides best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant issues were discussed with the group, which are required to make taped insulating sheathing a simple, long-term, and durable drainage plane: horizontal joints should be limited or eliminated wherever possible; where a horizontal joint exists use superior materials; and frequent installation inspection and regular trade training are required to maintain proper installation.

Universality Results for Multi-Layer Hele-Shaw and Porous Media Flows

Science.gov (United States)

Daripa, Prabir

2012-11-01

Saffman-Taylor instability is a well known viscosity driven instability of an interface. Motivated by a need to understand the effect of various injection policies currently in practice for chemical enhanced oil recovery, we study linear stability of displacement processes in a Hele-Shaw cell involving injection of an arbitrary number of immiscible fluid phases in succession. This is a problem involving many interfaces. Universal stability results have been obtained for this multi-layer (multi-region) flow in the sense that the results hold with arbitrary number of interfaces. These stability results have been applied to design injection policies that are considerably less unstable than the pure Saffman-Taylor case. In particular, we determine specific values of the viscosity of the fluid layers corresponding to smallest unstable band. Moreover, we discuss universal selection principle of optimal viscous profiles. The talk is based on following papers. Qatar National Fund (a member of the Qatar Foundation).

New bi-Hamiltonian systems on the plane

Science.gov (United States)

Tsiganov, A. V.

2017-06-01

We discuss several new bi-Hamiltonian integrable systems on the plane with integrals of motion of third, fourth, and sixth orders in momenta. The corresponding variables of separation, separated relations, compatible Poisson brackets, and recursion operators are also presented in the framework of the Jacobi method.

Self-Assembled Layered Supercell Structure of Bi2AlMnO6 with Strong Room-Temperature Multiferroic Properties.

Energy Technology Data Exchange (ETDEWEB)

Li, Leigang; Boullay, Philippe; Lu, Ping; Perez, Olivier; Steciuk, Gwladys; Wang, Xuejing; Jian, Jie; Huang, Jijie; Gao, Xingyao; Zhang, Wenrui; Zhang, Xinghang; Wang, Haiyan

2017-02-01

Room-temperature (RT) multiferroics, possessing ferroelectricity and ferromagnetism simultaneously at RT, hold great promise in miniaturized devices including sensors, actuators, transducers, and multi-state memories. In this work, we report a novel 2D layered RT multiferroic system with self-assembled layered supercell structure consisting of two mismatch-layered sub-lattices of [Bi₃O_3+δ] and [MO₂]_1.84 (M=Al/Mn, simply named as BAMO), i.e., alternative layered stacking of two mutually incommensurate sublattices made of a three-layer-thick Bi-O slab and a one-layer-thick Al/Mn-O octahedra slab along the out-of-plane direction. Strong room-temperature multiferroic responses, e.g., ferromagnetic and ferroelectric properties, have been demonstrated and attributed to the highly anisotropic 2D nature of the non-ferromagnetic and ferromagnetic sublattices which are highly mismatched. The work demonstrates an alternative design approach for new 2D layered oxide materials that hold promises as single-phase multiferroics, 2D oxides with tunable bandgaps, and beyond.

Preparation and properties of [(NdFeB)x/(Nb)z]n multi-layer films

International Nuclear Information System (INIS)

Tsai, J.-L.; Chin, T.-S.; Yao, Y.-D.; Melsheimer, A.; Fisher, S.; Drogen, T.; Kelsch, M.; Kronmueller, H.

2003-01-01

Multi-layer [(NdFeB) x /(Nb) z ] n films with 200 nm≥x≥10 nm, 10 nm≥z≥0, 40≥n≥2, prepared by ion beam sputtering and subsequent annealing, show significantly enhanced coercivity due to the reduced grain size that enhances the anisotropy of individual grains. After annealing at 630 deg. C, some Nd 2 Fe 14 B grains were enriched with Nb and isolated as the thickness of the Nb spacer layer increases. For multi-layer (NdFeB x /Nb z ) n films with 100 nm ≥x≥25 nm, 5 nm≥z≥2 nm, their coercivity and remanence ratio are better than that of a single NdFeB film. Up to 17.8 kOe room temperature coercivity has been obtained for a sample with x=25 nm, z=5 nm and n=16

PRESSURE-IMPULSE DIAGRAM OF MULTI-LAYERED ALUMINUM FOAM PANELS UNDER BLAST PRESSURE

Directory of Open Access Journals (Sweden)

CHANG-SU SHIM

2013-06-01

Full Text Available Anti-terror engineering has increasing demand in construction industry, but basis of design (BOD is normally not clear for designers. Hardening of structures has limitations when design loads are not defined. Sacrificial foam claddings are one of the most efficient methods to protect blast pressure. Aluminum foam can have designed yield strength according to relative density and mitigate the blast pressure below a target transmitted pressure. In this paper, multi-layered aluminum foam panels were proposed to enhance the pressure mitigation by increasing effective range of blast pressure. Through explicit finite element analyses, the performance of blast pressure mitigation by the multi-layered foams was evaluated. Pressure-impulse diagrams for the foam panels were developed from extensive analyses. Combination of low and high strength foams showed better applicability in wider range of blast pressure.

Tests of the Monte Carlo simulation of the photon-tagger focal-plane electronics at the MAX IV Laboratory

International Nuclear Information System (INIS)

Preston, M.F.; Myers, L.S.; Annand, J.R.M.; Fissum, K.G.; Hansen, K.; Isaksson, L.; Jebali, R.; Lundin, M.

2014-01-01

Rate-dependent effects in the electronics used to instrument the tagger focal plane at the MAX IV Laboratory were recently investigated using the novel approach of Monte Carlo simulation to allow for normalization of high-rate experimental data acquired with single-hit time-to-digital converters (TDCs). The instrumentation of the tagger focal plane has now been expanded to include multi-hit TDCs. The agreement between results obtained from data taken using single-hit and multi-hit TDCs demonstrate a thorough understanding of the behavior of the detector system

Tests of the Monte Carlo simulation of the photon-tagger focal-plane electronics at the MAX IV Laboratory

Energy Technology Data Exchange (ETDEWEB)

Preston, M.F. [Lund University, SE-221 00 Lund (Sweden); Myers, L.S. [Duke University, Durham, NC 27708 (United States); Annand, J.R.M. [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Fissum, K.G., E-mail: kevin.fissum@nuclear.lu.se [Lund University, SE-221 00 Lund (Sweden); Hansen, K.; Isaksson, L. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Jebali, R. [Arktis Radiation Detectors Limited, 8045 Zürich (Switzerland); Lundin, M. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden)

2014-04-21

Rate-dependent effects in the electronics used to instrument the tagger focal plane at the MAX IV Laboratory were recently investigated using the novel approach of Monte Carlo simulation to allow for normalization of high-rate experimental data acquired with single-hit time-to-digital converters (TDCs). The instrumentation of the tagger focal plane has now been expanded to include multi-hit TDCs. The agreement between results obtained from data taken using single-hit and multi-hit TDCs demonstrate a thorough understanding of the behavior of the detector system.

An Investigation on Corrosion Behavior of a Multi-layer Modified Aluminum Brazing Sheet

Directory of Open Access Journals (Sweden)

Liu Wei

2016-01-01

Full Text Available The corrosion behavior of a multi-layer modified aluminum brazing sheet (AA4045/3003Mod./AA7072/AA4045 was investigated. The results shows that, the existence of BDP, which forms at the interface between clad and core layer during brazing, changes the corrosion form of the air side of the material from inter-granular corrosion to local exfoliation corrosion. The addition of anti-corrosion layer makes the corrosion form of the water side from inter-granular corrosion into uniform exfoliation corrosion. Compared to the normal triple-layer brazing sheet at the same thickness, the time to perforation of the modified four-layer brazing sheet is increased by more than 200%.

Apparatus and methods for memory using in-plane polarization

Science.gov (United States)

Liu, Junwei; Chang, Kai; Ji, Shuai-Hua; Chen, Xi; Fu, Liang

2018-05-01

A memory device includes a semiconductor layer with an in-plane polarization component switchable between a first direction and a second direction. A writing electrode is employed to apply a writing voltage to the semiconductor layer to change the in-plane polarization component between the first direction and the second direction. A reading electrode is employed to apply a reading voltage to the semiconductor layer to measure a tunneling current substantially perpendicular to the polarization direction of the in-plane polarization component. The directions of the reading voltage and the writing voltage are substantially perpendicular to each other. Therefore, the reading process is non-destructive. Thin films (e.g., one unit cell thick) of ferroelectric material can be used in the memory device to increase the miniaturization of the device.

Nonlocal laser annealing to improve thermal contacts between multi-layer graphene and metals

International Nuclear Information System (INIS)

Ermakov, Victor A; Alaferdov, Andrei V; Vaz, Alfredo R; Moshkalev, Stanislav A; Baranov, Alexander V

2013-01-01

The accuracy of thermal conductivity measurements by the micro-Raman technique for suspended multi-layer graphene flakes has been shown to depend critically on the quality of the thermal contacts between the flakes and the metal electrodes used as the heat sink. The quality of the contacts can be improved by nonlocal laser annealing at increased power. The improvement of the thermal contacts to initially rough metal electrodes is attributed to local melting of the metal surface under laser heating, and increased area of real metal–graphene contact. Improvement of the thermal contacts between multi-layer graphene and a silicon oxide surface was also observed, with more efficient heat transfer from graphene as compared with the graphene–metal case. (paper)

Cross-Layer Scheme to Control Contention Window for Per-Flow in Asymmetric Multi-Hop Networks

Science.gov (United States)

Giang, Pham Thanh; Nakagawa, Kenji

The IEEE 802.11 MAC standard for wireless ad hoc networks adopts Binary Exponential Back-off (BEB) mechanism to resolve bandwidth contention between stations. BEB mechanism controls the bandwidth allocation for each station by choosing a back-off value from one to CW according to the uniform random distribution, where CW is the contention window size. However, in asymmetric multi-hop networks, some stations are disadvantaged in opportunity of access to the shared channel and may suffer severe throughput degradation when the traffic load is large. Then, the network performance is degraded in terms of throughput and fairness. In this paper, we propose a new cross-layer scheme aiming to solve the per-flow unfairness problem and achieve good throughput performance in IEEE 802.11 multi-hop ad hoc networks. Our cross-layer scheme collects useful information from the physical, MAC and link layers of own station. This information is used to determine the optimal Contention Window (CW) size for per-station fairness. We also use this information to adjust CW size for each flow in the station in order to achieve per-flow fairness. Performance of our cross-layer scheme is examined on various asymmetric multi-hop network topologies by using Network Simulator (NS-2).

Collaborative multi-layer network coding for cellular cognitive radio networks

KAUST Repository

Sorour, Sameh

2013-06-01

In this paper, we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in underlay cellular cognitive radio networks. This scheme allows the collocated primary and cognitive radio base-stations to collaborate with each other, in order to minimize their own and each other\\'s packet recovery overheads, and thus improve their throughput, without any coordination between them. This non-coordinated collaboration is done using a novel multi-layer instantly decodable network coding scheme, which guarantees that each network\\'s help to the other network does not result in any degradation in its own performance. It also does not cause any violation to the primary networks interference thresholds in the same and adjacent cells. Yet, our proposed scheme both guarantees the reduction of the recovery overhead in collocated primary and cognitive radio networks, and allows early recovery of their packets compared to non-collaborative schemes. Simulation results show that a recovery overhead reduction of 15% and 40% can be achieved by our proposed scheme in the primary and cognitive radio networks, respectively, compared to the corresponding non-collaborative scheme. © 2013 IEEE.

Aero Engine Component Fault Diagnosis Using Multi-Hidden-Layer Extreme Learning Machine with Optimized Structure

Directory of Open Access Journals (Sweden)

Shan Pang

2016-01-01

Full Text Available A new aero gas turbine engine gas path component fault diagnosis method based on multi-hidden-layer extreme learning machine with optimized structure (OM-ELM was proposed. OM-ELM employs quantum-behaved particle swarm optimization to automatically obtain the optimal network structure according to both the root mean square error on training data set and the norm of output weights. The proposed method is applied to handwritten recognition data set and a gas turbine engine diagnostic application and is compared with basic ELM, multi-hidden-layer ELM, and two state-of-the-art deep learning algorithms: deep belief network and the stacked denoising autoencoder. Results show that, with optimized network structure, OM-ELM obtains better test accuracy in both applications and is more robust to sensor noise. Meanwhile it controls the model complexity and needs far less hidden nodes than multi-hidden-layer ELM, thus saving computer memory and making it more efficient to implement. All these advantages make our method an effective and reliable tool for engine component fault diagnosis tool.

Universality Results for Multi-layer Radial Hele-Shaw Flows

Science.gov (United States)

Daripa, Prabir; Gin, Craig; Daripa Research Team

2014-03-01

Saffman-Taylor instability is a well known viscosity driven instability of an interface separating two immiscible fluids. We study linear stability of this displacement process in multi-layer radial Hele-Shaw geometry involving an arbitrary number of immiscible fluid phases. Universal stability results have been obtained and applied to design displacement processes that are considerably less unstable than the pure Saffman-Taylor case. In particular, we derive universal formula which gives specific values of the viscosities of the fluid layers corresponding to smallest unstable band. Other similar universal results will also be presented. The talk is based on ongoing work. Supported by an NPRP Grant # 08-777-1-141 from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors.

"Analysis of the multi-layered cloud radiative effects at the surface using A-train data"

Science.gov (United States)

Viudez-Mora, A.; Smith, W. L., Jr.; Kato, S.

2017-12-01

Clouds cover about 74% of the planet and they are an important part of the climate system and strongly influence the surface energy budget. The cloud vertical distribution has important implications in the atmospheric heating and cooling rates. Based on observations by active sensors in the A-train satellite constellation, CALIPSO [Winker et. al, 2010] and CloudSat [Stephens et. al, 2002], more than 1/3 of all clouds are multi-layered. Detection and retrieval of multi-layer cloud physical properties are needed in understanding their effects on the surface radiation budget. This study examines the sensitivity of surface irradiances to cloud properties derived from satellite sensors. Surface irradiances were computed in two different ways, one using cloud properties solely from MODerate resolution Imaging Spectroradiometer (MODIS), and the other using MODIS data supplemented with CALIPSO and CloudSat (hereafter CLCS) cloud vertical structure information [Kato et. al, 2010]. Results reveal that incorporating more precise and realistic cloud properties from CLCS into radiative transfer calculations yields improved estimates of cloud radiative effects (CRE) at the surface (CREsfc). The calculations using only MODIS cloud properties, comparisons of the computed CREsfc for 2-layer (2L) overcast CERES footprints, CLCS reduces the SW CRE by 1.5±26.7 Wm-2, increases the LW CRE by 4.1±12.7 Wm-2, and increases the net CREsfc by 0.9±46.7 Wm-2. In a subsequent analysis, we classified up to 6 different combinations of multi-layered clouds depending on the cloud top height as: High-high (HH), high-middle (HM), high-low (HL), middle-middle (MM), middle-low (ML) and low-low (LL). The 3 most frequent 2L cloud systems were: HL (56.1%), HM (22.3%) and HH (12.1%). For these cases, the computed CREsfc estimated using CLCS data presented the most significant differences when compared using only MODIS data. For example, the differences for the SW and Net CRE in the case HH was 12.3±47

Multi-Shaped Ag Nanoparticles in the Plasmonic Layer of Dye-Sensitized Solar Cells for Increased Power Conversion Efficiency

Directory of Open Access Journals (Sweden)

Da Hyun Song

2017-06-01

Full Text Available The use of dye-sensitized solar cells (DSSCs is widespread owing to their high power conversion efficiency (PCE and low cost of manufacturing. We prepared multi-shaped Ag nanoparticles (NPs and introduced them into DSSCs to further enhance their PCE. The maximum absorption wavelength of the multi-shaped Ag NPs is 420 nm, including the shoulder with a full width at half maximum (FWHM of 121 nm. This is a broad absorption wavelength compared to spherical Ag NPs, which have a maximum absorption wavelength of 400 nm without the shoulder of 61 nm FWHM. Therefore, when multi-shaped Ag NPs with a broader plasmon-enhanced absorption were coated on a mesoporous TiO2 layer on a layer-by-layer structure in DSSCs, the PCE increased from 8.44% to 10.22%, equivalent to an improvement of 21.09% compared to DSSCs without a plasmonic layer. To confirm the plasmon-enhanced effect on the composite film structure in DSSCs, the PCE of DSSCs based on the composite film structure with multi-shaped Ag NPs increased from 8.58% to 10.34%, equivalent to an improvement of 20.51% compared to DSSCs without a plasmonic layer. This concept can be applied to perovskite solar cells, hybrid solar cells, and other solar cells devices.

The light wave flow effect in a plane-parallel layer with a quasi-zero refractive index under the action of bounded light beams

International Nuclear Information System (INIS)

Gadomsky, O. N.; Shchukarev, I. A.

2016-01-01

It is shown that external optical radiation in the 450–1200 nm range can be efficiently transformed under the action of bounded light beams to a surface wave that propagates along the external and internal boundaries of a plane-parallel layer with a quasi-zero refractive index. Reflection regimes with complex and real angles of refraction in the layer are considered. The layer with a quasi-zero refractive index in this boundary problem is located on a highly reflective metal substrate; it is shown that the uniform low reflection of light is achieved in the wavelength range under study.

Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

Science.gov (United States)

Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

2017-09-01

Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

Heat transfer enhancement induced by electrically generated convection in a plane layer of dielectric liquid

International Nuclear Information System (INIS)

Traoré, P; Wu, J; Romat, H; Louste, C; Perez, A; Koulova, D

2012-01-01

The electro-thermo-convective motion in a plane horizontal dielectric liquid layer subjected to simultaneous action of electric field and thermal gradient is numerically investigated. We consider the case of a strong unipolar charge injection C = 10 from above or below. Therefore in this context, we only take into account the Coulomb force, disregarding the dielectric one. The effect of the electric field on the heat transfer is analyzed through the characterization of the time history of the Nusselt number as well as its evolution according to the characteristic dimensionless electric parameter T. It is demonstrated that the electric effects dominate the buoyancy ones resulting in an electrically induced convection which significantly enhance the heat transfer.

Optical network control plane for multi-domain networking

DEFF Research Database (Denmark)

Manolova, Anna Vasileva

This thesis focuses on multi-domain routing for traffice engineering and survivability support in optical transport networks under the Generalized Multi-Protocol Label Switching (GMPLS) control framework. First, different extensions to the Border Gateway Protocol for multi-domain Traffic...... process are not enough for efficient TE in mesh multi-domain networks. Enhancing the protocol with multi-path dissemination capability, combined with the employment of an end-to-end TE metric proves to be a highly efficient solution. Simulation results show good performance characteristics of the proposed...... is not as essential for improved network performance as the length of the provided paths. Second, the issue of multi-domain survivability support is analyzed. An AS-disjoint paths is beneficial not only for resilience support, but also for facilitating adequate network reactions to changes in the network, which...

TargetCrys: protein crystallization prediction by fusing multi-view features with two-layered SVM.

Science.gov (United States)

Hu, Jun; Han, Ke; Li, Yang; Yang, Jing-Yu; Shen, Hong-Bin; Yu, Dong-Jun

2016-11-01

The accurate prediction of whether a protein will crystallize plays a crucial role in improving the success rate of protein crystallization projects. A common critical problem in the development of machine-learning-based protein crystallization predictors is how to effectively utilize protein features extracted from different views. In this study, we aimed to improve the efficiency of fusing multi-view protein features by proposing a new two-layered SVM (2L-SVM) which switches the feature-level fusion problem to a decision-level fusion problem: the SVMs in the 1st layer of the 2L-SVM are trained on each of the multi-view feature sets; then, the outputs of the 1st layer SVMs, which are the "intermediate" decisions made based on the respective feature sets, are further ensembled by a 2nd layer SVM. Based on the proposed 2L-SVM, we implemented a sequence-based protein crystallization predictor called TargetCrys. Experimental results on several benchmark datasets demonstrated the efficacy of the proposed 2L-SVM for fusing multi-view features. We also compared TargetCrys with existing sequence-based protein crystallization predictors and demonstrated that the proposed TargetCrys outperformed most of the existing predictors and is competitive with the state-of-the-art predictors. The TargetCrys webserver and datasets used in this study are freely available for academic use at: http://csbio.njust.edu.cn/bioinf/TargetCrys .

Spectral properties of porphyrins in the systems with layered silicates

International Nuclear Information System (INIS)

Ceklovsky, A.

2009-03-01

This work is focused on investigation of hybrid materials based on layered silicates, representing host inorganic component, and porphyrin dyes as organic guest. Aqueous colloidal dispersions, as well as thin solid films of layered silicate/porphyrin systems were studied. Modification of photophysical properties, such as absorption and fluorescence of molecules, adsorbed or incorporated in layered silicate hosts, were studied mainly to spread the knowledge about the environments suitable for incorporating aromatic compounds, providing photoactive properties of potential technological interest. TMPyP cations interact with the surfaces of layered silicates via electrostatic interactions. The extent of dye adsorption on colloidal particles of the silicates is influenced by the CEC values and swelling ability of silicates. Interaction of porphyrins with layered silicate hosts leads to significant changes of dye spectral properties. One of the key parameters that has a crucial impact on this interaction is the layer charge of silicate template. Other factors influence the resulting spectral properties of hybrid systems, such as the method of hybrid material preparation, the material's type (colloid, film), and the modification of the silicate host. Molecular orientation studies using linearly-polarized spectroscopies in VIS and IR regions revealed that TMPyP molecules were oriented in almost parallel fashion with respect to the silicate surface plane. Slightly higher values of the orientation angle of TMPyP transition moment were observed for the TMPyP/FHT system. Thus, flattening of the guest TMPyP molecules is the next important factor (mainly in the systems with lower layer charge), influencing its spectral properties upon the interaction with layered silicates. Fluorescence was effectively quenched in the systems based on solid films prepared from the high concentration of the dye (10-3 mol.dm-3). The quenching is most probably related to the structure of the

Root profile in Multi-layered Dehesas: an approach to plant-to-plant Interaction

Science.gov (United States)

Rolo, V.; Moreno, G.

2009-04-01

Assessing plant-to-plant relationship is a key issue in agroforestry systems. Due to the sessile feature of plants most of these interactions take place within a restricted space, so characterizing the zone where the plant alters its environment is important to find overlapping areas where the facilitation or competition could occur. Main part of plan-to-plant interactions in the dehesa are located at belowground level, thus the main limited resources in Mediterranean ecosystems are soil nutrient and water. Hence a better knowledge of rooting plant profile can be useful to understand the functioning of the dehesa. The Iberian dehesa has always been considered as a silvopastoral system where, at least, two strata of vegetation coexist: native grasses and trees. However the dehesa is also a diverse system where cropland and encroached territories have been systematically combined, more or less periodically, with native pasture in order to obtain agricultural, pastoral and forestry outputs. These multipurpose mosaic-type systems generate several scenarios where the plant influence zone may be overlapped and the interaction, competition or facilitation, between plants can play an important role in the ecosystem functioning in terms of productivity and stability. In the present study our aim was to characterize the rooting profile of multi-layered dehesas in order to understand the competitive, and/or facilitative, relationships within the different plant strata. The root profile of Quercus ilex subsp. ballota, Cistus ladanifer, Retama spaherocarpa and natural grasses was studied. So 48 trenches, up to 2 meters deep, were excavated in 4 different environments: (i) grass; (ii) tree-grass; (iii) tree-shrub and (iv) tree-shrub-grass (12 trenches in each environment). The study was carried out in 4 dehesas, 2 encroached with C. ladanifer and 2 with R. spaherocarpa. In every trench soil samples were taken each 20 cm. Subsequently, all samples were sieved using different mesh

MULTI-LAYER MIRROR FOR RADIATION IN THE XUV WAVELENGHT RANGE AND METHOD FOR MANUFACTURE THEREOF

NARCIS (Netherlands)

Bijkerk, Frederik; Louis, Eric; Kessels, M.J.H.; Verhoeven, Jan; Den Hartog, Harmen Markus Johannes

2002-01-01

Multi-layer mirror for radiation with a wavelength in the wavelength range between 0.1 nm and 30 nm (the so-called XUV range), comprising a stack of thin films substantially comprising scattering particles which scatter the radiation, which thin films are separated by separating layers with a

Non-destructive Inspection of Multi-layered Composite Using Ultrasonic Signal Processing

International Nuclear Information System (INIS)

Ng, S C; Ismail, N; Ali, Aidy; Sahari, Barkawi; Yusof, J M; Chu, B W

2011-01-01

Composites exhibit higher strength and stiffness, better design practice and greater corrosion resistance compare to metal material. However, composites are susceptible to impact damage and the typical damage behaviour in the laminated composites is fibre-breakage and delamination. Detection of failure in laminated composites is complicated compared with ordinary non-destructive testing for metal materials as they are sensitive to echoes drown in noise due to the properties of the constituent materials and the multi-layered structure of the composites. In the current study, the detection of failure in multi-layered composite materials is investigated. To obtain a high probability of defect detection in composite materials, signal processing algorithms were used to resolve echoes associated with defects in glass fibre-reinforced plastics (GRP) detected by using ultrasonic testing. Pulse-echo method with single transducer was used to transmit and receive ultrasound. The obtained signals were processed to reduce noise and to extract suitable features. Results were validated on GRP with and without defects in order to demonstrate the feasibility of the method on defect detection in composites.

Partnering with Youth to Map Their Neighborhood Environments: A Multi-Layered GIS Approach

Science.gov (United States)

Topmiller, Michael; Jacquez, Farrah; Vissman, Aaron T.; Raleigh, Kevin; Miller-Francis, Jenni

2014-01-01

Mapping approaches offer great potential for community-based participatory researchers interested in displaying youth perceptions and advocating for change. We describe a multi-layered approach for gaining local knowledge of neighborhood environments that engages youth as co-researchers and active knowledge producers. By integrating geographic information systems (GIS) with environmental audits, an interactive focus group, and sketch mapping, the approach provides a place-based understanding of physical activity resources from the situated experience of youth. Youth report safety and a lack of recreational resources as inhibiting physical activity. Maps reflecting youth perceptions aid policy-makers in making place-based improvements for youth neighborhood environments. PMID:25423245

Enhanced Inter-Cell Interference Coordination in Co-Channel Multi-Layer LTE-Advanced Networks

DEFF Research Database (Denmark)

Pedersen, Klaus I.; Wang, Yuanye; Strzyz, Stanislav

2013-01-01

Different technical solutions and innovations are enabling the move from macro-only scenarios towards heterogeneous networks with a mixture of different base station types. In this article we focus on multi-layer LTE-Advanced networks, and especially address aspects related to interference...... management. The network controlled time-domain enhanced inter-cell interference coordination (eICIC) concept is outlined by explaining the benefits and characteristics of this solution. The benefits of using advanced terminal device receiver architectures with interference suppression capabilities...... are motivated. Extensive system level performance results are presented with bursty traffic to demonstrate the eICIC concepts ability to dynamically adapt according to the traffic conditions....

Effect of applied DC voltages and temperatures on space charge behaviour of multi-layer oil-paper insulation

Energy Technology Data Exchange (ETDEWEB)

Tang Chao; Liao Ruijin [The State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University (China); Chen, G [School of Electronics and Computer Science, University of Southampton (United Kingdom); Fu, M, E-mail: tangchao_1981@163.co [AVERA T and D Technology Centre, Stafford (United Kingdom)

2009-08-01

In this paper, space charge in a multi-layer oil-paper insulation system was investigated using the pulsed electroacoustic (PEA) technique. A series of measurements had been carried following subjection of the insulation system to different applied voltages and different temperatures. Charge behaviours in the insulation system were analyzed and the influence of temperature on charge dynamics was discussed. The test results shows that homocharge injection takes place under all the test conditions, the applied DC voltage mainly affects the amount of space charge, while the temperature has greater influence on the distribution and mobility of space charge inside oil-paper samples.

Interfacial characteristics of polyethylene terephthalate-based piezoelectric multi-layer films

International Nuclear Information System (INIS)

Liu, Z.H.; Pan, C.T.; Chen, Y.C.; Liang, P.H.

2013-01-01

The study examines the deformation between interfaces and the adhesion mechanism of multi-layer flexible electronic composites. Indium tin oxide (ITO), aluminum (Al), and zinc oxide (ZnO) were deposited on a polyethylene terephthalate (PET) substrate using radio frequency magnetron sputtering at room temperature to form flexible structures (e.g., ITO/PET, Al/PET, ZnO/ITO/PET, and ZnO/Al/PET) for piezoelectric transducers. ITO and Al films are used as the conductive layers. A ZnO thin film shows a high (002) c-axis preferred orientation at 2θ = 34.45° and excellent piezoelectric properties. Nanoscratching and nano-indention testing were conducted to analyze the adhesion following periodic mechanical stress. Additionally, two Berkovich and conical probes with a curvature radius of 40 nm and 10 μm are examined for the scratching test. A 4-point probe is used to measure the conductive properties. The plastic deformation between the ductile Al film and PET substrate is observed using scanning electron microscopy to examine the chip formation on the ITO/PET. Delamination between the ZnO and Al/PET substrate was not observed. The result suggests that ZnO film has excellent adhesion with Al/PET compared to ITO/PET. - Highlights: ► Interfaces and adhesion mechanism of multi-layer flexible electronic composites ► Polyethylene terephthalate (PET) based flexible structures ► Nano-scratching and nano-indention tests were used to analyze adhesion. ► Using two various probes of Berkovich and conical ► Piezoelectric zinc oxide film has excellent adhesion with aluminum/PET

Modeling of Nonlinear Propagation in Multi-layer Biological Tissues for Strong Focused Ultrasound

International Nuclear Information System (INIS)

Ting-Bo, Fan; Zhen-Bo, Liu; Zhe, Zhang; Dong, Zhang; Xiu-Fen, Gong

2009-01-01

A theoretical model of the nonlinear propagation in multi-layered tissues for strong focused ultrasound is proposed. In this model, the spheroidal beam equation (SBE) is utilized to describe the nonlinear sound propagation in each layer tissue, and generalized oblique incidence theory is used to deal with the sound transmission between two layer tissues. Computer simulation is performed on a fat-muscle-liver tissue model under the irradiation of a 1 MHz focused transducer with a large aperture angle of 35°. The results demonstrate that the tissue layer would change the amplitude of sound pressure at the focal region and cause the increase of side petals. (fundamental areas of phenomenology (including applications))

Matrix solution to longitudinal impedance of multi-layer circular structures

Energy Technology Data Exchange (ETDEWEB)

Hahn,H.

2008-10-01

A matrix method in which radial wave propagation is treated in analogy to longitudinal transmission lines is presented and applied to finding the longitudinal coupling impedance of axially symmetric multi-layer beam tubes. The method is demonstrated in the case of a Higher Order Mode ferrite absorber with an inserted coated ceramic beam tube. The screening of the ferrite damping properties by the dielectric beam tube is discussed.

A Method to Estimate the Dynamic Displacement and Stress of a Multi-layered Pavement with Bituminous or Concrete Materials

Directory of Open Access Journals (Sweden)

Zheng LU

2014-12-01

Full Text Available In this research work, a method to estimate the dynamic characteristics of a multilayered pavement with bituminous or concrete materials is proposed. A mechanical model is established to investigate the dynamic displacement and stress of the multi-layered pavement structure. Both the flexible and the rigid pavements, corresponding to bituminous materials and concrete materials, respectively, are studied. The theoretical solutions of the multi-layered pavement structure are deduced considering the compatibility condition at the interface of the structural layers. By introducing FFT (Fast Fourier Transform algorithm, some numerical results are presented. Comparisons of the theoretical and experimental result implied that the proposed method is reasonable in predicting the stress and displacement of a multi-layered pavement with bituminous or concrete materials. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6071

A comparison of mid-plane scrape-off-layer measurements with model predictions in MAST and the calculation of cross-field transport coefficients

International Nuclear Information System (INIS)

Kirk, A; Counsell, G F; Fundamenski, W; Ahn, J-W; Taylor, D; Walsh, M J; Yang, Y

2004-01-01

The outboard mid-plane values of electron density (n e ) and temperature (T e ) in the scrape-off-layer (SOL) of MAST are derived from target Langmuir probe measurements using OSM2-EIRENE and also using a simple two-point model. The values are compared with mid-plane measurements of n e and T e from a reciprocating probe and a Thomson scattering system for Ohmic, L- and H-modes single-null divertor (SND) discharges. The cross-field heat (χ perpendicular ) diffusion coefficient at the low field side of SND discharges is derived both using the OSM2-EIRENE model and a two-point model coupled with a simple theory. The results are found to be similar within the errors. Typically χ perpendicular values are found to lie in the range 0.5-2.0 m 2 s -1 for L-mode and 0.1-0.5 m 2 s -1 for H-mode. A comparison is made of the transport coefficients derived at the low and high field sides for a set of connected double-null discharges. These results are used to make preliminary observations of the effect of magnetic fields on SOL transport in MAST

Layering and Ordering in Electrochemical Double Layers

Energy Technology Data Exchange (ETDEWEB)

Liu, Yihua [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Kawaguchi, Tomoya [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Pierce, Michael S. [Rochester Institute of Technology, School of Physics and Astronomy, Rochester, New York 14623, United States; Komanicky, Vladimir [Faculty of Science, Safarik University, 041 54 Kosice, Slovakia; You, Hoydoo [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States

2018-02-26

Electrochemical double layers (EDL) form at electrified interfaces. While Gouy-Chapman model describes moderately charged EDL, formation of Stern layers was predicted for highly charged EDL. Our results provide structural evidence for a Stern layer of cations, at potentials close to hydrogen evolution in alkali fluoride and chloride electrolytes. Layering was observed by x-ray crystal truncation rods and atomic-scale recoil responses of Pt(111) surface layers. Ordering in the layer is confirmed by glancing-incidence in-plane diffraction measurements.

Modelling of migration from multi-layers and functional barriers: Estimation of parameters

NARCIS (Netherlands)

Dole, P.; Voulzatis, Y.; Vitrac, O.; Reynier, A.; Hankemeier, T.; Aucejo, S.; Feigenbaum, A.

2006-01-01

Functional barriers form parts of multi-layer packaging materials, which are deemed to protect the food from migration of a broad range of contaminants, e.g. those associated with reused packaging. Often, neither the presence nor the identity of the contaminants is known, so that safety assessment

Research and development of a control system for multi axis cooperative motion based on PMAC

Science.gov (United States)

Guo, Xiao-xiao; Dong, Deng-feng; Zhou, Wei-hu

2017-10-01

Based on Programmable Multi-axes Controller (PMAC), a design of a multi axis motion control system for the simulator of spatial targets' dynamic optical properties is proposed. According to analysis the properties of spatial targets' simulator motion control system, using IPC as the main control layer, TurboPMAC2 as the control layer to meet coordinated motion control, data acquisition and analog output. A simulator using 5 servomotors which is connected with speed reducers to drive the output axis was implemented to simulate the motion of both the sun and the space target. Based on PMAC using PID and a notch filter algorithm, negative feedback, the speed and acceleration feed forward algorithm to satisfy the axis' requirements of the good stability and high precision at low speeds. In the actual system, it shows that the velocity precision is higher than 0.04 s ° and the precision of repetitive positioning is better than 0.006° when each axis is at a low-speed. Besides, the system achieves the control function of multi axis coordinated motion. The design provides an important technical support for detecting spatial targets, also promoting the theoretical research.

Fretting wear behaviour of TiC/Ti(C,N)/TiN multi-layer coatings at elevated temperature in gross slip regime

International Nuclear Information System (INIS)

Liu Hanwei; Huang Kunpeng; Zhu Minhao; Zhou Zhongrong

2005-01-01

Tic/Ti(C,N)/TiN multi-layer coatings are prepared on the 1Cr13 stainless steel substrate by the technique of Chemical Vapour Deposition, and the fretting wear behaviour of 1Cr13 stainless steel and TiC/Ti(C,N)/TiN coatings are investigated and studied controversially from 25 degree C to 400 degree C in the gross slip regime. It shows that the temperature has great influence on the fretting wear in the gross slip regime for the 1Cr13 stainless steel but little for Ti/C/Ti(C,N)/TiN multi-layer coatings. With the temperature increasing, the friction coefficient and the wear volume of the 1Cr13 alloy decreases and the wear volume of TiC/Ti(C, N)/TiN multi-layer coatings is invariant. TiC/Ti(C,N)/TiN multi-layer coatings have better wear-resistant capability than the 1Cr13 stainless steel, but the wear volume of the substrate increases greatly because of the grain-abrasion resulted from hard debris when TiC/Ti(C,N)/TiN multi-layer coatings are ground off. (authors)

Uplink Contention-based CSI Feedback with Prioritized Layers for a Multi-Carrier System

DEFF Research Database (Denmark)

Kaneko, Megumi; Hayashi, Kazunori; Popovski, Petar

2012-01-01

, several works have considered contention-based CSI feedback in the UL control channel. We propose such a feedback scheme for a generic MC system, based on the idea of variable collision protection, where the probability that a feedback information experiences a collision depends on its importance......Optimized resource allocation of the Downlink (DL) in wireless systems utilizing Multi-Carrier (MC) transmission requires Channel State Information (CSI) feedback for each user/subchannel to the Base Station (BS), consuming a high amount of Uplink (UL) radio resources. To alleviate this problem...

High thermal conductivity lossy dielectric using a multi layer configuration

Science.gov (United States)

Tiegs, Terry N.; Kiggans, Jr., James O.

2003-01-01

Systems and methods are described for loss dielectrics. A loss dielectric includes at least one high dielectric loss layer and at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. A method of manufacturing a loss dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. The systems and methods provide advantages because the loss dielectrics are less costly and more environmentally friendly than the available alternatives.

Lattice Boltzmann method for short-pulsed laser transport in a multi-layered medium

International Nuclear Information System (INIS)

Zhang, Yong; Yi, Hong-Liang; Tan, He-Ping

2015-01-01

We construct a lattice Boltzmann method (LBM) for transient radiative transfer in one-dimensional multi-layered medium with distinct refractive index in each layer. The left boundary is irradiated normally by a short-pulsed laser. The Fresnel interfaces conditions, which incorporate reflection and refraction, are used at the boundaries and the interfaces. Based on the Fresnel's law and Snell's law, the interfacial intensity formulas are introduced. The collimated and diffuse intensities are treated individually. At a transient time step, the collimated component is first solved by LBM and then embedded into the transient radiative transfer equation as a source term. To keep the consistency of the directions in all the layers, angular interpolation of the intensities at the interfaces is adopted. The transient radiative transfer in a two-layer medium is first investigated, and the time-resolved results are validated by comparing with those by the Monte Carlo method (MCM). Of particular interest, the angular intensities along the slab at different times are presented to illustrate a variety of interesting phenomena, and the discontinuous nature of the intensity at the interfaces is discussed. The effects of various parameters on the time-resolved signals are examined. - Highlights: • Transient radiative transfer in a multi-layered medium is solved by LBM. • The boundary and interfaces are all considered as Fresnel surfaces. • The LBM solution for the collimated pulse is derived. • Discontinuous nature of the intensity at the interface is illustrated and discussed

Asymmetric bi-layer PFSA membranes as model systems for the study of water management in the PEMFC.

Science.gov (United States)

Peng, Z; Peng, A Z; Morin, A; Huguet, P; Lanteri, Y; Deabate, S

2014-10-14

New bi-layer PFSA membranes made of Nafion® NRE212 and Aquivion™ E79-05s with different equivalent weights are prepared with the aim of managing water repartition in the PEMFC. The membrane water transport properties, i.e. back-diffusion and electroosmosis, as well as the electrochemical performances, are compared to those of state-of-art materials. The actual water content (the inner water concentration profile across the membrane thickness) is measured under operation in the fuel cell by in situ Raman microspectroscopy. The orientation of the equivalent weight gradient with respect to the water external gradient and to the proton flow direction affects the membrane water content, the water transport ability and, thus, the fuel cell performances. Higher power outputs, related to lower ohmic losses, are observed when the membrane is assembled with the lower equivalent weight layer (Aquivion™) at the anode side. This orientation, corresponding to enhanced water transport by back-flow while electroosmosis remains unaffected, results in the higher hydration of the membrane and of the anode active layer during operation. Also, polarization data suggest a different water repartition in the fuel cell along the on-plane direction. Even if the interest in multi-layer PFSA membranes as perspective electrolytes for PEMFCs is not definitively attested, these materials appear to be excellent model systems to establish relationships between the membrane transport properties, the water distribution in the fuel cell and the electrochemical performances. Thanks to the micrometric resolution, in situ Raman microspectroscopy proves to be a unique tool to measure the actual hydration of the membrane at the surface swept by the hydrated feed gases during operation, so that it can be used as a local probe of the water concentration evolution along the gas distribution channels according to changing working conditions.

Characteristics of laser ultrasound interaction with multi-layered dissimilar metals adhesive interface by numerical simulation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kuanshuang, E-mail: zkuanshuang@buaa.edu.cn [School of Mechanical Engineering and Automation, BeiHang University, Beijing 100191 (China); Collaborative Innovation Center of Advanced Aero-Engine, Beijing 100191 (China); Zhou, Zhenggan; Zhou, Jianghua; Sun, Guangkai [School of Mechanical Engineering and Automation, BeiHang University, Beijing 100191 (China); Collaborative Innovation Center of Advanced Aero-Engine, Beijing 100191 (China)

2015-10-30

Highlights: • We investigate laser generated ultrasound in multi-layered adhesive structure. • We find the difference of waveforms with different probe points. • Probe points and frequency range influence characterization of the damage interface. • Reflection coefficients of longitudinal waves can quantify the void defect. - Abstract: The characteristics of laser-generated ultrasonic wave interaction with multi-layered dissimilar metals adhesive interface are investigated by finite element method (FEM). The physical model of laser-generated ultrasonic wave in the multi-layered dissimilar metals adhesive structure is built. The surface temperature evolution with different laser power densities is analyzed to obtain the parameters of pulsed laser with thermoelastic regime. The differences of laser ultrasonic waves with different center frequencies measured at the center of laser irradiation would verify the interfacial features of adhesive structures. The optimum frequency range and probe point would be beneficial for the detection of the small void defect. The numerical results indicate that the different frequency range and probe points would evidently influence the identification and quantitative characterization of the small void defect. The research findings would lay a foundation for testing interfacial integrity.

Characteristics of laser ultrasound interaction with multi-layered dissimilar metals adhesive interface by numerical simulation

International Nuclear Information System (INIS)

Zhang, Kuanshuang; Zhou, Zhenggan; Zhou, Jianghua; Sun, Guangkai

2015-01-01

Highlights: • We investigate laser generated ultrasound in multi-layered adhesive structure. • We find the difference of waveforms with different probe points. • Probe points and frequency range influence characterization of the damage interface. • Reflection coefficients of longitudinal waves can quantify the void defect. - Abstract: The characteristics of laser-generated ultrasonic wave interaction with multi-layered dissimilar metals adhesive interface are investigated by finite element method (FEM). The physical model of laser-generated ultrasonic wave in the multi-layered dissimilar metals adhesive structure is built. The surface temperature evolution with different laser power densities is analyzed to obtain the parameters of pulsed laser with thermoelastic regime. The differences of laser ultrasonic waves with different center frequencies measured at the center of laser irradiation would verify the interfacial features of adhesive structures. The optimum frequency range and probe point would be beneficial for the detection of the small void defect. The numerical results indicate that the different frequency range and probe points would evidently influence the identification and quantitative characterization of the small void defect. The research findings would lay a foundation for testing interfacial integrity.

Habit plane-driven P2-type manganese-based layered oxide as long cycling cathode for Na-ion batteries

Science.gov (United States)

Luo, Rui; Wu, Feng; Xie, Man; Ying, Yao; Zhou, Jiahui; Huang, Yongxin; Ye, Yusheng; Li, Li; Chen, RenJie

2018-04-01

Layered transition metal oxides are considered to be promising candidates as cathode materials for sodium-ion batteries. Herein, a facile solid-state reaction is developed to synthesize hexagons plate-like Na0.67Ni0.25Mn0.75O2+δ (denoted as P2-NNM) material with habit plane formed. The structure of this layered oxide is characterized by XRD, HR-TEM and SAED. The layered material delivers a high reversible capacity of 91.8 mAh g-1 at 0.2 C with a capacity retention of 94.4 % after 280 cycles, superior rate capability and long cycle life (84.2 % capacity retention after 1000 cycle). Ni2+ is an active ion and Ni doping alleviates the Jahn-Teller distortion, and Mn3+/Mn4+ coexist as Mn4+ is desired from the stability perspective. Particularly, CV and XPS results confirm these results. Moreover, the electrode exhibits a quasi-solid-solution reaction during the sodium extraction and insertion. This contribution demonstrates that P2-NNM is a promising cathode electrode for rechargeable long-life sodium-ion batteries.

Heterogeneous multi-layered IF steel with simultaneous high strength and good ductility

Science.gov (United States)

Zhang, Ling; Jiang, Xiaojuan; Wang, Yuhui; Chen, Qiang; Chen, Zhen; Zhang, Yonghong; Huang, Tianlin; Wu, Guilin

2017-07-01

Multi-layered IF steel samples were designed and fabricated by hot compression followed by cold forging of an alternating stack of cold-rolled and annealed IF steel sheets, with an aim to improve the strength of the material without losing much ductility. A very good combination of strength and ductility was achieved by proper annealing after deformation. Microstructural analysis by electron back-scatter diffraction revealed that the good combination of strength and ductility is related to a characteristic hierarchical structure that is characterized by layered and lamella structures with different length scales.

Microwave energy harvesting based on metamaterial absorbers with multi-layered square split rings for wireless communications

Science.gov (United States)

Karaaslan, Muharrem; Bağmancı, Mehmet; Ünal, Emin; Akgol, Oguzhan; Sabah, Cumali

2017-06-01

We propose the design of a multiband absorber based on multi-layered square split ring (MSSR) structure. The multi-layered metamaterial structure is designed to be used in the frequency bands such as WIMAX, WLAN and satellite communication region. The absorption levels of the proposed structure are higher than 90% for all resonance frequencies. In addition, the incident angle and polarization dependence of the multi-layered metamaterial absorber and harvester is also investigated and it is observed that the structure has polarization angle independent frequency response with good absorption characteristics in the entire working frequency band. The energy harvesting ratios of the structure is investigated especially for the resonance frequencies at which the maximum absorption occurs. The energy harvesting potential of the proposed MSSRs is as good as those of the structures given in the literature. Therefore, the suggested design having good absorption, polarization and angle independent characteristics with a wide bandwidth is a potential candidate for future energy harvesting applications in commonly used wireless communication bands, namely WIMAX, WLAN and satellite communication bands.

Pre-experiment testing of the Multi Channel Systems 16-channel preamplifier CPA16

International Nuclear Information System (INIS)

Patin, J B; Stoyer, M A; Moody, K J; Friensehner, A V

2003-01-01

The 16-channel preamplifier model CPA16 from Multi Channel Systems was studied. The CPA16 preamplifier/amplifier module is a candidate to be used as the preamplifiers and amplifiers for the focal plane detectors of the Mass Analyzer of Super Heavy Atoms (MASHA). The equipment used to test the CPA16, the results of testing the CPA16 with a pulser, a mixed 229 Th/ 148 Gd source and a 252 Cf source, and a summary of the results will be presented

Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope.

Science.gov (United States)

Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

2016-01-01

We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy.

Multi-layered see-through movie in diminished reality

Science.gov (United States)

Uematsu, Yuko; Hashimoto, Takanori; Inoue, Takuya; Shimizu, Naoki; Saito, Hideo

2012-03-01

This paper presents generating a multi-layered see-through movie for an auto-stereoscopic display. This work is based on Diminished Reality (DR), which is one of the research fields of Augmented Reality (AR). In the usual AR, some virtual objects are added on the real world. On the other hand, DR removes some real objects from the real world. Therefore, the background is visualized instead of the real objects (obstacles) to be removed. We use multiple color cameras and one TOF depth camera. The areas of obstacles are defined by using the depth camera based on the distance of obstacles. The background behind the obstacles is recovered by planarprojection of multiple cameras. Then, the recovered background is overlaid onto the removed obstacles. For visualizing it through the auto-stereoscopic display, the scene is divided into multiple layers such as obstacles and background. The pixels corresponding to the obstacles are not visualized or visualized semi-transparently at the center viewpoints. Therefore, we can see that the obstacles are diminished according to the viewpoints.

Multi-layered settlement Rudi XX (excavations in 1982

Directory of Open Access Journals (Sweden)

Ivan Vlasenko

2017-12-01

Full Text Available This publication presents the results of investigations, which had began in 1980 at the Rudi XX settlement in the Soroca District of the Republic of Moldova, obtained in 1982. There was confirmed the multi-layered structure of the site and the horizon of the Iron Age was first identified. But because of the small number and inexpressiveness of the ceramic findings, this layer was previously dated by a rather long period of time – from the late Hallstatt (7th-6th centuries BC to the Getic culture (4th-3rd centuries BC. The discovered structure in the form of a heavily burned pit was attributed, as a hypothesis, to the Getic crematorium. The production character of the early medieval settlement has been confirmed (presence of iron slag, fragments of ceramic blowing nozzles and iron ore. The remains of three ovens of the 8th-9th centuries were investigated. The collection of medieval pottery of the 6th-11th centuries and individual findings of iron, stone and bone objects was assembled.

Multi-layer Lanczos iteration approach to calculations of vibrational energies and dipole transition intensities for polyatomic molecules

International Nuclear Information System (INIS)

Yu, Hua-Gen

2015-01-01

We report a rigorous full dimensional quantum dynamics algorithm, the multi-layer Lanczos method, for computing vibrational energies and dipole transition intensities of polyatomic molecules without any dynamics approximation. The multi-layer Lanczos method is developed by using a few advanced techniques including the guided spectral transform Lanczos method, multi-layer Lanczos iteration approach, recursive residue generation method, and dipole-wavefunction contraction. The quantum molecular Hamiltonian at the total angular momentum J = 0 is represented in a set of orthogonal polyspherical coordinates so that the large amplitude motions of vibrations are naturally described. In particular, the algorithm is general and problem-independent. An application is illustrated by calculating the infrared vibrational dipole transition spectrum of CH based on the ab initio T8 potential energy surface of Schwenke and Partridge and the low-order truncated ab initio dipole moment surfaces of Yurchenko and co-workers. A comparison with experiments is made. The algorithm is also applicable for Raman polarizability active spectra

A multi-camera system for real-time pose estimation

Science.gov (United States)

Savakis, Andreas; Erhard, Matthew; Schimmel, James; Hnatow, Justin

2007-04-01

This paper presents a multi-camera system that performs face detection and pose estimation in real-time and may be used for intelligent computing within a visual sensor network for surveillance or human-computer interaction. The system consists of a Scene View Camera (SVC), which operates at a fixed zoom level, and an Object View Camera (OVC), which continuously adjusts its zoom level to match objects of interest. The SVC is set to survey the whole filed of view. Once a region has been identified by the SVC as a potential object of interest, e.g. a face, the OVC zooms in to locate specific features. In this system, face candidate regions are selected based on skin color and face detection is accomplished using a Support Vector Machine classifier. The locations of the eyes and mouth are detected inside the face region using neural network feature detectors. Pose estimation is performed based on a geometrical model, where the head is modeled as a spherical object that rotates upon the vertical axis. The triangle formed by the mouth and eyes defines a vertical plane that intersects the head sphere. By projecting the eyes-mouth triangle onto a two dimensional viewing plane, equations were obtained that describe the change in its angles as the yaw pose angle increases. These equations are then combined and used for efficient pose estimation. The system achieves real-time performance for live video input. Testing results assessing system performance are presented for both still images and video.

Multi-layer monochromator

International Nuclear Information System (INIS)

Schoenborn, B.P.; Caspar, D.L.D.

1975-01-01

This invention provides an artificial monochromator crystal for efficiently selecting a narrow band of neutron wavelengths from a neutron beam having a Maxwellian wavelength distribution, by providing on a substrate a plurality of germanium layers, and alternate periodic layers of a different metal having tailored thicknesses, shapes, and volumetric and neutron scattering densities. (U.S.)

Three-dimensional cell manipulation and patterning using dielectrophoresis via a multi-layer scaffold structure.

Science.gov (United States)

Chu, H K; Huan, Z; Mills, J K; Yang, J; Sun, D

2015-02-07

Cell manipulation is imperative to the areas of cellular biology and tissue engineering, providing them a useful tool for patterning cells into cellular patterns for different analyses and applications. This paper presents a novel approach to perform three-dimensional (3D) cell manipulation and patterning with a multi-layer engineered scaffold. This scaffold structure employed dielectrophoresis as the non-contact mechanism to manipulate cells in the 3D domain. Through establishing electric fields via this multi-layer structure, the cells in the medium became polarized and were attracted towards the interior part of the structure, forming 3D cellular patterns. Experiments were conducted to evaluate the manipulation and the patterning processes with the proposed structure. Results show that with the presence of a voltage input, this multi-layer structure was capable of manipulating different types of biological cells examined through dielectrophoresis, enabling automatic cell patterning in the time-scale of minutes. The effects of the voltage input on the resultant cellular pattern were examined and discussed. Viability test was performed after the patterning operation and the results confirmed that majority of the cells remained viable. After 7 days of culture, 3D cellular patterns were observed through SEM. The results suggest that this scaffold and its automated dielectrophoresis-based patterning mechanism can be used to construct artificial tissues for various tissue engineering applications.

Dynamic analysis of multi layer foundation of steam turbines in nuclear power plants

International Nuclear Information System (INIS)

Hosseni, D.

1999-01-01

In this work, the coupled Rotor-pedestal-foundation motion is modeled and formulated. Transfer matrix method is implemented in the modeling. The model is adequate for multi layer foundation systems of steam turbines in nuclear power plants. The rotor modeled used is distributed mass model. Bearings are modeled with eight stiffness and damping coefficients and pedestals by mass, stiffness and damping property. Foundation is modeled with distributed mass and stiffness properties in which properties in vertical and horizontal direction may be different. The model is examined using analytical results and good agreement is achieved. Results of the coupled modeling indicate less error in comparison with previous separate modeling and lumped-mass methods

Highly sensitive multi-layer pressure sensor with an active nanostructured layer of an organic molecular metal

International Nuclear Information System (INIS)

Laukhin, V; Lebedev, V; Laukhina, E; Rovira, C; Veciana, J

2016-01-01

This work addresses to the modern technologies that need to be instrumented with lightweight highly sensitive pressure sensors. The paper presents the development of a new plain flexible thin pressure sensor using a nanostructured layer of the highly sensitive organic piezoresistive metal β-(BEDT-TTF) 2 I 3 as an active component; BEDT-TTF=bis (ethylenedithio)tetrathiafulvalene. The original construction approach permits one to operate the developed sensor on the principle of electrical resistance variations when its piezoresistive layer is elongated under a pressure increase. The pressure sensing element and a set of gold electrodes were integrated into one compact multi-layer design. The construction was optimized to enable one generic design for pressure ranges from 1 to 400 bar. The pressure tests showed that the sensor is able to control a small pressure change as a well definite electrical signal. So the developed type of the sensors is very attractive as a new generation of compact, lightweight, low-cost sensors that might monitor pressure with a good level of measurement accuracy. (paper)

A Cross-Layer Routing Design for Multi-Interface Wireless Mesh Networks

Directory of Open Access Journals (Sweden)

Tzu-Chieh Tsai

2009-01-01

Full Text Available In recent years, Wireless Mesh Networks (WMNs technologies have received significant attentions. WMNs not only accede to the advantages of ad hoc networks but also provide hierarchical multi-interface architecture. Transmission power control and routing path selections are critical issues in the past researches of multihop networks. Variable transmission power levels lead to different network connectivity and interference. Further, routing path selections among different radio interfaces will also produce different intra-/interflow interference. These features tightly affect the network performance. Most of the related works on the routing protocol design do not consider transmission power control and multi-interface environment simultaneously. In this paper, we proposed a cross-layer routing protocol called M2iRi2 which coordinates transmission power control and intra-/interflow interference considerations as routing metrics. Each radio interface calculates the potential tolerable-added transmission interference in the physical layer. When the route discovery starts, the M2iRi2 will adopt the appropriate power level to evaluate each interface quality along paths. The simulation results demonstrate that our design can enhance both network throughput and end-to-end delay.

Diffusion layer modeling for condensation with multi-component noncondensable gases

International Nuclear Information System (INIS)

Peterson, P.F.

1999-01-01

Many condensation problems involving noncondensable gases have multiple noncondensable species, for example air (with nitrogen, oxygen, and other gases); and other problems where light gases like hydrogen may mix with heavier gases like nitrogen. Particularly when the binary mass diffusion coefficients of the noncondensable species are substantially different, the noncondensable species tend to segregate in the condensation boundary layer. This paper presents a fundamental analysis of the mass transport with multiple noncondensable species, identifying a simple method to calculate an effective mass diffusion coefficient that can be used with the simple diffusion layer model, and discusses in detail the effects of using mass and mole based quantities, and various simplifying approximations, on predicted condensation rates. The results are illustrated with quantitative examples to demonstrate the potential importance of multi-component noncondensable gas effects

Unusual ZFC and FC magnetic behavior in thin Co multi-layered structure

Energy Technology Data Exchange (ETDEWEB)

Ben-Dor, Oren; Yochelis, Shira [Department of Applied Physics, Center of Nanoscience and Nanotechnology, Hebrew University, Jerusalem 91904 (Israel); Felner, Israel [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Paltiel, Yossi [Department of Applied Physics, Center of Nanoscience and Nanotechnology, Hebrew University, Jerusalem 91904 (Israel)

2017-04-15

The observation of unusual magnetic phenomena in a Ni -based magnetic memory device ( O. Ben-Dor et al., 2013) encouraged us to conduct a systematic research on Co based multi-layered structure which contains a α-helix L polyalanine (AHPA-L) organic compound. The constant Co thickness is 7 nm and AHPA-L was also replaced by non-chiral 1-Decanethiol organic molecules. Both organic compounds were chemisorbed on gold by a thiol group. The dc magnetic field (H) was applied parallel and perpendicular to the surface layers. The perpendicular direction is the easy magnetization axis and along this orientation only, the zero-field-cooled (ZFC) plots exhibit a pronounced peak around 55–58 K. This peak is suppressed in the second ZFC and field-cooled (FC) runs performed shortly after the virgin ZFC one. Thus, around the peak position ZFC>FC a phenomenon seldom observed. This peak reappears after measuring the same material six months later. This behavior appears in layers with the non-chiral 1-Decanethiol and it is very similar to that obtained in sulfur doped amorphous carbon. The peak origin and the peculiar ZFC>FC case are qualitatively explained. - Highlights: • FC curve crosses ZFC curve in a 7 nm Co and thiol-based organic molecules multi-layered structure. • The ZFC>FC phenomena occurs for H perpendicular along the easy axis. • This phenomenon disappears in the second FC-ZFC run performed shortly after. • The unusual behavior reappears after six months.

Diffraction of love waves by two staggered perfectly weak half-planes

International Nuclear Information System (INIS)

Asghar, S.; Zaman, F.D.; Sajida Asghar

1989-01-01

Love wave travelling in a layer of uniform thickness overlying a half-space is assumed to be incident on two parallel but staggered perfectly weak half-planes lying in the upper layer. The diffracted fields is calculated using the modified Wiener-Hopf technique and contour integration method. The diffracted waves satisfy the dispersion relations appropriate to different regions formed by the perfectly weak half-planes

Coupled Chiral Structure in Graphene-Based Film for Ultrahigh Thermal Conductivity in Both In-Plane and Through-Plane Directions.

Science.gov (United States)

Meng, Xin; Pan, Hui; Zhu, Chengling; Chen, Zhixin; Lu, Tao; Xu, Da; Li, Yao; Zhu, Shenmin

2018-06-21

The development of high-performance thermal management materials to dissipate excessive heat both in plane and through plane is of special interest to maintain efficient operation and prolong the life of electronic devices. Herein, we designed and constructed a graphene-based composite film, which contains chiral liquid crystals (cellulose nanocrystals, CNCs) inside graphene oxide (GO). The composite film was prepared by annealing and compacting of self-assembled GO-CNC, which contains chiral smectic liquid crystal structures. The helical arranged nanorods of carbonized CNC act as in-plane connections, which bridge neighboring graphene sheets. More interestingly, the chiral structures also act as through-plane connections, which bridge the upper and lower graphene layers. As a result, the graphene-based composite film shows extraordinary thermal conductivity, in both in-plane (1820.4 W m -1 K -1 ) and through-plane (4.596 W m -1 K -1 ) directions. As a thermal management material, the heat dissipation and transportation behaviors of the composite film were investigated using a self-heating system and the results showed that the real-time temperature of the heater covered with the film was 44.5 °C lower than a naked heater. The prepared film shows a much higher efficiency of heat transportation than the commonly used thermal conductive Cu foil. Additionally, this graphene-based composite film exhibits excellent mechanical strength of 31.6 MPa and an electrical conductivity of 667.4 S cm -1 . The strategy reported here may open a new avenue to the development of high-performance thermal management films.

Formulation and pharmacokinetics of multi-layered matrix tablets: Biphasic delivery of diclofenac

Directory of Open Access Journals (Sweden)

Ehab Mostafa Elzayat

2017-07-01

Full Text Available The rapid availability of the drug at the site of action followed by maintaining its effect for a long period of time is of great clinical importance. Thus, the purpose of the present study was to prepare and evaluate multi-layered matrix tablets of diclofenac using Eudragit RL/RS blend to achieve both immediate and sustained therapeutic effects. Diclofenac potassium (25 mg was incorporated in an outer immediate release layer to provide immediate pain relief whereas diclofenac sodium (75 mg was incorporated in the inner core to provide extended drug release. Wet granulation was employed to prepare the inner core of the tablets that were further layered with an immediate release drug layer in the perforated pan coater. The in-vitro and in-vivo performance of the developed formulation was compared with the marketed products Voltaren® SR 75 mg and Cataflam® 25 mg. The in-vitro drug release of the prepared formulation showed similarity (f2 = 66.19 to the marketed product. The pharmacokinetic study showed no significant difference (p > 0.05 in AUC0-24 and Cmax between the test and reference formulations. The AUC0-24 values were 105.36 ± 83.3 and 92.87 ± 55.53 μg h/ml whereas the Cmax values were 11.25 ± 6.87 and 12.97 ± 8.45 μg/ml, for the test and reference, respectively. The multi-layered tablets were proved to be bioequivalent with the commercially available tablets and were in agreement with the observed in-vitro drug release results. Stable physical characteristics and drug release profiles were observed in both long term and accelerated conditions stability studies.

Scanned Image Projection System Employing Intermediate Image Plane

Science.gov (United States)

DeJong, Christian Dean (Inventor); Hudman, Joshua M. (Inventor)

2014-01-01

In imaging system, a spatial light modulator is configured to produce images by scanning a plurality light beams. A first optical element is configured to cause the plurality of light beams to converge along an optical path defined between the first optical element and the spatial light modulator. A second optical element is disposed between the spatial light modulator and a waveguide. The first optical element and the spatial light modulator are arranged such that an image plane is created between the spatial light modulator and the second optical element. The second optical element is configured to collect the diverging light from the image plane and collimate it. The second optical element then delivers the collimated light to a pupil at an input of the waveguide.

High speed display algorithm for 3D medical images using Multi Layer Range Image

International Nuclear Information System (INIS)

Ban, Hideyuki; Suzuki, Ryuuichi

1993-01-01

We propose high speed algorithm that display 3D voxel images obtained from medical imaging systems such as MRI. This algorithm convert voxel image data to 6 Multi Layer Range Image (MLRI) data, which is an augmentation of the range image data. To avoid the calculation for invisible voxels, the algorithm selects at most 3 MLRI data from 6 in accordance with the view direction. The proposed algorithm displays 256 x 256 x 256 voxel data within 0.6 seconds using 22 MIPS Workstation without a special hardware such as Graphics Engine. Real-time display will be possible on 100 MIPS class Workstation by our algorithm. (author)

Modeling Multi-Level Systems

CERN Document Server

Iordache, Octavian

2011-01-01

This book is devoted to modeling of multi-level complex systems, a challenging domain for engineers, researchers and entrepreneurs, confronted with the transition from learning and adaptability to evolvability and autonomy for technologies, devices and problem solving methods. Chapter 1 introduces the multi-scale and multi-level systems and highlights their presence in different domains of science and technology. Methodologies as, random systems, non-Archimedean analysis, category theory and specific techniques as model categorification and integrative closure, are presented in chapter 2. Chapters 3 and 4 describe polystochastic models, PSM, and their developments. Categorical formulation of integrative closure offers the general PSM framework which serves as a flexible guideline for a large variety of multi-level modeling problems. Focusing on chemical engineering, pharmaceutical and environmental case studies, the chapters 5 to 8 analyze mixing, turbulent dispersion and entropy production for multi-scale sy...

A computer program (FUGI) for design and operation of a conveyor type irradiator with multi-tier and multi-layer

International Nuclear Information System (INIS)

Hoshi, Tatsuo; Aggarwal, K.S.

1976-10-01

A computer program (FUGI) was established to facilitate the determination of factors related to design and operation of a conveyor type irradiator with multi-tier and multi-layer. The factors determined by this program are as follows: (1) maximum dose, minimum dose and dose uniformity in irradiated material; (2) dose rate distribution on the path of irradiated material; (3) mass flow rate of irradiated material; (4) requisite activity of source; (5) requisite speed of conveyor; (6) utilization efficiency. This program partly uses the program FUDGE 4A for determination of dose rate in irradiated material in static state by Galanter and Krishnamurthy. (auth.)

Development of a laser multi-layer cladding technology for damage mitigation of fuel spacers in Hanaro reactor

International Nuclear Information System (INIS)

Kim, J. S.; Lee, D. H.; Hwang, S. S.; Suh, J. H.

2002-01-01

A laser multi-layer cladding technology was developed to mitigate the fretting wear damages occurred at fuel spacers in Hanaro reactor. The detailed experimental results are as follows. 1) Analyses of fretting wear damages and fabrication process of fuel spacers 2) Development and analysis of spherical Al 6061 T-6 alloy powders for the laser cladding 3) Analysis of parameter effects on laser cladding process for clad bids, and optimization of laser cladding process 4) Analysis on the changes of cladding layers due to overlapping factor change 5) Microstructural observation and phase analysis 6) Characterization of materials properties (hardness and wear tests) 7) Manufacture of prototype fuel spacers 8) Development of a vision system and revision of its related softwares

Multi-layer imager design for mega-voltage spectral imaging

Science.gov (United States)

Myronakis, Marios; Hu, Yue-Houng; Fueglistaller, Rony; Wang, Adam; Baturin, Paul; Huber, Pascal; Morf, Daniel; Star-Lack, Josh; Berbeco, Ross

2018-05-01

The architecture of multi-layer imagers (MLIs) can be exploited to provide megavoltage spectral imaging (MVSPI) for specific imaging tasks. In the current work, we investigated bone suppression and gold fiducial contrast enhancement as two clinical tasks which could be improved with spectral imaging. A method based on analytical calculations that enables rapid investigation of MLI component materials and thicknesses was developed and validated against Monte Carlo computations. The figure of merit for task-specific imaging performance was the contrast-to-noise ratio (CNR) of the gold fiducial when the CNR of bone was equal to zero after a weighted subtraction of the signals obtained from each MLI layer. Results demonstrated a sharp increase in the CNR of gold when the build-up component or scintillation materials and thicknesses were modified. The potential for low-cost, prompt implementation of specific modifications (e.g. composition of the build-up component) could accelerate clinical translation of MVSPI.

A method for building low loss multi-layer wiring for superconducting microwave devices

Science.gov (United States)

Dunsworth, A.; Barends, R.; Chen, Yu; Chen, Zijun; Chiaro, B.; Fowler, A.; Foxen, B.; Jeffrey, E.; Kelly, J.; Klimov, P. V.; Lucero, E.; Mutus, J. Y.; Neeley, M.; Neill, C.; Quintana, C.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T. C.; Neven, H.; Martinis, John M.; Megrant, A.

2018-02-01

Complex integrated circuits require multiple wiring layers. In complementary metal-oxide-semiconductor processing, these layers are robustly separated by amorphous dielectrics. These dielectrics would dominate energy loss in superconducting integrated circuits. Here, we describe a procedure that capitalizes on the structural benefits of inter-layer dielectrics during fabrication and mitigates the added loss. We use a deposited inter-layer dielectric throughout fabrication and then etch it away post-fabrication. This technique is compatible with foundry level processing and can be generalized to make many different forms of low-loss wiring. We use this technique to create freestanding aluminum vacuum gap crossovers (airbridges). We characterize the added capacitive loss of these airbridges by connecting ground planes over microwave frequency λ/4 coplanar waveguide resonators and measuring resonator loss. We measure a low power resonator loss of ˜3.9 × 10-8 per bridge, which is 100 times lower than that of dielectric supported bridges. We further characterize these airbridges as crossovers, control line jumpers, and as part of a coupling network in gmon and fluxmon qubits. We measure qubit characteristic lifetimes (T1s) in excess of 30 μs in gmon devices.

Processes for multi-layer devices utilizing layer transfer

Science.gov (United States)

Nielson, Gregory N; Sanchez, Carlos Anthony; Tauke-Pedretti, Anna; Kim, Bongsang; Cederberg, Jeffrey; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

2015-02-03

A method includes forming a release layer over a donor substrate. A plurality of devices made of a first semiconductor material are formed over the release layer. A first dielectric layer is formed over the plurality of devices such that all exposed surfaces of the plurality of devices are covered by the first dielectric layer. The plurality of devices are chemically attached to a receiving device made of a second semiconductor material different than the first semiconductor material, the receiving device having a receiving substrate attached to a surface of the receiving device opposite the plurality of devices. The release layer is etched to release the donor substrate from the plurality of devices. A second dielectric layer is applied over the plurality of devices and the receiving device to mechanically attach the plurality of devices to the receiving device.

Numerical Analysis of Deflections of Multi-Layered Beams

Science.gov (United States)

Biliński, Tadeusz; Socha, Tomasz

2015-03-01

The paper concerns the rheological bending problem of wooden beams reinforced with embedded composite bars. A theoretical model of the behaviour of a multi-layered beam is presented. The component materials of this beam are described with equations for the linear viscoelastic five-parameter rheological model. Two numerical analysis methods for the long-term response of wood structures are presented. The first method has been developed with SCILAB software. The second one has been developed with the finite element calculation software ABAQUS and user subroutine UMAT. Laboratory investigations were conducted on sample beams of natural dimensions in order to validate the proposed theoretical model and verify numerical simulations. Good agreement between experimental measurements and numerical results is observed.

Centralized Routing and Scheduling Using Multi-Channel System Single Transceiver in 802.16d

Science.gov (United States)

Al-Hemyari, A.; Noordin, N. K.; Ng, Chee Kyun; Ismail, A.; Khatun, S.

This paper proposes a cross-layer optimized strategy that reduces the effect of interferences from neighboring nodes within a mesh networks. This cross-layer design relies on the routing information in network layer and the scheduling table in medium access control (MAC) layer. A proposed routing algorithm in network layer is exploited to find the best route for all subscriber stations (SS). Also, a proposed centralized scheduling algorithm in MAC layer is exploited to assign a time slot for each possible node transmission. The cross-layer optimized strategy is using multi-channel single transceiver and single channel single transceiver systems for WiMAX mesh networks (WMNs). Each node in WMN has a transceiver that can be tuned to any available channel for eliminating the secondary interference. Among the considered parameters in the performance analysis are interference from the neighboring nodes, hop count to the base station (BS), number of children per node, slot reuse, load balancing, quality of services (QoS), and node identifier (ID). Results show that the proposed algorithms significantly improve the system performance in terms of length of scheduling, channel utilization ratio (CUR), system throughput, and average end to end transmission delay.

Nonpolar a-plane light-emitting diode with an in-situ SiNx interlayer on r-plane sapphire grown by metal-organic chemical vapour deposition

International Nuclear Information System (INIS)

Fang Hao; Long Hao; Sang Li-Wen; Qi Sheng-Li; Xiong Chang; Yu Tong-Jun; Yang Zhi-Jian; Zhang Guo-Yi

2011-01-01

We report on the growth and fabrication of nonpolar a-plane light emitting diodes with an in-situ SiN x interlayer grown between the undoped a-plane GaN buffer and Si-doped GaN layer. X-ray diffraction shows that the crystalline quality of the GaN buffer layer is greatly improved with the introduction of the SiN x interlayer. The electrical properties are also improved. For example, electron mobility and sheet resistance are reduced from high resistance to 31.6 cm 2 /(V·s) and 460 Ω/□ respectively. Owing to the significant effect of the SiN x interlayer, a-plane LEDs are realized. Electroluminescence of a nonpolar a-plane light-emitting diode with a wavelength of 488nm is demonstrated. The emission peak remains constant when the injection current increases to over 20 mA. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Tidal synchronization of an anelastic multi-layered body: Titan's synchronous rotation

Science.gov (United States)

Folonier, Hugo A.; Ferraz-Mello, Sylvio

2017-12-01

Tidal torque drives the rotational and orbital evolution of planet-satellite and star-exoplanet systems. This paper presents one analytical tidal theory for a viscoelastic multi-layered body with an arbitrary number of homogeneous layers. Starting with the static equilibrium figure, modified to include tide and differential rotation, and using the Newtonian creep approach, we find the dynamical equilibrium figure of the deformed body, which allows us to calculate the tidal potential and the forces acting on the tide generating body, as well as the rotation and orbital elements variations. In the particular case of the two-layer model, we study the tidal synchronization when the gravitational coupling and the friction in the interface between the layers is added. For high relaxation factors (low viscosity), the stationary solution of each layer is synchronous with the orbital mean motion ( n) when the orbit is circular, but the rotational frequencies increase if the orbital eccentricity increases. This behavior is characteristic in the classical Darwinian theories and in the homogeneous case of the creep tide theory. For low relaxation factors (high viscosity), as in planetary satellites, if friction remains low, each layer can be trapped in different spin-orbit resonances with frequencies n/2,n,3n/2,2n,\\ldots . When the friction increases, attractors with differential rotations are destroyed, surviving only commensurabilities in which core and shell have the same velocity of rotation. We apply the theory to Titan. The main results are: (i) the rotational constraint does not allow us to confirm or reject the existence of a subsurface ocean in Titan; and (ii) the crust-atmosphere exchange of angular momentum can be neglected. Using the rotation estimate based on Cassini's observation (Meriggiola et al. in Icarus 275:183-192, 2016), we limit the possible value of the shell relaxation factor, when a deep subsurface ocean is assumed, to γ _s≲ 10^{-9} s^{-1}, which

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

DEFF Research Database (Denmark)

Bjerre, Troels; Crijns, Sjoerd; Rosenschöld, Per Munck af

2013-01-01

The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking...... of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path....... For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm...

On fault propagation in deterioration of multi-component systems

International Nuclear Information System (INIS)

Liang, Zhenglin; Parlikad, Ajith Kumar; Srinivasan, Rengarajan; Rasmekomen, Nipat

2017-01-01

In extant literature, deterioration dependence among components can be modelled as inherent dependence and induced dependence. We find that the two types of dependence may co-exist and interact with each other in one multi-component system. We refer to this phenomenon as fault propagation. In practice, a fault induced by the malfunction of a non-critical component may further propagate through the dependence amongst critical components. Such fault propagation scenario happens in industrial assets or systems (bridge deck, and heat exchanging system). In this paper, a multi-layered vector-valued continuous-time Markov chain is developed to capture the characteristics of fault propagation. To obtain the mathematical tractability, we derive a partitioning rule to aggregate states with the same characteristics while keeping the overall aging behaviour of the multi-component system. Although the detailed information of components is masked by aggregated states, lumpability is attainable with the partitioning rule. It means that the aggregated process is stochastically equivalent to the original one and retains the Markov property. We apply this model on a heat exchanging system in oil refinery company. The results show that fault propagation has a more significant impact on the system's lifetime comparing with inherent dependence and induced dependence. - Highlights: • We develop a vector value continuous-time Markov chain to model the meta-dependent characteristic of fault propagation. • A partitioning rule is derived to reduce the state space and attain lumpability. • The model is applied on analysing the impact of fault propagation in a heat exchanging system.

Co-firing behavior of ZnTiO3-TiO2 dielectrics/hexagonal ferrite composites for multi-layer LC filters

International Nuclear Information System (INIS)

Wang Mao; Zhou Ji; Yue Zhenxing; Li Longtu; Gui Zhilun

2003-01-01

The low-temperature co-firing compatibility between ferrite and dielectric materials is the key issue in the production process of multi-layer chip LC filters. This paper presents the co-firing behavior and interfacial diffusion of ZnTiO 3 -TiO 2 dielectric/Co 2 Z hexagonal ferrite multi-layer composites. It has been testified that proper constitutional modification is feasible to diminish co-firing mismatch and enhance co-firing compatibility. Interfacial reactions occur at the interface, which can strengthen combinations between ferrite layers and dielectric layers. Titanium and barium tend to concentrate at the interface; iron and zinc have a wide diffusion range

New Metaphors and Multi Layered in Khaqani´s Poem

Directory of Open Access Journals (Sweden)

Mohammadamir Mashhadi

2011-02-01

Full Text Available Abstract   Metaphor is the most important transmission device language than true application to figurative application, It plays a role more than other poetic elements in new creation and forming Personal Style. Khaqani is a creator of new metaphor in number and the most creative power speaking persian. He used artistic creation and hard to obtain in making poem. He profits of new and rare metaphors. Comprehension the metaphors of Kaqani ´ s Poem results to Underestanding his creation in Imaginary and his Poem. This article with this aim is studing background metaphor creation in Kaqani ´ s poem and his modernity new relation and similarity between objects and phenomenons that cause making new metaphor. Sometime his discovery relation between two objects formed in several relation layer that could call them Multi layered metaphor.

Automatic Generation of Agents using Reusable Soft Computing Code Libraries to develop Multi Agent System for Healthcare

OpenAIRE

Priti Srinivas Sajja

2015-01-01

This paper illustrates architecture for a multi agent system in healthcare domain. The architecture is generic and designed in form of multiple layers. One of the layers of the architecture contains many proactive, co-operative and intelligent agents such as resource management agent, query agent, pattern detection agent and patient management agent. Another layer of the architecture is a collection of libraries to auto-generate code for agents using soft computing techni...

Wafer plane inspection for advanced reticle defects

Science.gov (United States)

Nagpal, Rajesh; Ghadiali, Firoz; Kim, Jun; Huang, Tracy; Pang, Song

2008-05-01

Readiness of new mask defect inspection technology is one of the key enablers for insertion & transition of the next generation technology from development into production. High volume production in mask shops and wafer fabs demands a reticle inspection system with superior sensitivity complemented by a low false defect rate to ensure fast turnaround of reticle repair and defect disposition (W. Chou et al 2007). Wafer Plane Inspection (WPI) is a novel approach to mask defect inspection, complementing the high resolution inspection capabilities of the TeraScanHR defect inspection system. WPI is accomplished by using the high resolution mask images to construct a physical mask model (D. Pettibone et al 1999). This mask model is then used to create the mask image in the wafer aerial plane. A threshold model is applied to enhance the inspectability of printing defects. WPI can eliminate the mask restrictions imposed on OPC solutions by inspection tool limitations in the past. Historically, minimum image restrictions were required to avoid nuisance inspection stops and/or subsequent loss of sensitivity to defects. WPI has the potential to eliminate these limitations by moving the mask defect inspections to the wafer plane. This paper outlines Wafer Plane Inspection technology, and explores the application of this technology to advanced reticle inspection. A total of twelve representative critical layers were inspected using WPI die-to-die mode. The results from scanning these advanced reticles have shown that applying WPI with a pixel size of 90nm (WPI P90) captures all the defects of interest (DOI) with low false defect detection rates. In validating CD predictions, the delta CDs from WPI are compared against Aerial Imaging Measurement System (AIMS), where a good correlation is established between WPI and AIMSTM.

Research of future network with multi-layer IP address

Science.gov (United States)

Li, Guoling; Long, Zhaohua; Wei, Ziqiang

2018-04-01

The shortage of IP addresses and the scalability of routing systems [1] are challenges for the Internet. The idea of dividing existing IP addresses between identities and locations is one of the important research directions. This paper proposed a new decimal network architecture based on IPv9 [11], and decimal network IP address from E.164 principle of traditional telecommunication network, the IP address level, which helps to achieve separation and identification and location of IP address, IP address form a multilayer network structure, routing scalability problem in remission at the same time, to solve the problem of IPv4 address depletion. On the basis of IPv9, a new decimal network architecture is proposed, and the IP address of the decimal network draws on the E.164 principle of the traditional telecommunication network, and the IP addresses are hierarchically divided, which helps to realize the identification and location separation of IP addresses, the formation of multi-layer IP address network structure, while easing the scalability of the routing system to find a way out of IPv4 address exhausted. In addition to modifying DNS [10] simply and adding the function of digital domain, a DDNS [12] is formed. At the same time, a gateway device is added, that is, IPV9 gateway. The original backbone network and user network are unchanged.

A versatile multi-user polyimide surface micromachinning process for MEMS applications

KAUST Repository

Carreno, Armando Arpys Arevalo

2015-04-01

This paper reports a versatile multi-user micro-fabrication process for MEMS devices, the \\'Polyimide MEMS Multi-User Process\\' (PiMMPs). The reported process uses polyimide as the structural material and three separate metallization layers that can be interconnected depending on the desired application. This process enables for the first time the development of out-of-plane compliant mechanisms that can be designed using six different physical principles for actuation and sensing on a wafer from a single fabrication run. These principles are electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception. © 2015 IEEE.

Out-of-Plane Piezoelectricity and Ferroelectricity in Layered α-In2Se3 Nanoflakes.

Science.gov (United States)

Zhou, Yu; Wu, Di; Zhu, Yihan; Cho, Yujin; He, Qing; Yang, Xiao; Herrera, Kevin; Chu, Zhaodong; Han, Yu; Downer, Michael C; Peng, Hailin; Lai, Keji

2017-09-13

Piezoelectric and ferroelectric properties in the two-dimensional (2D) limit are highly desired for nanoelectronic, electromechanical, and optoelectronic applications. Here we report the first experimental evidence of out-of-plane piezoelectricity and ferroelectricity in van der Waals layered α-In 2 Se 3 nanoflakes. The noncentrosymmetric R3m symmetry of the α-In 2 Se 3 samples is confirmed by scanning transmission electron microscopy, second-harmonic generation, and Raman spectroscopy measurements. Domains with opposite polarizations are visualized by piezo-response force microscopy. Single-point poling experiments suggest that the polarization is potentially switchable for α-In 2 Se 3 nanoflakes with thicknesses down to ∼10 nm. The piezotronic effect is demonstrated in two-terminal devices, where the Schottky barrier can be modulated by the strain-induced piezopotential. Our work on polar α-In 2 Se 3 , one of the model 2D piezoelectrics and ferroelectrics with simple crystal structures, shows its great potential in electronic and photonic applications.

Multi-layer composite structure covered polytetrafluoroethylene for visible-infrared-radar spectral Compatibility

Science.gov (United States)

Qi, Dong; Cheng, Yongzhi; Wang, Xian; Wang, Fang; Li, Bowen; Gong, Rongzhou

2017-12-01

In this paper, a polytetrafluoroethylene (PTFE) top-covered multi-layer composite structure PTFE/H s/(Ge/ZnS)3 (H s represents the surface layer ZnS with various thicknesses) for spectral compatibility is proposed and investigated theoretically and experimentally. A substantial decline of glossiness from over 200 Gs to 74.2 Gs could be realized, due to high roughness and interface reflection of the 800 nm PTFE protection layer. In addition, similar to the structure of H s/(Ge/ZnS)3, the designed structure with a certain color exhibits ultra-low emissivity of average 0.196 at 8-14 µm and highly transparent performance of 96.45% in the radar frequency range of 2-18 GHz. Our design will provide an important reference for the practical applications of the spectral compatible multilayer films.

Timing system for multi-bunch/multi-train operation at ATF

International Nuclear Information System (INIS)

Naito, T.; Hayano, H.; Urakawa, J.; Imai, T.

2000-01-01

A timing system has been constructed for multi-bunch/multi-train operation at KEK-ATF. The linac accelerates 20 bunches of multi-bunch with 2.8 ns spacing. The Damping Ring stores up to 5 trains of multi-bunch. The timing system is required to provide flexible operation mode and bucket selection. A personal computer is used for manipulating the timing. The performance of kicker magnets at the injection/extruction is key issue for multi-train operation. The hardware and the test results are presented. (author)

Distributed Processing System for Restoration of Electric Power Distribution Network Using Two-Layered Contract Net Protocol

Science.gov (United States)

Kodama, Yu; Hamagami, Tomoki

Distributed processing system for restoration of electric power distribution network using two-layered CNP is proposed. The goal of this study is to develop the restoration system which adjusts to the future power network with distributed generators. The state of the art of this study is that the two-layered CNP is applied for the distributed computing environment in practical use. The two-layered CNP has two classes of agents, named field agent and operating agent in the network. In order to avoid conflicts of tasks, operating agent controls privilege for managers to send the task announcement messages in CNP. This technique realizes the coordination between agents which work asynchronously in parallel with others. Moreover, this study implements the distributed processing system using a de-fact standard multi-agent framework, JADE(Java Agent DEvelopment framework). This study conducts the simulation experiments of power distribution network restoration and compares the proposed system with the previous system. We confirmed the results show effectiveness of the proposed system.

Infinite elements for soil-structure interaction analysis in multi-layered halfspaces

International Nuclear Information System (INIS)

Yun, Chung Bang; Kim, Jae Min; Yang, Shin Chu

1994-01-01

This paper presents the theoretical aspects of a computer code (KIESSI) for soil-structure interaction analysis in a multi-layered halfspace using infinite elements. The shape functions of the infinite elements are derived from approximate expressions of the analytical solutions. Three different infinite elements are developed. They are the horizontal, the vertical and the comer infinite elements (HIE, VIE and CIE). Numerical example analyses are presented for demonstrating the effectiveness of the proposed infinite elements

Ion beam analysis of multi-layered structure in Nb/Cu system

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Shunya; Goppelt-Langer, P; Naramoto, Hiroshi; Aoki, Yasushi; Takeshita, Hidefumi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-03-01

The dependence of H concentration on the layer thickness in H charged Nb/Cu multilayer samples has been studied using {sup 15}N resonance nuclear reaction analysis({sup 15}N-NRA) and high energy elastic recoil detection analysis(HE-ERDA). Also a simulation code has been developed for accurate simulation of the {sup 1}H({sup 15}N,{alpha}{gamma}){sup 12}C4.43 MeV {gamma}-yields at 6.385 MeV and 13.365 MeV reaction energy. The simulation are in good agreement with the experimental results. The present results show smooth increase of the H concentrations in Nb layers with increasing layer thickness. (author)

Polyimide and Metals MEMS Multi-User Processes

KAUST Repository

Arevalo, Arpys

2016-11-01

The development of a polyimide and metals multi-user surface micro-machining process for Micro-electro-mechanical Systems (MEMS) is presented. The process was designed to be as general as possible, and designed to be capable to fabricate different designs on a single silicon wafer. The process was not optimized with the purpose of fabricating any one specific device but can be tweaked to satisfy individual needs depending on the application. The fabrication process uses Polyimide as the structural material and three separated metallization layers that can be interconnected depending on the desired application. The technology allows the development of out-of-plane compliant mechanisms, which can be combined with six variations of different physical principles for actuation and sensing on a single processed silicon wafer. These variations are: electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception.

Numerical Analysis of Deflections of Multi-Layered Beams

Directory of Open Access Journals (Sweden)

Biliński Tadeusz

2015-03-01

Full Text Available The paper concerns the rheological bending problem of wooden beams reinforced with embedded composite bars. A theoretical model of the behaviour of a multi-layered beam is presented. The component materials of this beam are described with equations for the linear viscoelastic five-parameter rheological model. Two numerical analysis methods for the long-term response of wood structures are presented. The first method has been developed with SCILAB software. The second one has been developed with the finite element calculation software ABAQUS and user subroutine UMAT. Laboratory investigations were conducted on sample beams of natural dimensions in order to validate the proposed theoretical model and verify numerical simulations. Good agreement between experimental measurements and numerical results is observed.

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes.

Science.gov (United States)

Bjerre, Troels; Crijns, Sjoerd; af Rosenschöld, Per Munck; Aznar, Marianne; Specht, Lena; Larsen, Rasmus; Keall, Paul

2013-07-21

The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path. For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm for a translation of 39.9 mm. We have demonstrated how interleaved acquired, orthogonal cine-MRI planes can be used for online tracking of soft-tissue target volumes.

Quantitative transmission electron microscopy analysis of multi-variant grains in present L10-FePt based heat assisted magnetic recording media

International Nuclear Information System (INIS)

Ho, Hoan; Zhu, Jingxi; Kulovits, Andreas; Laughlin, David E.; Zhu, Jian-Gang

2014-01-01

We present a study on atomic ordering within individual grains in granular L1 0 -FePt thin films using transmission electron microscopy techniques. The film, used as a medium for heat assisted magnetic recording, consists of a single layer of FePt grains separated by non-magnetic grain boundaries and is grown on an MgO underlayer. Using convergent-beam techniques, diffraction patterns of individual grains are obtained for a large number of crystallites. The study found that although the majority of grains are ordered in the perpendicular direction, more than 15% of them are multi-variant, or of in-plane c-axis orientation, or disordered fcc. It was also found that these multi-variant and in-plane grains have always grown across MgO grain boundaries separating two or more MgO grains of the underlayer. The in-plane ordered portion within a multi-variant L1 0 -FePt grain always lacks atomic coherence with the MgO directly underneath it, whereas, the perpendicularly ordered portion is always coherent with the underlying MgO grain. Since the existence of multi-variant and in-plane ordered grains are severely detrimental to high density data storage capability, the understanding of their formation mechanism obtained here should make a significant impact on the future development of hard disk drive technology

Forward modelling of multi-component induction logging tools in layered anisotropic dipping formations

International Nuclear Information System (INIS)

Gao, Jie; Xu, Chenhao; Xiao, Jiaqi

2013-01-01

Multi-component induction logging provides great assistance in the exploration of thinly laminated reservoirs. The 1D parametric inversion following an adaptive borehole correction is the key step in the data processing of multi-component induction logging responses. To make the inversion process reasonably fast, an efficient forward modelling method is necessary. In this paper, a modelling method has been developed to simulate the multi-component induction tools in deviated wells drilled in layered anisotropic formations. With the introduction of generalized reflection coefficients, the analytic expressions of magnetic field in the form of a Sommerfeld integral were derived. The fast numerical computation of the integral has been completed by using the fast Fourier–Hankel transform and fast Hankel transform methods. The latter is so time efficient that it is competent enough for real-time multi-parameter inversion. In this paper, some simulated results have been presented and they are in excellent agreement with the finite difference method code's solution. (paper)

Controlled multiple neutral planes by low elastic modulus adhesive for flexible organic photovoltaics.

Science.gov (United States)

Kim, Wansun; Lee, Inhwa; Yoon Kim, Dong; Yu, Youn-Yeol; Jung, Hae-Yoon; Kwon, Seyeoul; Seo Park, Weon; Kim, Taek-Soo

2017-05-12

To protect brittle layers in organic photovoltaic devices, the mechanical neutral plane strategy can be adopted through placing the brittle functional materials close to the neutral plane where stress and strain are zero during bending. However, previous research has been significantly limited in the location and number of materials to protect through using a single neutral plane. In this study, multiple neutral planes are generated using low elastic modulus adhesives and are controlled through quantitative analyses in order to protect the multiple brittle materials at various locations. Moreover, the protection of multiple brittle layers at various locations under both concave and convex bending directions is demonstrated. Multilayer structures that have soft adhesives are further analyzed using the finite element method analysis in order to propose guidelines for structural design when employing multiple neutral planes.

The formation of sporadic E layers by a vortical perturbation excited in a horizontal wind shear flow

Directory of Open Access Journals (Sweden)

G. G. Didebulidze

2008-06-01

Full Text Available The formation of the mid-latitude sporadic E layers (E_s layers by an atmospheric vortical perturbation excited in a horizontal shear flow (horizontal wind with a horizontal linear shear is investigated. A three-dimensional atmospheric vortical perturbation (atmospheric shear waves, whose velocity vector is in the horizontal plane and has a vertical wavenumber k_z≠0, can provide a vertical shear of the horizontal wind. The shear waves influence the vertical transport of heavy metallic ions and their convergence into thin and dense horizontal layers. The proposed mechanism takes into account the dynamical influence of the shear wave velocity in the horizontal wind on the vertical drift velocity of the ions. It also can explain the multi-layer structure of E_s layers. The pattern of the multi-layer structure depends on the value of the shear-wave vertical wavelength, the ion-neutral collision frequency and the direction of the background horizontal wind. The modelling of formation of sporadic E layers with a single and a double peak is presented. Also, the importance of shear wave coupling with short-period atmospheric gravity waves (AGWs on the variations of sporadic E layer ion density is examined and discussed.

Rail-Guided Multi-Robot System for 3D Cellular Hydrogel Assembly with Coordinated Nanomanipulation

Directory of Open Access Journals (Sweden)

Huaping Wang

2014-08-01

Full Text Available The 3D assembly of micro-/nano-building blocks with multi-nanomanipulator coordinated manipulation is one of the central elements of nanomanipulation. A novel rail-guided nanomanipulation system was proposed for the assembly of a cellular vascular-like hydrogel microchannel. The system was equipped with three nanomanipulators and was restricted on the rail in order to realize the arbitrary change of the end-effectors during the assembly. It was set up with hybrid motors to achieve both a large operating space and a 30 nm positional resolution. The 2D components such as the assembly units were fabricated through the encapsulation of cells in the hydrogel. The coordinated manipulation strategies among the multi-nanomanipulators were designed with vision feedback and were demonstrated through the bottom-up assembly of the vascular-like microtube. As a result, the multi-layered microchannel was assembled through the cooperation of the nanomanipulation system.

A High-resolution Multi-wavelength Simultaneous Imaging System with Solar Adaptive Optics

Energy Technology Data Exchange (ETDEWEB)

Rao, Changhui; Zhu, Lei; Gu, Naiting; Rao, Xuejun; Zhang, Lanqiang; Bao, Hua; Kong, Lin; Guo, Youming; Zhong, Libo; Ma, Xue’an; Li, Mei; Wang, Cheng; Zhang, Xiaojun; Fan, Xinlong; Chen, Donghong; Feng, Zhongyi; Wang, Xiaoyun; Wang, Zhiyong, E-mail: gunaiting@ioe.ac.cn [The Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, P.O. Box 350, Shuangliu, Chengdu 610209, Sichuan (China)

2017-10-01

A high-resolution multi-wavelength simultaneous imaging system from visible to near-infrared bands with a solar adaptive optics system, in which seven imaging channels, including the G band (430.5 nm), the Na i line (589 nm), the H α line (656.3 nm), the TiO band (705.7 nm), the Ca ii IR line (854.2 nm), the He i line (1083 nm), and the Fe i line (1565.3 nm), are chosen, is developed to image the solar atmosphere from the photosphere layer to the chromosphere layer. To our knowledge, this is the solar high-resolution imaging system with the widest spectral coverage. This system was demonstrated at the 1 m New Vaccum Solar Telescope and the on-sky high-resolution observational results were acquired. In this paper, we will illustrate the design and performance of the imaging system. The calibration and the data reduction of the system are also presented.

In situ crystallization of b-oriented MFI films on plane and curved substrates coated with a mesoporous silica layer

KAUST Repository

Deng, Zhiyong

2013-05-01

A simple and reproducible method is presented for preparing b-oriented MFI films on plane (disc) and curved (hollow fiber) supports by in situ hydrothermal synthesis. A mesoporous silica (sub-)layer was pre-coated on the supports by dip coating followed by a rapid thermal calcination step (973 K during 1 min) to reduce the number of grain boundaries while keeping the hydrophilic behavior of silica. The role of the silica sub-layer is not only to smoothen the substrate surface, but also to provide a silica source to promote the nucleation and growth of zeolite crystals via a heterogeneous nucleation mechanism (zeolitization), and adsorb zeolite moieties generated in the synthesis solution via a homogeneous nucleation mechanism. A monolayer of b-oriented MFI crystals was obtained on both supports after 3 h synthesis time with a moderate degree of twinning on the surface. © 2013 Elsevier Ltd.

Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part II: Multi-layered cloud

Energy Technology Data Exchange (ETDEWEB)

Morrison, H; McCoy, R B; Klein, S A; Xie, S; Luo, Y; Avramov, A; Chen, M; Cole, J; Falk, M; Foster, M; Genio, A D; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; McFarquhar, G; Poellot, M; Shipway, B; Shupe, M; Sud, Y; Turner, D; Veron, D; Walker, G; Wang, Z; Wolf, A; Xu, K; Yang, F; Zhang, G

2008-02-27

Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a deep, multi-layered, mixed-phase cloud system observed during the ARM Mixed-Phase Arctic Cloud Experiment. This cloud system was associated with strong surface turbulent sensible and latent heat fluxes as cold air flowed over the open Arctic Ocean, combined with a low pressure system that supplied moisture at mid-level. The simulations, performed by 13 single-column and 4 cloud-resolving models, generally overestimate the liquid water path and strongly underestimate the ice water path, although there is a large spread among the models. This finding is in contrast with results for the single-layer, low-level mixed-phase stratocumulus case in Part I of this study, as well as previous studies of shallow mixed-phase Arctic clouds, that showed an underprediction of liquid water path. The overestimate of liquid water path and underestimate of ice water path occur primarily when deeper mixed-phase clouds extending into the mid-troposphere were observed. These results suggest important differences in the ability of models to simulate Arctic mixed-phase clouds that are deep and multi-layered versus shallow and single-layered. In general, models with a more sophisticated, two-moment treatment of the cloud microphysics produce a somewhat smaller liquid water path that is closer to observations. The cloud-resolving models tend to produce a larger cloud fraction than the single-column models. The liquid water path and especially the cloud fraction have a large impact on the cloud radiative forcing at the surface, which is dominated by the longwave flux for this case.

Monte Carlo simulation of laser beam propagation in a plane layer of the erythrocyte suspension: comparison of contributions from different scattering orders to the angular distribution of light intensity

International Nuclear Information System (INIS)

Kirillin, M Yu; Priezzhev, A V

2002-01-01

The scattering phase functions of light are obtained for a layer of the erythrocyte suspension by the Monte Carlo method. At the erythrocyte concentration corresponding to a whole blood, these functions substantially differ from the phase function of a single erythrocyte. Contributions from the low-order and multiple scattering to the light intensity measured at different angles are compared. It is shown that scattering of light from a suspension layer of thickness of about 100 μm to the forward half-plane is mainly determined by the low-order scattering (by snake photons), whereas scattering to the back half-plane is mainly determined by multiple scattering. The possibility of using the diffuse approximation for the theoretical description of scattering is analysed.

A Framework for Supporting Survivability, Network Planning and Cross-Layer Optimization in Future Multi-Domain Terabit Networks

Energy Technology Data Exchange (ETDEWEB)

Baldin, Ilya [Renaissance Computing Inst. (RENCI), Chapel Hill, NC (United States); Huang, Shu [Renaissance Computing Inst. (RENCI), Chapel Hill, NC (United States); Gopidi, Rajesh [Univ. of North Carolina, Chapel Hill, NC (United States)

2015-01-28

This final project report describes the accomplishments, products and publications from the award. It includes the overview of the project goals to devise a framework for managing resources in multi-domain, multi-layer networks, as well the details of the mathematical problem formulation and the description of the prototype built to prove the concept.

On a perturbed Sparre Andersen risk model with multi-layer dividend strategy

Science.gov (United States)

Yang, Hu; Zhang, Zhimin

2009-10-01

In this paper, we consider a perturbed Sparre Andersen risk model, in which the inter-claim times are generalized Erlang(n) distributed. Under the multi-layer dividend strategy, piece-wise integro-differential equations for the discounted penalty functions are derived, and a recursive approach is applied to express the solutions. A numerical example to calculate the ruin probabilities is given to illustrate the solution procedure.

Multi-objective optimization of linear multi-state multiple sliding window system

International Nuclear Information System (INIS)

Konak, Abdullah; Kulturel-Konak, Sadan; Levitin, Gregory

2012-01-01

This paper considers the optimal element sequencing in a linear multi-state multiple sliding window system that consists of n linearly ordered multi-state elements. Each multi-state element can have different states: from complete failure up to perfect functioning. A performance rate is associated with each state. The failure of type i in the system occurs if for any i (1≤i≤I) the cumulative performance of any r i consecutive elements is lower than w i . The element sequence strongly affects the probability of any type of system failure. The sequence that minimizes the probability of certain type of failure can provide high probability of other types of failures. Therefore the optimization problem for the multiple sliding window system is essentially multi-objective. The paper formulates and solves the multi-objective optimization problem for the multiple sliding window systems. A multi-objective Genetic Algorithm is used as the optimization engine. Illustrative examples are presented.

Alternative Design Concepts for Multi-Circuit HTS Link Systems

CERN Document Server

Ballarino, A

2011-01-01

Superconducting cables for power transmission usually contain two conductors for DC application, or three conductors for AC, with high voltage insulation. In contrast, for some applications related to accelerators it is convenient to transfer high currents via superconducting links feeding a number of circuits at relatively low voltage, of the order of a kilovolt, over distances of up to a few hundred meters. For power transmission applications based on cooling via sub-cooled liquid nitrogen, suitable HTS conductors are only available in the form of tape, and a multi-layer variant can be envisaged for the multi-circuit links. However, where cooling to temperatures of the order of 20 K is feasible, MgB2 conductor, available in the form of both tape and wire, can also be envisaged and in the latter case used to assemble round cables. There are, therefore, two distinct topologies - based on the use of wires or tapes - that can be envisaged for use in applications to multi-circuit link systems. In this paper the ...