ITCA: Inter-Task Conflict-Aware CPU accounting for CMPs

OpenAIRE

Luque, Carlos; Moreto Planas, Miquel; Cazorla, Francisco; Gioiosa, Roberto; Buyuktosunoglu, Alper; Valero Cortés, Mateo

2009-01-01

Chip-MultiProcessor (CMP) architectures are becoming more and more popular as an alternative to the traditional processors that only extract instruction-level parallelism from an application. CMPs introduce complexities when accounting CPU utilization. This is due to the fact that the progress done by an application during an interval of time highly depends on the activity of the other applications it is co-scheduled with. In this paper, we identify how an inaccurate measurement of the CPU ut...

Life cycle assessment and additives: state of knowledge

DEFF Research Database (Denmark)

is to identify research needs within this area focusing on both risk assessment (RA) and life cycle assessment (LCA). Besides the sectors on paper and plastics also lubricants, textiles, electronics and leather are included in RiskCycle. On plastics a literature review regarding the state of knowledge......Concerns about possible toxic effects from additives/impurities accumulated in globally recycled waste/resources like paper and plastics was one of the main reasons for starting up the EU FP7 Coordination Action project RiskCycle (www.wadef.com/projects/riskcycle). A key aim of the project...... on additives/impurities in LCA has been performed within RiskCycle. Several inventory databases (LCI data) have been investigated and the result shows that most LCI databases use PlasticsEurope data for plastics production. Most of these data are aggregated and do not include additives. Regarding...

Reconstruction of the neutron spectrum using an artificial neural network in CPU and GPU; Reconstruccion del espectro de neutrones usando una red neuronal artificial (RNA) en CPU y GPU

Energy Technology Data Exchange (ETDEWEB)

Hernandez D, V. M.; Moreno M, A.; Ortiz L, M. A. [Universidad de Cordoba, 14002 Cordoba (Spain); Vega C, H. R.; Alonso M, O. E., E-mail: vic.mc68010@gmail.com [Universidad Autonoma de Zacatecas, 98000 Zacatecas, Zac. (Mexico)

2016-10-15

The increase in computing power in personal computers has been increasing, computers now have several processors in the CPU and in addition multiple CUDA cores in the graphics processing unit (GPU); both systems can be used individually or combined to perform scientific computation without resorting to processor or supercomputing arrangements. The Bonner sphere spectrometer is the most commonly used multi-element system for neutron detection purposes and its associated spectrum. Each sphere-detector combination gives a particular response that depends on the energy of the neutrons, and the total set of these responses is known like the responses matrix Rφ(E). Thus, the counting rates obtained with each sphere and the neutron spectrum is related to the Fredholm equation in its discrete version. For the reconstruction of the spectrum has a system of poorly conditioned equations with an infinite number of solutions and to find the appropriate solution, it has been proposed the use of artificial intelligence through neural networks with different platforms CPU and GPU. (Author)

A Hybrid CPU/GPU Pattern-Matching Algorithm for Deep Packet Inspection.

Directory of Open Access Journals (Sweden)

Chun-Liang Lee

Full Text Available The large quantities of data now being transferred via high-speed networks have made deep packet inspection indispensable for security purposes. Scalable and low-cost signature-based network intrusion detection systems have been developed for deep packet inspection for various software platforms. Traditional approaches that only involve central processing units (CPUs are now considered inadequate in terms of inspection speed. Graphic processing units (GPUs have superior parallel processing power, but transmission bottlenecks can reduce optimal GPU efficiency. In this paper we describe our proposal for a hybrid CPU/GPU pattern-matching algorithm (HPMA that divides and distributes the packet-inspecting workload between a CPU and GPU. All packets are initially inspected by the CPU and filtered using a simple pre-filtering algorithm, and packets that might contain malicious content are sent to the GPU for further inspection. Test results indicate that in terms of random payload traffic, the matching speed of our proposed algorithm was 3.4 times and 2.7 times faster than those of the AC-CPU and AC-GPU algorithms, respectively. Further, HPMA achieved higher energy efficiency than the other tested algorithms.

Performance analysis of the FDTD method applied to holographic volume gratings: Multi-core CPU versus GPU computing

Science.gov (United States)

Francés, J.; Bleda, S.; Neipp, C.; Márquez, A.; Pascual, I.; Beléndez, A.

2013-03-01

The finite-difference time-domain method (FDTD) allows electromagnetic field distribution analysis as a function of time and space. The method is applied to analyze holographic volume gratings (HVGs) for the near-field distribution at optical wavelengths. Usually, this application requires the simulation of wide areas, which implies more memory and time processing. In this work, we propose a specific implementation of the FDTD method including several add-ons for a precise simulation of optical diffractive elements. Values in the near-field region are computed considering the illumination of the grating by means of a plane wave for different angles of incidence and including absorbing boundaries as well. We compare the results obtained by FDTD with those obtained using a matrix method (MM) applied to diffraction gratings. In addition, we have developed two optimized versions of the algorithm, for both CPU and GPU, in order to analyze the improvement of using the new NVIDIA Fermi GPU architecture versus highly tuned multi-core CPU as a function of the size simulation. In particular, the optimized CPU implementation takes advantage of the arithmetic and data transfer streaming SIMD (single instruction multiple data) extensions (SSE) included explicitly in the code and also of multi-threading by means of OpenMP directives. A good agreement between the results obtained using both FDTD and MM methods is obtained, thus validating our methodology. Moreover, the performance of the GPU is compared to the SSE+OpenMP CPU implementation, and it is quantitatively determined that a highly optimized CPU program can be competitive for a wider range of simulation sizes, whereas GPU computing becomes more powerful for large-scale simulations.

Length-Bounded Hybrid CPU/GPU Pattern Matching Algorithm for Deep Packet Inspection

Directory of Open Access Journals (Sweden)

Yi-Shan Lin

2017-01-01

Full Text Available Since frequent communication between applications takes place in high speed networks, deep packet inspection (DPI plays an important role in the network application awareness. The signature-based network intrusion detection system (NIDS contains a DPI technique that examines the incoming packet payloads by employing a pattern matching algorithm that dominates the overall inspection performance. Existing studies focused on implementing efficient pattern matching algorithms by parallel programming on software platforms because of the advantages of lower cost and higher scalability. Either the central processing unit (CPU or the graphic processing unit (GPU were involved. Our studies focused on designing a pattern matching algorithm based on the cooperation between both CPU and GPU. In this paper, we present an enhanced design for our previous work, a length-bounded hybrid CPU/GPU pattern matching algorithm (LHPMA. In the preliminary experiment, the performance and comparison with the previous work are displayed, and the experimental results show that the LHPMA can achieve not only effective CPU/GPU cooperation but also higher throughput than the previous method.

The CMSSW benchmarking suite: Using HEP code to measure CPU performance

International Nuclear Information System (INIS)

Benelli, G

2010-01-01

The demanding computing needs of the CMS experiment require thoughtful planning and management of its computing infrastructure. A key factor in this process is the use of realistic benchmarks when assessing the computing power of the different architectures available. In recent years a discrepancy has been observed between the CPU performance estimates given by the reference benchmark for HEP computing (SPECint) and actual performances of HEP code. Making use of the CPU performance tools from the CMSSW performance suite, comparative CPU performance studies have been carried out on several architectures. A benchmarking suite has been developed and integrated in the CMSSW framework, to allow computing centers and interested third parties to benchmark architectures directly with CMSSW. The CMSSW benchmarking suite can be used out of the box, to test and compare several machines in terms of CPU performance and report with the wanted level of detail the different benchmarking scores (e.g. by processing step) and results. In this talk we describe briefly the CMSSW software performance suite, and in detail the CMSSW benchmarking suite client/server design, the performance data analysis and the available CMSSW benchmark scores. The experience in the use of HEP code for benchmarking will be discussed and CMSSW benchmark results presented.

SU-E-J-60: Efficient Monte Carlo Dose Calculation On CPU-GPU Heterogeneous Systems

Energy Technology Data Exchange (ETDEWEB)

Xiao, K; Chen, D. Z; Hu, X. S [University of Notre Dame, Notre Dame, IN (United States); Zhou, B [Altera Corp., San Jose, CA (United States)

2014-06-01

Purpose: It is well-known that the performance of GPU-based Monte Carlo dose calculation implementations is bounded by memory bandwidth. One major cause of this bottleneck is the random memory writing patterns in dose deposition, which leads to several memory efficiency issues on GPU such as un-coalesced writing and atomic operations. We propose a new method to alleviate such issues on CPU-GPU heterogeneous systems, which achieves overall performance improvement for Monte Carlo dose calculation. Methods: Dose deposition is to accumulate dose into the voxels of a dose volume along the trajectories of radiation rays. Our idea is to partition this procedure into the following three steps, which are fine-tuned for CPU or GPU: (1) each GPU thread writes dose results with location information to a buffer on GPU memory, which achieves fully-coalesced and atomic-free memory transactions; (2) the dose results in the buffer are transferred to CPU memory; (3) the dose volume is constructed from the dose buffer on CPU. We organize the processing of all radiation rays into streams. Since the steps within a stream use different hardware resources (i.e., GPU, DMA, CPU), we can overlap the execution of these steps for different streams by pipelining. Results: We evaluated our method using a Monte Carlo Convolution Superposition (MCCS) program and tested our implementation for various clinical cases on a heterogeneous system containing an Intel i7 quad-core CPU and an NVIDIA TITAN GPU. Comparing with a straightforward MCCS implementation on the same system (using both CPU and GPU for radiation ray tracing), our method gained 2-5X speedup without losing dose calculation accuracy. Conclusion: The results show that our new method improves the effective memory bandwidth and overall performance for MCCS on the CPU-GPU systems. Our proposed method can also be applied to accelerate other Monte Carlo dose calculation approaches. This research was supported in part by NSF under Grants CCF

Reconstruction of the neutron spectrum using an artificial neural network in CPU and GPU

International Nuclear Information System (INIS)

Hernandez D, V. M.; Moreno M, A.; Ortiz L, M. A.; Vega C, H. R.; Alonso M, O. E.

2016-10-01

The increase in computing power in personal computers has been increasing, computers now have several processors in the CPU and in addition multiple CUDA cores in the graphics processing unit (GPU); both systems can be used individually or combined to perform scientific computation without resorting to processor or supercomputing arrangements. The Bonner sphere spectrometer is the most commonly used multi-element system for neutron detection purposes and its associated spectrum. Each sphere-detector combination gives a particular response that depends on the energy of the neutrons, and the total set of these responses is known like the responses matrix Rφ(E). Thus, the counting rates obtained with each sphere and the neutron spectrum is related to the Fredholm equation in its discrete version. For the reconstruction of the spectrum has a system of poorly conditioned equations with an infinite number of solutions and to find the appropriate solution, it has been proposed the use of artificial intelligence through neural networks with different platforms CPU and GPU. (Author)

Towards 100,000 CPU Cycle-Scavenging by Genetic Algorithms

Science.gov (United States)

Globus, Al; Biegel, Bryan A. (Technical Monitor)

2001-01-01

We examine a web-centric design using standard tools such as web servers, web browsers, PHP, and mySQL. We also consider the applicability of Information Power Grid tools such as the Globus (no relation to the author) Toolkit. We intend to implement this architecture with JavaGenes running on at least two cycle-scavengers: Condor and United Devices. JavaGenes, a genetic algorithm code written in Java, will be used to evolve multi-species reactive molecular force field parameters.

Inhibition of CPU0213, a Dual Endothelin Receptor Antagonist, on Apoptosis via Nox4-Dependent ROS in HK-2 Cells

Directory of Open Access Journals (Sweden)

Qing Li

2016-06-01

Full Text Available Background/Aims: Our previous studies have indicated that a novel endothelin receptor antagonist CPU0213 effectively normalized renal function in diabetic nephropathy. However, the molecular mechanisms mediating the nephroprotective role of CPU0213 remain unknown. Methods and Results: In the present study, we first detected the role of CPU0213 on apoptosis in human renal tubular epithelial cell (HK-2. It was shown that high glucose significantly increased the protein expression of Bax and decreased Bcl-2 protein in HK-2 cells, which was reversed by CPU0213. The percentage of HK-2 cells that showed Annexin V-FITC binding was markedly suppressed by CPU0213, which confirmed the inhibitory role of CPU0213 on apoptosis. Given the regulation of endothelin (ET system to oxidative stress, we determined the role of redox signaling in the regulation of CPU0213 on apoptosis. It was demonstrated that the production of superoxide (O2-. was substantially attenuated by CPU0213 treatment in HK-2 cells. We further found that CPU0213 dramatically inhibited expression of Nox4 protein, which gene silencing mimicked the role of CPU0213 on the apoptosis under high glucose stimulation. We finally examined the role of CPU0213 on ET-1 receptors and found that high glucose-induced protein expression of endothelin A and B receptors was dramatically inhibited by CPU0213. Conclusion: Taken together, these results suggest that this Nox4-dependenet O2- production is critical for the apoptosis of HK-2 cells in high glucose. Endothelin receptor antagonist CPU0213 has an anti-apoptosis role through Nox4-dependent O2-.production, which address the nephroprotective role of CPU0213 in diabetic nephropathy.

Using the CPU and GPU for real-time video enhancement on a mobile computer

CSIR Research Space (South Africa)

Bachoo, AK

2010-09-01

Full Text Available . In this paper, the current advances in mobile CPU and GPU hardware are used to implement video enhancement algorithms in a new way on a mobile computer. Both the CPU and GPU are used effectively to achieve realtime performance for complex image enhancement...

Heterogeneous Gpu&Cpu Cluster For High Performance Computing In Cryptography

Directory of Open Access Journals (Sweden)

Michał Marks

2012-01-01

Full Text Available This paper addresses issues associated with distributed computing systems andthe application of mixed GPU&CPU technology to data encryption and decryptionalgorithms. We describe a heterogenous cluster HGCC formed by twotypes of nodes: Intel processor with NVIDIA graphics processing unit and AMDprocessor with AMD graphics processing unit (formerly ATI, and a novel softwareframework that hides the heterogeneity of our cluster and provides toolsfor solving complex scientific and engineering problems. Finally, we present theresults of numerical experiments. The considered case study is concerned withparallel implementations of selected cryptanalysis algorithms. The main goal ofthe paper is to show the wide applicability of the GPU&CPU technology tolarge scale computation and data processing.

Nuclear Fuel Cycle Options Catalog: FY16 Improvements and Additions

Energy Technology Data Exchange (ETDEWEB)

Price, Laura L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barela, Amanda Crystal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schetnan, Richard Reed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walkow, Walter M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-08-31

The United States Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Program sponsors nuclear fuel cycle research and development. As part of its Fuel Cycle Options campaign, the DOE has established the Nuclear Fuel Cycle Options Catalog. The catalog is intended for use by the Fuel Cycle Technologies Program in planning its research and development activities and disseminating information regarding nuclear energy to interested parties. The purpose of this report is to document the improvements and additions that have been made to the Nuclear Fuel Cycle Options Catalog in the 2016 fiscal year.

Nuclear Fuel Cycle Options Catalog FY15 Improvements and Additions.

Energy Technology Data Exchange (ETDEWEB)

Price, Laura L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Barela, Amanda Crystal [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Schetnan, Richard Reed [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Walkow, Walter M. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-11-01

The United States Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Program sponsors nuclear fuel cycle research and development. As part of its Fuel Cycle Options campaign, the DOE has established the Nuclear Fuel Cycle Options Catalog. The catalog is intended for use by the Fuel Cycle Technologies Program in planning its research and development activities and disseminating information regarding nuclear energy to interested parties. The purpose of this report is to document the improvements and additions that have been made to the Nuclear Fuel Cycle Options Catalog in the 2015 fiscal year.

LHCb: Statistical Comparison of CPU performance for LHCb applications on the Grid

CERN Multimedia

Graciani, R

2009-01-01

The usage of CPU resources by LHCb on the Grid id dominated by two different applications: Gauss and Brunel. Gauss the application doing the Monte Carlo simulation of proton-proton collisions. Brunel is the application responsible for the reconstruction of the signals recorded by the detector converting them into objects that can be used for later physics analysis of the data (tracks, clusters,…) Both applications are based on the Gaudi and LHCb software frameworks. Gauss uses Pythia and Geant as underlying libraries for the simulation of the collision and the later passage of the generated particles through the LHCb detector. While Brunel makes use of LHCb specific code to process the data from each sub-detector. Both applications are CPU bound. Large Monte Carlo productions or data reconstructions running on the Grid are an ideal benchmark to compare the performance of the different CPU models for each case. Since the processed events are only statistically comparable, only statistical comparison of the...

Responses of ecosystem nitrogen cycle to nitrogen addition: a meta-analysis.

Science.gov (United States)

Lu, Meng; Yang, Yuanhe; Luo, Yiqi; Fang, Changming; Zhou, Xuhui; Chen, Jiakuan; Yang, Xin; Li, Bo

2011-03-01

• Anthropogenic nitrogen (N) addition may substantially alter the terrestrial N cycle. However, a comprehensive understanding of how the ecosystem N cycle responds to external N input remains elusive. • Here, we evaluated the central tendencies of the responses of 15 variables associated with the ecosystem N cycle to N addition, using data extracted from 206 peer-reviewed papers. • Our results showed that the largest changes in the ecosystem N cycle caused by N addition were increases in soil inorganic N leaching (461%), soil NO₃⁻ concentration (429%), nitrification (154%), nitrous oxide emission (134%), and denitrification (84%). N addition also substantially increased soil NH₄+ concentration (47%), and the N content in belowground (53%) and aboveground (44%) plant pools, leaves (24%), litter (24%) and dissolved organic N (21%). Total N content in the organic horizon (6.1%) and mineral soil (6.2%) slightly increased in response to N addition. However, N addition induced a decrease in microbial biomass N by 5.8%. • The increases in N effluxes caused by N addition were much greater than those in plant and soil pools except soil NO₃⁻, suggesting a leaky terrestrial N system. © 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.

High performance technique for database applicationsusing a hybrid GPU/CPU platform

KAUST Repository

Zidan, Mohammed A.

2012-07-28

Many database applications, such as sequence comparing, sequence searching, and sequence matching, etc, process large database sequences. we introduce a novel and efficient technique to improve the performance of database applica- tions by using a Hybrid GPU/CPU platform. In particular, our technique solves the problem of the low efficiency result- ing from running short-length sequences in a database on a GPU. To verify our technique, we applied it to the widely used Smith-Waterman algorithm. The experimental results show that our Hybrid GPU/CPU technique improves the average performance by a factor of 2.2, and improves the peak performance by a factor of 2.8 when compared to earlier implementations. Copyright © 2011 by ASME.

Effective electron-density map improvement and structure validation on a Linux multi-CPU web cluster: The TB Structural Genomics Consortium Bias Removal Web Service.

Science.gov (United States)

Reddy, Vinod; Swanson, Stanley M; Segelke, Brent; Kantardjieff, Katherine A; Sacchettini, James C; Rupp, Bernhard

2003-12-01

Anticipating a continuing increase in the number of structures solved by molecular replacement in high-throughput crystallography and drug-discovery programs, a user-friendly web service for automated molecular replacement, map improvement, bias removal and real-space correlation structure validation has been implemented. The service is based on an efficient bias-removal protocol, Shake&wARP, and implemented using EPMR and the CCP4 suite of programs, combined with various shell scripts and Fortran90 routines. The service returns improved maps, converted data files and real-space correlation and B-factor plots. User data are uploaded through a web interface and the CPU-intensive iteration cycles are executed on a low-cost Linux multi-CPU cluster using the Condor job-queuing package. Examples of map improvement at various resolutions are provided and include model completion and reconstruction of absent parts, sequence correction, and ligand validation in drug-target structures.

A CFD Heterogeneous Parallel Solver Based on Collaborating CPU and GPU

Science.gov (United States)

Lai, Jianqi; Tian, Zhengyu; Li, Hua; Pan, Sha

2018-03-01

Since Graphic Processing Unit (GPU) has a strong ability of floating-point computation and memory bandwidth for data parallelism, it has been widely used in the areas of common computing such as molecular dynamics (MD), computational fluid dynamics (CFD) and so on. The emergence of compute unified device architecture (CUDA), which reduces the complexity of compiling program, brings the great opportunities to CFD. There are three different modes for parallel solution of NS equations: parallel solver based on CPU, parallel solver based on GPU and heterogeneous parallel solver based on collaborating CPU and GPU. As we can see, GPUs are relatively rich in compute capacity but poor in memory capacity and the CPUs do the opposite. We need to make full use of the GPUs and CPUs, so a CFD heterogeneous parallel solver based on collaborating CPU and GPU has been established. Three cases are presented to analyse the solver’s computational accuracy and heterogeneous parallel efficiency. The numerical results agree well with experiment results, which demonstrate that the heterogeneous parallel solver has high computational precision. The speedup on a single GPU is more than 40 for laminar flow, it decreases for turbulent flow, but it still can reach more than 20. What’s more, the speedup increases as the grid size becomes larger.

Parallelized computation for computer simulation of electrocardiograms using personal computers with multi-core CPU and general-purpose GPU.

Science.gov (United States)

Shen, Wenfeng; Wei, Daming; Xu, Weimin; Zhu, Xin; Yuan, Shizhong

2010-10-01

Biological computations like electrocardiological modelling and simulation usually require high-performance computing environments. This paper introduces an implementation of parallel computation for computer simulation of electrocardiograms (ECGs) in a personal computer environment with an Intel CPU of Core (TM) 2 Quad Q6600 and a GPU of Geforce 8800GT, with software support by OpenMP and CUDA. It was tested in three parallelization device setups: (a) a four-core CPU without a general-purpose GPU, (b) a general-purpose GPU plus 1 core of CPU, and (c) a four-core CPU plus a general-purpose GPU. To effectively take advantage of a multi-core CPU and a general-purpose GPU, an algorithm based on load-prediction dynamic scheduling was developed and applied to setting (c). In the simulation with 1600 time steps, the speedup of the parallel computation as compared to the serial computation was 3.9 in setting (a), 16.8 in setting (b), and 20.0 in setting (c). This study demonstrates that a current PC with a multi-core CPU and a general-purpose GPU provides a good environment for parallel computations in biological modelling and simulation studies. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

A high performance image processing platform based on CPU-GPU heterogeneous cluster with parallel image reconstroctions for micro-CT

International Nuclear Information System (INIS)

Ding Yu; Qi Yujin; Zhang Xuezhu; Zhao Cuilan

2011-01-01

In this paper, we report the development of a high-performance image processing platform, which is based on CPU-GPU heterogeneous cluster. Currently, it consists of a Dell Precision T7500 and HP XW8600 workstations with parallel programming and runtime environment, using the message-passing interface (MPI) and CUDA (Compute Unified Device Architecture). We succeeded in developing parallel image processing techniques for 3D image reconstruction of X-ray micro-CT imaging. The results show that a GPU provides a computing efficiency of about 194 times faster than a single CPU, and the CPU-GPU clusters provides a computing efficiency of about 46 times faster than the CPU clusters. These meet the requirements of rapid 3D image reconstruction and real time image display. In conclusion, the use of CPU-GPU heterogeneous cluster is an effective way to build high-performance image processing platform. (authors)

An Investigation of the Performance of the Colored Gauss-Seidel Solver on CPU and GPU

International Nuclear Information System (INIS)

Yoon, Jong Seon; Choi, Hyoung Gwon; Jeon, Byoung Jin

2017-01-01

The performance of the colored Gauss–Seidel solver on CPU and GPU was investigated for the two- and three-dimensional heat conduction problems by using different mesh sizes. The heat conduction equation was discretized by the finite difference method and finite element method. The CPU yielded good performance for small problems but deteriorated when the total memory required for computing was larger than the cache memory for large problems. In contrast, the GPU performed better as the mesh size increased because of the latency hiding technique. Further, GPU computation by the colored Gauss–Siedel solver was approximately 7 times that by the single CPU. Furthermore, the colored Gauss–Seidel solver was found to be approximately twice that of the Jacobi solver when parallel computing was conducted on the GPU.

An Investigation of the Performance of the Colored Gauss-Seidel Solver on CPU and GPU

Energy Technology Data Exchange (ETDEWEB)

Yoon, Jong Seon; Choi, Hyoung Gwon [Seoul Nat’l Univ. of Science and Technology, Seoul (Korea, Republic of); Jeon, Byoung Jin [Yonsei Univ., Seoul (Korea, Republic of)

2017-02-15

The performance of the colored Gauss–Seidel solver on CPU and GPU was investigated for the two- and three-dimensional heat conduction problems by using different mesh sizes. The heat conduction equation was discretized by the finite difference method and finite element method. The CPU yielded good performance for small problems but deteriorated when the total memory required for computing was larger than the cache memory for large problems. In contrast, the GPU performed better as the mesh size increased because of the latency hiding technique. Further, GPU computation by the colored Gauss–Siedel solver was approximately 7 times that by the single CPU. Furthermore, the colored Gauss–Seidel solver was found to be approximately twice that of the Jacobi solver when parallel computing was conducted on the GPU.

Liquid Cooling System for CPU by Electroconjugate Fluid

Directory of Open Access Journals (Sweden)

Yasuo Sakurai

2014-06-01

Full Text Available The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less.

CPU time reduction strategies for the Lambda modes calculation of a nuclear power reactor

Energy Technology Data Exchange (ETDEWEB)

Vidal, V.; Garayoa, J.; Hernandez, V. [Universidad Politecnica de Valencia (Spain). Dept. de Sistemas Informaticos y Computacion; Navarro, J.; Verdu, G.; Munoz-Cobo, J.L. [Universidad Politecnica de Valencia (Spain). Dept. de Ingenieria Quimica y Nuclear; Ginestar, D. [Universidad Politecnica de Valencia (Spain). Dept. de Matematica Aplicada

1997-12-01

In this paper, we present two strategies to reduce the CPU time spent in the lambda modes calculation for a realistic nuclear power reactor.The discretization of the multigroup neutron diffusion equation has been made using a nodal collocation method, solving the associated eigenvalue problem with two different techniques: the Subspace Iteration Method and Arnoldi`s Method. CPU time reduction is based on a coarse grain parallelization approach together with a multistep algorithm to initialize adequately the solution. (author). 9 refs., 6 tabs.

Research on the Prediction Model of CPU Utilization Based on ARIMA-BP Neural Network

Directory of Open Access Journals (Sweden)

Wang Jina

2016-01-01

Full Text Available The dynamic deployment technology of the virtual machine is one of the current cloud computing research focuses. The traditional methods mainly work after the degradation of the service performance that usually lag. To solve the problem a new prediction model based on the CPU utilization is constructed in this paper. A reference offered by the new prediction model of the CPU utilization is provided to the VM dynamic deployment process which will speed to finish the deployment process before the degradation of the service performance. By this method it not only ensure the quality of services but also improve the server performance and resource utilization. The new prediction method of the CPU utilization based on the ARIMA-BP neural network mainly include four parts: preprocess the collected data, build the predictive model of ARIMA-BP neural network, modify the nonlinear residuals of the time series by the BP prediction algorithm and obtain the prediction results by analyzing the above data comprehensively.

Heterogeneous CPU-GPU moving targets detection for UAV video

Science.gov (United States)

Li, Maowen; Tang, Linbo; Han, Yuqi; Yu, Chunlei; Zhang, Chao; Fu, Huiquan

2017-07-01

Moving targets detection is gaining popularity in civilian and military applications. On some monitoring platform of motion detection, some low-resolution stationary cameras are replaced by moving HD camera based on UAVs. The pixels of moving targets in the HD Video taken by UAV are always in a minority, and the background of the frame is usually moving because of the motion of UAVs. The high computational cost of the algorithm prevents running it at higher resolutions the pixels of frame. Hence, to solve the problem of moving targets detection based UAVs video, we propose a heterogeneous CPU-GPU moving target detection algorithm for UAV video. More specifically, we use background registration to eliminate the impact of the moving background and frame difference to detect small moving targets. In order to achieve the effect of real-time processing, we design the solution of heterogeneous CPU-GPU framework for our method. The experimental results show that our method can detect the main moving targets from the HD video taken by UAV, and the average process time is 52.16ms per frame which is fast enough to solve the problem.

CPU0213, a novel endothelin type A and type B receptor antagonist, protects against myocardial ischemia/reperfusion injury in rats

Directory of Open Access Journals (Sweden)

Z.Y. Wang

2011-11-01

Full Text Available The efficacy of endothelin receptor antagonists in protecting against myocardial ischemia/reperfusion (I/R injury is controversial, and the mechanisms remain unclear. The aim of this study was to investigate the effects of CPU0123, a novel endothelin type A and type B receptor antagonist, on myocardial I/R injury and to explore the mechanisms involved. Male Sprague-Dawley rats weighing 200-250 g were randomized to three groups (6-7 per group: group 1, Sham; group 2, I/R + vehicle. Rats were subjected to in vivo myocardial I/R injury by ligation of the left anterior descending coronary artery and 0.5% sodium carboxymethyl cellulose (1 mL/kg was injected intraperitoneally immediately prior to coronary occlusion. Group 3, I/R + CPU0213. Rats were subjected to identical surgical procedures and CPU0213 (30 mg/kg was injected intraperitoneally immediately prior to coronary occlusion. Infarct size, cardiac function and biochemical changes were measured. CPU0213 pretreatment reduced infarct size as a percentage of the ischemic area by 44.5% (I/R + vehicle: 61.3 ± 3.2 vs I/R + CPU0213: 34.0 ± 5.5%, P < 0.05 and improved ejection fraction by 17.2% (I/R + vehicle: 58.4 ± 2.8 vs I/R + CPU0213: 68.5 ± 2.2%, P < 0.05 compared to vehicle-treated animals. This protection was associated with inhibition of myocardial inflammation and oxidative stress. Moreover, reduction in Akt (protein kinase B and endothelial nitric oxide synthase (eNOS phosphorylation induced by myocardial I/R injury was limited by CPU0213 (P < 0.05. These data suggest that CPU0123, a non-selective antagonist, has protective effects against myocardial I/R injury in rats, which may be related to the Akt/eNOS pathway.

Electrolyte additive enabled fast charging and stable cycling lithium metal batteries

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jianming; Engelhard, Mark H.; Mei, Donghai; Jiao, Shuhong; Polzin, Bryant J.; Zhang, Ji-Guang; Xu, Wu

2017-03-01

Lithium (Li) metal battery is an attractive energy storage system owing to the ultrahigh specific capacity and the lowest redox potential of Li metal anode. However, safety concern associated with dendrite growth and limited cycle life especially at a high charge current density are two critical challenges hindering the practical applications of rechargeable Li metal batteries. Here, we report for the first time that an optimal amount (0.05 M) of LiPF6 as additive in the LiTFSI-LiBOB dual-salt/carbonate-based electrolyte can significantly enhance the charging capability and the long-term cycle life of Li metal batteries with a moderately high cathode loading of 1.75 mAh cm-2. Unprecedented stable-cycling (97.1% capacity retention after 500 cycles) along with very limited increase in electrode over-potential has been achieved at a high current density of 1.75 mA cm-2. This unparalleled fast charging and stable cycling performance is contributed from both the stabilized Al cathode current collector, and, more importantly, the robust and conductive SEI layer formed on Li metal anode in the presence of the LiPF6 additive.

Improving the Performance of CPU Architectures by Reducing the Operating System Overhead (Extended Version

Directory of Open Access Journals (Sweden)

Zagan Ionel

2016-07-01

Full Text Available The predictable CPU architectures that run hard real-time tasks must be executed with isolation in order to provide a timing-analyzable execution for real-time systems. The major problems for real-time operating systems are determined by an excessive jitter, introduced mainly through task switching. This can alter deadline requirements, and, consequently, the predictability of hard real-time tasks. New requirements also arise for a real-time operating system used in mixed-criticality systems, when the executions of hard real-time applications require timing predictability. The present article discusses several solutions to improve the performance of CPU architectures and eventually overcome the Operating Systems overhead inconveniences. This paper focuses on the innovative CPU implementation named nMPRA-MT, designed for small real-time applications. This implementation uses the replication and remapping techniques for the program counter, general purpose registers and pipeline registers, enabling multiple threads to share a single pipeline assembly line. In order to increase predictability, the proposed architecture partially removes the hazard situation at the expense of larger execution latency per one instruction.

High performance technique for database applicationsusing a hybrid GPU/CPU platform

KAUST Repository

Zidan, Mohammed A.; Bonny, Talal; Salama, Khaled N.

2012-01-01

Hybrid GPU/CPU platform. In particular, our technique solves the problem of the low efficiency result- ing from running short-length sequences in a database on a GPU. To verify our technique, we applied it to the widely used Smith-Waterman algorithm

Design Patterns for Sparse-Matrix Computations on Hybrid CPU/GPU Platforms

Directory of Open Access Journals (Sweden)

Valeria Cardellini

2014-01-01

Full Text Available We apply object-oriented software design patterns to develop code for scientific software involving sparse matrices. Design patterns arise when multiple independent developments produce similar designs which converge onto a generic solution. We demonstrate how to use design patterns to implement an interface for sparse matrix computations on NVIDIA GPUs starting from PSBLAS, an existing sparse matrix library, and from existing sets of GPU kernels for sparse matrices. We also compare the throughput of the PSBLAS sparse matrix–vector multiplication on two platforms exploiting the GPU with that obtained by a CPU-only PSBLAS implementation. Our experiments exhibit encouraging results regarding the comparison between CPU and GPU executions in double precision, obtaining a speedup of up to 35.35 on NVIDIA GTX 285 with respect to AMD Athlon 7750, and up to 10.15 on NVIDIA Tesla C2050 with respect to Intel Xeon X5650.

DSM vs. NSM: CPU Performance Tradeoffs in Block-Oriented Query Processing

NARCIS (Netherlands)

M. Zukowski (Marcin); N.J. Nes (Niels); P.A. Boncz (Peter)

2008-01-01

textabstractComparisons between the merits of row-wise storage (NSM) and columnar storage (DSM) are typically made with respect to the persistent storage layer of database systems. In this paper, however, we focus on the CPU efficiency tradeoffs of tuple representations inside the query

HEP specific benchmarks of virtual machines on multi-core CPU architectures

International Nuclear Information System (INIS)

Alef, M; Gable, I

2010-01-01

Virtualization technologies such as Xen can be used in order to satisfy the disparate and often incompatible system requirements of different user groups in shared-use computing facilities. This capability is particularly important for HEP applications, which often have restrictive requirements. The use of virtualization adds flexibility, however, it is essential that the virtualization technology place little overhead on the HEP application. We present an evaluation of the practicality of running HEP applications in multiple Virtual Machines (VMs) on a single multi-core Linux system. We use the benchmark suite used by the HEPiX CPU Benchmarking Working Group to give a quantitative evaluation relevant to the HEP community. Benchmarks are packaged inside VMs and then the VMs are booted onto a single multi-core system. Benchmarks are then simultaneously executed on each VM to simulate highly loaded VMs running HEP applications. These techniques are applied to a variety of multi-core CPU architectures and VM configurations.

Design improvement of FPGA and CPU based digital circuit cards to solve timing issues

International Nuclear Information System (INIS)

Lee, Dongil; Lee, Jaeki; Lee, Kwang-Hyun

2016-01-01

The digital circuit cards installed at NPPs (Nuclear Power Plant) are mostly composed of a CPU (Central Processing Unit) and a PLD (Programmable Logic Device; these include a FPGA (Field Programmable Gate Array) and a CPLD (Complex Programmable Logic Device)). This type of structure is typical and is maintained using digital circuit cards. There are no big problems with this device as a structure. In particular, signal delay causes a lot of problems when various IC (Integrated Circuit) and several circuit cards are connected to the BUS of the backplane in the BUS design. This paper suggests a structure to improve the BUS signal timing problems in a circuit card consisting of CPU and FPGA. Nowadays, as the structure of circuit cards has become complex and mass data at high speed is communicated through the BUS, data integrity is the most important issue. The conventional design does not consider delay and the synchronicity of signal and this causes many problems in data processing. In order to solve these problems, it is important to isolate the BUS controller from the CPU and maintain constancy of the signal delay by using a PLD

Design improvement of FPGA and CPU based digital circuit cards to solve timing issues

Energy Technology Data Exchange (ETDEWEB)

Lee, Dongil; Lee, Jaeki; Lee, Kwang-Hyun [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

The digital circuit cards installed at NPPs (Nuclear Power Plant) are mostly composed of a CPU (Central Processing Unit) and a PLD (Programmable Logic Device; these include a FPGA (Field Programmable Gate Array) and a CPLD (Complex Programmable Logic Device)). This type of structure is typical and is maintained using digital circuit cards. There are no big problems with this device as a structure. In particular, signal delay causes a lot of problems when various IC (Integrated Circuit) and several circuit cards are connected to the BUS of the backplane in the BUS design. This paper suggests a structure to improve the BUS signal timing problems in a circuit card consisting of CPU and FPGA. Nowadays, as the structure of circuit cards has become complex and mass data at high speed is communicated through the BUS, data integrity is the most important issue. The conventional design does not consider delay and the synchronicity of signal and this causes many problems in data processing. In order to solve these problems, it is important to isolate the BUS controller from the CPU and maintain constancy of the signal delay by using a PLD.

Enhancing Leakage Power in CPU Cache Using Inverted Architecture

OpenAIRE

Bilal A. Shehada; Ahmed M. Serdah; Aiman Abu Samra

2013-01-01

Power consumption is an increasingly pressing problem in modern processor design. Since the on-chip caches usually consume a significant amount of power so power and energy consumption parameters have become one of the most important design constraint. It is one of the most attractive targets for power reduction. This paper presents an approach to enhance the dynamic power consumption of CPU cache using inverted cache architecture. Our assumption tries to reduce dynamic write power dissipatio...

Effects of Litter and Nutrient Additions on Soil Carbon Cycling in a Tropical Forest

Science.gov (United States)

Cusack, D. F.; Halterman, S.; Turner, B. L.; Tanner, E.; Wright, S. J.

2014-12-01

Soil carbon (C) dynamics present one of the largest sources of uncertainty in global C cycle models, with tropical forest soils containing some of the largest terrestrial C stocks. Drastic changes in soil C storage and loss are likely to occur if global change alters plant net primary production (NPP) and/or nutrient availability in these ecosystems. We assessed the effects of litter removal and addition, as well as fertilization with nitrogen (N), phosphorus (P), and/or potassium (K), on soil C stocks in a tropical seasonal forest in Panama after ten and sixteen years, respectively. We used a density fractionation scheme to assess manipulation effects on rapidly and slowly cycling pools of C. Soil samples were collected in the wet and dry seasons from 0-5 cm and 5-10 cm depths in 15- 45x45 m plots with litter removal, 2x litter addition, and control (n=5), and from 32- 40x40 m fertilization plots with factorial additions of N, P, and K. We hypothesized that litter addition would increase all soil C fractions, but that the magnitude of the effect on rapidly-cycling C would be dampened by a fertilization effect. Results for the dry season show that the "free light" C fraction, or rapidly cycling soil C pool, was significantly different among the three litter treatments, comprising 5.1 ± 0.9 % of total soil mass in the litter addition plots, 2.7 ± 0.3 % in control plots, and 1.0 ± 0.1 % in litter removal plots at the 0-5cm depth (means ± one standard error, p < 0.05). Bulk soil C results are similar to observed changes in the rapidly cycling C pool for the litter addition and removal. Fertilization treatments on average diminished this C pool size relative to control plots, although there was substantial variability among fertilization treatments. In particular, addition of N and P together did not significantly alter rapidly cycling C pool sizes (4.1 ± 1.2 % of total soil mass) relative to controls (3.5 ± 0.4 %), whereas addition of P alone resulted in

Designing of Vague Logic Based 2-Layered Framework for CPU Scheduler

Directory of Open Access Journals (Sweden)

Supriya Raheja

2016-01-01

Full Text Available Fuzzy based CPU scheduler has become of great interest by operating system because of its ability to handle imprecise information associated with task. This paper introduces an extension to the fuzzy based round robin scheduler to a Vague Logic Based Round Robin (VBRR scheduler. VBRR scheduler works on 2-layered framework. At the first layer, scheduler has a vague inference system which has the ability to handle the impreciseness of task using vague logic. At the second layer, Vague Logic Based Round Robin (VBRR scheduling algorithm works to schedule the tasks. VBRR scheduler has the learning capability based on which scheduler adapts intelligently an optimum length for time quantum. An optimum time quantum reduces the overhead on scheduler by reducing the unnecessary context switches which lead to improve the overall performance of system. The work is simulated using MATLAB and compared with the conventional round robin scheduler and the other two fuzzy based approaches to CPU scheduler. Given simulation analysis and results prove the effectiveness and efficiency of VBRR scheduler.

Evaluation of the CPU time for solving the radiative transfer equation with high-order resolution schemes applying the normalized weighting-factor method

Science.gov (United States)

Xamán, J.; Zavala-Guillén, I.; Hernández-López, I.; Uriarte-Flores, J.; Hernández-Pérez, I.; Macías-Melo, E. V.; Aguilar-Castro, K. M.

2018-03-01

In this paper, we evaluated the convergence rate (CPU time) of a new mathematical formulation for the numerical solution of the radiative transfer equation (RTE) with several High-Order (HO) and High-Resolution (HR) schemes. In computational fluid dynamics, this procedure is known as the Normalized Weighting-Factor (NWF) method and it is adopted here. The NWF method is used to incorporate the high-order resolution schemes in the discretized RTE. The NWF method is compared, in terms of computer time needed to obtain a converged solution, with the widely used deferred-correction (DC) technique for the calculations of a two-dimensional cavity with emitting-absorbing-scattering gray media using the discrete ordinates method. Six parameters, viz. the grid size, the order of quadrature, the absorption coefficient, the emissivity of the boundary surface, the under-relaxation factor, and the scattering albedo are considered to evaluate ten schemes. The results showed that using the DC method, in general, the scheme that had the lowest CPU time is the SOU. In contrast, with the results of theDC procedure the CPU time for DIAMOND and QUICK schemes using the NWF method is shown to be, between the 3.8 and 23.1% faster and 12.6 and 56.1% faster, respectively. However, the other schemes are more time consuming when theNWFis used instead of the DC method. Additionally, a second test case was presented and the results showed that depending on the problem under consideration, the NWF procedure may be computationally faster or slower that the DC method. As an example, the CPU time for QUICK and SMART schemes are 61.8 and 203.7%, respectively, slower when the NWF formulation is used for the second test case. Finally, future researches to explore the computational cost of the NWF method in more complex problems are required.

Semiempirical Quantum Chemical Calculations Accelerated on a Hybrid Multicore CPU-GPU Computing Platform.

Science.gov (United States)

Wu, Xin; Koslowski, Axel; Thiel, Walter

2012-07-10

In this work, we demonstrate that semiempirical quantum chemical calculations can be accelerated significantly by leveraging the graphics processing unit (GPU) as a coprocessor on a hybrid multicore CPU-GPU computing platform. Semiempirical calculations using the MNDO, AM1, PM3, OM1, OM2, and OM3 model Hamiltonians were systematically profiled for three types of test systems (fullerenes, water clusters, and solvated crambin) to identify the most time-consuming sections of the code. The corresponding routines were ported to the GPU and optimized employing both existing library functions and a GPU kernel that carries out a sequence of noniterative Jacobi transformations during pseudodiagonalization. The overall computation times for single-point energy calculations and geometry optimizations of large molecules were reduced by one order of magnitude for all methods, as compared to runs on a single CPU core.

Fast CPU-based Monte Carlo simulation for radiotherapy dose calculation

Science.gov (United States)

Ziegenhein, Peter; Pirner, Sven; Kamerling, Cornelis Ph; Oelfke, Uwe

2015-08-01

Monte-Carlo (MC) simulations are considered to be the most accurate method for calculating dose distributions in radiotherapy. Its clinical application, however, still is limited by the long runtimes conventional implementations of MC algorithms require to deliver sufficiently accurate results on high resolution imaging data. In order to overcome this obstacle we developed the software-package PhiMC, which is capable of computing precise dose distributions in a sub-minute time-frame by leveraging the potential of modern many- and multi-core CPU-based computers. PhiMC is based on the well verified dose planning method (DPM). We could demonstrate that PhiMC delivers dose distributions which are in excellent agreement to DPM. The multi-core implementation of PhiMC scales well between different computer architectures and achieves a speed-up of up to 37× compared to the original DPM code executed on a modern system. Furthermore, we could show that our CPU-based implementation on a modern workstation is between 1.25× and 1.95× faster than a well-known GPU implementation of the same simulation method on a NVIDIA Tesla C2050. Since CPUs work on several hundreds of GB RAM the typical GPU memory limitation does not apply for our implementation and high resolution clinical plans can be calculated.

Analysis of blended fuel properties and cycle-to-cycle variation in a diesel engine with a diethyl ether additive

International Nuclear Information System (INIS)

Ali, Obed M.; Mamat, Rizalman; Masjuki, H.H.; Abdullah, Abdul Adam

2016-01-01

Highlights: • Viability of diethyl ether additive to improve palm biodiesel–diesel blend. • Numerical analysis of engine cyclic variation at different additive ratios. • Physicochemical properties of the blends improved with diethyl ether additive. • Blended fuel heating value is significantly affected. • Blended fuel with 4% diethyl ether shows comparable engine cyclic variation to diesel. - Abstract: In this study, the effect of adding small portions of a diethyl ether additive to biodiesel–diesel blended fuel (B30) was investigated. This study includes an evaluation of the fuel properties and a combustion analysis, specifically, an analysis of the cyclic variations in diesel engines. The amount of additive used with B30 is 2%, 4%, 6% and 8% (by volume). The experimental engine test was conducted at 2500 rpm which produce maximum torque, and the in-cylinder pressure data were collected over 200 consecutive engine cycles for each test. The indicated mean effective pressure time series is analyzed using the coefficient of variation and the wavelet analysis method. The test results for the properties show a slight improvement in density and acid value with a significant decrease in the viscosity, pour point and cloud point of the blended fuel with an 8% additive ratio by 26.5%, 4 °C and 3 °C, respectively, compared with blended fuel without additive. However, the heating value is reduced by approximately 4% with increasing the additive ratio to 8%. From the wavelet power spectrum, it is observed that the intermediate and long-term periodicities appear in diesel fuel, while the short-period oscillations become intermittently visible in pure blended fuel. The coefficient of variation for B30 was the lowest and increased as the additive ratios increased, which agrees with the wavelet analysis results. Furthermore, the spectral power increased with an increase in the additive ratio, indicating that the additive has a noticeable effect on increasing the

A Robust Ultra-Low Voltage CPU Utilizing Timing-Error Prevention

OpenAIRE

Hiienkari, Markus; Teittinen, Jukka; Koskinen, Lauri; Turnquist, Matthew; Mäkipää, Jani; Rantala, Arto; Sopanen, Matti; Kaltiokallio, Mikko

2015-01-01

To minimize energy consumption of a digital circuit, logic can be operated at sub- or near-threshold voltage. Operation at this region is challenging due to device and environment variations, and resulting performance may not be adequate to all applications. This article presents two variants of a 32-bit RISC CPU targeted for near-threshold voltage. Both CPUs are placed on the same die and manufactured in 28 nm CMOS process. They employ timing-error prevention with clock stretching to enable ...

The “Chimera”: An Off-The-Shelf CPU/GPGPU/FPGA Hybrid Computing Platform

Directory of Open Access Journals (Sweden)

Ra Inta

2012-01-01

Full Text Available The nature of modern astronomy means that a number of interesting problems exhibit a substantial computational bound and this situation is gradually worsening. Scientists, increasingly fighting for valuable resources on conventional high-performance computing (HPC facilities—often with a limited customizable user environment—are increasingly looking to hardware acceleration solutions. We describe here a heterogeneous CPU/GPGPU/FPGA desktop computing system (the “Chimera”, built with commercial-off-the-shelf components. We show that this platform may be a viable alternative solution to many common computationally bound problems found in astronomy, however, not without significant challenges. The most significant bottleneck in pipelines involving real data is most likely to be the interconnect (in this case the PCI Express bus residing on the CPU motherboard. Finally, we speculate on the merits of our Chimera system on the entire landscape of parallel computing, through the analysis of representative problems from UC Berkeley’s “Thirteen Dwarves.”

Nitrogen cycling in a forest stream determined by a 15N tracer addition

Science.gov (United States)

Patrick J. Mullholland; Jennifer L. Tank; Diane M. Sanzone; Wilfred M. Wollheim; Bruce J. Peterson; Jackson R. Webster; Judy L. Meyer

2000-01-01

Nitrogen uptake and cycling was examined using a six-week tracer addition of 15N-labeled ammonium in early spring in Waer Branch, a first-order deciduous forest stream in eastern Tennessee. Prior to the 15N addition, standing stocks of N were determined for the major biomass compartments. During and after the addition,

Cpu/gpu Computing for AN Implicit Multi-Block Compressible Navier-Stokes Solver on Heterogeneous Platform

Science.gov (United States)

Deng, Liang; Bai, Hanli; Wang, Fang; Xu, Qingxin

2016-06-01

CPU/GPU computing allows scientists to tremendously accelerate their numerical codes. In this paper, we port and optimize a double precision alternating direction implicit (ADI) solver for three-dimensional compressible Navier-Stokes equations from our in-house Computational Fluid Dynamics (CFD) software on heterogeneous platform. First, we implement a full GPU version of the ADI solver to remove a lot of redundant data transfers between CPU and GPU, and then design two fine-grain schemes, namely “one-thread-one-point” and “one-thread-one-line”, to maximize the performance. Second, we present a dual-level parallelization scheme using the CPU/GPU collaborative model to exploit the computational resources of both multi-core CPUs and many-core GPUs within the heterogeneous platform. Finally, considering the fact that memory on a single node becomes inadequate when the simulation size grows, we present a tri-level hybrid programming pattern MPI-OpenMP-CUDA that merges fine-grain parallelism using OpenMP and CUDA threads with coarse-grain parallelism using MPI for inter-node communication. We also propose a strategy to overlap the computation with communication using the advanced features of CUDA and MPI programming. We obtain speedups of 6.0 for the ADI solver on one Tesla M2050 GPU in contrast to two Xeon X5670 CPUs. Scalability tests show that our implementation can offer significant performance improvement on heterogeneous platform.

Acceleration of stereo-matching on multi-core CPU and GPU

OpenAIRE

Tian, Xu; Cockshott, Paul; Oehler, Susanne

2014-01-01

This paper presents an accelerated version of a\\ud dense stereo-correspondence algorithm for two different parallelism\\ud enabled architectures, multi-core CPU and GPU. The\\ud algorithm is part of the vision system developed for a binocular\\ud robot-head in the context of the CloPeMa 1 research project.\\ud This research project focuses on the conception of a new clothes\\ud folding robot with real-time and high resolution requirements\\ud for the vision system. The performance analysis shows th...

Electrolyte additive enabled fast charging and stable cycling lithium metal batteries

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jianming; Engelhard, Mark H.; Mei, Donghai; Jiao, Shuhong; Polzin, Bryant J.; Zhang, Ji-Guang; Xu, Wu

2017-03-01

Batteries using lithium (Li) metal as anodes are considered promising energy storage systems because of their high energy densities. However, safety concerns associated with dendrite growth along with limited cycle life, especially at high charge current densities, hinder their practical uses. Here we report that an optimal amount (0.05 M) of LiPF6 as an additive in LiTFSI-LiBOB dual-salt/carbonate-solvent-based electrolytes significantly enhances the charging capability and cycling stability of Li metal batteries. In a Li metal battery using a 4-V Li-ion cathode at a moderately high loading of 1.75mAh cm(-2), a cyclability of 97.1% capacity retention after 500 cycles along with very limited increase in electrode overpotential is accomplished at a charge/discharge current density up to 1.75 mA cm(-2). The fast charging and stable cycling performances are ascribed to the generation of a robust and conductive solid electrolyte interphase at the Li metal surface and stabilization of the Al cathode current collector.

Improvement of CPU time of Linear Discriminant Function based on MNM criterion by IP

Directory of Open Access Journals (Sweden)

Shuichi Shinmura

2014-05-01

Full Text Available Revised IP-OLDF (optimal linear discriminant function by integer programming is a linear discriminant function to minimize the number of misclassifications (NM of training samples by integer programming (IP. However, IP requires large computation (CPU time. In this paper, it is proposed how to reduce CPU time by using linear programming (LP. In the first phase, Revised LP-OLDF is applied to all cases, and all cases are categorized into two groups: those that are classified correctly or those that are not classified by support vectors (SVs. In the second phase, Revised IP-OLDF is applied to the misclassified cases by SVs. This method is called Revised IPLP-OLDF.In this research, it is evaluated whether NM of Revised IPLP-OLDF is good estimate of the minimum number of misclassifications (MNM by Revised IP-OLDF. Four kinds of the real data—Iris data, Swiss bank note data, student data, and CPD data—are used as training samples. Four kinds of 20,000 re-sampling cases generated from these data are used as the evaluation samples. There are a total of 149 models of all combinations of independent variables by these data. NMs and CPU times of the 149 models are compared with Revised IPLP-OLDF and Revised IP-OLDF. The following results are obtained: 1 Revised IPLP-OLDF significantly improves CPU time. 2 In the case of training samples, all 149 NMs of Revised IPLP-OLDF are equal to the MNM of Revised IP-OLDF. 3 In the case of evaluation samples, most NMs of Revised IPLP-OLDF are equal to NM of Revised IP-OLDF. 4 Generalization abilities of both discriminant functions are concluded to be high, because the difference between the error rates of training and evaluation samples are almost within 2%.   Therefore, Revised IPLP-OLDF is recommended for the analysis of big data instead of Revised IP-OLDF. Next, Revised IPLP-OLDF is compared with LDF and logistic regression by 100-fold cross validation using 100 re-sampling samples. Means of error rates of

Promise of a low power mobile CPU based embedded system in artificial leg control.

Science.gov (United States)

Hernandez, Robert; Zhang, Fan; Zhang, Xiaorong; Huang, He; Yang, Qing

2012-01-01

This paper presents the design and implementation of a low power embedded system using mobile processor technology (Intel Atom™ Z530 Processor) specifically tailored for a neural-machine interface (NMI) for artificial limbs. This embedded system effectively performs our previously developed NMI algorithm based on neuromuscular-mechanical fusion and phase-dependent pattern classification. The analysis shows that NMI embedded system can meet real-time constraints with high accuracies for recognizing the user's locomotion mode. Our implementation utilizes the mobile processor efficiently to allow a power consumption of 2.2 watts and low CPU utilization (less than 4.3%) while executing the complex NMI algorithm. Our experiments have shown that the highly optimized C program implementation on the embedded system has superb advantages over existing PC implementations on MATLAB. The study results suggest that mobile-CPU-based embedded system is promising for implementing advanced control for powered lower limb prostheses.

Accelerating Smith-Waterman Alignment for Protein Database Search Using Frequency Distance Filtration Scheme Based on CPU-GPU Collaborative System

Directory of Open Access Journals (Sweden)

Yu Liu

2015-01-01

Full Text Available The Smith-Waterman (SW algorithm has been widely utilized for searching biological sequence databases in bioinformatics. Recently, several works have adopted the graphic card with Graphic Processing Units (GPUs and their associated CUDA model to enhance the performance of SW computations. However, these works mainly focused on the protein database search by using the intertask parallelization technique, and only using the GPU capability to do the SW computations one by one. Hence, in this paper, we will propose an efficient SW alignment method, called CUDA-SWfr, for the protein database search by using the intratask parallelization technique based on a CPU-GPU collaborative system. Before doing the SW computations on GPU, a procedure is applied on CPU by using the frequency distance filtration scheme (FDFS to eliminate the unnecessary alignments. The experimental results indicate that CUDA-SWfr runs 9.6 times and 96 times faster than the CPU-based SW method without and with FDFS, respectively.

Accelerating Smith-Waterman Alignment for Protein Database Search Using Frequency Distance Filtration Scheme Based on CPU-GPU Collaborative System.

Science.gov (United States)

Liu, Yu; Hong, Yang; Lin, Chun-Yuan; Hung, Che-Lun

2015-01-01

The Smith-Waterman (SW) algorithm has been widely utilized for searching biological sequence databases in bioinformatics. Recently, several works have adopted the graphic card with Graphic Processing Units (GPUs) and their associated CUDA model to enhance the performance of SW computations. However, these works mainly focused on the protein database search by using the intertask parallelization technique, and only using the GPU capability to do the SW computations one by one. Hence, in this paper, we will propose an efficient SW alignment method, called CUDA-SWfr, for the protein database search by using the intratask parallelization technique based on a CPU-GPU collaborative system. Before doing the SW computations on GPU, a procedure is applied on CPU by using the frequency distance filtration scheme (FDFS) to eliminate the unnecessary alignments. The experimental results indicate that CUDA-SWfr runs 9.6 times and 96 times faster than the CPU-based SW method without and with FDFS, respectively.

CPU SIM: A Computer Simulator for Use in an Introductory Computer Organization-Architecture Class.

Science.gov (United States)

Skrein, Dale

1994-01-01

CPU SIM, an interactive low-level computer simulation package that runs on the Macintosh computer, is described. The program is designed for instructional use in the first or second year of undergraduate computer science, to teach various features of typical computer organization through hands-on exercises. (MSE)

Fatigue performance of laser additive manufactured Ti-6Al-4V in very high cycle fatigue (VHCF regime up to 10⁹ cycles

Directory of Open Access Journals (Sweden)

Eric eWycisk

2015-12-01

Full Text Available Additive manufacturing technologies are in the process of establishing themselves as an alternative production technology to conventional manufacturing such as casting or milling. Especially laser additive manufacturing (LAM enables the production of metallic parts with mechanical properties comparable to conventionally manufactured components. Due to the high geometrical freedom in LAM the technology enables the production of ultra-light weight designs and therefore gains increasing importance in aircraft and space industry. The high quality standards of these industries demand predictability of material properties for static and dynamic load cases. However, fatigue properties especially in the very high cycle fatigue regime until 109 cycles have not been sufficiently determined yet. Therefore this paper presents an analysis of fatigue properties of laser additive manufactured Ti-6Al-4V under cyclic tension-tension until 107 cycles and tension-compression load until 109 cycles.For the analysis of laser additive manufactured titanium alloy Ti-6Al-4V Woehler fatigue tests under tension-tension and tension-compression were carried out in the high cycle and very high cycle fatigue regime. Specimens in stress-relieved as well as hot-isostatic-pressed conditions were analyzed regarding crack initiation site, mean stress sensitivity and overall fatigue performance. The determined fatigue properties show values in the range of conventionally manufactured Ti-6Al-4V with particularly good performance for hot-isostatic-pressed additive-manufactured material. For all conditions the results show no conventional fatigue limit but a constant increase in fatigue life with decreasing loads. No effects of test frequency on life span could be determined. However, independently of testing principle, a shift of crack initiation from surface to internal initiation could be observed with increasing cycles to failure.

Der ATLAS LVL2-Trigger mit FPGA-Prozessoren : Entwicklung, Aufbau und Funktionsnachweis des hybriden FPGA/CPU-basierten Prozessorsystems ATLANTIS

CERN Document Server

Singpiel, Holger

2000-01-01

This thesis describes the conception and implementation of the hybrid FPGA/CPU based processing system ATLANTIS as trigger processor for the proposed ATLAS experiment at CERN. CompactPCI provides the close coupling of a multi FPGA system and a standard CPU. The system is scalable in computing power and flexible in use due to its partitioning into dedicated FPGA boards for computation, I/O tasks and a private communication. Main focus of the research activities based on the usage of the ATLANTIS system are two areas in the second level trigger (LVL2). First, the acceleration of time critical B physics trigger algorithms is the major aim. The execution of the full scan TRT algorithm on ATLANTIS, which has been used as a demonstrator, results in a speedup of 5.6 compared to a standard CPU. Next, the ATLANTIS system is used as a hardware platform for research work in conjunction with the ATLAS readout systems. For further studies a permanent installation of the ATLANTIS system in the LVL2 application testbed is f...

Energy consumption optimization of the total-FETI solver by changing the CPU frequency

Science.gov (United States)

Horak, David; Riha, Lubomir; Sojka, Radim; Kruzik, Jakub; Beseda, Martin; Cermak, Martin; Schuchart, Joseph

2017-07-01

The energy consumption of supercomputers is one of the critical problems for the upcoming Exascale supercomputing era. The awareness of power and energy consumption is required on both software and hardware side. This paper deals with the energy consumption evaluation of the Finite Element Tearing and Interconnect (FETI) based solvers of linear systems, which is an established method for solving real-world engineering problems. We have evaluated the effect of the CPU frequency on the energy consumption of the FETI solver using a linear elasticity 3D cube synthetic benchmark. In this problem, we have evaluated the effect of frequency tuning on the energy consumption of the essential processing kernels of the FETI method. The paper provides results for two types of frequency tuning: (1) static tuning and (2) dynamic tuning. For static tuning experiments, the frequency is set before execution and kept constant during the runtime. For dynamic tuning, the frequency is changed during the program execution to adapt the system to the actual needs of the application. The paper shows that static tuning brings up 12% energy savings when compared to default CPU settings (the highest clock rate). The dynamic tuning improves this further by up to 3%.

Simulation of small-angle scattering patterns using a CPU-efficient algorithm

Science.gov (United States)

Anitas, E. M.

2017-12-01

Small-angle scattering (of neutrons, x-ray or light; SAS) is a well-established experimental technique for structural analysis of disordered systems at nano and micro scales. For complex systems, such as super-molecular assemblies or protein molecules, analytic solutions of SAS intensity are generally not available. Thus, a frequent approach to simulate the corresponding patterns is to use a CPU-efficient version of the Debye formula. For this purpose, in this paper we implement the well-known DALAI algorithm in Mathematica software. We present calculations for a series of 2D Sierpinski gaskets and respectively of pentaflakes, obtained from chaos game representation.

Fast multipurpose Monte Carlo simulation for proton therapy using multi- and many-core CPU architectures

Energy Technology Data Exchange (ETDEWEB)

Souris, Kevin, E-mail: kevin.souris@uclouvain.be; Lee, John Aldo [Center for Molecular Imaging and Experimental Radiotherapy, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 54, 1200 Brussels, Belgium and ICTEAM Institute, Université catholique de Louvain, Louvain-la-Neuve 1348 (Belgium); Sterpin, Edmond [Center for Molecular Imaging and Experimental Radiotherapy, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 54, 1200 Brussels, Belgium and Department of Oncology, Katholieke Universiteit Leuven, O& N I Herestraat 49, 3000 Leuven (Belgium)

2016-04-15

Purpose: Accuracy in proton therapy treatment planning can be improved using Monte Carlo (MC) simulations. However the long computation time of such methods hinders their use in clinical routine. This work aims to develop a fast multipurpose Monte Carlo simulation tool for proton therapy using massively parallel central processing unit (CPU) architectures. Methods: A new Monte Carlo, called MCsquare (many-core Monte Carlo), has been designed and optimized for the last generation of Intel Xeon processors and Intel Xeon Phi coprocessors. These massively parallel architectures offer the flexibility and the computational power suitable to MC methods. The class-II condensed history algorithm of MCsquare provides a fast and yet accurate method of simulating heavy charged particles such as protons, deuterons, and alphas inside voxelized geometries. Hard ionizations, with energy losses above a user-specified threshold, are simulated individually while soft events are regrouped in a multiple scattering theory. Elastic and inelastic nuclear interactions are sampled from ICRU 63 differential cross sections, thereby allowing for the computation of prompt gamma emission profiles. MCsquare has been benchmarked with the GATE/GEANT4 Monte Carlo application for homogeneous and heterogeneous geometries. Results: Comparisons with GATE/GEANT4 for various geometries show deviations within 2%–1 mm. In spite of the limited memory bandwidth of the coprocessor simulation time is below 25 s for 10{sup 7} primary 200 MeV protons in average soft tissues using all Xeon Phi and CPU resources embedded in a single desktop unit. Conclusions: MCsquare exploits the flexibility of CPU architectures to provide a multipurpose MC simulation tool. Optimized code enables the use of accurate MC calculation within a reasonable computation time, adequate for clinical practice. MCsquare also simulates prompt gamma emission and can thus be used also for in vivo range verification.

Fast multipurpose Monte Carlo simulation for proton therapy using multi- and many-core CPU architectures

International Nuclear Information System (INIS)

Souris, Kevin; Lee, John Aldo; Sterpin, Edmond

2016-01-01

Purpose: Accuracy in proton therapy treatment planning can be improved using Monte Carlo (MC) simulations. However the long computation time of such methods hinders their use in clinical routine. This work aims to develop a fast multipurpose Monte Carlo simulation tool for proton therapy using massively parallel central processing unit (CPU) architectures. Methods: A new Monte Carlo, called MCsquare (many-core Monte Carlo), has been designed and optimized for the last generation of Intel Xeon processors and Intel Xeon Phi coprocessors. These massively parallel architectures offer the flexibility and the computational power suitable to MC methods. The class-II condensed history algorithm of MCsquare provides a fast and yet accurate method of simulating heavy charged particles such as protons, deuterons, and alphas inside voxelized geometries. Hard ionizations, with energy losses above a user-specified threshold, are simulated individually while soft events are regrouped in a multiple scattering theory. Elastic and inelastic nuclear interactions are sampled from ICRU 63 differential cross sections, thereby allowing for the computation of prompt gamma emission profiles. MCsquare has been benchmarked with the GATE/GEANT4 Monte Carlo application for homogeneous and heterogeneous geometries. Results: Comparisons with GATE/GEANT4 for various geometries show deviations within 2%–1 mm. In spite of the limited memory bandwidth of the coprocessor simulation time is below 25 s for 10"7 primary 200 MeV protons in average soft tissues using all Xeon Phi and CPU resources embedded in a single desktop unit. Conclusions: MCsquare exploits the flexibility of CPU architectures to provide a multipurpose MC simulation tool. Optimized code enables the use of accurate MC calculation within a reasonable computation time, adequate for clinical practice. MCsquare also simulates prompt gamma emission and can thus be used also for in vivo range verification.

Fast multipurpose Monte Carlo simulation for proton therapy using multi- and many-core CPU architectures.

Science.gov (United States)

Souris, Kevin; Lee, John Aldo; Sterpin, Edmond

2016-04-01

Accuracy in proton therapy treatment planning can be improved using Monte Carlo (MC) simulations. However the long computation time of such methods hinders their use in clinical routine. This work aims to develop a fast multipurpose Monte Carlo simulation tool for proton therapy using massively parallel central processing unit (CPU) architectures. A new Monte Carlo, called MCsquare (many-core Monte Carlo), has been designed and optimized for the last generation of Intel Xeon processors and Intel Xeon Phi coprocessors. These massively parallel architectures offer the flexibility and the computational power suitable to MC methods. The class-II condensed history algorithm of MCsquare provides a fast and yet accurate method of simulating heavy charged particles such as protons, deuterons, and alphas inside voxelized geometries. Hard ionizations, with energy losses above a user-specified threshold, are simulated individually while soft events are regrouped in a multiple scattering theory. Elastic and inelastic nuclear interactions are sampled from ICRU 63 differential cross sections, thereby allowing for the computation of prompt gamma emission profiles. MCsquare has been benchmarked with the gate/geant4 Monte Carlo application for homogeneous and heterogeneous geometries. Comparisons with gate/geant4 for various geometries show deviations within 2%-1 mm. In spite of the limited memory bandwidth of the coprocessor simulation time is below 25 s for 10(7) primary 200 MeV protons in average soft tissues using all Xeon Phi and CPU resources embedded in a single desktop unit. MCsquare exploits the flexibility of CPU architectures to provide a multipurpose MC simulation tool. Optimized code enables the use of accurate MC calculation within a reasonable computation time, adequate for clinical practice. MCsquare also simulates prompt gamma emission and can thus be used also for in vivo range verification.

Life Cycle Assessment of Fiber-Reinforced Additive Manufacturing for Injection Molding Insert Production

DEFF Research Database (Denmark)

Hofstätter, Thomas; Stotz, Philippe Maurice; Bey, Niki

2017-01-01

Additively manufactured (AM) injection molding (IM) inserts have proved to be capable to substitute conventionally manufactured metal inserts with polymer-based insert enforced with short, virgin, unseized carbon fibers (CFs). It has been shown that the implementation of AM technology resulted......, this contribution provides a comparison of environmental performance of conventionally vs. additively manufactured inserts in a full life cycle perspective indicated in Figure 1, including materials, production, use and end-of-life (EoL) stages....

Overtaking CPU DBMSes with a GPU in whole-query analytic processing with parallelism-friendly execution plan optimization

NARCIS (Netherlands)

A. Agbaria (Adnan); D. Minor (David); N. Peterfreund (Natan); E. Rozenberg (Eyal); O. Rosenberg (Ofer); Huawei Research

2016-01-01

textabstractExisting work on accelerating analytic DB query processing with (discrete) GPUs fails to fully realize their potential for speedup through parallelism: Published results do not achieve significant speedup over more performant CPU-only DBMSes when processing complete queries. This

Soil microbial community structure and nitrogen cycling responses to agroecosystem management and carbon substrate addition

Science.gov (United States)

Berthrong, S. T.; Buckley, D. H.; Drinkwater, L. E.

2011-12-01

Fertilizer application in conventional agriculture leads to N saturation and decoupled soil C and N cycling, whereas organic practices, e.g. complex rotations and legume incorporation, often results in increased SOM and tightly coupled cycles of C and N. These legacy effects of management on soils likely affect microbial community composition and microbial process rates. This project tested if agricultural management practices led to distinct microbial communities and if those communities differed in ability to utilize labile plant carbon substrates and to produce more plant available N. We addressed several specific questions in this project. 1) Do organic and conventional management legacies on similar soils produce distinct soil bacterial and fungal community structures and abundances? 2) How do these microbial community structures change in response to carbon substrate addition? 3) How do the responses of the microbial communities influence N cycling? To address these questions we conducted a laboratory incubation of organically and conventionally managed soils. We added C-13 labelled glucose either in one large dose or several smaller pulses. We extracted genomic DNA from soils before and after incubation for TRFLP community fingerprinting. We measured C in soil pools and respiration and N in soil extracts and leachates. Management led to different compositions of bacteria and fungi driven by distinct components in organic soils. Biomass did not differ across treatments indicating that differences in cycling were due to composition rather than abundance. C substrate addition led to convergence in bacterial communities; however management still strongly influenced the difference in communities. Fungal communities were very distinct between managements and plots with substrate addition not altering this pattern. Organic soils respired 3 times more of the glucose in the first week than conventional soils (1.1% vs 0.4%). Organic soils produced twice as much

Design of a Message Passing Model for Use in a Heterogeneous CPU-NFP Framework for Network Analytics

CSIR Research Space (South Africa)

Pennefather, S

2017-09-01

Full Text Available of applications written in the Go programming language to be executed on a Network Flow Processor (NFP) for enhanced performance. This paper explores the need and feasibility of implementing a message passing model for data transmission between the NFP and CPU...

Joint Optimized CPU and Networking Control Scheme for Improved Energy Efficiency in Video Streaming on Mobile Devices

Directory of Open Access Journals (Sweden)

Sung-Woong Jo

2017-01-01

Full Text Available Video streaming service is one of the most popular applications for mobile users. However, mobile video streaming services consume a lot of energy, resulting in a reduced battery life. This is a critical problem that results in a degraded user’s quality of experience (QoE. Therefore, in this paper, a joint optimization scheme that controls both the central processing unit (CPU and wireless networking of the video streaming process for improved energy efficiency on mobile devices is proposed. For this purpose, the energy consumption of the network interface and CPU is analyzed, and based on the energy consumption profile a joint optimization problem is formulated to maximize the energy efficiency of the mobile device. The proposed algorithm adaptively adjusts the number of chunks to be downloaded and decoded in each packet. Simulation results show that the proposed algorithm can effectively improve the energy efficiency when compared with the existing algorithms.

The effects of warming and nitrogen addition on soil nitrogen cycling in a temperate grassland, northeastern China.

Directory of Open Access Journals (Sweden)

Lin-Na Ma

Full Text Available Both climate warming and atmospheric nitrogen (N deposition are predicted to affect soil N cycling in terrestrial biomes over the next century. However, the interactive effects of warming and N deposition on soil N mineralization in temperate grasslands are poorly understood.A field manipulation experiment was conducted to examine the effects of warming and N addition on soil N cycling in a temperate grassland of northeastern China from 2007 to 2009. Soil samples were incubated at a constant temperature and moisture, from samples collected in the field. The results showed that both warming and N addition significantly stimulated soil net N mineralization rate and net nitrification rate. Combined warming and N addition caused an interactive effect on N mineralization, which could be explained by the relative shift of soil microbial community structure because of fungal biomass increase and strong plant uptake of added N due to warming. Irrespective of strong intra- and inter-annual variations in soil N mineralization, the responses of N mineralization to warming and N addition did not change during the three growing seasons, suggesting independence of warming and N responses of N mineralization from precipitation variations in the temperate grassland.Interactions between climate warming and N deposition on soil N cycling were significant. These findings will improve our understanding on the response of soil N cycling to the simultaneous climate change drivers in temperate grassland ecosystem.

A Robust Ultra-Low Voltage CPU Utilizing Timing-Error Prevention

Directory of Open Access Journals (Sweden)

Markus Hiienkari

2015-04-01

Full Text Available To minimize energy consumption of a digital circuit, logic can be operated at sub- or near-threshold voltage. Operation at this region is challenging due to device and environment variations, and resulting performance may not be adequate to all applications. This article presents two variants of a 32-bit RISC CPU targeted for near-threshold voltage. Both CPUs are placed on the same die and manufactured in 28 nm CMOS process. They employ timing-error prevention with clock stretching to enable operation with minimal safety margins while maximizing performance and energy efficiency at a given operating point. Measurements show minimum energy of 3.15 pJ/cyc at 400 mV, which corresponds to 39% energy saving compared to operation based on static signoff timing.

Effects of arbuscular mycorrhizal fungi and soil nutrient addition on the growth of Phragmites australis under different drying-rewetting cycles.

Science.gov (United States)

Liang, Jin-Feng; An, Jing; Gao, Jun-Qin; Zhang, Xiao-Ya; Yu, Fei-Hai

2018-01-01

The frequency of soil drying-rewetting cycles is predicted to increase under future global climate change, and arbuscular mycorrhizal fungi (AMF) are symbiotic with most plants. However, it remains unknown how AMF affect plant growth under different frequencies of soil drying-rewetting cycles. We subjected a clonal wetland plant Phragmites australis to three frequencies of drying-rewetting cycles (1, 2, or 4 cycles), two nutrient treatments (with or without), and two AMF treatments (with or without) for 64 days. AMF promoted the growth of P. australis, especially in the 2 cycles of the drying-rewetting treatment. AMF had a significant positive effect on leaf mass and number of ramets in the 2 cycles of the drying-rewetting treatment with nutrient addition. In the 2 cycles of drying-rewetting treatment without nutrient addition, AMF increased leaf area and decreased belowground to aboveground biomass ratio. These results indicate that AMF may assist P. australis in coping with medium frequency of drying-rewetting cycles, and provide theoretical guidance for predicting how wetland plants respond to future global climate change.

Improvement of high voltage cycling performance and thermal stability of lithium-ion cells by use of a thiophene additive

Energy Technology Data Exchange (ETDEWEB)

Lee, Ki-Soo; Sun, Yang-Kook; Kim, Dong-Won [Department of Chemical Engineering, Hanyang University, Seungdong-gu, Seoul 133-791 (Korea); Noh, Jaegeun [Department of Chemistry, Hanyang University, Seungdong-gu, Seoul 133-791 (Korea); Song, Kwang Soup [Advanced Medical Device Center, Korea Electrotechnology, Research Institute, Ansan, Gyeonggi-do 426-170 (Korea)

2009-10-15

This study demonstrates that the addition of thiophene improves the cycle life of lithium-ion cells at high voltage. Electrochemical impedance spectroscopy results suggest that addition of thiophene significantly suppresses the increase of the charge transfer resistance that occurs during cycling up to high voltage. Differential scanning calorimetric studies showed that the thermal stability of fully charged LiCoO{sub 2} cathode was also enhanced in the presence of thiophene. (author)

Orbital simulation life tests of nickel hydrogen batteries with additional non-eclipse cycles

Science.gov (United States)

Johnson, P. J.; Donley, S. W.; Verrier, D. C.

Nickel-hydrogen battery technology has established itself as the system of choice to provide energy storage on board Earth orbiting satellites. In addition to providing electrical power for the satellite during the periods the satellite's solar arrays are eclipsed by the Earth, applications are evolving (such as ion propulsion) where the battery is required to supplement the power supplied to the spacecraft by the solar panels in order to meet the peak power demands. In this paper, the results of a four-year accelerated life test programme, equivalent to more than 20 years in orbit, are reported. Additional non-eclipse cycles were added to both the eclipse and solstice seasons of each simulated spacecraft year. The results show that the additional discharges do not significantly effect the rates of performance degradation of the batteries.

Electron-microscopy studies of NaAlH{sub 4} with TiF{sub 3} additive: hydrogen-cycling effects

Energy Technology Data Exchange (ETDEWEB)

Andrei, C.M.; Holmestad, R. [Norwegian University of Science and Technology, Department of Physics, Trondheim (Norway); Walmsley, J.C. [SINTEF Materials and Chemistry, Trondheim (Norway); Brinks, H.W.; Hauback, B.C. [Institute for Energy Technology, P.O. Box 40, Kjeller (Norway); Srinivasan, S.S.; Jensen, C.M. [University of Hawaii, Department of Chemistry, Honolulu, HI (United States)

2005-02-01

NaAlH{sub 4} is a promising candidate material for hydrogen storage. Ti additives are effective in reducing the reaction temperatures and improving kinetics. In this work, the microstructure of NaAlH{sub 4} with 2% TiF{sub 3} has been studied in different conditions using a combination of transmission electron microscopy and scanning electron microscopy, both with energy-dispersive spectroscopic X-ray analysis. The effect of the additive on particle and grain size was examined after the initial ball-milling process and after 15 cycles. The additive has an uneven distribution in the sample after ball milling. Selected-area diffraction and high-resolution imaging confirmed the presence of TiF{sub 3}. This phase accounts for most of the Ti in the material at this stage and showed limited mixing with the alanate. The grain size within particles for TiF{sub 3} is larger than for the alanate particles. Diffraction from the latter was dominated by metallic aluminium. After cycling, the TiF{sub 3} has decomposed and energy-dispersive spectroscopic X-ray analysis maps showed some combination of Ti with the alanate phase. There is no significant change in the measurable grain size of the Al-containing alanate particles between the ball-milled and the 15-cycled samples, but more cycles result in agglomeration of the material. (orig.)

VMware vSphere performance designing CPU, memory, storage, and networking for performance-intensive workloads

CERN Document Server

Liebowitz, Matt; Spies, Rynardt

2014-01-01

Covering the latest VMware vSphere software, an essential book aimed at solving vSphere performance problems before they happen VMware vSphere is the industry's most widely deployed virtualization solution. However, if you improperly deploy vSphere, performance problems occur. Aimed at VMware administrators and engineers and written by a team of VMware experts, this resource provides guidance on common CPU, memory, storage, and network-related problems. Plus, step-by-step instructions walk you through techniques for solving problems and shed light on possible causes behind the problems. Divu

Enhanced round robin CPU scheduling with burst time based time quantum

Science.gov (United States)

Indusree, J. R.; Prabadevi, B.

2017-11-01

Process scheduling is a very important functionality of Operating system. The main-known process-scheduling algorithms are First Come First Serve (FCFS) algorithm, Round Robin (RR) algorithm, Priority scheduling algorithm and Shortest Job First (SJF) algorithm. Compared to its peers, Round Robin (RR) algorithm has the advantage that it gives fair share of CPU to the processes which are already in the ready-queue. The effectiveness of the RR algorithm greatly depends on chosen time quantum value. Through this research paper, we are proposing an enhanced algorithm called Enhanced Round Robin with Burst-time based Time Quantum (ERRBTQ) process scheduling algorithm which calculates time quantum as per the burst-time of processes already in ready queue. The experimental results and analysis of ERRBTQ algorithm clearly indicates the improved performance when compared with conventional RR and its variants.

An efficient implementation of 3D high-resolution imaging for large-scale seismic data with GPU/CPU heterogeneous parallel computing

Science.gov (United States)

Xu, Jincheng; Liu, Wei; Wang, Jin; Liu, Linong; Zhang, Jianfeng

2018-02-01

De-absorption pre-stack time migration (QPSTM) compensates for the absorption and dispersion of seismic waves by introducing an effective Q parameter, thereby making it an effective tool for 3D, high-resolution imaging of seismic data. Although the optimal aperture obtained via stationary-phase migration reduces the computational cost of 3D QPSTM and yields 3D stationary-phase QPSTM, the associated computational efficiency is still the main problem in the processing of 3D, high-resolution images for real large-scale seismic data. In the current paper, we proposed a division method for large-scale, 3D seismic data to optimize the performance of stationary-phase QPSTM on clusters of graphics processing units (GPU). Then, we designed an imaging point parallel strategy to achieve an optimal parallel computing performance. Afterward, we adopted an asynchronous double buffering scheme for multi-stream to perform the GPU/CPU parallel computing. Moreover, several key optimization strategies of computation and storage based on the compute unified device architecture (CUDA) were adopted to accelerate the 3D stationary-phase QPSTM algorithm. Compared with the initial GPU code, the implementation of the key optimization steps, including thread optimization, shared memory optimization, register optimization and special function units (SFU), greatly improved the efficiency. A numerical example employing real large-scale, 3D seismic data showed that our scheme is nearly 80 times faster than the CPU-QPSTM algorithm. Our GPU/CPU heterogeneous parallel computing framework significant reduces the computational cost and facilitates 3D high-resolution imaging for large-scale seismic data.

Effects of nutrient additions on ecosystem carbon cycle in a Puerto Rican tropical wet forest

Science.gov (United States)

YIQING LI; MING XU; XIAOMING ZOU

2006-01-01

Wet tropical forests play a critical role in global ecosystem carbon (C) cycle, but C allocation and the response of different C pools to nutrient addition in these forests remain poorly understood. We measured soil organic carbon (SOC), litterfall, root biomass, microbial biomass and soil physical and chemical properties in a wet tropical forest from May 1996 to July...

Comparison of the CPU and memory performance of StatPatternRecognitions (SPR) and Toolkit for MultiVariate Analysis (TMVA)

International Nuclear Information System (INIS)

Palombo, G.

2012-01-01

High Energy Physics data sets are often characterized by a huge number of events. Therefore, it is extremely important to use statistical packages able to efficiently analyze these unprecedented amounts of data. We compare the performance of the statistical packages StatPatternRecognition (SPR) and Toolkit for MultiVariate Analysis (TMVA). We focus on how CPU time and memory usage of the learning process scale versus data set size. As classifiers, we consider Random Forests, Boosted Decision Trees and Neural Networks only, each with specific settings. For our tests, we employ a data set widely used in the machine learning community, “Threenorm” data set, as well as data tailored for testing various edge cases. For each data set, we constantly increase its size and check CPU time and memory needed to build the classifiers implemented in SPR and TMVA. We show that SPR is often significantly faster and consumes significantly less memory. For example, the SPR implementation of Random Forest is by an order of magnitude faster and consumes an order of magnitude less memory than TMVA on Threenorm data.

Comparison of conventional Injection Mould Inserts to Additively Manufactured Inserts using Life Cycle Assessment

DEFF Research Database (Denmark)

Hofstätter, Thomas; Bey, Niki; Mischkot, Michael

2016-01-01

Polymer Additive Manufacturing can be used to produce soft tooling inserts for injection moulding. Compared to conventional tooling, the energy and time consumption during production are significantly lower. As the life time of such inserts is significantly shorter than the life time of traditional...... of their potential environmental impact and yield throughout the development and pilot phase. Insert geometry is particularly advantageous for pilot production and small production sizes. In this research, Life Cycle Assessment is used to compare the environmental impact of soft tooling by Additive Manufacturing...... (using Digital Light Processing) and three traditional methods for the manufacture of inserts (milling of brass, steel, and aluminium) for injection moulds during the pre-production phase....

A Programming Framework for Scientific Applications on CPU-GPU Systems

Energy Technology Data Exchange (ETDEWEB)

Owens, John

2013-03-24

At a high level, my research interests center around designing, programming, and evaluating computer systems that use new approaches to solve interesting problems. The rapid change of technology allows a variety of different architectural approaches to computationally difficult problems, and a constantly shifting set of constraints and trends makes the solutions to these problems both challenging and interesting. One of the most important recent trends in computing has been a move to commodity parallel architectures. This sea change is motivated by the industry’s inability to continue to profitably increase performance on a single processor and instead to move to multiple parallel processors. In the period of review, my most significant work has been leading a research group looking at the use of the graphics processing unit (GPU) as a general-purpose processor. GPUs can potentially deliver superior performance on a broad range of problems than their CPU counterparts, but effectively mapping complex applications to a parallel programming model with an emerging programming environment is a significant and important research problem.

hybrid\\scriptsize{{MANTIS}}: a CPU-GPU Monte Carlo method for modeling indirect x-ray detectors with columnar scintillators

Science.gov (United States)

Sharma, Diksha; Badal, Andreu; Badano, Aldo

2012-04-01

The computational modeling of medical imaging systems often requires obtaining a large number of simulated images with low statistical uncertainty which translates into prohibitive computing times. We describe a novel hybrid approach for Monte Carlo simulations that maximizes utilization of CPUs and GPUs in modern workstations. We apply the method to the modeling of indirect x-ray detectors using a new and improved version of the code \\scriptsize{{MANTIS}}, an open source software tool used for the Monte Carlo simulations of indirect x-ray imagers. We first describe a GPU implementation of the physics and geometry models in fast\\scriptsize{{DETECT}}2 (the optical transport model) and a serial CPU version of the same code. We discuss its new features like on-the-fly column geometry and columnar crosstalk in relation to the \\scriptsize{{MANTIS}} code, and point out areas where our model provides more flexibility for the modeling of realistic columnar structures in large area detectors. Second, we modify \\scriptsize{{PENELOPE}} (the open source software package that handles the x-ray and electron transport in \\scriptsize{{MANTIS}}) to allow direct output of location and energy deposited during x-ray and electron interactions occurring within the scintillator. This information is then handled by optical transport routines in fast\\scriptsize{{DETECT}}2. A load balancer dynamically allocates optical transport showers to the GPU and CPU computing cores. Our hybrid\\scriptsize{{MANTIS}} approach achieves a significant speed-up factor of 627 when compared to \\scriptsize{{MANTIS}} and of 35 when compared to the same code running only in a CPU instead of a GPU. Using hybrid\\scriptsize{{MANTIS}}, we successfully hide hours of optical transport time by running it in parallel with the x-ray and electron transport, thus shifting the computational bottleneck from optical to x-ray transport. The new code requires much less memory than \\scriptsize{{MANTIS}} and, as a result

Porting AMG2013 to Heterogeneous CPU+GPU Nodes

Energy Technology Data Exchange (ETDEWEB)

Samfass, Philipp [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-01-26

LLNL's future advanced technology system SIERRA will feature heterogeneous compute nodes that consist of IBM PowerV9 CPUs and NVIDIA Volta GPUs. Conceptually, the motivation for such an architecture is quite straightforward: While GPUs are optimized for throughput on massively parallel workloads, CPUs strive to minimize latency for rather sequential operations. Yet, making optimal use of heterogeneous architectures raises new challenges for the development of scalable parallel software, e.g., with respect to work distribution. Porting LLNL's parallel numerical libraries to upcoming heterogeneous CPU+GPU architectures is therefore a critical factor for ensuring LLNL's future success in ful lling its national mission. One of these libraries, called HYPRE, provides parallel solvers and precondi- tioners for large, sparse linear systems of equations. In the context of this intern- ship project, I consider AMG2013 which is a proxy application for major parts of HYPRE that implements a benchmark for setting up and solving di erent systems of linear equations. In the following, I describe in detail how I ported multiple parts of AMG2013 to the GPU (Section 2) and present results for di erent experiments that demonstrate a successful parallel implementation on the heterogeneous ma- chines surface and ray (Section 3). In Section 4, I give guidelines on how my code should be used. Finally, I conclude and give an outlook for future work (Section 5).

Effect of exogenous carbon addition and the freeze-thaw cycle on soil microbes and mineral nitrogen pools1

Science.gov (United States)

Hu, Xia; Yin, Peng; Nong, Xiang; Liao, Jinhua

2018-01-01

To elucidate the alpine soil process in winter, the response mechanism of soil mineral nitrogen and soil microbes to exogenous carbon (0 mg C, 1 mg C, 2 mg C, 4 mg C and 8 mg C·g-1 dry soil) and the freeze-thaw cycle (-2 °C, -2 ∼ 2 °C, -20 ∼2°C) were studied by laboratory simulation. The freeze-thaw treatment had no significant effect on microbial biomass nitrogen and the number of bacteria. The soil mineral N pool, the number of fungi, and enzyme activities were obviously affected by the freeze-thaw cycle. A mild freeze-thaw cycle (-2∼2°C) significantly increased the number of fungi and catalase activity, while severe freeze-thaw cycle (-20∼2°C) obviously decreased invertase activity. The results suggested that both the freeze-thaw rate and freeze-thaw temperature amplitudes have a strong effect on soil microbial dynamics in the alpine zone in winter. The results showed that exogenous carbon addition significantly decreased soil NO3-N and NH4 +-N contents, increased soil microbial biomass, the number of microbes, and soil enzyme activities. The results showed that microbial growth in the eastern Tibetan Plateau was somewhat limited by available C. It may represent a larger potential pulse of soil nutrient for alpine plants in the next spring, and may be instrumental for plant community shifts under future climate change predictions due to the possible increased litter addition.

Metabolic regulation at the tricarboxylic acid and glyoxylate cycles of the lignin-degrading basidiomycete Phanerochaete chrysosporium against exogenous addition of vanillin.

Science.gov (United States)

Shimizu, Motoyuki; Yuda, Naoki; Nakamura, Tomofumi; Tanaka, Hiroo; Wariishi, Hiroyuki

2005-10-01

A proteomic differential display technique was utilized to study cellular responses of Phanerochaete chrysosporium exposed to vanillin, one of the key intermediates found during lignin biodegradation. Intracellular proteins were resolved by 2-DE and target protein spots were identified using MALDI-MS after in-gel tryptic digestions. Upon addition of vanillin to P. chrysosporium, up-regulation of homogentisate 1,2-dioxygenase, 1,4-benzoquinone reductases, aldehyde dehydrogenase, and aryl-alcohol dehydrogenase, which seem to play roles in vanillin metabolism, was observed. Furthermore, enzymes involved in glycolysis, the tricarboxylic acid cycle, the pentose-phosphate cycle, and heme biosynthesis were also activated. Up-regulation of extracellular peroxidase was also observed. One of the most unique phenomena against exogenous vanillin was a switch from the glyoxylate cycle to the tricarboxylic acid cycle, where a drastic increase in isocitrate dehydrogenase activity was observed. The exogenous addition of other aromatic compounds also caused an increase in its activity, which in turn triggered NAD(P)H production via the action of dehydrogenases in the tricarboxylic acid cycle, heme biosynthesis via the action of aminolevulinic acid synthase on succinyl-CoA, and energy production via activation of the mitochondrial electron transfer system. These metabolic shifts seem to be required for activating a metabolic system for aromatic compounds.

Change in gene abundance in the nitrogen biogeochemical cycle with temperature and nitrogen addition in Antarctic soils.

Science.gov (United States)

Jung, Jaejoon; Yeom, Jinki; Kim, Jisun; Han, Jiwon; Lim, Hyoun Soo; Park, Hyun; Hyun, Seunghun; Park, Woojun

2011-12-01

The microbial community (bacterial, archaeal, and fungi) and eight genes involved in the nitrogen biogeochemical cycle (nifH, nitrogen fixation; bacterial and archaeal amoA, ammonia oxidation; narG, nitrate reduction; nirS, nirK, nitrite reduction; norB, nitric oxide reduction; and nosZ, nitrous oxide reduction) were quantitatively assessed in this study, via real-time PCR with DNA extracted from three Antarctic soils. Interestingly, AOB amoA was found to be more abundant than AOA amoA in Antarctic soils. The results of microcosm studies revealed that the fungal and archaeal communities were diminished in response to warming temperatures (10 °C) and that the archaeal community was less sensitive to nitrogen addition, which suggests that those two communities are well-adapted to colder temperatures. AOA amoA and norB genes were reduced with warming temperatures. The abundance of only the nifH and nirK genes increased with both warming and the addition of nitrogen. NirS-type denitrifying bacteria outnumbered NirK-type denitrifiers regardless of the treatment used. Interestingly, dramatic increases in both NirS and NirK-types denitrifiers were observed with nitrogen addition. NirK types increase with warming, but NirS-type denitrifiers tend to be less sensitive to warming. Our findings indicated that the Antarctic microbial nitrogen cycle could be dramatically altered by temperature and nitrogen, and that warming may be detrimental to the ammonia-oxidizing archaeal community. To the best of our knowledge, this is the first report to investigate genes associated with each process of the nitrogen biogeochemical cycle in an Antarctic terrestrial soil environment. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Portable implementation model for CFD simulations. Application to hybrid CPU/GPU supercomputers

Science.gov (United States)

Oyarzun, Guillermo; Borrell, Ricard; Gorobets, Andrey; Oliva, Assensi

2017-10-01

Nowadays, high performance computing (HPC) systems experience a disruptive moment with a variety of novel architectures and frameworks, without any clarity of which one is going to prevail. In this context, the portability of codes across different architectures is of major importance. This paper presents a portable implementation model based on an algebraic operational approach for direct numerical simulation (DNS) and large eddy simulation (LES) of incompressible turbulent flows using unstructured hybrid meshes. The strategy proposed consists in representing the whole time-integration algorithm using only three basic algebraic operations: sparse matrix-vector product, a linear combination of vectors and dot product. The main idea is based on decomposing the nonlinear operators into a concatenation of two SpMV operations. This provides high modularity and portability. An exhaustive analysis of the proposed implementation for hybrid CPU/GPU supercomputers has been conducted with tests using up to 128 GPUs. The main objective consists in understanding the challenges of implementing CFD codes on new architectures.

Event- and Time-Driven Techniques Using Parallel CPU-GPU Co-processing for Spiking Neural Networks.

Science.gov (United States)

Naveros, Francisco; Garrido, Jesus A; Carrillo, Richard R; Ros, Eduardo; Luque, Niceto R

2017-01-01

Modeling and simulating the neural structures which make up our central neural system is instrumental for deciphering the computational neural cues beneath. Higher levels of biological plausibility usually impose higher levels of complexity in mathematical modeling, from neural to behavioral levels. This paper focuses on overcoming the simulation problems (accuracy and performance) derived from using higher levels of mathematical complexity at a neural level. This study proposes different techniques for simulating neural models that hold incremental levels of mathematical complexity: leaky integrate-and-fire (LIF), adaptive exponential integrate-and-fire (AdEx), and Hodgkin-Huxley (HH) neural models (ranged from low to high neural complexity). The studied techniques are classified into two main families depending on how the neural-model dynamic evaluation is computed: the event-driven or the time-driven families. Whilst event-driven techniques pre-compile and store the neural dynamics within look-up tables, time-driven techniques compute the neural dynamics iteratively during the simulation time. We propose two modifications for the event-driven family: a look-up table recombination to better cope with the incremental neural complexity together with a better handling of the synchronous input activity. Regarding the time-driven family, we propose a modification in computing the neural dynamics: the bi-fixed-step integration method. This method automatically adjusts the simulation step size to better cope with the stiffness of the neural model dynamics running in CPU platforms. One version of this method is also implemented for hybrid CPU-GPU platforms. Finally, we analyze how the performance and accuracy of these modifications evolve with increasing levels of neural complexity. We also demonstrate how the proposed modifications which constitute the main contribution of this study systematically outperform the traditional event- and time-driven techniques under

Spurious Additional Warming Reconstructed From Borehole Temperatures Corrected for the Effect of the Last Glacial Cycle

Science.gov (United States)

Šafanda, Jan

2018-03-01

Reconstructions of past ground surface temperature changes from temperature logs conducted in several hundred meter deep boreholes have proved to be a valuable independent source of information on climate variations over the last millennium. The reconstruction techniques have been evolving for more than two decades to extract optimally the climate signal of the last millennium contained in the temperature logs of different length performed in sites with different histories of the Last Glacial Cycle. This paper analyzes the method of the Last Glacial Cycle thermal effect removal from such borehole temperature profiles used by Beltrami et al. (2017, https://doi.org/10.1002/2016GL071317) in reconstructing the last 500 year history. I show that the reported results of additional warming in this period reconstructed from the corrected borehole data for North America are an artifact generated by the correction.

Integration of Fiber-Reinforced Polymers in a Life Cycle Assessment of Injection Molding Process Chains with Additive Manufacturing

DEFF Research Database (Denmark)

Hofstätter, Thomas; Bey, Niki; Mischkot, Michael

2017-01-01

Additive manufacturing technologies applied to injection molding process chain have acquired an increasingly important role in the context of tool inserts production, especially by vat polymerization. Despite the decreased lifetime during their use in the injection molding process, the inserts come...... with improvements in terms of production time, costs, exibility, as well as potentially improved environmental performance as compared to conventional materials in a life cycle perspective.This contribution supports the development of additively manufactured injection molding inserts with the use of fiber...

Finite difference numerical method for the superlattice Boltzmann transport equation and case comparison of CPU(C) and GPU(CUDA) implementations

Energy Technology Data Exchange (ETDEWEB)

Priimak, Dmitri

2014-12-01

We present a finite difference numerical algorithm for solving two dimensional spatially homogeneous Boltzmann transport equation which describes electron transport in a semiconductor superlattice subject to crossed time dependent electric and constant magnetic fields. The algorithm is implemented both in C language targeted to CPU and in CUDA C language targeted to commodity NVidia GPU. We compare performances and merits of one implementation versus another and discuss various software optimisation techniques.

Finite difference numerical method for the superlattice Boltzmann transport equation and case comparison of CPU(C) and GPU(CUDA) implementations

International Nuclear Information System (INIS)

Priimak, Dmitri

2014-01-01

We present a finite difference numerical algorithm for solving two dimensional spatially homogeneous Boltzmann transport equation which describes electron transport in a semiconductor superlattice subject to crossed time dependent electric and constant magnetic fields. The algorithm is implemented both in C language targeted to CPU and in CUDA C language targeted to commodity NVidia GPU. We compare performances and merits of one implementation versus another and discuss various software optimisation techniques

Deployment of 464XLAT (RFC6877) alongside IPv6-only CPU resources at WLCG sites

Science.gov (United States)

Froy, T. S.; Traynor, D. P.; Walker, C. J.

2017-10-01

IPv4 is now officially deprecated by the IETF. A significant amount of effort has already been expended by the HEPiX IPv6 Working Group on testing dual-stacked hosts and IPv6-only CPU resources. Dual-stack adds complexity and administrative overhead to sites that may already be starved of resource. This has resulted in a very slow uptake of IPv6 from WLCG sites. 464XLAT (RFC6877) is intended for IPv6 single-stack environments that require the ability to communicate with IPv4-only endpoints. This paper will present a deployment strategy for 464XLAT, operational experiences of using 464XLAT in production at a WLCG site and important information to consider prior to deploying 464XLAT.

SAFARI digital processing unit: performance analysis of the SpaceWire links in case of a LEON3-FT based CPU

Science.gov (United States)

Giusi, Giovanni; Liu, Scige J.; Di Giorgio, Anna M.; Galli, Emanuele; Pezzuto, Stefano; Farina, Maria; Spinoglio, Luigi

2014-08-01

SAFARI (SpicA FAR infrared Instrument) is a far-infrared imaging Fourier Transform Spectrometer for the SPICA mission. The Digital Processing Unit (DPU) of the instrument implements the functions of controlling the overall instrument and implementing the science data compression and packing. The DPU design is based on the use of a LEON family processor. In SAFARI, all instrument components are connected to the central DPU via SpaceWire links. On these links science data, housekeeping and commands flows are in some cases multiplexed, therefore the interface control shall be able to cope with variable throughput needs. The effective data transfer workload can be an issue for the overall system performances and becomes a critical parameter for the on-board software design, both at application layer level and at lower, and more HW related, levels. To analyze the system behavior in presence of the expected SAFARI demanding science data flow, we carried out a series of performance tests using the standard GR-CPCI-UT699 LEON3-FT Development Board, provided by Aeroflex/Gaisler, connected to the emulator of the SAFARI science data links, in a point-to-point topology. Two different communication protocols have been used in the tests, the ECSS-E-ST-50-52C RMAP protocol and an internally defined one, the SAFARI internal data handling protocol. An incremental approach has been adopted to measure the system performances at different levels of the communication protocol complexity. In all cases the performance has been evaluated by measuring the CPU workload and the bus latencies. The tests have been executed initially in a custom low level execution environment and finally using the Real- Time Executive for Multiprocessor Systems (RTEMS), which has been selected as the operating system to be used onboard SAFARI. The preliminary results of the carried out performance analysis confirmed the possibility of using a LEON3 CPU processor in the SAFARI DPU, but pointed out, in agreement

Elevated CO2, not defoliation, enhances N cycling and increases short-term soil N immobilization regardless of N addition in a semiarid grassland

Science.gov (United States)

Elevated CO2 and defoliation effects on nitrogen (N) cycling in rangeland soils remain poorly understood. Here we tested whether effects of elevated CO2 and defoliation (clipping to 2.5 cm height) on N cycling depended on soil N availability (addition of 1 vs. 11 g N/m2) in intact mesocosms extracte...

Fast data reconstructed method of Fourier transform imaging spectrometer based on multi-core CPU

Science.gov (United States)

Yu, Chunchao; Du, Debiao; Xia, Zongze; Song, Li; Zheng, Weijian; Yan, Min; Lei, Zhenggang

2017-10-01

Imaging spectrometer can gain two-dimensional space image and one-dimensional spectrum at the same time, which shows high utility in color and spectral measurements, the true color image synthesis, military reconnaissance and so on. In order to realize the fast reconstructed processing of the Fourier transform imaging spectrometer data, the paper designed the optimization reconstructed algorithm with OpenMP parallel calculating technology, which was further used for the optimization process for the HyperSpectral Imager of `HJ-1' Chinese satellite. The results show that the method based on multi-core parallel computing technology can control the multi-core CPU hardware resources competently and significantly enhance the calculation of the spectrum reconstruction processing efficiency. If the technology is applied to more cores workstation in parallel computing, it will be possible to complete Fourier transform imaging spectrometer real-time data processing with a single computer.

An FPGA Based Multiprocessing CPU for Beam Synchronous Timing in CERN's SPS and LHC

CERN Document Server

Ballester, F J; Gras, J J; Lewis, J; Savioz, J J; Serrano, J

2003-01-01

The Beam Synchronous Timing system (BST) will be used around the LHC and its injector, the SPS, to broadcast timing meassages and synchronize actions with the beam in different receivers. To achieve beam synchronization, the BST Master card encodes messages using the bunch clock, with a nominal value of 40.079 MHz for the LHC. These messages are produced by a set of tasks every revolution period, which is every 89 us for the LHC and every 23 us for the SPS, therefore imposing a hard real-time constraint on the system. To achieve determinism, the BST Master uses a dedicated CPU inside its main Field Programmable Gate Array (FPGA) featuring zero-delay hardware task switching and a reduced instruction set. This paper describes the BST Master card, stressing the main FPGA design, as well as the associated software, including the LynxOS driver and the tailor-made assembler.

Collaborating CPU and GPU for large-scale high-order CFD simulations with complex grids on the TianHe-1A supercomputer

Energy Technology Data Exchange (ETDEWEB)

Xu, Chuanfu, E-mail: xuchuanfu@nudt.edu.cn [College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Deng, Xiaogang; Zhang, Lilun [College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Fang, Jianbin [Parallel and Distributed Systems Group, Delft University of Technology, Delft 2628CD (Netherlands); Wang, Guangxue; Jiang, Yi [State Key Laboratory of Aerodynamics, P.O. Box 211, Mianyang 621000 (China); Cao, Wei; Che, Yonggang; Wang, Yongxian; Wang, Zhenghua; Liu, Wei; Cheng, Xinghua [College of Computer Science, National University of Defense Technology, Changsha 410073 (China)

2014-12-01

Programming and optimizing complex, real-world CFD codes on current many-core accelerated HPC systems is very challenging, especially when collaborating CPUs and accelerators to fully tap the potential of heterogeneous systems. In this paper, with a tri-level hybrid and heterogeneous programming model using MPI + OpenMP + CUDA, we port and optimize our high-order multi-block structured CFD software HOSTA on the GPU-accelerated TianHe-1A supercomputer. HOSTA adopts two self-developed high-order compact definite difference schemes WCNS and HDCS that can simulate flows with complex geometries. We present a dual-level parallelization scheme for efficient multi-block computation on GPUs and perform particular kernel optimizations for high-order CFD schemes. The GPU-only approach achieves a speedup of about 1.3 when comparing one Tesla M2050 GPU with two Xeon X5670 CPUs. To achieve a greater speedup, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present a novel scheme to balance the loads between the store-poor GPU and the store-rich CPU. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per TianHe-1A node for HOSTA by 2.3×, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Further, to scale HOSTA on TianHe-1A, we propose a gather/scatter optimization to minimize PCI-e data transfer times for ghost and singularity data of 3D grid blocks, and overlap the collaborative computation and communication as far as possible using some advanced CUDA and MPI features. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 TianHe-1A nodes. With our method, we have successfully simulated an EET high-lift airfoil configuration containing 800M cells and China's large civil airplane configuration containing 150M cells. To our best knowledge, those are the largest-scale CPU–GPU collaborative simulations

Collaborating CPU and GPU for large-scale high-order CFD simulations with complex grids on the TianHe-1A supercomputer

International Nuclear Information System (INIS)

Xu, Chuanfu; Deng, Xiaogang; Zhang, Lilun; Fang, Jianbin; Wang, Guangxue; Jiang, Yi; Cao, Wei; Che, Yonggang; Wang, Yongxian; Wang, Zhenghua; Liu, Wei; Cheng, Xinghua

2014-01-01

Programming and optimizing complex, real-world CFD codes on current many-core accelerated HPC systems is very challenging, especially when collaborating CPUs and accelerators to fully tap the potential of heterogeneous systems. In this paper, with a tri-level hybrid and heterogeneous programming model using MPI + OpenMP + CUDA, we port and optimize our high-order multi-block structured CFD software HOSTA on the GPU-accelerated TianHe-1A supercomputer. HOSTA adopts two self-developed high-order compact definite difference schemes WCNS and HDCS that can simulate flows with complex geometries. We present a dual-level parallelization scheme for efficient multi-block computation on GPUs and perform particular kernel optimizations for high-order CFD schemes. The GPU-only approach achieves a speedup of about 1.3 when comparing one Tesla M2050 GPU with two Xeon X5670 CPUs. To achieve a greater speedup, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present a novel scheme to balance the loads between the store-poor GPU and the store-rich CPU. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per TianHe-1A node for HOSTA by 2.3×, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Further, to scale HOSTA on TianHe-1A, we propose a gather/scatter optimization to minimize PCI-e data transfer times for ghost and singularity data of 3D grid blocks, and overlap the collaborative computation and communication as far as possible using some advanced CUDA and MPI features. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 TianHe-1A nodes. With our method, we have successfully simulated an EET high-lift airfoil configuration containing 800M cells and China's large civil airplane configuration containing 150M cells. To our best knowledge, those are the largest-scale CPU–GPU collaborative simulations

A Bit String Content Aware Chunking Strategy for Reduced CPU Energy on Cloud Storage

Directory of Open Access Journals (Sweden)

Bin Zhou

2015-01-01

Full Text Available In order to achieve energy saving and reduce the total cost of ownership, green storage has become the first priority for data center. Detecting and deleting the redundant data are the key factors to the reduction of the energy consumption of CPU, while high performance stable chunking strategy provides the groundwork for detecting redundant data. The existing chunking algorithm greatly reduces the system performance when confronted with big data and it wastes a lot of energy. Factors affecting the chunking performance are analyzed and discussed in the paper and a new fingerprint signature calculation is implemented. Furthermore, a Bit String Content Aware Chunking Strategy (BCCS is put forward. This strategy reduces the cost of signature computation in chunking process to improve the system performance and cuts down the energy consumption of the cloud storage data center. On the basis of relevant test scenarios and test data of this paper, the advantages of the chunking strategy are verified.

GENIE: a software package for gene-gene interaction analysis in genetic association studies using multiple GPU or CPU cores

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Wang Kai

2011-05-01

Full Text Available Abstract Background Gene-gene interaction in genetic association studies is computationally intensive when a large number of SNPs are involved. Most of the latest Central Processing Units (CPUs have multiple cores, whereas Graphics Processing Units (GPUs also have hundreds of cores and have been recently used to implement faster scientific software. However, currently there are no genetic analysis software packages that allow users to fully utilize the computing power of these multi-core devices for genetic interaction analysis for binary traits. Findings Here we present a novel software package GENIE, which utilizes the power of multiple GPU or CPU processor cores to parallelize the interaction analysis. GENIE reads an entire genetic association study dataset into memory and partitions the dataset into fragments with non-overlapping sets of SNPs. For each fragment, GENIE analyzes: 1 the interaction of SNPs within it in parallel, and 2 the interaction between the SNPs of the current fragment and other fragments in parallel. We tested GENIE on a large-scale candidate gene study on high-density lipoprotein cholesterol. Using an NVIDIA Tesla C1060 graphics card, the GPU mode of GENIE achieves a speedup of 27 times over its single-core CPU mode run. Conclusions GENIE is open-source, economical, user-friendly, and scalable. Since the computing power and memory capacity of graphics cards are increasing rapidly while their cost is going down, we anticipate that GENIE will achieve greater speedups with faster GPU cards. Documentation, source code, and precompiled binaries can be downloaded from http://www.cceb.upenn.edu/~mli/software/GENIE/.

Gas fired combined cycle plant in Singapore: energy use, GWP and cost-a life cycle approach

International Nuclear Information System (INIS)

Kannan, R.; Leong, K.C.; Osman, Ramli; Ho, H.K.; Tso, C.P.

2005-01-01

A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established

Treatment-related fluctuations in guillain barre syndrome and the conundrum of additional cycles of plasmapheresis

Directory of Open Access Journals (Sweden)

Subasree Ramakrishnan

2017-01-01

Full Text Available Introduction: In Guillain Barre syndrome (GBS, worsening of weakness or disability after initial period of recovery or stabilization is described as treatment-related fluctuations (TRF. Aim: This study aims to describe the clinical characteristics and outcome of six patients with GBS and TRF. Patients and Methods: Six patients with GBS fulfilling NINCDS criteria, evaluated at a tertiary care university hospital during 2008–2017, were diagnosed to have TRF. They form the basis of this report. Results: All patients were men and their mean age was 40 years. At presentation, mean duration of illness was 15 days; the illness had plateaued in three and progressive in other three patients. Two of the four patients had variant GBS. Initially, five patients were treated with large volume plasmapheresis (LVPP and one patient with methyl prednisolone. At 17–28 days after disease onset, three patients developed new neurologic deficits (bilateral facial paresis in two; paralytic ileus in one. Other three patients with worsening of limb weakness (medical research council sum score of >5 and disability (Hughes disability grade by ≥1 fulfilled Kleyweg's criteria for TRF. All the six patients were treated with the completion of five cycles or additional cycles of LVPP. Conclusion: Awareness about TRF is essential for correct diagnosis and management of patients with GBS.

Short-Term Responses of Soil Respiration and C-Cycle Enzyme Activities to Additions of Biochar and Urea in a Calcareous Soil.

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Dali Song

Full Text Available Biochar (BC addition to soil is a proposed strategy to enhance soil fertility and crop productivity. However, there is limited knowledge regarding responses of soil respiration and C-cycle enzyme activities to BC and nitrogen (N additions in a calcareous soil. A 56-day incubation experiment was conducted to investigate the combined effects of BC addition rates (0, 0.5, 1.0, 2.5 and 5.0% by mass and urea (U application on soil nutrients, soil respiration and C-cycle enzyme activities in a calcareous soil in the North China Plain. Our results showed soil pH values in both U-only and U plus BC treatments significantly decreased within the first 14 days and then stabilized, and CO2emission rate in all U plus BC soils decreased exponentially, while there was no significant difference in the contents of soil total organic carbon (TOC, dissolved organic carbon (DOC, total nitrogen (TN, and C/N ratio in each treatment over time. At each incubation time, soil pH, electrical conductivity (EC, TOC, TN, C/N ratio, DOC and cumulative CO2 emission significantly increased with increasing BC addition rate, while soil potential activities of the four hydrolytic enzymes increased first and then decreased with increasing BC addition rate, with the largest values in the U + 1.0%BC treatment. However, phenol oxidase activity in all U plus BC soils showed a decreasing trend with the increase of BC addition rate. Our results suggest that U plus BC application at a rate of 1% promotes increases in hydrolytic enzymes, does not highly increase C/N and C mineralization, and can improve in soil fertility.

Short-Term Responses of Soil Respiration and C-Cycle Enzyme Activities to Additions of Biochar and Urea in a Calcareous Soil

Science.gov (United States)

Song, Dali; Xi, Xiangyin; Huang, Shaomin; Liang, Guoqing; Sun, Jingwen; Zhou, Wei; Wang, Xiubin

2016-01-01

Biochar (BC) addition to soil is a proposed strategy to enhance soil fertility and crop productivity. However, there is limited knowledge regarding responses of soil respiration and C-cycle enzyme activities to BC and nitrogen (N) additions in a calcareous soil. A 56-day incubation experiment was conducted to investigate the combined effects of BC addition rates (0, 0.5, 1.0, 2.5 and 5.0% by mass) and urea (U) application on soil nutrients, soil respiration and C-cycle enzyme activities in a calcareous soil in the North China Plain. Our results showed soil pH values in both U-only and U plus BC treatments significantly decreased within the first 14 days and then stabilized, and CO2emission rate in all U plus BC soils decreased exponentially, while there was no significant difference in the contents of soil total organic carbon (TOC), dissolved organic carbon (DOC), total nitrogen (TN), and C/N ratio in each treatment over time. At each incubation time, soil pH, electrical conductivity (EC), TOC, TN, C/N ratio, DOC and cumulative CO2 emission significantly increased with increasing BC addition rate, while soil potential activities of the four hydrolytic enzymes increased first and then decreased with increasing BC addition rate, with the largest values in the U + 1.0%BC treatment. However, phenol oxidase activity in all U plus BC soils showed a decreasing trend with the increase of BC addition rate. Our results suggest that U plus BC application at a rate of 1% promotes increases in hydrolytic enzymes, does not highly increase C/N and C mineralization, and can improve in soil fertility. PMID:27589265

LOSCAR: Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model v2.0.4

Directory of Open Access Journals (Sweden)

R. E. Zeebe

2012-01-01

Full Text Available The LOSCAR model is designed to efficiently compute the partitioning of carbon between ocean, atmosphere, and sediments on time scales ranging from centuries to millions of years. While a variety of computationally inexpensive carbon cycle models are already available, many are missing a critical sediment component, which is indispensable for long-term integrations. One of LOSCAR's strengths is the coupling of ocean-atmosphere routines to a computationally efficient sediment module. This allows, for instance, adequate computation of CaCO₃ dissolution, calcite compensation, and long-term carbon cycle fluxes, including weathering of carbonate and silicate rocks. The ocean component includes various biogeochemical tracers such as total carbon, alkalinity, phosphate, oxygen, and stable carbon isotopes. LOSCAR's configuration of ocean geometry is flexible and allows for easy switching between modern and paleo-versions. We have previously published applications of the model tackling future projections of ocean chemistry and weathering, pCO₂ sensitivity to carbon cycle perturbations throughout the Cenozoic, and carbon/calcium cycling during the Paleocene-Eocene Thermal Maximum. The focus of the present contribution is the detailed description of the model including numerical architecture, processes and parameterizations, tuning, and examples of input and output. Typical CPU integration times of LOSCAR are of order seconds for several thousand model years on current standard desktop machines. The LOSCAR source code in C can be obtained from the author by sending a request to loscar.model@gmail.com.

Additive action of ionizing and non-ionizing radiations throughout the Chinese hamster cell-cycle

International Nuclear Information System (INIS)

Han, A.; Elkind, M.M.

1977-01-01

X-rays and γ-rays produce lesions in nuclear DNA which are qualitatively different from those produced by UV-light. Studies have been made of the effects of X-rays and UV light on the survival of synchronous cultures of Chinese hamster V79 cells. There were qualitative differences in the age-response patterns for survival after single doses of the two types of radiation, but combined UV-and X-irradiation produced enhanced lethality at all ages throughout the cell cycle. The minimum survival from the combined irradiation was at the middle of the S period, and the survival curves at this stage of the cell cycle were further investigated. Exposure to UV immediately before graded X-ray doses removed the shoulder on the X-ray survival curve in a progressive manner, while the D 0 value increased only slightly. The results correspond to complete additivity of X-ray damage to UV damage. Exposure to X-rays immediately before graded UV doses indicated that only part of the damage produced by the X-rays could be added to the UV-damage. Even after X-ray doses which reduced survival to levels which surpassed the shoulder of the UV-only survival curve, the shoulder persisted on the combined treatment survival curves. Measurements were made of the time-course of the change in molecular weight of single-stranded DNA after X-irradiation preceded by UV-irradiation. Only a small amount of slowing of repair of X-ray induced lesions was detected after a large UV dose. Possible mechanisms for the interactions between the two types of damage are discussed. (U.K.)

Deployment of IPv6-only CPU resources at WLCG sites

Science.gov (United States)

Babik, M.; Chudoba, J.; Dewhurst, A.; Finnern, T.; Froy, T.; Grigoras, C.; Hafeez, K.; Hoeft, B.; Idiculla, T.; Kelsey, D. P.; López Muñoz, F.; Martelli, E.; Nandakumar, R.; Ohrenberg, K.; Prelz, F.; Rand, D.; Sciabà, A.; Tigerstedt, U.; Traynor, D.

2017-10-01

The fraction of Internet traffic carried over IPv6 continues to grow rapidly. IPv6 support from network hardware vendors and carriers is pervasive and becoming mature. A network infrastructure upgrade often offers sites an excellent window of opportunity to configure and enable IPv6. There is a significant overhead when setting up and maintaining dual-stack machines, so where possible sites would like to upgrade their services directly to IPv6 only. In doing so, they are also expediting the transition process towards its desired completion. While the LHC experiments accept there is a need to move to IPv6, it is currently not directly affecting their work. Sites are unwilling to upgrade if they will be unable to run LHC experiment workflows. This has resulted in a very slow uptake of IPv6 from WLCG sites. For several years the HEPiX IPv6 Working Group has been testing a range of WLCG services to ensure they are IPv6 compliant. Several sites are now running many of their services as dual-stack. The working group, driven by the requirements of the LHC VOs to be able to use IPv6-only opportunistic resources, continues to encourage wider deployment of dual-stack services to make the use of such IPv6-only clients viable. This paper presents the working group’s plan and progress so far to allow sites to deploy IPv6-only CPU resources. This includes making experiment central services dual-stack as well as a number of storage services. The monitoring, accounting and information services that are used by jobs also need to be upgraded. Finally the VO testing that has taken place on hosts connected via IPv6-only is reported.

A Novel CPU/GPU Simulation Environment for Large-Scale Biologically-Realistic Neural Modeling

Directory of Open Access Journals (Sweden)

Roger V Hoang

2013-10-01

Full Text Available Computational Neuroscience is an emerging field that provides unique opportunities to studycomplex brain structures through realistic neural simulations. However, as biological details are added tomodels, the execution time for the simulation becomes longer. Graphics Processing Units (GPUs are now being utilized to accelerate simulations due to their ability to perform computations in parallel. As such, they haveshown significant improvement in execution time compared to Central Processing Units (CPUs. Most neural simulators utilize either multiple CPUs or a single GPU for better performance, but still show limitations in execution time when biological details are not sacrificed. Therefore, we present a novel CPU/GPU simulation environment for large-scale biological networks,the NeoCortical Simulator version 6 (NCS6. NCS6 is a free, open-source, parallelizable, and scalable simula-tor, designed to run on clusters of multiple machines, potentially with high performance computing devicesin each of them. It has built-in leaky-integrate-and-fire (LIF and Izhikevich (IZH neuron models, but usersalso have the capability to design their own plug-in interface for different neuron types as desired. NCS6is currently able to simulate one million cells and 100 million synapses in quasi real time by distributing dataacross these heterogeneous clusters of CPUs and GPUs.

3D additive manufactured 316L components microstructural features and changes induced by working life cycles

Science.gov (United States)

Pace, M. L.; Guarnaccio, A.; Dolce, P.; Mollica, D.; Parisi, G. P.; Lettino, A.; Medici, L.; Summa, V.; Ciancio, R.; Santagata, A.

2017-10-01

The ability of processing through laser beams different kinds of metallic powders for direct production of 3D components with complex geometries has been gaining an impressive and growing attention for specific industrial applications. The process which can be distinguished as Selective Laser Sintering or Selective Laser Melting is even considered, more generally, as Additive Manufacturing where layer by layer material is built by the interaction between a laser beam and a powder bed. The rapid heating of the powder due to the laser beam energy transfer process followed by a rapid cooling rate induces within the manufactured material a cellular structure with fine sub-grains, which are in the range of few hundreds of micrometers. These metastable structures, which are smaller than the grain size in conventionally manufactured 316L stainless steel components, can undertake towards a recrystallization process due to either heat or mechanical treatments. For instance, when sub-grain boundaries of the cells are enriched with Mo and higher concentration of dislocation, dynamical processes occur generating local residual stresses. In these circumstances the segregation of Mo in cell boundaries is out of thermodynamic equilibrium conditions so that microstructures and phases are metastable. In the range of 1100-1400 °C heat treatments a complete dissolution of Mo in the Fe matrix with a gradual disappearance of sub-microns cell is observed feeding the growth of larger austenitic sub-grains formation. It follows a higher degree of Mo dissolution in the material matrix and a decrease of dislocation's concentration (Saeidi et al., 2015) [1]. In the work here presented we point out which are the microstructural features of stainless steel 316L components realized by Additive Manufacturing. Furthermore, the occurrence of a microstructural evolution is presented after experiencing to fatigue of 80000 cycles some door joints obtained by this technique. A decrease of dislocation

Endoplasmic reticulum stress mediating downregulated StAR and 3-beta-HSD and low plasma testosterone caused by hypoxia is attenuated by CPU86017-RS and nifedipine

Directory of Open Access Journals (Sweden)

Liu Gui-Lai

2012-01-01

Full Text Available Abstract Background Hypoxia exposure initiates low serum testosterone levels that could be attributed to downregulated androgen biosynthesizing genes such as StAR (steroidogenic acute regulatory protein and 3-beta-HSD (3-beta-hydroxysteroid dehydrogenase in the testis. It was hypothesized that these abnormalities in the testis by hypoxia are associated with oxidative stress and an increase in chaperones of endoplasmic reticulum stress (ER stress and ER stress could be modulated by a reduction in calcium influx. Therefore, we verify that if an application of CPU86017-RS (simplified as RS, a derivative to berberine could alleviate the ER stress and depressed gene expressions of StAR and 3-beta-HSD, and low plasma testosterone in hypoxic rats, these were compared with those of nifedipine. Methods Adult male Sprague-Dawley rats were randomly divided into control, hypoxia for 28 days, and hypoxia treated (mg/kg, p.o. during the last 14 days with nifedipine (Nif, 10 and three doses of RS (20, 40, 80, and normal rats treated with RS isomer (80. Serum testosterone (T and luteinizing hormone (LH were measured. The testicular expressions of biomarkers including StAR, 3-beta-HSD, immunoglobulin heavy chain binding protein (Bip, double-strand RNA-activated protein kinase-like ER kinase (PERK and pro-apoptotic transcription factor C/EBP homologous protein (CHOP were measured. Results In hypoxic rats, serum testosterone levels decreased and mRNA and protein expressions of the testosterone biosynthesis related genes, StAR and 3-beta-HSD were downregulated. These changes were linked to an increase in oxidants and upregulated ER stress chaperones: Bip, PERK, CHOP and distorted histological structure of the seminiferous tubules in the testis. These abnormalities were attenuated significantly by CPU86017-RS and nifedipine. Conclusion Downregulated StAR and 3-beta-HSD significantly contribute to low testosterone in hypoxic rats and is associated with ER stress

A heterogeneous CPU+GPU Poisson solver for space charge calculations in beam dynamics studies

Energy Technology Data Exchange (ETDEWEB)

Zheng, Dawei; Rienen, Ursula van [University of Rostock, Institute of General Electrical Engineering (Germany)

2016-07-01

In beam dynamics studies in accelerator physics, space charge plays a central role in the low energy regime of an accelerator. Numerical space charge calculations are required, both, in the design phase and in the operation of the machines as well. Due to its efficiency, mostly the Particle-In-Cell (PIC) method is chosen for the space charge calculation. Then, the solution of Poisson's equation for the charge distribution in the rest frame is the most prominent part within the solution process. The Poisson solver directly affects the accuracy of the self-field applied on the charged particles when the equation of motion is solved in the laboratory frame. As the Poisson solver consumes the major part of the computing time in most simulations it has to be as fast as possible since it has to be carried out once per time step. In this work, we demonstrate a novel heterogeneous CPU+GPU routine for the Poisson solver. The novel solver also benefits from our new research results on the utilization of a discrete cosine transform within the classical Hockney and Eastwood's convolution routine.

Accelerating the SCE-UA Global Optimization Method Based on Multi-Core CPU and Many-Core GPU

Directory of Open Access Journals (Sweden)

Guangyuan Kan

2016-01-01

Full Text Available The famous global optimization SCE-UA method, which has been widely used in the field of environmental model parameter calibration, is an effective and robust method. However, the SCE-UA method has a high computational load which prohibits the application of SCE-UA to high dimensional and complex problems. In recent years, the hardware of computer, such as multi-core CPUs and many-core GPUs, improves significantly. These much more powerful new hardware and their software ecosystems provide an opportunity to accelerate the SCE-UA method. In this paper, we proposed two parallel SCE-UA methods and implemented them on Intel multi-core CPU and NVIDIA many-core GPU by OpenMP and CUDA Fortran, respectively. The Griewank benchmark function was adopted in this paper to test and compare the performances of the serial and parallel SCE-UA methods. According to the results of the comparison, some useful advises were given to direct how to properly use the parallel SCE-UA methods.

Leveraging the checkpoint-restart technique for optimizing CPU efficiency of ATLAS production applications on opportunistic platforms

CERN Document Server

Cameron, David; The ATLAS collaboration

2017-01-01

Data processing applications of the ATLAS experiment, such as event simulation and reconstruction, spend considerable amount of time in the initialization phase. This phase includes loading a large number of shared libraries, reading detector geometry and condition data from external databases, building a transient representation of the detector geometry and initializing various algorithms and services. In some cases the initialization step can take as long as 10-15 minutes. Such slow initialization, being inherently serial, has a significant negative impact on overall CPU efficiency of the production job, especially when the job is executed on opportunistic, often short-lived, resources such as commercial clouds or volunteer computing. In order to improve this situation, we can take advantage of the fact that ATLAS runs large numbers of production jobs with similar configuration parameters (e.g. jobs within the same production task). This allows us to checkpoint one job at the end of its configuration step a...

GPScheDVS: A New Paradigm of the Autonomous CPU Speed Control for Commodity-OS-based General-Purpose Mobile Computers with a DVS-friendly Task Scheduling

OpenAIRE

Kim, Sookyoung

2008-01-01

This dissertation studies the problem of increasing battery life-time and reducing CPU heat dissipation without degrading system performance in commodity-OS-based general-purpose (GP) mobile computers using the dynamic voltage scaling (DVS) function of modern CPUs. The dissertation especially focuses on the impact of task scheduling on the effectiveness of DVS in achieving this goal. The task scheduling mechanism used in most contemporary general-purpose operating systems (GPOS) prioritizes t...

Discrepancy Between Clinician and Research Assistant in TIMI Score Calculation (TRIAGED CPU

Directory of Open Access Journals (Sweden)

Taylor, Brian T.

2014-11-01

Full Text Available Introduction: Several studies have attempted to demonstrate that the Thrombolysis in Myocardial Infarction (TIMI risk score has the ability to risk stratify emergency department (ED patients with potential acute coronary syndromes (ACS. Most of the studies we reviewed relied on trained research investigators to determine TIMI risk scores rather than ED providers functioning in their normal work capacity. We assessed whether TIMI risk scores obtained by ED providers in the setting of a busy ED differed from those obtained by trained research investigators. Methods: This was an ED-based prospective observational cohort study comparing TIMI scores obtained by 49 ED providers admitting patients to an ED chest pain unit (CPU to scores generated by a team of trained research investigators. We examined provider type, patient gender, and TIMI elements for their effects on TIMI risk score discrepancy. Results: Of the 501 adult patients enrolled in the study, 29.3% of TIMI risk scores determined by ED providers and trained research investigators were generated using identical TIMI risk score variables. In our low-risk population the majority of TIMI risk score differences were small; however, 12% of TIMI risk scores differed by two or more points. Conclusion: TIMI risk scores determined by ED providers in the setting of a busy ED frequently differ from scores generated by trained research investigators who complete them while not under the same pressure of an ED provider. [West J Emerg Med. 2015;16(1:24–33.

The Rate of Return to Schooling and the Business Cycle: Additional Estimates.

Science.gov (United States)

Kniesner, Thomas J.; And Others

1980-01-01

Illustrates that the business cycle does indeed disturb relative Black/White rates of return to schooling. Blacks fare relatively poorly in times of high unemployment. Data tables and formulas are presented to support the argument. (CT)

eWaterCycle: A high resolution global hydrological model

Science.gov (United States)

van de Giesen, Nick; Bierkens, Marc; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

2014-05-01

In 2013, the eWaterCycle project was started, which has the ambitious goal to run a high resolution global hydrological model. Starting point was the PCR-GLOBWB built by Utrecht University. The software behind this model will partially be re-engineered in order to enable to run it in a High Performance Computing (HPC) environment. The aim is to have a spatial resolution of 1km x 1km. The idea is also to run the model in real-time and forecasting mode, using data assimilation. An on-demand hydraulic model will be available for detailed flow and flood forecasting in support of navigation and disaster management. The project faces a set of scientific challenges. First, to enable the model to run in a HPC environment, model runs were analyzed to examine on which parts of the program most CPU time was spent. These parts were re-coded in Open MPI to allow for parallel processing. Different parallelization strategies are thinkable. In our case, it was decided to use watershed logic as a first step to distribute the analysis. There is rather limited recent experience with HPC in hydrology and there is much to be learned and adjusted, both on the hydrological modeling side and the computer science side. For example, an interesting early observation was that hydrological models are, due to their localized parameterization, much more memory intensive than models of sister-disciplines such as meteorology and oceanography. Because it would be deadly to have to swap information between CPU and hard drive, memory management becomes crucial. A standard Ensemble Kalman Filter (enKF) would, for example, have excessive memory demands. To circumvent these problems, an alternative to the enKF was developed that produces equivalent results. This presentation shows the most recent results from the model, including a 5km x 5km simulation and a proof of concept for the new data assimilation approach. Finally, some early ideas about financial sustainability of an operational global

Life Cycle Assessment of Functionally Enhanced Polymers-Engineered Nanomaterials or Conventional Additives?

DEFF Research Database (Denmark)

Miseljic, Mirko; Olsen, Stig Irving

2016-01-01

used to enhance material properties. The aim of this study is to perform life cycle assessments (LCAs) on 5 polymer products (polypropylene air-conditioner part for cars, polypropylene garden chair, polypropylene small electrical box for houses, polyvinylchloride-wood outdoor flooring and polystyrene...

Study of cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends

Energy Technology Data Exchange (ETDEWEB)

Wang, Jinhua; Chen, Hao; Liu, Bing; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2008-09-15

Cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends with hydrogen volumetric fraction of 0%, 12%, 23%, 30% and 40% were studied. The effect of hydrogen addition on cycle-by-cycle variations of the natural gas engine was analyzed. The results showed that the peak cylinder pressure, the maximum rate of pressure rise and the indicated mean effective pressure increased and their corresponding cycle-by-cycle variations decreased with the increase of hydrogen fraction at lean mixture operation. The interdependency between the combustion parameters and the corresponding crank angle tended to be strongly correlated with the increase of hydrogen fraction under lean mixture operation. Coefficient of variation of the indicated mean effective pressure gave a low level and is slightly influenced by hydrogen addition under the stoichiometric and relatively rich mixture operation while it decreased remarkably with the increase of hydrogen fraction under the lean mixture operation. The excessive air ratio at CoV{sub imep} = 10% extended to the leaner mixture side with the increase of hydrogen fraction and this indicated that the engine lean operating limit could be extended with hydrogen addition. (author)

Interactive dose shaping - efficient strategies for CPU-based real-time treatment planning

International Nuclear Information System (INIS)

Ziegenhein, P; Kamerling, C P; Oelfke, U

2014-01-01

Conventional intensity modulated radiation therapy (IMRT) treatment planning is based on the traditional concept of iterative optimization using an objective function specified by dose volume histogram constraints for pre-segmented VOIs. This indirect approach suffers from unavoidable shortcomings: i) The control of local dose features is limited to segmented VOIs. ii) Any objective function is a mathematical measure of the plan quality, i.e., is not able to define the clinically optimal treatment plan. iii) Adapting an existing plan to changed patient anatomy as detected by IGRT procedures is difficult. To overcome these shortcomings, we introduce the method of Interactive Dose Shaping (IDS) as a new paradigm for IMRT treatment planning. IDS allows for a direct and interactive manipulation of local dose features in real-time. The key element driving the IDS process is a two-step Dose Modification and Recovery (DMR) strategy: A local dose modification is initiated by the user which translates into modified fluence patterns. This also affects existing desired dose features elsewhere which is compensated by a heuristic recovery process. The IDS paradigm was implemented together with a CPU-based ultra-fast dose calculation and a 3D GUI for dose manipulation and visualization. A local dose feature can be implemented via the DMR strategy within 1-2 seconds. By imposing a series of local dose features, equal plan qualities could be achieved compared to conventional planning for prostate and head and neck cases within 1-2 minutes. The idea of Interactive Dose Shaping for treatment planning has been introduced and first applications of this concept have been realized.

Cycling in Sydney, Australia

Directory of Open Access Journals (Sweden)

Alexis Zander

2013-01-01

Full Text Available Introduction. Cycling can be an enjoyable way to meet physical activity recommendations and is suitable for older people; however cycling participation by older Australians is low. This qualitative study explored motivators, enablers, and barriers to cycling among older people through an age-targeted cycling promotion program. Methods. Seventeen adults who aged 50–75 years participated in a 12-week cycling promotion program which included a cycling skills course, mentor, and resource pack. Semistructured interviews at the beginning and end of the program explored motivators, enablers, and barriers to cycling. Results. Fitness and recreation were the primary motivators for cycling. The biggest barrier was fear of cars and traffic, and the cycling skills course was the most important enabler for improving participants’ confidence. Reported outcomes from cycling included improved quality of life (better mental health, social benefit, and empowerment and improved physical health. Conclusions. A simple cycling program increased cycling participation among older people. This work confirms the importance of improving confidence in this age group through a skills course, mentors, and maps and highlights additional strategies for promoting cycling, such as ongoing improvement to infrastructure and advertising.

Synergistic fuel cycles of the future

International Nuclear Information System (INIS)

Meneley, D.A.; Dastur, A.R.

1997-01-01

Good neutron economy is the basis of the fuel cycle flexibility in the CANDU reactor. This paper describes the fuel cycle options available to the CANDU owner with special emphasis on resource conservation and waste management. CANDU fuel cycles with low initial fissile content operate with relatively high conversion ratio. The natural uranium cycle provides over 55 % of energy from the plutonium that is created during fuel life. Resource utilization is over 7 MWd/kg NU. This can be improved by slight enrichment (between 0.9 and 1.2 wt % U235) of the fuel. Resource utilization increases to 11 MWd/kg NU with the Slightly Enriched Uranium cycle. Thorium based cycles in CANDU operate at near-breeder efficiency. Obey provide attractive options when used with natural uranium or separated (reactor grade and weapons grade) plutonium as driver fuels. In the latter case, the energy from the U233 plus the initial plutonium content amounts to 3.4 GW(th).d/kg Pu-fissile. The same utilization is expected from the use of FBR plutonium in a CANDU thorium cycle. Extension of natural resource is achieved by the use of spent fuels in CANDU. The LWR/CANDU Tandem cycle leads to an additional 77 % of energy through the use of reprocessed LWR fuel (which has a fissile content of 1.6 wt %) in CANDU. Dry reprocessing of LWR fuel with the OREOX process (a more safeguardable alternative to the PUREX process) provides an additional 50 % energy. Uranium recovered (RU) from separation of plutonium contained in spent LWR fuel provides an additional 15 MWd/kg RU. CANDU's low fissile requirement provides the possibility, through the use of non-fertile targets, of extracting energy from the minor actinides contained in spent fuel. In addition to the resource utilization advantage described above, there is a corresponding reduction in waste arisings with such cycles. This is especially significant when separated plutonium is available as a fissile resource. (author)

Will Solar Cycles 25 and 26 Be Weaker than Cycle 24?

Science.gov (United States)

Javaraiah, J.

2017-11-01

The study of variations in solar activity is important for understanding the underlying mechanism of solar activity and for predicting the level of activity in view of the activity impact on space weather and global climate. Here we have used the amplitudes (the peak values of the 13-month smoothed international sunspot number) of Solar Cycles 1 - 24 to predict the relative amplitudes of the solar cycles during the rising phase of the upcoming Gleissberg cycle. We fitted a cosine function to the amplitudes and times of the solar cycles after subtracting a linear fit of the amplitudes. The best cosine fit shows overall properties (periods, maxima, minima, etc.) of Gleissberg cycles, but with large uncertainties. We obtain a pattern of the rising phase of the upcoming Gleissberg cycle, but there is considerable ambiguity. Using the epochs of violations of the Gnevyshev-Ohl rule (G-O rule) and the `tentative inverse G-O rule' of solar cycles during the period 1610 - 2015, and also using the epochs where the orbital angular momentum of the Sun is steeply decreased during the period 1600 - 2099, we infer that Solar Cycle 25 will be weaker than Cycle 24. Cycles 25 and 26 will have almost same strength, and their epochs are at the minimum between the current and upcoming Gleissberg cycles. In addition, Cycle 27 is expected to be stronger than Cycle 26 and weaker than Cycle 28, and Cycle 29 is expected to be stronger than both Cycles 28 and 30. The maximum of Cycle 29 is expected to represent the next Gleissberg maximum. Our analysis also suggests a much lower value (30 - 40) for the maximum amplitude of the upcoming Cycle 25.

Multiprocessing MCNP on an IBN RS/6000 cluster

International Nuclear Information System (INIS)

McKinney, G.W.; West, J.T.

1993-01-01

The advent of high-performance computer systems has brought to maturity programming concepts like vectorization, multiprocessing, and multitasking. While there are many schools of thought as to the most significant factor in obtaining order-of-magnitude increases in performance, such speedup can only be achieved by integrating the computer system and application code. Vectorization leads to faster manipulation of arrays by overlapping instruction CPU cycles. Discrete ordinates codes, which require the solving of large matrices, have proved to be major benefactors of vectorization. Monte Carlo transport, on the other hand, typically contains numerous logic statements and requires extensive redevelopment to benefit from vectorization. Multiprocessing and multitasking provide additional CPU cycles via multiple processors. Such systems are generally designed with either common memory access (multitasking) or distributed memory access. In both cases, theoretical speedup, as a function of the number of processors P and the fraction f of task time that multiprocesses, can be formulated using Amdahl's law: S(f, P) =1/(1-f+f/P). However, for most applications, this theoretical limit cannot be achieved because of additional terms (e.g., multitasking overhead, memory overlap, etc.) that are not included in Amdahl's law. Monte Carlo transport is a natural candidate for multiprocessing because the particle tracks are generally independent, and the precision of the result increases as the square Foot of the number of particles tracked

Deposition Time and Thermal Cycles of Fabricating Thin-wall Steel Parts by Double Electrode GMAW Based Additive Manufacturing

Directory of Open Access Journals (Sweden)

Yang Dongqing

2017-01-01

Full Text Available The deposition time for fabricating the thin-wall part as well as the peak temperature of the substrate during the process was analyzed in the double electrode gas metal arc welding (DE-GMAW based additive manufacturing (AM. The total deposition time and the interlayer idle time of the manufacturing process decreased with the increasing of the bypass current under the same interlayer temperature and the same deposition rate. The thermal cycling curves illustrated that the peak temperature of the substrate was lower in the DE-GMAW base AM under the same conditions. When depositing the thin-wall parts, the DE-GMAW based AM can reduce the heat input to the substrate and improve the fabrication efficiency, compared with the GMAW based AM.

Effects of phosphorus addition on nitrogen cycle and fluxes of N2O and CH4 in tropical tree plantation soils in Thailand

Directory of Open Access Journals (Sweden)

Taiki Mori

2017-04-01

Full Text Available An incubation experiment was conducted to test the effects of phosphorus (P addition on nitrous oxide (N2O emissions and methane (CH4 uptakes, using tropical tree plantation soils in Thailand. Soil samples were taken from five forest stands—Acacia auriculiformis, Acacia mangium, Eucalyptus camaldulensis, Hopea odorata, and Xylia xylocarpa—and incubated at 80% water holding capacity. P addition stimulated N2O emissions only in Xylia xylocarpa soils. Since P addition tended to increase net ammonification rates in Xylia xylocarpa soils, the stimulated N2O emissions were suggested to be due to the stimulated nitrogen (N cycle by P addition and the higher N supply for nitrification and denitrification. In other soils, P addition had no effects on N2O emissions or soil N properties, except that P addition tended to increase the soil microbial biomass N in Acacia auriculiformis soils. No effects of P addition were observed on CH4 uptakes in any soil. It is suggested that P addition on N2O and CH4 fluxes at the study site were not significant, at least under laboratory conditions.

Combined advanced parental age has an additive negative effect on live birth rates-data from 4057 first IVF/ICSI cycles.

Science.gov (United States)

McPherson, Nicole O; Zander-Fox, Deirdre; Vincent, Andrew D; Lane, Michelle

2018-02-01

The purpose of this study is to determine if there is an additive effect of combined advanced maternal and paternal age on pregnancy and live birth rates. Retrospective data analysis of 4057 first cycles at a fertility centre between 2009 and 2013 was compiled. Donor, preimplantation genetic screening and double embryo transfer cycles were excluded. Main outcomes measured were clinical pregnancy, viable pregnancy, live birth and term birth. Logistic regression indicated strong negative associations for maternal ages exceeding 27 years with clinical pregnancies (p < 0.001), viable pregnancies (p < 0.001), live births (p < 0.001) and term births (p < 0.001). There was evidence of negative associations between paternal age and both viable pregnancies (p = 0.06) and live births (p = 0.04), such that the probability of pregnancy was 10% further reduced for women who were 35 years with a partner over 40 years vs. women aged 35 years with a partner under 30 years. There was evidence of an interaction between maternal age and the paternal age on term births (p = 0.02) such that advanced paternal age's effect on the probability of a term birth was only evident in couples where the maternal age ranged between ~27 and 35 years. There is an additive effect to pregnancy and live birth rates when both partners are of an advanced age, thus highlighting the need for pre-conception public health messaging and a combined approach to ART counselling assessing both parental ages in combination.

Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling.

Directory of Open Access Journals (Sweden)

Bing Mao

Full Text Available Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N mineralization and soil respiration, four single litter species and their mixtures consisting of all possible 2-, 3- and 4-species combinations were added to soils, respectively. In most instances, species mixing produced synergistic non-additive effects on soil microbial biomass N and soil respiration, but antagonistic non-additive effects on net N mineralization. Species composition rather than species richness explained the non-additive effects of species mixing on soil microbial biomass N and net N mineralization, due to the interspecific differences in litter chemical composition. Both litter species composition and richness explained non-additive soil respiration responses to mixed-species litter, while litter chemical diversity and chemical composition did not. Our study indicated that litter mixtures promoted soil microbial biomass N and soil respiration, and inhibited net N mineralization. Soil N related processes rather than soil respiration were partly explained by litter chemical composition and chemical diversity, highlighting the importance of functional diversity of litter on soil N cycling.

Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling.

Science.gov (United States)

Mao, Bing; Mao, Rong; Zeng, De-Hui

2017-01-01

Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N mineralization and soil respiration, four single litter species and their mixtures consisting of all possible 2-, 3- and 4-species combinations were added to soils, respectively. In most instances, species mixing produced synergistic non-additive effects on soil microbial biomass N and soil respiration, but antagonistic non-additive effects on net N mineralization. Species composition rather than species richness explained the non-additive effects of species mixing on soil microbial biomass N and net N mineralization, due to the interspecific differences in litter chemical composition. Both litter species composition and richness explained non-additive soil respiration responses to mixed-species litter, while litter chemical diversity and chemical composition did not. Our study indicated that litter mixtures promoted soil microbial biomass N and soil respiration, and inhibited net N mineralization. Soil N related processes rather than soil respiration were partly explained by litter chemical composition and chemical diversity, highlighting the importance of functional diversity of litter on soil N cycling.

Recycling cycle of materials applied to acrylonitrile-butadiene-styrene/policarbonate blends with styrene-butadiene-styrene copolymer addition

Science.gov (United States)

Cândido, L. H. A.; Ferreira, D. B.; Júnior, W. Kindlein; Demori, R.; Mauler, R. S.

2014-05-01

The scope of this research is the recycling of polymers from mobile phones hulls discarded and the performance evaluation when they are submitted to the Recycling Cycle of Materials (RCM). The studied material was the ABS/PC blend in a 70/30 proportion. Different compositions were evaluated adding virgin material, recycled material and using the copolymer SBS as impact modifier. In order to evaluate the properties of material's composition, the samples were characterized by TGA, FTIR, SEM, IZOD impact strength and tensile strength tests. At the first stage, the presented results suggest the composition containing 25% of recycled material and 5% of SBS combines good mechanical performance to the higher content of recycled material and lower content of impact modifier providing major benefits to recycling plans. Five cycles (RCM) were applied in the second stage; they evidenced a decrease trend considering the impact strength. At first and second cycle the impact strength was higher than reference material (ABS/PC blend) and from the fourth cycle it was lower. The superiority impact strength in the first and second cycles can be attributed to impact modifier effect. The thermal tests and the spectrometry didn't show the presence of degradation process in the material and the TGA curves demonstrated the process stability. The impact surface of each sample was observed at SEM. The microstructures are not homogeneous presenting voids and lamellar appearance, although the outer surface presents no defects, demonstrating good moldability. The present work aims to assess the life cycle of the material from the successive recycling processes.

Harnessing the Potential of Additive Manufacturing

Science.gov (United States)

2016-12-01

31 Defense AT&L: November-December 2016 Harnessing the Potential of Additive Manufacturing Bill Decker Decker is director of Technology...achieve its goal of competition throughout the acquisition life cycle. When we look at additive manufacturing , we have a much different environment. To...Titanium-6 Aluminum-4 Vanadium with Powder Bed Fusion. This specification covers additively manufactured titanium-6 aluminum-4 vanadium (Ti-6Al-4V

Hybrid GPU-CPU adaptive precision ray-triangle intersection tests for robust high-performance GPU dosimetry computations

International Nuclear Information System (INIS)

Perrotte, Lancelot; Bodin, Bruno; Chodorge, Laurent

2011-01-01

Before an intervention on a nuclear site, it is essential to study different scenarios to identify the less dangerous one for the operator. Therefore, it is mandatory to dispose of an efficient dosimetry simulation code with accurate results. One classical method in radiation protection is the straight-line attenuation method with build-up factors. In the case of 3D industrial scenes composed of meshes, the computation cost resides in the fast computation of all of the intersections between the rays and the triangles of the scene. Efficient GPU algorithms have already been proposed, that enable dosimetry calculation for a huge scene (800000 rays, 800000 triangles) in a fraction of second. But these algorithms are not robust: because of the rounding caused by floating-point arithmetic, the numerical results of the ray-triangle intersection tests can differ from the expected mathematical results. In worst case scenario, this can lead to a computed dose rate dramatically inferior to the real dose rate to which the operator is exposed. In this paper, we present a hybrid GPU-CPU algorithm to manage adaptive precision floating-point arithmetic. This algorithm allows robust ray-triangle intersection tests, with very small loss of performance (less than 5 % overhead), and without any need for scene-dependent tuning. (author)

Additional slack in the economy: the poor recovery in labor force participation during this business cycle

OpenAIRE

Katharine L. Bradbury

2005-01-01

This public policy brief examines labor force participation rates in this recession and recovery and compares them with the cyclical patterns in earlier business cycles. Measured relative to the business cycle peak in March 2001, labor force participation rates almost four years later have not recovered as much as usual, and the discrepancies are large. ; Among age-by-sex groups, the participation shortfall is especially pronounced at young and prime ages: Only for men and women age 55 and ol...

SpaceCubeX: A Framework for Evaluating Hybrid Multi-Core CPU FPGA DSP Architectures

Science.gov (United States)

Schmidt, Andrew G.; Weisz, Gabriel; French, Matthew; Flatley, Thomas; Villalpando, Carlos Y.

2017-01-01

The SpaceCubeX project is motivated by the need for high performance, modular, and scalable on-board processing to help scientists answer critical 21st century questions about global climate change, air quality, ocean health, and ecosystem dynamics, while adding new capabilities such as low-latency data products for extreme event warnings. These goals translate into on-board processing throughput requirements that are on the order of 100-1,000 more than those of previous Earth Science missions for standard processing, compression, storage, and downlink operations. To study possible future architectures to achieve these performance requirements, the SpaceCubeX project provides an evolvable testbed and framework that enables a focused design space exploration of candidate hybrid CPU/FPGA/DSP processing architectures. The framework includes ArchGen, an architecture generator tool populated with candidate architecture components, performance models, and IP cores, that allows an end user to specify the type, number, and connectivity of a hybrid architecture. The framework requires minimal extensions to integrate new processors, such as the anticipated High Performance Spaceflight Computer (HPSC), reducing time to initiate benchmarking by months. To evaluate the framework, we leverage a wide suite of high performance embedded computing benchmarks and Earth science scenarios to ensure robust architecture characterization. We report on our projects Year 1 efforts and demonstrate the capabilities across four simulation testbed models, a baseline SpaceCube 2.0 system, a dual ARM A9 processor system, a hybrid quad ARM A53 and FPGA system, and a hybrid quad ARM A53 and DSP system.

International nuclear fuel cycle fact book. Revision 6

International Nuclear Information System (INIS)

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.; Jeffs, A.G.

1986-01-01

The International Fuel Cycle Fact Book has been compiled in an effort to provide (1) an overview of worldwide nuclear power and fuel cycle programs and (2) current data concerning fuel cycle and waste management facilities, R and D programs and key personnel. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2

Nuclear fuel cycle system analysis

International Nuclear Information System (INIS)

Ko, W. I.; Kwon, E. H.; Kim, S. G.; Park, B. H.; Song, K. C.; Song, D. Y.; Lee, H. H.; Chang, H. L.; Jeong, C. J.

2012-04-01

The nuclear fuel cycle system analysis method has been designed and established for an integrated nuclear fuel cycle system assessment by analyzing various methodologies. The economics, PR(Proliferation Resistance) and environmental impact evaluation of the fuel cycle system were performed using improved DB, and finally the best fuel cycle option which is applicable in Korea was derived. In addition, this research is helped to increase the national credibility and transparency for PR with developing and fulfilling PR enhancement program. The detailed contents of the work are as follows: 1)Establish and improve the DB for nuclear fuel cycle system analysis 2)Development of the analysis model for nuclear fuel cycle 3)Preliminary study for nuclear fuel cycle analysis 4)Development of overall evaluation model of nuclear fuel cycle system 5)Overall evaluation of nuclear fuel cycle system 6)Evaluate the PR for nuclear fuel cycle system and derive the enhancement method 7)Derive and fulfill of nuclear transparency enhancement method The optimum fuel cycle option which is economical and applicable to domestic situation was derived in this research. It would be a basis for establishment of the long-term strategy for nuclear fuel cycle. This work contributes for guaranteeing the technical, economical validity of the optimal fuel cycle option. Deriving and fulfillment of the method for enhancing nuclear transparency will also contribute to renewing the ROK-U.S Atomic Energy Agreement in 2014

Study on the supercritical CO2 power cycles for landfill gas firing gas turbine bottoming cycle

International Nuclear Information System (INIS)

Kim, Min Seok; Ahn, Yoonhan; Kim, Beomjoo; Lee, Jeong Ik

2016-01-01

In this paper, a comparison of nine supercritical carbon dioxide (S-CO 2 ) bottoming power cycles in conjunction with a topping cycle of landfill gas (LFG) fired 5MWe gas turbine is presented. For the comparison purpose, a sensitivity study of the cycle design parameters for nine different cycles was conducted and each cycle thermodynamic performance is evaluated. In addition, the cycle performance evaluation dependency on the compressor inlet temperature variation is performed to investigate how S-CO 2 cycles sensitive to the heat sink temperature variation. Furthermore, the development of new S-CO 2 cycle layouts is reported and the suggested cycles' performances are compared to the existing cycle layouts. It was found that a recompression cycle is not suitable for the bottoming cycle application, but a partial heating cycle has relatively higher net produced work with a simple layout and small number of components. Although a dual heated and flow split cycle has the highest net produced work, it has disadvantages of having numerous components and complex process which requires more sophisticated operational strategies. This study identified that the recuperation process is much more important than the intercooling process to the S-CO 2 cycle design for increasing the thermal efficiency and the net produced work point of view. - Highlights: • Study of nine S-CO 2 power cycle layouts for a small scale landfill gas power generation application. • Development of new S-CO 2 cycle layouts. • Sensitivity analysis of S-CO 2 cycles to evaluate and compare nine cycles' performances.

International nuclear fuel cycle fact book. Revision 6

Energy Technology Data Exchange (ETDEWEB)

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.; Jeffs, A.G.

1986-01-01

The International Fuel Cycle Fact Book has been compiled in an effort to provide (1) an overview of worldwide nuclear power and fuel cycle programs and (2) current data concerning fuel cycle and waste management facilities, R and D programs and key personnel. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2.

Power generation from a 7700C heat source by means of a main steam cycle, a topping closed gas cycle and a ammonia bottoming cycle

International Nuclear Information System (INIS)

Tilliette, Z.P.

1981-03-01

For power generation, steam cycles make an efficient use of medium temperature heat sources. They can be adapted to dry cooling, higher power ratings and output increase in winter by addition of an ammonia bottoming cycle. Active development is carried out in this field by 'Electricite de France'. As far as heat sources at higher temperatures are concerned, particularly related to coal-fired or nuclear power plants, a more efficient way of converting energy is at first to expand a hot working fluid through a gas turbine. It is shown in this paper that a satisfactory result, for heat sources of about 770 0 C, is obtained with a topping closed gas cycle of moderate power rating, rejecting its waste heat into the main steam cycle. Attention has to be paid to this gas cycle waste heat recovery and to the coupling of the gas and steam cycles. This concept drastically reduces the importance of new technology components. The use and the significance of an ammonia bottoming cycle in this case are investigated

Extended fuel cycle length

International Nuclear Information System (INIS)

Bruyere, M.; Vallee, A.; Collette, C.

1986-09-01

Extended fuel cycle length and burnup are currently offered by Framatome and Fragema in order to satisfy the needs of the utilities in terms of fuel cycle cost and of overall systems cost optimization. We intend to point out the consequences of an increased fuel cycle length and burnup on reactor safety, in order to determine whether the bounding safety analyses presented in the Safety Analysis Report are applicable and to evaluate the effect on plant licensing. This paper presents the results of this examination. The first part indicates the consequences of increased fuel cycle length and burnup on the nuclear data used in the bounding accident analyses. In the second part of this paper, the required safety reanalyses are presented and the impact on the safety margins of different fuel management strategies is examined. In addition, systems modifications which can be required are indicated

Exergoeconomic comparison of TLC (trilateral Rankine cycle), ORC (organic Rankine cycle) and Kalina cycle using a low grade heat source

International Nuclear Information System (INIS)

Yari, M.; Mehr, A.S.; Zare, V.; Mahmoudi, S.M.S.; Rosen, M.A.

2015-01-01

Recently, the TLC (trilateral power cycle) has attracted significant interest as it provides better matching between the temperature profiles in the evaporator compared to conventional power cycles. This article investigates the performance of this cycle and compares it with those for the ORC (organic Rankine cycle) and the Kalina cycle, from the viewpoints of thermodynamics and thermoeconomics. A low-grade heat source with a temperature of 120 °C is considered for all the three systems. Parametric studies are performed for the systems for several working fluids in the ORC and TLC. The systems are then optimized for either maximum net output power or minimum product cost, using the EES (engineering equation solver) software. The results for the TLC indicate that an increase in the expander inlet temperature leads to an increase in net output power and a decrease in product cost for this power plant, whereas this is not the case for the ORC system. It is found that, although the TLC can achieve a higher net output power compared with the ORC and Kalina (KCS11 (Kalina cycle system 11)) systems, its product cost is greatly affected by the expander isentropic efficiency. It is also revealed that using n-butane as the working fluid can result in the lowest product cost in the ORC and the TLC. In addition, it is observed that, for both the ORC and Kalina systems, the optimum operating condition for maximum net output power differs from that for minimum product cost. - Highlights: • Exergoeconomic analysis of trilateral Rankine cycle is performed. • The system performance is compared with Organic Rankine and Kalina cycles. • Net power from trilateral Rankine cycle is higher than the other power systems. • Superiority of trilateral cycle depends on its expander isentropic efficiency

Fast Parallel Image Registration on CPU and GPU for Diagnostic Classification of Alzheimer's Disease

Directory of Open Access Journals (Sweden)

Denis P Shamonin

2014-01-01

Full Text Available Nonrigid image registration is an important, but time-consuming taskin medical image analysis. In typical neuroimaging studies, multipleimage registrations are performed, i.e. for atlas-based segmentationor template construction. Faster image registration routines wouldtherefore be beneficial.In this paper we explore acceleration of the image registrationpackage elastix by a combination of several techniques: iparallelization on the CPU, to speed up the cost function derivativecalculation; ii parallelization on the GPU building on andextending the OpenCL framework from ITKv4, to speed up the Gaussianpyramid computation and the image resampling step; iii exploitationof certain properties of the B-spline transformation model; ivfurther software optimizations.The accelerated registration tool is employed in a study ondiagnostic classification of Alzheimer's disease and cognitivelynormal controls based on T1-weighted MRI. We selected 299participants from the publicly available Alzheimer's DiseaseNeuroimaging Initiative database. Classification is performed with asupport vector machine based on gray matter volumes as a marker foratrophy. We evaluated two types of strategies (voxel-wise andregion-wise that heavily rely on nonrigid image registration.Parallelization and optimization resulted in an acceleration factorof 4-5x on an 8-core machine. Using OpenCL a speedup factor of ~2was realized for computation of the Gaussian pyramids, and 15-60 forthe resampling step, for larger images. The voxel-wise and theregion-wise classification methods had an area under thereceiver operator characteristic curve of 88% and 90%,respectively, both for standard and accelerated registration.We conclude that the image registration package elastix wassubstantially accelerated, with nearly identical results to thenon-optimized version. The new functionality will become availablein the next release of elastix as open source under the BSD license.

Can cycling safety be improved by opening all unidirectional cycle paths for cycle traffic in both directions? A theoretical examination of available literature and data.

Science.gov (United States)

Methorst, Rob; Schepers, Paul; Kamminga, Jaap; Zeegers, Theo; Fishman, Elliot

2017-08-01

Many studies have found bicycle-motor vehicle crashes to be more likely on bidirectional cycle paths than on unidirectional cycle paths because drivers do not expect cyclists riding at the right side of the road. In this paper we discuss the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions prevent this lack of expectancy and accordingly improves cycling safety. A new national standard requires careful consideration because a reversal is difficult once cyclists are used to their new freedom of route choice. We therefore explored the hypothesis using available data, research, and theories. The results show that of the length of cycle paths along distributor roads in the Netherlands, 72% is bidirectional. If drivers would become used to cyclists riding at the left side of the road, this result raises the question of why bidirectional cycle paths in the Netherlands still have a poor safety record compared to unidirectional cycle paths. Moreover, our exploration suggested that bidirectional cycle paths have additional safety problems. It increases the complexity of unsignalized intersections because drivers have to scan more directions in a short period of time. Moreover, there are some indications that the likelihood of frontal crashes between cyclists increases. We reject the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions will improve cycle safety. We recommend more attention for mitigating measures given the widespread application of bidirectional cycle paths in the Netherlands. Copyright © 2016 Elsevier Ltd. All rights reserved.

The thorium fuel cycle

International Nuclear Information System (INIS)

Merz, E.R.

1977-01-01

The utilization of the thorium fuel cycle has long since been considered attractive owing to the excellent neutronic characteristics of 233 U, and the widespread and cheap thorium resources. Rapidly increasing uranium prices, public reluctance for widespread Pu recycling and expected delays for the market penetration of fast breeders have led to a reconsideration of the thorium fuel cycle merits. In addition, problems associated with reprocessing and waste handling, particularly with re-fabrication by remote handling of 233 U, are certainly not appreciably more difficult than for Pu recycling. To divert from uranium as a nuclear energy source it seems worth while intensifying future efforts for closing the Th/ 233 U fuel cycle. HTGRs are particularly promising for economic application. However, further research and development activities should not concentrate on this reactor type alone. Light- and heavy-water-moderated reactors, and even future fast breeders, may just as well take advantage of a demonstrated thorium fuel cycle. (author)

Simplified nuclear fuel reprocessing flowsheet: a single-cycle Purex process

International Nuclear Information System (INIS)

Montuir, M.; Dinh, B.; Baron, P.

2004-01-01

A simplified flowsheet with only one purification cycle instead of three is proposed for reprocessing spent nuclear fuel using the Purex process. A single-cycle flowsheet minimizes the process equipment required, the number of control points before transfer between process units, and the solvent and effluent quantities. For the uranium stream, an alpha barrier is used to strip any residual contaminants (Np, Th, Pu) from the uranium-loaded solvent. This additional step eliminates the need for a second uranium cycle. For the plutonium stream, an additional βγ co-decontamination step and a higher plutonium concentration are required before the oxalate conversion step; a plutonium 'half-cycle' is added downstream. The unloaded solvent from this half-cycle is returned to the selective plutonium stripping step, allowing significant plutonium half-cycle losses. It should be possible to reduce the number of stages in the half-cycle extraction step by recycling the raffinate to the upstream separation process. (authors)

First Evaluation of the CPU, GPGPU and MIC Architectures for Real Time Particle Tracking based on Hough Transform at the LHC

CERN Document Server

Halyo, V.; Lujan, P.; Karpusenko, V.; Vladimirov, A.

2014-04-07

Recent innovations focused around {\\em parallel} processing, either through systems containing multiple processors or processors containing multiple cores, hold great promise for enhancing the performance of the trigger at the LHC and extending its physics program. The flexibility of the CMS/ATLAS trigger system allows for easy integration of computational accelerators, such as NVIDIA's Tesla Graphics Processing Unit (GPU) or Intel's \\xphi, in the High Level Trigger. These accelerators have the potential to provide faster or more energy efficient event selection, thus opening up possibilities for new complex triggers that were not previously feasible. At the same time, it is crucial to explore the performance limits achievable on the latest generation multicore CPUs with the use of the best software optimization methods. In this article, a new tracking algorithm based on the Hough transform will be evaluated for the first time on a multi-core Intel Xeon E5-2697v2 CPU, an NVIDIA Tesla K20c GPU, and an Intel \\x...

Thermal cycling behavior of La{sub 2}Zr{sub 2}O{sub 7} coating with the addition of Y{sub 2}O{sub 3} by EB-PVD

Energy Technology Data Exchange (ETDEWEB)

Xu Zhenhua [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); He Limin, E-mail: he_limin@yahoo.co [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Chen Xiaolong; Zhao Yu [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Mu Rende; He Shimei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Cao Xueqiang, E-mail: xcao@ciac.jl.c [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2010-10-15

Thermal barrier coatings (TBCs) of La{sub 2}Zr{sub 2}O{sub 7} (LZ) with the addition of 3 wt.% Y{sub 2}O{sub 3} (LZ3Y) were deposited by electron beam-physical vapor deposition (EB-PVD). The phase structures, surface and cross-sectional morphologies, cyclic oxidation behaviors of these coatings were studied in detail. The thermal cycling test at 1373 K in an air furnace indicates that the LZ3Y coating has a lifetime of 617 cycles which is about 10% longer than that of LZ coating. The improvement of chemical homogeneity of the coating, the superior growth behavior of columns and the favorable mechanical properties are all very helpful to the prolongation of thermal cycling life of LZ3Y coating. The failure of LZ and LZ3Y coatings is mainly a result of the excess La{sub 2}O{sub 3}, the chemical incompatibility of ceramic coatings with TGO layer, the thermal expansion mismatch between ceramic coatings and bond coat, and the outward diffusion of alloying elements into the ceramic coatings.

International Business Cycle

Directory of Open Access Journals (Sweden)

Marek Lubiński

2007-04-01

Full Text Available Prime stylized facts of international business cycle theory refer to positive correlation in the cyclical components of important macroeconomic variables across countries. However a number of indicators of business cycle synchronization do not point to clear trends. It can be ascribed to the fact that different forces influence level of business cycle correlation. When investigating into the forces behind the commonness in aggregate fluctuations economic research seems to have pointed in two directions. One strand of the literature examines the idea of common exogenous shocks that affect economies simultaneously. In addition to that economic interdependencies such as trade in goods and services or capital account transactions may serve as the channels through which disturbances spill over across countries.The observed degree of output co movement reflects both the nature of the shocks that have occurred and the degree of economic interdependence. In the periods when common shocks prevail level of synchronization is usually higher than in times of transmission dominance.

Additives as corrosion inhibitors in reinforced concrete

International Nuclear Information System (INIS)

Venegas, Ricardo; Vera, Rosa; Carvajal, Ana Maria; Villarroel, Maria; Vera, Enrique; Ortiz, Cesar

2008-01-01

This work studies the behavior of two additives as inhibitors of corrosion in reinforced concrete. The presence of Microsilica, a physical inhibitor, in the mixture decreases pore size in structures and improves compression. Calcium Nitrite, a chemical inhibitor, is an oxidizing agent and allows a more homogenous film to form over the steel that becomes more resistant to attacks from aggressive ions like anion chloride and others. Three pairs of concrete test pieces were used without additives and with additives with a/c ration of 0.55. The samples were exposed to an accelerated attack of chlorides, submerging them in a 4.27 M solution of NaCl for 24 hours and then drying them at room temperature for another 24 hours, completing a cycle every 48 hours. The tests were carried out at 1 cycle and 5 cycles of partial moistening and drying. The steel corrosion was evaluated with corrosion potential measurements. Conductivity, pH, chlorides and sulfate profiles were defined depending on the depth of the concrete. The composition of the corrosion products was determined using X-ray diffraction and the morphology of the film by scanning electron microscopy. The results show that for 1 test cycle, the corrosion potential of the steel in the sample with calcium nitrite was -54mV, which was a higher value than that measured in the sample with microsilica (-217.3mV) and without an additive (-159.1mV), corroborating its inhibitory power. The content of the free chlorides in the sample with micros ice allows greater capillary suction by adding high amounts of chloride to the structure (2.6% on the outside up to 2.20% near the steel); while the test pieces with calcium nitrite and without an additive had concentrations lower than 2% in all the evaluated points. After five cycles of exposing the samples to the saline solution the behavior is inverted. The measures of conductivity agreed with the previous results. Meanwhile, the pH of the solutions obtained from the powder from the

Additional guideline for the design of BWR reload patterns

International Nuclear Information System (INIS)

Burte, D.P.

1990-01-01

The problems of the high magnitude of the reactivity worths of control rods/notches and the thermal shocks to fuel due to control rod withdrawals are considered in this paper. These problems are shown to be mitigated if in addition to complying with the traditional guidelines for designing fuel bundles and reload patterns the proposed additional guideline (in the form of the condition that the shape of the K∞ distribution remains constant throughout the cycle) is also complied with. It is argued that application of the additional guideline for operating conditions ensures that the core can operate with a constant power profile throughout the cycle without control rod movement. Fixed (integral or stand-alone) burnable poisons are thought to be useful in this regard. Some comments on how this may be attempted are included. Additional advantages resulting from the additional guideline are discussed. (author)

Very fast mass balance and other fuel cycle response calculations for studying back end of fuel cycle scenari

International Nuclear Information System (INIS)

Dekens, O.; Marguet, S.; Risch, P.

1997-01-01

In order to optimize nuclear fuel utilization, as far as irradiation and storage are concerned, the Research and Development Division of Electricite de France (EDF) developed as fast and accurate software that simulates a fuel assembly life from the inside-reactor stay to the final repository: STRAPONTIN. The discrepancies between reference calculations and STRAPONTIN are generally smaller than 5 %. Moreover, the low calculation time enables to couple STRAPONTIN to any large code in order to widen its scope without impairing its CPU time. (authors)

Life Cycle Assessment and Risk Assessment

DEFF Research Database (Denmark)

Olsen, Stig Irving

Life Cycle Assessment (LCA) is a tool for environmental assessment of product and systems – over the whole life cycle from acquisition of raw materials to the end-of-life of the product – and encompassing all environmental impacts of emissions and resource usage, e.g. global warming, acidification...... cycle. The models for assessing toxic impacts in LCA are to a large extent based on those developed for RA, e.g. EUSES, and require basic information about the inherent properties of the emissions like solubility, LogKow,ED50 etc. Additionally, it is a prerequisite to know how to characterize...

Fast parallel image registration on CPU and GPU for diagnostic classification of Alzheimer's disease.

Science.gov (United States)

Shamonin, Denis P; Bron, Esther E; Lelieveldt, Boudewijn P F; Smits, Marion; Klein, Stefan; Staring, Marius

2013-01-01

Nonrigid image registration is an important, but time-consuming task in medical image analysis. In typical neuroimaging studies, multiple image registrations are performed, i.e., for atlas-based segmentation or template construction. Faster image registration routines would therefore be beneficial. In this paper we explore acceleration of the image registration package elastix by a combination of several techniques: (i) parallelization on the CPU, to speed up the cost function derivative calculation; (ii) parallelization on the GPU building on and extending the OpenCL framework from ITKv4, to speed up the Gaussian pyramid computation and the image resampling step; (iii) exploitation of certain properties of the B-spline transformation model; (iv) further software optimizations. The accelerated registration tool is employed in a study on diagnostic classification of Alzheimer's disease and cognitively normal controls based on T1-weighted MRI. We selected 299 participants from the publicly available Alzheimer's Disease Neuroimaging Initiative database. Classification is performed with a support vector machine based on gray matter volumes as a marker for atrophy. We evaluated two types of strategies (voxel-wise and region-wise) that heavily rely on nonrigid image registration. Parallelization and optimization resulted in an acceleration factor of 4-5x on an 8-core machine. Using OpenCL a speedup factor of 2 was realized for computation of the Gaussian pyramids, and 15-60 for the resampling step, for larger images. The voxel-wise and the region-wise classification methods had an area under the receiver operator characteristic curve of 88 and 90%, respectively, both for standard and accelerated registration. We conclude that the image registration package elastix was substantially accelerated, with nearly identical results to the non-optimized version. The new functionality will become available in the next release of elastix as open source under the BSD license.

A Thermodynamic Analysis of Two Competing Mid-Sized Oxyfuel Combustion Combined Cycles

Directory of Open Access Journals (Sweden)

Egill Thorbergsson

2016-01-01

Full Text Available A comparative analysis of two mid-sized oxyfuel combustion combined cycles is performed. The two cycles are the semiclosed oxyfuel combustion combined cycle (SCOC-CC and the Graz cycle. In addition, a reference cycle was established as the basis for the analysis of the oxyfuel combustion cycles. A parametric study was conducted where the pressure ratio and the turbine entry temperature were varied. The layout and the design of the SCOC-CC are considerably simpler than the Graz cycle while it achieves the same net efficiency as the Graz cycle. The fact that the efficiencies for the two cycles are close to identical differs from previously reported work. Earlier studies have reported around a 3% points advantage in efficiency for the Graz cycle, which is attributed to the use of a second bottoming cycle. This additional feature is omitted to make the two cycles more comparable in terms of complexity. The Graz cycle has substantially lower pressure ratio at the optimum efficiency and has much higher power density for the gas turbine than both the reference cycle and the SCOC-CC.

Fuel cycle

International Nuclear Information System (INIS)

Bahm, W.

1989-01-01

The situation of the nuclear fuel cycle for LWR type reactors in France and in the Federal Republic of Germany was presented in 14 lectures with the aim to compare the state-of-the-art in both countries. In addition to the momentarily changing fuilds of fuel element development and fueling strategies, the situation of reprocessing, made interesting by some recent developmnts, was portrayed and differences in ultimate waste disposal elucidated. (orig.) [de

From Cycling Between Coupled Reactions to the Cross-Bridge Cycle: Mechanical Power Output as an Integral Part of Energy Metabolism

Directory of Open Access Journals (Sweden)

Frank Diederichs

2012-10-01

Full Text Available ATP delivery and its usage are achieved by cycling of respective intermediates through interconnected coupled reactions. At steady state, cycling between coupled reactions always occurs at zero resistance of the whole cycle without dissipation of free energy. The cross-bridge cycle can also be described by a system of coupled reactions: one energising reaction, which energises myosin heads by coupled ATP splitting, and one de-energising reaction, which transduces free energy from myosin heads to coupled actin movement. The whole cycle of myosin heads via cross-bridge formation and dissociation proceeds at zero resistance. Dissipation of free energy from coupled reactions occurs whenever the input potential overcomes the counteracting output potential. In addition, dissipation is produced by uncoupling. This is brought about by a load dependent shortening of the cross-bridge stroke to zero, which allows isometric force generation without mechanical power output. The occurrence of maximal efficiency is caused by uncoupling. Under coupled conditions, Hill’s equation (velocity as a function of load is fulfilled. In addition, force and shortening velocity both depend on [Ca2+]. Muscular fatigue is triggered when ATP consumption overcomes ATP delivery. As a result, the substrate of the cycle, [MgATP2−], is reduced. This leads to a switch off of cycling and ATP consumption, so that a recovery of [ATP] is possible. In this way a potentially harmful, persistent low energy state of the cell can be avoided.

Contrasting the solar rotation rate of cycles 23 and 24

International Nuclear Information System (INIS)

Antia, H M; Basu, Sarbani

2013-01-01

The minimum between solar cycles 23 and 24 was quite unusual compared with other minima for which detailed data are available and this pointed to the possibility that cycle 24 will be unusual. Cycle 24 is almost at its maximum now and we take this opportunity to compare and contrast the solar rotation rate and zonal flows between the two cycles. We find that the rotation rate during cycle 24 is slightly lower than that during cycle 23. Additionally we find that the poleward branch of the zonal flow that is believed to be the harbinger of the next solar cycle is very week in cycle 24.

A hybrid CPU-GPU accelerated framework for fast mapping of high-resolution human brain connectome.

Directory of Open Access Journals (Sweden)

Yu Wang

Full Text Available Recently, a combination of non-invasive neuroimaging techniques and graph theoretical approaches has provided a unique opportunity for understanding the patterns of the structural and functional connectivity of the human brain (referred to as the human brain connectome. Currently, there is a very large amount of brain imaging data that have been collected, and there are very high requirements for the computational capabilities that are used in high-resolution connectome research. In this paper, we propose a hybrid CPU-GPU framework to accelerate the computation of the human brain connectome. We applied this framework to a publicly available resting-state functional MRI dataset from 197 participants. For each subject, we first computed Pearson's Correlation coefficient between any pairs of the time series of gray-matter voxels, and then we constructed unweighted undirected brain networks with 58 k nodes and a sparsity range from 0.02% to 0.17%. Next, graphic properties of the functional brain networks were quantified, analyzed and compared with those of 15 corresponding random networks. With our proposed accelerating framework, the above process for each network cost 80∼150 minutes, depending on the network sparsity. Further analyses revealed that high-resolution functional brain networks have efficient small-world properties, significant modular structure, a power law degree distribution and highly connected nodes in the medial frontal and parietal cortical regions. These results are largely compatible with previous human brain network studies. Taken together, our proposed framework can substantially enhance the applicability and efficacy of high-resolution (voxel-based brain network analysis, and have the potential to accelerate the mapping of the human brain connectome in normal and disease states.

Comparative assessment of nuclear fuel cycles. Light-water reactor once-through, classical fast breeder reactor, and symbiotic fast breeder reactor cycles

International Nuclear Information System (INIS)

Hardie, R.W.; Barrett, R.J.; Freiwald, J.G.

1980-06-01

The object of the Alternative Nuclear Fuel Cycle Study is to perform comparative assessments of nuclear power systems. There are two important features of this study. First, this evaluation attempts to encompass the complete, integrated fuel cycle from mining of uranium ore to disposal of waste rather than isolated components. Second, it compares several aspects of each cycle - energy use, economics, technological status, proliferation, public safety, and commercial potential - instead of concentrating on one or two assessment areas. This report presents assessment results for three fuel cycles. These are the light-water reactor once-through cycle, the fast breeder reactor on the classical plutonium cycle, and the fast breeder reactor on a symbiotic cycle using plutonium and 233 U as fissile fuels. The report also contains a description of the methodology used in this assessment. Subsequent reports will present results for additional fuel cycles

Towards Life Cycle Sustainability Assessment

Directory of Open Access Journals (Sweden)

Marzia Traverso

2010-10-01

Full Text Available Sustainability is nowadays accepted by all stakeholders as a guiding principle for both public policy making and corporate strategies. However, the biggest challenge for most organizations remains in the real and substantial implementation of the sustainability concept. The core of the implementation challenge is the question, how sustainability performance can be measured, especially for products and processes. This paper explores the current status of Life Cycle Sustainability Assessment (LCSA for products and processes. For the environmental dimension well established tools like Life Cycle Assessment are available. For the economic and social dimension, there is still need for consistent and robust indicators and methods. In addition to measuring the individual sustainability dimensions, another challenge is a comprehensive, yet understandable presentation of the results. The “Life Cycle Sustainability Dashboard” and the “Life Cycle Sustainability Triangle” are presented as examples for communication tools for both experts and non expert stakeholders.

Assessing large-scale weekly cycles in meteorological variables: a review

Directory of Open Access Journals (Sweden)

A. Sanchez-Lorenzo

2012-07-01

Full Text Available Several studies have claimed to have found significant weekly cycles of meteorological variables appearing over large domains, which can hardly be related to urban effects exclusively. Nevertheless, there is still an ongoing scientific debate whether these large-scale weekly cycles exist or not, and some other studies fail to reproduce them with statistical significance. In addition to the lack of the positive proof for the existence of these cycles, their possible physical explanations have been controversially discussed during the last years. In this work we review the main results about this topic published during the recent two decades, including a summary of the existence or non-existence of significant weekly weather cycles across different regions of the world, mainly over the US, Europe and Asia. In addition, some shortcomings of common statistical methods for analyzing weekly cycles are listed. Finally, a brief summary of supposed causes of the weekly cycles, focusing on the aerosol-cloud-radiation interactions and their impact on meteorological variables as a result of the weekly cycles of anthropogenic activities, and possible directions for future research, is presented.

A study of the multiple pinhole coded aperture and the application of the minicomputer in image decoding

International Nuclear Information System (INIS)

Hasegawa, Takeo; Hashiba, Hiroshi; Akagi, Kiyoshi; Kobayashi, Akitoshi; Matsuda, Magoichi

1979-01-01

Research has been done on optically reconstructed imaging employing the Multiple Pinhole Coded Aperture (hereafter abbreviated as MPCA) in radioisotope tomographic imaging. However, problems remain in the optically reconstructed image method. Therefore, we employed a minicomputer (hereafter abbreviated as CPU) and developed the software for decoding and managing the radioisotope tomographic image. Combining the MPCA and the CPU system, we were able to decode and manage the radioisotope tomographic image. 1) In comparison to the optically decoded MPCA image, various input commands are possibly in the CPU method according to the dialogue between the CPU and the on line typewriter. In addition to this, decoded tomographic images of unrestricted depth are readily attainable. 2) In the CPU method noise elimination and other aspects of image management can be easily performed. (author)

Wave Engine Topping Cycle Assessment

Science.gov (United States)

Welch, Gerard E.

1996-01-01

The performance benefits derived by topping a gas turbine engine with a wave engine are assessed. The wave engine is a wave rotor that produces shaft power by exploiting gas dynamic energy exchange and flow turning. The wave engine is added to the baseline turboshaft engine while keeping high-pressure-turbine inlet conditions, compressor pressure ratio, engine mass flow rate, and cooling flow fractions fixed. Related work has focused on topping with pressure-exchangers (i.e., wave rotors that provide pressure gain with zero net shaft power output); however, more energy can be added to a wave-engine-topped cycle leading to greater engine specific-power-enhancement The energy addition occurs at a lower pressure in the wave-engine-topped cycle; thus the specific-fuel-consumption-enhancement effected by ideal wave engine topping is slightly lower than that effected by ideal pressure-exchanger topping. At a component level, however, flow turning affords the wave engine a degree-of-freedom relative to the pressure-exchanger that enables a more efficient match with the baseline engine. In some cases, therefore, the SFC-enhancement by wave engine topping is greater than that by pressure-exchanger topping. An ideal wave-rotor-characteristic is used to identify key wave engine design parameters and to contrast the wave engine and pressure-exchanger topping approaches. An aerodynamic design procedure is described in which wave engine design-point performance levels are computed using a one-dimensional wave rotor model. Wave engines using various wave cycles are considered including two-port cycles with on-rotor combustion (valved-combustors) and reverse-flow and through-flow four-port cycles with heat addition in conventional burners. A through-flow wave cycle design with symmetric blading is used to assess engine performance benefits. The wave-engine-topped turboshaft engine produces 16% more power than does a pressure-exchanger-topped engine under the specified topping

Calcium constrains plant control over forest ecosystem nitrogen cycling.

Science.gov (United States)

Groffman, Peter M; Fisk, Melany C

2011-11-01

Forest ecosystem nitrogen (N) cycling is a critical controller of the ability of forests to prevent the movement of reactive N to receiving waters and the atmosphere and to sequester elevated levels of atmospheric carbon dioxide (CO2). Here we show that calcium (Ca) constrains the ability of northern hardwood forest trees to control the availability and loss of nitrogen. We evaluated soil N-cycling response to Ca additions in the presence and absence of plants and observed that when plants were present, Ca additions "tightened" the ecosystem N cycle, with decreases in inorganic N levels, potential net N mineralization rates, microbial biomass N content, and denitrification potential. In the absence of plants, Ca additions induced marked increases in nitrification (the key process controlling ecosystem N losses) and inorganic N levels. The observed "tightening" of the N cycle when Ca was added in the presence of plants suggests that the capacity of forests to absorb elevated levels of atmospheric N and CO2 is fundamentally constrained by base cations, which have been depleted in many areas of the globe by acid rain and forest harvesting.

Sensitivity study on nitrogen Brayton cycle coupled with a small ultra-long cycle fast reactor

International Nuclear Information System (INIS)

Seo, Seok Bin; Seo, Han; Bang, In Cheol

2014-01-01

The main characteristics of UCFR are constant neutron flux and power density. They move their positions every moment at constant speed along with axial position of fuel rod for 60 years. Simultaneously with the development of the reactors, a new power conversion system has been considered. To solve existing issues of vigorous sodium-water reaction in SFR with steam power cycle, many researchers suggested a closed Brayton cycle as an alternative technique for SFR power conversion system. Many inactive gases are selected as a working fluid in Brayton power cycle, mainly supercritical CO 2 (S-CO 2 ). However, S-CO 2 still has potential for reaction with sodium. CO 2 -sodium reaction produces solid product, which has possibility to have an auto ignition reaction around 600 .deg. C. Thus, instead of S-CO 2 , CEA in France has developed nitrogen power cycle for ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration). In addition to inactive characteristic of nitrogen with sodium, its thermal and physical similarity with air enables to easily adopt to existing air Brayton cycle technology. In this study, for an optimized power conversion system for UCFR, a nitrogen Brayton cycle was analyzed in thermodynamic aspect. Based on subchannel analysis data of UCFR-100, a parametric study for thermal performance of nitrogen Brayton cycle was achieved. The system maximum pressure significantly affects to the overall efficiency of cycle, while other parameters show little effects. Little differences of the overall efficiencies for all cases between three stages (BOC, MOC, EOC) indicate that the power cycle of UCFR-100 maintains its performance during the operation

Assessment of gas cooled fast reactor with indirect supercritical CO2 cycle

International Nuclear Information System (INIS)

Hejzlar, P.; Driscoll, M. J.; Dostal, V.; Dumaz, P.; Poullennec, G.; Alpy, N.

2006-01-01

Various indirect power cycle options for a helium cooled Gas cooled Fast Reactor (GFR) with particular focus on a supercritical CO 2 (SCO 2 ) indirect cycle are investigated as an alternative to a helium cooled direct cycle GFR. The Balance Of Plant (BOP) options include helium-nitrogen Brayton cycle, supercritical water Rankine cycle, and SCO 2 recompression Brayton power cycle in three versions: (1) basic design with turbine inlet temperature of 550 .deg. C, (2) advanced design with turbine inlet temperature of 650 .deg. C and (3) advanced design with the same turbine inlet temperature and reduced compressor inlet temperature. The indirect SCO 2 recompression cycle is found attractive since in addition to easier BOP maintenance it allows significant reduction of core outlet temperature, making design of the primary system easier while achieving very attractive efficiencies comparable to or slightly lower than, the efficiency of the reference GFR direct cycle design. In addition, the indirect cycle arrangement allows significant reduction of the GFR 'proximate-containment' and the BOP for the SCO 2 cycle is very compact. Both these factors will lead to reduced capital cost

40 CFR Appendix E to Subpart S of... - Transient Test Driving Cycle

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Transient Test Driving Cycle E Appendix... Driving Cycle (I) Driver's trace. All excursions in the transient driving cycle shall be evaluated by the... shall cause a test to be void. In addition, provisions shall be available to utilize cycle validation...

Investigation of palm methyl-ester bio-diesel with additive on performance and emission characteristics of a diesel engine under 8-mode testing cycle

Directory of Open Access Journals (Sweden)

S. Senthilkumar

2015-09-01

Full Text Available Biodiesel is receiving increasing attention each passing day because of its same diesel-like fuel properties and compatibility with petroleum-based diesel fueled engines. Therefore, in this paper the prospects and opportunities of using various blends of methyl esters of palm oil as fuel in an engine with and without the effect of multi-functional fuel additive (MFA, Multi DM 32 are studied to arrive at an optimum blend of bio-diesel best suited for low emissions and minimal power drop. Experimental tests were conducted on a four stroke, three cylinder and naturally aspirated D.I. Diesel engine with diesel and various blend percentages of 20%, 40%, 45%, and 50% under the 8 mode testing cycle. The effect of fuel additive was tested out on the optimum blend ratio of the bio-diesel so as to achieve further reduced emissions. Comparison of results shows that, 73% reduction in hydrocarbon emission, 46% reduction in carbon monoxide emission, and around 1% reduction in carbon dioxide emission characteristics. So it is observed that the blend ratio of 40% bio-diesel with MFA fuel additive creates reduced emission and minimal power drop due to effective combustion even when the calorific value is comparatively lower due to its higher cetane number.

Fast Simulation of Dynamic Ultrasound Images Using the GPU.

Science.gov (United States)

Storve, Sigurd; Torp, Hans

2017-10-01

Simulated ultrasound data is a valuable tool for development and validation of quantitative image analysis methods in echocardiography. Unfortunately, simulation time can become prohibitive for phantoms consisting of a large number of point scatterers. The COLE algorithm by Gao et al. is a fast convolution-based simulator that trades simulation accuracy for improved speed. We present highly efficient parallelized CPU and GPU implementations of the COLE algorithm with an emphasis on dynamic simulations involving moving point scatterers. We argue that it is crucial to minimize the amount of data transfers from the CPU to achieve good performance on the GPU. We achieve this by storing the complete trajectories of the dynamic point scatterers as spline curves in the GPU memory. This leads to good efficiency when simulating sequences consisting of a large number of frames, such as B-mode and tissue Doppler data for a full cardiac cycle. In addition, we propose a phase-based subsample delay technique that efficiently eliminates flickering artifacts seen in B-mode sequences when COLE is used without enough temporal oversampling. To assess the performance, we used a laptop computer and a desktop computer, each equipped with a multicore Intel CPU and an NVIDIA GPU. Running the simulator on a high-end TITAN X GPU, we observed two orders of magnitude speedup compared to the parallel CPU version, three orders of magnitude speedup compared to simulation times reported by Gao et al. in their paper on COLE, and a speedup of 27000 times compared to the multithreaded version of Field II, using numbers reported in a paper by Jensen. We hope that by releasing the simulator as an open-source project we will encourage its use and further development.

Advanced nuclear fuel cycles activities in IAEA

International Nuclear Information System (INIS)

Nawada, H.P.; Ganguly, C.

2007-01-01

Full text of publication follows. Of late several developments in reprocessing areas along with advances in fuel design and robotics have led to immense interest in partitioning and transmutation (P and T). The R and D efforts in the P and T area are being paid increased attention as potential answers to ever-growing issues threatening sustainability, environmental protection and non-proliferation. Any fuel cycle studies that integrate partitioning and transmutation are also known as ''advanced fuel cycles'' (AFC), that could incinerate plutonium and minor actinide (MA) elements (namely Am, Np, Cm, etc.) which are the main contributors to long-term radiotoxicity. The R and D efforts in developing these innovative fuel cycles as well as reactors are being co-ordinated by international initiatives such as Innovative Nuclear Power Reactors and Fuel Cycles (INPRO), the Generation IV International Forum (GIF) and the Global Nuclear Energy Partnership (GENP). For these advanced nuclear fuel cycle schemes to take shape, the development of liquid-metal-cooled reactor fuel cycles would be the most essential step for implementation of P and T. Some member states are also evaluating other concepts involving the use of thorium fuel cycle or inert-matrix fuel or coated particle fuel. Advanced fuel cycle involving novel partitioning methods such as pyrochemical separation methods to recover the transuranic elements are being developed by some member states which would form a critical stage of P and T. However, methods that can achieve a very high reduction (>99.5%) of MA and long-lived fission products in the waste streams after partitioning must be achieved to realize the goal of an improved protection of the environment. In addition, the development of MA-based fuel is also an essential and crucial step for transmutation of these transuranic elements. The presentation intends to describe progress of the IAEA activities encompassing the following subject-areas: minimization of

Exergy Losses in the Szewalski Binary Vapor Cycle

Directory of Open Access Journals (Sweden)

Tomasz Kowalczyk

2015-10-01

Full Text Available In this publication, we present an energy and exergy analysis of the Szewalski binary vapor cycle based on a model of a supercritical steam power plant. We used energy analysis to conduct a preliminary optimization of the cycle. Exergy loss analysis was employed to perform a comparison of heat-transfer processes, which are essential for hierarchical cycles. The Szewalski binary vapor cycle consists of a steam cycle bottomed with an organic Rankine cycle installation. This coupling has a negative influence on the thermal efficiency of the cycle. However, the primary aim of this modification is to reduce the size of the power unit by decreasing the low-pressure steam turbine cylinder and the steam condenser. The reduction of the “cold end” of the turbine is desirable from economic and technical standpoints. We present the Szewalski binary vapor cycle in addition to a mathematical model of the chosen power plant’s thermodynamic cycle. We elaborate on the procedure of the Szewalski cycle design and its optimization in order to attain an optimal size reduction of the power unit and limit exergy loss.

The Impact of Hydrocalumites Additives on the Electrochemical Performance of Zinc-Nickel Secondary Cells

International Nuclear Information System (INIS)

Wen, Xing; Yang, Zhanhong; Xiao, Xiang; Yang, Huan; Xie, Xiaoe; Huang, Jianhang

2016-01-01

Hydrocalumites additives are synthesized and proposed as an anodic additive for Zinc/Nickel alkaline secondary batteries. The as-prepared additives are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). And the results illustrate that hydrocalumites additives are successfully prepared and have the typical structure of layered double hydroxides (LDHs). The effects of hydrocalumites additives on electrochemical performances of ZnO have been investigated by cyclic voltammetry (CV), tafel polarization tests, electrochemical impedance spectroscopy (EIS) and galvanostatic charge and discharge. Compared to the electrode with pure ZnO, the electrodes containing hydrocalumites additives show better reversibility, reveal better anti-corrosion property and exhibit more stable cycle performance. Especially when the electrode added with 12% (wt.) hydrocalumites, it exhibits the best cycle performance than the other electrodes. And its discharge capacity is about 450 mAh g −1 all the time, and hardly declines over all the 400 cycles. Based on these observations, the prepared hydrocalumites may be a promising and efficient additive for the ZnO electrode.

Hybrid solar central receiver for combined cycle power plant

Science.gov (United States)

Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

1995-01-01

A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

Cell cycle arrest induced by radiation

International Nuclear Information System (INIS)

Okaichi, Yasuo; Matsumoto, Hideki; Ohnishi, Takeo

1994-01-01

It is known that various chemical reactions, such as cell cycle arrest, DNA repair and cell killing, can occur within the cells when exposed to ionizing radiation and ultraviolet radiation. Thus protein dynamics involved in such chemical reactions has received considerable attention. In this article, cell cycle regulation is first discussed in terms of the G2/M-phase and the G1/S-phase. Then, radiation-induced cell cycle arrest is reviewed. Cell cycle regulation mechanism involved in the G2 arrest, which is well known to occur when exposed to radiation, has recently been investigated using yeasts. In addition, recent study has yielded a noticeable finding that the G1 arrest can occur with intracellular accumulation of p53 product following ionization radiation. p53 is also shown to play an extremely important role in both DNA repair and cell killing due to DNA damage. Studies on the role of genes in protein groups induced by radiation will hold promise for the elucidation of cell cycle mechanism. (N.K.) 57 refs

Spectral shift controlled reactor, UO2 once-through cycle optimized

International Nuclear Information System (INIS)

1978-05-01

This paper presents technical and economic data on the SSCR which may be of use in the International Fuel Cycle Evaluation Program to intercompare alternative nuclear systems. Included in this data is information on the optimized UO 2 once-through fuel cycle. The ''optimized'' cycle refers to a UO 2 once-through cycle which has better fuel resource utilization than the conventional UO 2 cycle employed in current design PWRs. This fuel cycle uses more in-core batches and a higher discharge exposure than current PWR fuel management schemes. The proposed cycle is not optimal in a mathematical sense, however, since additional resource savings can be obtained if the discharge exposure is extended to even higher values and the number of in-core fuel batches is increased further. The present cycle was selected as ''optimal'' based on the assumption that it can be achieved with only an extension of fuel design technology and can therefore be deployed in a relatively short time frame. In the longer term, modification to reactor geometry as well as further extensions of discharge burnup might be considered to realize additional reduction in uranium resource requirements. The data contained in this paper has been developed by an ongoing program which at the present time is only 50% complete. The data presented here should therefore be considered preliminary and will be updated in the future as required

Bipolar mood cycles and lunar tidal cycles.

Science.gov (United States)

Wehr, T A

2018-04-01

In 17 patients with rapid cycling bipolar disorder, time-series analyses detected synchronies between mood cycles and three lunar cycles that modulate the amplitude of the moon's semi-diurnal gravimetric tides: the 14.8-day spring-neap cycle, the 13.7-day declination cycle and the 206-day cycle of perigee-syzygies ('supermoons'). The analyses also revealed shifts among 1:2, 1:3, 2:3 and other modes of coupling of mood cycles to the two bi-weekly lunar cycles. These shifts appear to be responses to the conflicting demands of the mood cycles' being entrained simultaneously to two different bi-weekly lunar cycles with slightly different periods. Measurements of circadian rhythms in body temperature suggest a biological mechanism through which transits of one of the moon's semi-diurnal gravimetric tides might have driven the patients' bipolar cycles, by periodically entraining the circadian pacemaker to its 24.84-h rhythm and altering the pacemaker's phase-relationship to sleep in a manner that is known to cause switches from depression to mania.

Overlooked runaway feedback in the marine nitrogen cycle: the vicious cycle

Directory of Open Access Journals (Sweden)

A. Landolfi

2013-03-01

Full Text Available The marine nitrogen (N inventory is thought to be stabilized by negative feedback mechanisms that reduce N inventory excursions relative to the more slowly overturning phosphorus inventory. Using a global biogeochemical ocean circulation model we show that negative feedbacks stabilizing the N inventory cannot persist if a close spatial association of N2 fixation and denitrification occurs. In our idealized model experiments, nitrogen deficient waters, generated by denitrification, stimulate local N2 fixation activity. But, because of stoichiometric constraints, the denitrification of newly fixed nitrogen leads to a net loss of N. This can enhance the N deficit, thereby triggering additional fixation in a vicious cycle, ultimately leading to a runaway N loss. To break this vicious cycle, and allow for stabilizing negative feedbacks to occur, inputs of new N need to be spatially decoupled from denitrification. Our idealized model experiments suggest that factors such as iron limitation or dissolved organic matter cycling can promote such decoupling and allow for negative feedbacks that stabilize the N inventory. Conversely, close spatial co-location of N2 fixation and denitrification could lead to net N loss.

Rethinking cell-cycle-dependent gene expression in Schizosaccharomyces pombe.

Science.gov (United States)

Cooper, Stephen

2017-11-01

Three studies of gene expression during the division cycle of Schizosaccharomyces pombe led to the proposal that a large number of genes are expressed at particular times during the S. pombe cell cycle. Yet only a small fraction of genes proposed to be expressed in a cell-cycle-dependent manner are reproducible in all three published studies. In addition to reproducibility problems, questions about expression amplitudes, cell-cycle timing of expression, synchronization artifacts, and the problem with methods for synchronizing cells must be considered. These problems and complications prompt the idea that caution should be used before accepting the conclusion that there are a large number of genes expressed in a cell-cycle-dependent manner in S. pombe.

CPU Server

CERN Multimedia

The CERN computer centre has hundreds of racks like these. They are over a million times more powerful than our first computer in the 1960's. This tray is a 'dual-core' server. This means it effectively has two CPUs in it (eg. two of your home computers minimised to fit into a single box). Also note the copper cooling fins, to help dissipate the heat.

The thorium fuel cycle

International Nuclear Information System (INIS)

Merz, E.R.

1977-01-01

The utilization of the thorium fuel cycle has long since been considered attractive due to the excellent neutronic characteristics of 233 U, and the widespread and cheap thorium resources. Although the uranium ore as well as the separative work requirements are usually lower for any thorium-based fuel cycle in comparison to present uranium-plutonium fuel cycles of thermal water reactors, interest by nuclear industry has hitherto been marginal. Fast increasing uranium prices, public reluctance against widespread Pu-recycling and expected retardations for the market penetration of fast breeders have led to a reconsideration of the thorium fuel cycle merits. In addition, it could be learned in the meantime that problems associated with reprocessing and waste handling, but particularly with a remote refabrication of 233 U are certainly not appreciably more difficult than for Pu-recycling. This may not only be due to psychological constraints but be based upon technological as well as economical facts, which have been mostly neglected up till now. In order to diversify from uranium as a nuclear energy source it seems to be worthwhile to greatly intensify efforts in the future for closing the Th/ 233 U fuel cycle. HTGR's are particularly promising for economic application. However, further R and D activites should not be solely focussed on this reactor type alone. Light and heavy-water moderated reactors, as well as even fast breeders later on, may just as well take advantage of a demonstrated thorium fuel cycle. A summary is presented of the state-of-the-art of Th/ 233 U-recycling technology and the efforts still necessary to demonstrate this technology all the way through to its industrial application

NICMOS Cycles 13 and 14 Calibration Plans

Science.gov (United States)

Arribas, Santiago; Bergeron, Eddie; de Jong, Roeof; Malhotra, Sangeeta; Mobasher, Bahram; Noll, Keith; Schultz, Al; Wiklind, Tommy; Xu, Chun

2005-11-01

This document summarizes the NICMOS Calibration Plans for Cycles 13 and 14. These plans complement the SMOV3b, the Cycle 10 (interim), and the Cycles 11 and 12 (regular) calibration programs executed after the installation of the NICMOS Cooling System (NCS).. These previous programs have shown that the instrument is very stable, which has motivated a further reduction in the frequency of the monitoring programs for Cycle 13. In addition, for Cycle 14 some of these programs were slightly modified to account for 2 Gyro HST operations. The special calibrations on Cycle 13 were focussed on a follow up of the spectroscopic recalibration initiated in Cycle 12. This program led to the discovery of a possible count rate non-linearity, which has triggered a special program for Cycle 13 and a number of subsequent tests and calibrations during Cycle 14. At the time of writing this is a very active area of research. We also briefly comment on other calibrations defined to address other specific issues like: the autoreset test, the SPAR sequences tests, and the low-frequency flat residual for NIC1. The calibration programs for the 2-Gyro campaigns are not included here, since they have been described somewhere else. Further details and updates on specific programs can be found via the NICMOS web site.

Optimizing antiemetic therapy in multiple-day and multiple cycles of chemotherapy

DEFF Research Database (Denmark)

Ellebaek, E.; Herrstedt, J.

2008-01-01

PURPOSE OF REVIEW: Only a few studies have investigated the effect of antiemetic therapy in patients treated with multiple-day or multiple cycles of chemotherapy. The present review will assess the available data, highlight the current recommendations and draw attention towards the remaining...... of chemotherapy the addition of a NK1-receptor antagonist aprepitant to standard antiemetic therapy has increased the antiemetic effect, and multiple cycle extension studies have demonstrated that this increment in effect is sustained during multiple cycles of chemotherapy. A recent study indicated...... that the dopamine D2-receptor antagonist metopimazine has some additive effect on delayed symptoms induced by multiple-day chemotherapy. SUMMARY: The development of the NK1-receptor antagonist aprepitant has significantly improved the antiemetic control in patients treated with multiple cycles of chemotherapy. Far...

Global operational hydrological forecasts through eWaterCycle

Science.gov (United States)

van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

2015-04-01

Central goal of the eWaterCycle project (www.ewatercycle.org) is the development of an operational hyper-resolution hydrological global model. This model is able to produce 14 day ensemble forecasts based on a hydrological model and operational weather data (presently NOAA's Global Ensemble Forecast System). Special attention is paid to prediction of situations in which water related issues are relevant, such as floods, droughts, navigation, hydropower generation, and irrigation stress. Near-real time satellite data will be assimilated in the hydrological simulations, which is a feature that will be presented for the first time at EGU 2015. First, we address challenges that are mainly computer science oriented but have direct practical hydrological implications. An important feature in this is the use of existing standards and open-source software to the maximum extent possible. For example, we use the Community Surface Dynamics Modeling System (CSDMS) approach to coupling models (Basic Model Interface (BMI)). The hydrological model underlying the project is PCR-GLOBWB, built by Utrecht University. This is the motor behind the predictions and state estimations. Parts of PCR-GLOBWB have been re-engineered to facilitate running it in a High Performance Computing (HPC) environment, run parallel on multiple nodes, as well as to use BMI. Hydrological models are not very CPU intensive compared to, say, atmospheric models. They are, however, memory hungry due to the localized processes and associated effective parameters. To accommodate this memory need, especially in an ensemble setting, a variation on the traditional Ensemble Kalman Filter was developed that needs much less on-chip memory. Due to the operational nature, the coupling of the hydrological model with hydraulic models is very important. The idea is not to run detailed hydraulic routing schemes over the complete globe but to have on-demand simulation prepared off-line with respect to topography and

Optimum heat power cycles for specified boundary conditions

International Nuclear Information System (INIS)

Ibrahim, O.M.; Klein, S.A.; Mitchell, J.W.

1991-01-01

In this paper optimization of the power output of Carnot and closed Brayton cycles is considered for both finite and infinite thermal capacitance rates of the external fluid streams. The method of Lagrange multipliers is used to solve for working fluid temperatures that yield maximum power. Analytical expressions for the maximum power and the cycle efficiency at maximum power are obtained. A comparison of the maximum power from the two cycles for the same boundary conditions, i.e., the same heat source/sink inlet temperatures, thermal capacitance rates, and heat exchanger conductances, shows that the Brayton cycle can produce more power than the Carnot cycle. This comparison illustrates that cycles exist that can produce more power than the Carnot cycle. The optimum heat power cycle, which will provide the upper limit of power obtained from any thermodynamic cycle for specified boundary conditions and heat exchanger conductances is considered. The optimum heat power cycle is identified by optimizing the sum of the power output from a sequence of Carnot cycles. The shape of the optimum heat power cycle, the power output, and corresponding efficiency are presented. The efficiency at maximum power of all cycles investigated in this study is found to be equal to (or well approximated by) η = 1 - sq. root T L.in /φT H.in where φ is a factor relating the entropy changes during heat rejection and heat addition

Parallelizing ATLAS Reconstruction and Simulation: Issues and Optimization Solutions for Scaling on Multi- and Many-CPU Platforms

International Nuclear Information System (INIS)

Leggett, C; Jackson, K; Tatarkhanov, M; Yao, Y; Binet, S; Levinthal, D

2011-01-01

Thermal limitations have forced CPU manufacturers to shift from simply increasing clock speeds to improve processor performance, to producing chip designs with multi- and many-core architectures. Further the cores themselves can run multiple threads as a zero overhead context switch allowing low level resource sharing (Intel Hyperthreading). To maximize bandwidth and minimize memory latency, memory access has become non uniform (NUMA). As manufacturers add more cores to each chip, a careful understanding of the underlying architecture is required in order to fully utilize the available resources. We present AthenaMP and the Atlas event loop manager, the driver of the simulation and reconstruction engines, which have been rewritten to make use of multiple cores, by means of event based parallelism, and final stage I/O synchronization. However, initial studies on 8 andl6 core Intel architectures have shown marked non-linearities as parallel process counts increase, with as much as 30% reductions in event throughput in some scenarios. Since the Intel Nehalem architecture (both Gainestown and Westmere) will be the most common choice for the next round of hardware procurements, an understanding of these scaling issues is essential. Using hardware based event counters and Intel's Performance Tuning Utility, we have studied the performance bottlenecks at the hardware level, and discovered optimization schemes to maximize processor throughput. We have also produced optimization mechanisms, common to all large experiments, that address the extreme nature of today's HEP code, which due to it's size, places huge burdens on the memory infrastructure of today's processors.

The Krebs Uric Acid Cycle: A Forgotten Krebs Cycle.

Science.gov (United States)

Salway, Jack G

2018-05-25

Hans Kornberg wrote a paper entitled 'Krebs and his trinity of cycles' commenting that every school biology student knows of the Krebs cycle, but few know that Krebs discovered two other cycles. These are (i) the ornithine cycle (urea cycle), (ii) the citric acid cycle (tricarboxylic acid or TCA cycle), and (iii) the glyoxylate cycle that was described by Krebs and Kornberg. Ironically, Kornberg, codiscoverer of the 'glyoxylate cycle', overlooked a fourth Krebs cycle - (iv) the uric acid cycle. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interventions to promote cycling: systematic review.

Science.gov (United States)

Yang, Lin; Sahlqvist, Shannon; McMinn, Alison; Griffin, Simon J; Ogilvie, David

2010-10-18

To determine what interventions are effective in promoting cycling, the size of the effects of interventions, and evidence of any associated benefits on overall physical activity or anthropometric measures. Systematic review. Published and unpublished reports in any language identified by searching 13 electronic databases, websites, reference lists, and existing systematic reviews, and papers identified by experts in the field. Review methods Controlled "before and after" experimental or observational studies of the effect of any type of intervention on cycling behaviour measured at either individual or population level. Twenty five studies (of which two were randomised controlled trials) from seven countries were included. Six studies examined interventions aimed specifically at promoting cycling, of which four (an intensive individual intervention in obese women, high quality improvements to a cycle route network, and two multifaceted cycle promotion initiatives at town or city level) were found to be associated with increases in cycling. Those studies that evaluated interventions at population level reported net increases of up to 3.4 percentage points in the population prevalence of cycling or the proportion of trips made by bicycle. Sixteen studies assessing individualised marketing of "environmentally friendly" modes of transport to interested households reported modest but consistent net effects equating to an average of eight additional cycling trips per person per year in the local population. Other interventions that targeted travel behaviour in general were not associated with a clear increase in cycling. Only two studies assessed effects of interventions on physical activity; one reported a positive shift in the population distribution of overall physical activity during the intervention. Community-wide promotional activities and improving infrastructure for cycling have the potential to increase cycling by modest amounts, but further controlled

Nitrogen Cycle Evaluation (NiCE) Chip for the Simultaneous Analysis of Multiple N-Cycle Associated Genes.

Science.gov (United States)

Oshiki, Mamoru; Segawa, Takahiro; Ishii, Satoshi

2018-02-02

Various microorganisms play key roles in the Nitrogen (N) cycle. Quantitative PCR (qPCR) and PCR-amplicon sequencing of the N cycle functional genes allow us to analyze the abundance and diversity of microbes responsible in the N transforming reactions in various environmental samples. However, analysis of multiple target genes can be cumbersome and expensive. PCR-independent analysis, such as metagenomics and metatranscriptomics, is useful but expensive especially when we analyze multiple samples and try to detect N cycle functional genes present at relatively low abundance. Here, we present the application of microfluidic qPCR chip technology to simultaneously quantify and prepare amplicon sequence libraries for multiple N cycle functional genes as well as taxon-specific 16S rRNA gene markers for many samples. This approach, named as N cycle evaluation (NiCE) chip, was evaluated by using DNA from pure and artificially mixed bacterial cultures and by comparing the results with those obtained by conventional qPCR and amplicon sequencing methods. Quantitative results obtained by the NiCE chip were comparable to those obtained by conventional qPCR. In addition, the NiCE chip was successfully applied to examine abundance and diversity of N cycle functional genes in wastewater samples. Although non-specific amplification was detected on the NiCE chip, this could be overcome by optimizing the primer sequences in the future. As the NiCE chip can provide high-throughput format to quantify and prepare sequence libraries for multiple N cycle functional genes, this tool should advance our ability to explore N cycling in various samples. Importance. We report a novel approach, namely Nitrogen Cycle Evaluation (NiCE) chip by using microfluidic qPCR chip technology. By sequencing the amplicons recovered from the NiCE chip, we can assess diversities of the N cycle functional genes. The NiCE chip technology is applicable to analyze the temporal dynamics of the N cycle gene

Performances of four magnetic heat-pump cycles

International Nuclear Information System (INIS)

Chen, F.C.; Murphy, R.W.; Mel, V.C.; Chen, G.L.

1990-01-01

Magnetic heat pumps have been successfully used for refrigeration applications at near absolute-zero-degree temperatures. In these applications, a temperature lift of a few degrees in a cryogenic environment is sufficient and can be easily achieved by a simple magnetic heat-pump cycle. To extend magnetic heat pumping to other temperature ranges and other types of applications in which the temperature lift is more than just a few degrees requires more involved cycle processes. This paper investigates the characteristics of a few better-known thermomagnetic heat-pump cycles (Carnot, Ericsson, Stirling, and regenerative) in extended ranges of temperature lift. The regenerative cycle is the most efficient one. For gadolinium operating between 0 and 7 T (Tesla) in a heat pump cycle with a heat-rejection temperature of 320 K, our analysis predicted a 42% loss in coefficient of performance at 260 K cooling temperature, and a 15% loss in capacity at 232 K cooling temperature for the constant-field cycle as compared with the ideal regenerative cycle. Such substantial penalties indicate that the potential irreversibilities from this one source (the additional heat transfer that would be needed for the constant-field vs. the ideal regenerative cycle) may adversely affect the viability of certain proposed MHP concepts if the relevant loss mechanisms are not adequately addressed

Solar-cycle variation of zonal and meridional flow

International Nuclear Information System (INIS)

Komm, R; Howe, R; Hill, F; Hernandez, I Gonzalez; Haber, D

2011-01-01

We study the variation with the solar cycle of the zonal and meridional flows in the near-surface layers of the solar convection zone. We have analyzed MDI Dynamics-Program data with ring-diagram analysis covering the rising phase of cycle 23, while the analyzed GONG high-resolution data cover the maximum and declining phase of cycle 23. For the zonal flow, the migration with latitude of the flow pattern is apparent in the deeper layers, while for the meridional flow, a migration with latitude is apparent only in the layers close to the surface. The faster-than-average bands of the zonal flow associated with the new cycle are clearly visible. Similarly, a pattern related to the new cycle appears in the residual meridional flow. We also study the flow differences between the hemispheres during the course of the solar cycle. The difference pattern of the meridional flow is slanted in latitude straddling the faster-than-average band of the torsional oscillation pattern in the zonal flow. The difference pattern of the zonal flow, on the other hand, resembles the cycle variation of the meridional flow. In addition, the meridional flow during the minimum of cycle 23/24 appears to be slightly stronger than during the previous minimum of cycle 22/23.

Economic aspects of Dukovany NPP fuel cycle

International Nuclear Information System (INIS)

Vesely, P.; Borovicka, M.

2001-01-01

The paper discusses some aspects of high burnup program implementation at Dukovany NPP and its influence on the fuel cycle costs. Dukovany internal fuel cycle is originally designed as a three years cycle of the Out-In-In fuel reloading patterns. These reloads are not only uneconomical but they additionally increased the radiation load of the reactor pressure vessel due to high neutron leakage typical for Out-In-In loading pattern. To avoid the high neutron leakage from the core a transition to 4-year fuel cycle is started in 1987. The neutron leakage from the core is sequentially decreased by insertion of older fuel assemblies at the core periphery. Other developments in fuel cycle are: 1) increasing of enrichment in control assemblies (3.6% of U-235); 2) improvement in fuel assembly design (reduce the assembly shroud thickness from 2.1 to 1.6 mm); 3) introduction of Zr spacer grid instead of stainless steel; 4) introduction of new type of assembly with profiled enrichment with average value of 3.82%. Due to increased reactivity of the new assemblies the transition to the partial 5-year fuel cycle is required. Typical fuel loading pattern for 3, 3.5, 4 and 5-year cycles are shown in the presented paper. An evaluation of fuel cost is also discussed by using comparative analysis of different fuel cycle options. The analysis shows that introduction of the high burnup program has decrease relative fuel cycle costs

Human Resource Development for Uranium Production Cycle

International Nuclear Information System (INIS)

Ganguly, C.

2014-01-01

Concluding Remarks & Suggestions: • HRD will be one of the major challenges in the expanding nuclear power program in countries like China and India. • China and India get uranium raw material from domestic mines and international market. In addition, China has overseas uranium property. India is also exploring the possibility of overseas Joint Venture and uranium properties. For uranium production cycle there is a need for trained geologist, mining engineers, chemical and mechanical engineers. • There is a need for introducing specialization course on “uranium production cycle” at post graduate levels in government and private universities. Overseas Utilities and private firms in India engaged in nuclear power and fuel cycle activities may like to sponsor MTech students with assurance of employment after the successful completion of the course. • The IAEA may consider to extend Technical Assistance to universities in HRD in nuclear power and fuel cycle in general and uranium production cycle in particular - IAEA workshops, with participation of international experts, on uranium geology, mining, milling and safety and best practices in uranium production cycle will be of great help. • The IAEA – UPSAT could play an important role in HRD in uranium production cycle

Implementation of the Additional Protocol in Japan

International Nuclear Information System (INIS)

Ogawa, T.

2001-01-01

The Additional Protocol between Japan and the IAEA entered into force in December 1999. To come into force a series of implementation trials of Additional Protocol was carried out at two Japanese representative nuclear research centers, i.e. Tokai Research Establishment of Japan Atomic Energy Research Institute (JAERI) and Oarai Engineering Center of Japan Nuclear Fuel Cycle Development Institute (JNC). These trials were proposed by Japan and were conducted in cooperation with the IAEA Secretariat. In addition, Japan amended 'the Law for the Regulation of Reactors etc.', to collect adequate information to submit to the IAEA, to arrange the surrounding for the complementary access, etc. In addition, Japan Submitted the Initial Declaration of the Additional Protocol within 180 days of the entry into force of the Protocol, in the middle of June, 2000

Performance of a Supercritical CO2 Bottoming Cycle for Aero Applications

Directory of Open Access Journals (Sweden)

Florian Jacob

2017-03-01

Full Text Available By 2050, the evolutionary approach to aero engine research may no longer provide meaningful returns on investment, whereas more radical approaches to improving thermal efficiency and reducing emissions might still prove cost effective. One such radical concept is the addition of a secondary power cycle that utilizes the otherwise largely wasted residual heat in the core engine’s exhaust gases. This could provide additional shaft power. Supercritical carbon dioxide closed-circuit power cycles are currently being investigated primarily for stationary power applications, but their high power density and efficiency, even for modest peak cycle temperatures, makes them credible bottoming cycle options for aero engine applications. Through individual geometric design and performance studies for each of the bottoming cycle’s major components, it was determined that a simple combined cycle aero engine could offer a 1.9% mission fuel burn benefit over a state-of-the-art geared turbofan for the year 2050. However, the even greater potential of more complex systems demands further investigation. For example, adding inter-turbine reheat (ITR to the combined cycle is predicted to significantly improve the fuel burn benefit.

Optimised heat recovery steam generators for integrated solar combined cycle plants

Science.gov (United States)

Peterseim, Jürgen H.; Huschka, Karsten

2017-06-01

The cost of concentrating solar power (CSP) plants is decreasing but, due to the cost differences and the currently limited value of energy storage, implementation of new facilities is still slow compared to photovoltaic systems. One recognized option to lower cost instantly is the hybridization of CSP with other energy sources, such as natural gas or biomass. Various references exist for the combination of CSP with natural gas in combined cycle plants, also known as Integrated Solar Combined Cycle (ISCC) plants. One problem with current ISCC concepts is the so called ISCC crisis, which occurs when CSP is not contributing and cycle efficiency falls below efficiency levels of solely natural gas only fired combined cycle plants. This paper analyses current ISCC concepts and compares them with two optimised designs. The comparison is based on a Kuraymat type ISCC plant and shows that cycle optimization enables a net capacity increase of 1.4% and additional daily generation of up to 7.9%. The specific investment of the optimised Integrated Solar Combined Cycle plant results in a 0.4% cost increase, which is below the additional net capacity and daily generation increase.

Estrogen receptor alpha is cell cycle-regulated and regulates the cell cycle in a ligand-dependent fashion.

Science.gov (United States)

JavanMoghadam, Sonia; Weihua, Zhang; Hunt, Kelly K; Keyomarsi, Khandan

2016-06-17

Estrogen receptor alpha (ERα) has been implicated in several cell cycle regulatory events and is an important predictive marker of disease outcome in breast cancer patients. Here, we aimed to elucidate the mechanism through which ERα influences proliferation in breast cancer cells. Our results show that ERα protein is cell cycle-regulated in human breast cancer cells and that the presence of 17-β-estradiol (E2) in the culture medium shortened the cell cycle significantly (by 4.5 hours, P cycle duration were observed in the S and G2/M phases, whereas the G1 phase was indistinguishable under liganded and unliganded conditions. In addition, ERα knockdown in MCF-7 cells accelerated mitotic exit, whereas transfection of ERα-negative MDA-MB-231 cells with exogenous ERα significantly shortened the S and G2/M phases (by 9.1 hours, P cycle progression through the S and G2/M phases than fulvestrant does, presumably because of the destabilizing effect of fulvestrant on ERα protein. Together, these results show that ERα modulates breast cancer cell proliferation by regulating events during the S and G2/M phases of the cell cycle in a ligand-dependent fashion. These results provide the rationale for an effective treatment strategy that includes a cell cycle inhibitor in combination with a drug that lowers estrogen levels, such as an aromatase inhibitor, and an antiestrogen that does not result in the degradation of ERα, such as tamoxifen.

Plant characteristics of an integrated solid oxide fuel cell cycle and a steam cycle

International Nuclear Information System (INIS)

Rokni, Masoud

2010-01-01

Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier hydrocarbons in an adiabatic steam reformer (ASR). The pre-treated fuel then entered to the anode side of the SOFC. The remaining fuels after the SOFC stacks entered a catalytic burner for further combusting. The burned gases from the burner were then used to produce steam for the Rankine cycle in a heat recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization and the pre-reformer had no effect on the plant efficiency, which was also true when decreasing the anode temperature. However, increasing the cathode temperature had a significant effect on the plant efficiency. In addition, decreasing the SOFC utilization factor from 0.8 to 0.7, increases the plant efficiency by about 6%. An optimal plant efficiency of about 71% was achieved by optimizing the plant.

Plant characteristics of an integrated solid oxide fuel cell cycle and a steam cycle

Energy Technology Data Exchange (ETDEWEB)

Rokni, Masoud [Technical University of Denmark, Dept. of Mechanical Engineering, Thermal Energy System, Building 402, 2800 Kgs, Lyngby (Denmark)

2010-12-15

Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier hydrocarbons in an adiabatic steam reformer (ASR). The pre-treated fuel then entered to the anode side of the SOFC. The remaining fuels after the SOFC stacks entered a catalytic burner for further combusting. The burned gases from the burner were then used to produce steam for the Rankine cycle in a heat recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization and the pre-reformer had no effect on the plant efficiency, which was also true when decreasing the anode temperature. However, increasing the cathode temperature had a significant effect on the plant efficiency. In addition, decreasing the SOFC utilization factor from 0.8 to 0.7, increases the plant efficiency by about 6%. An optimal plant efficiency of about 71% was achieved by optimizing the plant. (author)

Reprocessing in the thorium fuel cycle

International Nuclear Information System (INIS)

Merz, E.

1984-01-01

An overview of the authors personal view is presented on open questions in regard to still required research and development work for the thorium fuel cycle before its application in a technical-industrial scale may be tackled. For a better understanding, all stations of the back-end of the thorium fuel cycle are briefly illustrated and their special features discussed. They include storage and transportation measures, all steps of reprocessing, as well as the entire radioactive waste treatment. Knowledge gaps are, as far as they are obvious, identified and proposals put forward for additional worthwile investigations. (orig.) [de

Credit Spreads Across the Business Cycle

DEFF Research Database (Denmark)

Nielsen, Mads Stenbo

This paper studies how corporate bond spreads vary with the business cycle. I show that both level and slope of empirical credit spread curves are correlated with the state of the economy, and I link this to variation in idiosyncratic jump risk. I develop a structural credit risk model...... that accounts for both business cycle and jump risk, and show by estimation that the model captures the counter-cyclical level and pro-cyclical slope of empirical credit spread curves. In addition, I provide a new procedure for estimation of idiosyncratic jump risk, which is consistent with observed shocks...

Generalized Load Sharing for Homogeneous Networks of Distributed Environment

Directory of Open Access Journals (Sweden)

A. Satheesh

2008-01-01

Full Text Available We propose a method for job migration policies by considering effective usage of global memory in addition to CPU load sharing in distributed systems. When a node is identified for lacking sufficient memory space to serve jobs, one or more jobs of the node will be migrated to remote nodes with low memory allocations. If the memory space is sufficiently large, the jobs will be scheduled by a CPU-based load sharing policy. Following the principle of sharing both CPU and memory resources, we present several load sharing alternatives. Our objective is to reduce the number of page faults caused by unbalanced memory allocations for jobs among distributed nodes, so that overall performance of a distributed system can be significantly improved. We have conducted trace-driven simulations to compare CPU-based load sharing policies with our policies. We show that our load sharing policies not only improve performance of memory bound jobs, but also maintain the same load sharing quality as the CPU-based policies for CPU-bound jobs. Regarding remote execution and preemptive migration strategies, our experiments indicate that a strategy selection in load sharing is dependent on the amount of memory demand of jobs, remote execution is more effective for memory-bound jobs, and preemptive migration is more effective for CPU-bound jobs. Our CPU-memory-based policy using either high performance or high throughput approach and using the remote execution strategy performs the best for both CPU-bound and memory-bound job in homogeneous networks of distributed environment.

International Nuclear Fuel Cycle Fact Book. Revision 5

International Nuclear Information System (INIS)

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.; Jeffs, A.G.

1985-01-01

This Fact Book has been compiled in an effort to provide: (1) an overview of worldwide nuclear power and fuel cycle programs; and (2) current data concerning fuel cycle and waste management facilities, R and D programs, and key personnel in countries other than the United States. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2. The Fact Book is organized as follows: (1) Overview section - summary tables which indicate national involvement in nuclear reactor, fuel cycle, and waste management development activities; (2) national summaries - a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; (3) international agencies - a section for each of the international agencies which has significant fuel cycle involvement; (4) energy supply and demand - summary tables, including nuclear power projections; (5) fuel cycle - summary tables; and (6) travel aids international dialing instructions, international standard time chart, passport and visa requirements, and currency exchange rate

International Nuclear Fuel Cycle Fact Book. Revision 5

Energy Technology Data Exchange (ETDEWEB)

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.; Jeffs, A.G.

1985-01-01

This Fact Book has been compiled in an effort to provide: (1) an overview of worldwide nuclear power and fuel cycle programs; and (2) current data concerning fuel cycle and waste management facilities, R and D programs, and key personnel in countries other than the United States. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2. The Fact Book is organized as follows: (1) Overview section - summary tables which indicate national involvement in nuclear reactor, fuel cycle, and waste management development activities; (2) national summaries - a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; (3) international agencies - a section for each of the international agencies which has significant fuel cycle involvement; (4) energy supply and demand - summary tables, including nuclear power projections; (5) fuel cycle - summary tables; and (6) travel aids international dialing instructions, international standard time chart, passport and visa requirements, and currency exchange rate.

International nuclear fuel cycle fact book. Revision 4

Energy Technology Data Exchange (ETDEWEB)

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.

1984-03-01

This Fact Book has been compiled in an effort to provide (1) an overview of worldwide nuclear power and fuel cycle programs and (2) current data concerning fuel cycle and waste management facilities, R and D programs, and key personnel in countries other than the United States. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2. The Fact Book is organized as follows: (1) Overview section - summary tables which indicate national involvement in nuclear reactor, fuel cycle, and waste management development activities; (2) national summaries - a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; (3) international agencies - a section for each of the international agencies which has significant fuel cycle involvement; (4) energy supply and demand - summary tables, including nuclear power projections; (5) fuel cycle - summary tables; and (6) travel aids - international dialing instructions, international standard time chart, passport and visa requirements, and currency exchange rate.

International nuclear fuel cycle fact book. Revision 4

International Nuclear Information System (INIS)

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.

1984-03-01

This Fact Book has been compiled in an effort to provide (1) an overview of worldwide nuclear power and fuel cycle programs and (2) current data concerning fuel cycle and waste management facilities, R and D programs, and key personnel in countries other than the United States. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2. The Fact Book is organized as follows: (1) Overview section - summary tables which indicate national involvement in nuclear reactor, fuel cycle, and waste management development activities; (2) national summaries - a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; (3) international agencies - a section for each of the international agencies which has significant fuel cycle involvement; (4) energy supply and demand - summary tables, including nuclear power projections; (5) fuel cycle - summary tables; and (6) travel aids - international dialing instructions, international standard time chart, passport and visa requirements, and currency exchange rate

Alternative ORC bottoming cycles FOR combined cycle power plants

International Nuclear Information System (INIS)

Chacartegui, R.; Sanchez, D.; Munoz, J.M.; Sanchez, T.

2009-01-01

In this work, low temperature Organic Rankine Cycles are studied as bottoming cycle in medium and large scale combined cycle power plants. The analysis aims to show the interest of using these alternative cycles with high efficiency heavy duty gas turbines, for example recuperative gas turbines with lower gas turbine exhaust temperatures than in conventional combined cycle gas turbines. The following organic fluids have been considered: R113, R245, isobutene, toluene, cyclohexane and isopentane. Competitive results have been obtained for toluene and cyclohexane ORC combined cycles, with reasonably high global efficiencies. The paper is structured in four main parts. A review of combined cycle and ORC cycle technologies is presented, followed by a thermodynamic analysis of combined cycles with commercial gas turbines and ORC low temperature bottoming cycles. Then, a parametric optimization of an ORC combined cycle plant is performed in order to achieve a better integration between these two technologies. Finally, some economic considerations related to the use of ORC in combined cycles are discussed.

Menstrual cycle phase does not predict political conservatism.

Directory of Open Access Journals (Sweden)

Isabel M Scott

Full Text Available Recent authors have reported a relationship between women's fertility status, as indexed by menstrual cycle phase, and conservatism in moral, social and political values. We conducted a survey to test for the existence of a relationship between menstrual cycle day and conservatism. 2213 women reporting regular menstrual cycles provided data about their political views. Of these women, 2208 provided information about their cycle date, 1260 provided additional evidence of reliability in self-reported cycle date, and of these, 750 also indicated an absence of hormonal disruptors such as recent hormonal contraception use, breastfeeding or pregnancy. Cycle day was used to estimate day-specific fertility rate (probability of conception; political conservatism was measured via direct self-report and via responses to the "Moral Foundations" questionnaire. We also recorded relationship status, which has been reported to interact with menstrual cycle phase in determining political preferences. We found no evidence of a relationship between estimated cyclical fertility changes and conservatism, and no evidence of an interaction between relationship status and cyclical fertility in determining political attitudes. Our findings were robust to multiple inclusion/exclusion criteria and to different methods of estimating fertility and measuring conservatism. In summary, the relationship between cycle-linked reproductive parameters and conservatism may be weaker or less reliable than previously thought.

Menstrual cycle phase does not predict political conservatism.

Science.gov (United States)

Scott, Isabel M; Pound, Nicholas

2015-01-01

Recent authors have reported a relationship between women's fertility status, as indexed by menstrual cycle phase, and conservatism in moral, social and political values. We conducted a survey to test for the existence of a relationship between menstrual cycle day and conservatism. 2213 women reporting regular menstrual cycles provided data about their political views. Of these women, 2208 provided information about their cycle date, 1260 provided additional evidence of reliability in self-reported cycle date, and of these, 750 also indicated an absence of hormonal disruptors such as recent hormonal contraception use, breastfeeding or pregnancy. Cycle day was used to estimate day-specific fertility rate (probability of conception); political conservatism was measured via direct self-report and via responses to the "Moral Foundations" questionnaire. We also recorded relationship status, which has been reported to interact with menstrual cycle phase in determining political preferences. We found no evidence of a relationship between estimated cyclical fertility changes and conservatism, and no evidence of an interaction between relationship status and cyclical fertility in determining political attitudes. Our findings were robust to multiple inclusion/exclusion criteria and to different methods of estimating fertility and measuring conservatism. In summary, the relationship between cycle-linked reproductive parameters and conservatism may be weaker or less reliable than previously thought.

Cycling infrastructure for reducing cycling injuries in cyclists.

Science.gov (United States)

Mulvaney, Caroline A; Smith, Sherie; Watson, Michael C; Parkin, John; Coupland, Carol; Miller, Philip; Kendrick, Denise; McClintock, Hugh

2015-12-10

Cycling is an attractive form of transport. It is beneficial to the individual as a form of physical activity that may fit more readily into an individual's daily routine, such as for cycling to work and to the shops, than other physical activities such as visiting a gym. Cycling is also beneficial to the wider community and the environment as a result of fewer motorised journeys. Cyclists are seen as vulnerable road users who are frequently in close proximity to larger and faster motorised vehicles. Cycling infrastructure aims to make cycling both more convenient and safer for cyclists. This review is needed to guide transport planning. To:1. evaluate the effects of different types of cycling infrastructure on reducing cycling injuries in cyclists, by type of infrastructure;2. evaluate the effects of cycling infrastructure on reducing the severity of cycling injuries in cyclists;3. evaluate the effects of cycling infrastructure on reducing cycling injuries in cyclists with respect to age, sex and social group. We ran the most recent search on 2nd March 2015. We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library), MEDLINE (OvidSP), Embase Classic + Embase(OvidSP), PubMed and 10 other databases. We searched websites, handsearched conference proceedings, screened reference lists of included studies and previously published reviews and contacted relevant organisations. We included randomised controlled trials, cluster randomised controlled trials, controlled before-after studies, and interrupted time series studies which evaluated the effect of cycling infrastructure (such as cycle lanes, tracks or paths, speed management, roundabout design) on cyclist injury or collision rates. Studies had to include a comparator, that is, either no infrastructure or a different type of infrastructure. We excluded studies that assessed collisions that occurred as a result of competitive cycling. Two review authors examined the titles and

International nuclear cycle fact book: Revision 9

International Nuclear Information System (INIS)

Leigh, I.W.

1989-01-01

The International Nuclear Fuel Cycle Fact Book has been compiled in an effort to provide current data concerning fuel cycle and waste management facilities, R and D programs and key personnel. The Fact Book contains: national summaries in which a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; and international agencies in which a section for each of the international agencies which has significant fuel cycle involvement, and a listing of nuclear societies. The national summaries, in addition to the data described above, feature a small map for each country as well as some general information. The latter is presented from the perspective of the Fact Book user in the United States

EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS; FINAL

International Nuclear Information System (INIS)

Arsalan Razani; Kwang J. Kim

2001-01-01

The final report for the DOE/UNM grant number DE-FG26-98FT40148 discusses the accomplishments of both the theoretical analysis of advanced power cycles and experimental investigation of advanced falling film heat exchangers. This final report also includes the progress report for the third year (period of October 1, 2000 to September 30, 2001). Four new cycles were studied and two cycles were analyzed in detail based on the second law of thermodynamics. The first cycle uses a triple combined cycle, which consists of a topping cycle (Brayton/gas), an intermediate cycle (Rankine/steam), and a bottoming cycle (Rankine/ammonia). This cycle can produce high efficiency and reduces the irreversibility of the Heat Recovery Steam Generator (HRSC) of conventional combined power cycles. The effect of important system parameters on the irreversibility distribution of all components in the cycle under reasonable practical constraints was evaluated. The second cycle is a combined cycle, which consists of a topping cycle (Brayton/gas) and a bottoming cycle (Rankine/ammonia) with integrated compressor inlet air cooling. This innovative cycle can produce high power and efficiency. This cycle is also analyzed and optimized based on the second the second law to obtain the irreversibility distribution of all components in the cycle. The results of the studies have been published in peer reviewed journals and ASME conference proceeding. Experimental investigation of advanced falling film heat exchangers was conducted to find effective additives for steam condensation. Four additives have been selected and tested in a horizontal tube steam condensation facility. It has been observed that heat transfer additives have been shown to be an effective way to increase the efficiency of conventional tube bundle condenser heat exchangers. This increased condensation rate is due to the creation of a disturbance in the liquid condensate surround the film. The heat transfer through such a film has

On Non-Parallelizable Deterministic Client Puzzle Scheme with Batch Verification Modes

NARCIS (Netherlands)

Tang, Qiang; Jeckmans, Arjan

A (computational) client puzzle scheme enables a client to prove to a server that a certain amount of computing resources (CPU cycles and/or Memory look-ups) has been dedicated to solve a puzzle. Researchers have identified a number of potential applications, such as constructing timed cryptography,

Life cycle versus balanced funds: An emerging market perspective

Directory of Open Access Journals (Sweden)

Elbie Louw

2017-08-01

Full Text Available Background: Inadequate retirement savings is an international challenge. Additionally, individuals are not cognisant of how asset allocation choices ultimately impact retirement savings. Life cycle and balanced funds are popular asset allocation strategies to save towards retirement. However, recent research is questioning the efficacy of life cycle funds that switch to lower risk asset classes as retirement approaches. Aim: The purpose of this study is to compare the performance of life cycle funds with balanced funds to determine whether either dominates the other. The study compares balanced and life cycle funds with similar starting asset allocations as well as those where the starting asset allocations differ. Setting: The study has a South African focus and constructs funds using historical data for the main local asset classes; that is, equity, fixed income and cash, as well as a proxy for foreign equity covering the period 1986–2013. Method: The study makes use of Monte Carlo simulations and bootstrap with replacement, and compares the simulated outcomes using stochastic dominance as decision-making criteria. Results: The results indicate that life cycle funds fail to dominate balanced funds by first-order or almost stochastic dominance when funds have a similar starting asset allocation. It is noteworthy that there are instances where the opposite is true, that is, balanced funds dominate life cycle funds. These results highlight that while the life cycle funds provide more downside protection, they significantly suppress the upside potential compared to balanced funds. When the starting asset allocations of the balanced and life cycle funds differ, the stochastic dominance results are inconsistent as to the efficacy of the life cycle fund strategies considered. Conclusion: The study shows that whether one fund is likely to dominate the other is strongly dependent on the underlying asset allocation strategies of the funds

Multiaxial Cycle Deformation and Low-Cycle Fatigue Behavior of Mild Carbon Steel and Related Welded-Metal Specimen

Directory of Open Access Journals (Sweden)

Weilian Qu

2017-01-01

Full Text Available The low-cycle fatigue experiments of mild carbon Q235B steel and its related welded-metal specimens are performed under uniaxial, in-phase, and 90° out-of-phase loading conditions. Significant additional cyclic hardening for 90° out-of-phase loading conditions is observed for both base metal and its related weldment. Besides, welding process produces extra additional hardening under the same loading conditions compared with the base metal. Multiaxial low-cycle fatigue strength under 90° out-of-phase loading conditions is significantly reduced for both base-metal and welded-metal specimens. The weldment has lower fatigue life than the base metal under the given loading conditions, and the fatigue life reduction of weldment increases with the increasing strain amplitude. The KBM, FS, and MKBM critical plane parameters are evaluated for the fatigue data obtained. The FS and MKBM parameters are found to show better correlation with fatigue lives for both base-metal and welded-metal specimens.

Optimum gas turbine cycle for combined cycle power plant

International Nuclear Information System (INIS)

Polyzakis, A.L.; Koroneos, C.; Xydis, G.

2008-01-01

The gas turbine based power plant is characterized by its relatively low capital cost compared with the steam power plant. It has environmental advantages and short construction lead time. However, conventional industrial engines have lower efficiencies, especially at part load. One of the technologies adopted nowadays for efficiency improvement is the 'combined cycle'. The combined cycle technology is now well established and offers superior efficiency to any of the competing gas turbine based systems that are likely to be available in the medium term for large scale power generation applications. This paper has as objective the optimization of a combined cycle power plant describing and comparing four different gas turbine cycles: simple cycle, intercooled cycle, reheated cycle and intercooled and reheated cycle. The proposed combined cycle plant would produce 300 MW of power (200 MW from the gas turbine and 100 MW from the steam turbine). The results showed that the reheated gas turbine is the most desirable overall, mainly because of its high turbine exhaust gas temperature and resulting high thermal efficiency of the bottoming steam cycle. The optimal gas turbine (GT) cycle will lead to a more efficient combined cycle power plant (CCPP), and this will result in great savings. The initial approach adopted is to investigate independently the four theoretically possible configurations of the gas plant. On the basis of combining these with a single pressure Rankine cycle, the optimum gas scheme is found. Once the gas turbine is selected, the next step is to investigate the impact of the steam cycle design and parameters on the overall performance of the plant, in order to choose the combined cycle offering the best fit with the objectives of the work as depicted above. Each alterative cycle was studied, aiming to find the best option from the standpoint of overall efficiency, installation and operational costs, maintainability and reliability for a combined power

Thermodynamic assessment of a wind turbine based combined cycle

International Nuclear Information System (INIS)

Rabbani, M.; Dincer, I.; Naterer, G.F.

2012-01-01

Combined cycles use the exhaust gases released from a Gas Turbine (GT). Approximately 30–40% of the turbine shaft work is typically used to drive the Compressor. The present study analyzes a system that couples a Wind Turbine (WT) with a combined cycle. It demonstrates how a WT can be used to supply power to the Compressor in the GT cycle and pump fluid through a reheat Rankine cycle, in order to increase the overall power output. Three different configurations are discussed, namely high penetration, low penetration and wind power addition. In the case of a low electricity demand and high penetration configuration, extra wind power is used to compress air which can then be used in the low penetration configuration. During a high load demand, all the wind power is used to drive the pump and compressor and if required additional compressed air is supplied by a storage unit. The analysis shows that increasing the combustion temperature reduces the critical velocity and mass flow rate. Increases in wind speed reduce both energy and exergy efficiency of the overall system. -- Highlights: ► This study analyzes a system that couples a wind turbine with a combined power generation cycle. ► Surplus wind power is used to compress air, which is then stored and used at a later time. ► Increasing the pressure ratio will reduce the work ratio between the Rankine and Brayton cycles. ► A higher combustion temperature will increase the net work output, as well as the system energy and exergy efficiencies.

Additive manufacturing of metals

International Nuclear Information System (INIS)

Herzog, Dirk; Seyda, Vanessa; Wycisk, Eric; Emmelmann, Claus

2016-01-01

Additive Manufacturing (AM), the layer-by layer build-up of parts, has lately become an option for serial production. Today, several metallic materials including the important engineering materials steel, aluminium and titanium may be processed to full dense parts with outstanding properties. In this context, the present overview article describes the complex relationship between AM processes, microstructure and resulting properties for metals. It explains the fundamentals of Laser Beam Melting, Electron Beam Melting and Laser Metal Deposition, and introduces the commercially available materials for the different processes. Thereafter, typical microstructures for additively manufactured steel, aluminium and titanium are presented. Special attention is paid to AM specific grain structures, resulting from the complex thermal cycle and high cooling rates. The properties evolving as a consequence of the microstructure are elaborated under static and dynamic loading. According to these properties, typical applications are presented for the materials and methods for conclusion.

International nuclear fuel cycle fact book

International Nuclear Information System (INIS)

1992-09-01

The International Nuclear Fuel Cycle Fact Book has been compiled in an effort to provide current data concerning fuel cycle and waste management facilities, R ampersand D programs and key personnel on 23 countries, including the US, four multi-national agencies, and 21 nuclear societies. The Fact Book is organized as follows: National summaries-a section for each country which summarizes nuclear policy, describes organizational relationships, and provides addresses and names of key personnel and information on facilities. International agencies-a section for each of the international agencies which has significant fuel cycle involvement and a listing of nuclear societies. Glossary-a list of abbreviations/acronyms of organizations, facilities, technical and other terms. The national summaries, in addition to the data described above, feature a small map for each country as well as some general information. The latter presented from the perspective of the Fact Book user in the United States

DISASTER MANAGEMENT CYCLE – A THEORETICAL APPROACH

Directory of Open Access Journals (Sweden)

Himayatullah KHAN

2008-01-01

Full Text Available The present study explains the various concepts used in disastermanagement. The concepts explained include: Disaster, Hazard,Vulnerability, Capacity, Risk and Disaster Management Cycle. In addition tothe terminologies, the study also seeks to explain various types of disasters.

Gasification and combined cycles: Present situation and future prospects

International Nuclear Information System (INIS)

Brustia, G.F.; Bressan, L.; Domenichini, R.

1992-01-01

The gasification of coal and/or residual fuels from refineries together with the use of combined cycle power generation systems represents a technically and economically feasible method for the conversion of poor quality fossil fuels into electric power. The conversion is accomplished with maximum respect for the severest environmental normatives. In addition, foreseen technical improvements for components and plant systems are expected to heighten the marketing potential of gasification/combined cycle power plants. After Italy's moratorium on nuclear energy, the passing eras of conventional fossil fuel and then combined cycle power plants, the need for highly competitive industrial production technologies and the urgency of nation-wide energy conservation appear to be ushering in the new era of gasification with combined cycles

Emergency planning for fuel cycle facilities

International Nuclear Information System (INIS)

Lacey, L.R.

1991-01-01

In April 1989, NRC published new emergency planning regulations which apply to certain by-product, source, and special nuclear materials licensees including most fuel cycle facilities. In addition to these NRC regulations, other regulatory agencies such as EPA, OSHA, and DOT have regulations concerning emergency planning or notification that may apply to fuel cycle facilities. Emergency planning requirements address such areas as emergency classification, organization, notification and activation, assessment, corrective and protective measures, emergency facilities and equipment, maintaining preparedness, records and reports, and recovery. This article reviews applicable regulatory requirements and guidance, then concentrates on implementation strategies to produce an effective emergency response capability

Ocean Thermal Energy Conversion Using Double-Stage Rankine Cycle

Directory of Open Access Journals (Sweden)

Yasuyuki Ikegami

2018-03-01

Full Text Available Ocean Thermal Energy Conversion (OTEC using non-azeotropic mixtures such as ammonia/water as working fluid and the multistage cycle has been investigated in order to improve the thermal efficiency of the cycle because of small ocean temperature differences. The performance and effectiveness of the multistage cycle are barely understood. In addition, previous evaluation methods of heat exchange process cannot clearly indicate the influence of the thermophysical characteristics of the working fluid on the power output. Consequently, this study investigated the influence of reduction of the irreversible losses in the heat exchange process on the system performance in double-stage Rankine cycle using pure working fluid. Single Rankine, double-stage Rankine and Kalina cycles were analyzed to ascertain the system characteristics. The simple evaluation method of the temperature difference between the working fluid and the seawater is applied to this analysis. From the results of the parametric performance analysis it can be considered that double-stage Rankine cycle using pure working fluid can reduce the irreversible losses in the heat exchange process as with the Kalina cycle using an ammonia/water mixture. Considering the maximum power efficiency obtained in the study, double-stage Rankine and Kalina cycles can improve the power output by reducing the irreversible losses in the cycle.

Development of FBR cycle data base system (II)

International Nuclear Information System (INIS)

Kubota, Sadae; Ohtaki, Akira; Hirao, Kazuhiro

2003-05-01

In the 'Feasibility Study on Commercialized FBR Cycle Systems (F/S)', scenario evaluations, cost-benefit evaluations and system characteristic evaluations to show the significance of the FBR cycle system introduction concretely are performed while design studies for FBR plants, reprocessing systems and fabrication systems are conducted. In these evaluations, future society of various conditions and situation is assumed, and investigation and analysis about needs and social effects of FBR cycle are carried out. In this study, promising FBR cycle concepts are suggested by taking information such as domestic and foreign policies and bills, an economic prediction, a supply and demand prediction of resources, a project of technology development into consideration in addition to system design information. The development of the FBR Cycle Database which this report introduced started in 1999 fiscal year to enable managed unitarity and searched reference information to use for the above scenario evaluations, cost-benefit evaluations and system characteristic evaluations. In 2000 fiscal year, its prototype was made and used tentatively, and we extracted the problems in operation and functions from that, and, in 2001 fiscal year, the entry system and the search system using the Web page were made in order to solve problems of the prototype, and started use in our group. Moreover, in 2002 fiscal year, we expanded and improved the search system and promoted the efficiency of management work, and use in JNC through intranet of the database was started. In addition, as a result of having made the entry of about 350 data in 2002 fiscal year, the collected number of the database reaches about 7,250 by the end of March, 2003. We are to continue the entry of related information of various evaluations in F/S phase 2 from now on. In addition, we are to examine improvement of convenience of the search system and cooperation with the economy database. (author)

Supersonic propulsion technology. [variable cycle engines

Science.gov (United States)

Powers, A. G.; Coltrin, R. E.; Stitt, L. E.; Weber, R. J.; Whitlow, J. B., Jr.

1979-01-01

Propulsion concepts for commercial supersonic transports are discussed. It is concluded that variable cycle engines, together with advanced supersonic inlets and low noise coannular nozzles, provide good operating performance for both supersonic and subsonic flight. In addition, they are reasonably quiet during takeoff and landing and have acceptable exhaust emissions.

Exploiting Submodular Value Functions for Faster Dynamic Sensor Selection

NARCIS (Netherlands)

Satsangi, Y.; Whiteson, S.; Oliehoek, F.A.

2015-01-01

A key challenge in the design of multi-sensor systems is the efficient allocation of scarce resources such as bandwidth, CPU cycles, and energy, leading to the dynamic sensor selection problem in which a subset of the available sensors must be selected at each timestep. While partially observable

Fuel cycles - a key to future CANDU success

International Nuclear Information System (INIS)

Kuran, S.; Hopwood, J.; Hastings, I.J.

2011-01-01

Globally, fuel cycles are being evaluated as ways of extending nuclear fuel resources, addressing security of supply and reducing back-end spent-fuel management. Current-technology thermal reactors and future fast reactors are the preferred platform for such fuel cycle applications and as an established thermal reactor with unique fuel-cycle capability, CANDU will play a key role in fulfilling such a vision. The next step in the evolution of CANDU fuel cycles will be the introduction of Recovered Uranium (RU), derived from conventional reprocessing. A low-risk RU option applicable in the short term comprises a combination of RU and Depleted Uranium (DU), both former waste streams, giving a Natural Uranium Equivalent (NUE) fuel. This option has been demonstrated in China, and all test bundles have been removed from the Qinshan 1 reactor. Additionally, work is being done on an NUE full core, a Thorium demonstration irradiation and an Advanced Fuel CANDU Reactor(AFCR). AECL is developing other fuel options for CANDU, including actinide waste burning. AECL has developed the Enhanced CANDU 6 (EC6) reactor, upgraded from its best-performing CANDU 6 design. High neutron economy, on-power refueling and a simple fuel bundle provide the EC6 with the flexibility to accommodate a range of advanced fuels, in addition to its standard natural uranium. (author)

Comparison of the Organic Flash Cycle (OFC) to other advanced vapor cycles for intermediate and high temperature waste heat reclamation and solar thermal energy

International Nuclear Information System (INIS)

Ho, Tony; Mao, Samuel S.; Greif, Ralph

2012-01-01

The Organic Flash Cycle (OFC) is proposed as a vapor power cycle that could potentially improve the efficiency with which high and intermediate temperature finite thermal sources are utilized. The OFC's aim is to improve temperature matching and reduce exergy losses during heat addition. A theoretical investigation is conducted using high accuracy equations of state such as BACKONE, Span–Wagner, and REFPROP in a detailed thermodynamic and exergetic analysis. The study examines 10 different aromatic hydrocarbons and siloxanes as potential working fluids. Comparisons are drawn between the OFC and an optimized basic Organic Rankine Cycle (ORC), a zeotropic Rankine cycle using a binary ammonia-water mixture, and a transcritical CO 2 cycle. Results showed aromatic hydrocarbons to be the better suited working fluid for the ORC and OFC due to higher power output and less complex turbine designs. Results also showed that the single flash OFC achieves comparable utilization efficiencies to the optimized basic ORC. Although the OFC improved heat addition exergetic efficiency, this advantage was negated by irreversibilities introduced during flash evaporation. A number of potentially significant improvements to the OFC are possible though which includes using a secondary flash stage or replacing the throttling valve with a two-phase expander. -- Highlights: ► The Organic Flash Cycle (OFC) is proposed to improve temperature matching. ► Ten aromatic hydrocarbon and siloxane working fluids are considered. ► Accurate equations of state explicit in Helmholtz energy are used in the analysis. ► The OFC is compared to basic ORCs, zeotropic, and transcritical cycles. ► The OFC achieves comparable power output to the optimized basic ORC.

Heat exchanger inventory cost optimization for power cycles with one feedwater heater

International Nuclear Information System (INIS)

Qureshi, Bilal Ahmed; Antar, Mohamed A.; Zubair, Syed M.

2014-01-01

Highlights: • Cost optimization of heat exchanger inventory in power cycles is investigated. • Analysis for an endoreversible power cycle with an open feedwater heater is shown. • Different constraints on the power cycle are investigated. • The constant heat addition scenario resulted in the lowest value of the cost function. - Abstract: Cost optimization of heat exchanger inventory in power cycles with one open feedwater heater is undertaken. In this regard, thermoeconomic analysis for an endoreversible power cycle with an open feedwater heater is shown. The scenarios of constant heat rejection and addition rates, power as well as rate of heat transfer in the open feedwater heater are studied. All cost functions displayed minima with respect to the high-side absolute temperature ratio (θ 1 ). In this case, the effect of the Carnot temperature ratio (Φ 1 ), absolute temperature ratio (ξ) and the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ) are qualitatively the same. Furthermore, the constant heat addition scenario resulted in the lowest value of the cost function. For variation of all cost functions, the smaller the value of the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ), lower the cost at the minima. As feedwater heater to hot end unit cost ratio decreases, the minimum total conductance required increases

Improving High-Temperature Tensile and Low-Cycle Fatigue Behavior of Al-Si-Cu-Mg Alloys Through Micro-additions of Ti, V, and Zr

Science.gov (United States)

Shaha, S. K.; Czerwinski, F.; Kasprzak, W.; Friedman, J.; Chen, D. L.

2015-07-01

High-temperature tensile and low-cycle fatigue tests were performed to assess the influence of micro-additions of Ti, V, and Zr on the improvement of the Al-7Si-1Cu-0.5Mg (wt pct) alloy in the as-cast condition. Addition of transition metals led to modification of microstructure where in addition to conventional phases present in the Al-7Si-1Cu-0.5Mg base, new thermally stable micro-sized Zr-Ti-V-rich phases Al21.4Si4.1Ti3.5VZr3.9, Al6.7Si1.2TiZr1.8, Al2.8Si3.8V1.6Zr, and Al5.1Si35.4Ti1.6Zr5.7Fe were formed. The tensile tests showed that with increasing test temperature from 298 K to 673 K (25 °C to 400 °C), the yield stress and tensile strength of the present studied alloy decreased from 161 to 84 MPa and from 261 to 102 MPa, respectively. Also, the studied alloy exhibited 18, 12, and 5 pct higher tensile strength than the alloy A356, 354 and existing Al-Si-Cu-Mg alloy modified with additions of Zr, Ti, and Ni, respectively. The fatigue life of the studied alloy was substantially longer than those of the reference alloys A356 and the same Al-7Si-1Cu-0.5Mg base with minor additions of V, Zr, and Ti in the T6 condition. Fractographic analysis after tensile tests revealed that at the lower temperature up to 473 K (200 °C), the cleavage-type brittle fracture for the precipitates and ductile fracture for the matrix were dominant while at higher temperature fully ductile-type fracture with debonding and pull-out of cracked particles was identified. It is believed that the intermetallic precipitates containing Zr, Ti, and V improve the alloy performance at increased temperatures.

The Brazilian business and growth cycles

Directory of Open Access Journals (Sweden)

Chauvet Marcelle

2002-01-01

Full Text Available This paper uses several produceres to date and analyse the Brazilian business and growth cycles. In particular, a Markov switching model is fitted to quarterly and annual real production data. The smoothed probabilities of the Markov states are used as predictive rules to define different phases of cyclical fluctuations of real Brazilian production. The results are compared with different non-parametric rules. All methods implemented yield similar dating and reveal asymmetries across the different states of the Brazilian business and growth cycles, in which slowdowns and recessions are short and abrupt, while high growth phases and expansions are longer and less steep. The resulting dating of the Brazilian economic cycles can be used as a reference point for construction and evaluation of the predictive performance of coincident, leading, or lagging indicators of economic activity. In addition, the filtered probabilities obtained from the Markov switching model allow early recognition of the transition to a new business cycle phase, wich can be used, for example, for evaluation of the adequate strength and timing of countercyclical policies, for reassessment of projected sales or profits by businesses and investors, or for monitoring of inflation pressures.

Theoretical thermodynamic analysis of Rankine power cycle with thermal driven pump

International Nuclear Information System (INIS)

Lakew, Amlaku Abie; Bolland, Olav; Ladam, Yves

2011-01-01

Highlights: → The work is focused on theoretical aspects of thermal driven pump (TDP) Rankine cycle. → The mechanical pump is replaced by thermal driven pump. → Important parameters of thermal driven pump Rankine cycle are investigated. → TDP Rankine cycle produce more power but it requires additional low grade heat. - Abstract: A new approach to improve the performance of supercritical carbon dioxide Rankine cycle which uses low temperature heat source is presented. The mechanical pump in conventional supercritical carbon dioxide Rankine cycle is replaced by thermal driven pump. The concept of thermal driven pump is to increase the pressure of a fluid in a closed container by supplying heat. A low grade heat source is used to increase the pressure of the fluid instead of a mechanical pump, this increase the net power output and avoid the need for mechanical pump which requires regular maintenance and operational cost. The thermal driven pump considered is a shell and tube heat exchanger where the working fluid is contained in the tube, a tube diameter of 5 mm is chosen to reduce the heating time. The net power output of the Rankine cycle with thermal driven pump is compared to that of Rankine cycle with mechanical pump and it is observed that the net power output is higher when low grade thermal energy is used to pressurize the working fluid. The thermal driven pump consumes additional heat at low temperature (60 o C) to pressurize the working fluid.

Study on the FBR cycle introduction scenario. 4. Evaluation of the FBR cycle introduction scenario from the viewpoints of the fuel cycle requirements

International Nuclear Information System (INIS)

Ono, Kiyoshi; Shiotani, Hiroki; Hirao, Kazunori

2003-07-01

This report is intended to explain the outline of the scenario studies on FBR (Fast Breeder Reactor) cycle introduction. Recently, people value the reduction of environmental impact in addition to the recycle of energy resources and the energy security in these scenario studies. This report summarizes the analysis about the necessity of plutonium recycling in LWR (Light water Reactor) from short-term view and about the necessity of FBR cycle introduction from a long-term view in Japan, by comparing 'FBR scenario' with 'LWR once-through scenario' and 'Pu recycle in LWR scenario', from the viewpoints of cumulative uranium demand, spent fuel storage, radioactive waste arising, etc. It becomes clear that the plutonium recycling in LWR has a good effect on the reduction of spent fuel storage and the cumulative natural uranium demand before FBR cycle introduction, from short-term view (20-30 years). On the other hand, this analysis also shows that there is much effect of FBR deployment not only on saving amount of uranium use and energy security but also on reduction of high-level radioactive waste (spent fuels and vitrified waste) and minor actinide arising, from long-term view (100-200 years). (author)

Cycles and Common Cycles in Property and Related Sectors

OpenAIRE

Peijie Wang

2003-01-01

This paper examines cycles and common cycles in the property market and the economy. While focusing on common cycles, the study also incorporates common trends in the meantime, so it covers the whole spectrum of dynamic analysis. It has been found that property shares common cycles, particularly with those sectors that are the user markets of property. The mechanisms of common cycles and the relative magnitudes of cycles of the sectors related to property are discussed to shed light on proper...

Superelastic load cycling of Gum Metal

International Nuclear Information System (INIS)

Vorontsov, V.A.; Jones, N.G.; Rahman, K.M.; Dye, D.

2015-01-01

The superelastic beta titanium alloy, Gum Metal, has been found to accumulate plastic strain during tensile load cycling in the superelastic regime. This is evident from the positive drift of the macroscopic stress vs. strain hysteresis curve parallel to the strain axis and the change in its geometry subsequent to every load–unload cycle. In addition, there is a progressive reduction in the hysteresis loop width and in the stress at which the superelastic transition occurs. In situ synchrotron X-ray diffraction has shown that the lattice strain exhibited the same behaviour as that observed in macroscopic measurements and identified further evidence of plastic strain accumulation. The mechanisms responsible for the observed behaviour have been evaluated using transmission electron microscopy, which revealed a range of different defects that formed during load cycling. The formation of these defects is consistent with the classical mathematical theory for the bcc to orthorhombic martensitic transformation. It is the accumulation of these defects over time that alters its superelastic behaviour

Implementing risk-informed life-cycle design

International Nuclear Information System (INIS)

Hill, Ralph S.

2009-01-01

This paper describes a design process based on risk-informed probabilistic design methodologies that cover a facility's life-cycle from start of conceptual design through decontamination and decommissioning. The concept embodies use of probabilistic risk assessments to establish target reliabilities for facility systems and components. The target reliabilities are used for system based code margin exchange and performance simulation analyses to optimize design over all phases (design, construction, operation and decommissioning) of a facility's life-cycle. System based code margin exchange reduces excessive level of construction margins for passive components to appropriate levels resulting in a more flexible structure of codes and standards that improves facility reliability and cost. System and subsystem simulation analyses determine the optimum combination of initial system and component construction reliability, maintenance frequency, and inspection frequency for both active and passive components. The paper includes a description of these risk-informed life-cycle design processes, a summary of work being done, and a discussion of additional work needed to implement the process.

Polar coronal holes and solar cycles

International Nuclear Information System (INIS)

Simon, P.A.

1979-01-01

The relationship between the geomagnetic activity of the three years preceding a sunspot minimum and the peak of the next sunspot maximum confirms the polar origin of the solar wind during one part of the solar cycle. Pointing out that the polar holes have a very small size or disappear at the time of the polar field reversal, a low latitude origin of the solar-wind at sunspot maximum is suggested and the cycle variation of solar wind and geomagnetic activity is described. In addition a close relationship is noted between the maximum level of the geomagnetic activity reached a few years before a solar minimum and its level at the next sunspot maximum. Studying separately the effects of both the low latitude holes and the solar activity, the possibility of predicting both the level of geomagnetic activity and the sunspot number at the next sunspot maximum is pointed out. As a conclusion the different categories of phenomena contributing to a solar cycle are specified. (Auth.)

Affective cycling in thyroid disease

International Nuclear Information System (INIS)

Tapp, A.

1988-01-01

Depression in an elderly man with primary recurrent unipolar depression responded to radioactive iodine treatment of a thyrotoxic nodule, without the addition of psychotropic medications. Two months later, manic symptoms developed concomitant with the termination of the hyperthyroid state secondary to the radioactive iodine treatment. Clinical implications of these findings in relation to the possible mechanism of action of thyroid hormones on affective cycling are discussed

Prey-predator dynamics with prey refuge providing additional food to predator

International Nuclear Information System (INIS)

Ghosh, Joydev; Sahoo, Banshidhar; Poria, Swarup

2017-01-01

Highlights: • The effects of interplay between prey refugia and additional food are reported. • Hopf bifurcation conditions are derived analytically. • Existence of unique limit cycle is shown analytically. • Predator extinction may be possible at very high prey refuge ecological systems. - Abstract: The impacts of additional food for predator on the dynamics of a prey-predator model with prey refuge are investigated. The equilibrium points and their stability behaviours are determined. Hopf bifurcation conditions are derived analytically. Most significantly, existence conditions for unique stable limit cycle in the phase plane are shown analytically. The analytical results are in well agreement with the numerical simulation results. Effects of variation of refuge level as well as the variation of quality and quantity of additional food on the dynamics are reported with the help of bifurcation diagrams. It is found that high quality and high quantity of additional food supports oscillatory coexistence of species. It is observed that predator extinction possibility in high prey refuge ecological systems may be removed by supplying additional food to predator population. The reported theoretical results may be useful to conservation biologist for species conservation in real world ecological systems.

HCl removal using cycled carbide slag from calcium looping cycles

International Nuclear Information System (INIS)

Xie, Xin; Li, Yingjie; Wang, Wenjing; Shi, Lei

2014-01-01

Highlights: • Cycled carbide slag from calcium looping cycles is used to remove HCl. • The optimum temperature for HCl removal of cycled carbide slag is 700 °C. • The presence of CO 2 restrains HCl removal of cycled carbide slag. • CO 2 capture conditions have important effects on HCl removal of cycled carbide slag. • HCl removal capacity of carbide slag drops with cycle number rising from 1 to 50. - Abstract: The carbide slag is an industrial waste from chlor-alkali plants, which can be used to capture CO 2 in the calcium looping cycles, i.e. carbonation/calcination cycles. In this work, the cycled carbide slag from the calcium looping cycles for CO 2 capture was proposed to remove HCl in the flue gas from the biomass-fired and RDFs-fired boilers. The effects of chlorination temperature, HCl concentration, particle size, presence of CO 2 , presence of O 2 , cycle number and CO 2 capture conditions in calcium looping cycles on the HCl removal behavior of the carbide slag experienced carbonation/calcination cycles were investigated in a triple fixed-bed reactor. The chlorination product of the cycled carbide slag from the calcium looping after absorbing HCl is not CaCl 2 but CaClOH. The optimum temperature for HCl removal of the cycled carbide slag from the carbonation/calcination cycles is 700 °C. The chlorination conversion of the cycled carbide slag increases with increasing the HCl concentration. The cycled carbide slag with larger particle size exhibits a lower chlorination conversion. The presence of CO 2 decreases the chlorination conversions of the cycled carbide slag and the presence of O 2 has a trifling impact. The chlorination conversion of the carbide slag experienced 1 carbonation/calcination cycle is higher than that of the uncycled calcined sorbent. As the number of carbonation/calcination cycles increases from 1 to 50, the chlorination conversion of carbide slag drops gradually. The high calcination temperature and high CO 2

The C-N-cycle additional channels through the combinative resonances phenomenon (CIRs)

International Nuclear Information System (INIS)

Gafarov, A.A.; Khugaev, A.V.; Koblik, Yu.N.

2000-01-01

The Combinative Isobar Resonances are shown as new channels of the C-N-cycle. In 1994 we had firstly used our new developed approach - the M ethod of Spectra Superposition p roviding measurement of d σ (E) /d ω at every accelerator (including colliders ) with highest energy-resolution depending (for thin targets) only on energy-resolution of detectors [1-5]. Rarely one can read about this[6].That time the Excitation Function (EF) of the l2 C(p,p o ) elastic scattering with energy-resolution ∼10 keV for E p =16 ∼ 19.5 MeV of cyclotron protons by using the multi angular magnetic spectrograph as detector was measured.It was wonderful when after data processing so surprised curve with a saturated structure of overlapped resonances - fluctuations of cross-section (Fig.1) was obtained (in contrary to EF obtained by M.J. LeVine and P.D.Parker in 60 Th at the tandem generator [7]). The precise agreement between well known thresholds and nuclear levels with the brightest anomalies in our curve and not disappearing fine structures in full-events curve (stat.err. 3%) - all this, only, had satisfied me that these structures are not just a joke of statistics. Fig.l shows a comparison of our obtained EF with thresholds and levels of well known product-nuclei

Physical properties of cobia (Rachycentron canadum) surimi: effect of washing cycle at different salt concentrations.

Science.gov (United States)

Hamzah, N; Sarbon, N M; Amin, A M

2015-08-01

This study aimed to determine the effects of 2-5 wash cycles and the addition of tetrasodium pyrophosphate (TSPP) (0 %, 0.05 Surimi% and 0.1 % w/w)-with or without the addition of 0.4 % calcium chloride (CaCl2)-on the physical properties such as texture, colour, expressible moisture and microstructure of Cobia (Rachycentron canadum) surimi gel. The highest breaking force (484.85 g) was obtained with the addition 0.1 % TSPP alone on the fifth wash. However, a combination of 0.1 and 0.4 % CaCl2 in surimi gels at wash cycle 5 resulted in the highest degree of whiteness (86.8 %), as well as total expressible moisture (2.785 %) and deformation (17.11 mm). The highest surimi gel strength (6,923 g.mm) was obtained after three wash cycles with the addition of 0.1 % TSPP +0.4 % CaCl2. The physical properties of Cobia fish surimi gels were affected by the number of wash cycles and treatments with TSPP and CaCl2.

PDC Journeys to Product Analysis Development and Additive Manufacturing?

International Nuclear Information System (INIS)

Shalina Sheik Muhamad

2015-01-01

The technology for product development and manufacturing has gone through many advancements. It is widely recognised that it would provide competitive advantage for engineering organization in term of product development cycle, productivity, sustainability and efficiency. We begin by describing the general characteristic of design process that will need to be integrated in product life cycle management. In Nuclear Malaysia, especially in engineering design activities the majority have been using 3D modelling. This paper discusses on the current product design practiced in Nuclear Malaysia, new product development process and new manufacturing technique which is additive manufacturing. (author)

Effects of Water and Nitrogen Addition on Ecosystem Carbon Exchange in a Meadow Steppe

Science.gov (United States)

Wang, Yunbo; Jiang, Qi; Yang, Zhiming; Sun, Wei; Wang, Deli

2015-01-01

A changing precipitation regime and increasing nitrogen deposition are likely to have profound impacts on arid and semiarid ecosystem C cycling, which is often constrained by the timing and availability of water and nitrogen. However, little is known about the effects of altered precipitation and nitrogen addition on grassland ecosystem C exchange. We conducted a 3-year field experiment to assess the responses of vegetation composition, ecosystem productivity, and ecosystem C exchange to manipulative water and nitrogen addition in a meadow steppe. Nitrogen addition significantly stimulated aboveground biomass and net ecosystem CO2 exchange (NEE), which suggests that nitrogen availability is a primary limiting factor for ecosystem C cycling in the meadow steppe. Water addition had no significant impacts on either ecosystem C exchange or plant biomass, but ecosystem C fluxes showed a strong correlation with early growing season precipitation, rather than whole growing season precipitation, across the 3 experimental years. After we incorporated water addition into the calculation of precipitation regimes, we found that monthly average ecosystem C fluxes correlated more strongly with precipitation frequency than with precipitation amount. These results highlight the importance of precipitation distribution in regulating ecosystem C cycling. Overall, ecosystem C fluxes in the studied ecosystem are highly sensitive to nitrogen deposition, but less sensitive to increased precipitation. PMID:26010888

GridOrbit public display

DEFF Research Database (Denmark)

Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob

2010-01-01

We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...

Performance evaluation of an ejector subcooled vapor-compression refrigeration cycle

International Nuclear Information System (INIS)

Xing, Meibo; Yan, Gang; Yu, Jianlin

2015-01-01

Highlights: • An ejector subcooled vapor-compression refrigeration cycle is proposed. • The performance of the cycle with ejector subcooling is evaluated theoretically. • Increase in refrigeration capacity can be achieved by the ejector subcooled cycle. • The new cycle exhibits higher COP compared to the basic single-stage cycle. • Performance of the new cycle depends on the operation pressures of the ejector. - Abstract: In this study, a novel vapor-compression refrigeration cycle with mechanical subcooling using an ejector is proposed to improve the performance of a conventional single-stage vapor-compression refrigeration cycle. In the theoretical study, a mathematical model is developed to predict the performance of the cycle by using R404A and R290, and then compared with that of the conventional refrigeration cycle. The simulation results show that the performance of the ejector subcooled cycle is better than that of the conventional cycle. When the evaporator temperature ranges from −40 to −10 °C and the condenser temperature is 45 °C, the novel cycle displays volumetric refrigeration capacity improvements of 11.7% with R404A and 7.2% with R290. And the novel cycle achieves COP improvements of 9.5% with R404A and 7.0% with R290. In addition, the improvement of the COP and cooling capacity of this novel cycle largely depends on the operation pressures of the ejector. The potential practical advantages offered by the cycle may be worth further attention in future studies

Engine cycle design considerations for nuclear thermal propulsion systems

International Nuclear Information System (INIS)

Pelaccio, D.G.; Scheil, C.M.; Collins, J.T.

1993-01-01

A top-level study was performed which addresses nuclear thermal propulsion system engine cycle options and their applicability to support future Space Exploration Initiative manned lunar and Mars missions. Technical and development issues associated with expander, gas generator, and bleed cycle near-term, solid core nuclear thermal propulsion engines are identified and examined. In addition to performance and weight the influence of the engine cycle type on key design selection parameters such as design complexity, reliability, development time, and cost are discussed. Representative engine designs are presented and compared. Their applicability and performance impact on typical near-term lunar and Mars missions are shown

Thermal cycling behaviour of lanthanum zirconate as EB-PVD thermal barrier coating

International Nuclear Information System (INIS)

Bobzin, K.; Lugscheider, E.; Bagcivan, N.

2006-01-01

Thermal cycling tests with two different EB-PVD thermal barrier coatings (TBC) were performed in a furnace cycle test. The results of these tests showed an increase of endurable cycle number when pyrochloric La 2 Zr 2 O 7 was used as TBC. 1865 cycles were reached with La 2 Zr 2 O 7 and 1380 cycles with 7 weigth-% yttria stabilised zirconia (YSZ) EB-PVD TBC. Additional investigation was made with scanning electron microscope (SEM) to investigate morphology and to determine chemical composition by electron dispersive x-ray spectroscopy (EDS) analysis. X-Ray diffraction was performed to analyze structural constitution of deposited coatings. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Outlook on to fuel cycle perspectives at WWER-440

International Nuclear Information System (INIS)

Stech, S.; Bajgl, J.

2005-01-01

Current internal fuel cycle in NPP Dukovany 4x440 MWe is shortly characterized with new types of fuel assemblies and advanced fuel cycles which have been introduced in the last years. The modernization activities accomplished until now might be extrapolated to the further period in fuel design - mechanic, thermal-hydraulic and neutronic respectively - with additional increase in fuel enrichments and burnups on the way to the 6-year cycle. Reaktor power up rating together with Unit thermal efficiency improvements could bring an increase in the electric output to the value nearly 500 MWe. The reasons are given for long-term cooperation with Fuel Supplier and Plant Designer in the area of fuel cycle as well as in Unit Design Basis. All innovations mentioned in the article including future fuel and fuel cycle changes might be a quite realistic perspective at the end of the first decade of the new century (Authors)

Cost of the external MTR-fuel cycle. (Uranium , reprocessing and related services)

International Nuclear Information System (INIS)

Mueller, H.; Gruber, G.

1991-01-01

This paper points out how the RERTR program has affected NUKEM's fuel supplies for MTRs and how the prices in the External MTR Fuel Cycle have developed during this period. In addition other potential fuel sources and services on the External MTR Fuel Cycle are given. (orig.)

International nuclear fuel cycle fact book: Revision 9

Energy Technology Data Exchange (ETDEWEB)

Leigh, I.W.

1989-01-01

The International Nuclear Fuel Cycle Fact Book has been compiled in an effort to provide current data concerning fuel cycle and waste management facilities, R and D programs and key personnel. The Fact Book contains: national summaries in which a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; and international agencies in which a section for each of the international agencies which has significant fuel cycle involvement, and a listing of nuclear societies. The national summaries, in addition to the data described above, feature a small map for each country as well as some general information. The latter is presented from the perspective of the Fact Book user in the United States.

Compositional and expression analyses of the glideosome during the Plasmodium life cycle reveal an additional myosin light chain required for maximum motility.

Science.gov (United States)

Green, Judith L; Wall, Richard J; Vahokoski, Juha; Yusuf, Noor A; Ridzuan, Mohd A Mohd; Stanway, Rebecca R; Stock, Jessica; Knuepfer, Ellen; Brady, Declan; Martin, Stephen R; Howell, Steven A; Pires, Isa P; Moon, Robert W; Molloy, Justin E; Kursula, Inari; Tewari, Rita; Holder, Anthony A

2017-10-27

Myosin A (MyoA) is a Class XIV myosin implicated in gliding motility and host cell and tissue invasion by malaria parasites. MyoA is part of a membrane-associated protein complex called the glideosome, which is essential for parasite motility and includes the MyoA light chain myosin tail domain-interacting protein (MTIP) and several glideosome-associated proteins (GAPs). However, most studies of MyoA have focused on single stages of the parasite life cycle. We examined MyoA expression throughout the Plasmodium berghei life cycle in both mammalian and insect hosts. In extracellular ookinetes, sporozoites, and merozoites, MyoA was located at the parasite periphery. In the sexual stages, zygote formation and initial ookinete differentiation precede MyoA synthesis and deposition, which occurred only in the developing protuberance. In developing intracellular asexual blood stages, MyoA was synthesized in mature schizonts and was located at the periphery of segmenting merozoites, where it remained throughout maturation, merozoite egress, and host cell invasion. Besides the known GAPs in the malaria parasite, the complex included GAP40, an additional myosin light chain designated essential light chain (ELC), and several other candidate components. This ELC bound the MyoA neck region adjacent to the MTIP-binding site, and both myosin light chains co-located to the glideosome. Co-expression of MyoA with its two light chains revealed that the presence of both light chains enhances MyoA-dependent actin motility. In conclusion, we have established a system to study the interplay and function of the three glideosome components, enabling the assessment of inhibitors that target this motor complex to block host cell invasion. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Part-load performance of a high temperature Kalina cycle

International Nuclear Information System (INIS)

Modi, Anish; Andreasen, Jesper Graa; Kærn, Martin Ryhl; Haglind, Fredrik

2015-01-01

Highlights: • Detailed algorithm to solve high temperature Kalina cycle in part load. • A central receiver concentrating solar power plant with direct vapour generation considered as case study. • Part-load performance curves and fitted equations presented. - Abstract: The Kalina cycle has recently seen increased interest as an alternative to the conventional steam Rankine cycle. The cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine bottoming cycle, and solar power plants. The high temperature cycle layouts are inherently more complex than the low temperature layouts due to the presence of a distillation-condensation subsystem, three pressure levels, and several heat exchangers. This paper presents a detailed approach to solve the Kalina cycle in part-load operating conditions for high temperature (a turbine inlet temperature of 500 °C) and high pressure (100 bar) applications. A central receiver concentrating solar power plant with direct vapour generation is considered as a case study where the part-load conditions are simulated by changing the solar heat input to the receiver. Compared with the steam Rankine cycle, the Kalina cycle has an additional degree of freedom in terms of the ammonia mass fraction which can be varied in order to maximize the part-load efficiency of the cycle. The results include the part-load curves for various turbine inlet ammonia mass fractions and the fitted equations for these curves.

Monitoring of mass flux of catalyst FCC in a Cold Pilot Unit by gamma radiation transmission; Monitoramento da taxa de fluxo do catalisador FCC em uma unidade piloto a frio por medicao de transmissao gama

Energy Technology Data Exchange (ETDEWEB)

Brito, Marcio Fernando Paixao de

2014-09-01

This paper proposes a model for monitoring the mass flow of catalyst FCC - Fluid Catalytic Cracking - in a CPU - Cold Pilot unit - due to the injection of air and solid by gamma radiation transmission. The CPU simplifies the process of FCC, which is represented by the catalyst cycle, and it was constructed of acrylic, so that the flow can be visualized. The CPU consists of riser separation chamber and return column, and simulates the riser reactor of the FCC process. The catalyst is injected into the column back to the base of the riser, an inclined tube, where the compressed air means that there fluidization along the riser. When the catalyst comes in the separation chamber, the solid phase is sent to the return column, and the gas phase exits the system through one of the four cyclones at the top of the separation chamber. The transmission gamma of measures will be made by means of three test sections that have source and detector shielded. Pressure drop in the riser measurements are made through three pressure gauges positioned on the riser. The source used was Am-241 gamma ray with energy of 60 keV, and detector used was a scintillator of NaI (Tl) of 2 {sup x} 2{sup .} Measures the mass flow of catalyst are made by varying the seal of the catalyst, and density of solid in the riser because with the combination of these measures can determine the speed of the catalyst in the riser. The results show that the transmission gamma is a suitable technique for monitoring the flow of catalyst, flow model in CPU is annular, tomography third generation is more appropriate to study the CPU and the density variation in circulation in the CPU decreases linearly with increasing air flow. (author)

Monitoring of mass flux of catalyst FCC in a Cold Pilot Unit by gamma radiation transmission

International Nuclear Information System (INIS)

Brito, Marcio Fernando Paixao de

2014-01-01

This paper proposes a model for monitoring the mass flow of catalyst FCC - Fluid Catalytic Cracking - in a CPU - Cold Pilot unit - due to the injection of air and solid by gamma radiation transmission. The CPU simplifies the process of FCC, which is represented by the catalyst cycle, and it was constructed of acrylic, so that the flow can be visualized. The CPU consists of riser separation chamber and return column, and simulates the riser reactor of the FCC process. The catalyst is injected into the column back to the base of the riser, an inclined tube, where the compressed air means that there fluidization along the riser. When the catalyst comes in the separation chamber, the solid phase is sent to the return column, and the gas phase exits the system through one of the four cyclones at the top of the separation chamber. The transmission gamma of measures will be made by means of three test sections that have source and detector shielded. Pressure drop in the riser measurements are made through three pressure gauges positioned on the riser. The source used was Am-241 gamma ray with energy of 60 keV, and detector used was a scintillator of NaI (Tl) of 2 x 2 . Measures the mass flow of catalyst are made by varying the seal of the catalyst, and density of solid in the riser because with the combination of these measures can determine the speed of the catalyst in the riser. The results show that the transmission gamma is a suitable technique for monitoring the flow of catalyst, flow model in CPU is annular, tomography third generation is more appropriate to study the CPU and the density variation in circulation in the CPU decreases linearly with increasing air flow. (author)

Damage Features of Altered Rock Subjected to Drying-Wetting Cycles

Directory of Open Access Journals (Sweden)

Zhe Qin

2018-01-01

Full Text Available An abandoned open pit was used as a tailing pond for a concentrating mill, with the height of the water surface subject to cyclic fluctuation. The effects of drying and wetting cycles on the mechanical parameters of pit rock were tested. Interactions of the hydrochemical environment, due to the dissolution of tailings, and drying and wetting cycles caused degradation of mechanical properties in the rock. It was found that uniaxial compressive strength and elastic modulus decreased as the number of dry/wet cycles increased. The quantitative relationship between the mechanical parameters and the number of dry/wet cycles was indicated by an exponential function. In addition to uniaxial testing, cohesion and the internal friction angle were determined through triaxial testing. The shear strength index deteriorated under the drying and wetting cycles. The hydrochemical environment also negatively affected the mechanical parameters. Potential effects between drying and wetting cycles and slope displacement were analyzed by on-site monitoring. The results show that the displacement increased because of the drying and wetting cycles, which may lead to sudden failure of the slope.

Influence of water contamination and conductive additives on the intercalation of lithium into graphite

Energy Technology Data Exchange (ETDEWEB)

Joho, F; Rykart, B; Novak, P [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Spahr, M E; Monnier, A [Timcal AG, Sins (Switzerland)

1999-08-01

The irreversible charge loss in the first cycle of lithium intercalation into graphite electrodes for lithium-ion batteries is discussed as a function of water contamination of the electrolyte solution. Furthermore, the improvement of the electrode cycle life due to conductive additives to graphite is demonstrated. (author) 5 figs., 3 refs.

Thermal cycle efficiency of the indirect combined HTGR-GT power generation system

Energy Technology Data Exchange (ETDEWEB)

Muto, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1996-02-01

High thermal efficiency of 50% could be expected in a power generation system coupling a high temperature gas-cooled reactor(HTGR) with a closed cycle gas turbine(GT). There are three candidate systems such as a direct cycle(DC), an indirect cycle(ICD) and an indirect combined cycle(IDCC). The IDCC could solve many problems in both the DC and the IDC and consists of a primary circuit and a secondary circuit where a topping cycle is a Brayton cycle and a bottoming cycle is a steam cycle. In this report, the thermal cycle efficiency of the IDCC is examined regarding configurations of components and steam pressure. It has been shown that there are two types of configurations, that is, a perfect cascade type and a semi-cascade one and the latter can be further classified into Case A, Case B and Case C. The conditions achieving the maximum thermal cycle efficiency were revealed for these cases. In addition, the optimum system configurations were proposed considering the thermal cycle efficiency, safety and plant arrangement. (author).

Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

International Nuclear Information System (INIS)

Dai Yiping; Wang Jiangfeng; Gao Lin

2009-01-01

A new combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the ejector refrigeration cycle. This combined cycle produces both power output and refrigeration output simultaneously. It can be driven by the flue gas of gas turbine or engine, solar energy, geothermal energy and industrial waste heats. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. And a parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the performance of the combined cycle. In addition, a parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The results show that the biggest exergy loss due to the irreversibility occurs in heat addition processes, and the ejector causes the next largest exergy loss. It is also shown that the turbine inlet pressure, the turbine back pressure, the condenser temperature and the evaporator temperature have significant effects on the turbine power output, refrigeration output and exergy efficiency of the combined cycle. The optimized exergy efficiency is 27.10% under the given condition.

The Geologic Nitrogen Cycle

Science.gov (United States)

Johnson, B. W.; Goldblatt, C.

2013-12-01

N2 is the dominant gas in Earth's atmosphere, and has been so through the majority of the planet's history. Originally thought to only be cycled in significant amounts through the biosphere, it is becoming increasingly clear that a large degree of geologic cycling can occur as well. N is present in crustal rocks at 10s to 100s of ppm and in the mantle at 1s to perhaps 10s of ppm. In light of new data, we present an Earth-system perspective of the modern N cycle, an updated N budget for the silicate Earth, and venture to explain the evolution of the N cycle over time. In an fashion similar to C, N has a fast, biologically mediated cycle and a slower cycle driven by plate tectonics. Bacteria fix N2 from the atmosphere into bioavailable forms. N is then cycled through the food chain, either by direct consumption of N-fixing bacteria, as NH4+ (the primary waste form), or NO3- (the most common inorganic species in the modern ocean). Some organic material settles as sediment on the ocean floor. In anoxic sediments, NH4+ dominates; due to similar ionic radii, it can readily substitute for K+ in mineral lattices, both in sedimentary rocks and in oceanic lithosphere. Once it enters a subduction zone, N may either be volatilized and returned to the atmosphere at arc volcanoes as N2 or N2O, sequestered into intrusive igneous rocks (as NH4+?), or subducted deep into the mantle, likely as NH4+. Mounting evidence indicates that a significant amount of N may be sequestered into the solid Earth, where it may remain for long periods (100s m.y.) before being returned to the atmosphere/biosphere by volcanism or weathering. The magnitude fluxes into the solid Earth and size of geologic N reservoirs are poorly constrained. The size of the N reservoirs contained in the solid Earth directly affects the evolution of Earth's atmosphere. It is possible that N now sequestered in the solid Earth was once in the atmosphere, which would have resulted in a higher atmospheric pressure, and

Modular forms and special cycles on Shimura curves (AM-161)

CERN Document Server

Kudla, Stephen S; Yang, Tonghai

2006-01-01

Modular Forms and Special Cycles on Shimura Curves is a thorough study of the generating functions constructed from special cycles, both divisors and zero-cycles, on the arithmetic surface ""M"" attached to a Shimura curve ""M"" over the field of rational numbers. These generating functions are shown to be the q-expansions of modular forms and Siegel modular forms of genus two respectively, valued in the Gillet-Soulé arithmetic Chow groups of ""M"". The two types of generating functions are related via an arithmetic inner product formula. In addition, an analogue of the classical Siegel-Weil

Batu Pahat Driving Cycle for Light Duty Gasoline Engine

Science.gov (United States)

Zainul Abidin, Zainul Ameerul Ikhsan B.; Faisal Hushim, Mohd; Ahmad, Osman Bin

2017-08-01

Driving cycle is a series of data points that represents the vehicle speed versus time. Transient driving cycles involve many changes such as frequent speed changes during typical on-road driving condition [2]. Model driving cycles involve protracted periods at constant speeds. The Batu Pahat Driving Cycle (BPDC) developed to represent the driving pattern of people in a district of Batu Pahat. Based on this driving cycle, it will be a reference to other researchers to study about the gases emission release and fuel consumption by the vehicle on the dynamometer or automotive simulation based on this driving cycle. Existing driving cycles used such as the New European Driving Cycle (NEDC), the Federal Test Procedure (FTP-72/75, and Japan 10-15 Mode Cycle is not appropriate for Batu Pahat district because of different road conditions, driving habits and environmental of developed driving cycle countries are not same [2][14]. Batu Pahat drive cycle was developed for low-capacity gasoline engine under 150 cc and operating on urban roads, rural roads and road around Universiti Tun Hussein Onn. The importance of these driving cycle as the reference for other research to measure and do automotive simulation regarding fuel consumption and gas emission release from the motorcycle for these three type of driving cycle area. Another use for driving cycles is in vehicle simulations [3]. More specifically, they are used in propulsion system simulations to predict the performance of internal combustion engines, transmissions, electric drive systems, batteries, fuel cell systems, and similar components [18]. Data collection methods used in this study is the use of Global Positioning System (GPS). The results obtained are not similar to each other due to differences in congestion on data taken. From the driving cycle graph obtained, such as the average velocity, maximum velocity, the duration and Positive Acceleration Kinetic Energy (PKE) can be determined. In addition, the best

Functionality Selection Principle for High Voltage Lithium-ion Battery Electrolyte Additives

Energy Technology Data Exchange (ETDEWEB)

Su, Chi-Cheung; He, Meinan [Department; Peebles, Cameron; Zeng, Li; Tornheim, Adam; Liao, Chen; Zhang, Lu; Wang, Jie; Wang, Yan [Department; Zhang, Zhengcheng

2017-08-30

A new class of electrolyte additives based on cyclic fluorinated phosphate esters was rationally designed and identified as being able to stabilize the surface of a LiNi0.5Mn0.3Co0.2O2 (NMC532) cathode when cycled at potentials higher than 4.6 V vs Li+/Li. Cyclic fluorinated phosphates were designed to incorporate functionalities of various existing additives to maximize their utilization. The synthesis and characterization of these new additives are described and their electrochemical performance in a NMC532/graphite cell cycled between 4.6 and 3.0 V are investigated. With 1.0 wt % 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphospholane 2-oxide (TFEOP) in the conventional electrolyte the NMC532/graphite cell exhibited much improved capacity retention compared to that without any additive. The additive is believed to form a passivation layer on the surface of the cathode via a sacrificial polymerization reaction as evidenced by X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonsance (NMR) analysis results. The rational pathway of a cathode-electrolyte-interface formation was proposed for this type of additive. Both experimental results and the mechanism hypothesis suggest the effectiveness of the additive stems from both the polymerizable cyclic ring and the electron-withdrawing fluorinated alkyl group in the phosphate molecular structure. The successful development of cyclic fluorinated phosphate additives demonstrated that this new functionality selection principle, by incorporating useful functionalities of various additives into one molecule, is an effective approach for the development of new additives.

Nonproliferation norms in civilian nuclear fuel cycle

International Nuclear Information System (INIS)

Kawata, Tomio

2005-01-01

For sustainable use of nuclear energy in large scale, it seems inevitable to choose a closed cycle option. One of the important questions is, then, whether we can really achieve the compatibility between civilian nuclear fuel cycle and nonproliferation norms. In this aspect, Japan is very unique because she is now only one country with full-scope nuclear fuel cycle program as a non-nuclear weapon state in NPT regime. In June 2004 in the midst of heightened proliferation concerns in NPT regime, the IAEA Board of Governors concluded that, for Japanese nuclear energy program, non-diversion of declared nuclear material and the absence of undeclared nuclear material and activities were verified through the inspections and examinations under Comprehensive Safeguards and the Additional Protocol. Based on this conclusion, the IAEA announced the implementation of Integrated Safeguards in Japan in September 2004. This paper reviews how Japan has succeeded in becoming the first country with full-scope nuclear fuel cycle program to qualify for integrated Safeguards, and identifies five key elements that have made this achievement happen: (1) Obvious need of nuclear fuel cycle program, (2) Country's clear intention for renunciation of nuclear armament, (3) Transparency of national nuclear energy program, (4) Record of excellent compliance with nonproliferation obligations for many decades, and (5) Numerous proactive efforts. These five key elements will constitute a kind of an acceptance model for civilian nuclear fuel cycle in NNWS, and may become the basis for building 'Nonproliferation Culture'. (author)

Technical support for open-cycle MHD program

Energy Technology Data Exchange (ETDEWEB)

None

1978-05-01

The support program for open-cycle MHD at Argonne National Lab is developing the analytical tools needed to investigate the performance of the major components in the combined-cycle MHD/steam power system. The analytical effort is centered on the primary components of the system that are unique to MHD and also on the integration of these analytical representations into a model of the entire power producing system. The present project activities include modeling of the combustor, MHD channel, slag separator, and the high-temperature air preheater. In addition, these models are combined into a complete system model, which is at present capable of carrying out optimizations of the entire system on either thermodynamic efficiency or with less confidence, cost of electrical power. Also, in support of the open-cycle program, considerable effort has gone into the formulation of a CDIF Test Plan and a National MHD Test Program.

Advanced nuclear fuel cycles - Main challenges and strategic choices

International Nuclear Information System (INIS)

Le Biez, V.; Machiels, A.; Sowder, A.

2013-01-01

A graphical conceptual model of the uranium fuel cycles has been developed to capture the present, anticipated, and potential (future) nuclear fuel cycle elements. The once-through cycle and plutonium recycle in fast reactors represent two basic approaches that bound classical options for nuclear fuel cycles. Chief among these other options are mono-recycling of plutonium in thermal reactors and recycling of minor actinides in fast reactors. Mono-recycling of plutonium in thermal reactors offers modest savings in natural uranium, provides an alternative approach for present-day interim management of used fuel, and offers a potential bridging technology to development and deployment of future fuel cycles. In addition to breeder reactors' obvious fuel sustainability advantages, recycling of minor actinides in fast reactors offers an attractive concept for long-term management of the wastes, but its ultimate value is uncertain in view of the added complexity in doing so,. Ultimately, there are no simple choices for nuclear fuel cycle options, as the selection of a fuel cycle option must reflect strategic criteria and priorities that vary with national policy and market perspectives. For example, fuel cycle decision-making driven primarily by national strategic interests will likely favor energy security or proliferation resistance issues, whereas decisions driven primarily by commercial or market influences will focus on economic competitiveness

Advanced nuclear fuel cycles - Main challenges and strategic choices

Energy Technology Data Exchange (ETDEWEB)

Le Biez, V. [Corps des Mines, 35 bis rue Saint-Sabin, F-75011 Paris (France); Machiels, A.; Sowder, A. [Electric Power Research Institute, Inc. 3420, Hillview Avenue, Palo Alto, CA 94304 (United States)

2013-07-01

A graphical conceptual model of the uranium fuel cycles has been developed to capture the present, anticipated, and potential (future) nuclear fuel cycle elements. The once-through cycle and plutonium recycle in fast reactors represent two basic approaches that bound classical options for nuclear fuel cycles. Chief among these other options are mono-recycling of plutonium in thermal reactors and recycling of minor actinides in fast reactors. Mono-recycling of plutonium in thermal reactors offers modest savings in natural uranium, provides an alternative approach for present-day interim management of used fuel, and offers a potential bridging technology to development and deployment of future fuel cycles. In addition to breeder reactors' obvious fuel sustainability advantages, recycling of minor actinides in fast reactors offers an attractive concept for long-term management of the wastes, but its ultimate value is uncertain in view of the added complexity in doing so,. Ultimately, there are no simple choices for nuclear fuel cycle options, as the selection of a fuel cycle option must reflect strategic criteria and priorities that vary with national policy and market perspectives. For example, fuel cycle decision-making driven primarily by national strategic interests will likely favor energy security or proliferation resistance issues, whereas decisions driven primarily by commercial or market influences will focus on economic competitiveness.

Solar cycle variations of geocoronal balmer α emission

International Nuclear Information System (INIS)

Nossal, S.; Reynolds, R.J.; Roesler, F.L.; Scherb, F.

1993-01-01

Observations of the geocoronal Balmer in nightglow have been made from Wisconsin for more than a solar cycle with an internally consistent intensity reference to standard astronomical nebulae. These measurements were made with a double etalon, pressure-scanned, 15-cm aperture Fabry-Perot interferometer. The resulting long time data provides an opportunity to examine solar cycle influence on the mid-latitude exosphere and to address accompanying questions concerning the degree to which the exosphere is locally static or changing. The exospheric Balmer α absolute intensity measurements reported here show no statistically significant variations throughout the solar cycle when the variation with viewing geometry is removed by normalizing the data to reference exospheric model predictions by Anderson et al. However, the relative intensity dependence on solar depression angle does show a solar cycle variation. This variation suggests a possible related variation in the exospheric hydrogen density profile, although other interpretations are also possible. The results suggest that additional well-calibrated data taken over a longer time span could probe low-amplitude variations over the solar cycle and test predictions of a slow monotonic increase in exospheric hydrogen arising from greenhouse gases. 21 refs., 9 figs., 2 tabs

Electron sub-cycling in particle simulation of plasma

International Nuclear Information System (INIS)

Adam, J.C.; Serveniere, A.G.; Langdon, A.B.

1982-01-01

A straightforward modification which reduces by half the computational cost of standard particle-in-cell algorithms for simulation of plasmas is described. The saving is obtained by integrating only the electrons through a number of time steps (sub-cycle) in order to resolve their evolution, while integrating the much slower ions only once per cycle, i.e., to match the time step of each species to their characteristic frequencies. A dispersion relation is derived which describes the numerical instabilities expected by sampling frequency arguments. Simulations support the broad features of the analytical results, viz., the maximum growth rate and domain of the instability, and its stabilization by the addition of weak damping. An implicit sub-cycling algorithm is suggested which may provide further saving while avoiding a limitation of implicit algorithms described elsewhere

High-throughput protein crystallization on the World Community Grid and the GPU

International Nuclear Information System (INIS)

Kotseruba, Yulia; Cumbaa, Christian A; Jurisica, Igor

2012-01-01

We have developed CPU and GPU versions of an automated image analysis and classification system for protein crystallization trial images from the Hauptman Woodward Institute's High-Throughput Screening lab. The analysis step computes 12,375 numerical features per image. Using these features, we have trained a classifier that distinguishes 11 different crystallization outcomes, recognizing 80% of all crystals, 94% of clear drops, 94% of precipitates. The computing requirements for this analysis system are large. The complete HWI archive of 120 million images is being processed by the donated CPU cycles on World Community Grid, with a GPU phase launching in early 2012. The main computational burden of the analysis is the measure of textural (GLCM) features within the image at multiple neighbourhoods, distances, and at multiple greyscale intensity resolutions. CPU runtime averages 4,092 seconds (single threaded) on an Intel Xeon, but only 65 seconds on an NVIDIA Tesla C2050. We report on the process of adapting the C++ code to OpenCL, optimized for multiple platforms.

Thermodynamic Cycle and CFD Analyses for Hydrogen Fueled Air-breathing Pulse Detonation Engines

Science.gov (United States)

Povinelli, Louis A.; Yungster, Shaye

2002-01-01

This paper presents the results of a thermodynamic cycle analysis of a pulse detonation engine (PDE) using a hydrogen-air mixture at static conditions. The cycle performance results, namely the specific thrust, fuel consumption and impulse are compared to a single cycle CFD analysis for a detonation tube which considers finite rate chemistry. The differences in the impulse values were indicative of the additional performance potential attainable in a PDE.

Parametric studies on different gas turbine cycles for a high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Wang Jie; Gu Yihua

2005-01-01

The high temperature gas-cooled reactor (HTGR) coupled with turbine cycle is considered as one of the leading candidates for future nuclear power plants. In this paper, the various types of HTGR gas turbine cycles are concluded as three typical cycles of direct cycle, closed indirect cycle and open indirect cycle. Furthermore they are theoretically converted to three Brayton cycles of helium, nitrogen and air. Those three types of Brayton cycles are thermodynamically analyzed and optimized. The results show that the variety of gas affects the cycle pressure ratio more significantly than other cycle parameters, however, the optimized cycle efficiencies of the three Brayton cycles are almost the same. In addition, the turbomachines which are required for the three optimized Brayton cycles are aerodynamically analyzed and compared and their fundamental characteristics are obtained. Helium turbocompressor has lower stage pressure ratio and more stage number than those for nitrogen and air machines, while helium and nitrogen turbocompressors have shorter blade length than that for air machine

Perfluoroalkyl-substituted ethylene carbonates: Novel electrolyte additives for high-voltage lithium-ion batteries

Science.gov (United States)

Zhu, Ye; Casselman, Matthew D.; Li, Yan; Wei, Alexander; Abraham, Daniel P.

2014-01-01

A new family of polyfluoroalkyl-substituted ethylene carbonates is synthesized and tested as additives in lithium-ion cells containing EC:EMC + LiPF6-based electrolyte. The influence of these compounds is investigated in Li1.2Ni0.15Mn0.55Co0.1O2//graphite cells via a combination of galvanostatic cycling and electrochemical impedance spectroscopy (EIS) tests. Among the four additives studied in this work (4-(trifluoromethyl)-1,3-dioxolan-2-one (TFM-EC), 4-(perfluorobutyl)-1,3-dioxolan-2-one (PFB-EC), 4-(perfluorohexyl)-1,3-dioxolan-2-one (PFH-EC), and 4-(perfluorooctyl)-1,3-dioxolan-2-one (PFO-EC)), small amounts (0.5 wt%) of PFO-EC is found to be most effective in lessening cell performance degradation during extended cycling. Linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy are used to further characterize the effects of PFO-EC on the positive and negative electrodes. LSV data from the electrolyte, and XPS analyses of electrodes harvested after cycling, suggest that PFO-EC is oxidized on the cathode forming surface films that slow electrode/cell impedance rise. Differential capacity (dQ/dV) plots from graphite//Li cells suggest that PFO-EC is involved in solid electrolyte interphase (SEI) formation. Raman data from anodes after cycling suggest that structural disordering of graphite is reduced by the addition of PFO-EC, which may explain the improved cell capacity retention.

Time-to-Degree and the Business Cycle

Science.gov (United States)

Messer, Dolores; Wolter, Stefan C.

2010-01-01

This paper presents the results of an empirical investigation trying to explain individual time-to-degree variances with business cycle fluctuations. Assuming that students determine the optimum study length at university weighing up the cost of an additional semester against the consumption benefit of studying and not yet working, the general…

The economics of the fuel cycle (light water reactors)

International Nuclear Information System (INIS)

Lepine, J.

1979-01-01

The economical characteristics of the fuel cycle (of light water reactors) as well as the definition and calculation method for the average updated cost of the kWh are recalled. The evolution followed by the unit prices of the different operations of the cycle, their total cost and the part taken by this cost in the overall cost of nuclear kWh are described. The effects on the cost of fuel of certain hypotheses, operating requirements and additional cost factors are considered [fr

Culture in cycles: considering H.T. Odum's 'information cycle'

Science.gov (United States)

Abel, Thomas

2014-01-01

'Culture' remains a conundrum in anthropology. When recast in the mold of 'information cycles,' culture is transformed. New fault lines appear. Information is splintered into parallel or nested forms. Dynamics becomes cycling. Energy is essential. And culture has function in a directional universe. The 'information cycle' is the crowning component of H.T. Odum's theory of general systems. What follows is an application of the information cycle to the cultural domains of discourse, social media, ritual, education, journalism, technology, academia, and law, which were never attempted by Odum. In information cycles, cultural information is perpetuated - maintained against Second Law depreciation. Conclusions are that culture is in fact a nested hierarchy of cultural forms. Each scale of information production is semi-autonomous, with its own evolutionary dynamics of production and selection in an information cycle. Simultaneously, each information cycle is channeled or entrained by its larger scale of information and ultimately human-ecosystem structuring.

Economic evaluation of multilateral nuclear fuel cycle approach

International Nuclear Information System (INIS)

Takashima, Ryuta; Kuno, Yusuke; Omoto, Akira; Tanaka, Satoru

2011-01-01

Recently previous works have shown that multilateral nuclear fuel cycle approach has benefits not only of non-proliferation but also of cost effectiveness. This is because for most facilities in nuclear fuel cycle, there exist economies of scale, which has a significant impact on the costs of nuclear fuel cycle. Therefore, the evaluation of economic rationality is required as one of the evaluation factors for the multilateral nuclear fuel cycle approach. In this study, we consider some options with respect to multilateral approaches to nuclear fuel cycle in Asian-Pacific region countries that are proposed by the University of Tokyo. In particular, the following factors are embedded into each type: A) no involvement of assurance of services, B) provision of assurance of services including construction of new facility, without transfer of ownership, and C) provision of assurance of service including construction of new joint facilities with ownership transfer of facilities to multilateral nuclear fuel cycle approach. We show the overnight costs taking into account install and operation of nuclear fuel cycle facilities for each option. The economic parameter values such as uranium price, scale factor, and market output expansion influences the total cost for each option. Thus, we show how these parameter values and economic risks affect the total overnight costs for each option. Additionally, the international facilities could increase the risk of transportation for nuclear material compared to national facilities. We discuss the potential effects of this transportation risk on the costs for each option. (author)

Muscle glycogen resynthesis during recovery from cycle exercise: no effect of additional protein ingestion

DEFF Research Database (Denmark)

Van Hall, Gerrit; Shirreffs, S M; Calbet, J A

2000-01-01

In the present study, we have investigated the effect of carbohydrate and protein hydrolysate ingestion on muscle glycogen resynthesis during 4 h of recovery from intense cycle exercise. Five volunteers were studied during recovery while they ingested, immediately after exercise, a 600-ml bolus......, and 18 +/- 6 for the first 1.5 h of recovery and decreased to 30 +/- 6, 36 +/- 3, and 8 +/- 6 mmol. kg dry muscle(-1). h(-1) between 1.5 and 4 h for CHO/protein, CHO, and water ingestion, respectively. No differences could be observed between CHO/protein and CHO ingestion ingestion. It is concluded...... and then every 15 min a 150-ml bolus containing 1) 1.67 g. kg body wt(-1). l(-1) of sucrose and 0.5 g. kg body wt(-1). l(-1) of a whey protein hydrolysate (CHO/protein), 2) 1.67 g. kg body wt(-1). l(-1) of sucrose (CHO), and 3) water. CHO/protein and CHO ingestion caused an increased arterial glucose...

Proliferation in cycle

Energy Technology Data Exchange (ETDEWEB)

Piao Yunsong [College of Physical Sciences, Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: yspiao@gucas.ac.cn

2009-06-15

In the contracting phase with w{approx_equal}0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w{approx_equal}0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

Proliferation in cycle

International Nuclear Information System (INIS)

Piao Yunsong

2009-01-01

In the contracting phase with w≅0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w≅0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

Physico-chemical characterization of grease interceptors with and without biological product addition.

Science.gov (United States)

He, Xia; Osborne, Jason; de los Reyes, Francis L

2012-03-01

Hardened and insoluble fat, oil, and grease (FOG) deposits are the primary cause of sewer line blockages leading to sanitary sewer overflows (SSOs). However, there have been very few long-term assessments of the physico-chemical characteristics of full-scale grease interceptors (GIs), the first "line of defense" against FOG buildup in sewer lines. In this study, we assessed the physico-chemical characteristics of two full-scale GIs (at a restaurant and a retirement community kitchen) over a one-year period. Statistically significant differences between bioaugmented and untreated cycles were detected for several chemical and physical properties. The treated cycles had lower BOD and COD at the grease interceptor outlet. While the combined data for all treated cycles did not show lower FOG concentrations in the GI outlet compared to the combined data for all untreated cycles, comparison of specific individual treated and untreated cycles show a positive effect due to the addition of product.

Fuel Cycle Impacts of Uranium-Plutonium Co-extraction

International Nuclear Information System (INIS)

Taiwo, Temitope; Szakaly, Frank; Kim, Taek-Kyum; Hill, Robert

2008-01-01

A systematic investigation of the impacts of uranium and plutonium co-extraction during fuel separations on reactor performance and fuel cycle has been performed. Proliferation indicators, critical mass and radiation source levels of the separation products or fabricated fuel, were also evaluated. Using LWR-spent-uranium-based MOX fuel instead of natural-uranium-based fuel in a PWR MOX core requires a higher initial plutonium content (∼1%), and results in higher Np-237 content (factor of 5) in the spent fuel, and less consumption of Pu-238 (20%) and Am-241 (14%), indicating a reduction in the effective repository space utilization. Additionally, minor actinides continue to accumulate in the fuel cycle, and thus a separate solution is required for them. Differences were found to be quite smaller (∼0.4% in initial transuranics) between the equilibrium cycles of advanced fast reactor cores using spent and depleted uranium for make-up, in additional to transuranics. The critical masses of the co-extraction products were found to be higher than for weapons-grade plutonium (WG-Pu) and the decay heat and radiation sources of the materials (products) were also found to be generally higher than for WG-Pu in the transuranics content range of 10% to 100% in the heavy-metal. (authors)

A life cycle database for parasitic acanthocephalans, cestodes, and nematodes

Science.gov (United States)

Benesh, Daniel P.; Lafferty, Kevin D.; Kuris, Armand

2017-01-01

Parasitologists have worked out many complex life cycles over the last ~150 years, yet there have been few efforts to synthesize this information to facilitate comparisons among taxa. Most existing host-parasite databases focus on particular host taxa, do not distinguish final from intermediate hosts, and lack parasite life-history information. We summarized the known life cycles of trophically transmitted parasitic acanthocephalans, cestodes, and nematodes. For 973 parasite species, we gathered information from the literature on the hosts infected at each stage of the parasite life cycle (8510 host-parasite species associations), what parasite stage is in each host, and whether parasites need to infect certain hosts to complete the life cycle. We also collected life-history data for these parasites at each life cycle stage, including 2313 development time measurements and 7660 body size measurements. The result is the most comprehensive data summary available for these parasite taxa. In addition to identifying gaps in our knowledge of parasite life cycles, these data can be used to test hypotheses about life cycle evolution, host specificity, parasite life-history strategies, and the roles of parasites in food webs.

Evaluation and optimization of LWR fuel cycles

International Nuclear Information System (INIS)

Akbas, T.; Zabunoglu, O.; Tombakoglu, M.

2001-01-01

There are several options in the back-end of the nuclear fuel cycle. Discharge burn-up, length of interim storage period, choice of direct disposal or recycling and method of reprocessing in case of recycling affect the options and determine/define the fuel cycle scenarios. These options have been evaluated in viewpoint of some tangible (fuel cycle cost, natural uranium requirement, decay heat of high level waste, radiological ingestion and inhalation hazards) and intangible factors (technological feasibility, nonproliferation aspect, etc.). Neutronic parameters are calculated using versatile fuel depletion code ORIGEN2.1. A program is developed for calculation of cost related parameters. Analytical hierarchy process is used to transform the intangible factors into the tangible ones. Then all these tangible and intangible factors are incorporated into a form that is suitable for goal programming, which is a linear optimization technique and used to determine the optimal option among alternatives. According to the specified objective function and constraints, the optimal fuel cycle scenario is determined using GPSYS (a linear programming software) as a goal programming tool. In addition, a sensitivity analysis is performed for some selected important parameters

Dynamic ubiquitin signaling in cell cycle regulation.

Science.gov (United States)

Gilberto, Samuel; Peter, Matthias

2017-08-07

The cell division cycle is driven by a collection of enzymes that coordinate DNA duplication and separation, ensuring that genomic information is faithfully and perpetually maintained. The activity of the effector proteins that perform and coordinate these biological processes oscillates by regulated expression and/or posttranslational modifications. Ubiquitylation is a cardinal cellular modification and is long known for driving cell cycle transitions. In this review, we emphasize emerging concepts of how ubiquitylation brings the necessary dynamicity and plasticity that underlie the processes of DNA replication and mitosis. New studies, often focusing on the regulation of chromosomal proteins like DNA polymerases or kinetochore kinases, are demonstrating that ubiquitylation is a versatile modification that can be used to fine-tune these cell cycle events, frequently through processes that do not involve proteasomal degradation. Understanding how the increasing variety of identified ubiquitin signals are transduced will allow us to develop a deeper mechanistic perception of how the multiple factors come together to faithfully propagate genomic information. Here, we discuss these and additional conceptual challenges that are currently under study toward understanding how ubiquitin governs cell cycle regulation. © 2017 Gilberto and Peter.

Nuclear power and the nuclear fuel cycle

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-07-01

The IAEA is organizing a major conference on nuclear power and the nuclear fuel cycle, which is to be held from 2 to 13 May 1977 in Salzburg, Austria. The programme for the conference was published in the preceding issue of the IAEA Bulletin (Vol.18, No. 3/4). Topics to be covered at the conference include: world energy supply and demand, supply of nuclear fuel and fuel cycle services, radioactivity management (including transport), nuclear safety, public acceptance of nuclear power, safeguarding of nuclear materials, and nuclear power prospects in developing countries. The articles in the section that follows are intended to serve as an introduction to the topics to be discussed at the Salzburg Conference. They deal with the demand for uranium and nuclear fuel cycle services, uranium supplies, a computer simulation of regional fuel cycle centres, nuclear safety codes, management of radioactive wastes, and a pioneering research project on factors that determine public attitudes toward nuclear power. It is planned to present additional background articles, including a review of the world nuclear fuel reprocessing situation and developments in the uranium enrichment industry, in future issues of the Bulletin. (author)

Additional synthesis of starch from sucrose in leaves of arabidopsis in the light

International Nuclear Information System (INIS)

Keerberg, O.; Ivanova, H.; Keerberg, H.; Paernik, T.

2005-01-01

Full text: Accumulating during daytime starch is converted in the night into sucrose and consumed in respiratory, biosynthetic and transport processes. However in the light the degradation and conversion of starch are blocked. In pulse chase experiments with wild type plants and starchless mutants pgm or adg1 of arabidopsis an increase of starch radioactivity during chase in nonradioactive medium in the light was detected. These findings suggest that starch was additionally synthesized from labeled cytosolic soluble photosynthates, preferentially from sucrose. Radiogasometric studies of gas exchange have revealed that sucrose is consumed also in photorespiratory decarboxylations. To be involved in photorespiration the products of sucrose degradation must be transported from cytosol into chloroplast. We presume that derived from sucrose hexoses are transported into chloroplast by hexose transporter and phosphorylated there in hexokinase reaction. The phosphorylated hexoses may be consumed either for additional synthesis of starch or incorporated into the reductive pentose phosphate cycle and, via this cycle, into the glycolate cycle. (author)

Structure modification of Mg-Nb films under hydrogen sorption cycles

Energy Technology Data Exchange (ETDEWEB)

Mengucci, P., E-mail: p.mengucci@univpm.it [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Universita Politecnica delle Marche, Via Brecce Bianche, I-60131 Ancona (Italy); Barucca, G.; Majni, G. [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Universita Politecnica delle Marche, Via Brecce Bianche, I-60131 Ancona (Italy); Bazzanella, N.; Checchetto, R.; Miotello, A. [Dipartimento di Fisica, Universita di Trento, Via Sommarive, I-38123 Povo (Italy)

2011-09-15

Research highlights: > Influence of Nb additions on the hydrogen kinetics of Mg layers. > Structure modification of the Mg matrix during hydrogen cycling. > Lattice strains induced by Nb tends to decrease during hydrogen cycling. > Nb nanoparticles form during hydrogen cycling. > Nb enhances the porous structure of the Mg layer formed during hydrogen cycling. - Abstract: In the present work we focus our attention on the structural modifications induced by repeated absorption/desorption cycles on Mg-Nb layers. Samples consisting of a 30 {mu}m thick pure Mg or Mg-5 at.% Nb doped films, coated with a 20 nm thick Pd layer were submitted to repeated H{sub 2} sorption cycles in a volumetric apparatus. Isothermal desorption analysis at 350 deg. C was performed to evaluate the amount of absorbed hydrogen. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and electron microscopy techniques (SEM and TEM) were used for the structural characterisation of the samples. Analyses show a deep modification of the material upon cycling. The presence of Nb enhances the structural modifications and induces an initial lattice contraction of the Mg matrix that tends to decrease on cycling via the formation of Nb nanoparticles (with average size of {approx}10 nm). SEM and TEM observations performed in cross section evidenced the formation of a porous structure.

Modeling endocrine regulation of the menstrual cycle using delay differential equations.

Science.gov (United States)

Harris, Leona A; Selgrade, James F

2014-11-01

This article reviews an effective mathematical procedure for modeling hormonal regulation of the menstrual cycle of adult women. The procedure captures the effects of hormones secreted by several glands over multiple time scales. The specific model described here consists of 13 nonlinear, delay, differential equations with 44 parameters and correctly predicts blood levels of ovarian and pituitary hormones found in the biological literature for normally cycling women. In addition to this normal cycle, the model exhibits another stable cycle which may describe a biologically feasible "abnormal" condition such as polycystic ovarian syndrome. Model simulations illustrate how one cycle can be perturbed to the other cycle. Perturbations due to the exogenous administration of each ovarian hormone are examined. This model may be used to test the effects of hormone therapies on abnormally cycling women as well as the effects of exogenous compounds on normally cycling women. Sensitive parameters are identified and bifurcations in model behavior with respect to parameter changes are discussed. Modeling various aspects of menstrual cycle regulation should be helpful in predicting successful hormone therapies, in studying the phenomenon of cycle synchronization and in understanding many factors affecting the aging of the female reproductive endocrine system. Copyright © 2014 Elsevier Inc. All rights reserved.

Engineered safeguards system activities at Sandia Laboratories for back-end fuel cycle facilities

International Nuclear Information System (INIS)

Sellers, T.A.; Fienning, W.C.; Winblad, A.E.

1978-01-01

Sandia Laboratories have been developing concepts for safeguards systems to protect facilities in the back-end of the nuclear fuel cycle against potential threats of sabotage and theft of special nuclear material (SNM). Conceptual designs for Engineered Safeguards Systems (ESSs) have been developed for a Fuel Reprocessing Facility (including chemical separations, plutonium conversion, and waste solidification), a Mixed-Oxide Fuel Fabrication Facility, and a Plutonium Transport Vehicle. Performance criteria for the various elements of these systems and a candidate systematic design approach have been defined. In addition, a conceptual layout for a large-scale Fuel-Cycle Plutonium Storage Facility has been completed. Work is continuing to develop safeguards systems for spent fuel facilities, light-water reactors, alternative fuel cycles, and improved transportation systems. Additional emphasis will be placed on the problems associated with national diversion of special nuclear material. The impact on safeguards element performance criteria for surveillance and containment to protect against national diversion in various alternative fuel cycle complexes is also being investigated

A New High-Speed, High-Cycle, Gear-Tooth Bending Fatigue Test Capability

Science.gov (United States)

Stringer, David B.; Dykas, Brian D.; LaBerge, Kelsen E.; Zakrajsek, Andrew J.; Handschuh, Robert F.

2011-01-01

A new high-speed test capability for determining the high cycle bending-fatigue characteristics of gear teeth has been developed. Experiments were performed in the test facility using a standard spur gear test specimens designed for use in NASA Glenn s drive system test facilities. These tests varied in load condition and cycle-rate. The cycle-rate varied from 50 to 1000 Hz. The loads varied from high-stress, low-cycle loads to near infinite life conditions. Over 100 tests were conducted using AISI 9310 steel spur gear specimen. These results were then compared to previous data in the literature for correlation. Additionally, a cycle-rate sensitivity analysis was conducted by grouping the results according to cycle-rate and comparing the data sets. Methods used to study and verify load-path and facility dynamics are also discussed.

Life cycle assessment of a floating offshore wind turbine

Energy Technology Data Exchange (ETDEWEB)

Weinzettel, Jan [Department of Electrotechnology, Faculty of Electrical Engineering, Czech Technical University in Prague, Technicka 2, Praha 166 27 (Czech Republic); Charles University in Prague Environment Center, U Krize 8, Prague 158 00 (Czech Republic); Reenaas, Marte; Solli, Christian [Industrial Ecology Programme, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway); Hertwich, Edgar G. [Industrial Ecology Programme, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway); Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway)

2009-03-15

A development in wind energy technology towards higher nominal power of the wind turbines is related to the shift of the turbines to better wind conditions. After the shift from onshore to offshore areas, there has been an effort to move further from the sea coast to the deep water areas, which requires floating windmills. Such a concept brings additional environmental impact through higher material demand. To evaluate additional environmental burdens and to find out whether they can be rebalanced or even offset by better wind conditions, a prospective life cycle assessment (LCA) study of one floating concept has been performed and the results are presented in this paper. A comparison with existing LCA studies of conventional offshore wind power and electricity from a natural gas combined cycle is presented. The results indicate similar environmental impacts of electricity production using floating wind power plants as using non-floating offshore wind power plants. The most important stage in the life cycle of the wind power plants is the production of materials. Credits that are connected to recycling these materials at the end-of-life of the power plant are substantial. (author)

Nuclear design report for Yonggwang nuclear power plant unit 2 cycle 7

International Nuclear Information System (INIS)

Zee, Sung Kyun; Choi, Gyoo Hwan; Lee, Ki Bog; Park, Sang Yoon

1993-02-01

This report presents nuclear design calculations for Cycle 7 of Yonggwang Unit 2. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 64 KOFA's enriched by nominally 3.70 w/o U235. Among the KOFA's, 40 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of Cycle 7 amounts to 367 EFPD corresponding to a cycle burnup of 14770 MWD/MTU. (Author)

Lhe law of diminishing elasticity of demand in Harrod’s trade cycle

OpenAIRE

Michaël Assous; Olivier Bruno; Muriel Dal-Pont

2014-01-01

In The Trade Cycle, Roy Harrod [1936a] propounded the Law of Diminishing Elasticity of Demand. The present paper tries to clarify the precise role Harrod assigned to this law in his The Trade Cycle Theory. We discuss the micro and macro foundations of the Law of Diminishing Elasticity of Demand and argue that it explains one of the main mechanisms that stabilize the economy during the trade cycle. In addition, we highlight how the Law of Diminishing Elasticity of Demand allowed Harrod to micr...

Sensitivity Analysis and Optimization of the Nuclear Fuel Cycle: A Systematic Approach

Science.gov (United States)

Passerini, Stefano

For decades, nuclear energy development was based on the expectation that recycling of the fissionable materials in the used fuel from today's light water reactors into advanced (fast) reactors would be implemented as soon as technically feasible in order to extend the nuclear fuel resources. More recently, arguments have been made for deployment of fast reactors in order to reduce the amount of higher actinides, hence the longevity of radioactivity, in the materials destined to a geologic repository. The cost of the fast reactors, together with concerns about the proliferation of the technology of extraction of plutonium from used LWR fuel as well as the large investments in construction of reprocessing facilities have been the basis for arguments to defer the introduction of recycling technologies in many countries including the US. In this thesis, the impacts of alternative reactor technologies on the fuel cycle are assessed. Additionally, metrics to characterize the fuel cycles and systematic approaches to using them to optimize the fuel cycle are presented. The fuel cycle options of the 2010 MIT fuel cycle study are re-examined in light of the expected slower rate of growth in nuclear energy today, using the CAFCA (Code for Advanced Fuel Cycle Analysis). The Once Through Cycle (OTC) is considered as the base-line case, while advanced technologies with fuel recycling characterize the alternative fuel cycle options available in the future. The options include limited recycling in L WRs and full recycling in fast reactors and in high conversion LWRs. Fast reactor technologies studied include both oxide and metal fueled reactors. Additional fuel cycle scenarios presented for the first time in this work assume the deployment of innovative recycling reactor technologies such as the Reduced Moderation Boiling Water Reactors and Uranium-235 initiated Fast Reactors. A sensitivity study focused on system and technology parameters of interest has been conducted to test

Using OSG Computing Resources with (iLC)Dirac

CERN Document Server

AUTHOR|(SzGeCERN)683529; Petric, Marko

2017-01-01

CPU cycles for small experiments and projects can be scarce, thus making use of all available resources, whether dedicated or opportunistic, is mandatory. While enabling uniform access to the LCG computing elements (ARC, CREAM), the DIRAC grid interware was not able to use OSG computing elements (GlobusCE, HTCondor-CE) without dedicated support at the grid site through so called 'SiteDirectors', which directly submit to the local batch system. This in turn requires additional dedicated effort for small experiments on the grid site. Adding interfaces to the OSG CEs through the respective grid middleware is therefore allowing accessing them within the DIRAC software without additional sitespecific infrastructure. This enables greater use of opportunistic resources for experiments and projects without dedicated clusters or an established computing infrastructure with the DIRAC software. To allow sending jobs to HTCondor-CE and legacy Globus computing elements inside DIRAC the required wrapper classes were develo...

Mid-cycle headaches and their relationship to different patterns of premenstrual stress symptoms.

Science.gov (United States)

Kiesner, Jeff; Martin, Vincent T

2013-06-01

Recent research has shown that affective changes associated with the menstrual cycle may follow diverse patterns, including a classic premenstrual syndrome pattern, as well as the mirror opposite pattern, referred to as a mid-cycle pattern. Test for the presence of a mid-cycle pattern of headaches, in addition to a menstrual pattern and a noncyclic pattern; test for an association between experiencing a specific pattern of headaches and a specific (previously identified) pattern of depression/anxiety; and test for mean-level differences, across headache pattern groups, in average headache index and depression/anxiety scores (averaged across 2 menstrual cycles for each participant). A sample of 213 female university students completed daily questionnaires regarding symptoms of headaches and depression/anxiety for 2 menstrual cycles. Hierarchical linear modeling, polynomial multiple regression, analyses of variance, and chi-square analyses were used to test the hypotheses. Confirmed the existence of a mid-cycle pattern of headaches (16%), in addition to a menstrual pattern (51%), and a noncyclic pattern of headaches (33%). Patterns of headaches and affective change were significantly associated (χ(2) = 21.33, P = .0003; 54% correspondence), as were the average headache index and depression/anxiety scores (r = .49; P headache pattern groups on the average headache index scores or depression/anxiety scores. A significant number of women experience a mid-cycle pattern of headaches during the menstrual cycle. Moreover, women often, but not always, demonstrate the same pattern of headaches and depression/anxiety symptoms. © 2013 American Headache Society.

Optimizing the data life cycle

Energy Technology Data Exchange (ETDEWEB)

Schwarz, Kilian [GSI, Planckstr. 1, 64291 Darmstadt (Germany); Jung, Christopher [KIT, Kaiserstrasse 12, 76131 Karlsruhe (Germany)

2013-07-01

Today, data play a central role in most fields of Science. In recent years, the amount of data from experiment, observation, and simulation has increased rapidly and the data complexity has grown. Also, communities and shared storage have become geographically more distributed. Therefore, methods and techniques applied for scientific data need to be revised and partially be replaced, while keeping the community-specific needs in focus. The Helmholtz Portfolio Extension ''Large Scale Data Management and Analysis'' (LSDMA) focuses on the optimization of the data life cycle in different research areas. In its five Data Life Cycle Labs (DLCLs), data experts closely collaborate with the communities in joint research and development to optimize the respective data life cycle. In addition, the Data Services Integration Team provides data analysis tools and services which are common to several DLCLs. This presentation describes the various activities within LSDMA and focuses on the work done in the DLCL ''Structure of Matter''. The main topics of this DLCL are the support for the international projects FAIR (Facility for Anti Proton and Ion Research) which will evolve around GSI in Darmstadt and the European XFEL and PETRA III at DESY in Hamburg.

Your Menstrual Cycle

Science.gov (United States)

... your menstrual cycle What happens during your menstrual cycle The menstrual cycle includes not just your period, but the rise ... that take place over the weeks in your cycle. Want to know what happens on each day ...

Fuel cycle cost uncertainty from nuclear fuel cycle comparison

International Nuclear Information System (INIS)

Li, J.; McNelis, D.; Yim, M.S.

2013-01-01

This paper examined the uncertainty in fuel cycle cost (FCC) calculation by considering both model and parameter uncertainty. Four different fuel cycle options were compared in the analysis including the once-through cycle (OT), the DUPIC cycle, the MOX cycle and a closed fuel cycle with fast reactors (FR). The model uncertainty was addressed by using three different FCC modeling approaches with and without the time value of money consideration. The relative ratios of FCC in comparison to OT did not change much by using different modeling approaches. This observation was consistent with the results of the sensitivity study for the discount rate. Two different sets of data with uncertainty range of unit costs were used to address the parameter uncertainty of the FCC calculation. The sensitivity study showed that the dominating contributor to the total variance of FCC is the uranium price. In general, the FCC of OT was found to be the lowest followed by FR, MOX, and DUPIC. But depending on the uranium price, the FR cycle was found to have lower FCC over OT. The reprocessing cost was also found to have a major impact on FCC

Effects of nitrogen deposition on carbon cycle in terrestrial ecosystems of China: A meta-analysis

International Nuclear Information System (INIS)

Chen, Hao; Li, Dejun; Gurmesa, Geshere A.; Yu, Guirui; Li, Linghao; Zhang, Wei; Fang, Huajun; Mo, Jiangming

2015-01-01

Nitrogen (N) deposition in China has increased greatly, but the general impact of elevated N deposition on carbon (C) dynamics in Chinese terrestrial ecosystems is not well documented. In this study we used a meta-analysis method to compile 88 studies on the effects of N deposition C cycling on Chinese terrestrial ecosystems. Our results showed that N addition did not change soil C pools but increased above-ground plant C pool. A large decrease in below-ground plant C pool was observed. Our result also showed that the impacts of N addition on ecosystem C dynamics depend on ecosystem type and rate of N addition. Overall, our findings suggest that 1) decreased below-ground plant C pool may limit long-term soil C sequestration; and 2) it is better to treat N-rich and N-limited ecosystems differently in modeling effects of N deposition on ecosystem C cycle. - Highlights: • Meta-analysis was used to address the effects of N addition on C cycle. • N addition caused an large decease in belowground plant C pool. • N-rich and N-limited ecosystems had different responses to N addition. - N addition caused a large decrease in below-ground plant C pool.

Serum concentrations of progesterone and oestradiol during the ovarian cycle of Syrian Awassi ewes

International Nuclear Information System (INIS)

Zarkawi, M.

2005-01-01

It was possible, for the first time, to characterise hormonally and precisely the oestrous cycle of the Syrian Awassi ewes, and to determine normal progesterone and oestradiol concentrations during the different phases of oestrous cycle. It is concluded that progesterone and oestradiol concentrations showed a cyclic pattern during the oestrous cycle, in addition, a negative and significant correlation between the concentrations of the two hormones was found. (author)

DETECTING ALIEN LIMIT CYCLES NEAR A HAMILTONIAN 2-SADDLE CYCLE

OpenAIRE

LUCA, Stijn; DUMORTIER, Freddy; Caubergh, M.; Roussarie, R.

2009-01-01

This paper aims at providing and example of a cubic Hamiltonian 2-saddle cycle that after bifurcation can give rise to an alien limit cycle; this is a limit cycle that is not controlled by a zero of the related Abelian integral. To guarantee the existence of an alien limit cycle one can verify generic conditions on the Abelian integral and on the transition map associated to the connections of the 2-saddle cycle. In this paper, a general method is developed to compute the first and second der...

Auditory and visual cueing modulate cycling speed of older adults and persons with Parkinson's disease in a Virtual Cycling (V-Cycle) system.

Science.gov (United States)

Gallagher, Rosemary; Damodaran, Harish; Werner, William G; Powell, Wendy; Deutsch, Judith E

2016-08-19

Evidence based virtual environments (VEs) that incorporate compensatory strategies such as cueing may change motor behavior and increase exercise intensity while also being engaging and motivating. The purpose of this study was to determine if persons with Parkinson's disease and aged matched healthy adults responded to auditory and visual cueing embedded in a bicycling VE as a method to increase exercise intensity. We tested two groups of participants, persons with Parkinson's disease (PD) (n = 15) and age-matched healthy adults (n = 13) as they cycled on a stationary bicycle while interacting with a VE. Participants cycled under two conditions: auditory cueing (provided by a metronome) and visual cueing (represented as central road markers in the VE). The auditory condition had four trials in which auditory cues or the VE were presented alone or in combination. The visual condition had five trials in which the VE and visual cue rate presentation was manipulated. Data were analyzed by condition using factorial RMANOVAs with planned t-tests corrected for multiple comparisons. There were no differences in pedaling rates between groups for both the auditory and visual cueing conditions. Persons with PD increased their pedaling rate in the auditory (F 4.78, p = 0.029) and visual cueing (F 26.48, p auditory (F = 24.72, p visual cueing (F = 40.69, p visual condition in age-matched healthy adults showed a step-wise increase in pedaling rate (p = 0.003 to p visual cues (p visual cues in order to obtain an increase in cycling intensity. The combination of the VE and auditory cues was neither additive nor interfering. These data serve as preliminary evidence that embedding auditory and visual cues to alter cycling speed in a VE as method to increase exercise intensity that may promote fitness.

Addition of low dose hCG to rFSh benefits older women during ovarian stimulation for IVF

Directory of Open Access Journals (Sweden)

Gomaa Hala

2012-08-01

Full Text Available Abstract Background To compare the outcome of IVF cycles in women receiving controlled ovarian stimulation with recFSH or recFSH plus low dose hCG. Methods A retrospective case control study, performed at a private practice affiliated with an academic institute. Patients were infertile women who were treated with IVF/ICSI and controlled ovarian stimulation in a long GnRH agonist protocol using either low dose hCG in addition to recFSH [N = 88] or recFSH alone [N = 99]. Primary outcomes were mean FSH dose, number of mature eggs, number of fertilized eggs, and serum levels of estradiol. Secondary outcomes were endometrial thickness, cycle cancellations and pregnancy rates. Results A significant increase in number of mature and fertilized eggs was observed in women over 40 years of age using low dose hCG in addition to recFSH. The estradiol level was significantly higher on the day of hCG administration and the serum level of FSH on cycle day 7 and on the day of hCG administration were lower. Conclusion Addition of low dose hCG to recFSH compared with recFSH alone significantly modified cycle characteristics in patients >/= 40 years and could be of potential benefit for IVF cycles in older infertile women.

Sex differences in behavioral and PKA cascade responses to repeated cocaine administration.

Science.gov (United States)

Zhou, Luyi; Sun, Wei-Lun; Weierstall, Karen; Minerly, Ana Christina; Weiner, Jan; Jenab, Shirzad; Quinones-Jenab, Vanya

2016-10-01

Previous studies have shown sex different patterns in behavioral responses to cocaine. Here, we used between-subject experiment design to study whether sex differences exist in the development of behavioral sensitization and tolerance to repeated cocaine, as well as the role of protein kinase A (PKA) signaling cascade in this process. Ambulatory and rearing responses were recorded in male and female rats after 1 to 14 days of administration of saline or cocaine (15 mg/kg; ip). Correspondent PKA-associated signaling in the nucleus accumbens (NAc) and caudate-putamen (CPu) was measured at each time point. Our results showed that females exhibited higher cocaine-induced behavioral responses and developed behavioral sensitization and tolerance faster than males. Whereas females developed behavioral sensitization to cocaine after 2 days and tolerance after 14 days, male rats developed sensitization after 5 days. In addition, cocaine induced a sexual dimorphic pattern in the progression of neuronal adaptations on the PKA cascade signaling in region (NAc vs. CPu) and time (days of cocaine administration)-dependent manners. In general, more PKA signaling cascade changes were found in the NAc of males on day 5 and in the CPu of females with repeated cocaine injection. In addition, in females, behavioral activities positively correlated with FosB levels in the NAc and CPu and negatively correlated with Cdk5 and p35 in the CPu, while no correlation was observed in males. Our studies suggest that repeated cocaine administration induced different patterns of behavioral and molecular responses in the PKA cascade in male and female rats.

Proposal of a nuclear cycle research and development plan in Tokai works. The roadmap from LWR cycle to FBR cycle

International Nuclear Information System (INIS)

Nakamura, Hirofumi; Abe, Tomoyuki; Kashimura, Takuo; Nagai, Toshihisa; Maeda, Seichiro; Yamaguchi, Toshiya; Kuroki, Ryoichiro

2003-07-01

The Generation-II Project Task Force Team has investigated a research and development plan of a future nuclear fuel cycle in Tokai works for about three months from December 19, 2002. First we have discussed about the present condition of Japanese nuclear fuel cycle and have recognized it as the following. The relation of the technology between the LWR-cycle and the FBR-cycle is not clear. MOX Fuel Use in Light Water Reactors is important to establish technology of the FBR fuel cycle. Radioactive waste disposal issue is urgent. Next we have proposed the three basic policies on R and D plan of nuclear fuel cycle in consideration of the F.S. on FBR-cycle. Establishment and advancement of 'the tough nuclear fuel cycle'. Early establishment of the FBR cycle technology to be able to supply energy stably for long-term. Establishment of the radioactive waste treatment and disposal technology, and optimization of nuclear fuel cycle technology from the viewpoint of radioactive waste. And we have proposed the Japanese technical holder system to integrate all LWR and FBR cycle technology. (author)

Simulation of Cycle-to-Cycle Variation in Dual-Fuel Engines

KAUST Repository

Jaasim, Mohammed

2017-03-13

Standard practices of internal combustion (IC) engine experiments are to conduct the measurements of quantities averaged over a large number of cycles. Depending on the operating conditions, the cycle-to-cycle variation (CCV) of quantities, such as the indicated mean effective pressure (IMEP) are observed at different levels. Accurate prediction of CCV in IC engines is an important but challenging task. Computational fluid dynamics (CFD) simulations using high performance computing (HPC) can be used effectively to visualize such 3D spatial distributions. In the present study, a dual fuel large engine is considered, with natural gas injected into the manifold accompanied with direct injection of diesel pilot fuel to trigger ignition. Multiple engine cycles in 3D are simulated in series as in the experiments to investigate the potential of HPC based high fidelity simulations to accurately capture the cycle to cycle variation in dual fuel engines. Open cycle simulations are conducted to predict the combined effect of the stratification of fuel-air mixture, temperature and turbulence on the CCV of pressure. The predicted coefficient of variation (COV) of pressure compared to the results from closed cycle simulations and the experiments.

Nuclear design report for Yonggwang nuclear power plant unit 4 cycle 2

International Nuclear Information System (INIS)

Park, Chan Oh; Park, Sang Yoon; Yoo, Choon Sung; Ryu, Hyo Sang; Park, Jin Ha; Cho, Young Chul; Song, Jae Woong; Lee Chung Chan.

1996-10-01

This report presents nuclear design calculations for Cycle 2 of Yonggwang Unit 4. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths, and operational limits. In addition, the report contains necessary data for the startup tests and for the assurance of shutdown margin during reactor operation. The reload core consists of 48 fresh KSFAs. Among the 48 fresh KSFAs, 32 fuel assemblies contain burnable poison rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of Cycle 2 amounts to 275 EFPD corresponding to a cycle burnup of 10,100 MWD/MTU. (author). 31 tabs., 92 figs., 7 refs

Nuclear design report for Ulchin nuclear power plant unit 1, cycle 7

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Rae; Park, Yong soo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-04-01

This report presents nuclear design calculations for Cycle 7 of Ulchin Unit 1. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 56 KOFA`s enriched by nominally 4.00 w/o U{sub 235}. Among the KOFA`s 36 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of Cycle 7 amounts to 355 EFPD corresponding to a cycle burnup of 14280 MWD/MTU. (Author) 8 refs., 55 figs., 21 tabs.

Nuclear design report for Kori nuclear power plant unit 4 cycle 8

Energy Technology Data Exchange (ETDEWEB)

Zee, Sung Kyoon; Jung, Yil Sub; Kim, Si Yung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1993-07-01

This report presents nuclear design calculations for cycle 8 of Kori unit 4. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 76 KOFA`s enriched by nominally 3.70 w/o U{sub 235}. Among the KOFA`s 48 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 8 amounts to 421 EFPD corresponding to a cycle burnup of 16950 MWD/MTU. (Author) 8 refs., 55 figs., 17 tabs.

Nuclear design report for Kori nuclear power plant unit 1, cycle 13

Energy Technology Data Exchange (ETDEWEB)

Zee, Sung Kyun; Moon, Bok Ja; Cho, Byeong Ho; Jung, Yil Sup [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1993-04-01

This report presents nuclear design calculations for cycle 13 of Kori unit 1. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 44 KOFA`s enriched by nominally 3.70 w/o U{sub 235}. Among the KOFA`s, 16 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 13 amounts to 355 EFPD corresponding to a cycle burnup of 13240 MWD/MTU. (Author) 8 refs., 55 figs., 16 tabs.

Nuclear design report for Yonggwang nuclear power plant unit 1 cycle 9

Energy Technology Data Exchange (ETDEWEB)

Cho, Young chul; Kim, Jae Hak; Song, Jae Woong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-03-01

This report presents nuclear design calculations for Cycle 6 of Yonggwng Unit 1. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 76 KOFA`s enriched by nominally 4.00 w/o U{sub 235}. Among the KOFA`s, 60 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of Cycle 9 amounts to 434 EFPD corresponding to a cycle burnup of 17470 MWD/MTU. (Author) 8 refs., 55 figs., 19 tabs.

Nuclear design report for Ulchin nuclear power plant unit 1, cycle 6

Energy Technology Data Exchange (ETDEWEB)

Zee, Sung Kyun; Kim, Yong Rae; Park, Yong Soo; Cho, Byeong Ho; Lee, Sang Keun; Ahn, Dawk Hwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1993-12-01

This report presents nuclear design calculations for cycle 6 of Ulchin unit 1. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 64 KOFA`s enriched by nominally 3.70 w/o U{sub 235}. Among the KOFA`s, 32 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 6 amounts to 369 EFPD corresponding to a cycle burnup of 14850 MWD/MTU. (Author) 8 refs., 55 figs., 17 tabs.

Nuclear design report for Ulchin nuclear power plant unit 2, cycle 6

Energy Technology Data Exchange (ETDEWEB)

Park, Chan Oh; Park, Jin Ha; Kim, Yong Rae; Park, Sang Yoon; Lee, Jong Chul; Baik, Joo Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-08-01

This report presents nuclear design calculations for cycle 6 of Ulchin unit 2. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 64 KOFA`s enriched by nominally 3.80 w/o U{sub 235}. Among the KOFA`s, 36 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 6 amounts to 388 EFPD corresponding to a cycle burnup of 15610 MWD/MTU. (Author) 8 refs., 55 figs., 17 tabs.

The relationship between natural uranium and advanced fuel cycles in CANDU reactors

International Nuclear Information System (INIS)

Lane, A.D.; McDonnell, F.N.; Griffiths, J.

1988-11-01

CANDU is the most uranium-economic type of thermal power reactor, and is the only type used in Canada. CANDU reactors consume approximately 15% of Canadian uranium production and support a fuel service industry valued at ∼$250 M/a. In addition to their once-through, natural-uranium fuel cycle, CANDU reactors are capable of operating with slightly-enriched uranium (SEU), uranium-plutonium and thorium cycles, more efficiently than other reactors. Only SEU is economically attractive in Canada now, but the other cycles are of interest to countries without indigenous fuel resources. A program is underway to establish the fuel technologies necessary for the use of SEU and the other fuel cycles in CANDU reactors. 22 refs

Nuclear design report for Yonggwang nuclear power plant unit 1, cycle 8

International Nuclear Information System (INIS)

Cho, Young Chul; Kim, Jae Hak; Park, Sang Yoon; Zee, Sung Kyun; Lee, Sang Keun; Ahn, Dawk Hwan

1993-10-01

This report presents nuclear design calculations for cycle 8 of Kori unit 1. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 76 KOFA's enriched by nominally 3.70 w/o U 235 . Among the KOFA's, 56 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 8 amounts to 447 EFPD corresponding to a cycle burnup of 18020 MWD/MTU. (Author) 8 refs., 39 figs., 17 tabs

Nuclear design report for Ulchin nuclear power plant unit 2 cycle 5

International Nuclear Information System (INIS)

Park, Jin Ha; Park, Yong Soo; Cho, Byeong Ho; Zee, Sung Kyun; Lee, Sang Keun; Ahn, Dawk Hwan

1993-09-01

This report presents nuclear design calculations for cycle 5 of Ulchin unit it 2. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 48 KOFA's enriched by nominally 3.50 w/o U 235 . Among the KOFA's, 20 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 5 amounts to 293 EFPD corresponding to a cycle burnup of 11780 MWD/MTU. (Author) 8 refs., 55 figs., 16 tabs

Nuclear design report for Yonggwang nuclear power plant unit 1, cycle 8

Energy Technology Data Exchange (ETDEWEB)

Cho, Young Chul; Kim, Jae Hak; Park, Sang Yoon; Zee, Sung Kyun; Lee, Sang Keun; Ahn, Dawk Hwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1993-10-01

This report presents nuclear design calculations for cycle 8 of Kori unit 1. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 76 KOFA`s enriched by nominally 3.70 w/o U{sub 235}. Among the KOFA`s, 56 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 8 amounts to 447 EFPD corresponding to a cycle burnup of 18020 MWD/MTU. (Author) 8 refs., 39 figs., 17 tabs.

Lively quantum walks on cycles

International Nuclear Information System (INIS)

Sadowski, Przemysław; Miszczak, Jarosław Adam; Ostaszewski, Mateusz

2016-01-01

We introduce a family of quantum walks on cycles parametrized by their liveliness, defined by the ability to execute a long-range move. We investigate the behaviour of the probability distribution and time-averaged probability distribution. We show that the liveliness parameter, controlling the magnitude of the additional long-range move, has a direct impact on the periodicity of the limiting distribution. We also show that the introduced model provides a method for network exploration which is robust against trapping. (paper)

Effect of inorganic additive sodium pyrophosphate tetrabasic on positive electrolytes for a vanadium redox flow battery

International Nuclear Information System (INIS)

Park, Se-Kook; Shim, Joonmok; Yang, Jung Hoon; Jin, Chang-Soo; Lee, Bum Suk; Lee, Young-Seak; Shin, Kyoung-Hee; Jeon, Jae-Deok

2014-01-01

Sodium pyrophosphate tetrabasic (SPT) is employed as an inorganic additive in the positive electrolyte of a vanadium redox flow battery (VRFB) to improve its long-term stability and electrochemical performance. The results of precipitation tests show that the long-term stability of positive electrolytes (2 MV(V) solution in 4 M total sulfates with 0.05 M SPT additive) is improved compared to the blank one. UV-vis and cyclic voltammetry (CV) measurements also suggest that the addition of SPT can effectively delay the formation of precipitation in positive electrolytes, and no new substances are formed in V(V) electrolytes with SPT. The calcined precipitates extracted from the electrolytes with and without a SPT additive are identified as V 2 O 5 by X-ray diffraction (XRD) analysis. A VRFB single-unit cell employing positive electrolytes with an additive exhibits the high energy efficiency of 74.6% at a current density of 40 mA cm 2 at the 500 th cycle at 20°C, compared to 71.8% for the cell employing the electrolyte without an additive. Moreover, the cell employing the electrolyte with an additive exhibits less discharge capacity fading during cycling in comparison with the pristine one. The disassembled cell without an additive shows a large number of V 2 O 5 precipitation particles on the felt electrode after 500 cycles. Meanwhile, the felt electrode of the cell with an additive has little precipitation. That precipitation gives rise to an imbalance between the positive and negative half-cell electrolytes, which results in a significant capacity loss. The additive has shown positive results under limited laboratory short-term and small-scale conditions

Modeling and analysis of advanced binary cycles

Energy Technology Data Exchange (ETDEWEB)

Gawlik, K.

1997-12-31

A computer model (Cycle Analysis Simulation Tool, CAST) and a methodology have been developed to perform value analysis for small, low- to moderate-temperature binary geothermal power plants. The value analysis method allows for incremental changes in the levelized electricity cost (LEC) to be determined between a baseline plant and a modified plant. Thermodynamic cycle analyses and component sizing are carried out in the model followed by economic analysis which provides LEC results. The emphasis of the present work is on evaluating the effect of mixed working fluids instead of pure fluids on the LEC of a geothermal binary plant that uses a simple Organic Rankine Cycle. Four resources were studied spanning the range of 265{degrees}F to 375{degrees}F. A variety of isobutane and propane based mixtures, in addition to pure fluids, were used as working fluids. This study shows that the use of propane mixtures at a 265{degrees}F resource can reduce the LEC by 24% when compared to a base case value that utilizes commercial isobutane as its working fluid. The cost savings drop to 6% for a 375{degrees}F resource, where an isobutane mixture is favored. Supercritical cycles were found to have the lowest cost at all resources.

CPU time optimization and precise adjustment of the Geant4 physics parameters for a VARIAN 2100 C/D gamma radiotherapy linear accelerator simulation using GAMOS

Science.gov (United States)

Arce, Pedro; Lagares, Juan Ignacio

2018-02-01

We have verified the GAMOS/Geant4 simulation model of a 6 MV VARIAN Clinac 2100 C/D linear accelerator by the procedure of adjusting the initial beam parameters to fit the percentage depth dose and cross-profile dose experimental data at different depths in a water phantom. Thanks to the use of a wide range of field sizes, from 2  ×  2 cm2 to 40  ×  40 cm2, a small phantom voxel size and high statistics, fine precision in the determination of the beam parameters has been achieved. This precision has allowed us to make a thorough study of the different physics models and parameters that Geant4 offers. The three Geant4 electromagnetic physics sets of models, i.e. Standard, Livermore and Penelope, have been compared to the experiment, testing the four different models of angular bremsstrahlung distributions as well as the three available multiple-scattering models, and optimizing the most relevant Geant4 electromagnetic physics parameters. Before the fitting, a comprehensive CPU time optimization has been done, using several of the Geant4 efficiency improvement techniques plus a few more developed in GAMOS.

Plutonium fuel cycles in the spectral shift controlled reactor

International Nuclear Information System (INIS)

Sider, F.M.; Matzie, R.A.

1980-01-01

The spectral shift controlled reactor (SSCR) controls excess core reactivity during an operating cycle through the use of variable heavy water concentrations in the moderator. With heavy water in the coolant, the neutron spectrum is shifted to higher energy levels, thus increasing fertile conversion. In addition, since heavy water obviates the need for soluble boron, neutron losses to control poison are eliminated. As a result, better resource utilization is obtained in the SSCR employing plutonium fuel cycles compared to similarly fueled pressurized water reactors (PWRs). The SSCR, however, is not competitive with the PWR due to higher capital costs, operation and maintenance costs, and the heavy water costs, which outweigh the fuel cycle cost savings. The SSCR may become an attractive alternative to the PWR if uranium prices increase substantially

Effectiveness of indometacin to prevent ovulation in modified natural-cycle IVF : A randomized controlled trial

NARCIS (Netherlands)

Rijken-Zijlstra, T. M.; Haadsma, M. L.; Hammer, C.; Burgerhof, J. G. M.; Pelinck, M. J.; Simons, A. H. M.; van Echten-Arends, J.; Arts, J. G. E. M.; Land, J. A.; Groen, H.; Hoek, A.

Modified natural-cycle IVF has a lower pregnancy rate per started cycle as compared with IVF with ovarian stimulation due to, for example, premature ovulation. Indometacin administered before ovulation prevents follicle rupture. Therefore, addition of indometacin may improve the effectiveness of

Waste-to-energy: A review of life cycle assessment and its extension methods.

Science.gov (United States)

Zhou, Zhaozhi; Tang, Yuanjun; Chi, Yong; Ni, Mingjiang; Buekens, Alfons

2018-01-01

This article proposes a comprehensive review of evaluation tools based on life cycle thinking, as applied to waste-to-energy. Habitually, life cycle assessment is adopted to assess environmental burdens associated with waste-to-energy initiatives. Based on this framework, several extension methods have been developed to focus on specific aspects: Exergetic life cycle assessment for reducing resource depletion, life cycle costing for evaluating its economic burden, and social life cycle assessment for recording its social impacts. Additionally, the environment-energy-economy model integrates both life cycle assessment and life cycle costing methods and judges simultaneously these three features for sustainable waste-to-energy conversion. Life cycle assessment is sufficiently developed on waste-to-energy with concrete data inventory and sensitivity analysis, although the data and model uncertainty are unavoidable. Compared with life cycle assessment, only a few evaluations are conducted to waste-to-energy techniques by using extension methods and its methodology and application need to be further developed. Finally, this article succinctly summarises some recommendations for further research.

Simulation of Cycle-to-Cycle Variation in Dual-Fuel Engines

KAUST Repository

Jaasim, Mohammed; Pasunurthi, Shyamsundar; Jupudi, Ravichandra S.; Gubba, Sreenivasa Rao; Primus, Roy; Klingbeil, Adam; Wijeyakulasuriya, Sameera; Im, Hong G.

2017-01-01

Standard practices of internal combustion (IC) engine experiments are to conduct the measurements of quantities averaged over a large number of cycles. Depending on the operating conditions, the cycle-to-cycle variation (CCV) of quantities

Life-cycle cost analysis of adsorption cycles for desalination

KAUST Repository

Thu, Kyaw

2010-08-01

This paper presents the thermo-economic analysis of the adsorption desalination (AD) cycle that is driven by low-temperature waste heat from exhaust of industrial processes or renewable sources. The AD cycle uses an adsorbent such as the silica gel to desalt the sea or brackish water. Based on an experimental prototype AD plant, the life-cycle cost analysis of AD plants of assorted water production capacities has been simulated and these predictions are translated into unit cost of water production. Our results show that the specific energy consumption of the AD cycle is 1.38 kWh/m3 which is the lowest ever reported. For a plant capacity of 1000 m3/d, the AD cycle offers a unit cost of $0.457/m3 as compared to more than $0.9 for the average RO plants. Besides being cost-effective, the AD cycle is also environment-friendly as it emits less CO2 emission per m3 generated, typically 85% less, by comparison to an RO process. © 2010 Desalination Publications.

Preparation, Physicochemical Properties and Hemocompatibility of Biodegradable Chitooligosaccharide-Based Polyurethane

Directory of Open Access Journals (Sweden)

Weiwei Xu

2018-05-01

addition, many active amino and hydroxyl groups contained in the structure of CPU could carry out further modification, which made it an excellent candidate for wide application in biomedical field.

Thermodynamic Investigation of an Integrated Gasification Plant with Solid Oxide Fuel Cell and Steam Cycles

DEFF Research Database (Denmark)

Rokni, Masoud

2012-01-01

A gasification plant is integrated on the top of a solid oxide fuel cell (SOFC) cycle, while a steam turbine (ST) cycle is used as a bottoming cycle for the SOFC plant. The gasification plant was fueled by woodchips to produce biogas and the SOFC stacks were fired with biogas. The produced gas...... generator (HRSG). The steam cycle was modeled with a simple single pressure level. In addition, a hybrid recuperator was used to recover more energy from the HRSG and send it back to the SOFC cycle. Thus two different configurations were investigated to study the plants characteristic. Such system...

Accuracy and computational time of a hierarchy of growth rate definitions for breeder reactor fuel

International Nuclear Information System (INIS)

Maudlin, P.J.; Borg, R.C.; Ott, K.O.

1979-01-01

For a hierarchy of four logically different definitions for calculating the asymptotic growth of fast breeder reactor fuel, an investigation is performed concerning the comparative accuracy and computational effort associated with each definition. The definition based on detailed calculation of the accumulating fuel in an expanding park of reactors asymptotically yields the most accurate value of the infinite time growth rate, γ/sup infinity/, which is used as a reference value. The computational effort involved with the park definition is very large. The definition based on the single reactor calculation of the equilibrium surplus production rate and fuel inventory gives a value for γ/sup infinity of comparable accuracy to the park definition and uses significantly less central processor unit (CPU) time. The third definition is based on a continuous treatment of the reactor fuel cycle for a single reactor and gives a value for γ/sup infinity/ that accurately approximates the second definition. The continuous definition requires very little CPU time. The fourth definition employs the isotopic breeding worths, w/sub i//sup */, for a projection of the asymptotic growth rate. The CPU time involved in this definition is practically nil if its calculation is based on the few-cycle depletion calculation normally performed for core design and critical enrichment evaluations. The small inaccuracy (approx. = 1%) of the breeding-worth-based definition is well within the inaccuracy range that results unavoidably from other sources such as nuclear cross sections, group constants, and flux calculations. This fully justifies the use of this approach in routine calculations

How well can business cycle accounting account for business cycles?

OpenAIRE

Keisuke Otsu

2012-01-01

The business cycle accounting method introduced by Chari, Kehoe and McGrattan (2007) is a useful tool to decompose business cycle fluctuations into their contributing factors. However, the model estimated by the maximum likelihood method cannot replicate business cycle moments computed from data. Moment-based estimation might be an attractive alternative if the purpose of the research is to study business cycle properties such as volatility, persistence and cross-correlation of variables inst...

Microbially mediated transformations of phosphorus in the sea: new views of an old cycle.

Science.gov (United States)

Karl, David M

2014-01-01

Phosphorus (P) is a required element for life. Its various chemical forms are found throughout the lithosphere and hydrosphere, where they are acted on by numerous abiotic and biotic processes collectively referred to as the P cycle. In the sea, microorganisms are primarily responsible for P assimilation and remineralization, including recently discovered P reduction-oxidation bioenergetic processes that add new complexity to the marine microbial P cycle. Human-induced enhancement of the global P cycle via mining of phosphate-bearing rock will likely influence the pace of P-cycle dynamics, especially in coastal marine habitats. The inextricable link between the P cycle and cycles of other bioelements predicts future impacts on, for example, nitrogen fixation and carbon dioxide sequestration. Additional laboratory and field research is required to build a comprehensive understanding of the marine microbial P cycle.

Life-cycle air emissions from PV power systems

International Nuclear Information System (INIS)

Watt, M.E.; Johnson, A.J.; Outhred, H.R.; Ellis, M.

1998-01-01

This paper addresses the air emission of grid supply versus grid-connected and off-grid photovoltaic power generation, using the framework of life-cycle assessment, in the contents of rural household energy supply in Australia. Emissions of carbon dioxide, sulphur dioxde and nitrous oxides are calculated for the three life-cycle stages of manufacture, use and disposal. Sensitivities to materials and data inputs, as well as to component efficiencies, lifetimes and sizing are discussed. For each supply option, demand management options, including insulation and appliance choice, and the substitution of solar heating or bottled gas for electricity are considered. The best option in all cases, in terms of life-cycle air emissions, is a grid-connected photovoltaic system used to supply an energy-efficient household with a mix of solar, gas and electric appliances. However, in financial terms, with current Australian energy prices, this option represents a high capital and life-cycle costs. Additionally, for the grid options, electricity costs do not significantly disadvantage the high demand scenarios. Both results provide a clear illustration of current Australian energy-pricing policies being in conflict with long-term environmental sustainability. (Author)

Performance of supercritical Brayton cycle using CO2-based binary mixture at varying critical points for SFR applications

International Nuclear Information System (INIS)

Jeong, Woo Seok; Jeong, Yong Hoon

2013-01-01

Highlights: • Supercritical CO 2 -based gas mixture Brayton cycles were investigated for a SFR. • The critical point of CO 2 is the lowest cycle operating limit of the S-CO 2 cycles. • Mixing additives with CO 2 changes the CO 2 critical point. • CO 2 –Xe and CO 2 –Kr cycles achieve higher cycle efficiencies than the S-CO 2 cycles. • CO 2 –H 2 S and CO 2 –cyclohexane cycles perform better at higher heat sink temperatures. -- Abstract: The supercritical carbon dioxide Brayton cycle (S-CO 2 cycle) has attracted much attention as an alternative to the Rankine cycle for sodium-cooled fast reactors (SFRs). The higher cycle efficiency of the S-CO 2 cycle results from the considerably decreased compressor work because the compressor behaves as a pump in the proximity of the CO 2 vapor–liquid critical point. In order to fully utilize this feature, the main compressor inlet condition should be controlled to be close to the critical point of CO 2 . This indicates that the critical point of CO 2 is a constraint on the minimum cycle condition for S-CO 2 cycles. Modifying the CO 2 critical point by mixing additive gases could be considered as a method of enhancing the performance and broadening the applicability of the S-CO 2 cycle. Due to the drastic fluctuations of the thermo-physical properties of fluids near the critical point, an in-house cycle analysis code using the NIST REFPROP database was implemented. Several gases were selected as potential additives considering their thermal stability and chemical interaction with sodium in the temperature range of interest and the availability of the mixture property database: xenon, krypton, hydrogen sulfide, and cyclohexane. The performances of the optimized CO 2 -containing binary mixture cycles with simple recuperated and recompression layouts were compared with the reference S-CO 2 , CO 2 –Ar, CO 2 –N 2 , and CO 2 –O 2 cycles. For the decreased critical temperatures, the CO 2 –Xe and CO 2 �

Development of FBR cycle data base system

International Nuclear Information System (INIS)

Kubota, Sadae; Ohtaki, Akira; Hirao, Kazuhiro

2002-06-01

In the 'Feasibility Study on Commercialized Fast Reactor Cycle System (F/S)'. scenario evaluations, cost-benefit evaluations and system characteristic evaluations to show significance of the Fast Breeder Reactor (FBR) cycle system introduction concretely are performed in parallel with a design study for FBR plants, reprocessing systems and fabrication systems. In these evaluations, informations such as economic prospects, prospects for supply and demand of resources and a progress of engineering development are used in addition to design information. This report explains a FBR Cycle Database in order to carry out management and search of various design information and the relating information. The prototype system of the database was completed in the 2000 fiscal year, and the problem of the user number restriction of the prototype system has been improved by Web-ization in the 2001 fiscal year. About 7,000 data are stored in this data base (as of the end of March, 2002). The expansion of user etc., and the continuation of input work of various evaluation information will be carried out, in the phase 2 of F/S. (author)

The Law of Diminishing Elasticity of Demand in Harrod’s Trade Cycle (1936)

OpenAIRE

Michaël Assous; Olivier Bruno; Muriel Dal-Pont Legrand

2015-01-01

In The Trade Cycle, Roy Harrod [1936a] propounded the Law of Diminishing Elasticity of Demand. The present paper tries to clarify the precise role Harrod assigned to this law in order to understand his trade cycle theory. We discuss the micro and macro foundations of the Law of Diminishing Elasticity of Demand and how, according to Harrod, it explains one of the main mechanisms that stabilize the economy during the trade cycle. In addition, we show how the Law of Diminishing Elasticity of Dem...

Development of fusion fuel cycles: Large deviations from US defense program systems

Energy Technology Data Exchange (ETDEWEB)

Klein, James Edward, E-mail: james.klein@srnl.doe.gov; Poore, Anita Sue; Babineau, David W.

2015-10-15

Highlights: • All tritium fuel cycles start with a “Tritium Process.” All have similar tritium processing steps. • Fusion tritium fuel cycles minimize process tritium inventories for various reasons. • US defense program facility designs did not minimize in-process inventories. • Reduced inventory tritium facilities will lower public risk. - Abstract: Fusion energy research is dominated by plasma physics and materials technology development needs with smaller levels of effort and funding dedicated to tritium fuel cycle development. The fuel cycle is necessary to supply and recycle tritium at the required throughput rate; additionally, tritium confinement throughout the facility is needed to meet regulatory and environmental release limits. Small fuel cycle development efforts are sometimes rationalized by stating that tritium processing technology has already been developed by nuclear weapons programs and these existing processes only need rescaling or engineering design to meet the needs of fusion fuel cycles. This paper compares and contrasts features of tritium fusion fuel cycles to United States Cold War era defense program tritium systems. It is concluded that further tritium fuel cycle development activities are needed to provide technology development beneficial to both fusion and defense programs tritium systems.

Protein kinase C signaling and cell cycle regulation

Directory of Open Access Journals (Sweden)

Adrian R Black

2013-01-01

Full Text Available A link between T cell proliferation and the protein kinase C (PKC family of serine/threonine kinases has been recognized for about thirty years. However, despite the wealth of information on PKC-mediated control of T cell activation, understanding of the effects of PKCs on the cell cycle machinery in this cell type remains limited. Studies in other systems have revealed important cell cycle-specific effects of PKC signaling that can either positively or negatively impact proliferation. The outcome of PKC activation is highly context-dependent, with the precise cell cycle target(s and overall effects determined by the specific isozyme involved, the timing of PKC activation, the cell type, and the signaling environment. Although PKCs can regulate all stages of the cell cycle, they appear to predominantly affect G0/G1 and G2. PKCs can modulate multiple cell cycle regulatory molecules, including cyclins, cyclin-dependent kinases (cdks, cdk inhibitors and cdc25 phosphatases; however, evidence points to Cip/Kip cdk inhibitors and D-type cyclins as key mediators of PKC-regulated cell cycle-specific effects. Several PKC isozymes can target Cip/Kip proteins to control G0/G1→S and/or G2→M transit, while effects on D-type cyclins regulate entry into and progression through G1. Analysis of PKC signaling in T cells has largely focused on its roles in T cell activation; thus, observed cell cycle effects are mainly positive. A prominent role is emerging for PKCθ, with non-redundant functions of other isozymes also described. Additional evidence points to PKCδ as a negative regulator of the cell cycle in these cells. As in other cell types, context-dependent effects of individual isozymes have been noted in T cells, and Cip/Kip cdk inhibitors and D-type cyclins appear to be major PKC targets. Future studies are anticipated to take advantage of the similarities between these various systems to enhance understanding of PKC-mediated cell cycle regulation in

Marine nitrogen cycle

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A.

) such as the Marine nitrogen cycle The marine nitrogen cycle. ‘X’ and ‘Y’ are intra-cellular intermediates that do not accumulate in water column. (Source: Codispoti et al., 2001) Page 1 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www... and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85-105, 2001. Page 2 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www.eoearth.org/article/Marine_nitrogen_cycle square6 Gruber, N.: The dynamics...

Development of Virtual Reality Cycling Simulator

OpenAIRE

Schramka, Filip; Arisona, Stefan; Joos, Michael; Erath, Alexander

2017-01-01

This paper presents a cycling simulator implemented using consumer virtual reality hardware and additional off-the-shelf sensors. Challenges like real time motion tracking within the performance requirements of state of the art virtual reality are successfully mastered. Retrieved data from digital motion processors is sent over Bluetooth to a render machine running Unity3D. By processing this data a bicycle is mapped into virtual space. Physically correct behaviour is simulated and high quali...

Reproductive cycles in tropical intertidal gastropods are timed around tidal amplitude cycles.

Science.gov (United States)

Collin, Rachel; Kerr, Kecia; Contolini, Gina; Ochoa, Isis

2017-08-01

Reproduction in iteroparous marine organisms is often timed with abiotic cycles and may follow lunar, tidal amplitude, or daily cycles. Among intertidal marine invertebrates, decapods are well known to time larval release to coincide with large amplitude nighttime tides, which minimizes the risk of predation. Such bimonthly cycles have been reported for few other intertidal invertebrates. We documented the reproduction of 6 gastropod species from Panama to determine whether they demonstrate reproductive cycles, whether these cycles follow a 2-week cycle, and whether cycles are timed so that larval release occurs during large amplitude tides. Two of the species ( Crepidula cf. marginalis and Nerita scabricosta ) showed nonuniform reproduction, but without clear peaks in timing relative to tidal or lunar cycles. The other 4 species show clear peaks in reproduction occurring every 2 weeks. In 3 of these species ( Cerithideopsis carlifornica var. valida, Littoraria variegata , and Natica chemnitzi ), hatching occurred within 4 days of the maximum amplitude tides. Siphonaria palmata exhibit strong cycles, but reproduction occurred during the neap tides. Strong differences in the intensity of reproduction of Cerithideopsis carlifornica , and in particular, Littoraria variegata , between the larger and smaller spring tides of a lunar month indicate that these species time reproduction with the tidal amplitude cycle rather than the lunar cycle. For those species that reproduce during both the wet and dry seasons, we found that reproductive timing did not differ between seasons despite strong differences in temperature and precipitation. Overall, we found that most (4/6) species have strong reproductive cycles synchronized with the tidal amplitude cycle and that seasonal differences in abiotic factors do not alter these cycles.

Analysis of Online DBA Algorithm with Adaptive Sleep Cycle in WDM EPON

Science.gov (United States)

Pajčin, Bojan; Matavulj, Petar; Radivojević, Mirjana

2018-05-01

In order to manage Quality of Service (QoS) and energy efficiency in the optical access network, an online Dynamic Bandwidth Allocation (DBA) algorithm with adaptive sleep cycle is presented. This DBA algorithm has the ability to allocate an additional bandwidth to the end user within a single sleep cycle whose duration changes depending on the current buffers occupancy. The purpose of this DBA algorithm is to tune the duration of the sleep cycle depending on the network load in order to provide service to the end user without violating strict QoS requests in all network operating conditions.

Life-cycle cost analysis for Foreign Research Reactor, Spent Nuclear Fuel disposal

International Nuclear Information System (INIS)

Parks, P.B.; Geddes, R.L.; Jackson, W.N.; McDonell, W.R.; Dupont, M.E.; McWhorter, D.L.; Liutkus, A.S.

1994-01-01

DOE-EM-37 requested a life-cycle cost analysis for disposal of the Foreign Research Reactor-Spent Nuclear Fuel (FRR-SNF). The analysis was to address life-cycle and unit costs for a range of FRR-SNF elements from those currently available (6,000 elements) to the (then) bounding case (15,000 elements). Five alternative disposition strategies were devised for the FRR-SNF elements. Life-cycle costs were computed for each strategy. In addition, the five strategies were evaluated in terms of six societal and technical goals. This report summarizes the study that was originally documented to DOE-EM

Creeping of hysteresis cycles; Reptation des cycles d'hysteresis

Energy Technology Data Exchange (ETDEWEB)

Neel, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Faculte des Sciences de Grenoble, 38 (France)

1959-07-01

Creeping consists of a kind of progressive translation of dissymmetric ferromagnetic hysteresis cycles as a function of the order number of the cycle. It is interpreted here by means of a probable coupling field, the existence of which is connected to a statistical conception of the distribution of the elementary regions. (author) [French] La reptation consiste en une sorte de translation progressive des cycles d'hysteresis ferromagnetiques dissymetriques en fonction du numero d'ordre du cycle. L'auteur l'interprete au moyen d'un champ aleatoire de couplage dont l'existence est liee a une conception statistique de la distribution des domaines elementaires. (auteur)

Nuclear design report for Yonggwang nuclear power plant unit 3 cycle 2

Energy Technology Data Exchange (ETDEWEB)

Zee, Sung Kyun; Song, Jae Woong; Song, Jae Seung; Park, Sang Yoon; Yoo, Choon Sung; Baek, Byung Chan; Ryu, Hyo Sang; Park, Jin Ha; Cho, Young Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1996-01-01

This report presents nuclear design calculations for Cycle 2 of Yonggwang Unit 3. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths, and operational limits. In addition, the report contains necessary data for the startup tests and for the assurance of shutdown margin during reactor operation. The reload core consists of 48 fresh Korean Standard Fuel Assemblies (KSFAs)and 129 burned KSFAs. Among the 48 fresh KSFAs, 32 fuel assemblies contain burnable poison rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of Cycle 2 amounts to 276 EFPD corresponding to a cycle burnup of 10,160 MWD/MTU. 95 figs., 31 tabs., 7 refs. (Author) .new.

Nuclear design report for Ulchin nuclear power plant unit 2 cycle 5

Energy Technology Data Exchange (ETDEWEB)

Park, Jin Ha; Park, Yong Soo; Cho, Byeong Ho; Zee, Sung Kyun; Lee, Sang Keun; Ahn, Dawk Hwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1993-09-01

This report presents nuclear design calculations for cycle 5 of Ulchin unit it 2. Information is given on fuel loading, power density distributions, reactivity coefficients, control rod worths and operational limits. In addition, the report contains all necessary data for the startup tests including predicted values for the comparison with the measured data. The reload consists of 48 KOFA`s enriched by nominally 3.50 w/o U{sub 235}. Among the KOFA`s, 20 fuel assemblies contain gadolinia rods. The fuel assemblies in the core are arranged in a low leakage loading pattern. The cycle length of cycle 5 amounts to 293 EFPD corresponding to a cycle burnup of 11780 MWD/MTU. (Author) 8 refs., 55 figs., 16 tabs.

Thermo-economic assessment of the integration of steam cycles on offshore platforms

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; Tock, Laurence; Breuhaus, Peter

2014-01-01

thermodynamic and economic performance indicators. The results illustrate the benefits of converting the gas turbines into a combined cycle. Using seawater results in smaller power generation and greater CO2-emissions than using process water, as the additional power generation in the combined cycle......The integration of steam bottoming cycles on oil platforms is often seen as a possible route to mitigate the CO2-emissions offshore. In this paper, a North Sea platform and its energy requirements are systematically analysed. The site-scale integration of steam networks is assessed by using...... is compensated by the significant pumping demand. This work emphasises that energy improvement efforts should be analysed at the scale of the overall site and not solely at the level of the combined cycle....

Power generation costs for alternate reactor fuel cycles

International Nuclear Information System (INIS)

Smolen, G.R.; Delene, J.G.

1980-09-01

The total electric generating costs at the power plant busbar are estimated for various nuclear reactor fuel cycles which may be considered for power generation in the future. The reactor systems include pressurized water reactors (PWR), heavy-water reactors (HWR), high-temperature gas cooled reactors (HTGR), liquid-metal fast breeder reactors (LMFBR), light-water pre-breeder and breeder reactors (LWPR, LWBR), and a fast mixed spectrum reactor (FMSR). Fuel cycles include once-through, uranium-only recycle, and full recycle of the uranium and plutonium in the spent fuel assemblies. The U 3 O 8 price for economic transition from once-through LWR fuel cycles to both PWR recycle and LMFBR systems is estimated. Electric power generation costs were determined both for a reference set of unit cost parameters and for a range of uncertainty in these parameters. In addition, cost sensitivity parameters are provided so that independent estimations can be made for alternate cost assumptions

Glacial cycles

DEFF Research Database (Denmark)

Kaufmann, R. K.; Juselius, Katarina

We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexity...... and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...... to simulate glacial cycles accurately. Also, results suggest that non-linear 10 dynamics, threshold effects, and/or free oscillations may not play an overriding role in glacial cycles....

Combined cycle power plant with integrated low temperature heat (LOTHECO)

International Nuclear Information System (INIS)

Kakaras, E.; Doukelis, A.; Leithner, R.; Aronis, N.

2004-01-01

The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and large-scale applications, including thermodynamic and economic analysis. A commercial gas turbine (ALSTOM GT10C) has been selected and computed with the heat mass balance program ENBIPRO. The results from the energy analysis are presented and the features of each concept are discussed. In addition, the exergy analysis provides information on the irreversibilities of each process and suggested improvements. Finally, the economic analysis reveals that the combined cycle plant with a heavy-duty gas turbine is the most efficient and economic way to produce electricity at base load. However, on a smaller scale, innovative designs, such as the LOTHECO concept, are required to reach the same level of performance at feasible costs

Benchmarking hardware architecture candidates for the NFIRAOS real-time controller

Science.gov (United States)

Smith, Malcolm; Kerley, Dan; Herriot, Glen; Véran, Jean-Pierre

2014-07-01

As a part of the trade study for the Narrow Field Infrared Adaptive Optics System, the adaptive optics system for the Thirty Meter Telescope, we investigated the feasibility of performing real-time control computation using a Linux operating system and Intel Xeon E5 CPUs. We also investigated a Xeon Phi based architecture which allows higher levels of parallelism. This paper summarizes both the CPU based real-time controller architecture and the Xeon Phi based RTC. The Intel Xeon E5 CPU solution meets the requirements and performs the computation for one AO cycle in an average of 767 microseconds. The Xeon Phi solution did not meet the 1200 microsecond time requirement and also suffered from unpredictable execution times. More detailed benchmark results are reported for both architectures.

Microbial biomass dynamics dominate N cycle responses to warming in a sub-arctic peatland

Science.gov (United States)

Weedon, J. T.; Aerts, R.; Kowalchuk, G. K.; van Bodegom, P. M.

2012-04-01

The balance of primary production and decomposition in sub-arctic peatlands may shift with climate change. Nitrogen availability will modulate this shift, but little is known about the drivers of soil nitrogen dynamics in these environments, and how they are influenced by rising soil temperatures. We used a long-term open top chamber warming experiment in Abisko, Sweden, to test for the interactive effects of spring warming, summer warming and winter snow addition on soil organic and inorganic nitrogen fluxes, potential activities of carbon and nitrogen cycle enzymes, and the structure of the soil-borne microbial communities. Summer warming increased the flux of soil organic nitrogen over the growing season, while simultaneously causing a seasonal decrease in microbial biomass, suggesting that N flux is driven by large late-season dieback of microbes. This change in N cycle dynamics was not reflected in any of the measured potential enzyme activities. Moreover, the soil microbial community structure was stable across treatments, suggesting non-specific microbial dieback. To further test whether the observed patterns were driven by direct temperature effects or indirect effects (via microbial biomass dynamics), we conducted follow-up controlled experiments in soil mesocosms. Experimental additions of dead microbial cells had stronger effects on N pool sizes and enzyme activities than either plant litter addition or a 5 °C alteration in incubation temperatures. Peat respiration was positively affected by both substrate addition and higher incubation temperatures, but the temperature-only effect was not sufficient to account for the increases in respiration observed in previous field experiments. We conclude that warming effects on peatland N cycling (and to some extent C cycling) are dominated by indirect effects, acting through alterations to the seasonal flux of microbe-derived organic matter. We propose that climate change models of soil carbon and nitrogen

Combination of IVF and IVM in naturally cycling women

DEFF Research Database (Denmark)

Tang-Pedersen, Mikael; Westergaard, Lars Grabow; Erb, Karin

2012-01-01

This study investigated the combination of an unstimulated IVF cycle with in-vitro maturation (IVM) of additional immature cumulus-oocyte-complexes (COC) from the same cycle collected at the same time as the spontaneous preovulatory follicle. This could potentially improve rates of embryo transfer...... and pregnancy/live births compared with conventional unstimulated IVF treatment and at the same time eliminate the risk of ovarian hyperstimulation syndrome. This prospective trial included 77 women with regular menstrual cycles. Age at inclusion was between 20 and 37 years. Results showed a retrieval rate...... between endometrial factors and IVM oocytes together with unknown competence of IVM embryos is suspected. For some time, there has been an increasing interest in mild approaches for fertility treatment, in particular IVF. In-vitro maturation (IVM) of immature eggs outside the ovaries followed by IVF...

Preliminary Neutronic Design of High Burnup OTTO Cycle Pebble Bed Reactor

OpenAIRE

Setiadipura, T; Irwanto, D; Zuhair, Zuhair

2015-01-01

The pebble bed type High Temperature Gas-cooled Reactor (HTGR) is among the interesting nuclear reactor designs in terms of safety and flexibility for co-generation applications. In addition, the strong inherent safety characteristics of the pebble bed reactor (PBR) which is based on natural mechanisms improve the simplicity of the PBR design, in particular for the Once-Through-Then-Out (OTTO) cycle PBR design. One of the important challenges of the OTTO cycle PBR design, and nuclear reactor ...

The glutathione cycle: Glutathione metabolism beyond the γ-glutamyl cycle.

Science.gov (United States)

Bachhawat, Anand Kumar; Yadav, Shambhu

2018-04-17

Glutathione was discovered in 1888, over 125 years ago. Since then, our understanding of various functions and metabolism of this important molecule has grown over these years. But it is only now, in the last decade, that a somewhat complete picture of its metabolism has emerged. Glutathione metabolism has till now been largely depicted and understood by the γ-glutamyl cycle that was proposed in 1970. However, new findings and knowledge particularly on the transport and degradation of glutathione have revealed that many aspects of the γ-glutamyl cycle are incorrect. Despite this, an integrated critical analysis of the cycle has never been undertaken and this has led to the cycle and its errors perpetuating in the literature. This review takes a careful look at the γ-glutamyl cycle and its shortcomings and presents a "glutathione cycle" that captures the current understanding of glutathione metabolism. © 2018 IUBMB Life, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Single generation cycles and delayed feedback cycles are not separate phenomena.

Science.gov (United States)

Pfaff, T; Brechtel, A; Drossel, B; Guill, C

2014-12-01

We study a simple model for generation cycles, which are oscillations with a period of one or a few generation times of the species. The model is formulated in terms of a single delay-differential equation for the population density of an adult stage, with recruitment to the adult stage depending on the intensity of competition during the juvenile phase. This model is a simplified version of a group of models proposed by Gurney and Nisbet, who were the first to distinguish between single-generation cycles and delayed-feedback cycles. According to these authors, the two oscillation types are caused by different mechanisms and have periods in different intervals, which are one to two generation times for single-generation cycles and two to four generation times for delayed-feedback cycles. By abolishing the strict coupling between the maturation time and the time delay between competition and its effect on the population dynamics, we find that single-generation cycles and delayed-feedback cycles occur in the same model version, with a gradual transition between the two as the model parameters are varied over a sufficiently large range. Furthermore, cycle periods are not bounded to lie within single octaves. This implies that a clear distinction between different types of generation cycles is not possible. Cycles of all periods and even chaos can be generated by varying the parameters that determine the time during which individuals from different cohorts compete with each other. This suggests that life-cycle features in the juvenile stage and during the transition to the adult stage are important determinants of the dynamics of density limited populations. Copyright © 2014 Elsevier Inc. All rights reserved.

[Cycling in Zagreb].

Science.gov (United States)

Matos, Stipan; Krapac, Ladislav; Krapac, Josip

2007-01-01

Cycling in Zagreb, as means of urban transport inside and outside the city, has a bright past, hazy presence but a promising future. Every day, aggressive citizens who lack urban traffic culture mistreat many cyclists but also many pedestrians. Sedentary way of living, unhealthy eating habits and inadequate recreation would surely be reduced if Zagreb had a network of cycling tracks (190 cm) or lanes (80 cm). Main city roads were constructed at the beginning of the 20th century. Today, the lack of cycling tracks is particularly evident in terms of missing connections between northern and southern parts of the city. Transportation of bikes in public vehicles, parking of bikes as well as cycling along the foot of the mountains Medvednica and Zumberacko gorje is not adequately organized. Better organization is necessary not only because of the present young generation but also because of the young who will shortly become citizens of the EU, where cycling is enormously popular. Cycling tourism is not known in Zagreb, partly due to inadequate roads. The surroundings of Zagreb are more suitable for cycling tourism and attractive brochures and tourist guides offer information to tourists on bikes. Professional, acrobatic and sports cycling do not have a tradition in Zagreb and in Croatia. The same holds true for recreational cycling and indoor exercise cycling. The authors discuss the impact of popularization of cycling using print and electronic media. The role of district and local self-government in the construction and improvement of traffic roads in Zagreb is very important. It is also significant for the implementation of legal regulations that must be obeyed by all traffic participants in order to protect cyclists, the most vulnerable group of traffic participants besides passengers. Multidisciplinary action of all benevolent experts would surely increase safety and pleasure of cycling in the city and its surroundings. This would also help reduce daily stress and

Quantification of Underestimation of Physical Activity During Cycling to School When Using Accelerometry

DEFF Research Database (Denmark)

Tarp, Jakob; Andersen, Lars B; Østergaard, Lars

2015-01-01

Background: Cycling to and from school is an important source of physical activity (PA) in youth but it is not captured by the dominant objective method to quantify PA. The aim of this study was to quantify the underestimation of objectively assessed PA caused by cycling when using accelerometry....... Methods: Participants were 20 children aged 11-14 years from a randomized controlled trial performed in 2011. Physical activity was assessed by accelerometry with the addition of heart rate monitoring during cycling to school. Global positioning system (GPS) was used to identify periods of cycling...... to school. Results: Mean (95% CI) minutes of moderate-to-vigorous physical activity (MVPA) during round-trip commutes was 10.8 (7.1 - 16.6). Each kilometre of cycling meant an underestimation of 9314 (95%CI: 7719 - 11238) counts and 2.7 (95%CI: 2.1 - 3.5) minutes of MVPA. Adjusting for cycling to school...

Green technology effect of injection pressure, timing and compression ratio in constant pressure heat addition cycle by an eco-friendly material.

Science.gov (United States)

Karthikayan, S; Sankaranarayanan, G; Karthikeyan, R

2015-11-01

Present energy strategies focus on environmental issues, especially environmental pollution prevention and control by eco-friendly green technologies. This includes, increase in the energy supplies, encouraging cleaner and more efficient energy management, addressing air pollution, greenhouse effect, global warming, and climate change. Biofuels provide the panorama of new fiscal opportunities for people in rural area for meeting their need and also the demand of the local market. Biofuels concern protection of the environment and job creation. Renewable energy sources are self-reliance resources, have the potential in energy management with less emissions of air pollutants. Biofuels are expected to reduce dependability on imported crude oil with connected economic susceptibility, reduce greenhouse gases, other pollutants and invigorate the economy by increasing demand and prices for agricultural products. The use of neat paradise tree oil and induction of eco-friendly material Hydrogen through inlet manifold in a constant pressure heat addition cycle engine (diesel engine) with optimized engine operating parameters such as injection timing, injection pressure and compression ratio. The results shows the heat utilization efficiency for neat vegetable oil is 29% and neat oil with 15% Hydrogen as 33%. The exhaust gas temperature (EGT) for 15% of H2 share as 450°C at full load and the heat release of 80J/deg. crank angle for 15% Hydrogen energy share. Copyright © 2015 Elsevier Inc. All rights reserved.

The DISTO data acquisition system at SATURNE

International Nuclear Information System (INIS)

Balestra, F.; Bedfer, Y.; Bertini, R.

1998-01-01

The DISTO collaboration has built a large-acceptance magnetic spectrometer designed to provide broad kinematic coverage of multiparticle final states produced in pp scattering. The spectrometer has been installed in the polarized proton beam of the Saturne accelerator in Saclay to study polarization observables in the rvec pp → pK + rvec Y (Y = Λ, Σ 0 or Y * ) reaction and vector meson production (ψ, ω and ρ) in pp collisions. The data acquisition system is based on a VME 68030 CPU running the OS/9 operating system, housed in a single VME crate together with the CAMAC interface, the triple port ECL memories, and four RISC R3000 CPU. The digitization of signals from the detectors is made by PCOS III and FERA front-end electronics. Data of several events belonging to a single Saturne extraction are stored in VME triple-port ECL memories using a hardwired fast sequencer. The buffer, optionally filtered by the RISC R3000 CPU, is recorded on a DLT cassette by DAQ CPU using the on-board SCSI interface during the acceleration cycle. Two UNIX workstations are connected to the VME CPUs through a fast parallel bus and the Local Area Network. They analyze a subset of events for on-line monitoring. The data acquisition system is able to read and record 3,500 ev/burst in the present configuration with a dead time of 15%

Features of the Phosphatidylinositol Cycle and its Role in Signal Transduction.

Science.gov (United States)

Epand, Richard M

2017-08-01

The phosphatidylinositol cycle (PI-cycle) has a central role in cell signaling. It is the major pathway for the synthesis of phosphatidylinositol and its phosphorylated forms. In addition, some lipid intermediates of the PI-cycle, including diacylglycerol and phosphatidic acid, are also important lipid signaling agents. The PI-cycle has some features that are important for the understanding of its role in the cell. As a cycle, the intermediates will be regenerated. The PI-cycle requires a large amount of metabolic energy. There are different steps of the cycle that occur in two different membranes, the plasma membrane and the endoplasmic reticulum. In order to complete the PI-cycle lipid must be transferred between the two membranes. The role of the Nir proteins in the process has recently been elucidated. The lipid intermediates of the PI-cycle are normally highly enriched with 1-stearoyl-2-arachidonoyl molecular species in mammals. This enrichment will be retained as long as the intermediates are segregated from other lipids of the cell. However, there is a significant fraction (>15 %) of lipids in the PI-cycle of normal cells that have other acyl chains. Phosphatidylinositol largely devoid of arachidonoyl chains are found in cancer cells. Phosphatidylinositol species with less unsaturation will not be as readily converted to phosphatidylinositol-3,4,5-trisphosphate, the lipid required for the activation of Akt with resulting effects on cell proliferation. Thus, the cyclical nature of the PI-cycle, its dependence on acyl chain composition and its requirement for lipid transfer between two membranes, explain many of the biological properties of this cycle.

Cell cycle in egg cell and its progression during zygotic development in rice.

Science.gov (United States)

Sukawa, Yumiko; Okamoto, Takashi

2018-03-01

Rice egg is arrested at G1 phase probably by OsKRP2. After fusion with sperm, karyogamy, OsWEE1-mediated parental DNA integrity in zygote nucleus, zygote progresses cell cycle to produce two-celled embryo. In angiosperms, female and male gametes exist in gametophytes after the complementation of meiosis and the progression of nuclear/cell division of the haploid cell. Within the embryo sac, the egg cell is specially differentiated for fertilization and subsequent embryogenesis, and cellular programs for embryonic development, such as restarting the cell cycle and de novo gene expression, are halted. There is only limited knowledge about how the cell cycle in egg cells restarts toward zygotic division, although the conversion of the cell cycle from a quiescent and arrested state to an active state is the most evident transition of cell status from egg cell to zygote. This is partly due to the difficulty in direct access and analysis of egg cells, zygotes and early embryos, which are deeply embedded in ovaries. In this study, precise relative DNA amounts in the nuclei of egg cells, developing zygotes and cells of early embryos were measured, and the cell cycle of a rice egg cell was estimated as the G1 phase with a 1C DNA level. In addition, increases in DNA content in zygote nuclei via karyogamy and DNA replication were also detectable according to progression of the cell cycle. In addition, expression profiles for cell cycle-related genes in egg cells and zygotes were also addressed, and it was suggested that OsKRP2 and OsWEE1 function in the inhibition of cell cycle progression in egg cells and in checkpoint of parental DNA integrity in zygote nucleus, respectively.

Using a Cyclical Diagram to Visualize the Events of the Ovulatory Menstrual Cycle

Science.gov (United States)

Ho, Ivan Shun; Parmar, Navneet K.

2014-01-01

Over the past 10 years, college textbooks in human anatomy and physiology have typically presented the events of the ovulatory menstrual cycle in a linear format, with time in days shown on the x-axis, and hormone levels, follicular development, and uterine lining on the y-axis. In addition, the various events are often shown over a 28-day cycle,…

Cell cycle regulation in human embryonic stem cells: links to adaptation to cell culture.

Science.gov (United States)

Barta, Tomas; Dolezalova, Dasa; Holubcova, Zuzana; Hampl, Ales

2013-03-01

Cell cycle represents not only a tightly orchestrated mechanism of cell replication and cell division but it also plays an important role in regulation of cell fate decision. Particularly in the context of pluripotent stem cells or multipotent progenitor cells, regulation of cell fate decision is of paramount importance. It has been shown that human embryonic stem cells (hESCs) show unique cell cycle characteristics, such as short doubling time due to abbreviated G1 phase; these properties change with the onset of differentiation. This review summarizes the current understanding of cell cycle regulation in hESCs. We discuss cell cycle properties as well as regulatory machinery governing cell cycle progression of undifferentiated hESCs. Additionally, we provide evidence that long-term culture of hESCs is accompanied by changes in cell cycle properties as well as configuration of several cell cycle regulatory molecules.

Design and analysis of helium Brayton power cycles for HiPER reactor

Energy Technology Data Exchange (ETDEWEB)

Sánchez, Consuelo, E-mail: csanchez@ind.uned.es [Dpto. Ingeniería Energética UNED, Madrid (Spain); Juárez, Rafael; Sanz, Javier [Dpto. Ingeniería Energética UNED, Madrid (Spain); Instituto de Fusión Nuclear/UPM, Madrid (Spain); Perlado, Manuel [Instituto de Fusión Nuclear/UPM, Madrid (Spain)

2013-10-15

Highlights: ► A helium Brayton cycle has been designed integrating the two energy sources of HiPER. ► The Brayton cycle has intercooling stages and a recovery process. ► The low temperature of HiPER heat sources results in low cycle efficiency (35.2%). ► Two inter-cooling stages and a reheating process increases efficiency to over 37%. ► Helium Brayton cycles are to be considered as candidates for HiPER power cycles. -- Abstract: Helium Brayton cycles have been studied as power cycles for both fission and fusion reactors obtaining high thermal efficiency. This paper studies several technological schemes of helium Brayton cycles applied for the HiPER reactor proposal. Since HiPER integrates technologies available at short term, its working conditions results in a very low maximum temperature of the energy sources, something that limits the thermal performance of the cycle. The aim of this work is to analyze the potential of the helium Brayton cycles as power cycles for HiPER. Several helium Brayton cycle configurations have been investigated with the purpose of raising the cycle thermal efficiency under the working conditions of HiPER. The effects of inter-cooling and reheating have specifically been studied. Sensitivity analyses of the key cycle parameters and component performances on the maximum thermal efficiency have also been carried out. The addition of several inter-cooling stages in a helium Brayton cycle has allowed obtaining a maximum thermal efficiency of over 36%, and the inclusion of a reheating process may also yield an added increase of nearly 1 percentage point to reach 37%. These results confirm that helium Brayton cycles are to be considered among the power cycle candidates for HiPER.

Design and analysis of helium Brayton power cycles for HiPER reactor

International Nuclear Information System (INIS)

Sánchez, Consuelo; Juárez, Rafael; Sanz, Javier; Perlado, Manuel

2013-01-01

Highlights: ► A helium Brayton cycle has been designed integrating the two energy sources of HiPER. ► The Brayton cycle has intercooling stages and a recovery process. ► The low temperature of HiPER heat sources results in low cycle efficiency (35.2%). ► Two inter-cooling stages and a reheating process increases efficiency to over 37%. ► Helium Brayton cycles are to be considered as candidates for HiPER power cycles. -- Abstract: Helium Brayton cycles have been studied as power cycles for both fission and fusion reactors obtaining high thermal efficiency. This paper studies several technological schemes of helium Brayton cycles applied for the HiPER reactor proposal. Since HiPER integrates technologies available at short term, its working conditions results in a very low maximum temperature of the energy sources, something that limits the thermal performance of the cycle. The aim of this work is to analyze the potential of the helium Brayton cycles as power cycles for HiPER. Several helium Brayton cycle configurations have been investigated with the purpose of raising the cycle thermal efficiency under the working conditions of HiPER. The effects of inter-cooling and reheating have specifically been studied. Sensitivity analyses of the key cycle parameters and component performances on the maximum thermal efficiency have also been carried out. The addition of several inter-cooling stages in a helium Brayton cycle has allowed obtaining a maximum thermal efficiency of over 36%, and the inclusion of a reheating process may also yield an added increase of nearly 1 percentage point to reach 37%. These results confirm that helium Brayton cycles are to be considered among the power cycle candidates for HiPER

Orbit Transfer Vehicle Engine Study. Phase A, extension 1: Advanced expander cycle engine optimization

Science.gov (United States)

Mellish, J. A.

1979-01-01

The performance optimization of expander cycle engines at vacuum thrust levels of 10K, 15K, and 20K lb is discussed. The optimization is conducted for a maximum engine length with an extendible nozzle in the retracted position of 60 inches and an engine mixture ratio of 6.0:1. The thrust chamber geometry and cycle analyses are documented. In addition, the sensitivity of a recommended baseline expander cycle to component performance variations is determined and chilldown/start propellant consumptions are estimated.

On the rationality of cycling in the Theory of Moves framework

Science.gov (United States)

Olsen, Jolie; Sen, Sandip

2014-04-01

Theory of Moves (TOM) is a novel approach to game theory for determining rational strategies during the play of dynamic games [Brams, S J. (1994). Theory of moves. Cambridge, UK: Cambridge University Press]. While alternate models such as normal form games exist, players of these games are limited to single shot interactions with each other, but within TOM, sequences of moves and counter moves are allowed. As a consequence of this framework potential cyclic behaviour may arise. Unfortunately, standard TOM framework suggests that players do not move from the initial state if the possibility of cyclic behaviour is detected. However, in a plethora of real life scenarios, cycling can benefit a player over time. We first extend the TOM framework by allowing players to choose how much time to stay in each state while specifying time limits for moves. This generalisation allows for cycling behaviour in addition to normal, acyclic TOM play. We present additional rationality rules to handle the choice of move time and cyclic play and identify conditions for the existence of solutions that involve cycles. Moreover, if solutions do exist, equilibrium are determined so a player can predict the rational outcome upon engaging a cycle. A variety of time constraints on move times are investigated and the effects of these contrasts on the solution space and equilibrium are analysed.

Transportation risks in the US nuclear fuel cycle

International Nuclear Information System (INIS)

Rhoads, R.E.; Andrews, W.B.

1980-01-01

Estimated risks associated with accidental releases of materials transported for each step of the nuclear fuel cycle are presented. The risk estimates include both immediate and latent fatilities caused by releases of these materials in transportation accidents. Studies of the risk of transporting yellowcake, fresh nuclear and low level wastes from the front end of the fuel cycle have not been completed. Existing information does permit estimates of the risks to be made. The estimates presented result from the very low hazards associated with release of these materials. These estimates are consistent with the results of other studies. The results show that risks from all the fuel cycle transportation steps are low. The results also indicate that the total transportation risks associated with the nuclear fuel cycle are distributed about evenly between the fuel supply end and waste management end of the cycle. Risks in the front end of the cycle result primarily from the chemical toxicity of the materials transported. The results of the risk analysis studies for transportation of nuclear fuel cycle materials are compared with the results for the three studies that have been completed for non-nuclear systems. The risk analysis methodology used in these studies identifies the complete spectrum of potential accident consequences and estimates the probability of events producing that level of consequence. The maximum number of fatalities predicted for each material is presented. A variety of risk measures have been used because of the inherent difficulties in making risk comparisons. Examination of a number of risk measures can provide additional insights and help guard against conclusions that are dependent on the way the risk information has been developed and displayed. The results indicate that the risks from transporting these materials are all relatively low in comparison to other risks in society

Cycle to Cycle Variation Study in a Dual Fuel Operated Engine

KAUST Repository

Pasunurthi, Shyamsundar

2017-03-28

The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP) is captured from many consecutive combustion cycles for each test condition. However, obtaining 3D spatial distribution of all the relevant quantities such as fuel-air mixing, temperature, turbulence levels and emissions from such experiments is a challenging task. Computational Fluid Dynamics (CFD) simulations of engine flow and combustion can be used effectively to visualize such 3D spatial distributions. A dual fuel engine is considered in the current study, with manifold injected natural gas (NG) and direct injected diesel pilot for ignition. Multiple engine cycles in 3D are simulated in series like in the experiments to investigate the potential of high fidelity RANS simulations coupled with detailed chemistry, to accurately predict the CCV. Cycle to cycle variation (CCV) is expected to be due to variabilities in operating and boundary conditions, in-cylinder stratification of diesel and natural gas fuels, variation in in-cylinder turbulence levels and velocity flow-fields. In a previous publication by the authors [1], variabilities in operating and boundary conditions are incorporated into several closed cycle simulations performed in parallel. Stochastic variations/stratifications of fuel-air mixture, turbulence levels, temperature and internal combustion residuals cannot be considered in such closed cycle simulations. In this study, open cycle simulations with port injection of natural gas predicted the combined effect of the stratifications on the CCV of in-cylinder pressure. The predicted Coefficient of Variation (COV) of cylinder pressure is improved compared to the one captured by closed cycle simulations in parallel.

Internal cycle modeling and environmental assessment of multiple cycle consumer products

International Nuclear Information System (INIS)

Tsiliyannis, C.A.

2012-01-01

Highlights: ► Dynamic flow models are presented for remanufactured, reused or recycled products. ► Early loss and stochastic return are included for fast and slow cycling products. ► The reuse-to-input flow ratio (Internal Cycle Factor, ICF) is determined. ► The cycle rate, which is increasing with the ICF, monitors eco-performance. ► Early internal cycle losses diminish the ICF, the cycle rate and performance. - Abstract: Dynamic annual flow models incorporating consumer discard and usage loss and featuring deterministic and stochastic end-of-cycle (EOC) return by the consumer are developed for reused or remanufactured products (multiple cycle products, MCPs), including fast and slow cycling, short and long-lived products. It is shown that internal flows (reuse and overall consumption) increase proportionally to the dimensionless internal cycle factor (ICF) which is related to environmental impact reduction factors. The combined reuse/recycle (or cycle) rate is shown capable for shortcut, albeit effective, monitoring of environmental performance in terms of waste production, virgin material extraction and manufacturing impacts of all MCPs, a task, which physical variables (lifetime, cycling frequency, mean or total number of return trips) and conventional rates, via which environmental policy has been officially implemented (e.g. recycling rate) cannot accomplish. The cycle rate is shown to be an increasing (hyperbolic) function of ICF. The impact of the stochastic EOC return characteristics on total reuse and consumption flows, as well as on eco-performance, is assessed: symmetric EOC return has a small, positive effect on performance compared to deterministic, while early shifted EOC return is more beneficial. In order to be efficient, environmental policy should set higher minimum reuse targets for higher trippage MCPs. The results may serve for monitoring, flow accounting and comparative eco-assessment of MCPs. They may be useful in identifying

Effects of adrenalectomy and constant light on the rat estrous cycle.

Science.gov (United States)

Hoffmann, J C

1978-01-01

Adult female ARS/Sprague-Dawley rats were allowed to acclimatize to a a lighting schedule of 12L:12D (LD) for 5 weeks. At that time, half the animals were adrenalectomized, and all rats remained in LD for an additional 4 to 5 weeks. Subsequently, half of the control and half of the adrenalectomized rats were exposed to constant light (LL) for an additional 8 weeks, at which time all animals were sacificed. Operated rats with regenerated adrenal tissue, determined either by macroscopic examination or serum corticosterone assay (about 50% of the rats), were excluded from all data calculations. Acute disturbances of estrous cycle length were minor. The long-term effects revealed a significant increase in 5-day cycles among the adrenalectomized rats, although the majority of cycles recorded (80%) were still 4 days in length. None of the rats in LD showed spontaneous persistent estrus. Adrenalectomy did not affect the number of ova shed. When placed in LL, the adrenalectomized rats continued to cycle longer than the unoperated controls, but all rats showed persistent estrus (5 or more consecutive days of vaginal cornification) within 7--8 weeks. Adrenalectomized rats had significantly higher body weights than controls. Relative uterine weight was decreased in these animals in both lighting regimens but only reached statistical significance in LD. Ovarian weight, by contrast, was significantly increased among adrenalectomized rats in LD but was identical in both groups in LL. Adrenal weight of intact rats was not altered by LL. Since estrous cycles can continue for at least 6 months in the absence of the adrenal gland, the persistent estrus that occurs in LL is not merely due to the loss of a diurnal rhythm of corticosteroids. Indeed, when adrenalectomized rats are placed in LL, they continue to show estrous cycles longer than do intact rats. Adrenalectomy does appear to increase the length of the cycle in some animals, and the hormonal basis for this warrants further

An Integrated Framework for Life Cycle Engineering

DEFF Research Database (Denmark)

Hauschild, Michael Zwicky; Herrmann, Christoph; Kara, Sami

2017-01-01

Life Cycle Engineering (LCE) was introduced as a concept more than 24 years ago in order to address emerging concerns about environmental sustainability in engineering. A number of methods and tools have been introduced to operationalise the LCE concept, but since then, the scope of sustainability...... has broadened, and as a result, LCE has evolved in parallel with other disciplines with similar aims. Currently, in addition to LCE, there exist a number of concepts such as Industrial Ecology, Cleaner Production, Life Cycle Management (LCM), Industrial Symbiosis, and Circular Economy. As a result......-down and bottom-up approach, the framework establishes a relationship between LCE and the other concepts and positions them relative to the planetary boundaries and the concept of absolute environmental sustainability. (C) 2017 The Authors. Published by Elsevier B.V....

Inventories in the Australian business cycle

OpenAIRE

Chindamo, Phillip

2010-01-01

This Economics Research Note examines inventories in the business cycle for Australia covering the period since the mid 1980s. The Australian Bureau of Statistics (ABS) defines inventories as all materials etc., work in progress and finished goods owned by a business, whether held at locations of the business or elsewhere. These items are usually held by businesses in anticipation of a product’s sale. Inventory investment is counted as an additional contribution to gross domestic product (...

The continuous fuel cycle model and the gas cooled fast reactor

International Nuclear Information System (INIS)

Christie, Stuart; Lathouwers, Danny; Kloosterman, Jan Leen; Hagen, Tim van der

2011-01-01

The gas cooled fast reactor (GFR) is one of the generation IV designs currently being evaluated for future use. It is intended to behave as an isobreeder, producing the same amount of fuel as it consumes during operation. The actinides in the fuel will be recycled repeatedly in order to minimise the waste output to fission products only. Striking the balance of the fissioning of various actinides against transmutation and decay to achieve these goals is a complex problem. This is compounded by the time required for burn-up modelling, which can be considerable for a single cycle, and even longer for studies of fuel evolution over many cycles. The continuous fuel cycle model approximates the discrete steps of loading, operating and unloading a reactor as continuous processes. This simplifies the calculations involved in simulating the behaviour of the fuel, reducing the time needed to model the changes to the fuel composition over many cycles. This method is used to study the behaviour of GFR fuel over many cycles and compared to results obtained from direct calculations. The effects of varying fuel cycle properties such as feed material, recycling of additional actinides and reprocessing losses are also investigated. (author)

Numerical simulation and performance investigation of an advanced adsorption desalination cycle

KAUST Repository

Thu, Kyaw

2013-01-01

Low temperature waste heat-driven adsorption desalination (AD) cycles offer high potential as one of the most economically viable and environmental-friendly desalination methods. This article presents the development of an advanced adsorption desalination cycle that employs internal heat recovery between the evaporator and the condenser, utilizing an encapsulated evaporator-condenser unit for effective heat transfer. A simulation model has been developed based on the actual sorption characteristics of the adsorbent-adsorbate pair, energy and mass balances applied to the components of the AD cycle. With an integrated design, the temperature in the evaporator and the vapor pressurization of the adsorber are raised due to the direct heat recovery from the condenser, resulting in the higher water production rates, typically improved by as much as three folds of the conventional AD cycle. In addition, the integrated design eliminates two pumps, namely, the condenser cooling water and the chilled water pumps, lowering the overall electricity consumption. The performance of the cycle is analyzed at assorted heat source and cooling water temperatures, and different cycle times as well as the transient heat transfer coefficients of the evaporation and condensation. © 2012 Elsevier B.V.

Evaluation of plutonium, uranium, and thorium use in power reactor fuel cycles

International Nuclear Information System (INIS)

Kasten, P.R.; Homan, F.J.

1977-01-01

The increased cost of uranium and separative work has increased the attractiveness of plutonium use in both uranium and thorium fuel cycles in thermal reactors. A technology, fuel utilization, and economic evaluation is given for uranium and thorium fuel cycles in various reactor types, along with the use of plutonium and 238 U. Reactors considered are LWRs, HWRs, LWBRs, HTGRs, and FBRs. Key technology factors are fuel irradiation performance and associated physical property values. Key economic factors are unit costs for fuel fabrication and reprocessing, and for refabrication of recycle fuels; consistent cost estimates are utilized. In thermal reactors, the irradiation performance of ceramic fuels appears to be satisfactory. At present costs for uranium ore and separative work, recycle of plutonium with thorium rather than uranium is preferable from fuel utilization and economic viewpoints. Further, the unit recovery cost of plutonium is lower from LWR fuels than from natural-uranium HWR fuels; use of LWR product permits plutonium/thorium fueling to compete with uranium cycles. Converting uranium cycles to thorium cycles increases the energy which can be extracted from a given uranium resource. Thus, additional fuel utilization improvement can be obtained by fueling all thermal reactors with thorium, but this requires use of highly enriched uranium; use of 235 U with thorium is most economic in HTGRs followed by HWRs and then LWRs. Marked improvement in long-term fuel utilization can be obtained through high thorium loadings and short fuel cycle irradiations as in the LWBR, but this imposes significant economic penalties. Similar operating modes are possible in HWRs and HTGRs. In fast reactors, use of the plutonium-uranium cycle gives advantageous fuel resource utilization in both LMFBRs and GCFRs; use of the thorium cycle provides more negative core reactivity coefficients and more flexibility relative to use of recycle fuels containing uranium of less than 20

Microbial nitrogen cycling in Arctic snowpacks

International Nuclear Information System (INIS)

Larose, Catherine; Vogel, Timothy M; Dommergue, Aurélien

2013-01-01

Arctic snowpacks are often considered as chemical reactors for a variety of chemicals deposited through wet and dry events, but are overlooked as potential sites for microbial metabolism of reactive nitrogen species. The fate of deposited species is critical since warming leads to the transfer of contaminants to snowmelt-fed ecosystems. Here, we examined the role of microorganisms and the potential pathways involved in nitrogen cycling in the snow. Next generation sequencing data were used to follow functional gene abundances and a 16S rRNA (ribosomal ribonucleic acid) gene microarray was used to follow shifts in microbial community structure during a two-month spring-time field study at a high Arctic site, Svalbard, Norway (79° N). We showed that despite the low temperatures and limited water supply, microbial communities inhabiting the snow cover demonstrated dynamic shifts in their functional potential to follow several different pathways of the nitrogen cycle. In addition, microbial specific phylogenetic probes tracked different nitrogen species over time. For example, probes for Roseomonas tracked nitrate concentrations closely and probes for Caulobacter tracked ammonium concentrations after a delay of one week. Nitrogen cycling was also shown to be a dominant process at the base of the snowpack. (letter)

Physical Properties of Sandy Soil Affected by Soil Conditioner Under Wetting and Drying cycles

Directory of Open Access Journals (Sweden)

M.I. Choudhary

1998-06-01

Full Text Available Information on the effectiveness of soil conditioners over a prolonged period is scarce. A laboratory experiment was undertaken to evaluate the effectiveness of a polyacrylamide (Broadleaf P4 soil conditioner on the physical properties of sandy soil subjected to wetting and drying cycles. Four concentrations of Broadleaf P4 0, 0.2, 0.4, and 0.6% on dry weight basis were uniformly mixed with a calcareous sandy soil. Addition of Broadleaf P4 to sandy soil increased the water holding capacity, decreased the bulk density, and increased the porosity and void ratio at 0 and 16 wetting and drying cycles. The coefficient of linear extensibility increased considerably with increasing concentrations of the polymer. The addition of polymer at 0 and 16 cycles increased considerably the retention and availability of water in sandy soil. Saturated hydraulic conductivity decreased with increasing concentrations of Broadleaf P4 whereas unsaturated hydraulic conductivity at 0 and 16 cycles showed an increase with increasing soil moisture contents. After I6 wetting and drying cycles, the capacity of the soil to hold water was lost on average by 15.8% when compared to the 0 wetting and drying cycle. The effectiveness of the soil conditioner on bulk density, coefficient of linear extensibility, available water and saturated hydraulic conductivity was reduced on average by 14.1, 24.5, 21.l and 53.7% respectively. The significant changes in soil properties between 0 and 16 cycles suggested that the effectiveness of the conditioner decreased with the application of wetting and drying cycles. However, its effect was still considerable when compared to untreated soil under laboratory conditions.

Cycle to Cycle Variation Study in a Dual Fuel Operated Engine

KAUST Repository

Pasunurthi, Shyamsundar; Jupudi, Ravichandra; Wijeyakulasuriya, Sameera; Gubba, Sreenivasa Rao; Im, Hong G.; Jaasim, Mohammed; Primus, Roy; Klingbeil, Adam; Finney, Charles

2017-01-01

The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP

Are there two types of business cycles? a note on crisis detection

Directory of Open Access Journals (Sweden)

Robert Pater

2014-12-01

Full Text Available Business cycles are highly irregular fluctuations in economic activity. This article attempts to determine whether there are some properties of business cycles that can make them look more regular. This is done by analysing business cycle dynamics, especially by employing and adjusting to contemporary business cycle analysis the theories of growth cycles and classical cycles. The non-homogeneity of business cycles is surveyed in theory and practice with use of ad hoc filtering, spectral analysis and unobserved components models. With their use business cycles are extracted. Several macroeconomic indicators for 32 economies are analysed to draw up additional characteristics of contemporary business cycles. The author proposes that fluctuations in economic activity lasting 8-19 quarters should be called ‘growth cycles’ and those lasting 20-40 quarters – ‘classical cycles’. The value added of this article is the consideration of the two different type of cycles in light of the same methods of extraction, while to date they have been thought of as the ones that can be analysed with use of different methods of extraction. Another innovation is comparison of the cyclicality of different macroeconomic indicators from the point of view of the two types of cycles, while to date they have been analysed in the light of a single business cycle. In the article it is shown that dividing business cycles into such defined classical cycles and growth cycles enables us to understand the differences between the cyclicality of various macroeconomic aggregates and countries. It also enables us to distinguish between smaller downturns and severe recessions. Another conclusion is that the duration of contemporary business cycles around the world closes in a range of 2 to 10 years.

Critical firing and misfiring boundary in a spark ignition methanol engine during cold start based on single cycle fuel injection

International Nuclear Information System (INIS)

Li, Zhaohui; Gong, Changming; Qu, Xiang; Liu, Fenghua; Sun, Jingzhen; Wang, Kang; Li, Yufeng

2015-01-01

The influence of the mass of methanol injected per cycle, ambient temperature, injection and ignition timing, preheating methods, and supplying additional liquefied petroleum gas (LPG) injection into the intake manifold on the critical firing and misfiring boundary of an electronically injection controlled spark ignition (SI) methanol engine during cold start were investigated experimentally based on a single cycle fuel injection with cycle-by-cycle control strategy. The critical firing and misfiring boundary was restricted by all parameters. For ambient temperatures below 16 °C, methanol engines must use auxiliary start-aids during cold start. Optimal control of the methanol injection and ignition timing can realize ideal next cycle firing combustion after injection. Resistance wire and glow plug preheating can provide critical firing down to ambient temperatures of 5 °C and 0 °C, respectively. Using an additional LPG injection into the intake manifold can provide critical firing down to an ambient temperature of −13 °C during cold start. As the ambient temperature decreases, the optimal angle difference between methanol injection timing and LPG injection timing for critical firing of a methanol engine increases rapidly during cold start. - Highlights: • A single cycle fuel injection and cycle-by-cycle control strategy are used to study. • In-cylinder pressure and instantaneous speed were used to determine firing boundary. • For the ambient temperatures below 16 °C, an auxiliary start-aids must be used. • A preheating and additional LPG were used to expand critical firing boundary. • Additional LPG can result in critical firing down to ambient temperature of −13 °C

Effects of nitrogen addition and fire on plant nitrogen use in a temperate steppe.

Directory of Open Access Journals (Sweden)

Hai-Wei Wei

Full Text Available Plant nitrogen (N use strategies have great implications for primary production and ecosystem nutrient cycling. Given the increasing atmospheric N deposition received by most of the terrestrial ecosystems, understanding the responses of plant N use would facilitate the projection of plant-mediated N cycling under global change scenarios. The effects of N deposition on plant N use would be affected by both natural and anthropogenic disturbances, such as prescribed fire in the grassland. We examined the effects of N addition (5.25 g N m(-2 yr(-1 and prescribed fire (annual burning on plant N concentrations and N use characters at both species and community levels in a temperate steppe of northern China. We found that N addition and fire independently affected soil N availability and plant N use traits. Nitrogen addition increased aboveground net primary productivity (ANPP, inorganic N, and N uptake, decreased N response efficiency (NRE, but did not affect biomass-weighed N concentrations at community level. Prescribed fire did not change the community level N concentrations, but largely decreased N uptake efficiency and NRE. At the species level, the effects of N addition and fire on plant N use were species-specific. The divergent responses of plant N use at community and species levels to N addition and fire highlight the importance of the hierarchical responses of plant N use at diverse biological organization levels to the alteration of soil N availability. This study will improve our understanding of the responses of plant-mediated N cycling to global change factors and ecosystem management strategies in the semiarid grasslands.

The Menstrual Cycle Influences Emotion but Has Limited Effect on Cognitive Function.

Science.gov (United States)

Sundström-Poromaa, Inger

2018-01-01

From a psychological perspective, the menstrual cycle has been a research topic for more than 50 years. The most recent menstrual cycle research has been driven by an increased interest in sex differences in neuroscience, and the urge to understand sex disparities in prevalence, clinical presentation, and treatment response in psychiatric or neurologic disorders. Indeed, the menstrual cycle is an excellent model of ovarian steroid influence on emotion, behavior, and cognition. This review summarizes the emotion-related and cognitive findings of methodologically sound menstrual cycle studies. In particular, the review is devoted to the sex hormone-induced emotional disturbances in women with premenstrual dysphoric disorder, a subgroup of women responding with enhanced sensitivity to the normal fluctuations in endogenous hormone levels during the menstrual cycle. In addition, emotion processing and cognitive findings across the menstrual cycle in healthy women are also discussed. The overall conclusion is that that menstrual cycle differences in sexually dimorphic cognitive tasks are small and difficult to replicate. Emotion-related changes are more consistently found and are better associated with progesterone and the luteal phase, than with estradiol. © 2018 Elsevier Inc. All rights reserved.

Population exposure from the fuel cycle: Review and future direction

International Nuclear Information System (INIS)

Richmond, C.R.

1987-01-01

The legacy of radiation exposures confronting man arises from two historical sources of energy, the sun and radioactive decay. Contemporary man continues to be dependent on these two energy sources, which include the nuclear fuel cycle. Radiation exposures from all energy sources should be examined, with particular emphasis on the nuclear fuel cycle, incidents such as Chernobyl and Three Mile Island. In addition to risk estimation, concepts such as de minimis, life shortening as a measure of risk, and competing risks as projected into the future must be considered in placing radiation exposures in perspective. The utility of these concepts is in characterizing population exposures for decision makers in a manner that the public may judge acceptable. All these viewpoints are essential in the evaluation of population exposure from the nuclear fuel cycle

The Hamburg oceanic carbon cycle circulation model. Cycle 1

International Nuclear Information System (INIS)

Maier-Reimer, E.; Heinze, C.

1992-02-01

The carbon cycle model calculates the prognostic fields of oceanic geochemical carbon cycle tracers making use of a 'frozen' velocity field provided by a run of the LSG oceanic circulation model (see the corresponding manual, LSG=Large Scale Geostrophic). The carbon cycle model includes a crude approximation of interactions between sediment and bottom layer water. A simple (meridionally diffusive) one layer atmosphere model allows to calculate the CO 2 airborne fraction resulting from the oceanic biogeochemical interactions. (orig.)

Thermoeconomic Analysis and Optimization of a New Combined Supercritical Carbon Dioxide Recompression Brayton/Kalina Cycle

Directory of Open Access Journals (Sweden)

S. Mohammad S. Mahmoudi

2016-10-01

Full Text Available A new combined supercritical CO2 recompression Brayton/Kalina cycle (SCRB/KC is proposed. In the proposed system, waste heat from a supercritical CO2 recompression Brayton cycle (SCRBC is recovered by a Kalina cycle (KC to generate additional electrical power. The performances of the two cycles are simulated and compared using mass, energy and exergy balances of the overall systems and their components. Using the SPECO (Specific Exergy Costing approach and employing selected cost balance equations for the components of each system, the total product unit costs of the cycles are obtained. Parametric studies are performed to investigate the effects on the SCRB/KC and SCRBC thermodynamic and thermoeconomic performances of key decision parameters. In addition, considering the exergy efficiency and total product unit cost as criteria, optimization is performed for the SCRBC and SCRB/KC using Engineering Equation Solver software. The results indicate that the maximum exergy efficiency of the SCRB/KC is higher than that of the SCRBC by up to 10%, and that the minimum total product unit cost of the SCRB/KC is lower than that of the SCRBC by up to 4.9%.

Analysis of fuel cycle strategies and U.S. transition scenarios

Energy Technology Data Exchange (ETDEWEB)

Wigeland, Roald; Taiwo, Temitope A.

2016-10-17

The nuclear fuel cycle Evaluation and Screening (E&S) study that was completed in October 2014 [1] enabled the identification of four fuel cycle groups that are considered most promising based on a set of nine evaluation criteria: (a) six benefit criteria of Nuclear Waste Management, Proliferation Risk, Nuclear Material Security Risk, Safety, Environmental Impact, Resource Utilization, and (b) three challenge criteria of Development and Deployment Risk, Institutional Issues, Financial Risk and Economics. The E&S study was conducted at a level of analysis that is "technology- neutral," that is, without consideration of specific technologies, but using the fundamental physics characteristics of each part of the fuel cycle. The study focused on the fuel cycle performance benefits at the fuel cycle equilibrium state, with only limited consideration of transition and deployment impacts. Common characteristics of the four most promising fuel cycle options include continuous recycle of all U/Pu or U/TRU, the use of fast-spectrum reactors, and no use of uranium enrichment once fuel cycle equilibrium has been established. The high-level wastes are mainly from processing of irradiated fuel, and there would be no disposal of any spent fuel. Building on the findings of the E&S study, additional studies have been conducted in the last two years following the information exchange meeting, the 13th IEMPT, which was held in Seoul, the Republic of Korea in 2014. Insights are presented from the recent studies on the benefits and challenges of recycling minor actinides, and transition considerations to some of the most promising fuel cycle options.

Cell cycle-tailored targeting of metastatic melanoma: Challenges and opportunities.

Science.gov (United States)

Haass, Nikolas K; Gabrielli, Brian

2017-07-01

The advent of targeted therapies of metastatic melanoma, such as MAPK pathway inhibitors and immune checkpoint antagonists, has turned dermato-oncology from the "bad guy" to the "poster child" in oncology. Current targeted therapies are effective, although here is a clear need to develop combination therapies to delay the onset of resistance. Many antimelanoma drugs impact on the cell cycle but are also dependent on certain cell cycle phases resulting in cell cycle phase-specific drug insensitivity. Here, we raise the question: Have combination trials been abandoned prematurely as ineffective possibly only because drug scheduling was not optimized? Firstly, if both drugs of a combination hit targets in the same melanoma cell, cell cycle-mediated drug insensitivity should be taken into account when planning combination therapies, timing of dosing schedules and choice of drug therapies in solid tumors. Secondly, if the combination is designed to target different tumor cell subpopulations of a heterogeneous tumor, one drug effective in a particular subpopulation should not negatively impact on the other drug targeting another subpopulation. In addition to the role of cell cycle stage and progression on standard chemotherapeutics and targeted drugs, we discuss the utilization of cell cycle checkpoint control defects to enhance chemotherapeutic responses or as targets themselves. We propose that cell cycle-tailored targeting of metastatic melanoma could further improve therapy outcomes and that our real-time cell cycle imaging 3D melanoma spheroid model could be utilized as a tool to measure and design drug scheduling approaches. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Future fuel cycles

International Nuclear Information System (INIS)

Archinoff, G.H.

1980-01-01

A fuel cycle must offer both financial and resource savings if it is to be considered for introduction into Ontario's nuclear system. The most promising alternative CANDU fuel cycles are examined in the context of both of these factors over a wide range of installed capacity growth rates and economic assumptions, in order to determine which fuel cycle, or cycles, should be introduced, and when. It is concluded that the optimum path for the long term begins with the prompt introduction of the low-enriched-uranium fuel cycle. For a wide range of conditions, this cycle remains the optimum throughout the very long term. Conditions of rapid nuclear growth and very high uranium price escalation rates warrant the supersedure of the low-enriched-uranium cycle by either a plutonium-topped thorium cycle or plutonium recycle, beginning between 2010 and 2025. It is also found that the uranium resource position is sound in terms of both known resources and production capability. Moreover, introduction of the low-enriched-uranium fuel cycle and 1250 MWe reactor units will assure the economic viability of nuclear power until at least 2020, even if uranium prices increase at a rate of 3.5% above inflation. The interrelationship between these two conclusions lies in the tremendous incentive for exploration which will occur if the real uranium price escalation rate is high. From a competitive viewpoint, nuclear power can withstand increases in the price of uranium. However, such increases will likely further expand the resource base, making nuclear an even more reliable energy source. (auth)

Cell cycle sibling rivalry: Cdc2 vs. Cdk2.

Science.gov (United States)

Kaldis, Philipp; Aleem, Eiman

2005-11-01

It has been long believed that the cyclin-dependent kinase 2 (Cdk2) binds to cyclin E or cyclin A and exclusively promotes the G1/S phase transition and that Cdc2/cyclin B complexes play a major role in mitosis. We now provide evidence that Cdc2 binds to cyclin E (in addition to cyclin A and B) and is able to promote the G1/S transition. This new concept indicates that both Cdk2 and/or Cdc2 can drive cells through G1/S phase in parallel. In this review we discuss the classic cell cycle model and how results from knockout mice provide new evidence that refute this model. We focus on the roles of Cdc2 and p27 in regulating the mammalian cell cycle and propose a new model for cell cycle regulation that accommodates these novel findings.

Optimal fleet conversion policy from a life cycle perspective

International Nuclear Information System (INIS)

Hyung Chul Kim; Ross, M.H.; Keoleian, G.A.

2004-01-01

Vehicles typically deteriorate with accumulating mileage and emit more tailpipe air pollutants per mile. Although incentive programs for scrapping old, high-emitting vehicles have been implemented to reduce urban air pollutants and greenhouse gases, these policies may create additional sales of new vehicles as well. From a life cycle perspective, the emissions from both the additional vehicle production and scrapping need to be addressed when evaluating the benefits of scrapping older vehicles. This study explores an optimal fleet conversion policy based on mid-sized internal combustion engine vehicles in the US, defined as one that minimizes total life cycle emissions from the entire fleet of new and used vehicles. To describe vehicles' lifetime emission profiles as functions of accumulated mileage, a series of life cycle inventories characterizing environmental performance for vehicle production, use, and retirement was developed for each model year between 1981 and 2020. A simulation program is developed to investigate ideal and practical fleet conversion policies separately for three regulated pollutants (CO, NMHC, and NO x ) and for CO 2 . According to the simulation results, accelerated scrapping policies are generally recommended to reduce regulated emissions, but they may increase greenhouse gases. Multi- objective analysis based on economic valuation methods was used to investigate trade-offs among emissions of different pollutants for optimal fleet conversion policies. (author)

Interim assessment of the denatured 233U fuel cycle: feasibility and nonproliferation characteristics

International Nuclear Information System (INIS)

Abbott, L.S.; Bartine, D.E.; Burns, T.J.

1979-12-01

A fuel cycle that employs 233 U denatured with 238 U and mixed with thorium fertile material is examined with respect to its proliferation-resistance characteristics and its technical and economic feasibility. The rationale for considering the denatured 233 U fuel cycle is presented, and the impact of the denatured fuel on the performance of Light-Water Reactors, Spectral-Shift-Controlled Reactors, Gas-Cooled Reactors, Heavy-Water Reactors, and Fast Breeder Reactors is discussed. The scope of the R, D and D programs to commercialize these reactors and their associated fuel cycles is also summarized and the resource requirements and economics of denatured 233 U cycles are compared to those of the conventional Pu/U cycle. In addition, several nuclear power systems that employ denatured 233 U fuel and are based on the energy center concept are evaluated

Life Cycle Management

DEFF Research Database (Denmark)

Bey, Niki

2018-01-01

This chapter gives an overview of Life Cycle Management (LCM)—a discipline that deals with the managerial tasks related to practicing sustainable development in an organisation . Just as Life Cycle Assessment, LCM advocates the life cycle perspective , and it applies this perspective in decision...

Chromatin association of UHRF1 during the cell cycle

KAUST Repository

Al-Gashgari, Bothayna

2017-05-01

Ubiquitin-like with PHD and RING Finger domains 1 (UHRF1) is a nuclear protein that associates with chromatin. Regardless of the various functions of UHRF1 in the cell, one of its more important functions is its role in the maintenance of DNA methylation patterns by the recruitment of DNMT1. Studies on UHRF1 based on this function have revealed the importance of UHRF1 during the cell cycle. Moreover, based on different studies various factors were described to be involved in the regulation of UHRF1 with different functionalities that can control its binding affinity to different targets on chromatin. These factors are regulated differently in a cell cycle specific manner. In light of this, we propose that UHRF1 has different binding behaviors during the cell cycle in regard to its association with chromatin. In this project, we first analyzed the binding behavior of endogenous UHRF1 from different unsynchronized cell systems in pull-down assays with peptides and oligonucleotides. Moreover, to analyze UHRF1 binding behavior during the cell cycle, we used two different approaches. First we sorted Jurkat and HT1080 cells based on their cell cycle stage using FACS analysis. Additionally, we synchronized HeLa cells to different stages of the cell cycle by chemical treatments, and used extracts from cellsorting and cell synchronization experiments for pull-down assays. We observed that UHRF1 in different cell systems has different preferences in regard to its binding to H3 unmodified and H3K9me3. Moreover, we detected that UHRF1, in general, displays different patterns between different stages of cell cycle; however, we cannot draw a final model for UHRF1 binding pattern during cell cycle.

Closing the fuel cycle: A superior option for India

International Nuclear Information System (INIS)

Balu, K.; Purushotham, D.S.C.; Kakodkar, A.

1999-01-01

The closed fuel cycle option with reprocessing and recycle of uranium and plutonium (U and Pu) for power generation allows better utilization of the uranium resources. On its part, plutonium is a unique energy source. During the initial years of nuclear fuel cycle activities, reprocessing and recycle of uranium and plutonium for power generation was perceived by many countries to be among the best of long term strategies for the management of spent fuel. But, over the years, some of the countries have taken a position that once-through fuel cycle is both economical and proliferation-resistant. However, such perceptions do vary as a function of economic growth and energy security of a given country. This paper deals with techno-economic perspectives of reprocessing and recycling in the Indian nuclear power programme. Experience of developing Mixed Oxide UO 2 -PuO 2 (MOX) fuel and its actual use in a power reactor (BWR) is presented. The paper further deals with the use of MOX in PHWRs in the future and current thinking, in the Indian context, in respect of advanced fuel cycles for the future. From environmental safety considerations, the separation of long-lived isotopes and minor actinides from high level waste (HLW) would enhance the acceptability of reprocessing and recycle option. The separated actinides are suitable for recycling with MOX fuel. However, the advanced fuel cycles with such recycling of Uranium and transuranium elements call for additional sophisticated fuel cycle activities which are yet to be mastered. India is interested in both uranium and thorium fuel cycles. This paper describes the current status of the Indian nuclear power scenario with reference to the program on reactors, reprocessing and radioactive waste management, plutonium recycle options, thorium-U233 fuel cycle studies and investigations on partitioning of actinides from Purex HLW as relevant to PHWR spent fuels. (author)

A Comparison of Single-Cycle Versus Multiple-Cycle Proof Testing Strategies

Science.gov (United States)

McClung, R. C.; Chell, G. G.; Millwater, H. R.; Russell, D. A.; Millwater, H. R.

1999-01-01

Single-cycle and multiple-cycle proof testing (SCPT and MCPT) strategies for reusable aerospace propulsion system components are critically evaluated and compared from a rigorous elastic-plastic fracture mechanics perspective. Earlier MCPT studies are briefly reviewed. New J-integral estimation methods for semielliptical surface cracks and cracks at notches are derived and validated. Engineering methods are developed to characterize crack growth rates during elastic-plastic fatigue crack growth (FCG) and the tear-fatigue interaction near instability. Surface crack growth experiments are conducted with Inconel 718 to characterize tearing resistance, FCG under small-scale yielding and elastic-plastic conditions, and crack growth during simulated MCPT. Fractography and acoustic emission studies provide additional insight. The relative merits of SCPT and MCPT are directly compared using a probabilistic analysis linked with an elastic-plastic crack growth computer code. The conditional probability of failure in service is computed for a population of components that have survived a previous proof test, based on an assumed distribution of initial crack depths. Parameter studies investigate the influence of proof factor, tearing resistance, crack shape, initial crack depth distribution, and notches on the MCPT versus SCPT comparison. The parameter studies provide a rational basis to formulate conclusions about the relative advantages and disadvantages of SCPT and MCPT. Practical engineering guidelines are proposed to help select the optimum proof test protocol in a given application.

Evaluation of DD and DT fusion fuel cycles for different fusion-fission energy systems

International Nuclear Information System (INIS)

Gohar, Y.

1980-01-01

A study has been carried out in order to investigate the characteristics of an energy system to produce a new source of fissile fuel for existing fission reactors. The denatured fuel cycles were used because it gives additional proliferation resistance compared to other fuel cycles. DT and DD fusion drivers were examined in this study with a thorium or uranium blanket for each fusion driver. Various fuel cycles were studied for light-water and heavy-water reactors. The cost of electricity for each energy system was calculated

BWROPT: A multi-cycle BWR fuel cycle optimization code

Energy Technology Data Exchange (ETDEWEB)

Ottinger, Keith E.; Maldonado, G. Ivan, E-mail: Ivan.Maldonado@utk.edu

2015-09-15

Highlights: • A multi-cycle BWR fuel cycle optimization algorithm is presented. • New fuel inventory and core loading pattern determination. • The parallel simulated annealing algorithm was used for the optimization. • Variable sampling probabilities were compared to constant sampling probabilities. - Abstract: A new computer code for performing BWR in-core and out-of-core fuel cycle optimization for multiple cycles simultaneously has been developed. Parallel simulated annealing (PSA) is used to optimize the new fuel inventory and placement of new and reload fuel for each cycle considered. Several algorithm improvements were implemented and evaluated. The most significant of these are variable sampling probabilities and sampling new fuel types from an ordered array. A heuristic control rod pattern (CRP) search algorithm was also implemented, which is useful for single CRP determinations, however, this feature requires significant computational resources and is currently not practical for use in a full multi-cycle optimization. The PSA algorithm was demonstrated to be capable of significant objective function reduction and finding candidate loading patterns without constraint violations. The use of variable sampling probabilities was shown to reduce runtime while producing better results compared to using constant sampling probabilities. Sampling new fuel types from an ordered array was shown to have a mixed effect compared to random new fuel type sampling, whereby using both random and ordered sampling produced better results but required longer runtimes.

Development and applications of GREET 2.7 -- The Transportation Vehicle-Cycle Model

International Nuclear Information System (INIS)

Burnham, A.; Wang, M. Q.; Wu, Y.

2006-01-01

Argonne National Laboratory has developed a vehicle-cycle module for the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. The fuel-cycle GREET model has been cited extensively and contains data on fuel cycles and vehicle operations. The vehicle-cycle model evaluates the energy and emission effects associated with vehicle material recovery and production, vehicle component fabrication, vehicle assembly, and vehicle disposal/recycling. With the addition of the vehicle-cycle module, the GREET model now provides a comprehensive, lifecycle-based approach to compare the energy use and emissions of conventional and advanced vehicle technologies (e.g., hybrid electric vehicles and fuel cell vehicles). This report details the development and application of the GREET 2.7 model. The current model includes six vehicles--a conventional material and a lightweight material version of a mid-size passenger car with the following powertrain systems: internal combustion engine, internal combustion engine with hybrid configuration, and fuel cell with hybrid configuration. The model calculates the energy use and emissions that are required for vehicle component production; battery production; fluid production and use; and vehicle assembly, disposal, and recycling. This report also presents vehicle-cycle modeling results. In order to put these results in a broad perspective, the fuel-cycle model (GREET 1.7) was used in conjunction with the vehicle-cycle model (GREET 2.7) to estimate total energy-cycle results

Development and applications of GREET 2.7 -- The Transportation Vehicle-CycleModel.

Energy Technology Data Exchange (ETDEWEB)

Burnham, A.; Wang, M. Q.; Wu, Y.

2006-12-20

Argonne National Laboratory has developed a vehicle-cycle module for the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. The fuel-cycle GREET model has been cited extensively and contains data on fuel cycles and vehicle operations. The vehicle-cycle model evaluates the energy and emission effects associated with vehicle material recovery and production, vehicle component fabrication, vehicle assembly, and vehicle disposal/recycling. With the addition of the vehicle-cycle module, the GREET model now provides a comprehensive, lifecycle-based approach to compare the energy use and emissions of conventional and advanced vehicle technologies (e.g., hybrid electric vehicles and fuel cell vehicles). This report details the development and application of the GREET 2.7 model. The current model includes six vehicles--a conventional material and a lightweight material version of a mid-size passenger car with the following powertrain systems: internal combustion engine, internal combustion engine with hybrid configuration, and fuel cell with hybrid configuration. The model calculates the energy use and emissions that are required for vehicle component production; battery production; fluid production and use; and vehicle assembly, disposal, and recycling. This report also presents vehicle-cycle modeling results. In order to put these results in a broad perspective, the fuel-cycle model (GREET 1.7) was used in conjunction with the vehicle-cycle model (GREET 2.7) to estimate total energy-cycle results.

Technological study report on synthetic evaluation for FBR cycle. The report of the feasibility studies on commercialized FBR cycle system. Phase 1

International Nuclear Information System (INIS)

Shinoda, Yoshihiko; Ohtaki, Akira; Kofuji, Hirohide; Ono, Kiyoshi; Hirao, Kazunori

2001-03-01

This report is intended to explain the outline of the characteristic evaluation work on various FR cycle system concepts, following the design work, in the 1st phase of the JNC's 'Feasibility Study on Commercialized Fast Reactor Cycle System (the F/S)' (from 1999 to March 2001). The purpose of this characteristic evaluation is to reveal the performance of candidate FR cycle systems. For this synthetic estimation, six viewpoints, such as Economics, Effective utilization of uranium resource, Reduction of environmental impact, Safety, Proliferation resistance, and Technological feasibility, are selected. In addition, aiming at the practical use in phase 2, we examined an application to FBR research and development of cost benefit analysis method used for the policy evaluation. Furthermore, long-term nuclear material mass flow was analyzed and the scenario of 'FBR application for the hydrogen production' is proposed, considering how FBR would be utilized for the 21st century. And, a database including the various documents and data used for evaluation was constructed. (author)

Recent evidence on the muted inventory cycle

OpenAIRE

Andrew J. Filardo

1995-01-01

Inventories play an important role in business cycles. Inventory build-ups add momentum to the economy during expansions, while inventory liquidations sap economic strength during recessions. In addition, because inventory fluctuations are notoriously difficult to predict, they present considerable uncertainty in assessing the economic outlook.> The role of inventories in shaping the current outlook for the U.S. economy is particularly uncertain. In the early 1990s, inventory swings appeared ...

Mineralization and carbon turnover in subarctic heath soil as affected by warming and additional litter

DEFF Research Database (Denmark)

Rinnan, Riikka; Michelsen, Anders; Baath, Erland

2007-01-01

Arctic soil carbon (C) stocks are threatened by the rapidly advancing global warming. In addition to temperature, increasing amounts of leaf litter fall following from the expansion of deciduous shrubs and trees in northern ecosystems may alter biogeochemical cycling of C and nutrients. Our aim w...... on C and N transformations during field incubation suggest that microbial activity is an important control on the carbon balance of arctic soils under climate change.......Arctic soil carbon (C) stocks are threatened by the rapidly advancing global warming. In addition to temperature, increasing amounts of leaf litter fall following from the expansion of deciduous shrubs and trees in northern ecosystems may alter biogeochemical cycling of C and nutrients. Our aim...

Production of wood pellets. Influence of additives on production, quality, storage, combustion and life cycle analysis of wood pellets; Herstellung von Holzpellets. Einfluss von Presshilfsmitteln auf Produktion, Qualitaet, Lagerung, Verbrennung sowie Energie- und Oekobilanz von Holzpellets

Energy Technology Data Exchange (ETDEWEB)

Hasler, P.; Nussbaumer, T. [Verenum, Zuerich (Switzerland); Buerli, J. [Buerli Pellets, Willisau (Switzerland)

2001-07-01

This report for the Swiss Federal Office of Energy (SFOE) presents the results of a study concerning the influence of additives on the various factors related to the manufacture of wood pellets and their use. Results of tests concerning the production, storage and combustion of wood pellets with and without additives are presented. Process modifications are discussed. The report shows that for all investigated additives neither energy consumption nor pellet throughput was improved. The influence of additives on the mechanical strength of the pellets is discussed, as are the combustion characteristics of the pellets, which emit significantly lower levels of NO{sub x} and particulate matter than typical wood chips. The authors recommend the application of advanced control technology to ensure optimum combustion conditions. A life-cycle analysis is presented which shows that pellets are ecologically more favourable than wood chips. The ecological potential for improvement in the manufacturing process is discussed, including emission reductions and heat recovery.

Mole sieve cycle optimization

Energy Technology Data Exchange (ETDEWEB)

Croteau, P. [Petro-Canada Oil and Gas, Inc., Calgary, AB (Canada)

2004-07-01

Maturing gas basins and declining reservoirs have prompted the search for energy and cost reduction initiatives to maintain operation sustainability. This paper discusses the development of an algorithm to improve the efficiency of the Brazeau mole sieve dehydration system. Details of the operating unit and an outline of the system were provided, as well as an operator interface. The main objectives of the research were to reduce the number of corresponding regeneration cycles; reduce annual energy requirements; and extend the life of the dessicant. Reductions were anticipated at 35 per cent, leading towards fuel savings of $45,000 a year, and carbon dioxide reductions of 670 tonnes a year. However, significant barriers were also noted, including operations, maintenance and equipment replacement issues. Equations of state were used to estimate vapor pressure or water content in gases. Approximate water content was measured with gas flow rate. The resulting algorithm was implemented using a basic best fit curve generated for one variable with a correction factor applied as a second variable. Data books were provided to present water content of hydrocarbon gas, with implementation procedures. Benefits of the new system included longer service life and reduced chemical and outside service costs, and reduced lost production during sieve changes. Additional benefits included enhanced distributed computing system (DCS) interfaces within plant operations; extension of the adsorption cycle via the functionality of the algorithm; and the fact that during a plant upset, the algorithm froze cycle sequencing and eliminated the possibility of switching the beds and repeating regeneration. The improved system resulted in savings of $87,000. tabs, figs.

The process of isothermal compression of gasses at sub-atmospheric pressures through regulated water injection in Braysson cycles

International Nuclear Information System (INIS)

Georgiou, Demos P.; Xenos, Triantafyllos

2011-01-01

Although the Braysson cycle constitutes the ideal limit for the Combined Cycle Power Plants, its actual implementation has not been achieved due to the difficulty in building the required isothermal compressor. The present study proposes the incorporation of regulated water injection during the final compression, which could maintain the temperature constant due to the evaporation. The analysis for the thermodynamic implications of the injection on the ideal version of the Braysson cycle indicates that the (ideal cycle) efficiency reduction will be minimal. The study provides an analysis for the water injection rate that will permit such a process and shows that the additional work needed to drive the process will not be affected significantly by the injection. In addition, it shows that the minimum temperature of the Braysson cycle will be lower than the corresponding level of the conventional (Gas-Steam turbine Combined cycle plants), something that could improve the efficiency as well. Finally it shows that the process may be expressed by a polytropic relationship of the type pv β = constant, where β ∼ 1.06.

Long-term alternatives for nuclear fuel cycles

International Nuclear Information System (INIS)

Vira, J.; Vieno, T.

1981-07-01

Several technical alternatives have been proposed to the nuclear spent fuel management but the practical experience on any of these is small or totally lacking. Since the management method is also connected with the composition of fresh fuel, the comparison of the alternatives must include the whole fuel cycle of a nuclear power plant. In the planning of the nuclear fuel cycle over a time range of several decades a consideration must be given, in addition, to the potential of the new reactor types with increased efficiency of uranium utilization. For analyses and mutual comparisons of the fuel cycle alternatives a number of computer models have been designed and implemented at the Technical Research Centre of Finland. Given the estimated boundary conditions the models can be used to study the impact of different goals and requirements on the fuel cycle decisions. Further, they facilitate cost predictions and display information on the role of the intrinsic uncertainties in the decision-making. The conclusions of the study are tied to the questions of price and availability of uranium. Hence, for instance, the benefits from the reprocessing of spent fuel might prove to be small when compared to the costs required, especially as the current reprocessing contracts do not allow the custemer to dismiss the duty of building the final disposal facilities for high level radioactive waste. For a few decades the final decisions can be postponed by extending the interim storage period. Farther in the future the decisions in the nuclear fuel cycle arrangements will more link to the introduction of the fast breeder reactors. (author)

Life cycle assessment of the application of nanoclays in wire coating

International Nuclear Information System (INIS)

Tellaetxe, A; Blázquez, M; Unzueta, I; Arteche, A; Egizabal, A; Ermini, V; Rose, J; Chaurand, P

2012-01-01

A life cycle assessment (LCA) is carried out to compare nanoclay-reinforced polymer wire coatings with conventional ones. While the conventional wire coatings contain standard halogen free retardants, in reinforced coatings, montmorillonite (nanoclay) is incorporated into electric cable linings as a rheological agent for an increased resistance to fire. In addition, a reduced load of standard halogen free retardants is obtained. The synergistic effect of the montmorillonite on traditional flame retardant additives (by the formation of a three-dimensional char network) can lead to a revolution in wire production. The application of nanoclays contributes also to anti-dripping effect and flexibility increase. Some producers have already started commercializing wire with nanotechnology-based coating; in the short term the use of nanoclay in wire coating production will probably reach a significant market share replacing traditional formulations. The main aim of this study is to compare the environmental impacts along the life cycle of a traditional wire coating (mineral flame retardants like ATH or MDH in a polymer matrix) with the nanoclay-reinforced wire coating, where the montmorillonite replaces a low percentage of the mineral flame retardant. The system boundaries of the study include the following unit processes: nanoclay production, thermoplastic material and mineral flame retardants production, cable coating manufacturing by extrusion and different end of life scenarios (recycling, incineration and landfill disposal). Whereas nanoreinforced composites have shown and increased fire retardance, the addition of nanomaterials seems to have no significant relevance in the environmental assessment. However, the lack of nano-specific characterization factors for nanomaterials and emission rates associated to the different life cycle stages -mainly in the extrusion and use phase, where accidental combustions can take place- still remains a challenge for realistic life

Improving the Safety of Lithium-Ion Battery via a Redox Shuttle Additive 2,5-Di- tert-butyl-1,4-bis(2-methoxyethoxy)benzene (DBBB).

Science.gov (United States)

Leonet, Olatz; Colmenares, Luis C; Kvasha, Andriy; Oyarbide, Mikel; Mainar, Aroa R; Glossmann, Tobias; Blázquez, J Alberto; Zhang, Zhengcheng

2018-03-21

2,5-Di- tert-butyl-1,4-bis(2-methoxyethoxy)benzene (DBBB) is studied as a redox shuttle additive for overcharge protection for a 1.5 Ah graphite/C-LFP lithium-ion pouch cell for the first time. The electrochemical performance demonstrated that the protecting additive remains inert during the extended standard cycling for 4000 cycles. When a 100% overcharge is introduced in the charging protocol, the baseline cell fails rapidly during the first abusive event, whereas the cell containing DBBB additive withstands 700 overcharge cycles with 87% capacity retention and no gas evolution or cell swelling was observed. It is the first time the effectiveness of the DBBB as overcharge protection additive in a large pouch cell format is demonstrated.

Numerical Simulation of the Water Cycle Change Over the 20th Century

Science.gov (United States)

Bosilovich, Michael G.; Schubert, Siegfried D.

2003-01-01

We have used numerical models to test the impact of the change in Sea Surface Temperatures (SSTs) and carbon dioxide (CO2) concentration on the global circulation, particularly focusing on the hydrologic cycle, namely the global cycling of water and continental recycling of water. We have run four numerical simulations using mean annual SST from the early part of the 20th century (1900-1920) and the later part (1980-2000). In addition, we vary the CO2 concentrations for these periods as well. The duration of the simulations is 15 years, and the spatial resolution is 2 degrees. We use passive tracers to study the geographical sources of water. Surface evaporation from predetermined continental and oceanic regions provides the source of water for each passive tracer. In this way, we compute the percent of precipitation of each region over the globe. This can also be used to estimate precipitation recycling. In addition, we are using the passive tracers to independently compute the global cycling of water (compared to the traditional, Q/P calculation).

Sulfur cycle

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.

Microbes, especially bacteria, play an important role in oxidative and reductive cycle of sulfur. The oxidative part of the cycle is mediated by photosynthetic bacteria in the presence of light energy and chemosynthetic forms in the absence of light...

Fast Reactor Fuel Cycle Cost Estimates for Advanced Fuel Cycle Studies

International Nuclear Information System (INIS)

Harrison, Thomas

2013-01-01

Presentation Outline: • Why Do I Need a Cost Basis?; • History of the Advanced Fuel Cycle Cost Basis; • Description of the Cost Basis; • Current Work; • Fast Reactor Fuel Cycle Applications; • Sample Fuel Cycle Cost Estimate Analysis; • Future Work

Dual overcharge protection and solid electrolyte interphase-improving action in Li-ion cells containing a bis -annulated dialkoxyarene electrolyte additive

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jingjing; Shkrob, Ilya A.; Assary, Rajeev S.; Zhang, Shuo; Hu, Bin; Liao, Chen; Zhang, Zhengcheng; Zhang, Lu

2018-02-01

We demonstrate that 9,10-Bis(2-methoxyethoxy)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracene redox shuttle molecule survives over 120 cycles with 100% overcharge ratio at C/5 rate in litium-ion batteries. Equally remarkably, in the presence of this electrolyte additive, the cell impedance becomes significantly lower compared to the control cells without this additive during the formation, normal cycling, and even under overcharge conditions.

Essays on economic cycles

NARCIS (Netherlands)

Groot, de E.A. (Bert)

2006-01-01

Schumpeter’s line of thought of multiple economic cycles is further investigated. The existence of multiple cycles in economic variables is demonstrated. In basic innovations five different cycles are found. Multiple cycle structures are shown in various macro-economic variables from the United

Metal Additive Manufacturing: A Review of Mechanical Properties

Science.gov (United States)

Lewandowski, John J.; Seifi, Mohsen

2016-07-01

This article reviews published data on the mechanical properties of additively manufactured metallic materials. The additive manufacturing techniques utilized to generate samples covered in this review include powder bed fusion (e.g., EBM, SLM, DMLS) and directed energy deposition (e.g., LENS, EBF3). Although only a limited number of metallic alloy systems are currently available for additive manufacturing (e.g., Ti-6Al-4V, TiAl, stainless steel, Inconel 625/718, and Al-Si-10Mg), the bulk of the published mechanical properties information has been generated on Ti-6Al-4V. However, summary tables for published mechanical properties and/or key figures are included for each of the alloys listed above, grouped by the additive technique used to generate the data. Published values for mechanical properties obtained from hardness, tension/compression, fracture toughness, fatigue crack growth, and high cycle fatigue are included for as-built, heat-treated, and/or HIP conditions, when available. The effects of test orientation/build direction on properties, when available, are also provided, along with discussion of the potential source(s) (e.g., texture, microstructure changes, defects) of anisotropy in properties. Recommendations for additional work are also provided.

Fuel cycle cost considerations of increased discharge burnups

International Nuclear Information System (INIS)

Scherpereel, L.R.; Frank, F.J.

1982-01-01

Evaluations are presented that indicate the attainment of increased discharge burnups in light water reactors will depend on economic factors particular to individual operators. In addition to pure resource conserving effects and assuming continued reliable fuel performance, a substantial economic incentive must exist to justify the longer operating times necessary to achieve higher burnups. Whether such incentive will exist or not will depend on relative price levels of all fuel cycle cost components, utility operating practices, and resolution of uncertainties associated with the back-end of the fuel cycle. It is concluded that implementation of increased burnups will continue at a graduated pace similar to past experience, rather than finding universal acceptance of particular increased levels at any particular time

Nuclear-fuel-cycle education: Module 1. Nuclear fuel cycle overview

International Nuclear Information System (INIS)

Eckhoff, N.D.

1981-07-01

This educational module is an overview of the nuclear-fule-cycle. The overview covers nuclear energy resources, the present and future US nuclear industry, the industry view of nuclear power, the International Nuclear Fuel Cycle Evaluation program, the Union of Concerned Scientists view of the nuclear-fuel-cycle, an analysis of this viewpoint, resource requirements for a model light water reactor, and world nuclear power considerations

Wastes from selected activities in two light-water reactor fuel cycles

International Nuclear Information System (INIS)

Palmer, C.R.; Hill, O.F.

1980-07-01

This report presents projected volumes and radioactivities of wastes from the production of electrical energy using light-water reactors (LWR). The projections are based upon data developed for a recent environmental impact statement in which the transuranic wastes (i.e., those wastes containing certain long-lived alpha emitters at concentrations of at least 370 becquerels, or 10 nCi, per gram of waste) from fuel cycle activities were characterized. In addition, since the WG.7 assumed that all fuel cycle wastes except mill tailings are placed in a mined geologic repository, the nontransuranic wastes from several activities are included in the projections reported. The LWR fuel cycles considered are the LWR, once-through fuel cycle (Strategy 1), in which spent fuel is packaged in metal canisters and then isolated in geologic formations; and the LWR U/Pu recycle fuel cycle (Strategy 2), wherein spent fuel is reprocessed for recovery and recycle of uranium and plutonium in LWRs. The wastes projected for the two LWR fuel cycles are summarized. The reactor operations and decommissioning were found to dominate the rate of waste generation in each cycle. These activities account for at least 85% of the fuel cycle waste volume (not including head-end wastes) when normalized to per unit electrical energy generated. At 10 years out of reactor, however, spent fuel elements in Strategy 1 represent 98% of the fuel cycle activity but only 4% of the volume. Similarly, the packaged high-level waste, fuel hulls and hardware in Strategy 2 concentrate greater than 95% of the activity in 2% of the waste volume

Transition Analysis of Promising U.S. Future Fuel Cycles Using ORION

International Nuclear Information System (INIS)

Sunny, Eva E.; Worrall, Andrew; Peterson, Joshua L.; Powers, Jeffrey J.; Gehin, Jess C.; Gregg, Robert

2015-01-01

The US Department of Energy Office of Fuel Cycle Technologies performed an evaluation and screening (E&S) study of nuclear fuel cycle options to help prioritize future research and development decisions. Previous work for this E&S study focused on establishing equilibrium conditions for analysis examples of 40 nuclear fuel cycle evaluation groups (EGs) and evaluating their performance according to a set of 22 standardized metrics. Following the E&S study, additional studies are being conducted to assess transitioning from the current US fuel cycle to future fuel cycle options identified by the E&S study as being most promising. These studies help inform decisions on how to effectively achieve full transition, estimate the length of time needed to undergo transition from the current fuel cycle, and evaluate performance of nuclear systems and facilities in place during the transition. These studies also help identify any barriers to achieve transition. Oak Ridge National Laboratory (ORNL) Fuel Cycle Options Campaign team used ORION to analyze the transition pathway from the existing US nuclear fuel cycle—the once-through use of low-enriched-uranium (LEU) fuel in thermal-spectrum light water reactors (LWRs)—to a new fuel cycle with continuous recycling of plutonium and uranium in sodium fast reactors (SFRs). This paper discusses the analysis of the transition from an LWR to an SFR fleet using ORION, highlights the role of lifetime extensions of existing LWRs to aid transition, and discusses how a slight delay in SFR deployment can actually reduce the time to achieve an equilibrium fuel cycle.

Thorium cycles and proliferation

International Nuclear Information System (INIS)

Lovins, A.B.

1979-01-01

This paper analyzes several prevalent misconceptions about nuclear fuel cycles that breed fissile uranium-233 from thorium. Its main conclusions are: U-233, despite the gamma radioactivity of associated isotopes, is a rather attractive material for making fission bombs, and is a credible material for subnational as well as national groups to use for this purpose; (2) pure thorium cycles, which in effect merely substitute U-233 for Pu, would take many decades and much U to establish, and offer no significant safeguards advantage over Pu, cycles; (3) denatured Th-U cycles, which dilute the U-233 with inert U-238 to a level not directly usable in bombs, are not an effective safeguard even against subnational bomb-making; (4) several other features of mixed Th-U cycles are rather unattractive from a safeguards point of view; (5) thus, Th cycles of any kind are not a technical fix for proliferation (national or subnational) and, though probably more safeguardable than Pu cycles, are less so than once-through U cycles that entail no reprocessing; (6) while thorium cycles have some potential technical advantages, including flexibility, they cannot provide major savings in nuclear fuel resources compared to simpler ways of saving neutrons and U; and (7) while advocates of nuclear power may find Th cycles worth exploring, such cycles do not differ fundamentally from U cycles in any of the respects--including safeguards and fuel resources--that are relevant to the broader nuclear debate, and should not be euphorically embraced as if they did

Plant-Soil Relationships of Bromus tectorum L.: Interactions among Labile Carbon Additions, Soil Invasion Status, and Fertilizer

International Nuclear Information System (INIS)

Blank, R.R.; Young, J.A.

2010-01-01

Invasion of western North America by the annual exotic grass Bromus tectorum L. (cheatgrass) has been an ecological disaster. High soil bioavailability of nitrogen is a contributing factor in the invasive potential of B. tectorum. Application of labile carbon sources to the soil can immobilize soil nitrogen and favor native species. We studied the interaction of labile carbon addition (sucrose), with soil invasion status and fertilizer addition on the growth of B. tectorum. Soils were non invaded (BNI) and B. tectorum invaded (BI). Treatments were control, sucrose, combined fertilizer, and sucrose + fertilizer. The greenhouse experiment continued for 3 growth-cycles. After the 1st growth-cycle, sucrose addition reduced B. tectorum aboveground mass almost 70 times for the BI soil but did not significantly reduce growth in the BNI soil. B. tectorum aboveground mass, after the 1st growth-cycle, was over 27 times greater for BI control soils than BNI control soils. Although sucrose addition reduced soil-solution NO 3 , tissue N was not significantly lowered, suggesting that reduction of soil available N may not be solely responsible for reduction in B. tectorum growth. Non invaded soil inhibits growth of B. tectorum. Understanding this mechanism may lead to viable control strategies.

Plasma physical aspects of the solar cycle

International Nuclear Information System (INIS)

Raadu, M.A.

1982-08-01

Mass motions below the photosphere drive the solar cycle which is association with variations in the magnetic field structure and accompanying phenomena. In addition to semi-empirical models, dynamo theories have been used to explain the solar cycle. The emergence of magnetic field generated by these mechanisms and its expansions into the corona involves many plasma physical processes. Magnetic buoyancy aids the expulsion of magnetic flux. The corona may respond dynamically or by continually adjusting to a quasi-static force-free or pressure-balanced equilibrium. The formation and disruption of current sheets is significant for the overall structure of the coronal magnetic field and the physics of quiescent prominences. The corona has a fine structure consisting of magnetic loops. The structure and stability of these are important as they are one of the underlying elements which make up the corona. (Author)

The role of interest rates in the Brazilian business cycles

Directory of Open Access Journals (Sweden)

Nelson F. Souza-Sobrinho

2011-09-01

Full Text Available This paper offers additional insights on the relationship between interest rates and business cycles in Brazil. First, I document that Brazilian interest rates are very volatile, counter-cyclical and positively correlated with net exports, as observed in other emerging market economies. Next, I present a dynamic stochastic general equilibrium model in which firms face working capital constraints and labor supply is independent of consumption. This parsimonious model, appropriately calibrated to the Brazilian economy, predicts that interest rate shocks can explain about one third of output fluctuations and delivers business cycle regularities consistent with the Brazilian data.

SUNSPOT CYCLES IMPACTS ON TOURISM AND QUALITY OF LIFE

Directory of Open Access Journals (Sweden)

Tadeja Jere Jakulin

2017-09-01

Full Text Available We live under the influence of natural cycles caused by the rotation of our planet and its revolution around the sun. The nature of our nearest star is also subject to cyclical change. This article presents a study of a correlation between sunspot cycles and foreign tourists arrivals in Slovenia, based on historical data between sunspot cycles and sea salt production in Slovenia's Municipality of Piran during the Maunder Minimum period (1645-1715. The production of salt by the solar evaporation of brine in salt pans and tourist industry are seasonal economic activities that are affected by changes to the weather. The paper looks at sea salt production in Piran during a particular period in the past. The repetition of the sea salt production in the past is not possible. For this reason, the study uses mathematical tools and an additional case study, which analyses arrivals of foreign tourists to Slovenia over the past 65 years (1948-2012. The study has two purposes: to identify a linear correlation coefficient, which provides evidence of a correlation between arrivals of foreign tourists to Slovenia and sunspot cycles and to develop a causal loop diagram (CLD or so called qualitative model of a complex tourism system, which shows the interdependency of sunspot cycles, tourism system, and quality of life.

Use of polyethylene glycol for the improvement of the cycling stability of bischofite as thermal energy storage material

International Nuclear Information System (INIS)

Gutierrez, Andrea; Ushak, Svetlana; Galleguillos, Hector; Fernandez, Angel; Cabeza, Luisa F.; Grágeda, Mario

2015-01-01

Highlights: • Bischofite as phase change material for TES is studied. • Thermophysical properties of bischofite mixtures with PEG were determined. • The aim was to improve the cycling stability of bischofite. • The heating and cooling during 30 cycles were measured. • The most stable sample was bischofite + 5% PEG 2 000. - Abstract: Bischofite is a by-product of the non-metallic mining industry. It has been evaluated as phase change material in thermal energy storage, but it shows little cycling stability, therefore in this paper the mixture of bischofite with an additive was studied. Since polyethylene glycol (PEG) is a PCM itself, in this paper PEG (with different molecular weights) is used as additive in a PCM (bischofite) to improve its thermal behaviour. Results show that adding 5% PEG 2 000 to bischofite gives a more cycling stable PCM without affecting its melting temperature neither decreasing significantly its heat of fusion. This research shows that mixing an inorganic PCM with an organic additive can be a good option to improve the thermal performance of the PCM

Advanced fuel cycle cost estimation model and its cost estimation results for three nuclear fuel cycles using a dynamic model in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Sungki, E-mail: sgkim1@kaeri.re.kr [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ko, Wonil [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Youn, Saerom; Gao, Ruxing [University of Science and Technology, 217 Gajungro, Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Bang, Sungsig, E-mail: ssbang@kaist.ac.kr [Korea Advanced Institute of Science and Technology, Department of Business and Technology Management, 291 Deahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2015-11-15

Highlights: • The nuclear fuel cycle cost using a new cost estimation model was analyzed. • The material flows of three nuclear fuel cycle options were calculated. • The generation cost of once-through was estimated to be 66.88 mills/kW h. • The generation cost of pyro-SFR recycling was estimated to be 78.06 mills/kW h. • The reactor cost was identified as the main cost driver of pyro-SFR recycling. - Abstract: The present study analyzes advanced nuclear fuel cycle cost estimation models such as the different discount rate model and its cost estimation results. To do so, an analysis of the nuclear fuel cycle cost of three options (direct disposal (once through), PWR–MOX (Mixed OXide fuel), and Pyro-SFR (Sodium-cooled Fast Reactor)) from the viewpoint of economic sense, focusing on the cost estimation model, was conducted using a dynamic model. From an analysis of the fuel cycle cost estimation results, it was found that some cost gap exists between the traditional same discount rate model and the advanced different discount rate model. However, this gap does not change the priority of the nuclear fuel cycle option from the viewpoint of economics. In addition, the fuel cycle costs of OT (Once-Through) and Pyro-SFR recycling based on the most likely value using a probabilistic cost estimation except for reactor costs were calculated to be 8.75 mills/kW h and 8.30 mills/kW h, respectively. Namely, the Pyro-SFR recycling option was more economical than the direct disposal option. However, if the reactor cost is considered, the economic sense in the generation cost between the two options (direct disposal vs. Pyro-SFR recycling) can be changed because of the high reactor cost of an SFR.