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Sample records for vliw processing elements

  1. Rapid VLIW Processor Customization for Signal Processing Applications Using Combinational Hardware Functions

    Directory of Open Access Journals (Sweden)

    Hoare Raymond R

    2006-01-01

    Full Text Available This paper presents an architecture that combines VLIW (very long instruction word processing with the capability to introduce application-specific customized instructions and highly parallel combinational hardware functions for the acceleration of signal processing applications. To support this architecture, a compilation and design automation flow is described for algorithms written in C. The key contributions of this paper are as follows: (1 a 4-way VLIW processor implemented in an FPGA, (2 large speedups through hardware functions, (3 a hardware/software interface with zero overhead, (4 a design methodology for implementing signal processing applications on this architecture, (5 tractable design automation techniques for extracting and synthesizing hardware functions. Several design tradeoffs for the architecture were examined including the number of VLIW functional units and register file size. The architecture was implemented on an Altera Stratix II FPGA. The Stratix II device was selected because it offers a large number of high-speed DSP (digital signal processing blocks that execute multiply-accumulate operations. Using the MediaBench benchmark suite, we tested our methodology and architecture to accelerate software. Our combined VLIW processor with hardware functions was compared to that of software executing on a RISC processor, specifically the soft core embedded NIOS II processor. For software kernels converted into hardware functions, we show a hardware performance multiplier of up to times that of software with an average times faster. For the entire application in which only a portion of the software is converted to hardware, the performance improvement is as much as 30X times faster than the nonaccelerated application, with a 12X improvement on average.

  2. Efficient matrix inversion based on VLIW architecture

    Institute of Scientific and Technical Information of China (English)

    Li Zhang,Fu Li,; Guangming Shi

    2014-01-01

    Matrix inversion is a critical part in communication, signal processing and electromagnetic system. A flexible and scal-able very long instruction word (VLIW) processor with clustered architecture is proposed for matrix inversion. A global register file (RF) is used to connect al the clusters. Two nearby clusters share a local register file. The instruction sets are also designed for the VLIW processor. Experimental results show that the proposed VLIW architecture takes only 45 latency to invert a 4 × 4 matrix when running at 150 MHz. The proposed design is roughly five times faster than the DSP solution in processing speed.

  3. Stream Execution on Embedded Wide-Issue Clustered VLIW Architectures

    Directory of Open Access Journals (Sweden)

    Shan Yan

    2009-02-01

    Full Text Available Very long instruction word- (VLIW- based processors have become widely adopted as a basic building block in modern System-on-Chip designs. Advances in clustered VLIW architectures have extended the scalability of the VLIW architecture paradigm to a large number of functional units and very-wide-issue widths. A central challenge with wide-issue clustered VLIW architecture is the availability of programming and automated compiler methods that can fully utilize the available computational resources. Existing compilation approaches for clustered-VLIW architectures are based on extensions of previously developed scheduling algorithms that primarily focus on the maximization of instruction-level parallelism (ILP. However, many applications do not have sufficient ILP to fully utilize a large number of functional units. On the other hand, many applications in digital communications and multimedia processing exhibit enormous amounts of data-level parallelism (DLP. For these applications, the streaming programming paradigm has been developed to explicitly expose coarse-grained data-level parallelism as well as the locality of communication between coarse-grained computation kernels. In this paper, we investigate the mapping of stream programs to wide-issue clustered VLIW processors. Our work enables designers to leverage their existing investments in VLIW-based architecture platforms to harness the advantages of the stream programming paradigm.

  4. Stream Execution on Embedded Wide-Issue Clustered VLIW Architectures

    Directory of Open Access Journals (Sweden)

    Yan Shan

    2008-01-01

    Full Text Available Abstract Very long instruction word- (VLIW- based processors have become widely adopted as a basic building block in modern System-on-Chip designs. Advances in clustered VLIW architectures have extended the scalability of the VLIW architecture paradigm to a large number of functional units and very-wide-issue widths. A central challenge with wide-issue clustered VLIW architecture is the availability of programming and automated compiler methods that can fully utilize the available computational resources. Existing compilation approaches for clustered-VLIW architectures are based on extensions of previously developed scheduling algorithms that primarily focus on the maximization of instruction-level parallelism (ILP. However, many applications do not have sufficient ILP to fully utilize a large number of functional units. On the other hand, many applications in digital communications and multimedia processing exhibit enormous amounts of data-level parallelism (DLP. For these applications, the streaming programming paradigm has been developed to explicitly expose coarse-grained data-level parallelism as well as the locality of communication between coarse-grained computation kernels. In this paper, we investigate the mapping of stream programs to wide-issue clustered VLIW processors. Our work enables designers to leverage their existing investments in VLIW-based architecture platforms to harness the advantages of the stream programming paradigm.

  5. Reconfigurable VLIW Processor for Software Defined Radio Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We will design and formally verify a VLIW processor that is radiation-hardened, and where the VLIW instructions consist of predicated RISC instructions from the...

  6. VLIW DSP指令级精度模拟器的快速实现方法%Rapid implementation of instruction-level precision VLIW DSP simulator

    Institute of Scientific and Technical Information of China (English)

    朱大林; 郭德源; 何虎

    2013-01-01

    To Develop a simulator of a very long instruction word (VLIW) digital signal processor (DSP) with instruction-level precision at the lowest cost, and reduce the product develop lifecycle, a develop method based on an open source simulator (gem5) is presented. Firstly, the instruction execution processes of gem5 and VLIW DSP are analyzed respectively, it is pointed out that the conflict between the sequential execution with pure 32 bit instruction environment on gem5 simulator and the parallel execution with 16/32 mixed instruction environment on VLIW DSP is one of the difficulties in the development Then, based on the sequential execution model of gem5 simulator, a VLIW DSP model is constructed by adding a parallel judgment and execution mechanism and a 16/32 bit mix instruction fetch mechanism, A VLIW DSP simulator is implemented Finally, by running a set of test case for every instruction and a set of typical application of DSP, the validity and feasibility of the develop method is demonstrated%为了以最小代价开发出超长指令字(VLIW)数字信号处理器(DSP)的指令级精度的模拟器,缩短开发周期,提出了一种基于开源模拟器(gem5)的开发方法.对gem5模拟器和VLIW DSP的指令执行流程分别进行分析,指出指令在gem5模拟器上以纯32位指令环境顺序执行和指令在VLIW DSP上以16/32位混合指令环境并行执行之间的矛盾是开发的难点.在gem5的顺序执行模型的基础上,通过加入并行的判决、执行机制和16/32位混合指令的取指机制建立了VLIWDSP的模型,并具体实现了一款VLIW DSP的模拟器.通过一组针对每条指令的测试程序和一组DSP典型应用程序验证了该方法的正确性和可行性.

  7. Design and Implementation of 64-Bit Execute Stage for VLIW Processor Architecture on FPGA

    Directory of Open Access Journals (Sweden)

    Manju Rani

    2012-07-01

    Full Text Available FPGA implementation of 64-bit execute unit for VLIW processor, and improve power representation have been done in this paper. VHDL is used to modelled this architecture. VLIW stands for Very Long Instruction Word. This Processor Architecture is based on parallel processing in which more than one instruction is executed in parallel. This architecture is used to increase the instruction throughput. So this is the base of the modern Superscalar Processors. Basically VLIW is a RISC Processor. The difference is it contains long instruction as compared to RISC. This stage of the pipeline executes the instruction. This is the stage where the ALU (arithmetic logic unit is located. Execute stage are synthesized and targeted for Xilinx Virtex 4 FPGA and the results calculated for 64-bit Execute stage improve the power as compared to previous work done.

  8. Simulació d'arquitectures VLIW

    OpenAIRE

    2007-01-01

    L'objectiu d'aquest projecte es dissenyar i implementar en Java una interfície gràfica que permeti simular l'arquitectura VLIW. Ha d'interactuar amb un simulador ja existent, VEX, i amb l'usuari. VEX permet analitzar, desenvolupar i depurar codi escrit en C sobre un processador VLIW configurable, des dels recursos hardware fíns al comportament de la "caché". L'interfície gràfica desenvolupada es diu JavaVEX. Té el gran avantatge d'evitar la introducció de les comandes de text que necesita VEX...

  9. Optimizing Instruction Scheduling and Register Allocation for Register-File-Connected Clustered VLIW Architectures

    Directory of Open Access Journals (Sweden)

    Haijing Tang

    2013-01-01

    Full Text Available Clustering has become a common trend in very long instruction words (VLIW architecture to solve the problem of area, energy consumption, and design complexity. Register-file-connected clustered (RFCC VLIW architecture uses the mechanism of global register file to accomplish the inter-cluster data communications, thus eliminating the performance and energy consumption penalty caused by explicit inter-cluster data move operations in traditional bus-connected clustered (BCC VLIW architecture. However, the limit number of access ports to the global register file has become an issue which must be well addressed; otherwise the performance and energy consumption would be harmed. In this paper, we presented compiler optimization techniques for an RFCC VLIW architecture called Lily, which is designed for encryption systems. These techniques aim at optimizing performance and energy consumption for Lily architecture, through appropriate manipulation of the code generation process to maintain a better management of the accesses to the global register file. All the techniques have been implemented and evaluated. The result shows that our techniques can significantly reduce the penalty of performance and energy consumption due to access port limitation of global register file.

  10. Fast 2D-DCT implementations for VLIW processors

    OpenAIRE

    Sohm, OP; Canagarajah, CN; Bull, DR

    1999-01-01

    This paper analyzes various fast 2D-DCT algorithms regarding their suitability for VLIW processors. Operations for truncation or rounding which are usually neglected in proposals for fast algorithms have also been taken into consideration. Loeffler's algorithm with parallel multiplications was found to be most suitable due to its parallel structure

  11. Architecture Design of a Variable Length Instruction Set VLIW DSP

    Institute of Scientific and Technical Information of China (English)

    SHEN Zheng; HE Hu; YANG Xu; JIA Di; SUN Yihe

    2009-01-01

    The cost of the central register file and the size of the program code limit the scalability of very long instruction word (VLIW) processors with increasing numbers of functional units. This paper presents the architectural design of a six-way VLIW digital signal processor (DSP) with clustered register files. The archi-tecture uses a variable length instruction set and supports dynamic instruction dispatching. The one-level memory system architecture of the processor includes 16-KB instruction and data caches and 16-KB in-struction and data on-chip RAM. A compiler based on the Open64 was developed for the system. Evalua-tions show that the processor is suitable for high performance applications with a high code density and small program code size.

  12. Leakage-Aware Modulo Scheduling for Embedded VLIW Processors

    Institute of Scientific and Technical Information of China (English)

    Yong Guan; Jingling Xue

    2011-01-01

    As semi-conductor technologies move down to the nanometer scale, leakage power has become a significant component of the total power consumption. In this paper, we present a leakage-aware modulo scheduling algorithm to achieve leakage energy saving for applications with loops on Very Long Instruction Word (VLIW) architectures. The proposed algorithm is designed to maximize the idleness of function units integrated with the dual-threshold domino logic, and reduce the number of transitions between the active and sleep modes. We have implemented our technique in the Trimaran compiler and conducted experiments using a set of embedded benchmarks from DSPstone and Mibench on the cycle-accurate VLIW simulator of Trimaran. The results show that our technique achieves significant leakage energy saving compared with a previously published DAG-based (Directed Acyclic Graph) leakage-aware scheduling algorithm.

  13. The application of compiler-assisted multiple instruction retry to VLIW architectures

    Science.gov (United States)

    Chen, Shyh-Kwei; Fuchs, W. K.; Hwu, Wen-Mei W.

    1994-01-01

    Very Long Instruction Word (VLIW) architectures enhance performance by exploiting fine-grained instruction level parallelism. We describe the development of two compiler assisted multiple instruction word retry schemes for VLIW architectures. The first scheme utilizes the compiler techniques previously developed for processors with single functional units. A compiler generated hazard-free code with different degrees of rollback capability for uniprocessors is compacted by a modified VLIW trace scheduling algorithm. Nops are then inserted in the scheduled code words to resolve data hazards for VLIW architectures. Performance is compared under three parameters: the rollback distance for uni-processors; the number of functional units; and the rollback distance for VLIW architectures. The second scheme employs a hardware read buffer to resolve frequently occurring data hazards, and utilizes the compiler to resolve the remaining hazards. Performance results are shown for six benchmark programs.

  14. An advanced compiler designed for a VLIW DSP for sensors-based systems.

    Science.gov (United States)

    Yang, Xu; He, Hu

    2012-01-01

    The VLIW architecture can be exploited to greatly enhance instruction level parallelism, thus it can provide computation power and energy efficiency advantages, which satisfies the requirements of future sensor-based systems. However, as VLIW codes are mainly compiled statically, the performance of a VLIW processor is dominated by the behavior of its compiler. In this paper, we present an advanced compiler designed for a VLIW DSP named Magnolia, which will be used in sensor-based systems. This compiler is based on the Open64 compiler. We have implemented several advanced optimization techniques in the compiler, and fulfilled the O3 level optimization. Benchmarks from the DSPstone test suite are used to verify the compiler. Results show that the code generated by our compiler can make the performance of Magnolia match that of the current state-of-the-art DSP processors.

  15. An Advanced Compiler Designed for a VLIW DSP for Sensors-Based Systems

    Directory of Open Access Journals (Sweden)

    Hu He

    2012-04-01

    Full Text Available The VLIW architecture can be exploited to greatly enhance instruction level parallelism, thus it can provide computation power and energy efficiency advantages, which satisfies the requirements of future sensor-based systems. However, as VLIW codes are mainly compiled statically, the performance of a VLIW processor is dominated by the behavior of its compiler. In this paper, we present an advanced compiler designed for a VLIW DSP named Magnolia, which will be used in sensor-based systems. This compiler is based on the Open64 compiler. We have implemented several advanced optimization techniques in the compiler, and fulfilled the O3 level optimization. Benchmarks from the DSPstone test suite are used to verify the compiler. Results show that the code generated by our compiler can make the performance of Magnolia match that of the current state-of-the-art DSP processors.

  16. DEBUGGER DESIGN FOR MICROPROCESSOR WITH HYBRID ARCHITECTURE OF SUPERSCALAR-VLIW%面向 Superscalar与 VLIW 混合架构处理器的调试器设计

    Institute of Scientific and Technical Information of China (English)

    杨群; 李笑天; 何虎

    2015-01-01

    In this paper we describe the debugger design, which is based on GDB and with hybrid architecture of Superscalar and VLIW double-mode.The debugger design is divided into two parts, the proxy debugging side and the client.The proxy debugging side realises the RSP ( remote serial protocol )-based basic debugging proxy function, and the client side realises the target processor adding, debugger initialisation, and the processing of registers data and opcodes, etc.Test results demonstrate that this debugger achieves the program debugging functions such as remote debugging, checking, modifying the values of registers and memories, adding and deleting breakpoints, disassembly, checking stack information and single stepping, etc.%描述基于GDB的支持超标量( Superscalar)和超长指令字( VLIW)双模式混合架构的调试器设计. 该调试器设计分为代理调试端和客户端两部分,代理调试端实现基于RSP协议的基本调试代理功能,客户端实现目标处理器的添加,调试器初始化,寄存器数据、操作码等的处理. 测试结果表明调试器实现了远程调试,查看、修改寄存器及内存值,添加、删除断点,反汇编,查看栈信息及单步等程序调试功能.

  17. Run-time Adaptable VLIW Processors: Resources, Performance, Power Consumption, and Reliability Trade-offs

    NARCIS (Netherlands)

    Anjam, F.

    2013-01-01

    In this dissertation, we propose to combine programmability with reconfigurability by implementing an adaptable programmable VLIW processor in a reconfigurable hardware. The approach allows applications to be developed at high-level (C language level), while at the same time, the processor organizat

  18. Run-time Adaptable VLIW Processors: Resources, Performance, Power Consumption, and Reliability Trade-offs

    NARCIS (Netherlands)

    Anjam, F.

    2013-01-01

    In this dissertation, we propose to combine programmability with reconfigurability by implementing an adaptable programmable VLIW processor in a reconfigurable hardware. The approach allows applications to be developed at high-level (C language level), while at the same time, the processor

  19. Resource efficiency of hardware extensions of a 4-issue VLIW processor for elliptic curve cryptography

    Science.gov (United States)

    Jungeblut, T.; Puttmann, C.; Dreesen, R.; Porrmann, M.; Thies, M.; Rückert, U.; Kastens, U.

    2010-12-01

    The secure transmission of data plays a significant role in today's information era. Especially in the area of public-key-cryptography methods, which are based on elliptic curves (ECC), gain more and more importance. Compared to asymmetric algorithms, like RSA, ECC can be used with shorter key lengths, while achieving an equal level of security. The performance of ECC-algorithms can be increased significantly by adding application specific hardware extensions. Due to their fine grained parallelism, VLIW-processors are well suited for the execution of ECC algorithms. In this work, we extended the fourfold parallel CoreVA-VLIW-architecture by several hardware accelerators to increase the resource efficiency of the overall system. For the design-space exploration we use a dual design flow, which is based on the automatic generation of a complete C-compiler based tool chain from a central processor specification. Using the hardware accelerators the performance of the scalar multiplication on binary fields can be increased by the factor of 29. The energy consumption can be reduced by up to 90%. The extended processor hardware was mapped on a current 65 nm low-power standard-cell-technology. The chip area of the CoreVA-VLIW-architecture is 0.24 mm2 at a power consumption of 29 mW/MHz. The performance gain is analyzed in respect to the increased hardware costs, as chip area or power consumption.

  20. Elements of EAF automation processes

    Science.gov (United States)

    Ioana, A.; Constantin, N.; Dragna, E. C.

    2017-01-01

    Our article presents elements of Electric Arc Furnace (EAF) automation. So, we present and analyze detailed two automation schemes: the scheme of electrical EAF automation system; the scheme of thermic EAF automation system. The application results of these scheme of automation consists in: the sensitive reduction of specific consummation of electrical energy of Electric Arc Furnace, increasing the productivity of Electric Arc Furnace, increase the quality of the developed steel, increasing the durability of the building elements of Electric Arc Furnace.

  1. A scalable and low power VLIW DSP core for embedded system design

    Institute of Scientific and Technical Information of China (English)

    Sheraz Anjum; CHEN Jie; HAN Liang; LIN Chuan; ZHANG Xiao-xiao; SU Ye-hua; Chip Cheng

    2008-01-01

    Aims to provide the block architecture of CoStar3400 DSP that is a high performance, low power and scalable VLIW DSP core, it efficiently deployed a variable-length execution set (VLES) execution model which utilizes the maximum parallelism by allowing multiple address generations and data arithmetic logic units to exe-cute multiple instructions in a single clock cycle. The scalability was provided mainly in using more or less num-ber of functional units according to the intended application. Low power support was added by careful architectur-al design techniques such as fine-grain clock gating and activation of only the required number of control signals at each stage of the pipeline. The said features of the core make it a suitable candidate for many SoC configurations,especially for compute intensive applications such as wire-line and wireless communications, including infrastruc-ture and subscriber communications. The embedded system designers can efficiently use the scalability and VLIW features of the core by scaling the number of execution units according to specific needs of the application to effec-tively reduce the power consumption, chip area and time to market the intended final product.

  2. Elements of random walk and diffusion processes

    CERN Document Server

    Ibe, Oliver C

    2013-01-01

    Presents an important and unique introduction to random walk theory Random walk is a stochastic process that has proven to be a useful model in understanding discrete-state discrete-time processes across a wide spectrum of scientific disciplines. Elements of Random Walk and Diffusion Processes provides an interdisciplinary approach by including numerous practical examples and exercises with real-world applications in operations research, economics, engineering, and physics. Featuring an introduction to powerful and general techniques that are used in the application of physical and dynamic

  3. Finite Element Method in Machining Processes

    CERN Document Server

    Markopoulos, Angelos P

    2013-01-01

    Finite Element Method in Machining Processes provides a concise study on the way the Finite Element Method (FEM) is used in the case of manufacturing processes, primarily in machining. The basics of this kind of modeling are detailed to create a reference that will provide guidelines for those who start to study this method now, but also for scientists already involved in FEM and want to expand their research. A discussion on FEM, formulations and techniques currently in use is followed up by machining case studies. Orthogonal cutting, oblique cutting, 3D simulations for turning and milling, grinding, and state-of-the-art topics such as high speed machining and micromachining are explained with relevant examples. This is all supported by a literature review and a reference list for further study. As FEM is a key method for researchers in the manufacturing and especially in the machining sector, Finite Element Method in Machining Processes is a key reference for students studying manufacturing processes but al...

  4. Pyrometallurgical processes for recovery of actinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Battles, J.E.; Laidler, J.J.; McPheeters, C.C.; Miller, W.E.

    1994-01-01

    A metallic fuel alloy, nominally U-20-Pu-lOZr, is the key element of the Integral Fast Reactor (IFR) fuel cycle. Metallic fuel permits the use of an innovative, simple pyrometallurgical process, known as pyroprocessing, (the subject of this report), which features fused salt electrorefining of the spent fuel. Electrorefining separates the actinide elements from fission products, without producing a separate stream of plutonium. The plutonium-bearing product is contaminated with higher actinides and with a minor amount of rare earth fission products, making it diversion resistant while still suitable as a fuel material in the fast spectrum of the IFR core. The engineering-scale demonstration of this process will be conducted in the refurbished EBR-II Fuel Cycle Facility, which has entered the start-up phase. An additional pyrometallurgical process is under development for extracting transuranic (TRU) elements from Light Water Reactor (LWR) spent fuel in a form suitable for use as a feed to the IFR fuel cycle. Four candidate extraction processes have been investigated and shown to be chemically feasible. The main steps in each process are oxide reduction with calcium or lithium, regeneration of the reductant and recycle of the salt, and separation of the TRU product from the bulk uranium. Two processes, referred to as the lithium and salt transport (calcium reductant) processes, have been selected for engineering-scale demonstration, which is expected to start in late 1993. An integral part of pyroprocessing development is the treatment and packaging of high-level waste materials arising from the operations, along with the qualification of these waste forms for disposal in a geologic repository.

  5. Design of Simulator for VLIW Processor%VLIW架构处理器软件模拟器设计

    Institute of Scientific and Technical Information of China (English)

    黄光红; 王昊

    2014-01-01

    分析VLIW架构处理器特点,设计周期级精确的指令集模拟器。模拟器被按照功能划分为若干具有规范接口的模块。通过修改、替换模块可快速构建新模型,具有较好的可扩展性。采用高效的二进制指令译码算法和JIT-CCS技术提高性能。实践表明,本模拟器在处理器设计过程中起到重要作用。%Analyzing VLIW architecture processor, this paper designs a instruction set simulator with cycle accurate. According function, the simulator is divided to several module which with standard interface. The simulator is flexible and is able to become other processor prototype fast by modification and replacing.Adopting efficient decoding arithmetic for binary instruction and JIT-CCS, the simulator obtains excellent performance. The result demonstrates that the simulator can work effectively for design VLIW processor.

  6. Application of finite-element-methods in food processing

    DEFF Research Database (Denmark)

    Risum, Jørgen

    2004-01-01

    Presentation of the possible use of finite-element-methods in food processing. Examples from diffusion studies are given.......Presentation of the possible use of finite-element-methods in food processing. Examples from diffusion studies are given....

  7. Transplutonium elements processed from rock debris of underground detonations

    Science.gov (United States)

    Bloomquist, C. A. A.; Harvey, H. W.; Hoh, J. C.; Horwitz, E. P.

    1969-01-01

    Six-step chemical processing method extracts minute quantities of transplutonium elements found in rock debris following a nuclear detonation. The process consists of dissolution of rock, feed preparation, liquid-liquid extraction, final purification of transplutonium elements and plutonium, and separation of the transplutonium elements.

  8. Finite Element Simulation of Blanking Process

    Directory of Open Access Journals (Sweden)

    Afzal Ahmed

    2012-10-01

    Full Text Available ABSTRACT: The blanking process can be simulated by ABAQUS v 6.4 to select punch, die and press and ascertain punch wear and bur height. The experimental and the simulation results agree well with rising punch force up to the point of creation of crack. For a 2mm mild steel sheet, the simulation shows that for the punch force of 240 kN, the crack starts at 30% punch penetration depth and punch force suddenly drops to a value of 70 kN and remains steady till the blanking is complete. Comparing simulation and experimental results for a 3mm mild steel sheet, results agree well in the elastic range with the punch force rising up to point of crack creation. However, a discrepancy appears in punch force which increases with punch penetration. At 32% depth of penetration, the discrepancy is 12 % which increases to 60 % at punch penetration of 42%. Punch force for experimental and simulation results remains about 90kN beyond punch penetration of 62%. Also, increase of the thickness of sheet results in reduced crack height and improved quality of blank.ABSTRAK: Proses pengosongan boleh disimulasikan oleh ABAQUS versi 6.4 untuk memilih tebuk, alat dan tekan; dan menentukan haus tebuk dan ketinggian duri. Keputusan ujikaji dan simulasi adalah serupa dengan kenaikan daya tebuk hingga titik retakan diperolehi. Bagi kepingan keluli ringan 2mm simulasi menunjukkan bahawa untuk tenaga tebukan sebanyak 240 kN, retak bermula pada 30% kedalaman penembusan 30% tebukan dan daya tebuk tiba-tiba jatuh kepada 70 kN dan jumplah ini kekal sehingga proses pengosongan selesai.  Apabila hasil simulasi dan eksperimen dibandingkan, keputusan experimen untuk keluli lembut 3mm, bersetuju dengan baik dalam julat anjal dan daya tebukan meningkat sehingga titik penciptaan retak diperolehi. Walau bagaimanapun percanggahan muncul apabila daya tebukan meningkat dengan daya penembusan. Pada kedalaman penembusan 32% percanggahan adalah 12% dan nilai ini meningkat kepada 60% apabila

  9. Parallel direct solver for finite element modeling of manufacturing processes

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, P.A.F.

    2017-01-01

    The central processing unit (CPU) time is of paramount importance in finite element modeling of manufacturing processes. Because the most significant part of the CPU time is consumed in solving the main system of equations resulting from finite element assemblies, different approaches have been...

  10. Adaptive finite element-element-free Galerkin coupling method for bulk metal forming processes

    Institute of Scientific and Technical Information of China (English)

    Lei-chao LIU; Xiang-huai DONG; Cong-xin LI

    2009-01-01

    An adaptive finite element-element-free Galerkin (FE-EFG) coupling method is proposed and developed for the numerical simulation of bulk metal forming processes. This approach is able to adaptively convert distorted FE elements to EFG domain in analysis. A new scheme to implement adaptive conversion and coupling is presented. The coupling method takes both advantages of finite element method (FEM) and meshless methods. It is capable of handling large deformations with no need of remeshing procedures, while it is computationally more efficient than those full meshless methods. The effectiveness of the proposed method is demonstrated with the numerical simulations of the bulk metal forming processes including forging and extrusion.

  11. Surface processing methods for point sets using finite elements

    NARCIS (Netherlands)

    Clarenz, Ulrich; Rumpf, Martin; Telea, Alexandru

    2004-01-01

    We present a framework for processing point-based surfaces via partial differential equations (PDEs). Our framework efficiently and effectively brings well-known PDE-based processing techniques to the field of point-based surfaces. At the core of our method is a finite element discretization of PDEs

  12. Analysis of the ATR fuel element swaging process

    Energy Technology Data Exchange (ETDEWEB)

    Richins, W.D.; Miller, G.K.

    1995-12-01

    This report documents a detailed evaluation of the swaging process used to connect fuel plates to side plates in Advanced Test Reactor (ATR) fuel elements. The swaging is a mechanical process that begins with fitting a fuel plate into grooves in the side plates. Once a fuel plate is positioned, a lip on each of two side plate grooves is pressed into the fuel plate using swaging wheels to form the joints. Each connection must have a specified strength (measured in terms, of a pullout force capacity) to assure that these joints do not fail during reactor operation. The purpose of this study is to analyze the swaging process and associated procedural controls, and to provide recommendations to assure that the manufacturing process produces swaged connections that meet the minimum strength requirement. The current fuel element manufacturer, Babcock and Wilcox (B&W) of Lynchburg, Virginia, follows established procedures that include quality inspections and process controls in swaging these connections. The procedures have been approved by Lockheed Martin Idaho Technologies and are designed to assure repeatability of the process and structural integrity of each joint. Prior to July 1994, ATR fuel elements were placed in the Hydraulic Test Facility (HTF) at the Idaho National Engineering Laboratory (AGNAIL), Test Reactor Area (TRA) for application of Boehmite (an aluminum oxide) film and for checking structural integrity before placement of the elements into the ATR. The results presented in this report demonstrate that the pullout strength of the swaged connections is assured by the current manufacturing process (with several recommended enhancements) without the need for- testing each element in the HTF.

  13. Multimineral optimization processing method based on elemental capture spectroscopy logging

    Institute of Scientific and Technical Information of China (English)

    Feng Zhou; Li Xin-Tong; Wu Hong-Liang; Xia Shou-Ji; Liu Ying-Ming

    2014-01-01

    Calculating the mineral composition is a critical task in log interpretation. Elemental capture spectroscopy (ECS) log provides the weight percentages of twelve common elements, which lays the foundation for the accurate calculation of mineral compositions. Previous processing methods calculated the formation composition via the conversion relation between the formation chemistry and minerals. Thus, their applicability is limited and the method precision is relatively low. In this study, we present a multimineral optimization processing method based on the ECS log. We derived the ECS response equations for calculating the formation composition, then, determined the logging response values for the elements of common minerals using core data and theoretical calculations. Finally, a software module was developed. The results of the new method are consistent with core data and the mean absolute error is less than 10%.

  14. Rapid Neutron Capture Process in Supernovae and Chemical Element Formation

    Indian Academy of Sciences (India)

    Rulee Baruah; Kalpana Duorah; H. L. Duorah

    2009-09-01

    The rapid neutron capture process (r-process) is one of the major nucleosynthesis processes responsible for the synthesis of heavy nuclei beyond iron. Isotopes beyond Fe are most exclusively formed in neutron capture processes and more heavier ones are produced by the r-process. Approximately half of the heavy elements with mass number ≻ 70 and all of the actinides in the solar system are believed to have been produced in the r-process. We have studied the r-process in supernovae for the production of heavy elements beyond = 40 with the newest mass values available. The supernova envelopes at a temperature ≻ 109 K and neutron density of 1024 cm-3 are considered to be one of the most potential sites for the r-process. The primary goal of the r-process calculations is to fit the global abundance curve for solar system r-process isotopes by varying time dependent parameters such as temperature and neutron density. This method aims at comparing the calculated abundances of the stable isotopes with observation.We have studied the r-process path corresponding to temperatures ranging from 1.0 × 109 K to 3.0 × 109 K and neutron density ranging from 1020 cm-3 to 1030 cm-3. With temperature and density conditions of 3.0 × 109 K and 1020 cm-3 a nucleus of mass 273 was theoretically found corresponding to atomic number 115. The elements obtained along the r-process path are compared with the observed data at all the above temperature and density range.

  15. Process to determine light elements content of steel and alloys

    Energy Technology Data Exchange (ETDEWEB)

    Quintella, Cristina M.A.L.T.M.H.; Castro, Martha T.P.O. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica. LabLaser; Mac-Culloch, Joao N.L.M. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The present work reports a process to determine qualitatively and quantitatively elements of molar mass inferior to 23 within materials, by X rays spectra associated with multivariate data analysis, or chemometric analysis. The spectra is acquired between 5 keV and 22 keV when the materials are exposed to X radiation. Here is reported the direct determination of carbon content in steel and metallic alloys. The process is more effective when using spectral regions which are not usually used. From the analysis of these spectral regions which were not considered before, it was possible to detect light elements with molar mass lower than 23, which have low capacity of absorbing and emitting radiation, but have high capacity of scattering radiation. The process here reported has the advantage that X-Ray spectra obtained are calibrated multivariately, showing high potential for development in order to be used in a portable field equipment. (author)

  16. Design Process for Integrated Concepts with Responsive Building Elements

    DEFF Research Database (Denmark)

    Aa, Van der A.; Heiselberg, Per

    2008-01-01

    is needed. The hard question is however: how to make the right choice of the combination of individual measures from building components and building services elements. Within the framework of IEA-ECBCS Annex 44 research has been conducted about the design process for integrated building concepts......An integrated building concept is a prerequisite to come to an energy efficient building with a good and healthy IAQ indoor comfort. A design process that defines the targets and boundary conditions in the very first stage of the design and guarantees them until the building is finished and used...... with responsive building elements. The (Dutch) Toolkit Sustainable Residential Buildings is one of the examples of tools for an integrated design process....

  17. Influence of Alloying Elements on the Laser Cutting Process

    Science.gov (United States)

    Ivarson, Anders; Powell, John; Siltanen, Jukka

    This paper presents an experimental investigation into how different alloying elements affect the laser-oxygen cutting process. Small variations in chemical composition of the material can lead to major changes in the overall laser-oxygen cutting process. The changes can appear as differences in cut edge roughness and/or adherent dross on the bottom of the cut. The primary causes of the process sensitivity have been identified as changes in surface tension and viscosity of the molten material in combination with changes in the exothermal reaction in the cut zone.

  18. A High-performance Fetch Pipeline Based On the VLIW DSP Architecture%一种基于VLIW DSP架构的高性能取指流水线

    Institute of Scientific and Technical Information of China (English)

    杨惠; 陈书明; 万江华

    2011-01-01

    以超长指令字(VLIW)数字信号处理器(DSP)作为平台,针对现有提高单线程取指流水线效率的方法中存在的弊端,提出了一种高性能的取指流水架构.该架构支持无效取指的检测与作废,从而降低不必要的cacbe访问,减少取指流水停顿周期,该结构还引入专用硬件支持编译调度的循环软流水,有效提高指令并行性,降低代码存储空间,由此释放出的单线程取指流水线的空闲周期约达46.34%.实验结果表明,相比优化前的取指流水而言,代码空同压缩约11.93%,执行周期缩短约8.67%,cache访同次数下降约12.84%,指令cache暂停周期缩短约7.86%,处理器单线程的指令吞吐率平均提高约11.7%.%For the drawbacks existent in single-thread fetch pipeline to improve the efficiency, a high-performance fetch pipeline structure is proposed in tins paper based on the platform of the VIIW digital signal processor ( DSP). It can support the detection and void for the invalid fetch, bypass for die missing fetch, which reduces the unnecessary cache access and fetch pipeline stall. The structure also inducts dedicated hardware which supports the software pipeline of scheduled compilation to improve the parallelism of instruction. It reduces the code memory space) and the idle cycles of released single-threaded pipeline is reached up to about 46.34%. Compared with the fetch pipeline before optimized, experiment results show that the code storage space is reduced about 11.93%, the average execution cycle is shortened about 8.67%, the cache access times is decreased about 12.84%, the suspension period of instruction cache is shortened about 7.86%, and die single-threaded instruction throughput of processor is increased by 11.7%.

  19. Statistical process management: An essential element of quality improvement

    Science.gov (United States)

    Buckner, M. R.

    Successful quality improvement requires a balanced program involving the three elements that control quality: organization, people and technology. The focus of the SPC/SPM User's Group is to advance the technology component of Total Quality by networking within the Group and by providing an outreach within Westinghouse to foster the appropriate use of statistic techniques to achieve Total Quality. SPM encompasses the disciplines by which a process is measured against its intrinsic design capability, in the face of measurement noise and other obscuring variability. SPM tools facilitate decisions about the process that generated the data. SPM deals typically with manufacturing processes, but with some flexibility of definition and technique it accommodates many administrative processes as well. The techniques of SPM are those of Statistical Process Control, Statistical Quality Control, Measurement Control, and Experimental Design. In addition, techniques such as job and task analysis, and concurrent engineering are important elements of systematic planning and analysis that are needed early in the design process to ensure success. The SPC/SPM User's Group is endeavoring to achieve its objectives by sharing successes that have occurred within the member's own Westinghouse department as well as within other US and foreign industry. In addition, failures are reviewed to establish lessons learned in order to improve future applications. In broader terms, the Group is interested in making SPM the accepted way of doing business within Westinghouse.

  20. Systematic Integrated Process Design and Control of Reactive Distillation Processes Involving Multi-elements

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

    2016-01-01

    In this work, integrated process design and control of reactive distillation processes that involve multiple elements (more than two) is addressed through a computer-aided hierarchical decomposition-based framework. Multiple elements are encountered for reactive systems when four or more compounds...... (including inert compounds) are encountered. The reactive distillation design methods and tools which are similar in concept to design of binary non-reactive distillations and binary reactive distillations are used for design of multi-element reactive distillation processes, such as driving force approach...

  1. Experimental and Finite Element Investigation of Roll Drawing Process

    Science.gov (United States)

    Lambiase, F.; di Ilio, A.

    2012-02-01

    In this research, the wire drawing process with flat roller dies is investigated. A prototypal apparatus is developed to conduct experimental tests on such a process and analyze the influence of main roll drawing parameters (e.g., incoming wire diameter, forming rolls diameter, thickness reduction, and friction conditions) on geometrical characteristics of flattened wires. A finite element model (FEM) is developed to simulate the deformation of the wire during the process. Within the entire range of experiments, a good agreement between experimental data and numerical results is found which allows validating the FE model. A further observation from the experimental program and numerical simulations is that a complicated dependence of the lateral spread of wire and width of contact area on process parameters exists during wire drawing with roller dies.

  2. Organo-metallic elements for associative information processing

    Science.gov (United States)

    Potember, Richard S.; Poehler, Theodore O.

    1989-01-01

    In the three years of the program we have: (1) built and tested a 4 bit element matrix device for possible use in high density content-addressable memories systems; (2) established a test and evaluation laboratory to examine optical materials for nonlinear effects, saturable absorption, harmonic generation and photochromism; (3) successfully designed, constructed and operated a codeposition processing system that enables organic materials to be deposited on a variety of substrates to produce optical grade coatings and films. This system is also compatible with other traditional microelectronic techniques; (4) used the sol-gel process with colloidal AgTCNQ to fabricate high speed photochromic switches; (5) develop and applied for patent coverage to make VO2 optical switching materials via the sol-gel processing using vanadium (IV) alkoxide compounds.

  3. FINITE ELEMENT ANALYSIS ON EVOLUTION PROCESS FOR DAMAGE MICROCRACK HEALING

    Institute of Scientific and Technical Information of China (English)

    Huang Peizhen; Li Zhonghua; Sun Jun

    2000-01-01

    Based on the thermal kinetic and mass conservation, a series of controlling equations for the finite element are derived and related programs are developed to simulate the damage microcrack healing process controlled by surface diffusion. Two kinds of typical models for microcrack splitting are proposed, i.e., the grain boundary energy existing on the crack surface and residual stresses applying on the crack surface. And the conditions of microcrack splitting in the two models are given as a function of the microcrack aspect ratio. The microcrack with traction-free surfaces will directly evolve into a spheroid.

  4. L1 elements, processed pseudogenes and retrogenes in mammalian genomes.

    Science.gov (United States)

    Ding, Wenyong; Lin, Lin; Chen, Bing; Dai, Jianwu

    2006-12-01

    Long interspersed nuclear elements 1 (L1 elements or LINE1) are the most active autonomous retrotransposons in mammalian genomes. In addition to L1 elements themselves, other protein-coding mRNAs can also be reverse transcribed and integrated into the genome through the L1-mediated retrotransposition, leading to the formation of processed pseudogenes (PPs) and retrogenes, both of which are characterized by the lack of introns and the presence of a 3' polyA tract and flanking direct repeats. PPs are unable to encode a functional protein and have accumulated frameshift mutations and premature stop codons during evolution. A few of PPs are transcriptionally active. Retrogenes preserve undisrupted coding frames and are capable of encoding a functional protein that is identical or nearly identical to that of the progenitor gene. There is a significant excess of retrogenes that originate from the X chromosome and are retrotransposed into autosomes, and most of these retrogenes are specially expressed in male germ cells, suggesting the inactivation of X-linked genes during male meiosis provides a strong selection pressure on retrogenes originating from the X chromosome.

  5. NON-LINEAR FINITE ELEMENT MODELING OF DEEP DRAWING PROCESS

    Directory of Open Access Journals (Sweden)

    Hasan YILDIZ

    2004-03-01

    Full Text Available Deep drawing process is one of the main procedures used in different branches of industry. Finding numerical solutions for determination of the mechanical behaviour of this process will save time and money. In die surfaces, which have complex geometries, it is hard to determine the effects of parameters of sheet metal forming. Some of these parameters are wrinkling, tearing, and determination of the flow of the thin sheet metal in the die and thickness change. However, the most difficult one is determination of material properties during plastic deformation. In this study, the effects of all these parameters are analyzed before producing the dies. The explicit non-linear finite element method is chosen to be used in the analysis. The numerical results obtained for non-linear material and contact models are also compared with the experiments. A good agreement between the numerical and the experimental results is obtained. The results obtained for the models are given in detail.

  6. Solution processed integrated pixel element for an imaging device

    Science.gov (United States)

    Swathi, K.; Narayan, K. S.

    2016-09-01

    We demonstrate the implementation of a solid state circuit/structure comprising of a high performing polymer field effect transistor (PFET) utilizing an oxide layer in conjunction with a self-assembled monolayer (SAM) as the dielectric and a bulk-heterostructure based organic photodiode as a CMOS-like pixel element for an imaging sensor. Practical usage of functional organic photon detectors requires on chip components for image capture and signal transfer as in the CMOS/CCD architecture rather than simple photodiode arrays in order to increase speed and sensitivity of the sensor. The availability of high performing PFETs with low operating voltage and photodiodes with high sensitivity provides the necessary prerequisite to implement a CMOS type image sensing device structure based on organic electronic devices. Solution processing routes in organic electronics offers relatively facile procedures to integrate these components, combined with unique features of large-area, form factor and multiple optical attributes. We utilize the inherent property of a binary mixture in a blend to phase-separate vertically and create a graded junction for effective photocurrent response. The implemented design enables photocharge generation along with on chip charge to voltage conversion with performance parameters comparable to traditional counterparts. Charge integration analysis for the passive pixel element using 2D TCAD simulations is also presented to evaluate the different processes that take place in the monolithic structure.

  7. Method and system for processing optical elements using magnetorheological finishing

    Science.gov (United States)

    Menapace, Joseph Arthur; Schaffers, Kathleen Irene; Bayramian, Andrew James; Molander, William A

    2012-09-18

    A method of finishing an optical element includes mounting the optical element in an optical mount having a plurality of fiducials overlapping with the optical element and obtaining a first metrology map for the optical element and the plurality of fiducials. The method also includes obtaining a second metrology map for the optical element without the plurality of fiducials, forming a difference map between the first metrology map and the second metrology map, and aligning the first metrology map and the second metrology map. The method further includes placing mathematical fiducials onto the second metrology map using the difference map to form a third metrology map and associating the third metrology map to the optical element. Moreover, the method includes mounting the optical element in the fixture in an MRF tool, positioning the optical element in the fixture; removing the plurality of fiducials, and finishing the optical element.

  8. Finite Element Models for Electron Beam Freeform Fabrication Process

    Science.gov (United States)

    Chandra, Umesh

    2012-01-01

    Electron beam freeform fabrication (EBF3) is a member of an emerging class of direct manufacturing processes known as solid freeform fabrication (SFF); another member of the class is the laser deposition process. Successful application of the EBF3 process requires precise control of a number of process parameters such as the EB power, speed, and metal feed rate in order to ensure thermal management; good fusion between the substrate and the first layer and between successive layers; minimize part distortion and residual stresses; and control the microstructure of the finished product. This is the only effort thus far that has addressed computer simulation of the EBF3 process. The models developed in this effort can assist in reducing the number of trials in the laboratory or on the shop floor while making high-quality parts. With some modifications, their use can be further extended to the simulation of laser, TIG (tungsten inert gas), and other deposition processes. A solid mechanics-based finite element code, ABAQUS, was chosen as the primary engine in developing these models whereas a computational fluid dynamics (CFD) code, Fluent, was used in a support role. Several innovative concepts were developed, some of which are highlighted below. These concepts were implemented in a number of new computer models either in the form of stand-alone programs or as user subroutines for ABAQUS and Fluent codes. A database of thermo-physical, mechanical, fluid, and metallurgical properties of stainless steel 304 was developed. Computing models for Gaussian and raster modes of the electron beam heat input were developed. Also, new schemes were devised to account for the heat sink effect during the deposition process. These innovations, and others, lead to improved models for thermal management and prediction of transient/residual stresses and distortions. Two approaches for the prediction of microstructure were pursued. The first was an empirical approach involving the

  9. A finite element model for thermomechanical analysis in casting processes

    Energy Technology Data Exchange (ETDEWEB)

    Celentano, D. (International Center for Numerical Methods in Engineering, E.T.S. d' Enginyers de Camins, Canals i Ports, Univ. Politecnica de Catalunya, Barcelona (Spain)); Oller, S. (International Center for Numerical Methods in Engineering, E.T.S. d' Enginyers de Camins, Canals i Ports, Univ. Politecnica de Catalunya, Barcelona (Spain)); Onate, E. (International Center for Numerical Methods in Engineering, E.T.S. d' Enginyers de Camins, Canals i Ports, Univ. Politecnica de Catalunya, Barcelona (Spain))

    1993-11-01

    This paper summarizes the recent work of the authors in the numerical simulation of casting processes. In particular, a coupled thermomechanical model to simulate the solidification problem in casting has been developed. The model, based on a general isotropic thermoelasto-plasticity theory and formulated in a macroscopical point of view, includes generalized phase-change effects and considers the different thermomechanical behaviour of the solidifying material during its evolution from liquid to solid. For this purpose, a phase-change variable, plastic evolution equations and a temperature-dependent material constitutive law have been defined. Some relevant aspects of this model are presented here. Full thermomechanical coupling terms have been considered as well as variable thermal and mechanical boundary conditions: the first are due to air gap formation, while the second involve a contact formulation. Particular details concerning the numerical implementation of this model are also mentioned. An enhanced staggered scheme, used to solve the highly non-linear fully coupled finite element equations, is proposed. Furthermore, a proper convergence criterion to stop the iteration process is adopted and, although the quadratic convergence of Newton-Rapshon's method is not achieved, several numerical experiments demonstrate reasonable convergence rates. Finally, an experimental cylindrical casting test problem, including phase-change phenomena, temperature-dependent constitutive properties and contact effects, is analyzed. Numerical results are compared with some laboratory measurements. (orig.).

  10. Systematic Integrated Process Design and Control of Binary Element Reactive Distillation Processes

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

    2016-01-01

    In this work, integrated process design and control of reactive distillation processes is considered through a computer-aided framework. First, a set of simple design methods for reactive distillation column that are similar in concept to non-reactive distillation design methods are extended....... It is shown that the same design-control principles that apply to a non-reacting binary system of compounds are also valid for a reactive binary system of elements for distillation columns. Application of this framework shows that designing the reactive distillation process at the maximum driving force...... results in a feasible and reliable design of the process as well as the controller structure....

  11. Finite element meshing approached as a global minimization process

    Energy Technology Data Exchange (ETDEWEB)

    WITKOWSKI,WALTER R.; JUNG,JOSEPH; DOHRMANN,CLARK R.; LEUNG,VITUS J.

    2000-03-01

    The ability to generate a suitable finite element mesh in an automatic fashion is becoming the key to being able to automate the entire engineering analysis process. However, placing an all-hexahedron mesh in a general three-dimensional body continues to be an elusive goal. The approach investigated in this research is fundamentally different from any other that is known of by the authors. A physical analogy viewpoint is used to formulate the actual meshing problem which constructs a global mathematical description of the problem. The analogy used was that of minimizing the electrical potential of a system charged particles within a charged domain. The particles in the presented analogy represent duals to mesh elements (i.e., quads or hexes). Particle movement is governed by a mathematical functional which accounts for inter-particles repulsive, attractive and alignment forces. This functional is minimized to find the optimal location and orientation of each particle. After the particles are connected a mesh can be easily resolved. The mathematical description for this problem is as easy to formulate in three-dimensions as it is in two- or one-dimensions. The meshing algorithm was developed within CoMeT. It can solve the two-dimensional meshing problem for convex and concave geometries in a purely automated fashion. Investigation of the robustness of the technique has shown a success rate of approximately 99% for the two-dimensional geometries tested. Run times to mesh a 100 element complex geometry were typically in the 10 minute range. Efficiency of the technique is still an issue that needs to be addressed. Performance is an issue that is critical for most engineers generating meshes. It was not for this project. The primary focus of this work was to investigate and evaluate a meshing algorithm/philosophy with efficiency issues being secondary. The algorithm was also extended to mesh three-dimensional geometries. Unfortunately, only simple geometries were tested

  12. Iodox process tests in a transuranium element production campaign

    Energy Technology Data Exchange (ETDEWEB)

    Collins, E. D.; Benker, D. E.

    1979-06-01

    The Iodox process, an advanced method for removing gaseous radioiodine from airstreams, was tested at high activity levels during transuranium element production operations. Special equipment was used to remove radioiodine from 3-5M HNO/sub 3/ dissolver solutions by volatilization and to absorb the iodine from the dissolver off-gas into hyperazeotropic HNO/sub 3/. More than 96% of the /sup 131/I in the dissolver solutions was removed by heeating to 100/sup 0/C and air-sparging. Treatments such as boiling, sparging with 5% N/sub 2/O/sub 3/, and adjustment to 10/sup -4/ M KI or 1% H/sub 2/O/sub 2/ effected the additional removal of /sup 131/I by factors of 2 to 5. Other than /sup 131/I, no fission products were volatilized during the treatments. A six-stage bubble-cap column was used for the abosrpttion. Off-gas decontamination factors were in the range of 1 x 10/sup 4/ to 8 x 10/sub 4/, or 5 to 7 per stage; these values are similar to those obtained during previous low-activity studies.

  13. r-Process Elements as Tracers of Enrichment Processes in the Early Halo

    Science.gov (United States)

    Andersen, Johannes; Nordström, Birgitta; Hansen, Terese T.

    2016-08-01

    Significant minorities of extremely metal-poor (EMP) halo stars exhibit dramatic excesses of neutron capture elements. The standard scenario for their origin is mass transfer and dilution in binary systems, but requires them to be binaries. If not, these excesses must have been implanted in them from birth by processes that are not included in current models of SN II chemical enrichment. The binary population of such EMP subgroups is a test of this scenario.

  14. Finite Element Models for Electron Beam Freeform Fabrication Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase II proposal offers to develop a comprehensive computer simulation methodology based on the finite element method for...

  15. Finite Element Models for Electron Beam Freeform Fabrication Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research proposal offers to develop the most accurate, comprehensive and efficient finite element models to date for simulation of the...

  16. Integrated Process Design and Control of Multi-element Reactive Distillation Processes

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

    2016-01-01

    In this work, integrated process design and control of reactive distillation processes involving multi-elements is presented. The reactive distillation column is designed using methods and tools which are similar in concept to non-reactive distillation design methods, such as driving force approach......-state analysis it is shown that it has the least energy consumption and carbon footprint. Next, through analytical and dynamic analysis it is verified that the control structure, disturbance rejection and the controllability at the maximum driving force is the best compared to any other design alternative which...

  17. 3D Rigid-Plastic Finite Element Analysis for Skew Rolling Process of the Stepped Part

    Institute of Scientific and Technical Information of China (English)

    Gang FANG; Pan ZENG

    2003-01-01

    Based on rigid-plastic finite element method, a skew rolling process of stepped part is simulated. Considering nodesaving and effective remeshing, the tetrahedron solid elements are used to discrete workpiece. The workpiece material adopts rigid-plastic m

  18. Multivariate Hawkes process models of the occurrence of regulatory elements

    DEFF Research Database (Denmark)

    Carstensen, L; Sandelin, A; Winther, Ole;

    2010-01-01

    BACKGROUND: A central question in molecular biology is how transcriptional regulatory elements (TREs) act in combination. Recent high-throughput data provide us with the location of multiple regulatory regions for multiple regulators, and thus with the possibility of analyzing the multivariate di...... occurrences of multiple TREs along the genome that is capable of providing new insights into dependencies among elements involved in transcriptional regulation. The method is available as an R package from http://www.math.ku.dk/~richard/ppstat/.......BACKGROUND: A central question in molecular biology is how transcriptional regulatory elements (TREs) act in combination. Recent high-throughput data provide us with the location of multiple regulatory regions for multiple regulators, and thus with the possibility of analyzing the multivariate...

  19. Rapid neutron capture process in supernovae and chemical element formation

    NARCIS (Netherlands)

    Baruah, Rulee; Duorah, Kalpana; Duorah, H. L.

    2009-01-01

    The rapid neutron capture process (r-process) is one of the major nucleosynthesis processes responsible for the synthesis of heavy nuclei beyond iron. Isotopes beyond Fe are most exclusively formed in neutron capture processes and more heavier ones are produced by the r-process. Approximately half o

  20. Multivariate Hawkes process models of the occurrence of regulatory elements

    DEFF Research Database (Denmark)

    Carstensen, L; Sandelin, A; Winther, Ole

    2010-01-01

    BACKGROUND: A central question in molecular biology is how transcriptional regulatory elements (TREs) act in combination. Recent high-throughput data provide us with the location of multiple regulatory regions for multiple regulators, and thus with the possibility of analyzing the multivariate di...

  1. Process metallurgy simulation for metal drawing process optimization by using two-scale finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Nakamachi, Eiji; Yoshida, Takashi; Yamaguchi, Toshihiko; Morita, Yusuke [Dept. of Biomedical Engineering, Doshisha Univ., Kyotanabe, Kyoto, 610-0394 (Japan); Kuramae, Hiroyuki [Dept. of Technol. Management, Osaka Institute of Technol., Asahiku, Osaka, 535-8585 (Japan); Morimoto, Hideo [Furukawa Electric Co. Ltd., Okano, Nishiku, Yokohama, Kanagawa, 220-0073 (Japan)

    2014-10-06

    We developed two-scale FE analysis procedure based on the crystallographic homogenization method by considering the hierarchical structure of poly-crystal aluminium alloy metal. It can be characterized as the combination of two-scale structure, such as the microscopic polycrystal structure and the macroscopic elastic plastic continuum. Micro polycrystal structure can be modeled as a three dimensional representative volume element (RVE). RVE is featured as by 3×3×3 eight-nodes solid finite elements, which has 216 crystal orientations. This FE analysis code can predict the deformation, strain and stress evolutions in the wire drawing processes in the macro- scales, and further the crystal texture and hardening evolutions in the micro-scale. In this study, we analyzed the texture evolution in the wire drawing processes by our two-scale FE analysis code under conditions of various drawing angles of dice. We evaluates the texture evolution in the surface and center regions of the wire cross section, and to clarify the effects of processing conditions on the texture evolution.

  2. Process metallurgy simulation for metal drawing process optimization by using two-scale finite element method

    Science.gov (United States)

    Nakamachi, Eiji; Yoshida, Takashi; Kuramae, Hiroyuki; Morimoto, Hideo; Yamaguchi, Toshihiko; Morita, Yusuke

    2014-10-01

    We developed two-scale FE analysis procedure based on the crystallographic homogenization method by considering the hierarchical structure of poly-crystal aluminium alloy metal. It can be characterized as the combination of two-scale structure, such as the microscopic polycrystal structure and the macroscopic elastic plastic continuum. Micro polycrystal structure can be modeled as a three dimensional representative volume element (RVE). RVE is featured as by 3×3×3 eight-nodes solid finite elements, which has 216 crystal orientations. This FE analysis code can predict the deformation, strain and stress evolutions in the wire drawing processes in the macro- scales, and further the crystal texture and hardening evolutions in the micro-scale. In this study, we analyzed the texture evolution in the wire drawing processes by our two-scale FE analysis code under conditions of various drawing angles of dice. We evaluates the texture evolution in the surface and center regions of the wire cross section, and to clarify the effects of processing conditions on the texture evolution.

  3. Study on Cracking Process of Power Boiler Element

    Science.gov (United States)

    Mutwil, K.; Cieśla, M.

    2012-05-01

    This paper presents the study of the reasons for cracking of spray steam attemperator. The element being analysed is a temperature controller of steam for turbine; its proper functioning has considerable impact on operation of power generating set of boiler and turbine. Damage to the steam attemperator may affect the durability of neighbouring components, replacement or repair of which results in a long-term outage of power generation unit. The reason for attemperator cracking has been determined on the basis of strength calculations and micro-and macro-analysis of fracture surfaces. The conducted tests were the basis for modification of attemperator design, which will ensure reliable functioning of the analysed element.

  4. The design, fabrication, and test of a new VLSI hybrid analog-digital neural processing element

    Science.gov (United States)

    Deyong, Mark R.; Findley, Randall L.; Fields, Chris

    1992-01-01

    A hybrid analog-digital neural processing element with the time-dependent behavior of biological neurons has been developed. The hybrid processing element is designed for VLSI implementation and offers the best attributes of both analog and digital computation. Custom VLSI layout reduces the layout area of the processing element, which in turn increases the expected network density. The hybrid processing element operates at the nanosecond time scale, which enables it to produce real-time solutions to complex spatiotemporal problems found in high-speed signal processing applications. VLSI prototype chips have been designed, fabricated, and tested with encouraging results. Systems utilizing the time-dependent behavior of the hybrid processing element have been simulated and are currently in the fabrication process. Future applications are also discussed.

  5. The design, fabrication, and test of a new VLSI hybrid analog-digital neural processing element

    Science.gov (United States)

    Deyong, Mark R.; Findley, Randall L.; Fields, Chris

    1992-01-01

    A hybrid analog-digital neural processing element with the time-dependent behavior of biological neurons has been developed. The hybrid processing element is designed for VLSI implementation and offers the best attributes of both analog and digital computation. Custom VLSI layout reduces the layout area of the processing element, which in turn increases the expected network density. The hybrid processing element operates at the nanosecond time scale, which enables it to produce real-time solutions to complex spatiotemporal problems found in high-speed signal processing applications. VLSI prototype chips have been designed, fabricated, and tested with encouraging results. Systems utilizing the time-dependent behavior of the hybrid processing element have been simulated and are currently in the fabrication process. Future applications are also discussed.

  6. Trace elements as quantitative probes of differentiation processes in planetary interiors

    Science.gov (United States)

    Drake, M. J.

    1980-01-01

    The characteristic trace element signature that each mineral in the source region imparts on the magma constitutes the conceptual basis for trace element modeling. It is shown that abundances of trace elements in extrusive igneous rocks may be used as petrological and geochemical probes of the source regions of the rocks if differentiation processes, partition coefficients, phase equilibria, and initial concentrations in the source region are known. Although compatible and incompatible trace elements are useful in modeling, the present review focuses primarily on examples involving the rare-earth elements.

  7. Manufacturing processes for fabricating graphite/PMR 15 polyimide structural elements

    Science.gov (United States)

    Sheppard, C. H.; Hoggatt, J. T.; Symonds, W. A.

    1979-01-01

    Investigations were conducted to obtain commercially available graphite/PMR-15 polyimide prepreg, develop an autoclave manufacturing process, and demonstrate the process by manufacturing structural elements. Controls were established on polymer, prepreg, composite fabrication, and quality assurance, Successful material quality control and processes were demonstrated by fabricating major structural elements including flat laminates, hat sections, I beam sections, honeycomb sandwich structures, and molded graphite reinforced fittings. Successful fabrication of structural elements and simulated section of the space shuttle aft body flap shows that the graphite/PMR-15 polyimide system and the developed processes are ready for further evaluation in flight test hardware.

  8. Elemental Mercury Diffusion Processes and Concentration at the Lunar Poles

    Science.gov (United States)

    Moxley, Frederick; Killen, Rosemary M.; Hurley, Dana M.

    2011-01-01

    In 2009, the Lyman Alpha Mapping Project (LAMP) spectrograph onboard the Lunar Reconnaissance Orbiter (LRO) spacecraft made the first detection of element mercury (Hg) vapor in the lunar exosphere after the Lunar Crater Observing and Sensing Satellite (LCROSS) Centaur rocket impacted into the Cabeus crater in the southern polar region of the Moon. The lunar regolith core samples from the Apollo missions determined that Hg had a devolatilized pattern with a concentration gradient increasing with depth, in addition to a layered pattern suggesting multiple episodes of burial and volatile loss. Hg migration on the lunar surface resulted in cold trapping at the poles. We have modeled the rate at which indigenous Hg is lost from the regolith through diffusion out of lunar grains. We secondly modeled the migration of Hg vapor in the exosphere and estimated the rate of cold-trapping at the poles using a Monte Carlo technique. The Hg vapor may be lost from the exosphere via ionization, Jeans escape, or re-impact into the surface causing reabsorption.

  9. Focusing on natural elements in the early design process, new potentials for architects?

    DEFF Research Database (Denmark)

    Sjøstedt, Victoria

    2010-01-01

    There is a large body of research on environmental planning, but a shortage of means for architects to implement environmental concerns in the early design process. This paper investigates the potentials of a more elaborated and conscious use of natural elements in the early design process. Natural...... elements are understood as considerations on the local climatic conditions such as sun, wind, water, soil and vegetation. Based on a case study of two urban scale projects in China, drawn by Danish and Chinese firms respectively, integration of natural elements, and the extent to which natural elements...

  10. Elements of the theory of Markov processes and their applications

    CERN Document Server

    Bharucha-Reid, A T

    2010-01-01

    This graduate-level text and reference in probability, with numerous applications to several fields of science, presents nonmeasure-theoretic introduction to theory of Markov processes. The work also covers mathematical models based on the theory, employed in various applied fields. Prerequisites are a knowledge of elementary probability theory, mathematical statistics, and analysis. Appendixes. Bibliographies. 1960 edition.

  11. Film videorecording and image processing systems: structural element welding

    Science.gov (United States)

    Konovalov, Nikolai A.; Veselovsky, Vladimir B.; Kovalenko, Vladimir I.; Lakhno, Nikolay I.; Skorik, Alexander D.; Furmanov, Valeri B.; Polyakov, Gennadiy A.

    1999-06-01

    With the aim of technological process automatization and control for high-frequency welding of different diameters pipes the machine-program complex (APC) was designed. APC gives the opportunity to create the cine- and telerecording of process in production conditions at the mill '159 - 529' of Novomoskovsky Tube Rolling Mill, Ukraine). With the help of APC in real functioning mill conditions the character of flashing zone length changing and the angle of convergence depending on pipe welding speed was investigated, also the zone of jumpers is defined. The comparison of theoretical and experimental data gave an opportunity to define a welding rate which is optimal for the most qualitative values of welded joints in the range of pipe products of mill '159 - 529.'

  12. Finite Element Analysis in Concurrent Processing: Computational Issues

    Science.gov (United States)

    Sobieszczanski-Sobieski, Jaroslaw; Watson, Brian; Vanderplaats, Garrett

    2004-01-01

    The purpose of this research is to investigate the potential application of new methods for solving large-scale static structural problems on concurrent computers. It is well known that traditional single-processor computational speed will be limited by inherent physical limits. The only path to achieve higher computational speeds lies through concurrent processing. Traditional factorization solution methods for sparse matrices are ill suited for concurrent processing because the null entries get filled, leading to high communication and memory requirements. The research reported herein investigates alternatives to factorization that promise a greater potential to achieve high concurrent computing efficiency. Two methods, and their variants, based on direct energy minimization are studied: a) minimization of the strain energy using the displacement method formulation; b) constrained minimization of the complementary strain energy using the force method formulation. Initial results indicated that in the context of the direct energy minimization the displacement formulation experienced convergence and accuracy difficulties while the force formulation showed promising potential.

  13. Finite element modelling of manufacturing processes for plastic deformation

    Directory of Open Access Journals (Sweden)

    Fernando Mejía Umaña

    2010-04-01

    Full Text Available The object of the Mechanical and Electrical Engineering Departament's computational mechanics of solids section is to offer industry solutions to problems requiring deeper knowledge regarding the mechanincs of solids and how they can be numerically modelled. This article summarises the foundations of plastic deformation, together with the results obtained during the experimental phase and from modelling two applications of plastic deformation processes being studied as part of mechanical engineering students' undergraduate projects.

  14. Boiling process in oil coolers on porous elements

    Directory of Open Access Journals (Sweden)

    Genbach Alexander A.

    2016-01-01

    Full Text Available Holography and high-speed filming were used to reveal movements and deformations of the capillary and porous material, allowing to calculate thermo-hydraulic characteristics of boiling liquid in the porous structures. These porous structures work at the joint action of capillary and mass forces, which are generalised in the form of dependences used in the calculation for oil coolers in thermal power plants (TPP. Furthermore, the mechanism of the boiling process in porous structures in the field of mass forces is explained. The development process of water steam formation in the mesh porous structures working at joint action of gravitational and capillary forces is investigated. Certain regularities pertained to the internal characteristics of boiling in cells of porous structure are revealed, by means of a holographic interferometry and high-speed filming. Formulas for calculation of specific thermal streams through thermo-hydraulic characteristics of water steam formation in mesh structures are obtained, in relation to heat engineering of thermal power plants. This is the first calculation of heat flow through the thermal-hydraulic characteristics of the boiling process in a reticulated porous structure obtained by a photo film and holographic observations.

  15. Space Station Freedom pressurized element interior design process

    Science.gov (United States)

    Hopson, George D.; Aaron, John; Grant, Richard L.

    1990-01-01

    The process used to develop the on-orbit working and living environment of the Space Station Freedom has some very unique constraints and conditions to satisfy. The goal is to provide maximum efficiency and utilization of the available space, in on-orbit, zero G conditions that establishes a comfortable, productive, and safe working environment for the crew. The Space Station Freedom on-orbit living and working space can be divided into support for three major functions: (1) operations, maintenance, and management of the station; (2) conduct of experiments, both directly in the laboratories and remotely for experiments outside the pressurized environment; and (3) crew related functions for food preparation, housekeeping, storage, personal hygiene, health maintenance, zero G environment conditioning, and individual privacy, and rest. The process used to implement these functions, the major requirements driving the design, unique considerations and constraints that influence the design, and summaries of the analysis performed to establish the current configurations are described. Sketches and pictures showing the layout and internal arrangement of the Nodes, U.S. Laboratory and Habitation modules identify the current design relationships of the common and unique station housekeeping subsystems. The crew facilities, work stations, food preparation and eating areas (galley and wardroom), and exercise/health maintenance configurations, waste management and personal hygiene area configuration are shown. U.S. Laboratory experiment facilities and maintenance work areas planned to support the wide variety and mixtures of life science and materials processing payloads are described.

  16. Space Station Freedom pressurized element interior design process

    Science.gov (United States)

    Hopson, George D.; Aaron, John; Grant, Richard L.

    1990-01-01

    The process used to develop the on-orbit working and living environment of the Space Station Freedom has some very unique constraints and conditions to satisfy. The goal is to provide maximum efficiency and utilization of the available space, in on-orbit, zero G conditions that establishes a comfortable, productive, and safe working environment for the crew. The Space Station Freedom on-orbit living and working space can be divided into support for three major functions: (1) operations, maintenance, and management of the station; (2) conduct of experiments, both directly in the laboratories and remotely for experiments outside the pressurized environment; and (3) crew related functions for food preparation, housekeeping, storage, personal hygiene, health maintenance, zero G environment conditioning, and individual privacy, and rest. The process used to implement these functions, the major requirements driving the design, unique considerations and constraints that influence the design, and summaries of the analysis performed to establish the current configurations are described. Sketches and pictures showing the layout and internal arrangement of the Nodes, U.S. Laboratory and Habitation modules identify the current design relationships of the common and unique station housekeeping subsystems. The crew facilities, work stations, food preparation and eating areas (galley and wardroom), and exercise/health maintenance configurations, waste management and personal hygiene area configuration are shown. U.S. Laboratory experiment facilities and maintenance work areas planned to support the wide variety and mixtures of life science and materials processing payloads are described.

  17. Analytical solutions for the slow neutron capture process of heavy element nucleosynthesis

    Institute of Scientific and Technical Information of China (English)

    Wu Kai-Su

    2009-01-01

    In this paper,the network equation for the slow neutron capture process (s-process) of heavy element nucleosynthesis is investigated. Dividing the s-process network reaction chains into two standard forms and using the technique of matrix decomposition,a group of analytical solutions for the network equation are obtained. With the analytical solutions,a calculation for heavy element abundance of the solar system is carried out and the results are in good agreement with the astrophysical measurements.

  18. [Spectral analysis of elements in different samples of processed Foeniculum vulgare].

    Science.gov (United States)

    Zhang, Fan; Li, Zhen; Hamulati, Wufuer; Tian, Shu-Ge

    2010-03-01

    The compositions and contents of chemical compounds in traditional Chinese medicines would be changed after being processed using different methods, and their pharmacological activity may be influenced. ICP-AES, AAS and AFS were the first methods to be used to scan and analyze macro elements, trace elements and heavy metals in Foeniculum vulgare and its nine different processed samples in the present paper, which were correlated with people's health and lives. The experiment results showed that the three kinds of analyzing methods could be used to judge the contents and the changing trend of all elements in traditional Chinese medicine quickly and truly. Thirty two elements were found in F. vulgare, and there were noticeable changes in the contents of some elements in processed samples compared with F. vulgare without processing. These results indicated that there is great relevance between changes in the contends of elements with different processing methods, and auxiliary materials can not only change the contents of elements but also play a role in treating ills with effective constituents. Also, it was firstly found that the content of Hg rose greatly in the experiment, and these showed there was notable potential safety hazard when processed Foeniculum vulgare was used. These experiments widen the application of spectrum analyzing methods in safety evaluation of traditional Chinese medicine.

  19. Elastic-plastic finite element simulation for diamond turning process

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Using general commercial software, a coupled thermo-mechanieal plane strain larger deformation orthogonal cutting model is developed on the basis of updated Lagrangian formulation in this paper. The workpiece is oxygen free high conductivity copper ( OFHC copper), its flow stress is considered as a function of strain, strain rate and temperature to reflect its realistic changes in physical properties. In order to take into account the cutting edge radius effects of the single crystal diamond tool, rezoning technology is introduced into this simulation model. Diamond turning process is simulated from the initial stage to the steady stage of chip formation, and the distribution of temperature, equivalent stress, residual stress, strain rate and shear angle are obtained. The simulated principal force is compared with published experiment data and they are found to be in good agreement with each other, but poor for thrust force due to no consideration of elastic recovery for machined surface in the elastic-plastic material model.

  20. Enrichment history of r-process elements shaped by a merger of neutron star pairs

    CERN Document Server

    Tsujimoto, Takuji

    2014-01-01

    The origin of r-process elements remains unidentified and still puzzles us. The recent discovery of evidence for the ejection of r-process elements from a short-duration gamma-ray burst singled out neutron star mergers (NSMs) as their origin. In contrast, core-collapse supernovae are ruled out as the main origin of heavy r-process elements (A>110) by recent numerical simulations. However, the properties characterizing NSM events - their rarity and high yield of r-process elements per event - have been claimed to be incompatible with the observed stellar records on r-process elements in the Galaxy. We add to this picture with our results, which show that the observed constant [r-process/H] ratio in faint dwarf galaxies and one star unusually rich in r-process in the Sculptor galaxy agree well with this rarity of NSM events. Furthermore, we found that a large scatter in the abundance ratios of r-process elements to iron in the Galactic halo can be reproduced by a scheme that incorporates an assembly of various ...

  1. Determining e-Portfolio Elements in Learning Process Using Fuzzy Delphi Analysis

    Science.gov (United States)

    Mohamad, Syamsul Nor Azlan; Embi, Mohamad Amin; Nordin, Norazah

    2015-01-01

    The present article introduces the Fuzzy Delphi method results obtained in the study on determining e-Portfolio elements in learning process for art and design context. This method bases on qualified experts that assure the validity of the collected information. In particular, the confirmation of elements is based on experts' opinion and…

  2. Optimization of the flexible mould process for the production of double-curved concrete elements

    NARCIS (Netherlands)

    Schipper, H.R.; Grunewald, S.; Eigenraam, P.; Raghunath, P.; Kok, M.

    2014-01-01

    Free-form buildings tend to be expensive. By optimizing the production process, economical and wellperforming concrete structures and elements can be manufactured. In this paper, an innovative method is presented that allows producing highly accurate double curved-elements without the need for milli

  3. Progress in mixed Eulerian-Lagrangian finite element simulation of forming processes

    NARCIS (Netherlands)

    Huetink, Han; Vreede, P.T.; van der Lugt, J.

    1990-01-01

    A review is given of a mixed Eulerian-Lagrangian finite element method for simulation of forming processes. This method permits incremental adaptation of nodal point locations independently from the actual material displacements. Hence numerical difficulties due to large element distortions, as may

  4. Study of Delamination and Buckling of Paper during the Creping Process using Finite Element Method -- A Cohesive Element Approach

    Science.gov (United States)

    Gupta, Swapnil Sheelkumar

    Paper variants such as paper napkins, tissue paper are manufactured by a process called as creping during which a paper adhesively bonded to a rotating drum is continuously scraped off by a blade. Resulting low density paper provides critical attributes such as fluid absorbency, softness, and stretchiness to the final paper product. The macroscopic effect of creping is the formation of fine ridges called as " crepes". The quality of the final product is characterized by the length of the crepes. The process of creping has been hypothesized to be a periodic sequence of delamination, buckling and post-buckling compression of paper. A quasi-static comparison of a two dimensional finite element model implementing surface based cohesive zone theory and a critical stress criteria based fracture model is presented. The adhesive being a critical part of creping is represented by a zero thickness cohesive layer in the cohesive model . A comparison of a 1-D analytical model implementing an energy release rate approach and a Virtual Crack Closure Technique (VCCT) quasi-static finite element model is presented. An experimental investigation to quantitatively determine the adhesive fracture toughness during creping is conducted by an energy based approach. The influence of drum speed and adhesive concentration on the adhesive fracture energy is analyzed and comparison with a dynamic finite element model is obtained.

  5. Application of the dual reciprocity boundary element method for numerical modelling of solidification process

    Directory of Open Access Journals (Sweden)

    E. Majchrzak

    2008-12-01

    Full Text Available The dual reciprocity boundary element method is applied for numerical modelling of solidification process. This variant of the BEM is connected with the transformation of the domain integral to the boundary integrals. In the paper the details of the dual reciprocity boundary element method are presented and the usefulness of this approach to solidification process modelling is demonstrated. In the final part of the paper the examples of computations are shown.

  6. A mesh re-zoning technique for finite element simulations of metal forming processes

    Science.gov (United States)

    Cheng, J.-C.; Kikuchi, N.

    1986-01-01

    Based on some fundamental properties of finite element approximations, a mesh re-zoning scheme is proposed for finite element simulations of metal forming problems. It is demonstrated that this technique is indispensable in analyzing many difficult forming processes, especially when there exist corners or very irregular shapes on the boundaries. The algorithm is tested by a backward extrusion process and direct extrusion through a square die.

  7. Active Elements for Analog Signal Processing: Classification, Review, and New Proposals

    Directory of Open Access Journals (Sweden)

    Z. Kolka

    2008-12-01

    Full Text Available In the paper, an analysis of the state-of-the-art of active elements for analog signal processing is presented which support – in contrast to the conventional operational amplifiers – not only the voltage-mode but also the current- and mixed-mode operations. Several problems are addressed which are associated with the utilization of these elements in linear applications, particularly in frequency filters. A methodology is proposed which generates a number of fundamentally new active elements with their potential utilization in various areas of signal processing.

  8. Process for the Φ130 sapphire window element with long distance and high resolution

    Science.gov (United States)

    Xu, Zengqi; Su, Ying; Lei, Jianli; Guo, Rui; Zhang, Feng; Guo, Xinlong; Liu, Xuanmin; Sun, Taohui

    2016-10-01

    With the process test for the choice of materials, the test materials and the molds, the abrasives, the temperature and the different machining process monitoring parameters of the polishing machine, the process method and the quality control technology were figured out for the Φ130 sapphire window element with long distance and high resolution (hereinafter referred to as window element), meantime, the optimum process condition was determined to machine the element. The results were that the high resolution imaging window was processed with the surface roughness Ra of 0.639nm, the transmission distortion of λ/10 (λ=632.8nm), the parallel error of 5″, the resolution of 1.47″ and the focal length of 5 km, which can satisfy the imaging requirements better for the military photoelectric device for sapphire window with long distance and high resolution.

  9. A mixed Eulerian-Lagrangian finite element method for simulation of thermo-mechanical forming processes

    Science.gov (United States)

    Huetink, J.; Vanderlugt, J.

    1988-08-01

    A mixed Eulerian-Lagrangian finite element method is developed by which nodal point locations can be adapted independently from the actual material displacements. Numerical difficulties due to large element distortions, as many occur when the updated Lagrange method is applied, can be avoided by this method. Movement of (free) surfaces can be taken into account by adapting nodal surface points in a way that they remain on the surface. Hardening and other deformation path dependent properties are determined by incremental treatment of convective terms. A local and a weighed global smoothing procedure is introduced in order to avoid numerical instabilities. The method has been applied to simulations of an upsetting process, a wire drawing process and a cold rolling process. In the simulation of the rolling process, both workpiece and roll are simultaneously analyzed in order to predict the flattening of the roll. Special contact-slip elements are developed for the tool-workpiece interface.

  10. Focusing on natural elements in the early design process, new potentials for architects?

    DEFF Research Database (Denmark)

    Sjøstedt, Victoria

    2010-01-01

    There is a large body of research on environmental planning, but a shortage of means for architects to implement environmental concerns in the early design process. This paper investigates the potentials of a more elaborated and conscious use of natural elements in the early design process. Natural...

  11. A three-dimensional finite element model of the polymerization process in dental restorations.

    NARCIS (Netherlands)

    Barink, M.; Mark, P.C. van der; Fennis, W.M.M.; Kuys, R.H.; Kreulen, C.M.; Verdonschot, N.J.J.

    2003-01-01

    Restoration of dental restorations with resin composite is hampered by shrinkage of the material during the polymerization process. In this study, we simulated the polymerization process in a detailed three-dimensional finite element model of a human upper premolar with a cusp-replacing restoration.

  12. Geochemical Implication of Rare Earth Elements in Process of Soil Development

    Institute of Scientific and Technical Information of China (English)

    黄成敏; 龚子同

    2001-01-01

    The geochemical characteristics and behavior of rare earth elements (REE) in soils developed on the basalts in the northern part of Hainan Island erupted in different time were studied as well as the REE partition in the soil-formation process and its implication on soil development degree. The results show that the total REE content in soils is correlative with soil age significantly and can be selected as the index to show soil evolution. With the soil developing intensively, light rare earth elements (LREE) gain and heavy rare earth elements (HREE) lose. The trends of positive Ce-anomaly and negative Eu-anomaly are remarkable with soil development.

  13. Finite element modelling of creep process - steady state stresses and strains

    Directory of Open Access Journals (Sweden)

    Sedmak Aleksandar S.

    2014-01-01

    Full Text Available Finite element modelling of steady state creep process has been described. Using an analogy of visco-plastic problem with a described procedure, the finite element method has been used to calculate steady state stresses and strains in 2D problems. An example of application of such a procedure have been presented, using real life problem - cylindrical pipe with longitudinal crack at high temperature, under internal pressure, and estimating its residual life, based on the C*integral evaluation.

  14. Cost model relationships between textile manufacturing processes and design details for transport fuselage elements

    Science.gov (United States)

    Metschan, Stephen L.; Wilden, Kurtis S.; Sharpless, Garrett C.; Andelman, Rich M.

    1993-01-01

    Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design.

  15. Hydroforming Process Design Using Finite Element Simulation for a Vehicle Instrument Panel Support Frame

    Institute of Scientific and Technical Information of China (English)

    FAN Li-xia; ZHENG Zai-xiang; XIN Wen-xiu

    2006-01-01

    Tubular hydroforming has attracted increased attention in the vehicle industry recently. This paper covers a complete hydroforming process design for an instrument panel frame by finite element simulation using the explicit code LS-DYNA. The manufacturing process for the instrument panel frame consists of tube pre-bending and final hydroforming. To accomplish hydroforming process design successfully, a thorough investigation of proper combination of process parameters such as internal hydraulic pressure and axial feeding is carried out by finite element simulation to predict the tube wall thickness and shape. An optimized process parameter combination is obtained and verified by the instrument panel frame hydroforming experiment. The experiment shows that designed process parameters can be used in real production through FEA simulation, but tubular thinned amplitude by FEA is less than that with the experiment.

  16. Impact of nuclear fission on r-process nucleosynthesis and origin of solar r-process elements

    Energy Technology Data Exchange (ETDEWEB)

    Shibagaki, Shota, E-mail: shota.shibagaki@nao.ac.jp [Department of Astronomy, Graduate School of Science, University of Tokyo, 2 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kajino, Toshitaka [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, University of Tokyo, 2 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mathews, Grant J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Chiba, Satoshi [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8850 (Japan)

    2015-02-24

    Binary neutron star mergers (NSMs) are expected to be main production sites of r-process elements. Their ejecta are extremely neutron-rich (Y{sub e}<0.1), and the r-process path proceeds along the neutron drip line and enters the region of fissile nuclei. In this situation, although superheavy nuclei may be synthesized and the r-process path may reach the island of stability, those are sensitive to theoretical models of nuclear masses and nuclear fission. In this study, we carry out r-process nucleosynthesis simulations in the NSMs. Our new nuclear reaction network code include new theoretical models of nuclear masses and nuclear fission. Our r-process simulation of a binary NSM shows that the final r-process elemental abundances exhibit flat pattern for A∼110-160, and several fission cycling operate in extremely neutron-rich conditions of the NSM. We find that the combination of the NSMs and the magnetorotational supernovae can reproduce the solar r-process elements. We discuss the validity of this interpretation.

  17. A triangular prism solid and shell interactive mapping element for electromagnetic sheet metal forming process

    Science.gov (United States)

    Cui, Xiangyang; Li, She; Feng, Hui; Li, Guangyao

    2017-05-01

    In this paper, a novel triangular prism solid and shell interactive mapping element is proposed to solve the coupled magnetic-mechanical formulation in electromagnetic sheet metal forming process. A linear six-node ;Triprism; element is firstly proposed for transient eddy current analysis in electromagnetic field. In present ;Triprism; element, shape functions are given explicitly, and a cell-wise gradient smoothing operation is used to obtain the gradient matrices without evaluating derivatives of shape functions. In mechanical field analysis, a shear locking free triangular shell element is employed in internal force computation, and a data mapping method is developed to transfer the Lorentz force on solid into the external forces suffered by shell structure for dynamic elasto-plasticity deformation analysis. Based on the deformed triangular shell structure, a ;Triprism; element generation rule is established for updated electromagnetic analysis, which means inter-transformation of meshes between the coupled fields can be performed automatically. In addition, the dynamic moving mesh is adopted for air mesh updating based on the deformation of sheet metal. A benchmark problem is carried out for confirming the accuracy of the proposed ;Triprism; element in predicting flux density in electromagnetic field. Solutions of several EMF problems obtained by present work are compared with experiment results and those of traditional method, which are showing excellent performances of present interactive mapping element.

  18. High-speed nonlinear finite element analysis for surgical simulation using graphics processing units.

    Science.gov (United States)

    Taylor, Z A; Cheng, M; Ourselin, S

    2008-05-01

    The use of biomechanical modelling, especially in conjunction with finite element analysis, has become common in many areas of medical image analysis and surgical simulation. Clinical employment of such techniques is hindered by conflicting requirements for high fidelity in the modelling approach, and fast solution speeds. We report the development of techniques for high-speed nonlinear finite element analysis for surgical simulation. We use a fully nonlinear total Lagrangian explicit finite element formulation which offers significant computational advantages for soft tissue simulation. However, the key contribution of the work is the presentation of a fast graphics processing unit (GPU) solution scheme for the finite element equations. To the best of our knowledge, this represents the first GPU implementation of a nonlinear finite element solver. We show that the present explicit finite element scheme is well suited to solution via highly parallel graphics hardware, and that even a midrange GPU allows significant solution speed gains (up to 16.8 x) compared with equivalent CPU implementations. For the models tested the scheme allows real-time solution of models with up to 16,000 tetrahedral elements. The use of GPUs for such purposes offers a cost-effective high-performance alternative to expensive multi-CPU machines, and may have important applications in medical image analysis and surgical simulation.

  19. A MULTI-COUPLED FINITE ELEMENT ANALYSIS OF RESISTANCE SPOT WELDING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Hou Zhigang; Wang Yuanxun; Li Chunzhi; Chen Chuanyao

    2006-01-01

    A two-dimensional axisymmetric finite element model is developed to analyze the transient thermal and mechanical behaviors of the Resistance Spot Welding (RSW) process using commercial software ANSYS. Firstly a direct-coupled electrical-thermal Finite Element Analysis(FEA) is performed to analyze the transient thermal characteristics of the RSW process. Then based on the thermal results a sequential coupled thermo-elastic-plastic analysis is conducted to determine the mechanical features of the RSW process. The thermal history of the whole process and the temperature distribution of the weldment are obtained through the analysis.The mechanical features, including the distributions of the contact pressure at both the faying surface and the electrode-workpiece interface, the stress and strain distributions in the weldment and their changes during the RSW process, the deformation of the weldment and the electrode displacement are also calculated.

  20. Complete element abundances of nine stars in the r-process galaxy Reticulum II

    CERN Document Server

    Ji, Alexander P; Simon, Joshua D; Chiti, Anirudh

    2016-01-01

    We present chemical abundances derived from high-resolution Magellan/MIKE spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II. These stars span the full metallicity range of Ret II (-3.5 < [Fe/H] < -2). Seven of the nine stars have extremely high levels of r-process material ([Eu/Fe]~1.7), in contrast to the extremely low neutron-capture element abundances found in every other ultra-faint dwarf galaxy studied to date. The other two stars are the most metal-poor stars in the system ([Fe/H] < -3), and they have neutron-capture element abundance limits similar to those in other ultra-faint dwarf galaxies. We confirm that the relative abundances of Sr, Y, and Zr in these stars are similar to those found in r-process halo stars but ~0.5 dex lower than the solar r-process pattern. If the universal r-process pattern extends to those elements, the stars in Ret II display the least contaminated known r-process pattern. The abundances of lighter elements up to the...

  1. Are collapsars responsible for some r-process elements? How could we tell?

    Energy Technology Data Exchange (ETDEWEB)

    Pruet, J

    2004-04-05

    We consider the possibility that supernovae which form hyper-accreting black holes might be responsible for synthesis of r-process elements with mass A {approx}< 130. Calculations are presented which show that these elements are naturally synthesized in neutron-rich magnetically-dominated bubbles born in the inner regions of a black hole accretion disk. Simple considerations suggest that the total mass ejected in the form of these bubbles is about that needed to account for the entire galactic inventory of the 2nd-peak r-process elements. We also argue that if collapsars are responsible for, e.g., Ag synthesis, then Ag abundances should be correlated with Sc and/or Zn abundances in metal-poor stars.

  2. Enrichment of r-process elements in dwarf spheroidal galaxies in chemo-dynamical evolution model

    CERN Document Server

    Hirai, Yutaka; Saitoh, Takayuki R; Fujii, Michiko S; Hidaka, Jun; Kajino, Toshitaka

    2015-01-01

    The rapid neutron-capture process (r-process) is a major process to synthesize elements heavier than iron, but the astrophysical site(s) of r-process is not identified yet. Neutron star mergers (NSMs) are suggested to be a major r-process site from nucleosynthesis studies. Previous chemical evolution studies however require unlikely short merger time of NSMs to reproduce the observed large star-to-star scatters in the abundance ratios of r-process elements relative to iron, [Eu/Fe], of extremely metal-poor stars in the Milky Way (MW) halo. This problem can be solved by considering chemical evolution in dwarf spheroidal galaxies (dSphs) which would be building blocks of the MW and have lower star formation efficiencies than the MW halo. We demonstrate that enrichment of r-process elements in dSphs by NSMs using an N-body/smoothed particle hydrodynamics code. Our high-resolution model reproduces the observed [Eu/Fe] by NSMs with a merger time of 100 Myr when the effect of metal mixing is taken into account. Thi...

  3. Subaru/HDS study of CH stars: elemental abundances for stellar neutron-capture process studies

    Science.gov (United States)

    Goswami, Aruna; Aoki, Wako; Karinkuzhi, Drisya

    2016-01-01

    A comprehensive abundance analysis providing rare insight into the chemical history of lead stars is still lacking. We present results from high-resolution (R ˜ 50 000) spectral analyses of three CH stars, HD 26, HD 198269 and HD 224959, and, a carbon star with a dusty envelope, HD 100764. Previous studies on these objects are limited by both resolution and wavelength regions and the results differ significantly from each other. We have undertaken to reanalyse the chemical composition of these objects based on high-resolution Subaru spectra covering the wavelength regions 4020-6775 Å. Considering local thermodynamic equilibrium and using model atmospheres, we have derived the stellar parameters, the effective temperatures Teff, surface gravities log g, and metallicities [Fe/H] for these objects. The derived parameters for HD 26, HD 100764, HD 198269 and HD 224959 are (5000, 1.6, -1.13), (4750, 2.0 -0.86), (4500, 1.5, -2.06) and (5050, 2.1, -2.44), respectively. The stars are found to exhibit large enhancements of heavy elements relative to iron in conformity to previous studies. Large enhancement of Pb with respect to iron is also confirmed. Updates on the elemental abundances for several s-process elements (Y, Zr, La, Ce, Nd, Sm and Pb) along with the first-time estimates of abundances for a number of other heavy elements (Sr, Ba, Pr, Eu, Er and W) are reported. Our analysis suggests that neutron-capture elements in HD 26 primarily originate in the s-process while the major contributions to the abundances of neutron-capture elements in the more metal-poor objects HD 224959 and HD 198269 are from the r-process, possibly from materials that are pre-enriched with products of the r-process.

  4. A Finite-Element Analysis on the Rheorolling Process of Semi-Solid Spring Steel

    Institute of Scientific and Technical Information of China (English)

    Hongbo DONG; Yonglin KANG

    2003-01-01

    With a geometrical model of porous material, a 3D finite-element analysis on the rolling process of spring steel60Si2Mn in the semi-solid state is carried out using software MARC. In terms of flat and groove rolling conditions,stress field and strain fiel

  5. High Thinking Processes (HTP): Elements of Curricula and Teaching Able-Learners.

    Science.gov (United States)

    Kaniel, Shlomo

    2002-01-01

    This article discusses preparing able learners for the technologically dynamic future by teaching High Thinking Processes (HTP). It describes components of HTP and four main elements for developing HTP: well organized and justified curricula with appropriate tasks; metacognitive teaching; learning communities and challenging environments; and…

  6. New fission fragment distributions and r-process origin of the rare-earth elements

    CERN Document Server

    Goriely, S; Lemaitre, J -F; Panebianco, S; Dubray, N; Hilaire, S; Bauswein, A; Janka, H -Thomas

    2013-01-01

    Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers A > 140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular the fission fragment yields determine the creation of 110 140.

  7. Evaluation of selected risk elements removal processes from wastewater in constructed wetlands.

    OpenAIRE

    Mrázková, Ivana

    2008-01-01

    The purpose of this bachelor work is to provide a literature survey aimed at the processes responsible for removal of selected risk elements (arsenate, lead, nickel, Merkury, kadmium and manganese) during the wastewater treatment in constructed wetlands. Also, constructed wetlands are compared with conventional treatment plants.

  8. Preliminary Study on Element Leaching and Current Soil—Forming Process of Red Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANQI-GUO; XUESHI-KUI; 等

    1991-01-01

    The leaching characteristics and the element concentration in soil solution of red soils derived from sandstone,granite,Quaternary red clay and basalt have been studied in the Red Earth Ecological Experimental Station,Academia Sinica,using 12 lysimeters.Results obtained show that the element leaching process of red soils occurs mainly from January to the beginning of July annually.The elements with higher concentration in leaching solution of red soils are Si,Ca,Na,K,Mg,and N.The desilication and the leaching process of base cations occur simultaneously in the red soils.Using the first order differential equation and measured parameters of Si leaching,the leaching models of Si for red soils derived from different parent materials are constructed.The leaching process of Si is simulated with the models.Both the absolute and relative ages of red soils derived from different parent materials are discussed based on the simulation result.On the basis of element leaching,composition of soil solution and thermodynamics,the current soil-forming process is discussed.According to the phase diagram,the kaolinization is prevailing in the current formation of different red soils.

  9. Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

    DEFF Research Database (Denmark)

    Hovad, Emil; Larsen, P.; Walther, Jens Honore

    2015-01-01

    The DISAMATIC casting process production of sand moulds is simulated with DEM (discrete element method). The main purpose is to simulate the dynamics of the flow of green sand, during the production of the sand mould with DEM. The sand shot is simulated, which is the first stage of the DISAMATIC...

  10. Simulating the DISAMATIC process using the discrete element method — a dynamical study of granular flow

    DEFF Research Database (Denmark)

    Hovad, Emil; Spangenberg, Jon; Larsen, P.

    2016-01-01

    The discrete element method (DEM) is applied to simulate the dynamics of the flow of green sand while filling a mould using the DISAMATIC process. The focus is to identify relevant physical experiments that can be used to characterize the material properties of green sand in the numerical model...

  11. The maturing process: a vital element in the holistic care of women.

    Science.gov (United States)

    Gottesman, C

    1993-09-01

    The maturing process is a powerful holistic method for removing childhood blocks, thus freeing us to develop our full potential in the present. This health-patterning modality is an imagery process that assists us in reshaping the holograms in our memory banks. This process is effective with women coming from a variety of dysfunctional backgrounds, dealing with codependency, sexual abuse, and grief and loss issues. Female relationships and interactions are explored through the use of two case studies. The maturing process represents a missing and vital element in the holistic care of women.

  12. ENRICHMENT OF r-PROCESS ELEMENTS IN DWARF SPHEROIDAL GALAXIES IN CHEMO-DYNAMICAL EVOLUTION MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Yutaka; Kajino, Toshitaka [Department of Astronomy, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ishimaru, Yuhri [Department of Material Science,International Christian University, 3-10-2 Osawa, Mitaka, Tokyo 181-8585 (Japan); Saitoh, Takayuki R. [Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Fujii, Michiko S.; Hidaka, Jun, E-mail: yutaka.hirai@nao.ac.jp [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa Mitaka, Tokyo 181-8588 (Japan)

    2015-11-20

    The rapid neutron-capture process (r-process) is a major process for the synthesis of elements heavier than iron-peak elements, but the astrophysical site(s) of the r-process has not yet been identified. Neutron star mergers (NSMs) are suggested to be a major r-process site according to nucleosynthesis studies. Previous chemical evolution studies, however, required unlikely short merger times of NSMs to reproduce the observed large star-to-star scatters in the abundance ratios of r-process elements to iron: the [Eu/Fe] of extremely metal-poor stars in the Milky Way (MW) halo. This problem can be solved by considering chemical evolution in dwarf spheroidal galaxies (dSphs), which would be building blocks of the MW and have lower star formation efficiencies than the MW halo. We demonstrate the enrichment of r-process elements in dSphs by NSMs using an N-body/smoothed particle hydrodynamics code. Our high-resolution model reproduces the observed [Eu/Fe] due to NSMs with a merger time of 100 Myr when the effect of metal mixing is taken into account. This is because metallicity is not correlated with time ∼300 Myr from the start of the simulation due to the low star formation efficiency in dSphs. We also confirm that this model is consistent with observed properties of dSphs such as radial profiles and metallicity distribution. The merger time and the Galactic rate of NSMs are suggested to be ≲300 Myr and ∼10{sup −4} year{sup −1}, respectively, which are consistent with the values suggested by population synthesis and nucleosynthesis studies. This study supports the argument that NSMs are the major astrophysical site of the r-process.

  13. Abundances of s-process elements in planetary nebulae: Br, Kr & Xe

    CERN Document Server

    Zhang, Y; Pellegrini, E; Cavagnolo, K; Baldwin, J A; Sharpee, B; Phillips, M; Liu, X W

    2006-01-01

    We identify emission lines of post-iron peak elements in very high signal-to-noise spectra of a sample of planetary nebulae. Analysis of lines from ions of Kr and Xe reveals enhancements in most of the PNe, in agreement with the theories of s-process in AGB star. Surprisingly, we did not detect lines from Br even though s-process calculations indicate that it should be produced with Kr at detectable levels.

  14. A parallel Processing Method in Finite Element Analysis using Domain Division

    OpenAIRE

    Iwano, Kenji; Cingoski, Vlatko; Kaneda, Kazufumi; Yamashita, Hideo

    1994-01-01

    Current parallel processing aproaches in finite element analysis can be roughly classified into two categories: In the domain method, analysis region is divided into subdomains and one CPU assigned to each subdomain. Alternatively, one may calculate in parallel the matrix and vector products which arise in the process of solving the set of simultaneous equations. In this paper, we present a hybrid of the above two methods. Iteration to bring values on the subdomain boundaries coincide is not ...

  15. Systematic Integrated Process Design and Control of Binary Element Reactive Distillation Processes

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

    2016-01-01

    In this work, integrated process design and control of reactive distillation processes is considered through a computer-aided framework. First, a set of simple design methods for reactive distillation column that are similar in concept to non-reactive distillation design methods are extended to d...

  16. R-process and alpha-elements in the Galactic disk: Kinematic correlations

    CERN Document Server

    Koch, A

    2004-01-01

    Recent studies of elemental abundances in the Galactic halo and in the Galactic disk have underscored the possibility to kinematically separate different Galactic subcomponents. Correlations between the galactocentric rotation velocity and various element ratios were found, providing an important means to link different tracers of star formation and metal enrichment to the Galactic components of different origin (collapse vs. accretion). In the present work we determine stellar kinematics for a sample of 124 disk stars, which we derive from their orbits based on radial velocities and proper motions from the the literature. Our stars form a subsample of the Edvardsson et al. (1993) sample and we concentrate on three main tracers: (i) Europium as an r-process element is predominantly produced in Supernovae of type II. (ii) Likewise, alpha-elements, such as Ca, Si, Mg, are synthesised in SNe II, contrary to iron, which is being produced preferentially in SNe Ia. (iii) The s-process element Barium is a measure of...

  17. Simulation of the Resin Film Infusion Process Based on the Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    YANG Mei; YAN Shilin; TAN Hua

    2006-01-01

    A physically accurate and computationally effective pure finite element method (FEM) was developed to simulate the isothermal resin infusing process. The FEM was based on conservation of resin mass at any instant of time and was objective of resin film infusion (RFI) fiber impregnation and mold filling. The developed computer code was able to simulate the resin infusing visually. A numerical example presented here demonstrated that compared with traditional finite element/ control-volume (FE/CV), and FEM was physically accurate and computationally efficient.

  18. Effect of alloying elements on austempered ductile iron (ADI properties and its process: Review

    Directory of Open Access Journals (Sweden)

    Amir Sadighzadeh Benam

    2015-01-01

    Full Text Available Austempered ductile iron (ADI parts have a unique combination of high strength and toughness with excellent design flexibility and low cost. These excellent properties are directly related to its microstructure called "ausferrite" that is the result of austempering heat treatment applied to ductile irons. Alloying elements increase ADI austemperability and change speeds of austempering reactions. Thus, they can affect ADI resultant microstructure and mechanical properties. In this paper, the effects of alloying elements on ADI mechanical properties, microstructural changes, two-stage austempering reactions, processing windows, austemperability, and other aspects are reviewed.

  19. The effect of innovation competence on the choice of information elements in a simulated NPD process

    DEFF Research Database (Denmark)

    Søndergaard, Helle Alsted; Juhl, Hans Jørn

    to prompt different managerial behaviour. This study uses a role-play approach to investigating the relationship between innovation competence (exploitation or exploration competences) and the acquisition of information elements in a simulated new product development (NPD) process. Results show that two......This paper presents a study of the relationship between innovation competence and managerial behaviour. Within the resource-based view of the firm the development of new products is often related to the attainment of dynamic capabilities. Different levels of dynamic capabilities are expected...... differences in the purchase of information elements between the two clusters....

  20. Investigation on ductile fracture in fine-blanking process by finite element method

    Institute of Scientific and Technical Information of China (English)

    李昱明; 彭颖红

    2002-01-01

    In order to continuously analyze the whole fine-blanking process, from the beginning of the operation up to the total rupture of the sheet-metal, without computational divergence, a 3-D rigid visco-plastic finite-element method based on Gurson void model was developed. The void volume fraction was introduced into the finite element method to document the ductile fracture of the sheet-metal. A formulation of variation of the rigid visco-plastic material was presented according to the virtual work theory in which both the effects of equivalent stress and hydrostatic pressure in the deformation process were considered. The crack initiation of the sheet was predicted and the crack propagation was geometrically fulfilled in the simulation by separating the nodes according to the stress state. Furthermore, the influences of different state-variables on the deformation process were also studied.

  1. s- and r-process elements in two very metal-poor stars

    CERN Document Server

    Ryan, S G; Blake, L A J; Norris, J E; Beers, T C; Gallino, R; Busso, M; Ando, H; Ryan, Sean G.; Aoki, Wako; Blake, Lisa A. J.; Norris, John E.; Beers, Timothy C.; Gallino, Roberto; Busso, Maurizio; Ando, Hiroyasu

    2000-01-01

    New measurements of neutron-capture elements are presented for two very metal-poor stars ([Fe/H] ~ -3). One (LP 625-44) has an s-process signature believed to be due to mass transfer from a now-extinct metal-poor AGB companion, and the second (CS 22897-008) is one of a number of very metal-poor stars having high [Sr/Ba] ratios which is not expected from the r-process. In the s-process star, many elements including lead have been detected, providing strong constraints on the 13C pocket in the now-extinct AGB star. In the Sr-rich star, Zn, Y, and Zr are also seen to be overabundant, and several possible nucleosynthesis mechanisms are discussed.

  2. Finite Element Simulation of Hot Strip Continuous Rolling Process Coupling Microstructural Evolution

    Institute of Scientific and Technical Information of China (English)

    WANG Min-ting; ZANG Xin-liang; LI Xue-tong; DU Feng-shan

    2007-01-01

    Using the nonlinear rigid-viscoplastic finite element method (FEM), a finite element simulation of the hot strip continuous rolling process was done, which completely integrates different phenomena such as the metallurgical behavior of the strip and the thermo-mechanics in the strip based on the physical metallurgical microstructural evolution law. By combining with the process parameters of certain 2 050 mm hot strip rolling, an actual rolling process of low carbon steel SS400 was simulated using the FEM model. Based on the simulation results, the distributions of the strain field, the temperature field, and the microstructure were presented. Meanwhile, the simulated rolling force, temperature, and microstructure are in good agreement with the measured results.

  3. High speed vision processor with reconfigurable processing element array based on full-custom distributed memory

    Science.gov (United States)

    Chen, Zhe; Yang, Jie; Shi, Cong; Qin, Qi; Liu, Liyuan; Wu, Nanjian

    2016-04-01

    In this paper, a hybrid vision processor based on a compact full-custom distributed memory for near-sensor high-speed image processing is proposed. The proposed processor consists of a reconfigurable processing element (PE) array, a row processor (RP) array, and a dual-core microprocessor. The PE array includes two-dimensional processing elements with a compact full-custom distributed memory. It supports real-time reconfiguration between the PE array and the self-organized map (SOM) neural network. The vision processor is fabricated using a 0.18 µm CMOS technology. The circuit area of the distributed memory is reduced markedly into 1/3 of that of the conventional memory so that the circuit area of the vision processor is reduced by 44.2%. Experimental results demonstrate that the proposed design achieves correct functions.

  4. The yields of r-process elements and chemical evolution of the Galaxy

    CERN Document Server

    Chen, Z; Chen, Y P; Cui, W Y; Zhang, B; Chen, Zhe; Zhang, Jiang; Chen, YanPing; Cui, WenYuan; Zhang, Bo

    2006-01-01

    The supernova yields of r-process elements are obtained as a function of the mass of their progenitor stars from the abundance patterns of extremely metal-poor stars on the left-side [Ba/Mg]-[Mg/H] boundary with a procedure proposed by Tsujimoto and Shigeyama. The ejected masses of r-process elements associated with stars of progenitor mass $M_{ms}\\leq18M_{\\odot}$ are infertile sources and the SNe II with 20$M_{\\odot}\\leq M_{ms}\\leq 40M_{\\odot}$are the dominant source of r-process nucleosynthesis in the Galaxy. The ratio of these stars 20$M_{\\odot}\\leq M_{ms}\\leq40M_{\\odot}$ with compared to the all massive stars is about $\\sim$18%. In this paper, we present a simple model that describes a star's [r/Fe] in terms of the nucleosynthesis yields of r-process elements and the number of SN II explosions. Combined the r-process yields obtained by our procedure with the scatter model of the Galactic halo, the observed abundance patterns of the metal-poor stars can be well reproduced

  5. Astrophysical site(s of r-process elements in galactic chemodynamical evolution model

    Directory of Open Access Journals (Sweden)

    Hirai Yutaka

    2016-01-01

    Full Text Available Astrophysical site(s of rapid neutron-capture process (r-process is (are not identified yet. Although core-collapse supernovae have been regarded as one of the possible candidates of the astrophysical site of r-process, nucleosynthesis studies suggest that serious difficulties in core-collapse supernovae to produce heavy elements with mass number of ≳110. Recent studies show that neutron star mergers (NSMs can synthesize these elements due to their neutron rich environment. Some chemical evolution studies of the Milky Way halo, however, hardly reproduce the observed star-to-star scatters of the abundance ratios of r-process elements (e.g., Eu in extremely metal-poor stars. This is because of their low rate (∼ 10−4 yr−1 for a Milky Way size galaxy and long merger time (≳ 100 Myr. This problem might be solved if the stars in the Galactic halo are consisted of the stars formed in dwarf galaxies where the star formation efficiencies were very low. In this study, we carry out numerical simulations of galactic chemo-dynamical evolution using an N-body/smoothed particle hydrodynamics code. We construct detailed chemo-dynamical evolution model for the Local Group dwarf spheroidal galaxies (dSphs assuming that the NSMs are the major source of r-process elements. Our models successfully reproduce the observed dispersion in [Eu/Fe] as a function of [Fe/H] if we set merger time of NSMs, ≲ 300 Myr with the Galactic NSM rate of ∼ 10−4 yr−1. In addition, our results are consistent with the observed metallicity distribution of dSphs. In the early phase (≲1 Gyr of galaxy evolution is constant due to low star formation efficiency of dSphs. This study supports the idea that NSMs are the major site of r-process nucleosynthesis.

  6. Analysis of Metal Forming in Two-Roll Cross Wedge Rolling Process Using Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    WANG Min-ting; LI Xue-tong; DU Feng-shan

    2009-01-01

    A simulation model for two-roll cross wedge rolling (CWR) was presented by using three-dimensional rigid-plastic finite element method (FEM).The whole forming process of CWR,including knifing zone,guiding zone,stretching zone,and sizing zone,was simulated using the model in which dynamic adaptive remeshing technology for tetrahedral solid elements was used to fix element distortion.Based on the simulation results,the distributions of metal flow field,strain field,and damage field,and the geometry of the workpiece's end were analyzed.These results could provide theoretical guidance for realizing net shaping and reasonable design of tools.

  7. Coupled discrete element and smoothed particle hydrodynamics simulations of the die filling process

    Science.gov (United States)

    Breinlinger, Thomas; Kraft, Torsten

    2016-11-01

    Die filling is an important part of the powder compaction process chain, where defects in the final part can be introduced—or prevented. Simulation of this process is therefore a goal for many part producers and has been studied by some researchers already. In this work, we focus on the influence of the surrounding air on the powder flow. We demonstrate the implementing and coupling of the discrete element method for the granular powder and the smoothed particle hydrodynamics method for the gas flow. Application of the method to the die filling process is demonstrated.

  8. Costs of Quality: Exploratory Analysis of Hidden Elements and Prioritization using Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Sailaja A

    2015-02-01

    Full Text Available Cost of Quality analysis is emerged as an effective tool for the industrial managers for pinpointing the deficiencies in the system as well as for identifying the improvement areas by highlighting the cost reduction opportunities. However , this analysis will be fully effective only if it is further extended to identify the cost incurred in ensuring quality in all areas of the supply chain including the hidden costs and costs of missed out opportunities. Most of the hidden elements of quality costs are difficult to track and not accounted by the traditional accounting tools. An exploratory analysis is made in this research to identify the hidden elements of quality costs in manufacturing industry. Further, the identified cost elements are classified into various groups for better analysis and, finally, prioritized to identify the vital few among them. Analytic Hierarchy Process (AHP technique which is one of the most popular Multi Criteria Decision Method (MCDM and Pareto analysis were used in this study for prioritizing the hidden quality cost elements based on their degree of impact on overall cost of quality. By this analysis, the key cost elements which are to be addressed to reduce the overall cost of quality are identified.

  9. Trace and major element pollution originating from coal ash suspension and transport processes.

    Science.gov (United States)

    Popovic, A; Djordjevic, D; Polic, P

    2001-04-01

    Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

  10. 3D Finite Element Simulation of Tunnel Boring Machine Construction Processes in Deep Water Conveyance Tunnel

    Institute of Scientific and Technical Information of China (English)

    ZHONG Denghua; TONG Dawei

    2009-01-01

    Applying stiffness migration method, a 3D finite element mechanical model is established to simulate the excavation and advance processes. By using 3D nonlinear finite element method, the tunnel boring machine (TBM) excavation process is dynamically simulated to analyze the stress and strain field status of surrounding rock and segment. The maximum tensile stress of segment ring caused by tunnel construction mainly lies in arch bottom and presents zonal distribution. The stress increases slightly and limitedly in the course of excavation. The maxi-mum and minimum displacements of segment, manifesting as zonal distribution, distribute in arch bottom and vault respectively. The displacements slightly increase with the advance of TBM and gradually tend to stability.

  11. Probing non-perturbative QCD through hadronic matrix elements extracted from exclusive hard processes

    CERN Document Server

    Pire, B

    2009-01-01

    QCD is the theory of strong interactions and non-perturbative methods have been developed to address the confinement property of QCD. Many experimental measurements probe the confining dynamics, and it is well-known that hard scattering processes allow the extraction of non perturbative hadronic matrix elements. To study exclusive hard processes, such as electromagnetic form factors and reactions like gamma* N -> gamma N', gamma* N -> pi N', gamma* gamma -> pi pi, antiproton proton ->gamma* pi in particular kinematics (named as generalized Bjorken regime), one introduces specific non-perturbative objects, namely generalized parton distributions (GPDs), distribution amplitudes (DA) and transition distribution amplitudes (TDA), which are Fourier transformed non-diagonal matrix elements of non-local operators on the light-cone. We review here a selected sample of exclusive amplitudes in which the quark and gluon content of hadrons is probed, and emphasize that much remains to be done to successfully compute thei...

  12. Towards a culturally independent participatory design method: Fusing game elements into the design process

    DEFF Research Database (Denmark)

    Jensen, Mika Yasuoka; Nakatani, Momoko; Ohno, Takehiko

    2013-01-01

    Historically, Participatory Design (PD) was introduced and applied in the Scandinavian and American context as a practical design method for collective creativity and stakeholder involvement. In this paper, by fusing game elements into PD, we suggest a first step towards a culturally independent PD...... method called the ICT Service Design Game to ease the prevailing concern that PD has limited applicability in other cultural settings. We conduct four experiments on ICT Service Design Game in Scandinavia and Asia to evaluate its feasibility. The experiments identify some differences in the PD process...... and the created Persona characteristics, probably due to cultural differences. Of more interestingly, despite these process differences, the game elements of our PD variant were found to promote the key values of PD in culturally diverse settings by stimulating idea creation and participation. Our experiments...

  13. Towards a culturally independent participatory design method: Fusing game elements into the design process

    DEFF Research Database (Denmark)

    Jensen, Mika Yasuoka; Nakatani, Momoko; Ohno, Takehiko

    2013-01-01

    method called the ICT Service Design Game to ease the prevailing concern that PD has limited applicability in other cultural settings. We conduct four experiments on ICT Service Design Game in Scandinavia and Asia to evaluate its feasibility. The experiments identify some differences in the PD process......Historically, Participatory Design (PD) was introduced and applied in the Scandinavian and American context as a practical design method for collective creativity and stakeholder involvement. In this paper, by fusing game elements into PD, we suggest a first step towards a culturally independent PD...... and the created Persona characteristics, probably due to cultural differences. Of more interestingly, despite these process differences, the game elements of our PD variant were found to promote the key values of PD in culturally diverse settings by stimulating idea creation and participation. Our experiments...

  14. A staggered coupling strategy for the finite element analysis of warm deep drawing process

    Science.gov (United States)

    Martins, J. M. P.; Cunha, P. M.; Neto, D. M.; Alves, J. L.; Oliveira, M. C.; Laurent, H.; Menezes, L. F.

    2016-08-01

    The thermomechanical finite element analysis of warm forming processes enables an improved comprehension of the process parameters affecting the material formability. However, the thermal and mechanical coupling problem is still a challenge from the computational standpoint. A staggered strategy for the thermomechanical coupling problem is presented in this study, which is based on an isothermal split approach and allows the treatment of the two problems separately. The exchange of information between the mechanical and the thermal problem is performed to achieve a compromise between computational cost and accuracy. The proposed algorithm was implemented in DD3IMP in-house finite element code. Its performance is analysed and compared with a classical strategy commonly employed for solving thermomechanical problems.

  15. r-Process Elements in EMP stars: Indicators of Inhomogeneous Early Halo Enrichment

    Science.gov (United States)

    Andersen, Johannes; Nordström, Birgitta; Thidemann Hansen, Terese

    2015-08-01

    Extremely metal-poor (EMP) halo stars with [Fe/H] below ~ -3 are considered to be fossil records of conditions in the early halo. In the simplest picture where iron is a proxy for overall metallicity and indirectly for time, EMP stars formed before the oldest and most metal-poor Galactic globular clusters. High-resolution spectroscopy with 8m-class telescopes has shown the detailed abundance pattern of these stars to be surprisingly uniform (e.g. Bonifacio+ 2012) and essentially Solar, apart from the α-enhancement typical of SN II nucleosynthesis. A small fraction (~3%) of EMP stars, however, is strongly enhanced in the heaviest (r-process) neutron-capture elements, highlighting that the periodic system of elements was fully populated already this early.These striking departures from the general chemical homogeneity could be produced by local or distant sources. The former case is simple - mass transfer from a binary companion that evolved to produce a highly neutron-rich environment (one or more NS). Alternatively, the r-process elements were formed in a site at interstellar distance and preferentially seeded into the natal clouds of the present-day EMP-r stars. Our long-term, precise monitoring of the radial velocities of a sample of such stars (Hansen+ 2011) disproved the binary hypothesis, which would in fact also fail to explain the existence of r-process poor stars, such as HD 122653. We thus conclude that the chemical enrichment of the early halo was far more complex, patchy and likely anisotropic than assumed in current models of Galactic chemical evolution: The EMP-r stars are not just peculiarities to be ignored, but indicate that a new level of complexity must be invoked. That r-process elements have not (yet) been observed in high-redshift DLA systems is readily explained by their low abundance relative to the lighter species and the rarity of strong enrichment events.

  16. Optimization of Bending Process Parameters for Seamless Tubes Using Taguchi Method and Finite Element Method

    OpenAIRE

    Jui-Chang Lin; Kingsun Lee

    2015-01-01

    The three-dimensional tube (or pipe) is manufactured by CNC tube bending machine. The key techniques are determined by tube diameter, wall thickness, material, and bending radius. The obtained technique through experience and the trial and error method is unreliable. Finite element method (FEM) simulation for the tube bending process before production can avoid wasting manpower and raw materials. The computer-aided engineering (CAE) software ABAQUS 6.12 is applied to simulate bending characte...

  17. Detection of subsurface defects in metal materials using infrared thermography; Image processing and finite element modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ranjit, Shrestha; Kim, Won Tae [Dept. of Mechanical Engineering, Kongju National University, Cheonan (Korea, Republic of)

    2014-04-15

    Infrared thermography is an emerging approach to non-contact, non-intrusive, and non-destructive inspection of various solid materials such as metals, composites, and semiconductors for industrial and research interests. In this study, data processing was applied to infrared thermography measurements to detect defects in metals that were widely used in industrial fields. When analyzing experimental data from infrared thermographic testing, raw images were often not appropriate. Thus, various data analysis methods were used at the pre-processing and processing levels in data processing programs for quantitative analysis of defect detection and characterization; these increased the infrared non-destructive testing capabilities since subtle defects signature became apparent. A 3D finite element simulation was performed to verify and analyze the data obtained from both the experiment and the image processing techniques.

  18. Gear hot forging process robust design based on finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Xuewen, Chen [Henan University of Science and Technology, Luoyang (China); Won, Jung Dong [Jeju National University, Jeju (Korea, Republic of)

    2008-09-15

    During the hot forging process, the shaping property and forging quality will fluctuate because of die wear, manufacturing tolerance, dimensional variation caused by temperature and the different friction conditions, etc. In order to control this variation in performance and to optimize the process parameters, a robust design method is proposed in this paper, based on the finite element method for the hot forging process. During the robust design process, the Taguchi method is the basic robust theory. The finite element analysis is incorporated in order to simulate the hot forging process. In addition, in order to calculate the objective function value, an orthogonal design method is selected to arrange experiments and collect sample points. The ANOVA method is employed to analyze the relationships of the design parameters and design objectives and to find the best parameters. Finally, a case study for the gear hot forging process is conducted. With the objective to reduce the forging force and its variation, the robust design mathematical model is established. The optimal design parameters obtained from this study indicate that the forging force has been reduced and its variation has been controlled

  19. Sustainable technological process as an element of the sustainable development strategy realisation

    Directory of Open Access Journals (Sweden)

    R. Nowosielski

    2011-10-01

    Full Text Available Purpose: The aim of this work is a presentation of the possibility of the sustainable development conception realisation through the sustainable technological processes designing and implementation.Design/methodology/approach: The article includes analysis and estimation of the nickel and chromium coated on the metal elements. In order to modernization of the real process in direction to the sustainable process, the technical solutions which minimise influence on the environment of galvanic treatment process were presented.Findings: The sustainable technological process reduces the achievement of the sustainable development to small area analysis which is the technological process, what makes possible the quantitative estimation (in the internal area of technology.Research limitations/implications: The definition, the model of the sustainable technology and the sustainable development conception are relative and they have not clear character. It means there is no possibility of absolutely the best technology or technological process determination. Because of that we can only design the better process in the comparison with another with regard to adequate criteria.Practical implications: The solution presented in the paper can apply in the industry to estimation and selection of a group of technological processes which characterise different environmental influences.Originality/value: The paper presents search for the sustainable technological processes according to proposed procedure of the sustainable technology design and implementation. Application of the sustainable technological processes in the local scale can leads to the sustainable development conception realisation in the global scale.

  20. The Analysis Influence of Elements the Processing on Quality of Products

    Directory of Open Access Journals (Sweden)

    J. Sitko

    2007-07-01

    Full Text Available Present productive systems demand cooperating very much elements of complicated processing whose a superior target is the obtainment of the article about established functional proprieties. To important links of the productive system they belong the boundary strip other: the quality of raw materials, the technical state and the efficiency of productive devices , the choice and the organization of the processing and difficult to prognosing, so called the human factor. On the job one presented the initial analysis of connected problems with the preparation and the realization of the processing in the foundry of cast iron. Became introduced manner of administering resources of materials which to the state the complex connection of the row elements technological, such as: the analysis the quantity of orders and time-limits deliveries, qualifying the quantity of elements the given productive party , time-limits of beginning of the production and the manner of working of the warehouse- economy farm. The special attention became turned on analysing problem of storing productive materials.

  1. Geochemical Characteristics and Behaviors of Rare Earth Elements in Process of Vertisol Development

    Institute of Scientific and Technical Information of China (English)

    黄成敏; 王成善

    2004-01-01

    Vertisol developed on argillaceous rocks has its special pedogenic processes and properties, and formed some secondary nodules. In study area, contents of rare earth elements (REE) are significantly different in different sedimentary rocks due to varied contents of clay fraction and clay mineral composition, etc. Under the dry and hot climate, REEs were less differentiated than their parent sedimentary rocks. However, REEs in secondary nodules formed in pedogenic process display their specific behaviors. They are more concentrated in iron concretions, the content of heavy REEs increases relatively, and positive Ce-anomaly appeares. But, negative Ce-anomaly was found in calcium concretions, while normal Ce content in parent rocks and vertisol.

  2. Finite Element Simulation for Determining the Optimum Blank Shape for Deep Drawing Process

    Directory of Open Access Journals (Sweden)

    Mr. Ravikant Patel,

    2014-11-01

    Full Text Available Deep drawing is one of widely used sheet metal working process in industries to produce cup shaped components at a very high rate. The present study aims to determine the optimum shape of blank for deep drawing of cylindrical cup without ears. Earing is one of the major defects observed during deep drawing process due to anisotropic nature of sheet metal. Earing is defined as formation of waviness on uppermost portion of deep drawn cup. Earing defect occurs due to non-uniform material properties within plane of sheet (i.e. planar anisotropy. Knowledge about ear formation in deep drawing process allows a prior modification of process which can result in defect free final product with financial saving and time. In the present study efforts have been made to study the earing problem in deep drawing of cylindrical cups by finite element modeling software HYPERWORK-6.12. The blank material as EN10130Fe01 mild steel sheet of 1mm thickness has been considered as it has wide application a fabricating critical automobile parts. Mechanical parameters of mild steel are incorporated in finite element simulation of deep drawing process. Significant earing was observed at rolling and transverse direction on deformed cup form circular blank. Modification of initial blank is done to find the optimum blank to reduce the earing defect. Optimal blank shows significant reduction of % earing height, reduction in drawing load & improvement in maximum thickness variations.

  3. Numerical Simulation of Failure Process of Concrete Under Compression Based on Mesoscopic Discrete Element Model

    Institute of Scientific and Technical Information of China (English)

    WANG Zhuolin; LIN Feng; GU Xianglin

    2008-01-01

    A two-dimensional mesoscopic numerical method to simulate the failure process of concrete under compression was developed based on the discrete element method by modifying the dgid body-spdng model proposed by Nagai et al.In the calculation model,aggregates or aggregate elements inside the concrete were simplified as rigid bodies with regular polygon profiles,which were surrounded by mortar polygons or mortar elements.All of the adjacent elements were connected by springs.According to the random distribution of aggregates,the mesh was generated by using Voronoi diagram method.Plastic behavior after the elastic limit for a spring was considered to set up the constitutive model of the spring,and Mohr-Coulomb criterion was adopted to judge the failure of a spdng.Simulation examples show that the proposed method can be used to predict the mechanical behavior of concrete under compression descriptively and quantitatively both for small deformation problems and for larger deformation problems.

  4. The Release of Trace Elements in the Process of Coal Coking

    Directory of Open Access Journals (Sweden)

    Jan Konieczyński

    2012-01-01

    Full Text Available In order to assess the penetration of individual trace elements into the air through their release in the coal coking process, it is necessary to determine the loss of these elements by comparing their contents in the charge coal and in coke obtained. The present research covered four coke oven batteries differing in age, technology, and technical equipment. By using mercury analyzer MA-2 and the method of ICP MS As, Be, Cd, Co, Hg, Mn, Ni, Se, Sr, Tl, V, and Zn were determined in samples of charge coal and yielded coke. Basing on the analyses results, the release coefficients of selected elements were determined. Their values ranged from 0.5 to 94%. High volatility of cadmium, mercury, and thallium was confirmed. The tests have shown that although the results refer to the selected case studies, it may be concluded that the air purity is affected by controlled emission occurring when coke oven batteries are fired by crude coke oven gas. Fugitive emission of the trace elements investigated, occurring due to coke oven leaks and openings, is small and, is not a real threat to the environment except mercury.

  5. Three-dimensional finite element analysis of process-induced residual stress in resin transfer molding process

    Institute of Scientific and Technical Information of China (English)

    DAI Fu-hong; ZHANG Bo-ming; DU Shan-yi

    2008-01-01

    A three-dimensional finite element analysis of process-induced residual stress in resin transfer mold-ing (RTM) process is presented. The finite element method ( FEM ) was employed to solve the coupled equa-tions involved in the transient heat transfer and the cure kinetics of the resin, and the distributions of internal temperature and cure degree of the composite at any instant time were obtained. The self-consistent field micro-mechanics model was used to predict the cure-dependent mechanical properties of the composites. Thermal ex-pansion and cure shrinkage were included in the analysis. The thermo-elastie mechanical governing equationswere solved using the incremental stress-strain relationship based FEM and the residual stress development was predicted. The present results were validated by the comparisons with the pertinent literature. The numerical example of a half cylinder was presented. The results show that it is necessary to carry out the three-dimensional analysis due to the complex distributions of temperatures, cure degrees and process-induced stress for thick parts, which can be predicted at any point within composite structures in the present analysis.

  6. Empirical Modeling of Heating Element Power for the Czochralski Crystallization Process

    Directory of Open Access Journals (Sweden)

    Magnus Komperød

    2010-01-01

    Full Text Available The Czochralski (CZ crystallization process is used to produce monocrystalline silicon. Monocrystalline silicon is used in solar cell wafers and in computers and electronics. The CZ process is a batch process, where multicrystalline silicon is melted in a crucible and later solidifies on a monocrystalline seed crystal. The crucible is heated using a heating element where the power is manipulated using a triode for alternating current (TRIAC. As the electric resistance of the heating element increases by increased temperature, there are significant dynamics from the TRIAC input signal (control system output to the actual (measured heating element power. The present paper focuses on empirical modeling of these dynamics. The modeling is based on a dataset logged from a real-life CZ process. Initially the dataset is preprocessed by detrending and handling outliers. Next, linear ARX, ARMAX, and output error (OE models are identfied. As the linear models do not fully explain the process' behavior, nonlinear system identification is applied. The Hammerstein-Wiener (HW model structure is chosen. The final model identified is a Hammerstein model, i.e. a HW model with nonlinearity at the input, but not at the output. This model has only one more identified parameter than the linear OE model, but still improves the optimization criterion (mean squared ballistic simulation errors by a factor of six. As there is no nonlinearity at the output, the dynamics from the prediction error to the model output are linear, which allows a noise model to be added. Comparison of a Hammerstein model with noise model and the linear ARMAX model, both optimized for mean squared one-step-ahead prediction errors, shows that this optimization criterion is 42% lower for the Hammerstein model. Minimizing the number of parameters to be identified has been an important consideration throughout the modeling work.

  7. 3D Dynamic Finite Element Analysis of the Nonuniform Residual Stress in Ultrasonic Impact Treatment Process

    Science.gov (United States)

    Hu, Shengsun; Guo, Chaobo; Wang, Dongpo; Wang, Zhijiang

    2016-09-01

    The nonuniform distributions of the residual stress were simulated by a 3D finite element model to analyze the elastic-plastic dynamic ultrasonic impact treatment (UIT) process of multiple impacts on the 2024 aluminum alloy. The evolution of the stress during the impact process was discussed. The successive impacts during the UIT process improve the uniformity of the plastic deformation and decrease the maximum compressive residual stress beneath the former impact indentations. The influences of different controlled parameters, including the initial impact velocity, pin diameter, pin tip, device moving, and offset distances, on the residual stress distributions were analyzed. The influences of the controlled parameters on the residual stress distributions are apparent in the offset direction due to the different surface coverage in different directions. The influences can be used to understand the UIT process and to obtain the desired residual stress by optimizing the controlled parameters.

  8. Microwave plasma monitoring system for the elemental composition analysis of high temperature process streams

    Energy Technology Data Exchange (ETDEWEB)

    Woskov, Paul P. (Bedford, MA); Cohn, Daniel R. (Chestnuthill, MA); Titus, Charles H. (Newtown Square, PA); Surma, Jeffrey E. (Kennewick, WA)

    1997-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, high temperature capability refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. The invention may be incorporated into a high temperature process device and implemented in situ for example, such as with a DC graphite electrode plasma arc furnace. The invention further provides a system for the elemental analysis of process streams by removing particulate and/or droplet samples therefrom and entraining such samples in the gas flow which passes through the plasma flame. Introduction of and entraining samples in the gas flow may be facilitated by a suction pump, regulating gas flow, gravity or combinations thereof.

  9. Neutron Capture Elements in s-Process-Rich, Very Metal-Poor Stars

    CERN Document Server

    Aoki, W; Norris, J E; Beers, T C; Ando, H; Iwamoto, N; Kajino, T; Mathews, G J; Fujimoto, M; Aoki, Wako; Ryan, Sean G.; Norris, John E.; Beers, Timothy C.; Ando, Hiroyasu; Iwamoto, Nobuyuki; Kajino, Toshitaka; Mathews, Grant J.; Fujimoto, Masayuki

    2001-01-01

    We report abundance estimates for neutron-capture elements, including lead (Pb), and nucleosynthesis models for their origin, in two carbon-rich, very metal-poor stars, LP625-44 and LP706-7. These stars are subgiants whose surface abundances are likely to have been strongly affected by mass transfer from companion AGB stars that have since evolved to white dwarfs. The detections of Pb, which forms the final abundance peak of the s-process, enable a comparison of the abundance patterns from Sr (Z=38) to Pb (Z=82) with predictions of AGB models. The derived chemical compositions provide strong constraints on the AGB stellar models, as well as on s-process nucleosynthesis at low metallicity. The present paper reports details of the abundance analysis for 16 neutron-capture elements in LP 625-44, including the effects of hyperfine splitting and isotope shifts of spectral lines for some elements. A Pb abundance is also derived for LP706-7 by a re-analysis of a previously observed spectrum. We investigate the chara...

  10. Elemental balance of SRF production process: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Oinas, Pekka

    2016-01-01

    In the production of solid recovered fuel (SRF), certain waste components have excessive influence on the quality of product. The proportion of rubber, plastic (hard) and certain textiles was found to be critical as to the elemental quality of SRF. The mass flow of rubber, plastic (hard) and textiles (to certain extent, especially synthetic textile) components from input waste stream into the output streams of SRF production was found to play the decisive role in defining the elemental quality of SRF. This paper presents the mass flow of polluting and potentially toxic elements (PTEs) in SRF production. The SRF was produced from municipal solid waste (MSW) through mechanical treatment (MT). The results showed that of the total input chlorine content to process, 55% was found in the SRF and 30% in reject material. Of the total input arsenic content, 30% was found in the SRF and 45% in fine fraction. In case of cadmium, lead and mercury, of their total input content to the process, 62%, 38% and 30%, respectively, was found in the SRF. Among the components of MSW, rubber material was identified as potential source of chlorine, containing 8.0 wt.% of chlorine. Plastic (hard) and textile components contained 1.6 and 1.1. wt.% of chlorine, respectively. Plastic (hard) contained higher lead and cadmium content compared with other waste components, i.e. 500 mg kg(-1) and 9.0 mg kg(-1), respectively.

  11. A High Speed Networked Signal Processing Platform for Multi-element Radio Telescopes

    CERN Document Server

    Prasad, Peeyush; 10.1007/s10686-011-9216-7

    2011-01-01

    A new architecture is presented for a Networked Signal Processing System (NSPS) suitable for handling the real-time signal processing of multi-element radio telescopes. In this system, a multi-element radio telescope is viewed as an application of a multi-sensor, data fusion problem which can be decomposed into a general set of computing and network components for which a practical and scalable architecture is enabled by current technology. The need for such a system arose in the context of an ongoing program for reconfiguring the Ooty Radio Telescope (ORT) as a programmable 264-element array, which will enable several new observing capabilities for large scale surveys on this mature telescope. For this application, it is necessary to manage, route and combine large volumes of data whose real-time collation requires large I/O bandwidths to be sustained. Since these are general requirements of many multi-sensor fusion applications, we first describe the basic architecture of the NSPS in terms of a Fusion Tree ...

  12. Supervised Classification Processes for the Characterization of Heritage Elements, Case Study: Cuenca-Ecuador

    Science.gov (United States)

    Briones, J. C.; Heras, V.; Abril, C.; Sinchi, E.

    2017-08-01

    The proper control of built heritage entails many challenges related to the complexity of heritage elements and the extent of the area to be managed, for which the available resources must be efficiently used. In this scenario, the preventive conservation approach, based on the concept that prevent is better than cure, emerges as a strategy to avoid the progressive and imminent loss of monuments and heritage sites. Regular monitoring appears as a key tool to identify timely changes in heritage assets. This research demonstrates that the supervised learning model (Support Vector Machines - SVM) is an ideal tool that supports the monitoring process detecting visible elements in aerial images such as roofs structures, vegetation and pavements. The linear, gaussian and polynomial kernel functions were tested; the lineal function provided better results over the other functions. It is important to mention that due to the high level of segmentation generated by the classification procedure, it was necessary to apply a generalization process through opening a mathematical morphological operation, which simplified the over classification for the monitored elements.

  13. Nonlinear tracking in a diffusion process with a Bayesian filter and the finite element method

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Thygesen, Uffe Høgsbro; Madsen, Henrik

    2011-01-01

    A new approach to nonlinear state estimation and object tracking from indirect observations of a continuous time process is examined. Stochastic differential equations (SDEs) are employed to model the dynamics of the unobservable state. Tracking problems in the plane subject to boundaries...... become complicated using SMC because Monte Carlo randomness is introduced. The finite element (FE) method solves the Kolmogorov equations of the SDE numerically on a triangular unstructured mesh for which boundary conditions to the state-space are simple to incorporate. The FE approach to nonlinear state...... estimation is suited for off-line data analysis because the computed smoothed state densities, maximum a posteriori parameter estimates and state sequence are deterministic conditional on the finite element mesh and the observations. The proposed method is conceptually similar to existing point...

  14. The shock process and light element production in supernovae envelopes. Ph.D. Thesis - Chicago Univ.

    Science.gov (United States)

    Brown, Lawrence E.; Dearborn, David S.; Schramm, David N.; Larsen, Jon T.; Kurokawa, Shin

    1990-01-01

    Detailed hydrodynamic modeling of the passage of supernova shocks through the hydrogen envelopes of blue and red progenitor stars was carried out to explore the sensitivity to model conditions of light element production (specifically Li-7 and B-11) which was noted by Dearborn, Schramm, Steigman and Truran (1989) (DSST). It is found that, for stellar models with M is less than or approximately 100 M solar mass, current state of the art supernova shocks do not produce significant light element yields by hydrodynamic processes alone. The dependence of this conclusion on stellar models and on shock strengths is explored. Preliminary implications for Galactic evolution of lithium are discussed, and it is suspected that intermediate mass red giant stars may be the most consistent production site for lithium.

  15. Finite element analysis and die design of heading processes of magnesium alloy screws

    Science.gov (United States)

    Hwang, Y. M.; Chang, C. Y.

    2016-05-01

    This study is to develop related manufacturing technologies of LZ91 magnesium alloy M6 screws. Firstly, a warm heading process composed of three stages is proposed. The material flow pattern of the billet inside the die is analyzed using the finite element analyses. The effects of the friction factor, die speed and forming temperature on the heading load are discussed. The effects of the stroke at the first stage on the formability at the second stage are also discussed. Finally, warm heading experiments are conducted using a self-designed die set and a lubricant of MoS2. The experimental values of heading load and product shapes and dimensions are compared with the simulation results to verify the validity of the finite element models and the proposed warm heading procedures.

  16. Full Stokes finite-element modeling of ice sheets using a graphics processing unit

    Science.gov (United States)

    Seddik, H.; Greve, R.

    2016-12-01

    Thermo-mechanical simulation of ice sheets is an important approach to understand and predict their evolution in a changing climate. For that purpose, higher order (e.g., ISSM, BISICLES) and full Stokes (e.g., Elmer/Ice, http://elmerice.elmerfem.org) models are increasingly used to more accurately model the flow of entire ice sheets. In parallel to this development, the rapidly improving performance and capabilities of Graphics Processing Units (GPUs) allows to efficiently offload more calculations of complex and computationally demanding problems on those devices. Thus, in order to continue the trend of using full Stokes models with greater resolutions, using GPUs should be considered for the implementation of ice sheet models. We developed the GPU-accelerated ice-sheet model Sainō. Sainō is an Elmer (http://www.csc.fi/english/pages/elmer) derivative implemented in Objective-C which solves the full Stokes equations with the finite element method. It uses the standard OpenCL language (http://www.khronos.org/opencl/) to offload the assembly of the finite element matrix on the GPU. A mesh-coloring scheme is used so that elements with the same color (non-sharing nodes) are assembled in parallel on the GPU without the need for synchronization primitives. The current implementation shows that, for the ISMIP-HOM experiment A, during the matrix assembly in double precision with 8000, 87,500 and 252,000 brick elements, Sainō is respectively 2x, 10x and 14x faster than Elmer/Ice (when both models are run on a single processing unit). In single precision, Sainō is even 3x, 20x and 25x faster than Elmer/Ice. A detailed description of the comparative results between Sainō and Elmer/Ice will be presented, and further perspectives in optimization and the limitations of the current implementation.

  17. Tension optimization of the conductor-and-support cable elements during stranding process

    Directory of Open Access Journals (Sweden)

    I.M. Chayun

    2016-12-01

    Full Text Available Steel lifting ropes, cables and other similar products are rod statically undeterminable prestressed structures. Preliminary deformations of their elements (wires are caused by their manufacturing technology. Wires suffer stretching, bending with torsion in a stage of elastoplastic deformation. In this work the mechanic-mathematical model of residual forces determination in the wires of polymetallic conductor-and-support cable is offered. Aim: The aim of the work is studying of the mechanical and mathematical model defining residual forces in the wires of conductor-and-support cable and also the optimization of parameters of a twist by the criterion of residual forces lack after production process finishing. Materials and methods: The method developed by the authors earlier to the study the strain-stressed state of twisted wire products off-loading from technological internal forces has been applied to assess the impact of the approximate value of the longitudinal stiffness of the product. In this paper, each wire is considered as an element of the product individually. This is necessary to investigate the impact of uneven wire tensions on defects of conductor-and-support cable (out-of-straight in a free state and stripping-down. Results: On the basis of the conducted deformation studies of conductor-and-support cable during off-loading process from twist tension of its elements the dependencies of residual forces on the level and interrelation of elements tension has been determined. The condition of ensuring of zero residual forces in the wires of conductor-and-support cable after production is formulated. It was found that calculated values of residual forces are almost identical when using of the approximate and exact values of longitudinal stiffness of conductor-and-support cable.

  18. Numerical simulation of isothermal chemical vapor infiltration process in fabrication of carbon-carbon composites by finite element method

    Institute of Scientific and Technical Information of China (English)

    李克智; 李贺军; 姜开宇

    2000-01-01

    The chemical vapor infiltration process in fabrication of carbon-carbon composites is highly inefficient and requires long processing time. These limitations add considerably to the cost of fabrication and restrict the application of this material. Efforts have been made to study the CVI process in fabrication of carbon-carbon composites by computer simulation and predict the process parameters, density, porosity, etc. According to the characteristics of CVI process, the basic principle of FEM and mass transport, the finite element model has been established. Incremental finite element equations and the elemental stiffness matrices have been derived for the first time. The finite element program developed by the authors has been used to simulate the ICVI process in fabrication of carbon-carbon composites. Computer color display of simulated results can express the densification and distributions of density and porosity in preform clearly. The influence of process parameters on the densification of prefo

  19. Finite element synthesized analysis of the forming process of spiral welded pipe

    Institute of Scientific and Technical Information of China (English)

    Yu Jianrong; Wu Bo; Zhao Zenghui; Ling Xingzhong; Xiao Yunfeng; Chen Haiyang

    2006-01-01

    Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps: the first step was the stress analysis when the spiral was formed, and then the stress was regarded as initial condition of melding during the temperature field analysis in the process of welding, the last step was the thermal stress analysis of the weld seam after the welding was over. Moreover, when the steel strip was pushed, the stress was also calculated by non-linearity contact technology using Abaqus Software. By finite element modeling and calculating of the forming and welding process of the spiral welded pipe, the key points of the multi-fields synthetic simulating were studied and discussed.

  20. An experimental method for quantitatively evaluating the elemental processes of indoor radioactive aerosol behavior.

    Science.gov (United States)

    Yamazawa, H; Yamada, S; Xu, Y; Hirao, S; Moriizumi, J

    2015-11-01

    An experimental method for quantitatively evaluating the elemental processes governing the indoor behaviour of naturally occurring radioactive aerosols was proposed. This method utilises transient response of aerosol concentrations to an artificial change in aerosol removal rate by turning on and off an air purifier. It was shown that the indoor-outdoor exchange rate and the indoor deposition rate could be estimated by a continuous measurement of outdoor and indoor aerosol number concentration measurements and by the method proposed in this study. Although the scatter of the estimated parameters is relatively large, both the methods gave consistent results. It was also found that the size distribution of radioactive aerosol particles and hence activity median aerodynamic diameter remained not largely affected by the operation of the air purifier, implying the predominance of the exchange and deposition processes over other processes causing change in the size distribution such as the size growth by coagulation and the size dependence of deposition.

  1. Finite Element Modeling and Analysis of Powder Stream in Low Pressure Cold Spray Process

    Science.gov (United States)

    Goyal, Tarun; Walia, Ravinderjit Singh; Sharma, Prince; Sidhu, Tejinder Singh

    2016-07-01

    Low pressure cold gas dynamic spray (LPCGDS) is a coating process that utilize low pressure gas (5-10 bars instead of 25-30 bars) and the radial injection of powder instead of axial injection with the particle range (1-50 μm). In the LPCGDS process, pressurized compressed gas is accelerated to the critical velocity, which depends on length of the divergent section of nozzle, the propellant gas and particle characteristics, and the diameters ratio of the inlet and outer diameters. This paper presents finite element modeling (FEM) of powder stream in supersonic nozzle wherein adiabatic gas flow and expansion of gas occurs in uniform manner and the same is used to evaluate the resultant temperature and velocity contours during coating process. FEM analyses were performed using commercial finite volume package, ANSYS CFD FLUENT. The results are helpful to predict the characteristics of powder stream at the exit of the supersonic nozzle.

  2. Rapid Finite Element Analysis of Bulk Metal Forming Process Based on Deformation Theory

    Institute of Scientific and Technical Information of China (English)

    WANG Peng; DONG Xiang-huai; FU Li-jun

    2009-01-01

    The one-step finite element method (FEM), based on plastic deformation theory, has been widely used to simulate sheet metal forming processes, but its application in bulk metal forming simulation has been seldom investigated, because of the complexity involved. Thus, a bulk metal forming process was analyzed using a rapid FEM based on deformation theory. The material was assumed to be rigid-plastic and strain-hardened. The constitutive relationship between stress and total strain was adopted, whereas the incompressible condition was enforced by penalty function. The geometrical non-linearity in large plastic deformation was taken into consideration. Furthermore, the force boundary condition was treated by a simplified equivalent approach, considering the contact history. Based on constraint variational principle, the deformation FEM was proposed. The one-step forward simulation of axisymmetric upsetting process was performed using this method. The results were compared with those obtained by the traditional incremental FEM to verify the feasibility of the proposed method.

  3. Optimized baseplate geometry for ball swaging process by using finite element analysis

    Directory of Open Access Journals (Sweden)

    Pattaramon Jongpradist

    2009-11-01

    Full Text Available A ball swaging process is commonly used in the hard disk drive manufacturing process to attach a suspension arm to an actuator arm via a part known as the baseplate. The geometry of the baseplate affects the contact pressure profile between the baseplate and the arm, torque retention of the swaged connection, and deformation of the assembly parts. In the current study, the effects of altering the baseplate geometric parameters on its characteristics are studied. A large-deformation dynamic finite element analysis of a ball swaging process is performed by using a commercial program ABAQUS. Theproducts of combining several geometric parameters are also investigated so as to obtain the baseplate geometry with improved torque retention and reduced tilt angle. It is concluded that a proper design of the baseplate is in such way that the baseplate boss and the arm possess the largest contact area and that the stress concentration at the baseplate neck is minimal.

  4. New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars

    CERN Document Server

    Sneden, Christopher; Cowan, John J; Ivans, Inese I; Hartog, Elizabeth A Den

    2009-01-01

    We have derived new abundances of the rare-earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant stars. The photospheric values for all five elements are in good agreement with meteoritic abundances. For the low metallicity sample, these abundances have been combined with new Ce abundances from a companion paper, and reconsideration of a few other elements in individual stars, to produce internally-consistent Ba, rare-earth, and Hf (56<= Z <= 72) element distributions. These have been used in a critical comparison between stellar and solar r-process abundance mixes.

  5. Complete Element Abundances of Nine Stars in the r-process Galaxy Reticulum II

    Science.gov (United States)

    Ji, Alexander P.; Frebel, Anna; Simon, Joshua D.; Chiti, Anirudh

    2016-10-01

    We present chemical abundances derived from high-resolution Magellan/Magellan Inamori Kyocera Echelle spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II (Ret II). These stars span the full metallicity range of Ret II (‑3.5 date. The other two stars are the most metal-poor stars in the system ([Fe/H] up to the iron peak are otherwise similar to abundances of stars in the halo and in other ultra-faint dwarf galaxies. However, the scatter in abundance ratios is large enough to suggest that inhomogeneous metal mixing is required to explain the chemical evolution of this galaxy. The presence of low amounts of neutron-capture elements in other ultra-faint dwarf galaxies may imply the existence of additional r-process sites besides the source of r-process elements in Ret II. Galaxies like Ret II may be the original birth sites of r-process enhanced stars now found in the halo. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  6. Simulation of the cabling process for Rutherford cables: An advanced finite element model

    Science.gov (United States)

    Cabanes, J.; Garlasche, M.; Bordini, B.; Dallocchio, A.

    2016-12-01

    In all existing large particle accelerators (Tevatron, HERA, RHIC, LHC) the main superconducting magnets are based on Rutherford cables, which are characterized by having: strands fully transposed with respect to the magnetic field, a significant compaction that assures a large engineering critical current density and a geometry that allows efficient winding of the coils. The Nb3Sn magnets developed in the framework of the HL-LHC project for improving the luminosity of the Large Hadron Collider (LHC) are also based on Rutherford cables. Due to the characteristics of Nb3Sn wires, the cabling process has become a crucial step in the magnet manufacturing. During cabling the wires experience large plastic deformations that strongly modify the geometrical dimensions of the sub-elements constituting the superconducting strand. These deformations are particularly severe on the cable edges and can result in a significant reduction of the cable critical current as well as of the Residual Resistivity Ratio (RRR) of the stabilizing copper. In order to understand the main parameters that rule the cabling process and their impact on the cable performance, CERN has developed a 3D Finite Element (FE) model based on the LS-Dyna® software that simulates the whole cabling process. In the paper the model is presented together with a comparison between experimental and numerical results for a copper cable produced at CERN.

  7. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F. [Argonne National Lab., IL (United States); Landsberger, S. [Univ. of Illinois, Urbana, IL (United States)

    1995-05-01

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration.

  8. Abaqus2Matlab: A suitable tool for finite element post-processing

    DEFF Research Database (Denmark)

    Papazafeiropoulos, George; Muñiz-Calvente, Miguel; Martínez Pañeda, Emilio

    2017-01-01

    A suitable piece of software is presented to connect Abaqus, a sophisticated finite element package, with Matlab, the most comprehensive program for mathematical analysis. This interface between these well- known codes not only benefits from the image processing and the integrated graph-plotting ......A suitable piece of software is presented to connect Abaqus, a sophisticated finite element package, with Matlab, the most comprehensive program for mathematical analysis. This interface between these well- known codes not only benefits from the image processing and the integrated graph......-plotting features of Matlab but also opens up new opportunities in results post-processing, statistical analysis and mathemat- ical optimization, among many other possibilities. The software architecture and usage are appropriately described and two problems of particular engineering significance are addressed...... to demonstrate its capa- bilities. Firstly, the software is employed to assess cleavage fracture through a novel 3-parameter Weibull probabilistic framework. Then, its potential to create and train neural networks is used to identify damage parameters through a hybrid experimental–numerical scheme, and model...

  9. Transformations of particles, metal elements and natural organic matter in different water treatment processes

    Institute of Scientific and Technical Information of China (English)

    YAN Ming-quan; WANG Dong-sheng; SHI Bao-you; WEI Qun-shan; QU Jiu-hui; TANG Hong-xiao

    2007-01-01

    Characterizing namral organic matter(NOM),particles and elements in different water treatment processes Can give a useful information to optimize water treatment operations.In this article,transformations of particles,metal elements and NOM in a pilot-scale water treatment plant were investigated by laser light granularity system,particle counter,glass-fiber membrane filtration,inductively coupled plasma-optical emission spectroscopy,ultra filtration and resin absorbents fractionation.The results showed that particles,NOM and trihalomethane formation precursors were removed synergistically by sequential treamaent of different processes. Preozonation markedly changed the polarity and molecular weight of NOM.and it could be conducive to the following coagulation processthrough destabilizing particles and colloids;mid-ozonation enhanced the subsequent granular activated carbon(GAC)filtration process by decreasing molecular weight of organic matters.Coagulation-flotation and GAC were more efficient in removing fixed suspended solids and larger particles;while sand-filtration was more effcient in removing volatile suspended solids and smaller particles.Flotation performed better than sedimentation in terms of particle and NOM removal.The type of coagulant could greatly affect the performance of coagulation-flotation.Pre-hydrolyzed composite coagulant(HPAC)was superior to FeCl3 concerning the removals of hydrophobic dissolved organic carbon and volatile suspended solids.The leakages of flocs from sand-filtration and microorganisms from GAC should be mitigated to ensure the reliability of the whole treatment system.

  10. Rare earth elements tracing the soil erosion processes on slope surface under natural rainfall

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Mingyong [Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Tan Shuduan [College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128 (China); Dang Haishan [Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074 (China); Zhang Quanfa, E-mail: qzhang@wbgcas.cn [Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074 (China)

    2011-12-15

    A field experiment using rare earth elements (REEs) as tracers was conducted to investigate soil erosion processes on slope surfaces during rainfall events. A plot of 10 m x 2 m x 0.16 m with a gradient of 20{sup o} (36.4%) was established and the plot was divided into two layers and four segments. Various REE tracers were applied to the different layers and segments to determine sediment dynamics under natural rainfall. Results indicated that sheet erosion accounted for more than 90% of total erosion when the rainfall amount and density was not large enough to generate concentrated flows. Sediment source changed in different sections on the slope surface, and the primary sediment source area tended to move upslope as erosion progressed. In rill erosion, sediment discharge mainly originated from the toe-slope and moved upwards as erosion intensified. The results obtained from this study suggest that multi-REE tracer technique is valuable in understanding the erosion processes and determining sediment sources. - Highlights: > Soil erosion processes with rare earth elements was conducted under natural rainfall. > Experimental setup developed here has seldom implemented in the world. > Sheet erosion is the main erosion type and main contributor to sediment loss. > Sediment source changed in different sections on the slope surface. > The primary sediment source area tended to move upslope as erosion progressed.

  11. Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

    Directory of Open Access Journals (Sweden)

    Muriel Anne Lobier

    2014-07-01

    Full Text Available The visual attention (VA span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT in dyslexia have yet to be explored. Using fMRI, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric, similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined ROI, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity could predict vOT activity in each group. In the left hemisphere, SPL activity modulated vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity modulated vOT activity only for dyslexic readers. These results bring critical support to the visual attention interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia.

  12. Solvent Refined Coal (SRC) process: trace elements. Volume III. Pilot plant development work. Part 6. Fate of trace elements in the SRC process. [Ph. D. Thesis

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, C.S.

    1980-09-01

    A study of the forms of trace elements occurring in Solvent Refined Coal has been performed by chemical separation of the Solvent Refined Coal based on differences in the functionality and molecular weight of the organic matrix. Analysis of the fractions separated for various trace elements has revealed associations of certain elements with other elements as well as with certain fractions. The analysis of Solvent Refined Coal I by these methods provided data on the distribution of Ti, V, Ca, S, Al, Mn, As, Se, Cr, Fe, Ni, Zn, Sc, and Ga in the fractions generated. Because of the low trace element content of Solvent Refined Coal II only As, Se, and Cr could be detected in the silica fractions. Based on the distributions three different groups of elements have been based on the association of elements with each other and with certain fractions. The first group is composed of As, Se, and Cr associated with silica fractions of relatively low functionality; these elements have a high percent solubility in the starting Solvent Refined Coal II oil. The second group composed of Ti, V, and to a lesser extent a second form of Cr, is associated with fractions that have a high concentration of phenolic material and is probably present as phenoxide complexes. The third group composed of Fe, Ca, K, Al, and Mg is associated with the most functional fractions and is possibly present as humic acid type complexes or as submicron size particulates. The integration of chromatographic methods with trace element analysis of the fractions generated is capable of discerning the presence of different forms of the elements. The methods used are applicable to other important geologically occurring organic matter.

  13. The effect of innovation competence on the choice of information elements in a simulated NPD process

    DEFF Research Database (Denmark)

    Søndergaard, Helle Alsted; Juhl, Hans Jørn

    to prompt different managerial behaviour. This study uses a role-play approach to investigating the relationship between innovation competence (exploitation or exploration competences) and the acquisition of information elements in a simulated new product development (NPD) process. Results show that two......This paper presents a study of the relationship between innovation competence and managerial behaviour. Within the resource-based view of the firm the development of new products is often related to the attainment of dynamic capabilities. Different levels of dynamic capabilities are expected...

  14. Finite element modeling of cooled-tip probe radiofrequency ablation processes in liver tissue.

    Science.gov (United States)

    Barauskas, Rimantas; Gulbinas, Antanas; Vanagas, Tomas; Barauskas, Giedrius

    2008-06-01

    Finite element model of radiofrequency ablation (RFA) with cooled-tip probe in liver has been developed by employing COMSOL Multiphysics software. It describes coupled electric, thermal and sodium chloride solution infiltration flow phenomena taking place during ablation processes. Features of hydraulic capacity, saturation of the tissue by infiltration, and dependency of electrical conductivity on the damage integral of the tissue have been supplied to the model. RFA experiments have validated the model. Physical parameters describing hydraulic capacity and hydraulic conductivity in the tissue, as well as, the relation of electrical conductivity against the value of damage integral have been determined.

  15. Finite element modelling of high air pressure forming processes for polymer sheets

    Science.gov (United States)

    Jiang, W.-G.; Warby, M. K.; Whiteman, J. R.; Abbott, S.; Shorter, W.; Warwick, P.; Wright, T.; Munro, A.; Munro, B.

    In this paper we describe the mathematical modelling and computational simulation of the high air pressure (HAP) thermoforming process which is used in the creation of thin walled polymeric structures. This involves, using data from material tests, an elastic-plastic constitutive equation valid for large deformations and a constrained deformation in which there is frictional contact between the polymeric sheet and a constraining surface (the mould surface). Despite a number of simplifying assumptions and some uncertainities in the mathematical model the finite element computations presented predict quite well the actual shape and thickness distribution which are found on sample products.

  16. Extraction of rare earth elements from hydrate-phosphate precipitates of apatite processing

    Science.gov (United States)

    Andropov, M. O.; Anufrieva, A. V.; Buynovskiy, A. S.; Makaseev, Y. N.; Mazov, I. N.; Nefedov, R. A.; Sachkov, V. I.; Stepanova, O. B.; Valkov, AV

    2016-01-01

    The features of extraction of rare earth elements (REE) were considered from hydrate-phosphate precipitates of REE of apatite processing by nitric acid technology. The preliminary purification of nitrate solution of REE from impurities of titanium, aluminum, iron, uranium and thorium was suggested to obtain stable solutions not forming precipitates. Washing the extract was recommended with the evaporated reextract that allows to obtain directly on the cascade of REE extraction the concentrated solutions suitable for the separation into groups by the extraction method. Technical decisions were suggested for the separation of REE in groups without the use of salting-out agent.

  17. Study on the high-precision laser welding technology of nuclear fuel elements processing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Sung; Yang, M. S.; Kim, W. K.; Lee, D. Y

    2001-01-01

    The proper welding method for appendage of bearing pads and spacers of PHWR nuclear fuel elements is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of welding defects of the appendage parts is mostly apt to occur and it is connected directly with the safty and life prediction of the nuclear reactor in operation. Recently there has been studied all over the world to develope welding technology by laser in nuclear fuel processing, and the appendage of bearing pads and spacers of PHWR nuclear fuel elements. Therefore, the purpose of this study is to investigate the characteristics of the laser welded specimens and make some samples for the appendage of bearing pads of PHWR nuclear fuel elements. This study will be also provide the basic data for the fabrications of the appendage of bearing pads and spacers. Especially the laser welding is supposed to be used in the practical application such as precise materials manufacturing fields. In this respect this technology is not only a basic advanced technology with wide applications but also likely to be used for the development of directly applicable technologies for industries, with high potential benefits derived in the view point of economy and industry.

  18. Trace and major element pollution originating from coal ash suspension and transport processes

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, A.; Djordjevic, D.; Polic, P. [University of Belgrade, Belgrade (Yugoslavia). Faculty of Science, Dept. of Chemistry

    2001-07-01

    Coal ash obtained from Nikola Tesla A power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. It is concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

  19. Efficient and accurate evaluation of potential energy matrix elements for quantum dynamics using Gaussian process regression

    Science.gov (United States)

    Alborzpour, Jonathan P.; Tew, David P.; Habershon, Scott

    2016-11-01

    Solution of the time-dependent Schrödinger equation using a linear combination of basis functions, such as Gaussian wavepackets (GWPs), requires costly evaluation of integrals over the entire potential energy surface (PES) of the system. The standard approach, motivated by computational tractability for direct dynamics, is to approximate the PES with a second order Taylor expansion, for example centred at each GWP. In this article, we propose an alternative method for approximating PES matrix elements based on PES interpolation using Gaussian process regression (GPR). Our GPR scheme requires only single-point evaluations of the PES at a limited number of configurations in each time-step; the necessity of performing often-expensive evaluations of the Hessian matrix is completely avoided. In applications to 2-, 5-, and 10-dimensional benchmark models describing a tunnelling coordinate coupled non-linearly to a set of harmonic oscillators, we find that our GPR method results in PES matrix elements for which the average error is, in the best case, two orders-of-magnitude smaller and, in the worst case, directly comparable to that determined by any other Taylor expansion method, without requiring additional PES evaluations or Hessian matrices. Given the computational simplicity of GPR, as well as the opportunities for further refinement of the procedure highlighted herein, we argue that our GPR methodology should replace methods for evaluating PES matrix elements using Taylor expansions in quantum dynamics simulations.

  20. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-15

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration’s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  1. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-15

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration’s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  2. A CAD System for Tube Drawing Based on Finite Element Simulation of Drawing Process

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to develop a special CAD system for tube cold drawing,the practical data and experience have been put into consideration as usual, and with the help of MARC software, the finite element simulations have been carried out over 1 000 times under widely possible processing parameters. After being analyzed and modeled, the results of the simulations are directly introduced into the CAD system, so that the CAD is capable of helping tube manufacturers notonly arrange their drawing procedure system easily and efficiently, but also optimize their drawing processes in several aspects, such as drawing force, die geometry, plug geometry, distribution of reduction, accuracy of tube dimension, consumption of deforming work, quality of tube, and so on. The optimized cold drawing procedures are able to lower production cost by 1 %—5 % in average.

  3. Research on the Plasma Spray Process Applying the Finite Element Method

    Directory of Open Access Journals (Sweden)

    Raimonda Lukauskaitė

    2015-03-01

    Full Text Available The article investigates the physical processes of plasma spraying. The application of the finite element method has assisted in establishing the distribution of the voltage of the plasma arc and current density in the plasma stream during numerical simulation. With reference to the results of experimental data, the real location of an anode spot of the electric arc in the plasma spray process has been evaluated. The paper has calculated the values of electromagnetic Lorentz forces and established their influence on plasma flow. With the help of the two-layer model for the semi-molten nickel particle, contact between the particle and substrate during plasma spraying has been simulated.

  4. Study of KLL Auger processes for light elements above Z = 10. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, T.A.; Dress, W.B.; Nyberg, G.L.

    1977-01-01

    A comprehensive review is given of the KLL Auger spectrum for members of the third row of the periodic table. This group contains the lightest elements wherein an Auger process can occur without the direct participation of the valence shell. Recent Auger spectra induced by x-ray photoionization on Mg, Al, and Si metals and their oxides are given as well as preliminary results on salts of Na and K, and for comparison, the LMM spectra of RbCl. Results were combined with previous experimental data and theory in order to obtain an overview. Four topics concerned with Auger processes are discussed: Energies, relative intensities, chemical shifts, and satellite structure. Interlaced throughout is a discussion of the role played by the chemical environment and electron correlation.

  5. A piloted comparison of elastic and rigid blade-element rotor models using parallel processing technology

    Science.gov (United States)

    Hill, Gary; Du Val, Ronald W.; Green, John A.; Huynh, Loc C.

    1990-01-01

    A piloted comparison of rigid and aeroelastic blade-element rotor models was conducted at the Crew Station Research and Development Facility (CSRDF) at Ames Research Center. FLIGHTLAB, a new simulation development and analysis tool, was used to implement these models in real time using parallel processing technology. Pilot comments and quantitative analysis performed both on-line and off-line confirmed that elastic degrees of freedom significantly affect perceived handling qualities. Trim comparisons show improved correlation with flight test data when elastic modes are modeled. The results demonstrate the efficiency with which the mathematical modeling sophistication of existing simulation facilities can be upgraded using parallel processing, and the importance of these upgrades to simulation fidelity.

  6. Effects of industrial processing on essential elements and regulated and emerging contaminant levels in seafood

    DEFF Research Database (Denmark)

    Rasmussen, Rie Romme; Bøge Søndergaard, Annette; Bøknæs, Niels

    2017-01-01

    Mitigation of contaminants in industrial processing was studied for prawns (cooked and peeled), Greenland halibut (cold smoked) and Atlantic salmon (cold smoked and trimmed). Raw prawns had significantly higher cadmium, chromium, iron, selenium and zinc content in autumn than in spring, while...... summer levels typically were intermediate. Peeling raw prawns increased mercury concentration but reduced the concentration of all other elements including inorganic arsenic, total arsenic, chromium, zinc, selenium but especially cadmium, copper and iron (p ... and processing was observed. Non-toxic organic arsenic in raw Greenland halibut (N = 10) and salmon (N = 4) did not transform to carcinogenic inorganic arsenic during industrial cold smoking. Hence inorganic arsenic was low (arsenic (up to 9...

  7. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  8. Modelling of tunnelling processes and rock cutting tool wear with the particle finite element method

    Science.gov (United States)

    Carbonell, Josep Maria; Oñate, Eugenio; Suárez, Benjamín

    2013-09-01

    Underground construction involves all sort of challenges in analysis, design, project and execution phases. The dimension of tunnels and their structural requirements are growing, and so safety and security demands do. New engineering tools are needed to perform a safer planning and design. This work presents the advances in the particle finite element method (PFEM) for the modelling and the analysis of tunneling processes including the wear of the cutting tools. The PFEM has its foundation on the Lagrangian description of the motion of a continuum built from a set of particles with known physical properties. The method uses a remeshing process combined with the alpha-shape technique to detect the contacting surfaces and a finite element method for the mechanical computations. A contact procedure has been developed for the PFEM which is combined with a constitutive model for predicting the excavation front and the wear of cutting tools. The material parameters govern the coupling of frictional contact and wear between the interacting domains at the excavation front. The PFEM allows predicting several parameters which are relevant for estimating the performance of a tunnelling boring machine such as wear in the cutting tools, the pressure distribution on the face of the boring machine and the vibrations produced in the machinery and the adjacent soil/rock. The final aim is to help in the design of the excavating tools and in the planning of the tunnelling operations. The applications presented show that the PFEM is a promising technique for the analysis of tunnelling problems.

  9. Biomechanical changes of spinous process osteotomy with different amounts of facetectomy using finite element model

    Science.gov (United States)

    Kang, K.-T.; Kim, K.-Y.; Jung, H.-J.; Lee, H.-Y.; Chun, H.-J.; Lee, H.-M.; Moon, S.-H.; Kim, H.-J.

    2010-03-01

    The aim of this study is to evaluate the biomechanical changes after Spinous Process Osteotomy (SPO) with different amounts of facetectomy of the lumbar spine and to compare the models with SPO and intact models using finite element models. Intact spine models and one decompression models (L3-4) with SPO were developed. SPO models included three different amounts of facetectomy (25%, 50%, and 75%). After validation of the models, finite element analyses were performed to investigate the ranges of motion and disc stresses at each corresponding level among three SPO models and intact lumbar spine models. The ranges of motion in the SPO models were increased more than the intact models. According to increase of amounts of facetectomy, ranges of motion were also increased. Similar to range of motion, the von Mises stress of disc in the SPO models was higher than that of intact models. Moreover, with the increase of amount of facetectomy, the disc stress increased at each segments under various moments. The decompression procedures using spinous process osteotomy has been reported to provide better postoperative stability compared to the conventional laminectomy. However, facetectomy over 50 % is likely to attenuate this advantage.

  10. Method of manufacturing iron aluminide by thermomechanical processing of elemental powders

    Energy Technology Data Exchange (ETDEWEB)

    Deevi, S.C.; Lilly, A.C. Jr.; Sikka, V.K.; Hajaligol, M.R.

    2000-03-07

    A powder metallurgical process is dislosed for preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as {<=}1% Cr, {>=}05% Zr or ZrO{sub 2} stringers extending perpendicular to an exposed surface of the heating element, {<=}2% Ti, {<=}2% Mo, {<=}1% Zr, {<=}1% C, {<=}0.1% B, {<=}30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, {<=}1 % rare earth metal, {<=}1% oxygen, and/or {<=}3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

  11. Method of manufacturing iron aluminide by thermomechanical processing of elemental powders

    Energy Technology Data Exchange (ETDEWEB)

    Deevi, Seetharama C. (Midlothian, VA); Lilly, Jr., A. Clifton (Chesterfield, VA); Sikka, Vinod K. (Oak Ridge, TN); Hajaligol, Mohammed R. (Richmond, VA)

    2000-01-01

    A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

  12. Development and demonstration of manufacturing processes for fabricating graphite/PMR-15 polyimide structural elements. [space shuttle aft body flap

    Science.gov (United States)

    Sheppard, C. H.; Hoggatt, J. T.; Symonds, W. A.

    1979-01-01

    The processing requirements for graphite/PMR-15 polyimide composites developed to demonstrate the structural integrity of polyimide composite structural elements at temperatures up to 589K (600 F) are described. Major tasks included: quality assurance development; materials and process development; specification verification; flat panel fabrication; stiffened panel fabrication; honeycomb panel fabrication; chopped fiber moldings; and demonstration component fabrication. Materials, processing, and quality assurance documents were prepared from experimentally derived data. Structural elements consisting of flat panels, corrugated stiffeners, I-beams, hat stiffeners, honeycomb panels, and chopped fiber moldings were made and tested. Property data from 219K (-65 F) to 589K (600 F) were obtained. All elements were made in a production environment. The size of each element was sufficient to insure production capability and structural component applicability. Problems associated with adhesive bonding, laminate and structural element analysis, material variability, and test methods were addressed.

  13. Development and demonstration of manufacturing processes for fabricating graphite/PMR-15 polyimide structural elements. [space shuttle aft body flap

    Science.gov (United States)

    Sheppard, C. H.; Hoggatt, J. T.; Symonds, W. A.

    1979-01-01

    The processing requirements for graphite/PMR-15 polyimide composites developed to demonstrate the structural integrity of polyimide composite structural elements at temperatures up to 589K (600 F) are described. Major tasks included: quality assurance development; materials and process development; specification verification; flat panel fabrication; stiffened panel fabrication; honeycomb panel fabrication; chopped fiber moldings; and demonstration component fabrication. Materials, processing, and quality assurance documents were prepared from experimentally derived data. Structural elements consisting of flat panels, corrugated stiffeners, I-beams, hat stiffeners, honeycomb panels, and chopped fiber moldings were made and tested. Property data from 219K (-65 F) to 589K (600 F) were obtained. All elements were made in a production environment. The size of each element was sufficient to insure production capability and structural component applicability. Problems associated with adhesive bonding, laminate and structural element analysis, material variability, and test methods were addressed.

  14. Detection of Elements at All Three r-process Peaks in the Metal-Poor Star HD 160617

    CERN Document Server

    Roederer, Ian U; 10.1088/0004-637X/750/1/76

    2012-01-01

    We report the first detection of elements at all three r-process peaks in the metal-poor halo star HD 160617. These elements include arsenic and selenium, which have not been detected previously in halo stars, and the elements tellurium, osmium, iridium, and platinum, which have been detected previously. Absorption lines of these elements are found in archive observations made with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. We present up-to-date absolute atomic transition probabilities and complete line component patterns for these elements. Additional archival spectra of this star from several ground-based instruments allow us to derive abundances or upper limits of 45 elements in HD 160617, including 27 elements produced by neutron-capture reactions. The average abundances of the elements at the three r-process peaks are similar to the predicted solar system r-process residuals when scaled to the abundances in the rare earth element domain. This result for arsenic and selen...

  15. Carbon elemental and isotopic composition in mantle xenoliths from Spain: Insights on sources and petrogenetic processes

    Science.gov (United States)

    Bianchini, G.; Natali, C.

    2017-02-01

    The carbon elemental concentration (C wt%) and isotopic (δ13C ‰) composition of mantle xenoliths from the Tallante and Calatrava volcanic occurrences (in South-East and Central Spain, respectively) have been investigated to identify carbon sources and processes occurring in distinct geodynamic settings of the Iberian Peninsula. The peridotitic mantle xenoliths from Calatrava show elemental C ranging from 0.11 to 2.87 wt% which is coupled with a continuous isotopic variation from very negative values (δ13C - 26.1‰) to typical mantle values (δ13C - 5.9‰). On the other hand, the Tallante mantle xenolith suite displays lower C contents (0.06-0.15 wt%) showing a tighter variation with 13C-depleted values ranging between - 20.1 and - 23.7‰; higher elemental C up to 0.41 wt% displaying distinctly less negative isotopic values (δ13C between - 13.8 and - 11.9‰) have been recorded in veins crosscutting Tallante peridotites, plausibly representing the product of metasomatic reactions. The data from the two investigated xenolith suites invariably display a good correlation between elemental and isotopic composition, suggesting a mantle origin for carbon and Rayleigh-type fractionation as the process responsible for the observed C-δ13C variation. However, the correlation between the carbon isotopic data with other isotopic tracers (e.g. 87Sr/86Sr, 3He/4He) used to identify distinct mantle components and metasomatic reactions, indicates systematic differences between the two xenolith suites suggesting that beneath the Betic Cordillera (where Tallante is located) the deep C-cycle involves recycling, via subduction preceding/accompanying continental collision, of crustal components back in the mantle. Coherently, geochemical trends observed in the Tallante xenoliths seem to be influenced by metasomatic agents generated by melting of crustal lithologies that according to the analysis of a metasedimentary xenolith can contain C up to 1.2 wt% having δ13C of ca. - 18

  16. Assembly, integration, and verification (AIV) in ALMA: series processing of array elements

    Science.gov (United States)

    Lopez, Bernhard; Jager, Rieks; Whyborn, Nicholas D.; Knee, Lewis B. G.; McMullin, Joseph P.

    2012-09-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is a joint project between astronomical organizations in Europe, North America, and East Asia, in collaboration with the Republic of Chile. ALMA will consist of at least 54 twelve-meter antennas and 12 seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter wavelength range. It is the responsibility of ALMA AIV to deliver the fully assembled, integrated, and verified antennas (array elements) to the telescope array. After an initial phase of infrastructure setup AIV activities began when the first ALMA antenna and subsystems became available in mid 2008. During the second semester of 2009 a project-wide effort was made to put in operation a first 3- antenna interferometer at the Array Operations Site (AOS). In 2010 the AIV focus was the transition from event-driven activities towards routine series production. Also, due to the ramp-up of operations activities, AIV underwent an organizational change from an autonomous department into a project within a strong matrix management structure. When the subsystem deliveries stabilized in early 2011, steady-state series processing could be achieved in an efficient and reliable manner. The challenge today is to maintain this production pace until completion towards the end of 2013. This paper describes the way ALMA AIV evolved successfully from the initial phase to the present steady-state of array element series processing. It elaborates on the different project phases and their relationships, presents processing statistics, illustrates the lessons learned and relevant best practices, and concludes with an outlook of the path towards completion.

  17. Research results on productivity stabilization by ultrasonic camera (plant with membrane ceramic elements during vine processing

    Directory of Open Access Journals (Sweden)

    V. T. Antufyev

    2016-01-01

    Full Text Available The article describes solutions to the problems of declining productivity of ceramic membrane elements for wine processing on the final manufacturing phase. A relative stabilization of filtration velocity, venting efficiency and wine lightening were experimentally confirmed during contacts with oscillation waves of ultrasonic transmitter on the ceramic filter. Which significantly reduced the cost of various preservatives to increase periods storage. To study the processes of wine processing by the proposed method it was made an experimental installation on the basis of pilot machine MRp-1/2 for bottling of quiet liquids and an ultrasonic device "Volna– M" UZTA-1/22-OM with a firmly, waveguide which transmits sound, fixed filter frame on the ultrasound emitter. To stabilize the performance of ultrasonic units with ceramic membrane elements without quality deterioration of wines it was empirically determined rational parameters of power of ultrasound input and pressure in the system. The given derived dependencies and graphs allow to define the time of relatively stable operating filter regime. It was revealed a significant cost reduction on filtration, as it allows escape from the contamination of the product by various preservatives, and increasing of storage duration in a sealed container during aseptic filling without a thermal sterilization. Ultrasonic emitter contact by superposition wave vibrations on the ceramic filter increases not only the efficiency of gas removal, but also improves the organoleptic characteristics, stabilizes the filters, improves their productivity. Gas removal creates unfavorable conditions for development of the yeast, which in turn increases the shelf life of semisweet wine.

  18. The five elements process: designing optimal landscapes to meet bird conservation objectives

    Science.gov (United States)

    Will, T.C.; Ruth, J.M.; Rosenberg, K.V.; Krueper, D.; Hahn, D.; Fitzgerald, J.; Dettmers, R.; Beardmore, C.J.

    2005-01-01

    In February 2004 at Port Aransas, Texas, Partners in Flight (PIF) and representatives from the other NABCI bird initiative met to discuss the process of stepping down PIF continental population objectives (Rich et al. 2004) to regional and local scales. Participants also discussed rolling up local population estimates and targets to assess the feasibility of the landscape changes necessary to meet continental objectives. Since the process of stepping-down/rolling-up population objectives shifts focus from identifying priority species to formulating quantitative estimates of how much habitat was needed, where, and by when the Port Aransas group called the stepping-down/rolling-up process a??stepping forward.a?? Participants agreed that stepping forward objectives was the beginning of an inevitably iterative dialog necessary to evaluate the assumptions of PIF population estimates and objectives as well as the methods used to monitor local implementation. To facilitate the translation of continental population objectives into biologically sound, measurable regional and local population-based habitat targets the Port Aransas group recommended a process no commonly referred to as the Five Elements Processa?|

  19. Trace element differences between Archean, Proterozoic and Phanerozoic crustal components: Implications for crustal growth processes

    Science.gov (United States)

    Tarney, J.; Wyborn, L. E. A.; Sheraton, J. W.; Wyborn, D.

    1988-01-01

    Critical to models for continental crust growth and recycling are the processes through which crustal growth takes place. In particular, it is important to know whether these processes have changed fundamentally with time in response to the earth's thermal evolution, and whether the crustal compositions generated are compatible with crustal remobilization, crustal recycling, or represent primary additions. There are some significant and consistent differences in the major and trace element compositions of crustal components with time which have important implications for crustal growth processes. These will be illustrated with reference to Archean rocks from a number of shield areas, Proterozoic granitoids from Australia and elsewhere, Palaeozoic granitoids from Australia and Scotland, and Mesozoic - recent granitoids from present continental margin belts. Surprisingly some rather simple and consistent patterns energy using this technique. There are then significant differences in compositions of granitoid crustal additions throughout geological time, with a particular type of granitoid apparently dominating a particular time period. This implies that the tectonic processes giving rise to granite generation have changed in response to the earth's thermal evolution.

  20. Three-dimensional ultrasonic imaging of concrete elements using different SAFT data acquisition and processing schemes

    Science.gov (United States)

    Schickert, Martin

    2015-03-01

    Ultrasonic testing systems using transducer arrays and the SAFT (Synthetic Aperture Focusing Technique) reconstruction allow for imaging the internal structure of concrete elements. At one-sided access, three-dimensional representations of the concrete volume can be reconstructed in relatively great detail, permitting to detect and localize objects such as construction elements, built-in components, and flaws. Different SAFT data acquisition and processing schemes can be utilized which differ in terms of the measuring and computational effort and the reconstruction result. In this contribution, two methods are compared with respect to their principle of operation and their imaging characteristics. The first method is the conventional single-channel SAFT algorithm which is implemented using a virtual transducer that is moved within a transducer array by electronic switching. The second method is the Combinational SAFT algorithm (C-SAFT), also named Sampling Phased Array (SPA) or Full Matrix Capture/Total Focusing Method (TFM/FMC), which is realized using a combination of virtual transducers within a transducer array. Five variants of these two methods are compared by means of measurements obtained at test specimens containing objects typical of concrete elements. The automated SAFT imaging system FLEXUS is used for the measurements which includes a three-axis scanner with a 1.0 m × 0.8 m scan range and an electronically switched ultrasonic array consisting of 48 transducers in 16 groups. On the basis of two-dimensional and three-dimensional reconstructed images, qualitative and some quantitative results of the parameters image resolution, signal-to-noise ratio, measurement time, and computational effort are discussed in view of application characteristics of the SAFT variants.

  1. Three-dimensional ultrasonic imaging of concrete elements using different SAFT data acquisition and processing schemes

    Energy Technology Data Exchange (ETDEWEB)

    Schickert, Martin, E-mail: martin.schickert@mfpa.de [Materialforschungs- und -prüfanstalt an der Bauhaus-Universität Weimar, Coudraystr. 9, 99425 Weimar (Germany)

    2015-03-31

    Ultrasonic testing systems using transducer arrays and the SAFT (Synthetic Aperture Focusing Technique) reconstruction allow for imaging the internal structure of concrete elements. At one-sided access, three-dimensional representations of the concrete volume can be reconstructed in relatively great detail, permitting to detect and localize objects such as construction elements, built-in components, and flaws. Different SAFT data acquisition and processing schemes can be utilized which differ in terms of the measuring and computational effort and the reconstruction result. In this contribution, two methods are compared with respect to their principle of operation and their imaging characteristics. The first method is the conventional single-channel SAFT algorithm which is implemented using a virtual transducer that is moved within a transducer array by electronic switching. The second method is the Combinational SAFT algorithm (C-SAFT), also named Sampling Phased Array (SPA) or Full Matrix Capture/Total Focusing Method (TFM/FMC), which is realized using a combination of virtual transducers within a transducer array. Five variants of these two methods are compared by means of measurements obtained at test specimens containing objects typical of concrete elements. The automated SAFT imaging system FLEXUS is used for the measurements which includes a three-axis scanner with a 1.0 m × 0.8 m scan range and an electronically switched ultrasonic array consisting of 48 transducers in 16 groups. On the basis of two-dimensional and three-dimensional reconstructed images, qualitative and some quantitative results of the parameters image resolution, signal-to-noise ratio, measurement time, and computational effort are discussed in view of application characteristics of the SAFT variants.

  2. 3D Finite Element Modelling of Drilling Process of Al2024-T3 Alloy with solid tooling and Experimental Validation

    DEFF Research Database (Denmark)

    Davoudinejad, Ali; Tosello, Guido

    Drilling is an indispensable process for many manufacturing industries due to the importance of the process for assembling components. This study presents a 3D finite element modeling (3D FEM) approach for drilling process of aluminum 2024-T3. The 3D model of tool for two facet HSSCo and four facet...

  3. Simulation of Powder Layer Deposition in Additive Manufacturing Processes Using the Discrete Element Method

    Energy Technology Data Exchange (ETDEWEB)

    Herbold, E. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Walton, O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homel, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    This document serves as a final report to a small effort where several improvements were added to a LLNL code GEODYN-­L to develop Discrete Element Method (DEM) algorithms coupled to Lagrangian Finite Element (FE) solvers to investigate powder-­bed formation problems for additive manufacturing. The results from these simulations will be assessed for inclusion as the initial conditions for Direct Metal Laser Sintering (DMLS) simulations performed with ALE3D. The algorithms were written and performed on parallel computing platforms at LLNL. The total funding level was 3-­4 weeks of an FTE split amongst two staff scientists and one post-­doc. The DEM simulations emulated, as much as was feasible, the physical process of depositing a new layer of powder over a bed of existing powder. The DEM simulations utilized truncated size distributions spanning realistic size ranges with a size distribution profile consistent with realistic sample set. A minimum simulation sample size on the order of 40-­particles square by 10-­particles deep was utilized in these scoping studies in order to evaluate the potential effects of size segregation variation with distance displaced in front of a screed blade. A reasonable method for evaluating the problem was developed and validated. Several simulations were performed to show the viability of the approach. Future investigations will focus on running various simulations investigating powder particle sizing and screen geometries.

  4. Optimization of Bending Process Parameters for Seamless Tubes Using Taguchi Method and Finite Element Method

    Directory of Open Access Journals (Sweden)

    Jui-Chang Lin

    2015-01-01

    Full Text Available The three-dimensional tube (or pipe is manufactured by CNC tube bending machine. The key techniques are determined by tube diameter, wall thickness, material, and bending radius. The obtained technique through experience and the trial and error method is unreliable. Finite element method (FEM simulation for the tube bending process before production can avoid wasting manpower and raw materials. The computer-aided engineering (CAE software ABAQUS 6.12 is applied to simulate bending characteristics and to explore the maximum stress and strain conditions. The Taguchi method is used to find the optimal parameters of bending. The confirmation experiment is performed according to optimal parameters. Results indicate that the strain error between CAE simulation and bending experiments is within 6.39%.

  5. Finite element simulation of a ceramic drying process considering pore shape and porosity

    Science.gov (United States)

    Keum, Y. T.; Oh, J. W.

    2005-03-01

    When a green ceramic is dried, the particles flocculate into a fishnet structure in the gel phase. The range of pore size is between the micro-scale and the nano-scale. In general, the elastic properties of porous materials are affected by both pore shape and porosity. Using the homogenization method, the elastic tensor of nanoscopic gel unit cell, varying with the porosity, is first computed. Using the finite element method, the drying process of a green ceramic insulator is simulated, based on the elastic properties of a microscopic particle aggregate unit cell with circular and cross pores, found from the nanoscopic elastic tensor using the homogenization method. Consideration of the pore shape and porosities in a simulation can provide a more accurate residual stress distribution.

  6. Modeling and finite element analysis of rod and wire steel rolling process

    Institute of Scientific and Technical Information of China (English)

    Shulun Liao; Liwen Zhang; Siyu Yuan; Yu Zhen; Shuqi Guo

    2008-01-01

    Two thermomechanical coupled elastic-plastic finite element (FE) models were developed for predicting the 12-pass continuous rolling process of GCr15 rod and wire steel. The distances between stands in the proposed models were set according to the actual values, and the billets were shortened in the models to reduce the calculation time. To keep the continuity of simulation, a technique was developed to transfer temperature data between the meshes of different models in terms of nodal parameters by interpolation functions. The different process variables related to the rolling process, such as temperature, total equivalent plastic strain,equivalent plastic strain rate, and contact friction force, were analyzed. Also, the proposed models were applied to analyze the reason for the occurrence of an excessive spread in width. Meanwhile, it was also utilized to assess the influence of the roll diameter change on the simulated results such as temperature and rolling force. The simulated results of temperature are found to agree well with the measured results.

  7. RARE EARTH ELEMENTS: A REVIEW OF PRODUCTION, PROCESSING, RECYCLING, AND ASSOCIATED ENVIRONMENTAL ISSUES

    Science.gov (United States)

    Rare earth elements (REEs) are a group of 15 chemical elements in the periodic table, specifically the lanthanides. Two other elements, scandium and yttrium, have a similar physiochemistry to the lanthanides, are commonly found in the same mineral assemblages, and are often refe...

  8. Simulation of a soil loosening process by means of the modified distinct element method

    NARCIS (Netherlands)

    Momuzu, M.; Oida, A.; Yamazaki, M.; Koolen, A.J.

    2002-01-01

    We apply the Distinct Element Method (DEM) to analyze the dynamic behavior of soil. However, the conventional DEM model for calculation of contact forces between elements has some problems; for example, the movement of elements is too discrete to simulate real soil particle movement. Therefore, we m

  9. Spectroscopic Studies of Extremly Metal-Poor Stars with Subaru/HDS:II.The r-process Elements, Including Thorium

    CERN Document Server

    Honda, S; Kajino, T; Ando, H; Beers, T C; Izumiura, H; Sadakane, K; Takada-Hidai, M

    2004-01-01

    We present the abundance analyses for the neutron-capture elements, and discuss the observed abundance distributions in very metal-poor stars with excesses of r-process elements. As has been found by previous abundance studies, the star-to-star scatter in the abundances of neutron-capture elements are very large. The abundance patterns of the heavy neutron-capture elements (56 $\\leq$ Z $\\leq$ 70) in seven objects with moderate to large excesses of the neutron-capture elements are similar to that of the solar system r-process component. These results strongly suggest that the heavy neutron-capture elements in these objects are primarily synthesized by the r-process. On the other hand, the abundance ratios of the light neutron-capture elements (38 $\\leq$ Z $\\leq$ 46) exhibit a rather large dispersion. Our inspection of the correlation between Sr and Ba abundances in very metal-poor stars reveals that the dispersion of the Sr abundances clearly decreases with increasing Ba abundance. This results support previou...

  10. Finite element modelling and updating of a lively footbridge: The complete process

    Science.gov (United States)

    Živanović, Stana; Pavic, Aleksandar; Reynolds, Paul

    2007-03-01

    The finite element (FE) model updating technology was originally developed in the aerospace and mechanical engineering disciplines to automatically update numerical models of structures to match their experimentally measured counterparts. The process of updating identifies the drawbacks in the FE modelling and the updated FE model could be used to produce more reliable results in further dynamic analysis. In the last decade, the updating technology has been introduced into civil structural engineering. It can serve as an advanced tool for getting reliable modal properties of large structures. The updating process has four key phases: initial FE modelling, modal testing, manual model tuning and automatic updating (conducted using specialist software). However, the published literature does not connect well these phases, although this is crucial when implementing the updating technology. This paper therefore aims to clarify the importance of this linking and to describe the complete model updating process as applicable in civil structural engineering. The complete process consisting the four phases is outlined and brief theory is presented as appropriate. Then, the procedure is implemented on a lively steel box girder footbridge. It was found that even a very detailed initial FE model underestimated the natural frequencies of all seven experimentally identified modes of vibration, with the maximum error being almost 30%. Manual FE model tuning by trial and error found that flexible supports in the longitudinal direction should be introduced at the girder ends to improve correlation between the measured and FE-calculated modes. This significantly reduced the maximum frequency error to only 4%. It was demonstrated that only then could the FE model be automatically updated in a meaningful way. The automatic updating was successfully conducted by updating 22 uncertain structural parameters. Finally, a physical interpretation of all parameter changes is discussed. This

  11. Abundance of Weak r-Process Elements of Metal-Poor Stars ˜Universality or Diversity?˜

    Science.gov (United States)

    Aoki, Misa; Ishimaru, Yuhri; Aoki, Wako; Wanajo, Shinya

    The origin of the rapid neutron-capture process is a major question in astrophysics. The key to this question is the chemical abundance patterns of very metal-poor stars (VMP), which are believed to reflect the nucleosynthesis yields of single event. Recent observations of VMP indicate that there are at least two components to r-process; "main r-process" responsible for relatively heavy neutron-capture elements and "weak r-process" [1] responsible for relatively light neutron-capture elements. The VMP with heavier neutron-capture elements are known to have similar pattern to that of solar r-process, suggesting universality in main r-process nucleosynthesis [2]. A question is whether weak r-process also show such universality. We present the abundance analysis of neutron-capture elements in five stars (HD107752, HD110184, HD85773, HD23798, BD+6 648) in the Galactic halo observed by the Subaru Telescope High Dispersion Spectrograph. Their light neutron-capture elements (e.g., Sr, Y) show overabundance, inferring contribution of weak r-process, while heavy neutron-capture elements (e.g., Ba, Eu) are deficient. The overabundance of these stars, however, is not as significant as that found in HD122563 [3] known as the weak r-process star. These results suggests that there is diversity in the nucleosynthesis of the weak r-process. In addition, we compare our results with the latest nucleosynthesis models of electron capture supernova and core collapse supernova [4, 5].

  12. Remedial Investigation/Feasibility Study (RI/FS) process, elements and techniques guidance

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    This manual provides detailed guidance on Remedial Investigation/Feasibility Studies (RI/FSs) conducted pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) at Department of Energy (DOE) facilities. The purpose of the RI/FS, to assess the risk posed by a hazardous waste site and to determine the best way to reduce that risk, and its structure (site characterization, risk assessment, screening and detailed analysis of alternatives, etc.) is defined in the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and further explained in the Environmental Protection Agency`s (EPA`s) Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA (Interim Final) 540/G-89/004, OSWER Directive 9355.3-01, October 1988. Though issued in 1988, the EPA guidance remains an excellent source of information on the conduct and structure of an RI/FS. This document makes use of supplemental RI/FS-related guidance that EPA has developed since its initial document was issued in 1988, incorporates practical lessons learned in more than 12 years of experience in CERCLA hazardous site remediation, and drawing on those lessons, introduces the Streamlined Approach For Environmental Restoration (SAFER), developed by DOE as a way to proceed quickly and efficiently through the RI/FS process at DOE facilities. Thus as its title implies, this guidance is intended to describe in detail the process and component elements of an RI/FS, as well as techniques to manage the RI/FS effectively.

  13. Rare earth elements tracing the soil erosion processes on slope surface under natural rainfall.

    Science.gov (United States)

    Zhu, Mingyong; Tan, Shuduan; Dang, Haishan; Zhang, Quanfa

    2011-12-01

    A field experiment using rare earth elements (REEs) as tracers was conducted to investigate soil erosion processes on slope surfaces during rainfall events. A plot of 10m×2m×0.16m with a gradient of 20° (36.4%) was established and the plot was divided into two layers and four segments. Various REE tracers were applied to the different layers and segments to determine sediment dynamics under natural rainfall. Results indicated that sheet erosion accounted for more than 90% of total erosion when the rainfall amount and density was not large enough to generate concentrated flows. Sediment source changed in different sections on the slope surface, and the primary sediment source area tended to move upslope as erosion progressed. In rill erosion, sediment discharge mainly originated from the toe-slope and moved upwards as erosion intensified. The results obtained from this study suggest that multi-REE tracer technique is valuable in understanding the erosion processes and determining sediment sources.

  14. Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

    Science.gov (United States)

    Tan, Quanyin; Deng, Chao; Li, Jinhui

    2016-01-01

    With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency.

  15. Thermomechanical finite element simulations of selective electron beam melting processes: performance considerations

    Science.gov (United States)

    Riedlbauer, Daniel; Steinmann, Paul; Mergheim, Julia

    2014-07-01

    The present contribution is concerned with the macroscopic modelling of the selective electron beam melting process by using the finite element method. The modelling and simulation of the selective electron beam melting process involves various challenges: complex material behaviour, phase changes, thermomechanical coupling, high temperature gradients, different time and length scales etc. The present contribution focuses on performance considerations of solution approaches for thermomechanically coupled problems, i.e. the monolithic and the adiabatic split approach. The material model is restricted to nonlinear thermoelasticity with temperature-dependent material parameters. As a numerical example a straight scanning path is simulated, the predicted temperatures and stresses are analysed and the performance of the two algorithms is compared. The adiabatic split approach turned out to be much more efficient for linear thermomechanical problems, i.e. the solution time is three times less than with the monolithic approach. For nonlinear problems, stability issues necessitated the use of the Euler backward integration scheme, and therefore, the adiabatic split approach required small time steps for reasonable accuracy. Thus, for nonlinear problems and in combination with the Euler backward integration scheme, the monolithic solver turned out to be more efficient.

  16. Finite element analysis of laser irradiated metal heating and melting processes

    Science.gov (United States)

    Sowdari, Dharani; Majumdar, Pradip

    2010-09-01

    Laser technology has shown fast growth due to its demands in material processing and manufacturing. Laser material processing includes various applications like cutting, welding, drilling, cladding and surface treatment. In laser surface treatment, the material properties at the surface are altered through surface alloying and transformation hardening. In this study, an enthalpy-based computational model is developed for analyzing laser heating and melting of metals. The solution to the problem is obtained by using a finite element method and validated by comparing the results with that given by an analytical solution to a limiting case problem. A solution algorithm and a computational code are developed to estimate the temperature distribution, solid-liquid interface location and shape and size of the molten pool. The computational model is validated by comparing results with a limiting case analytical model. The study is conducted to analyze the heating rate, the heat affected zone, and the shape and size of the molten pool using a Gaussian laser beam.

  17. Elemental and spectroscopic characterization of fractions of an acidic extract of oil sands process water.

    Science.gov (United States)

    Jones, D; Scarlett, A G; West, C E; Frank, R A; Gieleciak, R; Hager, D; Pureveen, J; Tegelaar, E; Rowland, S J

    2013-11-01

    'Naphthenic acids' (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted. The unfractionated OSPW acidic extract was characterized by elemental analysis, electrospray ionization-Orbitrap-mass spectrometry (ESI-MS), and an esterified extract by Fourier Transform infrared (FTIR) and ultraviolet-visible (UV) absorption spectroscopy and by comprehensive multidimensional gas chromatography-MS (GCxGC-MS). Methyl esters were fractionated by argentation solid phase extraction (Ag(+) SPE) and fractions eluting with: hexane; diethyl ether: hexane and diethyl ether, examined. Each was weighed, examined by elemental analysis, FTIR, UV, GC-MS and GCxGC-MS (both nominal and high resolution MS). The ether fraction, containing sulfur, was also examined by GCxGC-sulfur chemiluminescence detection (GCxGC-SCD). The major ions detected by ESI-MS in the OSPW extract were assigned to alicyclic and aromatic 'O2' acids; sulfur was also present. Components recovered by Ag(+) SPE were also methyl esters of alicyclic and aromatic acids; these contained little sulfur or nitrogen. FTIR spectra showed that hydroxy acids and sulfoxides were absent or minor. UV spectra, along with the C/H ratio, further confirmed the aromaticity of the hexane:ether eluate. The more minor ether eluate contained further aromatics and 1.5% sulfur. FTIR spectra indicated free carboxylic acids, in addition to esters. Four major sulfur compounds were detected by GCxGC-SCD. GCxGC-high resolution MS indicated these were methyl esters of C18 S-containing, diaromatics with ≥C3 carboxylic acid side chains. Copyright © 2013 Crown Copyright and Elsevier Ltd. Published by Elsevier Ltd.. All rights reserved.

  18. 3D Finite Element Modelling of Drilling Process of Al2024-T3 Alloy with solid tooling and Experimental Validation

    DEFF Research Database (Denmark)

    Davoudinejad, Ali; Tosello, Guido

    2017-01-01

    Drilling is an indispensable process for many manufacturing industries due to its importance for assembling components. This study presents a 3D finite element modelling (3D FEM) approach for drilling process of aluminium 2024-T3. The 3D model of drilling tools for two facet HSSCo and four facet...

  19. [Software development of multi-element transient signal acquisition and processing with multi-channel ICP-AES].

    Science.gov (United States)

    Zhang, Y; Zhuang, Z; Wang, X; Zhu, E; Liu, J

    2000-02-01

    A software for multi-channel ICP-AES multi-element transient signal acquisition and processing were developed in this paper. It has been successfully applied to signal acquisition and processing in many transient introduction techniques on-line hyphenated with multi-channel ICP-AES.

  20. Specifications: Laboratory hot press process for {open_quotes}C{close_quotes}size I & E fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Tverberg, J.C.

    1959-09-25

    Hot press canning of internally and externally cooled fuel elements has been developed to a point where the process is feasible. Complete specifications have been written for the process covering component, dies and punches, furnace construction, nickel plating, component cleaning, component assembly, sizing, hot pressing and inspection. Drawings covering each major item are included.

  1. Interatomic interaction of additive elements and their influence on the processes in the double metal solutions

    Directory of Open Access Journals (Sweden)

    Марина Анатоліівна Рябікіна

    2016-07-01

    Full Text Available Modern industry uses a lot of elements as additives to improve the service characteristics of metal products that are to be used for various purposes. These elements can be divided into two groups: the first group includes the elements interacting with iron and improving its characteristics (alloying elements, and the second group includes the elements, that modify the characteristics of the structure and properties in an undesirable direction. These are trace elements: S, P, O, As, and others in steel. The negative impact of these elements shows itself as banding, the formation of non-metallic inclusions, flakes, grain boundary segregations et al. The influence of the elements of the both groups on the properties of steel depends on the nature and level of interatomic interaction in the alloy. Computational and analytical study of the major impurity elements in steel impact on the interatomic bond strength and the probability of forming complexes, clusters, and chemical compounds with the basic alloying elements in the steel has been carried out in the work. The theoretical parameter which defines the strength of the ion-covalent bond of two atoms: non-metallic – metallic is the electronegativity of elements. The electronegativity difference of the metal and non-metallic elements increasing, the ionic bonding and thermodynamic stability of these compounds  increase. On the other hand, concentration of valent electrons is a universal characteristic of an atomic element which determines many of its properties, and especially the energy of interatomic interaction. Energy calculations of pairwise interatomic impurity elements: H, C, N, S, P, As interaction with Fe and major alloying elements in steel: Mn, Cr, Si, V, Al, Ti, W, Cu, Mo, Nb were made. It has been stated that all the impurity elements except phosphorus, hydrogen and arsenic have sufficient high adhesion with the majority of the metal elements in the modern steels. Phosphorus does

  2. Understanding rhizosphere processes to enhance phytoextraction of germanium and rare earth elements

    Science.gov (United States)

    Wiche, Oliver

    2017-04-01

    Germanium (Ge) and rare earth elements (REEs) are economically valuable raw materials that are not actually rare in terms of concentrations in soils but they are hardly available for plant uptake due to interactions with organic matter (SOM), secondary soil constituents such as Fe/Mn oxides and P bearing soil fractions. Processes in the rhizosphere might influence availability of Ge and REEs in the soil-plant system, since lowering of the pH and presence of carboxylates and siderophores (small molecules that strongly chelate Fe and other elements) strongly influences the chemical speciation of Ge and REEs in soil and consequently this comprehensive knowledge helps us to improve phytomining. In a series of field and greenhouse experiments 16 plant species from the functional groups of grasses, herbs and legumes were tested with regard to their accumulation efficiency of Ge and REEs in shoots. Subsequently, we conducted mixed culture experiments in which inefficient species (e.g. cereals like Avena sativa, Hordeum vulgare, Panicum miliaceum) were cultivated in mixed cultures with efficient species (Lupinus albus, Lupinus angustifolius). Based on the plant concentrations a principal component analysis (PCA) was performed to identify significant factors that explain the accumulation behavior of different plant species with regard to Ge, REEs, Si, Fe and Mn. In this analysis Mn was used to identify plant species with efficient mechanisms to access sparingly available P-resources in soils. Particularly in nonmycorrhizal species concentrations of Mn in leaves often indicate a carboxylate based P-mobilising strategy. Herbaceous plant species accumulated significantly higher amounts of REEs while grasses accumulated significantly higher amounts of Ge. Concentrations of Ge in shoots of grasses correlated significantly positive with Si, but negatively with concentrations of Mn. Indeed, the results of the PCA clearly show that plants with high Mn concentrations tend to have

  3. The level of toxic and essential trace elements in hair of petrochemical workers involved in different technological processes.

    Science.gov (United States)

    Skalny, Anatoly V; Kaminskaya, Galina A; Krekesheva, Tatyana I; Abikenova, Sholpan K; Skalnaya, Margarita G; Berezkina, Elena S; Grabeklis, Andrei R; Tinkov, Alexey A

    2017-02-01

    The objective of the investigation is comparative analysis of hair trace element content in workers of different departments of petrochemical plant. A total of 75 men working in office (engineers), and departments 1 (D1), 3 (D3), and 4 (D4) of the petrochemical plant, as well as occupationally non-exposed persons, were examined. Hair trace element levels were analyzed using inductively coupled plasma mass spectrometry. The office workers were characterized by the highest hair As, Hg, Sn, I, and Si content as compared to the workers of other departments, whereas the level of those elements did not differ significantly from the control values. It is notable that hair Be levels in all employees of petrochemical plant were significantly lower, whereas Se content was significantly higher than that in unexposed controls. Hair toxic trace element content in workers directly involved in industrial processes did not differ significantly or was lower than that in the control group. At the same time, the highest levels of essential trace elements (Cr, Fe, and I) were observed in employees working in primary oil refining (D1). Hair levels of Co, I, and Li were maximal in persons of sulfur and bitumen-producing division (D4). The lowest levels of both essential and toxic trace elements in hair were detected in employees involved in production of liquefied gas, kerosene, and diesel fuel (D3). The obtained data demonstrate that involvement in different technological processes in petrochemical complex differentially affect hair trace element content in workers.

  4. On-line elemental analysis of fossil fuel process streams by inductively coupled plasma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, W.P.

    1995-06-01

    METC is continuing development of a real-time, multi-element plasma based spectrometer system for application to high temperature and high pressure fossil fuel process streams. Two versions are under consideration for development. One is an Inductively Coupled Plasma system that has been described previously, and the other is a high power microwave system. The ICP torch operates on a mixture of argon and helium with a conventional annular swirl flow plasma gas, no auxiliary gas, and a conventional sample stream injection through the base of the plasma plume. A new, demountable torch design comprising three ceramic sections allows bolts passing the length of the torch to compress a double O-ring seal. This improves the reliability of the torch. The microwave system will use the same data acquisition and reduction components as the ICP system; only the plasma source itself is different. It will operate with a 750-Watt, 2.45 gigahertz microwave generator. The plasma discharge will be contained within a narrow quartz tube one quarter wavelength from a shorted waveguide termination. The plasma source will be observed via fiber optics and a battery of computer controlled monochromators. To extract more information from the raw spectral data, a neural net computer program is being developed. This program will calculate analyte concentrations from data that includes analyte and interferant spectral emission intensity. Matrix effects and spectral overlaps can be treated more effectively by this method than by conventional spectral analysis.

  5. Finite Element Simulation of Dynamic Wetting Flows as an Interface Formation Process

    CERN Document Server

    Sprittles, James

    2012-01-01

    A mathematically challenging model of dynamic wetting as a process of interface formation has been, for the first time, fully incorporated into a numerical code based on the finite element method and applied, as a test case, to the problem of capillary rise. The motivation for this work comes from the fact that, as discovered experimentally more than a decade ago, the key variable in dynamic wetting flows -the dynamic contact angle - depends not just on the velocity of the three-phase contact line but on the entire flow field/geometry. Hence, to describe this effect, it becomes necessary to use the mathematical model that has this dependence as its integral part. A new physical effect, termed the `hydrodynamic resist to dynamic wetting', is discovered where the influence of the capillary's radius on the dynamic contact angle, and hence on the global flow, is computed. The capabilities of the numerical framework are then demonstrated by comparing the results to experiments on the unsteady capillary rise, where...

  6. A discrete element based simulation framework to investigate particulate spray deposition processes

    KAUST Repository

    Mukherjee, Debanjan

    2015-06-01

    © 2015 Elsevier Inc. This work presents a computer simulation framework based on discrete element method to analyze manufacturing processes that comprise a loosely flowing stream of particles in a carrier fluid being deposited on a target surface. The individual particulate dynamics under the combined action of particle collisions, fluid-particle interactions, particle-surface contact and adhesive interactions is simulated, and aggregated to obtain global system behavior. A model for deposition which incorporates the effect of surface energy, impact velocity and particle size, is developed. The fluid-particle interaction is modeled using appropriate spray nozzle gas velocity distributions and a one-way coupling between the phases. It is found that the particle response times and the release velocity distribution of particles have a combined effect on inter-particle collisions during the flow along the spray. It is also found that resolution of the particulate collisions close to the target surface plays an important role in characterizing the trends in the deposit pattern. Analysis of the deposit pattern using metrics defined from the particle distribution on the target surface is provided to characterize the deposition efficiency, deposit size, and scatter due to collisions.

  7. Finite element simulation of dynamic wetting flows as an interface formation process

    KAUST Repository

    Sprittles, J.E.

    2013-01-01

    A mathematically challenging model of dynamic wetting as a process of interface formation has been, for the first time, fully incorporated into a numerical code based on the finite element method and applied, as a test case, to the problem of capillary rise. The motivation for this work comes from the fact that, as discovered experimentally more than a decade ago, the key variable in dynamic wetting flows - the dynamic contact angle - depends not just on the velocity of the three-phase contact line but on the entire flow field/geometry. Hence, to describe this effect, it becomes necessary to use the mathematical model that has this dependence as its integral part. A new physical effect, termed the \\'hydrodynamic resist to dynamic wetting\\', is discovered where the influence of the capillary\\'s radius on the dynamic contact angle, and hence on the global flow, is computed. The capabilities of the numerical framework are then demonstrated by comparing the results to experiments on the unsteady capillary rise, where excellent agreement is obtained. Practical recommendations on the spatial resolution required by the numerical scheme for a given set of non-dimensional similarity parameters are provided, and a comparison to asymptotic results available in limiting cases confirms that the code is converging to the correct solution. The appendix gives a user-friendly step-by-step guide specifying the entire implementation and allowing the reader to easily reproduce all presented results, including the benchmark calculations. © 2012 Elsevier Inc.

  8. Connecting mechanics and bone cell activities in the bone remodeling process: an integrated finite element modeling.

    Science.gov (United States)

    Hambli, Ridha

    2014-01-01

    Bone adaptation occurs as a response to external loadings and involves bone resorption by osteoclasts followed by the formation of new bone by osteoblasts. It is directly triggered by the transduction phase by osteocytes embedded within the bone matrix. The bone remodeling process is governed by the interactions between osteoblasts and osteoclasts through the expression of several autocrine and paracrine factors that control bone cell populations and their relative rate of differentiation and proliferation. A review of the literature shows that despite the progress in bone remodeling simulation using the finite element (FE) method, there is still a lack of predictive models that explicitly consider the interaction between osteoblasts and osteoclasts combined with the mechanical response of bone. The current study attempts to develop an FE model to describe the bone remodeling process, taking into consideration the activities of osteoclasts and osteoblasts. The mechanical behavior of bone is described by taking into account the bone material fatigue damage accumulation and mineralization. A coupled strain-damage stimulus function is proposed, which controls the level of autocrine and paracrine factors. The cellular behavior is based on Komarova et al.'s (2003) dynamic law, which describes the autocrine and paracrine interactions between osteoblasts and osteoclasts and computes cell population dynamics and changes in bone mass at a discrete site of bone remodeling. Therefore, when an external mechanical stress is applied, bone formation and resorption is governed by cells dynamic rather than adaptive elasticity approaches. The proposed FE model has been implemented in the FE code Abaqus (UMAT routine). An example of human proximal femur is investigated using the model developed. The model was able to predict final human proximal femur adaptation similar to the patterns observed in a human proximal femur. The results obtained reveal complex spatio-temporal bone

  9. Effect of processing conditions on trace elements in fish roe from six commercial new zealand fish species.

    Science.gov (United States)

    Bekhit, Alaa El-Din A; Morton, James D; Dawson, Chris O

    2008-06-25

    The concentrations of trace elements in fish roes and the effect of processing conditions (karasumi-like or karashi mentaiko) were investigated in six commercial fish species from New Zealand. The studied elements were As, Cd, Cr, Cu, Hg, Pb, and Zn, and the roes were from the following species: chinook salmon ( Oncorhynchus tshawytscha), hoki ( Macruronus novaezelandiae), southern blue whiting ( Micromesistius australis), hake ( Merluccius australis), blue warehou ( Seriolella brama), and barracouta ( Thyrsites atun). The concentrations of As, Cd, Cr, Hg, and Pb in the roes were lower than literature values for fish muscles. Only Zn in barracouta roe and Cu in salmon roe and their products were relatively higher than the generally accepted levels in fish muscles and could be of safety concern. Hence, the consumption of barracouta and salmon roes among certain parts of the population needs to be monitored and assessed. Dry salting (karasumi-like) processing increased ( P elements while salting fermentation (karashi mentaiko) processing tended to decrease the levels of trace elements. Fermentation may be a useful process to decrease the level of toxic trace elements.

  10. Chemo-dynamical evolution of the Local Group dwarf galaxies: The origin of r-process elements

    Science.gov (United States)

    Hirai, Y.; Ishimaru, Y.; Saitoh, T. R.; Fujii, M. S.; Hidaka, J.; Kajino, T.

    2016-06-01

    The r-process elements such as Au, Eu, and U are observed in the extremely metal-poor stars in the Milky Way halo and the Local Group dwarf galaxies. However, the origin of r-process elements has not yet been identified. The abundance of r-process elements of stars in the Local Group galaxies provides clues to clarify early evolutionary history of galaxies. It is important to understand the chemical evolution of the Local Group dwarf galaxies which would be building blocks of the Milky Way. In this study, we perform a series of N-body/smoothed particle hydrodynamic simulations of dwarf galaxies. We show that neutron star mergers can reproduce the observation of r-process elements. We find that the effects of gas mixing processes including metals in the star-forming region of a typical scale of giant molecular clouds ¥sim 10-100 pc play significant roles in the early chemical enrichment of dwarf galaxies. We also find that the star formation rate of ˜ 10^{-3} M_{⊙}yr^{-1} in early epoch (<1 Gyr) of galactic halo evolution is necessary for these results. Our results suggest that neutron star mergers are a major site of r-process.

  11. A FINITE ELEMENT ANALYSIS OF THE FLANGE EARRINGS OF STRONG ANISOTROPIC SHEET METALS IN DEEP-DRAWING PROCESSES

    Institute of Scientific and Technical Information of China (English)

    柳玉起; 王锦程; 胡平

    2002-01-01

    Flange earrings of strong anisotropic sheet metals in deep-drawingprocess are numerically analyzed by the elastic-plastic large deformation finite ele-ment formulation based on a discrete Kirchhoff triangle plate shell element model.A Barlat-Lian anisotropic yield function and a quasi-flow corner theory are used inthe present formulation. The numerical results are compared with the experimentalones of cylindrical cup drawing process. The focus of the present researches is on thenumerical analysis and the constraining scheme of the flange earring of circular sheetswith strong anisotropy in square cup drawing process.

  12. The impact of transport processes on rare earth element patterns in marine authigenic and biogenic phosphates

    Science.gov (United States)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2017-04-01

    Rare earth elements (REEs) are commonly used proxies to reconstruct water chemistry and oxygen saturation during the formation of authigenic and biogenic phosphates in marine environments. In the modern ocean REEs exhibit a distinct pattern with enrichment of heavy REEs and strong depletion in cerium (Ce). The wide range of REE enrichment patterns found in ancient marine phosphates lead to the proposition that water chemistry has been very different in the Earth's past. However, both early and late diagenesis are known to affect REE signatures in phosphates altering primary marine signals. Herein we present a dataset of REE signatures in 38 grain specific LA-ICP-MS measurements of isolated phosphate and carbonate grains in three discrete rock samples. The phosphates mainly consist of authigenic phosphates and phosphatized microfossils that formed in a microbially mediated micro-milieu. In addition, isolated biogenic and reworked phosphatic grains are also present. The phosphates are emplaced in bioclastic grain- to packstones deposited on a carbonate ramp setting in the central Mediterranean Sea during the middle Miocene Monterey event. The results reveal markedly different REE patterns (normalized to the Post Archean Australian Shale standard) in terms of total enrichment and pattern shape. Analyses of REE diagenesis proxies show that diagenetic alteration affected the samples only to a minor degree. Grain shape and REE patterns together indicate that authigenic, biogenic and reworked phosphates have distinct REE patterns irrespective of the sample. Our study shows that while REE patterns in phosphates do reflect water chemistry during authigenesis, they are often already heavily altered during reworking, a process, which can occur in geologically negligible timespans. REE patterns are therefore more likely to reflect complex enrichment processes after their formation. Similarities in the REE patterns of reworked and biogenic phosphate further suggest that the

  13. Explosive Nucleosynthesis in Magnetohydrodynamical Jets from Collapsars II. Heavy-element nucleosynthesis of s, r, p-processes

    CERN Document Server

    Ono, Masaomi; Fujimoto, Shin-ichiro; Kotake, Kei; Yamada, Shoichi

    2012-01-01

    We investigate the nucleosynthesis in a massive star of 70 M_solar with solar metallicity in the main sequence stage. The helium core mass after hydrogen burning corresponds to 32 M_solar. Nucleosynthesis calculations have been performed during the stellar evolution and the jet-like supernova explosion of a collapsar model. We focus on the production of heavier elements than iron. Nucleosynthesis calculations have been done by using large nuclear reaction networks, where the weak s-, p-, and r-processes are taken into account. We confirm that s-elements of 60 90 are produced via photodisintegrations of seed s-elements. However, the produced p-elements are destructed in later stages except for ^{180}Ta. In the explosive nucleosynthesis, elements of 90 50) are overproduced relative to the solar values via the p-process because of the low peak temperatures in the oxygen and neon-rich layers. We confirm primary synthesis of light p-elements in the ejected matter of high peak temperature. The ejected matter has ...

  14. Concentrations and solubility of trace elements in fine particles at a mountain site, southern China: regional sources and cloud processing

    Science.gov (United States)

    Li, T.; Wang, Y.; Li, W. J.; Chen, J. M.; Wang, T.; Wang, W. X.

    2015-08-01

    The concentrations and solubility of twelve trace elements in PM2.5 at Mt. Lushan, southern China, were investigated during the summer of 2011 and the spring of 2012. The average PM2.5 mass was 55.2 ± 20.1 μg m-3 during the observation period. Temporal variations of all trace elements including total and water-soluble fractions with several dust storm spikes in total fractions of Al and Fe were observed. The enrichment factor (EF) values were 1 order of magnitude higher for the water-soluble fractions versus the total fractions of trace elements. Four major emission sources, namely nonferrous metal mining and smelting (for Cr, As, Ba and parts of Zn), coal combustion (for Pb, Zn, Se, Cu and Mn), crustal materials (for Al and Fe) and municipal solid waste incineration (for Cd and Mo), were classified by principal component analysis (PCA). Trajectory cluster analysis and the potential source contribution function (PSCF) consistently identified the Yangtze River delta (YRD), the Pearl River delta (PRD), and the neighbouring provinces of Mt. Lushan as the major source regions and transport pathways for anthropogenic elements. Northern China was identified as a major source region for crustal elements. It should be noted that apart from the YRD, the area around Mt. Lushan has become the most significant contributor to the solubility of most trace elements. Element solubility can be partially determined by emission sources. However, enhanced solubility of trace elements corresponding to increased concentrations of sulfate after the occurrence of cloud events indicated significant effects of cloud processing on aerosol element dissolution. Metal particles mixed with sulfate in cloud droplet residues were further investigated through transmission electron microscopy (TEM) analysis. Irreversible alteration of particle morphology by cloud processing was confirmed to be highly responsible for the enhancement of trace element solubility. The findings from this study imply an

  15. Development and demonstration of manufacturing processes for fabricating graphite/Larc-160 polyimide structural elements, part 4, paragraph C

    Science.gov (United States)

    1981-01-01

    Progress in the development of processes for production of Celion/LARC-160 graphite-polyimide materials, quality control methods, and the fabrication of Space Shuttle composite structure components is reported. The formulation and processing limits for three batches of resin are presented. Process improvements for simplification of the imidizing and autoclave cure cycles are described. Imidized and autoclave cured test panels were prepared. Celion/LARC-160 cure process verification and the fabrication of honeycomb sandwich panel elements and skin/stringer panels are described. C-scans of laminates imidized at 163 C to 218 C for periods from 30 to 180 minutes, and of process verification laminates made from different batches of prepreg are presented. Failure modes and load/strain characteristics of sandwich elements and C-scans of stringer to skin bond joints are also given.

  16. Elemental speciation of different stages of silver metal recovery process using PEDXRF

    Energy Technology Data Exchange (ETDEWEB)

    Ustuendag, Zafer [Ankara University, Faculty of Science, Department of Chemistry, Ankara (Turkey)]. E-mail: zustun@science.ankara.edu.tr; Kalfa, Orhan Murat [Gazi University, Faculty of Art and Science, Department of Chemistry, 06100 Ankara (Turkey); Erdogan, Yunus [Dumlupinar University, Faculty of Art and Science, Department of Chemistry, Kuetahya (Turkey); Kadioglu, Yusuf Kagan [Ankara University, Faculty of Engineering, Department of Geological Engineering, Ankara (Turkey)

    2006-09-15

    The silver ore, anode mud, chimney power, concentrator sample and waste damp samples obtained from the Guemueskoey Silver Plant have been analyzed for their elemental constituents. The prepared samples were analyzed using a polarized energy dispersive X-ray fluorescence (PEDXRF) spectrometer. The result of the analysis shows the presence of many elements including rare earth elements (from Na to Th). The accuracy and precision of the technique for chemical analysis is demonstrated by analyzing USGS standards, GEOL, SILVER, K07-CoO Cobalt oxide, GBW 7109 Ijolite Sy and GBW-7309 Sediment.

  17. Modulating the physical microenvironment to study regenerative processes in vitro using cells from mouse phalangeal elements.

    Science.gov (United States)

    Lynch, Kristen M; Ahsan, Tabassum

    2013-06-01

    Epimorphic regeneration in humans of complex multitissue structures is primarily limited to the digit tip. In a comparable mouse model, the response is level-specific in that regeneration occurs after amputation at the distal end of the terminal phalanx, but not more proximally. Recent isolation of stromal cells from CD1 murine phalangeal elements two and three (P2 and P3) allow for comparative studies of cells prevalent at the amputation plane of a more proximal region (considered nonregenerative) and a more distal region (considered regenerative), respectively. This study used adherent, suspension, and collagen gel cultures to investigate cellular processes relevant to the initial response to injury. Overall, P2 cells were both more migratory and able to compact collagen gels to a greater extent compared to P3 cells. This observed increased capacity of P2 cells to generate traction forces was likely related to the higher expression of key cytoskeletal proteins (e.g., microfilament, nonkeratin intermediate filaments, and microtubules) compared to P3 cells. In contrast, P3 cells were found to be more proliferative than P2 cells under all three culture conditions and to have higher expression of keratin proteins. In addition, when cultured in suspension rather than on adherent surfaces, P3 cells were both more proliferative and had greater gene expression for matrix proteins. Together these results add to the known inherent differences in these stromal cells by characterizing responses to the physical microenvironment. Further, while compaction by P2 cells confirm that collagen gels is a useful model to study wound healing, the response of P3 cells indicate that suspension culture, in which cell-cell interactions dominate like in the blastema, may be better suited to study regeneration. Therefore, this study can help develop clinical strategies for promoting regeneration through increased understanding in the properties of cells involved in endogenous repair as well

  18. DEVELOPMENT OF LOW-COST MANUFACTURING PROCESSES FOR PLANAR, MULTILAYER SOLID OXIDE FUEL CELL ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scott Swartz; Matthew Seabaugh; William Dawson; Harlan Anderson; Tim Armstrong; Michael Cobb; Kirby Meacham; James Stephan; Russell Bennett; Bob Remick; Chuck Sishtla; Scott Barnett; John Lannutti

    2004-06-12

    This report summarizes the results of a four-year project, entitled, ''Low-Cost Manufacturing Of Multilayer Ceramic Fuel Cells'', jointly funded by the U.S. Department of Energy, the State of Ohio, and by project participants. The project was led by NexTech Materials, Ltd., with subcontracting support provided by University of Missouri-Rolla, Michael A. Cobb & Co., Advanced Materials Technologies, Inc., Edison Materials Technology Center, Gas Technology Institute, Northwestern University, and The Ohio State University. Oak Ridge National Laboratory, though not formally a subcontractor on the program, supported the effort with separate DOE funding. The objective of the program was to develop advanced manufacturing technologies for making solid oxide fuel cell components that are more economical and reliable for a variety of applications. The program was carried out in three phases. In the Phase I effort, several manufacturing approaches were considered and subjected to detailed assessments of manufacturability and development risk. Estimated manufacturing costs for 5-kW stacks were in the range of $139/kW to $179/kW. The risk assessment identified a number of technical issues that would need to be considered during development. Phase II development work focused on development of planar solid oxide fuel cell elements, using a number of ceramic manufacturing methods, including tape casting, colloidal-spray deposition, screen printing, spin-coating, and sintering. Several processes were successfully established for fabrication of anode-supported, thin-film electrolyte cells, with performance levels at or near the state-of-the-art. The work in Phase III involved scale-up of cell manufacturing methods, development of non-destructive evaluation methods, and comprehensive electrical and electrochemical testing of solid oxide fuel cell materials and components.

  19. Studies on the finite element simulation in sheet metal stamping processes

    Science.gov (United States)

    Huang, Ying

    The sheet metal stamping process plays an important role in modern industry. With the ever-increasing demand for shape complexity, product quality and new materials, the traditional trial and error method for setting up a sheet metal stamping process is no longer efficient. As a result, the Finite Element Modeling (FEM) method has now been widely used. From a physical point of view, the formability and the quality of a product are influenced by several factors. The design of the product in the initial stage and the motion of the press during the production stage are two of these crucial factors. This thesis focuses on the numerical simulation for these two factors using FEM. Currently, there are a number of commercial FEM software systems available in the market. These software systems are based on an incremental FEM process that models the sheet metal stamping process in small incremental steps. Even though the incremental FEM is accurate, it is not suitable for the initial conceptual design for its needing of detailed design parameters and enormous calculation times. As a result, another type of FEM, called the inverse FEM method or one-step FEM method, has been proposed. While it is less accurate than that of the incremental method, this method requires much less computation and hence, has a great potential. However, it also faces a number of unsolved problems, which limits its application. This motivates the presented research. After the review of the basic theory of the inverse method, a new modified arc-length search method is proposed to find better initial solution. The methods to deal with the vertical walls are also discussed and presented. Then, a generalized multi-step inverse FEM method is proposed. It solves two key obstacles: the first one is to determine the initial solution of the intermediate three-dimensional configurations and the other is to control the movement of nodes so they could only slide on constraint surfaces during the search by

  20. MOLYBDENUM, RUTHENIUM, AND THE HEAVY r-PROCESS ELEMENTS IN MODERATELY METAL-POOR MAIN-SEQUENCE TURNOFF STARS

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Ruth C. [Astrophysical Advances, 607 Marion Place, Palo Alto, CA 94301 (United States)

    2013-05-01

    The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant production mechanisms of light trans-ironic elements were obscure until recently. This work investigates further our 2011 conclusion that the low-entropy regime of a high-entropy wind (HEW) produced molybdenum and ruthenium in two moderately metal-poor turnoff stars that showed extreme overabundances of those elements with respect to iron. Only a few, rare nucleosynthesis events may have been involved. Here we determine abundances for Mo, Ru, and other trans-Fe elements for 28 similar stars by matching spectral calculations to well-exposed near-UV Keck HIRES spectra obtained for beryllium abundances. In each of the 26 turnoff stars with Mo or Ru line detections and no evidence for s-process production (therefore old), we find Mo and Ru to be three to six times overabundant. In contrast, the maximum overabundance is reduced to factors of three and two for the neighboring elements zirconium and palladium. Since the overproduction peaks sharply at Mo and Ru, a low-entropy HEW is confirmed as its origin. The overabundance level of the heavy r-process elements varies significantly, from none to a factor of four, but is uncorrelated with Mo and Ru overabundances. Despite their moderate metallicity, stars in this group trace the products of different nucleosynthetic events: possibly very few events, possibly events whose output depended on environment, metallicity, or time.

  1. Conversion of calcium sulphide to calcium carbonate during the process of recovery of elemental sulphur from gypsum waste

    CSIR Research Space (South Africa)

    De Beer, Morris

    2014-11-01

    Full Text Available of hydrogen sulphide (H(sub2)S) and CaCO(sub3). H(sub2)S can subsequently be converted to elemental sulphur via the commercially available chemical catalytic Claus process. This study investigated the carbonation of CaS by examining both the solution chemistry...

  2. Supplemental specifications of laboratory hot press process -- For CV size self-supported I&E fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, C.A.; Schweikhardt, G.M.

    1964-06-01

    Some refinements have been introduced into the hot press canning of internally and externally cooled fuel elements. This report outlines the specifications for the process including these refinements. Specifications cover components, dies, and punches, furnace condition, nickel plating, component cleaning, component assembly, sizing, hot pressing and inspection.

  3. The Impact of Structural and Process Elements of Pre-school and Primary School Environments on Children's Cognitive Development at Four Years of Age

    OpenAIRE

    Moore, Nodlaig, (Thesis)

    1999-01-01

    The structural and process elements of the early years classroom have contributed to much research in the area of early childhood education. Structural elements have been referred to as regulatable features that are “assumed to indirectly affect the child” (Burchinal, Roberts, Nabors & Bryant et al 1990). Process elements are directly related to children’s experiences and are “more difficult if not impossible to regulate” (Howes, Phillips & Whitebook 1992, p. 480). The structural elements ...

  4. Molybdenum, Ruthenium, and the Heavy r-process Elements in Moderately Metal-Poor Main-Sequence Turnoff Stars

    CERN Document Server

    Peterson, Ruth C

    2013-01-01

    The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant production mechanisms of light trans-ironic elements were obscure until recently. This work investigates further our 2011 conclusion that the low-entropy regime of a high-entropy wind (HEW) produced molybdenum and ruthenium in two moderately metal-poor turnoff stars that showed extreme overabundances of those elements with respect to iron. Only a few, rare nucleosynthesis events may have been involved. Here we determine abundances for Mo, Ru, and other trans-Fe elements for 28 similar stars by matching spectral calculations to well-exposed near-UV Keck HIRES spectra obtained for beryllium abundances. In each of the 26 turnoff stars with Mo or Ru line detections and no evidence for s-process production (therefore old), we find Mo and Ru to be three to six ti...

  5. COST action TD1407: network on technology-critical elements (NOTICE)--from environmental processes to human health threats.

    Science.gov (United States)

    Cobelo-García, A; Filella, M; Croot, P; Frazzoli, C; Du Laing, G; Ospina-Alvarez, N; Rauch, S; Salaun, P; Schäfer, J; Zimmermann, S

    2015-10-01

    The current socio-economic, environmental and public health challenges that countries are facing clearly need common-defined strategies to inform and support our transition to a sustainable economy. Here, the technology-critical elements (which includes Ga, Ge, In, Te, Nb, Ta, Tl, the Platinum Group Elements and most of the rare-earth elements) are of great relevance in the development of emerging key technologies-including renewable energy, energy efficiency, electronics or the aerospace industry. In this context, the increasing use of technology-critical elements (TCEs) and associated environmental impacts (from mining to end-of-life waste products) is not restricted to a national level but covers most likely a global scale. Accordingly, the European COST Action TD1407: Network on Technology-Critical Elements (NOTICE)-from environmental processes to human health threats, has an overall objective for creating a network of scientists and practitioners interested in TCEs, from the evaluation of their environmental processes to understanding potential human health threats, with the aim of defining the current state of knowledge and gaps, proposing priority research lines/activities and acting as a platform for new collaborations and joint research projects. The Action is focused on three major scientific areas: (i) analytical chemistry, (ii) environmental biogeochemistry and (iii) human exposure and (eco)-toxicology.

  6. Improvement of range spatial resolution of medical ultrasound imaging by element-domain signal processing

    Science.gov (United States)

    Hasegawa, Hideyuki

    2017-07-01

    The range spatial resolution is an important factor determining the image quality in ultrasonic imaging. The range spatial resolution in ultrasonic imaging depends on the ultrasonic pulse length, which is determined by the mechanical response of the piezoelectric element in an ultrasonic probe. To improve the range spatial resolution without replacing the transducer element, in the present study, methods based on maximum likelihood (ML) estimation and multiple signal classification (MUSIC) were proposed. The proposed methods were applied to echo signals received by individual transducer elements in an ultrasonic probe. The basic experimental results showed that the axial half maximum of the echo from a string phantom was improved from 0.21 mm (conventional method) to 0.086 mm (ML) and 0.094 mm (MUSIC).

  7. Overabundance of s-process elements in the atmosphere of the active red giant

    CERN Document Server

    Pakhomov, Yu V

    2015-01-01

    Based on high-resolution (R=60000) spectra taken with the NES spectrograph (the 6-m BTA telescope, the Special Astrophysical Observatory of the Russian Academy of Science), we have determined the abundances of 26 elements, from lithium to europium, in the atmosphere of the active red giant PZ Mon, which belongs to the class of RS CVn variable stars, by the method of model stellar atmospheres. We have taken into account the hyperfine splitting, the isotopic shift, and the departure from local thermodynamic equilibrium. Analysis of our data has revealed an overabundance of lithium and neutron-capture elements compared to normal red giants. For lithium, this is explained by the activity of the star, while the overabundance of s-elements is presumably similar in nature to that in moderate barium stars.

  8. A new approach to finite element modeling, analysis and post-processing

    Science.gov (United States)

    White, Gil

    1987-01-01

    Recent advances in both hardware and software have opened the door to a new generation of finite element modeling systems. INTERGRAPH CORP has combined an innovative programming concept with a stand alone workstation hardware platform to produce a new standard in finite element modeling called I/FEM. The system offers the COSMIC NASTRAN user full integration between design and analysis. I/FEM not only addresses the needs of the NASTRAN user of today, it also provides for continued evolution of the COSMIC NASTRAN product.

  9. A Stringent Limit on the Mass Production Rate of $r$-Process Elements in the Milky Way

    CERN Document Server

    Macias, Phillip

    2016-01-01

    We analyze data from several studies of metal-poor stars in the Milky Way, focusing on both strong (Eu) and weak (Sr) $r$-process elements. Because these elements were injected in an explosion, we calculate the mass swept up when the blast wave first becomes radiative, yielding a lower limit for the dilution of such elements and hence a lower limit on the ejecta mass which is incorporated into the next generation of stars. Our study demonstrates that in order to explain the largest enhancements in [Eu/Fe] observed in stars at low [Fe/H] metallicities, individual $r$-process production events must synthesize a minimum of $10^{-3.5} M_{\\odot}$ of $r$-process material. We also show that if the site of Mg production is the same as that of Eu, individual injection events must synthesize up to $ \\sim 10^{-3} M_{\\odot}$ of $r$-process material. On the other hand, demanding that Sr traces Mg production results in $r$-process masses per event of $\\sim 10^{-5} M_{\\odot}$. This suggests that the astrophysical sites resp...

  10. Recent approaches for the direct use of elemental sulfur in the synthesis and processing of advanced materials.

    Science.gov (United States)

    Lim, Jeewoo; Pyun, Jeffrey; Char, Kookheon

    2015-03-09

    Elemental sulfur is an abundant and inexpensive material obtained as a by-product of natural-gas and petroleum refining operations. Recently, the need for the development of new energy-storage systems brought into light the potential of sulfur as a high-capacity cathode material in secondary batteries. Sulfur-containing materials were also shown to have useful IR optical properties. These developments coupled with growing environmental concerns related to the global production of excess elemental sulfur have led to a keen interest in its utilization as a feedstock in materials applications. This Minireview focuses on the recent developments on physical and chemical methods for directly processing elemental sulfur to produce functional composites and polymers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Thermal mechanically coupled finite element analysis in metal-forming processes

    NARCIS (Netherlands)

    Lugt, van der J.; Huetink, J.

    1986-01-01

    A combined Eulerian-Lagrangian finite element formulation is presented for the analysis of metal-forming, coupled with thermal effects. The procedure developed involves incrementally solving a coupled set of equations for both the displacement and the temperature. The material properties may be temp

  12. Hitomi results on the Perseus cluster thermodynamics, elemental abundances, and emission processes

    Science.gov (United States)

    Markevitch, Maxim L.; Hitomi Collaboration

    2017-01-01

    Hitomi SXS spectrum of the Perseus cluster above E=2 keV is a treasure trove of emission lines, most of them seen for the first time from a diffuse source such as the plasma atmosphere of a galaxy cluster. Several trace elements are detected for the first time in the intracluster medium, lines from several key elements, such as S/Ar and Fe/Ni, are disentangled, and sensitivity to faint lines is dramatically higher compared to previous, lower-resolution cluster studies. This allows us to determine accurate relative abundances of heavy elements, a sensitive test for sources of enrichment of the intergalactic medium. For many elements, lines from multiple ions are observed, as well as multiple transitions from the same ion, providing plasma temperature diagnostics previously unavailable for clusters. The brightest line -- the resonant component of the Fe He-alpha triplet -- is found to be affected by resonant scattering. For the most prominent ions, very high-level transitions are observed, placing constraints on such emission mechanisms as charge exchange with cold gas. Finally, we do not observe a previously reported 3.5 keV emission line from the Perseus core and place an upper limit on it.

  13. Thermal mechanically coupled finite element analysis in metal-forming processes

    NARCIS (Netherlands)

    van der Lugt, J.; Huetink, Han

    1986-01-01

    A combined Eulerian-Lagrangian finite element formulation is presented for the analysis of metal-forming, coupled with thermal effects. The procedure developed involves incrementally solving a coupled set of equations for both the displacement and the temperature. The material properties may be

  14. Study of a Compression-Molding Process for Ultraviolet Light-Emitting Diode Exposure Systems via Finite-Element Analysis.

    Science.gov (United States)

    Wu, Kuo-Tsai; Hwang, Sheng-Jye; Lee, Huei-Huang

    2017-06-15

    Although wafer-level camera lenses are a very promising technology, problems such as warpage with time and non-uniform thickness of products still exist. In this study, finite element simulation was performed to simulate the compression molding process for acquiring the pressure distribution on the product on completion of the process and predicting the deformation with respect to the pressure distribution. Results show that the single-gate compression molding process significantly increases the pressure at the center of the product, whereas the multi-gate compressing molding process can effectively distribute the pressure. This study evaluated the non-uniform thickness of product and changes in the process parameters through computer simulations, which could help to improve the compression molding process.

  15. A Subaru/HDS study of Lead (Pb) abundances in eight s-process-element-rich, metal-poor stars

    CERN Document Server

    Aoki, W; Norris, J E; Beers, T C; Ando, H

    2002-01-01

    We report the abundances of neutron-capture elements in eight carbon-rich, metal-poor (-2.7=<[Fe/H]=<-1.9) stars observed with the Subaru Telescope High Dispersion Spectrograph. The derived abundance patterns indicate that the neutron-capture elements in these objects primarily originated from s-process nucleosynthesis, although the [Ba/Eu] abundance ratios in some objects are lower than that of the solar-system s-process component. The present analysis has yielded the Pb abundances for seven objects, as well as an upper limit for one object, from use of the Pb I 4057A and 3683A lines. The values of [Pb/Ba] in these objects cover a wide range, between -0.3 and +1.2. Theoretical studies of s-process nucleosynthesis at low metallicity are required to explain this large dispersion of the [Pb/Ba] values. Variations in radial velocity have been found for two of the eight objects, suggesting that, at least in these instances, the observed excess of s-process elements is due to the transfer of material across ...

  16. Parallel finite element method for modeling two-phase flow processes in porous media using PETSc solver

    Science.gov (United States)

    Wang, W.; Zehner, B.; Böttcher, N.; Goerke, U.; Kolditz, O.

    2013-12-01

    Numerical modeling of the two-phase flow process in porous media for real applications, e.g. CO2 storage processes in saline aquifers, is computationally expensive due to the complexity and the non-linearity of the observed physical processes. In such modeling, a fine discretization of the considered domain is normally needed for a high degree of accuracy, and it leads to the requirement of extremely high computational resources. This work focuses on the parallel simulation of the two-phase flow process in porous media. The Galerkin finite element method is used to solve the governing equations. Based on the overlapping domain decomposition approach, the PETSc package is employed to parallelize the global equation assembly and the linear solver, respectively. A numerical model based on the real test site Ketzin in Germany is adopted for parallel computing. The model domain is discretized with more than four million tetrahedral elements. The parallel simulations are carried out on a Linux cluster with different number of cores. The obtained speedup shows a good scalability of the current parallel finite element approach of the two-phase flow modeling in geological CO2 storage applications.

  17. Stress analysis of the O-element pipe during the process of flue gases purification

    Directory of Open Access Journals (Sweden)

    Nekvasil R.

    2008-11-01

    Full Text Available Equipment for flue gases purification from undesired substances is used throughout power and other types of industry. This paper deals with damaging of the O-element pipe designed to remove sulphur from the flue gases, i.e. damaging of the pipe during flue gases purification. This purification is conducted by spraying the water into the O-shaped pipe where the flue gases flow. Thus the sulphur binds itself onto the water and gets removed from the flue gas. Injection of cold water into hot flue gases, however, causes high stress on the inside of the pipe, which can gradually damage the O-element pipe. In this paper initial injection of water into hot pipe all the way to stabilization of temperature fields will be analyzed and the most dangerous places which shall be considered for fatigue will be determined.

  18. Electrochemical machining process for forming surface roughness elements on a gas turbine shroud

    Science.gov (United States)

    Lee, Ching-Pang; Johnson, Robert Alan; Wei, Bin; Wang, Hsin-Pang

    2002-01-01

    The back side recessed cooling surface of a shroud defining in part the hot gas path of a turbine is electrochemically machined to provide surface roughness elements and spaces therebetween to increase the heat transfer coefficient. To accomplish this, an electrode with insulating dielectric portions and non-insulating portions is disposed in opposition to the cooling surface. By passing an electrolyte between the cooling surface and electrode and applying an electrical current between the electrode and a shroud, roughness elements and spaces therebetween are formed in the cooling surface in opposition to the insulating and non-insulating portions of the electrode, hence increasing the surface area and heat transfer coefficient of the shroud.

  19. On Advantages of the Kelvin Mapping in Finite Element Implementations of Deformation Processes

    CERN Document Server

    Nagel, Thomas; Moerman, Kevin M; Kolditz, Olaf

    2016-01-01

    Classical continuum mechanical theories operate on three-dimensional Eu-clidian space using scalar, vector, and tensor-valued quantities usually up to the order of four. For their numerical treatment, it is common practice to transform the relations into a matrix-vector format. This transformation is usually performed using the so-called Voigt mapping. This mapping does not preserve tensor character leaving significant room for error as stress and strain quantities follow from different mappings and thus have to be treated differently in certain mathematical operations. Despite its conceptual and notational difficulties having been pointed out, the Voigt mapping remains the foundation of most current finite element programmes. An alternative is the so-called Kelvin mapping which has recently gained recognition in studies of theoretical mechanics. This article is concerned with benefits of the Kelvin mapping in numerical modelling tools such as finite element software. The decisive difference to the Voigt mapp...

  20. Finite Element Surface Layer Inheritable Condition Residual Stresses Model in Surface Plastic Deformation Processes

    Science.gov (United States)

    Mahalov, M. S.; Blumenstein, V. Yu

    2016-04-01

    The residual stresses (RS) research and computational algorithms creation in complex types of loading on the product lifecycle stages relevance is shown. The RS forming finite element model at surface plastic deformation strengthening machining, including technological inheritance effect, is presented. A model feature is the production previous stages obtained transformation properties consideration, as well as these properties evolution during metal particles displacement through the deformation space in the present loading step.

  1. Effect of alloying elements on austempered ductile iron (ADI) properties and its process: Review

    OpenAIRE

    Amir Sadighzadeh Benam

    2015-01-01

    Austempered ductile iron (ADI) parts have a unique combination of high strength and toughness with excellent design flexibility and low cost. These excellent properties are directly related to its microstructure called "ausferrite" that is the result of austempering heat treatment applied to ductile irons. Alloying elements increase ADI austemperability and change speeds of austempering reactions. Thus, they can affect ADI resultant microstructure and mechanical properties. In this paper, the...

  2. Enhancing biogas production from vinasse in sugarcane biorefineries: Effects of urea and trace elements supplementation on process performance and stability.

    Science.gov (United States)

    Janke, Leandro; Leite, Athaydes F; Batista, Karla; Silva, Witan; Nikolausz, Marcell; Nelles, Michael; Stinner, Walter

    2016-10-01

    In this study, the effects of nitrogen, phosphate and trace elements supplementation were investigated in a semi-continuously operated upflow anaerobic sludge blanket system to enhance process stability and biogas production from sugarcane vinasse. Phosphate in form of KH2PO4 induced volatile fatty acids accumulation possibly due to potassium inhibition of the methanogenesis. Although nitrogen in form of urea increased the reactor's alkalinity, the process was overloaded with an organic loading rate of 6.1gCODL(-1)d(-1) and a hydraulic retention time of 3.6days. However, by supplementing urea and trace elements a stable operation even at an organic loading rate of 9.6gCODL(-1)d(-1) and a hydraulic retention time of 2.5days was possible, resulting in 79% higher methane production rate with a stable specific methane production of 239mLgCOD(-1).

  3. Conversion of calcium sulphide to calcium carbonate during the process of recovery of elemental sulphur from gypsum waste.

    Science.gov (United States)

    de Beer, M; Maree, J P; Liebenberg, L; Doucet, F J

    2014-11-01

    The production of elemental sulphur and calcium carbonate (CaCO3) from gypsum waste can be achieved by thermally reducing the waste into calcium sulphide (CaS), which is then subjected to a direct aqueous carbonation step for the generation of hydrogen sulphide (H2S) and CaCO3. H2S can subsequently be converted to elemental sulphur via the commercially available chemical catalytic Claus process. This study investigated the carbonation of CaS by examining both the solution chemistry of the process and the properties of the formed carbonated product. CaS was successfully converted into CaCO3; however, the reaction yielded low-grade carbonate products (i.e. 99 mass% as CaCO3) or precipitated calcium carbonate (PCC).

  4. Controlling the leakage of liquid bismuth cathode elements in ceramic crucibles used for the electrowinning process in pyroprocessing

    Science.gov (United States)

    Kim, Dae-Young; Hwang, Il-Soon; Lee, Jong-Hyeon

    2016-09-01

    Pyroprocessing has shown promise as an alternative to wet processing for the recycling of transuranics with a high proliferation resistance. However, a critical issue for pyroprocessing is the ceramic crucibles used in the electrowinning process. These ceramic crucibles are frequently damaged by thermal stress, which results in significant volumes of crucible waste that must be properly disposed. Transuranic waste (TRU) elements intrude throughout the pores of a damaged crucible. The volume of generated radioactive waste is a concern when dealing with nuclear power plants and decontamination issues. In this study, laser treatment and sintering were performed on the crucibles to minimize the TRU elements trapped within. Secondary ion mass spectroscopy was used to measure the intrusion depth of Li in the surface-treated ceramics.

  5. The Analytic Solution of the s-Process for Heavy Element

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, we investigate the net-work equation of s-process. After divide the s-process into twostandard forms, we get the analytic solution of the net-work equation. With our analytic solution, we

  6. Leaching of Light Rare Earth Elements from Sichuan Bastnaesite: A Facile Process to Leach Trivalent Rare Earth Elements Selectively from Tetravalent Cerium

    Science.gov (United States)

    Shen, Yueyue; Jiang, Ying; Qiu, Xianying; Zhao, Shilin

    2017-07-01

    The effects of the nitric acid concentration, leaching time, leaching temperature, and solid-to-liquid ratio on leaching efficiency were examined. From those results, a facile process for the selective leaching of trivalent rare earth elements (RE(III)) from tetravalent cerium (Ce(IV)) was proposed. The roasted bastnaesite was used to leach 34.87% of RE(III) and 2.15% of Ce(IV) at 60°C for 0.5 h with an acid concentration of 0.5 mol/L. This selective leaching process can be described by the shrinking-core model that follows the kinetic model 1 - 2/3α - (1 - α)2/3. Subsequently, the leached slag was hydrothermally treated and followed by thorough leaching with 4.0-mol/L nitric acid. Furthermore, the specific surface area of the final leached slag is 57.7 m2/g, which is approximately 650 times higher than that of raw ore. Finally, selective leaching of RE(III) (>90%) was achieved without using an organic solvent for extraction, whereas lower value Ce(IV)was presented in the leached slag (>92%).

  7. Process for Refining and Validating a Finite Element Model of an Experimental High-Altitude, Long-Endurance (HALE) Aircraft

    Science.gov (United States)

    2011-06-01

    wing. The Finite Element Modeling and post-processing Application (FEMAP) by Siemens PLM Software was utilized for all FE modeling produced for...research were built and tested using FEMAP, a Siemens PLM Software product. An advantage of using a commercial FE tool such as FEMAP is the ease of...static bending analysis using NX NASTRAN was conducted again. The results appeared realistic and closely matched the deflections from the static

  8. Radiation heat transfer model for complex superalloy turbine blade in directional solidification process based on finite element method

    Directory of Open Access Journals (Sweden)

    Dun-ming Liao

    2016-03-01

    Full Text Available For the sake of a more accurate shell boundary and calculation of radiation heat transfer in the Directional Solidification (DS process, a radiation heat transfer model based on the Finite Element Method (FEM is developed in this study. Key technologies, such as distinguishing boundaries automatically, local matrix and lumped heat capacity matrix, are also stated. In order to analyze the effect of withdrawing rate on DS process, the solidification processes of a complex superalloy turbine blade in the High Rate Solidification (HRS process with different withdrawing rates are simulated; and by comparing the simulation results, it is found that the most suitable withdrawing rate is determined to be 5.0 mm昺in-1. Finally, the accuracy and reliability of the radiation heat transfer model are verified, because of the accordance of simulation results with practical process.

  9. Discretisation of the non-linear heat transfer equation for food freezing processes using orthogonal collocation on finite elements

    Directory of Open Access Journals (Sweden)

    E. D. Resende

    2007-09-01

    Full Text Available The freezing process is considered as a propagation problem and mathematically classified as an "initial value problem." The mathematical formulation involves a complex situation of heat transfer with simultaneous changes of phase and abrupt variation in thermal properties. The objective of the present work is to solve the non-linear heat transfer equation for food freezing processes using orthogonal collocation on finite elements. This technique has not yet been applied to freezing processes and represents an alternative numerical approach in this area. The results obtained confirmed the good capability of the numerical method, which allows the simulation of the freezing process in approximately one minute of computer time, qualifying its application in a mathematical optimising procedure. The influence of the latent heat released during the crystallisation phenomena was identified by the significant increase in heat load in the early stages of the freezing process.

  10. Chemo-dynamical evolution model: Enrichment of r-process elements in the Local Group dwarf galaxies

    Science.gov (United States)

    Hirai, Yutaka; Ishimaru, Yuhri; Saitoh, Takayuki R.; Fujii, Michiko S.; Hidaka, Jun; Kajino, Toshitaka

    2016-08-01

    Neutron star mergers are one of the candidate astrophysical site(s) of r-process. Several chemical evolution studies however pointed out that the observed abundance of r-process is difficult to reproduce by neutron star mergers. In this study, we aim to clarify the enrichment of r-process elements in the Local Group dwarf galaxies. We carry out numerical simulations of galactic chemo-dynamical evolution using an N-body/smoothed particle hydrodynamics code, ASURA. We construct a chemo-dynamical evolution model for dwarf galaxies assuming that neutron star mergers are the major source of r-process elements. Our models reproduce the observed dispersion in [Eu/Fe] as a function of [Fe/H] with neutron star mergers with a merger time of 100 Myr. We find that star formation efficiency and metal mixing processes during the first <~ 300 Myr of galaxy evolution are important to reproduce the observations. This study supports that neutron star mergers are a major site of r-process.

  11. Development and demonstration of manufacturing processes for fabricating graphite/LARC 160 polyimide structural elements

    Science.gov (United States)

    Frost, R. K.; Jones, J. S.; Dynes, P. J.; Wykes, D. H.

    1981-01-01

    The development and demonstration of manufacturing technologies for the structural application of Celion graphite/LARC-160 polyimide composite material is discussed. Process development and fabrication of demonstration components are discussed. Process development included establishing quality assurance of the basic composite material and processing, nondestructive inspection of fabricated components, developing processes for specific structural forms, and qualification of processes through mechanical testing. Demonstration components were fabricated. The demonstration components consisted of flat laminates, skin/stringer panels, honeycomb panels, chopped fiber compression moldings, and a technology demonstrator segment (TDS) representative of the space shuttle aft body flap.

  12. A VISUAL BASIC program to pre-process MRI data for finite element modeling.

    Science.gov (United States)

    Todd, B A; Wang, H

    1996-11-01

    Investigators use non-invasive imaging to collect geometric data for finite element models. A preprocessor is described to facilitate model generation of anatomical regions from serial Magnetic Resonance Imaging (MRI) data stored in a bitmap format. The MRI Data Transfer System is a stand-alone Windows-based program developed in VISUAL BASIC 3.0 which generates a NASTRAN input file. The program can be modified to generate input files for other solvers. The software will executive on any IBM-compatible computer which runs Windows Version 3.1 or higher. To demonstrate the software, model generation of a portion of a tibia is described.

  13. Material characterization and finite element simulations of aluminum alloy sheets during non-isothermal forming process

    Science.gov (United States)

    Zhang, Nan

    The utilization of more non-ferrous materials is one of the key factors to succeed out of the constantly increasing demand for lightweight vehicles in automotive sector. Aluminum-magnesium alloys have been identified as the most promising substitutions to the conventional steel without significant compromise in structural stiffness and strength. However, the conventional forming methods to deform the aluminum alloy sheets are either costly or insufficient in formability which limit the wide applications of aluminum alloy sheets. A recently proposed non-isothermal hot stamping approach, which is also referred as Hot Blank - Cold Die (HB-CD) stamping, aims at fitting the commercial grade aluminum alloy sheets, such as AA5XXX and AA7XXX, into high-volume and cost-effective production for automotive sector. In essence, HB-CD is a mutation of the conventional hot stamping approach for boron steel (22MnB5) which deforms the hot blank within the cold tool set. By elevating the operation temperature, the formability of aluminum alloy sheets can be significantly improved. Meanwhile, heating the blank only and deforming within the cold tool sets allow to reduce the energy and time consumed. This research work aims at conducting a comprehensive investigation of HB-CD with particular focuses on material characterization, constitutive modeling and coupled thermo-mechanical finite element simulations with validation. The material properties of AA5182-O, a popular commercial grade of aluminum alloy sheet in automotive sector, are obtained through isothermal tensile testing at temperatures from 25° to 300°, covering a quasi-static strain-rate range (0.001--0.1s-1). As the state-of-the-art non-contact strain measurement technique, digital image correlation (DIC) system is utilized to evaluate the stress-strain curves as well as to reveal the details of material deformation with full-field and multi-axis strain measurement. Material anisotropy is characterized by extracting the

  14. Influence of near-edge processes in the elemental analysis using X-ray emission-based techniques

    Indian Academy of Sciences (India)

    Gurjeet Singh; Sunil Kumar; N Singh; J Goswamy; D Mehta

    2011-02-01

    The near-edge processes, such as X-ray absorption fine structure (XAFS) andresonant Raman scattering (RRS), are not incorporated in the available theoretical attenuation coefficients, which are known to be reliable at energies away from the shell/subshell ionization thresholds of the attenuator element. Theoretical coefficients are generally used to estimate matrix corrections in routine quantitative elemental analysis based on various X-ray emission techniques. A tabulation of characteristic X-ray energies across the periodic table is provided where those X-rays are expected to alter the attenuation coefficients due to XAFS from a particular shell/subshell of the attenuator element. The influence of XAFS to the attenuation coefficient depends upon the atomic environment and the photoelectron wave vector, i.e., difference in energies of incident X-ray and the shell/subshell ionization threshold of the attenuator element. Further, the XAFS at a shell/subshell will significantly alter the total attenuation coefficient if the jump ratio at that shell/subshell is large, e.g., the K shell, L3 subshell and M5 subshell. The tabulations can be considered as guidelines so as to know what can be expected due to XAFS in typical photon-induced X-ray emission spectrometry.

  15. Finite Element Modeling of Thermo Creep Processes Using Runge-Kutta Method

    Directory of Open Access Journals (Sweden)

    Yu. I. Dimitrienko

    2015-01-01

    Full Text Available Thermo creep deformations for most heat-resistant alloys, as a rule, nonlinearly depend on stresses and are practically non- reversible. Therefore, to calculate the properties of these materials the theory of plastic flow is most widely used. Finite-element computations of a stress-strain state of structures with account of thermo creep deformations up to now are performed using main commercial software, including ANSYS package. However, in most cases to solve nonlinear creep equations, one should apply explicit or implicit methods based on the Euler method of approximation of time-derivatives. The Euler method is sufficiently efficient in terms of random access memory in computations, however this method is cumbersome in computation time and does not always provide a required accuracy for creep deformation computations.The paper offers a finite-element algorithm to solve a three-dimensional problem of thermo creep based on the Runge-Kutta finite-difference schemes of different orders with respect to time. It shows a numerical test example to solve the problem on the thermo creep of a beam under tensile loading. The computed results demonstrate that using the Runge-Kutta method with increasing accuracy order allows us to obtain a more accurate solution (with increasing accuracy order by 1 a relative error decreases, approximately, by an order too. The developed algorithm proves to be efficient enough and can be recommended for solving the more complicated problems of thermo creep of structures.

  16. Optical signal processing of video surveillance for recognizing and measurement location railway infrastructure elements

    Science.gov (United States)

    Diyazitdinov, Rinat R.; Vasin, Nikolay N.

    2016-03-01

    Processing of optical signals, which are received from CCD sensors of video cameras, allows to extend the functionality of video surveillance systems. Traditional video surveillance systems are used for saving, transmitting and preprocessing of the video content from the controlled objects. Video signal processing by analytics systems allows to get more information about object's location and movement, the flow of technological processes and to measure other parameters. For example, the signal processing of video surveillance systems, installed on carriage-laboratories, are used for getting information about certain parameters of the railways. Two algorithms for video processing, allowing recognition of pedestrian crossings of the railways, as well as location measurement of the so-called "Anchor Marks" used to control the mechanical stresses of continuous welded rail track are described in this article. The algorithms are based on the principle of determining the region of interest (ROI), and then the analysis of the fragments inside this ROI.

  17. The Abundances of Light Neutron-Capture Elements in Planetary Nebulae II. s-process Enrichments and Interpretation

    CERN Document Server

    Sterling, N C

    2007-01-01

    We present the results of a large-scale survey of neutron(n)-capture elements in Galactic planetary nebulae (PNe), undertaken to study enrichments from s-process nucleosynthesis in their progenitor stars. From new K band observations of over 100 PNe supplemented by data from the literature, we have detected the emission lines [Kr III] 2.199 and/or [Se IV] 2.287 $\\mu$m in 81 of 120 objects. We determine Se and Kr elemental abundances, employing ionization correction formulae derived in the first paper of this series. We find a significant range in Se and Kr abundances, from near solar (no enrichment) to enhanced by >1.0 dex relative to solar, which we interpret as self-enrichment due to in situ s-process nucleosynthesis. Kr tends to be more strongly enriched than Se; in 18 objects exhibiting both Se and Kr emission, we find that [Kr/Se] = 0.5$\\pm$0.2. Our survey has increased the number of PNe with n-capture element abundance determinations by a factor of ten, enabling us for the first time to search for corre...

  18. Development of the manufacture and process for DUPIC fuel elements; development of the quality evaluation techniques for end cap welds of DUPIC fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Tae; Choi, Myong Seon; Yang, Hyun Tae; Kim, Dong Gyun; Park, Jin Seok; Kim, Jin Ho [Yeungnam University, Kyongsan (Korea)

    2002-04-01

    The objective of this research is to set up the quality evaluation techniques for end cap welds of DUPIC fuel element. High temperature corrosion test and the SCC test for Zircaloy-4 were performed, and also the possibility of the ultrasonic test technique was verified for the quality evaluation and control of the laser welds in the DUPIC fuel rod end cap. From the evaluation of corrosion properties with measuring the weight gain and observing oxide film of the specimen that had been in the circumstance of steam(400 .deg. C, 1,500 psi) by max. 70 days later, the weight gain of the welded specimens was larger than original tube and the weight increasing rate increased with the exposed days. For the Development of techniques for ultrasonic test, semi-auto ultrasonic test system has been made based on immersion pulse-echo technique using spherically concentrated ultrasonic beam. Subsequently, developed ultrasonic test technique is quite sensible to shape of welds in the inside and outside of tube as well as crack, undercut and expulsion, and also this ultrasonic test, together with metallurgical fracture test, has good reliance as enough to be used for control method of welding process. 43 refs., 47 figs., 8 tabs. (Author)

  19. Importance of Relativistic Effects for Intermediate-Z Elements:Photoionization Process of Excited Na

    Institute of Scientific and Technical Information of China (English)

    HAN Xiao-Ying; WANG Xiao-Lu; VOKY Lan; FEAUTRIER Nicole; LI Jia-Ming

    2007-01-01

    Using a modified R-matrix code,the fine-structure-resolved partial photoionization cross sections of excited Na (Z=11)are calculated within the Breit-Pauli approximation.Our calculated energy levels of Na+ and Na are in good agreement with the experimental values within 1% and the branching ratios of the J-resolved partial cross sections are consistent with the recent measurements within the experimental uncertainties.The agreements are impossible to be obtained without adequately taking into account the relativistic effects and the electron correlations together.Therefore,even for the intermediate-Z elements(e.g.Na with Z=11),the relativistic effects(mainly the spjn-orbit interactions)should not be neglected.

  20. Cis-regulatory elements: molecular mechanisms and evolutionary processes underlying divergence.

    Science.gov (United States)

    Wittkopp, Patricia J; Kalay, Gizem

    2011-12-06

    Cis-regulatory sequences, such as enhancers and promoters, control development and physiology by regulating gene expression. Mutations that affect the function of these sequences contribute to phenotypic diversity within and between species. With many case studies implicating divergent cis-regulatory activity in phenotypic evolution, researchers have recently begun to elucidate the genetic and molecular mechanisms that are responsible for cis-regulatory divergence. Approaches include detailed functional analysis of individual cis-regulatory elements and comparing mechanisms of gene regulation among species using the latest genomic tools. Despite the limited number of mechanistic studies published to date, this work shows how cis-regulatory activity can diverge and how studies of cis-regulatory divergence can address long-standing questions about the genetic mechanisms of phenotypic evolution.

  1. Parallel readout of two-element CdZnTe detectors with real-time digital signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Shi Zhubin; Wang Linjun; Qin Kaifeng; Min Jiahua; Zhang Jijun; Liang Xiaoyan; Huang Jian; Tang Ke; Xia Yiben, E-mail: ljwang@shu.edu.cn [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

    2010-12-15

    Readout electronics, especially digital electronics, for two-element CdZnTe (CZT) detectors in parallel are developed. The preliminary results show the detection efficiency of the two-element CZT detectors in parallel with analog electronics is as many as 1.8 and 2.1 times the single ones, and the energy resolution (FWHM) is limited by that of the single one by the means of analog electronics. However, the digital method for signal processing will be sufficiently better by contrast with an analog method especially in energy resolution. The energy resolution by the means of digital electronics can be improved by about 26.67%, compared to that only with analog electronics, while their detection efficiency is almost the same. The cause for this difference is also discussed. (semiconductor devices)

  2. SEMICONDUCTOR DEVICES Parallel readout of two-element CdZnTe detectors with real-time digital signal processing

    Science.gov (United States)

    Zhubin, Shi; Linjun, Wang; Kaifeng, Qin; Jiahua, Min; Jijun, Zhang; Xiaoyan, Liang; Jian, Huang; Ke, Tang; Yiben, Xia

    2010-12-01

    Readout electronics, especially digital electronics, for two-element CdZnTe (CZT) detectors in parallel are developed. The preliminary results show the detection efficiency of the two-element CZT detectors in parallel with analog electronics is as many as 1.8 and 2.1 times the single ones, and the energy resolution (FWHM) is limited by that of the single one by the means of analog electronics. However, the digital method for signal processing will be sufficiently better by contrast with an analog method especially in energy resolution. The energy resolution by the means of digital electronics can be improved by about 26.67%, compared to that only with analog electronics, while their detection efficiency is almost the same. The cause for this difference is also discussed.

  3. Design of Production Test IP-262-A-11-FP -- Evaluation of projection fuel elements for use in ribbed process tubes -- Demonstration loading

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, W.H.; Hall, R.E.

    1959-06-29

    For several years, a major category of fuel element failures has been the side corrosion type, characterized by localized accelerated fuel element jacket corrosion. Since it has been demonstrated {sup 1} that misalignment of fuel elements in a process tube will produce flow patterns and accelerated corrosion, termed ``hot spots``, failure to align the fuel elements in process tubes is considered a contributing factor in the production of side corrosion failures. Preliminary testing of both self-supporting and ``bumper`` fuel elements is underway. Data on the self-supporting fuel elements have demonstrated that the bridge-rail projections have sufficient support strength, do not of themselves create a corrosion problem and in actuality probably eliminate any hot-spot areas. Although one tube of bumper fuel elements in KW Reactor {sup 3} has been discharged, data are not as yet available. Potentially, the most sever corrosion conditions exist during the summer months when reactor inlet temperatures are high. It is desirable then, provided bumper fuel elements limit hot- spot corrosion, to evaluate the bumper concept for large scale use possibly by the summer of 1960. To accomplish this, a demonstration loading of the bumper type fuel elements must be underway by about July, 1959. The purpose of this report is to present the design of a test to evaluate the fabrication process and irradiation performance of fuel elements having projections, which may prevent misalignment in ribbed process tubes and meet the aforementioned goals.

  4. Analysis of the laser powder bed fusion additive manufacturing process through experimental measurement and finite element modeling

    Science.gov (United States)

    Dunbar, Alexander Jay

    The objective in this work is to provide rigourous experimental measurements to aid in the development of laser powder bed fusion (LPBF) additive manufacturing (AM). A specialized enclosed instrumented measurement system is designed to provide in situ experimental measurements of temperature and distortion. Experiments include comparisons of process parameters, materials and LPBF machines. In situ measurements of distortion and temperature made throughout the build process highlight inter-layer distortion effects previously undocumented for laser powder bed fusion. Results from these experiments are also be implemented in the development and validation of finite element models of the powder bed build process. Experimental analysis is extended from small-scale to larger part-scale builds where experimental post-build measurements are used in analysis of distortion profiles. Experimental results provided from this study are utilized in the validation of a finite element model capable of simulating production scale parts. The validated finite element model is then implemented in the analysis of the part to provide information regarding the distortion evolution process. A combination of experimental measurements and simulation results are used to identify the mechanism that results in the measured distortion profile for this geometry. Optimization of support structure primarily focuses on the minimization of material use and scan time, but no information regarding failure criteria for support structure is available. Tensile test samples of LPBF built support structure are designed, built, and tested to provide measurements of mechanical properties of the support structure. Experimental tests show that LPBF built support structure has only 30-40% of the ultimate tensile strength of solid material built in the same machine. Experimental measurement of LPBF built support structure provides clear failure criteria to be utilized in the future design and implementation of

  5. Parametric Finite Element Analysis for a square cup deep drawing process

    OpenAIRE

    F. Ayari; E. Bayraktar

    2011-01-01

    Purpose: This manuscript deals with the FEA of the sheet metal forming process that involves various nonlinearities. Our objective is to develop a parametric study that can leads mainly to predict accurately the final geometry of the sheet blank and the distribution of strains and stresses and also to control various forming defects, such as thinning as well as parameters affecting strongly the final form of the sheet after forming process.Design/methodology/approach: The main approach of the...

  6. Finite Element Analysis of Symmetric and Asymmetric Three-roll Rolling Process

    Directory of Open Access Journals (Sweden)

    Pesin A.

    2015-01-01

    Full Text Available A three-roll process is a significant technique in the production of wire rod, round bars and hexagonal profiles for structural applications. Better mechanical properties of wire rod, round bars and hexagonal profiles can be achieved due to large plastic deformation by the three-roll process. Asymmetric rolling is a novel technique characterised by a kinematic asymmetry linked to the difference in peripheral speed of the rolls, able to introduce additional shear strains through the bar thickness. In order to achieve this, asymmetrical three-roll rolling process was investigated to better control the deformation compared to the conventional three-roll rolling process in a stand with two three-roll calibers located very close to each other. Simulation of round-triangle-triangle pass rolling was performed. FEM simulations were carried out with using software DEFORM 3D. The influence of the friction coefficient and speed asymmetry on the shear strain and material flow was discussed. The results of simulation can be used to optimize the asymmetric three-roll rolling process to improve the mechanical properties of wire rod, round bars and hexagonal profiles.

  7. HEXAHEDRAL ELEMENT REFINEMENT FOR THE PREDICTION-CORRECTION ALE FEM SIMULATION OF 3D BULKING FORMING PROCESS

    Institute of Scientific and Technical Information of China (English)

    J. Chen; Y.X. Wang; W.P. Dong; X.Y. Ruan

    2004-01-01

    Based on the characteristics of 3D bulk forming process, the arbitrary Lagrangian-Eulerian (ALE)formulation-based FEM is studied, and a prediction-correction ALE-based FEM is proposed which integrates the advantages of precisely predicting the boundary configuration of the deformed material, and of efficiently avoiding hexahedron remeshing processes. The key idea of the prediction-correction ALE FEM is elaborated in detail. Accordingly, the strategy of mesh quality control, one of the key enabling techniques for the 3D bulk forming process numerical simulation by the prediction-correction ALE FEM is carefully investigated, and the algorithm for hexahedral element refinement is formulated based on the mesh distortion energy.

  8. Mathematical Modeling, Simulation and Optimization for Selected Robotic Processes related to Manufacturing of Unique Concrete Elements

    DEFF Research Database (Denmark)

    Cortsen, Jens

    Denne afhandling præsenterer vores arbejde i det danske projekt Unique Concrete Structures (Unikabeton) and EU projekt TailorMade Concrete Structures (TailorCrete) med at automatisere udvalgte processer for konstruktion af unike beton bygninger. Vi har primært fokus på robotfræsning af komplekse...... produktionstiden. De to mindre processer som varmetråd skæring af EPS blokke før fræsning og sprøjtning af slipmiddel på de færdige formwork blokke er også præsenteret efter de to hoved processer. Til sidst præsenterer vi en række af real life betonstrukturer baseret på vores arbejde i denne afhandling...

  9. 3D finite elements method (FEM Analysis of basic process parameters in rotary piercing mill

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2012-10-01

    Full Text Available In this paper 3D FEM analysis of process parameters and its infl uence in rotary piercing mill is presented. The FEM analyze of the rotary piercing process was made under the conditions of 3D state of strain with taking into consideration the thermal phenomena. The calculations were made with application of different rolls’ skew angles and different plug designs. In the result, progression of shapes, temperature and distributions of stress and strain were characterized. The numerical results of calculations were compared with results of stand test with use of 100Cr6 steel. The comparisons of numerical and experimental tests confirm good agreement between obtained results.

  10. Fabrication of continuous diffractive optical elements using a fast tool servo diamond turning process

    Science.gov (United States)

    Zhou, Jingbo; Li, Lei; Naples, Neil; Sun, Tao; Yi, Allen Y.

    2013-07-01

    Continuous diffractive optical elements (CDOEs) can be used for laser-beam reshaping, pattern generation and can help reduce large angle scattering. Lithography, the method for the production of binary diffractive surfaces, is not suitable for fabrication of CDOEs. Diamond turning using fast tool servo, on the other hand, is a non-cleanroom method for generating continuous microstructures with high precision and efficiency. In this paper, an algorithm for designing CDOEs is introduced. The moving least-squares (MLS) method is then used to obtain the local fitting equation of the diffractive surface. Based on the MLS fitting equation, the selection of diamond cutting tool geometries (including the tool nose radius, rake angle and clearance angle) is discussed and a tool nose radius compensation algorithm is included. This algorithm is a general method for the diamond turning of complex surfaces that can be represented by a point cloud. Surface measurements and diffractive patterns generated on test samples have shown that continuous diffractive surfaces were successfully machined. In the future, CDOEs can be machined on an optical mold surface for high-volume industrial production using methods such as injection molding.

  11. Estimation of suppliers as an important element of the rationalization of supply processes – case study

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available To increase the efficiency of the business in times of the globalization and increasing competition, the management of the companies looks for opportunities to achieve higher incomes or to reduce the costs of inputs. One of possible methods to obtain higher efficiency is to put the emphasize on the relationships with suppliers. This is very important element of an effective management of the company, because by determining the economical conditions of the cooperation, it is possibly to reduce the cost of business activities. The reliable classification of the suppliers is depended on the level of the detail of an assessment criteria and the scoring method. The main problem is the risk of the objective estimation of individual offers received from the suppliers. For this reason, the classification of suppliers is one of the key problems of the logistics controlling. Based on practical example, this paper presents the complexity of the problem of the classifications and the selection of suppliers according to different hierarchy of the importance of various criteria.

  12. Impact of Measuring Part Elements of Transformer Differential Protection on Input Signal Processing

    Directory of Open Access Journals (Sweden)

    Andreev M.V

    2017-08-01

    Full Text Available The electric power system (EPS is a large, multi-parameter, non-linear and dynamic system. The problem of calculation of relay protection (RP settings has become more urgent nowadays. The situation is exacerbated by the active implementation of renewable energy sources, FACTS, etc., which significantly change the “traditional” EPS and their operating modes. The problem can be solved by deep analysis of functioning of main elements of RP devices in the specific operating conditions and revision of coefficients used in settings calculation. That can be done using RPs detailed mathematical models and modern EPS simulators. The results of the analysis will make it possible to formulate a new methodology for setting up RP. That is a final goal. In the framework of solving this problem, the novel approach for developing RPs’ detailed mathematical models is formulated and theoretically proved. On the basis of this approach, mathematical models of the system “instrumental transformer - auxiliary transformer - analog filter” (measuring part of digital transformer differential protection for different types of auxiliary current transformers (active and passive and filters (Butterworth, Chebyshev, Bessel are developed. A comparative numerical analysis of their frequency and phase responses is carried out, including taking into account the magnetization of instrumental current transformers. Summarizing, the theoretical and practical studies presented in the article allows formulating requirements for RPs’ detailed mathematical models, which will be used in the further research.

  13. Elemental Mapping of Perovskite Solar Cells by Using Multivariate Analysis: An Insight into Degradation Processes.

    Science.gov (United States)

    Cacovich, Stefania; Divitini, Giorgio; Ireland, Christopher; Matteocci, Fabio; Di Carlo, Aldo; Ducati, Caterina

    2016-09-22

    The technology of perovskite-based solar cells is evolving rapidly, reaching certified power conversion efficiency values now exceeding 20 %. One of the main drawbacks hindering progress in the field is the long-term stability of the cells: the mixed halide perovskites used in most devices are sensitive to humidity and degrade on a timescale varying from hours to weeks. The degradation mechanisms are poorly understood, but likely arise from combined physical and chemical modifications at the nanometer scale. The characterization of pristine and degraded materials is difficult owing to their complex chemical and physical structure and their relatively poor stability. In this work, we investigated the changes in local composition and morphology of a standard device after 2 months of air exposure in the dark, using scanning transmission electron microscopy (STEM) with nanometer resolution for imaging and analysis. Because of a state-of-the-art technique that combines STEM and energy dispersive X-ray spectroscopy (EDX), and the use of different decomposition algorithms for multivariate analysis, we highlighted the migration of elements across the interfaces between the layers comprising the device. We also noticed a morphological degradation of the hole-transporting layer (HTL), representing one of the main factors enabling the infiltration of moisture in the device, which results in reduced performance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A study of the Apollo aqueous redox process for converting hydrogen sulfide in biogas to elemental sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Ellenor, D.T.

    2004-07-01

    An experimental study was conducted to develop a commercial biogas scrubber for municipal and agricultural use. The specific objectives were to provide design and scaling parameters that would improve the performance while minimizing the capital and operating costs of the biogas scrubber; provide a useful reaction model of the aqueous phase iron chelate catalyzed oxide of hydrogen sulfide to elemental sulfur; develop hypotheses and determine what data are of relevance in comprehending the interfacial phenomena of colloidal sulfur in aqueous solutions that could result in unwanted sulfur deposition and poor sulfur quality; obtain interfacial chemistry data that could improve the understanding of how sulfur particles behave during flocculation and deposition on surfaces, and the factors that lead to poor surface quality; and, determine whether crystal size and characteristics of deposited and flocculated sulfur could be changed by surfactants to enhance sulfur purity and reduce process operability. Interfacial chemistry experiments were performed to determine the factors that influence the operating problems and poor quality associated with the sulfur product. Results suggest that a low foaming nonionic surfactant can improve the quality and processability of the elemental sulfur product. It was concluded that the addition of surfactant to the redox solution reduces the mean hydrogen removal efficiency of the process. The addition of surfactants also decreases the mean particle size of the precipitated sulfur product, but increases the purity of the precipitated product. This study contributed to the successful installation by Apollo Environmental Systems of a commercial biogas scrubber that is very resistant to sulfur plugging.

  15. Finite element analysis on multi-step rolling process and controlling quality defect for steel wheel rim

    Directory of Open Access Journals (Sweden)

    Ping Lu

    2015-07-01

    Full Text Available To conduct an in-depth analysis of the wheel rim forming processes and effectively control rim forming quality defects, three-dimensional elastic–plastic finite element models of flaring and three rolling processes for 22.5 × 9.0-type steel wheel rim were established using ABAQUS software. Some key techniques in establishing models were investigated, such as methods of imposing boundary condition given by side guide wheels and enforcing load curve. The accuracy of the models was verified by comparing the simulation results with the point-cloud model of the actual produced rim in terms of exterior shape and thickness. Distributions and changes in the equivalent stress and equivalent plastic strain were analysed. The results indicate that the rim misalignment defect often occurs when the unequal width of the reserved material at the two ends of the rim is in the first rolling process. An improved die design is proposed. The results of the finite element analysis indicate that the improved dies are conducive to the flow of the material between the gap of the upper roller and the lower roller, and the difference in the rim width is significantly reduced.

  16. The Information Search Process: A Study of Elements Associated with Meaningful Research Tasks.

    Science.gov (United States)

    Garland, Kathleen

    1995-01-01

    Describes a study that investigated research projects at a secondary professional development school to determine successful task factors. Results show that student choice of topic, group work, topics related to course content, clear communication by teachers of goals and evaluation methods, and process instruction were related to student…

  17. Integrating Literature with Craft in a Learning Process with Creative Elements

    Science.gov (United States)

    Aerila, Juli-Anna; Rönkkö, Marja-Leena

    2015-01-01

    Art-related learning should be the central way of doing and playing in preschool, because the high quality of art-related education has a positive effect on children's well-being, identity development, and creative thinking. In our study we tested an integrated learning process where reading literature and telling stories is combined with the…

  18. Heterotrophic and elemental-sulfur-based autotrophic denitrification processes for simultaneous nitrate and Cr(VI) reduction.

    Science.gov (United States)

    Sahinkaya, Erkan; Kilic, Adem

    2014-03-01

    Nitrate and chromate can be present together in water resources as nitrate is a common co-contaminant in surface and ground waters. This study aims at comparatively evaluating simultaneous chromate and nitrate reduction in heterotrophic and sulfur-based autotrophic denitrifying column bioreactors. In sulfur-based autotrophic denitrification process, elemental sulfur and nitrate act as an electron donor and an acceptor, respectively, without requirement of organic supplementation. Autotrophic denitrification was complete and not adversely affected by chromate up to 0.5 mg/L. Effluent chromate concentration was water treatment due to the elimination of organic supplementation and the risk of treated effluent contamination.

  19. Rare earth elements as indicators of hydrothermal processes within the East Scotia subduction zone system

    Science.gov (United States)

    Cole, Catherine S.; James, Rachael H.; Connelly, Douglas P.; Hathorne, Ed C.

    2014-09-01

    The East Scotia subduction zone, located in the Atlantic sector of the Southern Ocean, hosts a number of hydrothermal sites in both back-arc and island-arc settings. High temperature (>348 °C) 'black smoker' vents have been sampled at three locations along segments E2 and E9 of the East Scotia back-arc spreading ridge, as well as 'white smoker' (Mg = 0 mmol/kg) is markedly different, with pH ranging from andesite-hosted, providing an ideal opportunity for investigating the geochemical controls on rare earth element (REE) behaviour. Endmember hydrothermal fluids from E2 and E9 have total REE concentrations ranging from 7.3 to 123 nmol/kg, and chondrite-normalised distribution patterns are either light REE-enriched (LaCN/YbCN = 12.8-30.0) with a positive europium anomaly (EuCN/Eu∗CN = 3.45-59.5), or mid REE-enriched (LaCN/NdCN = 0.61) with a negative Eu anomaly (EuCN/Eu∗CN = 0.59). By contrast, fluids from the Kemp Caldera have almost flat REE patterns (LaCN/YbCN = 2.1-2.2; EuCN/Eu∗CN = 1.2-2.2). We demonstrate that the REE geochemistry of fluids from the East Scotia back-arc spreading ridge is variably influenced by ion exchange with host minerals, phase separation, competitive complexation with ligands, and anhydrite deposition, whereas fluids from the Kemp submarine volcano are also affected by the injection of magmatic volatiles which enhances the solubility of all the REEs. We also show that the REE patterns of anhydrite deposits from Kemp differ from those of the present-day fluids, potentially providing critical information about the nature of hydrothermal activity in the past, where access to hydrothermal fluids is precluded.

  20. Advanced finite element analysis of die wear in sheet-bulk metal forming processes

    Science.gov (United States)

    Behrens, Bernd-Arno; Bouguecha, Anas; Vucetic, Milan; Chugreev, Alexander; Rosenbusch, Daniel

    2016-10-01

    The novel sheet-bulk metal forming (SBMF) technology allows the production of solid metal components with various functional design features out of flat sheet specimens. However, due to the high working pressures arising during the forming process the efficiency of SBMF is tightly related to the tool service life, which is mainly limited by die wear. In the forming processes involving high contact pressures (e.g. SBMF) the influence of contact normal stresses on the die wear can be overestimated. In order to provide a realistic estimation of the die wear, the shear friction stress must be considered. The presented paper introduces a die wear model that intends the tangential component of contact stress and its implementation in the commercial FE code.

  1. Integrating the human element into the systems engineering process and MBSE methodology.

    Energy Technology Data Exchange (ETDEWEB)

    Tadros, Michael Samir.

    2013-12-01

    In response to the challenges related to the increasing size and complexity of systems, organizations have recognized the need to integrate human considerations in the beginning stages of systems development. Human Systems Integration (HSI) seeks to accomplish this objective by incorporating human factors within systems engineering (SE) processes and methodologies, which is the focus of this paper. A representative set of HSI methods from multiple sources are organized, analyzed, and mapped to the systems engineering Vee-model. These methods are then consolidated and evaluated against the SE process and Models-Based Systems Engineering (MBSE) methodology to determine where and how they could integrate within systems development activities in the form of specific enhancements. Overall conclusions based on these evaluations are presented and future research areas are proposed.

  2. HD 187885 and s-process elements in high galactic latitude supergiants

    NARCIS (Netherlands)

    VanWinckel, H; Waelkens, C; Waters, LBFM

    1996-01-01

    We present an accurate LTE chemical analysis of HD 187885 on the basis of high-resolution, high signal-to-noise spectra. The low iron abundance of [Fe/H] = -0.5 confirms the old, low-mass nature of the supergiant. With [C/Fe] = +0.9, [N/Fe] = +0.7, [O/Fe] = +0.6 and above all the high s-process elem

  3. HD 187885 and s-process elements in high galactic latitude supergiants

    NARCIS (Netherlands)

    VanWinckel, H; Waelkens, C; Waters, LBFM

    We present an accurate LTE chemical analysis of HD 187885 on the basis of high-resolution, high signal-to-noise spectra. The low iron abundance of [Fe/H] = -0.5 confirms the old, low-mass nature of the supergiant. With [C/Fe] = +0.9, [N/Fe] = +0.7, [O/Fe] = +0.6 and above all the high s-process

  4. Laser and Surface Processes of NiTi Shape Memory Elements for Micro-actuation

    Science.gov (United States)

    Nespoli, Adelaide; Biffi, Carlo Alberto; Previtali, Barbara; Villa, Elena; Tuissi, Ausonio

    2014-04-01

    In the current microtechnology for actuation field, shape memory alloys (SMA) are considered one of the best candidates for the production of mini/micro devices thanks to their high power-to-weight ratio as function of the actuator weight and hence for their capability of generating high mechanical performance in very limited spaces. In the microscale the most suitable conformation of a SMA actuator is given by a planar wavy formed arrangement, i.e., the snake-like shape, which allows high strokes, considerable forces, and devices with very low sizes. This uncommon and complex geometry becomes more difficult to be realized when the actuator dimensions are scaled down to micrometric values. In this work, micro-snake-like actuators are laser machined using a nanosecond pulsed fiber laser, starting from a 120- μm-thick NiTi sheet. Chemical and electrochemical surface polishes are also investigated for the removal of the thermal damages of the laser process. Calorimetric and thermo-mechanical tests are accomplished to assess the NiTi microdevice performance after each step of the working process. It is shown that laser machining has to be followed by some post-processes in order to obtain a micro-actuator with good thermo-mechanical properties.

  5. Transport and mixing of r-process elements in neutron star binary merger blast waves

    CERN Document Server

    Montes, Gabriela; Naiman, Jill; Shen, Sijing; Lee, William H

    2016-01-01

    The r-process nuclei are robustly synthesized in the material ejected during a neutron star binary merger (NSBM), as tidal torques transport angular momentum and energy through the outer Lagrange point in the form of a vast tidal tail. If NSBM are indeed solely responsible for the solar system r- process abundances, a galaxy like our own would require to host a few NSBM per million years, with each event ejecting, on average, about 5x10^{-2} M_sun of r-process material. Because the ejecta velocities in the tidal tail are significantly larger than in ordinary supernovae, NSBM deposit a comparable amount of energy into the interstellar medium (ISM). In contrast to extensive efforts studying spherical models for supernova remnant evolution, calculations quantifying the impact of NSBM ejecta in the ISM have been lacking. To better understand their evolution in a cosmological context, we perform a suite of three-dimensional hydrodynamic simulations with optically-thin radiative cooling of isolated NSBM ejecta expa...

  6. Numerical Simulation of Evacuation Process in Malaysia By Using Distinct-Element-Method Based Multi-Agent Model

    Science.gov (United States)

    Abustan, M. S.; Rahman, N. A.; Gotoh, H.; Harada, E.; Talib, S. H. A.

    2016-07-01

    In Malaysia, not many researches on crowd evacuation simulation had been reported. Hence, the development of numerical crowd evacuation process by taking into account people behavioral patterns and psychological characteristics is crucial in Malaysia. On the other hand, tsunami disaster began to gain attention of Malaysian citizens after the 2004 Indian Ocean Tsunami that need quick evacuation process. In relation to the above circumstances, we have conducted simulations of tsunami evacuation process at the Miami Beach of Penang Island by using Distinct Element Method (DEM)-based crowd behavior simulator. The main objectives are to investigate and reproduce current conditions of evacuation process at the said locations under different hypothetical scenarios for the efficiency study of the evacuation. The sim-1 is initial condition of evacuation planning while sim-2 as improvement of evacuation planning by adding new evacuation area. From the simulation result, sim-2 have a shorter time of evacuation process compared to the sim-1. The evacuation time recuded 53 second. The effect of the additional evacuation place is confirmed from decreasing of the evacuation completion time. Simultaneously, the numerical simulation may be promoted as an effective tool in studying crowd evacuation process.

  7. Modelling a Skin-Pass Rolling Process by Means of Data Mining Techniques and Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    R Escribano; R Lostado; F J Martlnezde-Pison; A Pernla; E Vergara

    2012-01-01

    An experience is presented using the finite element method (FEM) and data mining (DM) techniques to develop models that can be used to optimieze the skin-pass rolling process based on its operating conditions. A FE model based on a real skin-pass process is built and validated. Based on this model, a group of FE models is simulated with different adjustment parameters and with different materials for the sheet; both variables are chosen from pre-set ranges, From all FE model simulations, a database is generated; this database is made up of the above mentioned adjustment parameters, sheet properties and the variables of the process arising from the simulation of the model. Various types of data mining algorithms are used to develop predictive models for each of the variables of the process.The best predictive models can be used to predict experimentally hard-to-measure variables (internal stresses, internal straine, etc.) which are useful in the optimal design of the process or to be applied in real time control systems of a skin-pass process in -plant.

  8. Investigation of processes controlling summertime gaseous elemental mercury oxidation at midlatitudinal marine, coastal, and inland sites

    Science.gov (United States)

    Ye, Zhuyun; Mao, Huiting; Lin, Che-Jen; Kim, Su Youn

    2016-07-01

    A box model incorporating a state-of-the-art chemical mechanism for atmospheric mercury (Hg) cycling was developed to investigate the oxidation of gaseous elemental mercury (GEM) at three locations in the northeastern United States: Appledore Island (AI; marine), Thompson Farm (TF; coastal, rural), and Pack Monadnock (PM; inland, rural, elevated). The chemical mechanism in this box model included the most up-to-date Hg and halogen chemistry. As a result, the box model was able to simulate reasonably the observed diurnal cycles of gaseous oxidized mercury (GOM) and chemical speciation bearing distinct differences between the three sites. In agreement with observations, simulated GOM diurnal cycles at AI and TF showed significant daytime peaks in the afternoon and nighttime minimums compared to flat GOM diurnal cycles at PM. Moreover, significant differences in the magnitude of GOM diurnal amplitude (AI > TF > PM) were captured in modeled results. At the coastal and inland sites, GEM oxidation was predominated by O3 and OH, contributing 80-99 % of total GOM production during daytime. H2O2-initiated GEM oxidation was significant (˜ 33 % of the total GOM) at the inland site during nighttime. In the marine boundary layer (MBL) atmosphere, Br and BrO became dominant GEM oxidants, with mixing ratios reaching 0.1 and 1 pptv, respectively, and contributing ˜ 70 % of the total GOM production during midday, while O3 dominated GEM oxidation (50-90 % of GOM production) over the remaining day when Br and BrO mixing ratios were diminished. The majority of HgBr produced from GEM+Br was oxidized by NO2 and HO2 to form brominated GOM species. Relative humidity and products of the CH3O2+BrO reaction possibly significantly affected the mixing ratios of Br or BrO radicals and subsequently GOM formation. Gas-particle partitioning could potentially be important in the production of GOM as well as Br and BrO at the marine site.

  9. Beyond data collection in digital mapping: interpretation, sketching and thought process elements in geological map making

    Science.gov (United States)

    Watkins, Hannah; Bond, Clare; Butler, Rob

    2016-04-01

    Geological mapping techniques have advanced significantly in recent years from paper fieldslips to Toughbook, smartphone and tablet mapping; but how do the methods used to create a geological map affect the thought processes that result in the final map interpretation? Geological maps have many key roles in the field of geosciences including understanding geological processes and geometries in 3D, interpreting geological histories and understanding stratigraphic relationships in 2D and 3D. Here we consider the impact of the methods used to create a map on the thought processes that result in the final geological map interpretation. As mapping technology has advanced in recent years, the way in which we produce geological maps has also changed. Traditional geological mapping is undertaken using paper fieldslips, pencils and compass clinometers. The map interpretation evolves through time as data is collected. This interpretive process that results in the final geological map is often supported by recording in a field notebook, observations, ideas and alternative geological models explored with the use of sketches and evolutionary diagrams. In combination the field map and notebook can be used to challenge the map interpretation and consider its uncertainties. These uncertainties and the balance of data to interpretation are often lost in the creation of published 'fair' copy geological maps. The advent of Toughbooks, smartphones and tablets in the production of geological maps has changed the process of map creation. Digital data collection, particularly through the use of inbuilt gyrometers in phones and tablets, has changed smartphones into geological mapping tools that can be used to collect lots of geological data quickly. With GPS functionality this data is also geospatially located, assuming good GPS connectivity, and can be linked to georeferenced infield photography. In contrast line drawing, for example for lithological boundary interpretation and sketching

  10. Formation of Medium-Heavy Elements in Rapid Neutron Capture Process

    Directory of Open Access Journals (Sweden)

    M. Ikram

    2014-08-01

    Full Text Available We predict the neutron drip-line and simulate the r—process path for Cu — Sn, based on the calculation of binding energy in the frame-work of relativistic and non-relativistic mean field formalisms. We also compare the quadrupole deformation parameter β2 , and one neutron separation energy Sn of these isotopic series with the results of finite range droplet model (FRDM prediction. The results produced by RMF and SHF are comparable to each other and also agreeable with the FRDM model.

  11. The relational unconscious: a core element of intersubjectivity, thirdness, and clinical process.

    Science.gov (United States)

    Gerson, Samuel

    2004-01-01

    The relational unconscious is the fundamental structuring property of each interpersonal relation; it permits, as well as constrains, modes of engagement specific to that dyad and influences individual subjective experience within the dyad. Three usages of the concept of thirdness are delineated and contrasted with the concept of the relational unconscious, which, it is suggested, has the advantage of being both consistent with existing views of unconscious processes and more directly applicable to therapeutic concerns. Enactments and intersubjective resistances are viewed as clinical manifestations of the relational unconscious, and the therapeutic action of psychoanalysis results, in part, from altering the structure of the relational unconscious that binds analysand and analyst.

  12. A finite element modeling on the fluid flow and solidification in a continuous casting process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.H.; Kim, D.S. [Hanyang University Graduate School, Seoul (Korea); Choi, H.C. [Agency for Defence Development, Taejon (Korea); Kim, S.W. [Hanyang University, Seoul (Korea); Lee, S.K. [Chung Buk National University, Chungju (Korea)

    1999-07-01

    The coupled turbulent flow and solidification is considered in a typical slab continuous casting process using commercial program FIDAP. Standard {kappa}-{epsilon} turbulence model is modified to decay turbulent viscosity in the mushy zone and laminar viscosity is set to a sufficiently large value at the solid region. This coupled turbulent flow and solidification model also contains thermal contact resistance due to the mold powder and air gap between the strand and mold using an effective thermal conductivity. From the computed flow pattern, the trajectory of inclusion particles was calculated. The comparison between the predicted and experimental solidified shell thickness shows a good agreement. (author). 27 refs., 11 figs., 2 tabs.

  13. Low Power, Area- Efficient and High Speed Fast Adder for Processing Element

    OpenAIRE

    J.Ponmalar; T.R.Sureshkumar; T.Kowsalya

    2015-01-01

    In electronics, adder is a digital circuit that performs addition of numbers. To perform fast arithmetic operations, carry select adder (CSLA) is one of the fastest adders used in many data- processing processors. The structure of CSLA is such that there is further scope of reducing the area, delay and power consumption. Simple and efficient gate – level modification is used in order to reduce the area, delay and power of CSLA. Based on the modifications, 8-bit, 16-bit, 32-bit and 64-bi...

  14. Elements in the Development of a Production Process for Modified Vaccinia Virus Ankara

    Directory of Open Access Journals (Sweden)

    Volker Sandig

    2013-11-01

    Full Text Available The production of several viral vaccines depends on chicken embryo fibroblasts or embryonated chicken eggs. To replace this logistically demanding substrate, we created continuous anatine suspension cell lines (CR and CR.pIX, developed chemically-defined media, and established production processes for different vaccine viruses. One of the processes investigated in greater detail was developed for modified vaccinia virus Ankara (MVA. MVA is highly attenuated for human recipients and an efficient vector for reactogenic expression of foreign genes. Because direct cell-to-cell spread is one important mechanism for vaccinia virus replication, cultivation of MVA in bioreactors is facilitated if cell aggregates are induced after infection. This dependency may be the mechanism behind our observation that a novel viral genotype (MVA-CR accumulates with serial passage in suspension cultures. Sequencing of a major part of the genomic DNA of the new strain revealed point mutations in three genes. We hypothesize that these changes confer an advantage because they may allow a greater fraction of MVA-CR viruses to escape the host cells for infection of distant targets. Production and purification of MVA-based vaccines may be simplified by this combination of designed avian cell line, chemically defined media and the novel virus strain.

  15. Comparisons of elastic and rigid blade-element rotor models using parallel processing technology for piloted simulations

    Science.gov (United States)

    Hill, Gary; Duval, Ronald W.; Green, John A.; Huynh, Loc C.

    1991-01-01

    A piloted comparison of rigid and aeroelastic blade-element rotor models was conducted at the Crew Station Research and Development Facility (CSRDF) at Ames Research Center. A simulation development and analysis tool, FLIGHTLAB, was used to implement these models in real time using parallel processing technology. Pilot comments and quantitative analysis performed both on-line and off-line confirmed that elastic degrees of freedom significantly affect perceived handling qualities. Trim comparisons show improved correlation with flight test data when elastic modes are modeled. The results demonstrate the efficiency with which the mathematical modeling sophistication of existing simulation facilities can be upgraded using parallel processing, and the importance of these upgrades to simulation fidelity.

  16. Comparison of elastic and rigid blade-element rotor models using parallel processing technology for piloted simulations

    Science.gov (United States)

    Hill, Gary; Du Val, Ronald W.; Green, John A.; Huynh, Loc C.

    1991-01-01

    A piloted comparison of rigid and aeroelastic blade-element rotor models was conducted at the Crew Station Research and Development Facility (CSRDF) at Ames Research Center. A simulation development and analysis tool, FLIGHTLAB, was used to implement these models in real time using parallel processing technology. Pilot comments and qualitative analysis performed both on-line and off-line confirmed that elastic degrees of freedom significantly affect perceived handling qualities. Trim comparisons show improved correlation with flight test data when elastic modes are modeled. The results demonstrate the efficiency with which the mathematical modeling sophistication of existing simulation facilities can be upgraded using parallel processing, and the importance of these upgrades to simulation fidelity.

  17. Cold Drawn Steel Wires-Processing, Residual Stresses and Ductility-Part I: Metallography and Finite Element Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Phelippeau,A.; Pommier, S.; Tsakalakos, T.; Clavel, M.; Prioul, C.

    2006-01-01

    Cold drawing steel wires lead to an increase of their mechanical strength and to a drop of their ductility. The increase of their mechanical strength has long been related to the reduction of the various material scales by plastic deformation, but the mechanisms controlling their elongation to failure have received relatively little attention. It is usually found that heavily deformed materials show a tendency to plastic strain localization and necking. However, in this paper it is shown that, though the steel wires are plastically deformed up to strain levels as high as 3.5, a significant capability of plastic deformation is preserved in as-drawn wires. This apparent contradiction is resolved by the existence of residual stresses inside the wire. Finite element analyses have been conducted in order to show that residual stresses, inherited from the drawing process, are sufficient to produce a significant hardening effect during a post-drawing tensile test, without introducing any hardening in the local material behavior. The main conclusion of this paper is that once the material has lost its hardening capabilities, residual stresses, inherited from the process, control the elongation of cold drawn wires. The finite element method allowed also the determination of the residual stress field that would lead to the best agreement between the simulated and the experimental stress strain curve of as-drawn wires.

  18. Bursting process of large- and small-scale structures in turbulent boundary layer perturbed by a cylinder roughness element

    Science.gov (United States)

    Tang, Zhanqi; Jiang, Nan; Zheng, Xiaobo; Wu, Yanhua

    2016-05-01

    Hot-wire measurements on a turbulent boundary layer flow perturbed by a wall-mounted cylinder roughness element (CRE) are carried out in this study. The cylindrical element protrudes into the logarithmic layer, which is similar to those employed in turbulent boundary layers by Ryan et al. (AIAA J 49:2210-2220, 2011. doi: 10.2514/1.j051012) and Zheng and Longmire (J Fluid Mech 748:368-398, 2014. doi: 10.1017/jfm.2014.185) and in turbulent channel flow by Pathikonda and Christensen (AIAA J 53:1-10, 2014. doi: 10.2514/1.j053407). The similar effects on both the mean velocity and Reynolds stress are observed downstream of the CRE perturbation. The series of hot-wire data are decomposed into large- and small-scale fluctuations, and the characteristics of large- and small-scale bursting process are observed, by comparing the bursting duration, period and frequency between CRE-perturbed case and unperturbed case. It is indicated that the CRE perturbation performs the significant impact on the large- and small-scale structures, but within the different impact scenario. Moreover, the large-scale bursting process imposes a modulation on the bursting events of small-scale fluctuations and the overall trend of modulation is not essentially sensitive to the present CRE perturbation, even the modulation extent is modified. The conditionally averaging fluctuations are also plotted, which further confirms the robustness of the bursting modulation in the present experiments.

  19. 滚动体加工工艺技术与装备发展方向%Machining Process Technology and Development Direction of Equipment for Rolling Elements

    Institute of Scientific and Technical Information of China (English)

    张永乾

    2015-01-01

    The machining process technology and equipment are introduced for rolling elements in China,and the cur-rent situation and existing main problems about machining process for rolling elements in China are analyzed.The de-velopment direction of machining process technology for rolling elements is discussed.%通过对国内滚动体加工工艺技术及装备的介绍,分析了我国滚动体加工工艺现状及存在的主要问题,探讨了滚动体加工工艺技术的发展方向。

  20. Static and dynamic finite element analysis of 304 stainless steel rod and wire hot continuous rolling process

    Institute of Scientific and Technical Information of China (English)

    Siyu Yuan; Liwen Zhang; Shulun Liao; Mao Li; Min Qi; Yu Zhen; Shuqi Guo

    2008-01-01

    Three-dimensional finite element models were developed to analyze 304 stainless steel rod and wire hot continuous rolling process with the help of MSC.Marc software. The entire 30-pass deformation process and the actual parameters of production line were taken into account. Static and dynamic procedures were used to study the continuous rolling process with the aid of the thermo-mechanical coupled FEM of elastic-plasticity. The properties of billets, such as deformation, temperature field and rolling force, were mainly discussed. The simulation results of temperature agree well with the measured values. Comparisons of the analysis results obtained using static implicit method and dynamic implicit method were presented. It is shown that static implicit proce-dure is more accurate than dynamic implicit procedure and is able to simulate the rolling process with a lower speed, such as a rough-ing mill. Whereas, dynamic analysis shows a higher efficiency than static analysis and is fit for simulating the rolling process with a higher speed, such as a finishing mill.

  1. Tracking transformation processes of organic micropollutants in aquatic environments using multi-element isotope fractionation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hofstetter, Thomas B., E-mail: thomas.hofstetter@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland)] [Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092 Zurich (Switzerland); Bolotin, Jakov [Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland); Skarpeli-Liati, Marita; Wijker, Reto [Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland)] [Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092 Zurich (Switzerland); Kurt, Zohre; Nishino, Shirley F.; Spain, Jim C. [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2011-06-15

    The quantitative description of enzymatic or abiotic transformations of man-made organic micropollutants in rivers, lakes, and groundwaters is one of the major challenges associated with the risk assessment of water resource contamination. Compound-specific isotope analysis enables one to identify (bio)degradation pathways based on changes in the contaminants' stable isotope ratios even if multiple reactive and non-reactive processes cause concentrations to decrease. Here, we investigated how the magnitude and variability of isotope fractionation in some priority pollutants is determined by the kinetics and mechanisms of important enzymatic and abiotic redox reactions. For nitroaromatic compounds and substituted anilines, we illustrate that competing transformation pathways can be assessed via trends of N and C isotope signatures.

  2. A study of the impact of moist-heat and dry-heat treatment processes on hazardous trace elements migration in food waste.

    Science.gov (United States)

    Chen, Ting; Jin, Yiying; Qiu, Xiaopeng; Chen, Xin

    2015-03-01

    Using laboratory experiments, the authors investigated the impact of dry-heat and moist-heat treatment processes on hazardous trace elements (As, Hg, Cd, Cr, and Pb) in food waste and explored their distribution patterns for three waste components: oil, aqueous, and solid components. The results indicated that an insignificant reduction of hazardous trace elements in heat-treated waste-0.61-14.29% after moist-heat treatment and 4.53-12.25% after dry-heat treatment-and a significant reduction in hazardous trace elements (except for Hg without external addition) after centrifugal dehydration (P treatment, over 90% of the hazardous trace elements in the waste were detected in the aqueous and solid components, whereas only a trace amount of hazardous trace elements was detected in the oil component (treatment process did not significantly reduce the concentration of hazardous trace elements in food waste, but the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk considerably. Finally, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment on the removal of external water-soluble ionic hazardous trace elements. An insignificant reduction of hazardous trace elements in heat-treated waste showed that heat treatment does not reduce trace elements contamination in food waste considerably, whereas the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk significantly. Moreover, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment for the removal of external water-soluble ionic hazardous trace elements, by exploring distribution patterns of trace elements in three waste components: oil, aqueous, and solid components.

  3. Processes of social flourishing and their liminal collapse: elements to a genealogy of globalization.

    Science.gov (United States)

    Szakolczai, Arpad

    2016-09-01

    This article aims at exploring a long-term historical perspective on which contemporary globalization can be more meaningfully situated. A central problem with established approaches to globalization is that they are even more presentist than the literature on modernization was. Presentism not only means the ignoring of history, but also the unreflective application to history of concepts taken from the study of the modern world. In contrast, it is argued that contemporary globalization is not a unique development, but rather is a concrete case of a historical type. Taking as its point of departure the spirit, rather than the word, of Max Weber, this article extends the scope of sociological investigation into archaeological evidence. Having a genealogical design and introducing the concept of 'liminality', the article approaches the modern process of globalization through reconstructing the internal dynamics of another type of historical change called 'social flourishing'. Taking up the Weberian approach continued by Eisenstadt in his writings on 'axial age', it moves away from situations of crisis as reference point, shifting attention to periods of revival by introducing the term 'epiphany'. Through the case of early Mesopotamia, it shows how social flourishing can be transmogrified into globalizing growth, gaining a new perspective concerning the kind of 'animating spirit' that might have driven the shift from Renaissance to Reformation, the rise of modern colonialism, or contemporary globalization. More generally, it will retrieve the long-term historical background of the axial age and demonstrate the usefulness and importance of archaeological evidence for sociology. © London School of Economics and Political Science 2016.

  4. Finite Element Optimization of Vee-ring Factor in Fine-blanking Process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The vee-ring is one of the most characteristic features of the fine-blanking process which is derived from the conventional blanking. With the vee-ring, a counter plate and some other working parameters, a component with a precise geometry and smoothly blanked surface can be produced without any major secondary operations.However, these working parameters are always empirically determined or determined by trial-and-error method,which is time-consuming and expensive. In this study, a numerical simulation method was used to analyze the effect of vee-ring factors on product quality, such as distance between vee-ring and punch, vee-ring height and blank holder force, so as to obtain as high clean cut ratio as possible. During the simulation, the model was assumed as axisymmetric one and the workpiece was considered as rigid plastic material, meanwhile the tools were defined as rigid bodies so as to shorten the computational time. A damage model taking into account the influence of hydrostatic stress was used to simulate material fracture in fine-blanking. The result obtained from the simulation indicated that with the help of vee-ring, the metal material near the shear band does not flow with the punch penetration and high compressive stress in the shear band is generated. Consequently, higher clean cut ratio can be obtained with a vee-ring model than the one obtained with a plane blank holder model. Furthermore, the longer the distance between vee-ring and punch is, the higher the height of roll-over becomes.

  5. A novel processing system of sterol regulatory element-binding protein-1c regulated by polyunsaturated fatty acid.

    Science.gov (United States)

    Nakakuki, Masanori; Kawano, Hiroyuki; Notsu, Tatsuto; Imada, Kazunori; Mizuguchi, Kiyoshi; Shimano, Hitoshi

    2014-05-01

    The proteolytic cascade is the key step in transactivation of sterol regulatory element-binding proteins (SREBPs), a transcriptional factor of lipid synthesis. Proteolysis of SREBP-2 is strictly regulated by sterols, but that of SREBP-1c was not strongly sterol-regulated, but inhibited by polyunsaturated fatty acids (PUFAs). In this study, the proteolytic processing of SREBP-1 and -2 was examined by transfection studies of cDNA-encoding mutants in which all the known cleavage sites were disrupted. In cultured cells, sterol-regulated SREBP-2 processing was completely eliminated by mutation of cleavage sites. In contrast, the corresponding SREBP-1c mutants as well as wild type exhibited large amounts of cleaved products in the nuclear extracts from culture cells and murine liver in vivo. The nuclear form of the mutant SREBP-1c was induced by delipidated condition and suppressed by eicosapentaenoic acid, an n-3 PUFA, but not by sterols. This novel processing mechanism was affected by neither SREBP cleavage-activating protein (SCAP) nor insulin-induced gene (Insig)-1, unlike SREBP-2, but abolished by a serine protease inhibitor. Through analysis of deletion mutant, a site-2 protease recognition sequence (DRSR) was identified to be involved in this novel processing. These findings suggest that SREBP-1c cleavage could be subjected to a novel PUFA-regulated cleavage system in addition to the sterol-regulatory SCAP/Insig system.

  6. A study on using pre-forming blank in single point incremental forming process by finite element analysis

    Science.gov (United States)

    Abass, K. I.

    2016-11-01

    Single Point Incremental Forming process (SPIF) is a forming technique of sheet material based on layered manufacturing principles. The edges of sheet material are clamped while the forming tool is moved along the tool path. The CNC milling machine is used to manufacturing the product. SPIF involves extensive plastic deformation and the description of the process is more complicated by highly nonlinear boundary conditions, namely contact and frictional effects have been accomplished. However, due to the complex nature of these models, numerical approaches dominated by Finite Element Analysis (FEA) are now in widespread use. The paper presents the data and main results of a study on effect of using preforming blank in SPIF through FEA. The considered SPIF has been studied under certain process conditions referring to the test work piece, tool, etc., applying ANSYS 11. The results show that the simulation model can predict an ideal profile of processing track, the behaviour of contact tool-workpiece, the product accuracy by evaluation its thickness, surface strain and the stress distribution along the deformed blank section during the deformation stages.

  7. Modeling of the inhomogeneity of grain refinement during combined metal forming process by finite element and cellular automata methods

    Energy Technology Data Exchange (ETDEWEB)

    Majta, Janusz; Madej, Łukasz; Svyetlichnyy, Dmytro S.; Perzyński, Konrad; Kwiecień, Marcin, E-mail: mkwiecie@agh.edu.pl; Muszka, Krzysztof

    2016-08-01

    The potential of discrete cellular automata technique to predict the grain refinement in wires produced using combined metal forming process is presented and discussed within the paper. The developed combined metal forming process can be treated as one of the Severe Plastic Deformation (SPD) techniques that consists of three different modes of deformation: asymmetric drawing with bending, namely accumulated angular drawing (AAD), wire drawing (WD) and wire flattening (WF). To accurately replicate complex stress state both at macro and micro scales during subsequent deformations two stage modeling approach was used. First, the Finite Element Method (FEM), implemented in commercial ABAQUS software, was applied to simulate entire combined forming process at the macro scale level. Then, based on FEM results, the Cellular Automata (CA) method was applied for simulation of grain refinement at the microstructure level. Data transferred between FEM and CA methods included set of files with strain tensor components obtained from selected integration points in the macro scale model. As a result of CA simulation, detailed information on microstructure evolution during severe plastic deformation conditions was obtained, namely: changes of shape and sizes of modeled representative volume with imposed microstructure, changes of the number of grains, subgrains and dislocation cells, development of grain boundaries angle distribution as well as changes in the pole figures. To evaluate CA model predictive capabilities, results of computer simulation were compared with scanning electron microscopy and electron back scattered diffraction images (SEM/EBSD) studies of samples after AAD+WD+WF process.

  8. Transfer characteristics of nutrient elements through hydrological process of a Pinus tabulaeformis stand in the West Mountain of Beijing

    Institute of Scientific and Technical Information of China (English)

    NIE Lishui; WANG Dengzhi; LI Jiyue

    2007-01-01

    Forest precipitation chemistry is a major issue in forest hydrology and forest ecology.Chemical contents in precipitation change significantly when different kinds of external chemical materials are added,removed,translocated and transformed to or in the forest ecosystem along with precipitation.The chemistry of precipitation was monitored and analyzed in a 31-year-old Pinus tabulaeformis forest in the West Mountain of Beijing.Movement patterns of nutrient elements in hydrological processes can be discovered by studying this monitored data.Also,the information is useful for diagnosing the function of ecosystems and evaluating the impact of the environment on the ecosystem.Samples of rainfall,throughfall and stemflow were collected on the site.In the lab,Ca2+ and Mg2+ were analyzed by flame atomic absorption and K+ and Na+ by flame emission.NH4+-N was analyzed by indophenol blue colorimetry and NO3--N was analyzed by phenoldisulfonic acid colorimetry.The results showed that:1) The concentration gradient of nutrient elements clearly changed except for Na+.The nutrients in stemflow were significantly higher than those of throughfall and rainfall as the precipitation passed through the P.tabulaeformis forest.The monthly patterns showed distinct differentiation.There are indications that a large amount of nutrients was leached from the canopy,which is a critical function of intra-ecosystem nutrient cycling to improve the efficiency of nutrient use.2) The concentrations of NO3--N and K+ changed more than those of the other nutrient elements.The concentration of NO3--N in throughfall and stemflow was 4.4 times and 9.9 times higher than those in rainfall,respectively.The concentration of K+ in throughfall and stemflow was 4.1 times and 8.1 times higher than those in rainfall,respectively.3) The leaching of nutrient elements from the stand was an important aspect of nutrient return to the P.tabulaeformis forest,which returned a total amount of nutrient of 54.1 kg/hm2,with

  9. Trace elements and petroleum hydrocarbons in the aquatic bird food chain of process water evaporation ponds at the Little America Refinery, Casper, Wyoming

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study determined the nature and extent of trace elements, metals, and petroleum hydrocarbons in evaporation ponds used for the disposal of process water from...

  10. Three-dimensional combined finite-discrete element approach for simulation of single layer powder compaction process

    Institute of Scientific and Technical Information of China (English)

    陈普庆; 夏伟; 周照耀; 朱权利; 李元元

    2004-01-01

    The application of a combined finite-discrete element modeling approach to simulate the three-dimensional microscopic compaction behavior of single-layer metal powder system was described. The process was treated as a static problem, with kinematical component being neglected. Due to ill condition, Cholesky's method failed to solve the system equations, while conjugate gradient method was tried and yielded good results. Deformation of the particles was examined and compared with the results of physical modeling experiments. In both cases, the inner particles were deformed from sphere to polygonal column, with the edges turning from arc to straight line. The edge number of a particle was equal to the number of particles surrounding it. And the experiments show that the ductile metal particles can be densified only by their plastic deformation without the occurrence of rearrangement phenomenon.

  11. Study of Interdigitated Electrode Arrays Using Experiments and Finite Element Models for the Evaluation of Sterilization Processes

    Directory of Open Access Journals (Sweden)

    Jan Oberländer

    2015-10-01

    Full Text Available In this work, a sensor to evaluate sterilization processes with hydrogen peroxide vapor has been characterized. Experimental, analytical and numerical methods were applied to evaluate and study the sensor behavior. The sensor set-up is based on planar interdigitated electrodes. The interdigitated electrode structure consists of 614 electrode fingers spanning over a total sensing area of 20 mm2. Sensor measurements were conducted with and without microbiological spores as well as after an industrial sterilization protocol. The measurements were verified using an analytical expression based on a first-order elliptical integral. A model based on the finite element method with periodic boundary conditions in two dimensions was developed and utilized to validate the experimental findings.

  12. Study of interdigitated electrode arrays using experiments and finite element models for the evaluation of sterilization processes.

    Science.gov (United States)

    Oberländer, Jan; Jildeh, Zaid B; Kirchner, Patrick; Wendeler, Luisa; Bromm, Alexander; Iken, Heiko; Wagner, Patrick; Keusgen, Michael; Schöning, Michael J

    2015-10-14

    In this work, a sensor to evaluate sterilization processes with hydrogen peroxide vapor has been characterized. Experimental, analytical and numerical methods were applied to evaluate and study the sensor behavior. The sensor set-up is based on planar interdigitated electrodes. The interdigitated electrode structure consists of 614 electrode fingers spanning over a total sensing area of 20 mm². Sensor measurements were conducted with and without microbiological spores as well as after an industrial sterilization protocol. The measurements were verified using an analytical expression based on a first-order elliptical integral. A model based on the finite element method with periodic boundary conditions in two dimensions was developed and utilized to validate the experimental findings.

  13. Analysis on Shear Deformation for High Manganese Austenite Steel during Hot Asymmetrical Rolling Process Using Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    Feng-li SUI; Xin WANG; Jun ZHAO; Biao MA; Chang-sheng LI

    2015-01-01

    Based on the rigid-plastic ifnite element method (FEM), the shear stress ifeld of deformation region for high manganese austenite steel during hot asymmetrical rolling process was analyzed. The inlfuences of rolling parameters, such as thevelocity ratio of upper to lower rolls, theinitial temperature of workpiece and the reduction rate, on the shear deformation of three nodes in the upper, center and lower layers were discussed. As the rolling parameters change, distinct shear deformation appears in the up-per and lower layers, but the shear deformation in the center layer appears only when the velocity ratio is more than 1.00, and the absolute value of the shear stress in this layer is changed with rolling parameters. A mathematical model which relfected the change of the maximal absolute shear stress for the center layer was established, by which the maximal absolute shear stress for the center layer can be easily calculated and the appropriate rolling technology can be designed.

  14. Characterization of kesterite thin films fabricated by rapid thermal processing of stacked elemental layers using spatially resolved cathodoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Künecke, Ulrike; Hetzner, Christina; Möckel, Stefan [Materials Department 6, University of Erlangen-Nürnberg (FAU), Martensstr, 7, D-91058 Erlangen (Germany); Yoo, Hyesun; Hock, Rainer [Crystallography and Structure Physics, University of Erlangen-Nürnberg (FAU), Staudtstr, 3, 91058 Erlangen (Germany); Wellmann, Peter, E-mail: peter.wellmann@fau.de [Materials Department 6, University of Erlangen-Nürnberg (FAU), Martensstr, 7, D-91058 Erlangen (Germany)

    2015-05-01

    We report on the microstructure analysis of kesterite (Cu{sub 2}ZnSnSe{sub 4}) layers from rapid thermal processing of sequential elemental layers by spatially resolved cathodoluminescence in a scanning electron microscope. Energy dispersive X-ray fluorescence, X-ray diffraction and Raman spectroscopy were carried out for the validation of the findings. Special emphasis is put on the discussion of the occurrence of the secondary phases Cu{sub 2}SnSe{sub 3}, Cu{sub 2}Se, ZnSe and SnSe. - Highlights: • Spectrally resolved cathodoluminescence of Cu{sub 2}ZnSnSe{sub 4} • Material analysis with a μm spatial resolution • Determination of secondary phases Cu{sub 2}SnSe{sub 3}, Cu{sub 2}Se, SnSe and ZnSe.

  15. Heat Transfer Model of Directional Solidification by LMC Process for Superalloy Casting Based on Finite Element Method

    Science.gov (United States)

    Cao, Liu; Liao, Dunming; Lu, Yuzhang; Chen, Tao

    2016-09-01

    With the rapid development of the aviation industry, the turbine blade, a critical component of the aeronautical engine, has come to be widely produced by liquid-metal cooling (LMC) process. A temperature- and time-dependent heat transfer coefficient was used to represent the heat convection between the shell and the cooling liquid, and an improved Monte Carlo ray-tracing approach was adopted to handle the boundary of radiation heat transfer. Unstructured mesh was used to fit the irregular shell boundary, and the heat transfer model of directional solidification by LMC process based on finite element method (FEM) was established. The concept of local matrix was here proposed to guarantee computational efficiency. The pouring experiments of directional solidification by LMC process were carried out, then simulation and experimental results were compared here. The accuracy of the heat transfer model was validated by the cooling curves and grain morphology, and the maximum relative error between simulation and experimental cooling curve was 2 pct. The withdrawal rate showed an important influence on the shape of solidification interface, and stray grain is liable to be generated on the bottom of platform at an excessive withdrawal rate.

  16. Production Cycle for Large Scale Fission Mo-99 Separation by the Processing of Irradiated LEU Uranium Silicide Fuel Element Targets

    Directory of Open Access Journals (Sweden)

    Abdel-Hadi Ali Sameh

    2013-01-01

    Full Text Available Uranium silicide fuels proved over decades their exceptional qualification for the operation of higher flux material testing reactors with LEU elements. The application of such fuels as target materials, particularly for the large scale fission Mo-99 producers, offers an efficient and economical solution for the related facilities. The realization of such aim demands the introduction of a suitable dissolution process for the applied U3Si2 compound. Excellent results are achieved by the oxidizing dissolution of the fuel meat in hydrofluoric acid at room temperature. The resulting solution is directly behind added to an over stoichiometric amount of potassium hydroxide solution. Uranium and the bulk of fission products are precipitated together with the transuranium compounds. The filtrate contains the molybdenum and the soluble fission product species. It is further treated similar to the in-full scale proven process. The generated off gas stream is handled also as experienced before after passing through KOH washing solution. The generated alkaline fluoride containing waste solution is noncorrosive. Nevertheless fluoride can be selectively bonded as in soluble CaF2 by addition of a mixture of solid calcium hydroxide calcium carbonate to the sand cement mixture used for waste solidification. The generated elevated amounts of LEU remnants can be recycled and retargeted. The related technology permits the minimization of the generated fuel waste, saving environment, and improving processing economy.

  17. Application of a space-time CE/SE (Conversation Element/Solution Element) method to the numerical solution of chromatographic separation processes

    DEFF Research Database (Denmark)

    For solving partial differential equations (or distributed dynamic systems), the method of lines (MOL) and the space-time conservation element and solution element (CE/SE) method are compared in terms of computational efficiency, solution accuracy and stability. Several representative examples...... including convection-difmsion-reaction PDEs are numerically solved using the two methods on the same spatial grid. Even though the CE/SE method uses a simple stencil structure and is developed on a simple mathematical basis (i.e., Gauss' divergence theorem), accurate and computationally-efficient solutions....... It is concluded that the CE/SE method is adequate to capturing shocks in PDEs but for diffusion-dominated stiff PDEs, the MOL with an ODE time integrator is complementary to the CE/SE method....

  18. Regularitis of distribution techno and toxic elements in the waste from the extraction and processing of coal Western Donbass

    Directory of Open Access Journals (Sweden)

    Kroyik H.A.,

    2012-09-01

    Full Text Available Study of especially spreading of toxic elements in wastes products of the coal mining Western Donbass. Ranging of elements is executed on their gross maintenance. The geochemical associations of elements are distinguished for their toxicness and prospects of the use in a technique.

  19. Finite Element Analysis and OADs Optimization of the Temperature in the Plane-strain Orthogonal Metal Cutting Process

    Institute of Scientific and Technical Information of China (English)

    刘龙权; 姚振强; 袁光杰

    2004-01-01

    In order to analyze the influences of the different tool's shape and surface conditions (such as different coated and material) and their interaction on the cutting temperature, a coupled thermo-mechanical finite element analysis (FEA)model of plane-strain orthogonal metal cutting process is constructed, and 16 simulation cases with 16 different types of tools, which cover 4 rake angles, - 10°, 0°, 10°, 20°,and 4 friction coefficient values, 0, 0.1, 0.2, 0.3 in the same cutting condition (cutting depth and cutting speed)have been performed. Finally the simulation results are analyzed according to the variance analysis method (VAM)of orthogonal array designs (OADs), the relationships between the rake angle, tool-workpiece interface's friction coefficient and their interact effect to the maximum temperature value and the temperature field of the chip are obtained. This result has some instructive meaning to analyze the causes of the cutting temperature and to control the maximum temperature value and the overall temperature field in the metal cutting process.

  20. Finite element modeling of the powder-in- tube process for manufacture of BSCCO-2212 superconducting wires

    Science.gov (United States)

    Shah, R.; Tangrila, S.; Rachakonda, S.; Thirukkonda, M.

    1995-12-01

    High-temperature superconductors have recently attracted a great deal of attention owing to their potential use in a variety of applications including power generators, superconducting magnets for mine sweepers or ship propulsion motors, and magnetic levitation transportation systems. The powder-in-tube (PIT) process has emerged as one of the most promising and economically feasible techniques to produce long lengths high-Tc oxide based superconducting wires. The PIT method involves multi-pass wire drawing followed by rolling and heat treatment. This work focuses on the development of finite element models to simulate the PIT drawing process for fabrication of silver sheathed Bi-2212 superconducting wires. The numerical models were used to predict the density of the oxide powder, the wire drawing forces, and the silver-oxide ratio during drawing. A cap-type pressure dependent constitutive equation was implemented in the model to simulate the powder behavior. The model incorporated experimentally obtained material data for the silver and powder. Data from wire drawing experiments were used to verify model predictions.

  1. Importance of vertical geochemical processes in controlling the oceanic profiles of dissolved rare earth elements in the northeastern Indian Ocean

    Science.gov (United States)

    Nozaki, Yoshiyuki; Alibo, Dia Sotto

    2003-01-01

    Vertical profiles of dissolved rare earth elements (REEs) were obtained in the Bay of Bengal and the Andaman Sea. The REE concentrations at various depths in the Bay of Bengal are the highest in the Indian Ocean. This is attributable ultimately to the large outflow of the Ganges-Brahmaputra and Irrawaddy rivers, but the dissolved REE flux to surface waters alone cannot explain the large and near-constant REE enrichment throughout the entire water column. The underlying fan sediments serve as not a source but a sink for dissolved REE(III)s. Absence of excess 228Ra in the deep waters suggests that lateral input of dissolved REEs from slope sediments is also small in these regions. Partial (rivers and lateral surface currents and subsequently settle through the water column, appears to be a predominant source for the dissolved REEs. Vertical profiles showing an almost linear increase with depth are common features for the light and middle REEs everywhere, but their concentration levels are variable from basin to basin and from element to element. This suggests that their oceanic distributions respond quickly to the variation of particle flux and its REE composition through reversible exchange equilibrium with suspended and sinking particles much like the case for Th. The relative importance of the vertical geochemical processes of reversible scavenging over the horizontal basin-scale ocean circulation with passive regeneration like nutrients decreases systematically from the light to the heavy REEs. Using a model, the mean oceanic residence times of REEs in the Bay of Bengal are estimated to range from 37 years for Ce to 140-1510 years for the strictly trivalent REEs. In the deep water of the Andaman Sea, isolated from the Bay of Bengal by the Andaman-Nicobar Ridge (maximum sill depth of ˜1800 m), the REE concentrations are almost uniform presumably due to rapid vertical mixing. The REE(III) concentrations are similar to that of ˜1250 m depth water in the Bay of

  2. tDCS application over the STG improves the ability to recognize and appreciate elements involved in humor processing.

    Science.gov (United States)

    Manfredi, Mirella; Proverbio, Alice Mado; Gonçalves Donate, Ana Paula; Macarini Gonçalves Vieira, Sofia; Comfort, William Edgar; De Araújo Andreoli, Mariana; Boggio, Paulo Sérgio

    2017-03-15

    The superior temporal gyrus (STG) has been found to play a crucial role in the recognition of actions and facial expressions and may, therefore, be critical for the processing of humorous information. Here we investigated whether tDCS application to the STG would modulate the ability to recognize and appreciate the comic element in serious and comedic situations of misfortune. To this aim, the effects of different types of tDCS stimulation on the STG were analyzed during a task in which the participants were instructed to categorize various misfortunate situations as "comic" or "not comic". Participants underwent three different tDCS conditions: Anodal-right/Cathodal-left; Cathodal-right/Anodal-left; Sham. Images depicting people involved in accidents were grouped into three categories based on the facial expression of the victim: angry or painful (Affective); bewildered and funny (Comic); and images that did not contain the victim's face (No Face). An improvement in mean reaction times in response to both the Comic and No Face stimuli was observed following Anodal-left/Cathodal-right stimulation when compared to sham stimulation. This suggests that this stimulation type reduced the reaction times to socio-emotional complex scenes, regardless of facial expression. The Anodal-right/Cathodal-left stimulation reduced the mean reaction times for Comic stimuli only, suggesting that specifically the right STG may be involved in facial expression recognition and in the appreciation of the comic element in misfortunate situations. These results suggest a functional hemispheric asymmetry in STG response to social stimuli: the left STG might have a role in a general comprehension of social complex situations, while the right STG may be involved in the ability to recognize and integrate specific emotional aspects in a complex scene.

  3. Nanomineralogy as a new dimension in understanding elusive geochemical processes in soils: The case of low-solubility-index elements

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Michael; Hochella, Michael F.

    2016-05-20

    Nanomineralogy is a new dimension in understanding chemical processes in soils. These processes are revealed at the nanoscale within the structures and compositions of phases that heretofore were not even known to exist in the soils in which they are found. The discovery and understanding of soil chemistry in this way is best accessible via a combination of focused ion beam technology (for sample preparation) and high resolution, analytical transmission electron microscopy (for phase identification). We have used this scientific framework and these techniques to decipher past and present chemical processes in a soil in Sudbury, Ontario, Canada that has been impacted by both smelter contamination (acidification) and subsequent remediation within the past century. In this study, we use these methods to investigate mobilization and sequestration of the relatively immobile elements Al, Ti and Zr. In a micrometer-thick alteration layer on an albite grain, a first generation of clay minerals represents weathering of the underlying mineral prior to the acidification of the soils. Complex assemblages of Ti- and Zr-bearing nanophases occur on the surfaces of Fe-(hydr)oxide crystals and are the result of the dissolution of silicates and oxides and the mobilization of Ti- and Zr-bearing colloids under acidic conditions. These phases include anatase (TiO2), kleberite (Fe3+Ti6O11(OH)5) Ti4O7, baddelyite (ZrO2), a structural analogue to kelyshite (NaZr[Si2O6(OH)]) and authigenic zircon (ZrSiO4). Subsequent remediation of the acidic soils has resulted in the sequestration of Al and in the neoformation of the clay minerals kaolinite, smectite and illite. These complex mineral assemblages form a porous layer that controls the interaction of the underlying mineral with the environment.

  4. A conserved helicase processivity factor is needed for conjugation and replication of an integrative and conjugative element.

    Directory of Open Access Journals (Sweden)

    Jacob Thomas

    Full Text Available Integrative and conjugative elements (ICEs are agents of horizontal gene transfer and have major roles in evolution and acquisition of new traits, including antibiotic resistances. ICEs are found integrated in a host chromosome and can excise and transfer to recipient bacteria via conjugation. Conjugation involves nicking of the ICE origin of transfer (oriT by the ICE-encoded relaxase and transfer of the nicked single strand of ICE DNA. For ICEBs1 of Bacillus subtilis, nicking of oriT by the ICEBs1 relaxase NicK also initiates rolling circle replication. This autonomous replication of ICEBs1 is critical for stability of the excised element in growing cells. We found a conserved and previously uncharacterized ICE gene that is required for conjugation and replication of ICEBs1. Our results indicate that this gene, helP (formerly ydcP, encodes a helicase processivity factor that enables the host-encoded helicase PcrA to unwind the double-stranded ICEBs1 DNA. HelP was required for both conjugation and replication of ICEBs1, and HelP and NicK were the only ICEBs1 proteins needed for replication from ICEBs1 oriT. Using chromatin immunoprecipitation, we measured association of HelP, NicK, PcrA, and the host-encoded single-strand DNA binding protein Ssb with ICEBs1. We found that NicK was required for association of HelP and PcrA with ICEBs1 DNA. HelP was required for association of PcrA and Ssb with ICEBs1 regions distal, but not proximal, to oriT, indicating that PcrA needs HelP to progress beyond nicked oriT and unwind ICEBs1. In vitro, HelP directly stimulated the helicase activity of the PcrA homologue UvrD. Our findings demonstrate that HelP is a helicase processivity factor needed for efficient unwinding of ICEBs1 for conjugation and replication. Homologues of HelP and PcrA-type helicases are encoded on many known and putative ICEs. We propose that these factors are essential for ICE conjugation, replication, and genetic stability.

  5. Priority Processing of Effective Packing Elements on Increasing Greenhouse Products Exports in Viewpoint of Russian Reporters (Case Study of Greenhouse Cucumber

    Directory of Open Access Journals (Sweden)

    Issa Fahim

    2012-12-01

    Full Text Available This research analyzed Priority processing of effective packing elements on increasing greenhouse products exports in viewpoint of Russian reporters. Statistics society of the research includes 44 people. Provided questionnaire was distributed among them which 30 questionnaire were returned. This is a questionnaire research in which questionnaire comprises two sections. To process the priority of packing elements from greenhouse products average index was used. To answer the main question of research, “Weather packing elements of goods influences increasing greenhouse products exports to Russia in viewpoint of Russian reports?” We examined five equations which are explained in the form of five hypotheses. In this research we try to determine that in view point of Russia reporter which elements of packing greenhouse cucumber has a meaningful relation to increasing exports and in other words, between which element and increasing exports to Russia there is no special relation. After doing some studies, interviews and distributing questionnaires, results showed that elements of package color, package weight and facility of opening the package influence increasing exports and in other side, two elements of package quality and package compatibility with environment don’t influence increasing exports.

  6. Application of LOD Technology in Groundwater Finite Element Post-processing%LOD技术在地下水有限元后处理中的应用

    Institute of Scientific and Technical Information of China (English)

    毕振波; 郑爱勤; 崔振东

    2011-01-01

    地下水有限元后处理阶段的数据量较大,这对模开重现、网络快速传输和计算结果的实时可视化造成困难.为此,分析地下水有限元后处理中面临的主要问题和LOD技术,指出顶点元素删除法是一种适应地下水有限元后处理的有效数据模型简化方法,设计顶点删除和恢复过程中的主要数据结构,并应用DT方法对“空洞”进行局部三角剖分.实例证明该方法在地下水有限元后处理中应用的有效性.%It is difficult for the reproducing, the rapid transmission based on network and the real time visualization of calculated results of finite element models that there is a large amount of data in finite element post-processing stage in groundwater. Therefore, based on analyzing the main problems existing in the post-processing of finite element in groundwater and Level of Detail(LOD) technology, this paper argues that vertex element deletion method is a effective data model simplification techniques adapted for finite element post-processing in groundwater, the main data structures of vertex element deletion and restoring are designed, DT method is used for the local triangulation meshing in the "hole" area. The real implemented example proves the effectiveness of vertex element deletion algorithm applied to finite element post-processing in groundwater.

  7. Finite element modelling of shot peening and peen forming processes and characterisation of peened AA2024-T351 aluminium alloy

    Science.gov (United States)

    Gariepy, Alexandre

    The main purpose of this thesis was to develop and validate finite element (FE) simulation tools for shot peening and peen forming. The specific aim was to achieve quantitatively accurate predictions for both processes and demonstrate the potential of reliable FE modelling for scientific investigation and industrial applications. First, an improved dynamic impact model that takes into account the stochastic nature of shot peening was proposed by carefully studying its dimensions, introducing a dispersion of shot sizes and significantly reducing its computational cost. In addition, cyclic mechanical testing was conducted to define a suitable material constitutive theory for aluminium alloy (AA) 2024-T3/T351 subjected to shot peening. By combining a realistic shot peening model with an appropriate material law, fairly good residual stress predictions were achieved for three different sets of shot peening parameters. Second, an experimental and numerical characterization of AA2024-T351 shot peened with parameters representative of fatigue life improvement applications was conducted. Multiple techniques, such as micro-indentation, residual stress determination and electron backscatter diffraction, were combined to gain a better understanding of the influence of shot peening on the material. The potential uses of finite element simulation to complement experimental data were also studied. The material heterogeneity arising from the random impact sequence was investigated and it was found that the impact modelling methodology could provide useful information on such heterogeneities. Third, a novel peen forming simulation methodology was introduced. The impact model provided the necessary input data as part of a multiscale approach. Numerically calculated unbalanced induced stress profiles were input into shell elements and the deformed shape after peen forming was computed as a springback analysis. In addition, a simple interpolation method was proposed to model the

  8. Hybrid Finite-Discrete Element Simulation of the EDZ Formation and Mechanical Sealing Process Around a Microtunnel in Opalinus Clay

    Science.gov (United States)

    Lisjak, Andrea; Tatone, Bryan S. A.; Mahabadi, Omid K.; Grasselli, Giovanni; Marschall, Paul; Lanyon, George W.; Vaissière, Rémi de la; Shao, Hua; Leung, Helen; Nussbaum, Christophe

    2016-05-01

    The analysis and prediction of the rock mass disturbance around underground excavations are critical components of the performance and safety assessment of deep geological repositories for nuclear waste. In the short term, an excavation damaged zone (EDZ) tends to develop due to the redistribution of stresses around the underground openings. The EDZ is associated with an increase in hydraulic conductivity of several orders of magnitude. In argillaceous rocks, sealing mechanisms ultimately lead to a partial reduction in the effective hydraulic conductivity of the EDZ with time. The goal of this study is to strengthen the understanding of the phenomena involved in the EDZ formation and sealing in Opalinus Clay, an indurated claystone currently being assessed as a host rock for a geological repository in Switzerland. To achieve this goal, hybrid finite-discrete element method (FDEM) simulations are performed. With its explicit consideration of fracturing processes, FDEM modeling is applied to the HG-A experiment, an in situ test carried out at the Mont Terri underground rock laboratory to investigate the hydro-mechanical response of a backfilled and sealed microtunnel. A quantitative simulation of the EDZ formation process around the microtunnel is first carried out, and the numerical results are compared with field observations. Then, the re-compression of the EDZ under the effect of a purely mechanical loading, capturing the increase of swelling pressure from the backfill onto the rock, is considered. The simulation results highlight distinctive rock failure kinematics due to the bedded structure of the rock mass. Also, fracture termination is simulated at the intersection with a pre-existing discontinuity, representing a fault plane oblique to the bedding orientation. Simulation of the EDZ re-compression indicates an overall reduction of the total fracture area as a function of the applied pressure, with locations of ineffective sealing associated with self

  9. Study of Spatial and Temporal Processes of Soil Erosion on Sloping Land Using Rare Earth Elements As Tracers

    Institute of Scientific and Technical Information of China (English)

    薛亚洲; 刘普灵; 杨明义; 琚彤军

    2004-01-01

    Rare earth elements(REE) were used to study the temporal and spatial processes of soil erosion from different depths and sections of a slope. Two simulated rainfall events were applied to a prepared plot with a slope of 22°. The total runoff and sediment yield were collected every minute during the rainfall events. During the first twenty minutes of the first rainfall event,the average rate of rill erosion and the accumulated sediment yield due to rill erosion was 0.5 and 0.3 times higher than for sheet erosion. During this time,most of the erosion occurred on the lower one third of the plot. After 20 min,rill erosion became the dominant process on the slope. The average acceleration in the rate of rill erosion,the rate of rill erosion and the accumulated sediment yield due to rill erosion were 42,6 and 4 times higher than that of sheet erosion,respectively. During the first 35 minutes of the second rainfall event,the average acceleration in the rate of rill erosion was 6~9 times higher than that of sheet erosion. Afterwards,the slope became nearly stable with little change in either rill or sheet erosion rates. Initially,most of the rill erosion occurred in the lower third of the slope but later the preexisting rillhead in the middle section of the slope became reactivated and erosion in this section of the slope increased rapidly. These results indicate that REE tracer technology is a valuable tool for quantifying spatial and temporal changes in erosion from a soil slope.

  10. LA-ICP-MS analysis of isolated phosphatic grains indicates selective rare earth element enrichment during reworking and transport processes

    Science.gov (United States)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2016-04-01

    Rare earth elements (REE) are a commonly used proxy to reconstruct water chemistry and oxygen saturation during the formation history of authigenic and biogenic phosphates in marine environments. In the modern ocean REE exhibit a distinct pattern with enrichment of heavy REE and strong depletion in Cerium. Studies of ancient phosphates and carbonates, however, showed that this 'modern' pattern is only rarely present in the geological past. Consequently, the wide range of REE enrichment patterns found in ancient marine phosphates lead to the proposition that water chemistry had to have been radically different in the earth's past. A wealth of studies has already shown that both early and late diagenesis can strongly affect REE signatures in phosphates and severely alter primary marine signals. However, no previous research was conducted on how alteration processes occurring prior to final deposition affect marine phosphates. Herein we present a dataset of multiple LA-ICP-MS measurements of REE signatures in isolated phosphate and carbonate grains deposited in a carbonate ramp setting in the central Mediterranean Sea during the middle Miocene "Monterey event". The phosphates are represented by authigenic, biogenic and detrital grains emplaced in bioclastic grain- to packstones dominated by bryozoan and echinoderm fragments, as well as abundant benthic and planktic foraminifers. The results of 39 grain specific LA-ICP-MS measurements in three discrete rock samples reveals four markedly different REE patterns (normalized to the Post Archean Australian Shale standard) in terms of total enrichment and pattern shape. Analyses of REE diagenesis proxies show that diagenetic alteration affected the samples only to a minor degree. Considering grain shape and REE patterns together indicate that authigenic, detrital and biogenic phosphates have distinct REE patterns irrespective of the sample. Our results show that the observed REE patterns in phosphates only broadly reflect

  11. The Binary Frequency of r-Process-Element Enhanced Metal-Poor Stars and its Implications: Chemical Tagging in the Primitive Halo of the Milky Way

    CERN Document Server

    Hansen, Terese; Nordström, Birgitta; Buchhave, Lars A; Beers, Timothy C

    2011-01-01

    A few rare halo giants in the range [Fe/H] $\\simeq -2.9\\pm0.3$ exhibit {\\it r}-process element abundances that vary as a group by factors up to [$r$/Fe] $\\sim80$, relative to those of the iron peak and below. Yet, the astrophysical production site of these {\\it r}-process elements remains unclear. We report initial results from four years of monitoring the radial velocities of 17 {\\it r}-process-enhanced metal-poor giants to detect and characterise binaries in this sample. We find three (possibly four) spectroscopic binaries with orbital periods and eccentricities that are indistinguishable from those of Population I binaries with giant primaries, and which exhibit no signs that the secondary components have passed through the AGB stage of evolution or exploded as supernovae. The other 14 stars in our sample appear to be single -- including the prototypical $r$-process-element enhanced star CS 22892-052, which is also enhanced in carbon, but not in {\\it s}-process elements. We conclude that the {\\it r}-proces...

  12. Puzzling Origin of CEMP-r/s Stars: An Interpretation of Abundance and Enrichment of s- and r-Process Elements from Asymptotic Giant Branch Supernovae

    Indian Academy of Sciences (India)

    Jiang Zhang; Fang Zhao; Yanping Chen; Wenyuan Cui; Bo Zhang

    2013-12-01

    CEMP-r/s stars at low metallicity are known as double-enhanced stars that show enhancements of both r-process and s-process elements. The chemical abundances of these very metal-poor stars provide us a lot of information for putting new restraints on models of neutron-capture processes. In this article, we put forward an accreted scenario in which the double enrichment of r-process and s-process elements is caused by a former intermediate-mass Asymptotic Giant Branch (AGB) companion in a detached binary system. As the AGB superwind is only present at the ultimate phase of AGB stars, there is thus a lot of potential that the degenerate-core mass of an intermediate-mass AGB star reaches the Chandrasekhar limit before the AGB superwind. In these circumstances, both s-process elements produced in the AGB shell and r-process elements synthesized in the subsequent explosion would be sprayed contemporaneously and accreted by its companion. Despite similarity to physical conditions of a core-collapse supernova, a major focus in this scenario is the degenerate C–O core surrounded by an envelope of a former intermediate-mass AGB donor that may collapse and explode. Due to the existence of an outer envelope, r-process nucleosynthesis is expected to occur. Hypothesizing the material-rich europium (Eu) accreted by the secondary via the wind from the supernova to be in proportion to the geometric fraction of the companion with respect to the exploding donor star, we find that the estimated yield of Eu (as representative of r-process elements) per AGB supernova event is about 1 × 10-9⊙ ∼ 5 × 10-9⊙. Using the yields of Eu, the overabundance of r-process elements in CEMP-r/s stars can be accounted for. The calculated results show that the value of parameter , standing for efficiency of wind pollution from the AGB supernova, will reach about 104, which means that the enhanced factor is much larger than unity due to the impact of gravity of the donor and the result of the

  13. Technical Report on the Behavior of Trace Elements, Stable Isotopes, and Radiogenic Isotopes During the Processing of Uranium Ore to Uranium Ore Concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Marks, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Borg, L. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eppich, G. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gaffney, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Genneti, V. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hutcheon, I. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kristo, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lindvall, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramon, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Robel, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, S. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schorzman, K. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sharp, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Singleton, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-09

    The goals of this SP-1 effort were to understand how isotopic and elemental signatures behave during mining, milling, and concentration and to identify analytes that might preserve geologic signatures of the protolith ores. The impurities that are preserved through the concentration process could provide useful forensic signatures and perhaps prove diagnostic of sample origin.

  14. The Diverse Origins of Neutron-Capture Elements in the Metal-Poor Star HD 94028: Possible Detection of Products of i-process Nucleosynthesis

    CERN Document Server

    Roederer, Ian U; Pignatari, Marco; Herwig, Falk

    2016-01-01

    We present a detailed analysis of the composition and nucleosynthetic origins of the heavy elements in the metal-poor ([Fe/H]=-1.62+/-0.09) star HD94028. Previous studies revealed that this star is mildly enhanced in elements produced by the slow neutron-capture process (s-process; e.g., [Pb/Fe]=+0.79+/-0.32) and rapid neutron-capture process (r-process; e.g., [Eu/Fe]=+0.22+/-0.12), including unusually large molybdenum ([Mo/Fe]=+0.97+/-0.16) and ruthenium ([Ru/Fe]=+0.69+/-0.17) enhancements. However, this star is not enhanced in carbon ([C/Fe]=-0.06+/-0.19). We analyze an archival near-ultraviolet spectrum of HD94028, collected using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, and other archival optical spectra collected from ground-based telescopes. We report abundances or upper limits derived from 64 species of 56 elements. We compare these observations with s-process yields from low-metallicity AGB evolution and nucleosynthesis models. No combination of s- and r-process pa...

  15. Application of an ecosystem model to evaluate the importance of different processes and food web structure for transfer of 13 elements in a shallow lake.

    Science.gov (United States)

    Konovalenko, L; Bradshaw, C; Andersson, E; Kautsky, U

    2017-01-18

    In environmental risk assessments of nuclear waste, there is need to estimate the potential risks of a large number of radionuclides over a long time period during which the environment is likely to change. Usually concentration ratios (CRs) are used to calculate the activity concentrations in organisms. However, CRs are not available for all radionuclides and they are not easily scalable to the varying environment. Here, an ecosystem transport model of elements, which estimates concentrations in organisms using carbon flows and food transfer instead of CR is presented. It is a stochastic compartment model developed for Lake Eckarfjärden at Forsmark in Sweden. The model was based on available data on carbon circulation, physical and biological processes from the site and identifies 11 functional groups of organisms. The ecosystem model was used to estimate the environmental transfer of 13 elements (Al, Ca, Cd, Cl, Cs, I, Ni, Nb, Pb, Se, Sr, Th, U) to various aquatic organisms, using element-specific distribution coefficients for suspended particles (Kd PM) and upper sediment (Kd sed), and subsequent transfer in the foodweb. The modelled CRs for different organism groups were compared with measured CRs from the lake and literature data, and showed good agreement for many elements and organisms, particularly for lower trophic levels. The model is, therefore, proposed as an alternative to measured CR, though it is suggested to further explore active uptake, assimilation and elimination processes to get better correspondence for some of the elements. The benthic organisms (i.e. bacteria, microphytobenthos and macroalgae) were identified as more important than pelagic organisms for transfer of elements to top predators. The element transfer model revealed that most of the radionuclides were channelled through the microbial loop, despite the fact that macroalgae dominated the carbon fluxes in this lake. Thus, element-specific adsorption of elements to the surface of

  16. Complex trace element effects of source mixing-fractional crystallization composite processes in Kalaan granodiorite pluton along Wulungu tectonic belt,northern Xinjiang

    Institute of Scientific and Technical Information of China (English)

    刘伟; A.Masuda

    1995-01-01

    Mixing-fractional crystallization composite processes generate 6 complex patterns,which aresynthesized into 3 models,on C21/C31-C11/C31 ratio correlation plots of trace eleroents E1,E2,E3 according totheir relative incompatibility.Three of the six effects are clearly displayed on ratio-ratio correlation plots oftrace elements in the Kalaan granodiorite pluton,indicative of a source mixing-fractional crystallization compositeprocess.The overlying lithospheric mantle was modified by the subduction of oceanic plate during Palaeozoic.The incompatibility order of the 7 concerned trace elements is DTa

  17. Effect of Ca, RE elements and semi-solid processing on the microstructure and creep properties of AZ91 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Nami, B. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Shabestari, S.G., E-mail: shabestari@iust.ac.ir [Center of Excellence for Advanced Materials and Processing (CEAMP), School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Razavi, H. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Mirdamadi, Sh. [Center of Excellence for Advanced Materials and Processing (CEAMP), School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Miresmaeili, S.M. [Department of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU), Lavizan, Tehran (Iran, Islamic Republic of)

    2011-01-25

    Research highlights: {yields} The size of solid globular {alpha}(Mg) particles decreases in semi-solid slurries of AZ91 alloy by adding Ca and RE elements, whereas it has no considerable effect on the shape factor of the solid particles. {yields} Particle growth in semi-solid slurries of AZ91 and AZRC91 alloys takes place by Ostwald ripening mechanism. {yields} The coarsening rate of solid particles in semi-solid slurries of AZRC91 alloy is lower than that of AZ91 alloy. {yields} Creep properties of AZ91 alloy was improved by adding Ca and RE elements. The thixoformed specimens exhibit the better creep resistance than the as-cast specimens. - Abstract: The effects of calcium and rare earth elements (RE) on the microstructure and creep properties of as-cast and thixoformed AZ91 magnesium alloy have been investigated. It has been shown that the amount of {beta}(Mg{sub 17}Al{sub 12}) intermetallic compound decreases by adding Ca and RE elements into AZ91 alloy and new Al{sub 11}RE{sub 3} and Al{sub 2}Ca intermetallic compounds form in the microstructure. The coarsening of primary {alpha}(Mg) particles in AZ91 alloy and in the Ca and RE containing (AZRC91) alloy takes place by Ostwald ripening mechanism. Adding Ca and RE elements into AZ91 alloy results in a decrease in the coarsening rate of solid particles in semi-solid slurry, whereas it has no visible effect on the shape factor of the solid-particles. The creep properties of AZ91 alloy are improved by adding Ca and RE elements particularly, in the thixoformed condition.

  18. Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

    Science.gov (United States)

    Saha, Abhishek; Manikyamba, C.; Santosh, M.; Ganguly, Sohini; Khelen, Arubam C.; Subramanyam, K. S. V.

    2015-06-01

    High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ΣPGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir

  19. Elemental and Sr-Nd-Pb isotope geochemistry of the Cenozoic basalts in Southeast China: Insights into their mantle sources and melting processes

    Science.gov (United States)

    Sun, Pu; Niu, Yaoling; Guo, Pengyuan; Ye, Lei; Liu, Jinju; Feng, Yuexing

    2017-02-01

    We analyzed whole-rock major and trace elements and Sr-Nd-Pb isotopes of the Cenozoic basalts in Southeast China to investigate their mantle source characteristics and melting process. These basalts are spatially associated with three extensional fault systems parallel to the coast line. After correction for the effect of olivine microlites on bulk-rock compositions and the effect of crystal fractionation, we obtained primitive melt compositions for these samples. These primitive melts show increasing SiO2, Al2O3 but decreasing FeO, MgO, TiO2, P2O5, CaO and CaO/Al2O3 from the interior to the coast. Such spatial variations of major element abundances and ratios are consistent with a combined effect of fertile source compositional variation and increasing extent and decreasing pressure of decompression melting from beneath the thick lithosphere in the interior to beneath the thin lithosphere in the coast. These basalts are characterized by incompatible element enrichment but varying extent of isotopic depletion. This element-isotope decoupling is most consistent with recent mantle source enrichment by means of low-degree melt metasomatism that elevated incompatible element abundances without yet having adequate time for isotopic ingrowth in the mantle source regions. Furthermore, Sr and Nd isotope ratios show significant correlations with Nb/Th, Nb/La, Sr/Sr* and Eu/Eu*, which substantiates the presence of recycled upper continental crustal material in the mantle sources of these basalts. Pb isotope ratios also exhibit spatial variation, increasing from the interior to the coastal area. The significant correlations of major element abundances with Pb isotope ratios indicate that the Pb isotope variations also result from varied extent and pressure of decompression melting. We conclude that the elevated Pb isotope ratios from the interior to coast are consistent with increasing extent of decompression melting of the incompatible element depleted mantle matrix, which

  20. To Ba or not to Ba: Enrichment in s-process elements in binary systems with WD companions of various masses

    CERN Document Server

    Merle, T; Van Eck, S; Masseron, T; Van Winckel, H

    2015-01-01

    The enrichment in s-process elements of barium stars is known to be due to pollution by mass transfer from a companion formerly on the thermally-pulsing asymptotic giant branch (AGB), now a carbon-oxygen white-dwarf (WD). This paper investigates the relationship between the s-process enrichment in the barium star and the mass of its WD companion. It is expected that helium WDs, which have masses smaller than about 0.5 Msun and never reached the AGB phase, should not pollute with s-process elements their giant companion, which should thus never turn into a barium star. Spectra with a resolution of R ~ 86000 were obtained with the HERMES spectrograph on the 1.2-m Mercator telescope for a sample of 11 binary systems involving WD companions of various masses. We use standard 1D LTE MARCS model atmospheres coupled with the Turbospectrum radiative-transfer code to derive the atmospheric parameters using equivalent widths of FeI and Fe II lines. The abundances of s-process elements for the entire sample of 11 binary...

  1. Behaviour of major, minor and trace elements (including REEs during kaolinization processes at Zonouz deposit, northeast of Marand, East Azarbaidjan province

    Directory of Open Access Journals (Sweden)

    Vahideh Alipour

    2011-11-01

    Full Text Available The Zonouz kaolin deposit is located ~15 km northeast of Marand, East-Azarbaidjan province. Based on physical features in field investigations, such as color, five distinct kaolin types including (1 white, (2 lemon, (3 gray, (4 brown, and (5 yellow are distinguished in the deposit. Field evidence and petrographic studies indicate that the deposit is genetically close to trachy-andesite rocks. According to mineralogical data, the deposit contains quartz, kaolinite, montmorillonite, calcite, pyrophyllite, chlorite, muscovite-illite, dolomite, hematite, and anatase minerals. Geochemical data indicate that function of alteration processes on trachy-andesite rocks during development of Zonouz ore deposit was accompanied by leaching of elements such as Al, Na, K, Rb, Ba, V, Hf, Cu, Zr, Tm, Yb, and Lu, enrichment of elements such as U, Nb, and Ta, and leaching-fixation of elements such as Si, Fe, Ca, Mg, Ti, Mn, P, Cs, Sr, Th, Co, Cr, Ni, Y, Ga, LREE, Tb, Dy, Ho, and Er. Incorporation of obtained results from mineralogical and geochemical studies show that physico-chemical conditions of alteration environment, the relative stability of primary minerals, surface adsorption, preferential sorption by metallic oxides, existing of organic matters, scavenging and concentration processes, and fixation in neomorphic mineralogical phases played important role in distribution of elements in the deposit. Geochemical studies show that development of the deposit is relative to two types of processes, (1 hypogene and (2 supergene. The distribution pattern of REEs indicates that differentiation degree of LREEs from HREEs in supergene kaolins is more than hypogene kaolins. Geochemical studies indicate that minerals such as Mn-oxides, zircon, anatase, hematite, cerianite, and secondary phosphates (monazite, rhabdophane, churchite, and zenotime are the potential hosts for rare earth elements in this deposit.

  2. Enhancement of canthaxanthin production from Dietzia natronolimnaea HS-1 in a fed-batch process using trace elements and statistical methods

    Directory of Open Access Journals (Sweden)

    M. R. Nasri Nasrabadi

    2010-12-01

    Full Text Available Under fed-batch process conditions, the statistical analysis of trace elements was performed by application of Plackett-Burman design (for screening tests and response surface methodology (for predicting the optimal points to achieve the highest level of canthaxanthin production from Dietzia natronolimnaea HS-1. Plackett-Burman design was conducted on eleven trace elements (i. e., aluminum, boron, cobalt, copper, iron, magnesium, manganese, molybdenum, selenium, vanadium and zinc to select out elements that significantly enhance the canthaxanthin production of D. natronolimnaea HS-1. Plackett-Burman design revealed that Fe3+, Cu2+ and Zn2+ ions had the highest effect on canthaxanthin production of D. natronolimnaea HS-1 (P<0.05. These three elements were used for further optimization. By means of response surface methodology for the fed-batch process, the optimum conditions to achieve the highest level of canthaxanthin (8923±18 µg/L were determined as follow: Fe3+ 30 ppm, Cu2+ 28.75 ppm and Zn2+ 27 ppm.

  3. THE DIVERSE ORIGINS OF NEUTRON-CAPTURE ELEMENTS IN THE METAL-POOR STAR HD 94028: POSSIBLE DETECTION OF PRODUCTS OF i-PROCESS NUCLEOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Roederer, Ian U. [Department of Astronomy, University of Michigan, 1085 S. University Ave., Ann Arbor, MI 48109 (United States); Karakas, Amanda I. [Research School of Astronomy and Astrophysics, The Australian National University, Canberra ACT 2611 (Australia); Pignatari, Marco [E.A. Milne Centre for Astrophysics, Department of Physics and Mathematics, University of Hull, HU6 7RX (United Kingdom); Herwig, Falk, E-mail: iur@umich.edu, E-mail: amanda.karakas@monash.edu, E-mail: mpignatari@gmail.com, E-mail: fherwig@uvic.ca [Joint Institute for Nuclear Astrophysics and Center for the Evolution of the Elements (JINA-CEE) (United States)

    2016-04-10

    We present a detailed analysis of the composition and nucleosynthetic origins of the heavy elements in the metal-poor ([Fe/H] = −1.62 ± 0.09) star HD 94028. Previous studies revealed that this star is mildly enhanced in elements produced by the slow neutron-capture process (s process; e.g., [Pb/Fe] = +0.79 ± 0.32) and rapid neutron-capture process (r process; e.g., [Eu/Fe] = +0.22 ± 0.12), including unusually large molybdenum ([Mo/Fe] = +0.97 ± 0.16) and ruthenium ([Ru/Fe] = +0.69 ± 0.17) enhancements. However, this star is not enhanced in carbon ([C/Fe] = −0.06 ± 0.19). We analyze an archival near-ultraviolet spectrum of HD 94028, collected using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, and other archival optical spectra collected from ground-based telescopes. We report abundances or upper limits derived from 64 species of 56 elements. We compare these observations with s-process yields from low-metallicity AGB evolution and nucleosynthesis models. No combination of s- and r-process patterns can adequately reproduce the observed abundances, including the super-solar [As/Ge] ratio (+0.99 ± 0.23) and the enhanced [Mo/Fe] and [Ru/Fe] ratios. We can fit these features when including an additional contribution from the intermediate neutron-capture process (i process), which perhaps operated through the ingestion of H in He-burning convective regions in massive stars, super-AGB stars, or low-mass AGB stars. Currently, only the i process appears capable of consistently producing the super-solar [As/Ge] ratios and ratios among neighboring heavy elements found in HD 94028. Other metal-poor stars also show enhanced [As/Ge] ratios, hinting that operation of the i process may have been common in the early Galaxy.

  4. Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New sand r-Process Paradigm

    Institute of Scientific and Technical Information of China (English)

    GUI Wen-Yuan; CUI Dong-Nuan; DU Yun-Shuang; ZHANG Bo

    2007-01-01

    The star HE 1305-0007 is a metal-poor double-enhanced star with metallicity [Fe/H] = -2.0,which is just at the upper limit of the metallicity for the observed double-enhanced stars. Using a parametric model, we find that almost all s-elements were made in a single neutron exposure. This star should be a member of a post-common-envelope binary. After the s-process material has experienced only one neutron exposure in the nucleosynthesis region and is dredged-up to its envelope, he AGB evolution is terminated by the onset of common-envelope evolution. Based on the high radial-velocity of HE 1305-0007,we speculate that the star could be a runaway star from a binary system, in which the AIC event has occurred and produced the r-process elements.

  5. The Assessment of Properties of the Information Flow in the Subsystem «The Measuring Sensor – The Processing Element»

    Directory of Open Access Journals (Sweden)

    Nikolaev Victor

    2016-01-01

    Full Text Available Analyzed the scope and types of automated information systems containing subsystems of the “measuring sensor – element processing”. On the basis of the Queuing theory a model of evaluating the properties of information flow in the subsystem. The time spent by the sensor data generation and processing time of the output data array to the processing elements described by an arbitrary distribution law. Using little’s formula the analytical solution allows to estimate the required level of performance of the subsystem. The research of the obtained solution in the range of parameters of interest. On the basis of General theoretical solutions identified four private practical case, different values of the coefficients of variation of information flows.

  6. Information Environment is an Integral Element of Informational Space in the Process of Professional Development of Future Teacher of Physical Culture

    Directory of Open Access Journals (Sweden)

    Yuri V. Dragnev

    2012-04-01

    Full Text Available The article examines information environment as an integral element of information space in the process of professional development of future teacher of physical culture, notes that the strategic objective of the system of higher education is training of competent future teacher of physical culture in the field of information technologies, when information competence and information culture are major components of professionalism in modern information-oriented society

  7. Solar Ion Processing of Major Element Surface Compositions of Mature Mare Soils: Insights from Combined XPS and Analytical TEM Observations

    Science.gov (United States)

    Christoffersen, R.; Dukes, C.; Keller, L. P.; Baragiola, R.

    2012-01-01

    Solar wind ions are capable of altering the sur-face chemistry of the lunar regolith by a number of mechanisms including preferential sputtering, radiation-enhanced diffusion and sputter erosion of space weathered surfaces containing pre-existing compositional profiles. We have previously reported in-situ ion irradiation experiments supported by X-ray photoelectron spectroscopy (XPS) and analytical TEM that show how solar ions potentially drive Fe and Ti reduction at the monolayer scale as well as the 10-100 nm depth scale in lunar soils [1]. Here we report experimental data on the effect of ion irradiation on the major element surface composition in a mature mare soil.

  8. The New Model of Chemical Evolution of r-process Elements Based on The Hierarchical Galaxy Formation I: Ba and Eu

    CERN Document Server

    Komiya, Yutaka; Suda, Takuma; Fujimoto, Masayuki Y

    2014-01-01

    We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy r-process elements, Ba and Eu, of extremely metal-poor (EMP) stars and give constraints on their astronomical sites. Our models take into account changes of the surface abundances of EMP stars by the accretion of interstellar matter (ISM). We also consider metal-enrichment of intergalactic medium (IGM) by galactic winds and the resultant pre-enrichment of proto-galaxies. The trend and scatter of the observed r-process abundances are well reproduced by our hierarchical model with $\\sim 10\\%$ of core-collapse supernovae in low-mass end ($\\sim 10M_{\\odot}$) as a dominant r-process source and the star formation efficiency of $\\sim 10^{-10} \\hbox{yr}^{-1}$. For neutron star mergers as an r-process source, their coalescence timescale has to be $ \\sim 10^7$yrs, and the event rates $...

  9. Hybrid calcium phosphate coatings with the addition of trace elements and polyaspartic acid by a low-thermal process

    Energy Technology Data Exchange (ETDEWEB)

    Xu Sanzhong; Lin Xiangjin [The First Affiliated Hospital, College of Medicine of Zhejiang University, Hangzhou 310003 (China); Yang Xianyan; Chen Xiaoyi; Gao Changyou; Gou Zhongru [Zhejiang-California International NanoSystems Institute, Zhejiang University, Hangzhou 310029 (China); Zhang Lei; Yang Guojing, E-mail: zhrgou@zju.edu.cn [Rui' an People' s Hospital and the 3rd Hospital Affiliated to Wenzhou Medical College, Rui' an 325200 (China)

    2011-06-15

    Research in the field of orthopedic implantology is currently focused on developing methodologies to potentiate osseointegration and to expedite the reestablishment of full functionality. We have developed a simple biomimetic approach for preparing trace elements-codoped calcium phosphate (teCaP) coatings on a titanium substrate. The reaction proceeded via low-thermal incubation in trace elements (TEs)-added simulated body fluid (teSBF) at 90 and 120 deg. C. The x-ray photoelectron spectroscopy, x-ray diffraction and energy-dispersive x-ray analyses demonstrated that the teCaP coating was the composite of hydroxyapatite and whitlockite, simultaneously doped with magnesium, strontium, zinc and silicon. The addition of polyaspartic acid and TEs into SBF significantly densified the coating. The incubation temperature is another important factor controlling the coating precipitation rate and bonding strength. An incubation temperature of 120 deg. C could accelerate the coating precipitation and improve the interface bonding strength. The in vitro cell culture investigation indicated that the teCaP coating supported the adhesion and spreading of ovariectomized rat mesenchymal stem cells (rMSCs) and particularly, promoted rMSCs proliferation compared to the CaP coating prepared in SBF. Collectively, from such a biomimetic route there potentially arises a general procedure to prepare a wide range of bioactive teCaP coatings of different composition for osteoporotic osteogenic cells activation response.

  10. TRANSIENT FINITE ELEMENT SIMULATION AND MICROSTRUCTURE EVOLUTION OF AA2219 WELD JOINT USING GAS TUNGSTEN ARC WELDING PROCESS

    Directory of Open Access Journals (Sweden)

    Sivaraman Arunkumar

    2016-09-01

    Full Text Available In this study we focus on finite element simulation of gas tungsten arc welding (GTAW of AA2219 aluminum alloy and the behavioral of the microstructure before and after weld. The simulations were performed using commercial COMSOL Multiphysics software. The thermal history of the weld region was studied by initially developed mathematical model. A sweep type meshing was used and transient analysis was performed for one welding cycle. The highest temperature noted was 3568 °C during welding. The welding operation was performed on 200×100×25 mm plates. Through metallurgical characterization, it was observed that a fair copper rich cellular (CRC network existed in the weld region. A small amount of intermetallic compounds like Al2Cu is observed through the XRD pattern.

  11. Heuristic Analysis Model of Nitrided Layers' Formation Consisting of the Image Processing and Analysis and Elements of Artificial Intelligence

    National Research Council Canada - National Science Library

    Tomasz Wójcicki; Michal Nowicki

    2016-01-01

    .... The objectives of the analyses of the materials for gas nitriding technology are described. The methods of the preparation of nitrided layers, the steps of the process and the construction and operation of devices for gas nitriding are given...

  12. Development and demonstration of manufacturing processes for fabricating graphite/Larc-160 polyimide structural elements, part 4, paragraph B

    Science.gov (United States)

    1981-01-01

    Progress in the development of processes for production of Celion/LARC-160 graphite-polyimide materials, quality control, and the fabrication of Space Shuttle composite structure components is reported. Liquid chromatographic analyses of three repeatibility batches were performed and are compared to previous Hexcel standard production and to variables study LARC-160 intermediate resins. Development of processes for chopped fiber molding are described and flexural strength, elastic modulus, and other physical and mechanical properties of the molding are presented.

  13. TO THE QUESTION OF THE ORGANIZATION OF DISTRIBUTED INFORMATION-ANALITICAL SYSTEMS WITH ELEMENTS OF INTELLECTUAL PROCESSES

    Directory of Open Access Journals (Sweden)

    Atroshchenko V. A.

    2015-06-01

    Full Text Available In the article we have allocated a number of poorly formalized functional tasks that significantly affect the efficiency of the operation of distributed information-analytical systems. The scheme has been developed for the iterative process, which in addition to the automation of the delivery process and the exchange of information between information systems based on grid integration, also includes funds for applied modeling situations on the basis of available information, developing alternatives, multi-criteria decision problems using techniques scenarios and peer review. Obtained during the evaluation of the effectiveness results allow us to control and manage the operation of distributed information-analytical systems with specific problems, as well as to conduct simulations and analytical processing of the results

  14. Environmental processes affecting plant root uptake of radioactive trace elements and variability of transfer factor data: a review.

    Science.gov (United States)

    Ehlke, Sabine; Kirchner, Gerald

    2002-01-01

    Soil-to-plant transfer factors are commonly used to estimate the food chain transfer of radionuclides. Their definition assumes that the concentration of a radionuclide in a plant relates linearly solely to its average concentration in the rooting zone of the soil. However, the large range of transfer factors reported in the literature shows that the concentration of a radionuclide in a soil is not the only factor influencing its uptake by a plant. With emphasis on radiocesium and -strontium, this paper reviews the effects of competition with major ions present in the soil-plant system, the effects of rhizosphere processes and soil micro-organisms on bioavailability, the factors influencing transport to and uptake by roots and the processes affecting long-term uptake rates. Attention is given to summarizing the results of recent novel electrophysiological and genetic techniques which provide a physiologically based understanding of the processes involved in the uptake and translocation of radiocesium and -strontium by plants.

  15. 3D Viscoelastic Finite Element Modelling of Polymer Flow in the Fiber Drawing Process for Microstructured Polymer Optical Fiber Fabrication

    DEFF Research Database (Denmark)

    Fasano, Andrea; Rasmussen, Henrik K.; Marín, J. M. R.

    2015-01-01

    The process of drawing an optical fiber from a polymer preform is still not completely understood,although it represents one of the most critical steps in the process chain for the fabrication of microstructuredpolymer optical fibers (mPOFs). Here we present a new approach for the numerical...... the numerical modelling of mPOF drawing has mainly beenbased on principles, such as generalized Newtonian fluid dynamics, which are not able to cope with the elasticcomponent in polymer flow. In the present work, we employ the K-BKZ constitutive equation, a non-linearsingle-integral model that combines both...

  16. The formulation of public policies for rural youth in Brazil and the constituent elements of social process

    Directory of Open Access Journals (Sweden)

    Sérgio Botton Barcellos

    2015-08-01

    Full Text Available The construction of the research problem occurred in trying to investigate the configuration of public policies for the rural youth and how this political agenda was introduced in the State of the Brazil. The main issue in the research is how the process of configuration of public policies for rural youth in federal government has occurred. The methodology for this study used was qualitative research procedures were triggered participant observation, interviews and documentary analysis. During the research the actors, the formulated policies and rural youth category expressed during this process were highlighted.

  17. Multi-scale finite element simulation of microstructure response to rolling ratio for ring rolling process based on 42CrMo ingot blank

    Energy Technology Data Exchange (ETDEWEB)

    Guo, L.; Pan, X.; Yang, H. [Northwestern Polytechnical Univ.. State Key Laboratory of Solidification Processing, Xi' an (China); Liu, X. [Univ. of Cumbria. Sustainable Engineering, Workington (United Kingdom)

    2012-07-01

    Combined casting-rolling of ring parts, such as large wind turbine bearing rings, is a short-process, energy-saving, material-saving and low-cost innovative forming process technology. Eliminating the casting defects in the ingot ring blank, such as uneven coarse grains, loose structure, pinholes, cracks and inclusions, has been the bottleneck for the combined casting-rolling process technology development. Due to the integrated prediction capabilities of macro plastic deformation and microstructure evolution, the multi-scale FE (finite element) modeling and simulation has been a powerful tool for optimal design and control of the geometry and microstructure of the deforming body during metal forming process. This paper addresses the high temperature deformation constitutive equations and dynamic recrystallization model of the as-cast 42CrMo steel, proposes a multi-scale FE model of ring rolling process based on 42CrMo ingot blank, and presents the multi-scale simulation of the geometry and microstructure for the process. With consideration of the significant impact of the rolling ratio (the characteristics of deformation degree in ring rolling) on the microstructure of the rolled ring, the influence rules and mechanism of the rolling ratio on the recrystallized microstructure of 42CrMo ingot ring blank are unfolded. The outcome establishes the foundation for the optimal design and steady control of the ring rolling process based on ingot blank. (Author)

  18. Search for rare processes with a Z+bb signature at the LHC, with the matrix element method

    CERN Document Server

    Beluffi, Camille; Lemaitre, Vincent

    This thesis presents a detailed study of the final state with the Z boson decaying into two leptons, produced in the CMS detector at the LHC. In order to tag this topology, sophisticated b jet tagging algorithms have been used, and the calibration of one of them, the Jet Probability (JP) tagger is exposed. A study of the tagger degradation at high energy has been done and led to a small gain of performance. This investigation is followed by the search for the associated production of the standard model (SM) Higgs boson with a Z boson and decaying into two b quarks (ZH channel), using the Matrix Element Method (MEM) and two b-taggers: JP and Combined Secondary Vertex (CSV). The MEM is an advanced tool that produces an event-by-event discriminating variable, called weight. To apply it, several sets of transfer function have been produced. The final results give an observed limit on the ZH production cross section with the H → bb branching ratio of 5.46xσSM when using the CSV tagger and 4.89xσSM when using t...

  19. Dependence of the functional characteristics of thermomechanically processed titanium nickelide on the size of the structural elements of austenite

    Science.gov (United States)

    Polyakova-Vachiyan, K. A.; Ryklina, E. P.; Prokoshkin, S. D.; Dubinskii, S. M.

    2016-08-01

    Effect of the size of the elements of the mixed structure of B2 austenite, which consists of nanosized grains and subgrains of a polygonized substructure, on the functional properties of the Ti-50.7 at % Ni alloy preliminarily subjected to a low-temperature thermomechanical treatment (LTMT) and post-deformation annealing (PDA), has been investigated. The generation of the shape-memory effect (SME) and reversible two-way SME (TWSME) was performed using bending deformation. A maximum (for the Ti-Ni alloys) value of the recovery strain ɛr = 15.5 ± 0.5% has been obtained after annealing at 600°C for 1 h (recrystallized structure) and after LTMT + PDA at 430°C for 10 h (mixed nanocrystalline and nanosubgrain structure). The behavior of the parameters of the SME and TWSME in different structural states has been considered. A comparative study of the effect of the temperature and time of holding at a temperature upon the PDA on the formation of the microstructure and submicrostructure of the B2 austenite has been performed.

  20. Mathematical model of process of redundant measurements with uninterrupted influence of measurand on sensing element of sensor

    Directory of Open Access Journals (Sweden)

    Redko V. V.

    2011-12-01

    Full Text Available The paper discusses improvement of accuracy of measurands measurements with the use of measuring channel with nonlinear calibration curve. There is proposed a mathematical model, which describes process of redundant measurements for measuring channel when it’s measurement function is a polynomial of third power.

  1. Synthesis of high-purity precipitated calcium carbonate during the process of recovery of elemental sulphur from gypsum waste

    CSIR Research Space (South Africa)

    De Beer, Morris

    2015-08-01

    Full Text Available (PCC). The process used an acid gas (H 2S) to improve the aqueous dissolution of CaS, which is otherwise poorly soluble. The carbonate product was primarily calcite (99.5%) with traces of quartz (0.5%). Calcite was the only CaCO3 polymorph obtained...

  2. A window on the efficiency of the s-process in AGB stars: chemical abundances of n-capture elements in the planetary nebula NGC 3918

    CERN Document Server

    Madonna, S; Luridiana, V; Sterling, N C; Morisset, C

    2015-01-01

    The chemical content of the planetary nebula NGC 3918 is investigated through deep, high-resolution (R~40000) UVES at VLT spectrophotometric data. We identify and measure more than 750 emission lines, making ours one of the deepest spectra ever taken for a planetary nebula. Among these lines we detect very faint lines of several neutron-capture elements (Se, Kr, Rb, and Xe), which enable us to compute their chemical abundances with unprecedented accuracy, thus constraining the efficiency of the s-process and convective dredge-up in the progenitor star of NGC 3918.

  3. Vibratory interneurons in the non-hearing cave cricket indicate evolutionary origin of sound processing elements in Ensifera.

    Science.gov (United States)

    Stritih, Natasa; Stumpner, Andreas

    2009-01-01

    Tympanal hearing organs in the front tibiae of ensiferan insects supposedly evolved from vibration-sensitive tibial organs (TO), like those in the cave cricket Troglophilus neglectus (Rhaphidophoridae). If this is true, one expects to find interneurons in the cave cricket that are homologous to auditory neurons from hearing Ensifera. Therefore, we examined the central projections of the foreleg TO of the cave cricket, as well as morphology and response properties of interneurons responding to foreleg vibration. Sensory axons of the TO adjoined to the "tympanal nerve" terminate in the equivalent portion of the ring tract neuropile in the prothoracic ganglion as corresponding receptors of crickets and weta. We found nine putatively homologous elements to sound- and/or vibration-sensitive interneurons of Ensifera--one local neuron (unpaired median, DUM), three T-fibres (TN), three descending (DN) and two ascending neurons (AN). Presumable first-order interneurons arborising in the ring tract correspond to a local auditory DUM cell of bush crickets and to TN1, DN1 and AN2 of various Ensifera, respectively. Homologues of some prominent auditory cells, the "omega" neuron(s) and the ascending neuron 1 (AN1), however, were not found. We conclude that (a) T. neglectus interneurons are morphologically primitive with respect to those of hearing taxa, (b) significant changes in the dendritic structure/synaptic connectivity have taken place during the evolution of the most specialised first-order auditory interneurons of Ensifera, (c) the data do not contradict independent evolution of hearing in Grylloidea and Tettigonoidea. Other interneurons appear morpho-physiologically conserved across hearing and non-hearing species, possibly as a part of a multimodal "alert" system.

  4. Effect of dissolved oxygen on elemental sulfur generation in sulfide and nitrate removal process: characterization, pathway, and microbial community analysis.

    Science.gov (United States)

    Wang, Xiaowei; Zhang, Yu; Zhang, Tingting; Zhou, Jiti

    2016-03-01

    Microaerobic bioreactor treatment for enriched sulfide and nitrate has been demonstrated as an effective strategy to improve the efficiencies of elemental sulfur (S(0)) generation, sulfide oxidation, and nitrate reduction. However, there is little detailed information for the effect and mechanism of dissolved oxygen (DO) on the variations of microbial community in sulfur generation, sulfide oxidation, and nitrate reduction systems. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was employed to evaluate the variations of microbial community structures in a sulfide oxidation and nitrate reduction reactor under different DO conditions (DO 0-0.7 mg · L(-1)). Experimental results revealed that the activity of sulfide-oxidizing bacteria (SOB) and nitrate-reducing bacteria (NRB) could be greatly stimulated in 0.1-0.3 mg-DO · L(-1). However, when the DO concentration was further elevated to more than 0.5 mg · L(-1), the abundance of NRB was markedly decreased, while the heterotrophic microorganisms, especially carbon degradation species, were enriched. The reaction pathways for sulfide and nitrate removal under microaerobic conditions were also deduced by combining batch experiments with functional species analysis. It was likely that the oxidation of sulfide to sulfur could be performed by both aerobic heterotrophic SOB and sulfur-based autotrophic denitrification bacteria with oxygen and nitrate as terminal electron acceptor, respectively. The nitrate could be reduced to nitrite by both autotrophic and heterotrophic denitrification, and then the generated nitrite could be completely converted to nitrogen gas via heterotrophic denitrification. This study provides new insights into the impacts of microaerobic conditions on the microbial community functional structures of sulfide-oxidizing, nitrate-reducing, and sulfur-producing bioreactors, which revealing the potential linkage between functional microbial communities and

  5. Characteristics of hydrothermal sedimentation process in the Yanchang Formation, south Ordos Basin, China: Evidence from element geochemistry

    Science.gov (United States)

    He, Cong; Ji, Liming; Wu, Yuandong; Su, Ao; Zhang, Mingzhen

    2016-11-01

    Hydrothermal sedimentation occurred in the Triassic Yanchang Formation, Ordos Basin, China. However, their macroscopic features at the scale of the stratum and hydrothermal sources still lack correlational research. This paper performed element geochemical study on a large number of core samples collected from the Yanchang Formation of a new drilling well located in the south Ordos Basin. The SiO2/(K2O + Na2O) vs. MnO/TiO2 crossplot and Fe vs. Mn vs. (Cu + Co + Ni) × 10 ternary diagram demonstrate that the Yanchang stratum in the study area has, in general, hydrothermal components. The Al/(Al + Fe + Mn) and (Fe + Mn)/Ti ratios of the core samples range from 0.34 to 0.84 and 4.81 to 50.54, averaging 0.66 and 10.67, respectively, indicating that the stratum is a set of atypical hydrothermal sedimentation with much terrigenous input. Data analysis shows that the hydrothermal source in the study area was from the deep North Qinling Orogen around the south margin of the basin, where some active tectonic and volcanic activities took place, rather than from the relatively stable internal basin. Early Indosinian movement and volcanic activities activated basement faults around the southern margin of the basin, providing vents for the deep hydrothermal fluid upwelling. The hydrothermal indicators suggest that the study area experienced 4 episodes of relatively stronger hydrothermal activity, namely during the Chang 10, Chang 9-1, Chang 7-3 and Chang 6-2 periods. We also propose a new hydrothermal sedimentation model of hydrothermal fluids overflowing from basin margin faults, for the Yanchang Formation, which is reported here for the first time.

  6. Development of educational policy discourses along the time: epistemological elements for the analysis of the official text recontextualization process

    Directory of Open Access Journals (Sweden)

    Viviane Gualter Peixoto da Cunha

    2014-07-01

    Full Text Available This study discusses the development of education policy critical analysis, focusing on theoretical and analytical contributions of poststructuralist perspectives proposed by Stephen Ball and its origin and articulation within the concept of recontextualization of discourse proposed by Bernstein Basil (1996 to capture the emergence and development of educational policy discourses over time. Based on the references provided, research is presented into the history of 14 years of the schooling organized in cycle policy, in a municipal system of the state of Rio de Janeiro, in which the process of recontextualization of discourses included in official texts is analyzed. These approaches were relevant in that they allowed the researchers to understand the policy within the processes of disputes over meaning, therefore, unstable and subject to several different objectives in its discourses.

  7. Aesthetic Learning: Art as an Integrating Element in the Teaching-Learning Process in the Superior Education

    Directory of Open Access Journals (Sweden)

    Anna Karenina Azevedo-Martins

    2014-05-01

    Full Text Available The educational process is considered a mean for the empowerment of the individual contributing to enlarge perspectives in the professional practice. Being consistent with this construction is that, in many areas, traditional teaching methodologies have been combined and/or replaced by strategies based on the interdisciplinarity and the recognition of students as main agents in the teaching-learning process. Among the available teaching-learning resources, we have proposed the use of dramatic performances to explore distinct aspects of the Endocrine System, where students are invited to act as molecules. This aesthetic experience inspired the preparation of the event “Dom Quixote Meeting: a trip to re(learn diabetes, whose idea was to discuss and (rebuild knowledge and practices concerning this disease. In this scenario, we find out that the art, through the corporeity, was an integrative experience for the knowledge construction, development of skills and humanistic learning.

  8. COMPARATIVE STUDY ON THE CONSERVATION OF NUTRITIONAL ELEMENTS OF PEAS DURING STORAGE AND FOOD PROCESSING II. SENSORY ANALYSIS

    Directory of Open Access Journals (Sweden)

    CAMELIA VIZIREANU

    2014-05-01

    Full Text Available The Romanian market has been flooded with a wide range of frozen products or products preserved by sterilization. The quality of these products is reduced or altered by the storage modules, suppliers or customers, product type, and last but not least, by the quality of raw materials subjected to conservation. This study followed the evolution of the nutritional characteristics of three varieties of peas grown in the Galati region subjected to freezing or sterilization, and their behavior during food processing.

  9. Assessing the biomineralization processes in the shell microstructure of modern brachiopods: variations in the oxygen isotope composition and minor element ratios

    Science.gov (United States)

    Milner Garcia, Sara Ana; Rollion-Bard, Claire; Burckel, Pierre; Tomašových, Adam; Angiolini, Lucia; Henkel, Daniela

    2017-04-01

    Brachiopods have been extensively used to reconstruct physicochemical conditions of ancient oceans due to their extensive fossil record and shells made of stable low-Mg calcite. In this context, it is important to assess the impact of brachiopod shell biomineralization processes on geochemical proxies. Six modern species of brachiopod specimen representing the three low-Mg calcite orders (i.e. Terebratulida, Rhynchonellida and Thecideida) were selected, in order to identify the most reliable taxa and the best shell portions to use for measurements of proxies. Three main different shell structures were identified: (1) only primary layer, (2) primary and secondary fibrous layers and (3) same as (2) with also a tertiary columnar layer. Oxygen isotope composition was measured at the micrometre scale with high-resolution ion microprobe. Generally, O isotope values of shells composed of primary and secondary layers show a progression towards more positive values from the outer primary layer to the inner secondary layer. The columnar tertiary shell layer, when present, has the most positive isotopic O values, the closest to the isotopic equilibrium. Variations at the micrometre scale are higher than those measured by conventional bulk techniques, as already shown by Cusack et al. (2012). Trace elements ratios (Li/Ca, B/Ca, Na/Ca, Mg/Ca, and Sr/Ca) were determined by laser ablation coupled to an ICP-MS. The trace element points define profiles parallel to the O isotope ion probe spots. The elemental ratio profiles of species composed by primary and secondary shell layers (Terebratalia transversa, Magasella sanguinea and Magellania venosa) show different behaviours depending on the elements. Mg/Ca and Sr/Ca values are constant throughout all profiles, even Mg/Ca values are more variable. The values of both ratios are in good agreement with previous studies (Perez-Huerta et al., 2008; Butler et al., 2015). Li/Ca values are also constant among the different profiles. In

  10. Heuristic Analysis Model of Nitrided Layers' Formation Consisting of the Image Processing and Analysis and Elements of Artificial Intelligence.

    Science.gov (United States)

    Wójcicki, Tomasz; Nowicki, Michał

    2016-04-01

    The article presents a selected area of research and development concerning the methods of material analysis based on the automatic image recognition of the investigated metallographic sections. The objectives of the analyses of the materials for gas nitriding technology are described. The methods of the preparation of nitrided layers, the steps of the process and the construction and operation of devices for gas nitriding are given. We discuss the possibility of using the methods of digital images processing in the analysis of the materials, as well as their essential task groups: improving the quality of the images, segmentation, morphological transformations and image recognition. The developed analysis model of the nitrided layers formation, covering image processing and analysis techniques, as well as selected methods of artificial intelligence are presented. The model is divided into stages, which are formalized in order to better reproduce their actions. The validation of the presented method is performed. The advantages and limitations of the developed solution, as well as the possibilities of its practical use, are listed.

  11. Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Zakrzewska-Koltuniewicz, Grażyna, E-mail: g.zakrzewska@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Herdzik-Koniecko, Irena [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Cojocaru, Corneliu [Institute of Macromolecular Chemistry “Petru Poni”, Aleea Grigore Ghica Voda, nr. 41A, 700487 Iasi (Romania); Chajduk, Ewelina [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland)

    2014-06-30

    Highlights: • The experimental design for optimization of leaching process of uranium from low-grade ores was applied. • Multi-objective optimization method based on desirability approach was employed. • The recovery of associated metals like vanadium, molybdenum and lanthanides was considered. • The effects of factors were identified by 3-D surface plots. • The optimum condition for valuable metals: P = 5 bar, T = 120 °C and t = 90 min has been determined. - Abstract: The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P = 5 bar, T = 120 °C and t = 90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th)

  12. The chemical composition of nearby young associations: s-process element abundances in AB Doradus, Carina-Near, and Ursa Major

    CERN Document Server

    D'Orazi, Valentina; Desidera, Silvano; Covino, Elvira; Andrievsky, Sergei M; Gratton, Raffaele G

    2012-01-01

    Recently, several studies have shown that young, open clusters are characterised by a considerable over-abundance in their barium content. In particular, D'Orazi et al. (2009) reported that in some younger clusters [Ba/Fe] can reach values as high as ~0.6 dex. The work also identified the presence of an anti-correlation between [Ba/Fe] and cluster age. For clusters in the age range ~4.5 Gyr-500 Myr, this is best explained by assuming a higher contribution from low-mass asymptotic giant branch stars to the Galactic chemical enrichment. The purpose of this work is to investigate the ubiquity of the barium over-abundance in young stellar clusters. We analysed high-resolution spectroscopic data, focusing on the s-process elemental abundance for three nearby young associations, i.e. AB Doradus, Carina-Near, and Ursa Major. The clusters have been chosen such that their age spread would complement the D'Orazi et al. (2009) study. We find that while the s-process elements Y, Zr, La, and Ce exhibit solar ratios in all...

  13. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors...... to human exposure. The occurrence of each element in food classes from different regions is presented. Some of the current toxicological risk assessments on toxic elements, the human health effect of each toxic element, and their contents in the food legislations are presented. An overview of analytical...... techniques and challenges for determination of toxic elements in food is also given....

  14. Effect of process variables on the Drucker-Prager cap model and residual stress distribution of tablets estimated by the finite element method.

    Science.gov (United States)

    Hayashi, Yoshihiro; Otoguro, Saori; Miura, Takahiro; Onuki, Yoshinori; Obata, Yasuko; Takayama, Kozo

    2014-01-01

    A multivariate statistical technique was applied to clarify the causal correlation between variables in the manufacturing process and the residual stress distribution of tablets. Theophylline tablets were prepared according to a Box-Behnken design using the wet granulation method. Water amounts (X1), kneading time (X2), lubricant-mixing time (X3), and compression force (X4) were selected as design variables. The Drucker-Prager cap (DPC) model was selected as the method for modeling the mechanical behavior of pharmaceutical powders. Simulation parameters, such as Young's modulus, Poisson rate, internal friction angle, plastic deformation parameters, and initial density of the powder, were measured. Multiple regression analysis demonstrated that the simulation parameters were significantly affected by process variables. The constructed DPC models were fed into the analysis using the finite element method (FEM), and the mechanical behavior of pharmaceutical powders during the tableting process was analyzed using the FEM. The results of this analysis revealed that the residual stress distribution of tablets increased with increasing X4. Moreover, an interaction between X2 and X3 also had an effect on shear and the x-axial residual stress of tablets. Bayesian network analysis revealed causal relationships between the process variables, simulation parameters, residual stress distribution, and pharmaceutical responses of tablets. These results demonstrated the potential of the FEM as a tool to help improve our understanding of the residual stress of tablets and to optimize process variables, which not only affect tablet characteristics, but also are risks of causing tableting problems.

  15. Elemental isomerization processes for a photochromic diarylethene film based on carrier injection toward all-electrically operable organic memory

    Science.gov (United States)

    Tsujioka, Tsuyoshi; Yamamoto, Kazuki

    2016-06-01

    We propose a basic concept of all-electrically operable organic memory with a photochromic diarylethene (DAE) film based on a transistor structure, in which the DAE memory layer is recordable, erasable, and nondestructively readable by an electrical method. To realize such memory, we investigated each elementary process for recording, erasing, or nondestructive reading by current injection and electrostatic methods for the DAE layer. Both ring-opening and ring-closure isomerization reactions were confirmed for the injection of both carriers (electrons and holes). Hole injection induced ring-opening reaction only. These reaction modes can be utilized in the recording and erasing modes. Since no reactions for electron injection and current modulation based on photoisomerization were observed, electron current injection can be applied to nondestructive readout.

  16. Elements for optimizing a one-step enzymatic bio-refinery process of shrimp cuticles: Focus on enzymatic proteolysis screening

    Directory of Open Access Journals (Sweden)

    R. Baron

    2017-09-01

    Full Text Available This article complements an earlier work published in 2015 Baron et al. (2015 that showed the interest of a shrimp shells bio-refining process. We compare here the effect of eleven commercial proteases at pH 3.5 or 4.0 on a residual amount of shrimp shells proteins after 6 h at 50 °C. The two pH are obtained when respectively 40 and 25 mmol of formic acid are added to 5 g of mild dried shell. Deproteinisation yield above 95% are obtained. Residual amino acids profile in the solid phase was identical for the eleven proteases except for pepsin which was similar to the raw material profile. A significant relative increase in the proportion of Glycine is observed for the ten other cases. Likewise, shapes of size exclusion chromatograms of the dissolved phase are similar except with pepsin.

  17. Detection of low Eu abundances in extremely metal-poor stars and the origin of r-process elements

    CERN Document Server

    Ishimaru, Y; Aoki, W; Ryan, S G; Aoki, Wako; Ishimaru, Yuhri; Ryan, Sean G.; Wanajo, Shinya

    2003-01-01

    We report detailed abundance analyses for three extremely metal-poor stars with [Fe/H] lesssim -3 in the Galactic halo, using the Subaru High Dispersion Spectrograph (HDS). All these stars are found to have sub-solar relative abundances of [Eu/Fe], and exhibit the lowest [Eu/H] values at their metallicities. Comparison of these low Eu abundances with our chemical evolution model of the Galactic halo implies the dominant source of Eu to be the low-mass end of the Type II supernova mass range. This suggests that collapsing O-Ne-Mg cores resulting from 8-10 Msun stars are the major r-process site.

  18. THE PROFESSIONAL COMPOSING PROJECTS AS ELEMENTS DYNAMIZERS OF THE PROCESS AND DEVELOPMENT OF THE PROFESSIONAL SKILLS OF THE COMPUTER ENGINEERS

    Directory of Open Access Journals (Sweden)

    Roberto Barrera Jimenez

    2013-05-01

    Full Text Available The Cuban Education Manner centers its attention in forming a professional in correspondence with the technological advances, capable of guiding their behavior in the exercise of the profession with initiative, flexibility and autonomy, in heterogeneous and diverse stages, starting from the integration of know-how, abilities and goods which are expressed in a professional efficient acting, ethically and socially commited. The present article centers its attention in approaching the dynamic role that grants to the professional composing projects in favor of the process of formation and development of abilities in the students of the engineering computer science career, proposal that is supported, essentially, by the relationships between the system of professional abilities of the career, the generalizing  abilities of every year and the courses that represent the different disciplines.

  19. HIV-1 TAR element is processed by Dicer to yield a viral micro-RNA involved in chromatin remodeling of the viral LTR

    Directory of Open Access Journals (Sweden)

    McCaffrey Timothy

    2007-07-01

    Full Text Available Abstract Background RNA interference (RNAi is a regulatory mechanism conserved in higher eukaryotes. The RNAi pathway generates small interfering RNA (siRNA or micro RNA (miRNA from either long double stranded stretches of RNA or RNA hairpins, respectively. The siRNA or miRNA then guides an effector complex to a homologous sequence of mRNA and regulates suppression of gene expression through one of several mechanisms. The suppression of gene expression through these mechanisms serves to regulate endogenous gene expression and protect the cell from foreign nucleic acids. There is growing evidence that many viruses have developed in the context of RNAi and express either a suppressor of RNAi or their own viral miRNA. Results In this study we investigated the possibility that the HIV-1 TAR element, a hairpin structure of ~50 nucleotides found at the 5' end of the HIV viral mRNA, is recognized by the RNAi machinery and processed to yield a viral miRNA. We show that the protein Dicer, the enzyme responsible for cleaving miRNA and siRNA from longer RNA sequences, is expressed in CD4+ T-cells. Interestingly, the level of expression of Dicer in monocytes is sub-optimal, suggesting a possible role for RNAi in maintaining latency in T-cells. Using a biotin labeled TAR element we demonstrate that Dicer binds to this structure. We show that recombinant Dicer is capable of cleaving the TAR element in vitro and that TAR derived miRNA is present in HIV-1 infected cell lines and primary T-cell blasts. Finally, we show that a TAR derived miRNA is capable of regulating viral gene expression and may be involved in repressing gene expression through transcriptional silencing. Conclusion HIV-1 TAR element is processed by the Dicer enzyme to create a viral miRNA. This viral miRNA is detectable in infected cells and appears to contribute to viral latency.

  20. An element

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K.; Iidzima, K.

    1983-03-30

    An anode of a light metal is used in the element, along with an electrolyte which consists of an ether solvent and an ionogenic additive in the form of a salt of dithiocarbamic acid. The element has good discharge characteristics.

  1. Mineral elements, lipoxygenase activity, and antioxidant capacity of okara as a byproduct in hydrothermal processing of soy milk.

    Science.gov (United States)

    Stanojevic, Sladjana P; Barac, Miroljub B; Pesic, Mirjana B; Zilic, Sladjana M; Kresovic, Mirjana M; Vucelic-Radovic, Biljana V

    2014-09-10

    Minerals and antioxidative capacity of raw okara that was obtained as a byproduct from six soybean varieties during hydrothermal cooking (HTC) of soy milk were assessed. Lipoxygenase (Lox), an enzyme deteriorating the sensory characteristics of okara, was also investigated. All genotypes had very similar concentrations of Lox (4.32-5.62%). Compared to raw soybeans, the applied HTC significantly reduced Lox content in okara (0.54-0.19%) and lowered its activity to 0.004-0.007 μmol g(-1) min (-1). Correlation between the content of Lox in soybeans and that in okara (r = 0.21;p process than on soybean genotype. Very strong correlation (r = 0.99; p minerals in raw okara were potassium (1.04-1.21 g/100g), phosphorus (0.45-0.50 g/100 g), calcium (0.26-0.39 g/100 g), and iron (5.45-10.95 mg/100 g). A very high antioxidant capacity (19.06-29.36 mmol Trolox kg(-1)) contributes to the nutritional value of raw okara.

  2. Develop and demonstrate manufacturing processes for fabricating graphite filament reinforced polymide (Gr/PI) composite structural elements

    Science.gov (United States)

    Chase, V. A.; Harrison, E. S.

    1985-01-01

    A study was conducted to assess the merits of using graphite/polyimide, NR-150B2 resin, for structural applications on advanced space launch vehicles. The program was divided into two phases: (1) Fabrication Process Development; and (2) Demonstration Components. The first phase of the program involved the selection of a graphite fiber, quality assurance of the NR-150B2 polyimide resin, and the quality assurance of the graphite/polyimide prepreg. In the second phase of the program, a limited number of components were fabricated before the NR-150B2 resin system was removed from the market by the supplier, Du Pont. The advancement of the NR-150B2 polyimide resin binder was found to vary significantly based on previous time and temperature history during the prepregging operation. Strength retention at 316C (600F) was found to be 50% that of room temperature strength. However, the composite would retain its initial strength after 200 hours exposure at 316C (600F). Basic chemistry studies are required for determining NR-150B2 resin binder quality assurance parameters. Graphite fibers are available that can withstand high temperature cure and postcure cycles.

  3. Determining Consistency of Tillage Direction with Soil Erosion Protection Requirements as The Element of Decision-Making Process in Planning and Applying Land Consolidation

    Science.gov (United States)

    Bozek, Piotr; Janus, Jaroslaw; Taszakowski, Jaroslaw; Glowacka, Agnieszka

    2016-10-01

    Water erosion is one of the factors which have negative effect on soil productivity. It often leads to irreversible soil degradation, making soil worthless for agricultural activities. One way of preventing water erosion is making the direction of cultivation perpendicular to the direction of rainwater run-off. Matching the direction with the shape of parcels boundaries in small and extended ones is often possible only through changes in the configuration of property boundaries, which is possible only in the process of land consolidation. The article presents methodology of qualifying the areas for changes in boundaries configuration and cultivation direction in view of existing erosion risk. A computation process was suggested that uses, among others, LIDAR data to model the terrain shape precisely as well as cadastral data that defines the geometry of parcels and, resulting from it, the direction of cultivation and form of use. The suggested process includes also the information on the texture of soil upper horizons from soil agricultural maps. The RUSLE erosion model was applied and the computation process took place in ArcGIS environment with the use of dedicated algorithms suggested and implemented to solve the formulated problem. Computations were conducted for test area of several hundred hectares which was characterized by vast diversity of soil types and landforms. The results prove the usefulness of the suggested method as an element of systems that support decision-making processes used in the stage of determining objects chosen for the realization of consolidating processes (including local consolidation, which covers only chosen fragment of a village). They can also be used in the stage of completing detailed plans of parcels distribution in land consolidation process. The importance of the method is particularly seen in the analysis of areas where land fragmentation indices are unfavourable. Especially in these cases, without the reorganization of

  4. Slab-derived halogens and noble gases illuminate closed system processes controlling volatile element transport into the mantle wedge

    Science.gov (United States)

    Kobayashi, Masahiro; Sumino, Hirochika; Nagao, Keisuke; Ishimaru, Satoko; Arai, Shoji; Yoshikawa, Masako; Kawamoto, Tatsuhiko; Kumagai, Yoshitaka; Kobayashi, Tetsuo; Burgess, Ray; Ballentine, Chris J.

    2017-01-01

    Halogen and noble gas systematics are powerful tracers of volatile recycling in subduction zones. We present halogen and noble gas compositions of mantle peridotites containing H2O-rich fluid inclusions collected at volcanic fronts from two contrasting subduction zones (the Avacha volcano of Kamchatka arc and the Pinatubo volcano of Luzon arcs) and orogenic peridotites from a peridotite massif (the Horoman massif, Hokkaido, Japan) which represents an exhumed portion of the mantle wedge. The aims are to determine how volatiles are carried into the mantle wedge and how the subducted fluids modify halogen and noble gas compositions in the mantle. The halogen and noble gas signatures in the H2O-rich fluids are similar to those of marine sedimentary pore fluids and forearc and seafloor serpentinites. This suggests that marine pore fluids in deep-sea sediments are carried by serpentine and supplied to the mantle wedge, preserving their original halogen and noble gas compositions. We suggest that the sedimentary pore fluid-derived water is incorporated into serpentine through hydration in a closed system along faults at the outer rise of the oceanic, preserving Cl/H2O and 36Ar/H2O values of sedimentary pore fluids. Dehydration-hydration process within the oceanic lithospheric mantle maintains the closed system until the final stage of serpentine dehydration. The sedimentary pore fluid-like halogen and noble gas signatures in fluids released at the final stage of serpentine dehydration are preserved due to highly channelized flow, whereas the original Cl/H2O and 36Ar/H2O ratios are fractionated by the higher incompatibility of halogens and noble gases in hydrous minerals.

  5. Socio-cultural models as an important element of the site selection process in rural waste management

    Directory of Open Access Journals (Sweden)

    Nenković-Riznić Marina

    2011-01-01

    Full Text Available The problem of waste management in rural areas has not been the subject of detailed specific researches since most of the research has been directed towards the study of means, mechanisms and procedures of waste elimination in urban settlements. The reason for the reduced scope of research in this field lies in the fact that rural settlements cannot be considered as "grateful" subjects due to usual deficiency of specific data (population number, fluctuations, amount of waste, waste composition, methods of waste elimination, etc.. In addition, for several decades the villages have primarily eliminated waste spontaneously. This has proven difficult to research because of the variations of methods applied to each specific locale, as well as different environmental variables. These criteria are based on patterns of behavior, customs and habits of the local population, but they also insist on absolute participation of local stakeholders in waste management. On the other hand, although Serbia has a legislative frame which is fully harmonized with European laws, there is a problem within unclearly defined waste management system which is oriented mainly on rural areas. The reason for this is the fact that waste management in rural areas is the part of regional waste management, and does not operate independently from the system in "urban" areas. However, since rural areas require the construction of recycling yards, this paper will present a new methodology, which equally valuates techno-economic criteria and social criteria in determining waste elimination locations. This paper will also point out varieties of actors in the process of waste elimination in rural areas, as well as the possibility of their participation.

  6. A regional inventory of the landslide processes and the elements at risk on the Rift flanks west of Lake Kivu (DRC)

    Science.gov (United States)

    Maki Mateso, Jean-Claude; Monsieurs, Elise; Jacobs, Liesbet; Bagalwa Mateso, Luc; Fiama Bondo, Silvanos; Delvaux, Damien; Albino, Fabien; Kervyn, François; Dewitte, Olivier

    2016-04-01

    The Rift flanks west of Lake Kivu (DRC) are one of the Congolese regions most affected by fatal landslides. However, information on the distribution of these processes and their impact on society is still lacking. Here we present a first regional landslide inventory and the associated elements at risk. The inventory was conducted in an area of 5,700 km² in three administrative territories between the cities of Bukavu and Goma. The region is one of the most densely populated area of DRC with a density of up to 200 persons/km². The approach for the inventory relies on visual analysis of Google Earth imagery and a 5 m resolution DEM that we produced from TanDEM-X interferometry. Field validation was performed in target places accounting for 5% of the study area. More than 2,000 landslides were mapped and distinction was made between deep and shallow, and slide and flow processes. Average landslide area is 6 ha (max. = 430 ha). Geomorphological analysis of landslide distribution shows topographic, lithologic, climatic and seismic controls. For 600 randomly-selected landslides, elements at risk (house, road, cultivated land, river) were inventoried in the areas affected and potentially affected by the instabilities; 10% of the landslides are inhabited and 25% do not present any risk. Numerous landslides have caused direct and indirect damage in recent years. In some places, the impact of mining activities on slope stability can be important. Google Earth was the only way to locate the recent shallow failures triggered by known extreme rainfall events. This inventory is a first step towards the understanding of the landslide processes in the region. Further studies are needed to complete and validate the information, to better infer about the triggers, and to compute susceptibility and risk maps.

  7. Light Elements in Plagioclase Phenocrysts of the Nea Kameni Dacites: What do they say about processes during and after crystallization, and just how fast crystallization can take place?

    Science.gov (United States)

    Cabato, M. A.; Altherr, R.; Ludwig, T.

    2005-12-01

    Nea Kameni is the larger of two intra-caldera islands in Santorini Volcano, the most active volcanic center of the Hellenic Arc in Greece. Phenocrysts of samples collected from the 1939-1941 dacite lava flows were analyzed for major and trace element compositions using the EMP and SIMS, with particular focus on concentrations of Li, Be and B. Three types of plagioclase phenocrysts are highlighted in this study. Type N is normally-zoned in terms of An content, with values ranging from 62 in the core to 40 at the rim. A general increase in Li, Be, B from core to rim characterizes this plagioclase, with values of 6.6-7.6 μg/g for Li, 0.37-0.75 μg/g for Be, and 0.10-0.18 μg/g for B. Type O crystals exhibit only oscillatory variations in An content, which ranges from 40 to 57. In terms of Li, however, two subtypes have been identified for this population. Type O1 crystals show Li concentrations that markedly decrease from core to rim, with a maximum value of 23.4 μg/g in the core and a minimum of 6.5 μg/g at the rim. Type O2 crystals are more common, where Li patterns are rather flat and have values within 6.6-11.0 μg/g. Be and B in both subtypes do not vary systematically, except for the slight inverse correlation with An content, and have values of 0.54-0.96 μg/g and 0.10-0.24 μg/g, respectively. Type C phenocrysts have inherited cores with higher An content compared to the outer portions. Within the core, An is between 54 and 63 and Li, Be, B tend to increase from the central portion outwards, with values of 6.5-9.6 μg/g, 0.31-0.60 μg/g, and 0.10-0.16 μg/g, respectively. Towards the rim, the profiles are disrupted: An content drops to 40-54, whereas light elements, especially Be, are elevated at the boundary but decrease gradually toward the rim. Values lie within 6.8-13.9 μg/g for Li, 0.61-0.97 μg/g for Be, and 0.14-0.24 μg/g for B. The different plagioclase types exhibit the complexity of processes involved in the formation of these phenocrysts: from

  8. Felsic Melt Generation at the MOR Magma Chamber Roof: Trace Element Evidence of Experimental Hydrous Partial Melts for Anatectic Processes at the East-Pacific Rise

    Science.gov (United States)

    Erdmann, M.; Fischer, L. A.; France, L.; Deloule, E.; Koepke, J.

    2013-12-01

    Felsic lithologies in oceanic crust environment are volumetrically small but occur frequently. Based on experimental and geochemical studies, different models for their generation are suggested, as fractional crystallization, partial melting of mafic lithologies, and liquid immiscibility. Geochemical studies on felsic lithologies from fast-spreading ridge systems imply that partial melting of previously hydrothermally altered mafic lithologies at the gabbro/dike transitions may play an important role (e.g., Wanless et al., 2010). For a detailed study of this process, we simulated experimentally anatexis at the gabbro/dike transition. In order to evaluate the potential of MORB contamination by anatectic melts, trace elements of the experimental melts were analyzed in-situ by applying secondary ion mass spectrometry (SIMS). As starting material we used rock powder (125-200 μm) of different hydrothermally altered dikes and basaltic hornfelses (so-called granoblastic dikes) from the base of the sheeted dike complex of the IODP site 1256 (East-Pacific Rise, EPR). Such lithologies are assumed to undergo partial melting due to an upward moving of the axial melt lens after replenishment, while granoblastic lithologies are regarded as restitic material of anatectic processes (France et al., 2010). Partial melting experiments under water-saturated conditions were performed in internally heated pressure vessels (IHPV) under conditions similar to those prevailing at the base of the sheeted dike complex (i.e. 100 MPa, 910 to 1030°C, fO2=ΔQFM+1). Our results show that melting of altered basalt with melt fractions less than 20 % (corresponding to temperatures ≤ 970°C) exhibit residual phases perfectly matching those observed in basalts with granoblastic texture (i.e. clinopyroxene, orthopyroxene, plagioclase, magnetite). Anatectic melts of these low degree melting experiments show trace element pattern which are very similar to those of natural dacites from the EPR

  9. Dust dispersal and Pb enrichment at the rare-metal Orlovka-Spokoinoe mining and ore processing site: insights from REE patterns and elemental ratios.

    Science.gov (United States)

    Dolgopolova, Alla; Weiss, Dominik J; Seltmann, Reimar; Dulski, Peter

    2006-04-30

    Different geological, technogenic and environmental samples from the Orlovka-Spokoinoe Ta-Nb-Sn-W mining site and ore processing complex in Eastern Transbaikalia (Russia), were analysed for Pb, Y, Zr, Hf and rare earth elements (REE) to assess the effect of dust and metal dispersal on the environment within the Orlovka-Spokoinoe mining site. Potential source material analysed included ore-bearing and barren granites, host rocks, tailing pond sediments, and ore concentrates. Lichens and birch leaves were used as receptor samples. The REE enrichment relative to chondrite, the extent of the Eu anomalies, the enrichments of heavy REE (HREE), and Zr/Hf and Yb/Y ratios suggest that tailings, barren granites, and metasedimentary host rocks are the main sources of dust in the studied mining environment. In addition, calculated lead enrichment (relative to host rocks) suggests that the environment is polluted with Pb. Our results clearly demonstrate the potential of REE patterns and elemental ratios as a reliable technique to trace dust and metals sources and dispersal within a confined mining area offering a new tool for environmental assessment studies.

  10. Dust dispersal and Pb enrichment at the rare-metal Orlovka-Spokoinoe mining and ore processing site: Insights from REE patterns and elemental ratios

    Energy Technology Data Exchange (ETDEWEB)

    Dolgopolova, Alla [Centre for Russian and Central EurAsian Mineral Studies (CERCAMS), Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)]. E-mail: allad@nhm.ac.uk; Weiss, Dominik J. [Centre for Russian and Central EurAsian Mineral Studies (CERCAMS), Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Seltmann, Reimar [Centre for Russian and Central EurAsian Mineral Studies (CERCAMS), Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Dulski, Peter [GFZ Potsdam, Telegrafenberg, D-14473 Potsdam (Germany)

    2006-04-30

    Different geological, technogenic and environmental samples from the Orlovka-Spokoinoe Ta-Nb-Sn-W mining site and ore processing complex in Eastern Transbaikalia (Russia), were analysed for Pb, Y, Zr, Hf and rare earth elements (REE) to assess the effect of dust and metal dispersal on the environment within the Orlovka-Spokoinoe mining site. Potential source material analysed included ore-bearing and barren granites, host rocks, tailing pond sediments, and ore concentrates. Lichens and birch leaves were used as receptor samples. The REE enrichment relative to chondrite, the extent of the Eu anomalies, the enrichments of heavy REE (HREE), and Zr/Hf and Yb/Y ratios suggest that tailings, barren granites, and metasedimentary host rocks are the main sources of dust in the studied mining environment. In addition, calculated lead enrichment (relative to host rocks) suggests that the environment is polluted with Pb. Our results clearly demonstrate the potential of REE patterns and elemental ratios as a reliable technique to trace dust and metals sources and dispersal within a confined mining area offering a new tool for environmental assessment studies.

  11. Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore.

    Science.gov (United States)

    Zakrzewska-Koltuniewicz, Grażyna; Herdzik-Koniecko, Irena; Cojocaru, Corneliu; Chajduk, Ewelina

    2014-06-30

    The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P=5 bar, T=120 °C and t=90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th).

  12. Antisense targeting of 3' end elements involved in DUX4 mRNA processing is an efficient therapeutic strategy for facioscapulohumeral dystrophy: a new gene-silencing approach.

    Science.gov (United States)

    Marsollier, Anne-Charlotte; Ciszewski, Lukasz; Mariot, Virginie; Popplewell, Linda; Voit, Thomas; Dickson, George; Dumonceaux, Julie

    2016-04-15

    Defects in mRNA 3'end formation have been described to alter transcription termination, transport of the mRNA from the nucleus to the cytoplasm, stability of the mRNA and translation efficiency. Therefore, inhibition of polyadenylation may lead to gene silencing. Here, we choose facioscapulohumeral dystrophy (FSHD) as a model to determine whether or not targeting key 3' end elements involved in mRNA processing using antisense oligonucleotide drugs can be used as a strategy for gene silencing within a potentially therapeutic context. FSHD is a gain-of-function disease characterized by the aberrant expression of the Double homeobox 4 (DUX4) transcription factor leading to altered pathogenic deregulation of multiple genes in muscles. Here, we demonstrate that targeting either the mRNA polyadenylation signal and/or cleavage site is an efficient strategy to down-regulate DUX4 expression and to decrease the abnormally high-pathological expression of genes downstream of DUX4. We conclude that targeting key functional 3' end elements involved in pre-mRNA to mRNA maturation with antisense drugs can lead to efficient gene silencing and is thus a potentially effective therapeutic strategy for at least FSHD. Moreover, polyadenylation is a crucial step in the maturation of almost all eukaryotic mRNAs, and thus all mRNAs are virtually eligible for this antisense-mediated knockdown strategy.

  13. Trace elements and REE geochemistry of Middle Devonian carbonate mounds (Maïder Basin, Eastern Anti-Atlas, Morocco): Implications for early diagenetic processes

    Science.gov (United States)

    Franchi, Fulvio; Turetta, Clara; Cavalazzi, Barbara; Corami, Fabiana; Barbieri, Roberto

    2016-08-01

    Trace and rare earth elements (REEs) have proven their utility as tools for assessing the genesis and early diagenesis of widespread geological bodies such as carbonate mounds, whose genetic processes are not yet fully understood. Carbonates from the Middle Devonian conical mud mounds of the Maïder Basin (eastern Anti-Atlas, Morocco) have been analysed for their REE and trace element distribution. Collectively, the carbonates from the Maïder Basin mud mounds appear to display coherent REE patterns. Three different geochemical patterns, possibly related with three different diagenetic events, include: i) dyke fills with a normal marine REE pattern probably precipitated in equilibrium with seawater, ii) mound micrite with a particular enrichment of overall REE contents and variable Ce anomaly probably related to variation of pH, increase of alkalinity or dissolution/remineralization of organic matter during early diagenesis, and iii) haematite-rich vein fills precipitated from venting fluids of probable hydrothermal origin. Our results reinforce the hypothesis that these mounds were probably affected by an early diagenesis induced by microbial activity and triggered by abundance of dispersed organic matter, whilst venting may have affected the mounds during a later diagenetic phase.

  14. Identification and geochemical modeling of processes controlling leaching of Cr(VI) and other major elements from chromite ore processing residue

    Science.gov (United States)

    Geelhoed, Jeanine S.; Meeussen, Johannes C. L.; Hillier, Stephen; Lumsdon, David G.; Thomas, Rhodri P.; Farmer, John G.; Paterson, Edward

    2002-11-01

    Chromite ore processing residue (COPR) contains very high levels of chromium as Cr(III) and Cr(VI) and has a pH of ˜11.5 to 12. Millions of tonnes of COPR have in the past been deposited in urban areas. We have studied the factors that control leaching of Cr(VI), Ca, Al, Si, and Mg from COPR by means of batch experiments, mineralogical characterization of COPR via X-ray powder diffraction and scanning electron microscopy, and chemical equilibrium modeling. Batch experiments at a range of pH values and two liquid:solid ratios showed that mineral solubility control exists for aqueous concentrations of Cr(VI) above pH 10. Calculations indicate that the solid phases that control the solubility of Cr(VI) at pH values above 11 are Cr(VI)-substituted hydrogarnet (Ca 3Al 2(H 4O 4,CrO 4) 3) and Cr(VI)-hydrocalumite (Ca 4Al 2(OH) 12CrO 4·6 H 2O), a layered double-hydroxide clay with chromate anions held in the interlayers. In the pH range 9.5 to 11, the description of the Cr(VI) concentration in solution was strongly improved by the incorporation in the model of Cr(VI)-ettringite (Ca 6Al 2(OH) 12(CrO 4) 3·26 H 2O), which precipitates as a secondary phase when hydrocalumite dissolves. The proposed model for leaching of COPR at high pH includes Cr(VI)-bearing hydrogarnet, Cr(VI)-hydrocalumite, Cr(VI)-ettringite, brucite, calcite, Ca 2Al 2(OH) 10·3 H 2O, CaH 2SiO 4, and gehlenite hydrate (Ca 2Al 2(OH) 6SiO 8H 8·H 2O). The model accurately predicts the concentrations of Cr(VI), Ca, Al, Si, and Mg in solution in the pH range 10 to 12 as well as the pH-buffering behavior. Below pH 8, a decrease in the Cr(VI) concentration in solution is observed, which may be attributed to sorption of chromate onto freshly precipitated Al and Fe hydroxide surfaces. Sulfate and carbonate show the same type of behavior as chromate. The chemistry of COPR shows similarities with cement and high-pH municipal waste incinerator bottom ash.

  15. Trace elements in magnetite from massive iron oxide-apatite deposits indicate a combined formation by igneous and magmatic-hydrothermal processes

    Science.gov (United States)

    Knipping, Jaayke L.; Bilenker, Laura D.; Simon, Adam C.; Reich, Martin; Barra, Fernando; Deditius, Artur P.; Wälle, Markus; Heinrich, Christoph A.; Holtz, François; Munizaga, Rodrigo

    2015-12-01

    Iron oxide-apatite (IOA) deposits are an important source of iron and other elements (e.g., REE, P, U, Ag and Co) vital to modern society. However, their formation, including the namesake Kiruna-type IOA deposit (Sweden), remains controversial. Working hypotheses include a purely magmatic origin involving separation of an Fe-, P-rich, volatile-rich oxide melt from a Si-rich silicate melt, and precipitation of magnetite from an aqueous ore fluid, which is either of magmatic-hydrothermal or non-magmatic surface or metamorphic origin. In this study, we focus on the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit (∼350 Mt Fe) located in the northern Chilean Iron Belt. Los Colorados has experienced minimal hydrothermal alteration that commonly obscures primary features in IOA deposits. Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping demonstrate distinct chemical zoning in magnetite grains, wherein cores are enriched in Ti, Al, Mn and Mg. The concentrations of these trace elements in magnetite cores are consistent with igneous magnetite crystallized from a silicate melt, whereas magnetite rims show a pronounced depletion in these elements, consistent with magnetite grown from an Fe-rich magmatic-hydrothermal aqueous fluid. Further, magnetite grains contain polycrystalline inclusions that re-homogenize at magmatic temperatures (>850 °C). Smaller inclusions (hydrothermal fluid, which manifests in magnetite rims that have trace element abundances consistent with growth from a magmatic-hydrothermal fluid. Mass balance calculations indicate that this process can leach and transport sufficient Fe from a magmatic source to form large IOA deposits such as Los Colorados. Furthermore, published experimental data demonstrate that a saline magmatic-hydrothermal ore fluid will scavenge significant quantities of metals

  16. Metals and Rare Earth Elements in polar aerosol as specific markers of natural and anthropogenic aerosol sources areas and atmospheric transport processes

    Science.gov (United States)

    Giardi, Fabio; Becagli, Silvia; Caiazzo, Laura; Cappelletti, David; Grotti, Marco; Malandrino, Mery; Salzano, Roberto; Severi, Mirko; Traversi, Rita; Udisti, Roberto

    2016-04-01

    Metals and Rare Earth Elements (REEs) in the aerosol have conservative properties from the formation to the deposition and can be useful to identify and quantify their natural and anthropic sources and to study the atmospheric transport processes. In spite of their importance relatively little is known about metals and especially REEs in the Artic atmosphere due to their low concentration in such environment. The present work reports the first attempt to determine and interpret the behaviour of metals and REEs in polar aerosol at high temporal resolution. Daily PM10 samples of arctic atmospheric particulate were collected on Teflon filters, during six spring-summer campaigns, since 2010, in the laboratory of Gruvebadet in Ny Ålesund (78°56' N, 11°56' E, Svalbard Islands, Norway). Chemical analyses were carried out through Inductively Coupled Plasma Mass Spectrometer provided with a desolvation nebulizer inlet system, allowing to reduce isobaric interferences and thus to quantify trace and ultra-trace metals in very low concentration in the Arctic aerosol samples. The results are useful in order to study sources areas, transport processes and depositional effects of natural and anthropic atmospheric particulate reaching the Arctic from southern industrialized areas; moreover, the observed seasonal trends give information about the different impact of natural and anthropic emissions driven by phenomena such as the Arctic Haze and the melting of the snow. In particular Rare Earth Elements (often in the ppt range) can be considered as soil's fingerprints of the particulate source areas and their determination, together with air-mass backtrajectory analysis, allow to identify dust source areas for the arctic mineral aerosol.

  17. A 2-D FINITE ELEMENT MODEL SIMULATION OF THE MELTING PROCESS OF Al-Ti ALLOY IN VACUUM INDUCTION FURNACE WITH COLD CRUCIBLE (VIFCC)

    Institute of Scientific and Technical Information of China (English)

    S.C. Chu; S.S. Lian; F.K. Chen

    2004-01-01

    The development of a numerical model for the melting process of Al-Ti alloy target material in vacuum induction furnace with cold crucible (VIFCC) was described. It is a two-dimensional computational methodology to calculate electromagnetic field, heat transfer field and fluid flow field . Based on the aid of the finite element method with the commercial software-ANSYS, a superimposition method of a layer of copper and a slit to simulate the VIFCC melting process was used. The method was effective to save large quantity of memory and computing time. Meanwhile, a temperature distribution profile during the melting process was obtained. Validity of the model was confirmed by comparison between the result from calculation and those from direct measurement by optical pyrometer and indirect investigation by ingot macrostructure.A relatively good agreement was found. Further, a nearly directional solidification structure was obtained under properly controlling the cooling rate and heating power.Therefore, such model developed in this article is feasible.

  18. Relaxase DNA Binding and Cleavage Are Two Distinguishable Steps in Conjugative DNA Processing That Involve Different Sequence Elements of the nic Site*

    Science.gov (United States)

    Lucas, María; González-Pérez, Blanca; Cabezas, Matilde; Moncalian, Gabriel; Rivas, Germán; de la Cruz, Fernando

    2010-01-01

    TrwC, the relaxase of plasmid R388, catalyzes a series of concerted DNA cleavage and strand transfer reactions on a specific site (nic) of its origin of transfer (oriT). nic contains the cleavage site and an adjacent inverted repeat (IR2). Mutation analysis in the nic region indicated that recognition of the IR2 proximal arm and the nucleotides located between IR2 and the cleavage site were essential for supercoiled DNA processing, as judged either by in vitro nic cleavage or by mobilization of a plasmid containing oriT. Formation of the IR2 cruciform and recognition of the distal IR2 arm and loop were not necessary for these reactions to take place. On the other hand, IR2 was not involved in TrwC single-stranded DNA processing in vitro. For single-stranded DNA nic cleavage, TrwC recognized a sequence embracing six nucleotides upstream of the cleavage site and two nucleotides downstream. This suggests that TrwC DNA binding and cleavage are two distinguishable steps in conjugative DNA processing and that different sequence elements are recognized by TrwC in each step. IR2-proximal arm recognition was crucial for the initial supercoiled DNA binding. Subsequent recognition of the adjacent single-stranded DNA binding site was required to position the cleavage site in the active center of the protein so that the nic cleavage reaction could take place. PMID:20061574

  19. Experimental Study and Finite Element Polycrystal Model Simulation of the Cold Rolling Textures in a Powder Metallurgy Processed Pure Aluminum Plate

    Institute of Scientific and Technical Information of China (English)

    Liqing CHEN; Naoyuki Kanetake

    2005-01-01

    Ingot metallurgy (IM) aluminum has long been the subject and attracted the attention of many metallurgists and textural researchers of materials. Due to the introduction of large amounts of ex situ interfaces, however, the textures in powder metallurgy (PM) processed aluminum has been rarely reported. In this article, a pure aluminum plate was prepared via PM route. The starting billet was first produced with uni-axially cold compaction and flat hot-extrusion and then followed by cold rolling processes. The hot-extruded and cold rolling deformation textures of the pure PM aluminum at 50%, 80% and 90% cold rolling reductions were studied by orientation distribution functions (ODFs) analysis. The finite element polycrystal model (FEPM) was finally utilized to simulate the cold rolling textural evolution at various stages of cold rolling. In FEPM simulation, the initial hot-extruded textures were taken into account as inputs. The results showed that typical β-fiber texture formed in pure PM aluminum with the cold rolling reduction increased till 80%, and there was not much change after excessive cold rolling deformation.Homogeneous slip is not the only deformation mode in PM processed pure aluminum plate at over 80% cold rolling reduction. The experimental results were qualitatively in good agreement with the simulated ones.

  20. Relaxase DNA binding and cleavage are two distinguishable steps in conjugative DNA processing that involve different sequence elements of the nic site.

    Science.gov (United States)

    Lucas, María; González-Pérez, Blanca; Cabezas, Matilde; Moncalian, Gabriel; Rivas, Germán; de la Cruz, Fernando

    2010-03-19

    TrwC, the relaxase of plasmid R388, catalyzes a series of concerted DNA cleavage and strand transfer reactions on a specific site (nic) of its origin of transfer (oriT). nic contains the cleavage site and an adjacent inverted repeat (IR(2)). Mutation analysis in the nic region indicated that recognition of the IR(2) proximal arm and the nucleotides located between IR(2) and the cleavage site were essential for supercoiled DNA processing, as judged either by in vitro nic cleavage or by mobilization of a plasmid containing oriT. Formation of the IR(2) cruciform and recognition of the distal IR(2) arm and loop were not necessary for these reactions to take place. On the other hand, IR(2) was not involved in TrwC single-stranded DNA processing in vitro. For single-stranded DNA nic cleavage, TrwC recognized a sequence embracing six nucleotides upstream of the cleavage site and two nucleotides downstream. This suggests that TrwC DNA binding and cleavage are two distinguishable steps in conjugative DNA processing and that different sequence elements are recognized by TrwC in each step. IR(2)-proximal arm recognition was crucial for the initial supercoiled DNA binding. Subsequent recognition of the adjacent single-stranded DNA binding site was required to position the cleavage site in the active center of the protein so that the nic cleavage reaction could take place.

  1. Finite Element Analysis of Residual Stress in Ti-6Al-4V Alloy Plate Induced by Deep Rolling Process under Complex Roller Path

    Directory of Open Access Journals (Sweden)

    J. J. Liou

    2014-01-01

    Full Text Available The kinematics of the deep rolling tool, contact stress, and induced residual stress in the near-surface material of a flat Ti-6Al-4V alloy plate are numerically investigated. The deep rolling tool is under multiaxis nonlinear motion in the process. Unlike available deep rolling simulations in the open literature, the roller motion investigated in this study includes penetrative and slightly translational motions. A three-dimensional finite element model with dynamic explicit technique is developed to simulate the instantaneous complex roller motions during the deep rolling process. The initial motion of the rollers followed by the penetration motion to apply the load and perform the deep rolling process, the load releasing, and material recovery steps is sequentially simulated. This model is able to capture the transient characteristics of the kinematics on the roller and contacts between the roller and the plate due to variations of roller motion. The predictions show that the magnitude of roller reaction force in the penetration direction starts to decrease with time when the roller motion changes to the deep rolling step and the residual stress distributions in the near-surface material after the material recovery step varies considerably along the roller path.

  2. Elements of EEG signal processing.

    Science.gov (United States)

    Rampil, I J

    1987-01-01

    It is difficult to find well controlled clinical studies comparing the utility of the numerous EEG measures which have been described. A brief summary of the literature reveals a number of promising case reports, a few large series of patients, and fewer well-designed, well-controlled studies. The very abundance of algorithms makes even technical comparisons of the ability of each to transduce and reflect clinical changes useful (27, 29). Most studies are positive; but thus far (as with so many procedures in medicine), there is no definitive study demonstrating an unequivocal benefit to patients who are monitored with automated, online EEG analysis. That such a study may never be done should not detract from the possible benefits these techniques may bring to clinical practice, most particularly preparing the way for effective brain monitoring in situations in which it was impractical before.

  3. Neutron Star Mergers as the Origin of r-Process Elements in the Galactic Halo Based on the Sub-halo Clustering Scenario

    CERN Document Server

    Ishimaru, Yuhri; Prantzos, Nikos

    2015-01-01

    Binary mergers (NSMs) of double neutron star (and black hole-neutron star) systems are suggested to be major sites of r-process elements in the Galaxy by recent hydrodynamical and nucleosynthesis studies. It has been pointed out, however, that the estimated long lifetimes of neutron star binaries are in conflict with the presence of r-process-enhanced halo stars at metallicities as low as [Fe/H] ~ -3. To resolve this problem, we examine the role of NSMs in the early Galactic chemical evolution on the assumption that the Galactic halo was formed from merging sub-halos. We present simple models for the chemical evolution of sub-halos with total final stellar masses between 10^4 M_solar and 2 x 10^8 M_solar. Typical lifetimes of compact binaries are assumed to be 100 Myr (for 95% of their population) and 1 Myr (for 5%), according to recent binary population synthesis studies. The resulting metallcities of sub-halos and their ensemble are consistent with the observed mass-metallicity relation of dwarf galaxies in...

  4. Determination of the elemental concentration of uranium and thorium in the products and by-products of amang tin tailings process

    Science.gov (United States)

    Alnour, I. A.; Wagiran, H.; Ibrahim, N.; Hamzah, S.; Elias, M. S.

    2017-01-01

    Amang or tin tailing is processed into concentrated ores and other economical valuable minerals such as monazite, zircon, xenotime, ilmenite etc. Besides that, the tailings from these ores may have a significant potential source of radiation exposure to amang plants' workers. This study was conducted to determine the elemental concentration of uranium and thorium in mineral samples collected from five amang tailing factories. The concentration of uranium and thorium was carried out by using instrumental neutron activation analysis (INAA) relative technique. The concentration of uranium and thorium in ppm obtained in this study are as follows: raw (189-1064) and (622-4965); monazite (1076-1988) and (3467-33578); xenotime 4053 and 5540; zircon (309-3090) and (387-6339); ilmenite (104-583) and (88-1205); rutile (212-889) and (44-1119); pyrite (7-43) and (9-132); and waste (5-338) and (9-1218) respectively. The analysis results shows that the monazite, xenotime and zircon have high content of uranium and thorium, whereas ilmenite, rutile, pyrite and waste have lower concentration compare with raw materials after tailing process. The highest values of uranium and thorium concentrations (4053 ± 428 ppm and 33578 ± 873 ppm, respectively) were observed in xenotime and monazite; whereas the lowest value was 5.48 ± 0.86 ppm of uranium recorded in waste (sand) and 9 ± 0.32 ppm of thorium for waste (sand) and pyrite.

  5. Importance of vertical geochemical processes in controlling the oceanic profiles of dissolved rare earth elements inferred from the study in the northeastern Indian Ocean

    Science.gov (United States)

    Nozaki, Y.

    2001-12-01

    The vertical profiles of dissolved rare earth elements (REEs) were obtained in the Bay of Bengal and the Andaman Sea. The REE concentrations at various depths in the Bay of Bengal are the highest in the Indian Ocean. This is attributable ultimately to the large outflow of the Ganges-Brahmaputra and Irrawaddy Rivers, but the dissolved REE flux to surface waters alone can not explain the REE enrichment throughout the entire water column. The underlying fan sediments serve as not a source but a sink for dissolved REE(III)s. Partial dissolution of detrital partilces which are carried by the rivers and lateral currents and subsequently settling through the water column appears to be a predominant source for dissolved REEs. The vertical profiles showing an almost linear increase with depth are common features for the light and middle REEs everywhere, but their concentration levels are variable from basin to basin and from element to element. This suggest that their oceanic distributions are quickly responding to the variation of detrital particle flux and its REE composition through a reversible exchange equilibirum with suspended and sinking particles much like the case for Th. The relative importance of the vertical geochemical processes of reversible scavenging over the horizontal basin-scale ocean circulation with passive regeneration like nutrients systematically decreases from the light to the heavy REEs. Using a model, the mean oceanic residence times of REEs in the Bay of Bengal are estimated to range from 37 years for Ce to 140-1510 years for the strictly trivalent REEs. In the deep water of the Andaman Sea isolated from the Bay of Bengal by the Andaman-Nicobar Ridge (maximum sill depth of sim1800 m), the REE concentrations are almost uniform presumably due to rapid vertical mixing. The REE(III) concentrations are similar to that of ~1250 m depth water in the Bay of Bengal being consistent with other oceanographic properties. However, the REE composition of the

  6. Simulation of nonlinear benchmarks and sheet metal forming processes using linear and quadratic solid–shell elements combined with advanced anisotropic behavior models

    Directory of Open Access Journals (Sweden)

    WangPeng

    2016-01-01

    Full Text Available A family of prismatic and hexahedral solid‒shell (SHB elements with their linear and quadratic versions is presented in this paper to model thin 3D structures. Based on reduced integration and special treatments to eliminate locking effects and to control spurious zero-energy modes, the SHB solid‒shell elements are capable of modeling most thin 3D structural problems with only a single element layer, while describing accurately the various through-thickness phenomena. In this paper, the SHB elements are combined with fully 3D behavior models, including orthotropic elastic behavior for composite materials and anisotropic plastic behavior for metallic materials, which allows describing the strain/stress state in the thickness direction, in contrast to traditional shell elements. All SHB elements are implemented into ABAQUS using both standard/quasi-static and explicit/dynamic solvers. Several benchmark tests have been conducted, in order to first assess the performance of the SHB elements in quasi-static and dynamic analyses. Then, deep drawing of a hemispherical cup is performed to demonstrate the capabilities of the SHB elements in handling various types of nonlinearities (large displacements and rotations, anisotropic plasticity, and contact. Compared to classical ABAQUS solid and shell elements, the results given by the SHB elements show good agreement with the reference solutions.

  7. Size distributions of elemental carbon in the atmosphere of a coastal urban area in South China: characteristics, evolution processes, and implications for the mixing state

    Science.gov (United States)

    Huang, X.-F.; Yu, J. Z.

    2008-10-01

    Elemental carbon (EC), as one of the primary light-absorbing components in the atmosphere, has a significant impact on both regional and global climate. The environmental impacts of EC are strongly dependent on its particle size. Little is known about the size distribution characteristics of EC particles in China's ambient environments. We report size distributions of EC particles in the urban area of Shenzhen in Southern China. In our samples, EC was consistently found in two modes, a fine mode and a coarse mode. The majority of EC mass (~80%) in this coastal metropolitan city resided in particles smaller than 3.2 μm in diameter. The fine mode peaked at around either 0.42 μm or 0.75 μm. While the mode at 0.42 μm could be ascribed to fresh vehicular emissions in the region, the mode at 0.75 μm was likely a result of particle growth from smaller EC particles. We theoretically investigated the particle growth processes that caused the EC particles to grow from 0.42 μm to 0.75 µm in the atmosphere. Our calculations indicate that the EC peak at 0.75 μm was not produced through either coagulation or H2SO4 condensation; both processes are too slow to lead to significant EC growth. Hygroscopic growth was also determined to be insignificant. Instead, addition of sulfate through in-cloud processing was found to cause significant growth of the EC particles and to explain the EC peak at 0.75 μm. We also estimated the mixing state of EC from the EC size distributions. In the droplet size, at least 45 60% of the EC mass in the summer samples and 68% of the EC mass in the winter samples was internally mixed with sulfate as a result of in-cloud processing. This information on EC should be considered in models of the optical properties of aerosols in this region. Our results also suggest that the in-cloud processing of primary EC particles could increase the light absorbing capacities through mixing EC with sulfate.

  8. Size distributions of elemental carbon in the atmosphere of a coastal urban area in South China: characteristics, evolution processes, and implications for the mixing state

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2008-10-01

    Full Text Available Elemental carbon (EC, as one of the primary light-absorbing components in the atmosphere, has a significant impact on both regional and global climate. The environmental impacts of EC are strongly dependent on its particle size. Little is known about the size distribution characteristics of EC particles in China's ambient environments. We report size distributions of EC particles in the urban area of Shenzhen in Southern China. In our samples, EC was consistently found in two modes, a fine mode and a coarse mode. The majority of EC mass (~80% in this coastal metropolitan city resided in particles smaller than 3.2 μm in diameter. The fine mode peaked at around either 0.42 μm or 0.75 μm. While the mode at 0.42 μm could be ascribed to fresh vehicular emissions in the region, the mode at 0.75 μm was likely a result of particle growth from smaller EC particles. We theoretically investigated the particle growth processes that caused the EC particles to grow from 0.42 μm to 0.75 µm in the atmosphere. Our calculations indicate that the EC peak at 0.75 μm was not produced through either coagulation or H2SO4 condensation; both processes are too slow to lead to significant EC growth. Hygroscopic growth was also determined to be insignificant. Instead, addition of sulfate through in-cloud processing was found to cause significant growth of the EC particles and to explain the EC peak at 0.75 μm. We also estimated the mixing state of EC from the EC size distributions. In the droplet size, at least 45–60% of the EC mass in the summer samples and 68% of the EC mass in the winter samples was internally mixed with sulfate as a result of in-cloud processing. This information on EC should be considered in models of the optical properties of aerosols in this region. Our results also suggest that the in-cloud processing of primary EC particles could increase the light absorbing capacities through mixing EC with sulfate.

  9. Reconfigurable VLIW Processor for Software Defined Radio Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We will implement an environment for design, formal verification, compilation of code, and performance and power evaluation of Systems on a Chip (SOCs) consisting of...

  10. Mass production of volume holographic optical elements (vHOEs) using Bayfol® HX photopolymer film in a roll-to-roll copy process

    Science.gov (United States)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Grote, Fabian; Hagen, Rainer; Hönel, Dennis; Koch, Eberhard; Rewitz, Christian; Walze, Günther; Wewer, Brita

    2017-03-01

    Volume Holographic Optical Elements (vHOEs) gained wide attention as optical combiners for the use in augmented and virtual reality (AR and VR, respectively) consumer electronics and automotive head-up display applications. The unique characteristics of these diffractive grating structures - being lightweight, thin and flat - make them perfectly suitable for use in integrated optical components like spectacle lenses and car windshields. While being transparent in Off-Bragg condition, they provide full color capability and adjustable diffraction efficiency. The instant developing photopolymer Bayfol® HX film provides an ideal technology platform to optimize the performance of vHOEs in a wide range of applications. Important for any commercialization are simple and robust mass production schemes. In this paper, we present an efficient and easy to control one-beam recording scheme to copy a so-called master vHOE in a step-and-repeat process. In this contact-copy scheme, Bayfol® HX film is laminated to a master stack before being exposed by a scanning laser line. Subsequently, the film is delaminated in a controlled fashion and bleached. We explain working principles of the one-beam copy concept and discuss the mechanical construction of the installed vHOE replication line. Moreover, we treat aspects like master design, effects of vibration and suppression of noise gratings. Furthermore, digital vHOEs are introduced as master holograms. They enable new ways of optical design and paths to large scale vHOEs.

  11. Processes in massive nuclei reactions and the way to complete fusion of reactants. What perspectives for the synthesis of heavier superheavy elements?

    Science.gov (United States)

    Mandaglio, G.; Nasirov, A. K.; Curciarello, F.; De Leo, V.; Romaniuk, M.; Fazio, G.; Giardina, G.

    2012-12-01

    By using the dinuclear system (DNS) model we determine the capture of reactants at the first stage of reaction, the competition between the DNS decay by the quasifission (QF) and the complete fusion (CF) process up to formation of the compound nucleus (CN) having compact shape. Further evolution of the CN is considered as its fission into two fragments or formation of evaporation residues (ER) by its cooling after emission of neutrons or/and charged light particles. Disappearance of the CN fission barrier due to its fast rotation leads to the fast fission (FF) by formation of fissionlike fragments. The results of calculations for the mass symmetric 136Xe+136Xe reaction, almost mass symmetric 108Mo+144Ba reaction, and mass asymmetric like 24Mg+238U and 34S+248Cm reactions are discussed. The fusion probability PCN calculated for many massive nuclei reactions leading to formation of superheavy nuclei have been analyzed. The reactions which can lead in perspective to the synthesis of superheavy elements in the Z = 120 - 126 range and, eventually, also to heaviest nuclei, are discussed.

  12. Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region.

    Science.gov (United States)

    Smolka-Danielowska, Danuta

    2010-11-01

    The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations ofTh-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: 226Ra - 85.4 Bq kg(-1), 40 K-689 Bq kg(-1), 232Th - 100.8 Bq kg(-1), 235U-13.5 Bq kg(-1), 238U-50 Bq kg(-1) and 228Ac - 82.4 Bq kg(-1).

  13. Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region

    Energy Technology Data Exchange (ETDEWEB)

    Smolka-Danielowska, D. [University of Silesia, Sosnowiec (Poland). Faculty of Earth Science

    2010-11-15

    The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations of Th-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: {sup 226}Ra - 85.4 Bq kg{sup -1}, {sup 40}K-689 Bq kg{sup -1}, {sup 232}Th - 100.8 Bq kg{sup -1}, {sup 235}U - 13.5 Bq kg{sup -1}, {sup 238}U - 50 Bq kg{sup -1} and {sup 228}Ac - 82.4 Bq kg{sup -1}.

  14. Complex sound analysis in the lesser bulldog bat: evidence for a mechanism for processing frequency elements of frequency modulated signals over restricted time intervals.

    Science.gov (United States)

    Roverud, R C

    1994-05-01

    A stereotypical approach phase vocalization response of the lesser bulldog bat, Noctilio albiventris, to artificial echoes simulating a virtual approaching object was used to assess the ability of the bat to analyze and extract distance information from the artificial echoes. The performance of the bat was not significantly different when presented with naturally structured CF/FM echoes containing FM elements that sweep continuously from about 75-55 kHz in 4 ms or with CF/FM echoes containing FM components constructed from a series of 98 pure tone frequency steps, each with a duration of 0.04 ms. The performance of the bat remained unchanged when the duration of the tone steps was increased up to 0.08 ms but declined sharply to a level that was significantly below that seen with a naturally structured echo when the steps were 0.09 ms or longer. The performance of the bat depended on the duration of the individual tone steps, which could not exceed a specific upper limit of about 0.08 ms. The study suggests that the bats have adaptations for processing individual narrow band segments of FM signals over specific time intervals.

  15. Processes in massive nuclei reactions and the way to complete fusion of reactants. What perspectives for the synthesis of heavier superheavy elements?

    Directory of Open Access Journals (Sweden)

    Romaniuk M.

    2012-12-01

    Full Text Available By using the dinuclear system (DNS model we determine the capture of reactants at the first stage of reaction, the competition between the DNS decay by the quasifission (QF and the complete fusion (CF process up to formation of the compound nucleus (CN having compact shape. Further evolution of the CN is considered as its fission into two fragments or formation of evaporation residues (ER by its cooling after emission of neutrons or/and charged light particles. Disappearance of the CN fission barrier due to its fast rotation leads to the fast fission (FF by formation of fissionlike fragments. The results of calculations for the mass symmetric 136Xe+136Xe reaction, almost mass symmetric 108Mo+144Ba reaction, and mass asymmetric like 24Mg+238U and 34S+248Cm reactions are discussed. The fusion probability PCN calculated for many massive nuclei reactions leading to formation of superheavy nuclei have been analyzed. The reactions which can lead in perspective to the synthesis of superheavy elements in the Z = 120 − 126 range and, eventually, also to heaviest nuclei, are discussed.

  16. COREX3000竖炉布料的离散元模型%Discrete Element Model for Charging Process of COREX 3000 Shaft

    Institute of Scientific and Technical Information of China (English)

    李强; 冯明霞; 邹宗树

    2012-01-01

    The gas distribution in a shaft furnace dominates the temperature profile, gas utilization ratio, metallization degree and is the only means for regulating the gas flow distribution. Through introducing kinematic theory of granular, a numerical simulation model of burden distribution in the shaft furnace of COREX 3000 was developed by means of discrete element method (DEM) based on the Newton second law and soft-sphere contact model. The model can intuitively and visually reproduce the charging process, and quantitatively access the material flow trajectories, landing and forming process of the burden surface shape. Applying the model to further analyze the mixing charging process of two different diameter particle, obtained the charge movement process and the formation of the stockpile and found that size segregation is serious. Therefore, the model provides an important research base established model to find and optimize the charge patterns.%竖炉内煤气流的分布主宰着其内温度分布、煤气利用率和金属化率的高低,其上部调节方式仅有布料模式。通过引入离散颗粒动力学理论,基于经典牛顿力学和颗粒碰撞软球模型建立了针对COREX3000竖炉布料过程的离散元数值模拟模型,模型直观可视化再现装料过程,可定量获得料流轨迹、炉料落点及形成料堆的过程。应用模型进一步分析混装2种不同粒径颗粒,获得了炉料运动及形成的料堆过程,发现混装布料过程粒度偏析严重。建立的模型可为寻找和优化合理的布料模式提供重要研究基础。

  17. Size distributions of elemental carbon in a coastal urban atmosphere in South China: characteristics, evolution processes, and implications for the mixing state

    Science.gov (United States)

    Huang, Xiao-Feng; Zhen Yu, Jian

    2007-07-01

    Elemental carbon (EC), as one of the primary light-absorbing components in the atmosphere, has a significant impact on both regional and global climate. The environmental impacts of EC are strongly dependent on its particle size. Little is known about the size distribution characteristics of EC particles in the ambient environments of China. We here report size distributions of EC in the urban area of Shenzhen in South China. EC consistently exhibited two modes, a fine and a coarse mode. The majority of EC (~80%) in this coastal metropolitan city resided in particles smaller than 3.2 μm in diameter. The fine mode peaked at around either 0.42 μm or 0.75 μm. While the mode at 0.42 μm could be ascribed to fresh vehicular emissions in this region, the mode at 0.75 μm had to be a result of particle growth from smaller EC particles. We made a theoretical investigation of the particle growth processes that were responsible for EC particles to grow from 0.42 μm to 0.75 μm in the atmosphere. Our calculations indicate that the EC peak at 0.75 μm could not be produced through either coagulation or H2SO4 condensation; both were too slow to lead to significant EC growth. Hygroscopic growth was also calculated to be impossible. Instead, addition of sulfate through in-cloud processing was found to be able to significantly grow EC particles to explain the EC peak at 0.75 μm. We also estimated from the EC size distributions the mixing state of EC. In the droplet size, at least 45-60% of EC mass in the summer samples and 68% of EC mass in the winter samples was internally mixed with sulfate as a result of in-cloud processing. Such information on EC needs to be considered in modeling aerosol optical properties in this region. Our results also suggest that the in-cloud processing of primary EC particles could enhance light absorbing capacities through mixing EC and sulfate.

  18. First determination of s-process element abundances in pre-main sequence clusters. Y, Zr, La, and Ce in IC 2391, the Argus association, and IC 2602

    Science.gov (United States)

    D'Orazi, V.; De Silva, G. M.; Melo, C. F. H.

    2017-02-01

    Context. Several high-resolution spectroscopic studies have provided compelling observational evidence that open clusters display a decreasing trend of their barium abundances as a function of the cluster's age. Young clusters (ages ≲ 200 Myr) exhibit significant enhancement in the [Ba/Fe] ratios, at variance with solar-age clusters where the Ba content has been found to be [Ba/Fe] 0 dex. Different viable solutions have been suggested in the literature; nevertheless, a conclusive interpretation of such a peculiar trend has not been found. Interestingly, it is debated whether the other species produced with Ba via s-process reactions follow the same trend with age. Aims: Pre-main sequence clusters (≈10-50 Myr) show the most extreme behaviour in this respect: their [Ba/Fe] ratios can reach 0.65 dex, which is higher than the solar value by a factor of four. Crucially, there are no investigations of the other s-process species for these young stellar populations. In this paper we present the first determination of Y, Zr, La, and Ce in clusters IC 2391, IC 2602, and the Argus association. The main objective of our work is to ascertain whether these elements reveal the same enhancement as Ba. Methods: We have exploited high-resolution, high signal-to-noise spectra in order to derive abundances for Y, Zr, La, and Ce via spectral synthesis calculations. Our sample includes only stars with very similar atmospheric parameters so that internal errors due to star-to-star inhomogeneity are negligible. The chemical analysis was carried out in a strictly differential way, as done in all our previous investigations, to minimise the impact of systematic uncertainties. Results: Our results indicate that, at variance with Ba, all the other s-process species exhibit a solar scaled pattern; these clusters confirm a similar trend discovered in the slightly older local associations (e.g. AB Doradus, Carina-Near), where only Ba exhibit enhanced value with all other s-process species

  19. Size distributions of elemental carbon in a coastal urban atmosphere in South China: characteristics, evolution processes, and implications for the mixing state

    Directory of Open Access Journals (Sweden)

    Xiao-Feng Huang

    2007-07-01

    Full Text Available Elemental carbon (EC, as one of the primary light-absorbing components in the atmosphere, has a significant impact on both regional and global climate. The environmental impacts of EC are strongly dependent on its particle size. Little is known about the size distribution characteristics of EC particles in the ambient environments of China. We here report size distributions of EC in the urban area of Shenzhen in South China. EC consistently exhibited two modes, a fine and a coarse mode. The majority of EC (~80% in this coastal metropolitan city resided in particles smaller than 3.2 μm in diameter. The fine mode peaked at around either 0.42 μm or 0.75 μm. While the mode at 0.42 μm could be ascribed to fresh vehicular emissions in this region, the mode at 0.75 μm had to be a result of particle growth from smaller EC particles. We made a theoretical investigation of the particle growth processes that were responsible for EC particles to grow from 0.42 μm to 0.75 μm in the atmosphere. Our calculations indicate that the EC peak at 0.75 μm could not be produced through either coagulation or H2SO4 condensation; both were too slow to lead to significant EC growth. Hygroscopic growth was also calculated to be impossible. Instead, addition of sulfate through in-cloud processing was found to be able to significantly grow EC particles to explain the EC peak at 0.75 μm. We also estimated from the EC size distributions the mixing state of EC. In the droplet size, at least 45–60% of EC mass in the summer samples and 68% of EC mass in the winter samples was internally mixed with sulfate as a result of in-cloud processing. Such information on EC needs to be considered in modeling aerosol optical properties in this region. Our results also suggest that the in-cloud processing of primary EC particles could enhance light absorbing capacities through mixing EC and sulfate.

  20. A Method to Increase Current Density in a Mono Element Internal Tin Processed Superconductor Utilizing Zr Oxide to Refine Grain Size

    Energy Technology Data Exchange (ETDEWEB)

    Bruce A. Zeitlin, Eric Gregory

    2008-04-07

    The effect of Oxygen on (Nb1Zr)3Sn multifilament conductors manufactured by the Mono Element Internal Tin (MEIT) process was explored to improve the current density by refining the grain size. This followed work first done by General Electric on the Nb3Sn tape process. Techniques to fabricate the more difficult Nb1Zr composites are described and allowed fabrication of long lengths of .254 mm diameter wire from an 88.9 mm diameter billet. Oxygen was incorporated through the use of SnO2 mixed with tin powder and incorporated into the core. These were compared to samples with Ti+Sn and Cu+Sn cores. Heat treatments covered the range of 700 C to 1000 C. Current density vs. H, grain size, and reaction percentages are provided for the materials tested. The Oxygen gave superior results in the temperature range of 815-1000 C. It also stabilized the filament geometry of the array in comparison to the other additions at the higher temperatures. At 815 C a peak in layer Jc yielded values of 2537 A/mm2 at 12 T and 1353 A/mm2 at 15T, 8-22% and 30-73% greater respectively than 700 C values. Results with Oxygen at high temperature show the possibility of high speed continuous reaction of the composite versus the current batch or react in place methods. In general the Ti additions gave superior results at the lower reaction temperature. Future work is suggested to determine if the 815 C reaction temperature can lead to higher current density in high tin (Nb1Zr+Ox)3Sn conductors. A second technique incorporated oxygen directly into the Nb1Zr rods through heat treatment with Nb2O5 at 1100 C for 100 hours in vacuum prior to extrusion. The majority of the filaments reduced properly in the composite but some local variations in hardness led to breakage at smaller diameters.

  1. Fuel Element Technical Manual

    Energy Technology Data Exchange (ETDEWEB)

    Burley, H.H. [ed.

    1956-08-01

    It is the purpose of the Fuel Element Technical Manual to Provide a single document describing the fabrication processes used in the manufacture of the fuel element as well as the technical bases for these processes. The manual will be instrumental in the indoctrination of personnel new to the field and will provide a single data reference for all personnel involved in the design or manufacture of the fuel element. The material contained in this manual was assembled by members of the Engineering Department and the Manufacturing Department at the Hanford Atomic Products Operation between the dates October, 1955 and June, 1956. Arrangement of the manual. The manual is divided into six parts: Part I--introduction; Part II--technical bases; Part III--process; Part IV--plant and equipment; Part V--process control and improvement; and VI--safety.

  2. Flow Element Models

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    Air distribution in ventilated rooms is a flow process that can be divided into different elements such as supply air jets, exhaust flows, thermal plumes, boundary layer flows, infiltration and gravity currents. These flow elements are isolated volumes where the air movement is controlled...... by a restricted number of parameters, and the air movement is fairly independent of the general flow in the enclosure. In many practical situations, the most convenient· method is to design the air distribution system using flow element theory....

  3. Discovery of element 112

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [GSI, Darmstadt (Germany)

    1996-12-31

    The new elements 110, 111, and 112 were synthesized and unambiguously identified in experiments at SHIP. Due to strong shell effects the dominant decay mode is not fission, but emission of alpha particles. Theoretical investigations predict that maximum shell effects should exist in nuclei near proton number 114 and neutron number 184. Measurements give hope that isotopes of element 114 close to the island of spherical Superheavy Elements could be produced by fusion reactions using {sup 118}Pb as target. systematic studies of the reaction cross-sections indicate that transfer of nucleons is the important process to initiate the fusion.

  4. PELTIER ELEMENTS

    CERN Document Server

    Tani, Laurits

    2015-01-01

    To control Peltier elements, temperature controller was used. I used TEC-1091 that was manufactured my Meerstetter Engineering. To gain control with the temperature controller, software had to be intalled on a controlling PC. There were different modes to control the Peltier: Tempererature controller to control temperature, Static current/voltage to control voltage and current and LIVE ON/OFF to auto-tune the controller respectively to the system. Also, since near the collision pipe there is much radiation, radiation-proof Peltier elements have to be used. To gain the best results, I had to find the most efficient Peltier elements and try to get their cold side to -40 degrees Celsius.

  5. Carbon and Nitrogen in the Lower Basin of the Paraíba do Sul River, Southeastern Brazil: Element fluxes and biogeochemical processes

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Martinelli

    2011-08-01

    Full Text Available The study was conducted in the lower basin of the Paraíba do Sul River (PSR, in which 57,000 km2 of the basin is located in the Brazilian states of São Paulo, Minas Gerais and Rio de Janeiro. We proposed to identify the main sources of C and N fluxes in the PSR waters, to evaluate biogeochemical processes in the watershed, and to estimate C and N riverine loads to the Atlantic Ocean in the context of the sugarcane plantation expansion for ethanol production. Riverine water samples were collected at seven stations along 12 months. Physicochemical and limnological parameters, as well as discharge, were measured together with organic and inorganic C and N species in the dissolved and suspended particulate material. C and N concentrations in bed fluvial sediments, and suspended particulate material were measured, and their elemental ([C:N]a and isotopic (δ13C compositions were compared with the [C:N]a and δ13C of the following sources: riparian soils, insular flooded soils, aquatic macrophytes, phytoplankton, pasture grass, sugarcane, sugarcane byproducts, and forest litterfall. Temporal patterns in the physicochemical and limnological environment were correlated to discharge. It also was observed that sugar cane production can increase riverine C and N fluxes. Riparian soils inputs were larger than insular soils, which was likely to act as a biogeochemical barrier. Effects of the macrophytes on riverine C and N were unclear, as well as urban sewage disposal effects. Although the PSR loads represented a very small percentage of the fluvial input to global biogeochemical cycles, we suggest that this and other medium sized watersheds in Eastern and Southeastern South America can be significant contributors to the continental biogeochemical riverine loads to the ocean, if their loads are considered together.

  6. Trace elements and mineral composition of waste produced in the process of combustion of solid fuels in individual household furnaces in the Upper Silesian Industrial Region (Poland

    Directory of Open Access Journals (Sweden)

    Smołka-Danielowska Danuta

    2015-12-01

    Full Text Available This study presents preliminary research results, with regard to the concentration of chosen trace elements (Mn, Cr, Tl, Ni, Cu, Zn, As, Cd, Ba, Pb in waste, which was produced in the process of combustion of solid fuels (hard coal and flotation concentrate of bituminous coal in individual household furnaces in Poland (in the Upper Silesian Industrial Region. 27 samples of ash, 4 samples of hard coal and 2 samples of flotation concentrate of bituminous coal were prepared for the research. Methods such as: ICP-MS, X-ray diffraction by means of the powder method and scanning electron microscopy were used during the research. In the ash samples obtained from the combustion of hard coal, the highest average concentrations were: Mn (1477.7 ppm, Ba (1336.4 ppm and Zn (599.7 ppm. In the samples obtained from the combustion of flotation concentrate of bituminous coal, the highest average concentrations was stated for: Zn (762.4 ppm, Mn (668.5 ppm, Pb (552.1 ppm and Ba (211.7 ppm. Crystalline components were determined by used the X-ray diffraction method and the samples of ash obtained from the combustion of hard coal contained: anhydrite, gypsum, hematite, magnetite, quartz, calcite, mullite, periclase, kaolinite, dolomite, pyrite, sphalerite, galena and feldspars (albite-anorthite. The samples of ash obtained from the combustion of flotation concentrate of bituminous coal contain: pyrite, quartz, potassium feldspar, muscovite and kaolinite. The scanning electron microscope analysis enabled the identification of the chemical composition of single ash grains and determined their morphology (aluminosilicate forms, substance PbS and ZnS, oxides of Ni, Cu and Mn, monazite, xenotime.

  7. Isotopic ratios and elemental contents as indicators of seagrass C processing and sewage influence in a tropical macrotidal ecosystem (Madagascar, Mozambique Channel

    Directory of Open Access Journals (Sweden)

    Gilles Lepoint

    2008-03-01

    Full Text Available Isotopic ratios and elemental concentrations of carbon and nitrogen were measured in seven seagrass species colonising different tidal flats near Toliara (SW Madagascar in order to determine the potential use of these parameters for assessing C processing and sewage use by tropical seagrasses. Nitrogen concentrations measured in upper intertidal seagrasses near Toliara were almost twice those measured on the tidal flat near a healthy mangrove situated 20 km away from Toliara town. At Toliara Beach, δ15N values were correlated with the N concentrations of Halodule sp., one of the dominant species on the tidal flat. This correlation did not exist for Halophila ovalis, the other dominant species. An increase in N concentrations and δ15N values demonstrates the influence of sewage coming directly onto Toliara Beach on the N cycles of intertidal seagrasses. Nevertheless, this influence seems restricted to the upper littoral zone and was not the main cause of seagrass die-off. On the other hand, at the mangrove site, δ15N values were not correlated with the N concentrations of Halodule sp. or Thalassia hemprichii, showing that natural δ15N variability is driven by other factors than the δ15N of N sources. Moreover, inter-individual variability of δ15N values was greater than inter-specific or inter-site variability, making the δ15N difficult to interpret in the context of human-disturbance influence on the N cycle of tropical seagrasses. δ13C values were close to -9‰, indicating the use of HCO3- inorganic carbon source by the seven investigated species. Contrary to our hypothesis, variation between sites and location on the tidal flat was limited, suggesting limited impact on δ13C values of sewage, emersion duration and mechanisms for HCO3- incorporation.

  8. Microbiological stability of selected beef elements, subjected to technological processes and stored under aerobic and vacuum conditions at 5°C

    Directory of Open Access Journals (Sweden)

    Bożena Danyluk

    2011-09-01

    contamination of beef stored at 5°C is statistically significantly affected by not only the time of storage, but also the type of the meat elements, as well as the applied technological processes.  

  9. Investigation on elimination of some trace elements during the processes of coagulation-flocculation-settling and of polishing through activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Montiel, A.

    1974-06-01

    Research report:flocculation-settling with iron or aluminium salts is described. elimination of some trace elements by filtration through sand or activated carbon is discussed. (in french) (1 diagram, 1 graph, 6 tables)

  10. Element Research.

    Science.gov (United States)

    Herald, Christine

    2001-01-01

    Describes a research assignment for 8th grade students on the elements of the periodic table. Students use web-based resources and a chemistry handbook to gather information, construct concept maps, and present the findings to the full class using the mode of their choice: a humorous story, a slideshow or gameboard, a brochure, a song, or skit.…

  11. Numerical experiments of dynamical processes during the 2011-2013 surge of the Bering-Bagley Glacier System, using a full-Stokes finite element model

    Science.gov (United States)

    Trantow, Thomas

    The Bering-Bagley Glacial System (BBGS) is the largest glacier system outside of the Greenland and Antarctic ice sheets, and is the Earth's largest surge-type glacier. Surging is one of three types of glacial acceleration and the least understood one. Understanding glacial acceleration is paramount when trying to explain ice discharge to the oceans and the glacial contribution to sea-level rise, yet there are currently no numerical glacial models that account for surging. The recent 2011-2013 surge of the BBGS provides a rare opportunity to study the surge process through observations and the subsequent data analysis and numerical modeling. Using radar, altimeter, and image data collected from airborne and satellite missions, various descriptions of ice geometry are created at different times throughout the surge. Using geostatistical estimation techniques including variography and ordinary kriging, surface and bedrock Digital Elevation Maps (DEMs) are derived. A time series analysis of elevation change during the current surge is then conducted and validated using a complete error analysis along with airborne observations. The derived DEMs are then used as inputs to a computer simulated model of glacier dynamics in the BBGS. Using the Finite Element software Elmer/Ice, a full-Stokes simulation, with Glen's flow law for temperate ice, is created for numerical experiments. With consideration of free surface evolution, glacial hydrology and surface mass balance, the model is able to predict a variety of field variables including velocity, stress, strain-rate, pressure and surface elevation change at any point forward in time. These outputs are compared and validated using observational data such as CryoSat-2 altimetry, airborne field data, imagery and previous detailed analysis of the BBGS. Preliminary results reveal that certain surge phenomena such as surface elevation changes, surge progression and locations at which the surge starts, can be recreated using the

  12. The effect of rare earth elements on the kinetics of the isothermal coarsening of the globular solid phase in semisolid AZ91 alloy produced via SIMA process

    Energy Technology Data Exchange (ETDEWEB)

    Nami, B. [Department of Materials and Metallurgical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Shabestari, S.G., E-mail: shabestari@iust.ac.i [Department of Materials and Metallurgical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Miresmaeili, S.M. [Department of Mechanical Engineering, Shahid Radjaei University, Lavizan, Tehran (Iran, Islamic Republic of); Razavi, H.; Mirdamadi, Sh. [Department of Materials and Metallurgical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of)

    2010-01-21

    In the present study, the effects of rare earth (RE) elements on the microstructure and coarsening kinetics of the solid globular particle in the semisolid slurry of AZ91 magnesium alloy have been studied at 570 {sup o}C and 580 {sup o}C. The results showed that the coarsening kinetics of the solid globular particles in semisolid slurry of AZ91 alloy satisfies the Ostwald ripening theory. It was shown that the coarsening rate of the solid particles decreases by adding RE elements into AZ91 alloy, specially at 580 {sup o}C, which results in the smaller particles size. It was attributed to the solid-liquid interfacial energy reduction due to the addition of RE elements.

  13. Change law of real vapor pressure of Al element in Ti- x Al ( x =25~50) melt during ISM process

    Institute of Scientific and Technical Information of China (English)

    刘贵仲; 苏彦庆; 郭景杰; 丁宏升; 贾均; 傅恒志

    2002-01-01

    A new model was established to calculate the real vapor pressure of the Al element in the molten Ti- x Al ( x =25~50,mole fraction,%) alloy.The effects of the holding time,chamber pressure,mole fraction of Al and melting temperature on the real vapor pressure of Al element in the vacuum chamber were analyzed.Because of the impeding effect of the real vapor pressure on the evaporation loss rate,within a short time (less than 10 s),the real vapor pressure tends to a constant value.When the chamber pressure is less than the saturated vapor pressure of the Al component,the real vapor pressure of Al is equal to the chamber pressure.While when the chamber pressure is larger than the saturated vapor pressure,the real vapor pressure is equal to the saturated vapor pressure of the Al element of the same condition.

  14. Petrology of HP metamorphic veins in coesite-bearing eclogite from western Tianshan, China: Fluid processes and elemental mobility during exhumation in a cold subduction zone

    Science.gov (United States)

    Lü, Zeng; Zhang, Lifei; Du, Jinxue; Yang, Xin; Tian, Zuolin; Xia, Bin

    2012-04-01

    , omphacite, phengite, glaucophane as well as the little deformed textures of HP veins, it is estimated that the vein-forming fluids would flow at about 1.3-2.1 GPa and 540-580 °C, corresponding to the stage of retrograde eclogite-facies recrystallization during exhumation of the UHP eclogites that formed at peak P-T conditions of > 2.7 GPa and 460-520 °C. The HP veins occur as a consequence of a regional tectonothermal event, triggering breakdown of lawsonite within the UHP eclogites. Based on the petrology of vein minerals, it is inferred that the HP fluids were enriched in Si, Ca, Na, Al and Ba. This suggests that these elements could be mobilized during the retrograde metamorphism of UHP eclogites in a cold subduction zone. Coeval pervasive flow of HP metamorphic fluids through the UHP eclogites at this stage may be an important process to eliminate most mineralogical evidence of the UHP metamorphism.

  15. Finite element analysis

    CERN Document Server

    2010-01-01

    Finite element analysis is an engineering method for the numerical analysis of complex structures. This book provides a bird's eye view on this very broad matter through 27 original and innovative research studies exhibiting various investigation directions. Through its chapters the reader will have access to works related to Biomedical Engineering, Materials Engineering, Process Analysis and Civil Engineering. The text is addressed not only to researchers, but also to professional engineers, engineering lecturers and students seeking to gain a better understanding of where Finite Element Analysis stands today.

  16. Dynamic modelling as an element of the availibility and process oriented behaviour investigation of complex power plants; Dynamische Modellbildung als Element von verfuegbarkeits- und prozessorientierten Untersuchungen komplexer kraftwerkstechnischer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Klatt, M.

    2007-12-20

    A software-tool was developed, which, with its specially built component library, allows the modelling of availability and dynamic behaviour of large scale power plant units. The requested graphic representation near to the process flow schema required a search for new ways of data and information flow modelling. The large quantity of components of a power plant unit with its most important components thereby requires a block oriented modelling approach based on lumped and distributed lumped parameters. (orig.)

  17. Regular Mechanical Transformation of Rotations Into Translations: Part 2. Kinematic Synthesis of the Elements of High Kinematic Joints, Realizing the Process of Motions Transformation

    Science.gov (United States)

    Abadjieva, Emilia; Abadjiev, Valentin

    2017-09-01

    This work is developed on the basis of the illustrated main parts of the kinematic theory (theory of gearing) of the spatial rack drives in Part 1 of this study. The applied theoretical approach to their synthesis, based on the T. Olivier's second principle is defined. A study of the geometric nature of the surface of action (mesh region, respectively) of these class transmissions is shown. Research software programs for synthesis and visualization of these transmissions and their specific elements are elaborated, on the basis of the given algorithms to the synthesis of the elements of high kinematic joints (active tooth surfaces), with which the movable links of the studied gear systems are equipped.

  18. The elements of life

    Directory of Open Access Journals (Sweden)

    Sergey P. Fedotov

    2016-11-01

    Full Text Available Article "Elements of Life" offers a hypothesis about the relationship of the phenomenon of traditional Chinese medicine with the physical laws. It shows the principle of forming a sequence of daily activity of the acupuncture meridians as a consequence of the Doppler effect in the process of flowing around the planet Earth by cosmic wind (by Ether. In accordance with this specification the daily structure of meridians had been built. It is suggested that the essence of the Chinese Qi (Chi are vibrations of a certain range in the medium. Consequently, it became possible to set the interrelation of frequencies of the visible spectrum with certain meridians. It is shown that the topological relationship of ancient (barrier points of the Five Elements (Wu-Shu points are associated with the wave lengths of the so-called Qi. It is shown also that the essence of the Wu-Xing law is based on daily circulation patterns of meridians. The examples of the surrounding world, including pulses processes in the human body, are confirming the above mentioned theses. A correlation diagram between the main elements by Dr. Samohotsky A.S. (dissertation "The experience of the definition of medical laws", 1946 and the Five Elements of traditional Chinese philosophy is established. The above represented hypotheses are yet introduced in practice in form of pulse spectral analysis system.

  19. Solution-processed highly efficient Cu2ZnSnSe4 thin film solar cells by dissolution of elemental Cu, Zn, Sn, and Se powders.

    Science.gov (United States)

    Yang, Yanchun; Wang, Gang; Zhao, Wangen; Tian, Qingwen; Huang, Lijian; Pan, Daocheng

    2015-01-14

    Solution deposition approaches play an important role in reducing the manufacturing cost of Cu2ZnSnSe4 (CZTSe) thin film solar cells. Here, we present a novel precursor-based solution approach to fabricate highly efficient CZTSe solar cells. In this approach, low-cost elemental Cu, Zn, Sn, and Se powders were simultaneously dissolved in the solution of thioglycolic acid and ethanolamine, forming a homogeneous CZTSe precursor solution to deposit CZTSe nanocrystal thin films. Based on high-quality CZTSe absorber layer, pure selenide CZTSe solar cell with a photoelectric conversion efficiency of 8.02% has been achieved without antireflection coating.

  20. 煤气化过程痕量元素迁移实验研究%Experimental Study of Trace Elements Release From Coal Gasification Process

    Institute of Scientific and Technical Information of China (English)

    蔡铭; 许世森; 郜时旺; 吴龙; 刘练波; D.Dugwell; R.Kandiyoti

    2012-01-01

    煤气化过程痕量元素排放引起的环境问题是成为关注的热点之一.为了研究和掌握气流床气化炉中的痕量元素排放规律,利用高温高压金属丝网(wire-mesh reactor,WMR)反应器模拟气流床气化不同的气化和热解条件,对煤样及反应器产生的煤焦样中的As、Se、Pb、V、Co、Ba、Cr、Mn.痕量元素进行电感耦合等离子体-质谱(inductively coupled plasma-mass spectrometry,ICP-MS)分析.WMR实验结果与气化炉中试装置试验煤、灰、渣样品中数据及热力学模型模拟结果进行对比分析.结果表明,中试试验与热力学模拟结果比较吻合,中试试验条件下痕量元素反应达到了平衡状态;WMR试验中Pb、V、Ba、Mn及Co的排放规律与热力学模拟结果比较一致,而As和Se的试验结果与热力学模拟结果相差较大,可能是WMR试验中反应时间较短,受动力学因素影响较大的原因.%The release of toxic trace elements from coal gasification is a matter of environmental concern.A laboratory scale wire-mesh reactor (WMR) was used to simulate trace element releases from coal particles in an entrained flow gasifier.Char samples were produced from WMR under various gasification and pyrolysis conditions,within the operating window of the gasifier.The samples of char as well as raw coal were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) for the contents of an array of mostly toxic trace elements: As,Se,Pb,V,Co,Ba,Cr and Mn.Coal and slag samples from a pilot scale,entrained flow gasifier were also analyzed for comparison with the WMR data.There is good agreement between the thermodynamic predictions and the pilot scale data,showing that equilibrium with respect to trace element partitioning is reached in the pilot scale gasifier.Agreement with the WMR data is less consistent.There is agreement for the elements Pb,V,Ba,Mn and possibly Co.It is inconsistent for As and Se,which may be due to a kinetic limitation

  1. Extrusion process of corn stalk powder in single orifice die processing based on discrete element method%玉米秸秆粉料单模孔致密成型过程离散元模拟

    Institute of Scientific and Technical Information of China (English)

    李永奎; 孙月铢; 白雪卫

    2015-01-01

    Mechanical behavior in the densification of biomass material is closely related to pellet quality. In order to explore the forming mechanism of typical biomass material from loose state to consolidation, the discrete element method (DEM) was introduced to investigate the movement and interaction of the milled corn stalk particles in the compacting process, and the verification experiments were carried out to test the effectiveness of the DEM simulation in this study. Firstly, the three-dimensional (3D) particle contact model of corn stalk powder based on the soft-sphere model of DEM was established, and the constraining walls in DEM model were completely consistent with the compressing cavity boundary conditions in geometric shape and dimension of experimental tests conducted in December, 2014; the loading speed in simulation was also set as the same value as the DEM model. Secondly, the diameter range of simulated particles was configured to 0.4-1.0 mm in accordance to the particle size distribution acquired through the screening experiment and calculation, and the generated particles were fully filled into the whole cavity at the original state before the compressing force was loaded. The mechanical parameters of the particles, such as normal stiffness, shear stiffness and friction coefficient between the 2 contact particles, were set to the values generated at random in specific range which was determined according to compacting experimental data. Thirdly, the comparison of compression stress relaxation data between tests and simulation was carried out and the validity of the simulation was verified by the hypothesis test. It was found that the force data with time from the hypothesis tests and DEM simulation followed the similar tendency, and the absolute error was not higher than 100 N in both initial loading stage and 20 seconds after stress relaxation. In the first 20 seconds of stress relaxation course, the values of absolute error were obviously higher

  2. Understanding communication between emergency and consulting physicians: a qualitative study that describes and defines the essential elements of the emergency department consultation-referral process for the junior learner.

    Science.gov (United States)

    Chan, Teresa; Orlich, Donika; Kulasegaram, Kulamakan; Sherbino, Jonathan

    2013-01-01

    To define the important elements of an emergency department (ED) consultation request and to develop a simple model of the process. From March to September 2010, 61 physicians (21 emergency medicine [EM], 20 general surgery [GS], 20 internal medicine [IM]; 31 residents, 30 attending staff) were questioned about how junior learners should be taught about ED consultation. Two investigators independently reviewed focus group and interview transcripts using grounded theory to generate an index of themes until saturation was reached. Disagreements were resolved by consensus, yielding an inventory of themes and subthemes. All transcripts were coded using this index of themes; 30% of transcripts were coded in duplicate to determine the agreement. A total of 245 themes and subthemes were identified. The agreement between reviewers was 77%. Important themes in the process were as follows: initial preparation and review of investigations by EM physician (overall endorsement 87% [range 70-100% in different groups]); identification of involved parties (patient and involved physicians) (100%); hypothesis of patient's diagnosis (75% [range 62-83%]) or question for the consulting physician (70% [range 55-95%]); urgency (100%) and stability (74% [range 62-80%]); questions from the consultant (100%); discussion/communication (98% [range 95-100%]); and feedback (98% [range 95-100%]). These components were reorganized into a simple framework (PIQUED). Each clinical specialty significantly contributed to the model (χ2  =  7.9; p value  =  0.019). Each group contributed uniquely to the final list of important elements (percent contributions: EM, 57%; GS, 41%; IM, 64%). We define important elements of an ED consultation with input from emergency and consulting physicians. We propose a model that organizes these elements into a simple framework (PIQUED) that may be valuable for junior learners.

  3. Discrete element modeling of the mass movement and loose material supplying the gully process of a debris avalanche in the Bayi Gully, Southwest China

    Science.gov (United States)

    Zhou, Jia-wen; Huang, Kang-xin; Shi, Chong; Hao, Ming-hui; Guo, Chao-xu

    2015-03-01

    The dynamic process of a debris avalanche in mountainous areas is influenced by the landslide volume, topographical conditions, mass-material composition, mechanical properties and other factors. A good understanding of the mass movement and loose material supplying the gully process is very important for understanding the dynamic properties of debris avalanches. Three-dimensional particle flow code (PFC3D) was used to simulate a debris avalanche in Quaternary deposits at the Bayi Gully, Southwest China. FORTRAN and AutoCAD were used for the secondary development to display the mass movement process and to quantitatively describe the mass movement and loose material supplying the gully process. The simulated results show that after the landslide is initiated, the gravitational potential energy is converted into kinetic energy with a variation velocity for the sliding masses. Two stages exist for the average-movement velocity: the acceleration stage and the slowdown stage, which are influenced by the topographical conditions. For the loose materials supplying the gully process, the cumulative volume of the sliding masses into the gully gradually increases over the time. When the landslide volume is not large enough, the increasing landslide volume does not obviously influence the movement process of the sliding masses. The travel distance and movement velocity increase with the decreasing numerical parameters, and the mass-movement process is finished more quickly using low-value parameters. The deposition area of the sliding masses decreases with the increasing numerical parameters and the corresponding deposition thickness increases. The mass movement of the debris avalanche is not only influenced by the mechanical parameters but is also controlled by the topographical conditions.

  4. Review paper The role of physiological elements in the future therapies of rheumatoid arthritis. II. The relevance of energy redistribution in the process of chronic inflammation

    Directory of Open Access Journals (Sweden)

    Michał Gajewski

    2015-04-01

    Full Text Available The reasons for development of chronic inflammation are complex and not fully understood. One of the factors affecting the prolongation of inflammation is changes in cell metabolism, occurring at the center of the inflammatory process. In chronic inflammation there is an imbalance between the processes of storage and consumption of energy reserves. Hypoxia that is a consequence of edema results in transition of white blood cells to anaerobic metabolism. Neutrophils, lymphocytes and macrophages produce active oxygen metabolites which on one hand facilitate the elimination of pathogens, and on the other hand, can cause damage to healthy cells located in the inflamed tissue. In this paper, we discuss the importance of disturbed redistribution of energy as one of the main reasons for transformation of the acute inflammatory process into the chronic one.

  5. The role of physiological elements in the future therapies of rheumatoid arthritis. II. The relevance of energy redistribution in the process of chronic inflammation.

    Science.gov (United States)

    Gajewski, Michał; Rzodkiewicz, Przemysław; Wojtecka-Łukasik, Elżbieta

    2015-01-01

    The reasons for development of chronic inflammation are complex and not fully understood. One of the factors affecting the prolongation of inflammation is changes in cell metabolism, occurring at the center of the inflammatory process. In chronic inflammation there is an imbalance between the processes of storage and consumption of energy reserves. Hypoxia that is a consequence of edema results in transition of white blood cells to anaerobic metabolism. Neutrophils, lymphocytes and macrophages produce active oxygen metabolites which on one hand facilitate the elimination of pathogens, and on the other hand, can cause damage to healthy cells located in the inflamed tissue. In this paper, we discuss the importance of disturbed redistribution of energy as one of the main reasons for transformation of the acute inflammatory process into the chronic one.

  6. Hydrogeochemical processes governing the origin, transport and fate of major and trace elements from mine wastes and mineralized rock to surface waters

    Science.gov (United States)

    Nordstrom, D. Kirk

    2011-01-01

    The formation of acid mine drainage from metals extraction or natural acid rock drainage and its mixing with surface waters is a complex process that depends on petrology and mineralogy, structural geology, geomorphology, surface-water hydrology, hydrogeology, climatology, microbiology, chemistry, and mining and mineral processing history. The concentrations of metals, metalloids, acidity, alkalinity, Cl-, F- and SO42- found in receiving streams, rivers, and lakes are affected by all of these factors and their interactions. Remediation of mine sites is an engineering concern but to design a remediation plan without understanding the hydrogeochemical processes of contaminant mobilization can lead to ineffective and excessively costly remediation. Furthermore, remediation needs a goal commensurate with natural background conditions rather than water-quality standards that might bear little relation to conditions of a highly mineralized terrain. This paper reviews hydrogeochemical generalizations, primarily from US Geological Survey research, that enhance our understanding of the origin, transport, and fate of contaminants released from mined and mineralized areas.

  7. SIMULATION IN THE STUDYING OF NON-STATIONARY PROCESSES AND LOADED ELEMENTS OF STEERING SYSTEM WITH INTEGRATED GEAR MECHANISM AND ROTARY VALVES

    OpenAIRE

    Mikhailov, V; E. Strock

    2013-01-01

    In the paper mathematical model of steering system is shown. The model was described through hydraulic and mechanical connections of differential equations. Some test results are represented.This model allows to analyze transient processes in different combination of kinematics disturbances and power factors, and also to determine functional suitability of System.This Model can be recommended for Control System testing. 

  8. Structural and elemental analysis of melt-processible high-temperature superconductors by surface science and x-ray diffraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, A.M.; Sheng, Z.Z.; El Ali, A.; Mooney, G.D.; Nelson, A.J.; Goral, J.; Kazmerski, L.L.

    1988-11-15

    We report the results of scanning electron microscopy (SEM), microprobe analysis (wavelength dispersive and energy dispersive spectroscopies), secondary-ion mass spectroscopy (SIMS), and x-ray diffraction measurements on a series of melt-processed high critical-temperature superconductors. The superconductors were synthesized through a melt reaction between TbBa/sub 2/Cu/sub 3/O/sub 7-//sub x/ and nonstoichiometric rare-earth Ba-Cu-O oxides. The melt-processed samples are dense, largely void-free superconductors with critical temperatures in the 90--95 K range. Microprobe and SIMS data show the absence of Tb in surfaces of the interiors of samples which had been fractured to expose the interior regions. Comparative microprobe and SEM data are included for conventionally prepared sintered samples. Comparative x-ray diffraction studies are presented which show that the melt-processed samples studied have diffraction patterns nearly identical to those of sintered (rare earth)Ba/sub 2/Cu/sub 3/O/sub 7-//sub x/ samples. In two of the three Y-based melt-processed superconductors studied, the compound stoichiometry from microprobe analysis is Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-//sub x/. The evidence presented indicates that the TbBa/sub 2/Cu/sub 3/O/sub 7-//sub x/ decomposes during the melt reaction.

  9. 激光熔覆搭接过程残余应力应变的有限元计算%Finite Element Calculation of the Residual Stress and Strain of Coating during Laser Cladding Process

    Institute of Scientific and Technical Information of China (English)

    马琳; 张平; 孟令东; 张二亮

    2011-01-01

    激光熔覆过程中产生的残余应力与应变对熔覆层的裂纹开裂倾向有重要影响。利用有限元法对激光多道搭接过程熔覆层的残余应力和应变进行计算,计算过程中主要考虑瞬时温度变化引起的热应力、σ-ε曲线、有限元网格、力学边界条件4个方面。热应力主要在温度场计算结果的基础上求得;σ-ε曲线采用的是线性强化材料的弹塑性曲线;有限元网格主要采用分区划分的形式进行。通过计算,得到了搭接后的熔覆层上关键点的残余应力和应变分别为1 400 MPa和2.2×10^-2。结果表明:搭接熔覆层交界处的点产生焊趾裂纹的倾向最大,第1道熔覆顶点处产生横向裂纹的倾向次之。%During laser cladding process,the residual stress and strain caused by the fast heating and cooling process make an important influence on cracks of coating.The residual stress and strain of coating during the laser cladding process are calculated by the finite element method.In the calculating process,the mainly considerations are given to the thermal stress,σ-ε curves of material,the finite element mesh of the model and the dynamics boundary conditions.The thermal stress is achieved through calculating results of the temperature field;the σ-ε curves are assumed to be that of linearity strengthened materials;and the finite element mesh adopted are divisional according to the subject investigated.With the help of finite element method,the residual stress and strain in the key points on the coating are gained respectively as 1 400 MPa and 2.2×10^-2.The results show that the cracking tendency on the crossing point of the substrate and lapped coating is largest while that on the apex of the first ring coating is the second.

  10. Finite Element Post-processing Data Field Visualization Research%有限元后处理数据场可视化研究

    Institute of Scientific and Technical Information of China (English)

    晁岱兵; 陈显呈; 邓伟; 彭清

    2012-01-01

    采用Python语言基于OpenGL的可视化开发,通过算法和程序的编制,对有限元分析结果数据进行重构显示.利用图形函数实现了八节点六面体三维数据场的网格模型建立,并进行面消隐;利用glColorPointer函数对网格模型各个节点上的标量场进行颜色映射,重构出效果良好的应力应变云图.比较了线性插值和余弦插值两种不同方法形成颜色渲染效果差异,同时对二次和三次不同颜色分量数学模型对渲染效果的影响进行对比研究.%Python is applied to visual development based on OpenGL interface. The result data of finite element analysis is reconstruc tured through algorithm and program. The data field of grid model with eight node hexahedron is built and the surfaces are hided by graphic function. The scalar field on nodes of the grid model is mapped with different colors by glColorPointer function; the stress-strain diagram is reconstructured well. The different render effect of linear interpolation is compared with one of consine interpolation, and the color rendering of second mathematical model is compared with one of third mathematical model and they are researched on.

  11. High-contrast process using a positive-tone resist with antistatic coating and high-energy (100-keV) e-beam lithography for fabricating diffractive optical elements (DOE) on quartz

    Science.gov (United States)

    Poli, Louis C.; Kondek, Christine A.; Shoop, Barry L.; McLane, George F.

    1995-06-01

    Diffractive optical elements (DOE) are becoming important as optical signal processing elements in increasingly diverse applications. These elements, fabricated on quartz, may be used as phase shift type masks or as embedded components that implement a transfer function within a processing network. A process is under development for the fabrication of a DOE implementing a Jervis error diffusion kernel for research in half tone image processing. Dry etching is performed after lithography and pattern transfer through a nickel mask. This results in etched areal features on the substrate. An optical diffraction medium is thus created. Lithographic patterning is done by e-beam lithography (EBL) to realize small features, but also offers the important advantage of a large depth of field which relaxes the problem of complex surface topology. The recent availability of high energy (100 KeV) lithography tools provides a capability for precision overlay, small feature resolution, and enhanced image contrast through a lower induced proximity effect. Patterning by EBL on insulating substrates is complicated by the necessity of providing a vehicle for the avoidance of charge buildup on the surface. In a previously presented paper a methodology was shown for the use of TQV-501 (Nitto Chemical) antistatic compound as a final spin on film for use with PMMA and SAL-601 (Shipley). In this current work, a process is described using EBL and a high performance positive resist working with a final film layer of antistatic TQV-501 on a nickel coated wafer. The process may then be reapplied to realize additional lithographic levels in registration, for multilevel DOE components. High energy (100 KeV) EBL is used to provide high quality pattern definition. The e-beam sensitive resist, ZEP-320-37 (Nagase Chemical) in dilution, together with a top film layer of TQV-501 serves as a bilevel resist system and is used for patterning the desired image before definition of the nickel mask through

  12. SIMULATION IN THE STUDYING OF NON-STATIONARY PROCESSES AND LOADED ELEMENTS OF STEERING SYSTEM WITH INTEGRATED GEAR MECHANISM AND ROTARY VALVES

    Directory of Open Access Journals (Sweden)

    V. Mikhailov

    2013-01-01

    Full Text Available In the paper mathematical model of steering system is shown. The model was described through hydraulic and mechanical connections of differential equations. Some test results are represented.This model allows to analyze transient processes in different combination of kinematics disturbances and power factors, and also to determine functional suitability of System.This Model can be recommended for Control System testing. 

  13. 基于特征加工元的复杂箱体类零件工艺路线优化%Process Route Optimization of Complex Housing-type Parts Based on Feature Machining Element

    Institute of Scientific and Technical Information of China (English)

    徐立云; 史楠; 段建国; 李爱平

    2013-01-01

    针对工艺设计过程中工艺路线的优化问题,通过分析复杂箱体类零件特征,并将其细分为加工元,在考虑优化过程中存在的问题和相关工艺约束的基础上,将工艺路线的优化转化为加工元的优先排序.以机床、夹具和刀具变换次数最少建立目标优化模型,利用改进的遗传算法进行求解,避免了遗传算法“早熟”的缺陷.以某型号缸体为研究对象验证该改进算法的有效性,结果表明该算法具有很好的收敛性.%According to the current problems of process route optimization during the process design, the complex part features were divided into several feature machining elements,then the optimization of process route was changed to the priority of feature machining elements considering the problems in the process of optimization and related process constraints. An objective function was built by minimizing the transform of machine tools,fixtures and cutting tools,using an improved genetic algorithm to avoid the premature defects of the genetic algorithm. Finally, a case of cylinder block was illustrated to verify the efficiency of the hybrid algorithm, and the results show that the improved al gorithm has a good convergence.

  14. Some Trace Elements Enrichment Features during Coal Gasification Process in Ningdong Coal Gasification Plant%宁东气化厂煤气化过程中几种微量元素的富集特性

    Institute of Scientific and Technical Information of China (English)

    王晓帅; 唐跃刚; 桓斌斌; 徐靖杰

    2016-01-01

    Through plasma mass spectrometric, atomic fluorescence spectrometric methods carried out trace elements V, Cr, Cu, Zn, Ba, Se, As and Pb content determination and analysis for coal and its residue during coal gasification process in the Ningdong coal gas⁃ification plant. The result has shown that compared with in the raw coal, the majority of these elements have showed better enrichment trend during gasification, enrichment extent of different gasified residues of same element can be 2~10 times as high. The lithophile ele⁃ments in the gasification coal showed better correlativity. Based on the GB15618-2008“Environmental Quality Standards for Soils”, el⁃ements As, Cu, Pb, Cr and Zn can be directly discharged, as for other elements should be continued to pay attention to and study their environmental effects further.%运用等离子体质谱分析法、原子荧光法等方法对宁东气化厂气化过程煤及其残渣进行了V、Cr、Cu、Zn、Ba、Se、As、Pb微量元素含量的测定与分析。结果表明:气化过程中这8种微量元素与原煤相比多数表现富集的趋势,相同元素不同气化残渣富集程度可达2~10倍;气化用煤中亲石元素表现出较好的相关性;根据GB15618-1995《土壤环境质量标准》,气化残渣中As、Cu、Pb、Cr、Zn元素可直接排放,其它元素需继续关注和进一步研究其环境效应。

  15. Algunos elementos para interpretar la presencia de los varones en los procesos de salud reproductiva Some elements for interpreting men's presence in reproductive health processes

    Directory of Open Access Journals (Sweden)

    Juan Guillermo Figueroa-Perea

    1998-01-01

    Full Text Available El objetivo del trabajo es identificar vertientes analíticas para ubicar a los varones en los procesos de salud reproductiva. Se propone cuestionar la interpretación que los identifica solamente como actores que pueden apoyar mejorías en la salud de las mujeres y de los hijos. Es reciente la inquietud por redimensionar su papel, como seres que se reproducen y enfrentan riesgos en su aparato, comportamiento y proceso reproductivos. Una posibilidad para explicitar la presencia de los varones en dichos procesos es identificar cuáles son sus ausencias y presencias que condicionan las consecuencias favorables o no para las mujeres y los hijos. Se trata de ver de qué manera dificultan o contribuyen a mejorar las condiciones de la morbimortalidad materna. Una segunda posibilidad es incursionar en el carácter relacional, social y potencialmente conflictivo de la reproducción "sexualizada". Implica replantear el análisis de la reproducción como un proceso relacional y no como eventos aislados de hombres y mujeres, al mismo tiempo que recuperar la especificidad de unos y de otras. Se utiliza la perspectiva de género con el fin de imaginar los procesos sin negar la dimensión del poder. Así, se replantean la sexualidad, la reproducción y la salud en términos de interacción, con el fin de construir referencias más claras respecto a la población masculina.This study aims to identify analytical approaches to situate men in processes pertaining to reproductive health. We challenge the position that identifies them only as actors that can support improvements in the health of women and children. More recently there has been a concern over reshaping their role, as individuals who both reproduce and face risks to their reproductive organs, behaviors, and processes. One possibility for explaining men's presence in such processes is to identify their absence or presence as conditioning the consequences for women and children. The issue is to

  16. Development of the technology for commercialization of the industrial solar system. ; Development of the advanced heat process system (research of low-cost elemental devices, etc. (examination of elemental devices, etc. )). Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. ; Advancedter dot heat process gata system no kaihatsu (tei cost yoso kiki nado no chosa kenkyu yoso kiki nado ni kansuru chosa)

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    To organize the technological schemes for lowering the costs of elemental devices, etc. in industrial solar systems, the factors that prevent cost reduction were examined and evaluated, and technologies that would lower costs were chosen. The factors that prevent the cost reduction of industrial solar systems were divided into economical factors (solar radiation, structure, strength, etc.) and efficiency factors (energy density, system, control, etc.) and investigation and evaluations were carried out for each type. The keywords for cost reduction were defined as a. new materials, new elemental devices, technology, b. unification, organization, integration, c. combined utilization, multi-aspect utilization, multi-function, d. practicality, comfortability, usability, e. mono-function, simplification, usage specific, f. policy, system, viewpoint, etc. While dividing the factors which would lower costs of elemental devices, etc. into elemental technology, devices, materials, unification with architectual structures, multi-purpose utilization, etc., the factors were also divided according to function: heatcollecting parts, heat transporting parts, heat storage parts, and systems. Performance evaluation according to the keywords and information about costs, etc. helped choose the problems.

  17. Uridine branch acceptor is a cis-acting element involved in regulation of the alternative processing of calcitonin/CGRP-l pre-mRNA.

    OpenAIRE

    Adema, G. J.; van Hulst, K L; Baas, P.D.

    1990-01-01

    The human calcitonin/CGRP-I (CALC-I) gene contains 6 exons and encodes two polypeptide precursors. In thyroid C-cells, calcitonin (CT) mRNA is produced by splicing of exons 1-2-3 to exon 4 (CT-encoding) and polyadenylation at exon 4. CGRP-I mRNA is produced in particular neural cells by splicing of exons 1-2-3 to exon 5 (CGRP-I-encoding) and the polyadenylated exon 6. We previously reported that model precursor RNAs containing the exon 3 to exon 5 region of the CALC-I gene are processed predo...

  18. Modern information and telecommunication technologies in educational process as the element of ongoing personnel training for high-tech Russian industry

    Science.gov (United States)

    Matyatina, A. N.; Isaev, A. A.; Samovarschikov, Y. V.

    2017-01-01

    In the current work the issues of staffing high-tech sectors of Russian industry are considered in the context of global geopolitical instability, the comparative analysis of the age structure of domestic companies with the leading Western industrial organizations was conducted, "growth points" of human resources development were defined. For the purpose of informational and telecommunicational implementation in the educational process the analysis of normative-legal documents regulating the requirements to the electronic educational environment and distance learning technologies is presented. The basic models of distance learning technologies and remote resources as part of teaching materials are used. Taking into account the specifics and requirements of industrial enterprises a number of tools and methodology of e-learning based on the identified needs of the industrial sector were offered. The basis of the proposed model is built on one-parameter model through a three-tier learning: kindergarten - secondary - higher education (professional) where the lifecycle of parameter is a list of the industrial enterprises demands to the educational process.

  19. Study on the Thinking Process and Elements of Collecting Audit Evidence%审计取证的思维流程与思维要素研究

    Institute of Scientific and Technical Information of China (English)

    陈太辉; 杨明月

    2011-01-01

    审计思想方法是从事审计实践活动不可或缺的重要工具,因此研究审计思想方法具有重要的理论意义和实践意义。审计取证作为审计工作中的重要一环,直接决定审计质量,关乎国家审计的“免疫系统”功能发挥,最终影响国家审计服务于国家治理的效用程度。基于此,本文以审计取证为研究对象,运用文献研究、访谈和归纳演绎等方法,在深入分析审计证据要满足条件的基础上,提出了审计取证的思维五步:合理怀疑——发现问题——证实问题——力求达成共识——解决问题。同时从肯定性取证、中性取证和否定性取证入手,深入分析了行为、结果、现象、主客观、主客体、原因、影响和责任主体等思维要素。旨在通过本研究,进一步丰富审计相关理论,并为审计人员改善思维方式提供一定参考。%The thinking methodology of auditing is an indispensable tool for auditing practice. The study of thinking methodology of auditing has important theoretical and practical significance. As an important part of the audit, collecting audit evidence directly affects audit quality, the national audit "immune system" functioning, and ultimately the national audit services in the effectiveness of national governance. The paper selected audit evidence collecting as the object of study, using literature study, interviews, inductive and deductive methods, firstly analyzed the conditions of audit evidence. Secondly, proposed five-step thinking of audit evidence collecting: reasonable doubt, identify problems, confirm problems, strive to reach consensus and solve problems. Finally from the positive, neutral and negative evidence, the paper analyzed the thinking elements of audit evidence collecting, such as behavior, result, phenomenon, subjective, objective, subject, object, cause, impact and person in charge. Through the thinking methodology study of

  20. Elements of energy conversion

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Elements of Energy Conversion brings together scattered information on the subject of energy conversion and presents it in terms of the fundamental thermodynamics that apply to energy conversion by any process. Emphasis is given to the development of the theory of heat engines because these are and will remain most important power sources. Descriptive material is then presented to provide elementary information on all important energy conversion devices. The book contains 10 chapters and opens with a discussion of forms of energy, energy sources and storage, and energy conversion. This is foll

  1. Finite element simulations on cutting process for carbon fiber composite%碳纤维复合材料切削过程的有限元模拟

    Institute of Scientific and Technical Information of China (English)

    熊威龙; 戴斌煜; 商景利; 王薇薇

    2014-01-01

    Based on failure criterion of Hashin,the two-dimensional orthogonal cutting model of carbon fiber composite material was presented in ABAQUS/Explicit. Effects of cutting condition on surface quality were analyzed by the model. In two-dimensional cutting simulation,the forming process of break,and the curve of force-tool stroke,and the stress distribution in chip and workpiece were obtained. The effects of tools with back engagement of cutting edge on the cutting process,surface quality and chip morphology were analyzed,and the methods to improve the surface quality of these materials were proposed theoretically.%基于Hashin失效准则,在ABAQUS/Explicit中建立碳纤维复合材料的二维正交切削模型。采用此模型研究切削条件对复合材料切削表面质量的影响。模拟得到了崩碎切屑的形成过程、切削力随刀具行程的变化曲线、应力在刀具及工件中的分布,并分析背吃刀量对切削过程中加工表面质量及切屑形貌的影响,从理论上提出改善复合材料切削表面质量的分析方法。

  2. Discursos pronunciados en los procesos éticos de enfermería: análisis de los elementos de sustentación Speeches given on nursing ethical processes: supporting elements analysis

    Directory of Open Access Journals (Sweden)

    Dulcinéia Ghizoni Schneider

    2011-12-01

    Full Text Available Objetivo principal: analizar los elementos de sustentación de discursos ético-profesionales, a partir de un caso ejemplar de proceso ético juzgado. Metodología: Estudio cualitativo con diseño exploratorio-descriptivo y documental, teniendo como fuente procesos éticos tramitados y archivados en el Consejo Regional de Enfermería/SC (Brasil, en el período de 1999 a 2007. Resultados principales: el caso ejemplar seleccionado (responsabilidad ético-profesional es representativo de discursos profesionales presentes en procesos éticos, en sus elementos de sustentación (enunciados, reglas y prácticas, y describe las referencias usadas por los profesionales para justificar sus deliberaciones morales, o dar legitimidad a los discursos accionados en estos juicios. Conclusión principal: los elementos de sustentación de los discursos, articulados en un modelo empírico analítico, son interesantes por dar visibilidad a los diseños de procesos de deliberación moral y, también, por suministrar un diseño general de los procesos éticos en su capacidad de "hablar para" y "hablar de la" Enfermería.Main goal: analyzing the supporting elements of ethical - professional discourses, from an exemplary case of a judged ethical process. Methodology: Qualitative study with documentary, descriptive and exploratory design, having as a source the ethical procedures conducted and filed at the Regional Council of Nursing / SC (Brazil, between 1999 and 2007. Main results: the exemplary case selected (ethical - professional responsibility is representative from professional discourses that are present in ethical processes, in their supporting elements (statements, rules and practices and describes references used by practitioners to justify their moral decisions or give legitimacy to the speeches triggered in those judgments. Main conclusion: discourses' supporting elements, articulated in the analytical -empirical model, are interesting for giving visibility

  3. Characterization of PZT Capacitor Structures with Various Electrode Materials Processed In-Situ Using AN Automated, Rotating Elemental Target, Ion Beam Deposition System

    Science.gov (United States)

    Gifford, Kenneth Douglas

    Ferroelectric thin film capacitor structures containing lead zirconate titanate (PZT) as the dielectric, with the chemical formula Pb(rm Zr_{x }Ti_{1-x})O_3, were synthesized in-situ with an automated ion beam sputter deposition system. Platinum (Pt), conductive ruthenium oxide (RuO_2), and two types of Pt-RuO_2 hybrid electrodes were used as the electrode materials. The capacitor structures are characterized in terms of microstructure and electrical characteristics. Reduction or elimination of non-ferroelectric phases, that nucleate during PZT processing on Pt/TiO _2/MgO and RuO_2/MgO substrates, is achieved by reducing the thickness of the individually deposited layers and by interposing a buffer layer (~100-200A) of PbTiO _3 (PT) between the bottom electrode and the PZT film. Capacitor structures containing a Pt electrode exhibit poor fatigue resistance, irregardless of the PZT microstructure or the use of a PT buffer layer. From these results, and results from similar capacitors synthesized with sol-gel and laser ablation, PZT-based capacitor structures containing Pt electrodes are considered to be unsuitable for use in memory devices. Using a PT buffer layer, in capacitor structures containing RuO_2 top and bottom electrodes and polycrystalline, highly (101) oriented PZT, reduces or eliminates the nucleation of zirconium-titanium oxide, non-ferroelectric species at the bottom electrode interface during processing. This results in good fatigue resistance up to ~2times10^ {10} switching cycles. DC leakage current density vs. time measurements follow the Curie-von Schweidler law, J(t) ~ t^ {rm -n}. Identification of the high electric field current conduction mechanism is inconclusive. The good fatigue resistance, low dc leakage current, and excellent retention, qualifies the use of these capacitor structures in non-volatile random access (NVRAM) and dynamic random access (DRAM) memory devices. Excellent fatigue resistance (10% loss in remanent polarization up to

  4. Finite Element Simulation of Quenching Process for 7075 Al Alloy%7075铝合金锻件淬火热处理有限元模拟

    Institute of Scientific and Technical Information of China (English)

    吴垠; 江雄心

    2012-01-01

    采用Deform-3D有限元软件,对7075铝合金锻件淬火热处理过程进行了数值模拟,讨论了固溶温度及淬火介质温度对淬火后残余应力的影响.结果表明:残余应力呈现表层受压、芯部受拉的分布:通过提高淬火介质温度或降低固溶温度可降低材料在淬火过程中产生的残余应力.%Numerical simulation of quenching process for 7075 Al-alloy forging was performed via Defrom-3D. The influences of temperature in solution treatment and qunechant temperature were discussed. The results show that the residual stress pattern consists of compressive stress at the surface and tensile stress at the center of the workpiece. In addition, the residual stress reduces with the decrease of solution treatment temperature or with the increase of quenching medium temperature.

  5. Chalcophile element (Ni, Cu, PGE, and Au) variations in the Tamarack magmatic sulfide deposit in the Midcontinent Rift System: implications for dynamic ore-forming processes

    Science.gov (United States)

    Taranovic, Valentina; Ripley, Edward M.; Li, Chusi; Rossell, Dean

    2016-10-01

    correlation between Pt and Pd, and between individual IPGE. At a given Pt or Pd content, however, the semi-massive sulfide ores have higher IPGE contents than the disseminated sulfide samples. Modeling results show that the variations in PGE tenors (metals in recalculated 100 % sulfide) in the Tamarack magmatic sulfide deposit are mainly controlled by variable R factors (magma/sulfide-liquid mass ratios) during sulfide-liquid segregation and subsequent monosulfide solid solution (MSS) fractionation during cooling. The initial contents of Ir, Pt, and Pd in the parental magma, estimated from the metal tenors of the disseminated sulfides, are 0.2, 2, and 1.8 ppb, respectively, which are ˜1/5 of the values for the PGE-undepleted primitive basalts of the Midcontinent Rift System. The variations of PGE tenors in the semi-massive and massive sulfide ores can be explained by MSS fractional crystallization from sulfide liquids. Extreme variations in the PGE contents of the massive sulfides may also in part reflect metal mobility during post-crystallization hydrothermal processes. The higher PGE tenors for the disseminated sulfides in the CGO dike relative to those in the FGO Intrusion are consistent with formation in a dynamic conduit where the early sulfide liquids left in the conduit by the FGO magma were subsequently upgraded by the subsequent surge of the CGO magma. The relatively low PGE tenors for the semi-massive and massive sulfides can be explained by lack of such an upgrading process for the sulfide due to their distal locations in a migrating conduit.

  6. Biogeochemical investigations on processes affecting the transport behaviour of trace elements in the tidal Elbe River; Biogeochemische Prozessuntersuchungen zum Transportverhalten von Spurenelementen in der Tide-Elbe

    Energy Technology Data Exchange (ETDEWEB)

    Hennies, K. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Gewaesserphysik

    1997-12-31

    This work concentrates on distribution and transport of micropollutants in anthropogenically affected estuary systems. Choosing the tidal Elbe River as an example, the influence of microlagae on two important partial processes of the transport regime, the remobilization (a) from undisturbed sediments and (b) from suspended particulate matter, was simulated and quantified in the laboratory. Benthic and planktonic release of Cd, Cu, Pb and Zn into the dissolved phase of the river pelagial were estimated and comparatively evaluated for summer/late summer situation. During that season natural decomposition of suspended particulate matter in the water column thus represents the quantitatively most significant mobilization pathway for particle bound heavy metals in the river section between Hamburg and Glueckstadt. Knowing the composition and heavy metal load of suspended particulate matter, rich in algae, mobilization rates can consequently be calculated for the water column with regard to conditions typical for estuaries. The prognosis of the differing transport behaviour of single heavy metals for greater sections of estuaries is also possible if these rates are implemented into transport-reaction models. (orig.) [Deutsch] Die vorliegende Arbeit befasst sich mit Verteilung und Transport von Spurenschadstoffen in anthropogen belasteten Aestuarsystemen. Am Beispiel der Tide-Elbe wurde der Einfluss von Mikroalgen auf zwei wichtige Teilprozesse des Transportregimes, die Remobilisierung (a) aus ungestoerten Sedimenten und (b) aus suspendierten Schwebstoffen, im Labor simuliert und quantifiziert. Benthische und planktische Freisetzung von Cd, Cu, Pb und Zn in die Loesungsphase des Flusspelagials der Tide-Elbe wurden fuer die Sommer-/Spaetsommer-Situation abgeschaetzt und vergleichend bewertet. Der natuerliche Schwebstoff-Abbau in der Wassersaeule stellt demnach in dieser Jahreszeit im Stromabschnitt zwischen Hamburg und Glueckstadt den quantitativ bedeutsamsten

  7. Influence of different sulfur to selenium ratios on the structural and electronic properties of Cu(In,Ga)(S,Se)2 thin films and solar cells formed by the stacked elemental layer process

    Science.gov (United States)

    Mueller, B. J.; Zimmermann, C.; Haug, V.; Hergert, F.; Koehler, T.; Zweigart, S.; Herr, U.

    2014-11-01

    In this study, we investigate the effect of different elemental selenium to elemental sulfur ratios on the chalcopyrite phase formation in Cu(In,Ga)(S,Se)2 thin films. The films are formed by the stacked elemental layer process. The structural and electronic properties of the thin films and solar cells are analyzed by means of scanning electron microscopy, glow discharge optical emission spectrometry, X-ray diffraction, X-ray fluorescence, Raman spectroscopy, spectral photoluminescence as well as current-voltage, and quantum efficiency measurements. The influence of different S/(S+Se) ratios on the anion incorporation and on the Ga/In distribution is investigated. We find a homogenous sulfur concentration profile inside the film from the top surface to the bottom. External quantum efficiency measurements show that the band edge of the solar cell device is shifted to shorter wavelength, which enhances the open-circuit voltages. The relative increase of the open-circuit voltage with S/(S+Se) ratio is lower than expected from the band gap energy trend, which is attributed to the presence of S-induced defects. We also observe a linear decrease of the short-circuit current density with increasing S/(S+Se) ratio which can be explained by a reduced absorption. Above a critical S/(S+Se) ratio of around 0.61, the fill factor drops drastically, which is accompanied by a strong series resistance increase which may be attributed to changes in the back contact or p-n junction properties.

  8. Discrete Element Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J; Johnson, S

    2007-12-03

    The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.

  9. The Chemical Abundances of Stars in the Halo (CASH) Project. III. A New Classification Scheme for Carbon-Enhanced Metal-poor Stars with S-process Element Enhancement

    CERN Document Server

    Hollek, Julie K; Placco, Vinicius M; Karakas, Amanda I; Shetrone, Matthew; Sneden, Christopher; Christlieb, Norbert

    2015-01-01

    We present a detailed abundance analysis of 23 elements for a newly discovered carbon-enhanced metal-poor (CEMP) star, HE 0414-0343, from the Chemical Abundances of Stars in the Halo (CASH) Project. Its spectroscopic stellar parameters are Teff = 4863 K, log g = 1.25, vmic = 2.20 km/s, and [Fe/H] = -2.24. Radial velocity measurements covering seven years indicate HE 0414-0343 to be a binary. HE 0414-0343 has [C/Fe] = 1.44 and is strongly enhanced in neutron-capture elements but its abundances cannot be reproduced by a solar-type s-process pattern alone. Traditionally, it could be classified as "CEMP-r/s" star. Based on abundance comparisons with AGB star nucleosynthesis models, we suggest a new physically-motivated origin and classification scheme for CEMP-s stars and the still poorly-understood CEMP-r/s. The new scheme describes a continuous transition between these two so-far distinctly treated subgroups: CEMP-sA, CEMP-sB, and CEMP-sC. Possible causes for a continuous transition include the number of therma...

  10. HTR-PM燃料元件生产穿衣工艺及设备研制%Overcoating Process and Equipments Development in Manufacture of Fuel Elements for HTR-PM

    Institute of Scientific and Technical Information of China (English)

    卢振明; 周湘文; 张杰; 刘兵

    2012-01-01

    The equipments used in the overcoating process was developed, which comprise overcoating system, rotating screen, sorting device, homogenize equipment, and recovery system for unqualified overcoated particles. The results of batch experiments using optimized parameters show that the yield is high and stable. The failure ratio of coated particles in fuel elements satisfies design parameter. The equipments are easy to operation and control, and can satisfy the large-scale production of overcoated particles of fuel elements for HTR-PM.%自主研制了穿衣工艺所用非标设备,包括穿衣系统、滚筒筛、振选台、均匀化设备、不合格颗粒回收系统等.工艺实验结果显示,穿衣颗粒成品率高且稳定,破损率满足设计要求.设备易于操作控制,完全能满足高温气冷堆示范电站燃料元件规模生产的需要.

  11. Damage Detection and Identification of Finite Element Models Using State-Space Based Signal Processing a Summation of Work Completed at the Lawrence Livermore National Laboratory February 1999 to April 2000

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, G.C.

    2000-04-28

    Until recently, attempts to update Finite Element Models (FEM) of large structures based upon recording structural motions were mostly ad hoc, requiring a large amount of engineering experience and skill. Studies have been undertaken at LLNL to use state-space based signal processing techniques to locate the existence and type of model mismatches common in FEM. Two different methods (Gauss-Newton gradient search and extended Kalman filter) have been explored, and the progress made in each type of algorithm as well as the results from several simulated and one actual building model will be discussed. The algorithms will be examined in detail, and the computer programs written to implement the algorithms will be documented.

  12. DSPACE hardware architecture for on-board real-time image/video processing in European space missions

    Science.gov (United States)

    Saponara, Sergio; Donati, Massimiliano; Fanucci, Luca; Odendahl, Maximilian; Leupers, Reiner; Errico, Walter

    2013-02-01

    The on-board data processing is a vital task for any satellite and spacecraft due to the importance of elaborate the sensing data before sending them to the Earth, in order to exploit effectively the bandwidth to the ground station. In the last years the amount of sensing data collected by scientific and commercial space missions has increased significantly, while the available downlink bandwidth is comparatively stable. The increasing demand of on-board real-time processing capabilities represents one of the critical issues in forthcoming European missions. Faster and faster signal and image processing algorithms are required to accomplish planetary observation, surveillance, Synthetic Aperture Radar imaging and telecommunications. The only available space-qualified Digital Signal Processor (DSP) free of International Traffic in Arms Regulations (ITAR) restrictions faces inadequate performance, thus the development of a next generation European DSP is well known to the space community. The DSPACE space-qualified DSP architecture fills the gap between the computational requirements and the available devices. It leverages a pipelined and massively parallel core based on the Very Long Instruction Word (VLIW) paradigm, with 64 registers and 8 operational units, along with cache memories, memory controllers and SpaceWire interfaces. Both the synthesizable VHDL and the software development tools are generated from the LISA high-level model. A Xilinx-XC7K325T FPGA is chosen to realize a compact PCI demonstrator board. Finally first synthesis results on CMOS standard cell technology (ASIC 180 nm) show an area of around 380 kgates and a peak performance of 1000 MIPS and 750 MFLOPS at 125MHz.

  13. Microstructural Finite Element Analysis of Asphalt Mixture Using Digital Image Processing%基于数字图像处理技术的沥青混合料微观结构有限元分析

    Institute of Scientific and Technical Information of China (English)

    陈佩林; 虞将苗; 李晓军; 张肖宁

    2006-01-01

    A methodology for relating the microstructure of asphalt mixture to its mechanical behavior was presented. Digital image processing technique was applied to convert computerized tomography (CT) image into a digital format that can be incorporated into finite element modeling. This CT discrimination based on finite element modeling is used to analyse mechanical behavior of asphalt mixture indirect tensile test by taking into account the actual heterogeneity and microstructures, especially air void distribution. It was pointed that the material heterogeneity and air voids distributions have significant effects on the tensile stress distribution along the loading directions of the specimen. The results indicate that it is feasible to use the finite element model based on CT image and digital image processing techniques to study the viscoelastic property of asphalt mixture.%论述一种将沥青混合料微结构和其力学行为仿真联系在一起的方法.该方法利用数字图像处理技术将计算机断层扫描(CT)图像转换为数字格式,并与有限元建模结合,使得根据CT图像建立的有限元模型可以较真实地再现沥青混合料的微结构,进行有限元分析时可以充分考虑沥青混合料颗粒和微空隙分布非均匀特性.计算分析了各向异性和空隙分布对沥青混合料劈裂试验的影响,数值计算结果发现沥青混合料颗粒和空隙分布的非均匀性对拉应力分布影响极大.研究结果表明:采用基于CT图像处理技术的有限元模型进行沥青混合料粘弹特性的研究是可行的.

  14. Element-Based Computational Model

    Directory of Open Access Journals (Sweden)

    Conrad Mueller

    2012-02-01

    Full Text Available A variation on the data-flow model is proposed to use for developing parallel architectures. While the model is a data driven model it has significant differences to the data-flow model. The proposed model has an evaluation cycleof processing elements (encapsulated data that is similar to the instruction cycle of the von Neumann model. The elements contain the information required to process them. The model is inherently parallel. An emulation of the model has been implemented. The objective of this paper is to motivate support for taking the research further. Using matrix multiplication as a case study, the element/data-flow based model is compared with the instruction-based model. This is done using complexity analysis followed by empirical testing to verify this analysis. The positive results are given as motivation for the research to be taken to the next stage - that is, implementing the model using FPGAs.

  15. Alloy element redistribution during sintering of powder metallurgy steels

    OpenAIRE

    Tahir, Abdul Malik

    2014-01-01

    Homogenization of alloying elements is desired during sintering of powder metallurgy components. The redistribution processes such as penetration of liquid phase into the interparticle/grain boundaries of solid particles and subsequent solid-state  diffusion of alloy element(s) in the base powder, are important for the effective homogenization of alloy element(s) during liquid phase sintering of the mixed powders. The aim of this study is to increase the understanding of alloy element redistr...

  16. Elements of a Spatial Web

    DEFF Research Database (Denmark)

    Jensen, Christian S.

    2010-01-01

    and are relevant to a text argument. An important element in enabling such queries is to be able to rank spatial web objects. Another is to be able to determine the relevance of an object to a query. Yet another is to enable the efficient processing of such queries. The talk covers recent results on spatial web...

  17. Finite Element Model Development and Application on Stretch Reducing Process of Seamless Tube%无缝钢管张力减径过程的有限元模型开发及应用

    Institute of Scientific and Technical Information of China (English)

    于辉; 杜凤山; 汪飞雪

    2011-01-01

    The stretch reducing process is divided into the rolling deformation of the stand and the remeshing generation between the stands taking the tension between the adjacent stands as the boundary conditions by means of the group modeling principle in order to study the metal deformation of hot rolling seamless tube in the process of stretch reducing. A higher-order fitting function is established to accurately describe the roll pass surface. A friction element model is applied to simulate the contact friction. Furthermore, the nonlinear equations are solved with a secant modulus method. On the basis of above theories, a elastic-plastic finite element model of stretch reducing process is developed, which is used to establish a FE model and to simulate the metal deformation of the stretch reducing unit of some factory. Through comparison, the shape of the product section simulated is similar to that of the actual rolled product, which is a slight hexagon shape. Moreover, the variation of wall thickness is the same. The geometry simulated is agreed very well with that of the measured. These show that the developed elastic-plastic finite element model for tube stretch reducing process met the requirements of engineering calculation, which provided an effective research method for predicting the section shape and finishing size accuracy.%为了研究热轧无缝钢管张力减径过程的金属变形,利用组元建模原理,把张力作为相邻机架之间的边界条件,使得张力减径过程分为机架上的轧制变形过程和机架之间的网格再生过程.建立高阶拟合函数来精确描述轧辊孔型曲面,应用摩擦元模型来模拟接触摩擦,并用正割模量法来求解非线性方程组,在上述理论基础上开发张力减径弹塑性有限元模型,利用该模型对某厂张力减径机组进行有限元建模分析.通过与实际轧制结果比较可知,模拟计算与实际轧制的产品断面形状接近,都呈现轻微内六方形

  18. 硫化砷渣全湿法制备单质砷的研究%Experimental Study of Elemental Arsenic Production by the Wet Process of Arsenic Sulfide Residue

    Institute of Scientific and Technical Information of China (English)

    侯汉娜; 陈甜甜

    2014-01-01

    In this experiment, arsenic sulfide residue was used as raw material and wet process of arsenic slag extraction with copper dichloride acid solution was applied. The research focused on the influences of the dose of copper dichloride, pH of the solution and leaching time on the leaching yield of arsenic during the leaching process with copper dichloride. Besides, the method of producing elemental arsenic from arsenic sulfide residue by reduction of arsenic acid solution with stannous chloride was also discussed.%以硫化砷渣为原料,用氯化铜酸性溶液浸出砷渣的全湿法进行实验,着重研究氯化铜浸出砷的过程中氯化铜用量、溶液pH和浸出时间对砷浸出率的影响,探讨用氯化亚锡还原砷盐酸溶液从硫化砷渣得到单质砷的方法。

  19. Effects of germination and high hydrostatic pressure processing on mineral elements, amino acids and antioxidants in vitro bioaccessibility, as well as starch digestibility in brown rice (Oryza sativa L.).

    Science.gov (United States)

    Xia, Qiang; Wang, Liping; Xu, Congcong; Mei, Jun; Li, Yunfei

    2017-01-01

    The effects of germination and high hydrostatic pressure (HHP) processing on the in vitro bioaccessibility of mineral elements, amino acids (AAs), antioxidants and starch in brown rice (BR) were investigated. Germinated BR (GBR) was obtained by incubating at 37°C for 36h and then subjected to HHP treatments at 0.1, 100, 300 and 500MPa for 10min. The in vitro bioaccessibility of calcium and copper was increased by 12.59-52.17% and 2.87-23.06% after HHP, respectively, but bioaccessible iron was decreased. In addition, HHP significantly improved individual AAs, particularly indispensable AAs and gama-aminobutyric acid, as well as bioaccessible total antioxidant activities and starch resistance to enzymatic hydrolysis. However, germination greatly increased starch digestibility. Atomic force microscopy characterization suggested an obvious structural change in bran fraction at pressures above 300MPa. These results can help to understand the effects of germination and HHP technologies on nutrients bioaccessibility and develop appropriate processing conditions. Copyright © 2016. Published by Elsevier Ltd.

  20. 一种稀有金属冶炼伴生放射性元素的去除方法%Removing Radioactive Elements Associated with Rare Metals in the Smelting Process

    Institute of Scientific and Technical Information of China (English)

    张选旭; 张洁

    2015-01-01

    Remove radioactive elements in smelting processes can ensure product quality and reduce environmental impact due to the associated radioactive elements with rare metal ores. This paper studied the two-step removal technology of radioactive thorium, uranium associated with ion adsorption rare earth by organic extraction. Parts of the radioactive elements were concentrated in the acid residue by acid decomposition with removal rate reaching 80%~90%;the remaining was removed by precipitating thorium, uranium in the waste water with removal rate reaching 8%~18 %. Testing results showed that thorium, uranium contents in wastewater discharge were lower than 0.1 mg/L, conforming with the limit requirements in the relevant rare earth industry emission standards. The removed radioactive materials were stockpiled, avoiding the radioactive contamination of the environment.%由于稀有金属矿物中往往伴生放射性元素,因此冶炼工艺中去除放射性元素具有保证产品质量和减少环境影响的双重意义。研究针对离子型稀土冶炼工艺去除放射性元素这一课题,提出了一种湿法冶金工艺中通过有机萃取去除稀有金属冶炼伴生放射性元素钍、铀的方法;该方法为两步去除法,即通过酸分解将一部分放射性元素富集在酸溶渣中,该工序去除率达到80%~90%,剩余部分通过有机萃取进行去除,采用中和法将废水中放射性元素钍、铀沉淀下来,去除率达到8%~18%;经测定,排放的废水中钍、铀含量小于0.1 mg/L,符合稀土工业污染物排放标准相关限值要求;去除的放射性物质集中堆存于低放库中,避免了放射性元素对环境的污染。此工艺可为其他稀有金属矿种冶炼去除钍、铀提供借鉴。