WorldWideScience

Sample records for authority compressed natural

  1. Worship of Authority and Human Nature

    Institute of Scientific and Technical Information of China (English)

    WangRuisheng

    2005-01-01

    Authority is a cultural phenomenon that by its nature implies social relations between individuals. At the heart of authority is power-holders' maximization of their own interests by virtue of their ruling positions. In ancient society based on the small-scale peasant economy, the concept of authority worship was unavoidable. It is rooted in the premise that man is by nature evil and hence needs the awe-inspiring powers of authority. A highly developed cult of authority exerts enormous influence on and seriously distorts human nature. But the authority cult was not the only ideology in feudal society;

  2. Rapidly Estimating Natural Gas Compressibility Factor

    Institute of Scientific and Technical Information of China (English)

    Alireza Bahadori; Saeid Mokhatab; Brian F. Towler

    2007-01-01

    Natural gases containing sour components exhibit different gas compressibility factor (Z) behavior than do sweet gases. Therefore, a new accurate method should be developed to account for these differences. Several methods are available today for calculating the Z-factor from an equation of state. However, these equations are more complex than the foregoing correlations, involving a large number of parameters, which require more complicated and longer computations. The aim of this study is to develop a simplified calculation method for a rapid estimating Z-factor for sour natural gases containing as much as 90% total acid gas. In this article, two new correlations are first presented for calculating the pseudo-critical pressure and temperature of the gas mixture as a function of the gas specific gravity. Then, a simple correlation on the basis of the standard gas compressibility factor chart is introduced for a quick estimation of sweet gases' compressibility factor as a function of reduced pressure and temperature. Finally, a new corrective term related to the mole fractions of carbon dioxide and hydrogen sulfide is developed.

  3. 78 FR 21349 - Orders Granting Authority To Import and Export Natural Gas, To Export Liquefied Natural Gas, To...

    Science.gov (United States)

    2013-04-10

    ... Irving Oil Commercial Order granting blanket GP. authority to export natural gas to Canada. 3214 01/02/13... Granting Authority To Import and Export Natural Gas, To Export Liquefied Natural Gas, To Export Compressed.... INC 12-113-LNG MAIN PASS ENERGY HUB, LLC 12-114-LNG IRVING OIL COMMERCIAL GP 12-164-NG XPRESS...

  4. 26 CFR 48.4041-21 - Compressed natural gas (CNG).

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Compressed natural gas (CNG). 48.4041-21 Section... natural gas (CNG). (a) Delivery of CNG into the fuel supply tank of a motor vehicle or motorboat—(1) Imposition of tax. Tax is imposed on the delivery of compressed natural gas (CNG) into the fuel supply...

  5. Costs Associated With Compressed Natural Gas Vehicle Fueling Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.; Gonzales, J.

    2014-09-01

    This document is designed to help fleets understand the cost factors associated with fueling infrastructure for compressed natural gas (CNG) vehicles. It provides estimated cost ranges for various sizes and types of CNG fueling stations and an overview of factors that contribute to the total cost of an installed station. The information presented is based on input from professionals in the natural gas industry who design, sell equipment for, and/or own and operate CNG stations.

  6. Compressed natural gas vehicles motoring towards a green Beijing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ming; Kraft-Oliver, T. [International Institute for Energy Conservation (IIEC) - Asia, Bangkok (Thailand); Guo Xiao Yan [China North Vehicle Research Institute (CNVRI), Beijing (China)

    1996-12-31

    This paper first describes the state-of-the-art of compressed natural gas (CNG) technologies and evaluates the market prospects for CNG vehicles in Beijing. An analysis of the natural gas resource supply for fleet vehicles follows. The costs and benefits of establishing natural gas filling stations and promoting the development of vehicle technology are evaluated. The quantity of GHG reduction is calculated. The objective of the paper is to provide information of transfer niche of CNG vehicle and equipment production in Beijing. This paper argues that the development of CNG vehicles is a cost-effective strategy for mitigating both air pollution and GHG.

  7. 49 CFR 571.303 - Standard No. 303; Fuel system integrity of compressed natural gas vehicles.

    Science.gov (United States)

    2010-10-01

    ... compressed natural gas vehicles. 571.303 Section 571.303 Transportation Other Regulations Relating to... system integrity of compressed natural gas vehicles. S1. Scope. This standard specifies requirements for the integrity of motor vehicle fuel systems using compressed natural gas (CNG), including the CNG...

  8. Compressed natural gas fueled vehicles: The Houston experience

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    The report describes the experience of the City of Houston in defining the compressed natural gas fueled vehicle research scope and issues. It details the ways in which the project met initial expectations, and how the project scope, focus, and duration were adjusted in response to unanticipated results. It provides examples of real world successes and failures in efforts to commercialize basic research in adapting a proven technology (natural gas) to a noncommercially proven application (vehicles). Phase one of the demonstration study investigates, develops, documents, and disseminates information regarding the economic, operational, and environmental implications of utilizing compressed natural gas (CNG) in various truck fueling applications. The four (4) truck classes investigated are light duty gasoline trucks, medium duty gasoline trucks, medium duty diesel trucks and heavy duty diesel trucks. The project researches aftermarket CNG conversions for the first three vehicle classes and original equipment manufactured (OEM) CNG vehicles for light duty gasoline and heavy duty diesel classes. In phase two of the demonstration project, critical issues are identified and assessed with respect to implementing use of CNG fueled vehicles in a large vehicle fleet. These issues include defining changes in local, state, and industry CNG fueled vehicle related codes and standards; addressing vehicle fuel storage limitations; using standardized vehicle emission testing procedures and results; and resolving CNG refueling infrastructure implementation issues and related cost factors. The report identifies which CNG vehicle fueling options were tried and failed and which were tried and succeeded, with and without modifications. The conclusions include a caution regarding overly optimistic assessments of CNG vehicle technology at the initiation of the project.

  9. CNG (compressed natural gas) as fuel for the transport sector in Trinidad and Tobago

    Energy Technology Data Exchange (ETDEWEB)

    So`Brien, G.C.; Persad, P.; Satcunanathan, S. [University of the West Indies, St. Augustine (Trinidad)

    1996-08-01

    Several studies have established that Trinidad and Tobago is well positioned to consider the substitution of compressed natural gas (CNG) for gasoline or diesel in the transport sector. Consequently a programme of conversion of private motors was initiated. Despite considerable advertisement programs projecting CNG as an environmentally friendly and cheap fuel, there is not yet widespread acceptance of the technology. The reasons for this are analysed. It is recommended that the policy of CNG usage be reviewed and the emphasis be shifted to transport fleets. It is also recommended that tax credits be considered as an incentive to users. (author)

  10. Improved Compressive Sensing of Natural Scenes Using Localized Random Sampling.

    Science.gov (United States)

    Barranca, Victor J; Kovačič, Gregor; Zhou, Douglas; Cai, David

    2016-01-01

    Compressive sensing (CS) theory demonstrates that by using uniformly-random sampling, rather than uniformly-spaced sampling, higher quality image reconstructions are often achievable. Considering that the structure of sampling protocols has such a profound impact on the quality of image reconstructions, we formulate a new sampling scheme motivated by physiological receptive field structure, localized random sampling, which yields significantly improved CS image reconstructions. For each set of localized image measurements, our sampling method first randomly selects an image pixel and then measures its nearby pixels with probability depending on their distance from the initially selected pixel. We compare the uniformly-random and localized random sampling methods over a large space of sampling parameters, and show that, for the optimal parameter choices, higher quality image reconstructions can be consistently obtained by using localized random sampling. In addition, we argue that the localized random CS optimal parameter choice is stable with respect to diverse natural images, and scales with the number of samples used for reconstruction. We expect that the localized random sampling protocol helps to explain the evolutionarily advantageous nature of receptive field structure in visual systems and suggests several future research areas in CS theory and its application to brain imaging. PMID:27555464

  11. Removal of methane from compressed natural gas fueled vehicle exhaust

    International Nuclear Information System (INIS)

    The objective of this paper is to investigate the modes of methane (CH4) removal from simulated compressed natural gas (CNG) fueled vehicle exhaust under net oxidizing, net reducing, and stoichiometric conditions. Model reaction studies were conducted. The results suggest that the oxidation of methane with oxygen contributes to the removal of methane under net oxidizing conditions. In contrast, the oxidation of methane with oxygen as well as nitric oxide contributes to its removal under net reducing conditions. The steam reforming reaction does not significantly contribute to the removal of methane. The methane conversions under net reducing conditions are higher than those observed under net oxidizing conditions. The study shows that the presence of carbon monoxide in the feed gas leads to a gradual decrease in the methane conversion with increasing redox ratio, under net oxidizing conditions. a minimum in methane conversion is observed at a redox ratio of 0. 8. The higher activity for the methane-oxygen reaction resulting from a lowering in the overall oxidation state of palladium and the contribution of the methane-nitric oxide reaction toward the removal of CH4 appear to account for the higher CH4 conversions observed under net reducing conditions

  12. Selection of Mother Wavelet For Image Compression on Basis of Nature of Image

    Directory of Open Access Journals (Sweden)

    Gajanan K. Kharate

    2007-11-01

    Full Text Available Recently discrete wavelet transform and wavelet packet has emerged as popular techniques for image compression. The wavelet transform is one of the major processing components of image compression. The results of the compression change as per the basis and tap of the wavelet used. This paper compares compression performance of Daubechies, Biorthogonal, Coiflets and other wavelets along with results for different frequency images. Based on the result, it is proposed that proper selection of mother wavelet on the basis of nature of images, improve the quality as well as compression ratio remarkably. The prime objective is to select the proper mother wavelet during the transform phase to compress the color image. This paper includes the discussion on principles of image compression, image compression methodology, the basics of wavelet and orthogonal wavelet transforms, the selection of discrete wavelet transform with results and conclusion.

  13. Structures in compressible magnetoconvection and the nature of umbral dots

    OpenAIRE

    C. Tian; Petrovay, K.

    2011-01-01

    Structures seen in idealized numerical experiments on compressible magnetoconvection in an imposed strong vertical magnetic field show important differences from those detected in observations or realistic numerical simulations of sunspot umbrae. To elucidate the origin of these discrepancies, we present a series of idealized 3D compressible magnetoconvection experiments that differ from previous such experiments in several details, bringing them closer to realistic solar conditions. An initi...

  14. The use of compressed natural gas as a strategy of development of natural gas industry; Utilizacao do GNC (Gas Natural Comprimido) como estrategia de desenvolvimento da industria do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Jucemara [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Coordenacao de Segmento Veicular; Rickmann, Cristiano [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Gerencia de Novos Negocios; Maestri, Juares [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Gerencia de Mercado de Grandes Consumidores

    2008-07-01

    This work emphasizes the Compressed Natural Gas (CNG) as modal of transport, used by the Company of Gas of the State of Rio Grande do Sul - Sulgas, through experience in pioneering project in Brazil: the introduction of the technology of Compressed Natural Gas (CNG) to assist areas where there is not the infrastructure of pipeline for the transport. The article offers a display of the project of expansion of the Natural gas in Rio Grande do Sul, through the supply of CNG to the company Tramontina in Carlos Barbosa's city in the year of 2002. The last aspect focused by this article demonstrates as the use of this transport technology impelled the development of the transport market in the State and it has been used as an important strategy for the development of the market of Natural Gas Vehicle (NGV) in the state. (author)

  15. Modification Design of Petrol Engine for Alternative Fueling using Compressed Natural Gas

    OpenAIRE

    Eliezer Uchechukwu Okeke; Barinaadaa Thaddeus Lebele-Alawa

    2013-01-01

    This paper is on the modification design of petrol engine for alternative fuelling using Compressed Natural Gas (CNG). It provides an analytical background in the modification design process. A petrol engine Honda CR-V 2.0 auto which has a compression ratio of 9.8 was selected as case study. In order for this petrol engine to run on CNG, its compression had to be increased. An optimal compression ratio of 11.97 was computed using the standard temperature-specific volume relationsh...

  16. On the phase transition nature in compressible Ising models

    International Nuclear Information System (INIS)

    The phase transition phenomenon is analysed in a compressible ferromagnetic Ising model at null field, through the mean-field approximation. The model studied is d-dimensional under the magnetic point of view and one-dimensional under the elastic point of view. This is achieved keeping the compressive interactions among the ions and rejecting annealing forces completely. The exchange parameter J is linear and the elastic potential quadratic in relation to the microscopic shifts of the lattice. In the one-dimensional case, this model shows no phase transition. In the two-dimensional case, the role of the Si spin of the i-the ion is crucial: a) for spin 1/2 the transitions are of second order; b) for spin 1, desides the second order transitions there is a three-critical point and a first-order transitions line. (L.C.)

  17. Structures in compressible magnetoconvection and the nature of umbral dots

    CERN Document Server

    Tian, C

    2011-01-01

    Structures seen in idealized numerical experiments on compressible magnetoconvection in an imposed strong vertical magnetical field show important differences with respect to those detected in observations or realistic numerical simulations of sunspot umbrae.In order to elucidate the origin of these discrepancies, here we present a series of idealized 3D compressible magnetoconvection experiments that differ from previous such experiments in several details, bringing them closer to realistic solar conditions. An initially vertical magnetic field $B_0$ is imposed on a time snapshot of fully developed solar-like turbulent convection in a layer bounded by a stable layer from above. Upon relaxation to a statistically steady state, the structure of the flow field and magnetic field is examined. Instead of the vigorous granular convection (GRC) well known to take place in nonmagnetized or weakly magnetized convection, for high values of $B_0$ heat is transported by small-scale convection (SSC) in the form of narrow...

  18. Compressed natural gas for vehicles and how we can develop and meet the market

    International Nuclear Information System (INIS)

    This paper reports that state and federal legislation have mandated the use of clean burning fuels. Clean fuels include: compressed natural gas (CNG), ethanol, methanol, liquefied petroleum gas (LPG), electricity, and reformulated gasoline. The Clean Air Amendments 1990 have created support for the rapid utilization of the compressed natural gas (CNG). Responsively, diverse occupations related to this industry are emerging. A coordinated infrastructure is vital to the successful promotion of clean fuels and synchronized endorsement of the law

  19. Natural Gas Compression Technician: Apprenticeship Course Outline. Apprenticeship and Industry Training. 5311.1

    Science.gov (United States)

    Alberta Advanced Education and Technology, 2011

    2011-01-01

    The graduate of the Natural Gas Compression Technician apprenticeship program is a certified journeyperson who will be able to install, commission, maintain and repair equipment used to gather store and transmit natural gas. Advanced Education and Technology has prepared this course outline in partnership with the Natural Gas Compression…

  20. Natural minerals mixture for enhancing concrete compressive strength

    OpenAIRE

    Abdoullah Namdar,

    2012-01-01

    The construction material quality is required to be improved in order to enhancing structure stability, optimizing construction cost and quality. The kaolin and bentonite have been mixed in equal quantity and treated by heat for 1 hour under 600 ºC, 800 ºC and 1000 ºC to create new minerals under high temperature condition to introduce an acceptable concrete additive for achieving concrete compressive strength in early age. To study micro properties of additive-cement mixture, X-ray and FESEM...

  1. Compressive elastic modulus of natural fiber based binary composites

    Science.gov (United States)

    Widayani, Susanah, Y.; Utami, L. S.; Khotimah, S. N.; Viridi, S.

    2012-06-01

    The composites made of bamboo apus fiber - epoxy resin and charcoal - tapioca starch with several compositions have been synthesized. Bamboo fiber powder as the rest of cutting process was refined and filtered by mesh 40 before used. Epoxy resin 1021A and hardener 1021B has been used as resin. The synthesis of epoxy resin-based composites was carried out via simple mixing method by adding adequate 70% ethanol solution before drying. The 100 mesh-filtered dry charcoal was mixed with tapioca mixture before it was pressed and dried to produce briquette composites. To study the compressive elastic modulus of the composites, pressure tests using Mark 10 Pressure Test Machine have been carried out. It was found that all the composites show maximum compressive elastic modulus at certain component compositions. The maximum elastic modulus for bamboo fiber-epoxy resin, charcoal - epoxy resin and charcoal-tapioca starch were observed at 52.9%, 56.3%, and 25.0% of mass fraction of bamboo fiber, charcoal and tapioca starch, respectively.

  2. 77 FR 19277 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

    Science.gov (United States)

    2012-03-30

    ... Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During February 2012 FE..., ULC 12-13-NG ENCANA NATURAL GAS INC 11-163-NG ALCOA INC 12-11-NG JPMORGAN LNG CO 12-15-LNG CNE GAS... 2012, it issued Orders granting authority to import and export natural gas and liquefied natural...

  3. 78 FR 46581 - Orders Granting Authority To Import and Export Natural Gas, and To Import Liquefied Natural Gas...

    Science.gov (United States)

    2013-08-01

    ... Granting Authority To Import and Export Natural Gas, and To Import Liquefied Natural Gas During June 2013... authority to import and export natural gas and to import liquefied natural gas. These orders are summarized... of Fossil Energy, Office of Natural Gas Regulatory Activities, Docket Room 3E-033, Forrestal...

  4. 77 FR 12274 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

    Science.gov (United States)

    2012-02-29

    ... Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During January 2012.... DOMINION COVE POINT LNG, LP 11-98-LNG ENERGY PLUS NATURAL GAS LLC 11-155-NG BROOKFIELD ENERGY MARKETING L.P... 2012, it issued Orders granting authority to import and export natural gas and liquefied natural...

  5. Structures in compressible magnetoconvection and the nature of umbral dots

    Science.gov (United States)

    Tian, C.; Petrovay, K.

    2013-03-01

    Context. Structures seen in idealized numerical experiments on compressible magnetoconvection in an imposed strong vertical magnetic field show important differences from those detected in observations or realistic numerical simulations of sunspot umbrae. Aims: To elucidate the origin of these discrepancies, we present a series of idealized 3D compressible magnetoconvection experiments that differ from previous such experiments in several details, bringing them closer to realistic solar conditions. Methods: An initially vertical magnetic field B0 is imposed on a time snapshot of fully developed solar-like turbulent convection in a layer bounded by a stable layer from above. Upon relaxation to a statistically steady state, the structure of the flow field and magnetic field is examined. Results: Instead of the vigorous granular convection (GRC) well known to take place in magnetized or weakly magnetized convection, for high values of B0 heat is transported by small-scale convection (SSC) in the form of narrow, persistent convective columns consisting of slender upflows accompanied by adjacent downflow patches, which are reminiscent of the "convectons" identified in earlier semianalytic models. For moderate field strengths, flux separation (FXS) is observed: isolated field-free inclusions of GRC are embedded in a strongly magnetized plasma with SSC. Between the SSC and FXS regimes, a transitional regime (F/S) is identified where convectons dynamically evolve into multiply segmented granular inclusions and back. Conclusions: Our results agree in some aspects more closely with observed umbral structures than earlier idealized models, because they do reproduce the strong localized, patchy downflows immediately adjacent to the narrow convective columns. Based on recent observations of umbral dots, we suggest that in some cases the conditions in sunspot umbræ correspond to the newly identified F/S transitional regime.

  6. TECHNOLOGIES TO ENHANCE OPERATION OF THE EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn

    2004-08-01

    This report documents work performed in Phase I of the project entitled: ''Technologies to Enhance Operation of the Existing Natural Gas Compression Infracture''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report describes a number of potential enhancements to the existing natural gas compression infrastructure that have been identified and tested on four different integral engine/compressors in natural gas transmission service.

  7. TECHNOLOGIES TO ENHANCE OPERATION OF THE EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn

    2004-03-01

    This report documents work performed in Phase I of the project entitled: ''Technologies to Enhance Operation of the Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report describes a number of potential enhancements to the existing natural gas compression infrastructure that have been identified and qualitatively demonstrated in tests on three different integral engine/compressors in natural gas transmission service.

  8. Modification Design of Petrol Engine for Alternative Fueling using Compressed Natural Gas

    Directory of Open Access Journals (Sweden)

    Eliezer Uchechukwu Okeke

    2013-04-01

    Full Text Available This paper is on the modification design of petrol engine for alternative fuelling using Compressed Natural Gas (CNG. It provides an analytical background in the modification design process. A petrol engine Honda CR-V 2.0 auto which has a compression ratio of 9.8 was selected as case study. In order for this petrol engine to run on CNG, its compression had to be increased. An optimal compression ratio of 11.97 was computed using the standard temperature-specific volume relationship for an isentropic compression process. This computation of compression ratio is based on an inlet air temperature of 30oC (representative of tropical ambient condition and pre-combustion temperature of 540oC (corresponding to the auto-ignition temperature of CNG. Using this value of compression ratio, a dimensional modification Quantity =1.803mm was obtained using simple geometric relationships. This value of 1.803mm is needed to increase the length of the connecting rod, the compression height of the piston or reducing the sealing plate’s thickness. After the modification process, a CNG engine of air standard efficiency 62.7% (this represents a 4.67% increase over the petrol engine, capable of a maximum power of 83.6kW at 6500rpm, was obtained.

  9. Experimental and Skeletal Kinetic Model Study of Compressed Natural Gas Fueled Homogeneous Charge Compression Ignition Engine

    Directory of Open Access Journals (Sweden)

    P. M. Diaz

    2012-01-01

    Full Text Available Problem statement: In homogeneous charge compression ignition engines fuel oxidation chemistry determines the auto-ignition timing, heat release, reaction intermediates and the ultimate products of combustion. To shorten development time and to understand combustion processes, the use of simulation is increasing. Approach: A model that correctly simulates fuel oxidation at these conditions would be a useful design tool. Detailed models of hydrocarbon fuel oxidation, consisting of hundreds of chemical species and thousands of reactions. A way to lessen the burden was to use a skeletal reaction model, containing only tens of species and reactions. Results: The model was developed from the existing pre-ignition model, which had 10 species, 5 elementary reactions for kinetic and 6 elementary reactions for equilibrium and the standard k-ε turbulence model had been used in this investigation. This model combines the chemistry of the low, intermediate and high temperature regions. Conclusion: Simulations are compared with measured and calculated data from the engine operating at the following conditions: speed 1500 RPM, inlet temperature 363-433 K, fuel CNG and λ range 3-5. The simulations are generally in good agreement with the experimental data including temperature, pressure, combustion duration and ignition delay and heat release.

  10. Life cycle greenhouse emissions of compressed natural gas-hydrogen mixtures for transportation in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, P. [Instituto de Energia y Desarrollo Sustentable, CNEA, CONICET, Av. del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina); Dawidowski, L.; Gomez, D. [Gerencia Quimica, CNEA, Av. Gral. Paz 1499, San Martin (Argentina); Pasquevich, D. [Instituto de Energia y Desarrollo Sustentable, CNEA, CONICET, Av. del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina); Centro Atomico Bariloche, CNEA, Av. Bustillo 9500, S.C. de Bariloche (Argentina)

    2010-06-15

    We have developed a model to assess the life cycle greenhouse emissions of compressed natural gas-hydrogen (CNG-H{sub 2}) mixtures used for transportation in Argentina. The overall fuel life cycle is assessed through a well-to-wheel (WTW) analysis for different hydrogen generation and distribution options. The combustion stage in road vehicles is modeled using the COPERT IV model. Hydrogen generation options include classical steam methane reforming (SMR) and water electrolysis (WE) in central plants and distributed facilities at the refueling stations. Centralized hydrogen generation by electrolysis in nuclear plants as well as the use of solar photovoltaic and wind electricity is also considered. Hydrogen distribution options include gas pipeline and refrigerated truck transportation for liquefied hydrogen. A total number of fifteen fuel pathways are studied; in all the cases the natural gas-hydrogen mixture is made at the refueling station. The use of WE using nuclear or wind electricity appears to be less contaminant that the use of pure CNG. (author)

  11. Optimal compression in natural gas networks: a geometric programming approach

    OpenAIRE

    Misra, Sidhant; Fisher, Michael W.; Backhaus, Scott; Bent, Russell; Chertkov, Michael; Pan, Feng

    2013-01-01

    Natural gas transmission pipelines are complex systems whose flow characteristics are governed by challenging non-linear physical behavior. These pipelines extend over hundreds and even thousands of miles. Gas is typically injected into the system at a constant rate, and a series of compressors are distributed along the pipeline to boost the gas pressure to maintain system pressure and throughput. These compressors consume a portion of the gas, and one goal of the operator is to control the c...

  12. Compressive Strength of Concrete Using Recycled Concrete Aggregate as Complete Replacement of Natural Aggregate

    OpenAIRE

    Osei, Daniel Yaw

    2013-01-01

    This paper presents a report of an experimental investigation on the effect of complete replacement of natural aggregate by recycled concrete aggregate in the production of concrete on the compressive strength of concrete. Two sets of concrete mixtures of ratios 1:3:6, 1:2:4, 1:11/2:3, 1:1:2 by mass were cast using natural aggregates and recycled aggregates concrete respectively. The 28-day compressive strengths of 1:3:6, 1:2:4, 1:11/2:3, 1:1:2 concrete using recycled concrete aggregates were...

  13. The effect of compression on natural graphite anode performance and matrix conductivity

    OpenAIRE

    Striebel, K.A.; A. Sierra; Shim, J.; Wang, C.-W.; Sastry, A.M.

    2004-01-01

    Anodes for lithium-ion cells were constructed from three types of natural graphite, two coated spherical and one flaky. Anode samples were compressed from 0 to 300 kg/cm2 and studied in half-cells to study the relations between anode density, SEI formation and anode cyclability. The C/25 formation of the SEI layer was found to depend on the nature of the graphite and the anode density. Compression of the uncoated graphite lead to an increased conductivity, but only slight improvements i...

  14. FACTORS INFLUENCING THE IMAGE COMPRESSION OF ARTIFICIAL AND NATURAL IMAGE USING WAVELET TRANSFORM

    Directory of Open Access Journals (Sweden)

    NIKKOO KHALSA,

    2010-11-01

    Full Text Available Images contain large amount of information that requires much storage space, large transmission bandwidths and long transmission times. Therefore it is advantageous to compress the image by storing only theessential information needed to reconstruct the image. An image can be thought of as a matrix of pixel (or intensity values. In order to compress the image, redundancies must be exploited, for example, areas where there is little or no change between pixel values. Therefore images having large areas of uniform colour will have largeredundancies, and conversely images that have frequent and large changes in colour will be less redundant and harder to compress. The paper discusses the factors which influence the compression of artificial and natural images using wavelet transform.

  15. Failure Analysis of a Compressed Natural Gas Storage Cylinder

    International Nuclear Information System (INIS)

    In this work the rupture of an 80 liters capacity CNG storage cylinder installed at a CNG sales station was investigated. It was reported that the cylinder had ruptured only a few months after installation. During the initial investigation, the material of the cylinder was found to be in compliance with the specifications of composition and mechanical properties. However, thorough visual examination of the ruptured surfaces indicated the presence of multiple crack initiation sites within a rusted region on the inner surface of cylinder. This observation indicated the potential for stress corrosion cracking. Further macro-examination of the crack established this feature. Metallographic examination of areas adjacent to the fractured surfaces showed the presence of deep draw-marks almost everywhere and a longitudinal fold of unusual depth. These defects might have acted as stress raisers to assist stress corrosion cracking. It is suggested that the defects were present in the failed cylinder due to improper inspection procedures. (author)

  16. 78 FR 35014 - Orders Granting Authority to Import and Export Natural Gas, and to Import Liquefied Natural Gas...

    Science.gov (United States)

    2013-06-11

    ... Granting Authority to Import and Export Natural Gas, and to Import Liquefied Natural Gas During April 2013... INC 13-41-NG CASCADE NATURAL GAS CORPORATION 13-43-NG ENCANA MARKETING (USA) INC 13-44-NG CITIGROUP... natural gas and to import liquefied natural gas. These orders are summarized in the attached appendix...

  17. The Nature of Teacher Authority and Teacher Expertise

    Science.gov (United States)

    Elliott, Julian G.

    2009-01-01

    The so-called "soft skills" utilised by teachers--including relationship building, awareness of the pupil's context and background and the demonstration of authority--to develop an appropriate learning culture in their classrooms have long been recognised as being a major contribution to effective promotion of positive behaviour. This article…

  18. Building a Business Case for Compressed Natural Gas in Fleet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, G.

    2015-03-19

    Natural gas is a clean-burning, abundant, and domestically produced source of energy. Compressed natural gas (CNG) has recently garnered interest as a transportation fuel because of these attributes and because of its cost savings and price stability compared to conventional petroleum fuels. The National Renewable Energy Laboratory (NREL) developed the Vehicle Infrastructure and Cash-Flow Evaluation (VICE) model to help businesses and fleets evaluate the financial soundness of CNG vehicle and CNG fueling infrastructure projects.

  19. A Technical Review of Compressed Natural Gas as an Alternative Fuel for Internal Combustion Engines

    OpenAIRE

    Semin; Rosli A. Bakar

    2008-01-01

    Natural gas is promising alternative fuel to meet strict engine emission regulations in many countries. Compressed natural gas (CNG) has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. Engine conversion technology is well established and suitable conversion equipment is readily available. For spark ignition engines there are two op...

  20. Prediction of Corrosion Resistance of Concrete Containing Natural Pozzolan from Compressive Strength

    Science.gov (United States)

    al-Swaidani, A. M.; Ismat, R.; Diyab, M. E.; Aliyan, S. D.

    2015-11-01

    A lot of Reinforced Concrete (RC) structures in Syria have suffered from reinforcement corrosion which shortened significantly their service lives. Probably, one of the most effective approaches to make concrete structures more durable and concrete industry on the whole - more sustainable is to substitute pozzolan for a portion of Portland cement (PC). Syria is relatively rich in natural pozzolan. In the study, in order to predict the corrosion resistance from compressive strength, concrete specimens were produced with seven cement types: one plain Portland cement (control) and six natural pozzolan-based cements with replacement levels ranging from 10 to 35%. The development of the compressive strengths of concrete cube specimens with curing time has been investigated. Chloride penetrability has also been evaluated for all concrete mixes after three curing times of 7, 28 and 90 days. The effect on resistance of concrete against damage caused by corrosion of the embedded reinforcing steel has been investigated using an accelerated corrosion test by impressing a constant anodic potential for 7, 28 and 90 days curing. Test results have been statistically analysed and correlation equations relating compressive strength and corrosion performance have been developed. Significant correlations have been noted between the compressive strength and both rapid chloride penetrability and corrosion initiation times. So, this prediction could be reliable in concrete mix design when using natural pozzolan as cement replacement.

  1. 75 FR 9921 - San Diego County Water Authority Natural Communities Conservation Program/Habitat Conservation...

    Science.gov (United States)

    2010-03-04

    ... Fish and Wildlife Service San Diego County Water Authority Natural Communities Conservation Program... the Draft Water Authority Natural Communities Conservation Program/Habitat Conservation Plan (NCCP/HCP... funded as a capital cost under the Water Authority Capital Improvement Program's (CIP) Mitigation...

  2. Modified Liu-Carter Compression Model for Natural Clays with Various Initial Water Contents

    Directory of Open Access Journals (Sweden)

    Sen Qian

    2016-01-01

    Full Text Available The initial water content has a significant effect on the compression behaviour of reconstituted clays. This effect has to be considered in the Liu-Carter model to ensure the addition voids ratio only related to soil structure. A modified Liu-Carter compression model is proposed by introducing the empirical equations for reconstituted clays at different initial water contents into the Liu-Carter model. The proposed model is verified against the experimental results from the literature. The simulations by the proposed method are also compared with that by old method where the influence of initial water content is not considered. The results show that the predicted virgin compression curves of natural clays are similar, but the values of b and Δey may be very different.

  3. 75 FR 3232 - Northern Natural Gas Company; Notice of Request Under Blanket Authorization

    Science.gov (United States)

    2010-01-20

    ... Energy Regulatory Commission Northern Natural Gas Company; Notice of Request Under Blanket Authorization January 8, 2010. Take notice that on December 30, 2009, Northern Natural Gas Company (Northern), 1111... sections 157.205 and 157.214 of the Commission's regulations under the Natural Gas Act for authorization...

  4. EFFECT OF NATURAL ZEOLITE ON THE COMPRESSIVE STRENGTH AND FREEZE-THAW RESISTANCE OF PORTLAND CEMENT

    OpenAIRE

    Bayartsetseg, E.; Lkhagvajargal, G.; Batgerel, D.; Sarangerel, D.; Ochirkhuyag, B

    2011-01-01

    Effects of zeolites in various natural deposits as replacement cementing material on mechanical performance of Portland cement were studied. The blended cement pastes with zeolites were cured at room temperature in air for various durations (1, 7 and 28 days). Mechanical performance of the blended cement samples such as setting time, volume of water, compressive strength, normal consistency and freeze-thaw resistance of the mortar are determined. The optimal substitution ratio was 20 wt. % of...

  5. Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temp...

  6. TECHNOLOGIES TO ENHANCE OPERATION OF THE EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn

    2003-10-01

    This report documents work performed in the fourth quarter of the project entitled: ''Technologies to Enhance Operation of the Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report describes the following work: second field test; test data analysis for the first field test; operational optimization plans.

  7. Characteristics of compressed natural gas jet and jet-wall impingement using the Schlieren imaging technique

    International Nuclear Information System (INIS)

    An experimental study was performed to investigate the compressed natural gas jet characteristics and jet-wall impingement using the Schlieren imaging technique and image processing. An injector driver was used to drive the natural gas injector and synchronized with camera triggering. A constant-volume optical chamber was designed to facilitate maximum optical access for the study of the jet macroscopic characteristics and jet-wall impingement at different injection pressures and injectors-wall distances. Measurement of the jet tip penetration and cone angle at different conditions are presented in this paper together with temporal presentation of the jet radial travel along the wall.

  8. 16 CFR 1.8 - Nature, authority and use of trade regulation rules.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Nature, authority and use of trade regulation rules. 1.8 Section 1.8 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND... Nature, authority and use of trade regulation rules. (a) For the purpose of carrying out the...

  9. Green Engines Development Using Compressed Natural Gas as an Alternative Fuel: A Review

    Directory of Open Access Journals (Sweden)

    Semin

    2009-01-01

    Full Text Available Problem statement: The Compressed Natural Gas (CNG is a gaseous form of natural gas, it have been recognized as one of the promising alternative fuel due to its substantial benefits compared to gasoline and diesel. Natural gas is produced from gas wells or tied in with crude oil production. Approach: Natural gas is promising alternative fuel to meet strict engine emission regulations in many countries. Compressed Natural Gas (CNG has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. Results: The technology of engine conversion was well established and suitable conversion equipment is readily available. For petrol engines or spark ignition engines there are two options, a bi-fuel conversion and use a dedicated to CNG engine. The diesel engines converted or designed to run on natural gas, there were two main options discussed. There are dual-fuel engines and normal ignition can be initiated. Natural gas engines can be operated at lean burn and stoichiometric conditions with different combustion and emission characteristics. Conclusions: In this study, the low exhaust gas emissions of CNG engines research and development were highlighted. Stoichiometric natural gas engines were briefly reviewed. To keep the output power, torque and emissions of natural gas engines comparable to their gasoline or diesel counterparts. High activity for future green CNG engines research and development to meet future stringent emissions standards was recorded in the study.

  10. A Technical Review of Compressed Natural Gas as an Alternative Fuel for Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Semin

    2008-01-01

    Full Text Available Natural gas is promising alternative fuel to meet strict engine emission regulations in many countries. Compressed natural gas (CNG has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. Engine conversion technology is well established and suitable conversion equipment is readily available. For spark ignition engines there are two options, a bi-fuel conversion and use a dedicated to CNG engine. For compression ignition engines converted to run on natural gas, there are two main options discussed, there are dual-fuel engines and normal ignition can be initiated. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the CNG engines research and development fueled using CNG are highlighted to keep the output power, torque and emissions of natural gas engines comparable to their gasoline or diesel counterparts. The high activities for future CNG engines research and development to meet future CNG engines is recorded in the paper.

  11. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTNG NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

    2005-01-28

    This quarterly report documents work performed under Tasks 15, 16, and 18 through 23 of the project entitled: ''Technologies to Enhance the Operation of the Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report first documents a survey test performed on an HBA-6 engine/compressor installed at Duke Energy's Bedford Compressor Station. This is one of several tests planned, which will emphasize identification and reduction of compressor losses. Additionally, this report presents a methodology for distinguishing losses in compressor attributable to valves, irreversibility in the compression process, and the attached piping (installation losses); it illustrates the methodology with data from the survey test. The report further presents the validation of the simulation model for the Air Balance tasks and outline of conceptual manifold designs.

  12. 76 FR 18216 - Southern Natural Gas Company; Notice of Request Under Blanket Authorization

    Science.gov (United States)

    2011-04-01

    ... Federal Energy Regulatory Commission Southern Natural Gas Company; Notice of Request Under Blanket Authorization Take notice that on March 16, 2011, Southern Natural Gas Company (Southern), Post Office Box 2563... and 157.216 of the Commission's Regulations under the Natural Gas Act (NGA) as amended, to abandon...

  13. 75 FR 13535 - Northern Natural Gas Company; Notice of Request Under Blanket Authorization

    Science.gov (United States)

    2010-03-22

    ... Energy Regulatory Commission Northern Natural Gas Company; Notice of Request Under Blanket Authorization March 16, 2010. Take notice that on March 12, 2010, Northern Natural Gas Company (Northern), 1111 South... External Affairs, Northern Natural Gas Company, 1111 South 103rd Street, Omaha, Nebraska 68124, at...

  14. 77 FR 31004 - Southern Natural Gas Company; Notice of Request Under Blanket Authorization

    Science.gov (United States)

    2012-05-24

    ... Energy Regulatory Commission Southern Natural Gas Company; Notice of Request Under Blanket Authorization Take notice that on May 9, 2012, Southern Natural Gas Company (Southern), 569 Brookwood Village, Suite....210 of the Federal Energy Regulatory Commission's regulations under the Natural Gas Act (NGA),...

  15. Compressed Natural Gas (CNG) Transit Bus Experience Survey: April 2009--April 2010

    Energy Technology Data Exchange (ETDEWEB)

    Adams, R.; Horne, D. B.

    2010-09-01

    This survey was commissioned by the U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) to collect and analyze experiential data and information from a cross-section of U.S. transit agencies with varying degrees of compressed natural gas (CNG) bus and station experience. This information will be used to assist DOE and NREL in determining areas of success and areas where further technical or other assistance might be required, and to assist them in focusing on areas judged by the CNG transit community as priority items.

  16. The co-evolution of alternative fuel infrastructure and vehicles. A study of the experience of Argentina with compressed natural gas

    International Nuclear Information System (INIS)

    In a quest for strategic and environmental benefits, the developed countries have been trying for many years to increase the share of alternative fuels in their transportation fuel mixes. They have met very little success though. In this paper, we examine the experience of Argentina with compressed natural gas. We conducted interviews with a wide range of stakeholders and analyzed econometrically data collected in Argentina to investigate the factors, economic, political, and others that determined the high rate of adoption of this fuel. A central objective of this research was to identify lessons that could be useful to developed countries in their efforts to deploy alternative fuel vehicles. We find that fuel price regulation was a significant determinant of the adoption of compressed natural gas, while, contrary to expectations, government financing of refueling infrastructure was minimal. (author)

  17. Wellhead compression

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Joe [Sertco Industries, Inc., Okemah, OK (United States); Vazquez, Daniel [Hoerbiger Service Latin America Inc., Deerfield Beach, FL (United States); Jacobs, Denis Richard [Hoerbiger do Brasil Industria de Equipamentos, Cajamar, SP (Brazil)

    2012-07-01

    Over time, all wells experience a natural decline in oil and gas production. In gas wells, the major problems are liquid loading and low downhole differential pressures which negatively impact total gas production. As a form of artificial lift, wellhead compressors help reduce the tubing pressure resulting in gas velocities above the critical velocity needed to surface water, oil and condensate regaining lost production and increasing recoverable reserves. Best results come from reservoirs with high porosity, high permeability, high initial flow rates, low decline rates and high total cumulative production. In oil wells, excessive annulus gas pressure tends to inhibit both oil and gas production. Wellhead compression packages can provide a cost effective solution to these problems by reducing the system pressure in the tubing or annulus, allowing for an immediate increase in production rates. Wells furthest from the gathering compressor typically benefit the most from wellhead compression due to system pressure drops. Downstream compressors also benefit from higher suction pressures reducing overall compression horsepower requirements. Special care must be taken in selecting the best equipment for these applications. The successful implementation of wellhead compression from an economical standpoint hinges on the testing, installation and operation of the equipment. Key challenges and suggested equipment features designed to combat those challenges and successful case histories throughout Latin America are discussed below.(author)

  18. Developing a Natural Gas-Powered Bus Rapid Transit Service: A Case Study on Leadership: Roaring Fork Transportation Authority (Presentation); NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, A.

    2015-03-01

    The Roaring Fork Transportation Authority (RFTA) represents a series of unique successes in alternative fuel deployment by pushing the envelope with innovative solutions. In the last year, RFTA demonstrated the ability to utilize compressed natural gas buses at a range of altitudes, across long distances, in extreme weather conditions and in a modern indoor fueling and maintenance facility - allwhile saving money and providing high-quality customer service. This case study will highlight how the leadership of organizations and communities that are implementing advances in natural gas vehicle technology is paving the way for broader participation.

  19. The relationship between the political authorities and the commercial actors in the European natural gas market

    International Nuclear Information System (INIS)

    In summarizing the reasons for the fall of the Roman empire one has found about 210 significant ones. Without too much comparison the Roman empire and the EU natural gas market have similarities in connections between political authorities and the commercial actors in the European natural gas market. The area has consisted of several independent markets with different solutions that from 1988 has been tried integrated in an inner energy market. Several governmental and private actors have interest in this sector and both inhabitants and businesses are affected by alterations in a national natural gas market. This process is not yet finished. The thesis gives a broad description of the topic by including as many as possible of the EU member states. The topic is large and complex and the author has had to make a choice which parts to emphasize. There are chapters on the theoretical basis, the natural gas industry, what factors may explain the relationship between the political authorities and the commercial actors in the national natural gas market in each EU member and how does the EU Commission goals regarding free competition in the energy market affect the relationship between the political authorities and commercial actors in the national natural gas market

  20. 77 FR 4028 - Orders Granting, Amending and Vacating Authority To Import and Export Natural Gas and Liquefied...

    Science.gov (United States)

    2012-01-26

    ... Granting, Amending and Vacating Authority To Import and Export Natural Gas and Liquefied Natural Gas FE Docket Nos. Gas Natural Caxitlan, S. DE R.L 11-147-NG Jordan Cove Energy Project, L.P 11-127-LNG Irving..., amending and vacating authority to import and export natural gas and liquefied natural gas. These...

  1. Utilization of compressed natural gas for the production of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Kim-Yang Lee; Wei-Ming Yeoh; Siang-Piao Chai; Abdul Rahman Mohamed

    2012-01-01

    The present work aims at utilizing compressed natural gas (CNG) as carbon source for the synthesis of carbon nanotubes (CNTs) over CoO-MoO/Al2O3 catalyst via catalytic chemical vapor deposition (CCVD) method.The as-produced carbonaceous product was characterized by thermal gravimetric analyzer (TGA),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and Raman spectroscopy.The experimental finding shows that CNTs were successfully produced from CNG while carbon nanofibers (CNFs) were formed as the side products.In addition,the catalytic activity and lifetime were found sustained and prolonged,as compared with using high purity methane as carbon source.The present study suggests an alternative route which can effectively produce CNTs and CNFs using low cost CNG.

  2. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

    2005-10-27

    This quarterly report documents work performed under Tasks 15, 16, and 18 through 23 of the project entitled: ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report first summarizes key results from survey site tests performed on an HBA-6 installed at Duke Energy's Bedford compressor station, and on a TCVC10 engine/compressor installed at Dominion's Groveport Compressor Station. The report then presents results of design analysis performed on the Bedford HBA-6 to develop options and guide decisions for reducing pulsations and enhancing compressor system efficiency and capacity. The report further presents progress on modifying and testing the laboratory GMVH6 at SwRI for correcting air imbalance.

  3. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

    2005-07-27

    This quarterly report documents work performed under Tasks 15, 16, and 18 through 23 of the project entitled: ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report first documents a survey site test performed on a TCVC10 engine/compressor installed at Dominion's Groveport Compressor Station. This test completes planned screening efforts designed to guide selection of one or more units for design analysis and testing with emphasis on identification and reduction of compressor losses. The report further presents the validation of the simulation model for the Air Balance tasks and outline of conceptual manifold designs.

  4. Developing compressed natural gas as an automotive fuel in Nigeria: Lessons from international markets

    International Nuclear Information System (INIS)

    The Nigerian government proposed the use of compressed natural gas (CNG) as an automotive fuel in 1997 as part of the initiatives to harness natural gas (NG) resources but progress has been slow. This paper examines the natural gas vehicle (NGV) implementation approaches and outcomes in seven countries with diverse experiences in order to gain an understanding of the barriers to the NGV market development in Nigeria. The analysis employs hermeneutic principles to secondary data derived from academic literature, published reports from a variety of international agencies, grey literature, and text from online sources and identifies eight success factors for NGV market development namely: strategic intent, legal backing, learning and adaptation, assignment of responsibilities, financial incentives, NG pricing, consumer confidence, and NG infrastructure. The paper concludes that the principal impediment to NGV market development in Nigeria is the uncoordinated implementation approach and that greater government involvement is required in setting strategic goals, developing the legal and regulatory frameworks, setting of clear standards for vehicles and refuelling stations as well as assigning responsibilities to specific agencies. Short-term low cost policy interventions identified include widening the existing NG and gasoline price gap and offering limited support for refuelling and retrofitting facilities. - Highlights: • We examined the NGV policies and implementation strategies in selected countries. • The use of legislative mandates help deepen NGV penetration. • Aligning stakeholder interest is critical to NGV adoption. • Making national interest a priority ahead of regional infrastructure is a critical success factor. • Government support drives participation

  5. Dual-fuelling of a direct-injection automotive diesel engine by diesel and compressed natural gas

    International Nuclear Information System (INIS)

    Application of Compressed Natural Gas in diesel engines has always been important, especially in the field of automotive engineering. This is due to easy accessibility, better mixing quality and good combustion characteristics of the Compressed Natural Gas fuel. In this study the application of Compressed Natural Gas fuel along with diesel oil in a heavy duty direct-injection automotive diesel engine is experimentally investigated. In order to convert a diesel engine into a diesel-gas one, the so called mixed diesel-gasapproach has been used and for this purpose a carbureted Compressed Natural Gas fuel system has been designed and manufactured. For controlling quantity of Compressed Natural Gas, the gas valve is linked to the diesel fuel injection system by means of a set of rods. Then, the dual-fuel system is adjusted so that, at full load conditions, the quantity of diesel fuel is reduced to 20% and 80% of its equivalent energy is substituted by Compressed Natural Gas fuel. Also injection pressure of pilot jet is increased by 11.4%. Performance and emission tests are conducted under variation of load and speed on both diesel and diesel-gas engines. Results show that, with equal power and torque, the diesel-gas engine has the potential to improve overall engine performance and emission. For example, at rated power and speed, fuel economy increases by 5.48%, the amount of smoke decreases by 78%, amount of CO decreases by 64.3% and mean exhaust gas temperature decreases by 6.4%

  6. Influence of the mechanical stress and the filler content on the hydrostatic compression behaviour of natural rubber

    International Nuclear Information System (INIS)

    The behaviour of natural rubber (NR) compounds under mechanical stress is often reported in literature. An important and widely discussed effect that occurs is the Mullins effect. During the first loading cycles in a tensile test for example, a stress-softening effect is observed. This and other effects on the mechanical behaviour are investigated for different rubber materials with and without different types of fillers and filler contents. Besides, the hydrostatic compression behaviour is affected by the type and content of filler as well, which is shown for an NR with and without waxes and different contents of carbon black (CB) in this contribution. In contrast to the Mullins effect, there is no dependence of the number of loading cycles on the volumetric behaviour determined in hydrostatic compression tests. Furthermore, the influence of the previous stress-softening due to mechanical stress on the compression behaviour is elaborated. Cyclic uniaxial tensile tests are performed to realize the stress-softening in the rubber materials. The subsequent compression tests are compared to compression tests without any pre-stretching to determine the influence of previous mechanical loading on the compression behaviour of natural rubber with different filler contents

  7. MECHANISM ON DISTRIBUTION OF PILOT FUEL SPRAY AND COMPRESSING IGNITION IN PREMIXED NATURAL GAS ENGINE IGNITED BY PILOT DIESEL

    Institute of Scientific and Technical Information of China (English)

    Yao Chunde; Yao Guangtao; Song Jinou; Wang Yinshan

    2005-01-01

    Numerical simulations of pilot fuel spray and compressing ignition for pre-mixed natural gas ignited by pilot diesel are described. By means of these modeling, the dual fuel and diesel fuel ignition mechanism of some phenomena investigated on an optional engine by technology of high-speed CCD is analyzed. It is demonstrated that the longer delay of ignition in dual fuel engine is not mainly caused by change of the mixture thermodynamics parameters. The analysis results illustrate that the ignition of pre-mixed natural gas ignited by pilot diesel taking place in dual fuel engine is a process of homogenous charge compression ignition.

  8. 75 FR 38092 - The Dow Chemical Company; Application for Blanket Authorization To Export Liquefied Natural Gas

    Science.gov (United States)

    2010-07-01

    ... The Dow Chemical Company (Dow), requesting blanket authorization to export liquefied natural gas (LNG... with its principal place of business in Midland, Michigan. Dow is an international chemical and...\\ The Dow Chemical Company, DOE/FE Order No. 2754 issued February 25, 2010. Current Application In...

  9. Thermal Charging Study of Compressed Expanded Natural Graphite/Phase Change Material Composites

    Energy Technology Data Exchange (ETDEWEB)

    Mallow, Anne M [ORNL; Abdelaziz, Omar [ORNL; Graham, Samuel [Georgia Institute of Technology, Atlanta

    2016-01-01

    The thermal charging performance of phase change materials, specifically paraffin wax, combined with compressed expanded natural graphite foam is studied under constant heat flux and constant temperature conditions. By varying the heat flux between 0.39 W/cm2 and 1.55 W/cm2 or maintaining a boundary temperature of 60 C for four graphite foam bulk densities, the impact on the rate of thermal energy storage is discussed. Thermal charging experiments indicate that thermal conductivity of the composite is an insufficient metric to compare the influence of graphite foam on the rate of thermal energy storage of the PCM composite. By dividing the latent heat of the composite by the time to melt for various boundary conditions and graphite foam bulk densities, it is determined that bulk density selection is dependent on the applied boundary condition. A greater bulk density is advantageous for samples exposed to a constant temperature near the melting temperature as compared to constant heat flux conditions where a lower bulk density is adequate. Furthermore, the anisotropic nature of graphite foam bulk densities greater than 50 kg/m3 is shown to have an insignificant impact on the rate of thermal charging. These experimental results are used to validate a computational model for future use in the design of thermal batteries for waste heat recovery.

  10. 78 FR 44940 - Orders Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied...

    Science.gov (United States)

    2013-07-25

    ... Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied Natural Gas During... orders granting authority to import and export natural gas and to import and export liquefied natural gas... Regulatory Activities, Office of Oil and Gas Global Security and Supply, Office of Fossil Energy....

  11. 78 FR 53739 - Orders Granting Authority To Import and Export Natural Gas, To Import and Export Liquefied...

    Science.gov (United States)

    2013-08-30

    ... Granting Authority To Import and Export Natural Gas, To Import and Export Liquefied Natural Gas and... export natural gas, to import and export liquefied natural gas and to vacate prior authority. These... inspection and copying in the Office of Fossil Energy, Office of Oil and Gas Global Security and...

  12. Representing the nature of science in a science textbook: Exploring author-editor-publisher interactions

    Science.gov (United States)

    Digiuseppe, Maurizio

    Current reforms in elementary and secondary science education call for students and teachers to develop more informed views of the nature of science---a process in which learning materials like science textbooks play a significant role. This dissertation reports on a case study of the development of representations of the nature of science in one unit of a senior high school chemistry textbook by the book's author, editor, and publisher. The study examines the multiple discourses that arose as the developers reflected on their personal and shared understandings of the nature of science; squared these understandings with mandated curricula, the educational needs of chemistry students and teachers, and the exigencies of large-scale commercial textbook publishing; and developed and incorporated into the textbook representations of the nature of science they believed were the most suitable. Analyses of the data in this study indicate that a number of factors significantly influenced the development of representations of the nature of science, including representational accuracy (the degree to which suggested representations of the nature of science conformed to what the developers believed were contemporary understandings of the nature of science), representational consistency (the degree to which similar representations of the nature of science in different parts of the textbook conveyed the same meaning), representational appropriateness (the age-, grade-, and reading-level suitability of the suggested nature of science representations), representational alignment (the degree to which suggested representations of the nature of science addressed the requirements of mandated curricula), representational marketability (the degree to which textbook developers believed suggested representations of the nature of science would affect sales of the textbook in the marketplace), and a number of "Workplace Resources" factors such as the availability of time, relevant expertise

  13. An Investigation of Compressed Natural Gas Engine for Nitrogen Oxides Reduction

    Directory of Open Access Journals (Sweden)

    P. M. Diaz

    2012-01-01

    Full Text Available Problem statement: This study describes the use of Reformer Gas (RG to alter NOx emission in a CNG-fueled HCCI engine. Comparison with diesel, natural gas has a very high octane number (≈120 and high auto-ignition temperature (≈600°C. Composed mostly of methane, natural gas is the only common fuel to manifest relatively pure, single-stage combustion. Other fuels have stronger low-temperature reaction and the required entropy for main stage combustion can be obtained from the low temperature heat release as a result of compression to moderate pressure and temperature. In deviation, the methane molecule resists destruction by free radicals and produces negligible heat release at low temperature. In consequences, in CNG-fueled HCCI engines the activation energy required for auto-ignition must be obtained by extreme levels of charge heating and compression. This causes inherently to a high rate of heat release. HCCI operation with pure CNG fuel was attained but not really practical due to very high NOx production. While HCCI operation is usually described as a low NOx technique, the knocking behavior when running with pure CNG raised the peak combustion temperature to a value well above normal combustion and the critical Zeldovich NOx production threshold, giving very high indicated NOx emissions. Approach: One approach to improving these properties is to convert part of the base CNG fuel to Reformer Gas (RG. In this study, modified COMET engine was operated in HCCI mode using a mixture of CNG fuel and simulated RG (75% H2 and 25% CO can be produced on-board from CNG using low current and non-thermal plasma boosted fuel converter. Results: This study shows that despite of having various RG mass fractions, λ was the dominant factor in reducing NOx production and increasing RG mass fraction had only a small effect on increasing NOx. This disconnect between the overall equivalence ratio and RG fraction shows that the real benefit of the

  14. Diesel vs. compressed natural gas for school buses: a cost-effectiveness evaluation of alternative fuels

    International Nuclear Information System (INIS)

    Reducing emissions from school buses is a priority for both state and federal regulators. Two popular alternative technologies to conventional diesel (CD) are emission controlled diesel (ECD), defined here to be diesel buses equipped with continuously regenerating particle filters, and engines fueled by compressed natural gas (CNG). This paper uses a previously published model to quantify the impact of particulate matter (PM), oxides of nitrogen (NOx), and sulfur dioxide (SO2) emissions on population exposure to ozone and to primary and secondary PM, and to quantify the resulting health damages, expressed in terms of lost quality adjusted life years (QALYs). Resource costs include damages from greenhouse gas-induced climate change, vehicle procurement, infrastructure development, and operations. I find that ECD and CNG produce very similar reductions in health damages compared to CD, although CNG has a modest edge because it may have lower NOx emissions. However, ECD is far more cost effective ($400,000-900,000 cost per QALY saved) than CNG (around $4 million per QALY saved). The results are uncertain because the model used makes a series of simplifying assumptions and because emissions data and cost data for school buses are very limited

  15. Analisis Kekuatan Tangki CNG Ditinjau dengan Material Logam Lapis Komposit pada Kapal Pengangkut Compressed Natural Gas

    Directory of Open Access Journals (Sweden)

    Aulia Firmansah

    2013-03-01

    Full Text Available Pada penelitian ini, dilakukan analisa perbandingan pada kekuatan pressure vessel compressed natural gas. Pressure vessel yang digunakan yaitu tipe satu dan tipe tiga, tipe satu adalah tabung menggunakan material logam yaitu Carbon Steel SA 516 Grade 70 dan Aluminium Alloy T6-6061. Pada tabung tipe tiga material menggunakan Aluminium Alloy T6-6061 dengan lapisan Komposit (Carbon Fibre – Epoxy pada seluruh tabung (full wrapped. Sudut orientasi serat yang digunakan 54.73560 dan terdiri dari 4 lapis komposit yang membungkus aluminium. Variasi yang dilakukan pada tebal komposit yaitu 25% komposit, 50% komposit, dan 75% komposit. Pressure vessel mendapat perlakuan internal pressure sebesar 125 bar dan temperatur -300C. Analisa dilakukan dengan dua metode yaitu dengan perhitungan manual dan software finite element method (NASTRAN 2010. Dari hasil perhitungan tersebut tabung tipe satu dengan material logam terbukti aman karena memenuhi dari faktor keamanan yang ditentukan tetapi pressure vessel sangat berat. Pada tabung tipe tiga lamina dengan komposisi 75% komposit dan 50% komposit dinyatakan aman karena memenuhi dari kriteria tegangan maksimum. Sedangkan pada komposisi 25% komposit lamina mengalami kegagalan yang disebabkan terlalu rendahnya lapisan komposit. Dari keseluruhan hasil perhitungan dan analisa didapatkan komposisi ideal pressure vessel yaitu 75% komposit dan 25% aluminium dari tebal keseluruhan sehingga menghasilkan tegangan yang sangat kecil dan memiliki berat yang paling ringan.

  16. Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

    Directory of Open Access Journals (Sweden)

    Semin

    2009-01-01

    Full Text Available Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temperature than diesel engine? This research was conducted to investigate the cylinder temperature of CNG engine as a new engine compared to diesel engine as a baseline engine. Approach: In this study, the combustion temperature was investigated in 7 cases engine speed. The engine speeds variation start from 1000 rpm until 4000 rpm with variation in 500 rpm. The engine conversion development and combustion temperature investigation was conducted at automotive laboratory, faculty of mechanical engineering, University Malaysia Pahang, Malaysia. Results: The results of the combustion temperature in the engine cylinder in variation engine speeds showed that diesel engine convert to CNG engine effect decrease the combustion temperature in the engine cylinder characteristics. Conclusion/Recommendations: In the low speed the conversion can be increase the combustion temperature, but the increasing engine speeds can be decrease the combustion temperature in the engine cylinder.

  17. A sensitivity study of the oxidation of compressed natural gas on platinum

    KAUST Repository

    Badra, Jihad

    2013-11-01

    This paper presents a sensitivity study for the oxidation of methane (CH4) over platinum (Pt). Some dominant reactions in the CH 4-Pt surface chemistry were identified and the rates of these reactions were subsequently modified to enhance the calculations. Initially, a range of CH4-Pt surface mechanisms available in the literature are used, along with the relevant detailed gaseous chemistry to compute the structure of premixed compressed natural gas (CNG)/air flames co-flowing around a flat, vertical, unconfined, rectangular, and platinum plate. Comparison with existing measurements of surface temperature and species concentrations revealed significant discrepancies for all mechanisms. Sensitivity analysis has identified nine key reactions which dominate the heterogeneous chemistry of methane over platinum. The rates of these reactions were modified over a reasonable range and in different combinations leading to an "optimal" mechanism for methane/air surface chemistry on platinum. The new mechanism is then used with the same flow geometry for different cases varying the temperature of the incoming mixture (Tjet), its equivalence ratio (Φ) and the Reynolds number (Re). Results from the modified surface mechanism demonstrate reasonably good agreement with the experimental data for a wide range of operating conditions. © 2013 Elsevier Ltd. All rights reserved.

  18. An evaluation of criteria for selecting vehicles fueled with diesel or compressed natural gas

    Directory of Open Access Journals (Sweden)

    Thomas Hesterberg

    2009-04-01

    Full Text Available We reviewed selection criteria for diesel and compressed natural gas (CNG fueled vehicles, comparing engine emissions, fire and safety, toxicity, economics, and operations. Diesel- and CNG-fueled vehicles with the latest emission-control technology, including engine-exhaust aftertreatment, have very similar emissions of regulated and unregulated compounds, particles through all size ranges, and greenhouse gases. Although toxicity data are limited, no significant toxicity differences of engine emissions were reported. Operating and maintenance costs are variable, with no consistent difference between diesel- and CNG-fueled vehicles. The main operating concern with CNG vehicles is that they are less fuel efficient. Higher infrastructure costs are involved with implementing a CNG-fueled vehicle fleet, giving diesel vehicles a distinct cost advantage over CNG vehicles. For a given budget, greater emissions reductions can thus be achieved with diesel+filter vehicles. Finally, diesel vehicles have a significant fire-and-safety advantage over CNG vehicles. In summary, infrastructure costs and fire-and-safety concerns are much greater for CNG-fueled vehicles. These considerations should be part of the decision-making process when selecting a fuel for a transportation system.

  19. TECHNOLOGIES TO ENHANCE OPERATION OF THE EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

    2005-01-01

    This quarterly report documents work performed under Tasks 10 through 14 of the project entitled: ''Technologies to Enhance Operation of the Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report first documents tests performed on a KVG103 engine/compressor installed at Duke's Thomaston Compressor Station. This is the first series of tests performed on a four-stroke engine under this program. Additionally, this report presents results, which complete a comparison of performance before and after modification to install High Pressure Fuel Injection and a Turbocharger on a GMW10 at Williams Station 60. Quarterly Reports 7 and 8 already presented detailed data from tests before and after this modification, but the final quantitative comparison required some further analysis, which is presented in Section 5 of this report. The report further presents results of detailed geometrical measurements and flow bench testing performed on the cylinders and manifolds of the Laboratory Cooper GMVH6 engine being employed for two-stroke engine air balance investigations. These measurements are required to enhance the detailed accuracy in modeling the dynamic interaction of air manifold, exhaust manifold, and in-cylinder fuel-air balance.

  20. 78 FR 65304 - Orders Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied...

    Science.gov (United States)

    2013-10-31

    ... Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied Natural Gas During... issued orders granting authority to import and export natural gas, and to import and export liquefied... available for inspection and copying in the Office of Oil and Gas Global Security and Supply, Office...

  1. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Ford A. Phillips; Danny M. Deffenbaugh

    2006-05-31

    This project has documented and demonstrated the feasibility of technologies and operational choices for companies who operate the large installed fleet of integral engine compressors in pipeline service. Continued operations of this fleet is required to meet the projected growth of the U.S. gas market. Applying project results will meet the goals of the DOE-NETL Natural Gas Infrastructure program to enhance integrity, extend life, improve efficiency, and increase capacity, while managing NOx emissions. These benefits will translate into lower cost, more reliable gas transmission, and options for increasing deliverability from the existing infrastructure on high demand days. The power cylinders on large bore slow-speed integral engine/compressors do not in general combust equally. Variations in cylinder pressure between power cylinders occur cycle-to-cycle. These variations affect both individual cylinder performance and unit average performance. The magnitude of the variations in power cylinder combustion is dependent on a variety of parameters, including air/fuel ratio. Large variations in cylinder performance and peak firing pressure can lead to detonation and misfires, both of which can be damaging to the unit. Reducing the variation in combustion pressure, and moving the high and low performing cylinders closer to the mean is the goal of engine balancing. The benefit of improving the state of the engine ''balance'' is a small reduction in heat rate and a significant reduction in both crankshaft strain and emissions. A new method invented during the course of this project is combustion pressure ratio (CPR) balancing. This method is more effective than current methods because it naturally accounts for differences in compression pressure, which results from cylinder-to-cylinder differences in the amount of air flowing through the inlet ports and trapped at port closure. It also helps avoid compensation for low compression pressure by the

  2. Numerical Analysis of the Combustion Process in a Compressed Natural Gas Direct Injection Engine

    Directory of Open Access Journals (Sweden)

    Abdullah Shahrir

    2008-01-01

    Full Text Available The design, development and optimization of an internal combustion engine require the application of a modern sophisticated analysis tool. In addition to experimental work, numerical calculations are now necessary to provide an insight into the complex in-cylinder process. The combustion process and its emission characteristics in a compressed natural gas direct injection engine were analyzed and investigated. The numerical studies were performed on a single cylinder of a 1.6-liter engine running at wide open throttle. The grid generation was established through an embedded algorithm for moving mesh and boundary in order to provide a more accurate transient condition. The combustion process was modelled with the eddy break-up model of Magnussen for unpremixed or diffusion reaction with three global reaction scheme. The computational fluid dynamics (CFD simulations at two baseline conditions are carried out to examine the fluid flow, air-fuel mixing formation, combustion process, carbon monoxide emission distribution as well as NO emission formation occurred inside engine cylinder. The CFD results were compared with the experimental data and showed a very good agreement for two baseline conditions. A set of parametric studies were carried out by varying the timings of start of injection (SOI and start of ignition (SI. The examined engine performance is in-cylinder pressure, while the considered emissions to be minimised are CO and NO levels. In order to study the effect of injection timing, the SOI timing was varied from 120º -140º with fixed ignition timing at 19º bTDC. On the other hand, SI timing was positioned from 15º-23º bTDC with fixed SOI timing for studying its influences. The CFD results indicated that slightly retarded SOI and SI timing can be chosen to reduce CO and NO levels while increasing engine performance.

  3. Comparative evaluation of a two stroke compressed natural gas mixer design using simulation and experimental techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, D.; Bakar, R.A.; Rahim, M.F.; Noor, M.M. [Malaysia Pahang Univ., Pahang (Malaysia). Automotive Focus Group

    2008-07-01

    A study was conducted in which a two-stroke engine was converted for use with bi-fuel, notably compressed natural gas and gasoline. The excessive by-products generated by two-stroke engine combustion can be attributed to the inefficient combustion process. This prototype uniflow-type single-cylinder engine was equipped with a bi-fuel conversion system. A dedicated mixer was also developed to meter the gaseous fuel through the engine intake system. It was designed to meet air and fuel requirement similar to its gasoline counterpart. The mixer was modeled to obtain optimum orifice diameter using three different sizes of 14, 16 and 18 mm respectively. A standard computational fluid dynamics (CFD) software package was used to simulate the flow. A pressure reading was obtained during the prototype test. The drop in pressure across the venturi was shown to be an important parameter as it determined the actual fuel-air ratio in the actual engine. A good agreement of CFD outputs with that of the experimental outputs was recorded. The experimental technique validated the pressure distribution predicted by CFD means on the effects of the three insert rings in the CNG mixer. The simulation exercise can be used to predict the amount of CNG consumed by the engine. It was concluded that the 14 mm throat ring was best suited for the CNG mixer because it provided the best suction. Once the mixer is tested on a real engine, it will clear any doubts as to whether the throat can function at high engine speeds. 5 refs., 3 tabs., 8 figs.

  4. 76 FR 2093 - Eni USA Gas Marketing LLC; Application for Blanket Authorization To Export Liquefied Natural Gas

    Science.gov (United States)

    2011-01-12

    ... Gas Marketing LLC; Application for Blanket Authorization To Export Liquefied Natural Gas AGENCY... November 30, 2010, by Eni USA Gas Marketing LLC (Eni USA), requesting blanket authorization to export... purchasing and marketing supplies of natural gas and LNG. Eni USA is a customer of the Cameron Terminal...

  5. Tensile and compressive properties of flax fibres for natural fibre reinforced composites

    NARCIS (Netherlands)

    Bos, H.L.; Oever, van den M.J.A.; Peters, O.C.J.J.

    2002-01-01

    Mechanical properties of standard decorticated and hand isolated flax bast fibres were determined in tension as well as in compression. The tensile strength of technical fibre bundles was found to depend strongly on the clamping length. The tensile strength of elementary flax fibres was found to ran

  6. Waste Heat Approximation for Understanding Dynamic Compression in Nature and Experiments

    Science.gov (United States)

    Jeanloz, R.

    2015-12-01

    Energy dissipated during dynamic compression quantifies the residual heat left in a planet due to impact and accretion, as well as the deviation of a loading path from an ideal isentrope. Waste heat ignores the difference between the pressure-volume isentrope and Hugoniot in approximating the dissipated energy as the area between the Rayleigh line and Hugoniot (assumed given by a linear dependence of shock velocity on particle velocity). Strength and phase transformations are ignored: justifiably, when considering sufficiently high dynamic pressures and reversible transformations. Waste heat mis-estimates the dissipated energy by less than 10-20 percent for volume compressions under 30-60 percent. Specific waste heat (energy per mass) reaches 0.2-0.3 c02 at impact velocities 2-4 times the zero-pressure bulk sound velocity (c0), its maximum possible value being 0.5 c02. As larger impact velocities are implied for typical orbital velocities of Earth-like planets, and c02 ≈ 2-30 MJ/kg for rock, the specific waste heat due to accretion corresponds to temperature rises of about 3-15 x 103 K for rock: melting accompanies accretion even with only 20-30 percent waste heat retained. Impact sterilization is similarly quantified in terms of waste heat relative to the energy required to vaporize H2O (impact velocity of 7-8 km/s, or 4.5-5 c0, is sufficient). Waste heat also clarifies the relationship between shock, multi-shock and ramp loading experiments, as well as the effect of (static) pre-compression. Breaking a shock into 2 steps significantly reduces the dissipated energy, with minimum waste heat achieved for two equal volume compressions in succession. Breaking a shock into as few as 4 steps reduces the waste heat to within a few percent of zero, documenting how multi-shock loading approaches an isentrope. Pre-compression, being less dissipative than an initial shock to the same strain, further reduces waste heat. Multi-shock (i.e., high strain-rate) loading of pre-compressed

  7. 32 CFR 537.15 - Statutory authority for maritime claims and claims involving civil works of a maritime nature.

    Science.gov (United States)

    2010-07-01

    ... claims involving civil works of a maritime nature. 537.15 Section 537.15 National Defense Department of....15 Statutory authority for maritime claims and claims involving civil works of a maritime nature. (a... affirmative claims involving civil works of a maritime nature is set out at 33 U.S.C. 408....

  8. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

    2005-12-01

    This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

  9. Use of compressed natural gas in automotive vehicles; Uso del gas natural comprimido aplicado en vehiculos automotores

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, Adrian [Comision Nacional para el Ahorro de Energia (CONAE) (Mexico)

    2005-07-01

    The natural gas is natural origin energy (fossil fuel); it contains predominantly 90 percent methane; does not require transformation process for its use; is supplied the 24 hours to commerce, industries and homes by underground pipes; it is lighter than air; it is not corrosive, nor absorbent or toxic. For those reasons a study was performed where it is widely justified why the natural gas ought to be used in vehicles. [Spanish] El gas natural es un energetico de origen natural (combustible fosil), contiene predominantemente 90 por ciento de metano, no requiere proceso de transformacion para su utilizacion, llega directamente las 24 horas del dia a los hogares, comercios e industrias por tuberias subterraneas, es mas ligero que el aire, no es corrosivo, no es absorbente y no es toxico. Por esas razones se hizo un estudio donde se justifica ampliamente porque el gas natural debe utilizarse en vehiculos.

  10. Representing Nature of Science in a Science Textbook: Exploring author-editor-publisher interactions

    Science.gov (United States)

    DiGiuseppe, Maurice

    2014-05-01

    Current reforms in elementary and secondary science education call for students and teachers to develop more informed views of the nature of science (NOS)-a process in which science textbooks play a significant role. This paper reports on a case study of the development of representations of the NOS in a senior high school chemistry textbook by the book's author, editor, and publisher. The study examines the multiple discourses that arose as the developers reflected on their personal and shared understandings of NOS; squared these with mandated curricula, the educational needs of chemistry students and teachers, and the exigencies of large-scale commercial textbook publishing. As a result, the team developed and incorporated, in the textbook, representations of NOS they believed were the most pedagogically suitable. Analysis of the data in this study indicates that a number of factors significantly influenced the development of representations of NOS, including representational accuracy (the degree to which representations of NOS conformed to informed views of the NOS), representational consistency (the degree to which representations of NOS in different parts of the book conveyed the same meaning), representational appropriateness (the age-, grade-, and reading-level appropriateness of the NOS representations), representational alignment (the degree to which NOS representations aligned with mandated curriculum), representational marketability (the degree to which NOS representations would affect sales of the textbook), and 'Workplace Resources' factors including availability of time, relevant expertise, and opportunities for professional development.

  11. Crystal-structure properties and the molecular nature of hydrostatically compressed realgar

    Science.gov (United States)

    Hejny, Clivia; Sagl, Raffaela; Többens, Daniel M.; Miletich, Ronald; Wildner, Manfred; Nasdala, Lutz; Ullrich, Angela; Balic-Zunic, Tonci

    2012-05-01

    The structure of realgar, As4S4, and its evolution with pressure have been investigated employing in situ X-ray diffraction, optical absorption and vibrational spectroscopy on single-crystal samples in diamond-anvil cells. Compression under true hydrostatic conditions up to 5.40 GPa reveals equation-of-state parameters of V 0 = 799.4(2.4) Å3 and K 0 = 10.5(0.4) GPa with K_0^' = 8.7. The remarkably high compressibility can be attributed to a denser packing of the As4S4 molecules with shortening of the intermolecular bonds of up to 12 %, while the As4S4 molecules remain intact showing rigid-unit behaviour. From ambient pressure to 4.5 GPa, Raman spectra exhibit a strong blue shift of the Raman bands of the lattice-phonon regime of 24 cm-1, whereas frequencies from intramolecular As-S stretching modes show negligible or no shifts at all. On pressurisation, realgar shows a continuous and reversible colour change from bright orange over deep red to black. Optical absorption spectroscopy shows a shift of the absorption edge from 2.30 to 1.81 eV up to 4.5 GPa, and DFT calculations show a corresponding reduction in the band gap. Synchrotron-based measurements on polycrystalline samples up to 45.5 GPa are indexed according to the monoclinic structure of realgar.

  12. Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

    Energy Technology Data Exchange (ETDEWEB)

    John Pratapas; Daniel Mather; Anton Kozlovsky

    2007-03-31

    The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen's significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

  13. Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

    Energy Technology Data Exchange (ETDEWEB)

    Pratapas, John; Mather, Daniel; Kozlovsky, Anton

    2013-03-31

    The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen’s significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

  14. Thinking about the Nature and Role of Authority in Democratic Education with Rousseau's "Emile"

    Science.gov (United States)

    Michaud, Olivier

    2012-01-01

    Educational authority is an issue in contemporary democracies. Surprisingly, little attention has been given to the problem of authority in Jean-Jacques Rousseau's "Emile" and his work has not been addressed in the contemporary debate on the issue of authority in democratic education. Olivier Michaud's goals are, first, to address both of these…

  15. Hot surface assisted compression ignition in a direct injection natural gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Aesoey, Vilmar

    1996-12-31

    This study investigates the problem of ignition in a direct injection natural gas engine. Due to poor auto-ignition properties of natural gas compared to regular diesel engine fuels, a special arrangement to assist and secure ignition is required. The objective was to investigate the feasibility of using a hot surface as ignition assistance, primarily for application in medium and large size engines, and further study the main mechanisms involved in the ignition process. A constant volume combustion bomb and a test engine are used for experiments, supported by theoretical analysis and numerical simulations. Variable composition of natural gas depending on the gas source and over time, is a important problem causing significant variation in ignition properties. It is shown that even small quantities of non-methane components, which are normally present in natural gases, strongly influence ignition. Actions to handle the ignition problem caused by variable natural composition, are also discussed. In order to estimate the ignition properties of natural gas, a simple correlation to gas composition is proposed, showing good correlation to the experimental data. Mathematical models for simulation of the processes are developed based on fundamental physical relations and experimental results. They are mainly used in this study to support and analyze the physical experiments, but can also be useful in future design and optimization processes. 71 refs., 80 figs., 6 tabs.

  16. 78 FR 21351 - Orders Granting Authority to Import and Export Natural Gas, To Import Liquefied Natural Gas, To...

    Science.gov (United States)

    2013-04-10

    ...-NG STATOIL NATURAL GAS LLC 13-14-LNG PACIFICORP 13-16-NG CARGILL, INCORPORATED 13-17-NG EXCELERATE... to import LNG from various international sources by vessel. 3242 02/20/13 13-14-LNG Statoil...

  17. The Effect of Injection Timings on Performance and Emissions of Compressed Natural-Gas Direct Injection Engine

    Directory of Open Access Journals (Sweden)

    Saad Aljamali

    2016-01-01

    Full Text Available This experimental part investigates the effect of injection timing on performance and emissions of homogenous mixture compressed natural-gas direct injection. The engine of 1.6 L capacity, 4 cylinders, spark ignition, and compression ratio of 14 was used. Performance and emission were recorded under wide-open throttle using an engine control system (Rotronics and the portable exhaust gas analyser (Kane. The engine was tested at speed ranging from 1500 revolutions per minute (RPM to 4000 RPM with 500 RPM increments. The engine control unit (ECU was modified using Motec 800. The injection timings investigated were at the end of injection (EOI 120 bTDC, 180 bTDC, 300 bTDC, and 360 bTDC. Results show high brake power, torque, and BMEP with 120 as compared with the other injection timings. At 4000 RPM the power, torque, and BMEP with 120 were 5% compared to that with 180. Furthermore, it shows low BSFC and high fuel conversion efficiency with 120. With 360, the engine produced less CO and CO2 at higher speeds.

  18. Temporal scaling of neural responses to compressed and dilated natural speech.

    Science.gov (United States)

    Lerner, Y; Honey, C J; Katkov, M; Hasson, U

    2014-06-15

    Different brain areas integrate information over different timescales, and this capacity to accumulate information increases from early sensory areas to higher order perceptual and cognitive areas. It is currently unknown whether the timescale capacity of each brain area is fixed or whether it adaptively rescales depending on the rate at which information arrives from the world. Here, using functional MRI, we measured brain responses to an auditory narrative presented at different rates. We asked whether neural responses to slowed (speeded) versions of the narrative could be compressed (stretched) to match neural responses to the original narrative. Temporal rescaling was observed in early auditory regions (which accumulate information over short timescales) as well as linguistic and extra-linguistic brain areas (which can accumulate information over long timescales). The temporal rescaling phenomenon started to break down for stimuli presented at double speed, and intelligibility was also impaired for these stimuli. These data suggest that 1) the rate of neural information processing can be rescaled according to the rate of incoming information, both in early sensory regions as well as in higher order cortexes, and 2) the rescaling of neural dynamics is confined to a range of rates that match the range of behavioral performance. PMID:24647432

  19. Diesel versus compressed natural gas in Transmilenio-Bogotá: innovation, precaution, and distribution of risk

    DEFF Research Database (Denmark)

    Pineda, Andres Felipe Valderrama

    2007-01-01

    During the period 1998–2000, municipal officials in Bogotá implemented a new transportation system for the city. Transmilenio became the first major mass transportation system in the world to use only buses. The authors examine here the process that led to the design decision to power all of the ...

  20. 76 FR 6491 - San Diego County Water Authority Subregional Natural Community Conservation Program/Habitat...

    Science.gov (United States)

    2011-02-04

    ... plant species: Encinitas baccharis (Baccharis vanessae; threatened), Otay mesa mint (Pogogyne nudiuscula... November 26, 2003 (68 FR 66478). The Service and Water Authority held a public scoping meeting on December... Authority NCCP/HCP, and draft IA in the Federal Register (75 FR 9921). Public meetings were held on March...

  1. Compressed nature : co-existing grazers in a small reserve in Kenya

    NARCIS (Netherlands)

    Mwasi, S.M.

    2002-01-01

    Wildlife habitats in Kenya are getting more fragmented and isolated due to increasing human activities within them. This has resulted in the establishment of several small nature reserves where wildlife is protected from human interference. Grazers contribute a large proportion of total herbivore bi

  2. 77 FR 31838 - Notice of Orders Granting Authority to Import and Export Natural Gas and Liquefied Natural Gas...

    Science.gov (United States)

    2012-05-30

    ... Nos. Prometheus Energy Group 12-24-LNG The Dow Chemical Company 12-27-NG Golden Pass LNG Terminal LLC.... authority to import/ export LNG from/to Canada by truck. 3083 04/20/12 12-27-NG The Dow Chemical...

  3. Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas

    International Nuclear Information System (INIS)

    Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high autoignition temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions

  4. Diesel versus compressed natural gas in Transmilenio-Bogotá: innovation, precaution, and distribution of risk

    Directory of Open Access Journals (Sweden)

    Andrés Valderrama

    2007-03-01

    Full Text Available During the period 1998–2000, municipal officials in Bogotá implemented a new transportation system for the city. Transmilenio became the first major mass transportation system in the world to use only buses. The authors examine here the process that led to the design decision to power all of the buses with diesel fuel. The main finding is that the various public and private partners sought to accommodate themselves to the alternative that was deemed to be less risky. The diesel option was the outcome of contingent negotiation and distribution of responsibilities among the different interests. The dynamics of these processes were heavily influenced by a precautionary posture.

  5. 75 FR 19954 - Cheniere Marketing, LLC; Application for Blanket Authorization To Export Liquefied Natural Gas

    Science.gov (United States)

    2010-04-16

    ..., Turkey, Brazil, Argentina, Chile, Mexico, the Dominican Republic, Japan, South Korea, India, China, and... * * * authorization * * * is completely consistent with, if not mandated by, the statutory directive.'' \\5\\ See 49 FR... trade is not prohibited by U.S. law or policy, over a two year period commencing on the date of...

  6. Hydrogen enriched compressed natural gas (HCNG: A futuristic fuel for internal combustion engines

    Directory of Open Access Journals (Sweden)

    Nanthagopal Kasianantham

    2011-01-01

    Full Text Available Air pollution is fast becoming a serious global problem with increasing population and its subsequent demands. This has resulted in increased usage of hydrogen as fuel for internal combustion engines. Hydrogen resources are vast and it is considered as one of the most promising fuel for automotive sector. As the required hydrogen infrastructure and refueling stations are not meeting the demand, widespread introduction of hydrogen vehicles is not possible in the near future. One of the solutions for this hurdle is to blend hydrogen with methane. Such types of blends take benefit of the unique combustion properties of hydrogen and at the same time reduce the demand for pure hydrogen. Enriching natural gas with hydrogen could be a potential alternative to common hydrocarbon fuels for internal combustion engine applications. Many researchers are working on this for the last few years and work is now focused on how to use this kind of fuel to its maximum extent. This technical note is an assessment of HCNG usage in case of internal combustion engines. Several examples and their salient features have been discussed. Finally, overall effects of hydrogen addition on an engine fueled with HCNG under various conditions are illustrated. In addition, the scope and challenges being faced in this area of research are clearly described.

  7. A Comparative study on VOCs and aldehyde-ketone emissions from a spark Ignition vehicle fuelled on compressed natural gas and gasoline

    International Nuclear Information System (INIS)

    In this work, an experimental study was conducted on a spark ignition (SI) vehicle fuelled on compressed natural gas (CNG), and gasoline to compare the unregulated emissions such as volatile organic compounds (VOCs) and aldehyde-ketones or carbonyls. In the meantime, ozone forming potential (OFP) of pollutants was also calculated on the basis of their specific reactivity (SR). The vehicle was run on a chassis dynamometer following the Chinese National Standards test scheduled for light duty vehicle (LDV) emissions. According to the results, total aldehyde-ketones were increased by 39.4% due to the substantial increase in formaldehyde and acrolein + acetone emissions, while VOCs and BTEX (benzene, toluene, ethyl benzene, and xylene) reduced by 85.2 and 86% respectively, in case of CNG fuelled vehicle as compared to gasoline vehicle. Although total aldehyde-ketones were higher with CNG relative to gasoline, their SR was lower due decrease in acetaldehyde, propionaldehyde, crotonaldehyde, and methacrolein species having higher maximum incremental reactivity (MIR) values. The SR of VOCs and aldehyde-ketones emitted from CNG fuelled vehicle was decreased by above 10% and 32% respectively, owing to better physicochemical properties and more complete burning of CNG as compared to gasoline. (author)

  8. An analysis of price competitiveness of CNG (compressed natural gas) versus gasoline: estimation of the elasticities of demand by CNG in a recent period in Brazil; Uma analise da competitividade de preco do GNV (Gas Natural Veicular) frente a gasolina: estimacao das elasticidades da demanda por GNV no Brasil no periodo recente

    Energy Technology Data Exchange (ETDEWEB)

    Iootty, Mariana; Pinto Junior, Helder; Roppa, Bruna; Biasi, Guilherme de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Economia

    2004-07-01

    One of the main determinants to the expansion of natural gas on the Brazilian domestic market is its price. Hence, it is important to analyze the price competitiveness of natural gas vis-a-vis its competitors. The current paper focuses on the market of natural gas in vehicles (the compressed natural gas - CNG), and uses co-integration techniques to estimate the price-elasticity of CNG, the cross-elasticity of CNG and gasoline, and the income-elasticity. The results suggest that price is a relevant factor in the long-run, while in the short-run income is the most significant determinant of the demand variation. In addition, the paper also shows an imperfect substitutability between CNG and gasoline. (author)

  9. A comparative life cycle assessment of diesel and compressed natural gas powered refuse collection vehicles in a Canadian city

    International Nuclear Information System (INIS)

    Consumers and organizations worldwide are searching for low-carbon alternatives to conventional gasoline and diesel vehicles to reduce greenhouse gas (GHG) emissions and their impact on the environment. A comprehensive technique used to estimate overall cost and environmental impact of vehicles is known as life cycle assessment (LCA). In this article, a comparative LCA of diesel and compressed natural gas (CNG) powered heavy duty refuse collection vehicles (RCVs) is conducted. The analysis utilizes real-time operational data obtained from the City of Surrey in British Columbia, Canada. The impact of the two alternative vehicles is assessed from various points in their life. No net gain in energy use is found when a diesel powered RCV is replaced by a CNG powered RCV. However, significant reductions (approximately 24% CO2-equivalent) in GHG and criteria air contaminant (CAC) emissions are obtained. Moreover, fuel cost estimations based on 2011 price levels and a 5-year lifetime for both RCVs reveal that considerable cost savings may be achieved by switching to CNG vehicles. Thus, CNG RCVs are not only favorable in terms of reduced climate change impact but also cost effective compared to conventional diesel RCVs, and provide a viable and realistic near-term strategy for cities and municipalities to reduce GHG emissions. - Highlights: ► Life cycle analysis is performed on two alternative refuse collection vehicle technologies. ► Real-time operational data obtained by the City of Surrey in British Columbia are utilized. ► The life cycle energy use is similar for diesel and CNG RCVs. ► A 24% reduction of GHG emissions (CO2-equivalent) may be realized by switching from diesel to CNG. ► CNG RCVs are estimated to be cost effective and may lead to reduced fuel costs.

  10. Mechanical stability of a salt cavern submitted to rapid pressure variations: Application to the underground storage of natural gas, compressed air and hydrogen

    International Nuclear Information System (INIS)

    Salt caverns used for the underground storage of large volumes of natural gas are in high demand given the ever-increasing energy needs. The storage of renewable energy is also envisaged in these salt caverns for example, storage of compressed air and hydrogen mass storage. In both cases, salt caverns are more solicited than before because they are subject to rapid injection and withdrawal rates. These new operating modes raise new mechanical problems, illustrated in particular by sloughing, and falling of overhanging blocks at cavern wall. Indeed, to the purely mechanical stress related to changes in gas pressure variations, repeated dozens of degrees Celsius of temperature variation are superimposed; causes in particular during withdrawal, additional tensile stresses whom may lead to fractures at cavern wall; whose evolution could be dangerous. The mechanical behavior of rock salt is known: it is elasto-viscoplastic, nonlinear and highly thermo sensitive. The existing rock salt constitutive laws and failures and damages criteria have been used to analyze the behavior of caverns under the effects of these new loading. The study deals with the thermo mechanics of rocks and helps to analyze the effects of these new operations modes on the structural stability of salt caverns. The approach was to firstly design and validate a thermodynamic model of the behavior of gas in the cavern. This model was used to analyze blowout in gas salt cavern. Then, with the thermo mechanical coupling, to analyze the effects of rapid withdrawal, rapid injection and daily cycles on the structural stability of caverns. At the experimental level, we sought the optimal conditions to the occurrence and the development of cracks on a pastille and a block of rock salt. The creep behavior of rock salt specimens in triaxial extension also was analyzed. (author)

  11. The omniscient authors, or impersonality?--Self-mentions of Chinese scholars’published papers in natural science journals

    Institute of Scientific and Technical Information of China (English)

    杜冰茜

    2015-01-01

    Arguably, novice writers were warned of using “I”,“we”, or equivalents in an academic essay of hard sciences to“pretend to a scientific scholarly style”(Spack, 1988, p.39), although the issue of impersonality and its interdisciplinary variations have been documented in the research literature (Hyland, 2002). Now, it was partially acknowledged that authors were omniscient, as captured by Ivanic? & Camps (2001): “There is no such thing as ‘impersonal' writing…”. (p.5) However, as self-mention was obviously subjective, it followed that natural science RAs should be more objective to include few “I”s or “we”s. To attest to this belief, this paper investigated whether there were self-mentions in 4 published works (of renown journals) written by Chinese scholars from the Chemistry Department.

  12. Compressed sensing & sparse filtering

    CERN Document Server

    Carmi, Avishy Y; Godsill, Simon J

    2013-01-01

    This book is aimed at presenting concepts, methods and algorithms ableto cope with undersampled and limited data. One such trend that recently gained popularity and to some extent revolutionised signal processing is compressed sensing. Compressed sensing builds upon the observation that many signals in nature are nearly sparse (or compressible, as they are normally referred to) in some domain, and consequently they can be reconstructed to within high accuracy from far fewer observations than traditionally held to be necessary. Apart from compressed sensing this book contains other related app

  13. 78 FR 34084 - Freeport-McMoRan Energy LLC; Application for Long-Term Authorization To Export Liquefied Natural...

    Science.gov (United States)

    2013-06-06

    ... the world. \\8\\ FME notes that exports of natural gas directly from the OCS may be subject to the... Imported Natural Gas, 49 FR 6,684 (Feb.22, 1984). \\12\\ Id. (citing, e.g., Phillips Alaska Natural Gas Corp... Produced From Domestic Natural Gas Resources to Non-Free Trade Agreement Countries for a 30- Year...

  14. The co-evolution of alternative fuel infrastructure and vehicles: A study of the experience of Argentina with compressed natural gas

    International Nuclear Information System (INIS)

    In a quest for strategic and environmental benefits, the developed countries have been trying for many years to increase the share of alternative fuels in their transportation fuel mixes. They have met very little success though. In this paper, we examine the experience of Argentina with compressed natural gas. We conducted interviews with a wide range of stakeholders and analyzed econometrically data collected in Argentina to investigate the factors, economic, political, and others that determined the high rate of adoption of this fuel. A central objective of this research was to identify lessons that could be useful to developed countries in their efforts to deploy alternative fuel vehicles. We find that fuel price regulation was a significant determinant of the adoption of compressed natural gas, while, contrary to expectations, government financing of refueling infrastructure was minimal. - Research Highlights: →The broad scale adoption of CNG for transportation in Argentina was initiated by a market demand for an effective fuel that was priced at a significantly lower level compared to the mainstream alternatives. →The Argentine played a marginal role in the development of refueling infrastructure. →The role of the government focused on sending clear signals to the marketplace and developing effective codes and standards. →Consumers willingness to switch to CNG increases as state of the economy deteriorates and disposable incomes decrease.

  15. 78 FR 75339 - Barca LNG LLC; Application for Long-Term Authorization To Export Liquefied Natural Gas Produced...

    Science.gov (United States)

    2013-12-11

    .... natural gas prices have fallen to the point where they are the lowest in the world. Barca states that LNG... Domestic Natural Gas Resources to Non-Free Trade Agreement Countries for a 25-Year Period AGENCY: Office of... Resources. Barca anticipates that several natural gas basins will supply the Project, including the...

  16. Use of a single-zone thermodynamic model with detailed chemistry to study a natural gas fueled homogeneous charge compression ignition engine

    International Nuclear Information System (INIS)

    Highlights: ► Auto-ignition characteristics of a natural gas fueled HCCI engine. ► Engine speed had the greatest effect on the auto-ignition process. ► Increases of C2H6 or C3H8 improved the auto-ignition process. ► Engine performance was not sensitive to small changes in C2H6 or C3H8. ► Nitric oxides concentrations decreased as engine speed or EGR level was increased. - Abstract: A single zone thermodynamic model with detailed chemical kinetics was used to simulate a natural gas fueled homogeneous charge compression ignition (HCCI) engine. The model employed Chemkin and used chemical kinetics for natural gas with 53 species and 325 reactions. This simulation was used to complete analyses for a modified 0.4 L single cylinder engine. The engine possessed a compression ratio of 21.5:1, and had a bore and stroke of 86 and 75 mm, respectively. Several sets of parametric studies were completed to investigate the minimal initial temperature, engine performance, and nitric oxide emissions of HCCI engine operation. The results show significant changes in combustion characteristics with varying engine operating conditions. Effects of varying equivalence ratios (0.3–1.0), engine speeds (1000–4000 RPM), EGR (0–40%), and fuel compositions were determined and analyzed in detail. In particular, every 0.1 increase in equivalence ratio or 500 rpm increase in engine speed requires about a 5 K higher initial temperature for complete combustion, and leads to around 0.7 bar increase in IMEP.

  17. Cycle-by-cycle Variations in a Direct Injection Hydrogen Enriched Compressed Natural Gas Engine Employing EGR at Relative Air-Fuel Ratios.

    Directory of Open Access Journals (Sweden)

    Olalekan Wasiu Saheed

    2014-07-01

    Full Text Available Since the pressure development in a combustion chamber is uniquely related to the combustion process, substantial variations in the combustion process on a cycle-by-cycle basis are occurring. To this end, an experimental study of cycle-by-cycle variation in a direct injection spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation at relative air-fuel ratios was conducted. The impacts of relative air-fuel ratios (i.e. λ = 1.0, 1.2, 1.3 and 1.4 which represent stoichiometric, moderately lean, lean and very lean mixtures respectively, hydrogen fractions and EGR rates were studied. The results showed that increasing the relative air-fuel ratio increases the COVIMEP. The behavior is more pronounced at the larger relative air-fuel ratios. More so, for a specified EGR rate; increasing the hydrogen fractions decreases the maximum COVIMEP value just as increasing in EGR rates increases the maximum COVIMEP value. (i.e. When percentage EGR rates is increased from 0% to 17% and 20% respectively. The maximum COVIMEP value increases from 6.25% to 6.56% and 8.30% respectively. Since the introduction of hydrogen gas reduces the cycle-by-cycle combustion variation in engine cylinder; thus it can be concluded that addition of hydrogen into direct injection compressed natural gas engine employing EGR at various relative air-fuel ratios is a viable approach to obtain an improved combustion quality which correspond to lower coefficient of variation in imep, (COVIMEP in a direct injection compressed natural gas engine employing EGR at relative air-fuel ratios.

  18. Participant Perceptions on the Nature of Stakeholder Dialogue Carried out by the United Kingdom's Nuclear Decommissioning Authority (NDA)

    International Nuclear Information System (INIS)

    The author comments the results of a research which concentrated on the dialogue used to engage participants to bi-annual stakeholder meetings with nuclear site community representatives held by the Nuclear Decommissioning Authority (NDA), and on a concept of fairness. The author notably compares the findings from a questionnaire issued in November 2006 to those of a questionnaire issued in May 2008 in order to assess any change in stakeholder perception (frustration, agreement, will of control, and so on). The author discusses the stakeholder-led approach, the links between the engagement process and NDA strategy, and the perceived deliberative characteristic of the dialogue

  19. 78 FR 17189 - Trunkline LNG Export, LLC; Application for Long-Term Authorization to Export Liquefied Natural...

    Science.gov (United States)

    2013-03-20

    ... to the Regulation of Imported Natural Gas, 49 FR 6,684 (February 22, 1984) (``Policy Guidelines... increase when LNG is exported, ``the global market limits how high U.S. natural gas prices can rise under... Outer Continental Shelf Lands Act, which in relevant part provides: ``Before any oil or gas subject...

  20. Time Compression

    OpenAIRE

    Aadland, David; Shaffer, Sherrill

    2012-01-01

    Economists have generally ignored the notion that perceived time may differ from clock time. Borrowing from the behavioral psychology literature, we investigate the case of time compression whereby perceived time passes more quickly than actual time. A framework is presented to embed time compression in economic models. We then apply the principle to a standard lifecycle permanent income model with endogenous labor. Time compression provides an alternative explanation of why older indi...

  1. 76 FR 33746 - Freeport LNG Development, L.P.; Application for Blanket Authorization To Export Liquefied Natural...

    Science.gov (United States)

    2011-06-09

    ..., which granted the Dow Chemical Company blanket authorization to export up to an amount equivalent to 390....'' \\7\\ \\7\\ The Dow Chemical Company, DOE/FE Order No. 2859, issued October 5, 2010. Additionally...) Texas LNG Holdings, LLC, a Delaware limited liability company and wholly-owned subsidiary of The...

  2. Compressed Teleportation

    CERN Document Server

    Jaffe, Arthur; Wozniakowski, Alex

    2016-01-01

    In a previous paper we introduced holographic software for quantum networks, inspired by work on planar para algebras. This software suggests the definition of a compressed transformation. Here we utilize the software to find a CT protocol to teleport compressed transformations. This protocol serves multiple parties with multiple persons.

  3. 78 FR 4401 - Orders Granting Authority To Import and Export Natural Gas, To Import and Export Liquefied...

    Science.gov (United States)

    2013-01-22

    ...) TRADING LTD......... 12-104-NG PEMEX GAS Y PETROQUIMICA BASICA 12-110-NG NORTH WESTERN CORPORATION d/b/a.../ (Canada) Trading export natural gas Ltd. from/to Canada. 3154 10/04/12 12-110-NG Pemex Gas y...

  4. Natural Ecosystem-Units in Israel and the Palestinian Authority - Representativeness in Protected Areas and Suggested Solutions for Biodiversity Conservation

    Directory of Open Access Journals (Sweden)

    Rotem Dotan

    2014-01-01

    Full Text Available The geographic location of Israel and the Palestinian Authorityon the border between Mediterranean and desert climate, and the strong topographic and geomorphological variation resulting from its position on the Great African Rift Valley, combine to sustain a great diversity of landscapes in a very small country. The purpose of this study is to determine whether the protected areas in Israel and the Palestinian Authority adequately represent the range of landscapes and ecosystems in the region.

  5. Data compression for digitally formatted radiographic examinations

    International Nuclear Information System (INIS)

    Most current teleradiology and PACS systems use data compression to improve performance. Data compression improves performance by reducing the quantity of data used to represent the diagnostic image. The most effiecient methods of data compression also alter the image. Some studies have been undertaken to evaluate the quality of compressed images, to our knowledge receiver operating characteristic curve (ROC) analysis has not been performed on compressed images. The authors present the results of ROC analysis on digital chest images of interstitial lung disease that have been compressed with cosine transform encoding (with varying degrees of compression)

  6. Analyzing the Performance of a Dual Loop Organic Rankine Cycle System for Waste Heat Recovery of a Heavy-Duty Compressed Natural Gas Engine

    Directory of Open Access Journals (Sweden)

    Baofeng Yao

    2014-11-01

    Full Text Available A dual loop organic Rankine cycle (DORC system is designed to recover waste heat from a heavy-duty compressed natural gas engine (CNGE, and the performance of the DORC–CNGE combined system is simulated and discussed. The DORC system includes high-temperature (HT and low-temperature (LT cycles. The HT cycle recovers energy from the exhaust gas emitted by the engine, whereas the LT cycle recovers energy from intake air, engine coolant, and the HT cycle working fluid in the preheater. The mathematical model of the system is established based on the first and second laws of thermodynamics. The characteristics of waste heat energy from the CNGE are calculated according to engine test data under various operating conditions. Moreover, the performance of the DORC–CNGE combined system is simulated and analyzed using R245fa as the working fluid. Results show that the maximum net power output and the maximum thermal efficiency of the DORC system are 29.37 kW and 10.81%, respectively, under the rated power output condition of the engine. Compared with the original CNG engine, the maximum power output increase ratio and the maximum brake specific fuel consumption improvement ratio are 33.73% and 25%, respectively, in the DORC–CNGE combined system.

  7. Electrical conductivity of compressed argon

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, R. [Univ. Regensburg (Germany); Windl, W.; Collins, L.; Kress, J.; Kwon, I. [Los Alamos National Lab., NM (United States)

    1997-10-01

    The authors report calculations of the electrical conductivity of solid argon as a function of compression within the density functional local density approximation formulation for a norm-conserving pseudopotential using both electron-phonon coupling and molecular dynamics techniques.

  8. Comportamento de um motor de ignição por compressão trabalhando com óleo Diesel e gás natural A dual fuel compression ignition engine performance, running with Diesel fuel and natural gas

    Directory of Open Access Journals (Sweden)

    José F. Schlosser

    2004-12-01

    Full Text Available A previsível escassez de petróleo aliada a uma consciência ecológica está levando pesquisadores a procurar novas fontes de energia e processos de combustão mais eficientes e menos poluentes. Entre os combustíveis menos poluentes está o gás natural, cujo consumo aumenta ano a ano. Os motores de combustão interna são transformadores de energia que têm baixa eficiência de conversão. Este trabalho avaliou um motor Diesel, bicombustível, movido a Diesel e gás natural. Nesse motor, a energia provém, basicamente, da combustão do gás natural. O Diesel tem a função de produzir o início da combustão do gás, que é o combustível principal. Assim, haverá uma substituição parcial de óleo Diesel por gás natural, aumentando o rendimento da combustão. Inicialmente, foi feito um ensaio-testemunha, somente com óleo Diesel e após foram feitos ensaios, com três repetições, para variadas proporções de óleo Diesel, gás natural e ângulos de avanço da injeção. O melhor desempenho foi obtido para 22% de óleo Diesel em relação ao máximo débito da bomba injetora e 13 L min-1 de gás natural com ângulo de avanço de injeção original (21º. Nesse caso, a potência média aumentou 14%, e o consumo específico (medido em valores monetários diminuiu 46% em relação ao ensaio-testemunha.The foresight of a petroleum shortage and an ecological conscience is moving scientists to look for new sources of energy and to develop more efficient combustion processes and reduced emissions. Natural gas is a reduced emission fuel, whose consumption increases every year. The present work evaluates a dual fuel compression ignition engine. The major portion of the fuel burned is natural gas. The Diesel fuel acts as combustion starter, which ignites under the compression heat. Diesel fuel is used only as an ignition source. The partial substitution of Diesel fuel by natural gas increases the combustion efficiency and achieves significant

  9. Effects of operating parameters on nitrogen oxides emissions for a natural gas fueled homogeneous charged compression ignition engine (HCCI): Results from a thermodynamic model with detailed chemistry

    International Nuclear Information System (INIS)

    Highlights: ► Nitrogen oxides emissions were determined for a natural gas fueled HCCI engine. ► The thermal NO mechanism accounts for the most of the NOx (around 70%). ► Among the parameters examined, equivalence ratio had the greatest effect on NOx. ► Reduction of NOx was due to decreased times at high temperatures. ► The nitrogen oxides emissions were reduced with increasing EGR level. -- Abstract: Past numerical studies on natural gas HCCI engines have provided few thorough analyses of the effects of operating parameters on nitrogen oxides (referring to the mixture of nitric oxide and nitrogen dioxide). A single zone thermodynamic model with detailed chemical kinetics was used to determine the effect of operating parameters on nitrogen oxides emissions. The model employed Chemkin and used chemical kinetics for natural gas with 53 species and 325 reactions. The simulation was conducted for a modified 0.4 l single cylinder engine, which possessed a compression ratio of 21.5:1, and had a bore and stroke of 86 and 75 mm, respectively. Several sets of parametric studies were completed to investigate the effect of engine load (imep = 200–600 kPa), speed (600–3000 RPM), equivalence ratio (0.3–1.0), EGR level (0–40%), temperature at IVC (390–460 K), and fuel compositions (0–10% C2H6) on nitrogen oxides emissions. Contributions of different NOx mechanisms have been examined, and the thermal mechanism accounts for over 70% of the total NOx at most of the conditions. The results show significant changes in nitrogen oxides concentrations with varying engine operating conditions. These changes are shown to be strongly dependent on the chemical kinetics and the resulting differences in gas temperature profiles. For this particular study, 50% reduction in nitrogen oxides emissions could result from a load (imep) decrease from 300 kPa to 200 kPa, or an EGR level increase from 0% to 20%.

  10. General-Purpose Compression for Efficient Retrieval.

    Science.gov (United States)

    Cannane, Adam; Williams, Hugh E.

    2001-01-01

    Discusses compression of databases that reduces space requirements and retrieval times; considers compression of documents in text databases based on semistatic modeling with words; and proposes a scheme for general purpose compression that can be applied to all types of data stored in large collections. (Author/LRW)

  11. Gasoline and other transportation fuels from natural gas in Canada

    International Nuclear Information System (INIS)

    Ways in which natural gas might displace cude oil as a source of fuels for the Canadian transportation market are reviewed. Three approaches are possible: (1) direct use as compressed natural gas; (2)conversion of natural gas to methanol; and (3) further conversion of methanol to synthetic gasoline. (author)

  12. 压缩天然气在乘用车上的应用%Application of Compressed Natural Gas in Passenger Car

    Institute of Scientific and Technical Information of China (English)

    李树会

    2011-01-01

    压缩天然气(CNG)是一种可替代汽油、柴油、丙烷或液化石油气的化石燃料。虽然它的燃烧会产生温室气体,但比其它燃料对环境的污染小得多,而且比其他燃料更安全,天然气比空气轻,泄露后很快发散在空气中。CNG通过压缩天然气(主要成分是甲烷[CH4])获得,常压下其体积仅占不足空气的1%,因此需要加压储存在20~25 MPa圆筒形或球形的压力容器中。CNG可以在传统的汽油机车辆的基础上改装,成为汽油、CNG双燃料车。由于汽油价格上涨,天然气车辆已经逐渐在亚太区域、拉丁美洲、欧洲和美国应用。受高燃料价格和环境要求的影%Compressed natural gas(CNG) is a fossil fuel substitute for gasoline(petrol),diesel,or propane/LPG.Although its combustion does produce greenhouse gases,it is a more environmentally clean alternative to those fuels,and it is much safer than other fuels in

  13. [Compression material].

    Science.gov (United States)

    Perceau, Géraldine; Faure, Christine

    2012-01-01

    The compression of a venous ulcer is carried out with the use of bandages, and for less exudative ulcers, with socks, stockings or tights. The system of bandages is complex. Different forms of extension and therefore different types of models exist. PMID:22489428

  14. Development and evaluation of natural gum-based extended release matrix tablets of two model drugs of different water solubilities by direct compression.

    Science.gov (United States)

    Ofori-Kwakye, Kwabena; Mfoafo, Kwadwo Amanor; Kipo, Samuel Lugrie; Kuntworbe, Noble; Boakye-Gyasi, Mariam El

    2016-01-01

    The study was aimed at developing extended release matrix tablets of poorly water-soluble diclofenac sodium and highly water-soluble metformin hydrochloride by direct compression using cashew gum, xanthan gum and hydroxypropylmethylcellulose (HPMC) as release retardants. The suitability of light grade cashew gum as a direct compression excipient was studied using the SeDeM Diagram Expert System. Thirteen tablet formulations of diclofenac sodium (∼100 mg) and metformin hydrochloride (∼200 mg) were prepared with varying amounts of cashew gum, xanthan gum and HPMC by direct compression. The flow properties of blended powders and the uniformity of weight, crushing strength, friability, swelling index and drug content of compressed tablets were determined. In vitro drug release studies of the matrix tablets were conducted in phosphate buffer (diclofenac: pH 7.4; metformin: pH 6.8) and the kinetics of drug release was determined by fitting the release data to five kinetic models. Cashew gum was found to be suitable for direct compression, having a good compressibility index (ICG) value of 5.173. The diclofenac and metformin matrix tablets produced generally possessed fairly good physical properties. Tablet swelling and drug release in aqueous medium were dependent on the type and amount of release retarding polymer and the solubility of drug used. Extended release of diclofenac (∼24 h) and metformin (∼8-12 h) from the matrix tablets in aqueous medium was achieved using various blends of the polymers. Drug release from diclofenac tablets fitted zero order, first order or Higuchi model while release from metformin tablets followed Higuchi or Hixson-Crowell model. The mechanism of release of the two drugs was mostly through Fickian diffusion and anomalous non-Fickian diffusion. The study has demonstrated the potential of blended hydrophilic polymers in the design and optimization of extended release matrix tablets for soluble and poorly soluble drugs by direct

  15. Overview of the Safety Issues Associated with the Compressed Natural Gas Fuel System and Electric Drive System in a Heavy Hybrid Electric Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, S.C.

    2002-11-14

    This report evaluates the hazards that are unique to a compressed-natural-gas (CNG)-fueled heavy hybrid electric vehicle (HEV) design compared with a conventional heavy vehicle. The unique design features of the heavy HEV are the CNG fuel system for the internal-combustion engine (ICE) and the electric drive system. This report addresses safety issues with the CNG fuel system and the electric drive system. Vehicles on U. S. highways have been propelled by ICEs for several decades. Heavy-duty vehicles have typically been fueled by diesel fuel, and light-duty vehicles have been fueled by gasoline. The hazards and risks posed by ICE vehicles are well understood and have been generally accepted by the public. The economy, durability, and safety of ICE vehicles have established a standard for other types of vehicles. Heavy-duty (i.e., heavy) HEVs have recently been introduced to U. S. roadways, and the hazards posed by these heavy HEVs can be compared with the hazards posed by ICE vehicles. The benefits of heavy HEV technology are based on their potential for reduced fuel consumption and lower exhaust emissions, while the disadvantages are the higher acquisition cost and the expected higher maintenance costs (i.e., battery packs). The heavy HEV is more suited for an urban drive cycle with stop-and-go driving conditions than for steady expressway speeds. With increasing highway congestion and the resulting increased idle time, the fuel consumption advantage for heavy HEVs (compared with conventional heavy vehicles) is enhanced by the HEVs' ability to shut down. Any increase in fuel cost obviously improves the economics of a heavy HEV. The propulsion system for a heavy HEV is more complex than the propulsion system for a conventional heavy vehicle. The heavy HEV evaluated in this study has in effect two propulsion systems: an ICE fueled by CNG and an electric drive system with additional complexity and failure modes. This additional equipment will result in a less

  16. Measurement and control for mechanical compressive stress

    Science.gov (United States)

    Li, Qing; Ye, Guang; Pan, Lan; Wu, Xiushan

    2001-12-01

    At present, the indirect method is applied to measuring and controlling mechanical compressive stress, which is the measurement and control of rotating torque of screw with torque transducer during screw revolving. Because the friction coefficient between every screw-cap and washer, of screw-thread is different, the compressive stress of every screw may is different when the machinery is equipped. Therefore, the accurate measurement and control of mechanical compressive stress is realized by the direct measurement of mechanical compressive stress. The author introduces the research of contrast between compressive stress and rotating torque in the paper. The structure and work principle of a special washer type transducer is discussed emphatically. The special instrument cooperates with the washer type transducer for measuring and controlling mechanical compressive stress. The control tactics based on the rate of compressive stress is put to realize accurate control of mechanical compressive stress.

  17. Image compression using constrained relaxation

    Science.gov (United States)

    He, Zhihai

    2007-01-01

    In this work, we develop a new data representation framework, called constrained relaxation for image compression. Our basic observation is that an image is not a random 2-D array of pixels. They have to satisfy a set of imaging constraints so as to form a natural image. Therefore, one of the major tasks in image representation and coding is to efficiently encode these imaging constraints. The proposed data representation and image compression method not only achieves more efficient data compression than the state-of-the-art H.264 Intra frame coding, but also provides much more resilience to wireless transmission errors with an internal error-correction capability.

  18. Compressive beamforming

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Mosegaard, Klaus

    2014-01-01

    Sound source localization with sensor arrays involves the estimation of the direction-of-arrival (DOA) from a limited number of observations. Compressive sensing (CS) solves such underdetermined problems achieving sparsity, thus improved resolution, and can be solved efficiently with convex...... optimization. The DOA estimation problem is formulated in the CS framework and it is shown that CS has superior performance compared to traditional DOA estimation methods especially under challenging scenarios such as coherent arrivals and single-snapshot data. An offset and resolution analysis is performed to...

  19. Compressed convolution

    CERN Document Server

    Elsner, F

    2013-01-01

    We introduce the concept of compressed convolution, a technique to convolve a given data set with a large number of non-orthogonal kernels. In typical applications our technique drastically reduces the effective number of computations. The new method is applicable to convolutions with symmetric and asymmetric kernels and can be easily controlled for an optimal trade-off between speed and accuracy. It is based on linear compression of the collection of kernels into a small number of coefficients in an optimal eigenbasis. The final result can then be decompressed in constant time for each desired convolved output. The method is fully general and suitable for a wide variety of problems. We give explicit examples in the context of simulation challenges for upcoming multi-kilo-detector cosmic microwave background (CMB) missions. For a CMB experiment with O(10,000) detectors with similar beam properties, we demonstrate that the algorithm can decrease the costs of beam convolution by two to three orders of magnitude...

  20. Toxicological properties of emission particles from heavy duty engines powered by conventional and bio-based diesel fuels and compressed natural gas

    Directory of Open Access Journals (Sweden)

    Jalava Pasi I

    2012-09-01

    Full Text Available Abstract Background One of the major areas for increasing the use of renewable energy is in traffic fuels e.g. bio-based fuels in diesel engines especially in commuter traffic. Exhaust emissions from fossil diesel fuelled engines are known to cause adverse effects on human health, but there is very limited information available on how the new renewable fuels may change the harmfulness of the emissions, especially particles (PM. We evaluated the PM emissions from a heavy-duty EURO IV diesel engine powered by three different fuels; the toxicological properties of the emitted PM were investigated. Conventional diesel fuel (EN590 and two biodiesels were used − rapeseed methyl ester (RME, EN14214 and hydrotreated vegetable oil (HVO either as such or as 30% blends with EN590. EN590 and 100% HVO were also operated with or without an oxidative catalyst (DOC + POC. A bus powered by compressed natural gas (CNG was included for comparison with the liquid fuels. However, the results from CNG powered bus cannot be directly compared to the other situations in this study. Results High volume PM samples were collected on PTFE filters from a constant volume dilution tunnel. The PM mass emission with HVO was smaller and with RME larger than that with EN590, but both biofuels produced lower PAH contents in emission PM. The DOC + POC catalyst greatly reduced the PM emission and PAH content in PM with both HVO and EN590. Dose-dependent TNFα and MIP-2 responses to all PM samples were mostly at the low or moderate level after 24-hour exposure in a mouse macrophage cell line RAW 264.7. Emission PM from situations with the smallest mass emissions (HVO + cat and CNG displayed the strongest potency in MIP-2 production. The catalyst slightly decreased the PM-induced TNFα responses and somewhat increased the MIP-2 responses with HVO fuel. Emission PM with EN590 and with 30% HVO blended in EN590 induced the strongest genotoxic responses, which were

  1. Nature

    OpenAIRE

    Ferretti, Federico; Schmidt Di Friedberg, Marcella

    2012-01-01

    International audience From the ancient times to the present debates on nature and environment, the idea of Nature has been one of the main concepts which interested Geographers. This paper deals with the representations of this idea in the works of thinkers who played a major role in shaping modern Geography, with a special focus on the Mediterranean world. It aims to clarify how Nature was important in defining heuristic strategies of the geographical sciences and their explications of r...

  2. Compressive Principal Component Pursuit

    CERN Document Server

    Wright, John; Min, Kerui; Ma, Yi

    2012-01-01

    We consider the problem of recovering a target matrix that is a superposition of low-rank and sparse components, from a small set of linear measurements. This problem arises in compressed sensing of structured high-dimensional signals such as videos and hyperspectral images, as well as in the analysis of transformation invariant low-rank recovery. We analyze the performance of the natural convex heuristic for solving this problem, under the assumption that measurements are chosen uniformly at random. We prove that this heuristic exactly recovers low-rank and sparse terms, provided the number of observations exceeds the number of intrinsic degrees of freedom of the component signals by a polylogarithmic factor. Our analysis introduces several ideas that may be of independent interest for the more general problem of compressed sensing and decomposing superpositions of multiple structured signals.

  3. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Chief Editor

    2016-06-01

    the clinical trial registration number at the end of the abstract. The ICMJE also recommends that, when a registration number is available, authors list that number the first time they use a trial acronym to refer to the trial they are reporting or to other trials that they mention in the manuscript. If the data have been deposited in a public repository, authors should state at the end of the abstract the data set name, repository name and number. c. Introduction Provide a context or background for the study (that is, the nature of the problem and its significance. State the specific purpose or research objective of, or hypothesis tested by, the study or observation. Cite only directly pertinent references, and do not include data or conclusions from the work being reported. d. Methods The guiding principle of the Methods section should be clarity about how and why a study was done in a particular way. Methods section should aim to be sufficiently detailed such that others with access to the data would be able to reproduce the results. In general, the section should include only information that was available at the time the plan or protocol for the study was being written; all information obtained during the study belongs in the Results section. If an organization was paid or otherwise contracted to help conduct the research (examples include data collection and management, then this should be detailed in the methods. The Methods section should include a statement indicating that the research was approved or exempted from the need for review by the responsible review committee (institutional or national. If no formal ethics committee is available, a statement indicating that the research was conducted according to the principles of the Declaration of Helsinki should be included. i. Selection and Description of ParticipantsClearly describe the selection of observational or experimental participants (healthy individuals or patients, including controls, including

  4. Evaluation of mammogram compression efficiency

    International Nuclear Information System (INIS)

    quality of 0.6 bpp and 0.1 bpp reconstructions was decreased. The compression performance of the most effective reversible coders is rather unsatisfactory. The subjective rating with the diagnostic criteria of image quality was more sensitive to distortions caused by lossy compression compared with the pathology detection test. The observers constituted 14:1 as the accepted ratio of lossy wavelet compression for test mammograms. This is significantly higher than the mean ratio of 2:1 achieved with lossless methods. (author)

  5. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Chief Editor

    2015-12-01

    .c. IntroductionProvide a context or background for the study (that is, the nature of the problem and its significance. State the specific purpose or research objective of, or hypothesis tested by, the study or observation. Cite only directly pertinent references, and do not include data or conclusions from the work being reported.d. MethodsThe guiding principle of the Methods section should be clarity about how and why a study was done in a particular way. Methods section should aim to be sufficiently detailed such that others with access to the data would be able to reproduce the results. In general, the section should include only information that was available at the time the plan or protocol for the study was being written; all information obtained during the study belongs in the Results section. If an organization was paid or otherwise contracted to help conduct the research (examples include data collection and management, then this should be detailed in the methods.The Methods section should include a statement indicating that the research was approved or exempted from the need for review by the responsible review committee (institutional or national. If no formal ethics committee is available, a statement indicating that the research was conducted according to the principles of the Declaration of Helsinki should be included.i. Selection and Description of ParticipantsClearly describe the selection of observational or experimental participants (healthy individuals or patients, in¬cluding controls, including eligibility and exclusion criteria and a description of the source population. Because the relevance of such variables as age, sex, or ethnicity is not always known at the time of study design, researchers should aim for inclusion of representative populations into all study types and at a minimum provide descriptive data for these and other relevant demographic variables. If the study was done involving an exclusive population, for example in only one sex, authors

  6. Thermal compression modulus of polarized neutron matter

    International Nuclear Information System (INIS)

    We applied the equation of state for pure polarized neutron matter at finite temperature, calculated previously, to calculate the compression modulus. The compression modulus of pure neutron matter at zero temperature is very large and reflects the stiffness of the equation of state. It has a little temperature dependence. Introducing the spin excess parameter in the equation of state calculations is important because it has a significant effect on the compression modulus. (author). 25 refs, 2 tabs

  7. Compressive Sensing for Quantum Imaging

    Science.gov (United States)

    Howland, Gregory A.

    . Entanglement imaging is demonstrated at 1024 dimensions-per-photon with channel capacities exceeding 8.4 bits-per-photon. In practice, the measurement time is reduced from 310 days for the standard technique to 8 hours for the compressive technique. An entropic steering inequality is violated to witness entanglement. The final application is a compressive wavefront sensor that unites compressive sensing with weak measurement. We show how a twisted-nematic spatial light modulator can be be used to weakly couple an optical field's position and polarization degrees of freedom. The complex nature of the weak value is used to directly measure random projections of the real and imaginary parts of the optical field, where polarization serves as an ancillary meter. We obtain 256 x 256 pixel wavefronts from only 10,000 random projections. Photon-counting detectors provide sub-picowatt sensitivity.

  8. Fractal image compression

    OpenAIRE

    Žemlo, Gražina

    2004-01-01

    One of the images compression methods – fractal image compression is analyzed in the work. After work carried out, it is possible to state, that selecting parameters of method of fractal compression depends on user’s demands.

  9. Compression limits in cascaded quadratic soliton compression

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw;

    2008-01-01

    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  10. Satellite data compression

    CERN Document Server

    Huang, Bormin

    2011-01-01

    Satellite Data Compression covers recent progress in compression techniques for multispectral, hyperspectral and ultra spectral data. A survey of recent advances in the fields of satellite communications, remote sensing and geographical information systems is included. Satellite Data Compression, contributed by leaders in this field, is the first book available on satellite data compression. It covers onboard compression methodology and hardware developments in several space agencies. Case studies are presented on recent advances in satellite data compression techniques via various prediction-

  11. Lossy Image Compression

    CERN Document Server

    Shukla, KK

    2011-01-01

    Image compression is concerned with minimization of the number of information carrying units used to represent an image. Lossy compression techniques incur some loss of information which is usually imperceptible. In return for accepting this distortion, we obtain much higher compression ratios than is possible with lossless compression. Salient features of this book include: four new image compression algorithms and implementation of these algorithms; detailed discussion of fuzzy geometry measures and their application in image compression algorithms; new domain decomposition based algorithms

  12. Development of recirculating RF pulse compression system

    International Nuclear Information System (INIS)

    An RF pulse compression technique using recirculating resonant cavity is under development for accelerating energy reinforcement for KEK B-factory. Cavity design and fabrication of cold model are described. (author)

  13. On Finite Alphabet Compressive Sensing

    OpenAIRE

    Das, Abhik Kumar; Vishwanath, Sriram

    2013-01-01

    This paper considers the problem of compressive sensing over a finite alphabet, where the finite alphabet may be inherent to the nature of the data or a result of quantization. There are multiple examples of finite alphabet based static as well as time-series data with inherent sparse structure; and quantizing real values is an essential step while handling real data in practice. We show that there are significant benefits to analyzing the problem while incorporating its finite alphabet natur...

  14. Author guidelines

    OpenAIRE

    Chief Editor

    2014-01-01

    AUTHOR GUIDELINESIndian Journal of Community Health (IJCH) accepts only online submission of manuscript(s) by using Open Journal software (OJS) at http://www.iapsmupuk.org/journal/index.php/IJCH/loginOnline SubmissionsAlready have a Username/Password for Indian Journal of Community Health (IJCH)? GO TO LOGINNeed a Username/Password?GO TO REGISTRATIONNote: Registration and login are required to submit items online and to track the status of current submissions.Author GuidelinesIJCH strictly ad...

  15. Author Guidelines

    OpenAIRE

    Chief Editor

    2015-01-01

    Author GuidelinesIJCH strictly adheres on the recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals as per the standard universal guidelines given by International Committee of Medical Journal Editors (ICMJE - Recommendations for Uniform Requirements for Manuscripts). Authors are requested to visit http://www.icmje.org/index.html before making online submission of their manuscript(s).SectionsEditorial:On issues of current public health needA...

  16. Preliminary technical and economic viability for the implantation of fluvial transport of CNG (Compressed Natural Gas) for barges in Amazon Region; Avaliacao preliminar de viabilidade tecnico-economica para implantacao de transporte fluvial de GNC (Gas Natual Comprimido) por barcacas na Regiao Amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Marcos C.C. de; Porto, Paulo L. Lemgruber [Interocean Engenharia e Ship Management, Rio de janeiro, RJ (Brazil); Cunha, Rafael H. da [Metro Rio, RJ (Brazil); Garcia, Rafael M. [Pic Brasil (Brazil); Almeida, Marco A.R. de [Universidade Gama Filho (UGF), Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The isolated regions of the Amazon present difficulties for integration with the electrical system which is creating some economic problems due to the consequent costs of electric generation of subsidies as a function of the fossil fuel use as oils diesel and fuel. A viable option is the use of Natural Gas - NG that is Also available in the region. Its modal of transport possible in the Region North they are for gas-lines or barges. The Compressed Natural Gas transport is distinguished that - CNG for barges was still not tested operationally in Brazil. Soon, to develop a Preliminary Study of Viability Technician - Economic - SVTE for the implantation of fluvial transport of CNG between the cities of Coari and Manaus is basic, therefore it is created strategical alternative for the electric generation in this region. The electric sector, the characteristics of the NG and the transport in this region had been analyzed to support to the work. The gas line and the fluvial transport of CNG for barges in this region are not conflicting, and they in a complementary form can act. The SVTE presented a Liquid Present Value and Internal Tax of very attractive Return justifying its implantation. (author)

  17. 5 CFR 532.513 - Flexible and compressed work schedules.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Flexible and compressed work schedules... REGULATIONS PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.513 Flexible and compressed work schedules. Federal Wage System employees who are authorized to work flexible and compressed work...

  18. Compressed sensing for wide-field radio interferometric imaging

    CERN Document Server

    McEwen, J D

    2010-01-01

    For the next generation of radio interferometric telescopes it is of paramount importance to incorporate wide field-of-view (WFOV) considerations in interferometric imaging, otherwise the fidelity of reconstructed images will suffer greatly. We extend compressed sensing techniques for interferometric imaging to a WFOV and recover images in the spherical coordinate space in which they naturally live, eliminating any distorting projection. The effectiveness of the spread spectrum phenomenon, highlighted recently by one of the authors, is enhanced when going to a WFOV, while sparsity is promoted by recovering images directly on the sphere. Both of these properties act to improve the quality of reconstructed interferometric images. We quantify the performance of compressed sensing reconstruction techniques through simulations, highlighting the superior reconstruction quality achieved by recovering interferometric images directly on the sphere rather than the plane.

  19. Vertebroplasty in osteoporotic vertebral compression

    International Nuclear Information System (INIS)

    Osteoporotic vertebral compression fractures are a frequently encountered clinical problem. We aimed to perform a critical, structured review of the current literature and to compare the results with our own experiences. A structured review of 7 studies about vertebroplasty in osteoporotic compression fractures was performed; each study assessed at least 16 patients and was published in English since 1997. The results were compared to our own experience in 22 patients treated in 2002. Over the past decade, vertebroplasty has increasingly been performed for the treatment of painful osteoporotic vertebral body compression fractures. In good correlation with our own results, all authors reported a significant improvement of pain immediately after treatment and a reduction of pain of up to 90% within 24 h after vertebroplasty. Furthermore, a significant reduction in the use of analgetics and a substantial improvement of functional status has been described in recent studies. In our own evaluation, we were also able to demonstrate a significant improvement of pain after vertebroplasty in 17 of 22 (77%) of our patients. 18 of 22 (82%) patients were able to diminish or even discontinue their analgesic medication. Reported results for vertebroplasty have demonstrated a rapid improvement in pain and physical functioning in patients with osteoporotic vertebral compression fractures. Percutaneous vertebroplasty has proven to provide a valuable treatment option for osteoporotic vertebral compression fractures. (orig.)

  20. Waves and compressible flow

    CERN Document Server

    Ockendon, Hilary

    2016-01-01

    Now in its second edition, this book continues to give readers a broad mathematical basis for modelling and understanding the wide range of wave phenomena encountered in modern applications.  New and expanded material includes topics such as elastoplastic waves and waves in plasmas, as well as new exercises.  Comprehensive collections of models are used to illustrate the underpinning mathematical methodologies, which include the basic ideas of the relevant partial differential equations, characteristics, ray theory, asymptotic analysis, dispersion, shock waves, and weak solutions. Although the main focus is on compressible fluid flow, the authors show how intimately gasdynamic waves are related to wave phenomena in many other areas of physical science.   Special emphasis is placed on the development of physical intuition to supplement and reinforce analytical thinking. Each chapter includes a complete set of carefully prepared exercises, making this a suitable textbook for students in applied mathematics, ...

  1. 压缩天然气管道输送应用分析%Application Analysis of Compressed Natural Gas Pipeline Transportation

    Institute of Scientific and Technical Information of China (English)

    赵辉; 金星; 胡晓露

    2015-01-01

    With the increasing of world energy demand, petroleum resources supply become nervous, in this situa⁃tion, we strengthen the developing of natural gas in our country. With the application of natural gas pipeline auto⁃mation technology, it meets the market demand, at the same time, also provides clean energy for people. This arti⁃cle mainly analyzed the transportation application of natural gas pipeline automation technology and provided cer⁃tain reference for related study.%随着世界能源需求量的增加,造成石油资源供应的短缺,在这种形势下,我国加大了天然气的开发力度。随着天然气管道自动化技术的应用,在满足市场需求的同时,也为人们提供了清洁能源。本文对压缩天然气输送应用进行了分析,为相关研究提供一定参考。

  2. Taking into care metastatic medullary compressions; Prise en charge des compressions medullaires metastatiques

    Energy Technology Data Exchange (ETDEWEB)

    Dupin, C.; Feuvret, L. [Groupe hospitalier Pitie-Salpetriere, 75 - Paris (France)

    2010-10-15

    As between 5 and 14 per cent of patients suffering from cancer will suffer from a metastatic medullary compression which severely impacts the vital and functional prognostic, the authors proposes an overview of the different techniques used to take these compressions into care: surgery, radiotherapy and cortico-therapy. They describe their positive and negative impacts. Short communication

  3. Learning in compressed space.

    Science.gov (United States)

    Fabisch, Alexander; Kassahun, Yohannes; Wöhrle, Hendrik; Kirchner, Frank

    2013-06-01

    We examine two methods which are used to deal with complex machine learning problems: compressed sensing and model compression. We discuss both methods in the context of feed-forward artificial neural networks and develop the backpropagation method in compressed parameter space. We further show that compressing the weights of a layer of a multilayer perceptron is equivalent to compressing the input of the layer. Based on this theoretical framework, we will use orthogonal functions and especially random projections for compression and perform experiments in supervised and reinforcement learning to demonstrate that the presented methods reduce training time significantly. PMID:23501172

  4. Study of CSR longitudinal bunch compression cavity

    International Nuclear Information System (INIS)

    The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring (CSR)is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch,which can be produced by non-adiabatic compression of bunch implemented by a fast compression with 90 degree rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RF-voltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMET-FT-1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238U72+ with 250 MeV/u will be compressed from 200 ns to 50 ns.The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80 kV, and the cavity can be used to compress heavy ions in the CSR. (authors)

  5. Cycle-by-cycle Variations in a Direct Injection Hydrogen Enriched Compressed Natural Gas Engine Employing EGR at Relative Air-Fuel Ratios.

    OpenAIRE

    Olalekan Wasiu Saheed; Rashid A.A.; Baharom Masri

    2014-01-01

    Since the pressure development in a combustion chamber is uniquely related to the combustion process, substantial variations in the combustion process on a cycle-by-cycle basis are occurring. To this end, an experimental study of cycle-by-cycle variation in a direct injection spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation at relative air-fuel ratios was conducted. The impacts of relative air-fuel ratios (i.e. λ = 1.0, 1.2, 1.3 and 1.4 whi...

  6. Experimental Study of Fractal Image Compression Algorithm

    Directory of Open Access Journals (Sweden)

    Chetan R. Dudhagara

    2012-08-01

    Full Text Available Image compression applications have been increasing in recent years. Fractal compression is a lossy compression method for digital images, based on fractals. The method is best suited for textures and natural images, relying on the fact that parts of an image often resemble other parts of the same image. In this paper, a study on fractal-based image compression and fixed-size partitioning will be made, analyzed for performance and compared with a standard frequency domain based image compression standard, JPEG. Sample images will be used to perform compression and decompression. Performance metrics such as compression ratio, compression time and decompression time will be measured in JPEG cases. Also the phenomenon of resolution/scale independence will be studied and described with examples. Fractal algorithms convert these parts into mathematical data called "fractal codes" which are used to recreate the encoded image. Fractal encoding is a mathematical process used to encode bitmaps containing a real-world image as a set of mathematical data that describes the fractal properties of the image. Fractal encoding relies on the fact that all natural, and most artificial, objects contain redundant information in the form of similar, repeating patterns called fractals.

  7. AUTHOR GUIDELINES

    Directory of Open Access Journals (Sweden)

    Chief Editor

    2014-12-01

    Full Text Available AUTHOR GUIDELINESIndian Journal of Community Health (IJCH accepts only online submission of manuscript(s by using Open Journal software (OJS at http://www.iapsmupuk.org/journal/index.php/IJCH/loginOnline SubmissionsAlready have a Username/Password for Indian Journal of Community Health (IJCH? GO TO LOGINNeed a Username/Password?GO TO REGISTRATIONNote: Registration and login are required to submit items online and to track the status of current submissions.Author GuidelinesIJCH strictly adheres on the recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals as per the standard universal guidelines given by International Committee of Medical Journal Editors (ICMJE - Recommendations for Uniform Requirements for Manuscripts. Authors are requested to visit http://www.icmje.org/index.html before making online submission of their manuscript(s.SectionsEditorial:On issues of current public health needAbout 1000 – 1200 wordsReferences: 5 – 10 (PubMed - Citation preferredInvited Commentary:Brief, provocative, opinionated communicationsOn issues of current public health needMain Text: 750-1000 words excluding referencesReferences: 5 – 10 (PubMed - Citation preferredOriginal Article:Articles from Original ResearchStructured abstract: 250 wordsMain Text: 2500 - 3000 words, IMRD formatKey Words: 5 - 8References: 20 – 25 (PubMed - Citation preferredTables / Figures: 3 – 4*Certificate of clearance from respective Institutional Ethical Committee (IECReview Article:On subject of public health relevanceAbstract: 250 wordsMain Text: 2500 - 3000 wordsKey Words: 3 - 4References: 20 – 25 (PubMed - Citation preferredTables / Figures: 3 – 4Short Communication / Article:Short report of a research project / outbreakMain Text : 1000 – 1200 wordsReferences: 10 – 15 (PubMed - Citation preferredTable / Figure: 01*Certificate of clearance from respective Institutional Ethical Committee (IECReport from the field

  8. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix

    2014-06-22

    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  9. Design of Hydrogen Enriched Compressed Natural Gas Engine Fuel System and Test Research%天然气掺氢发动机燃气供给系统设计与试验研究

    Institute of Scientific and Technical Information of China (English)

    张朝山; 熊树生; 任晓帅; 姚红; 徐进; 谢莲; 刘震涛

    2012-01-01

    提出了将滑动弧电解制氢装置应用到天然气发动机中,通过电解天然气制氢,轻松实现天然气(CNG)发动机到天然气掺氢(HCNG)发动机的改装.通过自制装置,进行了过量空气系数和点火提前角与燃用不同掺氢比例的HCNG对发动机排放特性影响的试验研究.结果表明,发动机燃用HCNG,其HC和CO的排放都减少,NOx排放量增加,但随着过量空气系数的增加或点火提前角的减少,NOx排放会大大减少,排放性能得到优化.同时进行了体积掺氢比20%的HCNG和纯CNG外特性对比试验研究,结果表明,相比纯CNG,燃用掺氢20% HCNG后,其动力性变化不大,燃料消耗率却相应的减少,经济性得到改善.%This paper put forward a device installed into the fuel system,which used the sliding electric arc to electrolyze the natural gas to make hydrogen and then blend them into the fuel pipe for final combustion. We could re-equip the compressed natural gas (CNG) engine to hydrogen enriched compressed natural gas (HCNG) engine easily. The test research of the engine emissions characteristics using different hydrogen-CNG ratios was conducted when the excess air ratios and the spark advance angles were different. The results show that HC and CO emissions of engine fueled with HCNG reduce when NOx emissions increase. The NOx emissions are reduced greatly with the increase of the excess air ratio or the decrease of the spark advance angle. Comparative experiments of the performance characteristics of engine burned with HCNG whose volume hydrogen-CNG ratio was 20% and CNG were conducted under wide open throttle operating conditions. The results show that the torque output is unchanged when 20% HCNG is burned compared with CNG engine,but the fuel consumption is reduced and the fuel economy is improved.

  10. An overview of semantic compression

    Science.gov (United States)

    Schmalz, Mark S.

    2010-08-01

    We live in such perceptually rich natural and manmade environments that detection and recognition of objects is mediated cerebrally by attentional filtering, in order to separate objects of interest from background clutter. In computer models of the human visual system, attentional filtering is often restricted to early processing, where areas of interest (AOIs) are delineated around anomalies of interest, then the pixels within each AOI's subtense are isolated for later processing. In contrast, the human visual system concurrently detects many targets at multiple levels (e.g., retinal center-surround filters, ganglion layer feature detectors, post-retinal spatial filtering, and cortical detection / filtering of features and objects, to name but a few processes). Intracranial attentional filtering appears to play multiple roles, including clutter filtration at all levels of processing - thus, we process individual retinal cell responses, early filtering response, and so forth, on up to the filtering of objects at high levels of semantic complexity. Computationally, image compression techniques have progressed from emphasizing pixels, to considering regions of pixels as foci of computational interest. In more recent research, object-based compression has been investigated with varying rate-distortion performance and computational efficiency. Codecs have been developed for a wide variety of applications, although the majority of compression and decompression transforms continue to concentrate on region- and pixel-based processing, in part because of computational convenience. It is interesting to note that a growing body of research has emphasized the detection and representation of small features in relationship to their surrounding environment, which has occasionally been called semantic compression. In this paper, we overview different types of semantic compression approaches, with particular interest in high-level compression algorithms. Various algorithms and

  11. Compressing Binary Decision Diagrams

    CERN Document Server

    Hansen, Esben Rune; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances.

  12. Microbunching and RF Compression

    International Nuclear Information System (INIS)

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  13. Hyperspectral data compression

    CERN Document Server

    Motta, Giovanni; Storer, James A

    2006-01-01

    Provides a survey of results in the field of compression of remote sensed 3D data, with a particular interest in hyperspectral imagery. This work covers topics such as compression architecture, lossless compression, lossy techniques, and more. It also describes a lossless algorithm based on vector quantization.

  14. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  15. Compressible turbulent mixing: Effects of compressibility

    Science.gov (United States)

    Ni, Qionglin

    2016-04-01

    We studied by numerical simulations the effects of compressibility on passive scalar transport in stationary compressible turbulence. The turbulent Mach number varied from zero to unity. The difference in driven forcing was the magnitude ratio of compressive to solenoidal modes. In the inertial range, the scalar spectrum followed the k-5 /3 scaling and suffered negligible influence from the compressibility. The growth of the Mach number showed (1) a first reduction and second enhancement in the transfer of scalar flux; (2) an increase in the skewness and flatness of the scalar derivative and a decrease in the mixed skewness and flatness of the velocity-scalar derivatives; (3) a first stronger and second weaker intermittency of scalar relative to that of velocity; and (4) an increase in the intermittency parameter which measures the intermittency of scalar in the dissipative range. Furthermore, the growth of the compressive mode of forcing indicated (1) a decrease in the intermittency parameter and (2) less efficiency in enhancing scalar mixing. The visualization of scalar dissipation showed that, in the solenoidal-forced flow, the field was filled with the small-scale, highly convoluted structures, while in the compressive-forced flow, the field was exhibited as the regions dominated by the large-scale motions of rarefaction and compression.

  16. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Yunisrina Qismullah Yusuf

    2016-03-01

    Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education. To be considered for publication, the article should be presented in the following system: First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page. Second p age and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion. Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION 1.1 Subheading of the Content 1.1.1 Subheading of the Content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table. For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure. The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples:   Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press. Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www.teachingenglish.org

  17. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Yunisrina Qismullah Yusuf

    2014-09-01

    Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education.To be considered for publication, the article should be presented in the following system:First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page.Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion.Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1         INTRODUCTION1.1      Subheading of the content 1.1.1   Subheading of the content  For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table.For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure.The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press.Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www

  18. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Yunisrina Qismullah Yusuf

    2015-10-01

    Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education.To be considered for publication, the article should be presented in the following system:First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page.Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion.Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1         INTRODUCTION1.1      Subheading of the Content 1.1.1   Subheading of the Content  For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table.For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure.The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press.Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www

  19. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Yunisrina Qismullah Yusuf

    2015-03-01

    Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education. To be considered for publication, the article should be presented in the following system: First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page. Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion. Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION 1.1 Subheading of the content 1.1.1 Subheading of the content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table. For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure. The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Back Matter| 79 80 | STUDIES IN ENGLISH LANGUAGE AND EDUCATION, Volume 1, Number 1, March 2014 Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press. Internet source: Andrewes, S. (2003. Group work v

  20. Author Guidelines

    Directory of Open Access Journals (Sweden)

    Yunisrina Qismullah Yusuf

    2014-03-01

    Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education.To be considered for publication, the article should be presented in the following system:First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page.Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion.Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1         INTRODUCTION1.1      Subheading of the content 1.1.1   Subheading of the content  For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table.For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure.The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press.Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www

  1. 基于气体组成的天然气压缩因子计算方法%Calculation methods of natural gas compressibility factor based on the gas composition

    Institute of Scientific and Technical Information of China (English)

    梁光川; 左果

    2014-01-01

    天然气压缩因子 Z在天然气工程计算中是最重要的物性参数之一,其获取方法主要分为查Standing-Katz图法、实验法、状态方程计算法和经验公式法。前两种方法在使用上有很大的限制性,目前状态方程计算法和经验公式法的应用优势明显。对基于气体组成来求解压缩因子的AGA8-92DC、Piper-DAK、Piper-Mahmoud、Elsharkawy-DAK和Elsharkawy-Mahmoud方程进行了计算准确度评价。将这5个待评价的计算关系式写入Visual Basic 6.0,并使用113个酸性贫气压缩因子实测值对5个方程的计算值进行了对比分析。分析结果认为,对于低中压含碳贫气, AGA8-92DC方程的计算误差最小;对于低中压含硫含碳贫气,Piper-Mahmoud的计算误差较其他方程最小。此外还发现,当天然气温度升高时,5个方程的计算值误差较原来均有所减小。%Natural gas compressibility factor Z is one of the most important physical parame-ters in the natural gas engineering calculations , and the determining methods mainly include Standing-Katz chart method ,laboratory experiments method ,equations of state law method and the empirical formulas method .Due to the usage limitations of the former two methods ,the ap-plication advantages of equations of state law method and the empirical formulas method become increasingly evident .In this paper ,the calculation accuracy of equations that calculate compressi-bility factor based gas composition was evaluated .The equations include AGA8-92DC ,Piper-DAK ,Piper-Mahmoud ,Elsharkawy-DAK and Elsharkawy-Mahmoud .These five calculation for-mulas to be valuated were written into Visual Basic 6 .0 and 113 measured values of acidic lean gas compressibility factor were used to compare with the calculated values of these five formulas . The comparison indicates that firstly for the lean gas with carbon dioxide at low pressure or medi-um pressure ,the calculation error of AGA8-92DC is less

  2. Evolution of some Los Alamos flux compression programs

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, C.M.; Goforth, J.H.

    1996-12-31

    When we were approached to give a general discussion of some aspects of the Los Alamos flux compression program, we decided to present historical backgrounds of a few topics that have some relevance to programs that we very much In the forefront of activities going on today. Of some thirty abstracts collected at Los Alamos for this conference, ten of them dealt with electromagnetic acceleration of materials, notably the compression of heavy liners, and five dealt with plasma compression. Both of these topics have been under investigation, off and on, from the time a formal flux compression program was organized at Los Alamos. We decided that a short overview of work done In these areas would be of some interest. Some of the work described below has been discussed in Laboratory reports that, while referenced and available, are not readily accessible. For completeness, some previously published, accessible work Is also discussed but much more briefly. Perhaps the most striking thing about the early work In these two areas is how primitive much of it was when compared to the far more sophisticated, related activities of today. Another feature of these programs, actually for most programs, Is their cyclic nature. Their relevance and/or funding seems to come land go. Eventually, many of the older programs come back into favor. Activities Involving the dense plasma focus (DPF), about which some discussions will be given later, furnish a classic example of this kind, coming Into and then out of periods of heightened interest. We devote the next two sections of this paper to a review of our work In magnetic acceleration of solids and of plasma compression. A final section gives a survey of our work In which thin foils are imploded to produce intense quantities of son x-rays. The authors are well aware of much excellent work done elsewhere In all of these topics, but partly because of space limitations, have confined this discussion to work done at Los Alamos.

  3. Compression for leg wounds.

    Science.gov (United States)

    Partsch, H; Mortimer, P

    2015-08-01

    The main points in this scholarly review on the use of compression therapy in leg ulcers are the different modes of action of this treatment and the tools that are available including their practical applicability and use for self management. Due to its effect of counteracting gravity, compression is also suggested for ulcers with aetiologies that are not usually thought to require compression. The clinical evidence reported in ulcer-healing studies are discussed and some considerations are made relating to the cost-effectiveness of this management. In general, the failures of compression therapy are not caused by poor compression material but due to poor knowledge and application techniques of the care providers. Future studies comparing different compression devices should also report details concerning the compression material used and the pressure exerted. PMID:26094638

  4. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2015-01-01

    navigational queries directly on the compressed representation. We show that the new compression scheme achieves close to optimal worst-case compression, can compress exponentially better than DAG compression, is never much worse than DAG compression, and supports navigational queries in logarithmic time....

  5. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2013-01-01

    navigational queries directly on the compressed representation. We show that the new compression scheme achieves close to optimal worst-case compression, can compress exponentially better than DAG compression, is never much worse than DAG compression, and supports navigational queries in logarithmic time....

  6. Compressed Recollection As a Constituent of “Talk” As a Hypergenre

    Directory of Open Access Journals (Sweden)

    Olga Petrovna Kormazina

    2015-11-01

    Full Text Available The article is devoted to the speech genre "recollection" that is described as a constituent of the hypergenre "talk"; the last is viewed by the author as a complex genre unity associated with natural communication. It is a tradition in linguistics while describing the recollection to point to its typological features – narrative character, which presupposes long retention of initiative by one speaker and, consequently, the great extension of replicas. The author singles out the "compressed recollection" and defines it as a short ascertaining message about some fact of the past, which might be deployed into a complete narrative. The transcribed records of Primorsky Region inhabitants' live speech in situations of family and companion communication made the material for this research; in particular, talks of 20 informants aged from 11 to 85 were recorded in 2013-2015. The compressed recollection is characterized in three aspects. A semantic aspect indicates to its main proposition types: proposition of event, proposition of object, ascertaining proposition. A communicative-pragmatic aspect uncovers its main functions: illustration of the author's words, appeal to the collocutor's memory, introduction of a new thematic fragment, introduction of a new sub-theme including. A structuralillocutionary aspect focuses on the compressed recollection as initial and reaction replicas in the dialogue. The set of diverse features verifies the notion of compressed recollection as a constituent of the hypergenre "talk".

  7. Using compression to identify acronyms in text

    OpenAIRE

    Yeates, Stuart; Bainbridge, David; Witten, Ian H

    2000-01-01

    Text mining is about looking for patterns in natural language text, and may be defined as the process of analyzing text to extract information from it for particular purposes. In previous work, we claimed that compression is a key technology for text mining, and backed this up with a study that showed how particular kinds of lexical tokens---names, dates, locations, etc.---can be identified and located in running text, using compression models to provide the leverage necessary to distinguish ...

  8. Probability estimation and compression involving large alphabets

    OpenAIRE

    Santhanam, Narayana

    2006-01-01

    Many results in statistics and information theory are asymptotic in nature, with the implicit assumption that we operate in a regime where the data size is much larger than the alphabet size. In this dissertation, we will be concerned with large alphabets, namely alphabets for which the above assumption does not hold. We consider universal compression, i.e., compression when data statistics are unknown, and probability estimation involving data drawn from large alphabets. Both these problems ...

  9. Spinal marrow compression in Hodgkin's disease

    International Nuclear Information System (INIS)

    Spinal marrow compression caused by tumorous tissue growth in vertebrae, epidural fatty tissue with the involvement of the dura mater encephali was noted in 23 (1.4%) out of 1600 patients with Hodgkin disease. Most patients were subjected to chemo- and radiotherapy. Therapeutic efficacy depended on the duration of the compression syndrome. Prognosis for patients was determined not by the nature of neurological disturbances but by the course of disease

  10. High compressive resistance drainage geocomposites

    International Nuclear Information System (INIS)

    There are several typologies of drainage geocomposites available in the market which can be classified according to their structures as: cuspated, mono filaments, geonets and those products formed by the combination of a draining blanket with a series of mini-pipes. Each one of them has its own range of compressive resistances. There are applications, such as are the new cells of landfills or mines and roads or railways over large embankments, where the pressure exerted on the geocomposite exceeds the compressive resistance of the majority of these typologies. For all this applications, besides providing and adequate flow capacity, it must be ensured that the chosen typology is able to withstand the required loading without collapsing and guaranteeing an adequate factor of safety. This article will expose that, currently, the only typology of drainage geocomposites that can bear these loadings while maintaining its drainage properties is the tri-planar geonet. (Author)

  11. Compressed Sensing in Astronomy

    CERN Document Server

    Bobin, J; Ottensamer, R

    2008-01-01

    Recent advances in signal processing have focused on the use of sparse representations in various applications. A new field of interest based on sparsity has recently emerged: compressed sensing. This theory is a new sampling framework that provides an alternative to the well-known Shannon sampling theory. In this paper we investigate how compressed sensing (CS) can provide new insights into astronomical data compression and more generally how it paves the way for new conceptions in astronomical remote sensing. We first give a brief overview of the compressed sensing theory which provides very simple coding process with low computational cost, thus favoring its use for real-time applications often found on board space mission. We introduce a practical and effective recovery algorithm for decoding compressed data. In astronomy, physical prior information is often crucial for devising effective signal processing methods. We particularly point out that a CS-based compression scheme is flexible enough to account ...

  12. Celiac Artery Compression Syndrome

    Directory of Open Access Journals (Sweden)

    Mohammed Muqeetadnan

    2013-01-01

    Full Text Available Celiac artery compression syndrome is a rare disorder characterized by episodic abdominal pain and weight loss. It is the result of external compression of celiac artery by the median arcuate ligament. We present a case of celiac artery compression syndrome in a 57-year-old male with severe postprandial abdominal pain and 30-pound weight loss. The patient eventually responded well to surgical division of the median arcuate ligament by laparoscopy.

  13. Instruction-Steam Compression

    OpenAIRE

    Carrillo, Christian James

    2001-01-01

    This thesis presents formal elements of instruction-stream compression. We introduce notions of instruction representations, compressors and the general "patternization" function for representations to sequences. We further introduce the Lua-ISC language, an implementation of these elements. Instruction-stream compression algorithms are expressed, independently of the target architecture, in Lua-ISC. The language itself handles instruction decoding and encoding, patternization and compression...

  14. Weighted universal image compression

    OpenAIRE

    Effros, Michelle; Chou, Philip A.; Gray, Robert M.

    1999-01-01

    We describe a general coding strategy leading to a family of universal image compression systems designed to give good performance in applications where the statistics of the source to be compressed are not available at design time or vary over time or space. The basic approach considered uses a two-stage structure in which the single source code of traditional image compression systems is replaced with a family of codes designed to cover a large class of possible sources. To illustrate this ...

  15. Coeliac artery compression syndrome

    OpenAIRE

    OKTAY, Özgür; MEMİŞ, Ahmet; Parildar, Mustafa; Oran, İsmail

    2003-01-01

    Celiac artery compression syndrome, also called median arcuate ligament compression syndrome, causes gastrointestinal ischemia secondary to compression of the proximal portion of the celiac artery just beyond its origin by the median arcuate ligament of the diaphragm. This syndrome is frequently demonstrated on aortography performed in patients without complaints of intestinal angina. Isolated stenosis or even occlusion of the celiac artery is always compensated for by collateral circul...

  16. Wavelet image compression

    CERN Document Server

    Pearlman, William A

    2013-01-01

    This book explains the stages necessary to create a wavelet compression system for images and describes state-of-the-art systems used in image compression standards and current research. It starts with a high level discussion of the properties of the wavelet transform, especially the decomposition into multi-resolution subbands. It continues with an exposition of the null-zone, uniform quantization used in most subband coding systems and the optimal allocation of bitrate to the different subbands. Then the image compression systems of the FBI Fingerprint Compression Standard and the JPEG2000 S

  17. Growing concern following compression mammography.

    Science.gov (United States)

    van Netten, Johannes Pieter; Hoption Cann, Stephen; Thornton, Ian; Finegan, Rory

    2016-01-01

    A patient without clinical symptoms had a mammogram in October 2008. The procedure caused intense persistent pain, swelling and development of a haematoma following mediolateral left breast compression. Three months later, a 9×11 cm mass developed within the same region. Core biopsies showed a necrotizing high-grade ductal carcinoma, with a high mitotic index. Owing to its extensive size, the patient began chemotherapy followed by trastuzumab and later radiotherapy to obtain clear margins for a subsequent mastectomy. The mastectomy in October 2009 revealed an inflammatory carcinoma, with 2 of 3 nodes infiltrated by the tumour. The stage IIIC tumour, oestrogen and progesterone receptor negative, was highly HER2 positive. A recurrence led to further chemotherapy in February 2011. In July 2011, another recurrence was removed from the mastectomy scar. She died of progressive disease in 2012. In this article, we discuss the potential influence of compression on the natural history of the tumour. PMID:27581236

  18. Sparsity Averaging for Compressive Imaging

    CERN Document Server

    Carrillo, Rafael E; Van De Ville, Dimitri; Thiran, Jean-Philippe; Wiaux, Yves

    2012-01-01

    We propose a novel regularization method for sparse image reconstruction from compressive measurements. The approach relies on the conjecture that natural images exhibit strong average sparsity over multiple coherent frames. The associated reconstruction algorithm, based on an analysis prior and a reweighted $\\ell_1$ scheme, is dubbed Sparsity Averaging Reweighted Analysis (SARA). We test our prior and the associated algorithm through extensive numerical simulations for spread spectrum and Gaussian acquisition schemes suggested by the recent theory of compressed sensing with coherent and redundant dictionaries. Our results show that average sparsity outperforms state-of-the-art priors that promote sparsity in a single orthonormal basis or redundant frame, or that promote gradient sparsity. We also illustrate the performance of SARA in the context of Fourier imaging, for particular applications in astronomy and medicine.

  19. Large Eddy Simulation for Compressible Flows

    CERN Document Server

    Garnier, E; Sagaut, P

    2009-01-01

    Large Eddy Simulation (LES) of compressible flows is still a widely unexplored area of research. The authors, whose books are considered the most relevant monographs in this field, provide the reader with a comprehensive state-of-the-art presentation of the available LES theory and application. This book is a sequel to "Large Eddy Simulation for Incompressible Flows", as most of the research on LES for compressible flows is based on variable density extensions of models, methods and paradigms that were developed within the incompressible flow framework. The book addresses both the fundamentals and the practical industrial applications of LES in order to point out gaps in the theoretical framework as well as to bridge the gap between LES research and the growing need to use it in engineering modeling. After introducing the fundamentals on compressible turbulence and the LES governing equations, the mathematical framework for the filtering paradigm of LES for compressible flow equations is established. Instead ...

  20. Arabic Short Text Compression

    Directory of Open Access Journals (Sweden)

    Eman Omer

    2010-01-01

    Full Text Available Problem statement: Text compression permits representing a document by using less space. This is useful not only to save disk space, but more importantly, to save disk transfer and network transmission time. With the continues increase in the number of Arabic short text messages sent by mobile phones, the use of a suitable compression scheme would allow users to use more characters than the default value specified by the provider. The development of an efficient compression scheme to compress short Arabic texts is not a straight forward task. Approach: This study combined the benefits of pre-processing, entropy reduction through splitting files and hybrid dynamic coding: A new technique proposed in this study that uses the fact that Arabic texts have single case letters. Experimental tests had been performed on short Arabic texts and a comparison with the well known plain Huffman compression was made to measure the performance of the proposed schema for Arabic short text. Results: The proposed schema can achieve a compression ratio around 4.6 bits byte-1 for very short Arabic text sequences of 15 bytes and around 4 bits byte-1 for 50 bytes text sequences, using only 8 Kbytes overhead of memory. Conclusion: Furthermore, a reasonable compression ratio can be achieved using less than 0.4 KB of memory overhead. We recommended the use of proposed schema to compress small Arabic text with recourses limited.

  1. Image quality meter using compression

    International Nuclear Information System (INIS)

    This paper proposed a new technique to compressed image blockiness/blurriness in frequency domain through edge detection method by applying Fourier transform. In image processing, boundaries are characterized by edges and thus, edges are the problems of fundamental importance. The edges have to be identified and computed thoroughly in order to retrieve the complete illustration of the image. Our novel edge detection scheme for blockiness and blurriness shows improvement of 60 and 100 blocks for high frequency components respectively than any other detection technique. (author)

  2. Compression of digital holographic data: an overview

    Science.gov (United States)

    Dufaux, Frederic; Xing, Yafei; Pesquet-Popescu, Beatrice; Schelkens, Peter

    2015-09-01

    Holography has the potential to become the ultimate 3D experience. Nevertheless, in order to achieve practical working systems, major scientific and technological challenges have to be tackled. In particular, as digital holographic data represents a huge amount of information, the development of efficient compression techniques is a key component. This problem has gained significant attention by the research community during the last 10 years. Given that holograms have very different signal properties when compared to natural images and video sequences, existing compression techniques (e.g. JPEG or MPEG) remain suboptimal, calling for innovative compression solutions. In this paper, we will review and analyze past and on-going work for the compression of digital holographic data.

  3. Hygienic and microbiological influences exerted on natural water biotopes by algae and the growth of water plants. 2. Communication: improvement of the chemical and bacteriological water quality by the natural growth of aquatic plants (author's transl)

    Energy Technology Data Exchange (ETDEWEB)

    Graef, W.; Kersch, D.; Pawlofsky, C.M.

    1981-12-01

    For a natural pond, whose waters are used for recreational purposes (swimming) and are subject to waste water inflow, the biological purifying function of a zone overgrown with reeds and aquatic plants was ascertained by means of chemical and bacteriological water quality parameters. In the years from 1975 to 1980 the contents of ammonia, nitrites, nitrates, phosphates and chlorides as well as the colony counts (CFU/ml), the coli titres and the content of fruiting myxobacteria were determined from water samples, both during the lush-growth summer period and the low-growth winter season. The location of the 6 sampling points systematically extended from the sewage outlet via the tributary ditch, in front of and behind the natural growth zone as far as the swimming waters. The test series showed - that in the tributary ditch and especially during the passage through the upper water zone densely overgrown with aquatic plants, the proportion of degradable nitrogen compounds and phosphates is distinctly reduced beyond the extent of reduction by dilution processes, - that the colony counts in the effluent water as well as the content of E. coli and of the fruiting myxobacteria, which act as indirect faecal indicator, are also reduced considerably, - that the biological purifying of the vegetation zone is definitely higher in summer than during the low-growth winter months. From this the conclusion can be drawn that for maintaining and furthering an adequate water quality of recreational waters compromised by waste water, the preservation of the naturally growing aquatic plants both in the water itself and on the banks is absolutely necessary.

  4. Analysis of the Alternate Extrusion and Multiaxial Compression Process

    Directory of Open Access Journals (Sweden)

    Kwapisz M.

    2015-04-01

    Full Text Available The paper present the results of numerical simulations of the alternate indirect extrusion and multiaxial compression process, performed using commercial software designed for the thermomechanical analysis of plastic working processes, Forge 2009. The novel method of alternate indirect extrusion and multiaxial compression, proposed by the authors, is characterized by the occurrence of strain states in the material being plastically worked, which are similar to those occurring in the equal channel angular pressing and cyclic extrusion compression processes.

  5. Ulnar Nerve Compression at Guyon's Canal by an Arteriovenous Malformation

    OpenAIRE

    Kim, Sung Soo; Kim, Jae Hoon; Kang, Hee In; Lee, Seung Jin

    2009-01-01

    Guyon's canal at the wrist is not the common site of ulnar nerve compression. Ganglion, lipoma, anomalous tendon and muscles, trauma related to an occupation, arthritis, and carpal bone fracture can cause ulnar nerve compression at the wrist. However, ulnar nerve compression at Guyon's canal by vascular lesion is rare. Ulnar artery aneurysm, tortous ulnar artery, hemangioma, and thrombosis have been reported in the literature as vascular lesions. The authors experienced a case of ulnar nerve ...

  6. Nuclear data compression and reconstruction via discrete wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Ryong; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Discrete Wavelet Transforms (DWTs) are recent mathematics, and begin to be used in various fields. The wavelet transform can be used to compress the signal and image due to its inherent properties. We applied the wavelet transform compression and reconstruction to the neutron cross section data. Numerical tests illustrate that the signal compression using wavelet is very effective to reduce the data saving spaces. 7 refs., 4 figs., 3 tabs. (Author)

  7. Experimental research on the compressibility of stale waste

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongxing; XIE Qiang; ZHANG Jianhua; WEI Yongfa

    2003-01-01

    The compressibility of stale waste is studied based on the investigation into the composition and properties of stale waste in the Chongqing City. Stale waste sampled at a landfill closed for over 8 a was analyzed indoors for its natural density,natural water content, relative density, grain size distribution curve, uniformity coefficient and curvature coefficient. Indoor compression tests for the stale waste were performed to find out the void ratio and its dependence upon applied pressure,compressibility coefficient, constrained modulus and volume compressibility coefficient. From the experimental data, the curvature coefficient and the preconsolidation pressure of the stale waste were worked out. The results indicates that the stale waste is of high compressibility, which is different from the other kinds of common soil, and is underconsolidated soil. The measured compressibility parameters are applicable to settlement calculation of closed landfills.

  8. Critical Data Compression

    CERN Document Server

    Scoville, John

    2011-01-01

    A new approach to data compression is developed and applied to multimedia content. This method separates messages into components suitable for both lossless coding and 'lossy' or statistical coding techniques, compressing complex objects by separately encoding signals and noise. This is demonstrated by compressing the most significant bits of data exactly, since they are typically redundant and compressible, and either fitting a maximally likely noise function to the residual bits or compressing them using lossy methods. Upon decompression, the significant bits are decoded and added to a noise function, whether sampled from a noise model or decompressed from a lossy code. This results in compressed data similar to the original. For many test images, a two-part image code using JPEG2000 for lossy coding and PAQ8l for lossless coding produces less mean-squared error than an equal length of JPEG2000. Computer-generated images typically compress better using this method than through direct lossy coding, as do man...

  9. ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)

    Energy Technology Data Exchange (ETDEWEB)

    Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler

    2005-12-01

    The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity

  10. Natural Gas Transport

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2009-06-01

    Full Text Available This paper reviews the present and future on natural gas transportation options, from oil and gas fields to markets, including liquefied natural gas, gas pipeline, compressed natural gas, natural gas hydrates, and gas to liquids and the perspectives of using them in Colombia, since this is the main fuel alternative to supply the world in at least the next 50 years.

  11. Natural Gas Transport

    OpenAIRE

    Tomás Correa; Nelson Osorio

    2009-01-01

    This paper reviews the present and future on natural gas transportation options, from oil and gas fields to markets, including liquefied natural gas, gas pipeline, compressed natural gas, natural gas hydrates, and gas to liquids and the perspectives of using them in Colombia, since this is the main fuel alternative to supply the world in at least the next 50 years.

  12. Adiabatic reversible compression: a molecular view

    International Nuclear Information System (INIS)

    The adiabatic compression (or expansion) of an ideal gas has been analysed. Using the kinetic theory of gases the usual relation between temperature and volume is obtained, while textbooks follow a thermodynamic approach. In this way we show, once again, the agreement between a macroscopic view (thermodynamics) and a microscopic one (kinetic theory). (author)

  13. Spinal cord compression due to metastases

    International Nuclear Information System (INIS)

    A study of 20 patients with medullary compression syndrome due to lesions not related to the central nervous system is presented. Plain films of the spine and myelography are made to determine the level of osseous involvement, the level of the spinal block and to planning radiotherapy. (Author)

  14. ICER-3D Hyperspectral Image Compression Software

    Science.gov (United States)

    Xie, Hua; Kiely, Aaron; Klimesh, matthew; Aranki, Nazeeh

    2010-01-01

    Software has been developed to implement the ICER-3D algorithm. ICER-3D effects progressive, three-dimensional (3D), wavelet-based compression of hyperspectral images. If a compressed data stream is truncated, the progressive nature of the algorithm enables reconstruction of hyperspectral data at fidelity commensurate with the given data volume. The ICER-3D software is capable of providing either lossless or lossy compression, and incorporates an error-containment scheme to limit the effects of data loss during transmission. The compression algorithm, which was derived from the ICER image compression algorithm, includes wavelet-transform, context-modeling, and entropy coding subalgorithms. The 3D wavelet decomposition structure used by ICER-3D exploits correlations in all three dimensions of sets of hyperspectral image data, while facilitating elimination of spectral ringing artifacts, using a technique summarized in "Improving 3D Wavelet-Based Compression of Spectral Images" (NPO-41381), NASA Tech Briefs, Vol. 33, No. 3 (March 2009), page 7a. Correlation is further exploited by a context-modeling subalgorithm, which exploits spectral dependencies in the wavelet-transformed hyperspectral data, using an algorithm that is summarized in "Context Modeler for Wavelet Compression of Hyperspectral Images" (NPO-43239), which follows this article. An important feature of ICER-3D is a scheme for limiting the adverse effects of loss of data during transmission. In this scheme, as in the similar scheme used by ICER, the spatial-frequency domain is partitioned into rectangular error-containment regions. In ICER-3D, the partitions extend through all the wavelength bands. The data in each partition are compressed independently of those in the other partitions, so that loss or corruption of data from any partition does not affect the other partitions. Furthermore, because compression is progressive within each partition, when data are lost, any data from that partition received

  15. SIMULACIÓN HORARIA DE UN SISTEMA DE REFRIGERACIÓN COMBINADO EYECTOR-COMPRESIÓN DE VAPOR ASISTIDO POR ENERGÍA SOLAR Y GAS NATURAL HOURLY SIMULATION OF A COMBINED EJECTOR-VAPOR COMPRESSION REFRIGERATION SYSTEM ASSISTED BY SOLAR ENERGY AND NATURAL GAS

    Directory of Open Access Journals (Sweden)

    Humberto Vidal

    2009-04-01

    double stage ejector cooling cycle assisted by solar energy system appears as an attractive solution to this problem. The first stage is performed by a mechanical compression cycle with R-134a as the working fluid, while the second stage is performed by a thermally driven ejector cycle with R-141b. Flat plate collectors and an auxiliary energy burner provide heat to the ejector cycle. This paper describes the hourly simulation of a combined ejector-vapor compression refrigeration system assisted by solar energy and natural gas. The combined solar refrigeration system is modeled using the TRNSYS-EES simulation tool and the typical meteorological year data containing the weather data of Florianópolis Brazil. The results obtained from the computational simulation performed in this system show that the combined ejector-vapor compression cooling cycle is more advantageous than the simple ejector cooling cycle. Finally, the computational model developed in this paper might be used to perform a thermo-economical optimization of the system in future works.

  16. Focus on Compression Stockings

    Science.gov (United States)

    ... therapy may be recommended as part of a treatment plan. There are several situations when compression may be helpful, including: tired legs, varicose veins, chronic venous insufficiency (CVI), lymphedema, or deep vein thrombosis (DVT). This brochure focuses ...

  17. Fingerprint Image Compression

    OpenAIRE

    Mansi Kambli,; Shalini Bhatia

    2010-01-01

    Modified Set Partitioning in Hierarchical Tree with Run Length Encoding is a new framework proposed for fingerprint image compression. The Proposed method is better because more number of images related to the fingerprint image are retrieved. Experiments on an image database of grayscale bitmap images show that the proposed technique performs well in compression and decompression. We use Peak Signal to noise ratio [3] and Mean Square Error [3] to compute the picture quality of fingerprint ima...

  18. Compressibility of bilayer graphene

    OpenAIRE

    Borghi, Giovanni; Polini, Marco; Asgari, Reza; MacDonald, A. H.

    2010-01-01

    Bilayer graphene is a recently isolated and intriguing class of many-body systems with massive chiral quasiparticles. We present theoretical results for the electronic compressibility of bilayer graphene that are based on a four-band continuum band structure model combined with a random phase approximation treatment of electronic correlations. We find that the compressibility is strongly suppressed by electron-electron interactions at low carrier densities. Correlations do not lead to any qua...

  19. The compressibility of graphene

    OpenAIRE

    Abergel, D. S. L.

    2012-01-01

    We present a review of the electronic compressibility of monolayer and bilayer graphene. We focus on describing theoretical calculations of the effects of electron--electron interactions and various types of disorder, and also give a summary of current experiments and describe which aspects of theory they support. We also include a full analysis of all commonly-used contributions to the tight-binding Hamiltonian of bilayer graphene and their effects on the compressibility.

  20. Operational experience of compressed air system for large accelerator complex

    International Nuclear Information System (INIS)

    Operation of various devices in Indus-1 and Indus-2 synchrotron radiation sources requires uninterrupted supply of instrument quality compressed air. For this purpose, a centralised compressed air system was commissioned in May 2005 and is operational on round the clock basis. Instrumentation was done for air quality monitoring at various stages of distribution. Availability and reliability of the system was analysed based on the failure data. In year 2008, compressed air system was upgraded to improve the reliability. In this paper, we present design philosophy, fabrication, installation, instrumentation, testing and availability of the compressed air system in Indus complex. (author)

  1. Refrigeration Carnot-type cycle based on isothermal vapour compression

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, F. [Laboratoire du Froid EA 21, Cnam-IFFI, 292 rue Saint-Martin (France)

    2006-01-01

    A refrigeration Carnot-type cycle based on isothermal compression and two reversible expansions is proposed. Although ideal, this cycle is close to a realistic one which could be designed with existing hardware. (author)

  2. Reply of the authors

    Institute of Scientific and Technical Information of China (English)

    Hossein AFZALIMEHR; Jueyi SUI; Razieh MOGHBEL

    2011-01-01

    The words of "wall" and "bank" have been used interactively in our past research works.However,to our knowledge,few published studies used natural vegetation cover along the flume walls.From hydraulic point of view,the description of flow characteristics is more important than the species of wall vegetation in a preliminary research study.The authors found that,if the same vegetation cover of natural channel is used as vegetation cover on the flume walls,it will result considerable noise and anomalies in capturing data by ADV.So,for this primary research,it has been decided to use the uniform specie as wall vegetation in this experimental study.

  3. Sensitivity and specificity of MR imaging in detecting cord compression from vertebral metastases and distinguishing malignant from benign compression fractures

    International Nuclear Information System (INIS)

    The authors reviewed 71 MR imaging studies in 65 patients with known primary neoplasms who were referred for evaluation of possible spinal cord compression. With myelography as the reference standard, the sensitivity and specificity of MR imaging were 100% and 66%, respectively. The intensity ratios of collapsed versus ''normal'' adjacent vertebral bodies were also calculated in 49 malignant and 11 benign collapsed vertebrae. The sensitivity and specificity of MR imaging in distinguishing malignant from benign compression fractures were 97% and 100%, respectively. They conclude that MR imaging is highly sensitive in detecting cord compression from vertebral metastases and is also highly specific in distinguishing malignant from benign compression fractures

  4. Natural frequency of a circular cylindrical shell filled with fluid

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyeong Hoon; Kim, Tae Wan; Kim, Kang Soo; Park, Keun Bae [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-08-01

    This report presents an analytical method for evaluating the free vibration of a circular cylindrical shell filled with bounded compressible fluid. The analytical method was developed by means of the finite Fourier series expansion method. The compressible fluid motion was determined by means of the linear velocity potential theory. To clarify the validity of the analytical method, the natural frequencies of a circular cylindrical shell with the clamped-clamped boundary condition, and filled with water, were obtained by the analytical method and the finite element method using a commercial ANSYS 5.2 software. Excellent agreement on the natural frequencies of the fluid-filled shell structure was found. The compressibility and density of fluid effects the normalized coupled natural frequencies were investigated. The density of fluid affects on all coupled natural frequencies of the shell,, whereas the compressibility and bounding of fluid affects mainly on the natural frequencies of lower circumferential modes. The theory developed in this report will be applicable to the dynamic analysis of a core support barrel in SMART integral reactor filled with coolant. (author). 15 refs., 14 figs., 1 tab.

  5. A Texas natural gas model

    International Nuclear Information System (INIS)

    The Railroad Commission of Texas, through its Gas Services Division, is responsible for the safety and economic regulation of natural gas downstream of the wellhead, including the gathering, processing, storage, transmission and distribution of natural gas. This responsibility requires an understanding of the movement of natural gas in Texas, which was the objective of a recently completed project of the Gas Services Division. The authors goal was to trace a molecule of gas from wellhead to burner tip and identify the incremental value added by each of the components along the path. The authors developed a Texas Natural Gas Model that relates the components of the path so that flow within individual segments of the industry, or between segments of the industry, can be analyzed. The Model links information on wellhead production and prices, marketing costs (reflecting gathering, processing, and compression), transmission costs, and end user consumption and costs. End user information is presented for the primary Texas local distribution companies (LDC) and electric utilities, as well as on an aggregate basis for industrial consumption. LDC costs are further subdivided into the city gate gas costs and average delivered cost to the residential, commercial and industrial sectors. The Model also quantifies by pipeline the significant amount of gas that leaves the state through the interstate pipeline system. The Texas Natural Gas Model provides a comprehensive volume and value balance of the natural gas system within Texas, recognizing the relationship between all segments of the industry

  6. Hydrodynamics compression in inertial confinement fusion (ICF) plasma

    International Nuclear Information System (INIS)

    The hydrodynamics compression in ICF plasma has been theoretically studied using conservation equations. The study is based on single fluid plasma model. A comparison is made between shock and adiabatic compression. It seems that the amount of energy required to compress the fusion fuel by same factor is greater for strong shocks but is nearly same for weak shocks in comparison with the adiabatic compression. It can be inferred as conclusion that weak shocks are appropriate for compression in ICF. The ratio of pressure, density and temperature are obtained in terms of shock speed, i.e., in terms of mach numbers. The limitation of achievable density of fuel in shock is calculated beyond which there is expansion rather than compression. (author)

  7. Magnetic resonance imaging of vertebral compression fractures

    International Nuclear Information System (INIS)

    Magnetic resonance (MR) imaging was performed on 112 patients with 210 vertebral compression fractures. Forty fractures were due to malignancy; 170 were caused by benign process. Pathological fractures showed low signal intensity (SI) on T1 weighted image (WI) and various SI on T2 WI. In 39 of the 40 fractures caused by malignancy, MRI showed complete replacement of normal bone marrow. Other findings of pathological fractures, such as involvement of posterior structures, paraspinal soft tissue masses, are useful for discrimination between benign and pathologic compression fractures. In 120 of the 157 fractures caused osteoporosis had complete preservation of normal bone marrow and isointense or high intense marrow SI on T1 WI and T2 WI. Compression fractures caused by trauma showed low SI on T1 WI and high SI on T2 WI with an irregular pattern. We suppose MRI may be a useful modality in differenciating benign and metastatic fractures. (author)

  8. Graph Compression by BFS

    Directory of Open Access Journals (Sweden)

    Alberto Apostolico

    2009-08-01

    Full Text Available The Web Graph is a large-scale graph that does not fit in main memory, so that lossless compression methods have been proposed for it. This paper introduces a compression scheme that combines efficient storage with fast retrieval for the information in a node. The scheme exploits the properties of the Web Graph without assuming an ordering of the URLs, so that it may be applied to more general graphs. Tests on some datasets of use achieve space savings of about 10% over existing methods.

  9. The compressed word problem for groups

    CERN Document Server

    Lohrey, Markus

    2014-01-01

    The Compressed Word Problem for Groups provides a detailed exposition of known results on the compressed word problem, emphasizing efficient algorithms for the compressed word problem in various groups. The author presents the necessary background along with the most recent results on the compressed word problem to create a cohesive self-contained book accessible to computer scientists as well as mathematicians. Readers will quickly reach the frontier of current research which makes the book especially appealing for students looking for a currently active research topic at the intersection of group theory and computer science. The word problem introduced in 1910 by Max Dehn is one of the most important decision problems in group theory. For many groups, highly efficient algorithms for the word problem exist. In recent years, a new technique based on data compression for providing more efficient algorithms for word problems, has been developed, by representing long words over group generators in a compres...

  10. Virtually Lossless Compression of Astrophysical Images

    Directory of Open Access Journals (Sweden)

    Stefano Baronti

    2005-09-01

    Full Text Available We describe an image compression strategy potentially capable of preserving the scientific quality of astrophysical data, simultaneously allowing a consistent bandwidth reduction to be achieved. Unlike strictly lossless techniques, by which moderate compression ratios are attainable, and conventional lossy techniques, in which the mean square error of the decoded data is globally controlled by users, near-lossless methods are capable of locally constraining the maximum absolute error, based on user's requirements. An advanced lossless/near-lossless differential pulse code modulation (DPCM scheme, recently introduced by the authors and relying on a causal spatial prediction, is adjusted to the specific characteristics of astrophysical image data (high radiometric resolution, generally low noise, etc.. The background noise is preliminarily estimated to drive the quantization stage for high quality, which is the primary concern in most of astrophysical applications. Extensive experimental results of lossless, near-lossless, and lossy compression of astrophysical images acquired by the Hubble space telescope show the advantages of the proposed method compared to standard techniques like JPEG-LS and JPEG2000. Eventually, the rationale of virtually lossless compression, that is, a noise-adjusted lossles/near-lossless compression, is highlighted and found to be in accordance with concepts well established for the astronomers' community.

  11. Image compression in local helioseismology

    CERN Document Server

    Löptien, Björn; Gizon, Laurent; Schou, Jesper

    2014-01-01

    Context. Several upcoming helioseismology space missions are very limited in telemetry and will have to perform extensive data compression. This requires the development of new methods of data compression. Aims. We give an overview of the influence of lossy data compression on local helioseismology. We investigate the effects of several lossy compression methods (quantization, JPEG compression, and smoothing and subsampling) on power spectra and time-distance measurements of supergranulation flows at disk center. Methods. We applied different compression methods to tracked and remapped Dopplergrams obtained by the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory. We determined the signal-to-noise ratio of the travel times computed from the compressed data as a function of the compression efficiency. Results. The basic helioseismic measurements that we consider are very robust to lossy data compression. Even if only the sign of the velocity is used, time-distance helioseismology is still...

  12. Guidelines for Authors

    Directory of Open Access Journals (Sweden)

    Abdullah Demir

    2016-06-01

    Full Text Available Guidelines for Authors cumhuriyet theology journal  reguires writers to use the The Chicago Manual of Style “notes and bibliography” system of referencing.First citation: author(s first name and last name, title, (if applicable first and last name of translator or editor, place of publication, publisher, date of publication, page number.Subsequent citations: author’s last name, the short title, and the page number should be indicated in all subsequent citations. Footnote citations should conform to the following examples.References: References should be placed at the end of the text in alphabetical order. If a source has more than one author, the surname and name of the first author should be written, and the other authors should be indicated by et.al. The titles of books and journals should be italicized; article titles and book chapters should be placed in quotation marks. Translator’s and editor’s names (if there are any should follow the title of the work: BOOKa One Author: 
1. Michael Pollan, The Omnivore’s Dilemma: A Natural History of Four Meals (New York: Penguin, 2006, 99–100.2. Pollan, Omnivore’s Dilemma, 3.Bibliography: Pollan, Michael. The Omnivore’s Dilemma: A Natural History of Four Meals. New York: Penguin, 2006.  b Two Authors1. Geoffrey C. Ward and Ken Burns, The War: An Intimate History 1941–1945 (New York: Knopf, 2007, 52.2. Ward and Burns, War, 59–61. Bibliography: Ward, Geoffrey C., and Ken Burns. The War: An Intimate History 1941–1945. New York: Knopf, 2007.c Three or More Authors
For three or more authors, list all of the authors in the bibliography; in the note, list only the first author, followed by et al. (“and others”:1. Mitchell L. Eisen, Jodi A. Quas, and Gail S. Goodman, eds., Memory and Suggestibility in the Forensic Interview (Mahwah, NJ: L. Erlbaum Assoicates, 2002, 65.2. Eisen and et al., Memory and Suggestibility in the Forensic Interview, 67.Bibliography: Eisen, Mitchell

  13. Compressive creep of simulated burnup fuel

    International Nuclear Information System (INIS)

    In order to study the nitride fuel mechanical properties, we measured the compressive steady state creep rates of uranium mononitride (UN) and UN containing neodymium which was simulated burnup fuel. The stress exponent n'' and the apparent activation energy ''Q'' of the creep rate were determined in the range of 27.5 ≤ σ ≤ 200.0 MPa and 950 ≤ T ≤ 1500 degC. (author)

  14. A singular limit for compressible rotating fluids

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Gallagher, I.; Novotný, A.

    2012-01-01

    Roč. 44, č. 1 (2012), s. 192-205. ISSN 0036-1410 R&D Projects: GA ČR GA201/08/0315 Institutional research plan: CEZ:AV0Z10190503 Keywords : rotating fluid * low Rossby and Mach number * compressible fluid Subject RIV: BA - General Mathematics Impact factor: 1.573, year: 2012 http://epubs.siam.org/sima/resource/1/sjmaah/v44/i1/p192_s1?isAuthorized=no

  15. Data Compression for Helioseismology

    Science.gov (United States)

    Löptien, Björn

    2015-10-01

    Efficient data compression will play an important role for several upcoming and planned space missions involving helioseismology, such as Solar Orbiter. Solar Orbiter, to be launched in October 2018, will be the next space mission involving helioseismology. The main characteristic of Solar Orbiter lies in its orbit. The spacecraft will have an inclined solar orbit, reaching a solar latitude of up to 33 deg. This will allow, for the first time, probing the solar poles using local helioseismology. In addition, combined observations of Solar Orbiter and another helioseismic instrument will be used to study the deep interior of the Sun using stereoscopic helioseismology. The Doppler velocity and continuum intensity images of the Sun required for helioseismology will be provided by the Polarimetric and Helioseismic Imager (PHI). Major constraints for helioseismology with Solar Orbiter are the low telemetry and the (probably) short observing time. In addition, helioseismology of the solar poles requires observations close to the solar limb, even from the inclined orbit of Solar Orbiter. This gives rise to systematic errors. In this thesis, I derived a first estimate of the impact of lossy data compression on helioseismology. I put special emphasis on the Solar Orbiter mission, but my results are applicable to other planned missions as well. First, I studied the performance of PHI for helioseismology. Based on simulations of solar surface convection and a model of the PHI instrument, I generated a six-hour time-series of synthetic Doppler velocity images with the same properties as expected for PHI. Here, I focused on the impact of the point spread function, the spacecraft jitter, and of the photon noise level. The derived power spectra of solar oscillations suggest that PHI will be suitable for helioseismology. The low telemetry of Solar Orbiter requires extensive compression of the helioseismic data obtained by PHI. I evaluated the influence of data compression using

  16. Digital cinema video compression

    Science.gov (United States)

    Husak, Walter

    2003-05-01

    The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.

  17. Advances in data compression

    Science.gov (United States)

    Davisson, L. D.; Gray, R. M.

    1975-01-01

    A rigorous real-variables treatment of general data compression and encoding problems, centered on formulation and proof of relevant existence theorems and a unified formulation of source coding (both noiseless and with a fidelity criterion) in inaccurately or incompletely specified statistical environments. Difficulties in modeling of sources with unknown or imperfectly known statistical descriptions are analyzed and source codes (SC) are classified (variable-rate noiseless SC, fixed-rate noiseless SC) and analyzed, along with types of code sequences (weighted-universal, maximin-universal, strongly or weakly minimax-universal). Universal coding on video data, variable-rate coding with distortion, and distortion-rate functions are discussed. Design strategies for universal coding algorithms are suggested, but the article is not oriented to specific methods of synthesizing data compression systems.

  18. Compressible motion fields

    OpenAIRE

    Ottaviano, Giuseppe; Kohli, Pushmeet

    2013-01-01

    Traditional video compression methods obtain a compact representation for image frames by computing coarse motion fields defined on patches of pixels called blocks, in order to compensate for the motion in the scene across frames. This piecewise constant approximation makes the motion field efficiently encodable, but it introduces block artifacts in the warped image frame. In this paper, we address the problem of estimating dense motion fields that, while accurately predicting one frame from ...

  19. Compressibility of solids

    Science.gov (United States)

    Vinet, P.; Ferrante, J.; Rose, J. H.; Smith, J. R.

    1987-01-01

    A universal form is proposed for the equation of state (EOS) of solids. Good agreement is found for a variety of test data. The form of the EOS is used to suggest a method of data analysis, which is applied to materials of geophysical interest. The isothermal bulk modulus is discussed as a function of the volume and of the pressure. The isothermal compression curves for materials of geophysical interest are examined.

  20. Compression-based similarity

    OpenAIRE

    Vitányi, Paul

    2011-01-01

    First we consider pair-wise distances for literal objects consisting of finite binary files. These files are taken to contain all of their meaning, like genomes or books. The distances are based on compression of the objects concerned, normalized, and can be viewed as similarity distances. Second, we consider pair-wise distances between names of objects, like "red" or "christianity." In this case the distances are based on searches of the Internet. Such a search can be performed by any search...

  1. Compressibility of graphene

    OpenAIRE

    Abergel, D. S. L.; Hwang, E. H.; Sarma, S. Das

    2010-01-01

    We develop a theory for the compressibility and quantum capacitance of disordered monolayer and bilayer graphene including the full hyperbolic band structure and band gap in the latter case. We include the effects of disorder in our theory, which are of particular importance at the carrier densities near the Dirac point. We account for this disorder statistically using two different averaging procedures: first via averaging over the density of carriers directly, and then via averaging in the ...

  2. Economic Modeling of Compressed Air Energy Storage

    OpenAIRE

    Rui Bo; Ming Ni; Yang Gu; James McCalley

    2013-01-01

    Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES) in systems with large-scale wind power generation. The co-optimizatio...

  3. Restricted Conformal Property of Compressive Sensing

    OpenAIRE

    Cheng, Tao

    2014-01-01

    Energy and direction are tow basic properties of a vector. A discrete signal is a vector in nature. RIP of compressive sensing can not show the direction information of a signal but show the energy information of a signal. Hence, RIP is not complete. Orthogonal matrices can preserve angles and lengths. Preservation of length can show energies of signals like RIP do; and preservation of angle can show directions of signals. Therefore, Restricted Conformal Property (RCP) is proposed according t...

  4. Compressed random access memory

    CERN Document Server

    Jansson, Jesper; Sung, Wing-Kin

    2010-01-01

    Motivated by applications which need to store huge amounts of data in the main memory of a computer, this paper proposes a new dynamic data-structure for compressed random access memory. Ferragina and Venturini [SODA 2007, TCS 2007] recently gave a compressed data-structure for storing a string that allows substrings to be retrieved efficiently, but it requires the string to be static. Here, we extend their results in a non-trivial way to also allow the stored compressed string to be modified during execution. Our results are as follows. A memory (or string) $T[1..n]$, where each character $T[i]$ is of $\\log\\sigma$ bits, can be stored in $n H_k(T) + O(n \\log \\sigma \\frac{(k+1) (\\log \\sigma +\\log \\log n)}{\\log n})$ bits, where $H_k(T)$ is the $k$-th order empirical entropy of $T$, such that (1) accessing $T[i..j]$ takes optimal $O(1 + (j-i) / \\log_{\\sigma} n)$ time and (2) replacing $T[i..i+\\log_{\\sigma} n - 1]$ by another string of length $\\log_{\\sigma} n$ takes $O(\\log n/\\log\\log n)$ time. We can also suppor...

  5. Compressed sensing electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Leary, Rowan, E-mail: rkl26@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Saghi, Zineb; Midgley, Paul A. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Holland, Daniel J. [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom)

    2013-08-15

    The recent mathematical concept of compressed sensing (CS) asserts that a small number of well-chosen measurements can suffice to reconstruct signals that are amenable to sparse or compressible representation. In addition to powerful theoretical results, the principles of CS are being exploited increasingly across a range of experiments to yield substantial performance gains relative to conventional approaches. In this work we describe the application of CS to electron tomography (ET) reconstruction and demonstrate the efficacy of CS–ET with several example studies. Artefacts present in conventional ET reconstructions such as streaking, blurring of object boundaries and elongation are markedly reduced, and robust reconstruction is shown to be possible from far fewer projections than are normally used. The CS–ET approach enables more reliable quantitative analysis of the reconstructions as well as novel 3D studies from extremely limited data. - Highlights: • Compressed sensing (CS) theory and its application to electron tomography (ET) is described. • The practical implementation of CS–ET is outlined and its efficacy demonstrated with examples. • High fidelity tomographic reconstruction is possible from a small number of images. • The CS–ET reconstructions can be more reliably segmented and analysed quantitatively. • CS–ET is applicable to different image content by choice of an appropriate sparsifying transform.

  6. Compression of Cake

    Science.gov (United States)

    Nason, Sarah; Houghton, Brittany; Renfro, Timothy

    2012-03-01

    The fall university physics class, at McMurry University, created a compression modulus experiment that even high school students could do. The class came up with this idea after a Young's modulus experiment which involved stretching wire. A question was raised of what would happen if we compressed something else? We created our own Young's modulus experiment, but in a more entertaining way. The experiment involves measuring the height of a cake both before and after a weight has been applied to the cake. We worked to derive the compression modulus by applying weight to a cake. In the end, we had our experimental cake and, ate it too! To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.TSS.B1.1 APS Home | APS Meetings | Join APS | Help | Contact APS Meetings var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try var pageTracker = gat.getTracker("UA-324916-13"); pageTracker.trackPageview(); catch(err)

  7. Compressibility of municipal solid waste codisposed with fly ash.

    Science.gov (United States)

    Park, Hyun Il; Lee, Seung Rae

    2005-03-01

    If a municipal solid waste (MSW) landfill is used as the foundation for a construction site, the change in the loading conditions may cause considerable compression of the landfill. Therefore, reinforcement to compensate for the loose compression nature of a MSW landfill is a very important design factor for geotechnical engineers when considering the end-use of the landfill. In this study, we discuss a possible technique for stabilizing MSW landfills through the codisposal of municipal solid waste and fly ash. To estimate the stabilization based on the compression characteristics of the codisposed landfill, we performed tests using a large compression set and experimental cells. According to the test results, if the proportion of fly ash is increased, initial and long-term compression could be reduced. PMID:15828670

  8. Ultraspectral sounder data compression review

    Institute of Scientific and Technical Information of China (English)

    Bormin HUANG; Hunglung HUANG

    2008-01-01

    Ultraspectral sounders provide an enormous amount of measurements to advance our knowledge of weather and climate applications. The use of robust data compression techniques will be beneficial for ultraspectral data transfer and archiving. This paper reviews the progress in lossless compression of ultra-spectral sounder data. Various transform-based, pre-diction-based, and clustering-based compression methods are covered. Also studied is a preprocessing scheme for data reordering to improve compression gains. All the coding experiments are performed on the ultraspectral compression benchmark dataset col-lected from the NASA Atmospheric Infrared Sounder (AIRS) observations.

  9. Compressed clay and its applications. Stampflehm und seine Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    Minke, G.

    1985-01-01

    This is the second book in a series books on the subject of building with clay. It contains contributions from various authors on research and practice of building with compressed clay. Building with compressed clay is a technique with a rich tradition, but which has sunk largely into oblivion in the 20th century. It was not until new machinery for working it that it again became economically interesting. Compressed clay is a useful material for walls, ceilings and floors. Stoves and furnances can also be built with it. The book also contains a list of historic clay buildings in Lower Saxony, Hamburg and Bremen. (BWI).

  10. Analysis of the Alternate Extrusion and Multiaxial Compression Process

    OpenAIRE

    Kwapisz M.; Knapiński M.; Dyja H.; Kawałek A.

    2015-01-01

    The paper present the results of numerical simulations of the alternate indirect extrusion and multiaxial compression process, performed using commercial software designed for the thermomechanical analysis of plastic working processes, Forge 2009. The novel method of alternate indirect extrusion and multiaxial compression, proposed by the authors, is characterized by the occurrence of strain states in the material being plastically worked, which are similar to those occurring in the equal cha...

  11. Equations of state in soil compression based on statistical mechanics

    OpenAIRE

    González Tejada, Ignacio; Jimenez Rodriguez, Rafael

    2010-01-01

    The authors have published a very interesting contribution in which they present a new and general relationship between void ratio and overburden pressure in the compression process of soils. The study is based on the law of interparticle energy distribution used in statistical mechanics and, in particular, the compression process of a soil is described according to its initial and final void ratios, and to a parameter /? which is related to the potential energy of a soil element. Such p...

  12. Compression Aware Physical Database Design

    CERN Document Server

    Kimura, Hideaki; Syamala, Manoj

    2011-01-01

    Modern RDBMSs support the ability to compress data using methods such as null suppression and dictionary encoding. Data compression offers the promise of significantly reducing storage requirements and improving I/O performance for decision support queries. However, compression can also slow down update and query performance due to the CPU costs of compression and decompression. In this paper, we study how data compression affects choice of appropriate physical database design, such as indexes, for a given workload. We observe that approaches that decouple the decision of whether or not to choose an index from whether or not to compress the index can result in poor solutions. Thus, we focus on the novel problem of integrating compression into physical database design in a scalable manner. We have implemented our techniques by modifying Microsoft SQL Server and the Database Engine Tuning Advisor (DTA) physical design tool. Our techniques are general and are potentially applicable to DBMSs that support other co...

  13. Bunch compression for an FEL at NLCTA

    International Nuclear Information System (INIS)

    As part of the design effort for a free electron laser driven by the Next Linear Collider Test Accelerator (NLCTA), the author reports studies of bunch-length compression utilizing the existing infrastructure and hardware. In one possible version of the NLCTA FEL, bunches with 900-microm FWHM length, generated by an S-band photo-injector, would be compressed to an rms length of 60--120 microm before entering the FEL undulator. It is shown that, using the present magnetic chicane, the bunch compression is essentially straightforward, and that almost all emittance-diluting effects, e.g. wakefields, chromaticity, or space charge in the bending magnets, are small. The only exception to this finding is the predicted increase of the horizontal emittance due to coherent synchrotron radiation (CSR). Estimates based on existing theories of coherent synchrotron radiation suggest a tripling or quadrupling of the initial emittance, which seems to preclude bunch compression during regular FEL operation. Serendipitously, the magnitude of the predicted emittance growth would, on the other hand, make the NLCTA chicane an excellent tool for measuring the effects of coherent synchrotron radiation. This will be of considerable interest to many future projects, in particular to the Linac Coherent Light Source (LCLS). As an aside, it is shown that coherent synchrotron radiation in a bending magnet gives rise to a minimum possible bunch length, which is very reminiscent of the Oide limit on the vertical spot size at the interaction point of a linear collider

  14. Performance evaluation of breast image compression techniques

    International Nuclear Information System (INIS)

    Novel diagnosis orienting tele working systems manipulate, store, and process medical data through real time communication - conferencing schemes. One of the most important factors affecting the performance of these systems is image handling. Compression algorithms can be applied to the medical images, in order to minimize : a) the volume of data to be stored in the database, b) the demanded bandwidth from the network, c) the transmission costs, and to minimize the speed of the transmitted data. In this paper an estimation of all the factors of the process that affect the presentation of breast images is made, from the time the images are produced from a modality, till the compressed images are stored, or transmitted in a Broadband network (e.g. B-ISDN). The images used were scanned images of the TOR(MAX) Leeds breast phantom, as well as typical breast images. A comparison of seven compression techniques has been done, based on objective criteria such as Mean Square Error (MSE), resolution, contrast, etc. The user can choose the appropriate compression ratio in order to achieve the desired image quality. (authors)

  15. A hyperspectral image compression algorithm based on wavelet transformation and fractal composition (AWFC)

    Institute of Scientific and Technical Information of China (English)

    HU; Xingtang; ZHANG; Bing; ZHANG; Xia; ZHENG; Lanfen; TONG; Qingxi

    2006-01-01

    Starting with a fractal-based image-compression algorithm based on wavelet transformation for hyperspectral images, the authors were able to obtain more spectral bands with the help of of hyperspectral remote sensing. Because large amounts of data and limited bandwidth complicate the storage and transmission of data measured by TB-level bits, it is important to compress image data acquired by hyperspectral sensors such as MODIS, PHI, and OMIS; otherwise, conventional lossless compression algorithms cannot reach adequate compression ratios. Other loss-compression methods can reach high compression ratios but lack good image fidelity, especially for hyperspectral image data. Among the third generation of image compression algorithms, fractal image compression based on wavelet transformation is superior to traditional compression methods,because it has high compression ratios and good image fidelity, and requires less computing time. To keep the spectral dimension invariable, the authors compared the results of two compression algorithms based on the storage-file structures of BSQ and of BIP, and improved the HV and Quadtree partitioning and domain-range matching algorithms in order to accelerate their encode/decode efficiency. The authors' Hyperspectral Image Process and Analysis System (HIPAS) software used a VC++6.0 integrated development environment (IDE), with which good experimental results were obtained. Possible modifications of the algorithm and limitations of the method are also discussed.

  16. Electrical properties of Egyptian natural graphite

    International Nuclear Information System (INIS)

    The electrical properties of Egyptian natural graphite flakes, obtained from the graphite schists of Wadi Bent, Eastern Desert, were measured. The flakes were ground and compressed into pellets. The standard four probe dc method was used to measure the temperature dependence of the electric resistivity from room temperature down to 12 K. The transverse and longitudinal magnetoresistance were measured in the low magnetic field range at temperatures 300 K, 77 K and 12 K. The transverse magnetoresistance data was used to estimate the average mobility, assuming a simple two-band model. (author). 20 refs, 4 figs, 1 tab

  17. Performance studies on mechanical + adsorption hybrid compression refrigeration cycles with HFC 134a

    Energy Technology Data Exchange (ETDEWEB)

    Banker, N.D.; Dutta, P.; Srinivasan, K. [Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012 (India); Prasad, M. [Thermal Systems Division, ISRO Satellite Centre, Bangalore 560 017 (India)

    2008-12-15

    This paper presents the results of an investigation on the efficacy of hybrid compression process for refrigerant HFC 134a in cooling applications. The conventional mechanical compression is supplemented by thermal compression using a string of adsorption compressors. Activated carbon is the adsorbent for the thermal compression segment. The alternatives of bottoming either mechanical or thermal compression stages are investigated. It is shown that almost 40% energy saving is realizable by carrying out a part of the compression in a thermal compressor compared to the case when the entire compression is carried out in a single-stage mechanical compressor. The hybrid compression is feasible even when low grade heat is available. Some performance indictors are defined and evaluated for various configurations. (author)

  18. Nature Detectives

    Science.gov (United States)

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  19. Comparative data compression techniques and multi-compression results

    International Nuclear Information System (INIS)

    Data compression is very necessary in business data processing, because of the cost savings that it offers and the large volume of data manipulated in many business applications. It is a method or system for transmitting a digital image (i.e., an array of pixels) from a digital data source to a digital data receiver. More the size of the data be smaller, it provides better transmission speed and saves time. In this communication, we always want to transmit data efficiently and noise freely. This paper will provide some compression techniques for lossless text type data compression and comparative result of multiple and single compression, that will help to find out better compression output and to develop compression algorithms

  20. Comparative data compression techniques and multi-compression results

    Science.gov (United States)

    Hasan, M. R.; Ibrahimy, M. I.; Motakabber, S. M. A.; Ferdaus, M. M.; Khan, M. N. H.

    2013-12-01

    Data compression is very necessary in business data processing, because of the cost savings that it offers and the large volume of data manipulated in many business applications. It is a method or system for transmitting a digital image (i.e., an array of pixels) from a digital data source to a digital data receiver. More the size of the data be smaller, it provides better transmission speed and saves time. In this communication, we always want to transmit data efficiently and noise freely. This paper will provide some compression techniques for lossless text type data compression and comparative result of multiple and single compression, that will help to find out better compression output and to develop compression algorithms.

  1. Analysis by compression

    DEFF Research Database (Denmark)

    Meredith, David

    MEL is a geometric music encoding language designed to allow for musical objects to be encoded parsimoniously as sets of points in pitch-time space, generated by performing geometric transformations on component patterns. MEL has been implemented in Java and coupled with the SIATEC pattern...... discovery algorithm to allow for compact encodings to be generated automatically from in extenso note lists. The MEL-SIATEC system is founded on the belief that music analysis and music perception can be modelled as the compression of in extenso descriptions of musical objects....

  2. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben; Damkilde, Lars

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation is...

  3. Multiple snapshot compressive beamforming

    DEFF Research Database (Denmark)

    Gerstoft, Peter; Xenaki, Angeliki; Mecklenbrauker, Christoph F.;

    2015-01-01

    For sound fields observed on an array, compressive sensing (CS) reconstructs the multiple source signals at unknown directions-of-arrival (DOAs) using a sparsity constraint. The DOA estimation is posed as an underdetermined problem expressing the field at each sensor as a phase-lagged superposition...... of source amplitudes at all hypothetical DOAs. CS is applicable even for a single observation snapshot achieving a higher resolution than conventional beamforming. For multiple snapshots, CS outperforms conventional high-resolution methods, even with coherent arrivals and at low signal-to-noise ratio....

  4. Parental authority in flux

    OpenAIRE

    Reiter, Herwig; Kuhar, Metka

    2015-01-01

    The aim of this article is to investigate the workings of parental authority in Slovenian families: how is parental authority asserted and how do adolescents react to parental authority? Based on a qualitative exploration, the study shows that parental authority is accommodated in ways that comply with the general culture of intergenerational negotiations

  5. Atomic Energy Authority Bill

    International Nuclear Information System (INIS)

    On the third reading of the Atomic Energy Authority Bill the following matters were discussed: safety research and thermal reactor work - how funded when the Authority is operating on trading fund basis; future financial framework of the Authority; capital investment; loans; effect of change on Authority employees. (U.K.)

  6. Data compression of digital X-ray images from a clinical viewpoint

    International Nuclear Information System (INIS)

    For the PACS (picture archiving and communication system), large storage capacity recording media and a fast data transfer network are necessary. When the PACS are working, these technology requirements become an large problem. So we need image data compression having a higher recording efficiency media and an improved transmission ratio. There are two kinds of data compression methods, one is reversible compression and other is the irreversible one. By these reversible compression methods, a compressed-expanded image is exactly equal to the original image. The ratio of data compression is about between 1/2 an d1/3. On the other hand, for irreversible data compression, the compressed-expanded image is a distorted image, and we can achieve a high compression ratio by using this method. In the medical field, the discrete cosine transform (DCT) method is popular because of the low distortion and fast performance. The ratio of data compression is actually from 1/10 to 1/20. It is important for us to decide the compression ratio according to the purposes and modality of the image. We must carefully select the ratio of the data compression because the suitable compression ratio alters in the usage of image for education, clinical diagnosis and reference. (author)

  7. Ultrasound beamforming using compressed data.

    Science.gov (United States)

    Li, Yen-Feng; Li, Pai-Chi

    2012-05-01

    The rapid advancements in electronics technologies have made software-based beamformers for ultrasound array imaging feasible, thus facilitating the rapid development of high-performance and potentially low-cost systems. However, one challenge to realizing a fully software-based system is transferring data from the analog front end to the software back end at rates of up to a few gigabits per second. This study investigated the use of data compression to reduce the data transfer requirements and optimize the associated trade-off with beamforming quality. JPEG and JPEG2000 compression techniques were adopted. The acoustic data of a line phantom were acquired with a 128-channel array transducer at a center frequency of 3.5 MHz, and the acoustic data of a cyst phantom were acquired with a 64-channel array transducer at a center frequency of 3.33 MHz. The receive-channel data associated with each transmit event are separated into 8 × 8 blocks and several tiles before JPEG and JPEG2000 data compression is applied, respectively. In one scheme, the compression was applied to raw RF data, while in another only the amplitude of baseband data was compressed. The maximum compression ratio of RF data compression to produce an average error of lower than 5 dB was 15 with JPEG compression and 20 with JPEG2000 compression. The image quality is higher with baseband amplitude data compression than with RF data compression; although the maximum overall compression ratio (compared with the original RF data size), which was limited by the data size of uncompressed phase data, was lower than 12, the average error in this case was lower than 1 dB when the compression ratio was lower than 8. PMID:22434817

  8. Kyphoplasty for severe osteoporotic vertebral compression fractures

    International Nuclear Information System (INIS)

    Objective: To evaluate the clininal efficacy of kyphoplasty for severe osteoporotic vertebral compression fractures. Methods: Forty-five patients with severe osteoporotic compressive fractures were treated by kyphoplasty from Jan 2005 to Jan 2009. The compressive rate of the fractured vertebral bodies was more than 75%. According to the morphology of the vertebral compression fracture bodies the unilateral or bilateral balloon kyphoplasty were selected. The anterior vertebral height was measured on a standing lateral radiograph at pre-operative, post-operative (one day after operation) and final follow-up time. A visual analog scale(VAS) and the Oswestry disability index (ODI) were chosen to evaluate pain status and functional activity. Results: The mean follow-up was for 21.7 months (in range from 18 to 48 months). The anterior vertebral body height of fracture vertebra was restored from preoperative (18.7 ± 3.1)% to postoperative (51.4 ± 2.3)%, the follow-up period (50.2 ± 2.7)%. There was a significant improvement between preoperative and postoperative values (P0.05). The VAS was 8.1 ± 1.4 at preoperative, 2.6 ± 0.9 at postoperative, 2.1 ± 0.5 at final follow-up time; and the ODI was preoperative 91.1 ± 2.3, postoperative 30.7 ± 7.1, follow-up period 26.1 ± 5.1. There was statistically significant improvement in the VAS and ODI in the post-operative assessment compared with the pre-operative assessment (P0.05). Asymptomatic cement leakage occurred in three cases. New vertebral fracture occurred in one case. Conclusion: The study suggests that balloon kyphoplasty is a safe and effective procedure in the treatment of severe osteoporotic vertebral compression fractures. (authors)

  9. Compressive Bilateral Filtering.

    Science.gov (United States)

    Sugimoto, Kenjiro; Kamata, Sei-Ichiro

    2015-11-01

    This paper presents an efficient constant-time bilateral filter that produces a near-optimal performance tradeoff between approximate accuracy and computational complexity without any complicated parameter adjustment, called a compressive bilateral filter (CBLF). The constant-time means that the computational complexity is independent of its filter window size. Although many existing constant-time bilateral filters have been proposed step-by-step to pursue a more efficient performance tradeoff, they have less focused on the optimal tradeoff for their own frameworks. It is important to discuss this question, because it can reveal whether or not a constant-time algorithm still has plenty room for improvements of performance tradeoff. This paper tackles the question from a viewpoint of compressibility and highlights the fact that state-of-the-art algorithms have not yet touched the optimal tradeoff. The CBLF achieves a near-optimal performance tradeoff by two key ideas: 1) an approximate Gaussian range kernel through Fourier analysis and 2) a period length optimization. Experiments demonstrate that the CBLF significantly outperforms state-of-the-art algorithms in terms of approximate accuracy, computational complexity, and usability. PMID:26068315

  10. Fingerprints in Compressed Strings

    DEFF Research Database (Denmark)

    Bille, Philip; Cording, Patrick Hagge; Gørtz, Inge Li;

    2013-01-01

    The Karp-Rabin fingerprint of a string is a type of hash value that due to its strong properties has been used in many string algorithms. In this paper we show how to construct a data structure for a string S of size N compressed by a context-free grammar of size n that answers fingerprint queries....... That is, given indices i and j, the answer to a query is the fingerprint of the substring S[i,j]. We present the first O(n) space data structures that answer fingerprint queries without decompressing any characters. For Straight Line Programs (SLP) we get O(logN) query time, and for Linear SLPs (an SLP...... derivative that captures LZ78 compression and its variations) we get O(loglogN) query time. Hence, our data structures has the same time and space complexity as for random access in SLPs. We utilize the fingerprint data structures to solve the longest common extension problem in query time O(logNlogℓ) and O...

  11. Compressive Sensing DNA Microarrays

    Directory of Open Access Journals (Sweden)

    Sheikh Mona A

    2009-01-01

    Full Text Available Compressive sensing microarrays (CSMs are DNA-based sensors that operate using group testing and compressive sensing (CS principles. In contrast to conventional DNA microarrays, in which each genetic sensor is designed to respond to a single target, in a CSM, each sensor responds to a set of targets. We study the problem of designing CSMs that simultaneously account for both the constraints from CS theory and the biochemistry of probe-target DNA hybridization. An appropriate cross-hybridization model is proposed for CSMs, and several methods are developed for probe design and CS signal recovery based on the new model. Lab experiments suggest that in order to achieve accurate hybridization profiling, consensus probe sequences are required to have sequence homology of at least 80% with all targets to be detected. Furthermore, out-of-equilibrium datasets are usually as accurate as those obtained from equilibrium conditions. Consequently, one can use CSMs in applications in which only short hybridization times are allowed.

  12. Molecular dynamics simulations of shock compressed graphite

    International Nuclear Information System (INIS)

    We present molecular dynamic simulations of the shock compression of graphite with the LCBOPII potential. The range of shock intensities covers the full range of available experimental data, including near-tera-pascal pressures. The results are in excellent agreement with the available DFT data and point to a graphite-diamond transition for shock pressures above 65 GPa, a value larger than the experimental data (20 to 50 GPa). The transition mechanism leads preferentially to hexagonal diamond through a diffusion-less process but is submitted to irreversible re-graphitization upon release: this result is in good agreement with the lack of highly ordered diamond observed in post-mortem experimental samples. Melting is found for shock pressures ranging from 200 to 300 GPa, close to the approximate LCBOPII diamond melting line. A good overall agreement is found between the calculated and experimental Hugoniot data up to 46% compression rate. (authors)

  13. Data compression on the sphere

    CERN Document Server

    McEwen, J D; Eyers, D M; 10.1051/0004-6361/201015728

    2011-01-01

    Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty mega-pixels respectively. The compression of such data is therefore becoming increasingly important. We develop algorithms to compress data defined on the sphere. A Haar wavelet transform on the sphere is used as an energy compression stage to reduce the entropy of the data, followed by Huffman and run-length encoding stages. Lossless and lossy compression algorithms are developed. We evaluate compression performance on simulated CMB data, Earth topography data and environmental illumination maps used in computer graphics. The CMB data can be compressed to approximately 40% of its original size for essentially no loss to the cosmological information content of the data, and to approximately 20% if a small cosmological information loss is tolerated. For the topographic and il...

  14. Speech Compression Using Multecirculerletet Transform

    Directory of Open Access Journals (Sweden)

    Sulaiman Murtadha

    2012-01-01

    Full Text Available Compressing the speech reduces the data storage requirements, leading to reducing the time of transmitting the digitized speech over long-haul links like internet. To obtain best performance in speech compression, wavelet transforms require filters that combine a number of desirable properties, such as orthogonality and symmetry.The MCT bases functions are derived from GHM bases function using 2D linear convolution .The fast computation algorithm methods introduced here added desirable features to the current transform. We further assess the performance of the MCT in speech compression application. This paper discusses the effect of using DWT and MCT (one and two dimension on speech compression. DWT and MCT performances in terms of compression ratio (CR, mean square error (MSE and peak signal to noise ratio (PSNR are assessed. Computer simulation results indicate that the two dimensions MCT offer a better compression ratio, MSE and PSNR than DWT.

  15. libpolycomp: Compression/decompression library

    Science.gov (United States)

    Tomasi, Maurizio

    2016-04-01

    Libpolycomp compresses and decompresses one-dimensional streams of numbers by means of several algorithms. It is well-suited for time-ordered data acquired by astronomical instruments or simulations. One of the algorithms, called "polynomial compression", combines two widely-used ideas (namely, polynomial approximation and filtering of Fourier series) to achieve substantial compression ratios for datasets characterized by smoothness and lack of noise. Notable examples are the ephemerides of astronomical objects and the pointing information of astronomical telescopes. Other algorithms implemented in this C library are well known and already widely used, e.g., RLE, quantization, deflate (via libz) and Burrows-Wheeler transform (via libbzip2). Libpolycomp can compress the timelines acquired by the Planck/LFI instrument with an overall compression ratio of ~9, while other widely known programs (gzip, bzip2) reach compression ratios less than 1.5.

  16. 1999 Annual report: compression + power + service

    International Nuclear Information System (INIS)

    Enerflex manufactures, services and leases compression systems for the production and processing of natural gas and gas-fueled power generation systems. Design, engineering, project management, financing, installation commissioning and after-sales service are also part of Enerflex's arsenal of tools to ensure innovation, and high standards of quality and service. In 1999, Enerflex suffered an 18 per cent decline in revenues from $315 million in 1998 to $257 million in 1999, entirely due to lower sales of big ticket compression equipment in Canada. At the same time, revenues from international sales and service increased to $ 61.8 million in 1999, from $ 53 million in 1998. The company successfully completed the move to a new 328,000 sq. ft state-of-the-art manufacturing facility, and made its first significant sale to the United States in 1999 in the form of delivering a coal bed methane project in the Powder River area of Wyoming, and power generation equipment to Massachusetts. Although in the short term unusually warm average temperatures, industry cash flows, and access to capital may determine demand for the company's products and services, the long-term fundamentals are positive and demand for compression equipment and power generation systems is likely to grow. Indeed, in the fourth quarter of 1999, market conditions improved significantly and the company recorded its highest quarterly revenues and earnings during the last quarter. The annual review provides further details about the operations of the company's various divisions, (Compression and Power Systems, Parts and Compression Services, Leasing and Financing), management's review of the company's overall operations and finances, audited financial statements, and shareholders' information

  17. Biomedical sensor design using analog compressed sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

  18. Introduction to compressible fluid flow

    CERN Document Server

    Oosthuizen, Patrick H

    2013-01-01

    IntroductionThe Equations of Steady One-Dimensional Compressible FlowSome Fundamental Aspects of Compressible FlowOne-Dimensional Isentropic FlowNormal Shock WavesOblique Shock WavesExpansion Waves - Prandtl-Meyer FlowVariable Area FlowsAdiabatic Flow with FrictionFlow with Heat TransferLinearized Analysis of Two-Dimensional Compressible FlowsHypersonic and High-Temperature FlowsHigh-Temperature Gas EffectsLow-Density FlowsBibliographyAppendices

  19. q-ary Compressive Sensing

    OpenAIRE

    Mroueh, Youssef; Rosasco, Lorenzo

    2013-01-01

    We introduce q-ary compressive sensing, an extension of 1-bit compressive sensing. We propose a novel sensing mechanism and a corresponding recovery procedure. The recovery properties of the proposed approach are analyzed both theoretically and empirically. Results in 1-bit compressive sensing are recovered as a special case. Our theoretical results suggest a tradeoff between the quantization parameter q, and the number of measurements m in the control of the error of the resulting recovery a...

  20. Lossless Compression of Broadcast Video

    DEFF Research Database (Denmark)

    Martins, Bo; Eriksen, N.; Faber, E.;

    1998-01-01

    We investigate several techniques for lossless and near-lossless compression of broadcast video.The emphasis is placed on the emerging international standard for compression of continous-tone still images, JPEG-LS, due to its excellent compression performance and moderatecomplexity. Except for one...... artificial sequence containing uncompressible data all the 4:2:2, 8-bit test video material easily compresses losslessly to a rate below 125 Mbit/s. At this rate, video plus overhead can be contained in a single telecom 4th order PDH channel or a single STM-1 channel. Difficult 4:2:2, 10-bit test material...

  1. Building indifferentiable compression functions from the PGV compression functions

    DEFF Research Database (Denmark)

    Gauravaram, P.; Bagheri, Nasour; Knudsen, Lars Ramkilde

    2016-01-01

    Preneel, Govaerts and Vandewalle (PGV) analysed the security of single-block-length block cipher based compression functions assuming that the underlying block cipher has no weaknesses. They showed that 12 out of 64 possible compression functions are collision and (second) preimage resistant. Bla...

  2. Instructions for Authors

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>1. Items of the paper Title, author’s name and working unit,abstract, key words, text and reference.2. Author and working unit Entitled authors should be those involved in the research and would

  3. Instructions for Authors

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>1. Items of the paper Title, author’s name and working unit,abstract, key words, text andreference.2. Author and working unitEntitled authors should be those involved in the research and wouldbe able to answer

  4. An automated Certification Authority

    CERN Document Server

    Shamardin, L V

    2002-01-01

    This note describe an approach to building an automated Certification Authority. It is compatible with basic requirements of RFC2527. It also supports Registration Authorities and Globus Toolkit grid-cert-renew automatic certificate renewal.

  5. Compressed quantum simulation

    International Nuclear Information System (INIS)

    Here, I summarize the results presented in B. Kraus, Phys. Rev. Lett. 107, 250503 (2011). Recently, it has been shown that certain circuits, the so-called match gate circuits, can be compressed to an exponentially smaller universal quantum computation. We use this result to demonstrate that the simulation of a 1-D Ising chain consisting of n qubits can be performed on a universal quantum computer running on only log(n) qubits. We show how the adiabatic evolution can be simulated on this exponentially smaller system and how the magnetization can be measured. Since the Ising model displays a quantum phase transition, this result implies that a quantum phase transition of a very large system can be observed with current technology

  6. Compressed hyperspectral sensing

    Science.gov (United States)

    Tsagkatakis, Grigorios; Tsakalides, Panagiotis

    2015-03-01

    Acquisition of high dimensional Hyperspectral Imaging (HSI) data using limited dimensionality imaging sensors has led to restricted capabilities designs that hinder the proliferation of HSI. To overcome this limitation, novel HSI architectures strive to minimize the strict requirements of HSI by introducing computation into the acquisition process. A framework that allows the integration of acquisition with computation is the recently proposed framework of Compressed Sensing (CS). In this work, we propose a novel HSI architecture that exploits the sampling and recovery capabilities of CS to achieve a dramatic reduction in HSI acquisition requirements. In the proposed architecture, signals from multiple spectral bands are multiplexed before getting recorded by the imaging sensor. Reconstruction of the full hyperspectral cube is achieved by exploiting a dictionary of elementary spectral profiles in a unified minimization framework. Simulation results suggest that high quality recovery is possible from a single or a small number of multiplexed frames.

  7. Population attribute compression

    Science.gov (United States)

    White, James M.; Faber, Vance; Saltzman, Jeffrey S.

    1995-01-01

    An image population having a large number of attributes is processed to form a display population with a predetermined smaller number of attributes that represent the larger number of attributes. In a particular application, the color values in an image are compressed for storage in a discrete look-up table (LUT). Color space containing the LUT color values is successively subdivided into smaller volumes until a plurality of volumes are formed, each having no more than a preselected maximum number of color values. Image pixel color values can then be rapidly placed in a volume with only a relatively few LUT values from which a nearest neighbor is selected. Image color values are assigned 8 bit pointers to their closest LUT value whereby data processing requires only the 8 bit pointer value to provide 24 bit color values from the LUT.

  8. Adaptively Compressed Exchange Operator

    CERN Document Server

    Lin, Lin

    2016-01-01

    The Fock exchange operator plays a central role in modern quantum chemistry. The large computational cost associated with the Fock exchange operator hinders Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals, even for systems consisting of hundreds of atoms. We develop the adaptively compressed exchange operator (ACE) formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. In an iterative framework for solving Hartree-Fock-like systems, the ACE formulation only requires moderate modification of the code, and can be potentially beneficial for all electronic structure software packages involving exchange calculations. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens...

  9. Compressed quantum simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, B. [Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

    2014-12-04

    Here, I summarize the results presented in B. Kraus, Phys. Rev. Lett. 107, 250503 (2011). Recently, it has been shown that certain circuits, the so-called match gate circuits, can be compressed to an exponentially smaller universal quantum computation. We use this result to demonstrate that the simulation of a 1-D Ising chain consisting of n qubits can be performed on a universal quantum computer running on only log(n) qubits. We show how the adiabatic evolution can be simulated on this exponentially smaller system and how the magnetization can be measured. Since the Ising model displays a quantum phase transition, this result implies that a quantum phase transition of a very large system can be observed with current technology.

  10. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation is...... observed between stiffness reduction and accumulated creep. A failure model based on the total work during the fatigue life is rejected, and a modified work model based on elastic, viscous and non-recovered viscoelastic work is experimentally supported, and an explanation at a microstructural level is...

  11. Central cooling: compressive chillers

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1978-03-01

    Representative cost and performance data are provided in a concise, useable form for three types of compressive liquid packaged chillers: reciprocating, centrifugal, and screw. The data are represented in graphical form as well as in empirical equations. Reciprocating chillers are available from 2.5 to 240 tons with full-load COPs ranging from 2.85 to 3.87. Centrifugal chillers are available from 80 to 2,000 tons with full load COPs ranging from 4.1 to 4.9. Field-assemblied centrifugal chillers have been installed with capacities up to 10,000 tons. Screw-type chillers are available from 100 to 750 tons with full load COPs ranging from 3.3 to 4.5.

  12. The experimental research of GFRPand BFRP operation under compression

    Directory of Open Access Journals (Sweden)

    Lapshinov Andrey Evgenievich

    2014-01-01

    Full Text Available In the foreign countries there are not only design guidelines but also standards for testing FRP materials. These codes do not recommend using FRP bars in compressive members, such as columns. But the compressive strength shouldn’t be neglected according to those design codes. In our country the standards for FRP testing and design codes are just in the process of development.This paper contains the results of a compression testing of GFRP and BFRP with different configurations. The proposed height of the specimen was 1d, 3d and 5d. The results of the tests and failure mechanisms of the samples are discussed. The author also gives strain distribution in dependence with the specimen type. The conclusions and proposals for the use of FRP reinforcement in compression are offered. One of the main conclusions is that with the height increase the compressive strength also increases, while the strain decreases.Basing on the survey results the ratio of tensile strength to compressive strength and the ratio of compressive elasticity modulus to tensile elasticity modulus are given.

  13. Authority in Engineering Education

    Science.gov (United States)

    Stephan, Karl D.

    2012-01-01

    Authority as a philosophical concept is defined both in general and as it applies to engineering education. Authority is shown to be a good and necessary part of social structures, in contrast to some cultural trends that regard it as an unnecessary and outmoded evil. Technical, educational, and organizational authority in their normal functions…

  14. Communication of authority

    DEFF Research Database (Denmark)

    Holt, Else Kragelund

    2009-01-01

    The Book of Jeremiah emphasises that the prophet has his authority from God, who communicated this authority to the prophet by calling him. Being invested with divine authority, the prophet was disjuncted from the people, but conjuncted with God, in a process where the divine word is closely...

  15. Compression and decompression of digital seismic waveform data for storage and communication

    International Nuclear Information System (INIS)

    Two different classes of data compression schemes, namely physical data compression schemes and logical data compression schemes are examined for their use in storage and communication of digital seismic waveform data. In physical data compression schemes, the physical size of the waveform is reduced. One, therefore, gets only a broad picture of the original waveform, when the data are retrieved and the waveform is reconstituted. Coerrelation between original and decompressed waveform varies inversely with the data compresion ratio. In the logical data compression schemes, the data are stored in a logically encoded form. Storage of unnecessary characters like blank space is avoided. On decompression original data are retrieved and compression error is nil. Three algorithms of logical data compression schemes have been developed and studied. These are : 1) optimum formatting schemes, 2) differential bit reduction scheme, and 3) six bit compression scheme. Results of the above three algorithms of logical compression class are compared with those of physical compression schemes reported in literature. It is found that for all types of data, six bit compression scheme gives the highest value of data compression ratio. (author). 6 refs., 8 figs., 1 appendix, 2 tabs

  16. Oxygen isotope ratios from tree rings containing compression wood

    International Nuclear Information System (INIS)

    Oxygen isotope determinations on the alpha-cellulose of tree rings cut from two leaning Picea engelmannii revealed significant differences between results from normal and compression wood radii. Nine samples (10-year periods) from the normal wood radius (1721-1953) in one tree showed good agreement with proxy climate information and maximum differences of 1.80/00 between the ''warmest'' and ''coolest'' decades sampled. Differences of equivalent magnitude were found between samples from the same decade from normal and compression wood radii. These differences are strongly related to the amount and/or density of compression wood present and suggest that sampling for paleoclimatic work should be restricted to complacent, erect trees without compression wood rings. (author)

  17. Coabsorbent and thermal recovery compression heat pumping technologies

    CERN Document Server

    Staicovici, Mihail-Dan

    2014-01-01

    This book introduces two of the most exciting heat pumping technologies, the coabsorbent and the thermal recovery (mechanical vapor) compression, characterized by a high potential in primary energy savings and environmental protection. New cycles with potential applications of nontruncated, truncated, hybrid truncated, and multi-effect coabsorbent types are introduced in this work.   Thermal-to-work recovery compression (TWRC) is the first of two particular methods explored here, including how superheat is converted into work, which diminishes the compressor work input. In the second method, thermal-to-thermal recovery compression (TTRC), the superheat is converted into useful cooling and/or heating, and added to the cycle output effect via the coabsorbent technology. These and other methods of discharge gas superheat recovery are analyzed for single-, two-, three-, and multi-stage compression cooling and heating, ammonia and ammonia-water cycles, and the effectiveness results are given.  The author presen...

  18. Unilateral lower extremity edema in iliac compression syndrome

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical value of iliac compression syndrome for etiological diagnosis and treatment of unilateral lower extremity edema. Methods: The diagnosis of iliac compression syndrome was confirmed with venography in 32 cases presented with left lower extremity edema. The compressed or occluded venous segment was dilated with a 10 mm or 12 mm diameter balloon and then followed by self-expandable stent placement with a diameter from 10 to 16 mm in the diseased left iliac vein. Oral anticoagulant was taken for 6 months. Results: Left lower extremity edema was resolved within 2 days after the procedure in all 32 cases without any major complications. The primary patency of stents reached 100% and no deep venous thrombosis occurred afterwards. Conclusion: Early recognition and treatment of iliac compression syndrome could prevent DVT. (authors)

  19. Ombuds’ corner: Relationship to authority

    CERN Multimedia

    Vincent Vuillemin

    2012-01-01

    In this series, the Bulletin aims to explain the role of the Ombuds at CERN by presenting practical examples of misunderstandings that could have been resolved by the Ombuds if he had been contacted earlier. Please note that, in all the situations we present, the names are fictitious and used only to improve clarity.   Among the cases brought to the Ombuds, many of them have to do with difficulties between supervisees and supervisors. In fact, they form the majority of the cases. For both parties, the source of the conflict boils down to the relationship that people entertain with what can be called "the authority". The relationship with the authority is somewhat different within the various Sectors of CERN, as are the relationships between personnel and supervisors. Generally one considers that natural authority can either come from a respected technical knowledge, or from charisma along with a good understanding of human relationships. Of course together these qualities ge...

  20. Application specific compression : final report.

    Energy Technology Data Exchange (ETDEWEB)

    Melgaard, David Kennett; Byrne, Raymond Harry; Myers, Daniel S.; Harrison, Carol D.; Lee, David S.; Lewis, Phillip J.; Carlson, Jeffrey J.

    2008-12-01

    With the continuing development of more capable data gathering sensors, comes an increased demand on the bandwidth for transmitting larger quantities of data. To help counteract that trend, a study was undertaken to determine appropriate lossy data compression strategies for minimizing their impact on target detection and characterization. The survey of current compression techniques led us to the conclusion that wavelet compression was well suited for this purpose. Wavelet analysis essentially applies a low-pass and high-pass filter to the data, converting the data into the related coefficients that maintain spatial information as well as frequency information. Wavelet compression is achieved by zeroing the coefficients that pertain to the noise in the signal, i.e. the high frequency, low amplitude portion. This approach is well suited for our goal because it reduces the noise in the signal with only minimal impact on the larger, lower frequency target signatures. The resulting coefficients can then be encoded using lossless techniques with higher compression levels because of the lower entropy and significant number of zeros. No significant signal degradation or difficulties in target characterization or detection were observed or measured when wavelet compression was applied to simulated and real data, even when over 80% of the coefficients were zeroed. While the exact level of compression will be data set dependent, for the data sets we studied, compression factors over 10 were found to be satisfactory where conventional lossless techniques achieved levels of less than 3.

  1. Data Compression with Prime Numbers

    OpenAIRE

    Chalmers, Gordon

    2005-01-01

    A compression algorithm is presented that uses the set of prime numbers. Sequences of numbers are correlated with the prime numbers, and labeled with the integers. The algorithm can be iterated on data sets, generating factors of doubles on the compression.

  2. Video Compression Using Neural Network

    Directory of Open Access Journals (Sweden)

    Sangeeta Mishra

    2012-08-01

    Full Text Available Apart from the existing technology on image compression represented by series of JPEG, MPEG and H.26x standards, new technology such as neural networks and genetic algorithms are being developed to explore the future of image coding. Successful applications of neural networks to basic propagation algorithm have now become well established and other aspects of neural network involvement in this technology. In this paper different algorithms were implemented like gradient descent back propagation, gradient descent with momentum back propagation, gradient descent with adaptive learning back propagation, gradient descent with momentum and adaptive learning back propagation and Levenberg-Marquardt algorithm. The size of original video clip is 25MB and after compression it becomes 21.3MB giving the compression ratio as 85.2% and compression factor of 1.174. It was observed that the size remains same after compression but the difference is in the clarity.

  3. Analytical model for ramp compression

    Science.gov (United States)

    Xue, Quanxi; Jiang, Shaoen; Wang, Zhebin; Wang, Feng; Hu, Yun; Ding, Yongkun

    2016-08-01

    An analytical ramp compression model for condensed matter, which can provide explicit solutions for isentropic compression flow fields, is reported. A ramp compression experiment can be easily designed according to the capability of the loading source using this model. Specifically, important parameters, such as the maximum isentropic region width, material properties, profile of the pressure pulse, and the pressure pulse duration can be reasonably allocated or chosen. To demonstrate and study this model, laser-direct-driven ramp compression experiments and code simulation are performed successively, and the factors influencing the accuracy of the model are studied. The application and simulation show that this model can be used as guidance in the design of a ramp compression experiment. However, it is verified that further optimization work is required for a precise experimental design.

  4. Metastatic compression fractures of vertebral bodies

    International Nuclear Information System (INIS)

    Magnetic resonance (MR) imaging was performed on 65 patients with 76 vertebral compression fractures. Thirty three fractures were due to metastatic tumors; 43 were caused by benign process except for known spinal trauma. Metastatic fractures showed low signal intensity on T1 weighted image (T1WI) and various signal intensities on T2WI. In 27 of the 33 fractures caused by metastases, MRI showed complete replacement of normal bone marrow. Vertebral arches and spinous processes were frequently involved by the tumor. Paravertebral and/or intraspinal soft tissue masses were also highly associated with metastatic fractures. In metastatic fractures, the compression of the spinal cord was more frequent compared to benign processes. Disk involvement was rare in either type of fracture. We suppose MRI is a useful modality in diagnosing metastatic compression fractures. The involvement of vertebral arches and spinous processes due to metastasis, and the presence of paravertebral and/or intraspinal masses are helpful findings for discriminating between malignant and benign processes. (author)

  5. Equilibrium states of homogeneous sheared compressible turbulence

    Directory of Open Access Journals (Sweden)

    M. Riahi

    2011-06-01

    Full Text Available Equilibrium states of homogeneous compressible turbulence subjected to rapid shear is studied using rapid distortion theory (RDT. The purpose of this study is to determine the numerical solutions of unsteady linearized equations governing double correlations spectra evolution. In this work, RDT code developed by authors solves these equations for compressible homogeneous shear flows. Numerical integration of these equations is carried out using a second-order simple and accurate scheme. The two Mach numbers relevant to homogeneous shear flow are the turbulent Mach number Mt, given by the root mean square turbulent velocity fluctuations divided by the speed of sound, and the gradient Mach number Mg which is the mean shear rate times the transverse integral scale of the turbulence divided by the speed of sound. Validation of this code is performed by comparing RDT results with direct numerical simulation (DNS of [A. Simone, G.N. Coleman, and C. Cambon, Fluid Mech. 330, 307 (1997] and [S. Sarkar, J. Fluid Mech. 282, 163 (1995] for various values of initial gradient Mach number Mg0. It was found that RDT is valid for small values of the non-dimensional times St (St 10 in particular for large values of Mg0. This essential feature justifies the resort to RDT in order to determine equilibrium states in the compressible regime.

  6. Cartesian anisotropic mesh adaptation for compressible flow

    International Nuclear Information System (INIS)

    Simulating transient compressible flows involving shock waves presents challenges to the CFD practitioner in terms of the mesh quality required to resolve discontinuities and prevent smearing. This paper discusses a novel two-dimensional Cartesian anisotropic mesh adaptation technique implemented for compressible flow. This technique, developed for laminar flow by Ham, Lien and Strong, is efficient because it refines and coarsens cells using criteria that consider the solution in each of the cardinal directions separately. In this paper the method will be applied to compressible flow. The procedure shows promise in its ability to deliver good quality solutions while achieving computational savings. The convection scheme used is the Advective Upstream Splitting Method (Plus), and the refinement/ coarsening criteria are based on work done by Ham et al. Transient shock wave diffraction over a backward step and shock reflection over a forward step are considered as test cases because they demonstrate that the quality of the solution can be maintained as the mesh is refined and coarsened in time. The data structure is explained in relation to the computational mesh, and the object-oriented design and implementation of the code is presented. Refinement and coarsening algorithms are outlined. Computational savings over uniform and isotropic mesh approaches are shown to be significant. (author)

  7. Compressive sensing exploiting wavelet-domain dependencies for ECG compression

    Science.gov (United States)

    Polania, Luisa F.; Carrillo, Rafael E.; Blanco-Velasco, Manuel; Barner, Kenneth E.

    2012-06-01

    Compressive sensing (CS) is an emerging signal processing paradigm that enables sub-Nyquist sampling of sparse signals. Extensive previous work has exploited the sparse representation of ECG signals in compression applications. In this paper, we propose the use of wavelet domain dependencies to further reduce the number of samples in compressive sensing-based ECG compression while decreasing the computational complexity. R wave events manifest themselves as chains of large coefficients propagating across scales to form a connected subtree of the wavelet coefficient tree. We show that the incorporation of this connectedness as additional prior information into a modified version of the CoSaMP algorithm can significantly reduce the required number of samples to achieve good quality in the reconstruction. This approach also allows more control over the ECG signal reconstruction, in particular, the QRS complex, which is typically distorted when prior information is not included in the recovery. The compression algorithm was tested upon records selected from the MIT-BIH arrhythmia database. Simulation results show that the proposed algorithm leads to high compression ratios associated with low distortion levels relative to state-of-the-art compression algorithms.

  8. PLURALIZING NATURE

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Denmark is widely recognised for its democratic approach to planning and the idea of planning for the common good. This interest in the common good and common values seems also to be reflected in the way which nature restoration is planned and managed – one common nature directed by the public...... authorities. But nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site-specificity. As...... exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. However, evidence from Switzerland suggests that planning for the common good, in the case of nature restoration, does not...

  9. Compression ratio effect on methane HCCI combustion

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S. M.; Pitz, W.; Smith, J. R.; Westbrook, C.

    1998-09-29

    We have used the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to simulate HCCI (homogeneous charge compression ignition) combustion of methane-air mixtures. HCT is applied to explore the ignition timing, bum duration, NOx production, gross indicated efficiency and gross IMEP of a supercharged engine (3 atm. Intake pressure) with 14:1, 16:l and 18:1 compression ratios at 1200 rpm. HCT has been modified to incorporate the effect of heat transfer and to calculate the temperature that results from mixing the recycled exhaust with the fresh mixture. This study uses a single control volume reaction zone that varies as a function of crank angle. The ignition process is controlled by adjusting the intake equivalence ratio and the residual gas trapping (RGT). RGT is internal exhaust gas recirculation which recycles both thermal energy and combustion product species. Adjustment of equivalence ratio and RGT is accomplished by varying the timing of the exhaust valve closure in either 2-stroke or 4-stroke engines. Inlet manifold temperature is held constant at 300 K. Results show that, for each compression ratio, there is a range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50% and NOx levels below 100 ppm. HCT results are also compared with a set of recent experimental data for natural gas.

  10. Weak compressibility of surface wave turbulence

    Science.gov (United States)

    Vucelja, Marija; Fouxon, Itzhak; Falkovich, Gregory

    2010-11-01

    Clustering of matter on the surface of lakes and pools and of oil slicks and seaweed on the sea surface is well-known empirically but there is no theory that describes it. Since surface flows are always compressible, such a theory should be based on the description of the development of density of inhomogeneities in a compressible flow. We studied the growth of small-scale inhomogeneities in the density of particles floating in weakly nonlinear small-amplitude surface waves. Despite the small amplitude, the accumulated effect of the long-time evolution may produce a strongly inhomogeneous distribution of the floaters: density fluctuations grow exponentially with a small but finite exponent. We have shown that the exponent is of sixth or higher order in wave amplitude. As a result, the inhomogeneities do not form within typical time scales of the natural environment. Thus the turbulence of surface waves is weakly compressible and alone it cannot be a realistic mechanism of the clustering of matter on liquid surfaces. However if besides waves there are also currents, the interplay of waves with currents, might be in some cases responsible for the patchiness of the floaters.

  11. Noiseless compression using non-Markov models

    Science.gov (United States)

    Blumer, Anselm

    1989-01-01

    Adaptive data compression techniques can be viewed as consisting of a model specified by a database common to the encoder and decoder, an encoding rule and a rule for updating the model to ensure that the encoder and decoder always agree on the interpretation of the next transmission. The techniques which fit this framework range from run-length coding, to adaptive Huffman and arithmetic coding, to the string-matching techniques of Lempel and Ziv. The compression obtained by arithmetic coding is dependent on the generality of the source model. For many sources, an independent-letter model is clearly insufficient. Unfortunately, a straightforward implementation of a Markov model requires an amount of space exponential in the number of letters remembered. The Directed Acyclic Word Graph (DAWG) can be constructed in time and space proportional to the text encoded, and can be used to estimate the probabilities required for arithmetic coding based on an amount of memory which varies naturally depending on the encoded text. The tail of that portion of the text which was encoded is the longest suffix that has occurred previously. The frequencies of letters following these previous occurrences can be used to estimate the probability distribution of the next letter. Experimental results indicate that compression is often far better than that obtained using independent-letter models, and sometimes also significantly better than other non-independent techniques.

  12. Respect My Authority

    Directory of Open Access Journals (Sweden)

    Jonathan Gorman

    2008-03-01

    Full Text Available Some simple modifications to VuFind, an open source library resource portal, improve the retrieval of both lists of works and information about authors from Wikipedia. These modifications begin to address ways that current "next-generation" catalogs fail to fully harness all of the bibliographic tools available for indexing and presenting author information. Simple methods such as those described in this article, which make use of full headings for authors, can offer marked improvements to these systems.

  13. An efficient and extensible approach for compressing phylogenetic trees

    KAUST Repository

    Matthews, Suzanne J

    2011-01-01

    Background: Biologists require new algorithms to efficiently compress and store their large collections of phylogenetic trees. Our previous work showed that TreeZip is a promising approach for compressing phylogenetic trees. In this paper, we extend our TreeZip algorithm by handling trees with weighted branches. Furthermore, by using the compressed TreeZip file as input, we have designed an extensible decompressor that can extract subcollections of trees, compute majority and strict consensus trees, and merge tree collections using set operations such as union, intersection, and set difference.Results: On unweighted phylogenetic trees, TreeZip is able to compress Newick files in excess of 98%. On weighted phylogenetic trees, TreeZip is able to compress a Newick file by at least 73%. TreeZip can be combined with 7zip with little overhead, allowing space savings in excess of 99% (unweighted) and 92%(weighted). Unlike TreeZip, 7zip is not immune to branch rotations, and performs worse as the level of variability in the Newick string representation increases. Finally, since the TreeZip compressed text (TRZ) file contains all the semantic information in a collection of trees, we can easily filter and decompress a subset of trees of interest (such as the set of unique trees), or build the resulting consensus tree in a matter of seconds. We also show the ease of which set operations can be performed on TRZ files, at speeds quicker than those performed on Newick or 7zip compressed Newick files, and without loss of space savings.Conclusions: TreeZip is an efficient approach for compressing large collections of phylogenetic trees. The semantic and compact nature of the TRZ file allow it to be operated upon directly and quickly, without a need to decompress the original Newick file. We believe that TreeZip will be vital for compressing and archiving trees in the biological community. © 2011 Matthews and Williams; licensee BioMed Central Ltd.

  14. Advanced compressed hydrogen fuel storage systems

    International Nuclear Information System (INIS)

    Dynetek was established in 1991 by a group of private investors, and since that time efforts have been focused on designing, improving, manufacturing and marketing advanced compressed fuel storage systems. The primary market for Dynetek fuel systems has been Natural Gas, however as the automotive industry investigates the possibility of using hydrogen as the fuel source solution in Alternative Energy Vehicles, there is a growing demand for hydrogen storage on -board. Dynetek is striving to meet the needs of the industry, by working towards developing a fuel storage system that will be efficient, economical, lightweight and eventually capable of storing enough hydrogen to match the driving range of the current gasoline fueled vehicles

  15. Collaborative authoring workshop

    NARCIS (Netherlands)

    Klemke, Roland; Schmitz, Birgit

    2009-01-01

    Klemke, R., & Schmitz, B. (2009). Collaborative authoring workshop. Workshop presentation at the Joint Technology Enhanced Learning Summerschool (JTELSS 2009). May, 30-June, 6, 2009, Terchova, Slovakia.

  16. Instructions for authors

    Directory of Open Access Journals (Sweden)

    Editors Editorial Board

    2012-11-01

    Full Text Available

    INSTRUCTIONS FOR AUTHORS
    Author Guidelines
    Authors must submit their papers via email to brain@edusoft.ro (please! or they can create an account and submit their papers online, at www.brain.edusoft.ro. Submited papers must be written in DOC format (Microsoft Word document, in as clear and as simple as possible English. Preferred maximum paper length for the papers is 20 pages, including figures.
    The template for the paper is at this address:
    http://www.edusoft.ro/Template_for_BRAIN.docRAIN vol. 3, issue 3, Instructions for authors

  17. Texture evolution during compression in Zircaloy-2

    International Nuclear Information System (INIS)

    The deformation of Zircaloy-2 is influenced by many factors; one being bulk texture. The texture can greatly affect the development of both the macro-mechanical (e.g. stress-strain curve) and micro-mechanical behavior (e.g. intergranular stresses). Thus studies on texture evolution are of practical significance. This introduces our current work on texture development during uniaxial loading of warm rolled Zircaloy-2 slab. As manufactured, most basal poles are orientated along the normal direction (ND), with a spread of ±50o towards the transverse direction (TD) and ±30o towards the rolling direction (RD). The {1 1 2-bar 0} normals are moderately concentrated in RD. Compression tests were performed in-situ during neutron diffraction to follow the development of lattice strain and intensity for eight diffraction peaks, with two tests each for compression along ND, TD and RD. Pole figures were then measured for the deformed samples. In this paper, we report the results for compression along RD. The development of intensity measured in two perpendicular directions during compression along RD showed that tensile twinning occurred during the deformation, which was confirmed by the subsequent texture measurement. Modeling work was performed with a visco-plastic self-consistent model (VPSC), assuming that prism slip, basal slip, pyramidal slip and tensile twinning are the active deformation mechanisms. The model successfully reproduced the macroscopic stress-strain responses, and also predicted the final texture reasonably well. Although further work is needed to refine the results, the model predicts reasonably well tensile twinning activity, and the twinning-induced reorientation of basal poles from ND to RD, and prism poles from RD to ND. (author)

  18. Advances in compressible turbulent mixing

    International Nuclear Information System (INIS)

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately

  19. Advances in compressible turbulent mixing

    Energy Technology Data Exchange (ETDEWEB)

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  20. ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT). FINAL REPORT

    International Nuclear Information System (INIS)

    The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity

  1. Enhancement of hydrogen sorption in magnesium hydride using expanded natural graphite

    Energy Technology Data Exchange (ETDEWEB)

    Chaise, A.; de Rango, P.; Fruchart, D.; Miraglia, S.; Garrier, S. [Institut NEEL and CRETA, CNRS, BP 166, 38042 Grenoble cedex (France); Marty, Ph. [Laboratoire des Ecoulements Geophysiques et Industriels, BP53, 38041 Grenoble cedex (France); Olives, R. [PROMES, CNRS, Tecnosud Rambla de la Thermodynamique, 66100 Perpignan (France)

    2009-10-15

    Magnesium hydrogenation reaction being exothermic and limited by heat removal, the thermal conductivity of ball-milled magnesium hydride (BM MgH{sub 2}) powders has to be improved. The compression of BM MgH{sub 2} associated to Expanded Natural Graphite (ENG) to form compacted disks has been investigated. Using BM MgH{sub 2} without ENG, its compression reduces the porosity and increases its volumetric hydrogen storage capacity. Incorporating ENG before compression drastically improves the thermal conductivity in the direction normal to compression axis. Moreover, the thermal conductivity increases linearly with ENG content, and can be adjusted to fulfill the loading time requirements. The thermodynamic properties and intrinsic sorption kinetics remain unchanged. However, both compression and ENG incorporation reduce the hydrogen permeability, especially in the direction parallel to the compression axis, which imposes a limit to the disk thickness. A small-size instrumented tank has been loaded with either pure BM MgH{sub 2} powder or with disks having different ENG contents. The results obtained for both cases are compared. (author)

  2. Difference Sequence Compression of Multidimensional Databases

    OpenAIRE

    Szépkúti, István

    2011-01-01

    The multidimensional databases often use compression techniques in order to decrease the size of the database. This paper introduces a new method called difference sequence compression. Under some conditions, this new technique is able to create a smaller size multidimensional database than others like single count header compression, logical position compression or base-offset compression. Keywords: compression, multidimensional database, On-line Analytical Processing, OLAP.

  3. The Authors Reply

    Science.gov (United States)

    Guilloteaux, Marie J.; Dornyei, Zoltan

    2009-01-01

    This article presents the authors' reply to Rod Ellis's comments on their study on motivated classroom behavior. As Ellis correctly summarizes, the three student variables selected for investigation in the authors' study were attention, participation, and volunteering for teacher-fronted activity. These three components were then summed up in a…

  4. Instructions for Authors

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>1.Items of the paper Title,author’s name and working unit,abstract,key words,text and reference. 2.Author and working unit Entitled authors should be those involved in the research and would be able to answer relevant questions.The working units,cities and

  5. American Indian Authors.

    Science.gov (United States)

    Momaday, Natachee Scott

    Twenty-six selections by 15 contemporary American Indian authors are given in this book. The selections--legends, ceremonial chants and prayers, poems, and stories--are accompanied by topics for discussion. Some of the selections deal with the supernatural, and some tell an actual story about the author. Pictures and short biographies of each…

  6. Multimedia Authoring and Annotation

    NARCIS (Netherlands)

    Bulterman, D.C.A.; Cesar Garcia, P.S.; Munson, E.; Pimentel, M.G.C.

    2014-01-01

    With the massive amount of captured multimedia, authoring is more relevant than ever. Multimedia content is available in many settings including the web, mobile devices, desktop applications, as well as games and interactive TV. The authoring and production of multimedia documents demands attention

  7. The Authors Reply

    Science.gov (United States)

    File, Kieran A.; Adams, Rebecca

    2010-01-01

    This article presents the authors' reply to Beniko Mason and Stephen Krashen's comments on their recent article published in "TESOL Quarterly." Mason and Krashen have provided an interesting reinterpretation of the authors' results and have also brought up several valid points regarding the efficiency of vocabulary learning from instruction,…

  8. Compressive adaptive computational ghost imaging

    CERN Document Server

    Aßmann, Marc; 10.1038/srep01545

    2013-01-01

    Compressive sensing is considered a huge breakthrough in signal acquisition. It allows recording an image consisting of $N^2$ pixels using much fewer than $N^2$ measurements if it can be transformed to a basis where most pixels take on negligibly small values. Standard compressive sensing techniques suffer from the computational overhead needed to reconstruct an image with typical computation times between hours and days and are thus not optimal for applications in physics and spectroscopy. We demonstrate an adaptive compressive sampling technique that performs measurements directly in a sparse basis. It needs much fewer than $N^2$ measurements without any computational overhead, so the result is available instantly.

  9. Learning Representations by Maximizing Compression

    CERN Document Server

    Gregor, Karol

    2011-01-01

    We give an algorithm that learns a representation of data through compression. The algorithm 1) predicts bits sequentially from those previously seen and 2) has a structure and a number of computations similar to an autoencoder. The likelihood under the model can be calculated exactly, and arithmetic coding can be used directly for compression. When training on digits the algorithm learns filters similar to those of restricted boltzman machines and denoising autoencoders. Independent samples can be drawn from the model by a single sweep through the pixels. The algorithm has a good compression performance when compared to other methods that work under random ordering of pixels.

  10. Compressive sensing for urban radar

    CERN Document Server

    Amin, Moeness

    2014-01-01

    With the emergence of compressive sensing and sparse signal reconstruction, approaches to urban radar have shifted toward relaxed constraints on signal sampling schemes in time and space, and to effectively address logistic difficulties in data acquisition. Traditionally, these challenges have hindered high resolution imaging by restricting both bandwidth and aperture, and by imposing uniformity and bounds on sampling rates.Compressive Sensing for Urban Radar is the first book to focus on a hybrid of two key areas: compressive sensing and urban sensing. It explains how reliable imaging, tracki

  11. Longitudinal compression of ion beams

    International Nuclear Information System (INIS)

    This paper examines the longitudinal compression of ion beams which is necessary in some designs of drivers intended to realize inertial thermonuclear fusion by heavy ions. Taking space-charge forces in the beams into account, two compression schemes are investigated: the first preserves the longitudinal phase-space area of the beams, and the second allows an increase of the phase-space area. The compression-system parameters are optimized for an example of a driver for inertial thermonuclear fusion by heavy ions with an energy of 10 MJ and with a pulse length of 25 ns on the target

  12. Dataset of long-term compressive strength of concrete with manufactured sand.

    Science.gov (United States)

    Ding, Xinxin; Li, Changyong; Xu, Yangyang; Li, Fenglan; Zhao, Shunbo

    2016-03-01

    This paper presents 186 groups compressive strength tests data of concrete with manufactured sand (MSC) in different curing age and 262 groups compressive strength tests data of MSC at 28 days collected from authors' experiments and other researches in China. Further interpretation and discussion were described in this issues. PMID:26949726

  13. A model for economic evaluation of the use of Adsorbed Natural Gas (ANG); Modelo de avaliacao economica do uso do Gas Natural Adsorvido (GNA)

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Diana C.S.; Cavalcante Junior, Celio L.; Torres, A. Eurico B.; Oliveira Junior, Jose A.; Medeiros, Vanildo M. de [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Campos, Flavio B.; Moura, Newton R. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Gas e Energia; Campos, Michel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Gerencia de Tecnologia de Gas e Energia; Alexandre, Francisco de Assis Souza

    2004-07-01

    Natural gas is currently transported by two main ways: through pipelines and stored in reservoirs, under compressed (CNG) or liquefied (LNG) forms. Adsorbed natural gas (ANG) is a third alternative to vessel storage, which has been intensively reported in the scientific and technical literature. Working pressures are considerably lower for ANG (3,5 MPa as compared to 25 MPa for CNG), which results in lower costs with vessel construction and compression and safer handling. The project ADSPOR, sponsored by PETROBRAS and part of the R and D portfolio of RedeGasEnergia, aims to assess the technical and economical feasibility of storing and transporting natural gas confined in carbon adsorbents. The objectives of this project are the production of high-capacity active carbons, the collection of adsorption data for NG storage and the economic evaluation of ANG. The present work presents a model for cost estimation of the ANG business, which comprises from the compression into ANG vessels until the distribution to the final costumer, taking into account several shipping modes. The variables involved in the model were: compression costs, equipment and materials technical data, costs with product handling and shipping costs for motor ways, railways and inland waterways. These variables were linked so as to generate a cost matrix that may be used to assess investment and calculate the final cost for GNA transport. The model may be used to carry out parameter sensitivity analysis, for decision-making and management purposes. (author)

  14. Preservation and storage of food using natural gas as an energy source; Preservacao e armazenamento de alimentos usando gas natural como fonte de energia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gabriel F. da; Lira, Moema de Lima; Carnelossi, Marcelo A.G.; Sousa, Mabel R. [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Dept. de Engenharia Quimica; Jesus, Marcos Fabio de [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Engenharia Quimica; Campos, Michel Fabianski; Martins, Ronaldo M.; Furini Filho, Roberto [PETROBRAS, Rio de Janeiro, RJ (Brazil); Santos, Sara Macedo dos [Centro de Tecnologias do Gas (CTGAS), Natal, RN (Brazil)

    2004-07-01

    In this work a study on preservation and storage of agricultural products was undertaken in chambers cooled through an absorption system, which used natural gas in the power plant and the results were compared with the compression system using electric energy. For the study a refrigeration pilot unit was mounted which consisted of chiller through water/ammonia absorption with direct natural gas burning, having a maximum consumption of 2,7{sup 3}/ h and capacity of 5 TR's, three refrigerating chambers with isopanel walls polyurethane, dimensions 2mx3mx2m with maximum capacity of storage of 2.000 kg each, control panel, a system of compressed natural gas supplying two carts each containing three cylinders with capacity of 71,4{sup 3} and a compression system connected to a chamber of same characteristics. Optimization studies in the storage of some fruits and vegetables were undertaken. A program was established which takes in account the food properties and characteristics of refrigeration systems to estimate the operational cost with the two systems. A techno-economic feasibility study was carried out on the two system of absorption and compression. This project was developed in the UFS, and is part of RedeGasEnergia, support for the financial aid was provided by PETROBRAS and FINEP/CTPETRO programs. (author)

  15. Venous velocity increase with a pneumatic foot compression garment.

    Science.gov (United States)

    Ilgenfritz, F M; Meier, J R

    1994-11-01

    Intermittent compression garments have been widely accepted for prophylaxis of deep venous thrombosis. They have broad applicability in both elective and emergent situations. Development of a new type of garment that acts to compress the plantar plexus of the foot provides a potential method of prophylaxis for patients with contraindications to the traditional calf- or thigh-high garments. Evaluation of the ability of the foot compression garment demonstrates a statistically significant increase in peak femoral venous velocity (40.6 cm/sec) as compared with the resting state (25.9 cm/sec). This increase in femoral venous velocity is comparable to that seen with single-cell compression socks. The authors conclude that the recently introduced foot garment produces increases in peak femoral venous velocity similar to those produced by existing garments and that use of the foot compression garment may provide deep venous thrombosis prophylaxis in patients who previously have not been candidates for a compression garment. PMID:7978509

  16. Compressed sensing for distributed systems

    CERN Document Server

    Coluccia, Giulio; Magli, Enrico

    2015-01-01

    This book presents a survey of the state-of-the art in the exciting and timely topic of compressed sensing for distributed systems. It has to be noted that, while compressed sensing has been studied for some time now, its distributed applications are relatively new. Remarkably, such applications are ideally suited to exploit all the benefits that compressed sensing can provide. The objective of this book is to provide the reader with a comprehensive survey of this topic, from the basic concepts to different classes of centralized and distributed reconstruction algorithms, as well as a comparison of these techniques. This book collects different contributions on these aspects. It presents the underlying theory in a complete and unified way for the first time, presenting various signal models and their use cases. It contains a theoretical part collecting latest results in rate-distortion analysis of distributed compressed sensing, as well as practical implementations of algorithms obtaining performance close to...

  17. [New aspects of compression therapy].

    Science.gov (United States)

    Partsch, Bernhard; Partsch, Hugo

    2016-06-01

    In this review article the mechanisms of action of compression therapy are summarized and a survey of materials is presented together with some practical advice how and when these different devices should be applied. Some new experimental findings regarding the optimal dosage (= compression pressure) concerning an improvement of venous hemodynamics and a reduction of oedema are discussed. It is shown, that stiff, non-yielding material applied with adequate pressure provides hemodynamically superior effects compared to elastic material and that relatively low pressures reduce oedema. Compression over the calf is more important to increase the calf pump function compared to graduated compression. In patients with mixed, arterial-venous ulcers and an ABPI over 0.6 inelastic bandages not exceeding a sub-bandage pressure of 40 mmHg may increase the arterial flow and improve venous pumping function. PMID:27259340

  18. Spectral Matching through Data Compression

    OpenAIRE

    Cerra, Daniele; Bieniarz, Jakub; Avbelj, Janja; Müller, Rupert; Reinartz, Peter

    2011-01-01

    This paper proposes to use compression-based similarity measures to cluster spectral signatures on the basis of their similarities. Such universal distances estimate the shared information between two objects by comparing their compression factors, which can be obtained by any standard compressor. Experiments on spectra, both collected in the field and selected from a hyperspectral scene, show that these methods may outperform traditional choices for spectral distances based on vecto...

  19. Learning Representations by Maximizing Compression

    OpenAIRE

    Gregor, Karol; LeCun, Yann

    2011-01-01

    We give an algorithm that learns a representation of data through compression. The algorithm 1) predicts bits sequentially from those previously seen and 2) has a structure and a number of computations similar to an autoencoder. The likelihood under the model can be calculated exactly, and arithmetic coding can be used directly for compression. When training on digits the algorithm learns filters similar to those of restricted boltzman machines and denoising autoencoders. Independent samples ...

  20. Geometric Results for Compressible Magnetohydrodynamics

    OpenAIRE

    Arter, Wayne

    2013-01-01

    Recently, compressible magnetohydrodynamics (MHD) has been elegantly formulated in terms of Lie derivatives. This paper exploits the geometrical properties of the Lie bracket to give new insights into the properties of compressible MHD behaviour, both with and without feedback of the magnetic field on the flow. These results are expected to be useful for the solution of MHD equations in both tokamak fusion experiments and space plasmas.

  1. Wet Gas Compression : Impeller Rig

    OpenAIRE

    Amundsen, Siren Carstens

    2009-01-01

    Wet gas compression technology is of great value to the oil and gas industry for boosting of unprocessed well stream and to reduce investment costs related to equipment and personnel. The growing interest in wet gas compression leads to a general request for accurate performance calculation procedures and proper measurement techniques for multiphase flow metering in compressors. An impeller rig for examination of single-phase and multiphase performance and aerodynamic stability is under con...

  2. Towards Conceptual Compression

    OpenAIRE

    Gregor, Karol; Besse, Frederic; Rezende, Danilo Jimenez; Danihelka, Ivo; Wierstra, Daan

    2016-01-01

    We introduce a simple recurrent variational auto-encoder architecture that significantly improves image modeling. The system represents the state-of-the-art in latent variable models for both the ImageNet and Omniglot datasets. We show that it naturally separates global conceptual information from lower level details, thus addressing one of the fundamentally desired properties of unsupervised learning. Furthermore, the possibility of restricting ourselves to storing only global information ab...

  3. Hidden force opposing ice compression

    CERN Document Server

    Sun, Chang Q; Zheng, Weitao

    2012-01-01

    Coulomb repulsion between the unevenly-bound bonding and nonbonding electron pairs in the O:H-O hydrogen-bond is shown to originate the anomalies of ice under compression. Consistency between experimental observations, density functional theory and molecular dynamics calculations confirmed that the resultant force of the compression, the repulsion, and the recovery of electron-pair dislocations differentiates ice from other materials in response to pressure. The compression shortens and strengthens the longer-and-softer intermolecular O:H lone-pair virtual-bond; the repulsion pushes the bonding electron pair away from the H+/p and hence lengthens and weakens the intramolecular H-O real-bond. The virtual-bond compression and the real-bond elongation symmetrize the O:H-O as observed at ~60 GPa and result in the abnormally low compressibility of ice. The virtual-bond stretching phonons ( 3000 cm-1) softened upon compression. The cohesive energy of the real-bond dominates and its loss lowers the critical temperat...

  4. Development of ultra-short high voltage pulse technology using magnetic pulse compression

    International Nuclear Information System (INIS)

    The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs

  5. Development of ultra-short high voltage pulse technology using magnetic pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L

    1998-01-01

    The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs.

  6. Compressive impact strength of high temperature gas-cooled reactor graphite

    International Nuclear Information System (INIS)

    To investigate the effect of strain rate on fracture behavior for coarse grained nuclear graphite, PGX, a hydraulic servo type impact testing machine has been constructed and compressive impact strength test was performed at various strain up to more than 100(1/s). From the results, the following conclusions were derived. (1) Compressive impact strength of graphite increases with increasing of strain rate in the range of 10-3 to 100(1/s). (2) Compressive impact strength decreases drastically for strain rates more than 100(1/s). (3) Compressive impact strength dose not depend on specimen volume. (author)

  7. Organization Authority File

    Data.gov (United States)

    National Archives and Records Administration — The Organization Authority Files data set contains a highly detailed presentation of the evolution of names and administrative histories of Federal and non-Federal...

  8. Copyright Authorization Statement

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclu-sively to the editorial department of Meteorological and Environmental Research the digital reproduction

  9. Copyright Authorization Statement

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclu-sively to the editorial department of Meteorological and Environmental Research the digital reproduction

  10. GUIDE TO AUTHOR

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sciences in Cold and Arid Regions has no page chargesManuscript Submission.Sciences in Cold and Arid Regions operates an online submission and peer review system that allows authors to submit articles onlineand track their

  11. Distributed Authorization in Vanadium

    OpenAIRE

    Taly, Ankur; Shankar, Asim

    2016-01-01

    In this tutorial, we present an authorization model for distributed systems that operate with limited internet connectivity. Reliable internet access remains a luxury for a majority of the world's population. Even for those who can afford it, a dependence on internet connectivity may lead to sub-optimal user experiences. With a focus on decentralized deployment, we present an authorization model that is suitable for scenarios where devices right next to each other (such as a sensor or a frien...

  12. Author Identification in Dialnet

    OpenAIRE

    Bergasa, Eduardo

    2012-01-01

    26 slides.-- Presentation delivered at the Topic Session "Identifiers". The presentation introduces the Dialnet Foundation, a public non-profit organisation founded 2009 as a Spin-off from the University of La Rioja in Spain, and the Dialnet portal whose database holds nearly 4M documents, mostly in Spanish. Authority control is one of the strategic Dialnet worklines and permanent cleaning work is done on the over 2.5M author records in cooperation with universities and other institutions....

  13. Authority Control for INVENIO

    CERN Document Server

    Dickinson, Christopher Michael; Omar, Abou Khaled; Felber, Pascal

    This is the final report for a Bachelor project at the École d'Ingénieurs et d'Architectes (EIA-FR), in collaboration with the European Organization for Nuclear Research (CERN) near Geneva. The official starting date for this project was June 30th 2011. All of the work described in this document was done at CERN during an internship in the IT-UDS-CDS team. The goal of the project was to add authority contro1 to INVENIO. Authority control provides a library management software with two main functions. 1. It allows the disambiguation between similar or identical terms, such as author names referring to different people. 2. It allows for the collocation of seemingly distinct information that logically belongs together, e.g. alternate names for an author or institution. In recent years, INVENIO users have seen the need to control standardized ways of managing the names of authors and institutions, journals and subjects. “Authority records” keep track of the standard way (e.g. “Curie, Marie”) as well as...

  14. MRI analysis of vascular compressive trigeminal neuralgia

    International Nuclear Information System (INIS)

    Objective: To analyze the offending vessels of vascular compressive trigeminal neuralgia by magnetic resonance tomographic angiography (MRTA). Methods: MRTA images of 235 asymptomatic trigeminal nerves and 147 symptomatic trigeminal nerves were analyzed by two radiologists who were blinded to the clinical findings. Judgment was made on if there were some vessels close to the trigeminal nerve. The diameter of the offending vessel, the distance from the offending vessel's contact point to the pons and the direction of the vessel toward the nerve were also recorded at the same time. Group t-test and Chi-Square test were used for statistics. Results: Two hundred and forty-two trigeminal nerves of all 382 nerves can be detected offending vessels on MRTA images, 111 of 242 trigeminal nerves were asymptomatic, the rest 131 were symptomatic. Statistical analysis indicated that the distance from the offending vessel's contact point to the pons in symptomatic group (the median is 2 mm) was shorter than that in the asymptomatic group (the median is 4 mm) (P<0.01). In 89.3% cases (117/131) of the symptomatic group the angle between the vessel and the nerve is larger than 45 degree, but only in 67.6% cases (75/111) in the asymptomatic group the angle is larger than 45 degree. That means significant difference is between the two groups (P<0.01). Vessel-nerve compression can be seen in 1 case of asymptomatic group (0.4%, 1/235) and 45 eases in symptomatic group (30.6%, 45/147). The vessel-nerve compression rate of the symptomatic group was much higher than that of the asymptomatic group (P<0.01). Conclusion: MR is a useful tool to evaluate the offending vessels of vascular compressive trigeminal neuralgia. The distance from the offending vessel's contact point to the pons and the direction of the vessel toward the nerve are related to the onset of vascular compressive trigeminal neuralgia. (authors)

  15. Fast and Adaptive Lossless Onboard Hyperspectral Data Compression System

    Science.gov (United States)

    Aranki, Nazeeh I.; Keymeulen, Didier; Kimesh, Matthew A.

    2012-01-01

    Modern hyperspectral imaging systems are able to acquire far more data than can be downlinked from a spacecraft. Onboard data compression helps to alleviate this problem, but requires a system capable of power efficiency and high throughput. Software solutions have limited throughput performance and are power-hungry. Dedicated hardware solutions can provide both high throughput and power efficiency, while taking the load off of the main processor. Thus a hardware compression system was developed. The implementation uses a field-programmable gate array (FPGA). The implementation is based on the fast lossless (FL) compression algorithm reported in Fast Lossless Compression of Multispectral-Image Data (NPO-42517), NASA Tech Briefs, Vol. 30, No. 8 (August 2006), page 26, which achieves excellent compression performance and has low complexity. This algorithm performs predictive compression using an adaptive filtering method, and uses adaptive Golomb coding. The implementation also packetizes the coded data. The FL algorithm is well suited for implementation in hardware. In the FPGA implementation, one sample is compressed every clock cycle, which makes for a fast and practical realtime solution for space applications. Benefits of this implementation are: 1) The underlying algorithm achieves a combination of low complexity and compression effectiveness that exceeds that of techniques currently in use. 2) The algorithm requires no training data or other specific information about the nature of the spectral bands for a fixed instrument dynamic range. 3) Hardware acceleration provides a throughput improvement of 10 to 100 times vs. the software implementation. A prototype of the compressor is available in software, but it runs at a speed that does not meet spacecraft requirements. The hardware implementation targets the Xilinx Virtex IV FPGAs, and makes the use of this compressor practical for Earth satellites as well as beyond-Earth missions with hyperspectral instruments.

  16. Object-Based Image Compression

    Science.gov (United States)

    Schmalz, Mark S.

    2003-01-01

    Image compression frequently supports reduced storage requirement in a computer system, as well as enhancement of effective channel bandwidth in a communication system, by decreasing the source bit rate through reduction of source redundancy. The majority of image compression techniques emphasize pixel-level operations, such as matching rectangular or elliptical sampling blocks taken from the source data stream, with exemplars stored in a database (e.g., a codebook in vector quantization or VQ). Alternatively, one can represent a source block via transformation, coefficient quantization, and selection of coefficients deemed significant for source content approximation in the decompressed image. This approach, called transform coding (TC), has predominated for several decades in the signal and image processing communities. A further technique that has been employed is the deduction of affine relationships from source properties such as local self-similarity, which supports the construction of adaptive codebooks in a self-VQ paradigm that has been called iterated function systems (IFS). Although VQ, TC, and IFS based compression algorithms have enjoyed varying levels of success for different types of applications, bit rate requirements, and image quality constraints, few of these algorithms examine the higher-level spatial structure of an image, and fewer still exploit this structure to enhance compression ratio. In this paper, we discuss a fourth type of compression algorithm, called object-based compression, which is based on research in joint segmentaton and compression, as well as previous research in the extraction of sketch-like representations from digital imagery. Here, large image regions that correspond to contiguous recognizeable objects or parts of objects are segmented from the source, then represented compactly in the compressed image. Segmentation is facilitated by source properties such as size, shape, texture, statistical properties, and spectral

  17. Six beam spherical compression of plasma focus guns

    International Nuclear Information System (INIS)

    A preliminary experiment with a one beam plasma focus is carried out to confirm plasma formation with the lowest input energy of 0.2 kJ for six beam spherical compression of plasma focus guns. The plasma front of this cableless gun can be used for compression and for the coupling of six guns situated along three rectangular axes, providing a good plasma focus pinch instantaneously or many plasma focus pinches continuously. The whole device with the energy bank is mounted on a sphere, and the minimum requirement for the plasma chamber of this sphere is a diameter of ∼ 22 cm. (author). 4 refs, 3 figs

  18. High-order compressibility integrals in classical fluids

    International Nuclear Information System (INIS)

    The normalization condition of the 3- and 4-particle distribution functions is used to integrate the closure relations that generalize the well-known Ornstein-Zernike (OZ) integral for the compressibility and the two-particle correlation. In a similar way to the two-body OZ relation, the 3- and 4-particle closure integrals are written in terms of the compressibility and its derivatives, allowing their immediate evaluation. These explicit expressions are useful in the perturbation theory of fluids and in testing approximations for the 3- and 4-particle correlations, such as Kirkwood's superposition approximation. As an illustration, these closure integrals are evaluated for the hard-sphere system. (Author)

  19. TRIAXIAL COMPRESSIVE STRENGTH OF ULTRA HIGH PERFORMANCE CONCRETE

    Directory of Open Access Journals (Sweden)

    Radoslav Sovják

    2013-12-01

    Full Text Available The aim of this work is to describe the strength of Ultra High Performance Concrete (UHPC under triaxial compression. The main goal is to find a trend in the triaxial compressive strength development under various values of confinement pressure. The importance of triaxial tests lies in the spatial loading of the sample, which simulates the real loading of the material in the structure better than conventional uniaxial strength tests. In addition, the authors describe a formulation process for UHPC that has been developed without using heat treatment, pressure or a special mixer. Only ordinary materials available commercially in the Czech Republic were utilized throughout the material design process.

  20. Expanding Window Compressed Sensing for Non-Uniform Compressible Signals

    Directory of Open Access Journals (Sweden)

    Sung Ho Cho

    2012-09-01

    Full Text Available Many practical compressible signals like image signals or the networked data in wireless sensor networks have non-uniform support distribution in their sparse representation domain. Utilizing this prior information, a novel compressed sensing (CS scheme with unequal protection capability is proposed in this paper by introducing a windowing strategy called expanding window compressed sensing (EW-CS. According to the importance of different parts of the signal, the signal is divided into several nested subsets, i.e., the expanding windows. Each window generates its own measurements using a random sensing matrix. The more significant elements are contained by more windows, so they are captured by more measurements. This design makes the EW-CS scheme have more convenient implementation and better overall recovery quality for non-uniform compressible signals than ordinary CS schemes. These advantages are theoretically analyzed and experimentally confirmed. Moreover, the EW-CS scheme is applied to the compressed acquisition of image signals and networked data where it also has superior performance than ordinary CS and the existing unequal protection CS schemes.

  1. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Science in China Series D:Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science in China Press and Springer, is com-

  2. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    SCIENCE CHINA Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press and Springer, is committed to

  3. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Science in China Series D:Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science in China Press and

  4. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    SCIENCE CHINA Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press and Springer,

  5. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Science in China Series B: Chemistry, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is committed to

  6. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series E: Technological Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and

  7. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is committed to

  8. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer,

  9. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    SCIENCE CHINA Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press and Springer, is committed

  10. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series E:Technological Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science in China

  11. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer,

  12. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series E:Technological Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science in China Pr

  13. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    SCIENCE CHINA Physics, Mechanics & Astronomy, a monthly peer-reviewed academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Founation of China, and published by Science China Press and

  14. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    SCIENCE CHINA Mathematics, a peer review mathematical journal cosponsored by Chinese Academy of Sciences and National Natural Science Foundation of China, and published monthly in both print and electronic

  15. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    SCIENCE CHINA Mathematics,a peer review mathematical journal cosponsored by Chinese Academy of Sciences and National Natural Science Foundation of China,and published monthly in both print and electronic

  16. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    SCIENCE CHINA Physics, Mechanics & Astronomy, a monthly peer-reviewed academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press and

  17. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    SCIENCE CHINA Physics, Mechanics & Astronomy, a monthly peer-reviewed academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press and

  18. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Journal of Resources and Ecology is an international journal for the publication of recent works in the related fields of natural resources and ecology. The journal was established in 2010 and is published quarterly.

  19. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The Journal of Natural Gas Chemistry, a quarterly journal jointly edited by the Dalian Institute of Chemical Physics and the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, is devoted to reporting new and original experimental and theoretical research in the fields of natural gas chemistry, C1 chemistry, lower hydrocarbons chemistry, and hydrogen energy sources. The manuscripts should not have been published previously in any form or have been submitted for publication elsewhere.

  20. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The Journal of Natural Gas Chemistry, a quarterly journal jointly edited by the Dalian Institute of Chemical Physics and the Chengdu InStitute of Organic Chemistry, Chinese Academy of Sciences, is devoted to reporting new and original experimental and theoretical research in the fields of natural gas chemistry, C1 chemistry, lower hydrocarbons chemistry, and hydrogen energy sources. The manuscripts should not have been published previously in any form or have been submitted for publication elsewhere.

  1. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ The Journal of Natural Gas Chemistry, a quarterly journal jointly edited by the Dalian Institute of Chemical Physics and the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, is devoted to reporting new and original experimental and theoretical research in the fields of natural gas chemistry, C1 chemistry, lower hydrocarbons chemistry, and hydrogen energy sources. The manuscripts should not have been published previously in any form or have been submitted for publication elsewhere.

  2. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Journal of Resources and Ecology is an international journal for the publication of recent works in the related fields of natural resources and ecology.The journal was established in 2010 and is published quarterly. Journal of Resources and Ecology will consider manuscripts in the following categories: 1)Research articles:to present primary results from a completed key research project in the related fields of natural resources and

  3. 29 CFR 1926.803 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Compressed air. 1926.803 Section 1926.803 Labor Regulations... Compressed Air § 1926.803 Compressed air. (a) General provisions. (1) There shall be present, at all times... medical aspects of compressed air work and the treatment of decompression illness. He shall be...

  4. 29 CFR 1917.154 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  5. Restructuring Compressed Texts without Explicit Decompression

    CERN Document Server

    Goto, Keisuke; Inenaga, Shunsuke; Bannai, Hideo; Sakamoto, Hiroshi; Takeda, Masayuki

    2011-01-01

    We consider the problem of {\\em restructuring} compressed texts without explicit decompression. We present algorithms which allow conversions from compressed representations of a string $T$ produced by any grammar-based compression algorithm, to representations produced by several specific compression algorithms including LZ77, LZ78, run length encoding, and some grammar based compression algorithms. These are the first algorithms that achieve running times polynomial in the size of the compressed input and output representations of $T$. Since most of the representations we consider can achieve exponential compression, our algorithms are theoretically faster in the worst case, than any algorithm which first decompresses the string for the conversion.

  6. Authority and leadership in Surma society (Ethiopia)

    OpenAIRE

    Abbink, J.

    1997-01-01

    This article examines recent developments of local authority and 'leadership' among the Surma of southern Ethiopia, where the author carried out field research over the years 1990-1995. The intention is to analyse the nature of 'authority' in a non-State social formation, in which 'chiefs' in the proper sense of the word are absent. The author gives an overview of the three different political systems which have succeeded each other in Ethiopia since the late 19th century: Haile Selassie's fe...

  7. Contested sources of authority

    DEFF Research Database (Denmark)

    Kyed, Helene Maria; Buur, Lars

    2006-01-01

    In Mozambique, the current legal framework institutionalizes a rural–urban differentiation of local governance, allowing for elected representation in thirty-three urban settings and the recognition of ‘community authorities’ in rural areas. This article deals with the latter by exploring the......, are inadequate for understanding the current situation. In formerly war-torn Sussundenga District, kin-based authorities drew on elements from ‘traditional’ and ‘state-administrative’ domains of authority in order to be recognized. Varied definitions of tradition came to justify leadership, but the...

  8. Information for Authors

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Submission.All submitted manuscripts should contain original research not previously published and not under consideration for publication elsewhere.Authors are recommended to use the online submission service.To submit a manuscript,please visit http://www.climatechange.cn/,and follow the instructions to upload the paper files(in word format).Authors are encouraged to suggest the names and full contact details of potential referees on the understanding that the editor has the final decision on the selection of referees.

  9. The Reader as Author

    OpenAIRE

    Gillian Beer

    2014-01-01

    "The Reader as Author" explores how readers become co-authors of the literary experience, through the imaginative act of filling gaps or, indeed, through their resistance to authorial propositions. The “virtual witnessing” in Charles Darwin’s The Voyage of the Beagle and the companionable tone of Lewis Carroll’s Alice books—testify to the broad range of literary genres that invite readers to interact with and react to “author” texts beyond the initial writer’s control.

  10. Brief Guide for Authors

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Crop Journal is a bimonthly scientif ic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science, Chinese Academy of Agricultural Sciences and China Science Publishing & Media Group Ltd. Published by Elsevier and Science Press. General Requirements Contributions submitted to The Crop Journal must be original works of the author(s) that have not been previously published or simultaneously submitted to any other journals. The experiment related to crop yield should be conducted at least two locations or growing seasons with replications. All the results should be supported by appropriate statistical analyses. Scopes ? Crop Germplasm Resources ? Crop Genetics, Genomics and Molecular Biology

  11. Instructions to authors

    Directory of Open Access Journals (Sweden)

    2011-05-01

    Full Text Available This section is to be used by authors of the special issue "Social media and language learning: (revolution?" who write their text in English. Please use the model article file attached when writing your text. 1. Submission and publication principles Authors whose texts have been accepted agree to transfer the associated rights permanently to the Alsic journal. They are free to re-publish these works (in printed or electronic form subject to the following conditions: they clearly indicate t...

  12. Compressibility, turbulence and high speed flow

    CERN Document Server

    Gatski, Thomas B

    2013-01-01

    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  13. Natural gas in India

    International Nuclear Information System (INIS)

    Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

  14. Data Compression of Fingerprint Minutiae

    Directory of Open Access Journals (Sweden)

    VISHAL SHRIVASTAVA

    2012-02-01

    Full Text Available Biometric techniques have usual advantages over conventional personal identification technique. Among various commercially available biometric techniques such as face, fingerprint, Iris etc., fingerprint-based techniques are the most accepted recognition system. Fingerprints are trace or impression of patterns created byfriction ridges of the skin in the fingers and thumbs. Steganography usually used in smart card is a safe technique for authenticating a person. In steganography, biometric characteristic similar to fingerprint is hidden in an picture. As the quantity of information that can be stored by means of steganography is extremely restricted, compression mechanisms are essential in order to achieve reasonably little errors when finally checking fingerprints against the encoded templates. To decrease the volume of smart card, compression can beapplied to fingerprint template in order to make it take up fewer space. This paper is presenting the minutiae based inexpensive fingerprint compression technique. In minutiae based systems, the discontinuities in the regular ridge structure of fingerprint images are acknowledged in feature extraction step. During matching, asimilarity value between the features extracted from the template and the enter fingerprint images is calculated. This similarity value is used to appear at an accept / reject decision. We present a new approach based on delta compression for robustly compressing the fingerprint templates.

  15. New safety issues when moving from liquid fuels to natural gas

    International Nuclear Information System (INIS)

    Natural gas (NG) is produced whenever organic matter is decomposed in the absence of oxygen. The main constituent of natural gas is methane. In contrast to liquid fuels, methane has a boiling point far below normal ambient temperatures. Even the critical temperature is well below ambient. Therefore natural gas must be stored either as compressed natural gas (CNG) at very high pressures at ambient temperatures, or as liquefied natural gas (LNG) at very low temperatures. The basic safety issues are caused by loss confinement of either CNG or LNG. In both cases the issues are: global greenhouse effects of natural gas (methane); local fire and explosion hazards; and local asphyxiation hazards due to reduced oxygen content in the atmosphere breathed when air is mixed with methane. (author)

  16. Convergence of Compressible Euler-Maxwell Equations to Compressible Euler-Poisson Equations

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the convergence of time-dependent Euler-Maxwell equations to compressible Euler-Poisson equations in a torus via the non-relativistic limit is studied.The local existence of smooth solutions to both systems is proved by using energy estimates for first order symmetrizable hyperbolic systems. For well prepared initial data the convergence of solutions is rigorously justified by an analysis of asymptotic expansions up to any order. The authors perform also an initial layer analysis for general initial data and prove the convergence of asymptotic expansions up to first order.

  17. A radiative diffusion model for laser-compression simulations

    International Nuclear Information System (INIS)

    A radiation diffusion package is described which can handle the transport of continuum radiation arising from free-free and free-bound transitions in a laser-compressed plasma. This model has been incorporated into MEDUSA, a two temperature, 1-D Lagrangian computer code, and numerous computer runs have been carried out to study the effect of radiative preheat on target compression. The calculations show that in compression of a 10-μg solid carbon microsphere the radiation effects reduce the final target density by up to a factor of 6. In the case of a neon filled thin glass microballoon, the radiative preheat reduces maximum neon density by a factor of 3 while the maximum shell density drops from 105 Kg/m3 to 1.8 x 104 Kg/m3. (author)

  18. Sustainability of compressive residual stress by stress improvement processes

    International Nuclear Information System (INIS)

    Stress improvement processes are countermeasures against stress corrosion cracking in nuclear power plant components. It is necessary to confirm whether a compressive residual stress induced by stress improvement processes can be sustained under operation environment. In order to evaluate stability of the compressive residual stress in 60-year operating conditions, the 0.07% cyclic strains of 200 times at 593 K were applied to the welded specimens, then a thermal aging treatment for 1.66×106 s at 673 K was carried out. As the result, it was confirmed that the compressive residual stresses were sustained on both surfaces of the dissimilar welds of austenitic stainless steel (SUS316L) and nickel base alloy (NCF600 and alloy182) processed by laser peening (LP), water jet peening (WJP), ultrasonic shot peening (USP), shot peening (SP) and polishing under 60-year operating conditions. (author)

  19. The Author Strikes Back

    DEFF Research Database (Denmark)

    Jansen, Hanne

    Many internationally published writers supply their translators with additional comments on the work to be translated. The aim of this paper is to study the kind of information that authors choose to convey to their translators, and to reflect on the degree in which, besides conveying factual and...

  20. Brief Guide for Authors

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The Crop Journal is a bimonthly scientific journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences and China Science Publishing&Media; Group Ltd.Published by Elsevier and Science Press.General Requirements Contributions submitted to The Crop Journal must be original works of the author(s)that

  1. Instructions for authors

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正Aims and scope Chinese Birds, launched from March 2010, is an international journal of ornithology jointly sponsored by Beijing Forestry University and the China Ornithological Society. The Journal intents to publish primarily peer-reviewed original articles, reviews and short communications produced by authors across the world, covering the full

  2. Instruction for authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Aims and scope Chinese Birds, launched from March 2010, is an international journal of ornithology jointly sponsored by Beijing Forestry University and the China Ornithological Society. The Journal intents to publish primarily peer-reviewed original articles, reviews and short communications produced by authors across the world, covering the full spectrum of subjects in ornithology,

  3. GUIDE TO AUTHOR

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sciences in Cold and Arid Regions has no page charges Manuscript Submission. Sciences in Cold and Arid Regions operates an online submission and peer review system that allows authors to submit articles online and track their progress via a web interface.

  4. GUIDE TO AUTHOR

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Sciences in Cold and Arid Regions has no page charges Manuscript Submission.Sciences in Cold and Arid Regions operates an online submission and peer review system that allows authors to submit articles online and track their progress via a web interface. To submit a manuscript, please visit http://www.SCAR.ac.cn/, log on, get an account, and follow

  5. GUIDE TO AUTHOR

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Sciences in Cold and Arid Regions has no page charges Manuscript Scbmission.Sciences in Cold and Arid Regions operates an online submission and peer review system that allows authors to submit articles online and track their progress via a web interface.to submit a manuscript,

  6. GUIDE TO AUTHOR

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Sciences in Cold and Arid Regions has no page charges Manuscript Submission. Sciences in Cold and Arid Regions operates an online submission and peer review system that allows authors to submit articles onlineand track their progress via a web interface. To submit a manuscript,

  7. GUIDE TO AUTHOR

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sciences in Cold and Arid Regions has no page chargesManuscript Submission. Sciences in Cold and Arid Regions operates an online submission and peer review system that allows authors to submit articles onlineand track their progress via a web interface. To submit a manuscript, please visit http://www.SCAR.ac.cn/, log on, get an account, and follow the

  8. Dynamic compression test of ceramics using modified compression split Hopkinson bar

    International Nuclear Information System (INIS)

    The misalignment of the flat anvil of a testing machine with the end of a circular rod specimen causes local crushing due to the stress concentration and bending moment, which must be avoided in compression tests. When very hard material, such as fine ceramics, is tested using the compression split Hopkinson bar, the hard specimen may be indented into the incident and transmission bars. In this paper, the insertion of a thin metal plate between the bar-specimen interface in the conventional compression split Hopkinson bar system was examined to prevent indentation. The stress pulse in the incident and transmission bars in measured using the thin steel plate (thickness 0.4 and 1 mm), copper (1 mm) and aluminium (1 mm), and the pulse profile is investigated. The configuration of the wave observed using the thin steel plate (0.4 mm) is the sharpest, and is similar to that without the plate. The rise of pulses using the steel plate (1 mm) is ramplike. With use of a copper plate and aluminium, the two-step profile appears. The stress-strain relationship evaluated from these stress pulses was compared with that obtained in the static test. The dynamic strength of ceramics is less than about half the static strength. (author)

  9. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Journal of Resources and Ecology is an international journal for the publication of recent works in the related fields of natural resources and ecology.The journal was established in 2010 and is published quarterly. Journal of Resources and Ecology will consider manuscripts in the following categories: 1) Research articles:to present primary results from a completed key research project in the related fields of natural resources and ecology. 2) Subject Reports:to introduce interim results from a key research project,experimental reports,and progresses in the research on specific regions or specific topics.

  10. A new class of low compressibility materials: Clathrates of silicon and related materials

    OpenAIRE

    San Miguel, Alfonso; Mélinon, Patrice; Blase, Xavier; Tournus, Florent; Connétable, Damien; Reny, Édouard; Yamanaka, Shoji; Itié, Jean-Paul; Cros, Christian; Pouchard, Michel

    2002-01-01

    We discuss the high pressure properties of different silicon clathrate structures that we have investigated by means of X-ray diffraction and ab initio calculations. Compressibility transition pressures or phase transformations are interpreted as a function of the nature of the guest atom intercalation, The compressibility of the clathrate structure is in all cases close to that of silicon diamond whereas transition pressures or the high pressure phases are extremely depending on the nature o...

  11. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  12. Compressive Sensing for MIMO Radar

    CERN Document Server

    Yu, Yao; Poor, H Vincent

    2009-01-01

    Multiple-input multiple-output (MIMO) radar systems have been shown to achieve superior resolution as compared to traditional radar systems with the same number of transmit and receive antennas. This paper considers a distributed MIMO radar scenario, in which each transmit element is a node in a wireless network, and investigates the use of compressive sampling for direction-of-arrival (DOA) estimation. According to the theory of compressive sampling, a signal that is sparse in some domain can be recovered based on far fewer samples than required by the Nyquist sampling theorem. The DOA of targets form a sparse vector in the angle space, and therefore, compressive sampling can be applied for DOA estimation. The proposed approach achieves the superior resolution of MIMO radar with far fewer samples than other approaches. This is particularly useful in a distributed scenario, in which the results at each receive node need to be transmitted to a fusion center for further processing.

  13. Compressive Sensing in Communication Systems

    DEFF Research Database (Denmark)

    Fyhn, Karsten

    2013-01-01

    Wireless communication is omnipresent today, but this development has led to frequency spectrum becoming a limited resource. Furthermore, wireless devices become more and more energy-limited, due to the demand for continual wireless communication of higher and higher amounts of information. The...... need for cheaper, smarter and more energy efficient wireless devices is greater now than ever. This thesis addresses this problem and concerns the application of the recently developed sampling theory of compressive sensing in communication systems. Compressive sensing is the merging of signal...... acquisition and compression. It allows for sampling a signal with a rate below the bound dictated by the celebrated Shannon-Nyquist sampling theorem. In some communication systems this necessary minimum sample rate, dictated by the Shannon-Nyquist sampling theorem, is so high it is at the limit of what the...

  14. Compressive Hyperspectral Imaging via Approximate Message Passing

    Science.gov (United States)

    Tan, Jin; Ma, Yanting; Rueda, Hoover; Baron, Dror; Arce, Gonzalo R.

    2016-03-01

    We consider a compressive hyperspectral imaging reconstruction problem, where three-dimensional spatio-spectral information about a scene is sensed by a coded aperture snapshot spectral imager (CASSI). The CASSI imaging process can be modeled as suppressing three-dimensional coded and shifted voxels and projecting these onto a two-dimensional plane, such that the number of acquired measurements is greatly reduced. On the other hand, because the measurements are highly compressive, the reconstruction process becomes challenging. We previously proposed a compressive imaging reconstruction algorithm that is applied to two-dimensional images based on the approximate message passing (AMP) framework. AMP is an iterative algorithm that can be used in signal and image reconstruction by performing denoising at each iteration. We employed an adaptive Wiener filter as the image denoiser, and called our algorithm "AMP-Wiener." In this paper, we extend AMP-Wiener to three-dimensional hyperspectral image reconstruction, and call it "AMP-3D-Wiener." Applying the AMP framework to the CASSI system is challenging, because the matrix that models the CASSI system is highly sparse, and such a matrix is not suitable to AMP and makes it difficult for AMP to converge. Therefore, we modify the adaptive Wiener filter and employ a technique called damping to solve for the divergence issue of AMP. Our approach is applied in nature, and the numerical experiments show that AMP-3D-Wiener outperforms existing widely-used algorithms such as gradient projection for sparse reconstruction (GPSR) and two-step iterative shrinkage/thresholding (TwIST) given a similar amount of runtime. Moreover, in contrast to GPSR and TwIST, AMP-3D-Wiener need not tune any parameters, which simplifies the reconstruction process.

  15. Natural regularization

    International Nuclear Information System (INIS)

    We formulate natural regularization (NR) as a variant of dimensional regularization (DR). We replace the conventional dimensional reduction by a dimensionless regulator, allowing a transparent regularization of standard D-dimensional Feynman integrals. For arbitrary dimensions, we motivate and demonstrate explicitly the transition from the dimensionally reduced integration space to natural regularization. We establish the relation to cut-off regularization and point out the basic differences from dimensional regularization. Possible applications, such as to the axial anomaly or to gauge theories are briefly touched upon. (author)

  16. Schwarz-based algorithms for compressible flows

    Energy Technology Data Exchange (ETDEWEB)

    Tidriri, M.D. [ICASE, Hampton, VA (United States)

    1996-12-31

    To compute steady compressible flows one often uses an implicit discretization approach which leads to a large sparse linear system that must be solved at each time step. In the derivation of this system one often uses a defect-correction procedure, in which the left-hand side of the system is discretized with a lower order approximation than that used for the right-hand side. This is due to storage considerations and computational complexity, and also to the fact that the resulting lower order matrix is better conditioned than the higher order matrix. The resulting schemes are only moderately implicit. In the case of structured, body-fitted grids, the linear system can easily be solved using approximate factorization (AF), which is among the most widely used methods for such grids. However, for unstructured grids, such techniques are no longer valid, and the system is solved using direct or iterative techniques. Because of the prohibitive computational costs and large memory requirements for the solution of compressible flows, iterative methods are preferred. In these defect-correction methods, which are implemented in most CFD computer codes, the mismatch in the right and left hand side operators, together with explicit treatment of the boundary conditions, lead to a severely limited CFL number, which results in a slow convergence to steady state aerodynamic solutions. Many authors have tried to replace explicit boundary conditions with implicit ones. Although they clearly demonstrate that high CFL numbers are possible, the reduction in CPU time is not clear cut.

  17. Expandable image compression system: A modular approach

    International Nuclear Information System (INIS)

    The full-frame bit allocation algorithm for radiological image compression developed in the authors' laboratory can achieve compression ratios as high as 30:1. The software development and clinical evaluation of this algorithm has been completed. It involves two stages of operations: a two-dimensional discrete cosine transform and pixel quantization in the transform space with pixel depth kept accountable by a bit allocation table. Their design took an expandable modular approach based on the VME bus system which has a maximum data transfer rate of 48 Mbytes per second and a Motorola 68020 microprocessor as the master controller. The transform modules are based on advanced digital signal processor (DSP) chips microprogrammed to perform fast cosine transforms. Four DSP's built into a single-board transform module can process an 1K x 1K image in 1.7 seconds. Additional transform modules working in parallel can be added if even greater speeds are desired. The flexibility inherent in the microcode extends the capabilities of the system to incorporate images of variable sizes. Their design allows for a maximum image size of 2K x 2K

  18. Information for Authors

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  1. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The Journal of Natural Gas Chemistry is a quarterly Journal jointly edited by the Dalian Institute of Chemical Physics and the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences. Starting in 2006, Elsevier will publish the Journal on ScienceDirect, the online full text and bibliographic information resource, and take care of the Journal's international institutional print subscriptions.

  2. Instructions to Author

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ The Journal of Natural Gas Chemistry is a bimonthlyJournal jointly edited by the Dalian Institute of Chemical Physics and the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences in 2010.Starting in 2006, Elsevier published the Journal on ScienceDirect, the online full text and bibliographic information resource, and take care of the Journal's international institutional print subscriptions.

  3. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Journal of Resources and Ecology is an international journal for the publication of recent works in the related fields of natural resources and ecology.The journal was established in 2010 and is published quarterly.Journal of Resources and Ecology will consider manuscripts in the following categories:

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    Institute of Scientific and Technical Information of China (English)

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    SCIENCE CHINA Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press and Springer, is committed to pub-lishing high-quality, original results in both basic and applied research.

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    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is com- mitted to publishing high-quality, original results in both basic and applied research.

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    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is committed to publishing high-quality, original results in both basic and applied research.

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    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is com-mitted to publishing high-quality, original results in both basic and applied research.

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    SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to pub-lishing high-quality,original results in both basic and applied research.

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    Science in China Series D: Earth Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is com- mitted to publishing high-quality, original results in both basic and applied research.

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  15. Guide to Authors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Aims and scope With the tenet of concerning ecology and serving economy, aimed at constructing a harmonious society of man and nature, Ecological Economy focuses on the sustainable development of economy and the ecological environment, and puts attention on theories, methods and technical innovations concerning ecological/green economy, recycling/circular economy and ecological/green industry.

  16. Detecting Double Compressed JPEG Images

    Czech Academy of Sciences Publication Activity Database

    Mahdian, Babak; Saic, Stanislav

    Rostrevor : Curran Associates, Inc, 2010, P12. ISBN 978-1-84919-207-1. [3rd International Conference on Imaging for Crime Detection and Prevention (ICDP-09). London (GB), 03.12.2009-03.12.2009] R&D Projects: GA ČR GA102/08/0470 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image forensics * Blind forgery detection * double jpeg compression Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2011/ZOI/mahdian-detecting double compressed jpeg images.pdf

  17. Small helical flux compression amplifiers

    International Nuclear Information System (INIS)

    Small, explosively compressed, magnetic flux transducers with many closely spaced helical turns are investigated theoretically and experimentally. The analysis is limited to linear operation, but takes into account load influence, proximity effects, and switching delays. The latter are due to retarded breakdown in the wire insulation and to the finite decay time of the magnetic field in the wire. More than 150 experiments showed considerable data scatter. Shots which exhibited low clocking and high amplification were in good agreement with the theory. The main conclusion is that device performance is limited not only by flux loss, but by flux remaining in the generator after compression

  18. Instability of ties in compression

    DEFF Research Database (Denmark)

    Buch-Hansen, Thomas Cornelius

    2013-01-01

    Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from the...... temperature gradient between the outer and the inner wall, which results in critical increase of the bending moments in the ties. Since the ties are loaded by combined compression and moment forces, the loadbearing capacity is derived from instability equilibrium equations. Most of them are iterative, since...

  19. Compressibility of Nickel Nanoparticle Chain

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Dong; TANG Ling-Yun; LI Yan-Chun; LIU Jing

    2007-01-01

    We perform the high-pressure energy dispersive x-ray diffraction experiments of nickel nanoparticle chain using a synchrotron source under quasi-hydrostatic compression up to 44.7GPa. There is no phase transition over the pressure range. The bulk modulus Kg, the first pressure derivative of bulk modulus K'0 and the volume Vo are calculated from the pressure-volume data using the Birch-Murnaghan equation of state. A decrease of compressibility is observed, in agreement with the Hall-Petch effect.

  20. Extended testing of compression distillation.

    Science.gov (United States)

    Bambenek, R. A.; Nuccio, P. P.

    1972-01-01

    During the past eight years, the NASA Manned Spacecraft Center has supported the development of an integrated water and waste management system which includes the compression distillation process for recovering useable water from urine, urinal flush water, humidity condensate, commode flush water, and concentrated wash water. This paper describes the design of the compression distillation unit, developed for this system, and the testing performed to demonstrate its reliability and performance. In addition, this paper summarizes the work performed on pretreatment and post-treatment processes, to assure the recovery of sterile potable water from urine and treated urinal flush water.

  1. Simulating Ramp Compression of Diamond

    Science.gov (United States)

    Godwal, B. K.; Gonzàlez-Cataldo, F. J.; Jeanloz, R.

    2014-12-01

    We model ramp compression, shock-free dynamic loading, intended to generate a well-defined equation of state that achieves higher densities and lower temperatures than the corresponding shock Hugoniot. Ramp loading ideally approaches isentropic compression for a fluid sample, so is useful for simulating the states deep inside convecting planets. Our model explicitly evaluates the deviation of ramp from "quasi-isentropic" compression. Motivated by recent ramp-compression experiments to 5 TPa (50 Mbar), we calculate the room-temperature isotherm of diamond using first-principles density functional theory and molecular dynamics, from which we derive a principal isentrope and Hugoniot by way of the Mie-Grüneisen formulation and the Hugoniot conservation relations. We simulate ramp compression by imposing a uniaxial strain that then relaxes to an isotropic state, evaluating the change in internal energy and stress components as the sample relaxes toward isotropic strain at constant volume; temperature is well defined for the resulting hydrostatic state. Finally, we evaluate multiple shock- and ramp-loading steps to compare with single-step loading to a given final compression. Temperatures calculated for single-step ramp compression are less than Hugoniot temperatures only above 500 GPa, the two being close to each other at lower pressures. We obtain temperatures of 5095 K and 6815 K for single-step ramp loading to 600 and 800 GPa, for example, which compares well with values of ~5100 K and ~6300 K estimated from previous experiments [PRL,102, 075503, 2009]. At 800 GPa, diamond is calculated to have a temperature of 500 K along the isentrope; 900 K under multi-shock compression (asymptotic result after 8-10 steps); and 3400 K under 3-step ramp loading (200-400-800 GPa). Asymptotic multi-step shock and ramp loading are indistinguishable from the isentrope, within present uncertainties. Our simulations quantify the manner in which current experiments can simulate the

  2. Compressing the Inert Doublet Model

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, Nikita [TRIUMF and Univ. of British Columbia, Vancouver, BC (Canada); SLAC National Accelerator Lab., Menlo Park, CA (United States; Kozaczuk, Jonathan [TRIUMF and Univ. of British Columbia, Vancouver, BC (Canada); Morrissey, David E. [TRIUMF and Univ. of British Columbia, Vancouver, BC (Canada); de la Puente, Alejandro [TRIUMF and Univ. of British Columbia, Vancouver, BC (Canada); Carleton Univ., Ontario (Canada)

    2015-10-29

    The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. We found that this stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. Furthermore, we derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.

  3. PREPARATION OF BIOACTIVE NANOSTRUCTURE SCAFFOLD WITH IMPROVED COMPRESSIVE STRENGTH

    Directory of Open Access Journals (Sweden)

    R. EMADI

    2011-03-01

    Full Text Available Highly porous scaffolds with open structure are today the best candidates for bone substitution to ensure bone oxygenation and angiogenesis. In this study, we developed a new route to enhance the compressive strength of porous hydroxyapatite scaffold made of natural bone. Briefly, the spongy bone of an adult bovine was extracted, annealed, and coated by a nanostructure bioactive glass layer to be subsequently sintered at different temperatures. The apatite formation ability on the surfaces of the coated scaffolds was investigated by standard procedures. Our results showed that the scaffold and coating microstructure consisted of the grains smaller than 100 nm. These nanostructures improved the compressive strength and bioactivity of highly porous scaffold. The results showed that with increasing the sintering temperature, the compressive strength of scaffolds increased while their in vitro bioactivity decreased.

  4. Analysis on soil compressibility changes of samples stabilized with lime

    Directory of Open Access Journals (Sweden)

    Elena-Andreea CALARASU

    2016-12-01

    Full Text Available In order to manage and control the stability of buildings located on difficult foundation soils, several techniques of soil stabilization were developed and applied worldwide. Taking into account the major significance of soil compressibility on construction durability and safety, the soil stabilization with a binder like lime is considered one of the most used and traditional methods. The present paper aims to assess the effect of lime content on soil geotechnical parameters, especially on compressibility ones, based on laboratory experimental tests, for several soil categories in admixture with different lime dosages. The results of this study indicate a significant improvement of stabilized soil parameters, such as compressibility and plasticity, in comparison with natural samples. The effect of lime stabilization is related to an increase of soil structure stability by increasing the bearing capacity.

  5. Use of compressed-air storage systems; Einsatz von Druckluftspeichersystemen

    Energy Technology Data Exchange (ETDEWEB)

    Cyphely, I.; Rufer, A.; Brueckmann, Ph.; Menhardt, W.; Reller, A.

    2004-07-01

    This final report issued by the Swiss Federal Office of Energy (SFOE) looks at the use of compressed air as a means of storing energy. Historical aspects are listed and compressed-air storage as an alternative to current ideas that use electrolysis and hydrogen storage is discussed. The storage efficiency advantages of compressed-air storage is stressed and the possibilities it offers for compensating the stochastic nature of electricity production from renewable energy sources are discussed. The so-called BOP (Battery with Oil-hydraulics and Pneumatics) principle for the storage of electricity is discussed and its function is described. The advantages offered by such a system are listed and the development focus necessary is discussed.

  6. Compression characteristics and permeability of saturated Gaomiaozi ca-bentonite

    International Nuclear Information System (INIS)

    The compression characteristics and permeability of compacted Gaomiaozi Ca-bentonite saturated by the water uptake tests are studied by conducting a series of one-dimension compression tests. The permeability coefficient can be calculated by the Terzaghi's one-dimensional consolidation theory after the consolidation coefficient is obtained by the square root of time method. It is found that the compression curves of compacted specimens saturated by the water uptake tests tend to be consistent in the relatively high stress range. The compression indexes show a linear decrease with increasing dry density and the swelling index is a constant. The permeability coefficient decreases with increasing compression stress, and they show the linear relationship in double logarithmic coordinates. Meanwhile, the permeability coefficient shows a linear decrease with decreasing void ratio, which has no relationship with initial states, stress states and stress paths. The permeability coefficient k of GMZ Ca-bentonite at dry density Pd of 1.75 g/cm3 can be calculated as 2.0 × 10-11 cm/s by the linear relationship between Pd and log k. It is closed to the permeability coefficient of GMZ Ca-bentonite with the same dry density published in literature, which testifies that the method calculating the permeability coefficient is feasible from the consolidation coefficient obtained by the consolidation test. (authors)

  7. Equation of state of laser-shocked compressed iron

    International Nuclear Information System (INIS)

    This thesis enters the field of highly compressed materials equation of state studies. In particular, it focuses on the case of laser shock compressed iron. This work indeed aims at getting to the conditions of the earth's core, comprising a solid inner core and a liquid outer core. The understanding of phenomena governing the core's thermodynamics and the geodynamic process requires the knowledge of iron melting line locus around the solid-liquid interface at 3.3 Mbar. Several experiments were performed to that extent. First, an absolute measurement of iron Hugoniot was obtained. Following is a study of partially released states of iron into a window material: lithium fluoride (LiF). This configuration enables direct access to compressed iron optical properties such as reflectivity and self-emission. Interface velocity measurement is dominated by compressed LiF optical properties and is used as a pressure gauge. Using a dual wavelength reflectivity diagnostic, compressed iron electrical conductivity was estimated and found to be in good agreement with previous results found in geophysics literature. Self-emission diagnostic was used to measure temperature of partially released iron and revealed a solid-liquid phase transition at Mbar pressures. (author)

  8. Measurement of compressed breast thickness by optical stereoscopic photogrammetry

    International Nuclear Information System (INIS)

    The determination of volumetric breast density (VBD) from mammograms requires accurate knowledge of the thickness of the compressed breast. In attempting to accurately determine VBD from images obtained on conventional mammography systems, the authors found that the thickness reported by a number of mammography systems in the field varied by as much as 15 mm when compressing the same breast or phantom. In order to evaluate the behavior of mammographic compression systems and to be able to predict the thickness at different locations in the breast on patients, they have developed a method for measuring the local thickness of the breast at all points of contact with the compression paddle using optical stereoscopic photogrammetry. On both flat (solid) and compressible phantoms, the measurements were accurate to better than 1 mm with a precision of 0.2 mm. In a pilot study, this method was used to measure thickness on 108 volunteers who were undergoing mammography examination. This measurement tool will allow us to characterize paddle surface deformations, deflections and calibration offsets for mammographic units.

  9. INFORMATION FOR AUTHORS

    Directory of Open Access Journals (Sweden)

    Revista Ciencias Biomedicas

    2015-01-01

    Full Text Available REVISTA CIENCIAS BIOMEDICAS (Rev.cienc.biomed. is included in: IMBIOMED, ACADEMIC GOOGLE, ENCOLOMBIA.COM, GOOGLE SCHOLAR, DOAJ, PUBLINDEX, WORLD CAT and ACADEMIC.EDU. It receives original scientific articles about a variety of topics that keep relation with the health sciences, so much of basic as clinical application. These issues need to be inside knowledge area that could interest both undergraduate as postgraduate students, as well as professionals in the health area. The following recommendations should be considered. 1. Authorship. Each author must have contributed substantially to the successful development of the research process. According to international standards, the criteria that each author must meet are: • Substantial contributions to conception, design, data acquisition or analysis and data interpretation. • To write the article and to check it for intellectually important content. • Final approval of the version to be published. “Courtesy authors” identifications or designations will not be accepted if the researcher has not met the delineated criteria (e.g. head of school / department / research group that presents the paper. 2. Interest conflicts and funding. An author of an article to be considered may be involved in two types of interest conflicts. The first one relates directly to the work authors and the financial and personal relationships that could influence or bias the manuscript in some way. The second type of interest conflict is related to the financial backer of the research. The authors must admit and say when sending the paper if there is any interference or limitation of the financial backer with regard to the analysis and interpretation of the information, writing or manuscript submission. The existence or absence of interest conflicts must be specified at the end of the article. It must be also specified whether it has received money by way of funding, specifying the origins and codes of calls where

  10. Authors: who contributes what?

    Science.gov (United States)

    Squires, B P

    1996-10-01

    In this issue (see pages 877 to 882) Dr. H. Dele Davies and associates examine how a sample of pediatric department chairs and faculty deans' offices perceive the involvement of faculty members in medical research. Their findings point to the confusion that surrounds the question of authorship in collaborative research. Dr. Drummond Rennie, deputy editor of the Journal of the American Medical Association, has proposed that a complete and descriptive list of "contributors" replace author lists and acknowledgements. Slight modifications to the International Committee of Medical Journal Editors guidelines on authorship retain the designation "author" and the use of acknowledgements but encourage the explicit description of each investigator's contribution. Researchers and editors should continue to explore ways to ensure that contributions to published research are clearly and honestly identified. PMID:8837537

  11. About the author

    OpenAIRE

    Olukoju, Ayodeji

    2013-01-01

    Ayodeji Olukoju is Professor and Head, Department of History, University of Lagos. A First Class Honours graduate of the University of Nigeria. Nsukka. and holder of the M.A. and Ph.D. Degrees in History of the University of Ibadan. He has authored and co-edited several books and monographs, including Maritime Trade, Port Development and Administration (Tokyo, 1996), Nigeria Peoples and Cultures (Ibadan 1997) and Positive Leadership in Colonial and Post-Colonial Africa (Ikorodu, Nigeria, 2002...

  12. Instructions for authors

    OpenAIRE

    Mostovski, Mike

    2015-01-01

    The Israel Journal of Entomology is a peer-reviewed journal that publishes original contributions in all areas of entomology and has a world-wide scope. Authors are entirely responsible for statements, whether fact or opinion. Manuscripts are considered on the understanding that they have not been submitted elsewhere for prior or simultaneous publication. Manuscripts are reviewed by at least two independent referees and approved by the Editorial Board before acceptance. ...

  13. Brief Guide for Authors

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Crop Journal is a bimonthly scientific journal co-sponsored by the Crop Science Society of China and the institute of Crop Science,Chinese Academy of Agricultural Sciences and China Science Publishing&Media Group Ltd.Published by Elsevier and Science Press.General Requirements Contributions submitted to The Crop Journal must be original works of the author(s)that have not been previously published or simultaneously

  14. Brief Guide for Authors

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Crop Journal is a bimonthly scientific journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences and China Science Publishing&Media Group Ltd.Published by Elsevier and Science Press.General Requirements Contributions submitted to The Crop Journal must be original works of the author(s)that have not been previously published or simultaneously submitted to any other journals.

  15. Brief Guide for Authors

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    <正>The Crop Journal is a bimonthly scientific journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences and China Science Publishing&Media Group Ltd.Published by Elsevier and Science Press.General Requirements Contributions submitted to The Crop Journal must be original works of the author(s)that have not been previously published or simultaneously submitted to any other journals.

  16. Instructions for Authors

    Directory of Open Access Journals (Sweden)

    Editors Editorial Board

    2012-05-01

    Full Text Available Authors must submit their papers via email to brain@edusoft.ro or they can create an account and submit their papers online, at www.brain.edusoft.ro. Submited papers must be written in DOC format (Microsoft Word document, in as clear and as simple as possible English. Preferred maximum paper length for the papers is 20 pages, including figures. The template for the paper is at this address: http://www.edusoft.ro/Template_for_BRAIN.doc

  17. Instructions for authors

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Aims and scope Chinese Birds,launched from March 2010,is an international journal of ornithology jointly sponsored by Beijing Forestry University and the China Ornithological Society.The Journal intents to publish primarily peer-reviewed original articles,reviews and short communications produced by authors across the world,covering the full spectrum of subjects in ornithology,including research in fossil birds.

  18. Instructions for authors

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Aims and scope Chinese Birds,launched from march 2010,is an international journal of ornithology jointly sponsored by Beijing forestry University and the china ornithological Society.the Journal intents to publish primarily peer-reviewed original articles,reviews and short communications produced by authors across the world,covering the full spectrum of subjects in ornithology,including research in fossil birds.

  19. Instructions for authors

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    正Aims and scope Chinese Birds, launched from March 2010, is an international journal of ornithology jointly sponsored by Beijing Forestry University and the China Ornithological Society. The Journal intents to publish primarily peer-reviewed original articles, reviews and short communications produced by authors across the world, covering the full spectrum of subjects in ornithology, including research in fossil birds. Manuscript requirements Title page

  20. Viscoelasticity of Tendons Under Transverse Compression.

    Science.gov (United States)

    Paul Buckley, C; Samuel Salisbury, S T; Zavatsky, Amy B

    2016-10-01

    Tendons are highly anisotropic and also viscoelastic. For understanding and modeling their 3D deformation, information is needed on their viscoelastic response under off-axis loading. A study was made, therefore, of creep and recovery of bovine digital extensor tendons when subjected to transverse compressive stress of up to ca. 100 kPa. Preconditioned tendons were compression tested between glass plates at increasing creep loads. The creep response was anomalous: the relative rate of creep reduced with the increasing stress. Over each ca. 100 s creep period, the transverse creep deformation of each tendon obeyed a power law dependence on time, with the power law exponent falling from ca. 0.18 to an asymptote of ca. 0.058 with the increasing stress. A possible explanation is stress-driven dehydration, as suggested previously for the similar anomalous behavior of ligaments. Recovery after removal of each creep load was also anomalous. Relative residual strain reduced with the increasing creep stress, but this is explicable in terms of the reducing relative rate of creep. When allowance was made for some adhesion occurring naturally between tendon and the glass plates, the results for a given load were consistent with creep and recovery being related through the Boltzmann superposition principle (BSP). The tendon tissue acted as a pressure-sensitive adhesive (PSA) in contact with the glass plates: explicable in terms of the low transverse shear modulus of the tendons. PMID:27496279

  1. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Cellular & Molecular Immunology (CMI) is the official publication of the Chinese Society of Immunology. The Journal is published bimonthly in English and edited at the University of Science & Technology of China (USTC). Papers in all areas of cellular and molecular immunology are welcome including immunobiology, comparative immunology, immunogenetics, neuroimmunology, immunopathology, immunopharmacology, tumor immunology, infection immunology, clinical immunology, transplantation immunology, veterinary immunology and immunological techniques. All international immunologists and irnmunologyrelated investigators will find CMI suitable for their publications. CMI publishes articles and brief reports for original investigations. Reviews and minireviews are also accepted from authors on request by the editorial board of the journal A paper is submitted to CMI with the understanding that it has not been and will not be published elsewhere. The submission must have the approval of all of the authors. The preferred medium of final submission to the accepting editor is on computer disk with the accompanying reviewed and revised manuscript (see 'electronic manuscripts' below). Publication in CMI is taken to imply the authors' willingness to comply with reasonable requests to supply reagents such as recombinant clones and monoclonal antibodies, and sequence data in electronic form to persons lacking access to computer databases.

  2. Instructions to Authors

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Cellular & Molecular Immunology (CMI) is the official publication of the Chinese Society of Immunology. The Journal is published bimonthly in English and edited at the University of Science & Technology of China (USTC). Papers in all areas of cellular and molecular immunology are welcome including immunobiology, comparative immunology, immunogenetics, neuroimmunology, immunopathology, immunopharmacology, tumor immunology, infection immunology, clinical immunology, transplantation immunology, veterinary immunology and immunological techniques. All international immunologists and immunologyrelated investigators will find CMI suitable for their publications. CMI publishes articles and brief reports for original investigations. Reviews and minireviews are also accepted from authors on request by the editorial board of the journal. A paper is submitted to CMI with the understanding that it has not been and will not be published elsewhere. The submission must have the approval of all of the authors. The preferred medium of final submission to the accepting editor is on computer disk with the accompanying reviewed and revised manuscript (see'electronic manuscripts' below). Publication in CMI is taken to imply the authors' willingness to comply with reasonable requests to supply reagents such as recombinant clones and monoclonal antibodies, and sequence data in electronic form to persons lacking access to computer databases.

  3. GUIDELINES FOR AUTHORS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    1 THE JOURNAL The Journal publishes original papers in all fields of sustainable development. Papers are peer-reviewed according to the generally accepted criteria for scientific work. 2 AUTHORS' RESPONSIBILITIES Authors are responsible for the originality of the work, permission to publish and permission to reproduce any cited figures, and proofreading. 3 MANUSCRIPT PREPARATION All papers must be in English. Papers are restricted to 5000 words in length. Papers with fewer than 1500 words will be considered as Short Notes. Manuscripts must be double-spaced, on one side of the paper only and on standard sized paper (e. g. European A4 - 21 by 29.6 cm). Each paper should consist of the following sections, in order: title, abstract, key words, text, acknowledgments, references, intemet references, figure captions, figures, table captions, tables and appendices (if any), photograph captions, photographs. Pages should be numbered. Author should provide e-mail of corresponding author. Title - The title should be brief but accurately descriptive of the contents. The title should be followed by authors' names,( as they are to appear in print) and institutional affiliations. The corresponding author's e-mail address should follow (or fax- number if no e-mail is available).

  4. Authentication and Authorization Models

    Directory of Open Access Journals (Sweden)

    More V.N

    2011-04-01

    Full Text Available In computer science distributed systems could be more secured with a distributed trust model based on either PKIor Kerberos. However, it becomes difficult to establish trust relationship across heterogeneous domains due todifferent actual trust mechanism and security policy as well as the intrinsic flaw of each trust model. Since Internethas been used commonly in information systems technologies, many applications need some security capabilitiesto protect against threats to the communication of information. Two critical procedures of these capabilities areauthentication and authorization. This report presents a strong authentication and authorization model using threestandard frameworks. They are PKI, PMI, and Directory. The trust in this approach is enabled by the use of publickey infrastructure (PKI which is applied for client two-factor authentication and secures the infrastructure. Weintroduce the preventive activity-based authorization policy for dynamic user privilege controls. It helps preventsuccessive unauthorized requests in a formal manner. At the core, we apply An Improved Trust Model to facilitatethe authentication with the different keys with work flow of model efficiently. Also describes the X.509 standard todefine the directory schemas of PKI and PMI to find the object classes and optional attributes.

  5. INFORMATION FOR AUTHORS

    Directory of Open Access Journals (Sweden)

    Revista Ciencias Biomedicas

    2015-12-01

    Full Text Available REVISTA CIENCIAS BIOMEDICAS (Rev.cienc.biomed. is included in: IMBIOMED, ACADEMIC GOOGLE, ENCOLOMBIA.COM, GOOGLE SCHOLAR, DOAJ, PUBLINDEX, WORLD CAT and ACADEMIC.EDU. It receives original scientific articles about a variety of topics that keep relation with the health sciences, so much of basic as clinical application. These issues need to be inside knowledge area that could interest both undergraduate as postgraduate students, as well as professionals in the health area. The following recommendations should be considered. 1. Authorship. Each author must have contributed substantially to the successful development of the research process. According to international standards, the criteria that each author must meet are: • Substantial contributions to conception, design, data acquisition or analysis and data interpretation. • To write the article and to check it for intellectually important content. • Final approval of the version to be published. “Courtesy authors” identifications or designations will not be accepted if the researcher has not met the delineated criteria (e.g. head of school / department / research group that presents the paper. 2. Interest conflicts and funding. An author of an article to be considered may be involved in two types of interest conflicts. The first one relates directly to the work authors and the financial and personal relationships that could influence or bias the manuscript in some way. The second type of interest conflict is related to the financial backer of the research. The authors must admit and say when sending the paper if there is any interference or limitation of the financial backer with regard to the analysis and interpretation of the information, writing or manuscript submission. The existence or absence of interest conflicts must be specified at the end of the article. It must be also specified whether it has received money by way of funding, specifying the origins and codes of calls where

  6. Effects of Local Compression on Peroneal Nerve Function in Humans

    Science.gov (United States)

    Hargens, Alan R.; Botte, Michael J.; Swenson, Michael R.; Gelberman, Richard H.; Rhoades, Charles E.; Akeson, Wayne H.

    1993-01-01

    A new apparatus was developed to compress the anterior compartment selectively and reproducibly in humans. Thirty-five normal volunteers were studied to determine short-term thresholds of local tissue pressure that produce significant neuromuscular dysfunction. Local tissue fluid pressure adjacent to the deep peroneal nerve was elevated by the compression apparatus and continuously monitored for 2-3 h by the slit catheter technique. Elevation of tissue fluid pressure to within 35-40 mm Hg of diastolic blood pressure (approx. 40 mm Hg of in situ pressure in our subjects) elicited a consistent progression of neuromuscular deterioration including, in order, (a) gradual loss of sensation, as assessed by Semmes-Weinstein monofilaments, (b) subjective complaints, (c) reduced nerve conduction velocity, (d) decreased action potential amplitude of the extensor digitorum brevis muscle, and (e) motor weakness of muscles within the anterior compartment. Generally, higher intracompartment at pressures caused more rapid deterioration of neuromuscular function. In two subjects, when in situ compression levels were 0 and 30 mm Hg, normal neuromuscular function was maintained for 3 h. Threshold pressures for significant dysfunction were not always the same for each functional parameter studied, and the magnitudes of each functional deficit did not always correlate with compression level. This variable tolerance to elevated pressure emphasizes the need to monitor clinical signs and symptoms carefully in the diagnosis of compartment syndromes. The nature of the present studies was short term; longer term compression of myoneural tissues may result in dysfunction at lower pressure thresholds.

  7. Information for Authors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    正>Science in China Series G-Physics,Mechanics & Astronomy(Sci China Ser G-Phys Mech Astrori) is a bimonthly peer-reviewed academic journal supervised by the Chinese Academy of Sciences,and co-sponsored by the Chinese Academy of Sciences and National Natural Science Foundation of China.Its primary mission is to encourage communication of basic and innovative research results of high quality in the fields of physics,mechanics and astronomy.

  8. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series D:Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science in China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research.Science in China Series D:Earth Sciences is published monthly in both print and electronic forms.It is indexed by

  9. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series C:Life Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science in China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research.Science in China Series C:Life Sciences is published monthly

  10. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series C: Life Sciences, an academic jour-nal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and pub-lished by Science in China Press and Springer, is committed to publishing high-quality, original results in both basic and applied research. Science in China Series C: Life Sciences is published monthly in both print and electronic forms. It is indexed by Aquatic Science & Fisheries, Abstracts, BIOBASE, BioEngineering

  11. Information for authors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Science in China Series C: Life Sciences, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science in China Press and Springer, is committed to publishing high-quality, original results in both basic and applied research.Science in China Series C: Life Sciences is published monthly in both print and electronic forms. It is indexed by Aquatic Science & Fisheries, Abstracts, BIOBASE, BioEngineering Abstracts, Biological Abstracts, BIOSIS,

  12. Information for Authors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Science in China Series E-Technological Sciences (Sci China Ser E-Tech Sci) is a monthly peerreviewed academic journal supervised by the Chinese Academy of Sciences, and co-sponsored by the Chinese Academy of Sciences and National Natural Science Foundation of China. Its primary mission is to encourage communication of basic and innova-tive research results of high quality in the fields of techno-logical sciences. The subject areas featured include materials,

  13. Shock compression of synthetic opal

    Science.gov (United States)

    Inoue, A.; Okuno, M.; Okudera, H.; Mashimo, T.; Omurzak, E.; Katayama, S.; Koyano, M.

    2010-03-01

    Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO4 tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO2 glass. However, internal silanole groups still remain even at 38.1 GPa.

  14. Compression fractures of the back

    Science.gov (United States)

    ... the fracture was due to an injury More surgery to join spine bones together or to relieve pressure on a ... type of tumor involved. Tumors that involve the spine include: Breast cancer Lung cancer Lymphoma Prostate ... to fuse after surgery Humpback Spinal cord or nerve root compression When ...

  15. Hyperspectral imaging using compressed sensing

    Science.gov (United States)

    Ramirez I., Gabriel Eduardo; Manian, Vidya B.

    2012-06-01

    Compressed sensing (CS) has attracted a lot of attention in recent years as a promising signal processing technique that exploits a signal's sparsity to reduce its size. It allows for simple compression that does not require a lot of additional computational power, and would allow physical implementation at the sensor using spatial light multiplexers using Texas Instruments (TI) digital micro-mirror device (DMD). The DMD can be used as a random measurement matrix, reflecting the image off the DMD is the equivalent of an inner product between the images individual pixels and the measurement matrix. CS however is asymmetrical, meaning that the signals recovery or reconstruction from the measurements does require a higher level of computation. This makes the prospect of working with the compressed version of the signal in implementations such as detection or classification much more efficient. If an initial analysis shows nothing of interest, the signal need not be reconstructed. Many hyper-spectral image applications are precisely focused on these areas, and would greatly benefit from a compression technique like CS that could help minimize the light sensor down to a single pixel, lowering costs associated with the cameras while reducing the large amounts of data generated by all the bands. The present paper will show an implementation of CS using a single pixel hyper-spectral sensor, and compare the reconstructed images to those obtained through the use of a regular sensor.

  16. Compressing spatio-temporal trajectories

    DEFF Research Database (Denmark)

    Gudmundsson, Joachim; Katajainen, Jyrki; Merrick, Damian;

    2009-01-01

    A trajectory is a sequence of locations, each associated with a timestamp, describing the movement of a point. Trajectory data is becoming increasingly available and the size of recorded trajectories is getting larger. In this paper we study the problem of compressing planar trajectories such tha...

  17. Teaching Time-Space Compression

    Science.gov (United States)

    Warf, Barney

    2011-01-01

    Time-space compression shows students that geographies are plastic, mutable and forever changing. This paper justifies the need to teach this topic, which is rarely found in undergraduate course syllabi. It addresses the impacts of transportation and communications technologies to explicate its dynamics. In summarizing various conceptual…

  18. In-situ evaluation of compressed brick veneer using the flatjack technique

    Energy Technology Data Exchange (ETDEWEB)

    Bell, G.R.; Gabby, B.A.

    1999-07-01

    The flatjack is a relatively nondestructive tool that allows engineers engaged in the repair and retrofit of masonry buildings (both historic and non-historic) to directly determine the in-situ state of compressive stress in masonry walls. The flatjack technique recently was used on a large modern apartment complex to quantify the compression in a brick veneer that was distressed and had questionable wind-load resistance. The compression in the veneer was due to a combination of concrete frame shrinkage and brick growth in a wall system that lacked horizontal control joints under the steel shelf angles. Although the compression caused spalling in the veneer, it also contributed beneficially to the walls' wind resistance. The amount of compression in the veneer was determined in several location throughout the height of one elevation of the building using flatjacks. The authors found that the compression in the veneer was greater than the flexural tension produced by design wind loads (including a reasonable factor of safety), but below the compressive strength of the brick masonry. This finding allowed a repair solution that was modest relative to strengthening the wall for inadequate wind resistance. Prior to employing the flatjack in the field, the authors conducted in-house research to check the accuracy and reliability of method, and develop their technique. The authors found that by altering gauge points from those locations prescribed by current ASTM standards to those recommended in recent research, greater accuracy could be obtained.

  19. NOTICE TO AUTHORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@CELL RESEARCH is an international academic journal, the only one publishes papers in En glish in all branches of animal and plant cell biology in China. It is edited by Shanghai Institute of Cell Biology, Chinese Academy of Sciences, published and distributed by Science Press, Beijing, China, and New York Agency, Ltd., USA, as well as by the Institute. The journal started pub lication semiannully in 1990 and changed to quarterly beginning from Volume 8, in 1998. This periodical has been accepted to be included in Index Medicus and MEDLINE on the MEDLARS system beginning from volume7(1), 1997 by National Library of Medicine, USA, and it was informed recently by Institute for Scientific Information, USA that ISI will be indexing CELL RESEARCH beginning with volume 9(1), 1999 in the following products: Science Citation Index-Expanded, available as SciSearch on Dialog or as the ISI Web of Science on the Internet-Research Alert. Manuscripts must be written in a clear and concise style. The principle criteria for acceptance are originality and scientific excelence. Papers judged by two referees and a member of the Editorial Board to be inapppropriate for the journal's scope and content will be returned to author. One original and two copies of each manuscript should be submitted. Authors are encouraged to submit text by a computer disk (3.5' disk with clearly labbled file name) in IBM compatible PC in Word, Write, under Windows prograne, Wordperfect 5.1, WPS 3.0 or Wordstar 4.0. Text sent by e mail are also welcomed. These all should be accompanied with an identical hard copy printout. Manuscripts are requested to be send to Ms. Ai Lan CHANG, Editorial office of CELL RESEARCH, Shanghai Institute of Cell Biology, Chinese Academy of Sciences, 320 Yue-yang Road, Shanghai 200031, China. e-mail: edto@sunm.shcnc.ac.cn. Author(s) from other countries can also send their manuscript(s) to three reginal editors in UK or USA (Dr. Jing De ZHU, Cathcart Laboratory, Division of

  20. Guidelines for Authors

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>TYPES OF ARTICLES●FORMATS OF ARTICLES●HOW TO SUBMIT A MANUSCRIPT●PUBLICATION FEES●TYPES OF ARTICLES1.Research articles Research articles belong to the full length article type,and should include elements as follows:title,running title,and byline;correspondent footnote;abstract;introduction;materials and methods;results;discussion;acknowledgements;author contributions;references;figure legends and figures/tables.The article length should not exceed 6,000 words,and detailed requirements are in the