WorldWideScience

Sample records for multi-layer printed circuit

  1. 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.

  2. 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.

  3. Printed circuit for ATLAS

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    A printed circuit board made by scientists in the ATLAS collaboration for the transition radiaton tracker (TRT). This will read data produced when a high energy particle crosses the boundary between two materials with different electrical properties.

  4. 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.

  5. 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

  6. Primer printed circuit boards

    CERN Document Server

    Argyle, Andrew

    2009-01-01

    Step-by-step instructions for making your own PCBs at home. Making your own printed circuit board (PCB) might seem a daunting task, but once you master the steps, it's easy to attain professional-looking results. Printed circuit boards, which connect chips and other components, are what make almost all modern electronic devices possible. PCBs are made from sheets of fiberglass clad with copper, usually in multiplelayers. Cut a computer motherboard in two, for instance, and you'll often see five or more differently patterned layers. Making boards at home is relatively easy

  7. "Printed-circuit" rectenna

    Science.gov (United States)

    Dickinson, R. M.

    1977-01-01

    Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.

  8. Bendable transparent conductive meshes based on multi-layer inkjet-printed silver patterns

    International Nuclear Information System (INIS)

    Yu, Po-Chin; Hong, Chien-Chong; Liou, Tong-Miin

    2016-01-01

    Many consumer electronics manufacturers have used transparent conductive films in solar cells, LED devices, and touch panels as a medium for simultaneous electric charge transportation and light transmission. The conductivity and transmittance of transparent conductive films greatly affect the efficiency of these optoelectronic devices. This study presents a transparent and conductive mesh based on inkjet-printed silver and conductive polymer. Also, we propose a mathematical model for calculating the optimized mesh pattern. The proposed model precisely calculates an optimized line-width-to-line-spacing ratio. Furthermore, the results of our experiment verify the relationship between the line-width-to-line-spacing ratio and figure of merit. Compared with the equations of past studies, the equation proposed in this study is valid for a broader range of line-width-to-line-spacing ratios. In addition, the theoretical results of our study correlate more strongly with the experimental data of this study than with that of previous studies. To achieve the highest figure of merit, the values of the filling factor and the line-width-to-line-spacing ratio should be 0.05 and 19, respectively. Finally, we reduced the sheet resistance of the inkjet-printed mesh by 97.9% by applying multilayer printing. However, we were able to reduce only the optical transmittance of the mesh by 3.0%. The developed inkjet-printed silver meshes can survive more than 3500 bending tests simultaneous with application of 300 mA current. (paper)

  9. A guide to printed circuit board design

    CERN Document Server

    Hamilton, Charles

    1984-01-01

    A Guide to Printed Circuit Board Design discusses the basic design principles of printed circuit board (PCB). The book consists of nine chapters; each chapter provides both text discussion and illustration relevant to the topic being discussed. Chapter 1 talks about understanding the circuit diagram, and Chapter 2 covers how to compile component information file. Chapter 3 deals with the design layout, while Chapter 4 talks about preparing the master artworks. The book also covers generating computer aided design (CAD) master patterns, and then discusses how to prepare the production drawing a

  10. Improving Heat Transfer Performance of Printed Circuit Boards

    Science.gov (United States)

    Schatzel, Donald V.

    2009-01-01

    This paper will explore the ability of printed circuit boards laminated with a Carbon Core Laminate to transfer heat vs. standard printed circuit boards that use only thick layers of copper. The paper will compare the differences in heat transfer performance of printed circuit boards with and without CCL.

  11. CAD-CAM printed circuit board design

    Science.gov (United States)

    Agy, W. E.

    A step-by-step procedure for a printed circuit design achieved by CAD is presented. The operator at the interactive CRT station moves a stylus across a graphics tablet and intersperses commands which result in computer-generated pictorial forms on the screen that were drawn on the pad. Standard symbols are used for commands allowing, for instance, connections to be made of specific types in certain locations, which can be automatically edited from a materials list. An entire network of drawn lines can be referenced by a signal name for recall, and a finished circuit schematic can be checked for designs rules compliance, including fault reporting in terms of designator/pin number. A map may be present delineating the boundaries of the circuitry area, and previously completed circuitry segments can be recalled for piece-by-piece assembly of the circuit board.

  12. Direct Desktop Printed-Circuits-on-Paper Flexible Electronics

    Science.gov (United States)

    Zheng, Yi; He, Zhizhu; Gao, Yunxia; Liu, Jing

    2013-01-01

    There currently lacks of a way to directly write out electronics, just like printing pictures on paper by an office printer. Here we show a desktop printing of flexible circuits on paper via developing liquid metal ink and related working mechanisms. Through modifying adhesion of the ink, overcoming its high surface tension by dispensing machine and designing a brush like porous pinhead for printing alloy and identifying matched substrate materials among different papers, the slightly oxidized alloy ink was demonstrated to be flexibly printed on coated paper, which could compose various functional electronics and the concept of Printed-Circuits-on-Paper was thus presented. Further, RTV silicone rubber was adopted as isolating inks and packaging material to guarantee the functional stability of the circuit, which suggests an approach for printing 3D hybrid electro-mechanical device. The present work paved the way for a low cost and easygoing method in directly printing paper electronics.

  13. Printed organic thin-film transistor-based integrated circuits

    International Nuclear Information System (INIS)

    Mandal, Saumen; Noh, Yong-Young

    2015-01-01

    Organic electronics is moving ahead on its journey towards reality. However, this technology will only be possible when it is able to meet specific criteria including flexibility, transparency, disposability and low cost. Printing is one of the conventional techniques to deposit thin films from solution-based ink. It is used worldwide for visual modes of information, and it is now poised to enter into the manufacturing processes of various consumer electronics. The continuous progress made in the field of functional organic semiconductors has achieved high solubility in common solvents as well as high charge carrier mobility, which offers ample opportunity for organic-based printed integrated circuits. In this paper, we present a comprehensive review of all-printed organic thin-film transistor-based integrated circuits, mainly ring oscillators. First, the necessity of all-printed organic integrated circuits is discussed; we consider how the gap between printed electronics and real applications can be bridged. Next, various materials for printed organic integrated circuits are discussed. The features of these circuits and their suitability for electronics using different printing and coating techniques follow. Interconnection technology is equally important to make this product industrially viable; much attention in this review is placed here. For high-frequency operation, channel length should be sufficiently small; this could be achievable with a combination of surface treatment-assisted printing or laser writing. Registration is also an important issue related to printing; the printed gate should be perfectly aligned with the source and drain to minimize parasitic capacitances. All-printed organic inverters and ring oscillators are discussed here, along with their importance. Finally, future applications of all-printed organic integrated circuits are highlighted. (paper)

  14. Printed circuits and their applications: Which way forward?

    Science.gov (United States)

    Cantatore, E.

    2015-09-01

    The continuous advancements in printed electronics make nowadays feasible the design of printed circuits which enable meaningful applications. Examples include ultra-low cost sensors embedded in food packaging, large-area sensing surfaces and biomedical assays. This paper offers an overview of state-of-the-art digital and analog circuit blocks, manufactured with a printed complementary organic TFT technology. An analog to digital converter and an RFID tag implemented exploiting these building blocks are also described. The main remaining drawbacks of the printed technology described are identified, and new approaches to further improve the state of the art, enabling more innovative applications are discussed.

  15. Modelling, analysis, and acceleration of a printed circuit board ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    discuss lead time reduction in a qualitative way with illustrative case studies. Krishnan ... industry practices, and research questions that should drive new methods and computer ... There are three types of printed circuit boards available today.

  16. Printed circuits and their applications : Which way forward?

    NARCIS (Netherlands)

    Cantatore, Eugenio; Kratochvil, E.J.W.L.

    2015-01-01

    The continuous advancements in printed electronics make nowadays feasible the design of printed circuits which enable meaningful applications. Examples include ultra-low cost sensors embedded in food packaging, large-area sensing surfaces and biomedical assays. This paper offers an overview of

  17. Development and verification of printed circuit board toroidal transformer model

    DEFF Research Database (Denmark)

    Pejtersen, Jens; Mønster, Jakob Døllner; Knott, Arnold

    2013-01-01

    An analytical model of an air core printed circuit board embedded toroidal transformer configuration is presented. The transformer has been developed for galvanic isolation of very high frequency switch-mode dc-dc power converter applications. The theoretical model is developed and verified...... by comparing calculated parameters with 3D finite element simulations and experimental measurement results. The developed transformer model shows good agreement with the simulated and measured results. The model can be used to predict the parameters of printed circuit board toroidal transformer configurations...

  18. Printed circuit board permittivity measurement using waveguide and resonator rings

    NARCIS (Netherlands)

    Op 't Land, Sjoerd; Tereshchenko, O.V.; Ramdani, Mohamed; Leferink, Frank Bernardus Johannes; Perdriau, Richard

    2014-01-01

    Knowing the frequency dependent complex permittivity of Printed Circuit Board (PCB) substrates is important in modern electronics. In this paper, two methods for measuring the permittivity are applied to the same Flame Resistant (FR4) substrate and the results are compared. The reference measurement

  19. Gas microstrip detectors based on flexible printed circuit

    International Nuclear Information System (INIS)

    Salomon, M.; Crowe, K.; Faszer, W.; Lindsay, P.; Curran Maier, J.M.

    1995-09-01

    We have studied the properties of a new type of Gas Microstrip Counter built using flexible printed circuit technology. We describe the manufacturing procedures, the assembly of the device, as well as its operation under a variety of conditions, gases and types of radiation. We also describe two new passivation materials, Tantalum and Niobium, which produce effective surfaces. (author)

  20. Printed Graphene Derivative Circuits as Passive Electrical Filters

    Directory of Open Access Journals (Sweden)

    Dogan Sinar

    2018-02-01

    Full Text Available The objective of this study is to inkjet print resistor-capacitor (RC low pass electrical filters, using a novel water-based cellulose graphene ink, and compare the voltage-frequency and transient behavior to equivalent circuits constructed from discrete passive components. The synthesized non-toxic graphene-carboxymethyl cellulose (G-CMC ink is deposited on mechanically flexible polyimide substrates using a customized printer that dispenses functionalized aqueous solutions. The design of the printed first-order and second-order low-pass RC filters incorporate resistive traces and interdigitated capacitors. Low pass filter characteristics, such as time constant, cut-off frequency and roll-off rate, are determined for comparative analysis. Experiments demonstrate that for low frequency applications (<100 kHz the printed graphene derivative circuits performed as well as the circuits constructed from discrete resistors and capacitors for both low pass filter and RC integrator applications. The impact of mechanical stress due to bending on the electrical performance of the flexible printed circuits is also investigated.

  1. Merging polygons on two-layer printed circuit board

    Directory of Open Access Journals (Sweden)

    Murov S. Yu.

    2011-12-01

    Full Text Available A method is proposed for solving the problem of connection of maximum number of isolated islands of metallized areas of the same chain, located on different layers of the printed circuit board. The method can be used in the automatic tracing of the boards.

  2. A Printed Organic Circuit System for Wearable Amperometric Electrochemical Sensors.

    Science.gov (United States)

    Shiwaku, Rei; Matsui, Hiroyuki; Nagamine, Kuniaki; Uematsu, Mayu; Mano, Taisei; Maruyama, Yuki; Nomura, Ayako; Tsuchiya, Kazuhiko; Hayasaka, Kazuma; Takeda, Yasunori; Fukuda, Takashi; Kumaki, Daisuke; Tokito, Shizuo

    2018-04-23

    Wearable sensor device technologies, which enable continuous monitoring of biological information from the human body, are promising in the fields of sports, healthcare, and medical applications. Further thinness, light weight, flexibility and low-cost are significant requirements for making the devices attachable onto human tissues or clothes like a patch. Here we demonstrate a flexible and printed circuit system consisting of an enzyme-based amperometric sensor, feedback control and amplification circuits based on organic thin-film transistors. The feedback control and amplification circuits based on pseudo-CMOS inverters were successfuly integrated by printing methods on a plastic film. This simple system worked very well like a potentiostat for electrochemical measurements, and enabled the quantitative and real-time measurement of lactate concentration with high sensitivity of 1 V/mM and a short response time of a hundred seconds.

  3. Highly Conductive Nano-Silver Circuits by Inkjet Printing

    Science.gov (United States)

    Zhu, Dongbin; Wu, Minqiang

    2018-06-01

    Inkjet technology has become popular in the field of printed electronics due to its superior properties such as simple processes and printable complex patterns. Electrical conductivity of the circuits is one of the key factors in measuring the performance of printed electronics, which requires great material properties and a manufactured process. With excellent conductivity and ductility, silver is an ideal material as the wire connecting components. This review summarizes the progress of conductivity studies on inkjet printed nano-silver lines, including ink composition and nanoparticle morphology, deposition of nano-silver lines with uniform and high aspect ratios, sintering mechanisms and alternative methods of thermal sintering. Finally, the research direction on inkjet printed electronics is proposed.

  4. Printed Graphene Derivative Circuits as Passive Electrical Filters.

    Science.gov (United States)

    Sinar, Dogan; Knopf, George K

    2018-02-23

    The objective of this study is to inkjet print resistor-capacitor ( RC ) low pass electrical filters, using a novel water-based cellulose graphene ink, and compare the voltage-frequency and transient behavior to equivalent circuits constructed from discrete passive components. The synthesized non-toxic graphene-carboxymethyl cellulose (G-CMC) ink is deposited on mechanically flexible polyimide substrates using a customized printer that dispenses functionalized aqueous solutions. The design of the printed first-order and second-order low-pass RC filters incorporate resistive traces and interdigitated capacitors. Low pass filter characteristics, such as time constant, cut-off frequency and roll-off rate, are determined for comparative analysis. Experiments demonstrate that for low frequency applications (graphene derivative circuits performed as well as the circuits constructed from discrete resistors and capacitors for both low pass filter and RC integrator applications. The impact of mechanical stress due to bending on the electrical performance of the flexible printed circuits is also investigated.

  5. PUZZLE - A program for computer-aided design of printed circuit artwork

    Science.gov (United States)

    Harrell, D. A. W.; Zane, R.

    1971-01-01

    Program assists in solving spacing problems encountered in printed circuit /PC/ design. It is intended to have maximum use for two-sided PC boards carrying integrated circuits, and also aids design of discrete component circuits.

  6. Gas microstrip detectors based on flexible printed circuit

    International Nuclear Information System (INIS)

    Salomon, M.; Crowe, K.; Faszer, W.; Lindsay, P.; Curran Maier, J.M.

    1995-09-01

    Microstrip Gas Detectors (MSGC's) were introduced some years ago as position sensitive detectors capable of operating at very high rates. The authors have studied the properties of a new type of Gas Microstrip Counter built using flexible printed circuit technology. They describe the manufacturing procedures, the assembly of the device, as well as its operation under a variety of conditions, gases and types of radiation. They also describe two new passivation materials, tantalum and niobium, which produce effective surfaces

  7. Improving intrinsic corrosion reliability of printed circuit board assembly

    DEFF Research Database (Denmark)

    Ambat, Rajan; Conseil, Helene

    2016-01-01

    conditions, therefore the protection of electronic devices is becoming a critical factor in system design. Humidity and local condensation inside electronic enclosures can significantly alter the performance of electronic devices. The presence of moisture in a PCB alters its quality, functionality, thermal...... performance, and thermo-mechanical properties, while condensation on the surface of printed circuit board assemblies (PCBAs) can lead to electrical failures, like electrochemical migration. The result is reduced life span for electronic products and heavy economic loss due to failures....

  8. Organic printed photonics: From microring lasers to integrated circuits.

    Science.gov (United States)

    Zhang, Chuang; Zou, Chang-Ling; Zhao, Yan; Dong, Chun-Hua; Wei, Cong; Wang, Hanlin; Liu, Yunqi; Guo, Guang-Can; Yao, Jiannian; Zhao, Yong Sheng

    2015-09-01

    A photonic integrated circuit (PIC) is the optical analogy of an electronic loop in which photons are signal carriers with high transport speed and parallel processing capability. Besides the most frequently demonstrated silicon-based circuits, PICs require a variety of materials for light generation, processing, modulation, and detection. With their diversity and flexibility, organic molecular materials provide an alternative platform for photonics; however, the versatile fabrication of organic integrated circuits with the desired photonic performance remains a big challenge. The rapid development of flexible electronics has shown that a solution printing technique has considerable potential for the large-scale fabrication and integration of microsized/nanosized devices. We propose the idea of soft photonics and demonstrate the function-directed fabrication of high-quality organic photonic devices and circuits. We prepared size-tunable and reproducible polymer microring resonators on a wafer-scale transparent and flexible chip using a solution printing technique. The printed optical resonator showed a quality (Q) factor higher than 4 × 10(5), which is comparable to that of silicon-based resonators. The high material compatibility of this printed photonic chip enabled us to realize low-threshold microlasers by doping organic functional molecules into a typical photonic device. On an identical chip, this construction strategy allowed us to design a complex assembly of one-dimensional waveguide and resonator components for light signal filtering and optical storage toward the large-scale on-chip integration of microscopic photonic units. Thus, we have developed a scheme for soft photonic integration that may motivate further studies on organic photonic materials and devices.

  9. Ruggedizing Printed Circuit Boards Using a Wideband Dynamic Absorber

    Directory of Open Access Journals (Sweden)

    V.C. Ho

    2003-01-01

    Full Text Available The existing approaches to ruggedizing inherently fragile and sensitive critical components of electronic equipment such as printed circuit boards (PCB for use in hostile industrial and military environment are either insufficient or expensive. This paper addresses a novel approach towards ruggedizing commercial-off-the-shelf PCBs using a miniature wideband dynamic absorber. The optimisation technique used relies on the experimentally measured vibration spectra and complex receptance of the original PCB.

  10. Recycling of WEEE: Characterization of spent printed circuit boards from mobile phones and computers

    International Nuclear Information System (INIS)

    Yamane, Luciana Harue; Tavares de Moraes, Viviane; Crocce Romano Espinosa, Denise; Soares Tenorio, Jorge Alberto

    2011-01-01

    Highlights: → This paper presents new and important data on characterization of wastes of electric and electronic equipments. → Copper concentration is increasing in mobile phones and remaining constant in personal computers. → Printed circuit boards from mobile phones and computers would not be mixed prior treatment. - Abstract: This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineral processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results

  11. Soft-Matter Printed Circuit Board with UV Laser Micropatterning.

    Science.gov (United States)

    Lu, Tong; Markvicka, Eric J; Jin, Yichu; Majidi, Carmel

    2017-07-05

    When encapsulated in elastomer, micropatterned traces of Ga-based liquid metal (LM) can function as elastically deformable circuit wiring that provides mechanically robust electrical connectivity between solid-state elements (e.g., transistors, processors, and sensor nodes). However, LM-microelectronics integration is currently limited by challenges in rapid fabrication of LM circuits and the creation of vias between circuit terminals and the I/O pins of packaged electronics. In this study, we address both with a unique layup for soft-matter electronics in which traces of liquid-phase Ga-In eutectic (EGaIn) are patterned with UV laser micromachining (UVLM). The terminals of the elastomer-sealed LM circuit connect to the surface mounted chips through vertically aligned columns of EGaIn-coated Ag-Fe 2 O 3 microparticles that are embedded within an interfacial elastomer layer. The processing technique is compatible with conventional UVLM printed circuit board (PCB) prototyping and exploits the photophysical ablation of EGaIn on an elastomer substrate. Potential applications to wearable computing and biosensing are demonstrated with functional implementations in which soft-matter PCBs are populated with surface-mounted microelectronics.

  12. Fast optoelectric printing of plasmonic nanoparticles into tailored circuits

    Science.gov (United States)

    Rodrigo, José A.

    2017-04-01

    Plasmonic nanoparticles are able to control light at nanometre-scale by coupling electromagnetic fields to the oscillations of free electrons in metals. Deposition of such nanoparticles onto substrates with tailored patterns is essential, for example, in fabricating plasmonic structures for enhanced sensing. This work presents an innovative micro-patterning technique, based on optoelectic printing, for fast and straightforward fabrication of curve-shaped circuits of plasmonic nanoparticles deposited onto a transparent electrode often used in optoelectronics, liquid crystal displays, touch screens, etc. We experimentally demonstrate that this kind of plasmonic structure, printed by using silver nanoparticles of 40 nm, works as a plasmonic enhanced optical device allowing for polarized-color-tunable light scattering in the visible. These findings have potential applications in biosensing and fabrication of future optoelectronic devices combining the benefits of plasmonic sensing and the functionality of transparent electrodes.

  13. Packaging printed circuit boards: A production application of interactive graphics

    Science.gov (United States)

    Perrill, W. A.

    1975-01-01

    The structure and use of an Interactive Graphics Packaging Program (IGPP), conceived to apply computer graphics to the design of packaging electronic circuits onto printed circuit boards (PCB), were described. The intent was to combine the data storage and manipulative power of the computer with the imaginative, intuitive power of a human designer. The hardware includes a CDC 6400 computer and two CDC 777 terminals with CRT screens, light pens, and keyboards. The program is written in FORTRAN 4 extended with the exception of a few functions coded in COMPASS (assembly language). The IGPP performs four major functions for the designer: (1) data input and display, (2) component placement (automatic or manual), (3) conductor path routing (automatic or manual), and (4) data output. The most complex PCB packaged to date measured 16.5 cm by 19 cm and contained 380 components, two layers of ground planes and four layers of conductors mixed with ground planes.

  14. [Flexible print circuit technology application in biomedical engineering].

    Science.gov (United States)

    Jiang, Lihua; Cao, Yi; Zheng, Xiaolin

    2013-06-01

    Flexible print circuit (FPC) technology has been widely applied in variety of electric circuits with high precision due to its advantages, such as low-cost, high specific fabrication ability, and good flexibility, etc. Recently, this technology has also been used in biomedical engineering, especially in the development of microfluidic chip and microelectrode array. The high specific fabrication can help making microelectrode and other micro-structure equipment. And good flexibility allows the micro devices based on FPC technique to be easily packaged with other parts. In addition, it also reduces the damage of microelectrodes to the tissue. In this paper, the application of FPC technology in biomedical engineering is introduced. Moreover, the important parameters of FPC technique and the development trend of prosperous applications is also discussed.

  15. Application of parallel processing for automatic inspection of printed circuits

    International Nuclear Information System (INIS)

    Lougheed, R.M.

    1986-01-01

    Automated visual inspection of printed electronic circuits is a challenging application for image processing systems. Detailed inspection requires high speed analysis of gray scale imagery along with high quality optics, lighting, and sensing equipment. A prototype system has been developed and demonstrated at the Environmental Research Institute of Michigan (ERIM) for inspection of multilayer thick-film circuits. The central problem of real-time image processing is solved by a special-purpose parallel processor which includes a new high-speed Cytocomputer. In this chapter the inspection process and the algorithms used are summarized, along with the functional requirements of the machine vision system. Next, the parallel processor is described in detail and then performance on this application is given

  16. Potential up-scaling of inkjet-printed devices for logical circuits in flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Kalyan Yoti, E-mail: kalyan-yoti.mitra@mb.tu-chemnitz.de, E-mail: enrico.sowade@mb.tu-chemnitz.de; Sowade, Enrico, E-mail: kalyan-yoti.mitra@mb.tu-chemnitz.de, E-mail: enrico.sowade@mb.tu-chemnitz.de [Technische Universität Chemnitz, Department of Digital Printing and Imaging Technology, Chemnitz (Germany); Martínez-Domingo, Carme [Printed Microelectronics Group, CAIAC, Universitat Autònoma de Barcelona, Bellaterra, Spain and Nanobioelectronics and Biosensors Group, Catalan Institute of Nanotechnology (ICN), Universitat Autònoma de Barcelona, Bellaterra, Catalonia (Spain); Ramon, Eloi, E-mail: eloi.ramon@uab.cat [Printed Microelectronics Group, CAIAC, Universitat Autònoma de Barcelona, Bellaterra (Spain); Nanobioelectronics and Biosensors Group, Catalan Institute of Nanotechnology (ICN), Universitat Autònoma de Barcelona, Bellaterra, Catalonia (Spain); Carrabina, Jordi, E-mail: jordi.carrabina@uab.cat [Printed Microelectronics Group, CAIAC, Universitat Autònoma de Barcelona, Bellaterra (Spain); Gomes, Henrique Leonel, E-mail: hgomes@ualg.pt [Universidade do Algarve, Institute of Telecommunications, Faro (Portugal); Baumann, Reinhard R., E-mail: reinhard.baumann@mb.tu-chemnitz.de [Technische Universität Chemnitz, Department of Digital Printing and Imaging Technology, Chemnitz (Germany); Fraunhofer Institute for Electronic Nano Systems (ENAS), Department of Printed Functionalities, Chemnitz (Germany)

    2015-02-17

    Inkjet Technology is often mis-believed to be a deposition/patterning technology which is not meant for high fabrication throughput in the field of printed and flexible electronics. In this work, we report on the 1) printing, 2) fabrication yield and 3) characterization of exemplary simple devices e.g. capacitors, organic transistors etc. which are the basic building blocks for logical circuits. For this purpose, printing is performed first with a Proof of concept Inkjet printing system Dimatix Material Printer 2831 (DMP 2831) using 10 pL small print-heads and then with Dimatix Material Printer 3000 (DMP 3000) using 35 pL industrial print-heads (from Fujifilm Dimatix). Printing at DMP 3000 using industrial print-heads (in Sheet-to-sheet) paves the path towards industrialization which can be defined by printing in Roll-to-Roll format using industrial print-heads. This pavement can be termed as 'Bridging Platform'. This transfer to 'Bridging Platform' from 10 pL small print-heads to 35 pL industrial print-heads help the inkjet-printed devices to evolve on the basis of functionality and also in form of up-scaled quantities. The high printed quantities and yield of inkjet-printed devices justify the deposition reliability and potential to print circuits. This reliability is very much desired when it comes to printing of circuits e.g. inverters, ring oscillator and any other planned complex logical circuits which require devices e.g. organic transistors which needs to get connected in different staged levels. Also, the up-scaled inkjet-printed devices are characterized and they reflect a domain under which they can work to their optimal status. This status is much wanted for predicting the real device functionality and integration of them into a planned circuit.

  17. Potential up-scaling of inkjet-printed devices for logical circuits in flexible electronics

    International Nuclear Information System (INIS)

    Mitra, Kalyan Yoti; Sowade, Enrico; Martínez-Domingo, Carme; Ramon, Eloi; Carrabina, Jordi; Gomes, Henrique Leonel; Baumann, Reinhard R.

    2015-01-01

    Inkjet Technology is often mis-believed to be a deposition/patterning technology which is not meant for high fabrication throughput in the field of printed and flexible electronics. In this work, we report on the 1) printing, 2) fabrication yield and 3) characterization of exemplary simple devices e.g. capacitors, organic transistors etc. which are the basic building blocks for logical circuits. For this purpose, printing is performed first with a Proof of concept Inkjet printing system Dimatix Material Printer 2831 (DMP 2831) using 10 pL small print-heads and then with Dimatix Material Printer 3000 (DMP 3000) using 35 pL industrial print-heads (from Fujifilm Dimatix). Printing at DMP 3000 using industrial print-heads (in Sheet-to-sheet) paves the path towards industrialization which can be defined by printing in Roll-to-Roll format using industrial print-heads. This pavement can be termed as 'Bridging Platform'. This transfer to 'Bridging Platform' from 10 pL small print-heads to 35 pL industrial print-heads help the inkjet-printed devices to evolve on the basis of functionality and also in form of up-scaled quantities. The high printed quantities and yield of inkjet-printed devices justify the deposition reliability and potential to print circuits. This reliability is very much desired when it comes to printing of circuits e.g. inverters, ring oscillator and any other planned complex logical circuits which require devices e.g. organic transistors which needs to get connected in different staged levels. Also, the up-scaled inkjet-printed devices are characterized and they reflect a domain under which they can work to their optimal status. This status is much wanted for predicting the real device functionality and integration of them into a planned circuit

  18. 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.

  19. Evaluation of a recycling process for printed circuit board by physical separation and heat treatment

    International Nuclear Information System (INIS)

    Fujita, Toyohisa; Ono, Hiroyuki; Dodbiba, Gjergj; Yamaguchi, Kunihiko

    2014-01-01

    Highlights: • The parts mounted on printed circuit board (PCB) were liberated by underwater explosion and mechanical crushing. • The crushed PCB without surface-mounted parts was carbonized under inert atmosphere at 873 K to recover copper. • The multi-layered ceramic capacitors including nickel was carbonized at 873 K to recover nickel by the magnetic separation. • The tantalum powders were recovered from the molded resins by heat treatment at 723 and 823 K in air atmosphere and screening. • Energy and treatment cost of new process increased, however, the environmental burden decreased comparing conventional one. - Abstract: Printed circuit boards (PCBs) from discarded personal computer (PC) and hard disk drive were crushed by explosion in water or mechanical comminution in order to disintegrate the attached parts. More parts were stripped from PCB of PC, composed of epoxy resin; than from PCB of household appliance, composed of phenol resin. In an attempt to raise the copper grade of PCB by removing other components, a carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under a nitrogen atmosphere at 873–1073 K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment. As one of the mounted parts, the multi-layered ceramic capacitors (MLCCs), which contain nickel, were carbonized at 873 K. The magnetic separation is carried out at a lower magnetic field strength of 0.1 T and then at 0.8 T. In the +0.5 mm size fraction the nickel grade in magnetic product was increased from 0.16% to 6.7% and the nickel recovery is 74%. The other useful mounted parts are tantalum capacitors. The tantalum capacitors were collected from mounted parts. The tantalum-sintered bodies were separated from molded resins

  20. Inkjet printed large-area flexible circuits: a simple methodology for optimizing the printing quality

    Science.gov (United States)

    Cheng, Tao; Wu, Youwei; Shen, Xiaoqin; Lai, Wenyong; Huang, Wei

    2018-01-01

    In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjet-printed silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics. Project supported by the National Key Basic Research Program of China (Nos. 2014CB648300, 2017YFB0404501), the National Natural Science Foundation of China (Nos. 21422402, 21674050), the Natural Science Foundation of Jiangsu Province (Nos. BK20140060, BK20130037, BK20140865, BM2012010), the Program for Jiangsu Specially-Appointed Professors (No. RK030STP15001), the Program for New Century Excellent Talents in University (No. NCET-13-0872), the NUPT "1311 Project" and Scientific Foundation (Nos. NY213119, NY213169), the Synergetic Innovation Center for Organic Electronics and Information Displays, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of China, the Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions (No. TJ217038), the Program for Graduate Students Research and Innovation of Jiangsu Province (No. KYZZ16-0253), and the 333 Project of Jiangsu Province (Nos. BRA2017402, BRA2015374).

  1. Recent Progress in the Development of Printed Thin-Film Transistors and Circuits with High-Resolution Printing Technology.

    Science.gov (United States)

    Fukuda, Kenjiro; Someya, Takao

    2017-07-01

    Printed electronics enable the fabrication of large-scale, low-cost electronic devices and systems, and thus offer significant possibilities in terms of developing new electronics/optics applications in various fields. Almost all electronic applications require information processing using logic circuits. Hence, realizing the high-speed operation of logic circuits is also important for printed devices. This report summarizes recent progress in the development of printed thin-film transistors (TFTs) and integrated circuits in terms of materials, printing technologies, and applications. The first part of this report gives an overview of the development of functional inks such as semiconductors, electrodes, and dielectrics. The second part discusses high-resolution printing technologies and strategies to enable high-resolution patterning. The main focus of this report is on obtaining printed electrodes with high-resolution patterning and the electrical performance of printed TFTs using such printed electrodes. In the final part, some applications of printed electronics are introduced to exemplify their potential. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. A study of liberation and separation process of metals from printed circuit boards (PCBs) scrap

    International Nuclear Information System (INIS)

    Noorliyana, H.A.; Zaheruddin, K.; Mohd Fazlul Bari; M. Sri Asliza; Nurhidayah, A.Z.; Kamarudin, H.

    2009-01-01

    Since the metallic elements are covered with or encapsulated by various plastic or ceramic materials on printed circuit boards, a mechanical pre-treatment process allowing their liberation and separation is first needed in order to facilitate their efficient extraction with hydrometallurgy route. Even though many studies have been performed on the mechanical pre-treatment processing for the liberation and separation of the metallic components of printed circuit boards scrap, further studies are required to pave the way for efficient recycling of waste printed circuit boards through a combination of mechanical pre-treatment and hydrometallurgical technology. In this work, a fundamental study has been carried out on the mechanical pre-treatment that is necessary to recover metallic concentrates from printed circuit boards scraps. The most important problem is to separate or release particles from the associated gangue minerals at the possible liberation particle size. The distribution of metallic elements has been also investigated in relation to the particle size of the milled printed circuit boards. The samples of printed circuit boards were separated into the magnetic and non-magnetic fractions by Rare-earth Roll Magnetic separator. Thereafter, the magnetic and non-magnetic fractions were separated to heavy fraction (metallic elements) and light fraction (plastic) by Mozley Laboratory Table Separator. The recovery ratios and the evaluation of the metallic concentrates recovered by each separation process were also investigated. This study is expected to provide useful data for the efficient mechanical separation of metallic components from printed circuit boards scraps. (author)

  3. PHYSICAL CHEMISTRY CHARACTERIZATION OF PRINTED CIRCUIT BOARD OF MOBILE PHONES

    Directory of Open Access Journals (Sweden)

    Hellington Bastos da Silva de Sant’ana

    2015-07-01

    Full Text Available Nowadays, electronics industry is the leading sector in developing new technologies. These new technologies lead to cheaper products increasing the consumption. The lifetime of such products is relatively short and soon it becomes waste, known as electronic waste. Cell phone is a common electronic waste. This waste represents an interesting raw material, because it contains large amount of base metals, considerable amount of valuable metals and also those dangerous. In this work, the electronic waste was submitted to mechanical processing: initially the devices were separated into two categories, as year of release (2002 and disassembled manually. The printed circuit boards were milled below 1 mm and then submitted to density and magnetic separation processes. The fractions obtained during the mechanical processing were characterized by chemical analysis. Using mechanical processing it was possible to obtain metal fractions of 80 wt%. A leaching test was carried out to determine if a waste needs to be managed as a hazardous; so that, cell phone waste must be considered in the category of hazardous residue because the lead concentration was above the limit established by Brazilian Standards

  4. Waste printed circuit board recycling techniques and product utilization

    International Nuclear Information System (INIS)

    Hadi, Pejman; Xu, Meng; Lin, Carol S.K.; Hui, Chi-Wai; McKay, Gordon

    2015-01-01

    Highlights: • There is a major environmental issue about the printed circuit boards throughout the world. • Different physical and chemical recycling techniques have been reviewed. • Nonmetallic fraction of PCBs is the unwanted face of this waste stream. • Several applications of the nonmetallic fraction of waste PCBs have been introduced. - Abstract: E-waste, in particular waste PCBs, represents a rapidly growing disposal problem worldwide. The vast diversity of highly toxic materials for landfill disposal and the potential of heavy metal vapors and brominated dioxin emissions in the case of incineration render these two waste management technologies inappropriate. Also, the shipment of these toxic wastes to certain areas of the world for eco-unfriendly “recycling” has recently generated a major public outcry. Consequently, waste PCB recycling should be adopted by the environmental communities as an ultimate goal. This article reviews the recent trends and developments in PCB waste recycling techniques, including both physical and chemical recycling. It is concluded that the physical recycling techniques, which efficiently separate the metallic and nonmetallic fractions of waste PCBs, offer the most promising gateways for the environmentally-benign recycling of this waste. Moreover, although the reclaimed metallic fraction has gained more attention due to its high value, the application of the nonmetallic fraction has been neglected in most cases. Hence, several proposed applications of this fraction have been comprehensively examined

  5. Recovery of high purity precious metals from printed circuit boards

    International Nuclear Information System (INIS)

    Park, Young Jun; Fray, Derek J.

    2009-01-01

    Waste printed circuit boards (WPCB) have an inherent value because of the precious metal content. For an effective recycling of WPCB, it is essential to recover the precious metals. This paper reports a promising method to recover the precious metals. Aqua regia was used as a leachant and the ratio between metals and leachant was fixed at 1/20 (g/ml). Silver is relatively stable so the amount of about 98 wt.% of the input was recovered without an additional treatment. Palladium formed a red precipitate during dissolution, which were consisted of Pd(NH 4 ) 2 Cl 6 . The amount precipitated was 93 wt.% of the input palladium. A liquid-liquid extraction with toluene was used to extract gold selectively. Also, dodecanethiol and sodium borohydride solution were added to make gold nanoparticles. Gold of about 97 wt.% of the input was recovered as nanoparticles which was identified with a high-resolution transmission electron microscopy through selected area electron diffraction and nearest-neighbor lattice spacing.

  6. Advances in Current Rating Techniques for Flexible Printed Circuits

    Science.gov (United States)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

  7. A microelectromechanical accelerometer fabricated using printed circuit processing techniques

    Science.gov (United States)

    Rogers, J. E.; Ramadoss, R.; Ozmun, P. M.; Dean, R. N.

    2008-01-01

    A microelectromechanical systems (MEMS) capacitive-type accelerometer fabricated using printed circuit processing techniques is presented. A Kapton polymide film is used as the structural layer for fabricating the MEMS accelerometer. The accelerometer proof mass along with four suspension beams is defined in the Kapton polyimide film. The proof mass is suspended above a Teflon substrate using a spacer. The deflection of the proof mass is detected using a pair of capacitive sensing electrodes. The top electrode of the accelerometer is defined on the top surface of the Kapton film. The bottom electrode is defined in the metallization on the Teflon substrate. The initial gap height is determined by the distance between the bottom electrode and the Kapton film. For an applied external acceleration (normal to the proof mass), the proof mass deflects toward or away from the fixed bottom electrode due to inertial force. This deflection causes either a decrease or increase in the air-gap height thereby either increasing or decreasing the capacitance between the top and the bottom electrodes. An example PCB MEMS accelerometer with a square proof mass of membrane area 6.4 mm × 6.4 mm is reported. The measured resonant frequency is 375 Hz and the Q-factor in air is 0.52.

  8. A microelectromechanical accelerometer fabricated using printed circuit processing techniques

    International Nuclear Information System (INIS)

    Rogers, J E; Ramadoss, R; Ozmun, P M; Dean, R N

    2008-01-01

    A microelectromechanical systems (MEMS) capacitive-type accelerometer fabricated using printed circuit processing techniques is presented. A Kapton polymide film is used as the structural layer for fabricating the MEMS accelerometer. The accelerometer proof mass along with four suspension beams is defined in the Kapton polyimide film. The proof mass is suspended above a Teflon substrate using a spacer. The deflection of the proof mass is detected using a pair of capacitive sensing electrodes. The top electrode of the accelerometer is defined on the top surface of the Kapton film. The bottom electrode is defined in the metallization on the Teflon substrate. The initial gap height is determined by the distance between the bottom electrode and the Kapton film. For an applied external acceleration (normal to the proof mass), the proof mass deflects toward or away from the fixed bottom electrode due to inertial force. This deflection causes either a decrease or increase in the air-gap height thereby either increasing or decreasing the capacitance between the top and the bottom electrodes. An example PCB MEMS accelerometer with a square proof mass of membrane area 6.4 mm × 6.4 mm is reported. The measured resonant frequency is 375 Hz and the Q-factor in air is 0.52

  9. Waste printed circuit board recycling techniques and product utilization

    Energy Technology Data Exchange (ETDEWEB)

    Hadi, Pejman; Xu, Meng [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); Lin, Carol S.K. [School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Hui, Chi-Wai [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); McKay, Gordon, E-mail: kemckayg@ust.hk [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); Division of Sustainable Development, College of Science, Engineering and Technology, Hamad Bin Khalifa University, Qatar Foundation, Doha (Qatar)

    2015-02-11

    Highlights: • There is a major environmental issue about the printed circuit boards throughout the world. • Different physical and chemical recycling techniques have been reviewed. • Nonmetallic fraction of PCBs is the unwanted face of this waste stream. • Several applications of the nonmetallic fraction of waste PCBs have been introduced. - Abstract: E-waste, in particular waste PCBs, represents a rapidly growing disposal problem worldwide. The vast diversity of highly toxic materials for landfill disposal and the potential of heavy metal vapors and brominated dioxin emissions in the case of incineration render these two waste management technologies inappropriate. Also, the shipment of these toxic wastes to certain areas of the world for eco-unfriendly “recycling” has recently generated a major public outcry. Consequently, waste PCB recycling should be adopted by the environmental communities as an ultimate goal. This article reviews the recent trends and developments in PCB waste recycling techniques, including both physical and chemical recycling. It is concluded that the physical recycling techniques, which efficiently separate the metallic and nonmetallic fractions of waste PCBs, offer the most promising gateways for the environmentally-benign recycling of this waste. Moreover, although the reclaimed metallic fraction has gained more attention due to its high value, the application of the nonmetallic fraction has been neglected in most cases. Hence, several proposed applications of this fraction have been comprehensively examined.

  10. Inkjet-printed conductive features for rapid integration of electronic circuits in centrifugal microfluidics

    CSIR Research Space (South Africa)

    Kruger, J

    2015-05-01

    Full Text Available This work investigates the properties of conductive circuits inkjet-printed onto the polycarbonate discs used in CD-based centrifugal microfluidics, contributing towards rapidly prototyped electronic systems in smart ubiquitous biosensors, which...

  11. Analytical Study on Thermal and Mechanical Design of Printed Circuit Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Su-Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sabharwall, Piyush [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kim, Eung-Soo [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-09-01

    The analytical methodologies for the thermal design, mechanical design and cost estimation of printed circuit heat exchanger are presented in this study. In this study, three flow arrangements of parallel flow, countercurrent flow and crossflow are taken into account. For each flow arrangement, the analytical solution of temperature profile of heat exchanger is introduced. The size and cost of printed circuit heat exchangers for advanced small modular reactors, which employ various coolants such as sodium, molten salts, helium, and water, are also presented.

  12. Colorimetric visualization of tin corrosion: A method for early stage corrosion detection on printed circuit boards

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2017-01-01

    A majority of printed circuit board surfaces are covered with tin, therefore tin corrosion under humid conditions and movement of tin ions under the influence of an electric field plays an important role in the corrosion failure development. Tracking tin corrosion products spread on the printed c...

  13. Development of a miniaturized watch-type dosimeter using a silicon printed-circuit board

    International Nuclear Information System (INIS)

    Ishikura, Takeshi; Sakamaki, Tsuyoshi; Matsumoto, Iwao; Aoyama, Kei; Nakamura, Takashi

    2008-01-01

    The electrical personal dosimeter using a silicon semiconductor sensor has the advantage of real time response and alarm function, which can prevent unexpected over-exposure. We tried to develop a miniaturized watch-type dosimeter by incorporating the silicon semiconductor sensor on a silicon printed-circuit board. Thin film resistors, capacitors and wiring patterns are formed on a downsized printed-circuit board. Electronic parts including transistors are mounted by soldering on the silicon printed-circuit board. The dosimeter is further miniaturized by downsizing the amplifier circuit, the semiconductor radiation sensor, the power supply circuit, setting parts and alarm part. The performance of the developed dosimeter was evaluated with respect to the gamma-ray spectra, angular dependence and linearity to dose equivalent rate, and it was confirmed that this dosimeter has the performance equivalent to a commercially available electrical personal dosimeter. (author)

  14. Assembling surface mounted components on ink-jet printed double sided paper circuit board

    International Nuclear Information System (INIS)

    Andersson, Henrik A; Manuilskiy, Anatoliy; Haller, Stefan; Sidén, Johan; Nilsson, Hans-Erik; Hummelgård, Magnus; Olin, Håkan; Hummelgård, Christine

    2014-01-01

    Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed. (paper)

  15. Assembling surface mounted components on ink-jet printed double sided paper circuit board.

    Science.gov (United States)

    Andersson, Henrik A; Manuilskiy, Anatoliy; Haller, Stefan; Hummelgård, Magnus; Sidén, Johan; Hummelgård, Christine; Olin, Håkan; Nilsson, Hans-Erik

    2014-03-07

    Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed.

  16. Assembling surface mounted components on ink-jet printed double sided paper circuit board

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Henrik A; Manuilskiy, Anatoliy; Haller, Stefan; Sidén, Johan; Nilsson, Hans-Erik [Department of Electronics Design, Mid Sweden University, SE-851 70 Sundsvall (Sweden); Hummelgård, Magnus; Olin, Håkan [Department of Natural Science, Mid Sweden University, SE-851 70 Sundsvall (Sweden); Hummelgård, Christine [Acreo Swedish ICT AB, Håstaholmen 4, SE-824 42 Hudiksvall (Sweden)

    2014-03-07

    Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed. (paper)

  17. Experimental and numerical study of a printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Chen, Minghui; Sun, Xiaodong; Christensen, Richard N.; Shi, Shanbin; Skavdahl, Isaac; Utgikar, Vivek; Sabharwall, Piyush

    2016-01-01

    Highlights: • A dynamic model is developed for transient analysis of the straight-channel PCHE. • Transient scenarios of the straight-channel PCHE subject to helium temperature and mass flow rate variations are numerically investigated. • Steady-state temperature distribution inside the straight-channel PCHE is obtained in calculation. • Experiments are conducted to study the dynamic behavior of the straight-channel PCHE. - Abstract: Printed circuit heat exchangers (PCHEs) are promising to be employed in very-high-temperature gas-cooled reactors (VHTRs) due to their high robustness for high-temperature, high-pressure applications and high compactness. PCHEs typically serve as intermediate heat exchangers (IHXs) that isolate the secondary loop from the reactor’s primary system and hence must be sufficiently robust to maintain the system integrity during normal and off-normal conditions. In addition, the performance of the PCHE-type IHX could considerably affect the nuclear power plant overall operation since any transients on the secondary side would be propagated back to the reactor’s primary coolant system via the IHX. It is therefore imperative to understand how the PCHE would dynamically respond to a variety of transients. In the current study, experiments were first conducted to examine the steady-state thermal performance of a reduced-scale straight-channel PCHE. A dynamic model benchmarked in a previous study was then used to predict the steady-state and transient behavior of the PCHE. The steady-state temperature profiles of the working fluids on both the hot and cold sides and in the solid plates of the heat exchanger were obtained, which served as the initial condition for the transient simulations. The detailed dynamic response of the straight-channel PCHE, subject to inlet temperature variations, helium mass flow variations, and combinations of the two, was simulated and analyzed. In addition, two sets of transient tests, one for helium inlet

  18. Unit: Electric Circuits, Inspection Pack, National Trial Print.

    Science.gov (United States)

    Australian Science Education Project, Toorak, Victoria.

    As a part of the unit materials in the series produced by the Australian Science Education Project, this teacher edition is primarily composed of a core relating to simple circuits, a test form, and options. Options are given under the headings: Your Invention; "How Long Does a Call Last?"; One, Two, Three Wires; Parallel Circuits; More…

  19. RECYCLING OF PRINTED CIRCUIT BOARDS AIMING SILVER RECOVERY: A HYDROMETALLURGICAL ROUTE STUDY

    Directory of Open Access Journals (Sweden)

    Marcos Paulo Kohler Caldas

    2015-06-01

    Full Text Available The aim of this paper is characterize printed circuit board of computers and propose a hydrometallurgical route for silver recovery present in its composition. Initially, the printed circuit board was comminuted in both knife and hammer mills. The comminuted material was characterized by sieve analysis, chemical analysis by inductively coupled plasma optical emission spectrometry (ICP-OES and loss on ignition. Leaching tests were conducted in sulfuric acid, sulfuric acid in an oxidizing medium and nitric acid. The results indicated that the printed circuit board is mainly composed of copper (19.42%. Silver content of 0.045% was found. The route for silver recovery was leaching in sulfuric acid at 75°C for 18 hours. Then, leaching in sulfuric acid at 75°C in an oxidizing medium for 6 hours and nitric acid leaching at room temperature for 2 hours. Through of this route, 96.6% of silver was recovered.

  20. Investigation, development and verification of printed circuit board embedded air-core solenoid transformers

    DEFF Research Database (Denmark)

    Mønster, Jakob Døllner; Madsen, Mickey Pierre; Pedersen, Jeppe Arnsdorf

    2015-01-01

    A new printed circuit board embedded air-core transformer/coupled inductor is proposed and presented. The transformer is intended for use in power converter applications operating at very high frequency between 30 MHz to 300 MHz. The transformer is based on two or more solenoid structures...

  1. Effect of ionic contamination on climatic reliability of printed circuit board assemblies

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2012-01-01

    The effect of NaCl and weak organic acids (WOAs) in “no-clean” wave solder flux residues was studied on electrochemical migration (ECM), leakage current, and corrosion on surface mount chip capacitors using a test printed circuit board assembly (PCBA) substrate having known chip components...

  2. An interactive system for the automatic layout of printed circuit boards (ARAIGNEE)

    International Nuclear Information System (INIS)

    Combet, M.; Eder, J.; Pagny, C.

    1974-12-01

    A software package for the automatic layout of printed circuit boards is presented. The program permits an interaction of the user during the layout process. The automatic searching of paths can be interrupted at any step and convenient corrections can be inserted. This procedure improves strongly the performance of the program as far as the number of unresolved connections is concerned

  3. Printed Circuit Board Embedded Inductors for Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    The paper describes the design of three different structures for printed circuit board embedded inductors. Direct comparison of spirals, solenoids and toroids are made with regard to inductance, dc and ac resistance, electromagnetic field and design flexibility. First the equations for the impeda...

  4. Radiation evaluation method of commercial off-the-shelf (COTS) electronic printed circuit boards (PCBs)

    International Nuclear Information System (INIS)

    LaBel, K.A.; Gruner, T.D.; Reed, R.A.; Settles, B.; Wilmot, J.; Dougherty, L.F.; Russo, A.; Yuknis, W.; Foster, M.G.; Garrisson-Darrin, A.; Marshall, P.W.

    1999-01-01

    We present a radiation evaluation methodology and proton ground test results for candidate COTS PCBs (commercial off-the-shelf electronic printed circuit boards) and their associated electronics for low-altitude, low-inclination orbits. We will also discuss the implications associated with mission orbit and duration. (authors)

  5. Development of an Economical Interfacing Circuit for Upgrading of SEM Data Printing System

    International Nuclear Information System (INIS)

    Punnachaiya, S.; Thong-Aram, D.

    2002-01-01

    The operating conditions of a Scanning Electron Microscope (SEM) i.e., magnification, accelerating voltage, micron mark and film identification labeling, are very important for the accurate interpretation of a micrograph picture. In the old model SEM, the built-in data printing system for film identification can be inputted only the numerical number. This will be made a confusing problems when various operating conditions were applied in routine work. An economical interfacing circuit, therefore, was developed to upgrade the data printing system for capable of alphanumerical labeling. The developed circuit was tested on both data printing systems of JSM-T220 and JSM-T330 (JEOL SEM). It was found that the interfacing function worked properly and easily installed

  6. A Method for Automatic Inspection of Printed Circuit Boards by Using the Thermal Signature

    International Nuclear Information System (INIS)

    Amer, H.H.; Zekry, A.A.; Elaraby, S.; Ghareeb, K.E.

    2012-01-01

    This paper aims to design a system for automating inspection of the printed circuit boards (PCBs) by using the thermal signature of the different integrated circuits (I.C). The proposed inspection system consists of the inspection circuit, data acquisition system (DAS) and personal computer. Inspection is done by comparing the thermal signature of normally operated circuit with the thermal signature of circuit under test. One thermistor is assigned to each component in the circuit. The thermistor must touch tightly the surface of the I.C. to sense its temperature during the inspection process. Matlab software is used to represent the thermal signature through different colors. The Turbo C software is used to develop a program for acquiring and comparing the thermal signature of the circuit under the test with the reference circuit. If the colors of the two thermal signatures for the same I.C. are same then the circuit under test is fault free and does not contain any defect. On the other side, if the colors of the two thermal signatures for the same I.C. are different then the circuit under test is defective

  7. DC arc plasma disposal of printed circuit board

    International Nuclear Information System (INIS)

    Huang Jianjun; Shenzhen Univ., Shenzhen; Shi Jiabiao; Meng Yuedong; Liu Zhengzhi

    2004-01-01

    A new solid waste disposal technology setup with DC arc plasma is presented. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled high-temperature pyrolysis, the thermal destruction and recovery process. The results of vitrification of the circuit board are presented. The properties of vitrified product including hardness and leaching test results are presented. The final product (vitrified material) and air emission from the plasma treatment is environmentally acceptable. (authors)

  8. Chemically programmed ink-jet printed resistive WORM memory array and readout circuit

    International Nuclear Information System (INIS)

    Andersson, H; Manuilskiy, A; Sidén, J; Gao, J; Kunninmel, G V; Nilsson, H-E; Hummelgård, M

    2014-01-01

    In this paper an ink-jet printed write once read many (WORM) resistive memory fabricated on paper substrate is presented. The memory elements are programmed for different resistance states by printing triethylene glycol monoethyl ether on the substrate before the actual memory element is printed using silver nano particle ink. The resistance is thus able to be set to a broad range of values without changing the geometry of the elements. A memory card consisting of 16 elements is manufactured for which the elements are each programmed to one of four defined logic levels, providing a total of 4294 967 296 unique possible combinations. Using a readout circuit, originally developed for resistive sensors to avoid crosstalk between elements, a memory card reader is manufactured that is able to read the values of the memory card and transfer the data to a PC. Such printed memory cards can be used in various applications. (paper)

  9. Inkjet printing and adhesion characterisation of conductive tracks on a commercial printed circuit board material

    International Nuclear Information System (INIS)

    Sridhar, A.; Dijk, D.J. van; Akkerman, R.

    2009-01-01

    Silver nanoparticle-based conductive tracks were inkjet printed using a piezoelectric drop-on-demand inkjet printer on a commercially available electronics grade fibre glass (E-glass) reinforced substrate material, and the experimental results have been summarised. Ink jetting was done on two variants of this substrate material, viz. etched and unetched, to determine the influence of substrate surface topography on adhesion and accuracy of the printed tracks. The pull-off adhesion test method was used to quantify adhesive strength. The dependence of the pull-off test results on local geometry of the test area are illustrated with the aid of scanning electron microscope images and interferometer studies. Based on the outcomes of the experiments, conclusions concerning the suitable surface topography for inkjet printing have been arrived at.

  10. Enrichment of the metallic components from waste printed circuit boards by a mechanical separation process using a stamp mill

    International Nuclear Information System (INIS)

    Yoo, Jae-Min; Jeong, Jinki; Yoo, Kyoungkeun; Lee, Jae-chun; Kim, Wonbaek

    2009-01-01

    Printed circuit boards incorporated in most electrical and electronic equipment contain valuable metals such as Cu, Ni, Au, Ag, Pd, Fe, Sn, and Pb. In order to employ a hydrometallurgical route for the recycling of valuable metals from printed circuit boards, a mechanical pre-treatment step is needed. In this study, the metallic components from waste printed circuit boards have been enriched using a mechanical separation process. Waste printed circuit boards shredded to 5.0 mm. The fractions of milled printed circuit boards of size 5.0 mm fraction and the heavy fraction were subjected to two-step magnetic separation. Through the first magnetic separation at 700 Gauss, 83% of the nickel and iron, based on the whole printed circuit boards, was recovered in the magnetic fraction, and 92% of the copper was recovered in the non-magnetic fraction. The cumulative recovery of nickel-iron concentrate was increased by a second magnetic separation at 3000 Gauss, but the grade of the concentrate decreased remarkably from 76% to 56%. The cumulative recovery of copper concentrate decreased, but the grade increased slightly from 71.6% to 75.4%. This study has demonstrated the feasibility of the mechanical separation process consisting of milling/size classification/gravity separation/two-step magnetic separation for enriching metallic components such as Cu, Ni, Al, and Fe from waste printed circuit boards

  11. A novel and simple method of printing flexible conductive circuits on PET fabrics

    International Nuclear Information System (INIS)

    Wang, Zehong; Wang, Wei; Jiang, Zhikang; Yu, Dan

    2017-01-01

    Highlights: • A simple preparation of nano-silver conductive ink was proposed. • Conductive pattern was printed on PET fabrics without heat sintering. • The surface resistivity of printed pattern is low to 0.197 Ω cm. - Abstract: Flexible conductive circuits on PET fabrics were fabricated by a simple approach. Firstly, well dispersed nano-silver colloids with average size of 87 nm were synthesized with poly (vinyl pyrrolidone). Then, by adding polyurethane and thickening agent into these colloids, Ag NP-based ink was produced and printed on PET fabrics by screen printing. Conductive patterns were achieved through the swelling process of polyurethane and the decrease of contact resistance between nano-silver particles when immersed in dichloromethane (DCM) and diallyldimethylammonium chloride (DMDAAC) mixed solution. After it was dried at 40 °C,the surface resistivity was about 0.197 Ω cm with width 1.9 mm, and thickness 20 μm. Moreover, the effects of different DCM contents on the conductivity and the film forming ability have been investigated. We believe these foundings will provide some important analysis for printing flexible conductive circuits on textiles.

  12. A novel and simple method of printing flexible conductive circuits on PET fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zehong; Wang, Wei [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Key Laboratory of Textile Science & Technology, Ministry of Education (China); Jiang, Zhikang [Saintyear Holding Group Co., Ltd. (China); Yu, Dan, E-mail: vchtian@163.com [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Key Laboratory of Textile Science & Technology, Ministry of Education (China); Saintyear Holding Group Co., Ltd. (China)

    2017-02-28

    Highlights: • A simple preparation of nano-silver conductive ink was proposed. • Conductive pattern was printed on PET fabrics without heat sintering. • The surface resistivity of printed pattern is low to 0.197 Ω cm. - Abstract: Flexible conductive circuits on PET fabrics were fabricated by a simple approach. Firstly, well dispersed nano-silver colloids with average size of 87 nm were synthesized with poly (vinyl pyrrolidone). Then, by adding polyurethane and thickening agent into these colloids, Ag NP-based ink was produced and printed on PET fabrics by screen printing. Conductive patterns were achieved through the swelling process of polyurethane and the decrease of contact resistance between nano-silver particles when immersed in dichloromethane (DCM) and diallyldimethylammonium chloride (DMDAAC) mixed solution. After it was dried at 40 °C,the surface resistivity was about 0.197 Ω cm with width 1.9 mm, and thickness 20 μm. Moreover, the effects of different DCM contents on the conductivity and the film forming ability have been investigated. We believe these foundings will provide some important analysis for printing flexible conductive circuits on textiles.

  13. Development of high-performance printed organic field-effect transistors and integrated circuits.

    Science.gov (United States)

    Xu, Yong; Liu, Chuan; Khim, Dongyoon; Noh, Yong-Young

    2015-10-28

    Organic electronics is regarded as an important branch of future microelectronics especially suited for large-area, flexible, transparent, and green devices, with their low cost being a key benefit. Organic field-effect transistors (OFETs), the primary building blocks of numerous expected applications, have been intensively studied, and considerable progress has recently been made. However, there are still a number of challenges to the realization of high-performance OFETs and integrated circuits (ICs) using printing technologies. Therefore, in this perspective article, we investigate the main issues concerning developing high-performance printed OFETs and ICs and seek strategies for further improvement. Unlike many other studies in the literature that deal with organic semiconductors (OSCs), printing technology, and device physics, our study commences with a detailed examination of OFET performance parameters (e.g., carrier mobility, threshold voltage, and contact resistance) by which the related challenges and potential solutions to performance development are inspected. While keeping this complete understanding of device performance in mind, we check the printed OFETs' components one by one and explore the possibility of performance improvement regarding device physics, material engineering, processing procedure, and printing technology. Finally, we analyze the performance of various organic ICs and discuss ways to optimize OFET characteristics and thus develop high-performance printed ICs for broad practical applications.

  14. Integrated digital printing of flexible circuits for wireless sensing (Conference Presentation)

    Science.gov (United States)

    Mei, Ping; Whiting, Gregory L.; Schwartz, David E.; Ng, Tse Nga; Krusor, Brent S.; Ready, Steve E.; Daniel, George; Veres, Janos; Street, Bob

    2016-09-01

    Wireless sensing has broad applications in a wide variety of fields such as infrastructure monitoring, chemistry, environmental engineering and cold supply chain management. Further development of sensing systems will focus on achieving light weight, flexibility, low power consumption and low cost. Fully printed electronics provide excellent flexibility and customizability, as well as the potential for low cost and large area applications, but lack solutions for high-density, high-performance circuitry. Conventional electronics mounted on flexible printed circuit boards provide high performance but are not digitally fabricated or readily customizable. Incorporation of small silicon dies or packaged chips into a printed platform enables high performance without compromising flexibility or cost. At PARC, we combine high functionality c-Si CMOS and digitally printed components and interconnects to create an integrated platform that can read and process multiple discrete sensors. Our approach facilitates customization to a wide variety of sensors and user interfaces suitable for a broad range of applications including remote monitoring of health, structures and environment. This talk will describe several examples of printed wireless sensing systems. The technologies required for these sensor systems are a mix of novel sensors, printing processes, conventional microchips, flexible substrates and energy harvesting power solutions.

  15. Study of the computer-aided implantation and layout of printed circuits

    International Nuclear Information System (INIS)

    Baudry, Marc

    1973-01-01

    This research thesis reports the design and implementation of a software aimed at a computer-aided implantation and layout of printed circuits. This work comprises the use of heuristic algorithms and the search for a minimum cost by reduction of computing time and of memory size. The software comprises four independent parts which respectively address data analysis and control, circuit implantation, connection layout, and the exploitation of the obtained results. These four parts and their subroutines are presented. Two examples are reported in appendix

  16. In-situ fabrication of flexible vertically integrated electronic circuits by inkjet printing

    International Nuclear Information System (INIS)

    Wang Zhuo; Wu Wenwen; Yang Qunbao; Li Yongxiang; Noh, Chang-Ho

    2009-01-01

    In this paper, a facile approach for fabricating flexible vertically integrated electronic circuits is demonstrated. A desktop inkjet printer was modified and employed to print silver precursor on a polymer-coated buffer substrates. In-situ reaction was taken place and a conducting line was formed without need of a high temperature treatment. Through this process, several layers of metal integrated circuits were deposited sequentially with polymer buffer layers sandwiched between each layer. Hence, vertically integrated electronic components of diodes, solar cells, flexible flat panel displays, and electrochromic devices can be built with this simple and low-cost technique.

  17. An Enhanced Random Vibration and Fatigue Model for Printed Circuit Boards

    Directory of Open Access Journals (Sweden)

    Bruno de Castro Braz

    Full Text Available Abstract Aerospace vehicles are mostly exposed to random vibration loads during its operational lifetime. These harsh conditions excites vibration responses in the vehicles printed circuit boards, what can cause failure on mission functionality due to fatigue damage of electronic components. A novel analytical model to evaluate the useful life of embedded electronic components (capacitors, chips, oscillators etc. mounted on Printed Circuit Boards (PCB is presented. The fatigue damage predictions are calculated by the relative displacement between the PCB and the component, the lead stiffness, as well the natural vibration modes of the PCB and the component itself. Statistical methods are used for fatigue cycle counting. The model is applied to experimental fatigue tests of PCBs available on literature. The analytical results are of the same magnitude order of the experimental findings.

  18. Research on Toxicity Evaluation of Waste Incineration Residues of Printed Circuit Boards

    Directory of Open Access Journals (Sweden)

    Rasa Volungevičienė

    2014-10-01

    Full Text Available Recycling waste printed circuit boards (PCB is an extremely complicated process, because PCBs consist of a number of complex components – hazardous and non-hazardous materials sets. Pyrolysis and combustion are currently the most effective treatment technologies for waste printed circuit boards. Pyrolysis can be used for thermally decomposing PCBs allowing for the simultaneous recovery of valuable materials. Following the extraction of valuable materials, the problem of residual ash utilization is encountered. Determining the qualitative and quantitative characteristics of incineration residue helps with choosing effective ash management technologies. This paper analyzes PCB ash generated at three different temperatures of 400 °C, 500 °C and 600 °C. Ash residues have been analysed to determine the quantity and type of metals present. Furthermore, the experiment of leaching heavy metals from ash has been described.

  19. 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

  20. Leaching of gold and silver from printed circuit board of mobile phones

    OpenAIRE

    Petter,Patrícia Melo Halmenschlager; Veit,Hugo Marcelo; Bernardes,Andréa Moura

    2015-01-01

    Nowadays there is a wide variety of models, sizes and configurations of mobile phones available for consumption. After the life cycle of this equipment, the recycling and reuse of the precious metals found in the printed circuit boards (PCB) of the mobile phones are principal objectives. Thus, the objective of this work was to characterize the gold and silver present in a PCB and develop a recycling route using alternative reagents for cyanide, such as sodium and ammonium thiosulfate. These r...

  1. Search for the optimal size of printed circuit boards for mechanical structures for electronic equipment

    Directory of Open Access Journals (Sweden)

    Yefimenko A. A.

    2014-12-01

    Full Text Available The authors present a method, an algorithm and a program, designed to determine the optimal size of printed circuit boards (PCB of mechanical structures and different kinds of electronic equipment. The PCB filling factor is taken as an optimization criterion. The method allows one to quickly determine the dependence of the filling factor on the size of the PCB for various components.

  2. SPRINT - An Interactive System for Printed Circuit Board Design User’s Guide.

    Science.gov (United States)

    1977-06-01

    effect as decreasing the time limit - your priority and turnaround time are improved. B) You have a very large circuit and an error message says...previous segment. If no path is found, a message is printed to that effect . If HIWIRE thinks the failure may have been due to too small a value of...USAF Academy, Colorado 80840 AUL/LSE-9663 Maxwell AFB, Alabama 36112 AFETR Technical Library P.O. Box 4608, MU 5650 Patrick AFB

  3. EMC and the printed circuit board design theory and layout made simple

    CERN Document Server

    Montrose, Mark I

    1999-01-01

    "This reference text shows how and why RF energy is created within a printed circuit board, and the manner in which propagation occurs. With thorough explanations, this book enables engineers to grasp both the fundamentals of EMC theory and signal integrity, along with the mitigation process needed to prevent an EMC event while maintaining optimal functionality for low- and high-technology products. Mr. Montrose also shows the relationship between time and frequency domains, helping one meet mandatory compliance requirements."--Jacket.

  4. Integration of f-MWCNT Sensor and Printed Circuits on Paper Substrate

    OpenAIRE

    Xie, Li; Feng, Yi; Mantysalo, Matti; Chen, Qiang; Zheng, Li-Rong

    2013-01-01

    The integration of sensors endows the packages with intelligence and interactivity. This paper is considered the most suitable substrate of smart packages because it is cost-effective, light, flexible, and recyclable. However, common concern exists regarding the reliability of paper-based system against bending and folding. In this paper, inkjet-printing of silver nanoparticles is used to form circuit pattern as well as interconnections for system integration on paper substrate. A humidity se...

  5. Preliminary Study of Printed Circuit Heat Exchanger (PCHE) for various power conversion systems for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jinsu; Baik, Seungjoon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    The steam-Rankine cycle was the most widely used power conversion system for a nuclear power plant. The size of the heat exchanger is important for the modulation. Such a challenge was conducted by Kang et al. They change the steam generator type for the SMART from helical type heat exchanger to Printed Circuit Heat Exchanger (PCHE). Recently, there has been a growing interest in the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle as the most promising power conversion system. The reason is high efficiency with simple layout and compact power plant due to small turbomachinery and compact heat exchanger technology. That is why the SCO{sub 2} Brayton cycle can enhance the existing advantages of Small Modular Reactor (SMR) like SMART, such as reduction in size, capital cost, and construction period. Thermal hydraulic and geometric parameters of a PCHE for the S-CO{sub 2} power cycle coupled to SMART. The results show that the water - CO{sub 2} printed circuit heat exchanger size is smaller than printed circuit steam generator for the superheated steam Rankine cycle. This results show the potential benefit of using the S-CO-2 Brayton power cycle to a water-cooled small modular reactor.

  6. Study of Photosensitive Dry Films Absorption for Printed Circuit Boards by Photoacoustic Technique

    Science.gov (United States)

    Hernández, R.; Zaragoza, J. A. Barrientos; Jiménez-Pérez, J. L.; Orea, A. Cruz; Correa-Pacheco, Z. N.

    2017-08-01

    In this work, the study of photosensitive dry-type films by photoacoustic technique is proposed. The dry film photoresist is resistant to chemical etching for printed circuit boards such as ferric chloride, sodium persulfate or ammonium, hydrochloric acid. It is capable of faithfully reproducing circuit pattern exposed to ultraviolet light (UV) through a negative. Once recorded, the uncured portion is removed with alkaline solution. It is possible to obtain good results in surface mount circuits with tracks of 5 mm. Furthermore, the solid resin films are formed by three layers, two protective layers and a UV-sensitive optical absorption layer in the range of 325 nm to 405 nm. By means of optical absorption of UV-visible rays emitted by a low-power Xe lamp, the films transform this energy into thermal waves generated by the absorption of optical radiation and subsequently no-radiative de-excitation occurs. The photoacoustic spectroscopy is a useful technique to measure the transmittance and absorption directly. In this study, the optical absorption spectra of the three layers of photosensitive dry-type films were obtained as a function of the wavelength, in order to have a knowledge of the absorber layer and the protective layers. These analyses will give us the physical properties of the photosensitive film, which are very important in curing the dry film for applications in printed circuit boards.

  7. Optimized circuit design for flexible 8-bit RFID transponders with active layer of ink-jet printed small molecule semiconductors

    NARCIS (Netherlands)

    Kjellander, B.K.C.; Smaal, W.T.T.; Myny, K.; Genoe, J.; Dehaene, W.; Heremans, P.; Gelinck, G.H.

    2013-01-01

    We ink-jet print a blend of 6,13-bis(triisopropyl-silylethynyl)pentacene and polystyrene as the active layer for flexible circuits. The discrete ink-jet printed transistors exhibit a saturation mobility of 0.5 cm2 V -1 s-1. The relative spread in transistor characteristics can be very large. This

  8. A FPGA implementation of solder paste deposit on printed circuit boards errors detector based in a bright and contrast algorithm

    OpenAIRE

    De Luca-Pennacchia, A.; Sánchez-Martínez, M. Á.

    2007-01-01

    Solder paste deposit on printed circuit boards (PCB) is a critical stage. It is known that about 60% of functionality defects in this type of boards are due to poor solder paste printing. These defects can be diminished by means of automatic optical inspection of this printing. Actually, this process is implemented by image processing software with its inherent high computational time cost. In this paper we propose to implement a high parallel degree image comparison algorithm suitable to be ...

  9. Toward printed integrated circuits based on unipolar or ambipolar polymer semiconductors.

    Science.gov (United States)

    Baeg, Kang-Jun; Caironi, Mario; Noh, Yong-Young

    2013-08-21

    For at least the past ten years printed electronics has promised to revolutionize our daily life by making cost-effective electronic circuits and sensors available through mass production techniques, for their ubiquitous applications in wearable components, rollable and conformable devices, and point-of-care applications. While passive components, such as conductors, resistors and capacitors, had already been fabricated by printing techniques at industrial scale, printing processes have been struggling to meet the requirements for mass-produced electronics and optoelectronics applications despite their great potential. In the case of logic integrated circuits (ICs), which constitute the focus of this Progress Report, the main limitations have been represented by the need of suitable functional inks, mainly high-mobility printable semiconductors and low sintering temperature conducting inks, and evoluted printing tools capable of higher resolution, registration and uniformity than needed in the conventional graphic arts printing sector. Solution-processable polymeric semiconductors are the best candidates to fulfill the requirements for printed logic ICs on flexible substrates, due to their superior processability, ease of tuning of their rheology parameters, and mechanical properties. One of the strongest limitations has been mainly represented by the low charge carrier mobility (μ) achievable with polymeric, organic field-effect transistors (OFETs). However, recently unprecedented values of μ ∼ 10 cm(2) /Vs have been achieved with solution-processed polymer based OFETs, a value competing with mobilities reported in organic single-crystals and exceeding the performances enabled by amorphous silicon (a-Si). Interestingly these values were achieved thanks to the design and synthesis of donor-acceptor copolymers, showing limited degree of order when processed in thin films and therefore fostering further studies on the reason leading to such improved charge

  10. Bioleaching of metals from printed circuit boards supported with surfactant-producing bacteria

    International Nuclear Information System (INIS)

    Karwowska, Ewa; Andrzejewska-Morzuch, Dorota; Łebkowska, Maria; Tabernacka, Agnieszka; Wojtkowska, Małgorzata; Telepko, Alicja; Konarzewska, Agnieszka

    2014-01-01

    Highlights: • Bioleaching of metals from printed circuit boards by BSAC-producing bacteria was estimated. • Aeration increased the release of all metals in medium with sulphur and biosurfactant. • Increase in Cu, Pb, Ni and Cr removal rate was observed at 37 °C in acidic medium. -- Abstract: This study has evaluated the possibility of bioleaching zinc, copper, lead, nickel, cadmium and chromium from printed circuit boards by applying a culture of sulphur-oxidising bacteria and a mixed culture of biosurfactant-producing bacteria and sulphur-oxidising bacteria. It was revealed that zinc was removed effectively both in a traditional solution acidified by a way of microbial oxidation of sulphur and when using a microbial culture containing sulphur-oxidising and biosurfactant-producing bacteria. The average process efficiency was 48% for Zn dissolution. Cadmium removal was similar in both media, with a highest metal release of 93%. For nickel and copper, a better effect was obtained in the acidic medium, with a process effectiveness of 48.5% and 53%, respectively. Chromium was the only metal that was removed more effectively in the bioleaching medium containing both sulphur-oxidising and biosurfactant-producing bacteria. Lead was removed from the printed circuit boards with very low effectiveness (below 0.5%). Aerating the culture medium with compressed air increased the release of all metals in the medium with sulphur and biosurfactant, and of Ni, Cu, Zn and Cr in the acidic medium. Increasing the temperature of the medium (to 37 °C) had a more significant impact in the acidic environment than in the neutral environment

  11. Bioleaching of metals from printed circuit boards supported with surfactant-producing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Karwowska, Ewa, E-mail: ewa.karwowska@is.pw.edu.pl [Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw (Poland); Andrzejewska-Morzuch, Dorota; Łebkowska, Maria [Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw (Poland); Tabernacka, Agnieszka, E-mail: agnieszka.tabernacka@is.pw.edu.pl [Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw (Poland); Wojtkowska, Małgorzata; Telepko, Alicja; Konarzewska, Agnieszka [Warsaw University of Technology, Faculty of Environmental Engineering, Nowowiejska 20, 00-653 Warsaw (Poland)

    2014-01-15

    Highlights: • Bioleaching of metals from printed circuit boards by BSAC-producing bacteria was estimated. • Aeration increased the release of all metals in medium with sulphur and biosurfactant. • Increase in Cu, Pb, Ni and Cr removal rate was observed at 37 °C in acidic medium. -- Abstract: This study has evaluated the possibility of bioleaching zinc, copper, lead, nickel, cadmium and chromium from printed circuit boards by applying a culture of sulphur-oxidising bacteria and a mixed culture of biosurfactant-producing bacteria and sulphur-oxidising bacteria. It was revealed that zinc was removed effectively both in a traditional solution acidified by a way of microbial oxidation of sulphur and when using a microbial culture containing sulphur-oxidising and biosurfactant-producing bacteria. The average process efficiency was 48% for Zn dissolution. Cadmium removal was similar in both media, with a highest metal release of 93%. For nickel and copper, a better effect was obtained in the acidic medium, with a process effectiveness of 48.5% and 53%, respectively. Chromium was the only metal that was removed more effectively in the bioleaching medium containing both sulphur-oxidising and biosurfactant-producing bacteria. Lead was removed from the printed circuit boards with very low effectiveness (below 0.5%). Aerating the culture medium with compressed air increased the release of all metals in the medium with sulphur and biosurfactant, and of Ni, Cu, Zn and Cr in the acidic medium. Increasing the temperature of the medium (to 37 °C) had a more significant impact in the acidic environment than in the neutral environment.

  12. Homogenization on Multi-Materials’ Elements: Application to Printed Circuit Boards and Warpage Analysis

    Directory of Open Access Journals (Sweden)

    Araújo Manuel

    2016-01-01

    Full Text Available Multi-material domains are often found in industrial applications. Modelling them can be computationally very expensive due to meshing requirements. The finite element properties comprising different materials are hardly accurate. In this work, a new homogenization method that simplifies the computation of the homogenized Young modulus, Poisson ratio and thermal expansion coefficient is proposed, and applied to composite-like material on a printed circuit board. The results show a good properties correspondence between the homogenized domain and the real geometry simulation.

  13. Comparative study of electromagnetic compatibility methods in printed circuit board design tools

    International Nuclear Information System (INIS)

    Marinova, Galia

    2002-01-01

    The paper considers the state-of-the art in electromagnetic compatibility (EMC) oriented printed circuit board (PCB) design. A general methodology of EMC oriented PCB design is synthesized. The main CAD tools available today are estimated and compared for their abilities to treat EMC oriented design. To help non experts a knowledge-base containing more than 50 basic rules for EMC-oriented PCB design is proposed. It can be applied in the PCB design CAD tools that possess rule-builders or it can help interactive design. Trends in this area of EMC-oriented PCB design are deduced. (Author)

  14. Contamination profile on typical printed circuit board assemblies vs soldering process

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    Purpose – The purpose of this paper was to analyse typical printed circuit board assemblies (PCBAs) processed by reflow, wave or selective wave soldering for typical levels of process-related residues, resulting from a specific or combination of soldering processes. Typical solder flux residue...... structure was identified by Fourier transform infrared spectroscopy, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined by measuring the leak current using a twin platinum electrode set-up. Localized extraction of residue was carried...

  15. Contamination profile of Printed Circuit Board Assemblies in relation to soldering types and conformal coating

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition......, and concentration are profiled and reported. Presence of localized flux residues were visualized using a commercial Residue RAT gel test and chemical structure was identified by FT-IR, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined...

  16. Effects of mould on electrochemical migration behaviour of immersion silver finished printed circuit board.

    Science.gov (United States)

    Yi, Pan; Xiao, Kui; Dong, Chaofang; Zou, Shiwen; Li, Xiaogang

    2018-02-01

    The role played by mould in the electrochemical migration (ECM) behaviour of an immersion silver finished printed circuit board (PCB-ImAg) under a direct current (DC) bias was investigated. An interesting phenomenon is found whereby mould, especially Aspergillus niger, can preferentially grow well on PCB-ImAg under electrical bias and then bridge integrated circuits and form a migration path. The cooperation of the mould and DC bias aggravates the ECM process occurring on PCB-ImAg. When the bias voltage is below 15V, ECM almost does not occur for Ag coating. Mechanisms that explain the ECM processes of PCB-ImAg in the presence of mould and DC bias are proposed. Copyright © 2017. Published by Elsevier B.V.

  17. Field analysis and enhancement of multi-pole magnetic components fabricated on printed circuit board

    International Nuclear Information System (INIS)

    Chiu, K.-C.; Chen, C.-S.

    2007-01-01

    A multi-pole magnetic component magnetized with a fine magnetic pole pitch of less than 1 mm is very difficult to achieve by using traditional methods. Moreover, it requires a precise mechanical process and a complicated magnetization system. Different fine magnetic pole pitches of 300, 350 and 400 μm have been accomplished on 9-pole magnetic components through the printed circuit board (PCB) manufacturing technology. Additionally, another fine magnetic pole pitch of 500 μm was also fabricated on a dual-layered (DL) wire circuit structure to investigate the field enhancement. After measurements, a gain factor of 1.37 was obtained in the field strength. The field variations among different magnetic pole pitches were analyzed in this paper

  18. Preparing printed circuit boards for rapid turn-around time on a protomat plotter

    International Nuclear Information System (INIS)

    Hawtree, J.

    1998-01-01

    This document describes the use of the LPKF ProtoMat mill/drill unit circuit board Plotter, with the associated CAD/CAM software BoardMaster and CircuitCAM. At present its primarily use here at Fermilab's Particle Physics Department is for rapid-turnover of prototype PCBs double-sided and single-sided copper clad printed circuit boards (PCBs). (The plotter is also capable of producing gravure films and engraving aluminum or plastic although we have not used it for this.) It has the capability of making traces 0.004 inch wide with 0.004 inch spacings which is appropriate for high density surface mount circuits as well as other through-mounted discrete and integrated components. One of the primary benefits of the plotter is the capability to produce double-sided drilled boards from CAD files in a few hours. However to achieve this rapid turn-around time, some care must be taken in preparing the files. This document describes how to optimize the process of PCB fabrication. With proper preparation, researchers can often have a completed circuit board in a day's time instead of a week or two wait with usual procedures. It is assumed that the software and hardware are properly installed and that the machinist is acquainted with the Win95 operating system and the basics of the associated software. This paper does not describe its use with pen plotters, lasers or rubouts. The process of creating a PCB (printed circuit board) begins with the CAD (computer-aided design) software, usually PCAD or VeriBest. These files are then moved to CAM (computer-aided machining) where they are edited and converted to put them into the proper format for running on the ProtoMat plotter. The plotter then performs the actual machining of the board. This document concentrates on the LPKF programs CircuitCam BASIS and BoardMaster for the CAM software. These programs run on a Windows 95 platform to run an LPKF ProtoMat 93s plotter

  19. Hydrothermal modification and recycling of nonmetallic particles from waste print circuit boards.

    Science.gov (United States)

    Gao, Xuehua; Li, Qisheng; Qiu, Jun

    2018-04-01

    Nonmetallic particles recycled from waste print circuit boards (NPRPs) were modified by a hydrothermal treatment method and the catalysts, solvents, temperature and time were investigated, which affected the modification effect of NPRPs. The mild hydrothermal treatment method does not need high temperature, and would not cause secondary pollution. Further, the modified NPRPs were used as the raw materials for the epoxy resin and glass fibers/epoxy resin composites, which were prepared by pouring and hot-pressing method. The mechanical properties and morphology of the composites were discussed. The results showed that relative intensity of the hydroxyl bonds on the surface of NPRPs increased 58.9% after modification. The mechanical tests revealed that both flexural and impact properties of the composites can be significantly improved by adding the modified NPRPs. Particularly, the maximum increment of flexural strength, flexural modulus and impact strength of the epoxy matrix composites with 30% modified NPRPs is 40.1%, 80.0% and 79.0%, respectively. Hydrothermal treatment can modify surface of NPRPs successfully and modified NPRPs can not only improve the properties of the composites, but also reduce the production cost of the composites and environmental pollution. Thus, we develop a new way to recycle nonmetallic materials of waste print circuit boards and the highest level of waste material recycling with the raw materials-products-raw materials closed cycle can be realized through the hydrothermal modification and reuse of NPRPs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Microwave assisted leaching and electrochemical recovery of copper from printed circuit boards of computer waste

    Science.gov (United States)

    Ivǎnuş, R. C.; ǎnuş, D., IV; Cǎlmuc, F.

    2010-06-01

    Due to the rapid technological progress, the replacement of electronic equipment is very often necessary, leading to huge amounts that end up as waste. In addition, waste electrical and electronic equipment (WEEE) contains metals of high commercial value and others that are supposed to be hazardous for the environment. Consequently, WEEE could be considered as a significant source for recovery of nonferrous metals. Among these wastes, computers appear to be distinctive, as far as further exploitation is concerned. The most ″useful″ parts of the computers are the printed circuit boards that contain many metals of interest. A study on microwave assisted electronic scrap (printed circuit boards of computer waste - PCBs) leaching was carried out with a microwave hydrothermal reactor. The leaching was conducted with thick slurries (50-100 g/L). The leaching media is a mixed solution of CuCl2 and NaCl. Preliminary electrolysis from leaching solution has investigated the feasibility of electrodeposition of copper. The results were discussed and compared with the conventional leaching method and demonstrated the potential for selective extraction of copper from PCBs.

  1. Microwave assisted leaching and electrochemical recovery of copper from printed circuit boards of computer waste

    Directory of Open Access Journals (Sweden)

    Ivănuş R.C.

    2010-06-01

    Full Text Available Due to the rapid technological progress, the replacement of electronic equipment is very often necessary, leading to huge amounts that end up as waste. In addition, waste electrical and electronic equipment (WEEE contains metals of high commercial value and others that are supposed to be hazardous for the environment. Consequently, WEEE could be considered as a significant source for recovery of nonferrous metals. Among these wastes, computers appear to be distinctive, as far as further exploitation is concerned. The most ″useful″ parts of the computers are the printed circuit boards that contain many metals of interest. A study on microwave assisted electronic scrap (printed circuit boards of computer waste – PCBs leaching was carried out with a microwave hydrothermal reactor. The leaching was conducted with thick slurries (50-100 g/L. The leaching media is a mixed solution of CuCl2 and NaCl. Preliminary electrolysis from leaching solution has investigated the feasibility of electrodeposition of copper. The results were discussed and compared with the conventional leaching method and demonstrated the potential for selective extraction of copper from PCBs.

  2. Two-Phase Instability Characteristics of Printed Circuit Steam Generator for the Low Pressure Condition

    International Nuclear Information System (INIS)

    Kang, Han-Ok; Han, Hun Sik; Kim, Young-In; Kim, Keung Koo

    2015-01-01

    Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall manufacturing cost for the components. A PCHE(Printed Circuit Heat Exchanger) is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. PCSG(Printed Circuit Steam Generator) is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. For the introduction of new steam generator, design requirement for the two-phase flow instability should be considered. This paper describes two-phase flow instability characteristics of PCSG for the low pressure condition. PCSG is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. Interconnecting flow path was developed to mitigate the two-phase flow instability in the cold side. The flow characteristics of two-phase flow instability at the PCSG is examined experimentally in this study

  3. Simultaneous detection of lactate and glucose by integrated printed circuit board based array sensing chip

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuelian [Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China); School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Zang, Jianfeng [Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708 (United States); Liu, Yingshuai; Lu, Zhisong [Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China); Li, Qing, E-mail: Qli@swu.edu.cn [School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Li, Chang Ming, E-mail: ecmli@swu.edu.cn [Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China)

    2013-04-10

    Highlights: ► An integrated printed circuit board (PCB) based array sensing chip was developed. ► Simultaneous detection of lactate and glucose in serum has been demonstrated. ► The array electronic biochip has high signal to noise ratio and high sensitivity. ► Additional electrodes were designed on the chip to correct interferences. -- Abstract: An integrated printed circuit board (PCB) based array sensing chip was developed to simultaneously detect lactate and glucose in mouse serum. The novelty of the chip relies on a concept demonstration of inexpensive high-throughput electronic biochip, a chip design for high signal to noise ratio and high sensitivity by construction of positively charged chitosan/redox polymer Polyvinylimidazole-Os (PVI-Os)/carbon nanotube (CNT) composite sensing platform, in which the positively charged chitosan/PVI-Os is mediator and electrostatically immobilizes the negatively charged enzyme, while CNTs function as an essential cross-linker to network PVI-Os and chitosan due to its negative charged nature. Additional electrodes on the chip with the same sensing layer but without enzymes were prepared to correct the interferences for high specificity. Low detection limits of 0.6 μM and 5 μM were achieved for lactate and glucose, respectively. This work could be extended to inexpensive array sensing chips with high sensitivity, good specificity and high reproducibility for various sensor applications.

  4. Nuclear code case development of printed-circuit heat exchangers with thermal and mechanical performance testing

    Energy Technology Data Exchange (ETDEWEB)

    Aakre, Shaun R. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering; Jentz, Ian W. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering; Anderson, Mark H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering

    2018-03-27

    The U.S. Department of Energy has agreed to fund a three-year integrated research project to close technical gaps involved with compact heat exchangers to be used in nuclear applications. This paper introduces the goals of the project, the research institutions, and industrial partners working in collaboration to develop a draft Boiler and Pressure Vessel Code Case for this technology. Heat exchanger testing, as well as non-destructive and destructive evaluation, will be performed by researchers across the country to understand the performance of compact heat exchangers. Testing will be performed using coolants and conditions proposed for Gen IV Reactor designs. Preliminary observations of the mechanical failure mechanisms of the heat exchangers using destructive and non-destructive methods is presented. Unit-cell finite element models assembled to help predict the mechanical behavior of these high-temperature components are discussed as well. Performance testing methodology is laid out in this paper along with preliminary modeling results, an introduction to x-ray and neutron inspection techniques, and results from a recent pressurization test of a printed-circuit heat exchanger. The operational and quality assurance knowledge gained from these models and validation tests will be useful to developers of supercritical CO2 systems, which commonly employ printed-circuit heat exchangers.

  5. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor

    Energy Technology Data Exchange (ETDEWEB)

    Hadi, Pejman; Ning, Chao; Ouyang, Weiyi; Xu, Meng [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); Lin, Carol S.K. [School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong Special Administrative Region (Hong Kong); McKay, Gordon, E-mail: kemckayg@ust.hk [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); Division of Sustainable Development, College of Science, Engineering and Technology, Hamad bin Khalifa University, Doha (Qatar)

    2015-01-15

    Highlights: • Environmental impacts of electronic waste and specifically waste printed circuit boards. • Review of the recycling techniques of waste printed circuit boards. • Advantages of physico-mechanical recycling techniques over chemical methods. • Utilization of nonmetallic fraction of waste printed circuit boards as modifier/filler. • Recent advances in the use of nonmetallic fraction of waste printed circuit boards as precursor. - Abstract: Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced.

  6. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor

    International Nuclear Information System (INIS)

    Hadi, Pejman; Ning, Chao; Ouyang, Weiyi; Xu, Meng; Lin, Carol S.K.; McKay, Gordon

    2015-01-01

    Highlights: • Environmental impacts of electronic waste and specifically waste printed circuit boards. • Review of the recycling techniques of waste printed circuit boards. • Advantages of physico-mechanical recycling techniques over chemical methods. • Utilization of nonmetallic fraction of waste printed circuit boards as modifier/filler. • Recent advances in the use of nonmetallic fraction of waste printed circuit boards as precursor. - Abstract: Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced

  7. Impact of NaCl Contamination and Climatic Conditions on the Reliability of Printed Circuit Board Assemblies

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    The effect of climatic conditions and ionic contamination on the reliability of printed circuit board assembly has been investigated in terms of leakage current (LC) and electrochemical migration susceptibility. The change in LC as a function of relative humidity (RH) and temperature was measured...... and 15 $^{\\circ}\\hbox{C}$ –65 $^{\\circ}\\hbox{C}$. The variation of RH at the surface of the test specimens was imposed by 1) increasing the RH of the surrounding air and 2) reducing the temperature of the printed circuit boards using a cooling stage, while maintaining a constant climatic condition...

  8. Fabrication of Ultra-Thin Printed Organic TFT CMOS Logic Circuits Optimized for Low-Voltage Wearable Sensor Applications.

    Science.gov (United States)

    Takeda, Yasunori; Hayasaka, Kazuma; Shiwaku, Rei; Yokosawa, Koji; Shiba, Takeo; Mamada, Masashi; Kumaki, Daisuke; Fukuda, Kenjiro; Tokito, Shizuo

    2016-05-09

    Ultrathin electronic circuits that can be manufactured by using conventional printing technologies are key elements necessary to realize wearable health sensors and next-generation flexible electronic devices. Due to their low level of power consumption, complementary (CMOS) circuits using both types of semiconductors can be easily employed in wireless devices. Here, we describe ultrathin CMOS logic circuits, for which not only the source/drain electrodes but also the semiconductor layers were printed. Both p-type and n-type organic thin film transistor devices were employed in a D-flip flop circuit in the newly developed stacked structure and exhibited excellent electrical characteristics, including good carrier mobilities of 0.34 and 0.21 cm(2) V(-1) sec(-1), and threshold voltages of nearly 0 V with low operating voltages. These printed organic CMOS D-flip flop circuits exhibit operating frequencies of 75 Hz and demonstrate great potential for flexible and printed electronics technology, particularly for wearable sensor applications with wireless connectivity.

  9. Comparative Study of Crosstalk Reduction Techniques in RF Printed Circuit Board Using FDTD Method

    Directory of Open Access Journals (Sweden)

    Rajeswari Packianathan

    2015-01-01

    Full Text Available Miniaturization of the feature size in modern electronic circuits results from placing interconnections in close proximity with a high packing density. As a result, coupling between the adjacent lines has increased significantly, causing crosstalk to become an important concern in high-performance circuit design. In certain applications, microstriplines may be used in printed circuit boards for propagating high-speed signals, rather than striplines. Here, the electromagnetic coupling effects are analyzed for various microstrip transmission line structures, namely, microstriplines with a guard trace, double stub microstriplines, and parallel serpentine microstriplines using the finite-difference time-domain method. The numerical results are compared with simulation results, where the variants are simulated using an Ansoft high-frequency structure simulator. The analysis and simulation results are experimentally validated by fabricating a prototype and establishing a good correspondence between them. Numerical results are compared with simulation and experimental results, showing that double stub microstriplines reduce the far end crosstalk by 7 dB and increase the near end crosstalk by about 2 dB compared with the parallel microstriplines. Parallel serpentine microstriplines reduce the far end crosstalk by more than 10 dB and also reduce more than 15 mV of peak far end crosstalk voltage, compared with parallel microstriplines.

  10. Influence Of Used Bacterial Culture On Zinc And Aluminium Bioleaching From Printed Circuit Boards

    Directory of Open Access Journals (Sweden)

    Mrazikova Anna

    2015-06-01

    Full Text Available Bioleaching processes were used to solubilize metals (Cu, Ni, Zn and Al from printed circuit boards (PCBs. In this study, a PCBs-adapted pure culture of Acidithiobacillus ferrooxidans, pure culture of Acidithiobacillus thiooxidans and PCBs-adapted mixed culture of A. ferrooxidans and A. thiooxidans were used for recovery of the metals. The study showed that the mixed bacterial culture has the greatest potential to dissolve metals. The maximum metal bioleaching efficiencies were found to be 100, 92, 89 and 20% of Cu, Ni, Zn and Al, respectively. The mixed culture revealed higher bacterial stability. The main factor responsible for high metal recovery was the ability of the mixed culture to maintain the low pH during the whole process. The pure culture of A. thiooxidans had no significant effect on metal bioleaching from PCBs.

  11. Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones.

    Science.gov (United States)

    Jing-ying, Li; Xiu-li, Xu; Wen-quan, Liu

    2012-06-01

    The present communication deals with the leaching of gold and silver from the printed circuit boards (PCBs) of waste mobile phones using an effective and less hazardous system, i.e., a thiourea leaching process as an alternative to the conventional and toxic cyanide leaching of gold. The influence of particle size, thiourea and Fe(3+) concentrations and temperature on the leaching of gold and silver from waste mobile phones was investigated. Gold extraction was found to be enhanced in a PCBs particle size of 100 mesh with the solutions containing 24 g/L thiourea and Fe(3+) concentration of 0.6% under the room temperature. In this case, about 90% of gold and 50% of silver were leached by the reaction of 2h. The obtained data will be useful for the development of processes for the recycling of gold and silver from the PCBs of waste mobile phones. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Ductile electroless Ni-P coating onto flexible printed circuit board

    Science.gov (United States)

    Wang, Wenchang; Zhang, Weiwei; Wang, Yurong; Mitsuzak, Naotoshi; Chen, Zhidong

    2016-03-01

    In this study, a ductile electroless Ni-P coating on the flexible printed circuit board (FPCB) was prepared in an acidic nickel plating bath. The addition of dipropylamine (DPA) in electroless plating not only improves the ductility of the Ni-P coating, but also enhances the corrosion resistance. The further analysis reveals that the ductility improvement and enhancement of corrosion resistance for the Ni-P coating may be due to the fact that the addition of DPA significantly refines the volume of columnar nodule and reduce the porosity, thus leading to the released internal stress. In addition, it was found that the nodule within the Ni-P coating grew into a columnar structure, which may be also contribute to the improvement of ductility.

  13. A miniature rigid/flex salinity measurement device fabricated using printed circuit processing techniques

    International Nuclear Information System (INIS)

    Broadbent, H A; Ketterl, T P; Reid, C S

    2010-01-01

    The design, fabrication and initial performance of a single substrate, miniature, low-cost conductivity, temperature, depth (CTD) sensor board with interconnects are presented. In combination these sensors measure ocean salinity. The miniature CTD device board was designed and fabricated as the main component of a 50 mm × 25 mm × 25 mm animal-attached biologger. The board was fabricated using printed circuit processes and consists of two distinct regions on a continuous single liquid crystal polymer substrate: an 18 mm × 28 mm rigid multi-metal sensor section and a 72 mm long flexible interconnect section. The 95% confidence intervals for the conductivity, temperature and pressure sensors were demonstrated to be ±0.083 mS cm −1 , 0.01 °C, and ±0.135 dbar, respectively.

  14. 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...

  15. New technology for recovering residual metals from nonmetallic fractions of waste printed circuit boards.

    Science.gov (United States)

    Zhang, Guangwen; He, Yaqun; Wang, Haifeng; Zhang, Tao; Wang, Shuai; Yang, Xing; Xia, Wencheng

    2017-06-01

    Recycling of waste printed circuit boards is important for environmental protection and sustainable resource utilization. Corona electrostatic separation has been widely used to recycle metals from waste printed circuit boards, but it has poor separation efficiency for finer sized fractions. In this study, a new process of vibrated gas-solid fluidized bed was used to recycle residual metals from nonmetallic fractions, which were treated using the corona electrostatic separation technology. The effects of three main parameters, i.e., vibration frequency, superficial air flow velocity, and fluidizing time on gravity segregation, were investigated using a vibrating gas-solid fluidized bed. Each size fraction had its own optimum parameters. Corresponding to their optimal segregation performance, the products from each experiment were analyzed using an X-ray fluorescence (XRF) and a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). From the results, it can be seen that the metal recoveries of -1+0.5mm, -0.5+0.25mm, and -0.25mm size fractions were 86.39%, 82.22% and 76.63%, respectively. After separation, each metal content in the -1+0.5 or -0.5+0.25mm size fraction reduced to 1% or less, while the Fe and Cu contents are up to 2.57% and 1.50%, respectively, in the -0.25mm size fraction. Images of the nonmetallic fractions with a size of -0.25mm indicated that a considerable amount of clavate glass fibers existed in these nonmetallic fractions, which may explain why fine particles had the poorest segregation performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Pressure drop and heat transfer characteristics of a high-temperature printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Chen, Minghui; Sun, Xiaodong; Christensen, Richard N.; Skavdahl, Isaac; Utgikar, Vivek; Sabharwall, Piyush

    2016-01-01

    Highlights: • Pressure drop and heat transfer characteristics of a high-temperature printed circuit heat exchanger have been obtained. • Comparisons of experimental data and available correlations have been performed. • New Fanning friction factor and heat transfer correlations for the test PCHE are developed. - Abstract: Printed circuit heat exchanger (PCHE) is one of the leading intermediate heat exchanger (IHX) candidates to be employed in the very-high-temperature gas-cooled reactors (VHTRs) due to its capability for high-temperature, high-pressure applications. In the current study, a reduced-scale zigzag-channel PCHE was fabricated using Alloy 617 plates for the heat exchanger core and Alloy 800H pipes for the headers. The pressure drop and heat transfer characteristics of the PCHE were investigated experimentally in a high-temperature helium test facility (HTHF) at The Ohio State University. The PCHE helium inlet temperatures and pressures were varied up to 464 °C/2.7 MPa for the cold side and 802 °C/2.7 MPa for the hot side, respectively, while the maximum helium mass flow rates on both sides of the PCHE reached 39 kg/h. The corresponding maximum channel Reynolds number was approximately 3558, covering the laminar flow and laminar-to-turbulent flow transition regimes. New pressure drop and heat transfer correlations for the current zigzag channels with rounded bends were developed based on the experimental data. Comparisons between the experimental data and the results obtained from the available PCHE and straight circular pipe correlations were conducted. Compared to the heat transfer performance in straight circular pipes, the zigzag channels provided little advantage in the laminar flow regime but significant advantage near the transition flow regime.

  17. Evaluation of gold and silver leaching from printed circuit board of cellphones

    International Nuclear Information System (INIS)

    Petter, P.M.H.; Veit, H.M.; Bernardes, A.M.

    2014-01-01

    Highlights: • Printed circuit boards (PCB) of mobile phones have large amounts of metals with high economic value such as gold and silver. • Dissolution of gold was done with a cyanide-based reagent and silver with nitric acid. • Leaching of PCB with Na 2 S 2 O 3 and (NH 4 ) 2 S 2 O 3 to examine the feasibility of using these reagents was done. - Abstract: Electronic waste has been increasing proportionally with the technology. So, nowadays, it is necessary to consider the useful life, recycling, and final disposal of these equipment. Metals, such as Au, Ag, Cu, Sn and Ni can be found in the printed circuit boards (PCB). According to this, the aims of this work is to characterize the PCBs of mobile phones with aqua regia; obtaining “reference” values of leaching, to gold and silver, with cyanide and nitric acid, respectively; and study the process of leaching of these metals in alternative leaching with sodium thiosulfate and ammonium thiosulfate. The metals were characterized by digesting the sample with aqua regia for 1 and 2 h at 60 °C and 80 °C. The leaching of Au with a commercial reagent (cyanide) and the Ag with HNO 3 were made. The leaching of Au and Ag with alternative reagents: Na 2 S 2 O 3, and (NH 4 ) 2 S 2 O 3 in 0.1 M concentration with the addition of CuSO 4 , NH 4 OH, and H 2 O 2 , was also studied. The results show that the digestion with aqua regia was efficient to characterize the metals present in the PCBs of mobile phones. However, the best method to solubilize silver was by digesting the sample with nitric acid. The leaching process using sodium thiosulfate was more efficient when an additional concentration of 0.015 and 0.030 M of the CuSO 4 was added

  18. Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Ortuño, Nuria; Conesa, Juan A., E-mail: ja.conesa@ua.es; Moltó, Julia; Font, Rafael

    2014-11-15

    The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment. Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 °C. Apart from carbon oxides, HBr was the main decomposition product, followed by high amounts of methane, ethylene, propylene, phenol and benzene. The maximum formation of PAHs was found in pyrolysis at 850 °C, naphthalene being the most abundant. High levels of 2-, 4-, 2,4-, 2,6- and 2,4,6-bromophenols were found, especially at 600 °C. Emissions of PCDD/Fs and dioxin-like PCBs were quite low and much lower than that of PBDD/Fs, due to the higher bromine content of the samples. Combustion at 600 °C was the run with the highest PBDD/F formation: the total content of eleven 2,3,7,8-substituted congeners (tetra- through heptaBDD/Fs) was 7240 and 3250 ng WHO{sub 2005}-TEQ/kg sample, corresponding to the sample with and without metals, respectively. - Highlights: • Thermal decomposition of printed circuit boards (with and without metals) is studied. • Important differences were found at the different experimental conditions. • Emission of brominated pollutants is much higher than that of chlorinated. • Metal enhances emission of halogenated compounds. • An increase in the temperature produces the destruction of pollutants.

  19. Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Hung-Lung, E-mail: hlchiang@mail.cmu.edu.tw [Department of Health Risk Management, China Medical University, Taichung, Taiwan (China); Lin, Kuo-Hsiung [Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan (China)

    2014-01-15

    Highlights: • Recycling of waste printed circuit boards is an important issue. • Pyrolysis is an emerging technology for PCB treatment. • Emission factors of VOCs are determined for PCB pyrolysis exhaust. • Iron-Al{sub 2}O{sub 3} catalyst was employed for the exhaust control. -- Abstract: The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H{sub 2}, CH{sub 4}, CO{sub 2}, and NOx, were 60–115, 0.4–4.0, 1.1–10, 30–95, and 0–0.7 mg/g, corresponding to temperatures ranging from 200 to 500 °C. When the pyrolysis temperature was lower than 300 °C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400 °C. When VOC exhaust was flowed through the bed of Fe-impregnated Al{sub 2}O{sub 3}, the emission of ozone precursor VOCs could be reduced by 70–80%.

  20. Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

    International Nuclear Information System (INIS)

    Ortuño, Nuria; Conesa, Juan A.; Moltó, Julia; Font, Rafael

    2014-01-01

    The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment. Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 °C. Apart from carbon oxides, HBr was the main decomposition product, followed by high amounts of methane, ethylene, propylene, phenol and benzene. The maximum formation of PAHs was found in pyrolysis at 850 °C, naphthalene being the most abundant. High levels of 2-, 4-, 2,4-, 2,6- and 2,4,6-bromophenols were found, especially at 600 °C. Emissions of PCDD/Fs and dioxin-like PCBs were quite low and much lower than that of PBDD/Fs, due to the higher bromine content of the samples. Combustion at 600 °C was the run with the highest PBDD/F formation: the total content of eleven 2,3,7,8-substituted congeners (tetra- through heptaBDD/Fs) was 7240 and 3250 ng WHO 2005 -TEQ/kg sample, corresponding to the sample with and without metals, respectively. - Highlights: • Thermal decomposition of printed circuit boards (with and without metals) is studied. • Important differences were found at the different experimental conditions. • Emission of brominated pollutants is much higher than that of chlorinated. • Metal enhances emission of halogenated compounds. • An increase in the temperature produces the destruction of pollutants

  1. 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...

  2. Effect of solder flux residue on the performance of silicone conformal coatings on printed circuit board assemblies

    DEFF Research Database (Denmark)

    Rathinavelu, Umadevi; Jellesen, Morten Stendahl; Ambat, Rajan

    2013-01-01

    Conformal coatings are applied on printed circuit board assemblies (PCBAs) in order to protect the assembly from environmental influence and silicone-based coating is commonly used. A systematic study on the performance of silicone conformal coating in connection with process-related contaminants...

  3. Treatment of Wastewater from Electroplating, Metal Finishing and Printed Circuit Board Manufacturing. Operation of Wastewater Treatment Plants Volume 4.

    Science.gov (United States)

    California State Univ., Sacramento. Dept. of Civil Engineering.

    One of four manuals dealing with the operation of wastewater plants, this document was designed to address the treatment of wastewater from electroplating, metal finishing, and printed circuit board manufacturing. It emphasizes how to operate and maintain facilities which neutralize acidic and basic waters; treat waters containing metals; destroy…

  4. Modelling the transient analysis of flat miniature heat pipes in printed circuit boards using a control volume approacht

    NARCIS (Netherlands)

    Wits, W.W.; Kok, J.B.W.; van Steenhoven, A.A.; van der Meer, T.H.; Stoffels, G.G.M.

    2008-01-01

    The heat pipe is a two-phase cooling solution, offering very high thermal coefficients, for heat transport. Therefore, it is increasingly used in the design of electronic products. Flat miniature heat pipes are able to effectively remove heat from several hot spots on a Printed Circuit Board (PCB).

  5. SOURCES OF COPPER IONS AND SELECTED METHODS OF THEIR REMOVAL FROM WASTEWATER FROM THE PRINTED CIRCUITS BOARD PRODUCTION

    Directory of Open Access Journals (Sweden)

    Maciej Thomas

    2014-10-01

    Full Text Available This paper presents the issues related to the presence and removal of copper compounds from industrial effluents with including wastewater from plants involved in the production of printed circuit boards. Characterized the toxicological properties of selected copper compounds, described the applicable technological processes, sources of copper ions in the effluents and selected methods for their removal.

  6. Modular integration of electronics and microfluidic systems using flexible printed circuit boards.

    Science.gov (United States)

    Wu, Amy; Wang, Lisen; Jensen, Erik; Mathies, Richard; Boser, Bernhard

    2010-02-21

    Microfluidic systems offer an attractive alternative to conventional wet chemical methods with benefits including reduced sample and reagent volumes, shorter reaction times, high-throughput, automation, and low cost. However, most present microfluidic systems rely on external means to analyze reaction products. This substantially adds to the size, complexity, and cost of the overall system. Electronic detection based on sub-millimetre size integrated circuits (ICs) has been demonstrated for a wide range of targets including nucleic and amino acids, but deployment of this technology to date has been limited due to the lack of a flexible process to integrate these chips within microfluidic devices. This paper presents a modular and inexpensive process to integrate ICs with microfluidic systems based on standard printed circuit board (PCB) technology to assemble the independently designed microfluidic and electronic components. The integrated system can accommodate multiple chips of different sizes bonded to glass or PDMS microfluidic systems. Since IC chips and flex PCB manufacturing and assembly are industry standards with low cost, the integrated system is economical for both laboratory and point-of-care settings.

  7. Natural printed silk substrate circuit fabricated via surface modification using one step thermal transfer and reduction graphene oxide

    Science.gov (United States)

    Cao, Jiliang; Huang, Zhan; Wang, Chaoxia

    2018-05-01

    Graphene conductive silk substrate is a preferred material because of its biocompatibility, flexibility and comfort. A flexible natural printed silk substrate circuit was fabricated by one step transfer of graphene oxide (GO) paste from transfer paper to the surface of silk fabric and reduction of the GO to reduced graphene oxide (RGO) using a simple hot press treatment. The GO paste was obtained through ultrasonic stirring exfoliation under low temperature, and presented excellent printing rheological properties at high concentration. The silk fabric was obtained a surface electric resistance as low as 12.15 KΩ cm-1, in the concentration of GO 50 g L-1 and hot press at 220 °C for 120 s. Though the whiteness and strength decreased with the increasing of hot press temperature and time slowly, the electric conductivity of RGO surface modification silk substrate improved obviously. The surface electric resistance of RGO/silk fabrics increased from 12.15 KΩ cm-1 to 18.05 KΩ cm-1, 28.54 KΩ cm-1 and 32.53 KΩ cm-1 after 10, 20 and 30 washing cycles, respectively. The results showed that the printed silk substrate circuit has excellent washability. This process requires no chemical reductant, and the reduction efficiency and reduction degree of GO is high. This time-effective and environmentally-friendly one step thermal transfer and reduction graphene oxide onto natural silk substrate method can be easily used to production of reduced graphene oxide (RGO) based flexible printed circuit.

  8. Printing low-melting-point alloy ink to directly make a solidified circuit or functional device with a heating pen.

    Science.gov (United States)

    Wang, Lei; Liu, Jing

    2014-12-08

    A new method to directly print out a solidified electronic circuit through low-melting-point metal ink is proposed. A functional pen with heating capability was fabricated. Several typical thermal properties of the alloy ink Bi 35 In 48.6 Sn 16 Zn 0.4 were measured and evaluated. Owing to the specifically selected melting point of the ink, which is slightly higher than room temperature, various electronic devices, graphics or circuits can be manufactured in a short period of time and then rapidly solidified by cooling in the surrounding air. The liquid-solid phase change mechanism of the written lines was experimentally characterized using a scanning electron microscope. In order to determine the matching substrate, wettability between the metal ink Bi 35 In 48.6 Sn 16 Zn 0.4 and several materials, including mica plate and silicone rubber, was investigated. The resistance-temperature curve of a printed resistor indicated its potential as a temperature control switch. Furthermore, the measured reflection coefficient of a printed double-diamond antenna accords well with the simulated result. With unique merits such as no pollution, no requirement for encapsulation and easy recycling, the present printing approach is an important supplement to current printed electronics and has enormous practical value in the future.

  9. Evaluation of gold and silver leaching from printed circuit board of cellphones

    Energy Technology Data Exchange (ETDEWEB)

    Petter, P.M.H., E-mail: patymhp@yahoo.com.br; Veit, H.M.; Bernardes, A.M.

    2014-02-15

    Highlights: • Printed circuit boards (PCB) of mobile phones have large amounts of metals with high economic value such as gold and silver. • Dissolution of gold was done with a cyanide-based reagent and silver with nitric acid. • Leaching of PCB with Na{sub 2}S{sub 2}O{sub 3} and (NH{sub 4}){sub 2}S{sub 2}O{sub 3} to examine the feasibility of using these reagents was done. - Abstract: Electronic waste has been increasing proportionally with the technology. So, nowadays, it is necessary to consider the useful life, recycling, and final disposal of these equipment. Metals, such as Au, Ag, Cu, Sn and Ni can be found in the printed circuit boards (PCB). According to this, the aims of this work is to characterize the PCBs of mobile phones with aqua regia; obtaining “reference” values of leaching, to gold and silver, with cyanide and nitric acid, respectively; and study the process of leaching of these metals in alternative leaching with sodium thiosulfate and ammonium thiosulfate. The metals were characterized by digesting the sample with aqua regia for 1 and 2 h at 60 °C and 80 °C. The leaching of Au with a commercial reagent (cyanide) and the Ag with HNO{sub 3}were made. The leaching of Au and Ag with alternative reagents: Na{sub 2}S{sub 2}O{sub 3,} and (NH{sub 4}){sub 2}S{sub 2}O{sub 3} in 0.1 M concentration with the addition of CuSO{sub 4}, NH{sub 4}OH, and H{sub 2}O{sub 2}, was also studied. The results show that the digestion with aqua regia was efficient to characterize the metals present in the PCBs of mobile phones. However, the best method to solubilize silver was by digesting the sample with nitric acid. The leaching process using sodium thiosulfate was more efficient when an additional concentration of 0.015 and 0.030 M of the CuSO{sub 4} was added.

  10. Design of a CMOS readout circuit on ultra-thin flexible silicon chip for printed strain gauges

    Directory of Open Access Journals (Sweden)

    M. Elsobky

    2017-09-01

    Full Text Available Flexible electronics represents an emerging technology with features enabling several new applications such as wearable electronics and bendable displays. Precise and high-performance sensors readout chips are crucial for high quality flexible electronic products. In this work, the design of a CMOS readout circuit for an array of printed strain gauges is presented. The ultra-thin readout chip and the printed sensors are combined on a thin Benzocyclobutene/Polyimide (BCB/PI substrate to form a Hybrid System-in-Foil (HySiF, which is used as an electronic skin for robotic applications. Each strain gauge utilizes a Wheatstone bridge circuit, where four Aerosol Jet® printed meander-shaped resistors form a full-bridge topology. The readout chip amplifies the output voltage difference (about 5 mV full-scale swing of the strain gauge. One challenge during the sensor interface circuit design is to compensate for the relatively large dc offset (about 30 mV at 1 mA in the bridge output voltage so that the amplified signal span matches the input range of an analog-to-digital converter (ADC. The circuit design uses the 0. 5 µm mixed-signal GATEFORESTTM technology. In order to achieve the mechanical flexibility, the chip fabrication is based on either back thinned wafers or the ChipFilmTM technology, which enables the manufacturing of silicon chips with a thickness of about 20 µm. The implemented readout chip uses a supply of 5 V and includes a 5-bit digital-to-analog converter (DAC, a differential difference amplifier (DDA, and a 10-bit successive approximation register (SAR ADC. The circuit is simulated across process, supply and temperature corners and the simulation results indicate excellent performance in terms of circuit stability and linearity.

  11. Two-step bioleaching of copper and gold from discarded printed circuit boards (PCB).

    Science.gov (United States)

    Işıldar, Arda; van de Vossenberg, Jack; Rene, Eldon R; van Hullebusch, Eric D; Lens, Piet N L

    2016-11-01

    An effective strategy for environmentally sound biological recovery of copper and gold from discarded printed circuit boards (PCB) in a two-step bioleaching process was experimented. In the first step, chemolithotrophic acidophilic Acidithiobacillus ferrivorans and Acidithiobacillus thiooxidans were used. In the second step, cyanide-producing heterotrophic Pseudomonas fluorescens and Pseudomonas putida were used. Results showed that at a 1% pulp density (10g/L PCB concentration), 98.4% of the copper was bioleached by a mixture of A. ferrivorans and A. thiooxidans at pH 1.0-1.6 and ambient temperature (23±2°C) in 7days. A pure culture of P. putida (strain WCS361) produced 21.5 (±1.5)mg/L cyanide with 10g/L glycine as the substrate. This gold complexing agent was used in the subsequent bioleaching step using the Cu-leached (by A. ferrivorans and A. thiooxidans) PCB material, 44.0% of the gold was mobilized in alkaline conditions at pH 7.3-8.6, and 30°C in 2days. This study provided a proof-of-concept of a two-step approach in metal bioleaching from PCB, by bacterially produced lixiviants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Leaching of metals from large pieces of printed circuit boards using citric acid and hydrogen peroxide.

    Science.gov (United States)

    Jadhav, Umesh; Su, C; Hocheng, Hong

    2016-12-01

    In the present study, the leaching of metals from large pieces of computer printed circuit boards (CPCBs) was studied. A combination of citric acid (0.5 M) and 1.76 M hydrogen peroxide (H 2 O 2 ) was used to leach the metals from CPCB piece. The influence of system variables such as H 2 O 2 concentration, concentration of citric acid, shaking speed, and temperature on the metal leaching process was investigated. The complete metal leaching was achieved in 4 h from a 4 × 4 cm CPCB piece. The presence of citric acid and H 2 O 2 together in the leaching solution is essential for complete metal leaching. The optimum addition amount of H 2 O 2 was 5.83 %. The citric acid concentration and shaking speed had an insignificant effect on the leaching of metals. The increase in the temperature above 30 °C showed a drastic effect on metal leaching process.

  13. Leaching Studies for Copper and Solder Alloy Recovery from Shredded Particles of Waste Printed Circuit Boards

    Science.gov (United States)

    Kavousi, Maryam; Sattari, Anahita; Alamdari, Eskandar Keshavarz; Fatmehsari, Davoud Haghshenas

    2018-06-01

    Printed circuit boards (PCBs) comprise various metals such as Cu, Sn, and Pb, as well as platinum group metals. The recovery of metals from PCBs is important not only due to the waste treatment but also for recycling of valuable metals. In the present work, the leaching process of Cu, Sn, and Pb from PCBs was studied using fluoroboric acid and hydrogen peroxide as the leaching agent and oxidant, respectively. Pertinent factors including concentration of acid, temperature, liquid-solid ratio, and concentration of oxidizing agent were evaluated. The results showed 99 pct of copper and 90 pct solder alloy were dissolved at a temperature of 298 K (25 °C) for 180 minutes using 0.6 M HBF4 for the particle size range of 0.15 to 0.4 mm. Moreover, solid/liquid ratio had insignificant effect on the recovery of metals. Kinetics analysis revealed that the chemical control regime governs the process with activation energy 41.25 and 38.9 kJ/mol for copper and lead leaching reactions, respectively.

  14. Comparative study on copper leaching from waste printed circuit boards by typical ionic liquid acids.

    Science.gov (United States)

    Chen, Mengjun; Huang, Jinxiu; Ogunseitan, Oladele A; Zhu, Nengming; Wang, Yan-min

    2015-07-01

    Waste printed circuit boards (WPCBs) are attracting increasing concerns because the recovery of its content of valuable metallic resources is hampered by the presence of hazardous substances. In this study, we used ionic liquids (IL) to leach copper from WPCBs. [BSO3HPy]OTf, [BSO3HMIm]OTf, [BSO4HPy]HSO4, [BSO4HMim]HSO4 and [MIm]HSO4 were selected. Factors that affect copper leaching rate were investigated in detail and their leaching kinetics were also examined with the comparison of [Bmim]HSO4. The results showed that all six IL acids could successfully leach copper out, with near 100% recovery. WPCB particle size and leaching time had similar influences on copper leaching performance, while IL acid concentration, hydrogen peroxide addition, solid to liquid ratio, temperature, showed different influences. Moreover, IL acid with HSO4(-) was more efficient than IL acid with CF3SO3(-). These six IL acids indicate a similar behavior with common inorganic acids, except temperature since copper leaching rate of some IL acids decreases with its increase. The results of leaching kinetics studies showed that diffusion plays a more important role than surface reaction, whereas copper leaching by inorganic acids is usually controlled by surface reaction. This innovation provides a new option for recovering valuable materials such as copper from WPCBs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Printed circuit board recycling: Physical processing and copper extraction by selective leaching.

    Science.gov (United States)

    Silvas, Flávia P C; Correa, Mónica M Jiménez; Caldas, Marcos P K; de Moraes, Viviane T; Espinosa, Denise C R; Tenório, Jorge A S

    2015-12-01

    Global generation of waste electrical and electronic equipment (WEEE) is about 40 million tons per year. Constant increase in WEEE generation added to international legislations has improved the development of processes for materials recovery and sustainability of electrical and electronic industry. This paper describes a new hydrometallurgical route (leaching process) to recycle printed circuit boards (PCBs) from printers to recover copper. Methodology included PCBs characterization and a combined route of physical and hydrometallurgical processing. Magnetic separation, acid digestion and chemical analysis by ICP-OES were performed. On leaching process were used two stages: the first one in a sulfuric media and the second in an oxidant media. The results showed that the PCBs composition was 74.6 wt.% of non-magnetic material and 25.4 wt.% of magnetic one. The metallic fraction corresponded to 44.0 wt.%, the polymeric to 28.5 wt.% and the ceramic to 27.5 wt.%. The main metal was copper and its initial content was 32.5 wt.%. On sulfuric leaching 90 wt.% of Al, 40 wt.% of Zn and 8.6 wt.% of Sn were extracted, whereas on oxidant leaching tests the extraction percentage of Cu was 100 wt.%, of Zn 60 wt.% and of Al 10 wt.%. At the end of the hydrometallurgical processing was obtained 100% of copper extraction and the recovery factor was 98.46%, which corresponds to a 32 kg of Cu in 100 kg of PCB. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A Novel Designed Bioreactor for Recovering Precious Metals from Waste Printed Circuit Boards

    Science.gov (United States)

    Jujun, Ruan; Jie, Zheng; Jian, Hu; Zhang, Jianwen

    2015-01-01

    For recovering precious metals from waste printed circuit boards (PCBs), a novel hybrid technology including physical and biological methods was developed. It consisted of crushing, corona-electrostatic separation, and bioleaching. Bioleaching process is the focus of this paper. A novel bioreactor for bioleaching was designed. Bioleaching was carried out using Pseudomonas chlororaphis. Bioleaching experiments using mixed particles of Au and Cu were performed and leachate contained 0.006 mg/L, 2823 mg/L Au+ and Cu2+ respectively. It showed when Cu existed, the concentrations of Au were extremely small. This provided the feasibility to separate Cu from Au. The method of orthogonal experimental design was employed in the simulation bioleaching experiments. Experimental results showed the optimized parameters for separating Cu from Au particles were pH 7.0, temperature 22.5 °C, and rotation speed 80 r/min. Based on the optimized parameters obtained, the bioreactor was operated for recovering mixed Au and Cu particles. 88.1 wt.% of Cu and 76.6 wt.% of Au were recovered. The paper contributed important information to recover precious metals from waste PCBs. PMID:26316021

  17. Heat Transfer and Pressure Drop Characteristics in Straight Microchannel of Printed Circuit Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Jang-Won Seo

    2015-05-01

    Full Text Available Performance tests were carried out for a microchannel printed circuit heat exchanger (PCHE, which was fabricated with micro photo-etching and diffusion bonding technologies. The microchannel PCHE was tested for Reynolds numbers in the range of 100‒850 varying the hot-side inlet temperature between 40 °C–50 °C while keeping the cold-side temperature fixed at 20 °C. It was found that the average heat transfer rate and heat transfer performance of the countercurrrent configuration were 6.8% and 10%‒15% higher, respectively, than those of the parallel flow. The average heat transfer rate, heat transfer performance and pressure drop increased with increasing Reynolds number in all experiments. Increasing inlet temperature did not affect the heat transfer performance while it slightly decreased the pressure drop in the experimental range considered. Empirical correlations have been developed for the heat transfer coefficient and pressure drop factor as functions of the Reynolds number.

  18. Leaching Studies for Copper and Solder Alloy Recovery from Shredded Particles of Waste Printed Circuit Boards

    Science.gov (United States)

    Kavousi, Maryam; Sattari, Anahita; Alamdari, Eskandar Keshavarz; Fatmehsari, Davoud Haghshenas

    2018-03-01

    Printed circuit boards (PCBs) comprise various metals such as Cu, Sn, and Pb, as well as platinum group metals. The recovery of metals from PCBs is important not only due to the waste treatment but also for recycling of valuable metals. In the present work, the leaching process of Cu, Sn, and Pb from PCBs was studied using fluoroboric acid and hydrogen peroxide as the leaching agent and oxidant, respectively. Pertinent factors including concentration of acid, temperature, liquid-solid ratio, and concentration of oxidizing agent were evaluated. The results showed 99 pct of copper and 90 pct solder alloy were dissolved at a temperature of 298 K (25 °C) for 180 minutes using 0.6 M HBF4 for the particle size range of 0.15 to 0.4 mm. Moreover, solid/liquid ratio had insignificant effect on the recovery of metals. Kinetics analysis revealed that the chemical control regime governs the process with activation energy 41.25 and 38.9 kJ/mol for copper and lead leaching reactions, respectively.

  19. Copper recovery and gold enrichment from waste printed circuit boards by mediated electrochemical oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Fogarasi, Szabolcs [“Babeş-Bolyai” University, Faculty of Chemistry and Chemical Engineering, Department of Chemical Engineering, 11 Arany Janos Street, Cluj-Napoca RO-400028 (Romania); Imre-Lucaci, Florica [“Babeş-Bolyai” University, Interdisciplinary Research Institute on Bio-Nano-Sciences, 42 Treboniu Laurian Street, Cluj-Napoca RO-400271 (Romania); Imre-Lucaci, Árpád, E-mail: aimre@chem.ubbcluj.ro [“Babeş-Bolyai” University, Faculty of Chemistry and Chemical Engineering, Department of Chemical Engineering, 11 Arany Janos Street, Cluj-Napoca RO-400028 (Romania); Ilea, Petru [“Babeş-Bolyai” University, Faculty of Chemistry and Chemical Engineering, Department of Chemical Engineering, 11 Arany Janos Street, Cluj-Napoca RO-400028 (Romania)

    2014-05-01

    Highlights: • We developed a mediated electrochemical process for electronic waste treatment. • We achieved the simultaneous recovery of copper and gold enrichment. • Process scale up was realized based on the optimal values of operating parameters. • The waste does not require mechanical pretreatment in the scaled process. • The process proved to be efficient and eco-friendly as well. - Abstract: The present study aims to develop an eco-friendly chemical–electrochemical process for the simultaneous recovery of copper and separation of a gold rich residue from waste printed circuit boards (WPCBs). The process was carried out by employing two different types of reactors coupled in series: a leaching reactor with a perforated rotating drum, for the dissolution of base metals and a divided electrochemical reactor for the regeneration of the leaching solution with the parallel electrowinning of copper. The process performances were evaluated on the basis of the dissolution efficiency, current efficiency and specific energy consumptions. Finally a process scale up was realized taking into consideration the optimal values of the operating parameters. The laboratory scale leaching plant allowed the recovery of a high purity copper deposit (99.04 wt.%) at a current efficiency of 63.84% and specific energy consumption of 1.75 kW h/kg cooper. The gold concentration in the remained solid residue was 25 times higher than the gold concentration in the initial WPCB samples.

  20. Application of glass-nonmetals of waste printed circuit boards to produce phenolic moulding compound

    International Nuclear Information System (INIS)

    Guo Jie; Rao Qunli; Xu Zhenming

    2008-01-01

    The aim of this study was to investigate the feasibility of using glass-nonmetals, a byproduct of recycling waste printed circuit boards (PCBs), to replace wood flour in production of phenolic moulding compound (PMC). Glass-nonmetals were attained by two-step crushing and corona electrostatic separating processes. Glass-nonmetals with particle size shorter than 0.07 mm were in the form of single fibers and resin powder, with the biggest portion (up to 34.6 wt%). Properties of PMC with glass-nonmetals (PMCGN) were compared with reference PMC and the national standard of PMC (PF2C3). When the adding content of glass-nonmetals was 40 wt%, PMCGN exhibited flexural strength of 82 MPa, notched impact strength of 2.4 kJ/m 2 , heat deflection temperature of 175 deg. C, and dielectric strength of 4.8 MV/m, all of which met the national standard. Scanning electron microscopy (SEM) showed strong interfacial bonding between glass fibers and the phenolic resin. All the results showed that the use of glass-nonmetals as filler in PMC represented a promising method for resolving the environmental pollutions and reducing the cost of PMC, thus attaining both environmental and economic benefits

  1. Integration of microelectronic chips in microfluidic systems on printed circuit board

    International Nuclear Information System (INIS)

    Burdallo, I; Jimenez-Jorquera, C; Fernández-Sánchez, C; Baldi, A

    2012-01-01

    A new scheme for the integration of small semiconductor transducer chips with microfluidic structures on printed circuit board (PCB) is presented. The proposed approach is based on a packaging technique that yields a large and flat area with small and shallow (∼44 µm deep) openings over the chips. The photocurable encapsulant material used, based on a diacrylate bisphenol A polymer, enables irreversible bonding of polydimethylsiloxane microfluidic structures at moderate temperatures (80 °C). This integration scheme enables the insertion of transducer chips in microfluidic systems with a lower added volume than previous schemes. Leakage tests have shown that the bonded structures withstand more than 360 kPa of pressure. A prototype microfluidic system with two detection chips, including one inter-digitated electrode (IDE) chip for conductivity and one ion selective field effect transistor (ISFET) chip for pH, has been implemented and characterized. Good electrical insulation of the chip contacts and silicon edge surfaces from the solution in the microchannels has been achieved. This integration procedure opens the door to the low-cost fabrication of complex analytical microsystems that combine the extraordinary potential of both the microfluidics and silicon microtechnology fields. (paper)

  2. Copper recovery and gold enrichment from waste printed circuit boards by mediated electrochemical oxidation

    International Nuclear Information System (INIS)

    Fogarasi, Szabolcs; Imre-Lucaci, Florica; Imre-Lucaci, Árpád; Ilea, Petru

    2014-01-01

    Highlights: • We developed a mediated electrochemical process for electronic waste treatment. • We achieved the simultaneous recovery of copper and gold enrichment. • Process scale up was realized based on the optimal values of operating parameters. • The waste does not require mechanical pretreatment in the scaled process. • The process proved to be efficient and eco-friendly as well. - Abstract: The present study aims to develop an eco-friendly chemical–electrochemical process for the simultaneous recovery of copper and separation of a gold rich residue from waste printed circuit boards (WPCBs). The process was carried out by employing two different types of reactors coupled in series: a leaching reactor with a perforated rotating drum, for the dissolution of base metals and a divided electrochemical reactor for the regeneration of the leaching solution with the parallel electrowinning of copper. The process performances were evaluated on the basis of the dissolution efficiency, current efficiency and specific energy consumptions. Finally a process scale up was realized taking into consideration the optimal values of the operating parameters. The laboratory scale leaching plant allowed the recovery of a high purity copper deposit (99.04 wt.%) at a current efficiency of 63.84% and specific energy consumption of 1.75 kW h/kg cooper. The gold concentration in the remained solid residue was 25 times higher than the gold concentration in the initial WPCB samples

  3. The ultrasonically assisted metals recovery treatment of printed circuit board waste sludge by leaching separation.

    Science.gov (United States)

    Xie, Fengchun; Li, Haiying; Ma, Yang; Li, Chuncheng; Cai, Tingting; Huang, Zhiyuan; Yuan, Gaoqing

    2009-10-15

    This paper provides a practical technique that realized industrial scale copper and iron separation from printed circuit board (PCB) waste sludge by ultrasonically assisted acid leaching in a low cost, low energy consumption and zero discharge of wastes manner. The separation efficiencies of copper and iron from acid leaching with assistance of ultrasound were compared with the one without assistance of ultrasound and the effects of the leaching procedure, pH value, and ultrasonic strength have been investigated in the paper. With the appropriate leaching procedure, a final pH of 3.0, an ultrasonic generator power of 160 W (in 1l tank), leaching time of 60 min, leaching efficiencies of copper and iron had reached 97.83% and 1.23%, respectively. Therefore the separation of copper and iron in PCB waste sludge was virtually achieved. The lab results had been successfully applied to the industrial scaled applications in a heavy metal recovery plant in city of Huizhou, China for more than two years. It has great potentials to be used in even the broad metal recovery practices.

  4. Copper recovery and gold enrichment from waste printed circuit boards by mediated electrochemical oxidation.

    Science.gov (United States)

    Fogarasi, Szabolcs; Imre-Lucaci, Florica; Imre-Lucaci, Arpád; Ilea, Petru

    2014-05-30

    The present study aims to develop an eco-friendly chemical-electrochemical process for the simultaneous recovery of copper and separation of a gold rich residue from waste printed circuit boards (WPCBs). The process was carried out by employing two different types of reactors coupled in series: a leaching reactor with a perforated rotating drum, for the dissolution of base metals and a divided electrochemical reactor for the regeneration of the leaching solution with the parallel electrowinning of copper. The process performances were evaluated on the basis of the dissolution efficiency, current efficiency and specific energy consumptions. Finally a process scale up was realized taking into consideration the optimal values of the operating parameters. The laboratory scale leaching plant allowed the recovery of a high purity copper deposit (99.04wt.%) at a current efficiency of 63.84% and specific energy consumption of 1.75kWh/kg cooper. The gold concentration in the remained solid residue was 25 times higher than the gold concentration in the initial WPCB samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Quantitative Leaching of a Spent Cell Phone Printed Circuit Board by Hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Alafara A. Baba

    2014-07-01

    Full Text Available This paper presents a kinetic data on the hydrometallurgical recovery of some metal ions from a printed circuit board (PCB of a spent cell phone by hydrochloric acid leaching. The effects of acid concentration, temperature and particle diameter on the dissolution efficiency at various leaching time intervals were examined. The results of the leaching investigations showed that the powdered cell phone dissolution increases with increasing acid concentration, system temperature with decreasing particle diameter at 360 rpm. With 2M HCl solution, about 88.49% of the sample was dissolved within 120 minutes using 0.075-0.112 mm particle diameter at 800 C. The results of the study indicated that the dissolution reaction could be represented by a shrinking core model with surface chemical reaction. A value of 0.61, 60.67 kJ/mol and 12.9s-1 were calculated as reaction order, activation energy and frequency factor, respectively for the dissolution process.

  6. Characterization of Printed Circuit Boards for Metal and Energy Recovery after Milling and Mechanical Separation

    Directory of Open Access Journals (Sweden)

    Waldir A. Bizzo

    2014-06-01

    Full Text Available The proper disposal of electrical and electronic waste is currently a concern of researchers and environmental managers not only because of the large volume of such waste generated, but also because of the heavy metals and toxic substances it contains. This study analyzed printed circuit boards (PCBs from discarded computers to determine their metal content and characterized them as solid waste and fuel. The analysis showed that PCBs consist of approximately 26% metal, made up mainly of copper, lead, aluminum, iron and tin, as well as other heavy metals such as cadmium and nickel. Comparison with the results of other studies indicated that the concentration of precious metals (gold and silver has declined over time. Analysis of the leachate revealed high concentrations of cadmium and lead, giving the residue the characteristics of hazardous waste. After milling the PCBs, we found that larger amounts of metal were concentrated in smaller fractions, while the lightest fraction, obtained by density separation, had a gross calorific value of approximately 11 MJ/kg, although with a high ash content. Milling followed by density separation proved potentially useful for recovery of metals and energy-rich fractions.

  7. High-Temperature Test of 800HT Printed Circuit Heat Exchanger in HELP

    International Nuclear Information System (INIS)

    Kim, Chan Soo; Hong, Sung-Deok; Kim, Min Hwan; Shim, Jaesool

    2014-01-01

    Korea Atomic Energy Research Institute has developed high-temperature Printed Circuit Heat Exchangers (PCHE) for a Very High Temperature gas-cooled Reactor and operated a very high temperature Helium Experimental LooP (HELP) to verify the performance of the high temperature heat exchanger at the component level environment. PCHE is one of the candidates for the intermediate heat exchanger in a VHTR, because its design temperature and pressure are larger than any other compact heat exchanger types. High temperature PCHEs in HELP consist of an alloy617 PCHE and an 800HT PCHE. This study presents the high temperature test of an 800HT PCHE in HELP. The experimental data include the pressure drops, the overall heat transfer coefficients, and the surface temperature distributions under various operating conditions. The experimental data are compared with the thermo-hydraulic analysis from COMSOL. In addition, the single channel tests are performed to quantify the friction factor under normal nitrogen and helium inlet conditions. (author)

  8. CFD Analysis on the Periodic Element of a Printed Circuit Heat Exchanger

    International Nuclear Information System (INIS)

    Tak, Nam-il; Kim, Min-Hwan; Lee, Won-Jae

    2007-01-01

    A typical printed circuit heat exchanger (PCHE) is composed of a large number of flow channels with lateral corrugations. In an effort to investigate fundamental thermo-fluid characteristics of a PCHE with corrugated channels, computational fluid dynamics (CFD) analyses were previously made in. One pair of flow channels (i.e., cold and hot channels) with the entire flow path was considered for the computational domain in the previous studies. Although only one pair of flow channels with coarse meshes was used, computational loads were found to be very high to simulate the entire flow path of the PCHE. Fortunately a recent study has shown that a simplified CFD methodology with a stream wise periodic assumption (called periodic CFD analysis) is feasible for a CFD evaluation of the thermo-fluid performance of compact heat exchangers. Since the periodic CFD analysis focuses on the periodic element of a flow channel, the required computing resources are dramatically reduced. In the present paper, the periodic CFD analysis has been applied to the periodic element of the PCHE. The results are compared with those of the full elements which have an entire flow path. Based on the periodic approach the effects of the corrugation parameters on the thermo-fluid performance of the PCHE are investigated

  9. Study on characteristics of printed circuit board liberation and its crushed products.

    Science.gov (United States)

    Quan, Cui; Li, Aimin; Gao, Ningbo

    2012-11-01

    Recycling printed circuit board waste (PCBW) waste is a hot issue of environmental protection and resource recycling. Mechanical and thermo-chemical methods are two traditional recycling processes for PCBW. In the present research, a two-step crushing process combined with a coarse-crushing step and a fine-pulverizing step was adopted, and then the crushed products were classified into seven different fractions with a standard sieve. The liberation situation and particle shape in different size fractions were observed. Properties of different size fractions, such as heating value, thermogravimetric, proximate, ultimate and chemical analysis were determined. The Rosin-Rammler model was applied to analyze the particle size distribution of crushed material. The results indicated that complete liberation of metals from the PCBW was achieved at a size less than 0.59 mm, but the nonmetal particle in the smaller-than-0.15 mm fraction is liable to aggregate. Copper was the most prominent metal in PCBW and mainly enriched in the 0.42-0.25 mm particle size. The Rosin-Rammler equation adequately fit particle size distribution data of crushed PCBW with a correlation coefficient of 0.9810. The results of heating value and proximate analysis revealed that the PCBW had a low heating value and high ash content. The combustion and pyrolysis process of PCBW was different and there was an obvious oxidation peak of Cu in combustion runs.

  10. E-waste: development of recycling process and chemical characterization of circuit printed - motherboard

    International Nuclear Information System (INIS)

    Junior, O.L.F.; Vargas, R.A.; Andreoli, M.; Martinelli, J.R.; Seo, E.S.M.

    2011-01-01

    The electro-electronic industry has been regulated by the National Politic of Solid Residues Act (PNRS) and Bill no. 7.404, concerning the actions, procedures, and method to collect, recycle and promotion of environmentally acceptable final destination of residues. The present work contributes to develop recycling process of printed circuit used in microcomputers and in its chemical characterization. The experimental procedure consisted of grinding, classification, magnetic and electrostatic separation, and separation based on density difference, followed by chemical characterization of the metallic and non metallic materials in the motherboard. It was determined that the amounts of Ag, Al, Ba, Cl, Cr, Cu, Fe, Mn, Pb, and Zn in the residue are above the toxicity allowable levels, and they are in the samples of the decanted material. Among the samples of the floating material, Al, Ba, Br, Ca, Cu, Fe, Pb (in less quantity), Si (in more quantity), and Sn, Ti and Zn were detected. Those materials can be useful in the preparation of red ceramics. (author)

  11. Fast copper extraction from printed circuit boards using supercritical carbon dioxide.

    Science.gov (United States)

    Calgaro, C O; Schlemmer, D F; da Silva, M D C R; Maziero, E V; Tanabe, E H; Bertuol, D A

    2015-11-01

    Technological development and intensive marketing support the growth in demand for electrical and electronic equipment (EEE), for which printed circuit boards (PCBs) are vital components. As these devices become obsolete after short periods, waste PCBs present a problem and require recycling. PCBs are composed of ceramics, polymers, and metals, particularly Cu, which is present in highest percentages. The aim of this study was to develop an innovative method to recover Cu from the PCBs of old mobile phones, obtaining faster reaction kinetics by means of leaching with supercritical CO2 and co-solvents. The PCBs from waste mobile phones were characterized, and evaluation was made of the reaction kinetics during leaching at atmospheric pressure and using supercritical CO2 with H2O2 and H2SO4 as co-solvents. The results showed that the PCBs contained 34.83 wt% of Cu. It was found that the supercritical extraction was 9 times faster, compared to atmospheric pressure extraction. After 20 min of supercritical leaching, approximately 90% of the Cu contained in the PCB was extracted using a 1:20 solid:liquid ratio and 20% of H2O2 and H2SO4 (2.5 M). These results demonstrate the efficiency of the process. Therefore the supercritical CO2 employment in the PCBs recycling is a promising alternative and the CO2 is environmentally acceptable and reusable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Disposing and recycling waste printed circuit boards: disconnecting, resource recovery, and pollution control.

    Science.gov (United States)

    Wang, Jianbo; Xu, Zhenming

    2015-01-20

    Over the past decades, China has been suffering from negative environmental impacts from distempered e-waste recycling activities. After a decade of effort, disassembly and raw materials recycling of environmentally friendly e-waste have been realized in specialized companies, in China, and law enforcement for illegal activities of e-waste recycling has also been made more and more strict. So up to now, the e-waste recycling in China should be developed toward more depth and refinement to promote industrial production of e-waste resource recovery. Waste printed circuit boards (WPCBs), which are the most complex, hazardous, and valuable components of e-waste, are selected as one typical example in this article that reviews the status of related regulations and technologies of WPCBs recycling, then optimizes, and integrates the proper approaches in existence, while the bottlenecks in the WPCBs recycling system are analyzed, and some preliminary experiments of pinch technologies are also conducted. Finally, in order to provide directional guidance for future development of WPCBs recycling, some key points in the WPCBs recycling system are proposed to point towards a future trend in the e-waste recycling industry.

  13. Experimental Investigation of Pool Boiling for Single and Double Heaters Using Printed Circuit Board

    International Nuclear Information System (INIS)

    Han, Won Seok; Lee, Jae Young

    2012-01-01

    Over the past several decades, a considerable number of studies have been conducted on boiling heat transfer in pool boiling. Boiling heat transfer is used in a variety of cooling applications, such as heat exchangers, high powered electronics, and nuclear reactors. Nucleate boiling is one of the most efficient heat transfer mechanisms in boiling regime, but it is imperative that the critical heat flux(CHF) should not be exceeded. CHF phenomenon leads to a dramatic rise in wall temperature, decreased heat transfer, and material failure. Although numerous attempts have been made by researchers to demonstrate the CHF, there is little agreement with the CHF mechanism. In recent years, many researchers have been focusing on surface condition using nanoparticles and surface enhancements, such as a micro structure and artificial cavities, due to enhancement of the CHF point. Cooke and Kandlikar used chips etched with microchannels to prove that these structure has the most enhancement effect. They found that the most efficient boiling surface is with a larger channel size and deep etch. The purpose of this paper is to evaluate the heat transfer and CHF of double heaters on printed circuit board(PCB) in pool boiling. In addition, bubble dynamics of nucleate boiling were observed with high speed observation on single and double heaters using PCB heater

  14. Numerical investigation on thermal-hydraulic performance of new printed circuit heat exchanger model

    International Nuclear Information System (INIS)

    Kim, Dong Eok; Kim, Moo Hwan; Cha, Jae Eun; Kim, Seong O.

    2008-01-01

    Three-dimensional numerical analysis was performed to investigate heat transfer and pressure drop characteristics of supercritical CO 2 flow in new Printed Circuit Heat Exchanger (PCHE) model using commercial CFD code, Fluent 6.3. First, numerical analysis for conventional zigzag channel PCHE model was performed and compared with previous experimental data. Maximum deviation of in-outlet temperature difference and pressure drop from experimental data is about 10%. A new PCHE model has been designed to optimize thermal-hydraulic performance of PCHE. The new PCHE model has several airfoil shape fins (NACA 0020 model), which are designed to streamlined shape. Simulation results showed that in the airfoil shape fin PCHE, total heat transfer rate per unit volume was almost same with zigzag channel PCHE and the pressure drop was reduced to one-twentieth of that in zigzag channel PCHE. In airfoil shape fin PCHE model, the enhancement of heat transfer area and the uniform flow configuration contributed to obtain the same heat transfer performance with zigzag channel PCHE model. And the reduction of pressure drop in airfoil shape fin PCHE model was caused by suppressing generation of separated flow owing to streamlined shape of airfoil fins

  15. Synthesis of carbon nanotubes and porous carbons from printed circuit board waste pyrolysis oil

    International Nuclear Information System (INIS)

    Quan Cui; Li Aimin; Gao Ningbo

    2010-01-01

    The possibility and feasibility of using pyrolysis oil from printed circuit board (PCB) waste as a precursor for advanced carbonaceous materials is presented. The PCB waste was first pyrolyzed in a laboratory scale fixed bed reactor at 600 deg. C to prepare pyrolysis oil. The analysis of pyrolysis oil by gas chromatography-mass spectroscopy indicated that it contained a very high proportion of phenol and phenol derivatives. It was then polymerized in formaldehyde solution to synthesize pyrolysis oil-based resin which was used as a precursor to prepare carbon nanotubes (CNTs) and porous carbons. Scanning electron microscopy and transmission microscopy investigation showed that the resulting CNTs had hollow cores with outer diameter of ∼338 nm and wall thickness of ∼86 nm and most of them were filled with metal nanoparticles or nanorods. X-ray diffraction reveals that CNTs have an amorphous structure. Nitrogen adsorption isotherm analysis indicated the prepared porous carbons had a Brunauer-Emmett-Teller surface area of 1214 m 2 /g. The mechanism of the formation of the CNTs and porous carbons was discussed.

  16. Separation of the metallic and non-metallic fraction from printed circuit boards employing green technology

    Energy Technology Data Exchange (ETDEWEB)

    Estrada-Ruiz, R.H., E-mail: rhestrada@itsaltillo.edu.mx; Flores-Campos, R., E-mail: rcampos@itsaltillo.edu.mx; Gámez-Altamirano, H.A., E-mail: hgamez@itsaltillo.edu.mx; Velarde-Sánchez, E.J., E-mail: ejvelarde@itsaltillo.edu.mx

    2016-07-05

    Highlights: • Small sizes of particles are required in order to separate the different fractions. • Inverse flotation process is an efficient green technology to separate fractions. • Superficial air velocity is the main variable in the inverse flotation process. • Inverse flotation is a green process because the pulṕs pH is 7.0 during the test. - Abstract: The generation of electrical and electronic waste is increasing day by day; recycling is attractive because of the metallic fraction containing these. Nevertheless, conventional techniques are highly polluting. The comminution of the printed circuit boards followed by an inverse flotation process is a clean technique that allows one to separate the metallic fraction from the non-metallic fraction. It was found that particle size and superficial air velocity are the main variables in the separation of the different fractions. In this way an efficient separation is achieved by avoiding the environmental contamination coupled with the possible utilization of the different fractions obtained.

  17. Supergravity separation of Pb and Sn from waste printed circuit boards at different temperatures

    Science.gov (United States)

    Meng, Long; Wang, Zhe; Zhong, Yi-wei; Chen, Kui-yuan; Guo, Zhan-cheng

    2018-02-01

    Printed circuit boards (PCBs) contain many toxic substances as well as valuable metals, e.g., lead (Pb) and tin (Sn). In this study, a novel technology, named supergravity, was used to separate different mass ratios of Pb and Sn from Pb-Sn alloys in PCBs. In a supergravity field, the liquid metal phase can permeate from solid particles. Hence, temperatures of 200, 280, and 400°C were chosen to separate Pb and Sn from PCBs. The results depicted that gravity coefficient only affected the recovery rates of Pb and Sn, whereas it had little effect on the mass ratios of Pb and Sn in the obtained alloys. With an increase in gravity coefficient, the recovery values of Pb and Sn in each step of the separation process increased. In the single-step separation process, the mass ratios of Pb and Sn in Pb-Sn alloys were 0.55, 0.40, and 0.64 at 200, 280, and 400°C, respectively. In the two-step separation process, the mass ratios were 0.12 and 0.55 at 280 and 400°C, respectively. Further, the mass ratio was observed to be 0.76 at 400°C in the three-step separation process. This process provides an innovative approach to the recycling mechanism of Pb and Sn from PCBs.

  18. Towards Practical Application of Paper based Printed Circuits: Capillarity Effectively Enhances Conductivity of the Thermoplastic Electrically Conductive Adhesives

    Science.gov (United States)

    Wu, Haoyi; Chiang, Sum Wai; Lin, Wei; Yang, Cheng; Li, Zhuo; Liu, Jingping; Cui, Xiaoya; Kang, Feiyu; Wong, Ching Ping

    2014-09-01

    Direct printing nanoparticle-based conductive inks onto paper substrates has encountered difficulties e.g. the nanoparticles are prone to penetrate into the pores of the paper and become partially segmented, and the necessary low-temperature-sintering process is harmful to the dimension-stability of paper. Here we prototyped the paper-based circuit substrate in combination with printed thermoplastic electrically conductive adhesives (ECA), which takes the advantage of the capillarity of paper and thus both the conductivity and mechanical robustness of the printed circuitsweredrastically improved without sintering process. For instance, the electrical resistivity of the ECA specimen on a pulp paper (6 × 10-5Ω.cm, with 50 wt% loading of Ag) was only 14% of that on PET film than that on PET film. This improvement has been found directly related to the sizing degree of paper, in agreement with the effective medium approximation simulation results in this work. The thermoplastic nature also enables excellent mechanical strength of the printed ECA to resist repeated folding. Considering the generality of the process and the wide acceptance of ECA technique in the modern electronic packages, this method may find vast applications in e.g. circuit boards, capacitive touch pads, and radio frequency identification antennas, which have been prototyped in the manuscript.

  19. Design analysis of a lead–lithium/supercritical CO2 Printed Circuit Heat Exchanger for primary power recovery

    International Nuclear Information System (INIS)

    Fernández, Iván; Sedano, Luis

    2013-01-01

    Highlights: • A design for a PbLi/CO 2 (SC) Printed Circuit Heat Exchanger which optimizes the pressure drop performance is proposed. • Numerical analyses have been performed to optimize the airfoil fins shape and arrangement. • SiC is proposed as structural material and tritium permeation barrier for the PCHE. • The integrated flux is larger than expected and allows reducing the CO 2 mass flow in this sector of the power cycle. • A transport model has been developed to evaluate the permeation of tritium from the liquid metal to the secondary CO 2 . -- Abstract: One of the key issues for fusion power plant technology is the efficient, reliable and safe recovery of the power extracted by the primary coolants. An interesting design option for power conversion cycles based on Dual Coolant Breeding Blankets (DCBB) is a Printed Circuit Heat Exchanger, which is supported by the advantages of its compactness, thermal effectiveness, high temperature and pressure capability and corrosion resistance. This work presents a design analysis of a silicon carbide Printed Circuit Heat Exchanger for lead–lithium/supercritical CO 2 at DEMO ranges (4× segmentation)

  20. 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.

  1. Prioritizing material recovery for end-of-life printed circuit boards

    International Nuclear Information System (INIS)

    Wang Xue; Gaustad, Gabrielle

    2012-01-01

    Highlights: ► Material recovery driven by composition, choice of ranking, and weighting. ► Economic potential for new recycling technologies quantified for several metrics. ► Indicators developed for materials incurring high eco-toxicity costs. ► Methodology useful for a variety of stakeholders, particularly policy-makers. - Abstract: The increasing growth in generation of electronic waste (e-waste) motivates a variety of waste reduction research. Printed circuit boards (PCBs) are an important sub-set of the overall e-waste stream due to the high value of the materials contained within them and potential toxicity. This work explores several environmental and economic metrics for prioritizing the recovery of materials from end-of-life PCBs. A weighted sum model is used to investigate the trade-offs among economic value, energy saving potentials, and eco-toxicity. Results show that given equal weights for these three sustainability criteria gold has the highest recovery priority, followed by copper, palladium, aluminum, tin, lead, platinum, nickel, zinc, and silver. However, recovery priority will change significantly due to variation in the composition of PCBs, choice of ranking metrics, and weighting factors when scoring multiple metrics. These results can be used by waste management decision-makers to quantify the value and environmental savings potential for recycling technology development and infrastructure. They can also be extended by policy-makers to inform possible penalties for land-filling PCBs or exporting to the informal recycling sector. The importance of weighting factors when examining recovery trade-offs, particularly for policies regarding PCB collection and recycling are explored further.

  2. Liquid oil and residual characteristics of printed circuit board recycle by pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Kuo-Hsiung [Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan (China); Chiang, Hung-Lung, E-mail: hlchiang@mail.cmu.edu.tw [Department of Health Risk Management, China Medical University, Taichung, Taiwan (China)

    2014-04-01

    Highlights: • Pyrolysis is a technology for recycling of the non-metal fraction of PCBs. • Liquid product constituents were analyzed for PCB pyrolysis. • Water-soluble ionic species were determined for PCB pyrolysis exhaust. - Abstract: Non-metal fractions of waste printed circuit boards (PCBs) were thermally treated (200–500 °C) under nitrogen atmosphere. Carbon, hydrogen, and nitrogen were determined by elemental analyzer, bromine by instrumental neutron activation analysis (INAA), phosphorus by energy dispersive X-ray spectrometer (EDX), and 29 trace elements by inductively coupled plasma atomic emission spectrometer (ICP-AES) and mass spectrometry (ICP-MS) for raw material and pyrolysis residues. Organic compositions of liquid oil were identified by GC (gas chromatography)–MS, trace element composition by ICP system, and 12 water-soluble ions by IC (ionic chromatography). Elemental content of carbon was >450 mg/g, oxygen 300 mg/g, bromine and hydrogen 60 mg/g, nitrogen 30 mg/g, and phosphorus 28 mg/g. Sulfur was trace in PCBs. Copper content was 25–28 mg/g, iron 1.3–1.7 mg/g, tin 0.8–1.0 mg/g and magnesium 0.4–1.0 mg/g; those were the main metals in the raw materials and pyrolytic residues. In the liquid products, carbon content was 68–73%, hydrogen was 10–14%, nitrogen was 4–5%, and sulfur was less than 0.05% at pyrolysis temperatures from 300 to 500 °C. Phenol, 3-bromophenol, 2-methylphenol and 4-propan-2-ylphenol were major species in liquid products, accounting for >50% of analyzed organic species. Bromides, ammonium and phosphate were the main species in water sorption samples for PCB pyrolysis exhaust.

  3. Using vacuum pyrolysis and mechanical processing for recycling waste printed circuit boards

    International Nuclear Information System (INIS)

    Long Laishou; Sun Shuiyu; Zhong Sheng; Dai Wencan; Liu Jingyong; Song Weifeng

    2010-01-01

    The constant growth in generation of waste printed circuit boards (WPCB) poses a huge disposal problem because they consist of a heterogeneous mixture of organic and metallic chemicals as well as glass fiber. Also the presence of heavy metals, such as Pb and Cd turns this scrap into hazardous waste. Therefore, recycling of WPCB is an important subject not only from the recovery of valuable materials but also from the treatment of waste. The aim of this study was to present a recycling process without negative impact to the environment as an alternative for recycling WPCB. In this work, a process technology containing vacuum pyrolysis and mechanical processing was employed to recycle WPCB. At the first stage of this work, the WPCB was pyrolyzed under vacuum in a self-made batch pilot-scale fixed bed reactor to recycle organic resins contained in the WPCB. By vacuum pyrolysis the organic matter was decomposed to gases and liquids which could be used as fuels or chemical material resources, however, the inorganic WPCB matter was left unaltered as solid residues. At the second stage, the residues obtained at the first stage were investigated to separate and recover the copper through mechanical processing such as crushing, screening, and gravity separation. The copper grade of 99.50% with recovery of 99.86% based on the whole WPCB was obtained. And the glass fiber could be obtained by calcinations in a muffle furnace at 600 deg. C for 10 min. This study had demonstrated the feasibility of vacuum pyrolysis and mechanical processing for recycling WPCB.

  4. Evaluation of gold and silver leaching from printed circuit board of cellphones.

    Science.gov (United States)

    Petter, P M H; Veit, H M; Bernardes, A M

    2014-02-01

    Electronic waste has been increasing proportionally with the technology. So, nowadays, it is necessary to consider the useful life, recycling, and final disposal of these equipment. Metals, such as Au, Ag, Cu, Sn and Ni can be found in the printed circuit boards (PCB). According to this, the aims of this work is to characterize the PCBs of mobile phones with aqua regia; obtaining "reference" values of leaching, to gold and silver, with cyanide and nitric acid, respectively; and study the process of leaching of these metals in alternative leaching with sodium thiosulfate and ammonium thiosulfate. The metals were characterized by digesting the sample with aqua regia for 1 and 2h at 60°C and 80°C. The leaching of Au with a commercial reagent (cyanide) and the Ag with HNO3were made. The leaching of Au and Ag with alternative reagents: Na2S2O3, and (NH4)2S2O3 in 0.1M concentration with the addition of CuSO4, NH4OH, and H2O2, was also studied. The results show that the digestion with aqua regia was efficient to characterize the metals present in the PCBs of mobile phones. However, the best method to solubilize silver was by digesting the sample with nitric acid. The leaching process using sodium thiosulfate was more efficient when an additional concentration of 0.015 and 0.030 M of the CuSO4 was added. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Disassembly and physical separation of electric/electronic components layered in printed circuit boards (PCB).

    Science.gov (United States)

    Lee, Jaeryeong; Kim, Youngjin; Lee, Jae-chun

    2012-11-30

    Although printed circuit boards (PCBs) contain various elements, only the major elements (i.e., those with content levels in wt% or over grade) of and precious metals (e.g., Ag, Au, and platinum groups) contained within PCBs can be recycled. To recover other elements from PCBs, the PCBs should be properly disassembled as the first step of the recycling process. The recovery of these other elements would be beneficial for efforts to conserve scarce resources, reuse electric/electronic components (EECs), and eliminate environmental problems. This paper examines the disassembly of EECs from wasted PCBs (WPCBs) and the physical separation of these EECs using a self-designed disassembling apparatus and a 3-step separation process of sieving, magnetic separation, and dense medium separation. The disassembling efficiencies were evaluated by using the ratio of grinding area (E(area)) and the weight ratio of the detached EECs (E(weight)). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (E(area)) and 98% (E(weight)) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5mm. Through a series of physical separations, most groups of the EECs (except for the diode, transistor, and IC chip groups) could be sorted at a relatively high separation efficiency of about 75% or more. To evaluate the separation efficiency with regard to the elemental composition, the distribution ratio (R(dis)) and the concentration ratio (R(conc)) were used. 15 elements could be separated with the highest R(dis) and R(conc) in the same separated division. This result implies that the recyclability of the elements is highly feasible, even though the initial content in EECs is lower than several tens of mg/kg. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Performance Evaluation of a Printed Circuit Steam Generator for Integral Reactors: A Feasibility Test

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hun Sik; Kang, Han-Ok; Yoon, Juhyeon; Kim, Young In; Kim, Keung Koo [KAERI, Daejeon (Korea, Republic of); Seo, Jang-won; Choi, Brain [Alfa Laval Korea Ltd., Daejeon (Korea, Republic of)

    2015-05-15

    SMART (System-integrated Modular Advanced ReacTor) is a small-sized integral type pressurized water reactor. It adopts advanced design features such as structural safety improvement, system simplification, and component modularization to achieve highly enhanced safety and improved economics. The design issues related to further safety enhancement and cost reduction have received significant attention to increase its competitiveness in the global small reactor market. For the cost reduction, it is important to design the reactor vessel as small as possible. Thus, it is necessary to reduce the volume of main components such as a steam generator. Its manufacturing processes of the chemical etching and diffusion bonding provide high effectiveness, high compactness, and inherent structural safety under high temperatures and high pressures. Thus, it is expected to be an alternative to the conventional shell and tube type steam generator in SMART. In this paper, simple thermal-hydraulic performance measurement of a small-scale printed circuit steam generator (PCSG) is conducted to investigate the feasibility of applying it to SMART. The simple thermal-hydraulic performance of the PCSG has been experimentally evaluated. A small-scale PCHE is employed to investigate the feasibility of operating it as a steam generator. The performance assessment reveals that the PCSG stably produces superheated steam, and the increased degree of superheat is obtained at lower water flow rate. However, the flow instability is increased with the decrease of the water flow rate. Thus, it is required to apply the orifice design into the cold side plate to suppress the density-wave oscillations. The pressure drops and heat transfer rates increase with the water flow rate.

  7. Investigation of printed circuit heat exchanger for VHTRs - HTR2008-58097

    International Nuclear Information System (INIS)

    Mylavarapu, S. K.; Sun, X.; Figley, J.; Needler, N. J.; Christensen, R. N.

    2008-01-01

    Very High Temperature Reactors (VHTRs) require high temperature (900-950 deg. C), high integrity, and high efficiency heat exchangers during normal and off-normal conditions. A class of compact heat exchangers, namely, the Printed Circuit Heat Exchangers (PCHEs), made of high temperature materials, found to have the above characteristics, are being increasingly pursued for heavy duty applications. A high-temperature helium experimental test facility, primarily aimed at investigating the heat transfer and pressure drop characteristics of the PCHEs, was designed and is being built at the Ohio State Univ.. The test facility was designed for a maximum operating temperature and pressure of 900 deg. C and 3 MPa, respectively. Owing to the high operating conditions, a detailed investigation various high temperature materials was carried out to aid in design of the test facility and the heat exchangers. The study showed that alloy 617 is the leading candidate material for high temperature heat exchangers. Two PCHEs, each having 10 hot 10 cold plates with 12 channels in each plate, are currently being fabricated from alloy 617 plates and will be tested once test facility is constructed. To supplement the experiments, computational fluid dynamics modeling of a simplified PCHE model is being performed and the results for three flow rate cases of 15, 40, and 90 kg/h and a system pressure of 3 MPa are discussed. In summary, this paper focuses on the study of the high-temperature materials, the design of the helium test facility, the design and fabrication of the PCHEs, and the computational modeling of a simplified PCHE model. (authors)

  8. Effect of fin-endwall fillet on thermal hydraulic performance of airfoil printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Ma, Ting; Xin, Fei; Li, Lei; Xu, Xiang-yang; Chen, Yi-tung; Wang, Qiu-wang

    2015-01-01

    Printed circuit heat exchanger (PCHE) is recommended to be used for intermediate heat exchanger in Very High Temperature Reactor (VHTR). One of the key features is that it is manufactured by the photochemical etching in order to maintain the internal structure and metal properties. In this paper, a photochemical etching experiment is conducted to manufacture the airfoil PCHE plate. The result indicates that the airfoil fin is not an ideal airfoil profile, but has a fin-endwall fillet. For the purpose of simplifying the numerical model and saving computational time, a validated model with a single fluid is used to further study the effect of fin-endwall fillet on the thermal hydraulic performance of airfoil PCHE. It is found that the fin-endwall fillet can increase the heat transfer and pressure drop in the cases with the non-dimensional longitudinal pitch being 1.63. The effect of fin-endwall fillet on thermal hydraulic performance decreases with the increase of transverse pitch, but the longitudinal pitch has little effect when the non-dimensional longitudinal pitch is greater than 1.88. In the studied cases, the maximum difference of Nusselt number and friction factor between the two models with and without fin-endwall fillet is up to 6.7% and 6.4%. - Highlights: • Fillets are formed in the endwall of airfoil fins during the photochemical etching. • Two-fluid model can be replaced by single-fluid model to perform simulation. • Fin-endwall fillet can increase heat transfer and pressure drop at ζ_l = 1.63. • Effect of fin-endwall fillet decreases as transverse pitch increases at ζ_l = 1.63. • Longitudinal pitch has little effect at ζ_l ≥ 1.88.

  9. Quality control process improvement of flexible printed circuit board by FMEA

    Science.gov (United States)

    Krasaephol, Siwaporn; Chutima, Parames

    2018-02-01

    This research focuses on the quality control process improvement of Flexible Printed Circuit Board (FPCB), centred around model 7-Flex, by using Failure Mode and Effect Analysis (FMEA) method to decrease proportion of defective finished goods that are found at the final inspection process. Due to a number of defective units that were found at the final inspection process, high scraps may be escaped to customers. The problem comes from poor quality control process which is not efficient enough to filter defective products from in-process because there is no In-Process Quality Control (IPQC) or sampling inspection in the process. Therefore, the quality control process has to be improved by setting inspection gates and IPCQs at critical processes in order to filter the defective products. The critical processes are analysed by the FMEA method. IPQC is used for detecting defective products and reducing chances of defective finished goods escaped to the customers. Reducing proportion of defective finished goods also decreases scrap cost because finished goods incur higher scrap cost than work in-process. Moreover, defective products that are found during process can reflect the abnormal processes; therefore, engineers and operators should timely solve the problems. Improved quality control was implemented for 7-Flex production lines from July 2017 to September 2017. The result shows decreasing of the average proportion of defective finished goods and the average of Customer Manufacturers Lot Reject Rate (%LRR of CMs) equal to 4.5% and 4.1% respectively. Furthermore, cost saving of this quality control process equals to 100K Baht.

  10. Recycling of non-metallic fractions from waste printed circuit boards: A review

    Energy Technology Data Exchange (ETDEWEB)

    Guo Jiuyong; Guo Jie [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Xu Zhenming, E-mail: zmxu@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2009-09-15

    The major economic driving force for recycling of waste printed circuit boards (PCBs) is the value of the metallic fractions (MFs) of PCBs. The non-metallic fractions (NMFs), which take up almost 70 wt% of waste PCBs, were treated by combustion or land filling in the past. However, combustion of the NMFs will cause the formation of highly toxic polybrominated dibenzodioxins and dibenzofurans (PBDD/Fs) while land filling of the NMFs will lead to secondary pollution caused by heavy metals and brominated flame retardants (BFRs) leaching to the groundwater. Therefore, recycling of the NMFs from waste PCBs is drawing more and more attention from the public and the governments. Currently, how to recycle the NMFs environmental soundly has become a significant topic in recycling of waste PCBs. In order to fulfill the better resource utilization of the NMFs, the compositions and characteristics of the NMFs, methods and outcomes of recycling the NMFs from waste PCBs and analysis and treatment for the hazardous substances contained in the NMFs were reviewed in this paper. Thermosetting resin matrix composites, thermoplastic matrix composites, concrete and viscoelastic materials are main applications for physical recycling of the NMFs. Chemical recycling methods consisting of pyrolysis, gasification, supercritical fluids depolymerization and hydrogenolytic degradation can be used to convert the NMFs to chemical feedstocks and fuels. The toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) can be used to determine the toxicity characteristic (TC) of the NMFs and to evaluate the environmental safety of products made from the recycled NMFs. It is believed that physical recycling of the NMFs has been a promising recycling method. Much more work should be done to develop comprehensive and industrialized usage of the NMFs recycled by physical methods. Chemical recycling methods have the advantages in eliminating hazardous substances

  11. Recycling of non-metallic fractions from waste printed circuit boards: A review

    International Nuclear Information System (INIS)

    Guo Jiuyong; Guo Jie; Xu Zhenming

    2009-01-01

    The major economic driving force for recycling of waste printed circuit boards (PCBs) is the value of the metallic fractions (MFs) of PCBs. The non-metallic fractions (NMFs), which take up almost 70 wt% of waste PCBs, were treated by combustion or land filling in the past. However, combustion of the NMFs will cause the formation of highly toxic polybrominated dibenzodioxins and dibenzofurans (PBDD/Fs) while land filling of the NMFs will lead to secondary pollution caused by heavy metals and brominated flame retardants (BFRs) leaching to the groundwater. Therefore, recycling of the NMFs from waste PCBs is drawing more and more attention from the public and the governments. Currently, how to recycle the NMFs environmental soundly has become a significant topic in recycling of waste PCBs. In order to fulfill the better resource utilization of the NMFs, the compositions and characteristics of the NMFs, methods and outcomes of recycling the NMFs from waste PCBs and analysis and treatment for the hazardous substances contained in the NMFs were reviewed in this paper. Thermosetting resin matrix composites, thermoplastic matrix composites, concrete and viscoelastic materials are main applications for physical recycling of the NMFs. Chemical recycling methods consisting of pyrolysis, gasification, supercritical fluids depolymerization and hydrogenolytic degradation can be used to convert the NMFs to chemical feedstocks and fuels. The toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) can be used to determine the toxicity characteristic (TC) of the NMFs and to evaluate the environmental safety of products made from the recycled NMFs. It is believed that physical recycling of the NMFs has been a promising recycling method. Much more work should be done to develop comprehensive and industrialized usage of the NMFs recycled by physical methods. Chemical recycling methods have the advantages in eliminating hazardous substances

  12. Recycling-oriented characterization of plastic frames and printed circuit boards from mobile phones by electronic and chemical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Palmieri, Roberta; Bonifazi, Giuseppe; Serranti, Silvia, E-mail: silvia.serranti@uniroma1.it

    2014-11-15

    Highlights: • A recycling oriented characterization of end-of-life mobile phones was carried out. • Characterization was developed in a zero-waste-perspective, aiming to recover all the mobile phone materials. • Plastic frames and printed circuit boards were analyzed by electronic and chemical imaging. • Suitable milling/classification strategies were set up to define specialized-pre-concentrated-streams. • The proposed approach can improve the recovery of polymers, base/precious metals, rare earths and critical raw materials. - Abstract: This study characterizes the composition of plastic frames and printed circuit boards from end-of-life mobile phones. This knowledge may help define an optimal processing strategy for using these items as potential raw materials. Correct handling of such a waste is essential for its further “sustainable” recovery, especially to maximize the extraction of base, rare and precious metals, minimizing the environmental impact of the entire process chain. A combination of electronic and chemical imaging techniques was thus examined, applied and critically evaluated in order to optimize the processing, through the identification and the topological assessment of the materials of interest and their quantitative distribution. To reach this goal, end-of-life mobile phone derived wastes have been systematically characterized adopting both “traditional” (e.g. scanning electronic microscopy combined with microanalysis and Raman spectroscopy) and innovative (e.g. hyperspectral imaging in short wave infrared field) techniques, with reference to frames and printed circuit boards. Results showed as the combination of both the approaches (i.e. traditional and classical) could dramatically improve recycling strategies set up, as well as final products recovery.

  13. Recycling-oriented characterization of plastic frames and printed circuit boards from mobile phones by electronic and chemical imaging

    International Nuclear Information System (INIS)

    Palmieri, Roberta; Bonifazi, Giuseppe; Serranti, Silvia

    2014-01-01

    Highlights: • A recycling oriented characterization of end-of-life mobile phones was carried out. • Characterization was developed in a zero-waste-perspective, aiming to recover all the mobile phone materials. • Plastic frames and printed circuit boards were analyzed by electronic and chemical imaging. • Suitable milling/classification strategies were set up to define specialized-pre-concentrated-streams. • The proposed approach can improve the recovery of polymers, base/precious metals, rare earths and critical raw materials. - Abstract: This study characterizes the composition of plastic frames and printed circuit boards from end-of-life mobile phones. This knowledge may help define an optimal processing strategy for using these items as potential raw materials. Correct handling of such a waste is essential for its further “sustainable” recovery, especially to maximize the extraction of base, rare and precious metals, minimizing the environmental impact of the entire process chain. A combination of electronic and chemical imaging techniques was thus examined, applied and critically evaluated in order to optimize the processing, through the identification and the topological assessment of the materials of interest and their quantitative distribution. To reach this goal, end-of-life mobile phone derived wastes have been systematically characterized adopting both “traditional” (e.g. scanning electronic microscopy combined with microanalysis and Raman spectroscopy) and innovative (e.g. hyperspectral imaging in short wave infrared field) techniques, with reference to frames and printed circuit boards. Results showed as the combination of both the approaches (i.e. traditional and classical) could dramatically improve recycling strategies set up, as well as final products recovery

  14. Computational algorithms for analysis of data from thin-film thermoresistors on a radio-electronic printed circuit board

    International Nuclear Information System (INIS)

    Korneeva, Anna; Shaydurov, Vladimir

    2016-01-01

    In the paper, the data analysis is considered for thin-film thermoresistors coated on to a radio-electronic printed circuit board to determine possible zones of its overheating. A mathematical model consists in an underdetermined system of linear algebraic equations with an infinite set of solutions. For computing a more real solution, two additional conditions are used: the smoothness of a solution and the positiveness of an increase of temperature during overheating. Computational experiments demonstrate that an overheating zone is determined exactly with a tolerable accuracy of temperature in it.

  15. Estimation of Relative Permittivity of Printed Circuit Board with Fiber Glass Epoxy as Dielectric for UHF Applications

    Directory of Open Access Journals (Sweden)

    Ronal D. Montoya-Montoya

    2013-11-01

    Full Text Available This paper presents the results of measuring relative permittivity of fiber glass printed circuit board (PCB’s, using a rectangular resonant cavity. The relative permittivity is presented as function of frequency. To obtain resonant frequencies, the return loss was measured using a network analyzer. Relative permittivity was calculated by finding frequencies of resonant cavity modes. The results are presented in a frequency span of 1 to 3.5GHz. It was clearly shown the nonlinear behavior of the relative permittivity for the dielectric laminate evaluated, even what happens respect to the frequency of the resonant modes below and above to frequency of 2 GHz.

  16. Integrating integrated circuit chips on paper substrates using inkjet printed electronics

    CSIR Research Space (South Africa)

    Bezuidenhout, Petrone H

    2016-11-01

    Full Text Available This paper investigates the integration of silicon and paper substrates using rapid prototyping inkjet printed electronics. Various Dimatix DMP-2831 material printer settings and adhesives are investigated. The aim is to robustly and effectively...

  17. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor.

    Science.gov (United States)

    Hadi, Pejman; Ning, Chao; Ouyang, Weiyi; Xu, Meng; Lin, Carol S K; McKay, Gordon

    2015-01-01

    Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Thermo-hydraulic Analysis of a Water-cooled Printed Circuit Heat Exchanger in a Small-scale Nitrogen Loop

    International Nuclear Information System (INIS)

    Kim, Chan Soo; Hong, Sung Deok; Kim, Min Hwan; Shim, Jaesool; Lee, Gyung Dong

    2013-01-01

    The development of high-temperature heat exchangers is very important because of its higher operation temperature and pressure than those of common light water reactors and industrial process plants. In particular, the intermediate heat exchanger is a key-challenged high temperature component in a Very High Temperature gas-cooled Reactor (VHTR). A printed circuit heat exchanger is one of the candidates for an intermediate heat exchanger in a VHTR. The printed circuit heat exchanger (PCHE) was developed and commercialized by HEATRIC. The compactness is better than any other heat exchanger types, because its core matrices are fabricated by diffusion bonding with photo-chemically etched micro-channels. Various tests and analysis have been performed to verify the performance of PCHE. The thermal stress analysis of the high temperature PCHE is necessary to endure the extremely operation condition of IHX. In this study, the thermo-hydraulic analysis for the laboratory-scale PCHE is performed to provide the input data for the boundary conditions of a structural analysis. The results from the first-principal calculation are compared with those from computational fluid dynamics code analysis. COMSOL 4.3a analysis is successfully performed at the uniform pressure drop condition in a set of flow channel stacks. The heat-exchanged region concentrated to the nitrogen inlet cause the uniform mass velocity distribution in the channels, therefore there is little difference between two analytical results

  19. Fabrication of a capacitive relative humidity sensor using aluminum thin films deposited on etched printed circuit board

    Directory of Open Access Journals (Sweden)

    Lee Jacqueline Ann L.

    2016-01-01

    Full Text Available A capacitive humidity-sensing device was created by thermal evaporation of 99.999% aluminum. The substrate used for the coating was etched double-sided printed circuit board. The etched printed circuit board serves as the dielectric of the capacitor while the aluminum thin films deposited on either side serve as the plates of the capacitor. The capacitance was measured before and after exposure to humidity. The device was then calibrated by comparing the readings of capacitance with that of the relative humidity sensor of the Vernier LabQuest2. It was found that there is a linear relationship between the capacitance and relative humidity given by the equation C=1.418RH+29.139 where C is the capacitance and RH is the relative humidity. The surface of the aluminum films is porous and it is through these pores that water is adsorbed and capillary condensation occurs, thereby causing the capacitance to change upon exposure to humidity.

  20. Removing lead from metallic mixture of waste printed circuit boards by vacuum distillation: factorial design and removal mechanism.

    Science.gov (United States)

    Li, Xingang; Gao, Yujie; Ding, Hui

    2013-10-01

    The lead removal from the metallic mixture of waste printed circuit boards by vacuum distillation was optimized using experimental design, and a mathematical model was established to elucidate the removal mechanism. The variables studied in lead evaporation consisted of the chamber pressure, heating temperature, heating time, particle size and initial mass. The low-level chamber pressure was fixed at 0.1 Pa as the operation pressure. The application of two-level factorial design generated a first-order polynomial that agreed well with the data for evaporation efficiency of lead. The heating temperature and heating time exhibited significant effects on the efficiency, which was validated by means of the copper-lead mixture experiments. The optimized operating conditions within the region studied were the chamber pressure of 0.1 Pa, heating temperature of 1023 K and heating time of 120 min. After the conditions were employed to remove lead from the metallic mixture of waste printed circuit boards, the efficiency was 99.97%. The mechanism of the effects was elucidated by mathematical modeling that deals with evaporation, mass transfer and condensation, and can be applied to a wider range of metal removal by vacuum distillation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Graphene-based inkjet printing of flexible bioelectronic circuits and sensors

    Science.gov (United States)

    Sinar, Dogan; Knopf, George K.; Nikumb, Suwas

    2013-03-01

    Bioelectronics involves interfacing functional biomolecules or living cells with electronic circuitry. Recent advances in electrically conductive inks and inkjet printing technologies have enabled bioelectronic devices to be fabricated on mechanically flexible polymers, paper and silk. In this research, non-conductive graphene-oxide (GO) inks are synthesized from inexpensive graphite powders. Once printed on the flexible substrate the electrical conductivity of the micro-circuitry can be restored through thermal reduction. Laser irradiation is one method being investigated for transforming the high resistance printed GO film into conductive oxygen reduced graphene-oxide (rGO). Direct laser writing is a precision fabrication process that enables the imprinting of conductive and resistive micro-features on the GO film. The mechanically flexible rGO microcircuits can be further biofunctionalized using molecular self-assembly techniques. Opportunities and challenges in exploiting these emerging technologies for developing biosensors and bioelectronic cicruits are briefly discussed.

  2. Checking a printed board

    CERN Multimedia

    1977-01-01

    An 'Interactive Printed Circuit Board Design System' has been developed by a company in a Member-State. Printed circuits are now produced at the SB's surface treatment workshop using a digitized photo-plotter.

  3. 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%.

  4. 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...

  5. Influence of nonmetals recycled from waste printed circuit boards on flexural properties and fracture behavior of polypropylene composites

    International Nuclear Information System (INIS)

    Zheng Yanhong; Shen Zhigang; Cai Chujiang; Ma Shulin; Xing Yushan

    2009-01-01

    Flexural strength and flexural modulus of the composites can be successfully improved by filling nonmetals recycled from waste printed circuit boards (PCBs) into polypropylene (PP). By using scanning electron microscopy (SEM), the influence of nonmetals on fracture behavior of PP composites is investigated by in situ flexural test. Observation results show that the particles can effectively lead to mass micro cracks instead of the breaking crack. The process of the crack initiation, propagation and fiber breakage dissipate a great amount of energy. As a result, the flexural properties of the composites can be reinforced significantly. Results of the in situ SEM observation and analysis to the dynamic flexural process supply effective test evidence for the reinforcing mechanism of the nonmetals/PP composites on the basis of the energy dissipation theory

  6. Integrated bioleaching of copper metal from waste printed circuit board-a comprehensive review of approaches and challenges.

    Science.gov (United States)

    Awasthi, Abhishek Kumar; Zeng, Xianlai; Li, Jinhui

    2016-11-01

    Waste electrical and electronic equipment (e-waste) is the most rapidly growing waste stream in the world, and the majority of the residues are openly disposed of in developing countries. Waste printed circuit boards (WPCBs) make up the major portion of e-waste, and their informal recycling can cause environmental pollution and health risks. Furthermore, the conventional disposal and recycling techniques-mechanical treatments used to recover valuable metals, including copper-are not sustainable in the long term. Chemical leaching is rapid and efficient but causes secondary pollution. Bioleaching is a promising approach, eco-friendly and economically feasible, but it is slower process. This review considers the recycling potential of microbes and suggests an integrated bioleaching approach for Cu extraction and recovery from WPCBs. The proposed recycling system should be more effective, efficient and both technically and economically feasible.

  7. Performance of the electrical generator cell by the ferrous alloys of printed circuit board scrap and Iron Metal 1020

    Science.gov (United States)

    Sahan, Y.; Sudarsono, S.; Silviana, E.; Chairul; Wisrayetti

    2018-04-01

    Galvani cell is one of thealternative energy. This cell can be used as an electric resources. In this research, the generator cell was designed and builds to generate the electric. The generator cell consisted of the iron metal 1020 were used as anode, the ferrous alloys of printed circuit board scrapwas then used as chatode, and NaCl solution as an electrolyte. The aim of this research is to estimate the performance of this generator cell by using variation of NaCl concentration (i.e. 1%, 3%, 5%, 7%, and 9%) with the electrodes pair ( 1 and 8 pairs). The performance of the cell was measured with a multi tester equipment and a LED bulb (5-watt 3Volt). The Results shown that the generator cell can produce the electric power of 3.679 Volt maximally by using NaCl 9% and 8 electrode pairs applied for this condition.

  8. Tailored benzoxazines as novel resin systems for printed circuit boards in high temperature e-mobility applications

    International Nuclear Information System (INIS)

    Troeger, K.; Darka, R. Khanpour; Neumeyer, T.; Altstaedt, V.

    2014-01-01

    This study focuses on the development of Bisphenol-F-benzoxazine resins blended with different ratios of a trifunctional epoxy resin suitable as matrix for substrates for high temperature printed circuit board (HT-PCB) applications. With the benzoxazine blends glass transition temperatures of more than 190 °C could be achieved in combination with a coefficient of thermal expansion in thickness direction (z-CTE) of less than 60 ppm/K without adding any fillers. This shows the high potential of the benzoxazine-epoxy blend systems as substrate materials for HT-PCBs. To understand the thermal behavior of the different formulations, the apparent crosslink density was calculated based on data from Dynamic Mechanical Analysis. Laminates in laboratory scale were prepared and characterized to demonstrate the transformation of the neat resin properties into real electronic substrate properties. The produced laminates exhibit a z-CTE below 40 ppm/K

  9. Influence of incorporation of powder of printed circuit boards on technological properties and microstructure of triaxial ceramics

    International Nuclear Information System (INIS)

    Stafford, F.N.; Hotza, D.

    2012-01-01

    Using the methodology of experiments with mixtures, seven formulations of clay, phyllite, and printed circuit boards (PCB) were obtained to study the influence of this waste on triaxial ceramic tiles. Each formulation was processed under conditions similar to those used in the ceramic tiles industry, and characterized for fired modulus of rupture (FMoR) and water absorption (WA). The samples sintered at 1180°C were also subjected to analysis by XRD and SEM. The lowest resistance was observed in samples with 40% residue, while the highest strength occurred for samples with 14% residue, which reached average values of mechanical strength and water absorption of 35.0 MPa and 2.0%, respectively. The microstructure showed that it is possible to use waste of PCB in triaxial ceramic, which exhibits a fluxing behavior and it has an important effect on the sinterability and the development of appropriate microstructures. (author)

  10. Tailored benzoxazines as novel resin systems for printed circuit boards in high temperature e-mobility applications

    Energy Technology Data Exchange (ETDEWEB)

    Troeger, K., E-mail: altstaedt@uni-bayreuth.de; Darka, R. Khanpour, E-mail: altstaedt@uni-bayreuth.de; Neumeyer, T., E-mail: altstaedt@uni-bayreuth.de; Altstaedt, V., E-mail: altstaedt@uni-bayreuth.de [Polymer Engineering, University of Bayreuth, Germany and Polymer Engineering, Universitaetsstrasse 30, 95447 Bayreuth (Germany)

    2014-05-15

    This study focuses on the development of Bisphenol-F-benzoxazine resins blended with different ratios of a trifunctional epoxy resin suitable as matrix for substrates for high temperature printed circuit board (HT-PCB) applications. With the benzoxazine blends glass transition temperatures of more than 190 °C could be achieved in combination with a coefficient of thermal expansion in thickness direction (z-CTE) of less than 60 ppm/K without adding any fillers. This shows the high potential of the benzoxazine-epoxy blend systems as substrate materials for HT-PCBs. To understand the thermal behavior of the different formulations, the apparent crosslink density was calculated based on data from Dynamic Mechanical Analysis. Laminates in laboratory scale were prepared and characterized to demonstrate the transformation of the neat resin properties into real electronic substrate properties. The produced laminates exhibit a z-CTE below 40 ppm/K.

  11. 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

  12. Embedding electromagnetic band gap structures in printed circuit boards for electromagnetic interference reduction

    NARCIS (Netherlands)

    Tereshchenko, O.V.

    2015-01-01

    Due to the tendency of faster data rates and lower power supply voltage in the integrated circuit (IC) design, Simultaneously Switching Noise (SSN) and ground bounce become serious concerns for designers and testers. This noise can be a source of electromagnetic interference (EMI). It propagates

  13. Development of high-resolution two-dimensional magnetic field measurement system by use of printed-circuit technology

    Science.gov (United States)

    Akimitsu, Moe; Qinghong, Cao; Sawada, Asuka; Hatano, Hironori; Tanabe, Hiroshi; Ono, Yasushi; TS-Group Team

    2017-10-01

    We have developed a new-types of high-resolution magnetic probe array for our new magnetic reconnection experiments: TS-3U (ST, FRC: R =0.2m, 2017-) and TS-4U (ST, FRC: R =0.5m, 2018-), using the advanced printed-circuit technology. They are equipped with all three-components of magnetic pick-up coils whose size is 1-5mm x 3mm. Each coil is composed of two-sided coil pattern with line width of 0.05mm. We can install two or three printed arrays in a single glass (ceramic) tube for two or three component measurements. Based on this new probe technique, we started high-resolution and high-accuracy measurement of the current sheet thickness and studied its plasma parameter dependence. We found that the thickness of current sheet increases inversely with the guide toroidal field. It is probably determined by the ion gyroradius in agreement with the particle simulation by Horiuchi etc. While the reconnection speed is steady under low guide field condition, it is observed to oscillate in the specific range of guide field, suggesting transition from the quasi-steady reconnection to the intermittent reconnection. Cause and mechanism for intermittent reconnection will be discussed using the current sheet dissipation and dynamic balance between plasma inflow and outflow. This work supported by JSPS KAKENHI Grant Numbers 15H05750, 15K14279 and 17H04863.

  14. Flexible integrated diode-transistor logic (DTL) driving circuits based on printed carbon nanotube thin film transistors with low operation voltage.

    Science.gov (United States)

    Liu, Tingting; Zhao, Jianwen; Xu, Weiwei; Dou, Junyan; Zhao, Xinluo; Deng, Wei; Wei, Changting; Xu, Wenya; Guo, Wenrui; Su, Wenming; Jie, Jiansheng; Cui, Zheng

    2018-01-03

    Fabrication and application of hybrid functional circuits have become a hot research topic in the field of printed electronics. In this study, a novel flexible diode-transistor logic (DTL) driving circuit is proposed, which was fabricated based on a light emitting diode (LED) integrated with printed high-performance single-walled carbon nanotube (SWCNT) thin-film transistors (TFTs). The LED, which is made of AlGaInP on GaAs, is commercial off-the-shelf, which could generate free electrical charges upon white light illumination. Printed top-gate TFTs were made on a PET substrate by inkjet printing high purity semiconducting SWCNTs (sc-SWCNTs) ink as the semiconductor channel materials, together with printed silver ink as the top-gate electrode and printed poly(pyromellitic dianhydride-co-4,4'-oxydianiline) (PMDA/ODA) as gate dielectric layer. The LED, which is connected to the gate electrode of the TFT, generated electrical charge when illuminated, resulting in biased gate voltage to control the TFT from "ON" status to "OFF" status. The TFTs with a PMDA/ODA gate dielectric exhibited low operating voltages of ±1 V, a small subthreshold swing of 62-105 mV dec -1 and ON/OFF ratio of 10 6 , which enabled DTL driving circuits to have high ON currents, high dark-to-bright current ratios (up to 10 5 ) and good stability under repeated white light illumination. As an application, the flexible DTL driving circuit was connected to external quantum dot LEDs (QLEDs), demonstrating its ability to drive and to control the QLED.

  15. Superconducting Multilayer High-Density Flexible Printed Circuit Board for Very High Thermal Resistance Interconnections

    Science.gov (United States)

    de la Broïse, Xavier; Le Coguie, Alain; Sauvageot, Jean-Luc; Pigot, Claude; Coppolani, Xavier; Moreau, Vincent; d'Hollosy, Samuel; Knarosovski, Timur; Engel, Andreas

    2018-05-01

    We have successively developed two superconducting flexible PCBs for cryogenic applications. The first one is monolayer, includes 552 tracks (10 µm wide, 20 µm spacing), and receives 24 wire-bonded integrated circuits. The second one is multilayer, with one track layer between two shielding layers interconnected by microvias, includes 37 tracks, and can be interconnected at both ends by wire bonding or by connectors. The first cold measurements have been performed and show good performances. The novelty of these products is, for the first one, the association of superconducting materials with very narrow pitch and bonded integrated circuits and, for the second one, the introduction of a superconducting multilayer structure interconnected by vias which is, to our knowledge, a world-first.

  16. Adhesion and failure analysis of metal-polymer interface in flexible printed circuits boards

    Science.gov (United States)

    Park, Sanghee; Kim, Ye Chan; Choi, Kisuk; Chae, Heeyop; Suhr, Jonghwan; Nam, Jae-Do

    2017-12-01

    As device miniaturization in microelectronics is currently requested in the development of high performance device, which usually include highly-integrated metal-polyimide multilayer structures. A redistribution layer (RDL) process is currently emerging as one of the most advance fabrication techniques for on-chip interconnect and packaging. One of the major issues in this process is the poor adhesion of the metal-polyimide interfaces particularly in flexible circuit boards due to the flexibility and bendability of devices. In this study, low pressure O2 plasma treatment was investigated to improve the adhesion of metal-polyimide interfaces, using inductively coupled plasma (ICP) treatment. We identified that the adhesion of metal-polyimide interfaces was greatly improved by the surface roughness control providing 46.1 MPa of shear force in the ball shear test after O2 plasma treatment, compared 14.2 MPa without O2 plasma treatment. It was seemingly due to the fact that the adhesion in metal-polyimide interfaces was improved by a chemical conversion of C=O to C-O bonds and by a ring opening reaction of imide groups, which was confirmed with FT-IR analysis. In the finite element numerical analysis of metal-polyimide interfaces, the O2 plasma treated interface showed that the in-plane stress distribution and the vertical directional deformation agreed well with real failure modes in flexible circuits manufacturing.

  17. Laser printed glass planar lightwave circuits with integrated fiber alignment structures

    Science.gov (United States)

    Desmet, A.; Radosavljevic, A.; Missinne, J.; Van Thourhout, D.; Van Steenberge, G.

    2018-02-01

    Femtosecond laser inscription allows straightforward manufacturing of glass planar lightwave circuits such as waveguides, interferometers, directional couplers, resonators and more complex structures. Fiber alignment structures are needed to facilitate communication with the glass planar lightwave circuit. In this study, a technique is described to create optical waveguides and alignment structures in the same laser exposure step. Using an industrial ytterbium-doped 1030 nm fiber laser pulses of 400 fs were focused into glass with a 0.4 NA objective causing permanent alteration of the material. Depending on laser parameters this modification allows direct writing of waveguides or the creation of channels after exposing the irradiated volumes to an etchant such as KOH. Writing of channels and waveguides with different laser powers, frequencies, polarisations, stage translation speeds and scan densities were investigated in fused silica and borosilicate glass. Waveguides with controlled dimensions were created, as well as etched U-grooves with a diameter of 126 μm and a sidewall roughness Ra of 255 nm. Cut back measurements were performed giving a waveguide propagation loss of 1.1 dB/cm in borosilicate glass. A coupling loss of 0.7 dB was measured for a transition between the waveguide and standard single mode fiber at 1550 nm, using index matching liquid. The described technique eliminates active alignment requirements and is useful for many applications such as microfluidic sensing, PLCs, fan-out connectors for multicore fibers and quantum optical networks.

  18. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  20. 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...

  1. 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)

  2. 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.

  3. Occurrences and inventories of heavy metals and brominated flame retardants in wastes from printed circuit board production.

    Science.gov (United States)

    Zhou, Xiaoyu; Guo, Jie; Zhang, Wei; Zhou, Peng; Deng, Jingjing; Lin, Kuangfei

    2014-09-01

    Pollutants including heavy metals and brominated flame retardant were detected in 10 types of production wastes from a typical printed circuit board manufacturing plant, and their inventories were estimated. Rinsing water from etching process had the highest concentrations of copper (665.51 mg/L), lead (1.02 mg/L), nickel (3.60 mg/L), chromium (0.97 mg/L), and tin (1.79 mg/L). Powdered solid waste (SW) from the cut lamination process contained the highest tetrabromobisphenol-A (TBBPA) levels (49.86 mg/kg). Polybrominated diphenyl ethers (PBDEs) were absent in this plant, in agreement with the international regulations of PBDE phase out. The pollutant inventories in the wastes exhibited in the order of copper > > zinc > tin ≈ nickel > lead > chromium > > TBBPA. The potential environmental impact of pollutants in SW during production and disposal were further investigated. A high partitioning of pollutant concentration between the total suspended particle and SW (-0.10 < log K TS < 2.12) was observed for most pollutants, indicating the emission pathway from SW to the airborne atmosphere in the workshop. Although SW met the toxicity characteristic leaching procedure, drilling powder with the smallest particle diameter still showed high leachabilities of lead and tin which may lead to a negative environmental impact during disposal.

  4. Electrical Differentiation of Mesenchymal Stem Cells into Schwann-Cell-Like Phenotypes Using Inkjet-Printed Graphene Circuits.

    Science.gov (United States)

    Das, Suprem R; Uz, Metin; Ding, Shaowei; Lentner, Matthew T; Hondred, John A; Cargill, Allison A; Sakaguchi, Donald S; Mallapragada, Surya; Claussen, Jonathan C

    2017-04-01

    Graphene-based materials (GBMs) have displayed tremendous promise for use as neurointerfacial substrates as they enable favorable adhesion, growth, proliferation, spreading, and migration of immobilized cells. This study reports the first case of the differentiation of mesenchymal stem cells (MSCs) into Schwann cell (SC)-like phenotypes through the application of electrical stimuli from a graphene-based electrode. Electrical differentiation of MSCs into SC-like phenotypes is carried out on a flexible, inkjet-printed graphene interdigitated electrode (IDE) circuit that is made highly conductive (sheet resistance electrically stimulated/treated (etMSCs) display significant enhanced cellular differentiation and paracrine activity above conventional chemical treatment strategies [≈85% of the etMSCs differentiated into SC-like phenotypes with ≈80 ng mL -1 of nerve growth factor (NGF) secretion vs. 75% and ≈55 ng mL -1 for chemically treated MSCs (ctMSCs)]. These results help pave the way for in vivo peripheral nerve regeneration where the flexible graphene electrodes could conform to the injury site and provide intimate electrical simulation for nerve cell regrowth. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Novel Application of Glass Fibers Recovered From Waste Printed Circuit Boards as Sound and Thermal Insulation Material

    Science.gov (United States)

    Sun, Zhixing; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

    2013-10-01

    The aim of this study is to investigate the feasibility of using glass fibers, a recycled material from waste printed circuit boards (WPCB), as sound absorption and thermal insulation material. Glass fibers were obtained through a fluidized-bed recycling process. Acoustic properties of the recovered glass fibers (RGF) were measured and compared with some commercial sound absorbing materials, such as expanded perlite (EP), expanded vermiculite (EV), and commercial glass fiber. Results show that RGF have good sound absorption ability over the whole tested frequency range (100-6400 Hz). The average sound absorption coefficient of RGF is 0.86, which is prior to those of EP (0.81) and EV (0.73). Noise reduction coefficient analysis indicates that the absorption ability of RGF can meet the requirement of II rating for sound absorbing material according to national standard. The thermal insulation results show that RGF has a fair low thermal conductivity (0.046 W/m K), which is comparable to those of some insulation materials (i.e., EV, EP, and rock wool). Besides, an empirical dependence of thermal conductivity on material temperature was determined for RGF. All the results showed that the reuse of RGF for sound and thermal insulation material provided a promising way for recycling WPCB and obtaining high beneficial products.

  6. Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    2010-01-01

    The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

  7. Real-time monitoring system for improving corona electrostatic separation in the process of recovering waste printed circuit boards.

    Science.gov (United States)

    Li, Jia; Zhou, Quan; Xu, Zhenming

    2014-12-01

    Although corona electrostatic separation is successfully used in recycling waste printed circuit boards in industrial applications, there are problems that cannot be resolved completely, such as nonmetal particle aggregation and spark discharge. Both of these problems damage the process of separation and are not easy to identify during the process of separation in industrial applications. This paper provides a systematic study on a real-time monitoring system. Weight monitoring systems were established to continuously monitor the separation process. A Virtual Instrumentation program written by LabVIEW was utilized to sample and analyse the mass increment of the middling product. It includes four modules: historical data storage, steady-state analysis, data computing and alarm. Three kinds of operating conditions were used to verify the applicability of the monitoring system. It was found that the system achieved the goal of monitoring during the separation process and realized the function of real-time analysis of the received data. The system also gave comprehensible feedback on the accidents of material blockages in the feed inlet and high-voltage spark discharge. With the warning function of the alarm system, the whole monitoring system could save the human cost and help the new technology to be more easily applied in industry. © The Author(s) 2014.

  8. Removal of organic compounds from wastewater originating from the production of printed circuit boards by UV-Fenton method

    Directory of Open Access Journals (Sweden)

    Thomas Maciej

    2017-12-01

    Full Text Available The possibility of removing organic compounds from wastewater originating from the photochemical production of printed circuit boards by use of waste acidification and disposal of precipitated photopolymer in the first stage and the UV-Fenton method in a second stage has been presented. To optimize the process of advanced oxidation, the RSM (Response Surface Methodology for three independent factors was applied, i.e. pH, the concentration of Fe(II and H2O2 concentration. The use of optimized values of individual parameters in the process of wastewater treatment caused a decrease in the concentration of the organic compounds denoted as COD by approx. 87% in the first stage and approx. 98% after application of both processes. Precipitation and the decomposition of organic compounds was associated with a decrease of wastewater COD to below 100 mg O2/L whereas the initial value was 5550 mg O2/L. Decomposition of organic compounds and verification of the developed model of photopolymers removal was also carried out with use of alternative H2O2 sources i.e. CaO2, MgO2, and Na2CO3·1,5H2O2.

  9. Feature-Learning-Based Printed Circuit Board Inspection via Speeded-Up Robust Features and Random Forest

    Directory of Open Access Journals (Sweden)

    Eun Hye Yuk

    2018-06-01

    Full Text Available With the coming of the 4th industrial revolution era, manufacturers produce high-tech products. As the production process is refined, inspection technologies become more important. Specifically, the inspection of a printed circuit board (PCB, which is an indispensable part of electronic products, is an essential step to improve the quality of the process and yield. Image processing techniques are utilized for inspection, but there are limitations because the backgrounds of images are different and the kinds of defects increase. In order to overcome these limitations, methods based on machine learning have been used recently. These methods can inspect without a normal image by learning fault patterns. Therefore, this paper proposes a method can detect various types of defects using machine learning. The proposed method first extracts features through speeded-up robust features (SURF, then learns the fault pattern and calculates probabilities. After that, we generate a weighted kernel density estimation (WKDE map weighted by the probabilities to consider the density of the features. Because the probability of the WKDE map can detect an area where the defects are concentrated, it improves the performance of the inspection. To verify the proposed method, we apply the method to PCB images and confirm the performance of the method.

  10. Recovery of copper and lead from waste printed circuit boards by supercritical water oxidation combined with electrokinetic process

    International Nuclear Information System (INIS)

    Xiu Furong; Zhang Fushen

    2009-01-01

    An effective and benign process for copper and lead recovery from waste printed circuit boards (PCBs) was developed. In the process, the PCBs was pre-treated in supercritical water, then subjected to electrokinetic (EK) process. Experimental results showed that supercritical water oxidation (SCWO) process was strong enough to decompose the organic compounds of PCBs, and XRD spectra indicated that copper and lead were oxidized into CuO, Cu 2 O and β-PbO 2 in the process. The optimum SCWO treatment conditions were 60 min, 713 K, 30 MPa, and EK treatment time, constant current density were 11 h, 20 mA cm -2 , respectively. The recovery percentages of copper and lead under optimum SCWO + EK treatment conditions were around 84.2% and 89.4%, respectively. In the optimized EK treatment, 74% of Cu was recovered as a deposit on the cathode with a purity of 97.6%, while Pb was recovered as concentrated solutions in either anode (23.1%) or cathode (66.3%) compartments but little was deposited on the electrodes. It is believed that the process is effective and practical for Cu and Pb recovery from waste electric and electronic equipments.

  11. Structural assessment of intermediate printed circuit heat exchanger for sodium-cooled fast reactor with supercritical CO2 cycle

    International Nuclear Information System (INIS)

    Lee, Youho; Lee, Jeong Ik

    2014-01-01

    Highlights: • We numerically model PCHE stress arising from pressure, and thermal loadings. • Stress levels are the highest around S-CO 2 channels, due to high pressure of S-CO 2 . • The conventional analytic models for PCHE underestimate actual stress levels. • Plasticity sufficiently lowers stress levels at channel tips. • PCHE for SFR-SCO 2 is anticipated to assure compliance with ASME design standards. - Abstract: Structural integrity of intermediate Printed Circuit Heat Exchanger (PCHE) for Sodium-cooled Fast Reactor (SFR) attached to Supercritical CO 2 (S-CO 2 ) is investigated. ANSYS-Mechanical was used to simulate stress fields of representative PCHE channels, with temperature fields imported from FLUENT simulation. Mechanical stress induced by pressure loading is found to be the primary source of stress. As plasticity sufficiently lowers local stress concentration at PCHE channel tips, PCHE type intermediate heat exchangers made of SS316 are anticipated to reliably assure compliance with design standards prescribed in the ASME standards, thanks to the structure temperature that is below the effective creep inducing point. The actual life time of PCHE for SFR-SCO 2 is likely to be affected by mechanical behavior change of SS316 with reactions with S-CO 2 and fatigue

  12. Preparation of hierarchical porous carbon from waste printed circuit boards for high performance electric double-layer capacitors

    Science.gov (United States)

    Du, Xuan; Wang, Li; Zhao, Wei; Wang, Yi; Qi, Tao; Li, Chang Ming

    2016-08-01

    Renewable clean energy and resources recycling have become inevitable choices to solve worldwide energy shortages and environmental pollution problems. It is a great challenge to recycle tons of waste printed circuit boards (PCB) produced every year for clean environment while creating values. In this work, low cost, high quality activated carbons (ACs) were synthesized from non-metallic fractions (NMF) of waste PCB to offer a great potential for applications of electrochemical double-layer capacitors (EDLCs). After recovering metal from waste PCB, hierarchical porous carbons were produced from NMF by carbonization and activation processes. The experimental results exhibit that some pores were formed after carbonization due to the escape of impurity atoms introduced by additives in NMF. Then the pore structure was further tailored by adjusting the activation parameters. Roles of micropores and non-micropores in charge storage were investigated when the hierarchical porous carbons were applied as electrode of EDLCs. The highest specific capacitance of 210 F g-1 (at 50 mA g-1) and excellent rate capability were achieved when the ACs possessing a proper micropores/non-micropores ratio. This work not only provides a promising method to recycle PCB, but also investigates the structure tailoring arts for a rational hierarchical porous structure in energy storage/conversion.

  13. Morphology, mechanical and thermal oxidative aging properties of HDPE composites reinforced by nonmetals recycled from waste printed circuit boards.

    Science.gov (United States)

    Yang, Shuangqiao; Bai, Shibing; Wang, Qi

    2016-11-01

    In this study nonmetals recycled from waste printed circuit boards (NPCB) is used as reinforce fillers in high-density polyethylene (HDPE) composites. The morphology, mechanical and thermal oxidative aging properties of NPCB reinforced HDPE composites are assessed and it compared with two other commercial functional filler for the first time. Mechanical test results showed that NPCB could be used as reinforcing fillers in the HDPE composites and mechanical properties especially for stiffness is better than other two commercial fillers. The improved mechanical property was confirmed by the higher aspect ratio and strong interfacial adhesion in scanning electron microscopy (SEM) studies. The heat deflection temperature (HDT) test showed the presence of fiberglass in NPCB can improve the heat resistance of composite for their potential applications. Meanwhile, the oxidation induction time (OIT) and the Fourier transform infrared (FTIR) spectroscopy results showed that NPCB has a near resistance to oxidation as two other commercial fillers used in this paper. The above results show the reuse of NPCB in the HDPE composites represents a promising way for resolving both the environmental pollution and the high-value reuse of resources. Copyright © 2015. Published by Elsevier Ltd.

  14. Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board under wet H2S environment

    International Nuclear Information System (INIS)

    Zou, Shiwen; Li, Xiaogang; Dong, Chaofang; Ding, Kangkang; Xiao, Kui

    2013-01-01

    Highlights: •The electrochemical migration, whisker formation, and corrosion behavior of PCB under wet H 2 S environment were observed and studied systematically. •The process of electrochemical migration of solder joints is explained. •The corrosion mechanism of PCB interconnectors induced by micro pores under wet H 2 S environment is discussed, and the corrosion reaction model is proposed. -- Abstract: Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board (PCB) under wet H 2 S environment were analyzed by environment scanning electron microscope (ESEM), Energy dispersive X-ray spectroscopy (EDS) with mapping and element phase cluster (EPC) techniques, Raman Spectrum analysis and electrochemical impedance spectroscopy (EIS) technology. The results showed that nonuniform corrosion behavior occurred on PCB surfaces under 1 ppm wet H 2 S at 40 °C; whiskers formed on the inner sidewall of via-holes with a growth rate of 1.2 Å/s; numerous corrosion products migrated through the pore of plated gold layer, which broke off the protective layer. The corrosion rate was accelerated according to the big-cathode-small-anode model

  15. Experimental and CFD Analysis of Printed Circuit Heat Exchanger for Supercritical CO{sub 2} Power Cycle Application

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Seungjoon; Kim, Hyeon Tae; Kim, Seong Gu; Lee, Jekyoung; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    The supercritical carbon dioxide (S-CO{sub 2}) power cycle has been suggested as an alternative for the SFR power generation system. First of all, relatively mild sodium-CO{sub 2} interaction can reduce the accident probability. Also the S-CO{sub 2} power conversion cycle can achieve high efficiency with SFR core thermal condition. Moreover, the S-CO{sub 2} power cycle can reduce cycle footprint due to high density of the working fluid. Recently, various compact heat exchangers have been studied for developing an optimal heat exchanger. In this paper, the printed circuit heat exchanger was selected for S-CO{sub 2} power cycle applications and was closely investigated experimentally and analytically. Recently, design and performance prediction of PCHE received attention due to its importance in high pressure power systems such as S-CO{sub 2} cycle. To evaluate a PCHE performance with CO{sub 2} to water, KAIST research team designed and tested a lab-scale PCHE. From the experimental data and CFD analysis, pressure drop and heat transfer correlations are obtained. For the CFD analysis, Ansys-CFX commercial code was utilized with RGP table implementation. In near future, the turbulence model sensitivity study will be followed.

  16. Potentials for Improvement of Resource Efficiency in Printed Circuit Board Manufacturing: A Case Study Based on Material Flow Cost Accounting

    Directory of Open Access Journals (Sweden)

    Yi-Xuan Wang

    2017-05-01

    Full Text Available The pursuit of sustainable resource use by manufacturing companies is driven by resource scarcity, environmental awareness, and cost savings potentials. To address these issues, Material Flow Cost Accounting (MFCA has been developed and applied as an effective environmental management tool. Within MFCA’s general allocation, the accounts of products and losses are overrated by weight or volume. However, such a method is incompatible with Printed Circuit Board (PCB manufacturing because of industry characteristics in which primary inputs and products are measured by area. Based on MFCA, this case study systematically established several linear cost calculation models along the production process for capturing the actual waste flows as well as performing cost-benefit analysis. The recognition of previously ignored losses offered the incentive to find appropriate indicators to conduct cost-benefit analysis on hotspots for losses. Loss identification and analysis indicated that machining and wiring are the necessities and priorities of process optimization for resource efficiency improvement measures. Therefore, this research could not only advance the achievement of a profitable and sustainable production while improving resource efficiency at the source but could also provide support for decision making in PCB manufacturing.

  17. Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2008-10-15

    The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

  18. Comprehensive characterization of printed circuit boards of various end-of-life electrical and electronic equipment for beneficiation investigation.

    Science.gov (United States)

    Anshu Priya; Hait, Subrata

    2018-05-01

    Comprehensive characterization of printed circuit board (PCB) of end-of-life electrical and electronic equipment (EEE) is obligatory for prospective profitable beneficiation. In this study, beneficiation oriented comprehensive characterization of two brands of PCBs each of 16 end-of-life EEE was conducted in terms of their physicochemical characteristics with special emphasis on the content of 16 general elements, 2 precious metals and 15 rare earth elements (REEs). General elements and their highest weight percent composition found in different PCBs of the EEEs were Cu (23% in laptop), Al (6% in computer), Pb (15% in DVD player) and Ba (7% in TV). The high abundant of precious metals such as Au (316 g/ton) and Ag (636 g/ton) in mobile phone and laptop, respectively coupled with rapid obsolescence age makes waste PCBs of information technology and telecommunication equipment the most potent resource reservoir. Additionally, most of the waste PCBs were observed to contain REEs in considerable quantity with Sc up to 31 g/ton and Ce up to 13 g/ton being the major constituents. Comprehensive characterization of waste PCBs therefore will systematically help towards better understanding of e-waste recycling processes for beneficiation purpose and sustainable resource circulation and conservation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Numerical Investigation on the Flow and Heat Transfer Characteristics of Supercritical Liquefied Natural Gas in an Airfoil Fin Printed Circuit Heat Exchanger

    OpenAIRE

    Zhongchao Zhao; Kai Zhao; Dandan Jia; Pengpeng Jiang; Rendong Shen

    2017-01-01

    As a new kind of highly compact and efficient micro-channel heat exchanger, the printed circuit heat exchanger (PCHE) is a promising candidate satisfying the heat exchange requirements of liquefied natural gas (LNG) vaporization at low and high pressure. The effects of airfoil fin arrangement on heat transfer and flow resistance were numerically investigated using supercritical liquefied natural gas (LNG) as working fluid. The thermal properties of supercritical LNG were tested by utilizing t...

  20. 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

  1. Heat transfer and pressure drop of supercritical carbon dioxide flowing in several printed circuit heat exchanger channel patterns

    International Nuclear Information System (INIS)

    Carlson, M.; Kruizenga, A.; Anderson, M.; Corradini, M.

    2012-01-01

    Closed-loop Brayton cycles using supercritical carbon dioxide (SCO 2 ) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO 2 Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO 2 Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO 2 flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)

  2. A novel reutilization method for waste printed circuit boards as flame retardant and smoke suppressant for poly (vinyl chloride)

    Energy Technology Data Exchange (ETDEWEB)

    Xiu, Fu-Rong, E-mail: xiu_chem@hotmail.com [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350108 (China); Weng, Huiwei; Qi, Yingying; Yu, Gending; Zhang, Zhigang [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350108 (China); Zhang, Fu-Shen [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2016-09-05

    Highlights: • We report a novel electronic waste-based flame retardant for PVC. • The SCWO-treated PCBs significantly improves the flame retardancy of PVC. • The flame retardant mechanism of SCWO-treated PCBs was studied. • Appropriate amount flame retardant does not degrade the mechanical property of PVC. - Abstract: In this study, a novel reutilization method for waste printed circuit boards (PCBs) as flame retardant and smoke suppressant for poly (vinyl chloride) (PVC) was successfully testified. A supercritical water oxidation (SCWO) process was applied to treat waste PCBs before they could be used as flame retardants of PVC. The results indicated that SCWO conditions had a significant effect on the flame retarding and smoke suppressing properties of waste PCBs for PVC. Cu{sub 2}O, CuO, and SnO{sub 2} were the main active ingredients in waste PCBs-derived flame retardants. A conversion of Cu elements (Cu{sup 0} → Cu{sup +} → Cu{sup 2+}) during SCWO process with the increase of reaction temperature was found to be the key influence factor for the flame retarding properties of SCWO-treated PCBs. The experiment results also showed that there was a synergistic effect of flame retardancy between Cu{sup +} and Cu{sup 2+}. After the optimized SCWO treatment, SCWO-treated PCBs significantly improved the flame retardancy and smoke suppression of PVC. Limiting oxygen index (LOI) and char yield (CY) increased with increasing SCWO-treated PCBs content in PVC, while smoke density rating (SDR) and maximum smoke density (MSD) decreased markedly. The mechanical properties of PVC samples were influenced in different degree by adding different content SCWO-treated PCBs.

  3. Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Michael L.M., E-mail: mitchel.marques@yahoo.com.br [Bio& Hydrometallurgy Laboratory, Department of Metallurgical and Materials Engineering, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-000 (Brazil); Leão, Versiane A., E-mail: versiane@demet.em.ufop.br [Bio& Hydrometallurgy Laboratory, Department of Metallurgical and Materials Engineering, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-000 (Brazil); Gomes, Otavio [Centre for Mineral Technology – CETEM, Av Pedro Calmon, 900, 21941-908 Rio de Janeiro (Brazil); Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan [Mineral Processing and Recycling, University of Liege, SartTilman, 4000 Liege (Belgium)

    2015-07-15

    Highlights: • Copper bioleaching from PCB (20 mm) by moderate thermophiles was demonstrated. • Larger PCB sheets enable a cost reduction due to the elimination of fine grinding. • Crushing generated cracks in PCB increasing the copper extraction. • A pre-treatment step was necessary to remove the lacquer coating. • High copper extractions (85%) were possible with pulp density of up to 25.0 g/L. - Abstract: The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (−208 μm + 147 μm), ferrous iron concentration (1.25–10.0 g/L) and pH (1.5–2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0 g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20 mm-long) working with increased solids concentration (up to 25.0 g/L). Because there was as the faster leaching kinetics at 50 °C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8 days and microscopic observations by SEM–EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20 mm-size sheets.

  4. A novel reutilization method for waste printed circuit boards as flame retardant and smoke suppressant for poly (vinyl chloride)

    International Nuclear Information System (INIS)

    Xiu, Fu-Rong; Weng, Huiwei; Qi, Yingying; Yu, Gending; Zhang, Zhigang; Zhang, Fu-Shen

    2016-01-01

    Highlights: • We report a novel electronic waste-based flame retardant for PVC. • The SCWO-treated PCBs significantly improves the flame retardancy of PVC. • The flame retardant mechanism of SCWO-treated PCBs was studied. • Appropriate amount flame retardant does not degrade the mechanical property of PVC. - Abstract: In this study, a novel reutilization method for waste printed circuit boards (PCBs) as flame retardant and smoke suppressant for poly (vinyl chloride) (PVC) was successfully testified. A supercritical water oxidation (SCWO) process was applied to treat waste PCBs before they could be used as flame retardants of PVC. The results indicated that SCWO conditions had a significant effect on the flame retarding and smoke suppressing properties of waste PCBs for PVC. Cu_2O, CuO, and SnO_2 were the main active ingredients in waste PCBs-derived flame retardants. A conversion of Cu elements (Cu"0 → Cu"+ → Cu"2"+) during SCWO process with the increase of reaction temperature was found to be the key influence factor for the flame retarding properties of SCWO-treated PCBs. The experiment results also showed that there was a synergistic effect of flame retardancy between Cu"+ and Cu"2"+. After the optimized SCWO treatment, SCWO-treated PCBs significantly improved the flame retardancy and smoke suppression of PVC. Limiting oxygen index (LOI) and char yield (CY) increased with increasing SCWO-treated PCBs content in PVC, while smoke density rating (SDR) and maximum smoke density (MSD) decreased markedly. The mechanical properties of PVC samples were influenced in different degree by adding different content SCWO-treated PCBs.

  5. Characterization and mechanical separation of metals from computer Printed Circuit Boards (PCBs) based on mineral processing methods.

    Science.gov (United States)

    Sarvar, Mojtaba; Salarirad, Mohammad Mehdi; Shabani, Mohammad Amin

    2015-11-01

    In this paper, a novel mechanical process is proposed for enriching metal content of computer Printed Circuit Boards (PCBs). The PCBs are crushed and divided into three different size fractions namely: -0.59, +0.59 to 1.68 and +1.68 mm. Wet jigging and froth flotation methods are selected for metal enrichment. The coarse size fraction (+1.68 mm) is processed by jigging. The plastic free product is grinded and screened. The oversized product is separated as the first concentrate. It was rich of metal because the grinding process was selective. The undersized product is processed by froth flotation. Based on the obtained results, the middle size fraction (+0.59 to 1.68 mm) and the small size fraction (-0.59 mm) are processed by wet jigging and froth flotation respectively. The wet jigging process is optimized by investigating the effect of pulsation frequency and water flow rate. The results of examining the effect of particle size, solid to liquid ratio, conditioning time and using apolar collector showed that collectorless flotation is a promising method for separating nonmetals of PCBs. 95.6%, 97.5% and 85% of metal content of coarse size, middle size and small size fraction are recovered. The grades of obtained concentrates were 63.3%, 92.5% and 75% respectively. The total recovery is calculated as 95.64% and the grade of the final concentrate was 71.26%. Determining the grade of copper and gold in the final product reveals that 4.95% of copper and 24.46% of gold are lost during the concentration. The major part of the lost gold is accumulated in froth flotation tail. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor

    International Nuclear Information System (INIS)

    Rodrigues, Michael L.M.; Leão, Versiane A.; Gomes, Otavio; Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan

    2015-01-01

    Highlights: • Copper bioleaching from PCB (20 mm) by moderate thermophiles was demonstrated. • Larger PCB sheets enable a cost reduction due to the elimination of fine grinding. • Crushing generated cracks in PCB increasing the copper extraction. • A pre-treatment step was necessary to remove the lacquer coating. • High copper extractions (85%) were possible with pulp density of up to 25.0 g/L. - Abstract: The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (−208 μm + 147 μm), ferrous iron concentration (1.25–10.0 g/L) and pH (1.5–2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0 g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20 mm-long) working with increased solids concentration (up to 25.0 g/L). Because there was as the faster leaching kinetics at 50 °C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8 days and microscopic observations by SEM–EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20 mm-size sheets

  7. 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.

  8. Spectroscopic characterization of ion-irradiated multi-layer graphenes

    Energy Technology Data Exchange (ETDEWEB)

    Tsukagoshi, Akira [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Honda, Shin-ichi, E-mail: s-honda@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Osugi, Ryo [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Okada, Hiraku [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); Niibe, Masahito [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Kamigori, Hyogo 678-1205 (Japan); Terasawa, Mititaka [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Kamigori, Hyogo 678-1205 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Hirase, Ryuji; Izumi, Hirokazu; Yoshioka, Hideki [Hyogo Prefectural Institute of Technology, Kobe 654-0037 (Japan); Niwase, Keisuke [Hyogo University of Teacher Education, Kato, Hyogo 673-1494 (Japan); Taguchi, Eiji [Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Lee, Kuei-Yi [Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Oura, Masaki [RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan)

    2013-11-15

    Low-energy Ar ions (0.5–2 keV) were irradiated to multi-layer graphenes and the damage process, the local electronic states, and the degree of alignment of the basal plane, and the oxidation process upon ion irradiation were investigated by Raman spectroscopy, soft X-ray absorption spectroscopy (XAS) and in situ X-ray photoelectron spectroscopy (XPS). By Raman spectroscopy, we observed two stages similar to the case of irradiated graphite, which should relate to the accumulations of vacancies and turbulence of the basal plane, respectively. XAS analysis indicated that the number of sp{sup 2}-hybridized carbon (sp{sup 2}-C) atoms decreased after ion irradiation. Angle-resolved XAS revealed that the orientation parameter (OP) decreased with increasing ion energy and fluence, reflecting the turbulence of the basal plane under irradiation. In situ XPS shows the oxidation of the irradiated multi-layer graphenes after air exposure.

  9. A Multi-Layer Phoswich Radioxenon Detection System

    International Nuclear Information System (INIS)

    David M. Hamby

    2007-01-01

    Further work was performed in optical modeling of the modified (dual planar) XEPHWICH design. Modeling capabilities and understanding were expanded through the performance of three additional simulations. The efficiency of the entire optical modeling process was increased by developing custom software to interface with both the input and output of the simulation program. Work continues on the design and implementation of the analog portion of the read-out system. This component is being prototyped and is nearing completion. The PCB (printed circuit board) is in its design phase for the two-channel digital pulse processor, necessary for the dual planar XEPHWICH. System components are being selected for the signal processor based on a balance of cost and our expectations of quality. Outside the scope of the grant, but entirely related, we continue to work on developing a source of fission-product xenon gases that will be produced in the OSU TRIGA reactor. The amount of HEU necessary to provide the needed activities of xenon fission products, as well as build-in times for each isotope of importance following irradiation, have been calculated. Irradiation times in the TRIGA have been determined. We've finalized our design of the xenon-fission-product collection chamber and initiated in-house fabrication. PNNL will be supplying the thin foils of enriched uranium necessary for xenon production

  10. Fabrication of hybrid molecular devices using multi-layer graphene break junctions

    Science.gov (United States)

    Island, J. O.; Holovchenko, A.; Koole, M.; Alkemade, P. F. A.; Menelaou, M.; Aliaga-Alcalde, N.; Burzurí, E.; van der Zant, H. S. J.

    2014-11-01

    We report on the fabrication of hybrid molecular devices employing multi-layer graphene (MLG) flakes which are patterned with a constriction using a helium ion microscope or an oxygen plasma etch. The patterning step allows for the localization of a few-nanometer gap, created by electroburning, that can host single molecules or molecular ensembles. By controlling the width of the sculpted constriction, we regulate the critical power at which the electroburning process begins. We estimate the flake temperature given the critical power and find that at low powers it is possible to electroburn MLG with superconducting contacts in close proximity. Finally, we demonstrate the fabrication of hybrid devices with superconducting contacts and anthracene-functionalized copper curcuminoid molecules. This method is extendable to spintronic devices with ferromagnetic contacts and a first step towards molecular integrated circuits.

  11. Calculation studies of a multi-layer decoupler system for a decoupled hydrogen moderator

    International Nuclear Information System (INIS)

    Ooi, M.; Kiyanagi, Y.

    2001-01-01

    We proposed a multi-layer decoupler as a method to improve pulse characteristics of emitted neutrons from a decoupled hydrogen moderator. Pulse shapes from a moderator with the multi layer-decoupler were compared with those with a traditional single layer decoupler. It was found that the multi-layer decoupler system gave better pulse characteristic with less decrease of peak intensity. (author)

  12. Design and Implementation of High Frequency Buck Converter Using Multi-Layer PCB Inductor

    DEFF Research Database (Denmark)

    Nour, Yasser; Ouyang, Ziwei; Knott, Arnold

    2016-01-01

    Increasing the switching frequency for switch mode power supplies is one of methods to achieve smaller, lighter weight and cheaper power converters. This work investigates the opportunity of using two layer circular spiral inductors implemented in a 150 μm finished thickness printed circuit board...

  13. Highly flexible self-powered sensors based on printed circuit board technology for human motion detection and gesture recognition.

    Science.gov (United States)

    Fuh, Yiin-Kuen; Ho, Hsi-Chun

    2016-03-04

    In this paper, we demonstrate a new integration of printed circuit board (PCB) technology-based self-powered sensors (PSSs) and direct-write, near-field electrospinning (NFES) with polyvinylidene fluoride (PVDF) micro/nano fibers (MNFs) as source materials. Integration with PCB technology is highly desirable for affordable mass production. In addition, we systematically investigate the effects of electrodes with intervals in the range of 0.15 mm to 0.40 mm on the resultant PSS output voltage and current. The results show that at a strain of 0.5% and 5 Hz, a PSS with a gap interval 0.15 mm produces a maximum output voltage of 3 V and a maximum output current of 220 nA. Under the same dimensional constraints, the MNFs are massively connected in series (via accumulation of continuous MNFs across the gaps ) and in parallel (via accumulation of parallel MNFs on the same gap) simultaneously. Finally, encapsulation in a flexible polymer with different interval electrodes demonstrated that electrical superposition can be realized by connecting MNFs collectively and effectively in serial/parallel patterns to achieve a high current and high voltage output, respectively. Further improvement in PSSs based on the effect of cooperativity was experimentally realized by rolling-up the device into a cylindrical shape, resulting in a 130% increase in power output due to the cooperative effect. We assembled the piezoelectric MNF sensors on gloves, bandages and stockings to fabricate devices that can detect different types of human motion, including finger motion and various flexing and extensions of an ankle. The firmly glued PSSs were tested on the glove and ankle respectively to detect and harvest the various movements and the output voltage was recorded as ∼1.5 V under jumping movement (one PSS) and ∼4.5 V for the clenched fist with five fingers bent concurrently (five PSSs). This research shows that piezoelectric MNFs not only have a huge impact on harvesting various external

  14. Highly flexible self-powered sensors based on printed circuit board technology for human motion detection and gesture recognition

    Science.gov (United States)

    Fuh, Yiin-Kuen; Ho, Hsi-Chun

    2016-03-01

    In this paper, we demonstrate a new integration of printed circuit board (PCB) technology-based self-powered sensors (PSSs) and direct-write, near-field electrospinning (NFES) with polyvinylidene fluoride (PVDF) micro/nano fibers (MNFs) as source materials. Integration with PCB technology is highly desirable for affordable mass production. In addition, we systematically investigate the effects of electrodes with intervals in the range of 0.15 mm to 0.40 mm on the resultant PSS output voltage and current. The results show that at a strain of 0.5% and 5 Hz, a PSS with a gap interval 0.15 mm produces a maximum output voltage of 3 V and a maximum output current of 220 nA. Under the same dimensional constraints, the MNFs are massively connected in series (via accumulation of continuous MNFs across the gaps ) and in parallel (via accumulation of parallel MNFs on the same gap) simultaneously. Finally, encapsulation in a flexible polymer with different interval electrodes demonstrated that electrical superposition can be realized by connecting MNFs collectively and effectively in serial/parallel patterns to achieve a high current and high voltage output, respectively. Further improvement in PSSs based on the effect of cooperativity was experimentally realized by rolling-up the device into a cylindrical shape, resulting in a 130% increase in power output due to the cooperative effect. We assembled the piezoelectric MNF sensors on gloves, bandages and stockings to fabricate devices that can detect different types of human motion, including finger motion and various flexing and extensions of an ankle. The firmly glued PSSs were tested on the glove and ankle respectively to detect and harvest the various movements and the output voltage was recorded as ∼1.5 V under jumping movement (one PSS) and ∼4.5 V for the clenched fist with five fingers bent concurrently (five PSSs). This research shows that piezoelectric MNFs not only have a huge impact on harvesting various external

  15. Reduction of adhesive stain defect in flexible printed circuit board on hot pressing process: A case study of electronic component factory

    Directory of Open Access Journals (Sweden)

    Sakulkaew Srisang

    2015-03-01

    Full Text Available The objective of this research is a reduction of an adhesive stain defect in flexible printed circuit board in hot pressing process, the electronic factory. The manufacturing have been processing by sheet type of products with ninety-six pieces of flexible printed circuit boards. Causes of the problem include the before and internal hot pressing process. In process beginning times, the most right row of products between the cooling plate and the hot pressing machine has temperature 71.2◦C that is higher than glass transition temperature (Tg 60◦C. Those products’ temperature lead to evaporate a polyimide adhesive before hot pressing process beginning. The internal hot pressing process include the preheat times and the pressure time. In the preheat time the problem is a gap between lower and upper plate, was under specification (Under 1 mm and leaded to adhesive polyimide stain. In the actuality this time requires temperature and low pressure that mean a gap within 1 – 2 mm (between lower and upper plate. In pressure times the hot pressing plate surface is not flat and products are pressed by insufficient force that it lead to generate an adhesive stain on flexible printed circuit boards. That force is measured by the pre-scale paper and a result, RGB color, is provided. And then color density (From standard color sample and RGB color (From pre-scale paper is found out the relation by Photoshop program and multiple regression theory using. The formula is applied to compare with defect so as to find out the suitable color density (Defects reducing. The solving solutions is provided including the gap reduced adjustment between cooling plate and hot pressing machine before hot pressing process, the plate adjustment within specification in the preheat time and the pressing plate polishing in the pressure time. Results of study and solving are provide defect reduction from 24.4 percentage to 7.2 percentage of total study product.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Improved Manufacturing Performance of Screen Printed Carbon Electrodes through Material Formulation.

    Science.gov (United States)

    Jewell, Eifion; Philip, Bruce; Greenwood, Peter

    2016-06-27

    Printed carbon graphite materials are the primary common component in the majority of screen printed sensors. Screen printing allows a scalable manufacturing solution, accelerating the means by which novel sensing materials can make the transition from laboratory material to commercial product. A common bottleneck in any thick film printing process is the controlled drying of the carbon paste material. A study has been undertaken which examines the interaction between material solvent, printed film conductivity and process consistency. The study illustrates that it is possible to reduce the solvent boiling point to significantly increase process productivity while maintaining process consistency. The lower boiling point solvent also has a beneficial effect on the conductivity of the film, reducing the sheet resistance. It is proposed that this is a result of greater film stressing increasing charge percolation through greater inter particle contact. Simulations of material performance and drying illustrate that a multi layered printing provides a more time efficient manufacturing method. The findings have implications for the volume manufacturing of the carbon sensor electrodes but also have implications for other applications where conductive carbon is used, such as electrical circuits and photovoltaic devices.

  1. Pronounced Photovoltaic Response from Multi-layered MoTe2 Phototransistor with Asymmetric Contact Form.

    Science.gov (United States)

    Liu, Junku; Guo, Nan; Xiao, Xiaoyang; Zhang, Kenan; Jia, Yi; Zhou, Shuyun; Wu, Yang; Li, Qunqing; Xiao, Lin

    2017-11-22

    In this study, we fabricate air-stable p-type multi-layered MoTe 2 phototransistor using Au as electrodes, which shows pronounced photovoltaic response in off-state with asymmetric contact form. By analyzing the spatially resolved photoresponse using scanning photocurrent microscopy, we found that the potential steps are formed in the vicinity of the electrodes/MoTe 2 interface due to the doping of the MoTe 2 by the metal contacts. The potential step dominates the separation of photoexcited electron-hole pairs in short-circuit condition or with small V sd biased. Based on these findings, we infer that the asymmetric contact cross-section between MoTe 2 -source and MoTe 2 -drain electrodes is the reason to form non-zero net current and photovoltaic response. Furthermore, MoTe 2 phototransistor shows a faster response in short-circuit condition than that with higher biased V sd within sub-millisecond, and its spectral range can be extended to the infrared end of 1550 nm.

  2. A comparison of different silver inks for printing of conductive tracks on paper substrates for rapid prototyping of electronic circuits

    CSIR Research Space (South Africa)

    Bezuidenhout, PH

    2015-11-01

    Full Text Available This study compares the performance between two commercially-available electrically conductive silver inks, Harima NPS-J nanopaste and the NBSIJ-FD02 Mitsubishi conductive ink, used in rapid prototyping of electronic circuits. The comparative...

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Reduction of adhesive stain defect in flexible printed circuit board on hot pressing process: a case study of electronic component factory

    Directory of Open Access Journals (Sweden)

    Sakulkaew Srisang

    2014-09-01

    Full Text Available The objective of this research is a reduction of an adhesive stain defect in flexible printed circuit board in hot pressing process, the electronic factory. The manufacturing have been processing by sheet type of products with ninety-six pieces of flexible printed circuit boards. Causes of the problem include the before and internal hot pressing process. In process beginning times, the most right row of products between the cooling plate and the hot pressing machine has temperature 71.2◦C that is higher than glass transition temperature (Tg 60◦C. Those products’ temperature lead to evaporate a polyimide adhesive before hot pressing process beginning. The internal hot pressing process include the preheat times and the pressure time. In the preheat time the problem is a gap between lower and upper plate, was under specification(Under 1 mm and leaded to adhesive polyimide stain. In the actuality this time requires temperature and low pressure that mean a gap within 1 – 2 mm (between lower and upper plate. In pressure times the hot pressing plate surface is not flat and products are pressed by insufficient force that it lead to generate an adhesive stain on flexible printed circuit boards. That force is measured by the pre-scale paper and a result, RGB color, is provided. And then color density (From standard color sample and RGB color (From pre-scale paper is found out the relation by Photoshop program and multiple regression theory using. The formula is applied to compare with defect so as to find out the suitable color density (Defects reducing. The solving solutions is provided including the gap reduced adjustment between cooling plate and hot pressing machine before hot pressing process, the plate adjustment within specification in the preheat time and the pressing plate polishing in the pressure time. Results of study and solving are provide defect reduction from 24.4 percentage to 7.2 percentage of total study product.

  10. INSULATION RESISTANCE OF PRINTED CIRCUIT BOARDS. BEHAVIOR OF CERTAIN TYPES AND MAKES UNDER DIFFERENT CLIMATIC CONDITIONS. En undersoegelse af en raekke typer og fabrikater under forskellige klimatiske forhold

    Energy Technology Data Exchange (ETDEWEB)

    Olesen, S. T.

    1971-11-15

    The present study embraces measurements of insulation resistance on a number of types and makes of printed-circuit boards. The insulation measurements were performed on boards just received from the manufacturer, as well as on boards exposed to humidity or to elevated temperatures. A total of 33 types from five different material categories were obtained. The test material used thus originated from a variety of independent sources. The purpose of the project was to investigate the frequency with which batches with insufficiently baked material - and consequently having a poor insulation resistance - were encountered in practice. No such batches were in fact found, and it is likely that they do not occur as often as had previously been assumed.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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)

  20. 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.

  1. A fully printed ferrite nano-particle ink based tunable antenna

    KAUST Repository

    Ghaffar, Farhan A.; Vaseem, Mohammad; Shamim, Atif

    2016-01-01

    on conventional microwave substrates. In order to have a fully printed fabrication process, the substrate also need to be printed. In this paper, a fully printed multi-layer process utilizing custom Fe2O3 based magnetic ink and a silver organic complex (SOC) ink

  2. 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.

  3. 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.

  4. Improved SVR Model for Multi-Layer Buildup Factor Calculation

    International Nuclear Information System (INIS)

    Trontl, K.; Pevec, D.; Smuc, T.

    2006-01-01

    The accuracy of point kernel method applied in gamma ray dose rate calculations in shielding design and radiation safety analysis is limited by the accuracy of buildup factors used in calculations. Although buildup factors for single-layer shields are well defined and understood, buildup factors for stratified shields represent a complex physical problem that is hard to express in mathematical terms. The traditional approach for expressing buildup factors of multi-layer shields is through semi-empirical formulas obtained by fitting the results of transport theory or Monte Carlo calculations. Such an approach requires an ad-hoc definition of the fitting function and often results with numerous and usually inadequately explained and defined correction factors added to the final empirical formula. Even more, finally obtained formulas are generally limited to a small number of predefined combinations of materials within relatively small range of gamma ray energies and shield thicknesses. Recently, a new approach has been suggested by the authors involving one of machine learning techniques called Support Vector Machines, i.e., Support Vector Regression (SVR). Preliminary investigations performed for double-layer shields revealed great potential of the method, but also pointed out some drawbacks of the developed model, mostly related to the selection of one of the parameters describing the problem (material atomic number), and the method in which the model was designed to evolve during the learning process. It is the aim of this paper to introduce a new parameter (single material buildup factor) that is to replace the existing material atomic number as an input parameter. The comparison of two models generated by different input parameters has been performed. The second goal is to improve the evolution process of learning, i.e., the experimental computational procedure that provides a framework for automated construction of complex regression models of predefined

  5. 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.

  6. Analysis of the treatment of plastic from electrical and electronic waste in the Republic of Serbia and the testing of the recycling potential of non-metallic fractions of printed circuit boards

    Directory of Open Access Journals (Sweden)

    Vučinić Aleksandra S.

    2017-01-01

    Full Text Available This paper presents the analysis of the quantity of plastic and waste printed circuit boards obtained after the mechanical treatment of electrical and electronic waste (E-waste in the Republic of Serbia, as well as the recycling of non-metallic fractions of waste printed circuit boards. The aim is to analyze the obtained recycled material and recommendation for possible application of recyclables. The data on the quantities and treatment of plastics and printed circuit boards obtained after the mechanical treatment of WEEE, were gained through questionnaires sent to the operators who treat this type of waste. The results of the questionnaire analysis showed that in 2014 the dismantling of E-waste isolated 1,870.95 t of plastic and 499.85 t of printed circuit boards. In the Republic of Serbia, E-waste recycling is performed exclusively by using mechanical methods. Mechanical methods consist of primary crushing and separation of the materials which have a utility value as secondary raw materials, from the components and materials that have hazardous properties. Respect to that, the recycling of printed circuit boards using some of the metallurgical processes with the aim of extracting copper, precious metals and non-metallic fraction is completely absent, and the circuit boards are exported as a whole. Given the number of printed circuit boards obtained by E-waste dismantling, and the fact that from an economic point of view, hydrometallurgical methods are very suitable technological solutions in the case of a smaller capacity, there is a possibility for establishing the facilities in the Republic of Serbia for the hydrometallurgical treatment that could be used for metals extraction, and non-metallic fractions, which also have their own value. Printed circuit boards granulate obtained after the mechanical pretreatment and the selective removal of metals by hydrometallurgical processes was used for the testing of the recycling potential

  7. Sensitivity Analysis and Stray Capacitance of Helical Flux Compression Generator with Multi Layer Filamentary Conductor in Rectangular Cross-Section

    Directory of Open Access Journals (Sweden)

    M. E. Mosleh

    2012-03-01

    Full Text Available This paper presents an approach to calculate the equivalent stray capacitance (SC of n-turn of the helical flux compression generator (HFCG coil with multi layer conductor wire filaments (MLCWF in the form of rectangular cross-section. This approach is based on vespiary regular hexagonal (VRH model. In this method, wire filaments of the generator coil are separated into many very small similar elementary cells. By the expanded explosion in the liner and move explosion to the end of the liner, the coil turns number will be reduced. So, the equivalent SC of the HFCG will increase. The results show that by progress of explosion and decrease of the turns’ number in the generator coil total capacitance of the generator increases until the explosion reaches to the second turn. When only one turn remains in the circuit, a decrease occurs in the total capacitance of the generator.

  8. Facile synthesis of Ni-decorated multi-layers graphene sheets as effective anode for direct urea fuel cells

    Directory of Open Access Journals (Sweden)

    Ahmed Yousef

    2017-09-01

    Full Text Available A large amount of urea-containing wastewater is produced as a by-product in the fertilizer industry, requiring costly and complicated treatment strategies. Considering that urea can be exploited as fuel, this wastewater can be treated and simultaneously exploited as a renewable energy source in a direct urea fuel cell. In this study, multi-layers graphene/nickel nanocomposites were prepared by a one-step green method for use as an anode in the direct urea fuel cell. Typically, commercial sugar was mixed with nickel(II acetate tetrahydrate in distilled water and then calcined at 800 °C for 1 h. Raman spectroscopy, X-ray diffraction (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM and energy dispersive spectroscopy (EDS were employed to characterize the final product. The results confirmed the formation of multi-layers graphene sheets decorated by nickel nanoparticles. To investigate the influence of metal nanoparticles content, samples were prepared using different amounts of the metal precursor; nickel acetate content was changed from 0 to 5 wt.%. Investigation of the electrochemical characterizations indicated that the sample prepared using the original solution with 3 wt.% nickel acetate had the best current density, 81.65 mA/cm2 in a 0.33 M urea solution (in 1 M KOH at an applied voltage 0.9 V vs Ag/AgCl. In a passive direct urea fuel cell based on the optimal composition, the observed maximum power density was 4.06 × 10−3 mW/cm2 with an open circuit voltage of 0.197 V at room temperature in an actual electric circuit. Overall, this study introduces a cheap and beneficial methodology to prepare effective anode materials for direct urea fuel cells.

  9. An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.

    1998-10-15

    A overview has been presented on the topic of alternative surface finishes for package I/Os and circuit board features. Aspects of processability and solder joint reliability were described for the following coatings: baseline hot-dipped, plated, and plated-and-fused 100Sn and Sn-Pb coatings; Ni/Au; Pd, Ni/Pd, and Ni/Pd/Au finishes; and the recently marketed immersion Ag coatings. The Ni/Au coatings appear to provide the all-around best option in terms of solderability protection and wire bondability. Nickel/Pal ftishes offer a slightly reduced level of performance in these areas that is most likely due to variable Pd surface conditions. It is necessmy to minimize dissolved Au or Pd contents in the solder material to prevent solder joint embrittlement. Ancillary aspects that included thickness measurement techniques; the importance of finish compatibility with conformal coatings and conductive adhesives; and the need for alternative finishes for the processing of non-Pb bearing solders were discussed.

  10. Recycling of waste printed circuit boards with simultaneous enrichment of special metals by using alkaline melts: A green and strategically advantageous solution.

    Science.gov (United States)

    Stuhlpfarrer, Philipp; Luidold, Stefan; Antrekowitsch, Helmut

    2016-04-15

    The increasing consumption of electric and electronic equipment has led to a rise in toxic waste. To recover the metal fraction, a separation of the organic components is necessary because harmful substances such as chlorine, fluorine and bromine cause ecological damage, for example in the form of dioxins and furans at temperature above 400°C. Hence, an alternative, environmentally friendly approach was investigated exploiting that a mixture of caustic soda and potassium hydroxide in eutectic composition melts below 200°C, enabling a fast cracking of the long hydrocarbon chains. The trials demonstrate the removal of organic compounds without a loss of copper and precious metals, as well as a suppressed formation of hazardous off-gases. In order to avoid an input of alkaline elements into the furnace and ensuing problems with refractory materials, a washing step generates a sodium and potassium hydroxide solution, in which special metals like indium, gallium and germanium are enriched. Their concentrations facilitate the recovery of these elements, because otherwise they become lost in the typical recycling processes. The aim of this work was to find an environmental solution for the separation of plastics and metals as well as a strategically important answer for the recycling of printed circuit boards and mobile phones. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Eco-friendly copper recovery process from waste printed circuit boards using Fe{sup 3+}/Fe{sup 2+} redox system

    Energy Technology Data Exchange (ETDEWEB)

    Fogarasi, Szabolcs [Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, Cluj-Napoca RO-400028 (Romania); Imre-Lucaci, Florica [Babeş-Bolyai University, Interdisciplinary Research Institute on Bio-Nano-Sciences, 42 Treboniu Laurian Street, Cluj-Napoca RO-400271 (Romania); Egedy, Attila [University of Pannonia, Department of Process Engineering, Egyetem Str. 10, H-8200 Veszprém (Hungary); Imre-Lucaci, Árpád, E-mail: aimre@chem.ubbcluj.ro [Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, Cluj-Napoca RO-400028 (Romania); Ilea, Petru [Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, Cluj-Napoca RO-400028 (Romania)

    2015-06-15

    Highlights: • We developed an ecofriendly mediated electrochemical process for copper recovery. • The recovery of copper was achieved without mechanical pretreatment of the samples. • We identified the optimal flow rate for the leaching and electrowinning of copper. • The copper content of the obtained cathodic deposits was over 99.9%. - Abstract: The present study aimed at developing an original and environmentally friendly process for the recovery of copper from waste printed circuit boards (WPCBs) by chemical dissolution with Fe{sup 3+} combined with the simultaneous electrowinning of copper and oxidant regeneration. The recovery of copper was achieved in an original set-up consisting of a three chamber electrochemical reactor (ER) connected in series with a chemical reactor (CR) equipped with a perforated rotating drum. Several experiments were performed in order to identify the optimal flow rate for the dissolution of copper in the CR and to ensure the lowest energy consumption for copper electrodeposition in the ER. The optimal hydrodynamic conditions were provided at 400 mL/min, leading to the 75% dissolution of metals and to a low specific energy consumption of 1.59 kW h/kg Cu for the electrodeposition process. In most experiments, the copper content of the obtained cathodic deposits was over 99.9%.

  12. Eco-friendly copper recovery process from waste printed circuit boards using Fe³⁺/Fe²⁺ redox system.

    Science.gov (United States)

    Fogarasi, Szabolcs; Imre-Lucaci, Florica; Egedy, Attila; Imre-Lucaci, Árpád; Ilea, Petru

    2015-06-01

    The present study aimed at developing an original and environmentally friendly process for the recovery of copper from waste printed circuit boards (WPCBs) by chemical dissolution with Fe(3+) combined with the simultaneous electrowinning of copper and oxidant regeneration. The recovery of copper was achieved in an original set-up consisting of a three chamber electrochemical reactor (ER) connected in series with a chemical reactor (CR) equipped with a perforated rotating drum. Several experiments were performed in order to identify the optimal flow rate for the dissolution of copper in the CR and to ensure the lowest energy consumption for copper electrodeposition in the ER. The optimal hydrodynamic conditions were provided at 400 mL/min, leading to the 75% dissolution of metals and to a low specific energy consumption of 1.59 kW h/kg Cu for the electrodeposition process. In most experiments, the copper content of the obtained cathodic deposits was over 99.9%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Use of large pieces of printed circuit boards for bioleaching to avoid 'precipitate contamination problem' and to simplify overall metal recovery.

    Science.gov (United States)

    Adhapure, N N; Dhakephalkar, P K; Dhakephalkar, A P; Tembhurkar, V R; Rajgure, A V; Deshmukh, A M

    2014-01-01

    Very recently bioleaching has been used for removing metals from electronic waste. Most of the research has been targeted to using pulverized PCBs for bioleaching where precipitate formed during bioleaching contaminates the pulverized PCB sample and making the overall metal recovery process more complicated. In addition to that, such mixing of pulverized sample with precipitate also creates problems for the final separation of non metallic fraction of PCB sample. In the present investigation we attempted the use of large pieces of printed circuit boards instead of pulverized sample for removal of metals. Use of large pieces of PCBs for bioleaching was restricted due to the chemical coating present on PCBs, the problem has been solved by chemical treatment of PCBs prior to bioleaching. In short,•Large pieces of PCB can be used for bioleaching instead of pulverized PCB sample.•Metallic portion on PCBs can be made accessible to bacteria with prior chemical treatment of PCBs.•Complete metal removal obtained on PCB pieces of size 4 cm × 2.5 cm with the exception of solder traces. The final metal free PCBs (non metallic) can be easily recycled and in this way the overall recycling process (metallic and non metallic part) of PCBs becomes simple.

  14. Use of large pieces of printed circuit boards for bioleaching to avoid ‘precipitate contamination problem’ and to simplify overall metal recovery

    Science.gov (United States)

    Adhapure, N.N.; Dhakephalkar, P.K.; Dhakephalkar, A.P.; Tembhurkar, V.R.; Rajgure, A.V.; Deshmukh, A.M.

    2014-01-01

    Very recently bioleaching has been used for removing metals from electronic waste. Most of the research has been targeted to using pulverized PCBs for bioleaching where precipitate formed during bioleaching contaminates the pulverized PCB sample and making the overall metal recovery process more complicated. In addition to that, such mixing of pulverized sample with precipitate also creates problems for the final separation of non metallic fraction of PCB sample. In the present investigation we attempted the use of large pieces of printed circuit boards instead of pulverized sample for removal of metals. Use of large pieces of PCBs for bioleaching was restricted due to the chemical coating present on PCBs, the problem has been solved by chemical treatment of PCBs prior to bioleaching. In short,•Large pieces of PCB can be used for bioleaching instead of pulverized PCB sample.•Metallic portion on PCBs can be made accessible to bacteria with prior chemical treatment of PCBs.•Complete metal removal obtained on PCB pieces of size 4 cm × 2.5 cm with the exception of solder traces. The final metal free PCBs (non metallic) can be easily recycled and in this way the overall recycling process (metallic and non metallic part) of PCBs becomes simple. PMID:26150951

  15. Bioleaching of Gold and Silver from Waste Printed Circuit Boards by Pseudomonas balearica SAE1 Isolated from an e-Waste Recycling Facility.

    Science.gov (United States)

    Kumar, Anil; Saini, Harvinder Singh; Kumar, Sudhir

    2018-02-01

    Indigenous bacterial strain Pseudomonas balearica SAE1, tolerant to e-waste toxicity was isolated from an e-waste recycling facility Exigo Recycling Pvt. Ltd., India. Toxicity tolerance of bacterial strain was analyzed using crushed (particle size ≤150 µm) waste computer printed circuit boards (PCBs)/liter (L) of culture medium. The EC 50 value for SAE1 was 325.7 g/L of the e-waste pulp density. Two-step bioleaching was then applied to achieve the dissolution of gold (Au) and silver (Ag) from the e-waste. To maximize precious metal dissolution, factors including pulp density, glycine concentration, pH level, and temperature were optimized. The optimization resulted in 68.5 and 33.8% of Au and Ag dissolution, respectively, at a pH of 9.0, a pulp density of 10 g/L, a temperature of 30 °C, and a glycine concentration of 5 g/L. This is the first study of Au and Ag bioleaching using indigenous e-waste bacteria and its analysis to determine e-waste toxicity tolerance.

  16. Recycling of waste printed circuit boards with simultaneous enrichment of special metals by using alkaline melts: A green and strategically advantageous solution

    Energy Technology Data Exchange (ETDEWEB)

    Stuhlpfarrer, Philipp, E-mail: philipp-johannes.stuhlpfarrer@stud.unileoben.ac.at; Luidold, Stefan; Antrekowitsch, Helmut

    2016-04-15

    Highlights: • Removal of plastics. • Enrichment of In, Ga and Ge. • Low temperature. • No dioxines. - Abstract: The increasing consumption of electric and electronic equipment has led to a rise in toxic waste. To recover the metal fraction, a separation of the organic components is necessary because harmful substances such as chlorine, fluorine and bromine cause ecological damage, for example in the form of dioxins and furans at temperature above 400 °C. Hence, an alternative, environmentally friendly approach was investigated exploiting that a mixture of caustic soda and potassium hydroxide in eutectic composition melts below 200 °C, enabling a fast cracking of the long hydrocarbon chains. The trials demonstrate the removal of organic compounds without a loss of copper and precious metals, as well as a suppressed formation of hazardous off-gases. In order to avoid an input of alkaline elements into the furnace and ensuing problems with refractory materials, a washing step generates a sodium and potassium hydroxide solution, in which special metals like indium, gallium and germanium are enriched. Their concentrations facilitate the recovery of these elements, because otherwise they become lost in the typical recycling processes. The aim of this work was to find an environmental solution for the separation of plastics and metals as well as a strategically important answer for the recycling of printed circuit boards and mobile phones.

  17. Numerical Investigation on the Flow and Heat Transfer Characteristics of Supercritical Liquefied Natural Gas in an Airfoil Fin Printed Circuit Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Zhongchao Zhao

    2017-11-01

    Full Text Available As a new kind of highly compact and efficient micro-channel heat exchanger, the printed circuit heat exchanger (PCHE is a promising candidate satisfying the heat exchange requirements of liquefied natural gas (LNG vaporization at low and high pressure. The effects of airfoil fin arrangement on heat transfer and flow resistance were numerically investigated using supercritical liquefied natural gas (LNG as working fluid. The thermal properties of supercritical LNG were tested by utilizing the REFPROF software database. Numerical simulations were performed using FLUENT. The inlet temperature of supercritical LNG was 121 K, and its pressure was 10.5 MPa. The reference mass flow rate of LNG was set as 1.22 g/s for the vertical pitch Lv = 1.67 mm and the staggered pitch Ls = 0 mm, with the Reynolds number of about 3750. The SST k-ω model was selected and verified by comparing with the experimental data using supercritical liquid nitrogen as cold fluid. The airfoil fin PCHE had better thermal-hydraulic performance than that of the straight channel PCHE. Moreover, the airfoil fins with staggered arrangement displayed better thermal performance than that of the fins with parallel arrangement. The thermal-hydraulic performance of airfoil fin PCHE was improved with increasing Ls and Lv. Moreover, Lv affected the Nusselt number and pressure drop of airfoil fin PCHE more obviously. In conclusion, a sparser staggered arrangement of fins showed a better thermal-hydraulic performance in airfoil fin PCHE.

  18. Optimizing the operating parameters of corona electrostatic separation for recycling waste scraped printed circuit boards by computer simulation of electric field.

    Science.gov (United States)

    Li, Jia; Lu, Hongzhou; Liu, Shushu; Xu, Zhenming

    2008-05-01

    The printed circuit board (PCB) has a metal content of nearly 28% metal, including an abundance of nonferrous metals such as copper, lead, and tin. The purity of precious metals in PCBs is more than 10 times that of rich-content minerals. Therefore, the recycling of PCBs is an important subject, not only from the viewpoint of waste treatment, but also with respect to the recovery of valuable materials. Compared with traditional process the corona electrostatic separation (CES) had no waste water or gas during the process and it had high productivity with a low-energy cost. In this paper, the roll-type corona electrostatic separator was used to separate metals and nonmetals from scraped waste PCBs. The software MATLAB was used to simulate the distribution of electric field in separating space. It was found that, the variations of parameters of electrodes and applied voltages directly influenced the distribution of electric field. Through the correlation of simulated and experimental results, the good separation results were got under the optimized operating parameter: U=20-30 kV, L=L(1)=L(2)=0.21 m, R(1)=0.114, R(2)=0.019 m, theta(1)=20 degrees and theta(2)=60 degrees .

  19. Recycling of waste printed circuit boards with simultaneous enrichment of special metals by using alkaline melts: A green and strategically advantageous solution

    International Nuclear Information System (INIS)

    Stuhlpfarrer, Philipp; Luidold, Stefan; Antrekowitsch, Helmut

    2016-01-01

    Highlights: • Removal of plastics. • Enrichment of In, Ga and Ge. • Low temperature. • No dioxines. - Abstract: The increasing consumption of electric and electronic equipment has led to a rise in toxic waste. To recover the metal fraction, a separation of the organic components is necessary because harmful substances such as chlorine, fluorine and bromine cause ecological damage, for example in the form of dioxins and furans at temperature above 400 °C. Hence, an alternative, environmentally friendly approach was investigated exploiting that a mixture of caustic soda and potassium hydroxide in eutectic composition melts below 200 °C, enabling a fast cracking of the long hydrocarbon chains. The trials demonstrate the removal of organic compounds without a loss of copper and precious metals, as well as a suppressed formation of hazardous off-gases. In order to avoid an input of alkaline elements into the furnace and ensuing problems with refractory materials, a washing step generates a sodium and potassium hydroxide solution, in which special metals like indium, gallium and germanium are enriched. Their concentrations facilitate the recovery of these elements, because otherwise they become lost in the typical recycling processes. The aim of this work was to find an environmental solution for the separation of plastics and metals as well as a strategically important answer for the recycling of printed circuit boards and mobile phones.

  20. A new model for simulating microbial cyanide production and optimizing the medium parameters for recovering precious metals from waste printed circuit boards.

    Science.gov (United States)

    Yuan, Zhihui; Ruan, Jujun; Li, Yaying; Qiu, Rongliang

    2018-04-10

    Bioleaching is a green recycling technology for recovering precious metals from waste printed circuit boards (WPCBs). However, this technology requires increasing cyanide production to obtain desirable recovery efficiency. Luria-Bertani medium (LB medium, containing tryptone 10 g/L, yeast extract 5 g/L, NaCl 10 g/L) was commonly used in bioleaching of precious metal. In this study, results showed that LB medium did not produce highest yield of cyanide. Under optimal culture conditions (25 °C, pH 7.5), the maximum cyanide yield of the optimized medium (containing tryptone 6 g/L and yeast extract 5 g/L) was 1.5 times as high as that of LB medium. In addition, kinetics and relationship of cell growth and cyanide production was studied. Data of cell growth fitted logistics model well. Allometric model was demonstrated effective in describing relationship between cell growth and cyanide production. By inserting logistics equation into allometric equation, we got a novel hybrid equation containing five parameters. Kinetic data for cyanide production were well fitted to the new model. Model parameters reflected both cell growth and cyanide production process. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Measuring the layer-average volumetric water content in the uppermost 5 cm of soil using printed circuit board TDR probes

    International Nuclear Information System (INIS)

    Wang, W.; Kobayashi, T.; Chikushi, J.

    2000-01-01

    Newly designed printed circuit board TDR probes (PCBPs) were made, and they were calibrated by indoor experiment. A regression equation for estimating the volumetric water content from the dielectric constant measured with the PCBP was determined, which is almost the same as the well-known Topp's equation when the soil is rather wet while the difference becomes larger as the soil dries. The PCBP was designed to measure the average water content over a soil layer 5 cm thick because the thickness of soil layer involved in measuring water content by microwave remote sensing is several centimeters. A comparison experiment of measurements with PCBPs and those by microwave remote sensing was conducted in an arid area in the northwest of China. The results of this experiment show that the newly designed TDR probe is promising as the sensor to get ground truth of the surface wetness. This paper describes only the calibration of probes and the observations taken using them

  2. Synthesis of pure colloidal silver nanoparticles with high electroconductivity for printed electronic circuits: the effect of amines on their formation in aqueous media.

    Science.gov (United States)

    Natsuki, Jun; Abe, Takao

    2011-07-01

    This paper describes a practical and convenient method to prepare stable colloidal silver nanoparticles for use in printed electronic circuits. The method uses a dispersant and two kinds of reducing agents including 2-(dimethylamino) ethanol (DMAE), which play important roles in the reduction of silver ions in an aqueous medium. The effect of DMAE and dispersant, as well as the factors affecting particle size and morphology are investigated. In the formation of the silver nanoparticles, reduction occurs rapidly at room temperature and the silver particles can be separated easily from the mixture in a short time. In addition, organic solvents are not used. Pure, small and relatively uniform particles with a diameter less than 10 nm can be obtained that exhibit high electroconductivity. The silver nanoparticles are stable, and can be isolated as a dried powder that can be fully redispersed in deionized water. This method of producing colloidal silver nanoparticles will find practical use in electronics applications. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Co-recycling of acrylonitrile-butadiene-styrene waste plastic and nonmetal particles from waste printed circuit boards to manufacture reproduction composites.

    Science.gov (United States)

    Sun, Zhixing; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2015-01-01

    This study investigated the feasibility of using acrylonitrile-butadiene-styrene (ABS) waste plastic and nonmetal particles from waste printed circuit boards (WPCB) to manufacture reproduction composites (RC), with the aim of co-recycling these two waste resources. The composites were prepared in a twin-crew extruder and investigated by means of mechanical testing, in situ flexural observation, thermogravimatric analysis, and dimensional stability evaluation. The results showed that the presence of nonmetal particles significantly improved the mechanical properties and the physical performance of the RC. A loading of 30 wt% nonmetal particles could achieve a flexural strength of 72.6 MPa, a flexural modulus of 3.57 GPa, and an impact strength of 15.5 kJ/m2. Moreover, it was found that the application of maleic anhydride-grafted ABS as compatilizer could effectively promote the interfacial adhesion between the ABS plastic and the nonmetal particles. This research provides a novel method to reuse waste ABS and WPCB nonmetals for manufacturing high value-added product, which represents a promising way for waste recycling and resolving the environmental problem.

  4. Hybrid Multi-Layer Network Control for Emerging Cyber-Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Summerhill, Richard [Internet2, Washington, DC (United States); Lehman, Tom [Univ. of Southern California, Los Angeles, CA (United States). Information Sciences Inst. (ISI); Ghani, Nasir [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical & Computer Engineering; Boyd, Eric [Univ. Corporation for Advanced Internet Development (UCAID), Washington, DC (United States)

    2009-08-14

    There were four basic task areas identified for the Hybrid-MLN project. They are: Multi-Layer, Multi-Domain, Control Plane Architecture and Implementation; Heterogeneous DataPlane Testing; Simulation; Project Publications, Reports, and Presentations.

  5. 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

  6. 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

  7. 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

  8. 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....

  9. 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....

  10. 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.

  11. Introduction to printed electronics

    CERN Document Server

    Suganuma, Katsuaki

    2014-01-01

    This book describes in detail modern technologies for printed electronics, explaining how nanotechnology and modern printing technology are merging to revolutionize electronics fabrication of thin, lightweight, large, and inexpensive products. Readers will benefit from the explanations of materials, devices and circuits used to design and implement the latest applications of printed electronics, such as thin flexible OLED displays, organic solar cells, OLED lighting, smart wallpaper, sensors, logic, memory and more.

  12. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    1991-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  13. A new technology for separation and recovery of materials from waste printed circuit boards by dissolving bromine epoxy resins using ionic liquid

    International Nuclear Information System (INIS)

    Zhu, P.; Chen, Y.; Wang, L.Y.; Qian, G.Y.; Zhou, M.; Zhou, J.

    2012-01-01

    Highlights: ► WPCBs were heated in [EMIM + ][BF 4 − ] for recovering solider at 240 °C. ► The bromine epoxy resins in WPCBs were all dissolved in [EMIM + ][BF 4 − ] at 260 °C. ► Used [EMIM + ][BF 4 − ] is treated by water to obtain regeneration. - Abstract: Recovery of valuable materials from waste printed circuit boards (WPCBs) is quite difficult because WPCBs is a heterogeneous mixture of polymer materials, glass fibers, and metals. In this study, WPCBs was treated using ionic liquid (1-ethyl-3-methylimizadolium tetrafluoroborate [EMIM + ][BF 4 − ]). Experimental results showed that the separation of the solders went to completion, and electronic components (ECs) were removed in WPCBs when [EMIM + ][BF 4 − ] solution containing WPCBs was heated to 240 °C. Meanwhile, metallographic observations verified that the WPCBs had an initial delamination. When the temperature increased to 260 °C, the separation of the WPCBs went to completion, and coppers and glass fibers were obtained. The used [EMIM + ][BF 4 − ] was treated by water to generate a solid–liquid suspension, which was separated completely to obtain solid residues by filtration. Thermal analyses combined with infrared ray spectra (IR) observed that the solid residues were bromine epoxy resins. NMR (nuclear magnetic resonance) showed that hydrogen bond played an important role for [EMIM + ][BF 4 − ] dissolving bromine epoxy resins. This clean and non-polluting technology offers a new way to recycle valuable materials from WPCBs and prevent environmental pollution from WPCBs effectively.

  14. Leaching of Au, Ag, and Pd from waste printed circuit boards of mobile phone by iodide lixiviant after supercritical water pre-treatment.

    Science.gov (United States)

    Xiu, Fu-Rong; Qi, Yingying; Zhang, Fu-Shen

    2015-07-01

    Precious metals are the most attractive resources in waste printed circuit boards (PCBs) of mobile phones. In this work, an alternative process for recovering Au, Ag, and Pd from waste PCBs of mobile phones by supercritical water oxidation (SCWO) pre-treatment combined with iodine-iodide leaching process was developed. In the process, the waste PCBs of mobile phones were pre-treated in supercritical water, then a diluted hydrochloric acid leaching (HL) process was used to recovery the Cu, whose leaching efficiency was approximately 100%, finally the resulting residue was subjected to the iodine-iodide leaching process for recovering the Au, Ag, and Pd. Experimental results indicated that SCWO pre-treatment temperature, time, and pressure had significant influence on the Au, Ag, and Pd leaching from (SCWO+HL)-treated waste PCBs. The optimal SCWO pre-treatment conditions were 420°C and 60min for Au and Pd, and 410°C and 30min for Ag. The optimum dissolution parameters for Au, Pd, and Ag in (SCWO+HL)-treated PCBs with iodine-iodide system were leaching time of 120min (90min for Ag), iodine/iodide mole ratio of 1:5 (1:6 for Ag), solid-to-liquid ratio (S/L) of 1:10g/mL (1:8g/mL for Ag), and pH of 9, respectively. It is believed that the process developed in this study is environment friendly for the recovery of Au, Ag, and Pd from waste PCBs of mobile phones by SCWO pre-treatment combined with iodine-iodide leaching process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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.

  16. 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)

  17. 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.

  18. 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

  19. 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).

  20. Printed Circuit Board Quality Assurance

    Science.gov (United States)

    Sood, Bhanu

    2016-01-01

    PCB Assurance Summary: PCB assurance actives are informed by risk in context of the Project. Lessons are being applied across Projects for continuous improvements. Newer component technologies, smaller/high pitch devices: tighter and more demanding PCB designs: Identifying new research areas. New materials, designs, structures and test methods.

  1. Collaborative-Hybrid Multi-Layer Network Control for Emerging Cyber-Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, Tom [USC; Ghani, Nasir [UNM; Boyd, Eric [UCAID

    2010-08-31

    At a high level, there were four basic task areas identified for the Hybrid-MLN project. They are: o Multi-Layer, Multi-Domain, Control Plane Architecture and Implementation, including OSCARS layer2 and InterDomain Adaptation, Integration of LambdaStation and Terapaths with Layer2 dynamic provisioning, Control plane software release, Scheduling, AAA, security architecture, Network Virtualization architecture, Multi-Layer Network Architecture Framework Definition; o Heterogeneous DataPlane Testing; o Simulation; o Project Publications, Reports, and Presentations.

  2. Process development for recovery of copper and precious metals from waste printed circuit boards with emphasize on palladium and gold leaching and precipitation.

    Science.gov (United States)

    Behnamfard, Ali; Salarirad, Mohammad Mehdi; Veglio, Francesco

    2013-11-01

    A novel hydrometallurgical process was proposed for selective recovery of Cu, Ag, Au and Pd from waste printed circuit boards (PCBs). More than 99% of copper content was dissolved by using two consecutive sulfuric acid leaching steps in the presence of H2O2 as oxidizing agents. The solid residue of 2nd leaching step was treated by acidic thiourea in the presence of ferric iron as oxidizing agent and 85.76% Au and 71.36% Ag dissolution was achieved. The precipitation of Au and Ag from acidic thiourea leachate was investigated by using different amounts of sodium borohydride (SBH) as a reducing agent. The leaching of Pd and remained gold from the solid reside of 3rd leaching step was performed in NaClO-HCl-H2O2 leaching system and the effect of different parameters was investigated. The leaching of Pd and specially Au increased by increasing the NaClO concentration up to 10V% and any further increasing the NaClO concentration has a negligible effect. The leaching of Pd and Au increased by increasing the HCl concentration from 2.5 to 5M. The leaching of Pd and Au were endothermic and raising the temperature had a positive effect on leaching efficiency. The kinetics of Pd leaching was quite fast and after 30min complete leaching of Pd was achieved, while the leaching of Au need a longer contact time. The best conditions for leaching of Pd and Au in NaClO-HCl-H2O2 leaching system were determined to be 5M HCl, 1V% H2O2, 10V% NaClO at 336K for 3h with a solid/liquid ratio of 1/10. 100% of Pd and Au of what was in the chloride leachate were precipitated by using 2g/L SBH. Finally, a process flow sheet for the recovery of Cu, Ag, Au and Pd from PCB was proposed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Leaching of Au, Ag, and Pd from waste printed circuit boards of mobile phone by iodide lixiviant after supercritical water pre-treatment

    International Nuclear Information System (INIS)

    Xiu, Fu-Rong; Qi, Yingying; Zhang, Fu-Shen

    2015-01-01

    Highlights: • We report a novel process for recovering Au, Ag, and Pd from waste PCBs. • The effect of SCWO on the leaching of Au, Ag, and Pd in waste PCBs was studied. • SCWO was highly efficient for enhancing the leaching of Au, Ag, and Pd. • The optimum leaching parameters for Au, Ag, and Pd in iodine–iodide were studied. - Abstract: Precious metals are the most attractive resources in waste printed circuit boards (PCBs) of mobile phones. In this work, an alternative process for recovering Au, Ag, and Pd from waste PCBs of mobile phones by supercritical water oxidation (SCWO) pre-treatment combined with iodine–iodide leaching process was developed. In the process, the waste PCBs of mobile phones were pre-treated in supercritical water, then a diluted hydrochloric acid leaching (HL) process was used to recovery the Cu, whose leaching efficiency was approximately 100%, finally the resulting residue was subjected to the iodine–iodide leaching process for recovering the Au, Ag, and Pd. Experimental results indicated that SCWO pre-treatment temperature, time, and pressure had significant influence on the Au, Ag, and Pd leaching from (SCWO + HL)-treated waste PCBs. The optimal SCWO pre-treatment conditions were 420 °C and 60 min for Au and Pd, and 410 °C and 30 min for Ag. The optimum dissolution parameters for Au, Pd, and Ag in (SCWO + HL)-treated PCBs with iodine–iodide system were leaching time of 120 min (90 min for Ag), iodine/iodide mole ratio of 1:5 (1:6 for Ag), solid-to-liquid ratio (S/L) of 1:10 g/mL (1:8 g/mL for Ag), and pH of 9, respectively. It is believed that the process developed in this study is environment friendly for the recovery of Au, Ag, and Pd from waste PCBs of mobile phones by SCWO pre-treatment combined with iodine–iodide leaching process

  4. Leaching of Au, Ag, and Pd from waste printed circuit boards of mobile phone by iodide lixiviant after supercritical water pre-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Xiu, Fu-Rong, E-mail: xiu_chem@hotmail.com [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350108 (China); Qi, Yingying [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350108 (China); Zhang, Fu-Shen [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2015-07-15

    Highlights: • We report a novel process for recovering Au, Ag, and Pd from waste PCBs. • The effect of SCWO on the leaching of Au, Ag, and Pd in waste PCBs was studied. • SCWO was highly efficient for enhancing the leaching of Au, Ag, and Pd. • The optimum leaching parameters for Au, Ag, and Pd in iodine–iodide were studied. - Abstract: Precious metals are the most attractive resources in waste printed circuit boards (PCBs) of mobile phones. In this work, an alternative process for recovering Au, Ag, and Pd from waste PCBs of mobile phones by supercritical water oxidation (SCWO) pre-treatment combined with iodine–iodide leaching process was developed. In the process, the waste PCBs of mobile phones were pre-treated in supercritical water, then a diluted hydrochloric acid leaching (HL) process was used to recovery the Cu, whose leaching efficiency was approximately 100%, finally the resulting residue was subjected to the iodine–iodide leaching process for recovering the Au, Ag, and Pd. Experimental results indicated that SCWO pre-treatment temperature, time, and pressure had significant influence on the Au, Ag, and Pd leaching from (SCWO + HL)-treated waste PCBs. The optimal SCWO pre-treatment conditions were 420 °C and 60 min for Au and Pd, and 410 °C and 30 min for Ag. The optimum dissolution parameters for Au, Pd, and Ag in (SCWO + HL)-treated PCBs with iodine–iodide system were leaching time of 120 min (90 min for Ag), iodine/iodide mole ratio of 1:5 (1:6 for Ag), solid-to-liquid ratio (S/L) of 1:10 g/mL (1:8 g/mL for Ag), and pH of 9, respectively. It is believed that the process developed in this study is environment friendly for the recovery of Au, Ag, and Pd from waste PCBs of mobile phones by SCWO pre-treatment combined with iodine–iodide leaching process.

  5. Nonlinear dynamic response of a 'flexible-and-heavy' printed circuit board (PCB) to an impact load applied to its support contour

    International Nuclear Information System (INIS)

    Suhir, E; Vujosevic, M; Reinikainen, T

    2009-01-01

    Based on the developed simple and physically meaningful analytical ('mathematical') stress model, we evaluate some major parameters (amplitude, frequency, maximum acceleration, stresses and strains) of the response of a 'flexible-and-heavy' square simply supported printed circuit board (PCB) to an impact drop load applied to its support contour. The analysis is restricted to the first mode of vibrations and is carried out in application to the PCB design employed in an advanced accelerated test setup (test vehicle). This setup is aimed at the assessment of the performance, in accelerated test conditions on the board level, of packaging materials (and, first of all, BGA solder joint interconnections) subjected to dynamic (drop or shock) loading. It is anticipated that heavy masses could be mounted on the PCB to accelerate its dynamic response to an impact load. These masses are expected to be small in size, so that while changing the total mass of the board and generating significant inertia forces, they do not affect the board's flexural rigidity or its stiffness with respect to the in-plane loading. The PCB's contour is considered non-deformable, which is indeed the case in many practical situations. This circumstance, if the drop height and/or the induced inertia forces are significant, leads to elevated in-plane ('membrane') stresses in the PCB and, as a result of that, to the nonlinear response of the board to the impact load: the relationship between the magnitude of the load (determined by the initial impact velocity) and the induced PCB deflections becomes geometrically nonlinear, with a rigid cubic characteristic of the restoring force. The carried out numerical example, although reflects the characteristics of the PCB and loading conditions in an actual experimental setup, is merely an illustration of the general concept and is intended to demonstrate the abilities of the suggested method. Predictions based on this method agree well with the finite element

  6. 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...

  7. 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)

  8. 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...

  9. 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

  10. 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.

  11. 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

  12. Plane strain deformation of a multi-layered poroelastic half-space by ...

    Indian Academy of Sciences (India)

    The Biot linearized quasi-static theory of fluid-infiltrated porous materials is used to formulate the problem of the two-dimensional plane strain deformation of a multi-layered poroelastic half-space by surface loads. The Fourier–Laplace transforms of the stresses, displacements, pore pressure and fluid flux in each ...

  13. 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

  14. 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.

  15. 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

  16. 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...

  17. 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...

  18. 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.

  19. 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

  20. 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

  1. 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)

  2. A laser printing based approach for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Hu, M.; Guo, Q.; Zhang, W.; Yang, J., E-mail: jyang@eng.uwo.ca [Department of Mechanical and Materials Engineering, Western University, London N6A 3K7 (Canada); Liu, Y.; Lau, W. [Chengdu Green Energy and Green Manufacturing Technology R& D Center, 355 Tengfei Road, 620107 Chengdu (China); Wang, X. [Department of Mechanical and Materials Engineering, Western University, London N6A 3K7 (Canada); Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-03-07

    Here we report a study of printing of electronics using an office use laser printer. The proposed method eliminates those critical disadvantages of solvent-based printing techniques by taking the advantages of electroless deposition and laser printing. The synthesized toner acts as a catalyst for the electroless copper deposition as well as an adhesion-promoting buffer layer between the substrate and deposited copper. The easy metallization of printed patterns and strong metal-substrate adhesion make it an especially effective method for massive production of flexible printed circuits. The proposed process is a high throughput, low cost, efficient, and environmentally benign method for flexible electronics manufacturing.

  3. A laser printing based approach for printed electronics

    International Nuclear Information System (INIS)

    Zhang, T.; Hu, M.; Guo, Q.; Zhang, W.; Yang, J.; Liu, Y.; Lau, W.; Wang, X.

    2016-01-01

    Here we report a study of printing of electronics using an office use laser printer. The proposed method eliminates those critical disadvantages of solvent-based printing techniques by taking the advantages of electroless deposition and laser printing. The synthesized toner acts as a catalyst for the electroless copper deposition as well as an adhesion-promoting buffer layer between the substrate and deposited copper. The easy metallization of printed patterns and strong metal-substrate adhesion make it an especially effective method for massive production of flexible printed circuits. The proposed process is a high throughput, low cost, efficient, and environmentally benign method for flexible electronics manufacturing.

  4. 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.

  5. An Investigation on the Extraction and Quantitation of a Hexavalent Chromium in Acrylonitrile Butadiene Styrene Copolymer (ABS) and Printed Circuit Board (PCB) by Ion Chromatography Coupled with Inductively Coupled Plasma Atomic Emission Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Sang Ho; Kim, Yu Na [Mokpo National University, Muan (Korea, Republic of)

    2012-06-15

    A hexavalent chromium (Cr (VI)) is one of the hazardous substances regulated by the RoHS. The determination of Cr (VI) in various polymers and printed circuit board (PCB) has been very important. In this study, the three different analytical methods were investigated for the determination of a hexavalent chromium in Acrylonitrile Butadiene Styrene copolymer (ABS) and PCB. The results by three analytical methods were obtained and compared. An analytical method by UV-Visible spectrometer has been generally used for the determination of Cr (VI) in a sample, but a hexavalent chromium should complex with diphenylcarbazide for the detection in the method. The complexation did make an adverse effect on the quantitative analysis of Cr (VI) in ABS. The analytical method using diphenylcarbazide was also not applicable to printed circuit board (PCB) because PCB contained lots of irons. The irons interfered with the analysis of hexavalent chromium because those also could complex with diphenylcarbazide. In this study, hexavalent chromiums in PCB have been separated by ion chromatography (IC), then directly and selectively detected by inductively coupled plasma atomic emission spectrometry (ICP-AES). The quantity of Cr (VI) in PCB was 0.1 mg/kg

  6. Sustainability issues in circuit board recycling

    DEFF Research Database (Denmark)

    Legarth, Jens Brøbech; Alting, Leo; Baldo, Gian Luca

    1995-01-01

    The resource recovery and environmental impact issues of printed circuit board recycling by secondary copper smelters are discussed. Guidelines concerning material selection for circuit board manufacture and concerning the recycling processes are given to enhance recovery efficiency and to lower...

  7. 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.

  8. 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.

  9. On the dynamics of relativistic multi-layer spherical shell systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, Merse E; Racz, Istvan, E-mail: merse@rmki.kfki.hu, E-mail: iracz@rmki.kfki.hu [RMKI, H-1121 Budapest, Konkoly Thege Miklos ut 29-33, Budapest (Hungary)

    2011-04-21

    The relativistic time evolution of multi-layer spherically symmetric shell systems-consisting of infinitely thin shells separated by vacuum regions-is examined. Whenever two shells collide the evolution is continued with the assumption that the collision is totally transparent. The time evolution of various multi-layer shell systems-comprising large number of shells thereby mimicking the behavior of a thick shell making it possible to study the formation of acoustic singularities-is analyzed numerically and compared in certain cases to the corresponding Newtonian time evolution. The analytic setup is chosen such that the developed code is capable of following the evolution even inside the black hole region. This, in particular, allowed us to investigate the mass inflation phenomenon in the chosen framework.

  10. 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...

  11. 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)

  12. 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

  13. 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)

  14. 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

  15. 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

  16. 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)

  17. 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.

  18. 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.

  19. 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.)

  20. 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.

  1. 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)

  2. 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...

  3. 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)

  4. 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

  5. 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.

  6. 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.

  7. The Multi-Layered Perceptrons Neural Networks for the Prediction of Daily Solar Radiation

    OpenAIRE

    Radouane Iqdour; Abdelouhab Zeroual

    2007-01-01

    The Multi-Layered Perceptron (MLP) Neural networks have been very successful in a number of signal processing applications. In this work we have studied the possibilities and the met difficulties in the application of the MLP neural networks for the prediction of daily solar radiation data. We have used the Polack-Ribière algorithm for training the neural networks. A comparison, in term of the statistical indicators, with a linear model most used in literature, is also perfo...

  8. 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....

  9. 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.

  10. 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)

  11. 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.

  12. 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.

  13. Development of planar CT system for multi-layer PCB inspection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Youn, Hanbean; Kam, Soohwa; Park, Eunpyeong; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

    2015-05-15

    X-ray defect inspection apparatus can be used in the production line to inspect the PCB. However, a simple X-ray radiography cannot discriminate defects from the multi-layer PCBs because the layers of them overlays the defects. To complement this issue, computed tomography (CT) technology is applied to the NDT system which can offer 3-dimensional information of object. However, CT requires hundreds of projection images to examine a single PCB, hence real-time inspection is nearly impossible. In this study, we develop a planar computed tomography (pCT) system appropriate for the multi-layer PCB inspection. For the image reconstruction of planar cross-section images, we use the digital tomosynthesis (DTS) concept in association with the limited angle scanning. and performance characterization of the pCT system for the PCB inspection. The 3-d Fourier characteristics and more quantitative performance, such as contrast, uniformity, depth resolution will be presented. The cross-sectional images of multi-layer PCBs will also be demonstrated.

  14. 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.

  15. 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.}.

  16. 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.

  17. 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.

  18. 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.

  19. Remote Multi-layer Soil Temperature Monitoring System Based on GPRS

    Directory of Open Access Journals (Sweden)

    Ming Kuo CHEN

    2014-02-01

    Full Text Available There is the temperature difference between the upper and lower layer of the shallow soil in the forest. It is a potential energy that can be harvested by thermoelectric generator for the electronic device in the forest. The temperature distribution at different depths of the soil is the first step for thermoelectric generation. A remote multi-layer soil temperature monitoring system based on GPRS is proposed in this paper. The MSP430F149 MCU is used as the main controller of multi-layer soil temperature monitoring system. A temperature acquisition module is designed with DS18B20 and 4 core shielded twisted-pair cable. The GPRS module sends the measured data to remote server through wireless communication network. From the experiments in the campus of Beijing Forestry University, the maximum error of measured temperature in this system is 0.2°C by comparing with professional equipment in the same condition. The results of the experiments show that the system can accurately realize real-time monitoring of multi-layer soil temperature, and the data transmission is stable and reliable.

  20. 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.

  1. AFFORDABLE MULTI-LAYER CERAMIC (MLC) MANUFACTURING FOR POWER SYSTEMS (AMPS)

    Energy Technology Data Exchange (ETDEWEB)

    E.A. Barringer, Ph.D.

    2002-11-27

    McDermott Technology, Inc. (MTI) is attempting to develop high-performance, cost-competitive solid oxide fuel cell (SOFC) power systems. Recognizing the challenges and limitations facing the development of SOFC stacks comprised of electrode-supported cells and metallic interconnects, McDermott Technology, Inc. (MTI) has chosen to pursue an alternate path to commercialization. MTI is developing a multi-layer, co-fired, planar SOFC stack that will provide superior performance and reliability at reduced costs relative to competing designs. The MTI approach combines state-of-the-art SOFC materials with the manufacturing technology and infrastructure established for multi-layer ceramic (MLC) packages for the microelectronics industry. The rationale for using MLC packaging technology is that high quality, low-cost manufacturing has been demonstrated at high volumes. With the proper selection of SOFC materials, implementation of MLC fabrication methods offers unique designs for stacks (cells and interconnects) that are not possible through traditional fabrication methods. The MTI approach eliminates use of metal interconnects and ceramic-metal seals, which are primary sources of stack performance degradation. Co-fired cells are less susceptible to thermal cycling stresses by using material compositions that have closely matched coefficients of thermal expansion between the cell and the interconnect. The development of this SOFC stack technology was initiated in October 1999 under the DOE cosponsored program entitled ''Affordable Multi-layer Ceramic Manufacturing for Power Systems (AMPS)''. The AMPS Program was conducted as a two-phase program: Phase I--Feasibility Assessment (10/99--9/00); and Phase II--Process Development for Co-fired Stacks (10/00-3/02). This report provides a summary of the results from Phase I and a more detailed review of the results for Phase II. Phase I demonstrated the feasibility for fabricating multi-layer, co-fired cells and

  2. 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))

  3. 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

  4. 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.

  5. 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.

  6. DC microgrid power flow optimization by multi-layer supervision control. Design and experimental validation

    International Nuclear Information System (INIS)

    Sechilariu, Manuela; Wang, Bao Chao; Locment, Fabrice; Jouglet, Antoine

    2014-01-01

    Highlights: • DC microgrid (PV array, storage, power grid connection, DC load) with multi-layer supervision control. • Power balancing following power flow optimization while providing interface for smart grid communication. • Optimization under constraints: storage capability, grid power limitations, grid time-of-use pricing. • Experimental validation of DC microgrid power flow optimization by multi-layer supervision control. • DC microgrid able to perform peak shaving, to avoid undesired injection, and to make full use of locally energy. - Abstract: Urban areas have great potential for photovoltaic (PV) generation, however, direct PV power injection has limitations for high level PV penetration. It induces additional regulations in grid power balancing because of lacking abilities of responding to grid issues such as reducing grid peak consumption or avoiding undesired injections. The smart grid implementation, which is designed to meet these requirements, is facilitated by microgrids development. This paper presents a DC microgrid (PV array, storage, power grid connection, DC load) with multi-layer supervision control which handles instantaneous power balancing following the power flow optimization while providing interface for smart grid communication. The optimization takes into account forecast of PV power production and load power demand, while satisfying constraints such as storage capability, grid power limitations, grid time-of-use pricing and grid peak hour. Optimization, whose efficiency is related to the prediction accuracy, is carried out by mixed integer linear programming. Experimental results show that the proposed microgrid structure is able to control the power flow at near optimum cost and ensures self-correcting capability. It can respond to issues of performing peak shaving, avoiding undesired injection, and making full use of locally produced energy with respect to rigid element constraints

  7. High color rendering index of remote-type white LEDs with multi-layered quantum dot-phosphor films and short-wavelength pass dichroic filters

    Science.gov (United States)

    Yoon, Hee Chang; Oh, Ji Hye; Do, Young Rag

    2014-09-01

    This paper introduces high color rendering index (CRI) white light-emitting diodes (W-LEDs) coated with red emitting (Sr,Ca)AlSiN3:Eu phosphors and yellowish-green emitting AgIn5S8/ZnS (AIS/ZS) quantum dots (QDs) on glass or a short-wavelength pass dichroic filter (SPDF), which transmit blue wavelength regions and reflect yellow wavelength regions. The red emitting (Sr,Ca)AlSiN3:Eu phosphor film is coated on glass and a SPDF using a screen printing method, and then the yellowish-green emitting AIS/ZS QDs are coated on the red phosphor (Sr,Ca)AlSiN3:Eu film-coated glass and SPDF using the electrospray (e-spray) method.To fabricate the red phosphor film, the optimum amount of phosphor is dispersed in a silicon binder to form a red phosphor paste. The AIS/ZS QDs are mixed with dimethylformamide (DMF), toluene, and poly(methyl methacrylate) (PMMA) for the e-spray coating. The substrates are spin-coated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to fabricate a conductive surface. The CRI of the white LEDs is improved through inserting the red phosphor film between the QD layer and the glass substrate. Furthermore, the light intensities of the multi-layered phosphor films are enhanced through changing the glass substrate to the SPDF. The correlated color temperatures (CCTs) vary as a function of the phosphor concentration in the phosphor paste. The optical properties of the yellowish-green AIS/ZS QDs and red (Sr,Ca)AlSiN3:Eu phosphors are characterized using photoluminescence (PL), and the multi-layered QD-phosphor films are measured using electroluminescence (EL) with an InGaN blue LED (λmax = 450 nm) at 60 mA.

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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)

  14. 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.

  15. 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

  16. 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)

  17. 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...

  18. Multi-layer composite mechanical modeling for the inhomogeneous biofilm mechanical behavior.

    Science.gov (United States)

    Wang, Xiaoling; Han, Jingshi; Li, Kui; Wang, Guoqing; Hao, Mudong

    2016-08-01

    Experiments showed that bacterial biofilms are heterogeneous, for example, the density, the diffusion coefficient, and mechanical properties of the biofilm are different along the biofilm thickness. In this paper, we establish a multi-layer composite model to describe the biofilm mechanical inhomogeneity based on unified multiple-component cellular automaton (UMCCA) model. By using our model, we develop finite element simulation procedure for biofilm tension experiment. The failure limit and biofilm extension displacement obtained from our model agree well with experimental measurements. This method provides an alternative theory to study the mechanical inhomogeneity in biological materials.

  19. Multi-layered dielectric cladding plasmonic microdisk resonator filter and coupler

    International Nuclear Information System (INIS)

    Han Cheng, Bo; Lan, Yung-Chiang

    2013-01-01

    This work develops the plasmonic microdisk filter/coupler, whose effectiveness is evaluated by finite-difference time-domain simulation and theoretical analyses. Multi-layer dielectric cladding is used to prevent the scattering of surface plasmons (SPs) from a silver microdisk. This method allows devices that efficiently perform filter/coupler functions to be developed. The resonant conditions and the effective refractive index of bounded SP modes on the microdisk are determined herein. The waveguide-to-microdisk distance barely influences the resonant wavelength but it is inversely related to the bandwidth. These findings are consistent with predictions made using the typical ring resonator model.

  20. Packaging Printing Today

    OpenAIRE

    Stanislav Bolanča; Igor Majnarić; Kristijan Golubović

    2015-01-01

    Printing packaging covers today about 50% of all the printing products. Among the printing products there are printing on labels, printing on flexible packaging, printing on folding boxes, printing on the boxes of corrugated board, printing on glass packaging, synthetic and metal ones. The mentioned packaging are printed in flexo printing technique, offset printing technique, intaglio halftone process, silk – screen printing, ink ball printing, digital printing and hybrid printing process. T...

  1. Bulk and interface quantum states of electrons in multi-layer heterostructures with topological materials

    Science.gov (United States)

    Nikolic, Aleksandar; Zhang, Kexin; Barnes, C. H. W.

    2018-06-01

    In this article we describe the bulk and interface quantum states of electrons in multi-layer heterostructures in one dimension, consisting of topological insulators (TIs) and topologically trivial materials. We use and extend an effective four-band continuum Hamiltonian by introducing position dependence to the eight material parameters of the Hamiltonian. We are able to demonstrate complete conduction-valence band mixing in the interface states. We find evidence for topological features of bulk states of multi-layer TI heterostructures, as well as demonstrating both complete and incomplete conduction-valence band inversion at different bulk state energies. We show that the linear k z terms in the low-energy Hamiltonian, arising from overlap of p z orbitals between different atomic layers in the case of chalcogenides, control the amount of tunneling from TIs to trivial insulators. Finally, we show that the same linear k z terms in the low-energy Hamiltonian affect the material’s ability to form the localised interface state, and we demonstrate that due to this effect the spin and probability density localisation in a thin film of Sb2Te3 is incomplete. We show that changing the parameter that controls the magnitude of the overlap of p z orbitals affects the transport characteristics of the topologically conducting states, with incomplete topological state localisation resulting in increased backscattering.

  2. 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.

  3. 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

  4. Multi-layered foil capture of micrometeoroids and orbital debris in low Earth orbit

    Science.gov (United States)

    Kearsley, A.; Graham, G.

    Much of our knowledge concerning the sub-millimetre orbital debris population that poses a threat to orbiting satellites has been gleaned from examination of surfaces retrieved and subsequently analysed as part of post-flight investigations. The preservation of the hypervelocity impact-derived remnants located on these surfaces is very variable, whether of space debris or micrometeoroid origin. Whilst glass and metallic materials show highly visible impact craters when examined using optical and electron microscopes, complex mixing between the target material and the impacting particle may make unambiguous interpretation of the impactor origin difficult or impossible. Our recent detailed examination of selected multi-layered insulation (MLI) foils from the ISAS Space Flyer Unit (SFU), and our preliminary study of NASA's Trek blanket, exposed on the Mir station, show that these constructions have the potential to preserve abundant residue material of a quality sufficient for detailed analysis. Although there are still limitations on the recognition of certain sources of orbital debris, the foils complement the metal and glass substrates. We suggest that a purpose-built multi-layered foil structure may prove to be extremely effective for rapid collection and unambiguous analysis of impact- derived residues. Such a collector could be used an environmental monitor for ISS, as it would have low mass, high durability, easy deployment, recovery and storage, making it an economically viable and attractive option.

  5. Molecular depth profiling of multi-layer systems with cluster ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Juan [Department of Chemistry, Penn State University, University Park, PA 16802 (United States); Winograd, Nicholas [Department of Chemistry, Penn State University, University Park, PA 16802 (United States)]. E-mail: nxw@psu.edu

    2006-07-30

    Cluster bombardment of molecular films has created new opportunities for SIMS research. To more quantitatively examine the interaction of cluster beams with organic materials, we have developed a reproducible platform consisting of a well-defined sugar film (trehalose) doped with peptides. Molecular depth profiles have been acquired with these systems using C{sub 60} {sup +} bombardment. In this study, we utilize this platform to determine the feasibility of examining buried interfaces for multi-layer systems. Using C{sub 60} {sup +} at 20 keV, several systems have been tested including Al/trehalose/Si, Al/trehalose/Al/Si, Ag/trehalose/Si and ice/trehalose/Si. The results show that there can be interactions between the layers during the bombardment process that prevent a simple interpretation of the depth profile. We find so far that the best results are obtained when the mass of the overlayer atoms is less than or nearly equal to the mass of the atoms in buried molecules. In general, these observations suggest that C{sub 60} {sup +} bombardment can be successfully applied to interface characterization of multi-layer systems if the systems are carefully chosen.

  6. A mixture model for robust point matching under multi-layer motion.

    Directory of Open Access Journals (Sweden)

    Jiayi Ma

    Full Text Available This paper proposes an efficient mixture model for establishing robust point correspondences between two sets of points under multi-layer motion. Our algorithm starts by creating a set of putative correspondences which can contain a number of false correspondences, or outliers, in addition to the true correspondences (inliers. Next we solve for correspondence by interpolating a set of spatial transformations on the putative correspondence set based on a mixture model, which involves estimating a consensus of inlier points whose matching follows a non-parametric geometrical constraint. We formulate this as a maximum a posteriori (MAP estimation of a Bayesian model with hidden/latent variables indicating whether matches in the putative set are outliers or inliers. We impose non-parametric geometrical constraints on the correspondence, as a prior distribution, in a reproducing kernel Hilbert space (RKHS. MAP estimation is performed by the EM algorithm which by also estimating the variance of the prior model (initialized to a large value is able to obtain good estimates very quickly (e.g., avoiding many of the local minima inherent in this formulation. We further provide a fast implementation based on sparse approximation which can achieve a significant speed-up without much performance degradation. We illustrate the proposed method on 2D and 3D real images for sparse feature correspondence, as well as a public available dataset for shape matching. The quantitative results demonstrate that our method is robust to non-rigid deformation and multi-layer/large discontinuous motion.

  7. 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.

  8. 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.

  9. 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.

  10. Smart Grid as Multi-layer Interacting System for Complex Decision Makings

    Science.gov (United States)

    Bompard, Ettore; Han, Bei; Masera, Marcelo; Pons, Enrico

    This chapter presents an approach to the analysis of Smart Grids based on a multi-layer representation of their technical, cyber, social and decision-making aspects, as well as the related environmental constraints. In the Smart Grid paradigm, self-interested active customers (prosumers), system operators and market players interact among themselves making use of an extensive cyber infrastructure. In addition, policy decision makers define regulations, incentives and constraints to drive the behavior of the competing operators and prosumers, with the objective of ensuring the global desired performance (e.g. system stability, fair prices). For these reasons, the policy decision making is more complicated than in traditional power systems, and needs proper modeling and simulation tools for assessing "in vitro" and ex-ante the possible impacts of the decisions assumed. In this chapter, we consider the smart grids as multi-layered interacting complex systems. The intricacy of the framework, characterized by several interacting layers, cannot be captured by closed-form mathematical models. Therefore, a new approach using Multi Agent Simulation is described. With case studies we provide some indications about how to develop agent-based simulation tools presenting some preliminary examples.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Solid particle effects on heat transfer in a multi-layered molten pool with gas injection

    International Nuclear Information System (INIS)

    Bilbao y Leon, Rosa Marina; Corradini, Michael L.

    2006-01-01

    In the very unlikely event of a severe reactor accident involving core melt and pressure vessel failure, it is important to identify the circumstances that would allow the molten core material to cool down and resolidify, bringing core debris to a stable coolable state. To achieve this, it has been proposed to flood the cavity with water from above forming a layered structure where upward heat loss from the molten pool to the water will cause the core material to quench and solidify. In this situation the molten pool would become a three-phase mixture: e.g., a solid and liquid slurry formed by the molten pool as it cools to a temperature below the temperature of liquidus, agitated by the gases formed in the concrete ablation process. The present work quantifies the partition of the heat losses upward and downward in this multi-layered configuration, considering the influence of the viscosity and the solid fraction in the pool, from test data obtained from intermediate scale experiments at the University of Wisconsin-Madison. These experimental results show heat transfer behavior for multi-layered pools for a range of viscosities and solid fractions. These results are compared to previous experimental studies and well known correlations and models

  19. Thermal conductivities of single- and multi-layer phosphorene: a molecular dynamics study.

    Science.gov (United States)

    Zhang, Ying-Yan; Pei, Qing-Xiang; Jiang, Jin-Wu; Wei, Ning; Zhang, Yong-Wei

    2016-01-07

    As a new two-dimensional (2D) material, phosphorene has drawn growing attention owing to its novel electronic properties, such as layer-dependent direct bandgaps and high carrier mobility. Herein we investigate the in-plane and cross-plane thermal conductivities of single- and multi-layer phosphorene, focusing on geometrical (sample size, orientation and layer number) and strain (compression and tension) effects. A strong anisotropy is found in the in-plane thermal conductivity with its value along the zigzag direction being much higher than that along the armchair direction. Interestingly, the in-plane thermal conductivity of multi-layer phosphorene is insensitive to the layer number, which is in strong contrast to that of graphene where the interlayer interactions strongly influence the thermal transport. Surprisingly, tensile strain leads to an anomalous increase in the in-plane thermal conductivity of phosphorene, in particular in the armchair direction. Both the in-plane and cross-plane thermal conductivities can be modulated by external strain; however, the strain modulation along the cross-plane direction is more effective and thus more tunable than that along the in-plane direction. Our findings here are of great importance for the thermal management in phosphorene-based nanoelectronic devices and for thermoelectric applications of phosphorene.

  20. Improved lumped models for transient combined convective and radiative cooling of multi-layer composite slabs

    International Nuclear Information System (INIS)

    An Chen; Su Jian

    2011-01-01

    Improved lumped parameter models were developed for the transient heat conduction in multi-layer composite slabs subjected to combined convective and radiative cooling. The improved lumped models were obtained through two-point Hermite approximations for integrals. Transient combined convective and radiative cooling of three-layer composite slabs was analyzed to illustrate the applicability of the proposed lumped models, with respect to different values of the Biot numbers, the radiation-conduction parameter, the dimensionless thermal contact resistances, the dimensionless thickness, and the dimensionless thermal conductivity. It was shown by comparison with numerical solution of the original distributed parameter model that the higher order lumped model (H 1,1 /H 0,0 approximation) yielded significant improvement of average temperature prediction over the classical lumped model. In addition, the higher order (H 1,1 /H 0,0 ) model was applied to analyze the transient heat conduction problem of steel-concrete-steel sandwich plates. - Highlights: → Improved lumped models for convective-radiative cooling of multi-layer slabs were developed. → Two-point Hermite approximations for integrals were employed. → Significant improvement over classical lumped model was achieved. → The model can be applied to high Biot number and high radiation-conduction parameter. → Transient heat conduction in steel-concrete-steel sandwich pipes was analyzed as an example.

  1. Multi-layer cube sampling for liver boundary detection in PET-CT images.

    Science.gov (United States)

    Liu, Xinxin; Yang, Jian; Song, Shuang; Song, Hong; Ai, Danni; Zhu, Jianjun; Jiang, Yurong; Wang, Yongtian

    2018-06-01

    Liver metabolic information is considered as a crucial diagnostic marker for the diagnosis of fever of unknown origin, and liver recognition is the basis of automatic diagnosis of metabolic information extraction. However, the poor quality of PET and CT images is a challenge for information extraction and target recognition in PET-CT images. The existing detection method cannot meet the requirement of liver recognition in PET-CT images, which is the key problem in the big data analysis of PET-CT images. A novel texture feature descriptor called multi-layer cube sampling (MLCS) is developed for liver boundary detection in low-dose CT and PET images. The cube sampling feature is proposed for extracting more texture information, which uses a bi-centric voxel strategy. Neighbour voxels are divided into three regions by the centre voxel and the reference voxel in the histogram, and the voxel distribution information is statistically classified as texture feature. Multi-layer texture features are also used to improve the ability and adaptability of target recognition in volume data. The proposed feature is tested on the PET and CT images for liver boundary detection. For the liver in the volume data, mean detection rate (DR) and mean error rate (ER) reached 95.15 and 7.81% in low-quality PET images, and 83.10 and 21.08% in low-contrast CT images. The experimental results demonstrated that the proposed method is effective and robust for liver boundary detection.

  2. A Complex Systems Approach to More Resilient Multi-Layered Security Systems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nathanael J. K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bandlow, Alisa [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nozick, Linda Karen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Waddell, Lucas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Levin, Drew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Whetzel, Jonathan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-01

    In July 2012, protestors cut through security fences and gained access to the Y-12 National Security Complex. This was believed to be a highly reliable, multi-layered security system. This report documents the results of a Laboratory Directed Research and Development (LDRD) project that created a consistent, robust mathematical framework using complex systems analysis algorithms and techniques to better understand the emergent behavior, vulnerabilities and resiliency of multi-layered security systems subject to budget constraints and competing security priorities. Because there are several dimensions to security system performance and a range of attacks that might occur, the framework is multi-objective for a performance frontier to be estimated. This research explicitly uses probability of intruder interruption given detection (PI) as the primary resilience metric. We demonstrate the utility of this framework with both notional as well as real-world examples of Physical Protection Systems (PPSs) and validate using a well-established force-on-force simulation tool, Umbra.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. A New Approach for Severity Estimation of Transversal Cracks in Multi-layered Beams

    Directory of Open Access Journals (Sweden)

    Gilbert-Rainer Gillich

    Full Text Available Abstract Nowadays, the damage severity evaluation in mechanical structures is mostly performed by analyzing the natural frequency shift. The non-isotropic materials, as the multi-layered ones, are wide-spread in industrial applications, due to their interesting physic-mechanical properties. Thus, a deeper approach of multi-layered beams becomes an important request in the research domain. This paper introduces a damage severity estimator by expressing the crack evolution as a function of stored energy. It is well known that the energy stored in a beam without damage is greater than the energy of that damaged beam. As a consequence, the beam deflection can be related to the stored energy. In this regard, the possibility to split the damage localization and the damage severity assessment has been proven, and also the graphical evolution of the natural frequency shift has been achieved as a function of the crack depth. The results achieved by the finite element method (FEM and experimental tests are given in tables and graphics. For the first five vibration modes, a comparison was made between frequencies accomplished by analytical, numerical and experimental analyses, in order to give more credibility to the accuracy of the research data presented in this paper.

  8. Color dithering methods for LEGO-like 3D printing

    Science.gov (United States)

    Sun, Pei-Li; Sie, Yuping

    2015-01-01

    Color dithering methods for LEGO-like 3D printing are proposed in this study. The first method is work for opaque color brick building. It is a modification of classic error diffusion. Many color primaries can be chosen. However, RGBYKW is recommended as its image quality is good and the number of color primary is limited. For translucent color bricks, multi-layer color building can enhance the image quality significantly. A LUT-based method is proposed to speed the dithering proceeding and make the color distribution even smoother. Simulation results show the proposed multi-layer dithering method can really improve the image quality of LEGO-like 3D printing.

  9. Fabric circuits and method of manufacturing fabric circuits

    Science.gov (United States)

    Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)

    2011-01-01

    A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.

  10. 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

  11. 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.

  12. Highly accurate thickness measurement of multi-layered automotive paints using terahertz technology

    Science.gov (United States)

    Krimi, Soufiene; Klier, Jens; Jonuscheit, Joachim; von Freymann, Georg; Urbansky, Ralph; Beigang, René

    2016-07-01

    In this contribution, we present a highly accurate approach for thickness measurements of multi-layered automotive paints using terahertz time domain spectroscopy in reflection geometry. The proposed method combines the benefits of a model-based material parameters extraction method to calibrate the paint coatings, a generalized Rouard's method to simulate the terahertz radiation behavior within arbitrary thin films, and the robustness of a powerful evolutionary optimization algorithm to increase the sensitivity of the minimum thickness measurement limit. Within the framework of this work, a self-calibration model is introduced, which takes into consideration the real industrial challenges such as the effect of wet-on-wet spray in the painting process.

  13. Highly accurate thickness measurement of multi-layered automotive paints using terahertz technology

    International Nuclear Information System (INIS)

    Krimi, Soufiene; Beigang, René; Klier, Jens; Jonuscheit, Joachim; Freymann, Georg von; Urbansky, Ralph

    2016-01-01

    In this contribution, we present a highly accurate approach for thickness measurements of multi-layered automotive paints using terahertz time domain spectroscopy in reflection geometry. The proposed method combines the benefits of a model-based material parameters extraction method to calibrate the paint coatings, a generalized Rouard's method to simulate the terahertz radiation behavior within arbitrary thin films, and the robustness of a powerful evolutionary optimization algorithm to increase the sensitivity of the minimum thickness measurement limit. Within the framework of this work, a self-calibration model is introduced, which takes into consideration the real industrial challenges such as the effect of wet-on-wet spray in the painting process.

  14. 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.

  15. Identification of determinants for globalization of SMEs using multi-layer perceptron neural networks

    International Nuclear Information System (INIS)

    Draz, U.; Jahanzaib, M.; Asghar, G.

    2016-01-01

    SMEs (Small and Medium Sized Enterprises) sector is facing problems relating to implementation of international quality standards. These SMEs need to identify factors affecting business success abroad for intelligent allocation of resources to the process of internationalization. In this paper, MLP NN (Multi-Layer Perceptron Neural Network) has been used for identifying relative importance of key variables related to firm basics, manufacturing, quality inspection labs and level of education in determining the exporting status of Pakistani SMEs. A survey has been conducted for scoring out the pertinent variables in SMEs and coded in MLP NNs. It is found that firm registered with OEM (Original Equipment Manufacturer) and size of firm are the most important in determining exporting status of SMEs followed by other variables. For internationalization, the results aid policy makers in formulating strategies. (author)

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. Reference Architecture for Multi-Layer Software Defined Optical Data Center Networks

    Directory of Open Access Journals (Sweden)

    Casimer DeCusatis

    2015-09-01

    Full Text Available As cloud computing data centers grow larger and networking devices proliferate; many complex issues arise in the network management architecture. We propose a framework for multi-layer; multi-vendor optical network management using open standards-based software defined networking (SDN. Experimental results are demonstrated in a test bed consisting of three data centers interconnected by a 125 km metropolitan area network; running OpenStack with KVM and VMW are components. Use cases include inter-data center connectivity via a packet-optical metropolitan area network; intra-data center connectivity using an optical mesh network; and SDN coordination of networking equipment within and between multiple data centers. We create and demonstrate original software to implement virtual network slicing and affinity policy-as-a-service offerings. Enhancements to synchronous storage backup; cloud exchanges; and Fibre Channel over Ethernet topologies are also discussed.

  1. Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner.

    Science.gov (United States)

    An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai

    2016-07-20

    There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation.

  2. 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.

  3. Non-invasive NMR stratigraphy of a multi-layered artefact: an ancient detached mural painting.

    Science.gov (United States)

    Di Tullio, Valeria; Capitani, Donatella; Presciutti, Federica; Gentile, Gennaro; Brunetti, Brunetto Giovanni; Proietti, Noemi

    2013-10-01

    NMR stratigraphy was used to investigate in situ, non-destructively and non-invasively, the stratigraphy of hydrogen-rich layers of an ancient Nubian detached mural painting. Because of the detachment procedure, a complex multi-layered artefact was obtained, where, besides layers of the original mural painting, also the materials used during the procedure all became constitutive parts of the artefact. NMR measurements in situ enabled monitoring of the state of conservation of the artefact and planning of minimum representative sampling to validate results obtained in situ by solid-state NMR analysis of the samples. This analysis enabled chemical characterization of all organic materials. Use of reference compounds and prepared specimens assisted data interpretation.

  4. Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner

    Directory of Open Access Journals (Sweden)

    Jhonghyun An

    2016-07-01

    Full Text Available There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1 static local coordinate occupancy grid map (SLOGM building and (2 intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation.

  5. 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.

  6. Microwave assisted synthesis and characterization of barium titanate nanoparticles for multi layered ceramic capacitor applications.

    Science.gov (United States)

    Thirumalai, Sundararajan; Shanmugavel, Balasivanandha Prabu

    2011-01-01

    Barium titanate is a common ferroelectric electro-ceramic material having high dielectric constant, with photorefractive effect and piezoelectric properties. In this research work, nano-scale barium titanate powders were synthesized by microwave assisted mechano-chemical route. Suitable precursors were ball milled for 20 hours. TGA studies were performed to study the thermal stability of the powders. The powders were characterized by XRD, SEM and EDX Analysis. Microwave and Conventional heating were performed at 1000 degrees C. The overall heating schedule was reduced by 8 hours in microwave heating thereby reducing the energy and time requirement. The nano-scale, impurity-free and defect-free microstructure was clearly evident from the SEM micrograph and EDX patterns. LCR meter was used to measure the dielectric constant and dielectric loss values at various frequencies. Microwave heated powders showed superior dielectric constant value with low dielectric loss which is highly essential for the fabrication of Multi Layered Ceramic Capacitors.

  7. 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))

  8. Development of multi-layer ionization chamber for heavy-ion therapy

    International Nuclear Information System (INIS)

    Yajima, Kaori; Kusano, Yohsuke; Shimojyu, Takuya; Kanai, Tatsuaki

    2007-01-01

    In heavy-ion radiotherapy, depth dose distributions measured in water phantom are applied to estimate the dose distributions in a patient body. In order to obtain depth dose distributions in water phantom easily and rapidly, Multi-Layer Ionization Chamber (MLIC) was developed and had been adapted as a field dosimeter at NIRS since 2002. Production cross section of fragments in high Z material of the MLIC, however, is very different from those in water material. Then, empirical correction should be required. In order to obtain depth dose distributions with high accuracy, we have to use low Z material as a phantom, which are thought to produce similar fragments with water phantom. From this point of view, we have developed a new MLIC made up of low Z materials, PMMA and graphite film. (author)

  9. 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%.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Condition Assessment of Metal Oxide Surge Arrester Based on Multi-Layer SVM Classifier

    Directory of Open Access Journals (Sweden)

    M Khodsuz

    2015-12-01

    Full Text Available This paper introduces the indicators for surge arrester condition assessment based on the leakage current analysis. Maximum amplitude of fundamental harmonic of the resistive leakage current, maximum amplitude of third harmonic of the resistive leakage current and maximum amplitude of fundamental harmonic of the capacitive leakage current were used as indicators for surge arrester condition monitoring. Also, the effects of operating voltage fluctuation, third harmonic of voltage, overvoltage and surge arrester aging on these indicators were studied. Then, obtained data are applied to the multi-layer support vector machine for recognizing of surge arrester conditions. Obtained results show that introduced indicators have the high ability for evaluation of surge arrester conditions.

  17. Rats track odour trails accurately using a multi-layered strategy with near-optimal sampling.

    Science.gov (United States)

    Khan, Adil Ghani; Sarangi, Manaswini; Bhalla, Upinder Singh

    2012-02-28

    Tracking odour trails is a crucial behaviour for many animals, often leading to food, mates or away from danger. It is an excellent example of active sampling, where the animal itself controls how to sense the environment. Here we show that rats can track odour trails accurately with near-optimal sampling. We trained rats to follow odour trails drawn on paper spooled through a treadmill. By recording local field potentials (LFPs) from the olfactory bulb, and sniffing rates, we find that sniffing but not LFPs differ between tracking and non-tracking conditions. Rats can track odours within ~1 cm, and this accuracy is degraded when one nostril is closed. Moreover, they show path prediction on encountering a fork, wide 'casting' sweeps on encountering a gap and detection of reappearance of the trail in 1-2 sniffs. We suggest that rats use a multi-layered strategy, and achieve efficient sampling and high accuracy in this complex task.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. MULPEX: A compact multi-layered polymer foil collector for micrometeoroids and orbital debris

    Science.gov (United States)

    Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

    Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MUlti- Layer Polymer EXperiment (MULPEX) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 and 40 μm) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 μm olivine) and space debris (4 μm alumina and 1 mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

  4. 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

  5. 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

  6. 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

  7. E-waste: development of recycling process and chemical characterization of circuit printed - motherboard; Lixo eletronico: desenvolvimento de processo de reciclagem e caracterizacao quimica de placa de circuito impresso - motherboard

    Energy Technology Data Exchange (ETDEWEB)

    Junior, O.L.F.; Vargas, R.A.; Andreoli, M.; Martinelli, J.R.; Seo, E.S.M., E-mail: olfjunior@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The electro-electronic industry has been regulated by the National Politic of Solid Residues Act (PNRS) and Bill no. 7.404, concerning the actions, procedures, and method to collect, recycle and promotion of environmentally acceptable final destination of residues. The present work contributes to develop recycling process of printed circuit used in microcomputers and in its chemical characterization. The experimental procedure consisted of grinding, classification, magnetic and electrostatic separation, and separation based on density difference, followed by chemical characterization of the metallic and non metallic materials in the motherboard. It was determined that the amounts of Ag, Al, Ba, Cl, Cr, Cu, Fe, Mn, Pb, and Zn in the residue are above the toxicity allowable levels, and they are in the samples of the decanted material. Among the samples of the floating material, Al, Ba, Br, Ca, Cu, Fe, Pb (in less quantity), Si (in more quantity), and Sn, Ti and Zn were detected. Those materials can be useful in the preparation of red ceramics. (author)

  8. An innovative "ChemicalVia" process for the production of high density interconnect printed circuit boards The ATLAS muon chamber quality control with the X-ray tomograph at CERN

    CERN Document Server

    Da Silva, Vitor; Watts, David; Van der Bij, Erik; Banhidi, Z; Berbiers, Julien; Lampl, W; Marchesotti, M; Rangod, Stephane; Sbrissa, E; Schuh, S; Voss, Rüdiger; Zhuravlov, V

    2004-01-01

    The ChemicalVia process, patented by CERN, provides a new method of making microvias in high-density multilayer printed circuit boards of different types, such as sequential build-up (SBU), high density interconnected (HDI), or laminated multi-chip modules (MCM-L). The process uses chemical etching instead of laser, plasma or other etching techniques and can be implemented in a chain production line. This results in an overall reduced operation and maintenance cost and a much shorter hole production time as compared with other microvia processes. copy Emerald Group Publishing Limited. 4 Refs.4 An essential part of the Muon Spectrometer of the ATLAS experiment is based on the Monitored Drift Tube (MDT) technology. About 1200 muon drift chambers are being built at 13 institutes all over the world. The MDT chambers require an exceptional mechanical construction accuracy of better than 20 mu m. A dedicated X-ray tomograph has been developed at CERN since 1996 to control the mechanical quality of the chambers. The...

  9. A fully printed ferrite nano-particle ink based tunable antenna

    KAUST Repository

    Ghaffar, Farhan A.

    2016-11-02

    Inkjet printing or printing in general has emerged as a very attractive method for the fabrication of low cost and large size electronic systems. However, most of the printed designs rely on nano-particle based metallic inks which are printed on conventional microwave substrates. In order to have a fully printed fabrication process, the substrate also need to be printed. In this paper, a fully printed multi-layer process utilizing custom Fe2O3 based magnetic ink and a silver organic complex (SOC) ink is demonstrated for tunable antennas applications. The ink has been characterized for high frequency and magnetostatic properties. Finally as a proof of concept, a microstrip patch antenna is realized using the proposed fabrication technique which shows a tuning range of 12.5 %.

  10. Application to printed resistors

    International Nuclear Information System (INIS)

    Hachiyanagi, Yoshimi; Uraki, Hisatsugu; Sawamura, Masashi

    1989-01-01

    Most of printed circuit boards are made at present by etching copper foils which are laminated on insulating composite boards of paper/phenol resin or glass nonwoven fabric/epoxy rein. This is called subtractive process, and since this is a wet process, the problem of coping with the pollution due to etching solution, plating solution and others is involved. As the method of solving this problem, attention has been paid to the dry process which forms conductor patterns by screen printing using electro-conductive paste. For such resin substrates, generally polymer thick films (PTF) using thermosetting resin as the binder are used. Also the research on the formation of resistors, condensers and other parts by printing using the technology of cermet thick films (CTF) and PTF is active, and it is partially put in practical use. The problems are the deformation and deterioration of substrates, therefore, as the countermeasures, electron beam hardening type PTF has been studied, and various pastes have been developed. In this paper, electron beam hardening type printed resistors are reported. The features, resistance paste, and a number of the experiments on printed resistors are described. (K.I.)

  11. Regional atmospheric budgets of reduced nitrogen over the British isles assessed using a multi-layer atmospheric transport model

    NARCIS (Netherlands)

    Fournier, N.; Tang, Y.S.; Dragosits, U.; Kluizenaar, Y.de; Sutton, M.A.

    2005-01-01

    Atmospheric budgets of reduced nitrogen for the major political regions of the British Isles are investigated with a multi-layer atmospheric transport model. The model is validated against measurements of NH3 concentration and is developed to provide atmospheric budgets for defined subdomains of the

  12. 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.

  13. 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...

  14. 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)

  15. 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.

  16. Uniformity of fully gravure printed organic field-effect transistors

    International Nuclear Information System (INIS)

    Hambsch, M.; Reuter, K.; Stanel, M.; Schmidt, G.; Kempa, H.; Fuegmann, U.; Hahn, U.; Huebler, A.C.

    2010-01-01

    Fully mass-printed organic field-effect transistors were made completely by means of gravure printing. Therefore a special printing layout was developed in order to avoid register problems in print direction. Upon using this layout, contact pads for source-drain electrodes of the transistors are printed together with the gate electrodes in one and the same printing run. More than 50,000 transistors have been produced and by random tests a yield of approximately 75% has been determined. The principle suitability of the gravure printed transistors for integrated circuits has been shown by the realization of ring oscillators.

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

    Directory of Open Access Journals (Sweden)

    Diniz Neto, O. O.

    1998-04-01

    Full Text Available In the work we examine the heating of multi-layered samples by a powerful Nd - YAG pulsed láser. The samples are made of two and three layers, conductor-isolator (Al-Al2O3, conductor-conductor (Al-Ag; Al-Au and conductor-conductor-conductor (Al-Au-Ag; Ag-Au-Al. The transient behaviour of the temperature distribution throughout the sample 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 beam as the heating source. We showed the influence of the substrate in the thermal profile, in space and time, and máximum temperature on the multi-layered samples.

    Em nosso trabalho examinamos o aquecimento de amostras compostas de duas e três camadas, condutor- isolante e condutor-condutor, com um pulso potente de láser. O comportamento transiente da distribuição de temperatura através da amostra foi calculado. Em nosso modelo de calculo para o processo de aquecimento levamos em conta a dependência com a temperatura dos parâmetros térmicos (difusividade, capacidade e condutividade térmica, óticos (refletividade e coeficiente de absorção, bem como a dependência das condições de contorno com o tempo e consequentemente com a temperatura. Aplicamos nossa metodología para calcular o aquecimento amostras compostas: Al-Au, Al-Ag, Al-Al2O3, Al-Au-Ag e Ag-Au-Al. Concluimos que o substrato influencia as temperaturas máximas nas superfície exposta ao láser e a forma com que a frente de calor se propaga nas amostras termicamente finas.

  18. 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

  19. 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

  20. 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

  1. Advanced circuit simulation using Multisim workbench

    CERN Document Server

    Báez-López, David; Cervantes-Villagómez, Ofelia Delfina

    2012-01-01

    Multisim is now the de facto standard for circuit simulation. It is a SPICE-based circuit simulator which combines analog, discrete-time, and mixed-mode circuits. In addition, it is the only simulator which incorporates microcontroller simulation in the same environment. It also includes a tool for printed circuit board design.Advanced Circuit Simulation Using Multisim Workbench is a companion book to Circuit Analysis Using Multisim, published by Morgan & Claypool in 2011. This new book covers advanced analyses and the creation of models and subcircuits. It also includes coverage of transmissi

  2. Multi-layered zinc oxide-graphene composite thin films for selective nitrogen dioxide sensing

    Science.gov (United States)

    Ghosh, A.; Bhowmick, T.; Majumder, S. B.

    2018-02-01

    In the present work, selective nitrogen dioxide (NO2) sensing characteristics of multi-layered graphene-zinc oxide (G-ZnO) thin films have been demonstrated at 150 °C. The response% of 5 ppm NO2 was measured to be 894% with response and recovery times estimated to be 150 s and 315 s, respectively. In these composite films, the interaction between graphene and zinc oxide is established through X-ray photoelectron spectroscopy in conjunction with the analyses of photoluminescence spectra. Superior NO2 sensing of these films is due to simultaneous chemiadsorption of molecular oxygen and NO2 gases onto graphene and ZnO surfaces, resulting in an appreciable increase in the depletion layer width and thereby the sensor resistance. The sensor responses for other reducing gases (viz., CO, H2, and i-C4H10) are postulated to be due to their catalytic oxidation on the sensor surface, resulting in a decrease in the sensor resistance upon gas exposure. At lower operating temperature, due to the molecular nature of the chemiadsorbed oxygen, poor catalytic oxidation leads to a far lower sensor response for reducing gases as compared to NO2. For mixed NO2 and reducing gas sensing, we have reported that fast Fourier transformation of the resistance transients of all these gases in conjunction with principal component analyses forms a reasonably distinct cluster and, therefore, could easily be differentiated.

  3. A Fast Multi-layer Subnetwork Connection Method for Time Series InSAR Technique

    Directory of Open Access Journals (Sweden)

    WU Hong'an

    2016-10-01

    Full Text Available Nowadays, times series interferometric synthetic aperture radar (InSAR technique has been widely used in ground deformation monitoring, especially in urban areas where lots of stable point targets can be detected. However, in standard time series InSAR technique, affected by atmospheric correlation distance and the threshold of linear model coherence, the Delaunay triangulation for connecting point targets can be easily separated into many discontinuous subnetworks. Thus it is difficult to retrieve ground deformation in non-urban areas. In order to monitor ground deformation in large areas efficiently, a novel multi-layer subnetwork connection (MLSC method is proposed for connecting all subnetworks. The advantage of the method is that it can quickly reduce the number of subnetworks with valid edges layer-by-layer. This method is compared with the existing complex network connecting mehod. The experimental results demonstrate that the data processing time of the proposed method is only 32.56% of the latter one.

  4. Operationalising resilience to drought: Multi-layered safety for flooding applied to droughts

    Science.gov (United States)

    Rijke, Jeroen; Smith, Jennifer Vessels; Gersonius, Berry; van Herk, Sebastiaan; Pathirana, Assela; Ashley, Richard; Wong, Tony; Zevenbergen, Chris

    2014-11-01

    This paper sets out a way of thinking about how to prepare for and respond to droughts in a holistic way using a framework developed for managing floods. It shows how the multi-layered safety (MLS) approach for flood resilience can be utilised in the context of drought in a way that three layers of intervention can be distinguished for operationalising drought resilience: (1) protection against water shortage through augmentation and diversification of water supplies; (2) prevention of damage in case of water shortage through increased efficiency of water use and timely asset maintenance; (3) preparedness for future water shortages through mechanisms to reduce the use of water and adopt innovative water technologies. Application of MLS to the cities of Adelaide, Melbourne and Sydney shows that recent water reforms in these cities were primarily focused on protection measures that aim to reduce the hazard source or exposure to insufficient water supplies. Prevention and preparedness measures could be considered in defining interventions that aim to further increase the drought resilience of these cities. Although further research is needed, the application suggests that MLS can be applied to the context of drought risk management. The MLS framework can be used to classify the suite of plans deployed by a city to manage future drought risks and can be considered a planning tool to identify opportunities for increasing the level of redundancy and hence resilience of the drought risk management system.

  5. Mechanical Behaviour of 3D Multi-layer Braided Composites: Experimental, Numerical and Theoretical Study

    Science.gov (United States)

    Deng, Jian; Zhou, Guangming; Ji, Le; Wang, Xiaopei

    2017-12-01

    Mechanical properties and failure mechanisms of a newly designed 3D multi-layer braided composites are evaluated by experimental, numerical and theoretical studies. The microstructure of the composites is introduced. The unit cell technique is employed to address the periodic arrangement of the structure. The volume averaging method is used in theoretical solutions while FEM with reasonable periodic boundary conditions and meshing technique in numerical simulations. Experimental studies are also conducted to verify the feasibility of the proposed models. Predicted elastic properties agree well with the experimental data, indicating the feasibility of the proposed models. Numerical evaluation is more accurate than theoretical assessment. Deformations and stress distributions of the unit cell under tension shows displacement and traction continuity, guaranteeing the rationality of the applied periodic boundary conditions. Although compression and tension modulus are close, the compressive strength only reaches 70% of the tension strength. This indicates that the composites can be weakened in compressive loading. Additionally, by analysing the micrograph of fracture faces and strain-stress curves, a brittle failure mechanism is observed both in composites under tension and compression.

  6. Examining the impact of multi-layer graphene using cellular and amphibian models

    International Nuclear Information System (INIS)

    Muzi, Laura; Russier, Julie; Ménard-Moyon, Cécilia; Bianco, Alberto; Mouchet, Florence; Cadarsi, Stéphanie; Pinelli, Eric; Gauthier, Laury; Janowska, Izabela; Risuleo, Gianfranco; Soula, Brigitte; Galibert, Anne-Marie; Flahaut, Emmanuel

    2016-01-01

    In the last few years, graphene has been defined as the revolutionary material showing an incredible expansion in industrial applications. Different graphene forms have been applied in several contexts, spreading from energy technologies and electronics to food and agriculture technologies. Graphene showed promises also in the biomedical field. Hopeful results have been already obtained in diagnostic, drug delivery, tissue regeneration and photothermal cancer ablation. In view of the enormous development of graphene-based technologies, a careful assessment of its impact on health and environment is demanded. It is evident how investigating the graphene toxicity is of fundamental importance in the context of medical purposes. On the other hand, the nanomaterial present in the environment, likely to be generated all along the industrial life-cycle, may have harmful effects on living organisms. In the present work, an important contribution on the impact of multi-layer graphene (MLG) on health and environment is given by using a multifaceted approach. For the first purpose, the effect of the material on two mammalian cell models was assessed. Key cytotoxicity parameters were considered such as cell viability and inflammatory response induction. This was combined with an evaluation of MLG toxicity towards Xenopus laevis, used as both in vivo and environmental model organism. (paper)

  7. Light source distribution and scattering phase function influence light transport in diffuse multi-layered media

    Science.gov (United States)

    Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Askoura, Mohamed Lamine

    2017-06-01

    Red and near-Infrared light is often used as a useful diagnostic and imaging probe for highly scattering media such as biological tissues, fruits and vegetables. Part of diffusively reflected light gives interesting information related to the tissue subsurface, whereas light recorded at further distances may probe deeper into the interrogated turbid tissues. However, modelling diffusive events occurring at short source-detector distances requires to consider both the distribution of the light sources and the scattering phase functions. In this report, a modified Monte Carlo model is used to compute light transport in curved and multi-layered tissue samples which are covered with a thin and highly diffusing tissue layer. Different light source distributions (ballistic, diffuse or Lambertian) are tested with specific scattering phase functions (modified or not modified Henyey-Greenstein, Gegenbauer and Mie) to compute the amount of backscattered and transmitted light in apple and human skin structures. Comparisons between simulation results and experiments carried out with a multispectral imaging setup confirm the soundness of the theoretical strategy and may explain the role of the skin on light transport in whole and half-cut apples. Other computational results show that a Lambertian source distribution combined with a Henyey-Greenstein phase function provides a higher photon density in the stratum corneum than in the upper dermis layer. Furthermore, it is also shown that the scattering phase function may affect the shape and the magnitude of the Bidirectional Reflectance Distribution (BRDF) exhibited at the skin surface.

  8. 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.

  9. 3D Polygon Mesh Compression with Multi Layer Feed Forward Neural Networks

    Directory of Open Access Journals (Sweden)

    Emmanouil Piperakis

    2003-06-01

    Full Text Available In this paper, an experiment is conducted which proves that multi layer feed forward neural networks are capable of compressing 3D polygon meshes. Our compression method not only preserves the initial accuracy of the represented object but also enhances it. The neural network employed includes the vertex coordinates, the connectivity and normal information in one compact form, converting the discrete and surface polygon representation into an analytic, solid colloquial. Furthermore, the 3D object in its compressed neural form can be directly - without decompression - used for rendering. The neural compression - representation is viable to 3D transformations without the need of any anti-aliasing techniques - transformations do not disrupt the accuracy of the geometry. Our method does not su.er any scaling problem and was tested with objects of 300 to 107 polygons - such as the David of Michelangelo - achieving in all cases an order of O(b3 less bits for the representation than any other commonly known compression method. The simplicity of our algorithm and the established mathematical background of neural networks combined with their aptness for hardware implementation can establish this method as a good solution for polygon compression and if further investigated, a novel approach for 3D collision, animation and morphing.

  10. Optical nonlinearities in Ag/BaTiO{sub 3} multi-layer nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Yang Guang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)], E-mail: gyang@hust.edu.cn; Zhou Youhua [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics and Information Engineering, Jianghan University, Wuhan 430056 (China); Long Hua; Li Yuhua; Yang Yifa [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2007-07-31

    The multi-layer structure of barium titanate composite thin films containing Ag nanoparticles were grown on MgO (100) substrates using pulsed laser deposition technique under the nitrogen pressure of 7.4 Pa. The X-ray photoelectron spectroscopy analysis indicated that the samples were composed of metal Ag embedded in the BaTiO{sub 3} matrices. The optical absorption properties were measured from 300 nm to 800 nm, and the absorption peaks due to the surface plasmon resonance of Ag particles were observed. With the increasing of Ag concentration in composite films, the peak absorption increased and shifted to longer wavelength (red-shift). Furthermore, the third-order optical nonlinearities of the films were determined by z-scan method and the nonlinear refractive index, n{sub 2}, and nonlinear absorption coefficient, {beta}, were determined to be about - 1.91 x 10{sup -13} m{sup 2}/W and - 5.80 x 10{sup -7} m/W, respectively.

  11. 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.

  12. 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.

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

    KAUST Repository

    Moubayed, Abdallah J.

    2014-05-01

    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 collaboration between the collocated primary and cognitive radio base-stations in order to minimize their own as well as each other’s packet recovery overheads, thus by improving their throughput. The proposed scheme ensures that each network’s performance is not degraded by its help to the other network. Moreover, it guarantees that the primary network’s interference threshold is not violated in the same and adjacent cells. Yet, the scheme allows the reduction of the recovery overhead in the collocated primary and cognitive radio networks. The reduction in the cognitive radio network is further amplified due to the perfect detection of spectrum holes which allows the cognitive radio base station to transmit at higher power without fear of violating the interference threshold of the primary network. For the secondary network, simulation results show reductions of 20% and 34% in the packet recovery overhead, compared to the non-collaborative scheme, for low and high probabilities of primary packet arrivals, respectively. For the primary network, this reduction was found to be 12%. Furthermore, with the use of fractional cooperation, the average recovery overhead is further reduced by around 5% for the primary network and around 10% for the secondary network when a high fractional cooperation probability is used.

  14. 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)

  15. Experimental Study of Weepage in Multi-layer Glass Reinforced Piping

    KAUST Repository

    Al Sinan, Hussain

    2014-05-01

    Glass Reinforced Polymer pipes, commonly used in water transport applications, are prone to long term weepage. Weepage is defined as the transfer of fluid through the pipe and is considered a functional failure. An experimental investigation of weepage in multi-layered GRP pipes was carried out in two parts aiming to understand the phenomenon to help enhance the weepage resistance of manufactured pipes. First, liner surface profilometry investigation was carried out to identify microscopic features that might serve in initiating weepage. Second, MRI and x-ray tomography and SEM imaging of pipe samples aged with water and dye penetrant was carried out to capture weepage development through the pipe thickness. Diffusion through liner fiber/resin interface, propagation in the direction of poorly wetted hoop fibers and transverse cracks were found to be the likely causes of accelerating weepage in the samples. Fiber rich zones in the liner were considered weak spots that water can use for fast penetration of the liner. Finally, polyester netting used to hold core layer was found to help in water accumulation and transport through the pipe increasing the chances of failure.

  16. A simple method for fabricating multi-layer PDMS structures for 3D microfluidic chips

    KAUST Repository

    Zhang, Mengying

    2010-01-01

    We report a simple methodology to fabricate PDMS multi-layer microfluidic chips. A PDMS slab was surface-treated by trichloro (1H,1H,2H,2H-perfluorooctyl) silane, and acts as a reusable transferring layer. Uniformity of the thickness of the patterned PDMS layer and the well-alignment could be achieved due to the transparency and proper flexibility of this transferring layer. Surface treatment results are confirmed by XPS and contact angle testing, while bonding forces between different layers were measured for better understanding of the transferring process. We have also designed and fabricated a few simple types of 3D PDMS chip, especially one consisting of 6 thin layers (each with thickness of 50 μm), to demonstrate the potential utilization of this technique. 3D fluorescence images were taken by a confocal microscope to illustrate the spatial characters of essential parts. This fabrication method is confirmed to be fast, simple, repeatable, low cost and possible to be mechanized for mass production. © The Royal Society of Chemistry 2010.

  17. Characterization of multi-layered impact damage in polymer matrix composites using lateral thermography

    Science.gov (United States)

    Whitlow, Travis; Sathish, Shamachary

    2017-02-01

    Polymer matrix composites (PMCs) are increasingly being integrated into aircraft structures. However, these components are susceptible to impact related delamination, which, on aircrafts, can occur due to a number of reasons during aircraft use and maintenance. Quantifying impact damage is an important aspect for life-management of aircraft and requires in-depth knowledge of the damage zone on a ply-by-ply level. Traditionally, immersion ultrasound has provided relative high resolution images of impact damage. Ultrasonic time-of-flight data can be used to determine the front surface delamination depth and an approximation of the delaminated area. However, such inspections require the material to be immersed in water and can be time consuming. The objective of this work is to develop a quick and robust methodology to non-destructively characterize multi-layered impact damage using lateral thermography. Initial results suggest lateral heat flow is sensitive to the depth of impact damage. The anticipated outcome of this project is to estimate the extent of through-thickness impact damage. Initial results are shown and future efforts are discussed.

  18. Unified Multi-Layer among Software Defined Multi-Domain Optical Networks (Invited

    Directory of Open Access Journals (Sweden)

    Hui Yang

    2015-06-01

    Full Text Available The software defined networking (SDN enabled by OpenFlow protocol has gained popularity which can enable the network to be programmable and accommodate both fixed and flexible bandwidth services. In this paper, we present a unified multi-layer (UML architecture with multiple controllers and a dynamic orchestra plane (DOP for software defined multi-domain optical networks. The proposed architecture can shield the differences among various optical devices from multi-vendors and the details of connecting heterogeneous networks. The cross-domain services with on-demand bandwidth can be deployed via unified interfaces provided by the dynamic orchestra plane. Additionally, the globalization strategy and practical capture of signal processing are presented based on the architecture. The overall feasibility and efficiency of the proposed architecture is experimentally verified on the control plane of our OpenFlow-based testbed. The performance of globalization strategy under heavy traffic load scenario is also quantitatively evaluated based on UML architecture compared with other strategies in terms of blocking probability, average hops, and average resource consumption.

  19. Multi-layer film flow down an inclined plane: experimental investigation

    KAUST Repository

    Henry, Daniel

    2014-11-19

    We report the results from an experimental study of the flow of a film down an inclined plane where the film itself is comprised of up to three layers of different liquids. By measuring the total film thickness for a broad range of parameters including flow rates and liquid physical properties, we provide a thorough and systematic test of the single-layer approximation for multi-layer films for Reynolds numbers Re = ρQ/μ≈0.03-60. In addition, we also measure the change in film thickness of individual layers as a function of flow rates for a variety of experimental configurations. With the aid of high-speed particle tracking, we derive the velocity fields and free-surface velocities to compare to the single-layer approximation. Furthermore, we provide experimental evidence of small capillary ridge formations close to the point where two layers merge and compare our experimental parameter range for the occurrence of this phenomenon to those previously reported.

  20. Enhancing sound absorption and transmission through flexible multi-layer micro-perforated structures.

    Science.gov (United States)

    Bravo, Teresa; Maury, Cédric; Pinhède, Cédric

    2013-11-01

    Theoretical and experimental results are presented into the sound absorption and transmission properties of multi-layer structures made up of thin micro-perforated panels (ML-MPPs). The objective is to improve both the absorption and insulation performances of ML-MPPs through impedance boundary optimization. A fully coupled modal formulation is introduced that predicts the effect of the structural resonances onto the normal incidence absorption coefficient and transmission loss of ML-MPPs. This model is assessed against standing wave tube measurements and simulations based on impedance translation method for two double-layer MPP configurations of relevance in building acoustics and aeronautics. Optimal impedance relationships are proposed that ensure simultaneous maximization of both the absorption and the transmission loss under normal incidence. Exhaustive optimization of the double-layer MPPs is performed to assess the absorption and/or transmission performances with respect to the impedance criterion. It is investigated how the panel volumetric resonances modify the excess dissipation that can be achieved from non-modal optimization of ML-MPPs.

  1. Achievable Rates of Cognitive Radio Networks Using Multi-Layer Coding with Limited CSI

    KAUST Repository

    Sboui, Lokman

    2016-03-01

    In a Cognitive Radio (CR) framework, the channel state information (CSI) feedback to the secondary transmitter (SU Tx) can be limited or unavailable. Thus, the statistical model is adopted in order to determine the system performance using the outage concept. In this paper, we adopt a new approach using multi-layer-coding (MLC) strategy, i.e., broadcast approach, to enhance spectrum sharing over fading channels. First, we consider a scenario where the secondary transmitter has no CSI of both the link between SU Tx and the primary receiver (cross-link) and its own link. We show that using MLC improves the cognitive rate compared to the rate provided by a singlelayer- coding (SLC). In addition, we observe numerically that 2-Layer coding achieves most of the gain for Rayleigh fading. Second, we analyze a scenario where SU Tx is provided by partial CSI about its link through quantized CSI. We compute its achievable rate adopting the MLC and highlight the improvement over SLC. Finally, we study the case in which the cross-link is perfect, i.e., a cooperative primary user setting, and compare the performance with the previous cases. We present asymptotic analysis at high power regime and show that the cooperation enhances considerably the cognitive rate at high values of the secondary power budget.

  2. 3D mechanical stratigraphy of a deformed multi-layer: Linking sedimentary architecture and strain partitioning

    Science.gov (United States)

    Cawood, Adam J.; Bond, Clare E.

    2018-01-01

    Stratigraphic influence on structural style and strain distribution in deformed sedimentary sequences is well established, in models of 2D mechanical stratigraphy. In this study we attempt to refine existing models of stratigraphic-structure interaction by examining outcrop scale 3D variations in sedimentary architecture and the effects on subsequent deformation. At Monkstone Point, Pembrokeshire, SW Wales, digital mapping and virtual scanline data from a high resolution virtual outcrop have been combined with field observations, sedimentary logs and thin section analysis. Results show that significant variation in strain partitioning is controlled by changes, at a scale of tens of metres, in sedimentary architecture within Upper Carboniferous fluvio-deltaic deposits. Coupled vs uncoupled deformation of the sequence is defined by the composition and lateral continuity of mechanical units and unit interfaces. Where the sedimentary sequence is characterized by gradational changes in composition and grain size, we find that deformation structures are best characterized by patterns of distributed strain. In contrast, distinct compositional changes vertically and in laterally equivalent deposits results in highly partitioned deformation and strain. The mechanical stratigraphy of the study area is inherently 3D in nature, due to lateral and vertical compositional variability. Consideration should be given to 3D variations in mechanical stratigraphy, such as those outlined here, when predicting subsurface deformation in multi-layers.

  3. 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.

  4. Cardiac Arrhythmia Classification by Multi-Layer Perceptron and Convolution Neural Networks

    Directory of Open Access Journals (Sweden)

    Shalin Savalia

    2018-05-01

    Full Text Available The electrocardiogram (ECG plays an imperative role in the medical field, as it records heart signal over time and is used to discover numerous cardiovascular diseases. If a documented ECG signal has a certain irregularity in its predefined features, this is called arrhythmia, the types of which include tachycardia, bradycardia, supraventricular arrhythmias, and ventricular, etc. This has encouraged us to do research that consists of distinguishing between several arrhythmias by using deep neural network algorithms such as multi-layer perceptron (MLP and convolution neural network (CNN. The TensorFlow library that was established by Google for deep learning and machine learning is used in python to acquire the algorithms proposed here. The ECG databases accessible at PhysioBank.com and kaggle.com were used for training, testing, and validation of the MLP and CNN algorithms. The proposed algorithm consists of four hidden layers with weights, biases in MLP, and four-layer convolution neural networks which map ECG samples to the different classes of arrhythmia. The accuracy of the algorithm surpasses the performance of the current algorithms that have been developed by other cardiologists in both sensitivity and precision.

  5. 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.

  6. Mechanical loading regulates human MSC differentiation in a multi-layer hydrogel for osteochondral tissue engineering.

    Science.gov (United States)

    Steinmetz, Neven J; Aisenbrey, Elizabeth A; Westbrook, Kristofer K; Qi, H Jerry; Bryant, Stephanie J

    2015-07-01

    A bioinspired multi-layer hydrogel was developed for the encapsulation of human mesenchymal stem cells (hMSCs) as a platform for osteochondral tissue engineering. The spatial presentation of biochemical cues, via incorporation of extracellular matrix analogs, and mechanical cues, via both hydrogel crosslink density and externally applied mechanical loads, were characterized in each layer. A simple sequential photopolymerization method was employed to form stable poly(ethylene glycol)-based hydrogels with a soft cartilage-like layer of chondroitin sulfate and low RGD concentrations, a stiff bone-like layer with high RGD concentrations, and an intermediate interfacial layer. Under a compressive load, the variation in hydrogel stiffness within each layer produced high strains in the soft cartilage-like layer, low strains in the stiff bone-like layer, and moderate strains in the interfacial layer. When hMSC-laden hydrogels were cultured statically in osteochondral differentiation media, the local biochemical and matrix stiffness cues were not sufficient to spatially guide hMSC differentiation after 21 days. However dynamic mechanical stimulation led to differentially high expression of collagens with collagen II in the cartilage-like layer, collagen X in the interfacial layer and collagen I in the bone-like layer and mineral deposits localized to the bone layer. Overall, these findings point to external mechanical stimulation as a potent regulator of hMSC differentiation toward osteochondral cellular phenotypes. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  7. Estimation of effective connectivity using multi-layer perceptron artificial neural network.

    Science.gov (United States)

    Talebi, Nasibeh; Nasrabadi, Ali Motie; Mohammad-Rezazadeh, Iman

    2018-02-01

    Studies on interactions between brain regions estimate effective connectivity, (usually) based on the causality inferences made on the basis of temporal precedence. In this study, the causal relationship is modeled by a multi-layer perceptron feed-forward artificial neural network, because of the ANN's ability to generate appropriate input-output mapping and to learn from training examples without the need of detailed knowledge of the underlying system. At any time instant, the past samples of data are placed in the network input, and the subsequent values are predicted at its output. To estimate the strength of interactions, the measure of " Causality coefficient " is defined based on the network structure, the connecting weights and the parameters of hidden layer activation function. Simulation analysis demonstrates that the method, called "CREANN" (Causal Relationship Estimation by Artificial Neural Network), can estimate time-invariant and time-varying effective connectivity in terms of MVAR coefficients. The method shows robustness with respect to noise level of data. Furthermore, the estimations are not significantly influenced by the model order (considered time-lag), and the different initial conditions (initial random weights and parameters of the network). CREANN is also applied to EEG data collected during a memory recognition task. The results implicate that it can show changes in the information flow between brain regions, involving in the episodic memory retrieval process. These convincing results emphasize that CREANN can be used as an appropriate method to estimate the causal relationship among brain signals.

  8. Cardiac Arrhythmia Classification by Multi-Layer Perceptron and Convolution Neural Networks.

    Science.gov (United States)

    Savalia, Shalin; Emamian, Vahid

    2018-05-04

    The electrocardiogram (ECG) plays an imperative role in the medical field, as it records heart signal over time and is used to discover numerous cardiovascular diseases. If a documented ECG signal has a certain irregularity in its predefined features, this is called arrhythmia, the types of which include tachycardia, bradycardia, supraventricular arrhythmias, and ventricular, etc. This has encouraged us to do research that consists of distinguishing between several arrhythmias by using deep neural network algorithms such as multi-layer perceptron (MLP) and convolution neural network (CNN). The TensorFlow library that was established by Google for deep learning and machine learning is used in python to acquire the algorithms proposed here. The ECG databases accessible at PhysioBank.com and kaggle.com were used for training, testing, and validation of the MLP and CNN algorithms. The proposed algorithm consists of four hidden layers with weights, biases in MLP, and four-layer convolution neural networks which map ECG samples to the different classes of arrhythmia. The accuracy of the algorithm surpasses the performance of the current algorithms that have been developed by other cardiologists in both sensitivity and precision.

  9. The creep of multi-layered moderately thick shells of revolution under asymmetrical loading

    International Nuclear Information System (INIS)

    Takezono, S.; Migita, K.

    1987-01-01

    In the present paper the authors study the creep deformation of the multi-layered thick shells of revolution under asymmetrical loads. The equations of equilibrium and the strain-displacement relations are derived from the Reissner-Naghdi theory (1941, 1957) for elastic shells where a consideration on the effect of shear deformation is given. In the theory of creep it is assumed that in a given increment of time the total strain increments are composed of an elastic part and a part due to creep. The elastic strains are proportional to the stresses by Hooke's law. For the constitutive equations in the creep range, McVetty's equation modified by Arrhenius' equation for thermal effect is employed. The basic differential equations on the creep problems derived for the incremental values with respect to time are numerically solved by a finite difference method and the solutions at any time are obtained by summation of the incremental values. Resultant forces and resultant moments are given from numerical integration of the stresses by Simpson's 1/3 rules. (orig./GL)

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

    KAUST Repository

    Moubayed, Abdallah J.

    2015-05-01

    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 collaboration between the collocated primary and cognitive radio base-stations in order to minimize their own as well as each other\\'s packet recovery overheads, thus by improving their throughput. The proposed scheme ensures that each network\\'s performance is not degraded by its help to the other network. Moreover, it guarantees that the primary network\\'s interference threshold is not violated in the same and adjacent cells. Yet, the scheme allows the reduction of the recovery overhead in the collocated primary and cognitive radio networks. The reduction in the cognitive radio network is further amplified due to the perfect detection of spectrum holes which allows the cognitive radio base station to transmit at higher power without fear of violating the interference threshold of the primary network. For the secondary network, simulation results show reductions of 20% and 34% in the packet recovery overhead, compared to the non-collaborative scheme, for low and high probabilities of primary packet arrivals, respectively. For the primary network, this reduction was found to be 12%. © 2015 IEEE.

  11. Hypothetical Pattern Recognition Design Using Multi-Layer Perceptorn Neural Network For Supervised Learning

    Directory of Open Access Journals (Sweden)

    Md. Abdullah-al-mamun

    2015-08-01

    Full Text Available Abstract Humans are capable to identifying diverse shape in the different pattern in the real world as effortless fashion due to their intelligence is grow since born with facing several learning process. Same way we can prepared an machine using human like brain called Artificial Neural Network that can be recognize different pattern from the real world object. Although the various techniques is exists to implementation the pattern recognition but recently the artificial neural network approaches have been giving the significant attention. Because the approached of artificial neural network is like a human brain that is learn from different observation and give a decision the previously learning rule. Over the 50 years research now a days pattern recognition for machine learning using artificial neural network got a significant achievement. For this reason many real world problem can be solve by modeling the pattern recognition process. The objective of this paper is to present the theoretical concept for pattern recognition design using Multi-Layer Perceptorn neural networkin the algorithm of artificial Intelligence as the best possible way of utilizing available resources to make a decision that can be a human like performance.

  12. 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.

  13. A tracer liquid image velocimetry for multi-layer radial flow in bioreactors.

    Science.gov (United States)

    Gao, Yu-Bao; Liang, Jiu-Xing; Luo, Yu-Xi; Yan, Jia

    2015-02-13

    This paper presents a Tracer Liquid Image Velocimetry (TLIV) for multi-layer radial flow in bioreactors used for cells cultivation of tissue engineering. The goal of this approach is to use simple devices to get good measuring precision, specialized for the case in which the uniform level of fluid shear stress was required while fluid velocity varied smoothly. Compared to the widely used Particles Image Velocimetry (PIV), this method adopted a bit of liquid as tracer, without the need of laser source. Sub-pixel positioning algorithm was used to overcome the adverse effects of the tracer liquid deformation. In addition, a neighborhood smoothing algorithm was used to restrict the measurement perturbation caused by diffusion. Experiments were carried out in a parallel plates flow chamber. And mathematical models of the flow chamber and Computational Fluid Dynamics (CFD) simulation were separately employed to validate the measurement precision of TLIV. The mean relative error between the simulated and measured data can be less than 2%, while in similar validations using PIV, the error was around 8.8%. TLIV avoided the contradiction between the particles' visibility and following performance with tested fluid, which is difficult to overcome in PIV. And TLIV is easier to popularize for its simple experimental condition and low cost.

  14. Multi-layer thin-film electrolytes for metal supported solid oxide fuel cells

    Science.gov (United States)

    Haydn, Markus; Ortner, Kai; Franco, Thomas; Uhlenbruck, Sven; Menzler, Norbert H.; Stöver, Detlev; Bräuer, Günter; Venskutonis, Andreas; Sigl, Lorenz S.; Buchkremer, Hans-Peter; Vaßen, Robert

    2014-06-01

    A key to the development of metal-supported solid oxide fuel cells (MSCs) is the manufacturing of gas-tight thin-film electrolytes, which separate the cathode from the anode. This paper focuses the electrolyte manufacturing on the basis of 8YSZ (8 mol.-% Y2O3 stabilized ZrO2). The electrolyte layers are applied by a physical vapor deposition (PVD) gas flow sputtering (GFS) process. The gas-tightness of the electrolyte is significantly improved when sequential oxidic and metallic thin-film multi-layers are deposited, which interrupt the columnar grain structure of single-layer electrolytes. Such electrolytes with two or eight oxide/metal layers and a total thickness of about 4 μm obtain leakage rates of less than 3 × 10-4 hPa dm3 s-1 cm-2 (Δp: 100 hPa) at room temperature and therefore fulfill the gas tightness requirements. They are also highly tolerant with respect to surface flaws and particulate impurities which can be present on the graded anode underground. MSC cell tests with double-layer and multilayer electrolytes feature high power densities more than 1.4 W cm-2 at 850 °C and underline the high potential of MSC cells.

  15. Experimental Study of Weepage in Multi-layer Glass Reinforced Piping

    KAUST Repository

    Al Sinan, Hussain

    2014-01-01

    Glass Reinforced Polymer pipes, commonly used in water transport applications, are prone to long term weepage. Weepage is defined as the transfer of fluid through the pipe and is considered a functional failure. An experimental investigation of weepage in multi-layered GRP pipes was carried out in two parts aiming to understand the phenomenon to help enhance the weepage resistance of manufactured pipes. First, liner surface profilometry investigation was carried out to identify microscopic features that might serve in initiating weepage. Second, MRI and x-ray tomography and SEM imaging of pipe samples aged with water and dye penetrant was carried out to capture weepage development through the pipe thickness. Diffusion through liner fiber/resin interface, propagation in the direction of poorly wetted hoop fibers and transverse cracks were found to be the likely causes of accelerating weepage in the samples. Fiber rich zones in the liner were considered weak spots that water can use for fast penetration of the liner. Finally, polyester netting used to hold core layer was found to help in water accumulation and transport through the pipe increasing the chances of failure.

  16. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  17. Measuring circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for measuring circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listings

  18. Bismuth-doped Cu(In,Ga)Se{sub 2} absorber prepared by multi-layer precursor method and its solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-06-15

    Bismuth (Bi)-doped Cu(In,Ga)Se{sub 2} (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V{sub OC}). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi{sub 4}Se{sub 3}. Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V{sub OC}. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Bismuth-doped Cu(In,Ga)Se2 absorber prepared by multi-layer precursor method and its solar cell

    International Nuclear Information System (INIS)

    Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi; Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori

    2015-01-01

    Bismuth (Bi)-doped Cu(In,Ga)Se 2 (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V OC ). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi 4 Se 3 . Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V OC . (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Integrated neuron circuit for implementing neuromorphic system with synaptic device

    Science.gov (United States)

    Lee, Jeong-Jun; Park, Jungjin; Kwon, Min-Woo; Hwang, Sungmin; Kim, Hyungjin; Park, Byung-Gook

    2018-02-01

    In this paper, we propose and fabricate Integrate & Fire neuron circuit for implementing neuromorphic system. Overall operation of the circuit is verified by measuring discrete devices and the output characteristics of the circuit. Since the neuron circuit shows asymmetric output characteristic that can drive synaptic device with Spike-Timing-Dependent-Plasticity (STDP) characteristic, the autonomous weight update process is also verified by connecting the synaptic device and the neuron circuit. The timing difference of the pre-neuron and the post-neuron induce autonomous weight change of the synaptic device. Unlike 2-terminal devices, which is frequently used to implement neuromorphic system, proposed scheme of the system enables autonomous weight update and simple configuration by using 4-terminal synapse device and appropriate neuron circuit. Weight update process in the multi-layer neuron-synapse connection ensures implementation of the hardware-based artificial intelligence, based on Spiking-Neural- Network (SNN).