WorldWideScience

Sample records for mechanical components alterungsmanagement

  1. Guideline for ageing management in nuclear power plants; Leitlinie zum Alterungsmanagement in Kernkraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Herter, K.H.; Schuler, X. [Materialpruefungsanstalt (MPA), Univ. Stuttgart, Stuttgart (Germany); Hienstorfer, W.; Pompe, W. [TUeV SUeD Energietechnik GmbH, Filderstadt (Germany)

    2007-07-01

    During operation of nuclear power plants, the quality of systems, structures and components may change as a result of ageing (conceptional ageing, technological ageing or physical ageing), which will affect the system quality. Ageing management is necessary to ensure safety and availability throughout the life of the systems. This necessitates a systematic, integrative and knowledge-based approach. Systems, structures and components are grouped according to their relevance for meeting the set goals. Ageing mangement should be process-oriented and should be integrated in the organisational procedure in cooperation with the safety manager. The procedure should follow the PDCA principle (plan - do - check - act). The data, documents, knowledge and evaluations required for ageing management are part of the knowledge base of the nuclear power station and are updated regularly. The efficiency of ageing management must be reassessed at regular intervals. (orig.)

  2. Mechanical vs. informational components of price impact

    Science.gov (United States)

    Doyne Farmer, J.; Zamani, N.

    2007-01-01

    We study the problem of what causes prices to change. It is well known that trading impacts prices — orders to buy drive the price up, and orders to sell drive it down. We introduce a means of decomposing the total impact of trading into two components, defining the mechanical impact of a trading order as the change in future prices in the absence of any future changes in decision making, and the informational impact as the remainder of the total impact once mechanical impact is removed. This decomposition is performed using order book data from the London Stock Exchange. The average mechanical impact of a market order decays to zero as a function of time, at an asymptotic rate that is consistent with a power law with an exponent of roughly 1.7. In contrast the average informational impact builds to approach a constant value. Initially the impact is entirely mechanical, and is about half as big as the asymptotic informational impact. The size of the informational impact is positively correlated to mechanical impact. For cases where the mechanical impact is zero for all times, we find that the informational impact is negative, i.e. buy market orders that have no mechanical impact at all generate strong negative price responses.

  3. Mechanical vs. informational components of price impact

    CERN Document Server

    Farmer, J D; Zamani, Neda

    2006-01-01

    We study the problem of what causes prices to change. We define the mechanical impact of a trading order as the change in future prices in the absence of any future changes in decision making, and its it informational impact as the remainder of the total impact once mechanical impact is removed. We introduce a method of measuring mechanical impact and apply it to order book data from the London Stock Exchange. The average mechanical impact of a market order decays to zero as a function of time, at an asymptotic rate that is consistent with a power law with an exponent of roughly 1.7. In contrast the average informational impact builds to approach a constant value. Initially the impact is entirely mechanical, and is about half as big as the asymptotic informational impact. The size of the informational impact is positively correlated to mechanical impact. For cases where the mechanical impact is zero for all times, we find that the informational impact is negative, i.e. buy market orders that have no mechanica...

  4. Mechanical Components from Highly Recoverable, Low Apparent Modulus Materials

    Science.gov (United States)

    Padula, Santo, II (Inventor); Noebe, Ronald D. (Inventor); Stanford, Malcolm K. (Inventor); DellaCorte, Christopher (Inventor)

    2015-01-01

    A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

  5. Nuclear Power Plant Mechanical Component Flooding Fragility Experiments Status

    Energy Technology Data Exchange (ETDEWEB)

    Pope, C. L. [Idaho State Univ., Pocatello, ID (United States); Savage, B. [Idaho State Univ., Pocatello, ID (United States); Johnson, B. [Idaho State Univ., Pocatello, ID (United States); Muchmore, C. [Idaho State Univ., Pocatello, ID (United States); Nichols, L. [Idaho State Univ., Pocatello, ID (United States); Roberts, G. [Idaho State Univ., Pocatello, ID (United States); Ryan, E. [Idaho State Univ., Pocatello, ID (United States); Suresh, S. [Idaho State Univ., Pocatello, ID (United States); Tahhan, A. [Idaho State Univ., Pocatello, ID (United States); Tuladhar, R. [Idaho State Univ., Pocatello, ID (United States); Wells, A. [Idaho State Univ., Pocatello, ID (United States); Smith, C. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-07-24

    This report describes progress on Nuclear Power Plant mechanical component flooding fragility experiments and supporting research. The progress includes execution of full scale fragility experiments using hollow-core doors, design of improvements to the Portal Evaluation Tank, equipment procurement and initial installation of PET improvements, designation of experiments exploiting the improved PET capabilities, fragility mathematical model development, Smoothed Particle Hydrodynamic simulations, wave impact simulation device research, and pipe rupture mechanics research.

  6. Analysis of soft rock mineral components and roadway failure mechanism

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie

    2001-01-01

    The mineral components and microstructure of soft rock sampled from ro adway floor in Xiagou pit are determined by X-ray diffraction and scanning elec t ron microscope. Combined with the test of expansion and water softening prop erty of the soft rock, the roadway failure mechanism is analyzed, and the reason able repair supporting principle of roadway is put forward.

  7. A 3D Printed Toolbox for Opto-Mechanical Components

    Science.gov (United States)

    P. Torres, Juan; Valencia, Alejandra

    2017-01-01

    In this article we present the development of a set of opto-mechanical components (a kinematic mount, a translation stage and an integrating sphere) that can be easily built using a 3D printer based on Fused Filament Fabrication (FFF) and parts that can be found in any hardware store. Here we provide a brief description of the 3D models used and some details on the fabrication process. Moreover, with the help of three simple experimental setups, we evaluate the performance of the opto-mechanical components developed by doing a quantitative comparison with its commercial counterparts. Our results indicate that the components fabricated are highly customizable, low-cost, require a short time to be fabricated and surprisingly, offer a performance that compares favorably with respect to low-end commercial alternatives. PMID:28099494

  8. Prestressing Shock Resistant Mechanical Components and Mechanisms Made from Hard, Superelastic Materials

    Science.gov (United States)

    DellaCorte, Christopher (Inventor)

    2014-01-01

    A method and an apparatus confer full superelastic properties to the active surface of a mechanical component constructed of a superelastic material prior to service. A compressive load is applied to the active surface of the mechanical component followed by removing the compressive load from the active surface whereby substantially all load strain is recoverable after applying and removing of subsequent compressive loads.

  9. Contactless Mechanical Components: Gears, Torque Limiters and Bearings

    Directory of Open Access Journals (Sweden)

    Jose Luis Perez-Diaz

    2014-12-01

    Full Text Available Contactless mechanical components are mechanical sets for conversion of torque/speed, whose gears and moving parts do not touch each other, but rather they provide movement with magnets and magnetic materials that exert force from a certain distance. Magneto-mechanical transmission devices have several advantages over conventional mechanisms: no friction between rotatory elements (no power losses or heat generation by friction so increase of efficiency, no lubrication is needed (oil-free mechanisms and no lubrication auxiliary systems, reduced maintenance (no lubricant so no need of oil replacements, wider operational temperature ranges (no lubricant evaporation or freezing, overload protection (if overload occurs magnet simply slides but no teeth brake, through-wall connection (decoupling of thermal and electrical paths and environmental isolation, larger operative speeds (more efficient operative conditions, ultralow noise and vibrations (no contact no noise generation. All these advantages permit us to foresee in the long term several common industrial applications in which including contactless technology would mean a significant breakthrough for their performance. In this work, we present three configurations of contactless mechanical passive components: magnetic gears, magnetic torque limiters and superconducting magnetic bearings. We summarize the main characteristic and range of applications for each type; we show experimental results of the most recent developments showing their performance.

  10. Mechanical and materials engineering of modern structure and component design

    CERN Document Server

    Altenbach, Holm

    2015-01-01

    This book presents the latest findings on mechanical and materials engineering as applied to the design of modern engineering materials and components. The contributions cover the classical fields of mechanical, civil and materials engineering, as well as bioengineering and advanced materials processing and optimization. The materials and structures discussed can be categorized into modern steels, aluminium and titanium alloys, polymers/composite materials, biological and natural materials, material hybrids and modern nano-based materials. Analytical modelling, numerical simulation, state-of-the-art design tools and advanced experimental techniques are applied to characterize the materials’ performance and to design and optimize structures in different fields of engineering applications.

  11. A 3D Printed Toolbox for Opto-Mechanical Components

    CERN Document Server

    Salazar-Serrano, L J; Torres, J P

    2016-01-01

    Nowadays is very common to find headlines in the media where it is stated that 3D printing is a technology called to change our lives in the near future. For many authors, we are living in times of a third industrial revolution. Howerver, we are currently in a stage of development where the use of 3D printing is advantageous over other manufacturing technologies only in rare scenarios. Fortunately, scientific research is one of them. Here we present the development of a set of opto-mechanical components that can be built easily using a 3D printer based on Fused Filament Fabrication (FFF) and parts that can be found on any hardware store. The components of the set presented here are highly customizable, low-cost, require a short time to be fabricated and offer a performance that compares favorably with respect to low-end commercial alternatives.

  12. Molecular Mechanisms of Two-Component Signal Transduction.

    Science.gov (United States)

    Zschiedrich, Christopher P; Keidel, Victoria; Szurmant, Hendrik

    2016-09-25

    Two-component systems (TCS) comprising sensor histidine kinases and response regulator proteins are among the most important players in bacterial and archaeal signal transduction and also occur in reduced numbers in some eukaryotic organisms. Given their importance to cellular survival, virulence, and cellular development, these systems are among the most scrutinized bacterial proteins. In the recent years, a flurry of bioinformatics, genetic, biochemical, and structural studies have provided detailed insights into many molecular mechanisms that underlie the detection of signals and the generation of the appropriate response by TCS. Importantly, it has become clear that there is significant diversity in the mechanisms employed by individual systems. This review discusses the current knowledge on common themes and divergences from the paradigm of TCS signaling. An emphasis is on the information gained by a flurry of recent structural and bioinformatics studies.

  13. Focal mechanism of seismic events with a dipolar component

    Directory of Open Access Journals (Sweden)

    R. Console

    1995-06-01

    Full Text Available In this paper we model the geometry of a seismic source as a dislocation occurring on an elemental flat fault in an arbitrary direction with respect to the fault plane. This implies the use of a fourth parameter in addition to the three usual ones describing a simple double couple mechanism. We applied the radiation pattern obtained from the theory to a computer code written for the inversion of the observation data (amplitudes and polarities of the first onsets recorded by a network of stations. It allows the determination of the fault mechanism gener- alized in the above mentioned way. The computer code was verified on synthetic data and then applied to real data recorded by the seismic network operated by the Ente Nazionale per l'Energia Elettrica (ENEL, monitoring the geothermal field of Larderello. The experimental data show that for some events the source mechanism exhibits a significant dipolar component. However, due to the high standard deviation of the amplitude data, F-test applied to the results of the analysis shows that only for two events the confidence level for the general- ized model exceeds 90%.

  14. The mechanism of signal transduction by two-component systems.

    Science.gov (United States)

    Casino, Patricia; Rubio, Vicente; Marina, Alberto

    2010-12-01

    Two-component systems, composed of a homodimeric histidine kinase (HK) and a response regulator (RR), are major signal transduction devices in bacteria. Typically the signal triggers HK autophosphorylation at one His residue, followed by phosphoryl transfer from the phospho-His to an Asp residue in the RR. Signal extinction frequently involves phospho-RR dephosphorylation by a phosphatase activity of the HK. Our understanding of these reactions and of the determinants of partner specificity among HK-RR couples has been greatly increased by recent crystal structures and biochemical experiments on HK-RR complexes. Cis-autophosphorylation (one subunit phosphorylates itself) occurs in some HKs while trans-autophosphorylation takes place in others. We review and integrate this new information, discuss the mechanism of the three reactions and propose a model for transmembrane signaling by these systems. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Dissection of the hormetic curve: analysis of components and mechanisms.

    Science.gov (United States)

    Lushchak, Volodymyr I

    2014-07-01

    The relationship between the dose of an effector and the biological response frequently is not described by a linear function and, moreover, in some cases the dose-response relationship may change from positive/adverse to adverse/positive with increasing dose. This complicated relationship is called "hormesis". This paper provides a short analysis of the concept along with a description of used approaches to characterize hormetic relationships. The whole hormetic curve can be divided into three zones: I - a lag-zone where no changes are observed with increasing dose; II - a zone where beneficial/adverse effects are observed, and III - a zone where the effects are opposite to those seen in zone II. Some approaches are proposed to analyze the molecular components involved in the development of the hormetic character of dose-response relationships with the use of specific genetic lines or inhibitors of regulatory pathways. The discussion is then extended to suggest a new parameter (half-width of the hormetic curve at zone II) for quantitative characterization of the hormetic curve. The problems limiting progress in the development of the hormesis concept such as low reproducibility and predictability may be solved, at least partly, by deciphering the molecular mechanisms underlying the hormetic dose-effect relationship.

  16. Reliability Assessment of Offshore Wind Turbines Considering Faults of Electrical / Mechanical Components

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2013-01-01

    of structural, mechanical and electrical components are important, in order to optimally plan Operation & Maintenance strategies. A general model for reliability estimation of structural, mechanical or electrical components is described. For a representative failure mode a corresponding limit state...

  17. 32. MPA seminar 2006. Lectures; 32. MPA Seminar 2006. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This conference CD contains the full text of 47 papers on the following subjects: 1. Ageing management; 2. Integrity analysis; 3. Materials engineering; 4. State monitoring; 5. Pressure equipment status monitoring; 6. Quality assurance; 7. Non-destructive testing; 8. Fracture-mechanical analysis of components. [German] Diese Tagungs-CD enthaelt den Text von 47 Vortraegen mit folgenden Themenschwerpunkten: 1. Alterungsmanagement; 2. Integritaetsanalyse; 3. Werkstofftechnik; 4. Zustandsueberwachung; 5. Beschaffenheit Druckgeraete; 6. Qualitaetssicherung; 7. Zerstoerungsfreie Pruefung; und 8. Bruchmechanische Bauteilanalyse.

  18. Validation Effectiveness of Develop Maintainability Allocation on Aircraft Mechanical Components

    Directory of Open Access Journals (Sweden)

    Wan Husain W.M.S.

    2016-01-01

    Full Text Available Maintainability Allocation is a process to identify the allowable maximum task time for each individual component. Consequently, this provides clear pictures to the designers to design and identify potential design improvement within allowable maintenance allocation time limits. During the design process elements such as missteps or misapplications most commonly occur. Here, the authors propose having the maximum target for each individual maintainability component. The main objective of this paper is to present the validation process of developed Maintainability Allocation to potentially eliminate previous problems. The process of validation begins with analysed all the data collected from Service Difficulty Reports (SDR for selected aircraft. This is to understand the problems from existing aircraft before a new design is proposed through the process of Maintainability Allocation prediction. The validation processes have discovered the importance of utilising historical information such as feedback information. The second area is looking at the element of quantifying the data collected from aircraft feedback information which contains various types of information that could be used for future improvement. Validation process shows that feedback information has helped to identify the critical and sensitive components that need more attention for further improvement. The study shows that the aircraft maintenance related feedback information systems analyses were very useful for deciding maintainability effectiveness; these include planning, organising maintenance and design improvement. There is no doubt that feedback information has the ability to contribute an important role in design activities. The results also show that maintainability is an important measure that can be used as a guideline for managing efforts made for the improvement of aircraft components.

  19. Successful implementation of ageing management exemplified at the cooling tower of Emsland nuclear power plant; Erfolgreiche Umsetzung von Alterungsmanagement am Beispiel Kuehlturm des Kernkraftwerkes Emsland

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Alexander [Hochtief Solutions AG, Consult IKS Energy, Frankfurt am Main (Germany). Design Kraftwerke; Dueweling, Carsten [Kernkraftwerke Lippe-Ems GmbH, Lingen (Germany). Abschnitt Bautechnik

    2013-07-15

    The present paper describes the successful implementation of the restoration of water-distribution channels at the cooling tower of the Emsland nuclear power plant under the aspect of ageing management. The main challenge of aging management is the determination of potential aging mechanism and to avoid systematically and effectively their damaging influences. In the course of the annual site inspections abnormalities at the lower side of the water-distribution channels of the cooling tower were detected, analysed, and repaired. The extraordinary high chlorine equivalent of the cooling water was identified as main reason of the damages located. Due to extensive infiltration into the concrete structure, chloride-induced corrosion generates a volume expansion of the reinforcement and thereby to a blast off of the concrete covering. According to the restoration concept, the damaged concrete was removed by maximum pressure water jet blasting; where necessary the reinforcement was retrofitted and a layered concrete substitution was applied by synthetic cement mortar. The realised procedures conserve the load bearing reinforcement only for a certain period, because the permanent chloride infiltration could not be stopped. Therefore, the structure has to be monitored permanently. (orig.)

  20. Design of mechanical components for vibration reduction in an atomic force microscope.

    Science.gov (United States)

    Kim, Chulsoo; Jung, Jongkyu; Youm, Woosub; Park, Kyihwan

    2011-03-01

    Vibration is a key factor to be considered when designing the mechanical components of a high precision and high speed atomic force microscope (AFM). It is required to design the mechanical components so that they have resonant frequencies higher than the external and internal vibration frequencies. In this work, the mechanical vibration in a conventional AFM system is analyzed by considering its mechanical components, and a vibration reduction is then achieved by reconfiguring the mechanical components. To analyze the mechanical vibration, a schematic of the lumped model of the AFM system is derived and the vibrational influences of the AFM components are experimentally examined. Based on this vibration analysis, a reconfigured AFM system is proposed and its effects are compared to a conventional system through a series of simulations and experiments.

  1. Business as a component mechanism of social protection of population

    Directory of Open Access Journals (Sweden)

    Tsintsadze Asie

    2014-01-01

    Full Text Available The social protection of population is a main direction of activities of any government. In modern period social protection of population is proceeding with the help of social policy. Mainly social policy implementation is done by the government. Currently in Georgia the main mechanism for social protection is social insurance, which is carried out by the Ministry of Labor, Health and Social Affairs. In Georgia social subsidy agency is responsible for the health insurance and medical programs. Under condition of marketing economy the limitation of interference of government in economy decreased means of social protection. In the modern conditions social protection mechanism should be developed jointly by the government and private sector measures. It becomes necessary to increase the role of business in the social protection of population, which with the difference of charity requests more social responsibility. The most important goal of any government is the effective employment of its population. The research objective is to explore the role of business in the social protection; to set the problems and find the concrete proposals for solving these problems. It is clear that operation of social policy measures can be entirely imposed on the business. As well as the business can ensure effective functioning of the employment level and thus contribute to the development of their own businesses as well as the social policy of government. This paper formulates proposals is direction of the interaction of business and government, their activities for effective social protection of population.

  2. Modern methodology of designing target reliability into rotating mechanical components

    Science.gov (United States)

    Kececioglu, D. B.; Chester, L. B.

    1973-01-01

    Experimentally determined distributional cycles-to-failure versus maximum alternating nominal strength (S-N) diagrams, and distributional mean nominal strength versus maximum alternating nominal strength (Goodman) diagrams are presented. These distributional S-N and Goodman diagrams are for AISI 4340 steel, R sub c 35/40 hardness, round, cylindrical specimens 0.735 in. in diameter and 6 in. long with a circumferential groove 0.145 in. radius for a theoretical stress concentration = 1.42 and 0.034 in. radius for a stress concentration = 2.34. The specimens are subjected to reversed bending and steady torque in specially built, three complex-fatigue research machines. Based on these results, the effects on the distributional S-N and Goodman diagrams and on service life of superimposing steady torque on reversed bending are established, as well as the effect of various stress concentrations. In addition a computer program for determining the three-parameter Weibull distribution representing the cycles-to-failure data, and two methods for calculating the reliability of components subjected to cumulative fatigue loads are given.

  3. Component

    Directory of Open Access Journals (Sweden)

    Tibor Tot

    2011-01-01

    Full Text Available A unique case of metaplastic breast carcinoma with an epithelial component showing tumoral necrosis and neuroectodermal stromal component is described. The tumor grew rapidly and measured 9 cm at the time of diagnosis. No lymph node metastases were present. The disease progressed rapidly and the patient died two years after the diagnosis from a hemorrhage caused by brain metastases. The morphology and phenotype of the tumor are described in detail and the differential diagnostic options are discussed.

  4. Automatic Detection of Repetitive Components in 3D Mechanical Engineering Models

    Directory of Open Access Journals (Sweden)

    Laixiang Wen

    2013-01-01

    Full Text Available We present an intelligent method to automatically detect repetitive components in 3D mechanical engineering models. In our work, a new Voxel-based Shape Descriptor (VSD is proposed for effective matching, based on which a similarity function is defined. It uses the voxels intersecting with 3D outline of mechanical components as the feature descriptor. Because each mechanical component may have different poses, the alignment before the matching is needed. For the alignment, we adopt the genetic algorithm to search for optimal solution where the maximum global similarity is the objective. Two components are the same if the maximum global similarity is over a certain threshold. Note that the voxelization of component during feature extraction and the genetic algorithm for searching maximum global similarity are entirely implemented on GPU; the efficiency is improved significantly than with CPU. Experimental results show that our method is more effective and efficient than that existing methods for repetitive components detection.

  5. Study on Mechanical Properties and Components of HRB400 Steel for High-strength Building

    OpenAIRE

    2016-01-01

    The study took five samples of screw-thread steel III, i.e. HRB400 steel bar of different diameters: 10mm, 12mm, 16mm, 20mm and 25mm; and conducted contrast experiments of their mechanical properties and components. The 600 sets of data collected from the experiments were processed by multivariate regression analysis of mechanical properties and components by diameter with MATLAB. The result showed that differentHRB400 screw-thread steel bars have different components with the mechanical prop...

  6. Investigation of Mechanical Loss Components and Heat Transfer in an Axial-Flux PM Machine

    OpenAIRE

    Wrobel, Rafal; Vaniel, Gyula; Copeland, Colin; Duda, Tomasz; Staton, David; Mellor, Phil

    2015-01-01

    This paper investigates components of mechanical loss together with heat transfer effects in an axial-flux permanent-magnet motor. The mechanical loss components generated within electrical machines are well known; however, their prediction or derivation has not been widely reported in the literature. These, together with the electromagnetic loss sources and heat transfer effects, are crucial and must be accounted for when considering high-power-density, high-speed, and/or compact machine des...

  7. A novel "four-component" two-component signal transduction mechanism regulates developmental progression in Myxococcus xanthus.

    Science.gov (United States)

    Jagadeesan, Sakthimala; Mann, Petra; Schink, Christian W; Higgs, Penelope I

    2009-08-07

    Histidine-aspartate phosphorelays are employed by two-component signal transduction family proteins to mediate responses to specific signals or stimuli in microorganisms and plants. The RedCDEF proteins constitute a novel signaling system in which four two-component proteins comprising a histidine kinase, a histidine-kinase like protein, and two response regulators function together to regulate progression through the elaborate developmental program of Myxococcus xanthus. A combination of in vivo phenotypic analyses of in-frame deletions and non-functional point mutations in each gene as well as in vitro autophosphorylation and phosphotransfer analyses of recombinant proteins indicate that the RedC histidine kinase protein autophosphorylates and donates a phosphoryl group to the single domain response regulator, RedF, to repress progression through the developmental program. To relieve this developmental repression, RedC instead phosphorylates RedD, a dual receiver response regulator protein. Surprisingly, RedD transfers the phosphoryl group to the histidine kinase-like protein RedE, which itself appears to be incapable of autophosphorylation. Phosphorylation of RedE may render RedE accessible to RedF, where it removes the phosphoryl group from RedF-P, which is otherwise an unusually stable phosphoprotein. These analyses reveal a novel "four-component" signaling mechanism that has probably arisen to temporally coordinate signals controlling the developmental program in M. xanthus. The RedCDEF signaling system provides an important example of how the inherent plasticity and modularity of the basic two-component signaling domains comprise a highly adaptable framework well suited to expansion into complex signaling mechanisms.

  8. THE STRATEGIC COMPONENTS OF THE INSTITUTIONAL MECHANISM OF THE AGRICULTURAL SECTOR OF THE ECONOMY OF UKRAINE

    Directory of Open Access Journals (Sweden)

    Viktoria Ivanivna KYFYAK

    2015-08-01

    Full Text Available The strategic components of the institutional mechanism of the agricultural sector should be: an institution of government regulation; institution of property; institution of employment; institution of entrepreneurship; institution of contracting; institution of pricing; institution of infrastructure; informal institutions are proposed. Directions of improving each component based on the principle of subsidiarity and solidarity of interaction in the same mechanism of agricultural development are identified. The integration of parts of the institutional strategy towards to achieving system of priorities of agricultural development will improve the institutional mechanism of the development of the agricultural sector towards the formation of "automated" market institutions. Synergistic effect of the realizing of strategic components of the institutional mechanism of the development of agricultural sector of the national economy are outlined.

  9. A contribution to the practical realization of aging management of electrical and control engineering according KTA 1403; Ein Beitrag zur praktischen Umsetzung des Alterungsmanagements der Elektro- und Leittechnik gemaess der KTA 1403

    Energy Technology Data Exchange (ETDEWEB)

    Disco, S.; Kaflowski, G.; Waber, P. [AREVA NP GmbH, Erlangen (Germany)

    2011-07-01

    The contribution is an exemplary demonstration of the practical aging management according KTA 1403. Aging management is aimed to insure sufficient availability of safety systems to control all design-based accidents and to avoid a significant increase of systematic failures. The special features of electrical and control engineering are identified. The implementation of aging management is actually stepwise realized as pilot project in the NPP Grafenrheinfeld (KKG). The pilot project is supposed to optimize the procedures. A deterministic quantitative evaluation of only restricted to few components of the electrical and control systems. For most components of the electrical and control systems a probabilistic experience-based evaluation without identification or quantification of materials damage mechanisms is performed using the AREVA software tool COMSY-ELT.

  10. Research on the mechanical behaviour of an airplane component made by selective laser melting technology

    Directory of Open Access Journals (Sweden)

    Păcurar Răzvan

    2017-01-01

    Full Text Available The main objective of the presented research consists in the redesign of an airplane component to decrease its weight, without affecting the mechanical behaviour of the component, at the end. Femap NX Nastran and ANSYS FEA programs were used for the shape optimization and for the estimation of the mechanical behaviour of a fixing clamp that was used to sustain the hydraulic pipes that are passing through an airplane fuselage, taking into consideration two types of raw materials – Ti6Al4V and AlSi12 powder from which this component could be manufactured by using the selective laser melting (SLM technology. Based on the obtained results, the airplane component was finally manufactured from titanium alloy using the SLM 250 HL equipment that is available at SLM Solutions GmbH company from Luebeck, in Germany.

  11. Three dimensional damage mechanics analysis of real life reactor piping components under various loading conditions

    Energy Technology Data Exchange (ETDEWEB)

    Durgaprasad, P.V.; Sahu, M.K.; Dutta, B.K. (Reactor Safety Division, Bhabha Atomic Research Centre Trombay, Mumbai (India)), e-mail: pvdp@barc.gov.in

    2009-07-01

    In this work, the Gurson-Tvergaard-Needleman (GTN) damage mechanics model is used for the crack growth analysis of real life reactor piping components. The paper also addresses the challenges involved in such analyses. As a part of component integrity testing, a comprehensive experimental program has been pursued to generate the fracture behavior of reactor piping components. Several real life pipes and elbows with various flaw sizes have been tested under different loading conditions like temperature, pressure, bending etc. In the present work, some of the selected components have been analyzed numerically by using parallel in-house finite element code 'MADAM' with GTN constitutive model. The strength of the micro mechanical models has been demonstrated by comparing the numerical results like load v/s. load-line displacements, J-R curves with the experimental data

  12. Independent component analysis based source number estimation and its comparison for mechanical systems

    Science.gov (United States)

    Cheng, Wei; Lee, Seungchul; Zhang, Zhousuo; He, Zhengjia

    2012-11-01

    It has been challenging to correctly separate the mixed signals into source components when the source number is not known a priori. In this paper, we propose a novel source number estimation based on independent component analysis (ICA) and clustering evaluation analysis. We investigate and benchmark three information based source number estimations: Akaike information criterion (AIC), minimum description length (MDL) and improved Bayesian information criterion (IBIC). All the above methods are comparatively studied in both numerical and experimental case studies with typical mechanical signals. The results demonstrate that the proposed ICA based source number estimation with nonlinear dissimilarity measures performs more stable and robust than the information based ones for mechanical systems.

  13. In-Built Customised Mechanical Failure of 316L Components Fabricated Using Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Andrei Ilie

    2017-02-01

    Full Text Available The layer-by-layer building methodology used within the powder bed process of Selective Laser Melting facilitates control over the degree of melting achieved at every layer. This control can be used to manipulate levels of porosity within each layer, effecting resultant mechanical properties. If specifically controlled, it has the potential to enable customisation of mechanical properties or design of in-built locations of mechanical fracture through strategic void placement across a component, enabling accurate location specific predictions of mechanical failure for fail-safe applications. This investigation examined the process parameter effects on porosity formation and mechanical properties of 316L samples whilst maintaining a constant laser energy density without manipulation of sample geometry. In order to understand the effects of customisation on mechanical properties, samples were manufactured with in-built porosity of up to 3% spanning across ~1.7% of a samples’ cross-section using a specially developed set of “hybrid” processing parameters. Through strategic placement of porous sections within samples, exact fracture location could be predicted. When mechanically loaded, these customised samples exhibited only ~2% reduction in yield strength compared to samples processed using single set parameters. As expected, microscopic analysis revealed that mechanical performance was closely tied to porosity variations in samples, with little or no variation in microstructure observed through parameter variation. The results indicate that there is potential to use SLM for customising mechanical performance over the cross-section of a component.

  14. Effect of Aging on the Mechanical Properties of Li-Ion Cell Components - A Preliminary Look

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Lei; Zhang, Chao; Santhanagopalan, Shriram; Pesaran, Ahmad

    2016-05-03

    DOE/VTO/ES initiated the Computer Aided Engineering for Batteries (CAEBAT) in 2010. CAEBAT had a strong focus on building electrochemical-thermal models that simulate the performance of lithium-ion batteries. Since the start of CAEBAT-2 projects in FY14, our emphasis has been on safety aspects -- mechanical deformation in particular. This presentation gives a preliminary look at the effect of aging on the mechanical properties of lithium-ion cell components.

  15. Electroluminescence and cathodoluminescence from polyethylene and polypropylene films: Spectra reconstruction from elementary components and underlying mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, B. [Université de Toulouse, UPS, INP, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse (France); Teyssedre, G.; Laurent, C. [Université de Toulouse, UPS, INP, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse (France); CNRS, LAPLACE, F-31062 Toulouse (France)

    2016-01-14

    The mechanisms of electroluminescence from large band gap polymers used as insulation in electric components are still under debate. It becomes important to unravel the underlying physics of the emission because of increasing thermo-electric stress and a possible relationship between electroluminescence and field withstand. We report herein on the cathodoluminescence spectra of polyethylene and polypropylene films as a way to uncover the nature of its contributions to electroluminescence emission. It is shown that spectra from the two materials are structured around four elementary components, each of them being associated with a specific process contributing to the overall emission with different weights depending on excitation conditions and on materials. The cathodoluminescence and electroluminescence spectra of each material are reconstructed from the four spectral components and their relative contribution are discussed. It is shown that electroluminescence from polyethylene and polypropylene has the same origin pointing towards generic mechanisms in both.

  16. Electroluminescence and cathodoluminescence from polyethylene and polypropylene films: Spectra reconstruction from elementary components and underlying mechanisms

    Science.gov (United States)

    Qiao, B.; Teyssedre, G.; Laurent, C.

    2016-01-01

    The mechanisms of electroluminescence from large band gap polymers used as insulation in electric components are still under debate. It becomes important to unravel the underlying physics of the emission because of increasing thermo-electric stress and a possible relationship between electroluminescence and field withstand. We report herein on the cathodoluminescence spectra of polyethylene and polypropylene films as a way to uncover the nature of its contributions to electroluminescence emission. It is shown that spectra from the two materials are structured around four elementary components, each of them being associated with a specific process contributing to the overall emission with different weights depending on excitation conditions and on materials. The cathodoluminescence and electroluminescence spectra of each material are reconstructed from the four spectral components and their relative contribution are discussed. It is shown that electroluminescence from polyethylene and polypropylene has the same origin pointing towards generic mechanisms in both.

  17. Mechanical and Fatigue Testing of Rapid Prototyped Aerospace Titanium Component by Electron Beam Melting Process

    Science.gov (United States)

    Forbush, Arrian B.

    The mechanical and fatigue behavior of a Ti-6Al-4V structural component that was manufactured by electron beam melting (EBM) was studied. Ti-6Al-4V EBM components were subjected to cyclic loading and monotonic loading tests. The results indicated that the EBM component did not fail before the fasteners in both tests. This was a preliminary study regarding an attempt to model an EBM component to validate the physical tests. An attempt was made to model the monotonic and cyclic testing in the linear elastic region using finite elements with the assumed loading conditions to investigate the stress distributions at each loading condition. Additionally, an attempt was made to use finite element modeling to validate the experimental results within the elastic range.

  18. A Network Framework Based on MechanicalComponent Design and Manufacturing

    Institute of Scientific and Technical Information of China (English)

    顾立志; 陈光军; 杨康

    2004-01-01

    Network manufacturing has been rapidly developed and is going to play an important role in modern indusu'y. The core of network manufacturing of mechanical products is the design and manufacturing based on the computer network technology. A network framework is introduced for manufacturing mechanical components at two main levels. On the design level features of the component are initially studied based on the structure and functions of the component. Details of the design procedure and contents are then analyzed with three main kinds of components. In this stage, selection of materials, calculation of sla'ess and deflection under load, determination of the size are carried out using CAD. On the manufacturing level various aspects of CAPP are discussed, including the principle and the modes of positioning the component, the exerted clamping forces, cutting engagement and input parameters, machine tools used, and machining fluids if necessary. Finally a prototype of the network framework is presented with several pieces of data terminal equipment through a local area network, the topological structure, and data sharing and security, without concerning the use of the concurrent engineering techniques and virtual manufacturing, and virtual measuring techniques.

  19. Interrater reliability of mechanical tests for functional classification of transtibial prosthesis components distal to the socket

    Directory of Open Access Journals (Sweden)

    Matthew J. Major, PhD

    2015-08-01

    Full Text Available Substantial evidence suggests that the design and associated mechanical function of lower-limb prostheses affects user health and mobility, supporting common standards of clinical practice for appropriate matching of prosthesis design and user needs. This matching process is dependent on accurate and reliable methods for the functional classification of prosthetic components. The American Orthotic & Prosthetic Association developed a set of tests for L-code characterization of prosthesis mechanical properties to facilitate functional classification of passive below-knee prosthetic components. The mechanical tests require use of test-specific fixtures to be installed in a materials testing machine by a test administrator. Therefore, the purpose of this study was to assess the interrater reliability of test outcomes between two administrators using the same testing facility. Ten prosthetic components (8 feet and 2 pylons that spanned the range of commercial designs were subjected to all appropriate tests. Tests with scalar outcomes demonstrated high interrater reliability (intraclass correlation coefficient (2,1 >/= 0.935, and there was no discrepancy in observation-based outcomes between administrators, suggesting that between-administrator variability may not present a significant source of error. These results support the integration of these mechanical tests for prosthesis classification, which will help enhance objectivity and optimization of the prosthesis-patient matching process for maximizing rehabilitation outcomes.

  20. Interrater reliability of mechanical tests for functional classification of transtibial prosthesis components distal to the socket.

    Science.gov (United States)

    Major, Matthew J; Johnson, William Brett; Gard, Steven A

    2015-01-01

    Substantial evidence suggests that the design and associated mechanical function of lower-limb prostheses affects user health and mobility, supporting common standards of clinical practice for appropriate matching of prosthesis design and user needs. This matching process is dependent on accurate and reliable methods for the functional classification of prosthetic components. The American Orthotic & Prosthetic Association developed a set of tests for L-code characterization of prosthesis mechanical properties to facilitate functional classification of passive below-knee prosthetic components. The mechanical tests require use of test-specific fixtures to be installed in a materials testing machine by a test administrator. Therefore, the purpose of this study was to assess the interrater reliability of test outcomes between two administrators using the same testing facility. Ten prosthetic components (8 feet and 2 pylons) that spanned the range of commercial designs were subjected to all appropriate tests. Tests with scalar outcomes demonstrated high interrater reliability (intraclass correlation coefficient(2,1) >/= 0.935), and there was no discrepancy in observation-based outcomes between administrators, suggesting that between-administrator variability may not present a significant source of error. These results support the integration of these mechanical tests for prosthesis classification, which will help enhance objectivity and optimization of the prosthesis-patient matching process for maximizing rehabilitation outcomes.

  1. Studies on the mechanism of efficient extraction of tea components by aqueous ethanol.

    Science.gov (United States)

    Hu, Ci-Jie; Gao, Ying; Liu, Yang; Zheng, Xin-Qiang; Ye, Jian-Hui; Liang, Yue-Rong; Lu, Jian-Liang

    2016-03-01

    Effect of solvent on the extraction yield and its relevant mechanism have been studied in this paper. Compared with extraction by water, catechins and caffeine could be easily extracted from green tea by aqueous ethanol, but hardly at all by absolute ethanol. Results of the vacuum-assisted extraction, solubility determination of EGCG and caffeine, as well as swelling ratio analysis of the infused leaves, indicated that an excellent leaf-matrix-swelling effect and high solubility of tea components might be the key mechanisms for high extraction efficiency by the aqueous ethanol. These mechanisms were further confirmed by the pre-swelling extraction. This is a first report on the mechanism of efficient extraction by aqueous organic solvent. Application of pre-swelling extraction is also discussed.

  2. Antioxidant property of coffee components: assessment of methods that define mechanisms of action.

    Science.gov (United States)

    Liang, Ningjian; Kitts, David D

    2014-11-19

    Coffee is a rich source of dietary antioxidants, and this property, coupled with the fact that coffee is one of the world's most popular beverages, has led to the understanding that coffee is a major contributor to dietary antioxidant intake. Brewed coffee is a complex food matrix with numerous phytochemical components that have antioxidant activity capable of scavenging free radicals, donating hydrogen and electrons, providing reducing activity and also acting as metal ion pro-oxidant chelators. More recent studies have shown that coffee components can trigger tissue antioxidant gene expression and protect against gastrointestinal oxidative stress. This paper will describe different in vitro, cell-free and cell-based assays that both characterize and compare the antioxidant capacity and mechanism of action of coffee and its bioactive constituents. Moreover, evidence of cellular antioxidant activity and correlated specific genomic events induced by coffee components, which are relevant to antioxidant function in both animal and human studies, will be discussed.

  3. Psychophysiological Mechanisms of Coordination Component of Psychomotor Abilities of the Musicians

    Directory of Open Access Journals (Sweden)

    Korlyakova S.G.

    2017-08-01

    Full Text Available Psychomotor abilities of the musician are implemented in performing technique and include muscle strength, endurance, speed of movements, coordination, motor memory. The article presents the materials of a theoretical study aimed to identify the level character of the coordination component of psychomotor abilities of musicians formation, to define the psychophysiological mechanisms that contribute to the effective development of musical-performing technique. The process of coordination component of psychomotor abilities of musicians formation reviewed in the light of N.. Bernstein theory on construction of movements, which most fully represents the interrelation of physiological and psychological mechanisms of a man motor activity. On the example of musical- performing activity of trained pianists the processes of intermuscular, spatial, sensory-motor (visual-motor, auditory-motor, tactile-motor coordination formation are reviewed and in general – psychomotor coordination processes involved in musicians performing technique development.

  4. Sleep and Arousal Mechanisms in Experimental Epilepsy: Epileptic Components of NREM and Antiepileptic Components of REM Sleep

    Science.gov (United States)

    Shouse, M. N.; Scordato, J. C.; Farber, P. R.

    2004-01-01

    Neural generators related to different sleep components have different effects on seizure discharge. These sleep-related systems can provoke seizure discharge propagation during nonrapid eye movement (NREM) sleep and can suppress propagation during REM sleep. Experimental manipulations of discrete physiological components were conducted in feline…

  5. Kinetics and mechanism of the oxidation process of two-component Fe-Al alloys

    Science.gov (United States)

    Przewlocka, H.; Siedlecka, J.

    1982-01-01

    The oxidation process of two-component Fe-Al alloys containing up to 7.2% Al and from 18 to 30% Al was studied. Kinetic measurements were conducted using the isothermal gravimetric method in the range of 1073-1223 K and 1073-1373 K for 50 hours. The methods used in studies of the mechanism of oxidation included: X-ray microanalysis, X-ray structural analysis, metallographic analysis and marker tests.

  6. Experimental research of drilling mud influence on mud motor mechanical rubber components

    OpenAIRE

    Epikhin, Anton Vladimirovich; Ushakov, A. V.; Barztaikin, V. V.; Melnikov, V. V.; Ulyanova, Oksana Sergeevna

    2015-01-01

    The paper describes the experimental research of drilling mud influence on engineering parameters of mud motor mechanical rubber components. It is believed to be urgent due to increase in using mud motors in oil and gas well construction now, and, consequently, the issue of increasing their exploitation is becoming current. The development test results of elastomer IRP-1226 dependent on the mud type (alkaline, hydrocarbon or salt-saturated ones) and the temperature are shown in the paper. It ...

  7. Structure and Mechanism of the S Component of a Bacterial ECF Transporter

    Energy Technology Data Exchange (ETDEWEB)

    P Zhang; J Wang; Y Shi

    2011-12-31

    The energy-coupling factor (ECF) transporters, responsible for vitamin uptake in prokaryotes, are a unique family of membrane transporters. Each ECF transporter contains a membrane-embedded, substrate-binding protein (known as the S component), an energy-coupling module that comprises two ATP-binding proteins (known as the A and A' components) and a transmembrane protein (known as the T component). The structure and transport mechanism of the ECF family remain unknown. Here we report the crystal structure of RibU, the S component of the ECF-type riboflavin transporter from Staphylococcus aureus at 3.6-{angstrom} resolution. RibU contains six transmembrane segments, adopts a previously unreported transporter fold and contains a riboflavin molecule bound to the L1 loop and the periplasmic portion of transmembrane segments 4-6. Structural analysis reveals the essential ligand-binding residues, identifies the putative transport path and, with sequence alignment, uncovers conserved structural features and suggests potential mechanisms of action among the ECF transporters.

  8. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    Energy Technology Data Exchange (ETDEWEB)

    Fok, Alex

    2013-10-30

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  9. Dynamic Reliability Analysis Method of Degraded Mechanical Components Based on Process Probability Density Function of Stress

    Directory of Open Access Journals (Sweden)

    Peng Gao

    2014-01-01

    Full Text Available It is necessary to develop dynamic reliability models when considering strength degradation of mechanical components. Instant probability density function (IPDF of stress and process probability density function (PPDF of stress, which are obtained via different statistical methods, are defined, respectively. In practical engineering, the probability density function (PDF for the usage of mechanical components is mostly PPDF, such as the PDF acquired via the rain flow counting method. For the convenience of application, IPDF is always approximated by PPDF when using the existing dynamic reliability models. However, it may cause errors in the reliability calculation due to the approximation of IPDF by PPDF. Therefore, dynamic reliability models directly based on PPDF of stress are developed in this paper. Furthermore, the proposed models can be used for reliability assessment in the case of small amount of stress process samples by employing the fuzzy set theory. In addition, the mechanical components in solar array of satellites are chosen as representative examples to illustrate the proposed models. The results show that errors are caused because of the approximation of IPDF by PPDF and the proposed models are accurate in the reliability computation.

  10. Mechanical Properties Studies of Components Formulation for Mixing Process Contain of Polypropylene, Polyethylene, and Aluminium Powder

    Science.gov (United States)

    Hamsi, A.; Dinzi, R.

    2017-03-01

    Certain powder and others components can induce toxic reactions if not properly handled in the mixing stage. During handling, the small particles can become airborne and be trapped in the lungs, another concern is inhomogeneities in the mixing process. Uniform quantities of the particles of the components are needed in all portions of the mixture. This paper reports the results of mechanical properties studies of mixing three components formulation for mixing process. Contain of Polyethylene (PE), Polyprophylene (PP) and Aluminium Powder. Powder mixer, Autodesk mold flow and computer based on excell method was carried out to study the influence of each formulation component on the flow %, PE 20% and Aluminium powder 2%. Macroscopic optic and macro photo was carried out to identify the homogenity of mixing, tensile test for identify the strength of component after mixing. Finally the optimal tensile test with composition PP 785,PE 20% and Aluminium powder 2% at speed 52 rpm, temperature 1500C, the tensile strength 20,92 N/mm2. At temperature 1600C, speed 100 rpm the optimum tensile strength 17,91 N/mm2. The result of simulation autodesk mold flow adviser the filling time 6 seconds. Otherwise on manual hot hidraulic press the time of filling 10 seconds.

  11. Long-term nano-mechanical properties of biomodified dentin-resin interface components.

    Science.gov (United States)

    Dos Santos, Paulo Henrique; Karol, Sachin; Bedran-Russo, Ana Karina

    2011-06-03

    Failures of dental composite restorative procedures are largely attributed to the degradation of dentin-resin interface components. Biomodification of dentin using bioactive agents may improve the quality and durability of the dentin-resin bonds. The aim of this study was to nanomechanically assess the reduced modulus of elasticity (Er) and nano-hardness (H) of major components of the dentin-resin interface (hybrid layer, adhesive layer and underlying dentin) biomodified by collagen cross-linkers at 24h, 3 and 6 months following restorative procedure. Demineralized dentin surfaces were biomodified with 5% glutaraldehyde (GD) or 6.5% grape seed extract (GSE) prior to placement of adhesive systems and composite resin. Nano-measurements of the interface components in a fluid cell showed that both agents increased the Er and H of underlying dentin after 3 and 6 months when compared to a control. The mechanical properties of the adhesive and hybrid layers decreased over time. Biomodification of the dentin-resin interface structures using GD and GSE can increase the mechanical properties of the interface over time and may contribute to the long-term quality of adhesive restorations.

  12. Full Scale Component Test Facility KOPRA - Qualification Test of EPR Control Rod Drive Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Sykora, Alexander; Herr, Wolfgang [AREVA NP GmbH, P.O. Box 3220, 91050 Erlangen (Germany); Champomier, Francois [AREVA NP SAS, Tour AREVA - Cedex 16, 92084 Paris-La Defense (France)

    2008-07-01

    The test facility KOPRA is designed for full scale-tests on nuclear components under operational conditions. One part of it is the component test loop for developing and qualifying nuclear core components respecting temperature, pressure and mass flow of pressurized water reactor conditions. The KOPRA test facility and its measuring equipment is presented through qualification tests for the control rod drive mechanism and the control rod drive line of the new European Pressurized Water Reactor (EPR). The control rod drive mechanism qualification test program is split into three different test phases. At first, performance tests are conducted to verify the adequate performance of the new equipment, e.g. measurement of rod cluster control assembly drop time under different thermal hydraulic conditions, impact velocity of drive rod on CRDM latch tips and drive rod acceleration during stepping operation by means of strain gauges or through direct measurement. After these functional tests follow the stability tests to ensure that proper functioning is reliably achieved over an appreciable amount of time and the endurance tests to quantify the amount of time and/or the number of steps during which no appreciable wear, that could possibly alter the correct behaviour, is to be expected. (authors)

  13. Tribo-Mechanical Investigation of the Functional Components used in Flexible Energy Harvesting Devices

    Science.gov (United States)

    Morris, Nicholas J.

    During the previous decade, the development of energy harvesting devices based on piezoelectric materials has garnered great interest. The ability to capture ambient mechanical energy and convert it to useable electricity is a potential solution to the ever-growing energy crisis. One of the most attractive functional materials used in these devices is zinc oxide (ZnO). This material's relative low cost and ease of large-area processing has spurred numerous device designs based around it. The ability to grow ZnO nanostructures of various geometries with low-temperature chemical methods makes this material even more attractive for flexible devices. Although numerous device architectures have been developed, the long-term mechanical reliability has not been addressed. This work focuses on the fabrication and mechanical failure analysis of the flexible components typically used in piezoelectric energy harvesting devices. A three-phase iterative design process was used to fabricate prototypical piezoelectric nanogenerators, based on ZnO nanowires. An output of several millivolts was achieved under normal contact and microtensile loading, but device failure occurred after only a few loading cycles, in all cases. Ex situ failure analysis confirmed the primary sources of failure, which became the focus of further, component-level studies. Failure was primarily seen in the flexible electrodes of the nanogenerating devices, but was also observed in the functional piezoelectric layer itself. Flexible electrodes comprised of polyester substrates with transparent conductive oxide (TCO) coatings were extensively investigated under various loading scenarios to mimic tribo-mechanical stresses applied during fabrication and use in flexible contact-based devices. The durability of these films was explored using microtensile testing, spherical nanoindentation, controlled mechanical buckling, stress corrosion cracking, and shear-contact reciprocating wear. The electro-mechanical

  14. Evolution of JAK-STAT pathway components: mechanisms and role in immune system development.

    Directory of Open Access Journals (Sweden)

    Clifford Liongue

    Full Text Available BACKGROUND: Lying downstream of a myriad of cytokine receptors, the Janus kinase (JAK-Signal transducer and activator of transcription (STAT pathway is pivotal for the development and function of the immune system, with additional important roles in other biological systems. To gain further insight into immune system evolution, we have performed a comprehensive bioinformatic analysis of the JAK-STAT pathway components, including the key negative regulators of this pathway, the SH2-domain containing tyrosine phosphatase (SHP, Protein inhibitors against Stats (PIAS, and Suppressor of cytokine signaling (SOCS proteins across a diverse range of organisms. RESULTS: Our analysis has demonstrated significant expansion of JAK-STAT pathway components co-incident with the emergence of adaptive immunity, with whole genome duplication being the principal mechanism for generating this additional diversity. In contrast, expansion of upstream cytokine receptors appears to be a pivotal driver for the differential diversification of specific pathway components. CONCLUSION: Diversification of JAK-STAT pathway components during early vertebrate development occurred concurrently with a major expansion of upstream cytokine receptors and two rounds of whole genome duplications. This produced an intricate cell-cell communication system that has made a significant contribution to the evolution of the immune system, particularly the emergence of adaptive immunity.

  15. An optimized ensemble local mean decomposition method for fault detection of mechanical components

    Science.gov (United States)

    Zhang, Chao; Li, Zhixiong; Hu, Chao; Chen, Shuai; Wang, Jianguo; Zhang, Xiaogang

    2017-03-01

    Mechanical transmission systems have been widely adopted in most of industrial applications, and issues related to the maintenance of these systems have attracted considerable attention in the past few decades. The recently developed ensemble local mean decomposition (ELMD) method shows satisfactory performance in fault detection of mechanical components for preventing catastrophic failures and reducing maintenance costs. However, the performance of ELMD often heavily depends on proper selection of its model parameters. To this end, this paper proposes an optimized ensemble local mean decomposition (OELMD) method to determinate an optimum set of ELMD parameters for vibration signal analysis. In OELMD, an error index termed the relative root-mean-square error (Relative RMSE) is used to evaluate the decomposition performance of ELMD with a certain amplitude of the added white noise. Once a maximum Relative RMSE, corresponding to an optimal noise amplitude, is determined, OELMD then identifies optimal noise bandwidth and ensemble number based on the Relative RMSE and signal-to-noise ratio (SNR), respectively. Thus, all three critical parameters of ELMD (i.e. noise amplitude and bandwidth, and ensemble number) are optimized by OELMD. The effectiveness of OELMD was evaluated using experimental vibration signals measured from three different mechanical components (i.e. the rolling bearing, gear and diesel engine) under faulty operation conditions.

  16. Initial mechanical stability of cementless highly-porous titanium tibial components

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Timothy Brandon [Los Alamos National Laboratory; Amer, Luke D [Los Alamos National Laboratory; Warren, Christopher P [Los Alamos National Laboratory; Cornwell, Phillip [Los Alamos National Laboratory; Meneghini, R Michael [UNIV OF CONNECTICUT HEALTH CENTER

    2008-01-01

    Cementless fixation in total knee replacement has seen limited use since reports of early failure surfaced in the late 80s and early 90s. However the emergence of improved biomaterials, particularly porous titanium and tantalum, has led to a renewed interest in developing a cementless tibial component to enhance long-term survivorship of the implants. Cement is commonly employed to minimize micromotion in new implants but represents a weak interface between the implant and bone. The elimination of cement and application of these new biomaterials, which theoretically provide improved stability and ultimate osseointegration, would likely result in greater knee replacement success. Additionally, the removal of cement from the procedure would help minimize surgical durations and get rid of the time needed for curing, thereby the chance of infection. The purpose of this biomechanical study was twofold. The first goal was to assess whether vibration analysis techniques can be used to evaluate and characterize initial mechanical stability of cementless implants more accurately than the traditional method of micromotion determination, which employs linear variable differential transducers (LVDTs). Second, an evaluative study was performed to determine the comparative mechanical stability of five designs of cementless tibial components under mechanical loading designed to simulate in vivo forces. The test groups will include a cemented Triathlon Keeled baseplate control group, three different 2-peg cementless baseplates with smooth, mid, and high roughnesses and a 4-peg cement/ess baseplate with mid-roughness.

  17. Reactor Materials Program: Mechanical properties of irradiated Types 304 and 304L stainless steel weldment components

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, R.L.; Caskey, G.R. Jr.

    1991-12-01

    The vessels (reactor tanks) of the Savannah River Site nuclear production reactors constructed in the 1950`s are comprised of Type 304 stainless steel with Type 308 stainless steel weld filler. Irradiation exposure to the reactor tank sidewalls through reactor operation has caused a change in the mechanical properties of these materials. A database of as-irradiated mechanical properties for site-specific materials and irradiation conditions has been produced for reactor tank structural analyses and to quantify the effects of radiation-induced materials degradation for evaluating reactor service life. The data has been collected from the SRL Reactor Materials Program (RMP) irradiations and testing of archival stainless steel weldment components and from previous SRL programs to measure properties of irradiated reactor Thermal Shield weldments and reactor tank (R-tank) sidewall material. Irradiation programs of the RMP are designed to quantify mechanical properties at tank operating temperatures following irradiation to present and future tank wall maximum exposure conditions. The exposure conditions are characterized in terms of fast neutron fluence (E{sub n} > 0.1 MeV) and displacements per atom (dpa){sup 3}. Tensile properties, Charpy-V notch toughness, and elastic-plastic fracture toughness were measured for base, weld, and weld heat-affected zone (HAZ) weldment components from archival piping specimens following a Screening Irradiation in the University of Buffalo Reactor (UBR) and following a Full-Term Irradiation in the High Flux Isotope Reactor (HFIR).

  18. Reactor Materials Program: Mechanical properties of irradiated Types 304 and 304L stainless steel weldment components

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, R.L.; Caskey, G.R. Jr.

    1991-12-01

    The vessels (reactor tanks) of the Savannah River Site nuclear production reactors constructed in the 1950's are comprised of Type 304 stainless steel with Type 308 stainless steel weld filler. Irradiation exposure to the reactor tank sidewalls through reactor operation has caused a change in the mechanical properties of these materials. A database of as-irradiated mechanical properties for site-specific materials and irradiation conditions has been produced for reactor tank structural analyses and to quantify the effects of radiation-induced materials degradation for evaluating reactor service life. The data has been collected from the SRL Reactor Materials Program (RMP) irradiations and testing of archival stainless steel weldment components and from previous SRL programs to measure properties of irradiated reactor Thermal Shield weldments and reactor tank (R-tank) sidewall material. Irradiation programs of the RMP are designed to quantify mechanical properties at tank operating temperatures following irradiation to present and future tank wall maximum exposure conditions. The exposure conditions are characterized in terms of fast neutron fluence (E{sub n} > 0.1 MeV) and displacements per atom (dpa){sup 3}. Tensile properties, Charpy-V notch toughness, and elastic-plastic fracture toughness were measured for base, weld, and weld heat-affected zone (HAZ) weldment components from archival piping specimens following a Screening Irradiation in the University of Buffalo Reactor (UBR) and following a Full-Term Irradiation in the High Flux Isotope Reactor (HFIR).

  19. Coupled phenomenological and fracture mechanics approach to assess the fracture behaviour of TWC piping component

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Sanjeev, E-mail: san_bpl@yahoo.co [Advanced Materials and Processes Research Institute (AMPRI), CSIR Concern, Hoshangabad Road, Bhopal 462026 (India); Ramakrishnan, N. [Advanced Materials and Processes Research Institute (AMPRI), CSIR Concern, Hoshangabad Road, Bhopal 462026 (India); Chouhan, J.S. [Civil Engineering Department, Samrat Ashok Technological Institute, Vidisha (India)

    2010-04-15

    The present study demonstrates the numerical prediction of experimental specimen J-R curve using Gurson-Tvergaard-Needleman phenomenologically based material model. The predicted specimen J-R curve is used to determine the geometric independent initiation fracture toughness (J{sub SZWc}) value that compares well with experimental result. Using the experimentally determined and numerically predicted J{sub SZWc} values and specimen J-R curves, the accuracy of predicting the fracture behaviour of the cracked component is judged. Thus the present study proposed a coupled phenomenological and fracture mechanics approach to predict the crack initiation and instability stages in cracked piping components using numerically predicted specimen J-R curve obtained from tensile specimens testing data.

  20. Reduction in intestinal cholesterol absorption by various food components: mechanisms and implications.

    Science.gov (United States)

    Cohn, Jeffrey S; Kamili, Alvin; Wat, Elaine; Chung, Rosanna W S; Tandy, Sally

    2010-06-01

    A number of different food components are known to reduce plasma and LDL-cholesterol levels by affecting intestinal cholesterol absorption. They include: soluble fibers, phytosterols, saponins, phospholipids, soy protein and stearic acid. These compounds inhibit cholesterol absorption by affecting cholesterol solubilization in the intestinal lumen, interfering with diffusion of luminal cholesterol to the gut epithelium and/or inhibiting molecular mechanisms responsible for cholesterol uptake by the enterocyte. Cholesterol content of intestinal chylomicrons is subsequently reduced, less cholesterol is transported to the liver within chylomicron remnants, hepatic LDL-receptor activity is increased and plasma levels of LDL-cholesterol are decreased. Reduced hepatic VLDL production and less conversion of VLDL to LDL also contribute to lower LDL levels. Certain food components may also affect intestinal bile acid metabolism. Further investigation of the way in which these functional ingredients affect intestinal lipid metabolism will facilitate their use and application as cardiovascular nutraceuticals.

  1. Experimental research of drilling mud influence on mud motor mechanical rubber components

    Science.gov (United States)

    Epikhin, A. V.; Ushakov, A. V.; Barztaikin, V. V.; Melnikov, V. V.; Ulyanova, S.

    2015-11-01

    The paper describes the experimental research of drilling mud influence on engineering parameters of mud motor mechanical rubber components. It is believed to be urgent due to increase in using mud motors in oil and gas well construction now, and, consequently, the issue of increasing their exploitation is becoming current. The development test results of elastomer IRP-1226 dependent on the mud type (alkaline, hydrocarbon or salt- saturated ones) and the temperature are shown in the paper. It is proved that the type of drilling mud and the temperature in bottom-hole zone have an influence on wear of mud motors elastomers.

  2. An Approach to Online Reliability Evaluation and Prediction of Mechanical Transmission Components

    Institute of Scientific and Technical Information of China (English)

    Matthias Maisch; Bernd Bertsche; Ralf Hettich

    2006-01-01

    New development trends in electronic operating data logging systems enable classification, recording and storage of load spectrums of mechanical transmission components during usage. Based on this fact, the application of online reliability evaluation and reliability prediction procedures are presented. Different methods are considered to calculate reliability, depending on actual load spectrum and a Wohler curve. The prediction of a reliability trend is analyzed by the application of time series models. For this purpose, exponential smoothing model, regression model, and the ARIMA model are considered to evaluate data and predict an decreasing reliability trends during usage.

  3. Reliability-based optimization of maintenance scheduling of mechanical components under fatigue.

    Science.gov (United States)

    Beaurepaire, P; Valdebenito, M A; Schuëller, G I; Jensen, H A

    2012-05-01

    This study presents the optimization of the maintenance scheduling of mechanical components under fatigue loading. The cracks of damaged structures may be detected during non-destructive inspection and subsequently repaired. Fatigue crack initiation and growth show inherent variability, and as well the outcome of inspection activities. The problem is addressed under the framework of reliability based optimization. The initiation and propagation of fatigue cracks are efficiently modeled using cohesive zone elements. The applicability of the method is demonstrated by a numerical example, which involves a plate with two holes subject to alternating stress.

  4. Large-scale Models Reveal the Two-component Mechanics of Striated Muscle

    Directory of Open Access Journals (Sweden)

    Robert Jarosch

    2008-12-01

    Full Text Available This paper provides a comprehensive explanation of striated muscle mechanics and contraction on the basis of filament rotations. Helical proteins, particularly the coiled-coils of tropomyosin, myosin and α-actinin, shorten their H-bonds cooperatively and produce torque and filament rotations when the Coulombic net-charge repulsion of their highly charged side-chains is diminished by interaction with ions. The classical “two-component model” of active muscle differentiated a “contractile component” which stretches the “series elastic component” during force production. The contractile components are the helically shaped thin filaments of muscle that shorten the sarcomeres by clockwise drilling into the myosin cross-bridges with torque decrease (= force-deficit. Muscle stretch means drawing out the thin filament helices off the cross-bridges under passive counterclockwise rotation with torque increase (= stretch activation. Since each thin filament is anchored by four elastic α-actinin Z-filaments (provided with forceregulating sites for Ca2+ binding, the thin filament rotations change the torsional twist of the four Z-filaments as the “series elastic components”. Large scale models simulate the changes of structure and force in the Z-band by the different Z-filament twisting stages A, B, C, D, E, F and G. Stage D corresponds to the isometric state. The basic phenomena of muscle physiology, i. e. latency relaxation, Fenn-effect, the force-velocity relation, the length-tension relation, unexplained energy, shortening heat, the Huxley-Simmons phases, etc. are explained and interpreted with the help of the model experiments.

  5. Thermo-mechanical study of high heat flux component mock-ups for ITER TBM

    Energy Technology Data Exchange (ETDEWEB)

    Bonelli, Flavia [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (Germany); Dipartimento Energia, Politecnico di Torino (Italy); Boccaccini, Lorenzo Virgilio, E-mail: lorenzo.boccaccini@kit.edu [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (Germany); Kunze, André; Maione, Ivan Alessio [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (Germany); Savoldi, Laura; Zanino, Roberto [Dipartimento Energia, Politecnico di Torino (Italy)

    2015-10-15

    Highlights: • Infrared radiation heaters for test of plasma facing component available at KIT. • Numerical model developed and validated to check uniformity of heat flux. • Thermo-mechanical calculations performed on a mock-up of the HCPB TBM FW. • Assessment done of representativity of stress conditions for the ITER TBMs. - Abstract: Commercial infrared heaters have been proposed to be used in the HELOKA facility under construction at Karlsruhe Institute of Technology (KIT) to test a mock-up of the first wall (FW), called thermo-cycle mock-up (TCM) plate, under stress loading comparable to those experienced by the test blanket modules (TBMs) in ITER. Two related issues are analyzed in this paper, in relation to the ongoing European project aimed at the design of the two EU TBMs: (1) the possibility to reproduce, by means of those heaters, high heat flux loading conditions on the TCM plate similar to those expected on the ITER TBMs, and (2) the thermo-mechanical analysis of the TCM itself, in order to define a suitable choice of experimental parameters and mechanical constraints leading to a relevant stress condition. A suitable heater model is developed and validated against experimental data from an ad-hoc test campaign. A thermo-mechanical study of the TCM plate is presented, showing that the structure is able to withstand high thermal loads, even in the most constrained case, reaching stress levels comparable to the ITER TBM.

  6. Antioxidant Property of Coffee Components: Assessment of Methods that Define Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Ningjian Liang

    2014-11-01

    Full Text Available Coffee is a rich source of dietary antioxidants, and this property, coupled with the fact that coffee is one of the world’s most popular beverages, has led to the understanding that coffee is a major contributor to dietary antioxidant intake. Brewed coffee is a complex food matrix with numerous phytochemical components that have antioxidant activity capable of scavenging free radicals, donating hydrogen and electrons, providing reducing activity and also acting as metal ion pro-oxidant chelators. More recent studies have shown that coffee components can trigger tissue antioxidant gene expression and protect against gastrointestinal oxidative stress. This paper will describe different in vitro, cell-free and cell-based assays that both characterize and compare the antioxidant capacity and mechanism of action of coffee and its bioactive constituents. Moreover, evidence of cellular antioxidant activity and correlated specific genomic events induced by coffee components, which are relevant to antioxidant function in both animal and human studies, will be discussed.

  7. Understanding deformation mechanisms during powder compaction using principal component analysis of compression data.

    Science.gov (United States)

    Roopwani, Rahul; Buckner, Ira S

    2011-10-14

    Principal component analysis (PCA) was applied to pharmaceutical powder compaction. A solid fraction parameter (SF(c/d)) and a mechanical work parameter (W(c/d)) representing irreversible compression behavior were determined as functions of applied load. Multivariate analysis of the compression data was carried out using PCA. The first principal component (PC1) showed loadings for the solid fraction and work values that agreed with changes in the relative significance of plastic deformation to consolidation at different pressures. The PC1 scores showed the same rank order as the relative plasticity ranking derived from the literature for common pharmaceutical materials. The utility of PC1 in understanding deformation was extended to binary mixtures using a subset of the original materials. Combinations of brittle and plastic materials were characterized using the PCA method. The relationships between PC1 scores and the weight fractions of the mixtures were typically linear showing ideal mixing in their deformation behaviors. The mixture consisting of two plastic materials was the only combination to show a consistent positive deviation from ideality. The application of PCA to solid fraction and mechanical work data appears to be an effective means of predicting deformation behavior during compaction of simple powder mixtures.

  8. Mechanical Behaviour of Inconel 718 Thin-Walled Laser Welded Components for Aircraft Engines

    Directory of Open Access Journals (Sweden)

    Enrico Lertora

    2014-01-01

    Full Text Available Nickel alloys are very important in many aerospace applications, especially to manufacture gas turbines and aero engine components, where high strength and temperature resistance are necessary. These kinds of alloys have to be welded with high energy density processes, in order to preserve their high mechanical properties. In this work, CO2 laser overlap joints between Inconel 718 sheets of limited thickness in the absence of postweld heat treatment were made. The main application of this kind of joint is the manufacturing of a helicopter engine component. In particular the aim was to obtain a specific cross section geometry, necessary to overcome the mechanical stresses found in these working conditions without failure. Static and dynamic tests were performed to assess the welds and the parent material fatigue life behaviour. Furthermore, the life trend was identified. This research pointed out that a full joint shape control is possible by choosing proper welding parameters and that the laser beam process allows the maintenance of high tensile strength and ductility of Inconel 718 but caused many liquation microcracks in the heat affected zone (HAZ. In spite of these microcracks, the fatigue behaviour of the overlap welds complies with the technical specifications required by the application.

  9. Testing Multiple Psychological Processes for Common Neural Mechanisms Using EEG and Independent Component Analysis.

    Science.gov (United States)

    Wessel, Jan R

    2016-03-08

    Temporal independent component analysis (ICA) is applied to an electrophysiological signal mixture (such as an EEG recording) to disentangle the independent neural source signals-independent components-underlying said signal mixture. When applied to scalp EEG, ICA is most commonly used either as a pre-processing step (e.g., to isolate physiological processes from non-physiological artifacts), or as a data-reduction step (i.e., to focus on one specific neural process with increased signal-to-noise ratio). However, ICA can be used in an even more powerful way that fundamentally expands the inferential utility of scalp EEG. The core assumption of EEG-ICA-namely, that individual independent components represent separable neural processes-can be leveraged to derive the following inferential logic: If a specific independent component shows activity related to multiple psychological processes within the same dataset (e.g., elicited by different experimental events), it follows that those psychological processes involve a common, non-separable neural mechanism. As such, this logic allows testing a class of hypotheses that is beyond the reach of regular EEG analyses techniques, thereby crucially increasing the inferential utility of the EEG. In the current article, this logic will be referred to as the 'common independent process identification' (CIPI) approach. This article aims to provide a tutorial into the application of this powerful approach, targeted at researchers that have a basic understanding of standard EEG analysis. Furthermore, the article aims to exemplify the usage of CIPI by outlining recent studies that successfully applied this approach to test neural theories of mental functions.

  10. Raman analysis of DLC coated engine components with complex shape: Understanding wear mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Jaoul, C., E-mail: jaoul@ensil.unilim.f [Universite de Limoges, CNRS, Sciences des Procedes Ceramiques et de Traitements de Surface, ENSIL, Parc Ester Technopole, 16 rue d' Atlantis, BP 6804, 87068 Limoges Cedex (France); Jarry, O. [Universite de Limoges, CNRS, Sciences des Procedes Ceramiques et de Traitements de Surface, ENSIL, Parc Ester Technopole, 16 rue d' Atlantis, BP 6804, 87068 Limoges Cedex (France); Sorevi, Parc Ester Technopole, 5 Allee Skylab, BP 6810, 87068 Limoges (France); Tristant, P. [Universite de Limoges, CNRS, Sciences des Procedes Ceramiques et de Traitements de Surface, ENSIL, Parc Ester Technopole, 16 rue d' Atlantis, BP 6804, 87068 Limoges Cedex (France); Merle-Mejean, T.; Colas, M. [Universite de Limoges, CNRS, Sciences des Procedes Ceramiques et de Traitements de Surface, Faculty of Sciences and Technics, 123 avenue Albert Thomas, 87060 Limoges Cedex (France); Dublanche-Tixier, C. [Universite de Limoges, CNRS, Sciences des Procedes Ceramiques et de Traitements de Surface, ENSIL, Parc Ester Technopole, 16 rue d' Atlantis, BP 6804, 87068 Limoges Cedex (France); Jacquet, J.-M. [Sorevi, Parc Ester Technopole, 5 Allee Skylab, BP 6810, 87068 Limoges (France)

    2009-12-31

    Hydrogenated amorphous carbon (a-C:H) films were deposited on flat samples and engine components using an industrial scale reactor. Characterization of the coating allowed validating its application on engine parts due to high hardness (32 GPa) and high level of adhesion achieved using sublayers. The original approach of this work concerned the use of Raman analysis not only on flat samples after tribometer tests but also directly on coated engine parts with complex shape (like cam/follower system), in order to understand wear mechanisms occurring in motorsport engines. As wear could lead to a coating thickness decrease, a particular attention was paid on the Raman signal of the sublayers. Among the different values extracted from Raman spectrum to characterize structural organization, the value of G peak intensity appeared as a criterion of validity of analyses because it is directly linked to the remaining thickness of the a-C:H layer. For flat samples tested on ball-on-disc tribometer, structure of a-C:H film observed by Raman spectroscopy in the wear track remained stable in depth. Then, a-C:H coated engine components were studied before and after working in real conditions. Two different wear mechanisms were identified. The first one did not show any structural modification of the bulk a-C:H layer. In the second one, the high initial roughness of samples (R{sub t} = 1.15 {mu}m) lead to coating delaminations after sliding. Massive graphitization which decreases drastically mechanical properties of the coatings was observed by Raman analyses on the contact area. The increase of the temperature on rough edges of the scratches could explain this graphitization.

  11. [Binding mechanism of traditional Chinese medicine active component 5-hydroxymethyl-furfural and HSA or BSA].

    Science.gov (United States)

    Guo, Ming; He, Ling; Lu, Xiao-Wang

    2012-03-01

    A combination of spectral experiment and molecular modeling techniques has been used to characterize the binding mechanism between an active component 5-hydroxymethyl-furfural (5-HMF) of traditional Chinese medicine and human serum albumin (HSA) or bovine serum albumin (BSA). The interaction mechanism of 5-HMF binding with HSA/BSA is analyzed. Although the drug can bind with HSA/BSA to form stable complexes, there are some differences in the bond strength. The values of binding distances (r) are different and low, which indicated the occurrence of energy transfer. The drug had conformational effect on HSA/BSA, which resulted in different changes of hydrophobic environment of the binding domain in HSA/BSA. The 'phase diagram' of fluorescence revealed that the changes on the conformational pattern of proteins have been affected by drug conformed to the "all-or-none" pattern. The interactions between drug and protein influenced by Co(II) were also discussed. Its effects acting on 5-HMF-HSA/BSA interactions are different. The computational modeling method was used to study the interaction between 5-HMF and HSA/BSA. The results of molecular model studies revealed that the binding modes for drug-serum albumin systems are mainly hydrophobic interactions and hydrogen bonding. These results are in accordance with spectral results. The research results have given a better theoretical reference for the study of pharmacological mechanism of 5-hydroxymethyl-furfural.

  12. Study of the failure mechanism for fiber composite materials taking account of physicochemical interaction of components

    Energy Technology Data Exchange (ETDEWEB)

    Zabolotskii, A.A.; Ignatova, N.P.

    1985-11-01

    An analytical approach is presented to study the failure process for fiber composite materials (CM). Failure processes are modelled in a computer, including a stage for model construction and a loading and failure stage for the model CM as a simulation of CM behavior. Three composite materials were considered with an aluminum matrix reinforced with fibers of carbon, boron (coated with B/sub 4/C), and silicon carbide. The authors found that failure of a CM develops by one of three micromechanisms depending on the ratio of mechanical characteristics of interaction, i.e., retention in the CM of fiber strength and matrix ductility and creation of strong component bonds. The sequence of elementary acts forming one or another failure macromechanism is presented.

  13. Compressibility effects on the dynamic characteristics of gas lubricated mechanical components

    Science.gov (United States)

    Arghir, Mihai; Matta, Pierre

    2009-11-01

    The present Note deals with the effects of compressibility on the linearized dynamic characteristics of gas lubricated mechanical components (journal and thrust bearings). Although the effect of compressibility on the static characteristics is well known, its influence on the dynamic characteristics is still not clearly understood. The present Note uses Lubrication's simplest model problems (the 1D slider) to qualitatively describe this effect. An analytic solution obtained for the parallel 1D slider depicts the variation of stiffness and damping with the excitation frequency and shows that this nonlinearity must be taken into account for squeeze number larger than 1. A convenient way of handling this nonlinearity in a dynamic system is described for an aerodynamic thrust bearing. To cite this article: M. Arghir, P. Matta, C. R. Mecanique 337 (2009).

  14. Mechanism of formation and accounting provision of social component reporting on sustainable development

    Directory of Open Access Journals (Sweden)

    O.M. Baryshnikova

    2016-12-01

    Full Text Available The study reports the social component of sustainable development mechanism for improving its performance by compiling the reporting algorithm on sustainable development for accounting data. The article outlines the directions of accounting improvement and the classification of social division costs by accounting objects in terms of reporting indicators on sustainable development. The paper describes the analytical accounting provision of enterprise’s social activity, typical economic operations of social activity in synthetic and analytical accounting accounts. It is established that improving accountability as the basis of the information providing process of formation of indicators of reporting social aspects on sustainable development allows to evaluate the social performance of positive and negative impacts on society, labor relations, human rights, and receive accurate and timely information for creation reporting indicators on sustainable development.

  15. Innovations in the design of mechanical components for a beamline -- The SRl`95 Workshop 2 summary

    Energy Technology Data Exchange (ETDEWEB)

    Kuzay, T.M. [Argonne National Lab., IL (United States); Warwick, T. [Lawrence Berkeley Lab., CA (United States)

    1995-12-31

    The Synchrotron Radiation Instrumentation 1995 Conference (SRI`95) was hosted by the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). Of the many workshops within the conference, the SRI`95 Workshop 2 was ``Innovations in the Design of Mechanical Components of a Beamline``. The workshop was attended well with over 140 registrants. The following topics were discussed. Industry`s perspective on the status and future was provided by Huber Diffrationtechnik, Oxford Instruments, and Kohzu Seiko Ltd. on goniometers/diffractometers, advanced manufacturing technique of high heat load components, such as the APS photon shutter, and the specialties of monochromators provided to the third-generation synchrotrons, respectively. This was followed by a description of the engineering of a dual function monochromator design for water-cooled diamond or cryogenically cooled silicon monochromators by CMC CAT/APS. Another category was the nagging problem of sensitivity of the photon beam position monitors (XBPM) to bending magnet radiation (``BM contamination``) and the undulator magnet gap changes. Problem descriptions and suggested solutions were provided by both the Advanced Light Source (ALS) and the APS. Other innovative ideas were the cooling schemes (enhanced cooling of beamline components using metallic porous meshes including cryo-cooled applications); Glidcop photon shutter design using microchannels at the ALS; and window/filter design, manufacture and operational experiences at CHESS and PETRA/HASYLAB. Additional discussions were held on designing for micromotions and precision in the optical support systems and smart user filter schemes. This is a summary of the presentations at the Workshop. 5 refs., 5 figs.

  16. Oxidative stress protection and stomatal patterning as components of salinity tolerance mechanism in quinoa (Chenopodium quinoa).

    Science.gov (United States)

    Shabala, Lana; Mackay, Alex; Tian, Yu; Jacobsen, Sven-Erik; Zhou, Daowei; Shabala, Sergey

    2012-09-01

    Two components of salinity stress are a reduction in water availability to plants and the formation of reactive oxygen species. In this work, we have used quinoa (Chenopodium quinoa), a dicotyledonous C3 halophyte species displaying optimal growth at approximately 150 mM NaCl, to study mechanisms by which halophytes cope with the afore-mentioned components of salt stress. The relative contribution of organic and inorganic osmolytes in leaves of different physiological ages (e.g. positions on the stem) was quantified and linked with the osmoprotective function of organic osmolytes. We show that the extent of the oxidative stress (UV-B irradiation) damage to photosynthetic machinery in young leaves is much less when compared with old leaves, and attribute this difference to the difference in the size of the organic osmolyte pool (1.5-fold difference under control conditions; sixfold difference in plants grown at 400 mM NaCl). Consistent with this, salt-grown plants showed higher Fv/Fm values compared with control plants after UV-B exposure. Exogenous application of physiologically relevant concentrations of glycine betaine substantially mitigated oxidative stress damage to PSII, in a dose-dependent manner. We also show that salt-grown plants showed a significant (approximately 30%) reduction in stomatal density observed in all leaves. It is concluded that accumulation of organic osmolytes plays a dual role providing, in addition to osmotic adjustment, protection of photosynthetic machinery against oxidative stress in developing leaves. It is also suggested that salinity-induced reduction in stomatal density represents a fundamental mechanism by which plants optimize water use efficiency under saline conditions.

  17. Research on the flywheel components' disturbance mechanism of a high resolution optical satellite

    Science.gov (United States)

    Lin, Li; Dong, Wang; Sitong, Zhou; Tan, Luyang

    2016-10-01

    According to the picture of a sub-meter resolution optical satellite acquired on the orbit, there is a phenomenon of jitter in the process of taking pictures. The flywheel as the main attitude control component of the satellite, the disturbance that it caused has great influence on the high resolution optical satellite in its normal action. This paper has respectively researched the flywheel components' disturbance mechanism from three parts, including uneven rotator, rotator friction, bearing disturbance, builds the mathematics model of disturbance to analysis the characteristic of disturbance. we get that the vibration system is not a fully linear system, the system is linear before the occurrence of rubbing. It also can be seen that the system has a number of different cross rigidity, it will often appear unstable motion that resulting in damage, or becomes the ultimate destruction due to the role of nonlinear damping. When the rolling roll in the surface, it will produce an alternative excitation force if there exist defects or damage in the rolling surface. This research would offer guidance for system optimization design and vibrating isolation compensation of the later type of improved satellite.

  18. Introduction of Enhanced Compressive Residual Stress Profiles in Aerospace Components Using Combined Mechanical Surface Treatments

    Science.gov (United States)

    Gopinath, Abhay; Lim, Andre; Nagarajan, Balasubramanian; Cher Wong, Chow; Maiti, Rajarshi; Castagne, Sylvie

    2016-11-01

    Mechanical surface treatments such as Shot Peening (SP) and Deep Cold Rolling (DCR) are being used to introduce Compressive Residual Stress (CRS) at the surface and subsurface layers of aerospace components, respectively. This paper investigates the feasibility of a combined introduction of both the surface and sub-surface compressive residual stress on Ti6Al4V material through a successive application of the two aforementioned processes, one after the other. CRS profiles between individual processes were compared to that of combination of processes to validate the feasibility. It was found out that shot peening introduces surface compressive residual stress into the already deep cold rolled sample, resulting in both surface and sub-surface compressive residual stresses in the material. However the drawback of such a combination would be the increased surface roughness after shot peening a deep cold rolled sample which can be critical especially in compressor components. Hence, a new technology, Vibro-Peening (VP) may be used as an alternative to SP to introduce surface stress at reduced roughness.

  19. Delayed fluorescence spectroscopy and mechanism of the 730 nm component of chloroplast

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng-long; XING Da; FAN Duo-wang; QIAN Long; LU Mai

    2006-01-01

    Charge recombination in reaction center (RC) of photosystem Ⅱ(PS Ⅱ)is regarded as the location of 685 nm delayed fluorescence (DF). The mechanism of 730 nm component appearing in the DF spectrum for chloroplast was studied by various spectral analysis methods. Experimental results of the DF spectrum at different chloroplast concentration show that the intensity of peaks at 685nm and 730 nm ascends with the chloroplast concentration increasing when the concentration is relatively low. When the concentration increases to the level of 7.8 μg/ml, a maximum intensity of the peak at 685 nm appears but the intensity of 730 nm peak still increases. The peak at 730 nm finally reaches a maximum intensity at the chloroplast concentration of 31.2 μg/ml while the intensity of the 685 nm peak has apparently fallen down. The results of absorption spectrum show that the ratios of A685 to A730 keep almost constant with the increasing of chloroplast concentration. Furthermore, the excitation spectrum for 730 nm fluorescence shows that the 685nm light has high excitation efficiency.These results indicate that the 730nm component of DF spectrum is the fluorescence of chlorophyll in PS Ⅰ RC excited by 685 nm DF. Meanwhile, this can be further verified by the invariability of DF spectrum at different delay time (1 second~9 seconds).

  20. Packaging solutions for MEMS/MOEMS using thin films as mechanical components

    Science.gov (United States)

    Boyle, P.; Syms, Richard R. A.; Moore, David F.

    2002-04-01

    Optoelectronic subsystems are becoming increasingly important to reduce the costs of assembly and packaging. The mechanical properties of vapor-deposited thin films can be used to advantage; for example three-micrometer thick silicon nitride microclips to hold single mode optic fibers in place in silicon V-shaped grooves. This paper describes the proposed use of pairs of thin film microcantilevers to precisely locate an optic component such as a filter or a mirror in an optical bench. In this configuration the precision of the lithographic process for the cantilevers determines the exact location of the component in the package, and to first order the etched shape in the substrate is unimportant. Simulation software based on variational principles has been developed to examine the behavior of structures undergoing large-scale elastic deflections. The design software consists of spreadsheet front end to enter parameters, and then Visual Basic (VBA) code and Frontline 'solver' software to run simulations. The fabrication process is described for 5 micrometers thick silicon carbide beams which are then tested by bending them using a surface profiler (such as a Dektak) to deflect the fifty micrometer wide silicon nitride cantilevers through large angles. The possible consequences for more efficient optoelectronic packaging are briefly assessed.

  1. Guarantee of remaining life time. Integrity of mechanical components and control of ageing phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Schuler, X.; Herter, K.H. [Stuttgart Univ. (Germany). MPA; Hienstorfer, W. [TUEV SUED Energietechnik GmbH, Filderstadt (Germany); Koenig, G. [EnBW-Kernkraftwerk GmbH, Neckarwestheim (Germany)

    2012-07-01

    The life time of safety relevant systems, structures and components (SSC) of Nuclear Power Plants (NPP) is determined by two main principles. First of all the required quality has to be produced during the design and fabrication process. This means that quality has to be produced and can't be improved by excessive inspections (Basis Safety - quality through production principle). The second one is assigned to the initial quality which has to be maintained during operation. This concerns safe operation during the total life time (life time management), safety against ageing phenomena (AM - ageing management) as well as proof of integrity (e.g. break preclusion or avoidance of fracture for SSC with high safety relevance). Initiated by the Fukushima Dai-ichi event in Japan in spring 2011 for German NPP's Long Term Operation (LTO) is out of question. In June 2011 legislation took decision to phase-out from nuclear by 2022. As a fact safe operation shall be guaranteed for the remaining life time. Within this technical framework the ageing management is a key element. Depending on the safety-relevance of the SSC under observation including preventive maintenance various tasks are required in particular to clarify the mechanisms which contribute systemspecifically to the damage of the components and systems and to define their controlling parameters which have to be monitored and checked. Appropriate continuous or discontinuous measures are to be considered in this connection. The approach to ensure a high standard of quality in operation for the remaining life time and the management of the technical and organizational aspects are demonstrated and explained. The basis for ageing management to be applied to NNPs is included in Nuclear Safety Standard 1403 which describes the ageing management procedures. For SSC with high safety relevance a verification analysis for rupture preclusion (proof of integrity, integrity concept) shall be performed (Nuclear Safety

  2. Creation of the mechanism of innovative safety of the enterprise on the basis of a marketing component

    Directory of Open Access Journals (Sweden)

    L.V. Vaganova

    2011-12-01

    Full Text Available The grounds of the creating an innovative enterprise security were considered in the article, the scheme of organizational and economic mechanism of providing was offered and principles of that formation were selected . Marketing component an innovations providing in the provision an innovative component of economic security at enterprise was determined.

  3. Newly Described Components and Regulatory Mechanisms of Circadian Clock Function in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Manuel Adrián Troncoso-Ponce; Paloma Mas

    2012-01-01

    The circadian clock temporally coordinates plant growth and metabolism in close synchronization with the diurnal and seasonal environmental changes.Research over the last decade has identified a number of clock components and a variety of regulatory mechanisms responsible for the rhythmic oscillations in metabolic and physiological activities.At the core of the clock,transcriptional/translational feedback loops modulate the expression of a significant proportion of the genome.In this article,we briefly describe some of the very recent advances that have improved our understanding of clock organization and function in Arabidopsis thaliana.The new studies illustrate the role of clock protein complex formation on circadian gating of plant growth and identify alternative splicing as a new regulatory mechanism for clock function.Examination of key clock properties such as temperature compensation has also opened new avenues for functional research within the plant clockwork.The emerging connections between the circadian clock and metabolism,hormone signaling and response to biotic and abiotic stress also add new layers of complexity to the clock network and underscore the significance of the circadian clock regulating the daily life of plants.

  4. Basic principles for the life time of mechanical NPP components and system

    Energy Technology Data Exchange (ETDEWEB)

    Herter, K.H.; Schuler, X. [Stuttgart Univ. (Germany). MPA; Bartonicek, J.

    2010-07-01

    The life time of systems, structures and components (SCC) is determined by two main principles. First of all the required quality has to be produced during the design and fabrication process. This means that quality has to be produced and can't be improved by excessive inspections. The second one is that the initial quality has to be maintained during operation. This concerns safe operation during the total lifetime (lifetime management), safety against ageing phenomena (ageing management) as well as proof of integrity (e.g. break exclusion or avoidance of fracture). Within this field life time and ageing management are key elements. The task of the design is to prove that the requirements for e.g. strength, integrity, functionality and leak-tightness with the required safety margins are fulfilled. The quality that can be reached during the design phase depends on the amount of knowledge about the possible degradation mechanism and on their causes, on the design assumptions (e.g. dimensions, material properties, etc.) and on the used analyses methods and verification procedures. During the erection phase of the plant, the design assumptions have to be verified and the actual design (as built) has to be documented. (Published in summary form only)

  5. Search for the active components and studies on the mechanism of the hematopoiesis improvement foods

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Sung Tae; Ha, Mee Hye; Jeong, Young Ran [Sunchon National University, Chonan (Korea)

    1999-04-01

    In this experiments, we established long-termed culture methods of bone marrow stromal cells for proliferation and differentiation of stem cells. And we selected some extracts which support maximal proliferation of stromal cells with this method. We conformed the synergic effects of herval mixture extracts for stromal cell growth. The proliferation of stromal cells was increased rather by the addition of mixture extracts than by addition of single strain extract. In the previous and cooperative experiments, we selected complex extracts which increased the number of nonadherent mononuclear cells. Different cytokine expression patterns were observed stromal cells cultured in the presence or absence of mixture extracts which support differentiation of nonadherent cells. Stimulation of macrophage cell line with herval extracts with the treatments of recombinant interferon-{gamma} resulted in increased nitric oxide synthesis in a dose-dependent manners. In addition, these extracts induced the same effects on the peritoneal macrophages. Altered patterns of cytokine mRNA expression - IL-1{beta}, IL-6, LT and iNOS-were observed in the stromals cells cultured with extracts of herbal plant. In regarding of the results, isolation and development of new and effective systems to screen for active hematopoietic component needs to be proceeded. Such studies on the hematopoietic modulation and mechanism of herbal plants would further lead to new avenues for the development of functional foods which effect such as radiation damages or leukemia. (author). 20 refs., 13 figs., 1 tab.

  6. The properties and the formation mechanism of the stellar counter-rotating components in NGC 4191

    CERN Document Server

    Coccato, Lodovico; Morelli, Lorenzo; Corsini, Enrico Maria; Pizzella, Alessandro; Erwin, Peter; Bonta', Elena Dalla; Saglia, Roberto P; Bender, Ralf; Williams, Michael

    2015-01-01

    We disentangle two counter-rotating stellar components in NGC 4191 and characterize their physical properties (kinematics, morphology, age, metallicity, and abundance ratio). We performed a spectroscopic decomposition on integral field data to separate the contribution of two stellar components to the observed galaxy spectrum across the field of view. We also performed a photometric decomposition, modelling the galaxy with a S\\'ersic bulge and two exponential disks of different scale length, with the aim of associating these structural components with the kinematic components. We measured the equivalent width of the absorption line indices on the best fit that represent the kinematic components and compared our measurements to the predictions of stellar population models. We have evidence that the line-of-sight velocity distributions (LOSVDs) are consistent with the presence of two distinct kinematic components. The combined information of the intensity of the LOSVDs and photometry allows us to associate the ...

  7. Fault mechanism analysis and simulation for continuity resistance test of electrical components in aircraft engine

    Science.gov (United States)

    Shi, Xudong; Yin, Yaping; Wang, Jialin; Sun, Zhaorong

    2017-01-01

    A large number of electrical components are used in civil aircraft engines, whose electrical circuits are usually intricate and complicated. Continuity resistance is an important parameter for the operating state of electrical components. Electrical continuity fault has serious impact on the reliability of the aircraft engine. In this paper, mathematical models of electrical components are established, and simulation is made by Simulink to analyze the electrical continuity fault.

  8. A Service Component-based Accounting and Charging Architecture to Support Interim Mechanisms across Multiple Domains

    NARCIS (Netherlands)

    Le, van M.; Beijnum, van B.J.F.; Huitema, G.B.

    2004-01-01

    Today, telematics services are often compositions of different chargeable service components offered by different service providers. To enhance component-based accounting and charging, the service composition information is used to match with the corresponding charging structure of a service session

  9. A service component-based accounting and charging architecture to support interim mechanisms across multiple domains

    NARCIS (Netherlands)

    Le, M. van; Beijnum, B.J.F. van; Huitema, G.B.

    2004-01-01

    Today, telematics services are often compositions of different chargeable service components offered by different service providers. To enhance component-based accounting and charging, the service composition information is used to match with the corresponding charging structure of a service session

  10. Utilization of En Ac-42100 Cast Aluminum Alloy for Casting of Critical Components. I. Preparation and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Vanko Branislav

    2014-12-01

    Full Text Available Requirement on the minimum value of elongation for critical components is about 15 %. The research deals with the possibility of replacing the dendritic morphology of primary solid solution and brittle eutectic silicon plates with finer particles with a more suitable morphology and size, and the possibility of increasing the mechanical properties. Introduced first part is focused on the process of preparation of experimental material and mechanical properties.

  11. Consequences for designer and manufacturer of mechanical components due to future requirements in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Hans-Joachim, Frank [Siemens/ SNP-NDM1, Erlangen (Germany)

    2001-07-01

    In the frame of European harmonization, a lot of changes on requirements for designer and manufacturer of mechanical components have been performed. Differed organizations are involved in preparing future requirements for nuclear application. On one side the French German cooperation on the development of EPR. At the origin of this project was the common decision in 1989 of Framatome and Siemens to cooperate through NPI, to design the Nuclear Island, which meets the future needs of utilities. EDF and a group of the main German Utilities joined this cooperation in 1991 and since then they have been totally involved to the progress of the work. In addition, all the process was backed up to the end by the strong cooperation between the French and the German. Safety Authorities, which have a long lasting cooperation to define common requirements, which have to be applied to future Nuclear Power Plants. Furthermore an organization has been set up to elaborate common codes related to the EPR design, at the level of the French design and construction rules (RCC) or the German KTA safety standards, the so-called EPR technical codes (ETC). On the other side, the European utilities co-operate on a much broader basis for the establishment of European Utilities Requirements (EUR). These requirements are prepared by a group of European utilities that represent the major European electricity generating companies that are determined to keep the nuclear option open. The technical requirements specified in the EUR document define the boundaries in which future plants need to be designed in order to be acceptable for the needs of the utilities and in order to fulfill the basic requirements of competitive power generation costs and licensability in all countries represented in the EUR group. All the new requirements have to be applied by designer and manufacturer. Siemens /SNP act as a designer of a lot of various vessels and tanks, heat exchangers and other items of process

  12. Consequences for designer and manufacturer of mechanical components due to future requirements in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Hans-Joachim, Frank [Siemens/ SNP-NDM1, Erlangen (Germany)

    2001-07-01

    In the frame of European harmonization, a lot of changes on requirements for designer and manufacturer of mechanical components have been performed. Differed organizations are involved in preparing future requirements for nuclear application. On one side the French German cooperation on the development of EPR. At the origin of this project was the common decision in 1989 of Framatome and Siemens to cooperate through NPI, to design the Nuclear Island, which meets the future needs of utilities. EDF and a group of the main German Utilities joined this cooperation in 1991 and since then they have been totally involved to the progress of the work. In addition, all the process was backed up to the end by the strong cooperation between the French and the German. Safety Authorities, which have a long lasting cooperation to define common requirements, which have to be applied to future Nuclear Power Plants. Furthermore an organization has been set up to elaborate common codes related to the EPR design, at the level of the French design and construction rules (RCC) or the German KTA safety standards, the so-called EPR technical codes (ETC). On the other side, the European utilities co-operate on a much broader basis for the establishment of European Utilities Requirements (EUR). These requirements are prepared by a group of European utilities that represent the major European electricity generating companies that are determined to keep the nuclear option open. The technical requirements specified in the EUR document define the boundaries in which future plants need to be designed in order to be acceptable for the needs of the utilities and in order to fulfill the basic requirements of competitive power generation costs and licensability in all countries represented in the EUR group. All the new requirements have to be applied by designer and manufacturer. Siemens /SNP act as a designer of a lot of various vessels and tanks, heat exchangers and other items of process

  13. Thermo-mechanical properties of SOFC components investigated by a combined method

    DEFF Research Database (Denmark)

    Teocoli, Francesca; Esposito, Vincenzo; Ramousse, Severine

    , and differential thermo-mechanical behavior at each layer. The combination of such factors can have a critical effect on the final shape and microstructure, and on the mechanical integrity. Thermo-mechanical properties and sintering mechanisms of important SOFC materials (CGO, YSZ, ScYSZ) were systematically...... characterized by mean of the combined use of optical dilatometry, cyclic loading thermo-mechanical analysis and scanning electron microscopy. The results from the different techniques were found complementary and the thorough understanding of viscoelastic properties of individual layers led to optimization...

  14. Development of Parking Brake Component : Product Development and Mechanical Design Process

    OpenAIRE

    Rintamäki, Julia

    2013-01-01

    This report represents the bachelor thesis examination by Julia Kastehelmi Rintamäki. The examination has been performed during spring semester 2013 at Volvo Construction Equipment in Eskilstuna. This report, Development of parking brake component, describes the product development process of the parking brake component for articulated hauler, wheel loader and grader. Volvo CE has problems with the parking brake switch that exist today on articulated hauler, wheel loader and grader. The purpo...

  15. Design Optimization of Mechanical Components Using an Enhanced Teaching-Learning Based Optimization Algorithm with Differential Operator

    Directory of Open Access Journals (Sweden)

    B. Thamaraikannan

    2014-01-01

    Full Text Available This paper studies in detail the background and implementation of a teaching-learning based optimization (TLBO algorithm with differential operator for optimization task of a few mechanical components, which are essential for most of the mechanical engineering applications. Like most of the other heuristic techniques, TLBO is also a population-based method and uses a population of solutions to proceed to the global solution. A differential operator is incorporated into the TLBO for effective search of better solutions. To validate the effectiveness of the proposed method, three typical optimization problems are considered in this research: firstly, to optimize the weight in a belt-pulley drive, secondly, to optimize the volume in a closed coil helical spring, and finally to optimize the weight in a hollow shaft. have been demonstrated. Simulation result on the optimization (mechanical components problems reveals the ability of the proposed methodology to find better optimal solutions compared to other optimization algorithms.

  16. MAXIMAL CONCENTRATIONS OF SENSITIVE COMPONENTS IN BURDEN, SUBJECT TO REACTIONARY MECHANICAL ALLOYING

    Directory of Open Access Journals (Sweden)

    F. G. Lovshenko

    2011-01-01

    Full Text Available The problem of detection of maximal content of reacting substances in burden, undergoing processing in mechanoreactor, providing safety of realization of the reaction mechanical alloying, is solved on the basis of the modern conceptions on mechanism of self-distributing high-temperature synthesis with using method of thermodynamic modeling.

  17. Correlation between magnetic field quality and mechanical components of the Large Hadron Collider main dipoles

    Energy Technology Data Exchange (ETDEWEB)

    Bellesia, B

    2006-12-15

    The 1234 superconducting dipoles of the Large Hadron Collider, working at a cryogenic temperature of 1.9 K, must guarantee a high quality magnetic field to steer the particles inside the beam pipe. Magnetic field measurements are a powerful way to detect assembly faults that could limit magnet performances. The aim of the thesis is the analysis of these measurements performed at room temperature during the production of the dipoles. In a large scale production the ideal situation is that all the magnets produced were identical. However all the components constituting a magnet are produced with certain tolerance and the assembly procedures are optimized during the production; due to these the reality drifts away from the ideal situation. We recollected geometrical data of the main components (superconducting cables, coil copper wedges and austenitic steel coil collars) and coupling them with adequate electro-magnetic models we reconstructed a multipolar field representation of the LHC dipoles defining their critical components and assembling procedures. This thesis is composed of 3 main parts: 1) influence of the geometry and of the assembling procedures of the dipoles on the quality of the magnetic field, 2) the use of measurement performed on the dipoles in the assembling step in order to solve production issues and to understand the behaviour of coils during the assembling step, and 3) a theoretical study of the uncertain harmonic components of the magnetic field in order to assess the dipole production.

  18. A Writing and Ethics Component for a Quantum Mechanics, Physical Chemistry Course

    Science.gov (United States)

    Reilly, John T.; Strickland, Michael

    2010-01-01

    A writing-across-the-curriculum and ethics component is presented for a second-semester, physical chemistry course. The activity involves introducing ethical issues pertinent to scientists. Students are asked to read additional material, participate in discussions, and write essays and a paper on an ethical issue. The writing and discussion…

  19. Thermo-Mechanical Fatigue of Compacted Graphite Iron in Diesel Engine Components

    NARCIS (Netherlands)

    Ghodrat , S.

    2013-01-01

    Cast iron components in combustion engines, such as cylinder blocks and heads of trucks, are exposed for long periods of time to elevated temperatures. Moreover, the engines are started and stopped frequently during their operational life, constituting a large number of heating and cooling cycles. I

  20. Thermo-Mechanical Fatigue of Compacted Graphite Iron in Diesel Engine Components

    NARCIS (Netherlands)

    Ghodrat , S.

    2013-01-01

    Cast iron components in combustion engines, such as cylinder blocks and heads of trucks, are exposed for long periods of time to elevated temperatures. Moreover, the engines are started and stopped frequently during their operational life, constituting a large number of heating and cooling cycles. I

  1. Antioxidant Property of Coffee Components: Assessment of Methods that Define Mechanisms of Action

    OpenAIRE

    Ningjian Liang; Kitts, David D.

    2014-01-01

    Coffee is a rich source of dietary antioxidants, and this property, coupled with the fact that coffee is one of the world’s most popular beverages, has led to the understanding that coffee is a major contributor to dietary antioxidant intake. Brewed coffee is a complex food matrix with numerous phytochemical components that have antioxidant activity capable of scavenging free radicals, donating hydrogen and electrons, providing reducing activity and also acting as metal ion pro-oxidant chela...

  2. Development of Component Mechanisms and Novel Actuation for Origami Inspired Designs

    Science.gov (United States)

    2016-11-17

    delamination problem. SNUMAX Patterned composite with mesh fabric fabrication To increase the adhesive force, mesh fabric is used for the fold...Pattern Enclosed Composite ," 2013 13th International Conference on Control, Automation and Systems , Oct. 2013 d) Manuscripts submitted but not yet...establishing fundamental design components that can be used to develop various active engineering systems inspired by origami designs, and provide

  3. A Coupled Thermo-Mechanical Simulation on Squeeze Casting Solidification Process of Three-Dimensional Geometrically Complex Components

    Science.gov (United States)

    Tang, Jie; Han, Zhiqiang; Wang, Feifan; Sun, Jue; Xu, Shanxin

    A coupled thermo-mechanical simulation method for three-dimensional squeeze casting components has been developed. The simulation was achieved by using ANSYS Parametric Design Language (APDL). The effect of volume shrinkage due to cooling and solidification, the effect of pressure on the latent heat release, the mutual dependence of interfacial heat transfer and casting deformation, and materials behavior under elevated temperatures were taken into account in the simulation. A step-shaped trial casting was simulated, which demonstrates the ability of the method to simulate the pressure transmission and decline inside the casting as well as the distribution and evolution of the interfacial heat transfer coefficient. Finally, the method was applied to simulate the solidification of an automotive sub-frame component, based on which the squeeze casting process of the component was optimized.

  4. Qualification test of the EPR control rod drive mechanism in the full scale component test facility KOPRA

    Energy Technology Data Exchange (ETDEWEB)

    Herr, Wolfgang; Sykora, Alexander; Kleideiter, Ansgar [AREVA NP GmbH, Erlangen (Germany); Champomier, Francois [AREVA NP SAS, Paris (France)

    2009-07-01

    The control rod drive mechanism (CRDM) and the mobile set consisting of rod cluster control assembly (RCC-A) of the evolutionary power reactor (EPR) had to pass a full scale qualification test in representative site conditions. The KOPRA core test section in Erlangen is precisely designed for full scale tests on nuclear core components in respect to coolant temperature and volume flow of PWR site conditions. In the test channel the complete geometry of the central core position of the reactor pressure vessel is simulated with 1:1 scale. The performance test program has led to an optimized test sequence through small adjustments in operating parameters of CRDM. The endurance test program has demonstrated that all tested components, i.e. the CRDN, the control rod driveline and the components of the drop channel are able to function properly and to meet the specification goals.

  5. Shape distortion and thermo-mechanical properties of dense SOFC components from green tape to sintered body

    DEFF Research Database (Denmark)

    Teocoli, Francesca; Esposito, Vincenzo; Ni, De Wei

    Sintering of ceramic materials is a critical process, especially when the components are shaped as multilayer. Microstructural changes and stresses take place in ceramics as single layer from the green stage to the densification stage, leading to shape distortion, delamination and cracks. The cha...... was carried out by thermo-mechanical analysis (TMA). The results from the different techniques were found complementary and viscous behavior of the layered ceramics was verified....

  6. The puzzle of the 1996 Bárdarbunga, Iceland, earthquake: no volumetric component in the source mechanism

    Science.gov (United States)

    Tkalcic, Hrvoje; Dreger, Douglas S.; Foulger, Gillian R.; Julian, Bruce R.

    2009-01-01

    A volcanic earthquake with Mw 5.6 occurred beneath the Bárdarbunga caldera in Iceland on 29 September 1996. This earthquake is one of a decade-long sequence of  events at Bárdarbunga with non-double-couple mechanisms in the Global Centroid Moment Tensor catalog. Fortunately, it was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. We investigated the event with a complete moment tensor inversion method using regional long-period seismic waveforms and a composite structural model. The moment tensor inversion using data from stations of the Iceland Hotspot Project yields a non-double-couple solution with a 67% vertically oriented compensated linear vector dipole component, a 32% double-couple component, and a statistically insignificant (2%) volumetric (isotropic) contraction. This indicates the absence of a net volumetric component, which is puzzling in the case of a large volcanic earthquake that apparently is not explained by shear slip on a planar fault. A possible volcanic mechanism that can produce an earthquake without a volumetric component involves two offset sources with similar but opposite volume changes. We show that although such a model cannot be ruled out, the circumstances under which it could happen are rare.

  7. The Effects of Fluid Absorption on the Mechanical Properties of Joint Prostheses Components

    Science.gov (United States)

    Yarbrough, David; Viano, Ann

    2010-02-01

    Ultra-high-molecular-weight polyethylene (UHMWPE) is the material playing the role of cartilage in human prosthetic joints. Wear debris from UHMWPE is a common reason for joint arthroplasty failure, and the exact mechanism responsible for wear remains an area of investigation. In this study, the microstructure of UHMWPE was examined as a function of fluid absorption. Samples with varying exposure to e-beam radiation (as part of the manufacturing process) were soaked for forty days in saline or artificial synovial fluid, under zero or 100 lbs load. Samples were then tensile-tested according to ASTM D-3895. The post-stressed material was then examined by transmission electron microscopy to evaluate the molecular response to stress, which correlates with macroscopic mechanical properties. Three parameters of the crystalline lamellae were measured: thickness, stacking ratio, and alignment to stress direction. Results indicate that fluid absorption does affect the mechanical properties of UHMWPE at both the microscopic and microscopic levels. )

  8. Aging mechanisms for concrete components of High-Level Waste storage tanks

    Energy Technology Data Exchange (ETDEWEB)

    Kassir, M.; Bandyopadhyay, K.; Bush, S.; Mather, B.; Shewmon, P.; Streicher, M.; Thompson, B.; van Rooyen, D.; Weeks, J.

    1995-05-01

    The age-related degradation mechanisms which affect the concrete and the reinforcing steel in the high-level waste (HLW) storage tanks art evaluated with respect to their potential significance to the continued performance of the concrete, and am classified into non-significant and potentially significant. The identified potentially significant degradation mechanisms include the effects of elevated temperature, freezing and thawing, leaching of calcium hydroxide, aggressive chemical attack, and corrosion of the reinforcing steel. To the extent that available knowledge permits, these mechanisms are generically evaluated and quantified so that site-specific plans may be developed to verify whether significant degradation has occurred in the concrete, and, if so, to formulate mitigating measures to avoid further deterioration and possibly repair the degradation or pursue other management options.

  9. Asymmetric Cooperative Catalysis in a Three-Component Reaction: Mechanism and Origin of Enantio- and Diastereoselectivities.

    Science.gov (United States)

    Kisan, Hemanta K; Sunoj, Raghavan B

    2016-08-05

    Mechanistic insights gained through density functional theory (DFT M06 and B3LYP) computations on a three-component cooperative asymmetric catalytic reaction between a diazo ester, a carbamate, and an imine, catalyzed by dirhodium acetate and chiral phosphoric acid (Brønsted acid), are presented. The addition of the dirhodium-bound enol to the imine yielding an α,β-diamino ester is energetically more preferred over a potentially competitive protonation of the same enol leading to an α-amino ester.

  10. Influence of mechanical and metabolic strain on the oxygen consumption slow component during forward pulled running.

    Science.gov (United States)

    Avogadro, Patrick; Kyröläinen, Heikki; Belli, Alain

    2004-10-01

    The possible influence of increased eccentric mechanical work on the increase in oxygen uptake ( V(.)O(2)) after 3 min of running (Delta V(.)O(2)) was investigated through forward pulled running. Ten subjects ran at individually predetermined constant velocity on a treadmill, while being pulled forward. Ground reaction forces, expired gas and EMGs from leg muscles were collected after 3 min and at the end of the run. V(.)O(2) and mechanical work were then calculated. The amplitude of Delta V(.)O(2) was 138 (139) ml x min(-1) [mean (SD)]. Increased ventilation explained only 8% of Delta V(.)O(2). Stride frequency slightly decreased, inducing a similar decrease in internal work and total mechanical work (all P<0.01), while integrated EMG showed no modifications. It was concluded that Delta V(.)O(2) does not come from either an increase in mechanical work production or an increase in muscular activity. Delta V(.)O(2) could come from a lower muscle efficiency that could be due to a modification of fibre type recruitment.

  11. Shape distortion and thermo-mechanical properties of SOFC components from green tape to sintering body

    DEFF Research Database (Denmark)

    Teocoli, Francesca; Ni, De Wei; Tadesse Molla, Tesfaye;

    to the strain rate difference between materials, was calculated using Cai’s model. Camber (curvature) development for in situ co-firing of a bi-layer ceramic green tape has been investigated. Analysis of shape evolution from green to sintered body can be carried out by the thermo-mechanical analysis techniques....

  12. Mechanical Behavior and Fatigue Studies of Rubber Components Used in Tracked Vehicles

    Science.gov (United States)

    2010-08-17

    relaxation as the cycles evolve. Fatigue Modeling A MultiStage Fatigue (MSF) model developed in [3] has been applied to many types of aluminum ...McDowell, K. Gall, M.F. Horstemeyer and J. Fan. “Microstructure-based Fatigue Modeling of Cast A356 - T6 Alloy.” Engineering Fracture Mechanics, vol. 70

  13. Mechanical Consequences of Molecular Composition on Failure in Polyolefin Composites Containing Glassy, Elastomeric, and Semicrystalline Components

    Energy Technology Data Exchange (ETDEWEB)

    Mahanthappa, Mahesh K.; Hillmyer, Marc A.; Bates, Frank S. (UMM)

    2008-10-24

    In order to gain insights into the mechanisms of deformation and ultimate failure in a homologous series of lamellae-forming polyolefin block copolymers comprised of glassy poly(cyclohexylethylene) (C), elastomeric poly(ethylene-alt-propylene) (P), and semicrystalline poly(ethylene) (E), the anisotropic tensile properties of samples in which the microphase separate structure is oriented on a macroscopic length scale were probed. Reciprocating shear processing of monodisperse CPCPC and CPEPC-{xi} polymers having mass fraction w{sub c} 0.39--0.44 and 0 {<=} {xi} {<=} 1, where {xi} = w{sub E}/(w{sub E} + w{sub P}), produces 'single-grain' polymer samples with perpendicular-oriented lamellae. Tensile deformation studies in which the strain axis coincides with the lamellar normal direction yield varied mechanical responses ranging from brittle fracture for CEC ({xi} = 0) to ductile behavior for CPEPC ({xi} > 0) and CPCPC. Tandem small- and wide-angle X-ray scattering analysis of samples undergoing deformation shows that application of strain along the lamellar normal in the CPEPC materials results in formation of a folded lamellar structure or 'chevron' morpohology within which the E crystals cant relative to the strain direction. Since the ultimate failure mechanism for materials strained in this direction is chain pullout in the glassy domains, a simple mechanical model applied to the data enables quantitation of the stress required for chain pullout at {approx}4 MPa. Additionally, the mechanical properties of miscible blends of CEC and CPC polymers with matched segregation strengths are shown to mimic those of the covalently linked CPEPC pentablock copolymer.

  14. Buffering mechanisms in aging: a systems approach toward uncovering the genetic component of aging.

    Directory of Open Access Journals (Sweden)

    Aviv Bergman

    2007-08-01

    Full Text Available An unrealized potential to understand the genetic basis of aging in humans, is to consider the immense survival advantage of the rare individuals who live 100 years or more. The Longevity Gene Study was initiated in 1998 at the Albert Einstein College of Medicine to investigate longevity genes in a selected population: the "oldest old" Ashkenazi Jews, 95 years of age and older, and their children. The study proved the principle that some of these subjects are endowed with longevity-promoting genotypes. Here we reason that some of the favorable genotypes act as mechanisms that buffer the deleterious effect of age-related disease genes. As a result, the frequency of deleterious genotypes may increase among individuals with extreme lifespan because their protective genotype allows disease-related genes to accumulate. Thus, studies of genotypic frequencies among different age groups can elucidate the genetic determinants and pathways responsible for longevity. Borrowing from evolutionary theory, we present arguments regarding the differential survival via buffering mechanisms and their target age-related disease genes in searching for aging and longevity genes. Using more than 1,200 subjects between the sixth and eleventh decades of life (at least 140 subjects in each group, we corroborate our hypotheses experimentally. We study 66 common allelic site polymorphism in 36 candidate genes on the basis of their phenotype. Among them we have identified a candidate-buffering mechanism and its candidate age-related disease gene target. Previously, the beneficial effect of an advantageous cholesteryl ester transfer protein (CETP-VV genotype on lipoprotein particle size in association with decreased metabolic and cardiovascular diseases, as well as with better cognitive function, have been demonstrated. We report an additional advantageous effect of the CETP-VV (favorable genotype in neutralizing the deleterious effects of the lipoprotein(a (LPA gene

  15. Chemical Kinetics Mechanism Reduction Based on Principal Component Analysis: Development and Testing of Some New Implementations

    Science.gov (United States)

    2013-05-01

    developed at the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC). Referred to as the impinging stream vortex... engine (ISVE), the concept was fueled at the time with monomethylhydrazine (MMH) and inhibited red fuming nitric acid (IRFNA). Even though MMH and IRFNA...reactions targeted, 190 reaction sets were constructed. (This number included nonunique assemblages.) The smallest mechanism that produced a

  16. Mechanics of transport phenomena in multi-component sessile drops with solidification

    Science.gov (United States)

    Su, Yeong-Jen; Yang, Wen-Jei; Liu, Jiaching

    1990-01-01

    The mechanics of transport phenomena in multicomponent sessile drops with internal solidification is determined on the basis of an experimental study. A shadowgraph-schlieren system and a microscope-video system are used for the study. It is suggested that present data can be used to enhance the solid or crystal quality in a reduced-gravity environment where both thermo- and diffuso-capillary effects of solidification and crystal growth are dominant.

  17. Structural and mechanical characterization of detonation coatings formed by reaction products of titanium with components of the spraying atmosphere

    Science.gov (United States)

    Ulianitsky, Vladimir Yu.; Dudina, Dina V.; Panin, Sergey V.; Vlasov, Ilya V.; Batraev, Igor S.; Bokhonov, Boris B.

    2016-11-01

    Structural characterization of detonation deposits formed by reaction products of titanium with the components of the spraying atmosphere showed that ceramic-based coatings of unique microstructures—consisting of alternating layers of different compositions—can be formed. For the first time, mechanical characteristics of the coatings formed by reaction-accompanied detonation spraying of titanium were evaluated. It was found that high-yield transformation of titanium into oxides and nitrides during spraying can result in the formation of coatings with high fracture resistance and interface fracture toughness. The hardness of the coatings measured along the cross-section of the specimens was higher than that on the surface of the coatings, which indicated mechanical anisotropy of the deposited material. In terms of mechanical properties, coatings formed by the reaction products appear to be more attractive than those specially treated to preserve metallic titanium.

  18. Standardization Efforts for Mechanical Testing and Design of Advanced Ceramic Materials and Components

    Science.gov (United States)

    Salem, Jonathan A.; Jenkins, Michael G.

    2003-01-01

    Advanced aerospace systems occasionally require the use of very brittle materials such as sapphire and ultra-high temperature ceramics. Although great progress has been made in the development of methods and standards for machining, testing and design of component from these materials, additional development and dissemination of standard practices is needed. ASTM Committee C28 on Advanced Ceramics and ISO TC 206 have taken a lead role in the standardization of testing for ceramics, and recent efforts and needs in standards development by Committee C28 on Advanced Ceramics will be summarized. In some cases, the engineers, etc. involved are unaware of the latest developments, and traditional approaches applicable to other material systems are applied. Two examples of flight hardware failures that might have been prevented via education and standardization will be presented.

  19. Evaluation of shear stress accumulation on blood components in normal and dysfunctional bileaflet mechanical heart valves using smoothed particle hydrodynamics.

    Science.gov (United States)

    Shahriari, S; Maleki, H; Hassan, I; Kadem, L

    2012-10-11

    Evaluating shear induced hemodynamic complications is one of the major concerns in design of the mechanical heart valves (MHVs). The monitoring of these events relies on both numerical simulations and experimental measurements. Currently, numerical approaches are mainly based on a combined Eulerian-Lagrangian approach. A more straightforward evaluation can be based on the Lagrangian analysis of the whole blood. As a consequence, Lagrangian meshfree methods are more adapted to such evaluation. In this study, smoothed particle hydrodynamics (SPH), a fully meshfree particle method originated to simulate compressible astrophysical flows, is applied to study the flow through a normal and a dysfunctional bileaflet mechanical heart valves (BMHVs). The SPH results are compared with the reference data. The accumulation of shear stress patterns on blood components illustrates the important role played by non-physiological flow patterns and mainly vortical structures in this issue. The statistical distribution of particles with respect to shear stress loading history provides important information regarding the relative number of blood components that can be damaged. This can be used as a measure of the response of blood components to the presence of the valve implant or any implantable medical device. This work presents the first attempt to simulate pulsatile flow through BMHVs using SPH method.

  20. Improvement of mechanical properties and life extension of high reliability structural components by laser shock processing

    Science.gov (United States)

    Ocaña, J. L.; Morales, M.; Porro, J. A.; Iordachescu, D.; Díaz, M.; Ruiz de Lara, L.; Correa, C.

    2011-05-01

    Profiting by the increasing availability of laser sources delivering intensities above 109 W/cm2 with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is being consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals and is being developed as a practical process amenable to production engineering. The main acknowledged advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Following a short description of the theoretical/computational and experimental methods developed by the authors for the predictive assessment and experimental implementation of LSP treatments, experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (specifically Al and Ti alloys) under different LSP irradiation conditions are presented. In particular, the analysis of the residual stress profiles obtained under different irradiation parameters and the evaluation of the corresponding induced surface properties as roughness and wear resistance are presented.

  1. Oriented clay nanopaper from biobased components--mechanisms for superior fire protection properties.

    Science.gov (United States)

    Carosio, F; Kochumalayil, J; Cuttica, F; Camino, G; Berglund, L

    2015-03-18

    The toxicity of the most efficient fire retardant additives is a major problem for polymeric materials. Cellulose nanofiber (CNF)/clay nanocomposites, with unique brick-and-mortar structure and prepared by simple filtration, are characterized from the morphological point of view by scanning electron microscopy and X-ray diffraction. These nanocomposites have superior fire protection properties to other clay nanocomposites and fiber composites. The corresponding mechanisms are evaluated in terms of flammability (reaction to a flame) and cone calorimetry (exposure to heat flux). These two tests provide a wide spectrum characterization of fire protection properties in CNF/montmorrilonite (MTM) materials. The morphology of the collected residues after flammability testing is investigated. In addition, thermal and thermo-oxidative stability are evaluated by thermogravimetric analyses performed in inert (nitrogen) and oxidative (air) atmospheres. Physical and chemical mechanisms are identified and related to the unique nanostructure and its low thermal conductivity, high gas barrier properties and CNF/MTM interactions for char formation.

  2. Analytical model of the contact interaction between the components of a special percussive mechanism for planetary exploration

    Science.gov (United States)

    Vila, Luis J.; Malla, Ramesh B.

    2016-01-01

    Special percussive mechanisms, e.g. Auto Gopher and UltraSonic/Sonic Driller/Corer (USDC) have been developed by NASA Jet Propulsion Laboratory and Honeybee Robotics Spacecraft Mechanisms, Corp. to address some of the limitations of current drilling techniques for planetary exploration. The percussive mechanism consists of an ultrasonic horn, a free mass (hammer) and the drill rod. This paper presents the analysis of the interaction between these three components. The impact between the components (i.e. ultrasonic horn and free mass, and free mass and drill rod) is analyzed using solid body collision analysis applying the principle of conservation of momentum. The drill rod is modeled for both undamped and damped cases with equivalent generalized single degree of freedom system. Various values are used for the coefficient of restitution to account for energy loss during impact. The energy transferred to the drill rod by the free mass is obtained determining the change in kinetic energy due to impact. It is observed that the free mass converts the high frequency of oscillation of the ultrasonic horn into lower frequency impacts on the drill rod. A decrease in the coefficient of restitution results in a decrease in the number of impacts, impulse imparted to the drill rod and energy transferred to the drill rod by the impact of the free mass.

  3. Two-Component Regulatory Systems – implication in the quorum sensing mechanisms and bacteriocin production in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Lia–Mara Ditu

    2014-08-01

    Full Text Available For lactic acid bacteria, the mechanisms of quorum sensing and response are mediated by peptides or pheromones that interfere with the synthesis of antimicrobial peptides (AMP called bacteriocins, when these molecules reach a certain critical level of concentration. Generally, the synthesis and activity of pheromones is adjusted by means of a two-component regulatory system. The observation that some microorganisms, in particular lactic acid bacteria, produce bacteriocins according to the cell density, has led to the discovery of the involvement of QS mechanisms in the synthesis of these peptides. Bacteriocins synthesis is inducible, the process requiring the extracellular accumulation of peptides that functions as chemical messengers activators of bacteriocins synthesis. This minireview presents the molecular architecture and functions of two-component regulatory systems and ABC transporters implicated in the synthesis and secretion of nisin, one of the most studied bacteriocin. The elucidation of the intimate mechanisms of bacteriocins synthesis is equally of biotechnological and medical importance, opening interesting perspectives for the development of improved technologies for the production of bacteriocins with good yields, and also, for increasing the beneficial anti-infective roles of probiotic bacteria when administered in vivo.

  4. Cleaning mechanism of particle contaminants on large aperture optical components by using air knife sweeping technology

    Science.gov (United States)

    Niu, Longfei; Liu, Hao; Miao, Xinxiang; Lv, Haibing; Yuan, Xiaodong; Zhou, Hai; Yao, Caizhen; Zhou, Guorui; Li, Qin

    2017-05-01

    The cleaning mechanism of optical surface particle contaminants in the light pneumatic tube was simulated based on the static equations and JKR model. Cleaning verification experiment based on air knife sweeping system and on-line monitoring system in high power laser facility was set up in order to verify the simulated results. Results showed that the removal ratio is significantly influenced by sweeping velocity and angle. The removal ratio can reach to 94.3% by using higher input pressure of the air knife, demonstrating that the air knife sweeping technology is useful for maintaining the surface cleanliness of optical elements, and thus guaranteeing the long-term stable running of the high power laser facility.

  5. Reliability in automotive and mechanical engineering determination of component and system reliability

    CERN Document Server

    Bertsche, Bernd

    2008-01-01

    In the present contemporary climate of global competition in every branch of engineering and manufacture it has been shown from extensive customer surveys that above every other attribute, reliability stands as the most desired feature in a finished product. To survive this relentless fight for survival any organisation, which neglect the plea of attaining to excellence in reliability, will do so at a serious cost Reliability in Automotive and Mechanical Engineering draws together a wide spectrum of diverse and relevant applications and analyses on reliability engineering. This is distilled into this attractive and well documented volume and practising engineers are challenged with the formidable task of simultaneously improving reliability and reducing the costs and down-time due to maintenance. The volume brings together eleven chapters to highlight the importance of the interrelated reliability and maintenance disciplines. They represent the development trends and progress resulting in making this book ess...

  6. Dynamic mechanical properties of PTFE-based composites filled with multi-component

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To improve performance of PTFE-based damping material, composites with several fillers were prepared by compressing and sintering. The dynamic mechanical properties of the composites were investigated by means of viscoanalyser. Temperature-dependent loss factors, storage modulus and loss modulus were obtained.And SEM was employed to study the compatibility between PTFE and fillers. The results show that, when blending PPS and PEEK at proper content, the loss factor curve appears double peaks, which can widen the high-damping temperature region of the composites. Blending graphite or alumina can increase the storage modulus obviously, but decrease the value of loss factor. And because graphite or alumina combines with matrix poorly, glide would happen at interface when bearing external load. The interface friction can dissipate vibration energy, which increases the loss modulus of the composites. Blending PPS, PEEK and graphite or alumina at right content, PTFE-based composites can meet demands as damping material in practical engineering.

  7. Nickel-Titanium Alloys: Corrosion "Proof" Alloys for Space Bearing, Components and Mechanism Applications

    Science.gov (United States)

    DellaCorte, Christopher

    2010-01-01

    An intermetallic nickel-titanium alloy, 60NiTi (60 wt% Ni, 40 wt% Ti), is shown to be a promising candidate tribological material for space mechanisms. 60NiTi offers a broad combination of physical properties that make it unique among bearing materials. 60NiTi is hard, electrically conductive, highly corrosion resistant, readily machined prior to final heat treatment, and is non-magnetic. Despite its high Ti content, 60NiTi is non-galling even under dry sliding. No other bearing alloy, metallic or ceramic, encompasses all of these attributes. Since 60NiTi contains such a high proportion of Ti and possesses many metallic properties, it was expected to exhibit poor tribological performance typical of Ti alloys, namely galling type behavior and rapid lubricant degradation. In this poster-paper, the oil-lubricated behavior of 60NiTi is presented.

  8. Mechanism of Irradiation Assisted Cracking of Core Components in Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary S; Atzmon, Michael; Wang, Lumin

    2003-04-28

    The overall goal of the project is to determine the mechanism of irradiation assisted stress corrosion cracking (IASCC). IASCC has been linked to hardening, microstructural and microchemical changes during irradiation. Unfortunately, all of these changes occur simultaneously and at similar rates during irradiation, making attribution of IASCC to any one of these features nearly impossible to determine. The strategy set forth in this project is to develop means to separate microstructural from microchemical changes to evaluate each separately for their effect on IASCC. In the first part, post irradiation annealing (PIA) treatments are used to anneal the irradiated microstructure, leaving only radiation induced segregation (RIS) for evaluation for its contribution to IASCC. The second part of the strategy is to use low temperature irradiation to produce a radiation damage dislocation loop microstructure without radiation induced segregation in order to evaluate the effect of the dislocation microstructure alone.

  9. Multi-parametric approach to identify coffee components that regulate mechanisms of gastric acid secretion.

    Science.gov (United States)

    Rubach, Malte; Lang, Roman; Seebach, Elisabeth; Somoza, Mark M; Hofmann, Thomas; Somoza, Veronika

    2012-02-01

    Chlorogenic acid (CA), caffeine (CAFF), pyrogallol (PYR), catechol (CAT), (β)N-alkanoyl-hydroxytryptamides (C5HT) and N-methylpyridinium (N-MP) were evaluated for their influence on mechanisms of gastric acid secretion as single compounds and in biomimetic mixtures. Compounds were tested in coffee representative concentrations. Human gastric cancer cells (HGT-1) were used to study the proton secretory activity by Ussing chamber experiments and FACS analysis. For activation of EGFr, Akt1, ERK1/2, ATF-2 and cAMP levels, we performed pathway screening assays. Time-dependent expression of related genes were determined by real-time PCR. Part of the data was used for neural network modeling to identify the most relevant compounds. N-MP increased the expression of the anti-secretory somatostatin receptor by 114%, whereas C5HT decreased its expression by 52%. N-MP down-regulated the pro-secretory CHRM3 receptor by 36% and the H⁺,K⁺-ATPase by 36%. CAFF stimulated the secretory activity in the functional assays, whereas N-MP and CA decreased proton secretion. After applying a pathway analysis, we were able to discriminate between CAFF, CA, CAT, C5HT, PYR and histamine-activating EGFr signaling and N-MP-associated ERK1/2 signaling. By applying a multi-parametric approach, N-MP was shown to effectively down-regulate mechanisms of gastric acid secretion in human parietal gastric cells. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

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

    2009-03-01

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

  11. Diversity of two-component systems: insights into the signal transduction mechanism by the  Staphylococcus aureus two-component system GraSR.

    Science.gov (United States)

    Muzamal, Uzma; Gomez, Daniel; Kapadia, Fenika; Golemi-Kotra, Dasantila

    2014-01-01

    The response to cationic antimicrobial peptides (CAMPs) in Staphylococcus aureus relies on a two-component system (TCS), GraSR, an auxiliary protein GraX and an ATP-binding cassette (ABC) transporter, VraF/G. To understand the signal transduction mechanism by GraSR, we investigated the kinase activity of the cytoplasmic domain of histidine kinase GraS and the interaction with its cognate response regulator GraR. We also investigated interactions among the auxiliary protein GraX, GraS/R and the ATPase protein of the ABC transporter, VraF. We found that GraS lacks autophosphorylation activity, unlike a similar histidine kinase, BceS, of Bacillus subtilis. In addition, the interaction between GraS and GraR is very weak in comparison to the stronger interaction observed between BceS and its conjugated response regulator, BceR, suggesting that CAMP signaling may not flow directly from GraS to GraR. We found that the auxiliary protein GraX interacts with VraF and GraR, and requires the histidine phosphotransfer and dimerization domain of GraS to interact with this protein. Further, VraF requires the GraS region that connects the membrane-bound domain with the cytoplasmic domain of this protein for interaction with GraS. The interactions of GraX with GraS/R and VraF indicate that GraX may serve as a scaffold to bring these proteins in close proximity to GraS, plausibly to facilitate activation of GraS to ultimately transduce the signal to GraR.

  12. Investigating Premature Ignition of Thruster Pressure Cartridges by Mechanical Impact of Internal Components

    Science.gov (United States)

    Woods, Stephen S.; Saulsberry, Regor

    2010-01-01

    Pyrotechnic thruster pressure cartridges (TPCs) are used for aeroshell separation on a new NASA crew launch vehicle. The premature ignition concern was hypothesized based on the potential range of motion of the subassemblies, projected worst case accelerations, and the internal geometry that could subject propellant grains to mechanical impact sufficiently high for ignition. This possibility was investigated by fabricating a high-fidelity model of the suspected contact geometry, placing a representative amount of propellant in it, and impacting the propellant with a range of forces equivalent to and greater than the maximum possible during launch. Testing demonstrated that the likelihood of ignition is less than 1 in 1,000,000. The test apparatus, methodology, and results are described in this paper. Nondestructive evaluation ( NDE) during TPC acceptance testing indicated that internal assemblies moved during shock and vibration testing due to an internal bond anomaly. This caused concerns that the launch environment might produce the same movement and release propellant grains that might be prematurely ignited through impact or through electrostatic discharge (ESD) as grains vibrated against internal surfaces. Since a new lot could not be fabricated in time, a determination had to be made as to whether the lot was acceptable to fly. This paper discusses the analysis and impact testing used to address the potential impact issue and a separate paper addresses the ESD issue.

  13. Diagnostics of the molecular component of PDRs with mechanical heating. II: line intensities and ratios

    CERN Document Server

    Kazandjian, M V; Pelupessy, I; Israel, F P; Spaans, M

    2014-01-01

    CO observations in active galactic nuclei and star-bursts reveal high kinetic temperatures. Those environments are thought to be very turbulent due to dynamic phenomena such as outflows and high supernova rates. We investigate the effect of mechanical heating (MH) on atomic fine-structure and molecular lines, and their ratios. We use those ratios as a diagnostic to constrain the amount of MH in an object and also study its significance on estimating the H2 mass. Equilibrium PDRs models were used to compute the thermal and chemical balance for the clouds. The equilibria were solved for numerically using the optimized version of the Leiden PDR-XDR code. Large velocity gradient calculations were done as post-processing on the output of the PDR models using RADEX. High-J CO line ratios are very sensitive to MH. Emission becomes at least one order of magnitude brighter in clouds with n~10^5~cm^-3 and a star formation rate of 1 Solar Mass per year (corresponding to a MH rate of 2 * 10^-19 erg cm^-3 s^-1). Emission ...

  14. Reliability of automotive and mechanical engineering. Determination of component and system reliability

    Energy Technology Data Exchange (ETDEWEB)

    Bertsche, Bernd [Stuttgart Univ. (Germany). Inst. fuer Maschinenelemente

    2008-07-01

    In the present contemporary climate of global competition in every branch of engineering and manufacture it has been shown from extensive customer surveys that above every other attribute, reliability stands as the most desired feature in a finished product. To survive this relentless fight for survival any organisation, which neglect the plea of attaining to excellence in reliability, will do so at a serious cost Reliability in Automotive and Mechanical Engineering draws together a wide spectrum of diverse and relevant applications and analyses on reliability engineering. This is distilled into this attractive and well documented volume and practising engineers are challenged with the formidable task of simultaneously improving reliability and reducing the costs and down-time due to maintenance. The volume brings together eleven chapters to highlight the importance of the interrelated reliability and maintenance disciplines. They represent the development trends and progress resulting in making this book essential basic material for all research academics, planners maintenance executives, who have the responsibility to implement the findings and maintenance audits into a cohesive reliability policy. Although, the book is centred on automotive engineering nevertheless, the examples and overall treatise can be applied to a wide range of professional practices. The book will be a valuable source of information for those concerned with improved manufacturing performance and the formidable task of optimising reliability. (orig.)

  15. Degradation Mechanisms of an Advanced Jet Engine Service-Retired TBC Component

    Science.gov (United States)

    Wu, Rudder T.; Osawa, Makoto; Yokokawa, Tadaharu; Kawagishi, Kyoko; Harada, Hiroshi

    Current use of TBCs is subjected to premature spallation failure mainly due to the formation of thermally grown oxides (TGOs). Although extensive research has been carried out to gain better understanding of the thermo - mechanical and -chemical characteristics of TBCs, laboratory-scale studies and simulation tests are often carried out in conditions significantly differed from the complex and extreme environment typically of a modern gas-turbine engine, thus, failed to truly model service conditions. In particular, the difference in oxygen partial pressure and the effects of contaminants present in the engine compartment have often been neglected. In this respect, an investigation is carried out to study the in-service degradation of an EB-PVD TBC coated nozzle-guide vane. Several modes of degradation were observed due to three factors: 1) presence of residual stresses induced by the thermal-expansion mismatches, 2) evolution of bond coat microstructure and subsequent formation of oxide spinels, 3) deposition of CMAS on the surface of TBC.

  16. Roles of prefrontal cortex and paraventricular thalamus in affective and mechanical components of visceral nociception.

    Science.gov (United States)

    Jurik, Angela; Auffenberg, Eva; Klein, Sabine; Deussing, Jan M; Schmid, Roland M; Wotjak, Carsten T; Thoeringer, Christoph K

    2015-12-01

    Visceral pain represents a major clinical challenge in the management of many gastrointestinal disorders, eg, pancreatitis. However, cerebral neurobiological mechanisms underlying visceral nociception are poorly understood. As a representative model of visceral nociception, we applied cerulein hyperstimulation in C57BL6 mice to induce acute pancreatitis and performed a behavioral test battery and c-Fos staining of brains. We observed a specific pain phenotype and a significant increase in c-Fos immunoreactivity in the paraventricular nucleus of the thalamus (PVT), the periaqueductal gray, and the medial prefrontal cortex (mPFC). Using neuronal tracing, we observed projections of the PVT to cortical layers of the mPFC with contacts to inhibitory GABAergic neurons. These inhibitory neurons showed more activation after cerulein treatment suggesting thalamocortical "feedforward inhibition" in visceral nociception. The activity of neurons in pancreatitis-related pain centers was pharmacogenetically modulated by designer receptors exclusively activated by designer drugs, selectively and cell type specifically expressed in target neurons using adeno-associated virus-mediated gene transfer. Pharmacogenetic inhibition of PVT but not periaqueductal gray neurons attenuated visceral pain and induced an activation of the descending inhibitory pain pathway. Activation of glutamatergic principle neurons in the mPFC, but not inhibitory neurons, also reversed visceral nociception. These data reveal novel insights into central pain processing that underlies visceral nociception and may trigger the development of novel, potent centrally acting analgesic drugs.

  17. Dynamic Mechanical Properties and Thermal Effect of an Epoxy Resin Composite, Encapsulation's Element of a New Electronic Component

    Science.gov (United States)

    Rmili, W.; Deffarges, M. P.; Chalon, F.; Ma, Z.; Leroy, R.

    2013-11-01

    Epoxy resin is used in many industrial applications principally in the microelectronic field to protect integrated circuits. However, these components are subject to various environments such as moisture and thermal fluctuations during packaging. Consequently, mechanical, physical and chemical properties of the resin can be affected. For an epoxy resin composite designed for a future application, an evaluation of the relevant properties was carried out using a dynamic mechanical analyzer and a thermogravimetric analysis (TGA) instrument. The surface morphology was investigated using scanning electron microscopy to examine the impact of post-cured treatment through evolution of the rigidity and of the glass transition temperature. Subsequently, a temperature classification was proposed to define the temperature limit for safe use of the material. Finally, temperature degradation was observed and confirmed by TGA tests. Results from all of these analyses bring understanding to the phenomenon of thermal degradation and its influence on the stability of the epoxy resin composite.

  18. Mechanism of the heterogeneous reaction of carbonyl sulfide with typical components of atmospheric aerosol

    Institute of Scientific and Technical Information of China (English)

    WU Hongbo; WANG Xiao; CHEN Jianmin; YU Hongkun; XUE Huaxin; PAN Xunxi; HOU Huiqi

    2004-01-01

    The homogeneous reactions of earbonyl sulfide (COS) with OH and oxygen radicals have been studied thoroughly. However, the heterogeneous chemical processes involving COS and atmospheric particles are still not well understood. The reactivity of COS with atmospheric mineral oxides such as A12O3, CaO, SiO2, Fe2O3 and MnO2 has been explored. The gaseous and solid products of the reaction were identified by in situ Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy respectively.The mechanism and kinetics of the heterogeneous reaction are also discussed in detail. The results showed that COS can be catalytically oxidized on the surfaces of different atmospheric mineral oxides with the products of CO2, S and SO42-.The reactivity of the oxides with COS differs widely. A12O3 exhibits excellent reactivity, and Fe2O3 is inferior to it. CaO shows weak reactivity, while SiO2 and MnO2 nearly have no activity for the oxidation of COS. The absorbed oxygen and hydroxyls on the surfaces of the oxides are the main active sites in the conversion of COS. When O2 in the experimental system was much excessive, the catalytic oxidation on the surface of AI2O3 is a pseudo first order reaction with respect to COS. The acidity of A12O3 influences the reactivity significantly. The rate constants of the catalytic oxidation of COS on the surface of basic, neutral and acidic A12O3 are respectively 1.51xl0-4, 9.81x10-s and 3.06x10-6 s-1.

  19. Tribological and mechanical performance evaluation of metal prosthesis components manufactured via metal injection molding.

    Science.gov (United States)

    Melli, Virginia; Juszczyk, Mateusz; Sandrini, Enrico; Bolelli, Giovanni; Bonferroni, Benedetta; Lusvarghi, Luca; Cigada, Alberto; Manfredini, Tiziano; De Nardo, Luigi

    2015-01-01

    The increasing number of total joint replacements, in particular for the knee joint, has a growing impact on the healthcare system costs. New cost-saving manufacturing technologies are being explored nowadays. Metal injection molding (MIM) has already demonstrated its suitability for the production of CoCrMo alloy tibial trays, with a significant reduction in production costs, by holding both corrosion resistance and biocompatibility. In this work, mechanical and tribological properties were evaluated on tibial trays obtained via MIM and conventional investment casting. Surface hardness and wear properties were evaluated through Vickers hardness, scratch and pin on disk tests. The MIM and cast finished tibial trays were then subjected to a fatigue test campaign in order to obtain their fatigue load limit at 5 millions cycles following ISO 14879-1 directions. CoCrMo cast alloy exhibited 514 HV hardness compared to 335 HV of MIM alloy, furthermore it developed narrower scratches with a higher tendency towards microploughing than microcutting, in comparison to MIM CoCrMo. The observed fatigue limits were (1,766 ± 52) N for cast tibial trays and (1,625 ± 44) N for MIM ones. Fracture morphologies pointed out to a more brittle behavior of MIM microstructure. These aspects were attributed to the absence of a fine toughening and surface hardening carbide dispersion in MIM grains. Nevertheless, MIM tibial trays exhibited a fatigue limit far beyond the 900 N of maximum load prescribed by ISO and ASTM standards for the clinical application of these devices.

  20. Probabilistic Material Strength Degradation Model for Inconel 718 Components Subjected to High Temperature, Mechanical Fatigue, Creep and Thermal Fatigue Effects

    Science.gov (United States)

    Bast, Callie Corinne Scheidt

    1994-01-01

    This thesis presents the on-going development of methodology for a probabilistic material strength degradation model. The probabilistic model, in the form of a postulated randomized multifactor equation, provides for quantification of uncertainty in the lifetime material strength of aerospace propulsion system components subjected to a number of diverse random effects. This model is embodied in the computer program entitled PROMISS, which can include up to eighteen different effects. Presently, the model includes four effects that typically reduce lifetime strength: high temperature, mechanical fatigue, creep, and thermal fatigue. Statistical analysis was conducted on experimental Inconel 718 data obtained from the open literature. This analysis provided regression parameters for use as the model's empirical material constants, thus calibrating the model specifically for Inconel 718. Model calibration was carried out for four variables, namely, high temperature, mechanical fatigue, creep, and thermal fatigue. Methodology to estimate standard deviations of these material constants for input into the probabilistic material strength model was developed. Using the current version of PROMISS, entitled PROMISS93, a sensitivity study for the combined effects of mechanical fatigue, creep, and thermal fatigue was performed. Results, in the form of cumulative distribution functions, illustrated the sensitivity of lifetime strength to any current value of an effect. In addition, verification studies comparing a combination of mechanical fatigue and high temperature effects by model to the combination by experiment were conducted. Thus, for Inconel 718, the basic model assumption of independence between effects was evaluated. Results from this limited verification study strongly supported this assumption.

  1. Gas sensitivity and sensing mechanism studies on Au-doped TiO₂ nanotube arrays for detecting SF₆ decomposed components.

    Science.gov (United States)

    Zhang, Xiaoxing; Yu, Lei; Tie, Jing; Dong, Xingchen

    2014-10-17

    The analysis to SF6 decomposed component gases is an efficient diagnostic approach to detect the partial discharge in gas-insulated switchgear (GIS) for the purpose of accessing the operating state of power equipment. This paper applied the Au-doped TiO2 nanotube array sensor (Au-TiO2 NTAs) to detect SF6 decomposed components. The electrochemical constant potential method was adopted in the Au-TiO2 NTAs' fabrication, and a series of experiments were conducted to test the characteristic SF6 decomposed gases for a thorough investigation of sensing performances. The sensing characteristic curves of intrinsic and Au-doped TiO2 NTAs were compared to study the mechanism of the gas sensing response. The results indicated that the doped Au could change the TiO2 nanotube arrays' performances of gas sensing selectivity in SF6 decomposed components, as well as reducing the working temperature of TiO2 NTAs.

  2. Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato.

    Science.gov (United States)

    Hao, Yanwei; Hu, Guojian; Breitel, Dario; Liu, Mingchun; Mila, Isabelle; Frasse, Pierre; Fu, Yongyao; Aharoni, Asaph; Bouzayen, Mondher; Zouine, Mohamed

    2015-12-01

    Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2) which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato.

  3. Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato.

    Directory of Open Access Journals (Sweden)

    Yanwei Hao

    2015-12-01

    Full Text Available Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2 which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato.

  4. Parametric Analysis to Study the Influence of Aerogel-Based Renders’ Components on Thermal and Mechanical Performance

    Directory of Open Access Journals (Sweden)

    Sofia Ximenes

    2016-05-01

    Full Text Available Statistical models using multiple linear regression are some of the most widely used methods to study the influence of independent variables in a given phenomenon. This study’s objective is to understand the influence of the various components of aerogel-based renders on their thermal and mechanical performance, namely cement (three types, fly ash, aerial lime, silica sand, expanded clay, type of aerogel, expanded cork granules, expanded perlite, air entrainers, resins (two types, and rheological agent. The statistical analysis was performed using SPSS (Statistical Package for Social Sciences, based on 85 mortar mixes produced in the laboratory and on their values of thermal conductivity and compressive strength obtained using tests in small-scale samples. The results showed that aerial lime assumes the main role in improving the thermal conductivity of the mortars. Aerogel type, fly ash, expanded perlite and air entrainers are also relevant components for a good thermal conductivity. Expanded clay can improve the mechanical behavior and aerogel has the opposite effect.

  5. Water extract of Ashwagandha leaves has anticancer activity: identification of an active component and its mechanism of action.

    Directory of Open Access Journals (Sweden)

    Renu Wadhwa

    Full Text Available BACKGROUND: Cancer is a leading cause of death accounting for 15-20% of global mortality. Although advancements in diagnostic and therapeutic technologies have improved cancer survival statistics, 75% of the world population live in underdeveloped regions and have poor access to the advanced medical remedies. Natural therapies hence become an alternative choice of treatment. Ashwagandha, a tropical herb used in Indian Ayurvedic medicine, has a long history of its health promoting and therapeutic effects. In the present study, we have investigated an anticancer activity in the water extract of Ashwagandha leaves (ASH-WEX. METHODOLOGY/PRINCIPAL FINDINGS: Anticancer activity in the water extract of Ashwagandha leaves (ASH-WEX was detected by in vitro and in vivo assays. Bioactivity-based size fractionation and NMR analysis were performed to identify the active anticancer component(s. Mechanism of anticancer activity in the extract and its purified component was investigated by biochemical assays. We report that the ASH-WEX is cytotoxic to cancer cells selectively, and causes tumor suppression in vivo. Its active anticancer component was identified as triethylene glycol (TEG. Molecular analysis revealed activation of tumor suppressor proteins p53 and pRB by ASH-WEX and TEG in cancer cells. In contrast to the hypophosphorylation of pRB, decrease in cyclin B1 and increase in cyclin D1 in ASH-WEX and TEG-treated cancer cells (undergoing growth arrest, normal cells showed increase in pRB phosphorylation and cyclin B1, and decrease in cyclin D1 (signifying their cell cycle progression. We also found that the MMP-3 and MMP-9 that regulate metastasis were down regulated in ASH-WEX and TEG-treated cancer cells; normal cells remained unaffected. CONCLUSION: We provide the first molecular evidence that the ASH-WEX and TEG have selective cancer cell growth arrest activity and hence may offer natural and economic resources for anticancer medicine.

  6. Environmentally responsive polymeric "intelligent" materials: the ideal components of non-mechanical valves that control flow in microfluidic systems

    Directory of Open Access Journals (Sweden)

    J. Ruben Morones-Ramirez

    2010-03-01

    Full Text Available Miniaturization and commercialization of integrated microfluidic systems has had great success with the development of a wide variety of techniques in microfabrication, since they allowed their construction at a low cost and by following simple step-series procedures. However, one of the major challenges in the design of microfluidic systems is to achieve control of flow and delivery of different chemical reagents. This feature is especially important when using microfluidic systems in the development of cell culture systems, the construction of labs on a chip and the fabrication and design of chemical microreactors. Spatiotemporal control of the microenvironment in microfluidic devices has been only partially achieved by incorporating actuator parts (mechanical and non-mechanical within these devices; nevertheless, recently there has been enormous progress due to advances in the materials sciences, and the development of novel polymeric "intelligent" materials. These materials have proved to be excellent candidates in the construction of non-mechanical actuators in the form of environmentally responsive valves. These valves can more efficiently control flows because these "intelligent" materials are capable of undergoing conformational changes and phase transitions in response to different local or external environmental stimuli; allowing them to turn the valves from "on" to "off". In addition, these valves have very simple designs, and are easy and cheap to incorporate into microfluidic systems. Therefore, although there are many reviews that focus on the development and design of non-mechanical actuators, the following review proceeds to describe the exciting characteristics, potential uses and synthesis methods of the building blocks of the most recent and innovative non-mechanical valves, environmentally responsive polymeric "intelligent" materials. In addition, the last section of this review will focus on the synthesis of composite

  7. Development of a novel technique to assess the vulnerability of micro-mechanical system components to environmentally assisted cracking.

    Energy Technology Data Exchange (ETDEWEB)

    Enos, David George; Goods, Steven Howard

    2006-11-01

    Microelectromechanical systems (MEMS) will play an important functional role in future DOE weapon and Homeland Security applications. If these emerging technologies are to be applied successfully, it is imperative that the long-term degradation of the materials of construction be understood. Unlike electrical devices, MEMS devices have a mechanical aspect to their function. Some components (e.g., springs) will be subjected to stresses beyond whatever residual stresses exist from fabrication. These stresses, combined with possible abnormal exposure environments (e.g., humidity, contamination), introduce a vulnerability to environmentally assisted cracking (EAC). EAC is manifested as the nucleation and propagation of a stable crack at mechanical loads/stresses far below what would be expected based solely upon the materials mechanical properties. If not addressed, EAC can lead to sudden, catastrophic failure. Considering the materials of construction and the very small feature size, EAC represents a high-risk environmentally induced degradation mode for MEMS devices. Currently, the lack of applicable characterization techniques is preventing the needed vulnerability assessment. The objective of this work is to address this deficiency by developing techniques to detect and quantify EAC in MEMS materials and structures. Such techniques will allow real-time detection of crack initiation and propagation. The information gained will establish the appropriate combinations of environment (defining packaging requirements), local stress levels, and metallurgical factors (composition, grain size and orientation) that must be achieved to prevent EAC.

  8. Anti-Inflammatory Applications of Melittin, a Major Component of Bee Venom: Detailed Mechanism of Action and Adverse Effects

    Directory of Open Access Journals (Sweden)

    Gihyun Lee

    2016-05-01

    Full Text Available Inflammation is a pervasive phenomenon triggered by the innate and adaptive immune systems to maintain homeostasis. The phenomenon normally leads to recovery from infection and healing, but when not properly phased, inflammation may cause immune disorders. Bee venom is a toxin that bees use for their protection from enemies. However, for centuries it has been used in the Orient as an anti-inflammatory medicine for the treatment of chronic inflammatory diseases. Bee venom and its major component, melittin, are potential means of reducing excessive immune responses and provide new alternatives for the control of inflammatory diseases. Recent experimental studies show that the biological functions of melittin could be applied for therapeutic use in vitro and in vivo. Reports verifying the therapeutic effects of melittin are accumulating in the literature, but the cellular mechanism(s of the anti-inflammatory effects of melittin are not fully elucidated. In the present study, we review the current knowledge on the therapeutic effects of melittin and its detailed mechanisms of action against several inflammatory diseases including skin inflammation, neuroinflammation, atherosclerosis, arthritis and liver inflammation, its adverse effects as well as future prospects regarding the use of melittin.

  9. The multi-step phosphorelay mechanism of unorthodox two-component systems in E. coli realizes ultrasensitivity to stimuli while maintaining robustness to noises.

    Science.gov (United States)

    Kim, Jeong-Rae; Cho, Kwang-Hyun

    2006-12-01

    E. coli has two-component systems composed of histidine kinase proteins and response regulator proteins. For a given extracellular stimulus, a histidine kinase senses the stimulus, autophosphorylates and then passes the phosphates to the cognate response regulators. The histidine kinase in an orthodox two-component system has only one histidine domain where the autophosphorylation occurs, but a histidine kinase in some unusual two-component systems (unorthodox two-component systems) has two histidine domains and one aspartate domain. So, the unorthodox two-component systems have more complex phosphorelay mechanisms than orthodox two-component systems. In general, the two-component systems are required to promptly respond to external stimuli for survival of E. coli. In this respect, the complex multi-step phosphorelay mechanism seems to be disadvantageous, but there are several unorthodox two-component systems in E. coli. In this paper, we investigate the reason why such unorthodox two-component systems are present in E. coli. For this purpose, we have developed simplified mathematical models of both orthodox and unorthodox two-component systems and analyzed their dynamical characteristics through extensive computer simulations. We have finally revealed that the unorthodox two-component systems realize ultrasensitive responses to external stimuli and also more robust responses to noises than the orthodox two-component systems.

  10. Phosphorelay of non-orthodox two component systems functions through a bi-molecular mechanism in vivo

    DEFF Research Database (Denmark)

    Jovanovic, Goran; Sheng, Xia; Ale, Angelique;

    2015-01-01

    the functional relevance of the dimerization of a non-orthodox or hybrid histidine kinase along which the phosphorelay takes place has been a subject of debate. We use a combination of molecular and genetic approaches, coupled to mathematical and statistical modelling, to demonstrate that the different possible...... intra- and inter-molecular mechanisms of phosphotransfer are formally non-identifiable in Escherichia coli expressing the ArcB non-orthodox histidine kinase used in anoxic redox control. In order to resolve this issue we further analyse the mathematical model in order to identify discriminatory...... in the histidine kinase. This is the first detailed mechanistic analysis of the molecular processes involved in non-orthodox two-component signalling and our results suggest strongly that dimerization facilitates more discriminatory proof-reading of external signals, via these allosteric reactions, prior to them...

  11. Process of interiorization, authentication, internalization, as component psychological-educational mechanism of study of eastern martial arts among student youngsters.

    Directory of Open Access Journals (Sweden)

    Gobenko Å.V.

    2011-04-01

    Full Text Available This article deals with the theoretical questions of essence of component parts of psychological-educational mechanism of study of eastern martial arts among student youngsters. Short description of process of interiorization, authentication, internalization of personality is conducted. The questions of analysis acturelizied scientifically pedagogical and scientifically psychological literatures, which make it possible to consider and ground processes being integral part during study of the East culture. Important factor which determines stable interest of student youngsters people to the martial arts of the East is an attractiveness for them of modern man of cultural and historical traditions, in which the valued orientations are organically set up on the amalgation of physical and spiritual development of a man.

  12. Dissection of the Mechanical Impedance Components of the Outer Hair Cell Using a Chloride-Channel Blocker

    Science.gov (United States)

    Harasztosi, Csaba; Gummer, Anthony W.

    2011-11-01

    The voltage-dependent chloride-channel blocker anthracene-9-carboxylic acid (9AC) has been found to reduce the imaginary but not the real part of the mechanical impedance of the organ of Corti, suggesting that the effective stiffness of outer hair cells (OHCs) is reduced by 9AC. To examine whether 9AC interacts directly with the motor protein prestin to reduce the membrane component of the impedance, the patch-clamp technique in whole-cell configuration was used to measure the nonlinear capacitance (NLC) of isolated OHCs and, as control, prestin-transfected human embryonic kidney 293 (HEK293) cells. Extracellular application of 9AC significantly reduced the NLC of both OHCs and HEK293 cells. Intracellular 9AC did not influence the blocking effect of the extracellular applied drug. These results suggest that 9AC interacts directly with prestin, reducing the effective stiffness of the motor, and that the interaction is extracellular.

  13. Innovations in the design of mechanical components for a beamline-The SRI'95 Workshop 2 Summary (invited)

    Science.gov (United States)

    Kuzay, T. M.; Warwick, T.

    1996-09-01

    The Synchrotron Radiation Instrumentation 1995 Conference (SRI'95) was hosted by the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). Of the many workshops within the conference, the SRI'95 Workshop 2 was ``Innovations in the Design of Mechanical Components of a Beamline.'' The workshop was well attended with over 140 registrants. The following topics were discussed. Industry's perspective on the status and future was provided by Huber Diffraktionstechnik GMBH on goniometers/diffractometers, Oxford Instruments on advanced manufacturing technique of high heat load components, such as the APS photon shutter, and Kohzu Seiki Co. Ltd. on the specialties of monochromators provided to the third-generation synchrotrons. This was followed by a description of the engineering of a dual function monochromator design for water-cooled diamond or cryogenically cooled silicon monochromators by CMC CAT/APS. Another category was the nagging problem of sensitivity of the photon beam position monitors (XBPM) to bending magnet radiation (``BM contamination'') and the undulator magnet gap changes. Problem descriptions and suggested solutions were provided by both the Advanced Light Source (ALS) and the APS. Other innovative ideas were the cooling schemes (enhanced cooling of beamline components using metallic porous meshes including cryo-cooled applications); Glidcop photon shutter design using microchannels at the ALS; and window/filter design, manufacture and operational experiences at CHESS and PETRA/HASYLAB. Additional discussions were held on designing for micromotions and precision in the optical support systems and smart user filter schemes. This is a summary of the presentations at the Workshop.

  14. ON THE ISSUE OF SUBSTANTIATION OF THE DESIGN SPECIFICATIONS ON MECHANICAL SYSTEM WITH RIGID ELASTIC LOADCARRYING COMPONENTS

    Directory of Open Access Journals (Sweden)

    Kurasov V. S.

    2016-04-01

    Full Text Available The main reason of the developmental delay of the RF livestock sector below the level of its inherent potential capacity is a detrimental alteration in methodological procedure of livestock and poultry management, occurring due to shortage of traditional feeds. As a result, a necessity to develop the yearlong production of additional fodders, allowing for balanced feeding throughout the year, arose. The method of hydroponic green fodder (HGF cultivation meets these requirements. Analysis of HGF production methods and labor saver mechanisms makes possible to claim that existing systems are characterized by high costs and difficulties in fabrication, and require a number of additional mechanical devices to work. In the FSBEI HE “KSMTU”, a one-tier hydroponic system has been developed, fitted with curved (arched guideways and rigid elastic load-carrying components, where loading of seeds and takeout of grown HGF occur by gravity without additional devices of labour input. Based on analysis performed on design features of the proposed system, it has been established that emergence of parametric resonances in the system under consideration is possible; and the study of tray dynamical stability has been carried out with the aim to prevent them. The motion of the hydroponic system tray under consideration is described by the classical Mathieu equation, including two parameters a and q. The further studies of sets of stable and unstable solutions in the plane of a and q parameters are presented by the Ince-Strutt diagram. As a result of the performed calculations, the diameter of the loadcarrying component was identified (d=5 mm, which should ensure reliable working capacity and stability of the hydroponic system in whole

  15. Data-driven mono-component feature identification via modified nonlocal means and MEWT for mechanical drivetrain fault diagnosis

    Science.gov (United States)

    Pan, Jun; Chen, Jinglong; Zi, Yanyang; Yuan, Jing; Chen, Binqiang; He, Zhengjia

    2016-12-01

    It is significant to perform condition monitoring and fault diagnosis on rolling mills in steel-making plant to ensure economic benefit. However, timely fault identification of key parts in a complicated industrial system under operating condition is still a challenging task since acquired condition signals are usually multi-modulated and inevitably mixed with strong noise. Therefore, a new data-driven mono-component identification method is proposed in this paper for diagnostic purpose. First, the modified nonlocal means algorithm (NLmeans) is proposed to reduce noise in vibration signals without destroying its original Fourier spectrum structure. During the modified NLmeans, two modifications are investigated and performed to improve denoising effect. Then, the modified empirical wavelet transform (MEWT) is applied on the de-noised signal to adaptively extract empirical mono-component modes. Finally, the modes are analyzed for mechanical fault identification based on Hilbert transform. The results show that the proposed data-driven method owns superior performance during system operation compared with the MEWT method.

  16. Functional properties of whey, whey components, and essential amino acids: mechanisms underlying health benefits for active people (review).

    Science.gov (United States)

    Ha, Ewan; Zemel, Michael B

    2003-05-01

    Whey proteins and amino acid supplements have a strong position in the sports nutrition market based on the purported quality of proteins and amino acids they provide. Recent studies employing stable isotope methodology demonstrate the ability of whey proteins or amino acid mixtures of similar composition to promote whole body and muscle protein synthesis. Other developing avenues of research explore health benefits of whey that extend beyond protein and basic nutrition. Many bioactive components derived from whey are under study for their ability to offer specific health benefits. These functions are being investigated predominantly in tissue culture systems and animal models. The capacity of these compounds to modulate adiposity, and to enhance immune function and anti-oxidant activity presents new applications potentially suited to the needs of those individuals with active lifestyles. This paper will review the recent literature that describes functional properties of essential amino acids, whey proteins, whey-derived minerals and other compounds and the mechanisms by which they may confer benefits to active people in the context that exercise is a form of metabolic stress. The response to this stress can be positive, as with the accretion of more muscle and improved functionality or greater strength. However, overall benefits may be compromised if immune function or general health is challenged in response to the stress. From a mechanistic standpoint, whey proteins, their composite amino acids, and/or associated compounds may be able to provide substrate and bioactive components to extend the overall benefits of physical activity.

  17. Kþ retention in leaf mesophyll, an overlooked component of salinity tolerance mechanism:A case study for barley

    Institute of Scientific and Technical Information of China (English)

    Sergey Shabala

    2015-01-01

    Plant salinity tolerance is a physiological y complex trait, with numerous mechanisms contributing to it. In this work, we show that the ability of leaf mesophyl to retain Kþ represents an important and essential y overlooked component of a salinity tolerance mechanism. The strong positive correlation between mesophyl Kþ retention ability under saline conditions (quantified by the magnitude of NaCl‐induced Kþ efflux from mesophyl ) and the overal salinity tolerance (relative fresh weight and/or survival or damage under salinity stress) was found while screening 46 barley (Hordeum vulgare L.) genotypes contrasting in their salinity tolerance. Genotypes with intrinsical y higher leaf Kþ content under control conditions were found to possess better Kþ retention ability under salinity and, hence, overal higher tolerance. Contrary to previous reports for barley roots, Kþ retention in mesophyl was not associated with an increased Hþ‐pumping in tolerant varieties but instead correlated negatively with this trait. These findings are explained by the fact that increased Hþ extrusion may be needed to charge balance the activity and provide the driving force for the high affinity HAK/KUP Kþ transporters required to restore cytosolic Kþ homeostasis in salt‐sensitive genotypes.

  18. Metallurgical And Mechanical Analyses Of Dissimilar Friction Weldments Of Ferrous And Non-Ferrous Metals For Lightweight Components

    Science.gov (United States)

    Figala, G.; Taschauer, M.; Wallner, S.; Buchmayr, B.

    2011-05-01

    The multi-material approach as quite often applied in the automotive and aircraft industry follows the idea of choosing the best performing material combination under specific service requirements. For metal-matrix composites, friction welding is a quite attractive technology, which can provide more insight into the property determining phenomena and processing parameters. A special rotational friction apparatus using a servo motor without brake system was built for the production of dissimilar weldments. The friction welding process was analysed using FEM to describe temperature history, material flow and forging force. By metallographic and mechanical testing, the microstructure and mechanical behaviour in the various subzones of the heat affected zone (HAZ) were determined. In addition, the strain distribution within the HAZ was measured by an optical device in order to characterize the weakest subzone and to study the local hardening behaviour. By variation of the main influencing parameters optimal component performance could be achieved. The fundamental understanding could be also applied for other technologies, like roll bonding.

  19. [Study of effective components and molecular mechanism for Guizhi Fuling formula treatment of dysmenorrhea, pelvic inflammatory disease and uterine fibroids].

    Science.gov (United States)

    Ke, Zhi-peng; Zhang, Xin-zhuang; Ding, Yue; Cao, Ze-yu; Li, Na; Cao, Liang; Wang, Tuan-jie; Zhang, Chen-feng; Ding, Gang; Wang, Zhen-zhong; Xiao, Wei; Xu, Xiao-jie

    2015-03-01

    In this study, the active components and potential molecular .mechanism of Guizhi Fuling formula in treatment on dysmenorrhea, pelvic inflammation, and hysteromyoma were investigated using network pharmacological methods. Sterols and pentacyclic triterpenes, with high moleculal network degree, revealed promising effects on anti-inflammatory, analgesic, anti-tumor, and immune-regulation, according to D-T network analysis. On the other hand, the targets with high degree were involved in inflammatory, coagulation, angiopoiesis, smooth muscle contraction, and cell reproduction, which showed the novel function in anti-dysmenorrhea, pelvic inflammation, and hysteromyoma. Furthermore, the formula was indicated to play a key role in smooth muscle proliferation, inhibition of new vessels, circulation improvement, reduction of hormone secretion, alleviation of smooth muscle, block of arachidonic acid metabolism, and inflammation in uterus. Thus, the main mechanism of Guizhi Fuling formula was summarized. In conclusion, Guizhi Fuling formula was proven to alleviated dysmenorrhea, pelvic inflammation, and hysteromyoma by acting on multiple targets through several bioactive compounds, regulating 21 biological pathways.

  20. Insights on the molecular mechanism for the recalcitrance of biochars: interactive effects of carbon and silicon components.

    Science.gov (United States)

    Guo, Jianhua; Chen, Baoliang

    2014-08-19

    Few studies have investigated the effects of structural heterogeneity (particularly the interactions of silicon and carbon) on the mechanisms for the recalcitrance of biochar. In this study, the molecular mechanisms for the recalcitrance of biochars derived from rice straw at 300, 500, and 700 °C (named RS300, RS500, and RS700, respectively) were elucidated. Short-term (24 h) and long-term (240 h) oxidation kinetics experiments were conducted under different concentrations of H2O2 to distinguish the stable carbon pools in the biochars. We discovered that the stabilities of the biochars were influenced not only by their aromaticity but also through possible protection by silicon encapsulation, which is regulated by pyrolysis temperatures. The aromatic components and recalcitrance of the biochars increased with increasing pyrolysis temperatures. The morphologies of the carbon forms in all of the biochars were also greatly associated with those of silica. Silica-encapsulation protection only occurred for RS500, not for RS300 and RS700. In RS300, carbon and silica were both amorphous, and they were easily decomposed by H2O2. The separation of crystalline silica from condensed aromatic carbon in RS700 eliminated the protective role of silicon on carbon. The effect of the biochar particle size on the stability of the biochar was greatly influenced by C-Si interactions and by the oxidation intensities. A novel silicon-and-carbon-coupled framework model was proposed to guide biochar carbon sequestration.

  1. Structural and mechanical properties of alkali hydrides investigated by the first-principles calculations and principal component analysis

    Science.gov (United States)

    Settouti, Nadera; Aourag, Hafid

    2016-08-01

    The structural and mechanical properties of alkali hydrides (LiH, NaH, KH, RbH, and CsH) were investigated via first-principles calculations which cover the optimized structural parameters. The density functional theory in combination with the generalized gradient approximation (GGA) were used in this study. From the present study, one could note that alkali hydrides are brittle materials and mechanically stable. It was found that stiffness and shear resistance are greater in LiH than in other hydrides. It is more brittle in nature, and comparatively harder than the other materials under study; it also presents a high degree of anisotropy. The results were then investigated and analyzed with principal component analysis (PCA), which is one of the most common techniques in multivariate analysis, was used to explore the correlations among material properties of alkali hydrides and to study their trends. The alkali hydrides obtained by the first-principles calculations were also compared with the alkaline-earth metal hydrides (BeH2, MgH2, CaH2, SrH2, and BaH2) and discussed in this work.

  2. Tests and analysis of mechanical behaviours of rock bolt components for China’s coal mine roadways

    Institute of Scientific and Technical Information of China (English)

    Hongpu Kang; Jinghe Yang; Xianzhi Meng

    2015-01-01

    A series of laboratory tests were performed to study the mechanical behaviours of newly developed high strength rock bolt components, including rebar, thread, plate, and domed washer. The characteristics of deformation and damage of each component were presented. The stress distribution of plate and domed washer was investigated through finite element modelling. The numerical results show that the yield and tensile strengths of the developed high strength rebar are 33.6%e58.3% and 17.2%e28.7% greater than those of the conventional rebar, respectively. The increase in yield strength was higher than that in tensile strength, suggesting an increase in yield to tensile strength ratio and a decrease in elongation. It is well-known that the thread processing may not be of high precision and accuracy as expected, which is characterised as rough thread surface, non-identical tooth height, toe stripping, and cracks in the surface. Hardening during thread processing tends to increase the thread yield and tensile strengths. In this paper, the typical deformation process of arch-shaped plate is classified into five stages. The tested plates exhibited distinct deformation characteristics and bearing capacities due to variations in shape, size, material and presence of washer. It was observed that uneven bottom surface, low bearing arch and large radius of the transitional arc connecting bearing arch and bottom surface were the major reasons ac-counting for low load-bearing capacity of plates. The performance of domed washer has a close relation with the shape, size, strength, and deformation compatibility with plate. Stress concentration was observed on the periphery of the contact surface between domed washer and plate, which is significantly influenced by the strength of domed washer and is considered to be 20%e30%higher than that of plate. Finally, a case study in the Datong coal mining district was presented, and the support pattern and effect of the developed rock bolt

  3. Improved Reliability Models for Mechanical and Electrical Components at Navigation Lock and Dam and Flood Risk Management Facilities

    Science.gov (United States)

    2013-04-01

    Brake Electromechanical 45 60 Clutch Slip 30 — Jaw — 70 Wire ropes ERDC/CERL TR-13-4 104 Type Component Navigation Components CL (years...navigation facilities. Current USACE ME reliability methods use generic component failure rate data from US Department of Defense (DoD) Military Standard...MIL-STD) 756B, in which failure rate data is processed for components that function in operating environments, failure modes, and maintenance

  4. An Empirical Correction Method for Improving off-Axes Response Prediction in Component Type Flight Mechanics Helicopter Models

    Science.gov (United States)

    Mansur, M. Hossein; Tischler, Mark B.

    1997-01-01

    Historically, component-type flight mechanics simulation models of helicopters have been unable to satisfactorily predict the roll response to pitch stick input and the pitch response to roll stick input off-axes responses. In the study presented here, simple first-order low-pass filtering of the elemental lift and drag forces was considered as a means of improving the correlation. The method was applied to a blade-element model of the AH-64 APache, and responses of the modified model were compared with flight data in hover and forward flight. Results indicate that significant improvement in the off-axes responses can be achieved in hover. In forward flight, however, the best correlation in the longitudinal and lateral off-axes responses required different values of the filter time constant for each axis. A compromise value was selected and was shown to result in good overall improvement in the off-axes responses. The paper describes both the method and the model used for its implementation, and presents results obtained at hover and in forward flight.

  5. Structure and mechanism of the essential two-component signal-transduction system WalKR in Staphylococcus aureus.

    Science.gov (United States)

    Ji, Quanjiang; Chen, Peter J; Qin, Guangrong; Deng, Xin; Hao, Ziyang; Wawrzak, Zdzislaw; Yeo, Won-Sik; Quang, Jenny Winjing; Cho, Hoonsik; Luo, Guan-Zheng; Weng, Xiaocheng; You, Qiancheng; Luan, Chi-Hao; Yang, Xiaojing; Bae, Taeok; Yu, Kunqian; Jiang, Hualiang; He, Chuan

    2016-03-18

    Most low GC Gram-positive bacteria possess an essential walKR two-component system (TCS) for signal transduction involved in regulating cell wall homoeostasis. Despite the well-established intracellular regulatory mechanism, the role of this TCS in extracellular signal recognition and factors that modulate the activity of this TCS remain largely unknown. Here we identify the extracellular receptor of the kinase 'WalK' (erWalK) as a key hub for bridging extracellular signal input and intracellular kinase activity modulation in Staphylococcus aureus. Characterization of the crystal structure of erWalK revealed a canonical Per-Arnt-Sim (PAS) domain for signal sensing. Single amino-acid mutation of potential signal-transduction residues resulted in severely impaired function of WalKR. A small molecule derived from structure-based virtual screening against erWalK is capable of selectively activating the walKR TCS. The molecular level characterization of erWalK will not only facilitate exploration of natural signal(s) but also provide a template for rational design of erWalK inhibitors.

  6. MECHANICAL RELAXATION TIME OF A TWO-COMPONENT EPOXY NETWORK-LiClO4 POLYMER ELECTROLYTE

    Institute of Scientific and Technical Information of China (English)

    PENG Xinsheng; WU Shuyun; CHEN Donglin

    1993-01-01

    The mechanical relaxation time of a two-component epoxy network-LiClO4 system as a polymer electrolyte was investigated.The network is composed of diglycidyl ether of polyethylene glycol (DGEPEG) and triglycidyl ether of glycerol (TGEG),wherein LiClO4 was incorporated and acts as both the ionic carrier and the curing catalyst.As the relaxation time is informative to the segmental mobility,which is known to be essential for ionic conductivity,the average relaxation times of the specimens were determined through master curve construction.Experimental results showed that the salt concentration,molecular weight of PEG in DGEPEG and DGEPEG/TGEG ratio have profound effect on the relaxation time of the specimen.Among these factors,the former reinforces the network hains,leading to lengthen the relaxation time,whereas the latter two are in favour of the chain flexibility and show an opposite effect.The findings was rationalized in terms of the free volume concept.

  7. Unsteady fluid dynamics of several mechanical prosthetic heart valves using a two component laser Doppler anemometer system.

    Science.gov (United States)

    Akutsu, T; Modi, V J

    1997-10-01

    Five typical mechanical heart valves (Starr-Edwards, Björk-Shiley convexo-concave (c-c), Björk-Shiley monostrut, Bicer-Val, and St. Jude Medical) were tested in the mitral position under the pulsatile flow condition. The test program included measurements of velocity and turbulent stresses at 5 downstream locations. The study was carried out using a sophisticated cardiac simulator in conjunction with a highly sensitive 2 component laser Doppler anemometer (LDA) system. The continuous monitoring of parametric time histories revealed useful details about the complex flow and helped to establish the locations and times of the peak parameter values. Based upon the nondimensional presentation of data, the following general conclusions can be made. First, all the 5 valve designs created elevated turbulent stresses during the accelerating and peak flow phases, presenting the possibility of thromboembolism and perhaps hemolysis. Second, the difference in valve configuration seemed to affect the flow characteristics; third, the bileaflet design of the St. Jude valve appeared to create a lower turbulence stress level.

  8. Two-component spin-coated Ag/CNT composite films based on a silver heterogeneous nucleation mechanism adhesion-enhanced by mechanical interlocking and chemical grafting

    Science.gov (United States)

    Zhang, Yang; Kang, Zhixin; Bessho, Takeshi

    2017-03-01

    In this paper, a new method for the synthesis of silver carbon nanotube (Ag/CNT) composite films as conductive connection units for flexible electronic devices is presented. This method is about a two-component solution process by spin coating with an after-treatment annealing process. In this method, multi-walled carbon nanotubes (MWCNTs) act as the core of silver heterogeneous nucleation, which can be observed and analyzed by a field-emission scanning electron microscope. With the effects of mechanical interlocking, chemical grafting, and annealing, the interfacial adhesive strength between films and PET sheets was enhanced to 12 N cm-1. The tensile strength of the Ag/CNT composite films was observed to increase by 38% by adding 5 g l-1 MWCNTs. In the four-probe method, the resistivity of Ag/CNT-5 declined by 78.2% compared with pristine Ag films. The anti-fatigue performance of the Ag/CNT composite films was monitored by cyclic bending deformation and the results revealed that the growth rate of electrical resistance during the deformation was obviously retarded. As for industrial application, this method provides an efficient low-cost way to prepare Ag/CNT composite films and can be further applied to other coating systems.

  9. Local reinforcement of magnesium components by friction processing. Determination of bonding mechanisms and assessment of joint properties

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, G.A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung

    2008-07-01

    The development of new creep-resistant and cost effective die casting magnesium alloys, such as AE, MRI, MEZ, ACM, AXJ, AJ, WE, have emerged as an alternative, to fulfil the modern demands in structurally relevant applications, such as engine blocks, gears and converter boxes. However, in most cases, magnesium components are screwed with aluminium and steel bolts, which lead the screwed joints to lose the preload force, due to relaxation. This barrier thereby limits the broad use of magnesium within this segment and should somehow find an adequate solution to help overcome this limitation. Furthermore, together with alloy development and the addition of reinforcement (MMCs), local material engineering processes have been conceived and are considered a method to improve the properties and therefore expand the number of potential applications for magnesium alloys. In this context, Friction Welding (FW) and particularly Friction Hydro Pillar Processing (FHPP), which can be described as a drill and fill process, appear to be an alternative to make the use of magnesium more widespread. For this reason, FHPP is intended to be used, to locally reinforce the mechanically fastened magnesium components. With this approach, regions submitted to the stresses imposed by tightening forces can be compensated by the use of a material with superior properties. It is not required to fabricate the whole structure from an expensive material, thus saving costs and thereby satisfying the economic pressures of an increasingly competitive global market. In the present work, a preliminary experimental matrix was defined and used to determine the optimal welding conditions for each specific material combination selected. Further, elaborate experimental techniques are used to describe the process parameters-microstructure-properties relationships and the consequent mechanisms leading to bonding in FHPP welds in similar and dissimilar configurations. The welds were performed using a hydraulic

  10. Local reinforcement of magnesium components by friction processing. Determination of bonding mechanisms and assessment of joint properties

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, G.A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung

    2008-07-01

    The development of new creep-resistant and cost effective die casting magnesium alloys, such as AE, MRI, MEZ, ACM, AXJ, AJ, WE, have emerged as an alternative, to fulfil the modern demands in structurally relevant applications, such as engine blocks, gears and converter boxes. However, in most cases, magnesium components are screwed with aluminium and steel bolts, which lead the screwed joints to lose the preload force, due to relaxation. This barrier thereby limits the broad use of magnesium within this segment and should somehow find an adequate solution to help overcome this limitation. Furthermore, together with alloy development and the addition of reinforcement (MMCs), local material engineering processes have been conceived and are considered a method to improve the properties and therefore expand the number of potential applications for magnesium alloys. In this context, Friction Welding (FW) and particularly Friction Hydro Pillar Processing (FHPP), which can be described as a drill and fill process, appear to be an alternative to make the use of magnesium more widespread. For this reason, FHPP is intended to be used, to locally reinforce the mechanically fastened magnesium components. With this approach, regions submitted to the stresses imposed by tightening forces can be compensated by the use of a material with superior properties. It is not required to fabricate the whole structure from an expensive material, thus saving costs and thereby satisfying the economic pressures of an increasingly competitive global market. In the present work, a preliminary experimental matrix was defined and used to determine the optimal welding conditions for each specific material combination selected. Further, elaborate experimental techniques are used to describe the process parameters-microstructure-properties relationships and the consequent mechanisms leading to bonding in FHPP welds in similar and dissimilar configurations. The welds were performed using a hydraulic

  11. Vibro-Acoustic Analysis of Computer Disk Drive Components with Emphasis on Electro-Mechanical Noise Sources.

    Science.gov (United States)

    Lee, Ming-Ran

    Vibro-acoustic characteristics of compact electro -mechanical devices are not well understood. This study examines fundamental research issues in this area through the example case of a 3.5" personal computer hard disk drive. In particular, a narrow band mathematical model of the drive has been developed to predict prominent pure tones over the high frequency range (1-6.5 KHz). Through detailed analytical studies, it has been found that the motor torque pulsation of the brushless d.c. motor is the source for this noise problem. Accordingly, a simplified disk drive model consisting of motor driving a single disk is used to investigate key components, with emphasis on the development of new mathematical models to describe the source, path and radiator characteristics. Two different mathematical models have been developed for brushless d.c. motor to predict the torque spectrum associated with invertor switching logic, pulse width modulation control scheme, eccentricity, and magnetic saturation. Frequency contents of predicted variables are identified and matched with measured sound data. Additionally, the Galerkin's method (or modified harmonic balance) is also employed successfully to develop an efficient computational scheme which predicts the Fourier coefficients of torque pulsations directly including various effects associated with inductance harmonics and the fluctuation of rotor angular velocity. For the radiator (annular disk), modal base formulations of sound radiation have been developed by approximating disk eigen-functions. Specifically, the effects of modal coupling and source rotation on radiated sound are investigated. Analytical predictions match well with numerical results obtained by using a boundary element program. New mobility transfer functions (path) are derived to couple the source and radiator formulations in order to construct an overall vibro-acoustic model. Potential areas of further research including experimental validation are discussed.

  12. Mechanisms of plastic deformation in highly cross-linked UHMWPE for total hip components--the molecular physics viewpoint.

    Science.gov (United States)

    Takahashi, Yasuhito; Shishido, Takaaki; Yamamoto, Kengo; Masaoka, Toshinori; Kubo, Kosuke; Tateiwa, Toshiyuki; Pezzotti, Giuseppe

    2015-02-01

    Plastic deformation is an unavoidable event in biomedical polymeric implants for load-bearing application during long-term in-vivo service life, which involves a mass transfer process, irreversible chain motion, and molecular reorganization. Deformation-induced microstructural alterations greatly affect mechanical properties and durability of implant devices. The present research focused on evaluating, from a molecular physics viewpoint, the impact of externally applied strain (or stress) in ultra-high molecular weight polyethylene (UHMWPE) prostheses, subjected to radiation cross-linking and subsequent remelting for application in total hip arthroplasty (THA). Two different types of commercial acetabular liners, which belong to the first-generation highly cross-linked UHMWPE (HXLPE), were investigated by means of confocal/polarized Raman microprobe spectroscopy. The amount of crystalline region and the spatial distribution of molecular chain orientation were quantitatively analyzed according to a combined theory including Raman selection rules for the polyethylene orthorhombic structure and the orientation distribution function (ODF) statistical approach. The structurally important finding was that pronounced recrystallization and molecular reorientation increasingly appeared in the near-surface regions of HXLPE liners with increasing the amount of plastic (compressive) deformation stored in the microstructure. Such molecular rearrangements, occurred in response to external strains, locally increase surface cross-shear (CS) stresses, which in turn trigger microscopic wear processes in HXLPE acetabular liners. Thus, on the basis of the results obtained at the molecular scale, we emphasize here the importance of minimizing the development of irrecoverable deformation strain in order to retain the pristine and intrinsically high wear performance of HXLPE components.

  13. Derivation of the reduced reaction mechanisms of ozone depletion events in the Arctic spring by using concentration sensitivity analysis and principal component analysis

    Science.gov (United States)

    Cao, Le; Wang, Chenggang; Mao, Mao; Grosshans, Holger; Cao, Nianwen

    2016-12-01

    The ozone depletion events (ODEs) in the springtime Arctic have been investigated since the 1980s. It is found that the depletion of ozone is highly associated with an auto-catalytic reaction cycle, which involves mostly the bromine-containing compounds. Moreover, bromide stored in various substrates in the Arctic such as the underlying surface covered by ice and snow can be also activated by the absorbed HOBr. Subsequently, this leads to an explosive increase of the bromine amount in the troposphere, which is called the "bromine explosion mechanism". In the present study, a reaction scheme representing the chemistry of ozone depletion and halogen release is processed with two different mechanism reduction approaches, namely, the concentration sensitivity analysis and the principal component analysis. In the concentration sensitivity analysis, the interdependence of the mixing ratios of ozone and principal bromine species on the rate of each reaction in the ODE mechanism is identified. Furthermore, the most influential reactions in different time periods of ODEs are also revealed. By removing 11 reactions with the maximum absolute values of sensitivities lower than 10 %, a reduced reaction mechanism of ODEs is derived. The onsets of each time period of ODEs in simulations using the original reaction mechanism and the reduced reaction mechanism are identical while the maximum deviation of the mixing ratio of principal bromine species between different mechanisms is found to be less than 1 %. By performing the principal component analysis on an array of the sensitivity matrices, the dependence of a particular species concentration on a combination of the reaction rates in the mechanism is revealed. Redundant reactions are indicated by principal components corresponding to small eigenvalues and insignificant elements in principal components with large eigenvalues. Through this investigation, aside from the 11 reactions identified as unimportant in the concentration

  14. On Mechanics and Thermodynamics of a stellar galaxy in a two-component virial system and the Fundamental Plane

    CERN Document Server

    Secco, L

    2005-01-01

    The paper confirms the existence of a special configuration (among the infinite number of virial states) which a B stellar(Baryonic) component may assume inside a given D dark halo potential well.This satisfies the d'Alembert Principle of virtual works and its typical dimension works as a scale length (tidal radius)induced on the gravitational field of the bright component by the dark one.Its dynamic and thermodynamic properties are here analyzed in connection with the physical reason for the existence of the Fundamental Plane (FP) for ellipticals.The analysis is performed by using 2-component models with two power-law density profiles and two homogeneous cores and compared with some observable scaling relations for pressure supported ellipticals.The virial equilibrium stages of the 2-component system have to occur after a previous violent relaxation phase. If the stellar B component is allowed to cool slowly its virial evolution consists of a sequence of contractions with enough time to rearrange the virial ...

  15. Bone-femoral component interface gap after sagittal mechanical axis alignment is filled with new bone after cementless total knee arthroplasty.

    Science.gov (United States)

    Kuriyama, Shinichi; Hyakuna, Katsufumi; Inoue, Satoshi; Kawai, Yasutsugu; Tamaki, Yasuyuki; Ito, Hiromu; Matsuda, Shuichi

    2017-02-14

    This study retrospectively evaluated the fate of mismatch between an uncemented femoral component and each femoral cut surface (i.e., wedge-shaped gap) relative to sagittal mechanical alignment in total knee arthroplasty (TKA). Primary TKA was performed on 99 consecutive knees. The femoral components were aligned to the sagittal mechanical axis with CT-based navigation. All patients were assessed with postoperative true lateral radiographs. Bone-side surfaces of the uncemented femoral component were divided into five zones: anterior flange, anterior chamfer, posterior chamfer, posterior part, and distal part, which were defined as zones 1 to 5, respectively. Bone filling of wedge-shaped gaps in each zone was evaluated after 1 year. Femoral anterior notching did not occur. However, wedge-shaped gaps were observed in at least one zone in 23 of 99 knees (23%), most frequently in zone 5 (18%). There were 9 and 7 gaps in zones 1 and 2, respectively. The femoral component showed malpositioning of approximately 3° of flexion in cases with wedge-shaped gaps in zones 2 and/or 5. After one year, 67% (6/9) of zone 1, 100% (7/7) of zone 2, and 94% (17/18) of zone 5 wedge-shaped gaps were filled in with new bone. Femoral alignment relative to sagittal mechanical axis caused wedge-shaped gaps due to unstable anterior bone cutting through hard bone, but the small gaps were not clinically significant and filled in within one year. Sagittal setting of the femoral component should aim for the anatomical axis rather than the mechanical axis. IV.

  16. The graphic representations for the one-dimensional solutions of problem from elastic mechanic deformations of two-component mixture

    Directory of Open Access Journals (Sweden)

    Ghenadie Bulgac

    2006-12-01

    Full Text Available In this paper we find the analytical solution of simple one-dimensional unsteady elastic problem of two-component mixture using Laplace integral transformation. The integral transformations simplify the initial motion systems for finding analytical solutions. The analytical solutions are represented as the graphic on time dependence in the fixed point of medium, and the graphic on the horizontal coordinate at the fixed time.

  17. Effects of Inflorescence Stem Structure and Cell Wall Components on the Mechanical Strength of Inflorescence Stem in Herbaceous Peony

    Directory of Open Access Journals (Sweden)

    Qingping Geng

    2012-04-01

    Full Text Available Herbaceous peony (Paeonia lactiflora Pall. is a traditional famous flower, but its poor inflorescence stem quality seriously constrains the development of the cut flower. Mechanical strength is an important characteristic of stems, which not only affects plant lodging, but also plays an important role in stem bend or break. In this paper, the mechanical strength, morphological indices and microstructure of P. lactiflora development inflorescence stems were measured and observed. The results showed that the mechanical strength of inflorescence stems gradually increased, and that the diameter of inflorescence stem was a direct indicator in estimating mechanical strength. Simultaneously, with the development of inflorescence stem, the number of vascular bundles increased, the vascular bundle was arranged more densely, the sclerenchyma cell wall thickened, and the proportion of vascular bundle and pith also increased. On this basis, cellulose and lignin contents were determined, PlCesA3, PlCesA6 and PlCCoAOMT were isolated and their expression patterns were examined including PlPAL. The results showed that cellulose was not strictly correlated with the mechanical strength of inflorescence stem, and lignin had a significant impact on it. In addition, PlCesA3 and PlCesA6 were not key members in cellulose synthesis of P. lactiflora and their functions were also different, but PlPAL and PlCCoAOMT regulated the lignin synthesis of P. lactiflora. These data indicated that PlPAL and PlCCoAOMT could be applied to improve the mechanical strength of P. lactiflora inflorescence stem in genetic engineering.

  18. Effects of inflorescence stem structure and cell wall components on the mechanical strength of inflorescence stem in herbaceous peony.

    Science.gov (United States)

    Zhao, Daqiu; Han, Chenxia; Tao, Jun; Wang, Jing; Hao, Zhaojun; Geng, Qingping; Du, Bei

    2012-01-01

    Herbaceous peony (Paeonia lactiflora Pall.) is a traditional famous flower, but its poor inflorescence stem quality seriously constrains the development of the cut flower. Mechanical strength is an important characteristic of stems, which not only affects plant lodging, but also plays an important role in stem bend or break. In this paper, the mechanical strength, morphological indices and microstructure of P. lactiflora development inflorescence stems were measured and observed. The results showed that the mechanical strength of inflorescence stems gradually increased, and that the diameter of inflorescence stem was a direct indicator in estimating mechanical strength. Simultaneously, with the development of inflorescence stem, the number of vascular bundles increased, the vascular bundle was arranged more densely, the sclerenchyma cell wall thickened, and the proportion of vascular bundle and pith also increased. On this basis, cellulose and lignin contents were determined, PlCesA3, PlCesA6 and PlCCoAOMT were isolated and their expression patterns were examined including PlPAL. The results showed that cellulose was not strictly correlated with the mechanical strength of inflorescence stem, and lignin had a significant impact on it. In addition, PlCesA3 and PlCesA6 were not key members in cellulose synthesis of P. lactiflora and their functions were also different, but PlPAL and PlCCoAOMT regulated the lignin synthesis of P. lactiflora. These data indicated that PlPAL and PlCCoAOMT could be applied to improve the mechanical strength of P. lactiflora inflorescence stem in genetic engineering.

  19. The plasma membrane aquaporin NtAQP1 is a key component of the leaf unfolding mechanism in tobacco

    NARCIS (Netherlands)

    Siefritz, F.; Otto, B.; Beinert, G.P.; Krol, van der A.R.; Kaldenhoff, R.

    2004-01-01

    Epinastic leaf movement of tobacco is based on differential growth of the upper and lower leaf surface and is distinct from the motor organ-driven mechanism of nyctinastic leaf movement of, for example, mimosa species. The epinastic leaf movement of tobacco is observed not only under diurnal light r

  20. Metabolic costs of the mechanical components of the apparent specific dynamic action in the Dungeness crab, Cancer magister.

    Science.gov (United States)

    McGaw, Iain J; Van Leeuwen, Travis E

    2017-08-01

    The specific dynamic action (SDA) describes the postprandial increase in metabolism. It is a composite of mechanical and chemical digestion, nutrient transport and protein synthesis. How these individual events contribute to the overall SDA has not been worked out fully for any organism. The mechanical events associated with the SDA were investigated in Dungeness crabs, Cancer magister. Following consumption of a meal, oxygen consumption (MO2) remained elevated for several hours. When the crabs were presented with fish scent there was a 2 fold increase in MO2, which rapidly decreased once the stimulus was removed. Crabs were then offered fish in a perforated tube. There was a rapid increase in MO2 associated with handling which returned to pre-treatment levels within an hour of removal of the tube. Finally the crabs were fed a piece of foam that had been soaked in fish water to determine the costs of mechanical digestion. The mechanical breakdown of the meal accounted for 29.9±3.3% of the overall SDA. Since food handling produced a large increase in MO2, it was reinvestigated using crabs that had one or both claws removed. Although there were no statistically significant differences as a function of claw removal there was a consistent trend in the data. The maximum MO2, scope, duration and SDA increased from animals with 0 claws through 1 claw to 2 claws. The results showed that the mechanical portion of the SDA can account for a significant portion of the overall budget in decapod crustaceans. Copyright © 2017. Published by Elsevier Inc.

  1. A Critical Review of Bioactive Food Components, and of their Functional Mechanisms, Biological Effects and Health Outcomes.

    Science.gov (United States)

    Perez-Gregorio, Rosa; Simal-Gandara, Jesus

    2017-01-01

    Eating behaviours are closely related to some medical conditions potentially leading to death such as cancer, cardiovascular disease and diabetes. Healthy eating practices, maintaining a normal weight, and regular physical activity could prevent up to 80% of coronary heart disease, 90% of type-2 diabetes and onethird of all cancers [1]. Over the last two decades, the food industry has invested much effort in research and development of healthier, more nutritious foods. These foods are frequently designated "functional" when they contain nutritional components required for healthy living or "nutraceuticals" when intended to treat or prevent disease or disorders through a variety of bioactive (e.g., antioxidant, antimicrobial, immunomodulatory, hypocholesterolaemic) functions that are performed by functional enzymes, probiotics, prebiotics, fibres, phytosterols, peptides, proteins, isoflavones, saponins or phytic acid, among other substances. Some agricultural and industrial residues have proven to be excellent choices as raw materials for producing bioactive compounds and have been proposed as potentially safe natural sources of antimicrobials and/or antioxidants for the food industry. Functional food ingredients containing bioactive compounds could be used as plant extracts by pharmaceutical and food industries. Bioactive food components influence health outcomes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. STUDY OF THE INFLUENCE OF SYNTHETIC COMPONENT IN MIXTURES WITH WOOL ON THE PHYSICAL-MECHANICAL PROPRIETIES

    Directory of Open Access Journals (Sweden)

    OANA Dorina

    2016-05-01

    Full Text Available The main physical-mechanical properties of the yarns are: linear density (Tex, tensile strength, tenacity, elongation at break, twisting and mechanical work of fracture, there is a strong correlation between them. The tensile properties are the basic characteristics of yarns, influencing how they behave in the technological processes of mechanical processing (preparation for weaving or knitting, proper weaving or knitting determining the technological parameters of equipment adjusting during the technological processes and also their productivity. The tensile properties of yarns constitute qualitative characteristics, because their value depends on the quality of the yarn and also on the finite product obtained from processing yarns. In this paper was done a comparative study of the tensile properties of two batches of mixed woolen yarns (wool with polyester and wool with polyamide, the mixture being in the same proportions, but the yarns have different fineness and have very close twist values, both batches of yarns were designed for knitted products. Batch I consists of 70% wool yarns and 30% polyester, linear density Ttex = 55.56 tex and twist of 350 twists/meter. Batch II consists of 70% wool yarns and 30% polyamide, a linear density of Ttex = 71.34 tex and twist of 330 twists/meter (so a thicker yarn than the one from batch I. Following the analysis between the two batches is clear that the woolen yarns in batch II have much higher tensile properties.

  3. Probabilistic fracture mechanics in the integrity evaluation of components; Mecanica de fractura probabilista en la evaluacion de la integridad de componentes

    Energy Technology Data Exchange (ETDEWEB)

    Franco Nava, Jose Manuel; Torres Toledano, Jose Gerardo; Sanchez Sanchez, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    Because of the importance of fracture mechanics in applications to pressure vessels, piping and other components used in thermal power plants, the Mechanical Engineering Unit of the Instituto de Investigaciones Electricas (IIE) has been developing activities in this field since some years ago. In this paper, the process for the analysis of probabilistic fracture mechanics is described. As an example, an application to the calculation of fault probability in piping systems, is presented. [Espanol] Dada la importancia de la mecanica de fractura en aplicaciones de recipientes a presion, tuberias y otros componentes utilizados en centrales termicas, la Unidad de Ingenieria Mecanica del Instituto de Investigaciones Electricas (IIE) ha venido desarrollando actividades en este campo desde hace algunos anos. En el presente trabajo, se describe el proceso para el analisis de mecanica de fractura probabilista. Como ejemplo se presenta una aplicacion al calculo de probabilidad de falla en tuberias.

  4. Probabilistic Material Strength Degradation Model for Inconel 718 Components Subjected to High Temperature, High-Cycle and Low-Cycle Mechanical Fatigue, Creep and Thermal Fatigue Effects

    Science.gov (United States)

    Bast, Callie C.; Boyce, Lola

    1995-01-01

    The development of methodology for a probabilistic material strength degradation is described. The probabilistic model, in the form of a postulated randomized multifactor equation, provides for quantification of uncertainty in the lifetime material strength of aerospace propulsion system components subjected to a number of diverse random effects. This model is embodied in the computer program entitled PROMISS, which can include up to eighteen different effects. Presently, the model includes five effects that typically reduce lifetime strength: high temperature, high-cycle mechanical fatigue, low-cycle mechanical fatigue, creep and thermal fatigue. Results, in the form of cumulative distribution functions, illustrated the sensitivity of lifetime strength to any current value of an effect. In addition, verification studies comparing predictions of high-cycle mechanical fatigue and high temperature effects with experiments are presented. Results from this limited verification study strongly supported that material degradation can be represented by randomized multifactor interaction models.

  5. Investigation of the mechanical performance of Siemens linacs components during arc: gantry, MLC, and electronic portal imaging device

    Directory of Open Access Journals (Sweden)

    Rowshanfarzad P

    2015-11-01

    Full Text Available Pejman Rowshanfarzad,1 Peter Häring,2 Hans L Riis,3 Sune J Zimmermann,3 Martin A Ebert1,4 1School of Physics, The University of Western Australia, Crawley, WA, Australia; 2German Cancer Research Center (DKFZ, Medical Physics in Radiation Oncology, Heidelberg, Germany; 3Radiofysisk Laboratorium, Odense University Hospital, Odense C, Denmark; 4Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia Background: In radiotherapy treatments, it is crucial to monitor the performance of linac components including gantry, collimation system, and electronic portal imaging device (EPID during arc deliveries. In this study, a simple EPID-based measurement method is suggested in conjunction with an algorithm to investigate the stability of these systems at various gantry angles with the aim of evaluating machine-related errors in treatments. Methods: The EPID sag, gantry sag, changes in source-to-detector distance (SDD, EPID and collimator skewness, EPID tilt, and the sag in leaf bank assembly due to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with five ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of image data. Three Siemens linacs were investigated. Results: The average EPID sag was within 1 mm for all tested linacs. Two machines showed >1 mm gantry sag. Changes in the SDD values were within 7.5 mm. EPID skewness and tilt values were <1° in all machines. The maximum sag in leaf bank assembly was <1 mm. Conclusion: The method and software developed in this study provide a simple tool for effective investigation of the behavior of Siemens linac components with gantry rotation. Such a comprehensive study has been performed for the first time on Siemens machines. Keywords: linac, Siemens, arc, sag, EPID, gantry

  6. To explain the variation of OGTT dynamics by biological mechanisms: a novel approach based on principal components analysis in women with history of GDM.

    Science.gov (United States)

    Göbl, Christian S; Bozkurt, Latife; Mittlböck, Martina; Leutner, Michael; Yarragudi, Rajashri; Tura, Andrea; Pacini, Giovanni; Kautzky-Willer, Alexandra

    2015-07-01

    Early reexamination of carbohydrate metabolism via an oral glucose tolerance test (OGTT) is recommended after pregnancy with gestational diabetes (GDM). In this report, we aimed to assess the dominant patterns of dynamic OGTT measurements and subsequently explain them by meanings of the underlying pathophysiological processes. Principal components analysis (PCA), a statistical procedure that aims to reduce the dimensionality of multiple interrelated measures to a set of linearly uncorrelated variables (the principal components) was performed on OGTT data of glucose, insulin and C-peptide in addition to age and body mass index (BMI) of 151 women (n = 110 females after GDM and n = 41 controls) at 3-6 mo after delivery. These components were explained by frequently sampled intravenous glucose tolerance test (FSIGT) parameters. Moreover, their relation with the later development of overt diabetes was studied. Three principal components (PC) were identified, which explained 71.5% of the variation of the original 17 variables. PC1 (explained 47.1%) was closely related to postprandial OGTT levels and FSIGT-derived insulin sensitivity (r = 0.68), indicating that it mirrors insulin sensitivity in the skeletal muscle. PC2 (explained 17.3%) and PC3 (explained 7.1%) were shown to be associated with β-cell failure and fasting (i.e., hepatic) insulin resistance, respectively. All three components were related with diabetes progression (occurred in n = 25 females after GDM) and showed significant changes in long-term trajectories. A high amount of the postpartum OGTT data is explained by principal components, representing pathophysiological mechanisms on the pathway of impaired carbohydrate metabolism. Our results improve our understanding of the underlying biological processes to provide an accurate postgestational risk stratification. Copyright © 2015 the American Physiological Society.

  7. Daphne oleoides Schreber ssp. oleoides Exhibits Potent Wound Healing Effect: Isolation of the Active Components and Elucidation of the Activity Mechanism

    Directory of Open Access Journals (Sweden)

    Ipek Süntar

    2014-03-01

    Full Text Available Ethnobotanical surveys revealed that Daphne oleoidesSchreber has been used against rheumatic pain and for wound healing in Turkish folk medicine. The aim of the present study is to verify the folkloric assertion of D. oleoides ssp. oleoides (DOO by bioassay-guided fractionation procedures leading to determination of the active component(s and to elucidate the activity mechanisms of the isolated compounds. The wound healing activity of the methanol extract, its subextracts, fractions and isolates was evaluated by using two different in vivo wound healing experimental techniques . Anti-inflammatory and antioxidant activities of the test materials were also evaluated. For the determination of the activity mechanisms, the isolated compounds were screened for hyaluronidase, collagenase and elastase enzyme inhibitory activities. The methanolic extract of DOO was found to possess potent wound healing activity. This extract was then subjected to successive solvent extractions with n-hexane, dichloromethane, ethyl acetate (EtOAc and n-butanol. EtOAc subextract yielded three compounds, quercetin 3-O-glucoside, triumbellin and rutarensin by using chromatographic separation techniques. The experimental study revealed that D. oleoides subsp. oleoides methanolic extract possesses significant wound healing effect and quercetin 3-O-glucoside was determined as the active component responsible from the activity.

  8. Differential Proteomic Profiles of Pleurotus ostreatus in Response to Lignocellulosic Components Provide Insights into Divergent Adaptive Mechanisms.

    Science.gov (United States)

    Xiao, Qiuyun; Ma, Fuying; Li, Yan; Yu, Hongbo; Li, Chengyun; Zhang, Xiaoyu

    2017-01-01

    Pleurotus ostreatus is a white rot fungus that grows on lignocellulosic biomass by metabolizing the main constituents. Extracellular enzymes play a key role in this process. During the hydrolysis of lignocellulose, potentially toxic molecules are released from lignin, and the molecules are derived from hemicellulose or cellulose that trigger various responses in fungus, thereby influencing mycelial growth. In order to characterize the mechanism underlying the response of P. ostreatus to lignin, we conducted a comparative proteomic analysis of P. ostreatus grown on different lignocellulose substrates. In this work, the mycelium proteome of P. ostreatus grown in liquid minimal medium with lignin, xylan, and carboxymethyl cellulose (CMC) was analyzed using the complementary two-dimensional gel electrophoresis (2-DE) approach; 115 proteins were identified, most of which were classified into five types according to their function. Proteins with an antioxidant function that play a role in the stress response were upregulated in response to lignin. Most proteins involving in carbohydrate and energy metabolism were less abundant in lignin. Xylan and CMC may enhanced the process of carbohydrate metabolism by regulating the level of expression of various carbohydrate metabolism-related proteins. The change of protein expression level was related to the adaptability of P. ostreatus to lignocellulose. These findings provide novel insights into the mechanisms underlying the response of white-rot fungus to lignocellulose.

  9. A unique mechanism of nuclear division in Giardia lamblia involves components of the ventral disk and the nuclear envelope.

    Science.gov (United States)

    Solari, Alberto J; Rahn, Monica I; Saura, Alicia; Lujan, Hugo D

    2003-12-01

    The fine structure of the binucleate, parasitic protist Giardia lamblia during interphase and divisional stages was studied by serial thin sectioning and three-dimensional reconstructions. The earlier sign of nuclear division is the development of a few peripheral areas of densely packed chromatin directly attached to the inner nuclear envelope. An intracytoplasmic sheet of ventral disk components grows from the cell periphery towards one of the nuclei, apparently constricting this nucleus, which becomes located at a ventral bulge. After the basal bodies become duplicated, a full nuclear division occurs in trophozoites, giving two pairs of parent-daughter nuclei. This full division occurs in a dorsal-ventral direction, with the resulting nuclear pairs located at the sides of the two sets of basal bodies. A new ventral disk is formed from the disk-derived sheets in the cell harboring the four nuclei. Cytokinesis is polymorphic, but at early stages is dorsal-to-dorsal. Encysting trophozoites show the development of Golgi cisternae stacks and dense, specific secretory granules. 3-D reconstructions show that cysts contain a single pair of incompletely strangled nuclei. The dividing Giardia lacks a typical, microtubular spindle either inside or outside the nuclei. The nuclear envelope seems to be the only structure involved in the final division of the parent-daughter nuclei.

  10. Enhancing mung bean hydration using the ultrasound technology: description of mechanisms and impact on its germination and main components

    Science.gov (United States)

    Miano, Alberto Claudio; Pereira, Jessica Da Costa; Castanha, Nanci; Júnior, Manoel Divino Da Matta; Augusto, Pedro Esteves Duarte

    2016-12-01

    The ultrasound technology was successfully used to improve the mass transfer processes on food. However, the study of this technology on the grain hydration and on its main components properties was still not appropriately described. This work studied the application of the ultrasound technology on the hydration process of mung beans (Vigna radiata). This grain showed sigmoidal hydration behavior with a specific water entrance pathway. The ultrasound reduced ~25% of the hydration process time. In addition, this technology caused acceleration of the seed germination – and some hypothesis for this enhancement were proposed. Moreover, it was demonstrated that the ultrasound did not change both structure and pasting properties of the bean starch. Finally, the flour rheological properties proved that the ultrasound increased its apparent viscosity, and as the starch was not modified, this alteration was attributed to the proteins. All these results are very desirable for industry since the ultrasound technology improves the hydration process without altering the starch properties, accelerates the germination process (that is important for the malting and sprouting process) and increases the flour apparent viscosity, which is desirable to produce bean-based products that need higher consistency.

  11. Enhancing mung bean hydration using the ultrasound technology: description of mechanisms and impact on its germination and main components.

    Science.gov (United States)

    Miano, Alberto Claudio; Pereira, Jessica da Costa; Castanha, Nanci; Júnior, Manoel Divino da Matta; Augusto, Pedro Esteves Duarte

    2016-12-19

    The ultrasound technology was successfully used to improve the mass transfer processes on food. However, the study of this technology on the grain hydration and on its main components properties was still not appropriately described. This work studied the application of the ultrasound technology on the hydration process of mung beans (Vigna radiata). This grain showed sigmoidal hydration behavior with a specific water entrance pathway. The ultrasound reduced ~25% of the hydration process time. In addition, this technology caused acceleration of the seed germination - and some hypothesis for this enhancement were proposed. Moreover, it was demonstrated that the ultrasound did not change both structure and pasting properties of the bean starch. Finally, the flour rheological properties proved that the ultrasound increased its apparent viscosity, and as the starch was not modified, this alteration was attributed to the proteins. All these results are very desirable for industry since the ultrasound technology improves the hydration process without altering the starch properties, accelerates the germination process (that is important for the malting and sprouting process) and increases the flour apparent viscosity, which is desirable to produce bean-based products that need higher consistency.

  12. Structure and mechanical properties of naturally occurring lightweight foam-filled cylinder--the peacock's tail coverts shaft and its components.

    Science.gov (United States)

    Liu, Z Q; Jiao, D; Meyers, M A; Zhang, Z F

    2015-04-01

    Feather shaft, which is primarily featured by a cylinder filled with foam, possesses a unique combination of mechanical robustness and flexibility with a low density through natural evolution and selection. Here the hierarchical structures of peacock's tail coverts shaft and its components are systematically characterized from millimeter to nanometer length scales. The variations in constituent and geometry along the length are examined. The mechanical properties under both dry and wet conditions are investigated. The deformation and failure behaviors and involved strengthening, stiffening and toughening mechanisms are analyzed qualitatively and quantitatively and correlated to the structures. It is revealed that the properties of feather shaft and its components have been optimized through various structural adaptations. Synergetic strengthening and stiffening effects can be achieved in overall rachis owing to increased failure resistance. This study is expected to aid in deeper understandings on the ingenious structure-property design strategies developed by nature, and accordingly, provide useful inspiration for the development of high-performance synthetic foams and foam-filled materials.

  13. Molecular Scanning and Morpho-Physiological Dissection of Component Mechanism in Lens Species in Response to Aluminium Stress

    Science.gov (United States)

    Singh, Dharmendra; Pal, Madan; Singh, Chandan Kumar; Taunk, Jyoti; Jain, Priyanka; Chaturvedi, Ashish Kumar; Maurya, Sadhana; Karwa, Sourabh; Singh, Rajendra; Tomar, Ram Sewak Singh; Nongthombam, Rita; Chongtham, Nandini; Singh, Moirangthem Premjit

    2016-01-01

    Aluminium (Al) stress was imposed on 285 lentil genotypes at seedling stage under hydroponics to study its effects on morpho-physiological traits where resistant cultigens and wilds showed minimum reduction in root and shoot length and maximum root re-growth (RRG) after staining. Molecular assortment based on 46 simple sequence repeat (SSR) markers clustered the genotypes into 11 groups, where wilds were separated from the cultigens. Genetic diversity and polymorphism information content (PIC) varied between 0.148–0.775 and 0.140–0.739, respectively. Breeding lines which were found to be most resistant (L-7903, L-4602); sensitive cultivars (BM-4, L-4147) and wilds ILWL-185 (resistant), ILWL-436 (sensitive) were grouped into different clusters. These genotypes were also separated on the basis of population structure and Jaccard’s similarity index and analysed to study Al resistance mechanism through determination of different attributes like localization of Al and callose, lipid peroxidation, secretion of organic acids and production of antioxidant enzymes. In contrast to sensitive genotypes, in resistant ones most of the Al was localized in the epidermal cells, where its movement to apoplastic region was restricted due to release of citrate and malate. Under acidic field conditions, resistant genotypes produced maximum seed yield/plant as compared to sensitive genotypes at two different locations i.e. Imphal, Manipur, India and Basar, Arunanchal Pradesh, India during 2012–13, 2013–14 and 2014–15. These findings suggest that Al stress adaptation in lentil is through exclusion mechanism and hybridization between the contrasting genotypes from distinct clusters can help in development of resistant varieties. PMID:27467074

  14. CRITERIA FOR SELECTION OF ALLOYING COMPONENTS AND BASE COMPOSITIONS FOR MANUFACTURING OF MECHANICALLY ALLOYED DISPERSION-STRENGTHENED MATERIALS ON THE BASIS OF METALS

    Directory of Open Access Journals (Sweden)

    F. G. Lovshenko

    2016-01-01

    Full Text Available The paper presents results of the investigations pertaining to creation of scientifically substantiated criteria for selection of alloying components and base compositions for manufacturing of mechanically alloyed dispersion-strengthened metallic materials. An analysis of dispersion strengthening mechanisms and regularities in mechanically activated phase and structural transformations serve as a reliable basis for solution of the assigned mission. Foer efficient strengthening at low and high temperatures as well materials must have fragmented and polygonized structure with maximum developed surface of grain and sub-grain boundaries which are stabilized by nano-sized inclusions of strengthening phases. Experimental investigations have shown that an optimum complex of mechanical properties is obtained in the case when nano-sized strengthening phase is equal to 3–5 % (volume. The phases applied for dispersion strengthening must have high value of shear modulus that determines their hardness and strength. Critical compressive stress should not cause deformation and destruction of disperse particles. Furthermore, they must have high stability in contact with a matrix. The substances applied as alloying components for realization of the developed technology on obtaining dispersion-strengthening materials must firstly meet the following requirements: they must be cheap, accessible and ecologically safety; they must interact with the basis or inter se at temperatures which are lower of material melting temperature; one of the phases which is formed in the process of the technology realization must have rather high thermodynamic stability and high value of the shear modulus; other formed phases must improve or, at the least, not reduce physical and mechanical properties of the materials. 

  15. The complete genome of a cyanobacterium from a soda lake reveals the presence of the components of CO2-concentrating mechanism.

    Science.gov (United States)

    Kupriyanova, Elena V; Cho, Sung Mi; Park, Youn-Il; Pronina, Natalia A; Los, Dmitry A

    2016-12-01

    At present geological epoch, the carbon concentrating mechanism (CCM) of cyanobacteria represents the obligatory tool for adaptation to low content of CO2 in the atmosphere and for the maintenance of sufficient photosynthetic activity. Functional CCM was found in modern cyanobacteria from different ecological niches. However, the presence of such mechanism in species that inhabit soda lakes is not obvious due to high content of inorganic carbon (C i) in the environment. Here we analyze CCM components that have been identified by sequencing of the whole genome of the alkaliphilic cyanobacterium Microcoleus sp. IPPAS B-353. The composition of the CCM components of Microcoleus is similar to that of 'model' β-cyanobacteria, freshwater and marine Synechococcus or Synechocystis spp. However, CahB1 protein of Microcoleus, which is the homolog of CcaA, the carboxysomal β-type carbonic anhydrase (CA) of β-cyanobacteria, appeared to be the only active CA located in cell envelopes. The conservative regions of CcmM, CahG (a homolog of archeal γ-CAs, Cam/CamH), and ChpX of Microcoleus possess single amino acid substitutions that may cause a lack of CA activities. Unlike model cyanobacteria, Microcoleus induces only one BicA-type bicarbonate transporter in response to C i limitation. The differences in the appearance of CCM components and in their characteristics between alkaliphilic Microcoleus and freshwater or marine cyanobacteria are described. The possible reasons for the maintenance of CCM components in cyanobacteria, which permanently live at high concentrations of C i in soda lakes, are discussed.

  16. Backside nonconformity and locking restraints affect liner/shell load transfer mechanisms and relative motion in modular acetabular components for total hip replacement.

    Science.gov (United States)

    Kurtz, S M; Ochoa, J A; White, C V; Srivastav, S; Cournoyer, J

    1998-05-01

    Nonconformity between the polyethylene liner and the metal shell may exist in modular acetabular components by design, due to manufacturing tolerances, or from locking mechanisms that attach the polyethylene liner to the metal shell. Relative motion at the liner/shell interface has been associated with backside wear, which may contribute to osteolysis which has been clinically observed near screw holes. The purpose of this study was to investigate the effect of nonconformity and locking restraints on the liner/shell relative motion and load transfer mechanisms in a commercially available, metal-backed acetabular component with a polar fenestration. The finite element method was used to explore the hypothesis that backside nonconformity and locking restraints play important roles in long-term surface damage mechanisms that are unique to modular components, such as backside wear and liner extrusion through screw holes. The three-body quasi-static contact problem was solved using a commercially available explicit finite element code, which modeled contact between the femoral head, polyethylene liner, and the metal shell. Four sets of liner boundary conditions were investigated: no restraints, rim restraints, equatorial restraints, and both rim and equatorial restraints. The finite element model with a conforming shell predicted between 8.5 and 12.8 microm of incremental extrusion of the polyethylene through the polar fenestration, consistent with in vitro experiments of the same design under identical loading conditions. Furthermore, idealized rim and/or equatorial liner restraints were found to share up to 71% of the load across the liner/shell interface. Consequently, the results of this study demonstrate that backside nonconformity and locking restraints substantially influence backside relative motion as well as load transfer at the liner/shell interface.

  17. Heat Transfer Analysis of Two Kinds of Mechanically Jointed GBST1308/CuCrZr Plasma Facing Components of EAST

    Institute of Scientific and Technical Information of China (English)

    CHONG Fali; CHEN Junling; LI Jiangang; ZHENG Xuebin; EAST team

    2008-01-01

    Doped graphite GBST1308,mechanically jointed to CuCrZr alloys,will be applied on EAST superconducting as plasma facing material (PFM).Two joint structures called joint-1 and joint-2 were evaluated by means of thermal response tests using electron beam facility.The experimental results showed that the temperature differences of two joints were not significant,and the maximum surface temperature was about 1055℃ at a load of 4 MW/m2,which had a good agreement with the simulated results by ANSYS code.The results indicated that the doped graphite GBST1308/CuCrZr mock-up can withstand heat flux deposition of 4 MW/m2 except at the screw-fastened region,and joint-2 could be more suitable to higher heat flux region such as divertor target.But under the higher heat flux,both joints are unacceptable,an advanced PFM and its integration with the heat sink have to be developed,for example,vacuum plasma spraying tungsten coatings on the CuCrZr might be a good choice.

  18. Mechanisms underlying the anti-proliferative effects of berry components in in vitro models of colon cancer.

    Science.gov (United States)

    Brown, Emma M; Gill, Chris I R; McDougall, Gordon J; Stewart, Derek

    2012-01-01

    Consumption of fruit and vegetables is associated with a decreased risk of several cancers, particularly colorectal cancer, possibly linked to their phytochemical content, which is of interest due to several proposed health benefits, including potential anticancer activity. Epidemiological data suggests that cancers of the digestive tract are most susceptible to dietary modification, possibly due to being in direct contact with bioactive food constituents and therefore investigating the effects of these bioactive compounds on the prevalent colorectal cancer is feasible. Berries are a common element of Western diets, with members of the Rubus, Fragria, Sorbus, Ribes and Vaccinum genus featuring in desserts, preserves, yoghurts and juices. These soft fruit are rich in bioactive phytochemicals including several classes of phenolic compounds such as flavonoids (anthocyanins, flavonols and flavanols) and phenolic acids (hydroxybenzoic and hydroxycinnamic acids). Whilst there is little data linking berry consumption to reduced risk of colorectal cancer, in vitro evidence from models representing colorectal cancer suggests that berry polyphenols may modulate cellular processes essential for cancer cell survival, such as proliferation and apoptosis. The exact mechanisms and berry constituents responsible for these potential anticancer activities remain unknown, but use of in vitro models provides a means to elucidate these matters.

  19. Experimental investigations on the state of the friction-welded joint zone in steel hybrid components after process-relevant thermo-mechanical loadings

    Science.gov (United States)

    Behrens, B.-A.; Bouguecha, A.; Vucetic, M.; Peshekhodov, I.; Matthias, T.; Kolbasnikov, N.; Sokolov, S.; Ganin, S.

    2016-10-01

    As a part of the newly established Collaborative Research Center 1153 (SFB 1153) "Process chain for the manufacturing of hybrid high-performance components by tailored forming" at the Leibniz Universität Hannover, the Institute of Forming Technology and Machines (IFUM) examines the influence of thermo-mechanical stresses on the reduced Young's modulus as well as the hardness of hybrid (steel-steel compound) joined semi-finished products. Currently the expertise in the production of bulk metal formed parts is limited to mono-materials. For manufacturing parts of hybrid materials and also for the methods of the new process routes, practical experience has to be gained. The subproject C1 within the collaborative research center 1153 with the short title "Failure Prediction" deals with the question, if the hybrid semi-finished products fulfill the thermo-mechanical demands or if they fail at the joining zone (JZ) during forging. For this purpose, stresses similar to those in the process were imposed on hybrid semi-finished products by torsion tests by using the thermo-mechanical test system Gleeble 3800. Afterwards, the specimens were examined metallographically and by nanoindentations with the help of a TriboIndenter TI950. Thus, first knowledge on the behaviour of thermo-mechanical stresses on the reduced Young's modulus and the hardness of hybrid joined semi-finished parts was gained.

  20. Gas Sensitivity and Sensing Mechanism Studies on Au-Doped TiO2 Nanotube Arrays for Detecting SF6 Decomposed Components

    Directory of Open Access Journals (Sweden)

    Xiaoxing Zhang

    2014-10-01

    Full Text Available The analysis to SF6 decomposed component gases is an efficient diagnostic approach to detect the partial discharge in gas-insulated switchgear (GIS for the purpose of accessing the operating state of power equipment. This paper applied the Au-doped TiO2 nanotube array sensor (Au-TiO2 NTAs to detect SF6 decomposed components. The electrochemical constant potential method was adopted in the Au-TiO2 NTAs’ fabrication, and a series of experiments were conducted to test the characteristic SF6 decomposed gases for a thorough investigation of sensing performances. The sensing characteristic curves of intrinsic and Au-doped TiO2 NTAs were compared to study the mechanism of the gas sensing response. The results indicated that the doped Au could change the TiO2 nanotube arrays’ performances of gas sensing selectivity in SF6 decomposed components, as well as reducing the working temperature of TiO2 NTAs.

  1. Prediction models of long-term leaching behavior and leaching mechanism of glass components and surrogated nuclides in radioactive vitrified waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. C.; Lee, K. S. [Department of Industrial Environment and Health, Yonsei University, Wonju (Korea, Republic of); Kim, I. T.; Kim, H. T.; Kim, J. H. [Korea Atomic Energy Research Institute (KAERI), Taejon (Korea, Republic of)

    1999-07-01

    Melting solidification is considered to be a perspective technology for stabilizing incineration ash remaining after incineration of combustible radioactive waste since it has the advantage of improving the physicochemical properties of waste forms. Final waste forms should be characterized to determine the degree to which they fulfills the acceptance criteria of the disposal facility. Chemical durability (leaching resistance) is known to be the most important factor in the assessment of waste forms. In this study, vitrified waste forms are manufactured and characterized. Feed materials consist of simulated radioactive incineration ash and base-glass with different mixing ratios. To assess the chemical durability of vitrified waste forms, the International Standard Organization (ISO) leach test has been conducted at 70 degree C with deionized distilled water as a leachant for 820 days, and the concentrations of glass components and surrogates in the leachates are then analyzed. Two models for predicting long-term leaching behavior of glass components and radionuclides in a glass form are applied to the leached data after 820 days. The model including a fitted parameter from the longer experimental data shows more accuracy, however, the model with shorter leaching test results offers the advantage of being able to predict the long-term behavior from the short-term experimental data. The leaching mechanisms of surrogates and glass components were also investigated by using two semi-empirical kinetic models and were found to be dissolution with diffusion. (author)

  2. Local mechanisms for the separation of optic flow-field components in the land crab, Cardisoma guanhumi: a role for motion parallax?

    Science.gov (United States)

    Johnson, Aaron P; Barnes, W Jon P; Macauley, Martin W S

    2004-01-01

    Although a number of global mechanisms have been proposed over the years that explain how crabs might separate the rotational and translational components of their optic flow field, there has been no evidence to date that local mechanisms such as motion parallax are used in this separation. We describe here a study that takes advantage of a recently developed suite of computer-generated visual stimuli that creates a three-dimensional world surrounding the crab in which we can simulate translational and rotational optic flow. We show that, while motion parallax is not the only mechanism used in flow-field separation, it does play a role in the recognition of translational optic flow fields in that, under conditions of low overall light intensity and low contrast ratio when crabs find the distinction between rotation and translation harder, smaller eye movements occur in response to translation when motion parallax cues are present than when they are absent. Thus, motion parallax is one of many cues that crabs use to separate rotational and translational optic flow by showing compensatory eye movements to only the former.

  3. Mechanisms of fatigue-crack initiation and their impact on fatigue life of AlSi7 die-cast components

    Directory of Open Access Journals (Sweden)

    Redik Sabine

    2014-06-01

    Full Text Available In the course of the present study, in-situ observations of crack initiation and crack growth of naturally induced cracks in cyclically loaded specimens along with conventional fatigue tests and fracture surface analyses were performed. The specimens used were taken from different sampling positions of standard and HIPed aluminum-die-cast engine blocks, with different cooling conditions. In one sampling position within the standard engine block microporosity was able to form, acting as a source for fatigue-crack initiation. While in the absence of microporosity, as observed in specimens taken from HIPed components, crack initiation occured via slip band mechanism. If material defects such as pores were present, premature crack initiation reduced the fatigue life yielding a lower fatigue life and fatigue strength than specimens where cracks formed by slip band mechanism. For cracks formed at pores, the pore size is the determining factor for fatigue behavior. While for cracks initiated via slip band mechanism fatigue strength is a function of the local material strength.

  4. Mechanical Components and Tribology Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory evaluates fundamental friction, wear, and lubrication technologies for improved, robust, and power-dense vehicle transmissions. The facility explores...

  5. Hair Regenerative Mechanisms of Red Ginseng Oil and Its Major Components in the Testosterone-Induced Delay of Anagen Entry in C57BL/6 Mice

    Directory of Open Access Journals (Sweden)

    Van-Long Truong

    2017-09-01

    Full Text Available Hair loss (alopecia is a universal problem for numerous people in the world. The present study was conducted to investigate the effects of red ginseng oil (RGO and its major components on hair re-growth using testosterone (TES-induced delay of anagen entry in C57BL/6 mice and their mechanisms of action. Seven-week-old C57BL/6 mice were daily treated with TES for 1 h prior to topical application of 10% RGO, 1% linoleic acid (LA, 1% β-sitosterol (SITOS, or 1% bicyclo(10.1.0tridec-1-ene (BICYCLO once a day for 28 days. Hair regenerative capacity was significantly restored by treatment of RGO and its major compounds in the TES-treated mice. Histological analysis showed that RGO along with LA and SITOS but not BICYCLO promoted hair growth through early inducing anagen phase that was delayed by TES in mice. Treatment of mice with RGO, LA, or SITOS up-regulated Wnt/β-catenin and Shh/Gli pathways-mediated expression of genes such as β-catenin, Lef-1, Sonic hedgehog, Smoothened, Gli-1, Cyclin D1, and Cyclin E in the TES-treated mice. In addition, RGO and its major components reduced the protein level of TGF-β but enhanced the expression of anti-apoptotic protein Bcl-2. These results suggest that RGO is a potent novel therapeutic natural product for treatment of androgenic alopecia possibly through hair re-growth activity of its major components such as LA and SITOS.

  6. Molecular Mechanism and Energy Basis of Conformational Diversity of Antibody SPE7 Revealed by Molecular Dynamics Simulation and Principal Component Analysis

    Science.gov (United States)

    Chen, Jianzhong; Wang, Jinan; Zhu, Weiliang

    2016-11-01

    More and more researchers are interested in and focused on how a limited repertoire of antibodies can bind and correspondingly protect against an almost limitless diversity of invading antigens. In this work, a series of 200-ns molecular dynamics (MD) simulations followed by principal component (PC) analysis and free energy calculations were performed to probe potential mechanism of conformational diversity of antibody SPE7. The results show that the motion direction of loops H3 and L3 is different relative to each other, implying that a big structural difference exists between these two loops. The calculated energy landscapes suggest that the changes in the backbone angles ψ and φ of H-Y101 and H-Y105 provide significant contributions to the conformational diversity of SPE7. The dihedral angle analyses based on MD trajectories show that the side-chain conformational changes of several key residues H-W33, H-Y105, L-Y34 and L-W93 around binding site of SPE7 play a key role in the conformational diversity of SPE7, which gives a reasonable explanation for potential mechanism of cross-reactivity of single antibody toward multiple antigens.

  7. A P-glycoprotein gene serves as a component of the protective mechanisms against 2-tridecanone and abamectin in Helicoverpa armigera.

    Science.gov (United States)

    Xiang, Min; Zhang, Lei; Lu, Yao; Tang, Qiuling; Liang, Pei; Shi, Xueyan; Song, Dunlun; Gao, Xiwu

    2017-09-05

    P-glycoprotein (P-gp) exists in animals, fungi and bacteria and likely evolved as a defense mechanism against harmful substances. Here a cDNA (4054bp) encoding a putative P-glycoprotein gene from Helicoverpa armigera was cloned and named HaPgp1. This putative HaPgp1 sequence encoded a protein of 1253 amino acids with a molecular mass of approximately 137kDa. qPCR analyses demonstrated that the expression of HaPgp1 was significantly higher in 4th instar larvae when compared to other developmental stages. HaPgp1 transcripts were more abundant in the head and fat bodies than in other tissues. Compared with the control, the expression of HaPgp1 reach a peak at 12h after the treatment by 2-tridecanone in all tissues. However, the expression of HaPgp1 increased from 12h to 48h after treatment with abamectin in all tissues. Immunohistochemistry analyses also verified that 2-tridecanone and abamectin can induce the increase of HaPgp1 expression. RNAi of HaPgp1 significantly raised the mortality rate of larvae treated by 2-tridecanone and abamectin, as compared to control larvae fed with GFP dsRNA. These results illustrate the possible involvement of HaPgp1 as a component of the protective mechanisms to plant secondary chemicals such as 2-tridecanone and to certain classes of insecticides, like abamectin. Copyright © 2017. Published by Elsevier B.V.

  8. Mechanism and experimental study on the photocatalytic performance of Ag/AgCl @ chiral TiO{sub 2} nanofibers photocatalyst: The impact of wastewater components

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dawei [Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University. Xi Kang Road #1, Nanjing 210098 (China); Li, Yi, E-mail: envly@hhu.edu.cn [Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University. Xi Kang Road #1, Nanjing 210098 (China); Li Puma, Gianluca [Environmental Nanocatalysis & Photoreaction Engineering, Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU (United Kingdom); Wang, Chao; Wang, Peifang; Zhang, Wenlong; Wang, Qing [Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University. Xi Kang Road #1, Nanjing 210098 (China)

    2015-03-21

    Highlights: • The effect of wastewater matrix on Ag/AgCl based nanomaterials was investigated. • DOM acted as a reactive oxygen species scavenger. • Cl{sup −} could accelerate the transformation from Ag to AgCl. • A relative rate technique was used to quantify these components impacts. - Abstract: The effect of the water matrix components of a secondary effluent of a urban wastewater treatment plant on the photocatalytic activity of Ag/AgCl @ chiral TiO{sub 2} nanofibers and the undergoing reaction mechanisms were investigated. These effects were evaluated through the water components-induced changes on the net rate of hydroxyl radical (·OH) generation and modeled using a relative rate technique. Dissolved organic matter DOM (k = −2.8 × 10{sup 8} M{sup −1} s{sup −1}) scavenged reactive oxygen species, Cl{sup −} (k = −5.3 × 10{sup 8} M{sup −1} s{sup −1}) accelerated the transformation from Ag to AgCl (which is not photocatalytically active under visible-light irradiation), while Ca{sup 2+} at concentrations higher than 50 mM (k = −1.3 × 10{sup 9} M{sup −1} s{sup −1}) induced aggregation of Ag/AgCl and thus all of them revealed inhibitory effects. In contrast, NO{sub 3}{sup −} (k = 6.9 × 10{sup 8} M{sup −1} s{sup −1}) and CO{sub 3}{sup 2−} (k = 3.7 × 10{sup 8} M{sup −1} s{sup −1}) improved the photocatalytic activity of Ag/AgCl slightly by improving the rate of HO· generation. Other ubiquitous secondary effluent components including SO{sub 4}{sup 2−} (k = 3.9 × 10{sup 5} M{sup −1} s{sup −1}), NH{sub 3}{sup +} (k = 3.5 × 10{sup 5} M{sup −1} s{sup −1}) and Na{sup +} (k = 2.6 × 10{sup 4} M{sup −1} s{sup −1}) had negligible effects. 90% of 17-α-ethynylestradiol (EE2) spiked in the secondary effluent was removed within 12 min, while the structure and size of Ag/AgCl @ chiral TiO{sub 2} nanofibers remained stable. This work may be helpful not only to uncover the photocatalytic mechanism of Ag/AgCl based

  9. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  10. Development of functional foods for radiation workers - Search for the active components and studies on the mechanism of the hematopoiesis improvement foods

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Sung Tae; Ha, Mee Hye; Jeong, Young Ran [Sunchon National University, Sunchon (Korea)

    2000-04-01

    In this experiments, we established long-termed culture methods of bone marrow stromal cells for proliferation and differentiation of stem cells. And we selected some extracts which support maximal proliferation of stromal cells with this method. We conformed the synergic effects of herbal mixture extracts for stromal cell growth. The proliferation of stromal cells was increased rather by the addition of mixture extracts than by addition of single strain extract. In the previous and cooperative experiments, we selected complex extracts (Him-I, Him-II) which increased the number of nonadherent mononuclear cells. Different cytokine expression patterns were observed stromal cells cultured in the presence or absence of mixture extracts which support differentiation of nonadherent cells. Some fractions of Him-I and Him-II increased the proliferation of bone marrow cells irradiated {gamma}-ray(4Gray). Stimulation of macrophage cell line with herval extracts with the treatments of recombinant interferon-{gamma} resulted in increased nitric oxide synthesis in a dose-dependent manners. Altered patterns of cytokine mRNA expression were observed in the stromals cells cultured with extracts of herbal plant. In regarding of the results, isolation and development of new and effective systems to screen for active hematopoietic component needs to be proceeded. Such studies on the hematopoietic modulation and mechanism of herbal plants would further lead to new avenues for the development of functional foods which effect such as radiation damages or leukemia. 20 refs., 23 figs. (Author)

  11. Novel two-component gels of cetylpyridinium chloride and the bola-amphiphile 6-amino caproic acid: phase evolution and mechanism of gel formation.

    Science.gov (United States)

    Ramakanth, Illa; Patnaik, Archita

    2012-03-08

    A two-component gel resulting from the amphiphilic cationic surfactant cetylpyridinium chloride (CPC) in the presence of a structure-forming bola-amphiphilic additive 6-aminocaproic acid (6-ACA) was realized and investigated. At a critical 6 wt % of 1:1 CPC:6-ACA, the yellow colored gel resulted from a 3:1 v/v CHCl(3):H(2)O critical binary solvent composition. The mixed amphiphilic system formed a 1:1 complex with a binding constant ~0.83 × 10(4) M(-1). Phase evolution and mechanism of gelation in the mixed CPC:6-ACA system was unraveled upon investigating the gel microstructure, based on spectroscopic, microscopic, and small-angle X-ray scattering (SAXS) investigations. The gel assembled as a lamellar organization, maintaining a loosely interdigitated bilayer structure of CPC and 6-ACA molecules through predominant charge transfer, H-bonding, and hydrophobic and intercomplex interactions. The SAXS pattern indicated a semicrystalline form to be the stable phase with alternating crystalline and amorphous layers; a novel mode of gelation with a widely disparate semicrystalline form of the lamellar gel was thus indicated, where the lamellar structure was deduced from the interplanar spacings. A transition from low viscosity reverse micellar solution to a yellow rigid gel upon aging was thus comprehended. The mixed amphiphile in varying polarity organic solvents in the presence of water indicated the nonconducive nature of gelation in very highly polar solvents, methanol, and DMF or, in very low polarity solvents, such as, cyclohexane and carbon tetrachloride.

  12. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  13. Mechanics

    Science.gov (United States)

    Cox, John

    2014-05-01

    Part 1. The Winning of the Principles: 1. Introduction; 2. The beginnings of statics. Archimedes. Problem of the lever and of the centre of gravity; 2. Experimental verification and applications of the principle of the lever; 3. The centre of gravity; 4. The balance; 5. Stevinus of Bruges. The principle of the inclined plane; 6. The parallelogram of forces; 7. The principle of virtual work; 8. Review of the principles of statics; 9. The beginnings of dynamics. Galileo. The problem of falling bodies; 10. Huyghens. The problem of uniform motion in a circle. 'Centrifugal force'; 11. Final statement of the principles of dynamics. Extension to the motions of the heavenly bodies. The law of universal gravitation. Newton; Part II. Mathematical Statement of the Principles: Introduction; 12. Kinematics; 13. Kinetics of a particle moving in a straight line. The laws of motion; 14. Experimental verification of the laws of motion. Atwood's machine; 15. Work and energy; 16. The parallelogram law; 17. The composition and resolution of forces. Resultant. Component. Equilibrium; 18. Forces in one plane; 19. Friction; Part III. Application to Various Problems: 20. Motion on an inclined plane. Brachistochrones; 21. Projectiles; 22. Simple harmonic motion; 23. The simple pendulum; 24. Central forces. The law of gravitation; 25. Impact and impulsive forces; Part IV. The Elements of Rigid Dynamics: 26. The compound pendulum. Huyghens' solution; 27. D'alembert's principle; 28. Moment of inertia; 29. Experimental determination of moments of inertia; 30. Determination of the value of gravity by Kater's pendulum; 31. The constant of gravitation, or weighing the Earth. The Cavendish experiment; Answers to the examples; Index.

  14. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  15. A Network Framework Based on Mechanical Component Design and Manufacturing%基于机械零件设计与制造的网络平台构建

    Institute of Scientific and Technical Information of China (English)

    顾立志; 陈光军; 杨康

    2004-01-01

    Network manufacturing has been rapidly developed and is going to play an important role in modern industry. The core of network manufacturing of mechanical products is the design and manufacturing based on the computer network technology. A network framework is inuoduced for manufacturing mechanical components at two main levels. On the design level features of the component are initially studied based on the structure and functions of the component. Details of the design procedure and contents are then analyzed with three main kinds of components. In this stage, selection of materials, calculation of stress and deflection under load, determination of the size are carried out using CAD. On the manufacturing level various aspects of CAPP are discussed, including the principle and the modes of positioning the component, the exerted clamping forces, cutting engagement and input parameters, machine tools used, and machining fluids if necessary. Finally a prototype of the network framework is presented with several pieces of data terminal equipment through a local area network, the topological structure, and data sharing and security, without concerning the use of the concurrent engineering techniques and virtual manufacturing, and virtual measuring techniques.

  16. Probability of mechanical loosening of the femoral component in high flexion total knee arthroplasty can be reduced by rather simple surgical techniques

    NARCIS (Netherlands)

    van de Groes, S.A.W.; De Waal Malefijt, M.C.; Verdonschot, Nicolaas Jacobus Joseph

    2014-01-01

    Background: Some follow-up studies of highflexion total knee arthoplasties report disturbingly high incidences of femoral component loosening. Femoral implantfixation is dependant on two interfaces: the cement–implant and the cement–bone interface. The present finite-element model (FEM) is the first

  17. Probability of mechanical loosening of the femoral component in high flexion total knee arthroplasty can be reduced by rather simple surgical techniques

    NARCIS (Netherlands)

    Groes, S.A.W. van de; Waal Malefijt, M.C. de; Verdonschot, N.J.J.

    2014-01-01

    BACKGROUND: Some follow-up studies of high flexion total knee arthoplasties report disturbingly high incidences of femoral component loosening. Femoral implant fixation is dependant on two interfaces: the cement-implant and the cement-bone interface. The present finite-element model (FEM) is the

  18. Development of multi-component diesel surrogate fuel models – Part I: Validation of reduced mechanisms of diesel fuel constituents in 0-D kinetic simulations

    DEFF Research Database (Denmark)

    Poon, Hiew Mun; Pang, Kar Mun; Ng, Hoon Kiat

    2016-01-01

    In the present work, development and validation of reduced chemical kinetic mechanisms for several different hydrocarbons are performed. These hydrocarbons are potential representative for practical diesel fuel constituents. n-Hexadecane (HXN), 2,2,4,4,6,8,8-heptamethylnonane (HMN), cyclohexane...... (CHX) and toluene are selected to represent straight-alkane, branched-alkane, cyclo-alkane and aromatic compounds in the diesel fuel. A five-stage chemical kinetic mechanism reduction scheme formulated in the previous work is applied to develop the reduced HMN and CHX models based on their respective...... developed fuel constituent reduced mechanisms, together with the formerly derived reduced HXN mechanism are comprehensively validated in zero-dimensional chemical kinetic simulations under a wide range of shock tube and jet-stirred reactor (JSR) conditions. Well agreement between the reduced and detailed...

  19. Development of multi-component diesel surrogate fuel models – Part II:Validation of the integrated mechanisms in 0-D kinetic and 2-D CFD spray combustion simulations

    DEFF Research Database (Denmark)

    Poon, Hiew Mun; Pang, Kar Mun; Ng, Hoon Kiat;

    2016-01-01

    The aim of this study is to develop compact yet comprehensive multi-component diesel surrogate fuel models for computational fluid dynamics (CFD) spray combustion modelling studies. The fuel constituent reduced mechanisms including n-hexadecane (HXN), 2,2,4,4,6,8,8-heptamethylnonane (HMN......), cyclohexane(CHX) and toluene developed in Part I are applied in this work. They are combined to produce two different versions of multi-component diesel surrogate models in the form of MCDS1 (HXN + HMN)and MCDS2 (HXN + HMN + toluene + CHX). The integrated mechanisms are then comprehensively validated in zero...... fuel model for diesel fuels with CN values ranging from 15 to100. It also shows that MCDS2 is a more appropriate surrogate model for fuels with aromatics and cyclo-paraffinic contents, particularly when soot calculation is of main interest....

  20. Redox Mechanisms of AVS022, an Oriental Polyherbal Formula, and Its Component Herbs in Protection against Induction of Matrix Metalloproteinase-1 in UVA-Irradiated Keratinocyte HaCaT Cells

    Directory of Open Access Journals (Sweden)

    Thanyawan Pluemsamran

    2013-01-01

    Full Text Available Ayurved Siriraj HaRak (AVS022 formula has been used for topical remedy of dermatologic disorders. Oxidative stress induced by ultraviolet (UV A irradiation could be implicated in photoaged skin through triggering matrix metalloproteinase-1 (MMP-1. We, therefore, explored the antioxidant mechanisms by which AVS022 formulation and its individual components protected against UVA-dependent MMP-1 upregulation in keratinocyte HaCaT cells. TLC analysis revealed the presence of multiple phenolics including gallic acid (GA in the AVS022 extracts. We demonstrated that pretreatment with the whole formula and individual herbal components except T. triandra protected against increased MMP-1 activity in irradiated HaCaT cells. Moreover, all herbal extracts and GA, used as the reference compound, were able to reverse cytotoxicity, oxidant production, glutathione (GSH loss, and inactivation of catalase and glutathione peroxidase (GPx. F. racemosa was observed to yield the strongest abilities to abolish UVA-mediated induction of MMP-1 and impairment of antioxidant defenses including GSH and catalase. Our observations suggest that upregulation of endogenous antioxidants could be the mechanisms by which AVS022 and its herbal components suppressed UVA-stimulated MMP-1 in HaCaT cells. In addition, pharmacological actions of AVS022 formula may be attributed to the antioxidant potential of its components, in particular F. racemosa, and several phenolics including GA.

  1. Different chronological patterns of appearance of blood derived milk components during mastitis indicate different mechanisms of transfer from blood into milk.

    Science.gov (United States)

    Wellnitz, Olga; Zbinden, Christina; Lüttgenau, Johannes; Bollwein, Heinrich; Bruckmaier, Rupert M

    2015-08-01

    This study aimed to describe chronological patterns of changes of various candidate blood components in milk during the acute phase of a mammary immune response in detail. Eight dairy cows were challenged with Escherichia coli lipopolysaccharide in one udder quarter. Milk from challenged and control quarters and blood samples were taken before, and 1 and 2 h after challenge and then every 15 min until 5 h after challenge. The SCC, serum albumin, immunoglobulin (Ig)G1, IgG2, lactate dehydrogenase (LDH), and L-lactate in milk and blood, and α-lactalbumin in blood were analysed. All selected parameters in milk increased in challenged quarters but did not increase in control quarters. Milk IgG1, IgG2, serum albumin, and LDH were already significantly increased at 2 h after challenge whereas a significant increase of SCC was detectable at 2.75 h and L-lactate was increased at 2.25 h after challenge. In blood L-lactate was increased at 3.75 h after challenge, however, other factors in blood did not change significantly within the 5 h of experiment. In conclusion, the increase of blood components in milk during inflammation follows two different patterns: There is a rapid increase for IgG1, IgG2, or LDH, before the increase of SCC, and their concentrations reach a plateau within 3 h. On the other hand, SCC and L-lactate show a slower but consistent increase not reaching a plateau within 5 h after LPS challenge. L-lactate increases to higher concentrations in milk than in blood. This clearly shows that the increase of blood components follows different patterns and is therefore a controlled and compound-specific process and not exclusively an unspecific type of leakage.

  2. Principal component analysis to assess the efficiency and mechanism for enhanced coagulation of natural algae-laden water using a novel dual coagulant system.

    Science.gov (United States)

    Ou, Hua-Se; Wei, Chao-Hai; Deng, Yang; Gao, Nai-Yun; Ren, Yuan; Hu, Yun

    2014-02-01

    A novel dual coagulant system of polyaluminum chloride sulfate (PACS) and polydiallyldimethylammonium chloride (PDADMAC) was used to treat natural algae-laden water from Meiliang Gulf, Lake Taihu. PACS (Aln(OH)mCl3n-m-2k(SO4)k) has a mass ratio of 10 %, a SO4 (2-)/Al3 (+) mole ratio of 0.0664, and an OH/Al mole ratio of 2. The PDADMAC ([C8H16NCl]m) has a MW which ranges from 5 × 10(5) to 20 × 10(5) Da. The variations of contaminants in water samples during treatments were estimated in the form of principal component analysis (PCA) factor scores and conventional variables (turbidity, DOC, etc.). Parallel factor analysis determined four chromophoric dissolved organic matters (CDOM) components, and PCA identified four integrated principle factors. PCA factor 1 had significant correlations with chlorophyll-a (r=0.718), protein-like CDOM C1 (0.689), and C2 (0.756). Factor 2 correlated with UV254 (0.672), humic-like CDOM component C3 (0.716), and C4 (0.758). Factors 3 and 4 had correlations with NH3-N (0.748) and T-P (0.769), respectively. The variations of PCA factors scores revealed that PACS contributed less aluminum dissolution than PAC to obtain equivalent removal efficiency of contaminants. This might be due to the high cationic charge and pre-hydrolyzation of PACS. Compared with PACS coagulation (20 mg L(-1)), the removal of PCA factors 1, 2, and 4 increased 45, 33, and 12 %, respectively, in combined PACS-PDADMAC treatment (0.8 mg L(-1) +20 mg L(-1)). Since PAC contained more Al (0.053 g/1 g) than PACS (0.028 g/1 g), the results indicated that PACS contributed less Al dissolution into the water to obtain equivalent removal efficiency.

  3. Evidence for ball-bearing mechanism of microparticulated whey protein as fat replacer in liquid and semi-solid multi-component model foods

    NARCIS (Netherlands)

    Liu, K.; Tian, Yujie; Stieger, M.A.; Linden, van der E.; Velde, van de F.

    2016-01-01

    The current understanding of the mechanisms underlying the fat mimicking properties of fat replacers, such as microparticulated whey protein (MWP), is limited. MWP is known to provide fat-related mouth-feel in specific foods, such as yoghurts and cheeses. Tribological and rheological properties are

  4. Evidence for ball-bearing mechanism of microparticulated whey protein as fat replacer in liquid and semi-solid multi-component model foods

    NARCIS (Netherlands)

    Liu, K.; Tian, Yujie; Stieger, M.A.; Linden, van der E.; Velde, van de F.

    2016-01-01

    The current understanding of the mechanisms underlying the fat mimicking properties of fat replacers, such as microparticulated whey protein (MWP), is limited. MWP is known to provide fat-related mouth-feel in specific foods, such as yoghurts and cheeses. Tribological and rheological properties are

  5. Theory and method research of mechanical components reliability design%机械零件可靠性设计理论与方法研究

    Institute of Scientific and Technical Information of China (English)

    邱继伟; 张瑞军; 丛东升; 郭楠

    2011-01-01

    In the mechanical product development stage, the ability to work or the life of the mechanical product under the prescriptive conditions are predicted by mechanical reliability design method, the basic task of which is to propose mathematical model and method of practical calculation. The theory of mechanical reliability design was expounded by integrating reliability theory of history and current status. A series of theory and methods, such as reliability optimization design, reliability sensitivity design, reliability robust design, reliability testing and traditional design methods combined with the reliability design, were explained clearly and systematically. All of these studies provided systematic and unitized theories and methods for mechanical reliability design.%机械可靠性设计的任务就是提供实际计算的数学模型和方法,在机械产品的研发阶段预测其在规定工作条件下的工作能力或寿命.结合可靠性理论研究的历史及现状对机械可靠性设计理论进行深入分析,阐明了可靠性优化设计、可靠性灵敏度设计、可靠性稳健设计、可靠性试验、传统设计方法与可靠性设计相结合等机械零件可靠性设计理论与方法的内涵,为机械零件可靠性设计提供系统的理论和方法.

  6. Evidence for a change in the radiation mechanism in the hard state of GRO J1655-40. Hysteresis in the broad-band noise components

    CERN Document Server

    Reig, P; Sobolewska, M A; Malzac, J

    2013-01-01

    We have analysed RXTE archival data to study the aperiodic variability of the black-hole binary GRO J1655-40 during the hard state of the 2005 outburst. We computed the 0.008-64 Hz power spectral density during the rise and decay of the 2005 outburst, and we found that they were reasonably well modelled by the sum of two, broad Lorenztian functions in most cases (plus a narrow QPO) which correspond to three different variability components. Our aim is to study the evolution of the timing properties of the source during the outburst, by studying the correlation between the characteristics of the broad-band noise components in the power spectra and the source luminosity. Our results suggest that the whole power spectrum shifts to high (low) frequencies as the source luminosity increases (decreases), in agreement with previous studies of other black hole binaries. However, we also detect a strong "hysteresis" pattern in the "frequency-luminosity" plots, and show that the "critical" luminosity limit, above which ...

  7. Fabrication of 13Cr-2Mo Ferritic/Martensitic Oxide-Dispersion-Strengthened Steel Components by Mechanical Alloying and Spark-Plasma Sintering

    Science.gov (United States)

    Bogachev, I.; Grigoryev, E.; Khasanov, O. L.; Olevsky, E.

    2014-06-01

    The outcomes of the mechanical alloying of 13Cr-2Mo ferritic/martensitic steel and yttria (oxide-dispersion-strengthened steel) powders in a ball mill are reported in terms of the powder particle size and morphology evolution. The optimal ball mill rotation speed and the milling time are discussed. The densification kinetics of the mechanically alloyed powder during the process of spark-plasma sintering is analyzed. An optimal set of the compaction processing parameters, including the maximum temperature, the dwell time, and the heating rate, is determined. The specifics of the densification are discussed in terms of the impact of major spark-plasma sintering parameters as well as the possible phase transformations occurring during compaction processing.

  8. Correlation between some thermo-mechanical and physico-chemical properties in multi-component glasses of Se-Te-Sn-Cd system

    Science.gov (United States)

    Kumar, Amit; Mehta, Neeraj

    2017-06-01

    The glass transition phenomenon is guided by the swift cooling of a melt (glass-forming liquid). Consequently, the glass as a final product consists of a considerable number of micro-voids having the size of the order of atomic and/or molecular sizes. The model of free volume fluctuation helps in describing the diverse physico-chemical properties of amorphous materials (like glasses and polymers). This theory is based on the fraction of fluctuation free frozen at the glass transition temperature and it forms a basis for determination of various significant thermo-mechanical properties. In the present work, Vickers hardness test method is employed that provides useful information concerning the mechanical behavior of brittle solids. The present work emphasizes the results of micro-indentation measurements on recently synthesized novel Se78- x Te20Sn2Cd x glassy system. Basic thermo-mechanical parameters such as micro-hardness, volume ( V h), formation energy ( E h) of micro-voids in the glassy network and modulus of elasticity ( E) have been determined and their variation with glass composition has been investigated.

  9. 大直径PLA长丝对3D打印构件力学性能的影响%Effect of Large-Diameter PLA Filament on MechanicalProperties of 3D Printing Component

    Institute of Scientific and Technical Information of China (English)

    权利军; 李丹丹; 赵勇; 祝成炎

    2017-01-01

    熔融沉积型3D打印机通过累积叠加大直径长丝形成构件,鉴于聚乳酸长丝在熔融沉积型3D打印机上的大量使用,本文重点研究了大直径聚乳酸长丝的直径、排列方式、排列密度对3D打印构件力学性能的影响.结果表明:聚乳酸长丝排列越紧密,所打印出构件的拉伸断裂强度越好;同等情况下,聚乳酸长丝以同心线方式排列的构件其拉伸断裂强度最好;当填充密度小于100%时,由0.4 mm聚乳酸长丝构成的3D打印构件机械性能更好.%FDM(fused deposition modeling) 3D printer forms the component through accumulating large-diameter filaments.In view of the extensive use of polylactic acid filaments in FDM 3D printer, the effects of diameter, arrangement and arrangement density of large-diameter polylactic acid filaments on the mechanical properties of 3D printing component were mainly studied in this paper.The experimental results demonstrate that the tensile failure strength of the polylactic acid filaments is better when the filaments are arranged closely;under the same conditions, the component with the arrangement mode of concentric line has the best tensile failure strength.When the packing density is less than 100%, the mechanical property of the component printed by the 0.4mm polylactic acid filament is better than that of the component printed by 0.2 mm polylactic acid filament.

  10. Effect of component substitution on the microstructure and mechanical properties of MCoCrFeNiTix (M = Cu,Al) solid-solution alloys

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    MCoCrFeNiTix (M = Cu,Al;x:molar ratio,x = 0,0.5) alloys were prepared using the new alloy-design strategy of equal-atomic ratio and high entropy.By the component substitution of Al for Cu,the microstructure changes from the face-centered cubic solid solution of original CuCoCrFeNiTix alloys to the body-centered cubic solid solution of AICoCrFeNiTix alloys.Compared with original CuCoCrFeNiTix alloys,AICoCrFeNiTix alloys keep the similar good ductility and simultaneously possess a much higher compressive strength,which are even superior to most of the reported high-strength alloys like bulk metallic glasses.

  11. The rigid shell component for superrotation in planetary atmospheres: Angular momentum budget, mechanical analog and simulation of the spin up process

    Science.gov (United States)

    Mayr, H. G.; Harris, I.

    1981-01-01

    An analysis of superrotation in the atmosphere of planets, with rotation axis perpendicular to the orbital plane is presented. As the atmosphere expands, Hadley cells develop producing a redistribution of mass and angular momentum. A three dimensional thermally driven zonally symmetric spectral model and Laplace transformation simulate the time evolution of a fluid leading from corotation under globally uniform heating to superrotation under globally nonuniform heating. For high viscosities the rigid shell component of atmospheric superrotation can be understood in analogy with a pirouette. During spin up angular momentum is transferred to the planet. For low iscosities, the process is reversed. A tendency toward geostrophy, combined with increase of surface pressure toward the poles (due to meridional mass transport), induces the atmosphere to subrotate temporarily at lower altitudes. Resultant viscous shear near the surface permits angular momentum to flow from the planet into the atmosphere propagating upwards to produce high altitude superrotation rates.

  12. Propolis and its Active Component, Caffeic Acid Phenethyl Ester (CAPE), Modulate Breast Cancer Therapeutic Targets via an Epigenetically Mediated Mechanism of Action.

    Science.gov (United States)

    Omene, Coral; Kalac, Matko; Wu, Jing; Marchi, Enrica; Frenkel, Krystyna; O'Connor, Owen A

    2013-10-21

    Alternative remedies for cancer treatment is a multi-billion dollar industry. In particular, breast cancer (BC) patients use alternative and natural remedies more frequently than patients with other malignancies. Propolis is an example of a honeybee-produced naturopathic formulation, contents of which differ by geographic location. It is readily available, affordable, and in use safely since ancient times globally. Caffeic acid phenethyl ester (CAPE) is a major active component in propolis and is thought to be responsible for its varied properties, including antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory and anticancer. CAPE is effective in many models of human cancer, including BC as we have previously shown. CAPE affects genes associated with tumor cell growth and survival, angiogenesis and chemoresistance. We demonstrate that these are related in part to CAPE's role as a histone deacetylase inhibitor, a class of drugs designated as epigenetic agents that modulate the activities of oncogenes and tumor suppressor genes. CAPE and propolis, cause an accumulation of acetylated histone proteins in MCF-7 (ER+) and MDA-MB-231 (ER-/PR-/Her2-) cells with associated decreases in ER and PR in MCF-7 cells, and upregulation of ER and decrease in EGFR in MDA-231 cells. In addition, these products reduced activated phosphorylated Her2 protein in SKBR3 (Her2 +) cells. Interestingly, propolis, when normalized for CAPE content, appears to be more potent than CAPE alone similarly to the greater effects of complete foods than isolated components. These data provide a potential mechanistic basis for one of the oldest naturopathic agents used in medicine and cancer treatment.

  13. Impact of Food Components on in vitro Calcitonin Gene-Related Peptide Secretion—A Potential Mechanism for Dietary Influence on Migraine

    Directory of Open Access Journals (Sweden)

    Margaret Slavin

    2016-07-01

    Full Text Available Calcitonin gene-related peptide (CGRP is a pivotal messenger in the inflammatory process in migraine. Limited evidence indicates that diet impacts circulating levels of CGRP, suggesting that certain elements in the diet may influence migraine outcomes. Interruption of calcium signaling, a mechanism which can trigger CGRP release, has been suggested as one potential route by which exogenous food substances may impact CGRP secretion. The objective of this study was to investigate the effects of foods and a dietary supplement on two migraine-related mechanisms in vitro: CGRP secretion from neuroendocrine CA77 cells, and calcium uptake by differentiated PC12 cells. Ginger and grape pomace extracts were selected for their anecdotal connections to reducing or promoting migraine. S-petasin was selected as a suspected active constituent of butterbur extract, the migraine prophylactic dietary supplement. Results showed a statistically significant decrease in stimulated CGRP secretion from CA77 cells following treatment with ginger (0.2 mg dry ginger equivalent/mL and two doses of grape pomace (0.25 and 1.0 mg dry pomace equivalent/mL extracts. Relative to vehicle control, CGRP secretion decreased by 22%, 43%, and 87%, respectively. S-petasin at 1.0 μM also decreased CGRP secretion by 24%. Meanwhile, S-petasin and ginger extract showed inhibition of calcium influx, whereas grape pomace had no effect on calcium. These results suggest that grape pomace and ginger extracts, and S-petasin may have anti-inflammatory propensity by preventing CGRP release in migraine, although potentially by different mechanisms, which future studies may elucidate further.

  14. VCP Is an integral component of a novel feedback mechanism that controls intracellular localization of catalase and H2O2 Levels.

    Directory of Open Access Journals (Sweden)

    Katsuhiro Murakami

    Full Text Available Catalase is a key antioxidant enzyme that catalyzes the decomposition of hydrogen peroxide (H2O2 to water and oxygen, and it appears to shuttle between the cytoplasm and peroxisome via unknown mechanisms. Valosin-containing protein (VCP belongs to the AAA class of ATPases and is involved in diverse cellular functions, e.g. cell cycle and protein degradation, etc. Here we show that VCP and PEX19, a protein essential for peroxisome biogenesis, interact with each other. Knockdown of either VCP or PEX19 resulted in a predominantly cytoplasmic redistribution of catalase, and loss of VCP ATPase activity also increased its cytoplasmic redistribution. Moreover, VCP knockdown decreased intracellular ROS levels in normal and H2O2-treated cells, and an oxidation-resistant VCP impaired the ROS-induced cytoplasmic redistribution of catalase. These observations reveal a novel feedback mechanism, in which VCP can sense H2O2 levels, and regulates them by controlling the localization of catalase.

  15. Aging of electrical components in nuclear power plants. Relationships between mechanical and chemical degradation after artificial aging and dielectric behaviour during LOCA

    Energy Technology Data Exchange (ETDEWEB)

    Spaang, K. [Ingemansson Tchnology AB, Goeteborg (Sweden)

    1997-10-01

    This study includes: (A) Extended thermal aging at 120 and 142 deg C. (B) LOCA testing on a selection of components which were aged in an earlier test. The cables included Lipalon type FSSR7x1, Daetwyler type FEAR-PG 8x(2x1) and Rockbestos Firewall 3, RXSR-G 5x1. The o-rings included two types, Viton and EPDM. Both had a diameter of 37,47 mm and a thickness of 5,34 mm. Coils of solenoids type Seitz 2A25, 110 VDC were used in some of the tests. Thermal aging was performed in dry heat test chambers, fulfilling the requirements for testing according to IEC Publ 68-2-2, test Bb: Dry heat testing of non heat-dissipating specimen. The irradiation test used a dose rate 10 kGy/h for 50 h. The measurement during LOCA testing included insulation resistance and dielectric loss factor. 4 refs, 48 figs, 42 tabs.

  16. Hypolipidaemic effects and mechanisms of the main component of Opuntia dillenii Haw. polysaccharides in high-fat emulsion-induced hyperlipidaemic rats.

    Science.gov (United States)

    Zhao, Long-Yan; Huang, Wei; Yuan, Qing-Xia; Cheng, Jie; Huang, Zhen-Chi; Ouyang, Le-Jun; Zeng, Fu-Hua

    2012-09-15

    The antihyperlipidaemic effects of ODP-Ia, one of the main components of Opuntia dillenii Haw. polysaccharides, were studied. Gavage administration of ODP-Ia was observed to significantly decrease serum lipid levels and to increase serum high-density lipoprotein cholesterol level in hyperlipidaemic rats. Similar suppressive patterns were also seen in hepatic total cholesterol and triglyceride levels. Moreover, the ODP-Ia administration significantly increased serum lecithin:cholesterol acyltransferase activity, increased the production of serum NO, inhibited hepatic HMG-CoA reductase activity, augmented serum and hepatic superoxide dismutase activities and decreased the serum and hepatic malondialdehyde contents in hyperlipidaemic rats. In addition, a histopathological examination revealed that ODP-Ia administration significantly suppressed inflammatory cell infiltration and the expression of VCAM-1. Together, these results indicate that ODP-Ia is a potential natural product for the treatment of hyperlipidaemia-related diseases by improving antioxidant levels, modulating the activities of enzymes involved in cholesterol metabolism, promoting the production of NO and suppressing the expression of VCAM-1, thereby suppressing lipid accumulation and inflammatory cell infiltration.

  17. Investigation of the Deposition and Densification Parameters on the Mechanical Properties of Pressurized Spray Deposited (PSD) 3-D Printed Ceramic Components

    Energy Technology Data Exchange (ETDEWEB)

    Menchhofer, Paul A [ORNL; Becker, Benjamin [Hot End Works

    2016-07-28

    Oak Ridge National Laboratory (ORNL) and HotEnd Works teamed to investigate the use of pressurized spray deposition (PSD) technology for the production of ceramic parts via additive manufacturing. Scanning electron microscopy of sintered parts provided by HotEnd Works revealed voids large enough to compromise the mechanical properties of PSD manufactured parts. Scanning electron microscopy and particle size analysis of the alumina oxide powder feedstocks indicated that the powders contained some large particles and some agglomerations in the powder. Further classification of the powder feedstocks and removal of the agglomerates by sonication in the liquid used for the PSD process are recommended. Analysis of sintered parts indicated that the sonic modulus for the alumina part is consistent with other known values for alumina. The density for this part was determined by standard Archimedes immersion density methods and was found to be > 99.7 % of the theoretical density for pure alumina.

  18. Effective components screening and anti-myocardial infarction mechanism study of the Chinese medicine NSLF6 based on "system to system" mode

    Directory of Open Access Journals (Sweden)

    Liang Qiong-Lin

    2012-02-01

    Full Text Available Abstract Background Shuanglong formula (SLF, a Chinese medicine composed of panax ginseng and salvia miltiorrhiza exhibited significant effect in the treatment of myocardial infarction (MI in clinical. Because of the complex nature and lack of stringent quality control, it's difficult to explain the action mechanism of SLF. Method In this study, we present a "system to system" (S2S mode. Based on this mode, SLF was simplified successively through bioactivity-guided screening to achieve an optimized minimal phytochemical composition (new formula NSLF6 while maintaining its curative effect for MI. Results Pharmacological test combining with the study of systems biology show that NSLF6 has activity for treatment MI through synergistic therapeutic efficacies between total ginsenosides and total salvianolic acids via promoting cardiac cell regeneration and myocardial angiogenesis, antagonistic myocardial cell oxidative damage. Conclusions The present S2S mode may be an effective way for the discovery of new composite drugs from traditional medicines.

  19. Assessment of strength-limiting flaws in ceramic heat exchanger components INEL support: Fracture mechanics and nondestructive evaluation technology. Final report, June 1, 1986--May 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, W.R.; Reuter, W.G.

    1993-06-01

    An examination of a siliconized SiC material, CS101K, has been performed to determine if linear fracture mechanics concepts can be used to characterize and predict the behavior of this material. Phase II of this project showed that a value that appeared to represent the true fracture toughness could be measured using small specimens with a machined notch, if the notch root radius was less than 75 {mu}m. Methods to produce sharply cracked specimens were then investigated to verify this hypothesis. A new technique, called the {open_quotes}beam support{close_quotes} precracking method, was subsequently developed and used to make sharply cracked SE(B) specimens. Tests of these specimens showed a slightly rising R-curve-type of behavior, with elevated values of plane strain fracture toughness. Interference of the crack surfaces in the precrack wake was hypothesized as the most likely cause of these phenomena. Subsequent testing with various precrack lengths provided preliminary verification of the hypothesis. Test results show that, for fracture mechanics-based design and assessment, adequate values of fracture toughness can be obtained from EDM-notched specimens, instead of the more costly precracked specimens. These results imply that, for the Si-SiC material tested, caution is warranted when using any of the methods of assessing fracture toughness that use a sharp precrack. It is also reasoned that these results may generally be more applicable to the coarser-grained structural ceramics that exhibit a rougher fracture surface. Based on results of testing EDM-notched bend specimens in 1250{degrees}C air, no degradation of material properties were observed for exposures, under applied stress, up to 900 h. Instead, some increase in fracture toughness was measured for these conditions. These same tests indicated that the threshold stress intensity factor for stress corrosion cracking (static fatigue) in the hot air environment was the same as the fracture toughness.

  20. Antibacterial activity and mechanism of action of Monarda punctata essential oil and its main components against common bacterial pathogens in respiratory tract.

    Science.gov (United States)

    Li, Hong; Yang, Tian; Li, Fei-Yan; Yao, Yan; Sun, Zhong-Min

    2014-01-01

    The aim of the current research work was to study the chemical composition of the essential oil of Monarda punctata along with evaluating the essential oil and its major components for their antibacterial effects against some frequently encountered respiratory infection causing pathogens. Gas chromatographic mass spectrometric analysis revealed the presence of 13 chemical constituents with thymol (75.2%), p-cymene (6.7%), limonene (5.4), and carvacrol (3.5%) as the major constituents. The oil composition was dominated by the oxygenated monoterpenes. Antibacterial activity of the essential oil and its major constituents (thymol, p-cymene, limonene) was evaluated against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Haemophilus influenzae and Escherichia coli. The study revealed that the essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against different strains. Among the tested strains, Streptococcus pyogenes, Escherichia coli and Streptococcus pneumoniae were the most susceptible bacterial strain showing lowest MIC and MBC values. Methicillin-resistant Staphylococcus aureus was the most resistant bacterial strain to the essential oil treatment showing relatively higher MIC and MBC values. Scanning electron microscopy revealed that the essential oil induced potent and dose-dependent membrane damage in S. pyogenes and MRSA bacterial strains. The reactive oxygen species generated by the Monarda punctata essential oil were identified using 2', 7'-dichlorofluorescein diacetate (DCFDA).This study indicated that the Monarda punctata essential oil to a great extent and thymol to a lower extent triggered a substantial increase in the ROS levels in S. pyogenes bacterial cultures which ultimately cause membrane damage as revealed by SEM results.

  1. Application of the results of pipe stress analyses into fracture mechanics defect analyses for welds of nuclear piping components; Uebernahme der Ergebnisse von Rohrsystemanalysen (Spannungsanalysen) fuer bruchmechanische Fehlerbewertungen fuer Schweissnaehte an Rohrleitungsbauteilen in kerntechnischen Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Dittmar, S.; Neubrech, G.E.; Wernicke, R. [TUeV Nord SysTec GmbH und Co.KG (Germany); Rieck, D. [IGN Ingenieurgesellschaft Nord mbH und Co.KG (Germany)

    2008-07-01

    For the fracture mechanical assessment of postulated or detected crack-like defects in welds of piping systems it is necessary to know the stresses in the un-cracked component normal to the crack plane. Results of piping stress analyses may be used if these are evaluated for the locations of the welds in the piping system. Using stress enhancing factors (stress indices, stress factors) the needed stress components are calculated from the component specific sectional loads (forces and moments). For this procedure the tabulated stress enhancing factors, given in the standards (ASME Code, German KTA regulations) for determination and limitation of the effective stresses, are not always and immediately adequate for the calculation of the stress component normal to the crack plane. The contribution shows fundamental possibilities and validity limits for adoption of the results of piping system analyses for the fracture mechanical evaluation of axial and circumferential defects in welded joints, with special emphasis on typical piping system components (straight pipe, elbow, pipe fitting, T-joint). The lecture is supposed to contribute to the standardization of a code compliant and task-related use of the piping system analysis results for fracture mechanical failure assessment. [German] Fuer die bruchmechanische Bewertung von postulierten oder bei der wiederkehrenden zerstoerungsfreien Pruefung detektierten rissartigen Fehlern in Schweissnaehten von Rohrsystemen werden die Spannungen in der ungerissenen Bauteilwand senkrecht zur Rissebene benoetigt. Hierfuer koennen die Ergebnisse von Rohrsystemanalysen (Spannungsanalysen) genutzt werden, wenn sie fuer die Orte der Schweissnaehte im Rohrsystem ausgewertet werden. Mit Hilfe von Spannungserhoehungsfaktoren (Spannungsindizes, Spannungsbeiwerten) werden aus den komponentenweise berechneten Schnittlasten (Kraefte und Momente) die benoetigten Spannungskomponenten berechnet. Dabei sind jedoch die in den Regelwerken (ASME

  2. Develop a Model Component

    Science.gov (United States)

    Ensey, Tyler S.

    2013-01-01

    During my internship at NASA, I was a model developer for Ground Support Equipment (GSE). The purpose of a model developer is to develop and unit test model component libraries (fluid, electrical, gas, etc.). The models are designed to simulate software for GSE (Ground Special Power, Crew Access Arm, Cryo, Fire and Leak Detection System, Environmental Control System (ECS), etc. .) before they are implemented into hardware. These models support verifying local control and remote software for End-Item Software Under Test (SUT). The model simulates the physical behavior (function, state, limits and 110) of each end-item and it's dependencies as defined in the Subsystem Interface Table, Software Requirements & Design Specification (SRDS), Ground Integrated Schematic (GIS), and System Mechanical Schematic.(SMS). The software of each specific model component is simulated through MATLAB's Simulink program. The intensiv model development life cycle is a.s follows: Identify source documents; identify model scope; update schedule; preliminary design review; develop model requirements; update model.. scope; update schedule; detailed design review; create/modify library component; implement library components reference; implement subsystem components; develop a test script; run the test script; develop users guide; send model out for peer review; the model is sent out for verifictionlvalidation; if there is empirical data, a validation data package is generated; if there is not empirical data, a verification package is generated; the test results are then reviewed; and finally, the user. requests accreditation, and a statement of accreditation is prepared. Once each component model is reviewed and approved, they are intertwined together into one integrated model. This integrated model is then tested itself, through a test script and autotest, so that it can be concluded that all models work conjointly, for a single purpose. The component I was assigned, specifically, was a

  3. Preclinical safety profile of trastuzumab emtansine (T-DM1): Mechanism of action of its cytotoxic component retained with improved tolerability

    Energy Technology Data Exchange (ETDEWEB)

    Poon, Kirsten Achilles, E-mail: achilles.kirsten@gene.com [Genentech, Inc., South San Francisco, CA (United States); Flagella, Kelly; Beyer, Joseph [Genentech, Inc., South San Francisco, CA (United States); Tibbitts, Jay [UCB, Brussels (Belgium); Kaur, Surinder; Saad, Ola; Yi, Joo-Hee; Girish, Sandhya; Dybdal, Noel; Reynolds, Theresa [Genentech, Inc., South San Francisco, CA (United States)

    2013-12-01

    Trastuzumab emtansine (T-DM1) is the first antibody-drug conjugate (ADC) approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. The therapeutic premise of ADCs is based on the hypothesis that targeted delivery of potent cytotoxic drugs to tumors will provide better tolerability and efficacy compared with non-targeted delivery, where poor tolerability can limit efficacious doses. Here, we present results from preclinical studies characterizing the toxicity profile of T-DM1, including limited assessment of unconjugated DM1. T-DM1 binds primate ErbB2 and human HER2 but not the rodent homolog c-neu. Therefore, antigen-dependent and non-antigen-dependent toxicity was evaluated in monkeys and rats, respectively, in both single- and repeat-dose studies; toxicity of DM1 was assessed in rats only. T-DM1 was well tolerated at doses up to 40 mg/kg (∼ 4400 μg DM1/m{sup 2}) and 30 mg/kg (∼ 6000 μg DM1/m{sup 2}) in rats and monkeys, respectively. In contrast, DM1 was only tolerated up to 0.2 mg/kg (1600 μg DM1/m{sup 2}). This suggests that at least two-fold higher doses of the cytotoxic agent are tolerated in T-DM1, supporting the premise of ADCs to improve the therapeutic index. In addition, T-DM1 and DM1 safety profiles were similar and consistent with the mechanism of action of DM1 (i.e., microtubule disruption). Findings included hepatic, bone marrow/hematologic (primarily platelet), lymphoid organ, and neuronal toxicities, and increased numbers of cells of epithelial and phagocytic origin in metaphase arrest. These adverse effects did not worsen with chronic dosing in monkeys and are consistent with those reported in T-DM1-treated patients to date. - Highlights: • T-DM1 was well tolerated in preclinical studies in rats and cynomolgus monkeys. • T-DM1 is associated with bone marrow/hematologic, hepatic, and neuronal toxicities. • T-DM1 toxicities are related to DM1 mechanisms of action and pharmacologic

  4. A review of the current studies on neural circuits and mechanisms underlying the affective component of pain%痛情绪的神经回路及其机制研究进展

    Institute of Scientific and Technical Information of China (English)

    卢波; 孙建良; 肖纯; 陈骏萍

    2016-01-01

    Background Pain is a complex experience,which consists of not only a sensory discriminative dimension but also an affective/motivational dimension.Although the neural systems responsible for the sensory component of pain have been studied extensively,the mechanism underlying pain affect is still unclear.Objective The aim of this article is to explore the neural circuits and mechanisms of the negative affective component of pain.Content This article reviews research advances in the neuronal mechanisms underlying pain-induced aversion.It focuses on the anterior cingulate cortex,amygdala,bed nucleus of the stria terminalis and other related brain regions involved in the processing of affective component of pain.Tread Persistent pain is frequently associated with psychological and emotional dysfunction,studies of the neural circuits and the molecular mechanisms involved in the affective component of pain may have considerable clinical importance in the treatment of chronic pain.%背景 疼痛是一种复杂的主观感觉和情绪体验,包括感觉分辨组分和情绪动机组分.目前,对痛感觉分辨的机制已有了较为深入的认识,但是痛情绪动机组分的具体机制仍不清楚. 目的 探讨痛情绪组分的中枢神经调控及其机制.内容 分别从痛情绪组分调控相关的前扣带回皮质、杏仁核、终纹床核等几方面阐述了痛情绪的神经回路及其机制研究进展.趋向 慢性病理性疼痛常常伴有心理和情绪功能障碍,研究痛情绪的神经回路及其分子机制对于慢性疼痛的治疗具有重要临床意义.

  5. RELIABILITY SENSITIVITY DESIGN FOR MECHANICAL COMPONENTS WITH MULTI-FAILURE MODES%多失效模式机械零部件可靠性灵敏度设计

    Institute of Scientific and Technical Information of China (English)

    张义民; 张旭方; 杨周; 黄贤振

    2009-01-01

    基于应力-强度干涉模型,应用概率摄动法及四阶矩技术,讨论多失效模式下机械零部件可靠性分析问题.利用灵敏度分析的梯度算法,确定各个随机参数对机械零部件可靠性灵敏度.在随机参数前四阶矩已知的情况下,放松对随机参数的分布概型限制,使之更接近于工程实际,从而为多失效模式作用下机械零部件可靠性分析和可靠性设计等方面提供理论依据和方法参考.%The failure criteria of reliability processes, which correspond to first excursion probabilities, are defined in terms of a single output state or system response function. However, for more general cases, failure criteria may be defined in terms of several output states. On the other hand, since most of mechanical components in engineering have common source of excitations, the different failure modes are mutually correlated. So the reliability solution for such mechanical components with failure dependencies has been an interesting and challenging subject. Sensitivity is one of the ways to evaluate the performance of structures when the design variables are under the influences of parametric changes. The reliability sensitivity design of structural responses represents an essential ingredient for gradient-based methods needed in structural reliability analysis, optimization, identification etc.An algorithm is presented for evaluating the analytical sensitivity of reliability for mechanical components with correlated failure modes. In doing so, based on the stress-strength interference model, probability perturbation theory and the fourth-order moments technology are extend to discuss the system reliability with multiple failure modes. The proposed formulation computes the analytical sensitivity gradient of reliability with respect to the random parameters. Then a numerical method for reliability sensitivity analysis is discussed and the effects of design parameters on system reliability are

  6. Kinetic and isotherm studies of bisphenol A adsorption onto orange albedo(Citrus sinensis): Sorption mechanisms based on the main albedo components vitamin C, flavones glycosides and carotenoids.

    Science.gov (United States)

    Kamgaing, Theophile; Doungmo, Giscard; Melataguia Tchieno, Francis Merlin; Gouoko Kouonang, Jimmy Julio; Mbadcam, Ketcha Joseph

    2017-07-03

    Orange albedo and its adsorption capacity towards bisphenol A (BPA) were studied. Adsorption experiments were conducted in batch mode at 25-55°C. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Fourier transform infrared (FTIR) spectroscopy were used to characterise the biosorbent. The effects of various parameters including adsorption time, equilibrium pH, adsorbent dosage and initial adsorbate concentration were investigated. The optimum contact time and pH for the removal of BPA were 60 min and 2, respectively. It was found that the adsorption isotherms best matched the Freundlich model, the adsorption of BPA being multilayer and that of the albedo surface heterogeneous. From the kinetic studies, it was found that the removal of BPA best matched the pseudo-second order kinetic model. An adsorption mechanism based on the albedo surface molecules is proposed and gives a good account of π-π interactions and hydrogen bonding. Orange albedo, with a maximum BPA loading capacity of 82.36 mg g(-1) (significantly higher than that of most agricultural residues), is a good candidate for BPA adsorption in aqueous media.

  7. Study of the mechanical properties of the electric power station components: the punch test; Etude des proprietes mecaniques des composants de centrales thermiques: l'essai punch test

    Energy Technology Data Exchange (ETDEWEB)

    Isselin, J

    2003-03-15

    The aging of the electric production park implies an increasing need of knowledge concerning the evolution of the mechanical properties of its components. With regard to this problem, the availability in material is more and more small. This work proposes to characterize these properties through a mechanical test called Punch test. The main characteristic of this test is to use very small volume samples. The development of this test has been carried out by the study of a 15 MDV 4-05 steel coming from a steam drum of a thermal power plant after 145000 hours of service. At first, we have measured the influence of the parameters of this test. Then, the study has dealt more particularly on the transition temperature of the material. With the finite element simulation method, the strain hardening coefficient of the material has been determined. (O.M.)

  8. 基于主成分分析法的碳市场交易机制影响因素%Influencing factors of trading mechanism of carbon market based on principal component analysis

    Institute of Scientific and Technical Information of China (English)

    顾英伟; 付信侠

    2012-01-01

    With the vigorous development of global trading of carbon dioxide emission rights,the scale of carbon trading market expands rapidly,and various countries established their carbon trading market one after another.As China being the signatory country of "Kyoto Protocol",it is imperative to establish transaction mechanism and platform for market participants,i.e.,an effective trading mechanism of carbon market in China.PEST analytic model is applied to analyze the macroscopic environmental factors,an evaluating indicator system is established according to the influencing factors of trading mechanism of carbon market,and principal component analysis with SPSS software is used to extract 4 principal components which can reflect overall information of indicators,in order to provide guidance for enterprises.%随着全球二氧化碳排放权交易的蓬勃发展,碳交易市场规模迅速膨胀,各国纷纷建立碳交易市场。我国作为《京都议定书》的签字国,为市场参与者建立交易的机制和平台,即建立一个有效的碳市场交易机制势在必行。应用PEST分析模型对宏观环境因素进行分析,针对碳市场交易机制的影响因素建立评价指标体系,并运用SPSS软件的主成分分析法进一步提取出4个主成分用以反映全部指标信息,以期为企业提供指导性意见。

  9. Further development of the structure mechanics analysis method for the calculation of the structure reliability of passive components, phase II. Final report; Weiterentwicklung der strukturmechanischen Analysemethodik zur Bestimmung der Strukturzuverlaessigkeit passiver Komponenten, Phase II. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grebner, H.; Wang, Y.; Schmipfke, T.; Sievers, J.

    2010-06-15

    Within the framework of research project RS 1163 the computer code PROST for the quantitative assessment of the structural reliability of pipe components has been further developed. Thereby models were provided and tested for the consideration of the damage mechanism 'corrosion' to determine leak and break probabilities in cylindrical structures of ferritic and austenitic reactor steels. These models are now additionally available to the model for the consideration of the damage mechanism 'fatigue'. Furthermore, the application range of the code was extended to complex geometries in regards to loading and boundary conditions. Additional code modules were developed to be able to include the results of finite element (FE) calculations. The extended analysis method was tested, amongst others, in the context of calculations for a cracked feedwater nozzle of a steam generator under thermal-mechanical cyclic loading. The stress on cracks was calculated with the FE-method. For the determination of leak probabilities the crack growth due to fatigue was estimated taking into account the ''mixed-mode'' - loading within the J-integral vector approach. Altogether, the analyses show that with the provided flexible probabilistic analysis method quantitative determination of leak probabilities of a detected or postulated crack in a complex structure geometry under thermal-mechanical loading as function of the operating time in the range of very small probability values (<1.0 E-8) to large values (>1.0 E-2) are possible. The next development steps should comprise especially the improvement of the accuracy of the method to determine break probabilities and also the consideration of approaches on crack formation due to the damage mechanisms 'fatigue' and 'corrosion', based on evaluations of national and international operating experiences.

  10. Possible involvement of membrane lipids peroxidation and oxidation of catalytically essential thiols of the cerebral transmembrane sodium pump as component mechanisms of iron-mediated oxidative stress-linked dysfunction of the pump's activity

    Directory of Open Access Journals (Sweden)

    T.I. Omotayo

    2015-04-01

    Full Text Available The precise molecular events defining the complex role of oxidative stress in the inactivation of the cerebral sodium pump in radical-induced neurodegenerative diseases is yet to be fully clarified and thus still open. Herein we investigated the modulation of the activity of the cerebral transmembrane electrogenic enzyme in Fe2+-mediated in vitro oxidative stress model. The results show that Fe2+ inhibited the transmembrane enzyme in a concentration dependent manner and this effect was accompanied by a biphasic generation of aldehydic product of lipid peroxidation. While dithiothreitol prevented both Fe2+ inhibitory effect on the pump and lipid peroxidation, vitamin E prevented only lipid peroxidation but not inhibition of the pump. Besides, malondialdehyde (MDA inhibited the pump by a mechanism not related to oxidation of its critical thiols. Apparently, the low activity of the pump in degenerative diseases mediated by Fe2+ may involve complex multi-component mechanisms which may partly involve an initial oxidation of the critical thiols of the enzyme directly mediated by Fe2+ and during severe progression of such diseases; aldehydic products of lipid peroxidation such as MDA may further exacerbate this inhibitory effect by a mechanism that is likely not related to the oxidation of the catalytically essential thiols of the ouabain-sensitive cerebral electrogenic pump.

  11. Development of standard components for remote handling

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, Kou; Kakudate, Satoshi; Nakahira, Masataka; Ito, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    The core of Fusion Experimental Reactor consists of various components such as superconducting magnets and forced-cooled in-vessel components, which are remotely maintained due to intense of gamma radiation. Mechanical connectors such as cooling pipe connections, insulation joints and electrical connectors are commonly used for maintenance of these components and have to be standardized in terms of remote handling. This paper describes these mechanical connectors developed as the standard component compatible with remote handling and tolerable for radiation. (author)

  12. Effect of plastic deformation on the structure and mechanical properties of an ultra-low carbon interstitial-free steel in the monolithic material and as a component of a sandwich composite

    Science.gov (United States)

    Gladkovsky, S. V.; Kuteneva, S. V.; Kamantsev, I. S.; Sergeev, S. N.; Safarov, I. M.

    2016-10-01

    The structure and mechanical properties of ultra-low carbon interstitial-free (IF) steel in the annealed state, after warm and cold rolling, and as a component of seven-layer steel-aluminum composite have been studied. A comparative analysis of the results of structural studies using optical microscopy and scanning and transmission electron microscopy have revealed the possibility of the formation of an ultrafinegrained structure in a steel layer during rolling at temperatures ranging from room temperature to 520°C. It has been found that the seven-layer composite has higher strength properties as compared to monolithic samples of the IF steel after analogous regime of the warm rolling.

  13. Mechanical design

    CERN Document Server

    Risitano, Antonino

    2011-01-01

    METHODOLOGICAL STATEMENT OF ENGINEERING DESIGNApproaches to product design and developmentMechanical design and environmental requirementsPROPERTIES OF ENGINEERING MATERIALSMaterials for mechanical designCharacterization of metalsStress conditionsFatigue of materialsOptimum material selection in mechanical designDESIGN OF MECHANICAL COMPONENTS AND SYSTEMSFailure theoriesHertz theoryLubrificationShafts and bearingsSplines and keysSpringsFlexible machine elementsSpur gearsPress and shrink fitsPressure tubesCouplingsClutchesBrakes

  14. Effect of Oxidant on Mechanical Properties of Four Component HTPB Propellant%氧化剂对四组元HTPB推进剂力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    祝世杰; 王菲; 范晓峰

    2015-01-01

    In order to explore the influence of oxidant on the mechanical properties of the four component HTPB composite solid propellant, the uniaxial tensile test results of HTPB propellant under the condition of 50℃, 20℃ and-40℃ were taken. The analysis results show that different oxidant, the same gradation of different batches and different curing time, have great influence on the mechanical properties of the four components of HTPB composite solid propellant, at the same time the crack of the propellant is mainly manifested in the oxide interface and the stress concentration is near the particle.%为了探寻氧化剂对四组元HTPB复合固体推进剂力学性能的影响方式和机理,采取对50℃、20℃和-40℃条件下的HTPB推进剂试件单轴拉伸试验结果和拉伸试件断面电镜照片对比分析方法.分析结果表明,氧化剂不同级配、相同级配不同批次及不同固化时间,对四组元HTPB复合固体推进剂相关力学性能有较大影响,同时推进剂的裂断主要表现在氧化剂界面的剥离,细氧化剂颗粒附近存在应力集中.

  15. Compression-bending of multi-component semi-rigid columns in response to axial loads and conjugate reciprocal extension-prediction of mechanical behaviours and implications for structural design.

    Science.gov (United States)

    Lau, Ernest W

    2013-01-01

    The mathematical modelling of column buckling or beam bending under an axial or transverse load is well established. However, the existent models generally assume a high degree of symmetry in the structure of the column and minor longitudinal and transverse displacements. The situation when the column is made of several components with different mechanical properties asymmetrically distributed in the transverse section, semi-rigid, and subjected to multiple axial loads with significant longitudinal and transverse displacements through compression and bending has not been well characterised. A more comprehensive theoretical model allowing for these possibilities and assuming a circular arc contour for the bend is developed, and used to establish the bending axes, balance between compression and bending, and equivalent stiffness of the column. In certain situations, such as with pull cable catheters commonly used for minimally invasive surgical procedures, the compression loads are applied via cables running through channels inside a semi-rigid column. The model predicts the mathematical relationships between the radius of curvature of the bend and the tension in and normal force exerted by such cables. Conjugate extension with reciprocal compression-bending is a special structural arrangement for a semi-rigid column such that extension of one segment is linked to compression-bending of another by inextensible cables running between them. Leads are cords containing insulated electrical conductor coil and cables between the heart muscle and cardiac implantable electronic devices. Leads can behave like pull cable catheters through differential component pulling, providing a possible mechanism for inside-out abrasion and conductor cable externalisation. Certain design features may predispose to this mode of structural failure. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 红条茶加工过程中茶黄素组分的动态变化%The Dynamic Mechanism of Theaflavin Components in Black tea Processing

    Institute of Scientific and Technical Information of China (English)

    龚志华; 刘昆言; 刘林峰; 向奕; 丰金玉

    2016-01-01

    By using one bud two leaves spring leaves of Political and white tea which was suitable for Black tea processing as material, the enzyme activity and its ratio of PPO and POD during processing of black tea were analy to discusses the catechins components and thealfavin components dynamic mechanism. The results indicated that in withering process PPO and POD enzyme activity reach to the maximum in the withering stage ,after the continued decline, catechins decreased slightly, thealfavins component TF to rise slightly, PPO/POD ratio decreased from 0.78 to 0.33;In rolling process, catechin content decreased faster, ECG, GCG, EC decreased greatly, theaflavin components rapid rise, the biggest and the growth of TFDG, the ratio of PPO/POD to 0.28;In fermenting process, catechin composition content decreased with rolling period slow, thealfavin components and the total fermentation in the 4 h reached a maximum value, then started to decline, the ratio of PPO/POD in the fermentation of 3 h down to a minimum of 0.27, then began to rise; In drying process, catechin content slightly reduced, which EGCG the largest decline, thealfavins composition decreased, its total to 0.47%dry weight, PPO/POD ratio increased to 0.47.From the results of this study shows, can be considered in the processing of black tea thealfavins catechin components and component variation is PPO and POD enzyme activity and its ratio of driven results,and can determine the withering, rolling, fermenting, drying process appropriate standards according to the ratio of PPO/POD.%以适制红茶茶树品种政和大白茶春季一芽二叶新梢为原料,通过分析其红条茶加工中多酚氧化酶(PPO)、过氧化物酶(POD)酶活性及其比值,探讨儿茶素组分与茶黄素组分动态变化。结果表明,萎凋期间,PPO、POD酶活性在萎凋末期达到最大值,儿茶素总量小幅下降,茶黄素组分TF小幅上升,PPO/POD比值从0.78下降到0.33;揉捻阶段,儿

  17. 机械装备构件轻量化主要技术途径的探讨%On the Main Technical Ways to Lightweight Mechanical Equipment Components

    Institute of Scientific and Technical Information of China (English)

    钟群鹏; 有移亮; 张峥; 吴素君; 骆红云

    2012-01-01

    在对机械装备构件轻量化的基本原则和主要技术依据进行概括的基础上,就机械装备构件轻量化强度设计技术进行探讨,分别在简单拉伸、弯曲、扭转、疲劳等受力状态下,对简单形状构件轻量化强度设计判据进行分析,并进一步得到构件轻量化强度设计通用判据;对铁、钛、铝、镁、钴等金属基体合金轻量化性能指标进行比较,并进一步提出逐步建立构件轻量化材料性能指标体系的设想;对机械装备构件轻量化成形工艺和表面改性技术的作用进行概括,并提出通过工艺技术提高构件材料的强度(或屈服强度)、提高构件截面形状的抗弯截面系数(或抗扭截面系数)、提高表面层材料的强度(或屈服强度)和改变构件表面为压应力状态等工艺途径来达到构件轻量化目的.%The basic principles and main technologies of lightweight mechanical equipment components are summarized. The strength design technologies for lightweight structures are discussed based upon the analysis of simple shape components strength design criteria under simple tension, bending, torsion and fatigue, which extended to the general lightweight structure strength design principles. The lightweight properties of iron, titanium, aluminum, magnesium and cobalt based alloys are compared, and the gradual establishment of lightweight components materials performance indicators system is proposed. The lightweight molding process and surface modification technique are summarized. It is concluded that, to realize the lightweight purpose for the mechanical equipment structures, the optimal processing technique must be employed to improve the strength (or yield strength), bending section modulus (or torsion section modulus), surface strength (or yield strength) and compressive stress state of surface.

  18. 考虑构件弹性的电动Stewart并联机构刚度建模与仿真%Stiffness modeling and simulation for an electric stewart parallel mechanism considering elasticity of components

    Institute of Scientific and Technical Information of China (English)

    吕帮俊; 彭利坤; 熊先锋

    2013-01-01

    基于集总解析建模方法和构件有限元分析建立包含驱动副、被动万向铰链和运动杆件弹性变形以及预载作用下的Stewart机构刚度矩阵模型.采用添加虚拟铰链等效构件弹性的方式,将分支等效为一系列刚性构件经由主、被动副以及虚拟铰链连接的形式,给出了运动关节和虚拟铰链变量对机构末端位姿的运动学Jacobian矩阵的数值计算方法,应用虚功原理得到静平衡方程,最终建立了机构无预载以及预载下的刚度矩阵模型.该模型不仅考虑了控制环路刚度,还将构件柔性的有限元分析结果与解析建模相结合,在降低计算成本的同时保证了精度.通过—机构分析实例,考察了两种模型下刚度分布的差异.%Based on lumped modeling and finite element analysis,the stiffness model of a Stewart mechanism was established considering elastic deformations of driving joints,passive universal joints and moving components and the effect of preloading.By adding virtual joints to describe the elasticity of components,a branch was equivalent to a series of rigid components connected with active,passive and virtual joints.The numerical method for moving and virtual joints' kinematic Jacobian matrix was developed.The static balance equation was obtained by applying the principle of virtual work,and the stiffness matrices of the mechanism without/under preloading were established.The proposed model considered the control loop stiffness,and combined the result of the finite element analysis with the analytical modeling.The computation cost was reduced while the accuracy was ensured.The stiffness distribution differences between the with/without preloading two models were examined with an example.

  19. Research on Cooperation Mechanism between Key Components Suppliers in Mega Project%重大工程关键部件供应商合作机制研究

    Institute of Scientific and Technical Information of China (English)

    时茜茜; 朱建波; 盛昭瀚; 陶莎

    2015-01-01

    针对重大工程关键部件供应商的合作问题,基于演化视角建立供应商的合作博弈模型,分析双方合作的影响因素,并进一步构建业主参与下的激励与惩罚机制,对其影响因素进行探讨. 研究结果表明,合作生产的超额收益与不合作时支付的租金的增加对双方合作有促进作用,合作投资成本与"搭便车"收益的增加则不利于博弈双方走向合作,投资成本的合理分担与业主参与下有效的激励和惩罚机制可以降低"搭便车"行为的产生,促进供应商间的合作.%By the evolutionary game theory, this paper researched on the cooperation mechanism between key components sup-pliers in mega project, and analyzed the influence factors of bilateral cooperation, and then studied the impact of the incentive and punishment mechanism when the owner participated in. Result showed that, the probability of cooperation of both sides had a positive correlation with excess income of cooperation and the rent paid when non-collaboration, and a negative correla-tion with cost of investment and extra income obtained by free-rider behavior. Reasonable sharing of investment cost and the incentive and punishment mechanism can control the free-rider behavior and promote the cooperation between suppliers.

  20. Laser generating metallic components

    Science.gov (United States)

    McLean, Marc A.; Shannon, G. J.; Steen, William M.

    1997-04-01

    Recent developments in rapid prototyping have led to the concept of laser generating, the first additive manufacturing technology. This paper presents an innovative process of depositing multi-layer tracks, by fusing successive powder tracks, to generate three dimensional components, thereby offering an alternative to casting for small metal component manufacture. A coaxial nozzle assembly has been designed and manufactured enabling consistent omni-directional multi-layer deposition. In conjunction with this the software route from a CAD drawing to machine code generation has been established. The part is manufactured on a six axes machining center incorporating a 1.8 kW carbon-dioxide laser, providing an integrated opto-mechanical workstation. The part build-up program is controlled by a P150 host computer, linked directly to the DNC machining center. The direct manufacturing route is shown, including initial examples of simple objects (primitives -- cube, cylinder, cone) leading to more complex turbine blade generation, incorporating build-up techniques and the associated mechanical properties.

  1. Comparison of mechanical properties obtained from conventional strength specimens and from as-sintered components%用常规强度试样与粉末冶金零件测定的力学性能的比较

    Institute of Scientific and Technical Information of China (English)

    Lorenz S.Sigl; Patrice Delarbre; Ulrike Jehring; 韩风麟

    2013-01-01

    由于零件的强度难以试验测定,因此通常都不使用这些数据.这篇论文介绍了一种可直接测定零件强度的新方法.这种方法是采用水射流切割(Water-jet Cutting),从零件上切割小型矩形试棒(尺寸约为40mm×5mm×5mm),经磨加工制备成试棒,用于测定力学性能.这篇论文将由高合金化Fe(Mo)-Ni-Cu粉末冶金钢制造的同步器齿毂作为典型零件,用由其上切割制成的矩形试棒测定了抗拉强度、冲击强度与三点弯曲的横向断裂强度,并将其和用常规拉伸试样(DIN EN ISO 2740)测定的强度与冲击性能进行了比较.由零件试棒和常规试样测定的性能完全一致,都在试验误差范围之内.为证明比较的有效性,还通过全面的化学与显微组织鉴定,对两种试样的相似性进行了核实.采用新方法评定了生产工艺变量对同步器齿毂的力学性能的影响.建立了小拉伸试棒的横向断裂强度与抗拉强度之间的相互关系.%Experimental access to the in-situ strength properties of components is difficult,which explains why such data are not generally available.The present paper introduces a new methodology which permits direct access to the strength properties of components.Such information is retrieved from small rectangular(40mm × 5mm × 5mm)which are prepared directiy from a component by water-jet cutting and subsequent grinding.Using a synchronizer-hub as a typical P/M component,the tensile strength,the impact resistance and the transverse rupture strength in 3-point bending were evaluated from these bars for a high-alloyed Fe (Mo)-Ni-Cu P/M steel,and compared to the strength and impact properties of conventional tensile specimens (DIN EN ISO 2740).Within the limits of experimental error,the data sets obtained from components and specimens are fully consistent.To confirm the validity of the comparison,the similarity of both specimen types is verified by a comprehensive chemical and microstructural

  2. Intervention analysis of a large number of component blood transfusion on blood coagulation mechanism%大量成分输血对患者凝血机制的干预分析

    Institute of Scientific and Technical Information of China (English)

    董永光

    2014-01-01

    目的:探讨大量成分输血对患者凝血机制的干预。方法73例大量成分输血患者,输注悬浮红细胞量平均11 U,输注冰冻血浆量平均8 U。输血前、输血后4 h检测凝血指标。结果73例患者输血前后凝血因子差异有统计学意义(P均<0.01);血小板显著下降,差异有统计学意义(P<0.01)。结论大量成分输血对凝血功能有重要影响,应及时检测凝血因子及血小板,并通过血液加温以及针对性的补充血小板和凝血因子来减少出血风险。%ObjectiveTo analyze intervention of a large number of component blood transfusion on blood coagulation mechanism.MethodsRetrospectively analyzed clinical data of 73 patients with a large number of component blood transfusion. The infusion of suspension red blood cell volume average of 11 U, infusion of average frozen plasma volume of 8 U. Blood clotting index 4 h before and after blood transfusion was detected.Results73 cases of patients before and after blood transfusion blood coagulation factor had significant changes, the difference was statistically significant(P<0.01), blood platelet reducted significantly, the difference was statistically significant(P<0.01).ConclusionA large number of component blood transfusion has important influence on blood coagulation function, blood platelet and clotting factors should be timely detected, and through blood heat and corresponding platelet and blood coagulation factor supplementary to reduce risk of bleeding.

  3. Variability and component composition

    NARCIS (Netherlands)

    Storm, T. van der

    2004-01-01

    In component-based product populations, feature models have to be described at the component level to be able to benefit from a product family approach. As a consequence, composition of components becomes very complex. We describe how component-level variability can be managed in the face of compone

  4. 基于主成分分析的湿疹效应机制研究%Research of the Effect Mechanism of Eczema Based on principal Component Analysis

    Institute of Scientific and Technical Information of China (English)

    温伟为; 王玉

    2015-01-01

    Objective To investigate the roles of various indicators in the effect mechanism of eczema and to build the mathematic model of the effect mechanism of eczema by the dimensionality reduction of various indicators of eczema. Methods Conducted a respective analysis of the clinical data of 90 patients who were diagnosed with eczema in the Third People's Hospital of Hangzhou from March 2013 to February 2014. Selected 19 representative indicators,including white blood cell count( X1 ), lymphocyte score ( X2 ), neutrophile granulocyte score ( X3 ), eosinophilic granulocyte score ( X4 ), the absolute value of eosinophilic granulocyte( X5 ),the absolute value of monocyte( X6 ),immunoglobulin E( X7 ),immunoglobulin A( X8 ), immunoglobulin G( X9 ),immunoglobulin M( X10 ),complement C3 ( X11 ),complement C4 ( X12 ),C -reaction protein ( X13 ),antistreptolysin O ( X14 ), erythrocyte sedimentation rate ( X15 ), T Lymphocyte ( X16 ), B lymphocytes ( X17 ), inhibiting /cytotoxic T cells(X18),helper T cell(X19). The SPSS 16. 0 statistical software was employed to conduct principal component analysis and factor analysis. Results According to the results of the analyses,we extracted 6 principle components, with an accumulated variance contribution rate of 84. 30%. Based on the principle component analysis,we build the mathematic model of the effect mechanism of eczema, which was F =37. 69%F1 +21. 02%F2 +17. 10%F3 +8. 65%F4 +8. 48%F5+7. 07%F6 . Conclusion The application of principle component analysis could avoid the troublesome effort of statistics and analysis required by multi-index comprehensive assessment,reduce the number of variables,remove redundant information, and enable the model to better reflect real condition. It also makes the most use of laboratory data and important details closely relevant with the efficacy characteristics,improves the accuracy and reproducibility of laboratory results,and helps with the extraction of major effect mechanism of eczema.%目的:研

  5. Near-term hybrid vehicle program, phase 1. Appendix B: Design trade-off studies. [various hybrid/electric power train configurations and electrical and mechanical drive-line components

    Science.gov (United States)

    1979-01-01

    The relative attractiveness of various hybrid/electric power train configurations and electrical and mechanical drive-line components was studied. The initial screening was concerned primarily with total vehicle weight and economic factors and identified the hybrid power train combinations which warranted detailed evaluation over various driving cycles. This was done using a second-by-second vehicle simulation program which permitted the calculations of fuel economy, electricity usage, and emissions as a function of distance traveled in urban and highway driving. Power train arrangement possibilities were examined in terms of their effect on vehicle handling, safety, serviceability, and passenger comfort. A dc electric drive system utilizing a separately excited motor with field control and battery switching was selected for the near term hybrid vehicle. Hybrid vehicle simulations showed that for the first 30 mi (the electric range of the vehicle) in urban driving, the fuel economy was 80 mpg using a gasoline engine and 100 mpg using a diesel engine. In urban driving the hybrid would save about 75% of the fuel used by the conventional vehicle and in combined urban/highway driving the fuel saving is about 50%.

  6. Sprayed skin turbine component

    Science.gov (United States)

    Allen, David B

    2013-06-04

    Fabricating a turbine component (50) by casting a core structure (30), forming an array of pits (24) in an outer surface (32) of the core structure, depositing a transient liquid phase (TLP) material (40) on the outer surface of the core structure, the TLP containing a melting-point depressant, depositing a skin (42) on the outer surface of the core structure over the TLP material, and heating the assembly, thus forming both a diffusion bond and a mechanical interlock between the skin and the core structure. The heating diffuses the melting-point depressant away from the interface. Subsurface cooling channels (35) may be formed by forming grooves (34) in the outer surface of the core structure, filling the grooves with a fugitive filler (36), depositing and bonding the skin (42), then removing the fugitive material.

  7. A comparative study of elemental components and mechanical properties of beta-titanium alloy wires%四种Beta-钛正畸弓丝合金成分及力学性能的比较研究

    Institute of Scientific and Technical Information of China (English)

    张颖; 李兴; 杨凯; 尤力; 宋西平

    2011-01-01

    目的 比较四种Beta-钛正畸弓丝的合金成分及力学性能,为临床选择提供参考.方法 选用EDAX X-射线能谱分析仪,联合SUPRA55热场发射扫描电子显微镜(SEM)分析弓丝的合金元素成分.采用纳米压痕技术测定弓丝纳米弹性模量及硬度;采用三点弯曲试验方法测定弓丝负荷-形变曲线,比较弓丝的力学性能.结果 四种Beta-钛丝合金成分中均含有Ti、Zr、Mo、Sn四种元素,Ti在四种Beta-钛丝中所占比重均高于70%.Ormco和Masel公司的Beta-钛丝弹性模量小于Smart与GAC公司的Beta-钛丝.GAC的Beta-钛丝硬度最大.当形变3mm的负荷完全去除时,四种Beta-钛丝均有残余形变,Smart和Ormco大于GAC和Masel公司的Beta-钛丝残余形变.结论 四种Beta-钛丝合金成分基本相同,力学性能有一定差异,可根据临床实际情况选取合适弓丝.%Objective To compare the elemental components and mechanical properties of Beta-titanium alloy wires from four different companies. Methods Beta-titanium alloy wires from Ormco, Masel, Smart and GAC company were selected in this study. Energy dispersive microanalysis of X-RAY and SUPRATm55 scanning electron microscope were used to analyze the alloy compositions. Nano Indenter XP was used to test elasticity modulus and hardness of Beta-titanium alloy wires. Three-Bending Test was performed to compare the differences in mechanical properties. Results All the wires tested contained Ti,and Ti accounted for more than 70% in weight. The values of elasticity modulus were lower in Ormco and Masel than in GAC and Smart The value of hardness was highest in GAC. There were residual deformations in all the wires when unloaded from 3mm deflection. The residual deformation was larger in Smart and Ormco than in GAC and MaseL Conclusion The elemental components of four kinds of Beta-titanium alloy wires were almost the same, but differences existed in mechanical properties. It suggests that we choose proper wires

  8. Indexing Mount For Rotation Of Optical Component

    Science.gov (United States)

    Reichle, Donald J., Jr.; Barnes, Norman P.

    1993-01-01

    Indexing mount for polarizer, wave plate, birefringent plate, or other optical component facilitates rotation of component to one or more preset angles. Includes hexagonal nut holding polarizer or other optical component. Ball bearing loaded by screw engages notch on cylindrical extension of nut engaging bracket. Time-consuming and tedious angular adjustment unnecessary: component turned quickly and easily, by hand or by use of wrench, to preset angular positions maintained by simple ball-detent mechanism.

  9. Component Fragility Research Program: Phase 1 component prioritization

    Energy Technology Data Exchange (ETDEWEB)

    Holman, G.S.; Chou, C.K.

    1987-06-01

    Current probabilistic risk assessment (PRA) methods for nuclear power plants utilize seismic ''fragilities'' - probabilities of failure conditioned on the severity of seismic input motion - that are based largely on limited test data and on engineering judgment. Under the NRC Component Fragility Research Program (CFRP), the Lawrence Livermore National Laboratory (LLNL) has developed and demonstrated procedures for using test data to derive probabilistic fragility descriptions for mechanical and electrical components. As part of its CFRP activities, LLNL systematically identified and categorized components influencing plant safety in order to identify ''candidate'' components for future NRC testing. Plant systems relevant to safety were first identified; within each system components were then ranked according to their importance to overall system function and their anticipated seismic capacity. Highest priority for future testing was assigned to those ''very important'' components having ''low'' seismic capacity. This report describes the LLNL prioritization effort, which also included application of ''high-level'' qualification data as an alternate means of developing probabilistic fragility descriptions for PRA applications.

  10. Evaluation and Safety Control Mechanism of Endotoxin Detection in Whole Blood and Blood Components%全血和成分血内毒素检测评估及其安全控制机制的评价

    Institute of Scientific and Technical Information of China (English)

    鲍自谦; 刘怡

    2013-01-01

    Objective Through dynamic monitoring bacterial endotoxin and cultivating whole blood and blood components,consistence between endotoxin level and bacterial culture results,association between the clinic fever reaction and blood endotoxin were evaluated.Furthermore,the effectiveness of safety control mechanism on bacterium and endotoxin was assessed.Methods From March to April 2009,a total of 300 blood samples of volunteer donors from our blood center were included in this study.Based on the sample varieties,all of these samples were divided into 3 groups:the whole blood group (n=50),suspended red blood cell (RBC) components group (n=150) and platelet (PLT) components group (n=100).Meanwhile 361 healthy donors from the street during January to February 2009,were chosen as a control group,and their endotoxin results would be used as normal reference range.Dynamic turbidity was used as the quantitative detection method of bacterial endotoxin.Endotoxin content in each group was individually detected during their blood preservations.And the endotoxin content results of each group in different blood preservation period and their bacterial cultivating results were analyzed by variance of repeated measurement data.Moreover,the samples from clinical transfusion fever reaction were detected for endotoxin level.Results Normal blood endotoxin reference range from the control group was (0-0.193) EU/mL.PLT suspension group (W=0.635,P =0.0585),and suspended RBC group (W =0.334,P =0.583) had no significant differences in endotoxin concentration of three periods.There were significant differences in endotoxin in whole blood group of three periods (W=0.860,P=0.014).The endotoxin level of whole blood and blood components was (0.005-0.188) EU/mL,and all bacterial cultivating results were negative.Endotoxin concentration in blood samples of transfusion fever reaction was (0.023-0.145) EU/mL.Conclusions While cultivating results of whole blood and blood components were negative

  11. Bone remodelling around a cementless glenoid component

    NARCIS (Netherlands)

    Suarez, D.R.; Weinans, H.; Van Keulen, F.

    2012-01-01

    Post-operative change in the mechanical loading of bone may trigger its (mechanically induced) adaptation and hamper the mechanical stability of prostheses. This is especially important in cementless components, where the final fixation is achieved by the bone itself. The aim of this study is,

  12. Bone remodelling around a cementless glenoid component

    NARCIS (Netherlands)

    D.R. Suárez (Daniel); H.H. Weinans (Harrie); F. van Keulen (Fred)

    2012-01-01

    textabstractPost-operative change in the mechanical loading of bone may trigger its (mechanically induced) adaptation and hamper the mechanical stability of prostheses. This is especially important in cementless components, where the final fixation is achieved by the bone itself. The aim of this

  13. Optical communication components

    Science.gov (United States)

    Eldada, Louay

    2004-03-01

    We review and contrast key technologies developed to address the optical components market for communication applications. We first review the component requirements from a network perspective. We then look at different material systems, compare their properties, and describe the functions achieved to date in each of them. The material systems reviewed include silica fiber, silica on silicon, silicon on insulator, silicon oxynitride, sol-gels, polymers, thin-film dielectrics, lithium niobate, indium phosphide, gallium arsenide, magneto-optic materials, and birefringent crystals. We then describe the most commonly used classes of optical device technology and present their pros and cons as well as the functions achieved to date in each of them. The technologies reviewed include passive, actuation, and active technologies. The passive technologies described include fused fibers, dispersion-compensating fiber, beam steering, Bragg gratings, diffraction gratings, holographic elements, thin-film filters, photonic crystals, microrings, and birefringent elements. The actuation technologies include thermo-optics, electro-optics, acousto-optics, magneto-optics, electroabsorption, liquid crystals, total internal reflection technologies, and mechanical actuation. The active technologies include heterostructures, quantum wells, rare-earth doping, dye doping, Raman amplification, and semiconductor amplification. We also investigate the use of different material systems and device technologies to achieve building-block functions, including lasers, amplifiers, detectors, modulators, polarization controllers, couplers, filters, switches, attenuators, isolators, circulators, wavelength converters, chromatic dispersion compensators, and polarization mode dispersion compensators. Some of the technologies presented are well established in the industry and in some cases have reached the commodity stage, others have recently become ready for commercial introduction, while some others

  14. Optimization of mechanically jointed doped graphite/copper plasma facing components%核聚变掺杂石墨第一壁材料连接优化分析

    Institute of Scientific and Technical Information of China (English)

    种法力

    2012-01-01

    Two kinds of mechanically jointed graphite/copper structures were introduced, and their heat transfer performances were evaluated by means of electron beam facility and ANSYS finite element analysis. The results show that the temperature differences of two joints are not significant, and the maximum surface temperature is about 1 05S ℃ at 4 MW/m2, which has a good agreement with the numerical simulation results by ANSYS. Due to its poor heal transfer, the screw-fastened region appears the higher temperature, especially for Joint_l, it reachs about 2 000 ℃. It's indicated that Joint_2 could be more suitable to the heat flux region of less than 4 MW/nr. But under the higher heat flux, both of them are un-acceptable, an advanced plasma facing component has to be developed.%介绍核聚变实验装置掺杂石墨第一壁材料的两种机械连接方法,通过电子束热负荷实验及ANSYS有限元分析评价两种连接方式传热效果的差异.结果表明,两种连接方式传热效果相当,在4MW/m2功率密度下表面最高温度约为1055℃.ANSYS分析结果与实验结果有较高的一致性,但是由于螺钉固定区域散热较差,此处温度最高达到2000℃.对于功率密度低于4MW/m2的区域,掺杂石墨第一壁材料采用第二种方式连接较为合适;对于较高热负荷功率密度沉积的区域或者聚变实验装置,发展先进第一壁材料及连接方法十分必要.

  15. 击发装置关重件磨损特性分析及失效寿命预测%Wearing Characteristics Analysis and Failure Life Forecast of Key Components in Gun Firing Mechanism

    Institute of Scientific and Technical Information of China (English)

    胡慧斌; 侯小锋; 曹立军; 马吉胜

    2014-01-01

    The recocking latch and the cocking cam shaft are the key components of gun breech-block firing mechanism.Wearing between the recocking latch bearing arm and the cocking cam shaft bearing arm is the usual failure reason that is difficult or impossible to open the breech-block.To timely and effectively realize the preventive maintenance,a new kind of wear failure life forecast method was put forward based on friction-wear test and virtual prototype.Their material PCrNiMo steel was used to fabricate pin samples and disk samples.The friction-wear tests were carried out based on MMS-1 G pin-on-disk tester to deeply study the friction-wear characteristics,and explore the surface wear mechanism and fit the wear failure rules under conditions of high-speed,heavy load and dry-sliding friction.Virtual prototype of gun firing device was established in environment of Pro/E and ADAMS to simulate the load spectrums of the recocking latch bearing arm and the cocking cam shaft bearing arm during the process of au-tomatic breechblock opening and closing.Their wear failure lives were forecasted based on out-line discretization and reconstruction,the results can provide the sufficient decision basis for preventive maintenance.%复拨器拨动子和拨动子轴是炮闩击发装置的关键零部件。复拨器拨动子支臂和拨动子轴支臂作用处磨损是导致不能开闩故障的常见原因。为了实现及时有效的预防性维修,采用其材料 PCrNiMo 钢制作销试样和盘试样,在 MMS 1 G型销盘式摩擦磨损试验机上进行摩擦磨损试验,研究高速、高载、干滑动摩擦条件下的摩擦磨损特性与表面磨损机制,拟合得到磨损失效规律。在 Pro/E 和 ADAMS环境下建立炮闩虚拟样机,基于动力学仿真获取复拨器拨动子支臂和拨动子轴支臂在自动开闩时的载荷谱,通过零部件外廓的离散化和外廓重构,预测其磨损失效寿命,为实现预防性维修提供决策依据。

  16. Reusable Component Services

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Reusable Component Services (RCS) is a super-catalog of components, services, solutions and technologies that facilitates search, discovery and collaboration in...

  17. Principal component analysis

    NARCIS (Netherlands)

    Bro, R.; Smilde, A.K.

    2014-01-01

    Principal component analysis is one of the most important and powerful methods in chemometrics as well as in a wealth of other areas. This paper provides a description of how to understand, use, and interpret principal component analysis. The paper focuses on the use of principal component analysis

  18. Method and apparatus for monitoring aircraft components

    Science.gov (United States)

    Dickens, Larry M.; Haynes, Howard D.; Ayers, Curtis W.

    1996-01-01

    Operability of aircraft mechanical components is monitored by analyzing the voltage output of an electrical generator of the aircraft. Alternative generators, for a turbine-driven rotor aircraft, include the gas producer turbine tachometer generator, the power turbine tachometer generator, and the aircraft systems power producing starter/generator. Changes in the peak amplitudes of the fundamental frequency and its harmonics are correlated to changes in condition of the mechanical components.

  19. Component- and plant safety. Bauteil- und Anlagensicherheit

    Energy Technology Data Exchange (ETDEWEB)

    Boehnert, R. (Fachhochschule Koeln (Germany). Fachbereich Anlagen- und Verfahrenstechnik)

    1992-01-01

    Since reliable plants depend on reliable components, the work of engineers entrusted with their planning or maintenance would be unthinkable today without a sufficiently founded safety-engineering knowledge. This book gives a profound introduction to component and plant safety and discusses important licensing aspects. It mainly addresses students of mechanical engineering, chemical engineering, supply and environmental engineering and experienced industrial-planning experts who have some elementary background knowledge of mathematics, mechanics, material science and plant construction. (orig.).

  20. 茶叶加工中品质关键组分的变化与调控机制%The Change and Regulation Mechanism of Key Components during Tea Processing

    Institute of Scientific and Technical Information of China (English)

    莫婷; 张婉璐; 李平

    2011-01-01

    Tea has originated from China, and it is one of the three world's popular beverage. A variety of compounds, such as polyphenols, proteins, amino acids, alkaloids, aromatic compounds, carbohydrates, lipids, vitamins, minerals, chlorophyll, enzymes, were rich in tea. After being non-fermented, slightly fermented, semi-fermented, fermented and secondary fermented which include withering, fixing, rolling, fermentation and drying treatment, catechins were oxidized and polymerized to theaflavins, thearuhigins and theabrownin by polyphenol oxidase and peroxidase because of the effect of temperature, pressure, enzymes and microorganisms. In addition, aroma precursors, β-D-glycosides were hydrolyzed into the correspongding alcohols and other aroma substances under the action of β -glucosidase andβ -primeverosidase. Proteins were hydrolyze into amino acids and further formed different chiral enantiomers. These would endow the unique color of tea, aroma, taste and appearance. Tea has many functions, such as antibacterial, antiviral, antioxidant, anti-aging, anti-cancer, immune enhancement, prevented of cardiovascular disease and so on. Now tea was classified into green tea, white tea, yellow tea, oolong tea, black tea and puerh tea. This paper explained the relevance and problems between the change regulation and technical control in the process from the key components of tea such as color, aroma and flavor. Moreover, the formation mechanism to provide a theoretical basis for improving the quality of tea was also discussed.%茶树起源于中国,茶叶是世界三大饮品之一.茶叶中富含茶多酚、蛋白质及氨基酸、生物碱、芳香族化合物、糖类、类脂化合物、维生素、无机物、叶绿素、酶等多种化合物.它们经过非发酵、微发酵、半发酵、全发酵及后发酵工艺,萎凋、杀青、揉捻、发酵、干燥等处理后,由于温度、压力、酶及微生物的作用,儿茶素在多酚氧化酶、过氧化物酶等的

  1. Supply chain components

    Directory of Open Access Journals (Sweden)

    Vieraşu, T.

    2011-01-01

    Full Text Available In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.

  2. Hot gas path component

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Porter, Christopher Donald; Schick, David Edward

    2017-09-12

    Various embodiments of the disclosure include a turbomachine component. and methods of forming such a component. Some embodiments include a turbomachine component including: a first portion including at least one of a stainless steel or an alloy steel; and a second portion joined with the first portion, the second portion including a nickel alloy including an arced cooling feature extending therethrough, the second portion having a thermal expansion coefficient substantially similar to a thermal expansion coefficient of the first portion, wherein the arced cooling feature is located within the second portion to direct a portion of a coolant to a leakage area of the turbomachine component.

  3. Psychological Component of Infertility

    Science.gov (United States)

    ... Home FAQs Frequently Asked Questions Quick Facts About Infertility FAQs About Infertility FAQs About the Psychological Component of Infertility FAQs About Cloning and Stem Cell Research SART's ...

  4. 空间探测磁强计安装部件的力学特性分析%Mechanical Characteristic Analysis of the Magnetometer Structure Component for the Space Exploration

    Institute of Scientific and Technical Information of China (English)

    庄红超; 王劲; 王柠; 史荣; 李岩

    2011-01-01

    对某深空探测器中的有效载荷-高精度磁强计的安装部件进行了有限元分析,分别获取了磁强计安装部件在升空过程中承受40g加速度冲击载荷以及-180~75℃的极限温度情况下,在x,y,z方向上的最大应力和最大位移,给出了由于磁强计安装部件的变形而导致的三个探头在x,y,z方向上的偏转角度,采用扫频实验法分析了磁强计安装部件的频谱特性,为空间探测磁强计的设计提供了依据.%Finite element technique is utilized to analyze payload of the detector, which is the high precision magnetometer structure component. When the magnetometer structure component bears impact load of 40 g in the blastoff process and simultaneously bears extreme temperature ranging from -180℃ to 75℃, the maximum stress and displacement are respectively obtained in the directions of x, y and z. Moreover, due to the deformed magnetometer structure component, deflective angles of three probes are also obtained in the three directions. Finally, the sweep experiment is utilized to analyze spectrum characteristics of the magnetometer structure component, and the objective of experimental date has been obtained. It verifies the dynamic characteristics of the magnetometer structure component and provides technical support for the space-borne magnetometer designing.

  5. Fracture of an uncemented tantalum patellar component

    Directory of Open Access Journals (Sweden)

    Nathan L. Grimm, MD

    2016-06-01

    Full Text Available A 62-year-old man presented with the acute, atraumatic onset of pain 3 years after uncemented right total knee arthroplasty. He complained of new mechanical locking with the knee held in extension on examination and unable to flex the knee. On the plain radiographs, the patellar component peg was fractured and the plate was dislocated. The knee was immobilized, and revision to a cemented 3-peg component was performed. Fracture of a single-peg, tantalum-backed uncemented patellar component has not been described. Clinical suspicion for this should be given in the setting of acute locking. We recommend revision with a cemented polyethylene component.

  6. Tokamak engineering mechanics

    CERN Document Server

    Song, Yuntao; Du, Shijun

    2013-01-01

    Tokamak Engineering Mechanics offers concise and thorough coverage of engineering mechanics theory and application for tokamaks, and the material is reinforced by numerous examples. Chapter topics include general principles, static mechanics, dynamic mechanics, thermal fluid mechanics and multiphysics structural mechanics of tokamak structure analysis. The theoretical principle of the design and the methods of the analysis for various components and load conditions are presented, while the latest engineering technologies are also introduced. The book will provide readers involved in the study

  7. Multilevel component analysis

    NARCIS (Netherlands)

    Timmerman, M.E.

    2006-01-01

    A general framework for the exploratory component analysis of multilevel data (MLCA) is proposed. In this framework, a separate component model is specified for each group of objects at a certain level. The similarities between the groups of objects at a given level can be expressed by imposing cons

  8. Design of Critical Components

    Science.gov (United States)

    Hendricks, Robert C.; Zaretsky, Erwin V.

    2001-01-01

    Critical component design is based on minimizing product failures that results in loss of life. Potential catastrophic failures are reduced to secondary failures where components removed for cause or operating time in the system. Issues of liability and cost of component removal become of paramount importance. Deterministic design with factors of safety and probabilistic design address but lack the essential characteristics for the design of critical components. In deterministic design and fabrication there are heuristic rules and safety factors developed over time for large sets of structural/material components. These factors did not come without cost. Many designs failed and many rules (codes) have standing committees to oversee their proper usage and enforcement. In probabilistic design, not only are failures a given, the failures are calculated; an element of risk is assumed based on empirical failure data for large classes of component operations. Failure of a class of components can be predicted, yet one can not predict when a specific component will fail. The analogy is to the life insurance industry where very careful statistics are book-kept on classes of individuals. For a specific class, life span can be predicted within statistical limits, yet life-span of a specific element of that class can not be predicted.

  9. Aligning component upgrades

    Directory of Open Access Journals (Sweden)

    Roberto Di Cosmo

    2011-08-01

    Full Text Available Modern software systems, like GNU/Linux distributions or Eclipse-based development environment, are often deployed by selecting components out of large component repositories. Maintaining such software systems by performing component upgrades is a complex task, and the users need to have an expressive preferences language at their disposal to specify the kind of upgrades they are interested in. Recent research has shown that it is possible to develop solvers that handle preferences expressed as a combination of a few basic criteria used in the MISC competition, ranging from the number of new components to the freshness of the final configuration. In this work we introduce a set of new criteria that allow the users to specify their preferences for solutions with components aligned to the same upstream sources, provide an efficient encoding and report on the experimental results that prove that optimising these alignment criteria is a tractable problem in practice.

  10. Aligning component upgrades

    CERN Document Server

    Di Cosmo, Roberto; Michel, Claude; 10.4204/EPTCS.65.1

    2011-01-01

    Modern software systems, like GNU/Linux distributions or Eclipse-based development environment, are often deployed by selecting components out of large component repositories. Maintaining such software systems by performing component upgrades is a complex task, and the users need to have an expressive preferences language at their disposal to specify the kind of upgrades they are interested in. Recent research has shown that it is possible to develop solvers that handle preferences expressed as a combination of a few basic criteria used in the MISC competition, ranging from the number of new components to the freshness of the final configuration. In this work we introduce a set of new criteria that allow the users to specify their preferences for solutions with components aligned to the same upstream sources, provide an efficient encoding and report on the experimental results that prove that optimising these alignment criteria is a tractable problem in practice.

  11. Research Progresses on the Chemical Components, Pharmacological Activity, and Antitumoral Mechanism of Zanthoxylum nitidum%两面针化学成分、药理活性及抗肿瘤机制研究进展

    Institute of Scientific and Technical Information of China (English)

    刘延成; 程风杰; 蒙衍强; 陈振锋; 梁宏

    2012-01-01

    In this paper,the research progress on the chemical components,pharmacological activity and clinical effects of Zanlhoxylum nilidum (TCM) mainly in the recent ten years was reviewed. As emphasis,several kinds of alkaloids, the main components of Z, nitidum,suck as nitidine chloride,liriodenine as well as its metal complexes with antitumour activity, were summarized.%本文主要结合近几年的国内外研究报道,综述了中国传统中草药-两面针的化学成分、药理活性及临床疗效等方面的研究进展;并结合作者所在课题组的研究成果,重点介绍了两面针生物碱及其金属配合物的抗肿瘤活性研究.

  12. Cylinder components properties, applications, materials

    CERN Document Server

    2016-01-01

    Owing to the ever-increasing requirements to be met by gasoline and diesel engines in terms of CO2 reduction, emission behavior, weight, and service life, a comprehensive understanding of combustion engine components is essential today. It is no longer possible for professionals in automotive engineering to manage without the corresponding expertise, whether they work in the field of design, development, testing, or maintenance. This technical book provides in-depth answers to questions about design, production, and machining of cylinder components. In this second edition, every section has been revised and expanded to include the latest developments in the combustion engine. Content Piston rings Piston pins and piston pin circlips Bearings Connecting rods Crankcase and cylinder liners Target audience Engineers in the field of engine development and maintenanceLecturers and students in the areas of mechanical engineering, engine technology, and vehicle constructionAnyone interested in technology Publisher MAH...

  13. Energy-efficient finishing in mechanical engineering. Vehicle manufacturers testing minimum quantity lubrication for precision machining engine components; Energieeffiziente Feinbearbeitung im Maschinenbau. Fahrzeughersteller erpropt Minimalmengenschmierung bei der Feinbearbeitung von Motorbauteilen

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Franz

    2013-06-01

    When producing machine components, the grinding stage is a production process with comparatively low energy efficiency. Up to 90% of the energy deployed is released as frictional heat. Large amounts of lubricants and coolants flood the workpieces and tools to cool them. The supply of coolants and their processing require enormous expenditure, including in terms of the energy. Researchers from industry and science have therefore jointly developed new processes that produce significant savings potential with minimum lubrication.

  14. GCS component development cycle

    Science.gov (United States)

    Rodríguez, Jose A.; Macias, Rosa; Molgo, Jordi; Guerra, Dailos; Pi, Marti

    2012-09-01

    The GTC1 is an optical-infrared 10-meter segmented mirror telescope at the ORM observatory in Canary Islands (Spain). First light was at 13/07/2007 and since them it is in the operation phase. The GTC control system (GCS) is a distributed object & component oriented system based on RT-CORBA8 and it is responsible for the management and operation of the telescope, including its instrumentation. GCS has used the Rational Unified process (RUP9) in its development. RUP is an iterative software development process framework. After analysing (use cases) and designing (UML10) any of GCS subsystems, an initial component description of its interface is obtained and from that information a component specification is written. In order to improve the code productivity, GCS has adopted the code generation to transform this component specification into the skeleton of component classes based on a software framework, called Device Component Framework. Using the GCS development tools, based on javadoc and gcc, in only one step, the component is generated, compiled and deployed to be tested for the first time through our GUI inspector. The main advantages of this approach are the following: It reduces the learning curve of new developers and the development error rate, allows a systematic use of design patterns in the development and software reuse, speeds up the deliverables of the software product and massively increase the timescale, design consistency and design quality, and eliminates the future refactoring process required for the code.

  15. Robust Principal Component Analysis?

    CERN Document Server

    Candes, Emmanuel J; Ma, Yi; Wright, John

    2009-01-01

    This paper is about a curious phenomenon. Suppose we have a data matrix, which is the superposition of a low-rank component and a sparse component. Can we recover each component individually? We prove that under some suitable assumptions, it is possible to recover both the low-rank and the sparse components exactly by solving a very convenient convex program called Principal Component Pursuit; among all feasible decompositions, simply minimize a weighted combination of the nuclear norm and of the L1 norm. This suggests the possibility of a principled approach to robust principal component analysis since our methodology and results assert that one can recover the principal components of a data matrix even though a positive fraction of its entries are arbitrarily corrupted. This extends to the situation where a fraction of the entries are missing as well. We discuss an algorithm for solving this optimization problem, and present applications in the area of video surveillance, where our methodology allows for th...

  16. Discriminant Incoherent Component Analysis.

    Science.gov (United States)

    Georgakis, Christos; Panagakis, Yannis; Pantic, Maja

    2016-05-01

    Face images convey rich information which can be perceived as a superposition of low-complexity components associated with attributes, such as facial identity, expressions, and activation of facial action units (AUs). For instance, low-rank components characterizing neutral facial images are associated with identity, while sparse components capturing non-rigid deformations occurring in certain face regions reveal expressions and AU activations. In this paper, the discriminant incoherent component analysis (DICA) is proposed in order to extract low-complexity components, corresponding to facial attributes, which are mutually incoherent among different classes (e.g., identity, expression, and AU activation) from training data, even in the presence of gross sparse errors. To this end, a suitable optimization problem, involving the minimization of nuclear-and l1 -norm, is solved. Having found an ensemble of class-specific incoherent components by the DICA, an unseen (test) image is expressed as a group-sparse linear combination of these components, where the non-zero coefficients reveal the class(es) of the respective facial attribute(s) that it belongs to. The performance of the DICA is experimentally assessed on both synthetic and real-world data. Emphasis is placed on face analysis tasks, namely, joint face and expression recognition, face recognition under varying percentages of training data corruption, subject-independent expression recognition, and AU detection by conducting experiments on four data sets. The proposed method outperforms all the methods that are compared with all the tasks and experimental settings.

  17. Failure Rate Model of Mechanical Components Based on Four Elements%基于四要素的机械零部件失效率计算模型

    Institute of Scientific and Technical Information of China (English)

    王正

    2011-01-01

    The factors affecting the typical failure rate curve were analyzed, and four elements including load, strength, strength degradation and life index(namely, the number of load application and time) were proposed for calculating the failure rate of components. Taking the number of load application and time as the life index, respectively, the failure rate models of components consisting of four elements were developed, which can embody the parameters of load, strength, strength degradation and life. Then, the behaviors of the reliability and failure rate of components changing as the life index were studied. The results show that the failure rate curves of components have the partial or whole characteristics of bathtub curve. For different parameters of load, strength and the rule of strength degradation, the failure rate curves of components have different shapes. The models derived herein can calculate the failure rate of components as long as the known parameters of load, strength and its degradation and life index, and can direct the reliability-based design of components more scientifically.%分析了影响典型失效率曲线变化的因素,提出了零部件失效率计算的四要素,即载荷、强度、强度退化规律以及寿命指标(载荷作用次数或时间)。分别在以载荷作用次数和时间为寿命度量指标框架下,建立了能够全面地体现载荷、强度、强度退化规律以及寿命指标等参数影响的零部件失效率计算四要素模型,并研究了零部件可靠度与失效率随寿命指标的变化规律。研究表明,零部件的可靠度随寿命指标的增大而逐渐减小,零部件的失效率随寿命指标变化具有浴盆曲线全部(或部分)特征。对于不同的强度分布、载荷分布和强度退化规律组合,零部件具有不同的可靠度,失效率曲线具有不同的形状。所建立的失效率模型无需依赖产品的失效数据信息,而只要在载荷、

  18. Scientific Software Component Technology

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, S.; Dykman, N.; Kumfert, G.; Smolinski, B.

    2000-02-16

    We are developing new software component technology for high-performance parallel scientific computing to address issues of complexity, re-use, and interoperability for laboratory software. Component technology enables cross-project code re-use, reduces software development costs, and provides additional simulation capabilities for massively parallel laboratory application codes. The success of our approach will be measured by its impact on DOE mathematical and scientific software efforts. Thus, we are collaborating closely with library developers and application scientists in the Common Component Architecture forum, the Equation Solver Interface forum, and other DOE mathematical software groups to gather requirements, write and adopt a variety of design specifications, and develop demonstration projects to validate our approach. Numerical simulation is essential to the science mission at the laboratory. However, it is becoming increasingly difficult to manage the complexity of modern simulation software. Computational scientists develop complex, three-dimensional, massively parallel, full-physics simulations that require the integration of diverse software packages written by outside development teams. Currently, the integration of a new software package, such as a new linear solver library, can require several months of effort. Current industry component technologies such as CORBA, JavaBeans, and COM have all been used successfully in the business domain to reduce software development costs and increase software quality. However, these existing industry component infrastructures will not scale to support massively parallel applications in science and engineering. In particular, they do not address issues related to high-performance parallel computing on ASCI-class machines, such as fast in-process connections between components, language interoperability for scientific languages such as Fortran, parallel data redistribution between components, and massively

  19. Components in Chemical Thermodynamics

    Science.gov (United States)

    Alberty, Robert A.

    1995-09-01

    Chemical equations are actually matrix equations, and this has important implications for their thermodynamic treatment. The fundamental equation for chemical thermodynamics for a chemical reaction system can be written in terms of species, but at chemical equilibrium, it has to be written in terms of components. The number of components is equal to the number of species minus the number of independent chemical reactions. The fundamental equation for the Gibbs energy of a system containing ethylene, methane, ethane, and propane is discussed. At chemical equilibrium there are two components, which can be taken to be carbon and hydrogen or ethylene and methane. There are advantages in using matrix notation.

  20. Explosive Components Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 98,000 square foot Explosive Components Facility (ECF) is a state-of-the-art facility that provides a full-range of chemical, material, and performance analysis...

  1. Emotional Components of Pain

    Directory of Open Access Journals (Sweden)

    Carla J Hale

    1997-01-01

    Full Text Available BACKGROUND: Current definitions of pain suggest that emotion is an essential component of pain, however, the presumed relationship between emotion and pain, and the specific emotions that are involved in pain experiences have yet to be clarified.

  2. Semantic network based component organization model for program mining

    Institute of Scientific and Technical Information of China (English)

    王斌; 张尧学; 陈松乔

    2003-01-01

    Based on the definition of component ontology, an effective component classification mechanism and a facet named component relationship are proposed. Then an application domain oriented, hierarchical component organization model is established. At last a hierarchical component semantic network (HCSN) described by ontology interchange language(OIL) is presented and then its function is described. Using HCSN and cooperating with other components retrieving algorithms based on component description, other components information and their assembly or composite modes related to the key component can be found. Based on HCSN, component directory library is catalogued and a prototype system is constructed. The prototype system proves that component library organization based on this model gives guarantee to the reliability of component assembly during program mining.

  3. Component fragility research program

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, N.C.; Mochizuki, G.L.; Holman, G.S. (NCT Engineering, Inc., Lafayette, CA (USA); Lawrence Livermore National Lab., CA (USA))

    1989-11-01

    To demonstrate how high-level'' qualification test data can be used to estimate the ultimate seismic capacity of nuclear power plant equipment, we assessed in detail various electrical components tested by the Pacific Gas Electric Company for its Diablo Canyon plant. As part of our Phase I Component Fragility Research Program, we evaluated seismic fragility for five Diablo Canyon components: medium-voltage (4kV) switchgear; safeguard relay board; emergency light battery pack; potential transformer; and station battery and racks. This report discusses our Phase II fragility evaluation of a single Westinghouse Type W motor control center column, a fan cooler motor controller, and three local starters at the Diablo Canyon nuclear power plant. These components were seismically qualified by means of biaxial random motion tests on a shaker table, and the test response spectra formed the basis for the estimate of the seismic capacity of the components. The seismic capacity of each component is referenced to the zero period acceleration (ZPA) and, in our Phase II study only, to the average spectral acceleration (ASA) of the motion at its base. For the motor control center, the seismic capacity was compared to the capacity of a Westinghouse Five-Star MCC subjected to actual fragility tests by LLNL during the Phase I Component Fragility Research Program, and to generic capacities developed by the Brookhaven National Laboratory for motor control center. Except for the medium-voltage switchgear, all of the components considered in both our Phase I and Phase II evaluations were qualified in their standard commercial configurations or with only relatively minor modifications such as top bracing of cabinets. 8 refs., 67 figs., 7 tabs.

  4. Communication adapter for use with a drilling component

    Science.gov (United States)

    Hall, David R.; Pixton, David S.; Hall; Jr.; H. Tracy; Bradford, Kline; Rawle, Michael

    2007-04-03

    A communication adapter is disclosed that provides for removable attachment to a drilling component when the drilling component is not actively drilling and for communication with an integrated transmission system in the drilling component. The communication adapter comprises a data transmission coupler that facilitates communication between the drilling component and the adapter, a mechanical coupler that facilitates removable attachment of the adapter to the drilling component, and a data interface.

  5. Scientific Component Technology Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, S; Bosl, B; Dahlgren, T; Kumfert, G; Smith, S

    2003-02-07

    The laboratory has invested a significant amount of resources towards the development of high-performance scientific simulation software, including numerical libraries, visualization, steering, software frameworks, and physics packages. Unfortunately, because this software was not designed for interoperability and re-use, it is often difficult to share these sophisticated software packages among applications due to differences in implementation language, programming style, or calling interfaces. This LDRD Strategic Initiative investigated and developed software component technology for high-performance parallel scientific computing to address problems of complexity, re-use, and interoperability for laboratory software. Component technology is an extension of scripting and object-oriented software development techniques that specifically focuses on the needs of software interoperability. Component approaches based on CORBA, COM, and Java technologies are widely used in industry; however, they do not support massively parallel applications in science and engineering. Our research focused on the unique requirements of scientific computing on ASCI-class machines, such as fast in-process connections among components, language interoperability for scientific languages, and data distribution support for massively parallel SPMD components.

  6. Cognitive Component Analysis

    DEFF Research Database (Denmark)

    Feng, Ling

    2008-01-01

    of audio contexts along with pattern recognition methods to map components to known contexts. It also involves looking for the right representations for auditory inputs, i.e. the data analytic processing pipelines invoked by human brains. The main ideas refer to Cognitive Component Analysis, defined......This dissertation concerns the investigation of the consistency of statistical regularities in a signaling ecology and human cognition, while inferring appropriate actions for a speech-based perceptual task. It is based on unsupervised Independent Component Analysis providing a rich spectrum...... as the process of unsupervised grouping of generic data such that the ensuing group structure is well-aligned with that resulting from human cognitive activity. Its hypothesis runs ecologically: features which are essentially independent in a context defined ensemble, can be efficiently coded as sparse...

  7. Adaptable component frameworks

    DEFF Research Database (Denmark)

    Katajainen, Jyrki; Simonsen, Bo

    2009-01-01

    The CPH STL is a special edition of the STL, the containers and algorithms part of the C++ standard library. The specification of the generic components of the STL is given in the C++ standard. Any implementation of the STL, e.g. the one that ships with your standard-compliant C++ compiler, should...... provide at least one realization for each container that has the specified characteristics with respect to performance and safety. In the CPH STL project, our goal is to provide several alternative realizations for each STL container. For example, for associative containers we can provide almost any kind...... of balanced search tree. Also, we do provide safe and compact versions of each container. To ease the maintenance of this large collection of implementations, we have developed component frameworks for the STL containers. In this paper, we describe the design and implementation of a component framework...

  8. An integrated magnetics component

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an integrated magnetics component comprising a magnetically permeable core comprising a base member extending in a horizontal plane and first, second, third and fourth legs protruding substantially perpendicularly from the base member. First, second, third...... extending substantially orthogonally to the first flux path. Another aspect of the invention relates to a multiple-input isolated power converter comprising the integrated magnetics component....... and fourth output inductor windings are wound around the first, second, third and fourth legs, respectively. A first input conductor of the integrated magnetics component has a first conductor axis and extends in-between the first, second, third and fourth legs to induce a first magnetic flux through a first...

  9. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  10. Towards Cognitive Component Analysis

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Ahrendt, Peter; Larsen, Jan

    2005-01-01

    Cognitive component analysis (COCA) is here defined as the process of unsupervised grouping of data such that the ensuing group structure is well-aligned with that resulting from human cognitive activity. We have earlier demonstrated that independent components analysis is relevant for representing...... semantics, not only in text, but also in dynamic text (chat), images, and combinations of text and images. Here we further expand on the relevance of the ICA model for representing context, including two new analyzes of abstract data: social networks and musical features....

  11. LDEF active optical system components experiment

    Science.gov (United States)

    Blue, M. D.

    1992-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  12. Multimode geodesic branching components

    Science.gov (United States)

    Schulz, D.; Voges, E.

    1983-01-01

    Geodesic branching components are investigated for multimode guided wave optics. Geodesic structures with particular properties, e.g. focussing star couplers, are derived by a synthesis technique based on a theorem of Toraldo di Francia. Experimentally, the geodesic surfaces are printed on acrylic glass and are spin-coated with organic film waveguides.

  13. Component School Construction Program.

    Science.gov (United States)

    New Brunswick Dept. of Economic Growth, Fredericton.

    In 1968, the Province of New Brunswick initiated a three-phase program to provide for elementary school facilities, employing a component systems approach to their construction. This booklet describes briefly the planning and construction of these schools, and provides graphic and photographic records of the construction in progress as well as of…

  14. Autonomous component carrier selection

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Pedersen, Klaus; Mogensen, Preben

    2009-01-01

    in local areas, basing our study case on LTE-Advanced. We present extensive network simulation results to demonstrate that a simple and robust interference management scheme, called autonomous component carrier selection allows each cell to select the most attractive frequency configuration; improving...

  15. Review on Prescription Compatibility of Shaoyao Gancao Decoction and Reflection on Pharmacokinetic Compatibility Mechanism of Traditional Chinese Medicine Prescription Based on In Vivo Drug Interaction of Main Efficacious Components

    Directory of Open Access Journals (Sweden)

    Xiaolin Bi

    2014-01-01

    Full Text Available Shaoyao Gancao Decoction (SGD derived from Zhang Zhongjing’s “Typhoid Theory” is composed of peony and licorice, having the efficacy of nourishing liver, relaxing spasm, and relieving pain. Modern compatibility studies of SGD on chemistry, pharmacology, and pharmacokinetics all demonstrate the reasonable compatibility of peony and licorice. However, the present research on pharmacokinetics is only descriptive and limited to the influence on in vivo dynamic process of certain ingredients; correspondingly, there is lack of studies on the essence of these efficacious substances’ in vivo changes; that is, whether it is because there exists in vivo drug interaction in absorption, distribution, metabolism, and excretion (ADME of active ingredients that leads to the improvement of bioavailability. We herein take SGD as an example and suggest that it is necessary to study in vivo drug interaction of main efficacious components mediated by metabolic enzymes, transport proteins, or plasma protein binding in the course of ADME, which is helpful to illustrate the principle of pharmacokinetic compatibility from the essence leading to the changes of effective substances in vivo.

  16. Mechanism of activation of PhoQ/PhoP two-component signal transduction by SafA, an auxiliary protein of PhoQ histidine kinase in Escherichia coli.

    Science.gov (United States)

    Ishii, Eiji; Eguchi, Yoko; Utsumi, Ryutaro

    2013-01-01

    The PhoQ/PhoP two-component signal transduction system in Escherichia coli is activated by SafA, a small membrane protein that modifies the PhoQ histidine kinase. The SafA C-terminal domain (41-65 aa) interacts directly with the sensory domain of PhoQ at the periplasm. We used in vitro and in vivo strategies to elucidate the way SafA modifies the PhoQ/PhoP phosphorelay system. First, the enzymatic activities of membranes from cells overexpressing PhoQ and cells expressing both PhoQ and SafA were compared in vitro. Increased autophosphorylation of PhoQ was observed in the presence of SafA, but it did not increase the dephosphorylation of phospho-PhoP by PhoQ. In addition, SafA increased the phospho-PhoP level on the phosphotransfer assay. We confirmed that induction of SafA results in an accumulation of phospho-PhoP in vivo by the Phos-tag system. Our results suggest that the accumulation of phospho-PhoP is linked to activation of PhoQ autophosphorylation by SafA.

  17. Developing a Model Component

    Science.gov (United States)

    Fields, Christina M.

    2013-01-01

    The Spaceport Command and Control System (SCCS) Simulation Computer Software Configuration Item (CSCI) is responsible for providing simulations to support test and verification of SCCS hardware and software. The Universal Coolant Transporter System (UCTS) was a Space Shuttle Orbiter support piece of the Ground Servicing Equipment (GSE). The initial purpose of the UCTS was to provide two support services to the Space Shuttle Orbiter immediately after landing at the Shuttle Landing Facility. The UCTS is designed with the capability of servicing future space vehicles; including all Space Station Requirements necessary for the MPLM Modules. The Simulation uses GSE Models to stand in for the actual systems to support testing of SCCS systems during their development. As an intern at Kennedy Space Center (KSC), my assignment was to develop a model component for the UCTS. I was given a fluid component (dryer) to model in Simulink. I completed training for UNIX and Simulink. The dryer is a Catch All replaceable core type filter-dryer. The filter-dryer provides maximum protection for the thermostatic expansion valve and solenoid valve from dirt that may be in the system. The filter-dryer also protects the valves from freezing up. I researched fluid dynamics to understand the function of my component. The filter-dryer was modeled by determining affects it has on the pressure and velocity of the system. I used Bernoulli's Equation to calculate the pressure and velocity differential through the dryer. I created my filter-dryer model in Simulink and wrote the test script to test the component. I completed component testing and captured test data. The finalized model was sent for peer review for any improvements. I participated in Simulation meetings and was involved in the subsystem design process and team collaborations. I gained valuable work experience and insight into a career path as an engineer.

  18. A Comparative Study of Structural Stability and Mechanical and Optical Properties of Fluorapatite (Ca5(PO4)3F) and Lithium Disilicate (Li2Si2O5) Components Forming Dental Glass-Ceramics: First Principles Study

    Science.gov (United States)

    Biskri, Z. E.; Rached, H.; Bouchear, M.; Rached, D.; Aida, M. S.

    2016-10-01

    The aim of this paper is a comparative study of structural stability and mechanical and optical properties of fluorapatite (FA) (Ca5(PO4)3F) and lithium disilicate (LD) (Li2Si2O5), using the first principles pseudopotential method based on density functional theory (DFT) within the generalized gradient approximation (GGA). The stability of fluorapatite and lithium disilicate compounds has been evaluated on the basis of their formation enthalpies. The results show that fluorapatite is more energetically stable than lithium disilicate. The independent elastic constants and related mechanical properties, including bulk modulus ( B), shear modulus ( G), Young's modulus ( E) and Poisson's ratio ( ν) as well as the Vickers hardness ( H v), have been calculated for fluorapatite compound and compared with other theoretical and experimental results. The obtained values of the shear modulus, Young's modulus and Vickers hardness are smaller in comparison with those of lithium disilicate compound, implying that lithium disilicate is more rigid than fluorapatite. The brittle and ductile properties were also discussed using B/ G ratio and Poisson's ratio. Optical properties such as refractive index n( ω), extinction coefficient k( ω), absorption coefficient α( ω) and optical reflectivity R( ω) have been determined from the calculations of the complex dielectric function ɛ( ω), and interpreted on the basis of the electronic structures of both compounds. The calculated values of static dielectric constant ɛ 1(0) and static refractive index n(0) show that the Li2Si2O5 compound has larger values compared to those of the Ca5(PO4)3F compound. The results of the extinction coefficient show that Li2Si2O5 compound exhibits a much stronger ultraviolet absorption. According to the absorption and reflectivity spectra, we inferred that both compounds are theoretically the best visible and infrared transparent materials.

  19. 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.

  20. Speed Rotating Components

    Directory of Open Access Journals (Sweden)

    S. Wittig

    1998-01-01

    Full Text Available Cooling of high speed rotating components is a typical situation found in turbomachinery as well as in automobile engines. Accurate knowledge of discharge coefficients and heat transfer of related components is essential for the high performance of the whole engine. This can be achieved by minimized cooling air flows and avoidance of hot spots. In high speed rotating clutches for example aerodynamic investigations improving heat transfer have not been considered in the past. Advanced concepts of modern plate design try to reduce thermal loads by convective cooling methods. Therefore, secondary cooling air flows have to be enhanced by an appropriate design of the rotor stator system with orifices. CFD modelling is used to improve the basic understanding of the flow field in typical geometries used in these systems.

  1. Food Components and Supplements

    DEFF Research Database (Denmark)

    Parlesak, Alexandr

    2012-01-01

    The major part of food consists of chemical compounds that can be used for energy production, biological synthesis, or maintenance of metabolic processes by the host. These components are defined as nutrients, and can be categorized into macronutrients (proteins, carbohydrates, triglycerides.......g., secondary plant metabolites such as flavonoids), or as contaminants that enter the food chain at different stages or during the food production process. For these components, a wide spectrum of biological effects was observed that ranges from health-threatening impacts (e.g., polycyclic aromatic amines...... the growth of these bacteria (prebiotics) are added to food to achieve health effects exceeding its pure nutritional function. Several of these effects are mediated by enzyme systems involved in xenobiotic and drug metabolism, and in some cases this might lead to undesired interactions with medication...

  2. Food Components and Supplements

    DEFF Research Database (Denmark)

    Parlesak, Alexandr

    2012-01-01

    .g., secondary plant metabolites such as flavonoids), or as contaminants that enter the food chain at different stages or during the food production process. For these components, a wide spectrum of biological effects was observed that ranges from health-threatening impacts (e.g., polycyclic aromatic amines...... the growth of these bacteria (prebiotics) are added to food to achieve health effects exceeding its pure nutritional function. Several of these effects are mediated by enzyme systems involved in xenobiotic and drug metabolism, and in some cases this might lead to undesired interactions with medication...... cases, nutrients, food contaminants, and secondary plant metabolites can themselves become substrates for xenobiotic-metabolizing enzymes, resulting in health-promoting or health-threatening products. This chapter focuses on how important components of our daily nutrition and supplements can interfere...

  3. Bayesian Independent Component Analysis

    DEFF Research Database (Denmark)

    Winther, Ole; Petersen, Kaare Brandt

    2007-01-01

    In this paper we present an empirical Bayesian framework for independent component analysis. The framework provides estimates of the sources, the mixing matrix and the noise parameters, and is flexible with respect to choice of source prior and the number of sources and sensors. Inside the engine...... in a Matlab toolbox, is demonstrated for non-negative decompositions and compared with non-negative matrix factorization....

  4. Optimized Kernel Entropy Components.

    Science.gov (United States)

    Izquierdo-Verdiguier, Emma; Laparra, Valero; Jenssen, Robert; Gomez-Chova, Luis; Camps-Valls, Gustau

    2016-02-25

    This brief addresses two main issues of the standard kernel entropy component analysis (KECA) algorithm: the optimization of the kernel decomposition and the optimization of the Gaussian kernel parameter. KECA roughly reduces to a sorting of the importance of kernel eigenvectors by entropy instead of variance, as in the kernel principal components analysis. In this brief, we propose an extension of the KECA method, named optimized KECA (OKECA), that directly extracts the optimal features retaining most of the data entropy by means of compacting the information in very few features (often in just one or two). The proposed method produces features which have higher expressive power. In particular, it is based on the independent component analysis framework, and introduces an extra rotation to the eigen decomposition, which is optimized via gradient-ascent search. This maximum entropy preservation suggests that OKECA features are more efficient than KECA features for density estimation. In addition, a critical issue in both the methods is the selection of the kernel parameter, since it critically affects the resulting performance. Here, we analyze the most common kernel length-scale selection criteria. The results of both the methods are illustrated in different synthetic and real problems. Results show that OKECA returns projections with more expressive power than KECA, the most successful rule for estimating the kernel parameter is based on maximum likelihood, and OKECA is more robust to the selection of the length-scale parameter in kernel density estimation.

  5. Stable Principal Component Pursuit

    CERN Document Server

    Zhou, Zihan; Wright, John; Candes, Emmanuel; Ma, Yi

    2010-01-01

    In this paper, we study the problem of recovering a low-rank matrix (the principal components) from a high-dimensional data matrix despite both small entry-wise noise and gross sparse errors. Recently, it has been shown that a convex program, named Principal Component Pursuit (PCP), can recover the low-rank matrix when the data matrix is corrupted by gross sparse errors. We further prove that the solution to a related convex program (a relaxed PCP) gives an estimate of the low-rank matrix that is simultaneously stable to small entrywise noise and robust to gross sparse errors. More precisely, our result shows that the proposed convex program recovers the low-rank matrix even though a positive fraction of its entries are arbitrarily corrupted, with an error bound proportional to the noise level. We present simulation results to support our result and demonstrate that the new convex program accurately recovers the principal components (the low-rank matrix) under quite broad conditions. To our knowledge, this is...

  6. Inkjet deposited circuit components

    Science.gov (United States)

    Bidoki, S. M.; Nouri, J.; Heidari, A. A.

    2010-05-01

    All-printed electronics as a means of achieving ultra-low-cost electronic circuits has attracted great interest in recent years. Inkjet printing is one of the most promising techniques by which the circuit components can be ultimately drawn (i.e. printed) onto the substrate in one step. Here, the inkjet printing technique was used to chemically deposit silver nanoparticles (10-200 nm) simply by ejection of silver nitrate and reducing solutions onto different substrates such as paper, PET plastic film and textile fabrics. The silver patterns were tested for their functionality to work as circuit components like conductor, resistor, capacitor and inductor. Different levels of conductivity were achieved simply by changing the printing sequence, inks ratio and concentration. The highest level of conductivity achieved by an office thermal inkjet printer (300 dpi) was 5.54 × 105 S m-1 on paper. Inkjet deposited capacitors could exhibit a capacitance of more than 1.5 nF (parallel plate 45 × 45 mm2) and induction coils displayed an inductance of around 400 µH (planar coil 10 cm in diameter). Comparison of electronic performance of inkjet deposited components to the performance of conventionally etched items makes the technique highly promising for fabricating different printed electronic devices.

  7. Influence of sputtering power on components and mechanical properties of boron carbide films%溅射功率对碳化硼薄膜组分与力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    张玲; 何智兵; 李俊; 许华; 谌家军

    2013-01-01

    Boron carbide films were fabricated by radio frequency magnetron sputtering at different sputtering powers.The structure and components of the boron carbide films were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.Using MTS Nano Indenter XP with CSM method,the hardness and modulus of the boron carbide films were analyzed.The results show that B prefers to combining with C to form B-C bond as the RF power increases.When the sputtering power reaches 250 W,the number of B-C bonds is the most,and the atomic concentration ratio between B and C reaches to the maximum of 5.66.Both the hardness and modulus of the boron carbide films increase firstly and then decrease with the sputtering powers increasing.Both of them reach to the maximum of 28.22 GPa and 314.62 GPa,respectively.%采用射频磁控溅射技术,在不同溅射功率条件下制备了碳化硼薄膜,并用X射线光电子能谱(XPS)和傅里叶变换红外吸收光谱(FT-IR)对碳化硼薄膜的组分进行了定量表征,分析了功率变化对碳化硼组分的影响.利用纳米压入仪通过连续刚度法(CSM)对碳化硼薄膜的硬度和模量等力学性能进行了分析.研究表明:随着功率的增大,硼与碳更易结合形成B-C键,在功率增大到250 W时,B-C键明显增多;在250 W时,硼与碳的原子分数比出现了最大值5.66;碳化硼薄膜的硬度与模量都随功率的增大呈现出先增大后减小的趋势,且在250 W时均出现了最大值,分别为28.22 GPa和314.62 GPa.

  8. Structural characterization of the heme-based oxygen sensor, AfGcHK, its interactions with the cognate response regulator, and their combined mechanism of action in a bacterial two-component signaling system.

    Science.gov (United States)

    Stranava, Martin; Martínek, Václav; Man, Petr; Fojtikova, Veronika; Kavan, Daniel; Vaněk, Ondřej; Shimizu, Toru; Martinkova, Marketa

    2016-10-01

    The oxygen sensor histidine kinase AfGcHK from the bacterium Anaeromyxobacter sp. Fw 109-5 forms a two-component signal transduction system together with its cognate response regulator (RR). The binding of oxygen to the heme iron of its N-terminal sensor domain causes the C-terminal kinase domain of AfGcHK to autophosphorylate at His183 and then transfer this phosphate to Asp52 or Asp169 of the RR protein. Analytical ultracentrifugation revealed that AfGcHK and the RR protein form a complex with 2:1 stoichiometry. Hydrogen-deuterium exchange coupled to mass spectrometry (HDX-MS) suggested that the most flexible part of the whole AfGcHK protein is a loop that connects the two domains and that the heme distal side of AfGcHK, which is responsible for oxygen binding, is the only flexible part of the sensor domain. HDX-MS studies on the AfGcHK:RR complex also showed that the N-side of the H9 helix in the dimerization domain of the AfGcHK kinase domain interacts with the helix H1 and the β-strand B2 area of the RR protein's Rec1 domain, and that the C-side of the H8 helix region in the dimerization domain of the AfGcHK protein interacts mostly with the helix H5 and β-strand B6 area of the Rec1 domain. The Rec1 domain containing the phosphorylable Asp52 of the RR protein probably has a significantly higher affinity for AfGcHK than the Rec2 domain. We speculate that phosphorylation at Asp52 changes the overall structure of RR such that the Rec2 area containing the second phosphorylation site (Asp169) can also interact with AfGcHK. Proteins 2016; 84:1375-1389. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Mechanisms in biomedical ontology

    National Research Council Canada - National Science Library

    Röhl, Johannes

    2012-01-01

    .... Taking some hints from an "ontology of devices" I suggest as a general approach for this task the introduction of functional kinds and functional parts by which the particular relations between a mechanism and its components can be captured.

  10. Component Commonality and Its Cost Implications - Increasing the Commonality of the Right Components

    DEFF Research Database (Denmark)

    Lyly-Yrjänäinen, Jouni; Suomala, Petri; Israelsen, Poul

    constructions was identified as the most important bottleneck for the delivery process causing many indirect costs, especially with respect to project-management-related activities. Interestingly, by eliminating the need for mechanical engineering, the context starts to approach assembly-to-order context, also......Component commonality (Labro 2004, Zhou & Gruppström 2004) can be defined as the use of the same version of a component across multiple products. It is usually seen as a means to manage costs without sacrificing product variety. However, when managing costs with component commonality, the managers...... should be able to identify rather rapidly which group of components would enable the most significant cost reductions. Unfortunately, the existing literature lacks profound discussion of how to identify the right components for increased component commonality. The objective of the paper is to discuss how...

  11. Kinetics and Mechanism Investigation on Green and Three –Component One Spot Synthesis of 4H-Tetrahydrobenzo[B]Pyrans using Caffeine as A Facile and Green Catalyst

    Directory of Open Access Journals (Sweden)

    Sayyed Mostafa Habibi-Khorassani

    2016-06-01

    Full Text Available In this article, UV-vis spectroscopy has been used in order to study the reaction kinetics between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of (ethanol / water, 1:2 as solvents in the presence of caffeine as a biodegradable catalyst. A mechanistic insight into the synthesis of 4H-tetrahydrobenzo[b]pyrans included spectral kinetics approaches is revealed. To investigate the influence of various parameters (temperature, solvent, concentration on the degradation efficiency and to discuss whether describing the reaction by the means of the pseudo-first order kinetic model is convenient. The overall order of reaction for the formation of tetrahydrobenzo[b]pyran followed second-order kinetics and the partial orders with respect to 1, 2 and 3 were one, one and zero, respectively. The calculation of kinetic parameters would be an integral part of the report. The results showed that the first step of the reaction mechanism is a rate determining step (RDS and this is confirmed based upon the steady state approximation.

  12. System design of electronic vehicles and components

    OpenAIRE

    Смолій, Вікторія Миколаївна

    2015-01-01

    The oscillation mechanical and thermal mathematical models of electronic vehicles that allow to take into account properties and cooperation of making model elements of replacement and design oscillation stability of PCBS and components in the conditions of technological process of their production are worked out

  13. Research Development on Mechanism of Fly Ash-based Geopolymer and Effect of Each Component%粉煤灰基地聚合物反应机理及各组分作用的研究进展

    Institute of Scientific and Technical Information of China (English)

    施惠生; 夏明; 郭晓潞

    2013-01-01

      地聚合物指采用天然矿物或固体废弃物及人工硅铝化合物为原料,在高碱性条件下通过矿物缩聚而形成的由硅氧四面体与铝氧四面体组成的三维网状聚合胶凝材料。地聚合物兼有陶瓷、水泥、高分子材料的特点,是近年来国内外新型绿色胶凝材料研究的热点。针对粉煤灰基地聚合物反应机理综述了国内外研究现状;介绍了 Glukhovsky 模型、受碱激发的描述性机理模型、纳米结构模型以及体积分数量化模型;并重点介绍了碱、硅铝组分、钙组分和水在地聚合反应中的作用。%Geopolymer is a kind of inorganic polymer cementitious materials, which has a 3D network of silico-aluminate structures. Geopolymer can be synthesized from calcined clays, industrial waste or other alumino-silicate containing source materials under strongly alkaline conditions. Compared with organic polymers, cements, ceramics and metals, geopolymer has superior performances. Recently, geopolymer has become a research focus in the green cementitious materials field. Current status of the researches on the reaction mechanism of fly ash-based geopolymer are reviewed. The Glukhovsky model, the descriptive model, the nanostructural model and the volumetric model are introduced, and emphasis is placed on the effect of alkali, aluminum, silica, calcium and water on geopolymerization.

  14. Molecular Mechanism of Cinnamomum verum Component Cuminaldehyde Inhibits Cell Growth and Induces Cell Death in Human Lung Squamous Cell Carcinoma NCI-H520 Cells In Vitro and In Vivo.

    Science.gov (United States)

    Yang, Shu-Mei; Tsai, Kuen-Daw; Wong, Ho-Yiu; Liu, Yi-Heng; Chen, Ta-Wei; Cherng, Jonathan; Hsu, Kwang-Ching; Ang, Yao-Uh; Cherng, Jaw-Ming

    2016-01-01

    Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine. We evaluated the effects and the molecular mechanisms of cuminaldehyde (CuA), a constituent of the bark of Cinnamomum verum, on human lung squamous cell carcinoma NCI-H520 cells. Specifically, cell viability was evaluated by colorimetric assay; cytotoxicity by LDH release; apoptosis was determined by Western blotting, and morphological analysis with, acridine orange and neutral red stainings and comet assay; topoisomerase I activity was assessed using assay based upon DNA relaxation and topoisomerase II by DNA relaxation plus decatentation of kinetoplast DNA; lysosomal vacuolation and volume of acidic compartments (VAC) were evaluated with neutral red staining. The results show that CuA suppressed proliferation and induced apoptosis as indicated by an up-regulation of pro-apoptotic bax and bak genes and a down-regulation of anti-apoptotic bcl-2 and bcl-XL genes, mitochondrial membrane potential loss, cytochrome c release, activation of caspase 3 and 9, and morphological characteristics of apoptosis, including blebbing of the plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and comet with elevated tail intensity and moment. In addition, CuA also induced lysosomal vacuolation with increased VAC, cytotoxicity, as well as suppressions of both topoisomerase I and II activities in a dose-dependent manner. Further study revealed the growth-inhibitory effect of CuA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of CuA against NCI-H520 cells is accompanied by downregulations of proliferative control involving apoptosis and both topoisomerase I and II activities, and upregulation of lysosomal with increased VAC and cytotoxicity. Similar effects were found in other cell lines, including human lung adenocarcinoma A549 cells and colorectal adenocarcinoma COLO 205 (results not

  15. Structural integrity and life extension of high-temperature components

    Institute of Scientific and Technical Information of China (English)

    WANG Chun; SHEN Shi-ming

    2005-01-01

    Four different topics for high-temperature components, namely the development of the assessment codes for the structural integrity of high-temperature components, the application of continuous damage mechanics and probabilistic damage mode on the life assessment of high-temperature components, the life extension for high-tem perature components and a proposed strategy for remanufacturing of high-temperature components were discussed in this paper. These topics should provide some important insights for the design and re-design of high- temperature components.

  16. Computational mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Raboin, P J

    1998-01-01

    The Computational Mechanics thrust area is a vital and growing facet of the Mechanical Engineering Department at Lawrence Livermore National Laboratory (LLNL). This work supports the development of computational analysis tools in the areas of structural mechanics and heat transfer. Over 75 analysts depend on thrust area-supported software running on a variety of computing platforms to meet the demands of LLNL programs. Interactions with the Department of Defense (DOD) High Performance Computing and Modernization Program and the Defense Special Weapons Agency are of special importance as they support our ParaDyn project in its development of new parallel capabilities for DYNA3D. Working with DOD customers has been invaluable to driving this technology in directions mutually beneficial to the Department of Energy. Other projects associated with the Computational Mechanics thrust area include work with the Partnership for a New Generation Vehicle (PNGV) for ''Springback Predictability'' and with the Federal Aviation Administration (FAA) for the ''Development of Methodologies for Evaluating Containment and Mitigation of Uncontained Engine Debris.'' In this report for FY-97, there are five articles detailing three code development activities and two projects that synthesized new code capabilities with new analytic research in damage/failure and biomechanics. The article this year are: (1) Energy- and Momentum-Conserving Rigid-Body Contact for NIKE3D and DYNA3D; (2) Computational Modeling of Prosthetics: A New Approach to Implant Design; (3) Characterization of Laser-Induced Mechanical Failure Damage of Optical Components; (4) Parallel Algorithm Research for Solid Mechanics Applications Using Finite Element Analysis; and (5) An Accurate One-Step Elasto-Plasticity Algorithm for Shell Elements in DYNA3D.

  17. Significant concentration changes of chemical components of PM{sub 1} in the Yangtze River Delta area of China and the implications for the formation mechanism of heavy haze–fog pollution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.W. [Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081 (China); Zhang, X.Y., E-mail: xiaoye@cams.cma.gov.cn [Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081 (China); Zhang, Y.M.; Shen, X.J. [Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081 (China); Sun, J.Y. [Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081 (China); State Key Laboratory of Cryospheric Sciences, Cold and Arid Region Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000 (China); Ma, Q.L.; Yu, X.M. [Lin' an Regional Air Background Station, Lin' an 311307 (China); Zhu, J.L. [School of Atmospheric Sciences, Nanjing University, Nanjing 210093 (China); Zhang, L.; Che, H.C. [Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081 (China); College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049 (China)

    2015-12-15

    : • Formation mechanism of a heavy haze-fog event that occurred in the YRD region of china was discussed. • Nitrate exhibited the largest increase on the heavy haze-fog days. • Increased biomass burning and atmospheric oxidizing capacity were the major reasons for the significant increase of OA. • Short-distance transport, low wind speed and high RH were highly responsible for the formation of the pollution event.

  18. Recursive principal components analysis.

    Science.gov (United States)

    Voegtlin, Thomas

    2005-10-01

    A recurrent linear network can be trained with Oja's constrained Hebbian learning rule. As a result, the network learns to represent the temporal context associated to its input sequence. The operation performed by the network is a generalization of Principal Components Analysis (PCA) to time-series, called Recursive PCA. The representations learned by the network are adapted to the temporal statistics of the input. Moreover, sequences stored in the network may be retrieved explicitly, in the reverse order of presentation, thus providing a straight-forward neural implementation of a logical stack.

  19. Similar component analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; WANG Xin; LI Junwei; CAO Xianguang

    2006-01-01

    A new unsupervised feature extraction method called similar component analysis (SCA) is proposed in this paper. SCA method has a self-aggregation property that the data objects will move towards each other to form clusters through SCA theoretically,which can reveal the inherent pattern of similarity hidden in the dataset. The inputs of SCA are just the pairwise similarities of the dataset,which makes it easier for time series analysis due to the variable length of the time series. Our experimental results on many problems have verified the effectiveness of SCA on some engineering application.

  20. Analysis Components Investigation Report

    Science.gov (United States)

    2014-10-01

    value is t ds each te rms presen t, and !()*+) PREVIOUS WRI open sour a training , tagged -1 t or... measure tion and Analys 2 is Component THIS DOCU The mis pro inte cou For sele con The use as solu ran .3 Prot In t be A G and wh and sec Wh info Thi...ASSIFIED December 2 LOSED TO ANY P d to specif c. The valu , the user c keywords p as relevan ument’s me system cou the docum iterion and/ e

  1. Electronic components and technology

    CERN Document Server

    Sangwine, Stephen

    2007-01-01

    Most introductory textbooks in electronics focus on the theory while leaving the practical aspects to be covered in laboratory courses. However, the sooner such matters are introduced, the better able students will be to include such important concerns as parasitic effects and reliability at the very earliest stages of design. This philosophy has kept Electronic Components and Technology thriving for two decades, and this completely updated third edition continues the approach with a more international outlook.Not only does this textbook introduce the properties, behavior, fabrication, and use

  2. Impedance of accelerator components

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N. [Center for Beam Physics, Lawrence Berkeley National Laboratory, I Cyclotron Road, Berkeley, California 94720 (United States)

    1997-01-01

    As demands for high luminosity and low emittance particle beams increase, an understanding of the electromagnetic interaction of these beams with their vacuum chamber environment becomes more important in order to maintain the quality of the beam. This interaction is described in terms of the wake field in time domain, and the beam impedance in frequency domain. These concepts are introduced, and related quantities such as the loss factor are presented. The broadband Q=1 resonator impedance model is discussed. Perturbation and coaxial wire methods of measurement of real components are reviewed. {copyright} {ital 1997 American Institute of Physics.}

  3. Automotive component failures

    CSIR Research Space (South Africa)

    Heyes, AM

    1998-06-01

    Full Text Available be expected[ 023 A[ M[ HEYES Fig[ 6[ Low magni_cation fractograph showing the seam defect "S#\\ fatigue area "F# and the brittle fracture area "B#[ Fig[ 7[ Fracture surface marked F in Fig[ 6\\ typical of a fatigue fracture surface in a high strength steel... Ltd[ All rights reserved[ Keywords] Accident investigation\\ automotive failures\\ decarburization\\ fatigue\\ weld fatigue[ 0[ INTRODUCTION Failure of automotive components is an occurrence which a}ects the life of almost every person at one stage...

  4. Component Interaction Graph: A new approach to test component composition

    CERN Document Server

    Acharya, Arup Abhinna

    2010-01-01

    The key factor of component based software development is component composition technology. A Component interaction graph is used to describe the interrelation of components. Drawing a complete component interaction graph (CIG) provides an objective basis and technical means for making the testing outline. Although many researches have focused on this subject, the quality of system that is composed of components has not been guaranteed. In this paper, a CIG is constructed from a state chart diagram and new test cases are generated to test the component composition.

  5. Management of maintenance and ageing in electrical engineering and routing technology; Strategie fuer den Lebensdauererhalt der Hauptleittechnik. Instandhaltungs- und Alterungsmanagement in der Elektrotechnik und Leittechnik

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, W.; Markhardt, R. [Kraftwerksinstandhaltung Leittechnik, Hamburgische Electrizitaets-Werke AG, Hamburg (Germany)

    2001-05-21

    When companies decide to build a major technical installation such as a power station, they must also take the installation's expected operating life as their basis for doing so. This operating life is usually between 30 and 40 years for a power station. Various alterations are carried out to the insing technology is largely retained in the condition which existed when the installation was originally commissioned. This situation begs the question: >>Which maintenance strategy enables the operation of main routing technology for the installation's planned operating life?<< (orig.) [German] Im Lauf der Anlagenbetriebszeit eines Kraftwerks von ueblicherweise 30 bis 40 Jahren werden aus unterschiedlichen Gruenden vielfaeltige Veraenderungen an den Anlagen vorgenommen. In der Leittechnik sind davon in der Regel die Nebenanlagen und die Feldgeraete betroffen. Im Gegensatz dazu bleibt die Hauptleittechnik weitgehend auf dem Stand der Inbetriebsetzung der Anlage erhalten. Daraus leitet sich die Kernfrage ab: >>Welche Instandhaltungsstrategie ermoeglicht den Betrieb der Hauptleittechnik fuer die geplante Anlagenbetriebszeit?<< (orig.)

  6. VASOACTIVE COMPONENTS OF DIALYSIS SOLUTION

    Science.gov (United States)

    Zakaria, El Rasheid; Patel, Anuj A.; Li, Na; Matheson, Paul J.; Garrison, Richard N.

    2008-01-01

    , Deerfield, Illinois, USA). Conclusions (1) Hyperosmolarity is the major vasoactive component of PD solution. (2) Hyperosmolarity and active intracellular glucose uptake account together for approximately 75% of PD solution-induced dilation, whereas GDPs contribute to approximately 25%. (3) Lactate is vasoactive only at low pH (high [H+]). (4) The magnitude of PD solution-mediated vasodilation is partially dependent on the nature of the osmotic solute, the GDP contents, and the [H+], which determine the vasoactivity of the lactate-buffer anion system. Studies are required to define the molecular mechanisms of PD-induced vasodilation and to determine the vasoactive properties of these solutions after chronic infusion. PMID:18474922

  7. 基于机械轴承飞轮储能系统损耗的构成分析%Loss component analysis of flywheel energy storage system with mechanical bearings

    Institute of Scientific and Technical Information of China (English)

    冯奕; 林鹤云; 颜建虎; 黄允凯

    2013-01-01

    为研究飞轮储能系统(FESS)的性能,设计并制作了一套基于机械轴承的、采用无刷直流电机驱动的飞轮储能系统,对驱动电机及整套系统在转速小于10 000 r/min时的损耗分别进行了测量.分析了电损、风损和轴承损耗3种主要损耗,采用最小二乘法,对电损与转速的关系进行指数函数拟合,对风损、轴承损耗与转速的关系进行了多项式拟合,从而分离了3种损耗.对处于不同待机转速的飞轮储能系统的恒功率放电时间和经历了不同待机时间的能量利用系数进行了计算分析.结果表明:要提高FESS的效率必须采用磁悬浮轴承并将系统置于真空环境中;FESS恒功率放电时间与待机转速成1.8次方关系;待机转速和待机时间是能量利用系数的重要影响因素.研究结果为新能源发电系统对FESS的选择提供了理论依据.%In order to study the performance of flywheel energy storage system (FESS), an FESS with mechanical bearings driven by a brushless DC motor (BLDCM) was designed and manufactured and the loss of BLDCM and the system under 10 000 r/min were tested, respectively. The three main losses including electrical loss, wind loss and bearing loss were analyzed. The least square method was adopted to fit the relationship between the electrical loss and the rotation speed by exponential function and the relationship between the wind loss and bearing loss and the rotation speed by polynomial function, thus separating the three main losses. The discharging time by constant power under different stand-by speeds and the energy utilization ratio through different stand-by time were calculated and analyzed. The result reveals that the magnetic bearings and vacuum environment are extremely important to improve the efficiency of the FESS. Besides, the constant-power discharging time is proportional to the 1. 8th power of the stand-by speed, and the energy utilization ratio is significantly affected

  8. Interactions between photodegradation components

    Directory of Open Access Journals (Sweden)

    Abdollahi Yadollah

    2012-09-01

    Full Text Available Abstract Background The interactions of p-cresol photocatalytic degradation components were studied by response surface methodology. The study was designed by central composite design using the irradiation time, pH, the amount of photocatalyst and the p-cresol concentration as variables. The design was performed to obtain photodegradation % as actual responses. The actual responses were fitted with linear, two factor interactions, cubic and quadratic model to select an appropriate model. The selected model was validated by analysis of variance which provided evidences such as high F-value (845.09, very low P-value (2 = 0.999, adjusted R-squared (Radj2 = 0.998, predicted R-squared (Rpred2 = 0.994 and the adequate precision (95.94. Results From the validated model demonstrated that the component had interaction with irradiation time under 180 min of the time while the interaction with pH was above pH 9. Moreover, photocatalyst and p-cresol had interaction at minimal amount of photocatalyst (p-cresol. Conclusion These variables are interdependent and should be simultaneously considered during the photodegradation process, which is one of the advantages of the response surface methodology over the traditional laboratory method.

  9. One-component nanomedicine.

    Science.gov (United States)

    Su, Hao; Koo, Jin Mo; Cui, Honggang

    2015-12-10

    One-component nanomedicine (OCN) represents an emerging class of therapeutic nanostructures that contain only one type of chemical substance. This one-component feature allows for fine-tuning and optimization of the drug loading and physicochemical properties of nanomedicine in a precise manner through molecular engineering of the underlying building blocks. Using a precipitation procedure or effective molecular assembly strategies, molecularly crafted therapeutic agents (e.g. polymer-drug conjugates, small molecule prodrugs, or drug amphiphiles) could involuntarily aggregate, or self-assemble into nanoscale objects of well-defined sizes and shapes. Unlike traditional carrier-based nanomedicines that are inherently multicomponent systems, an OCN does not require the use of additional carriers and could itself possess desired physicochemical features for preferential accumulation at target sites. We review here recent progress in the molecular design, conjugation methods, and fabrication strategies of OCN, and analyze the opportunities that this emerging platform could open for the new and improved treatment of devastating diseases such as cancer.

  10. Advanced Power Electronics Components

    Science.gov (United States)

    Schwarze, Gene E.

    2004-01-01

    This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

  11. Prognostics for Microgrid Components

    Science.gov (United States)

    Saxena, Abhinav

    2012-01-01

    Prognostics is the science of predicting future performance and potential failures based on targeted condition monitoring. Moving away from the traditional reliability centric view, prognostics aims at detecting and quantifying the time to impending failures. This advance warning provides the opportunity to take actions that can preserve uptime, reduce cost of damage, or extend the life of the component. The talk will focus on the concepts and basics of prognostics from the viewpoint of condition-based systems health management. Differences with other techniques used in systems health management and philosophies of prognostics used in other domains will be shown. Examples relevant to micro grid systems and subsystems will be used to illustrate various types of prediction scenarios and the resources it take to set up a desired prognostic system. Specifically, the implementation results for power storage and power semiconductor components will demonstrate specific solution approaches of prognostics. The role of constituent elements of prognostics, such as model, prediction algorithms, failure threshold, run-to-failure data, requirements and specifications, and post-prognostic reasoning will be explained. A discussion on performance evaluation and performance metrics will conclude the technical discussion followed by general comments on open research problems and challenges in prognostics.

  12. Component Based Testing with ioco

    NARCIS (Netherlands)

    van der Bijl, H.M.; Rensink, Arend; Tretmans, G.J.

    Component based testing concerns the integration of components which have already been tested separately. We show that, with certain restrictions, the ioco-test theory for conformance testing is suitable for component based testing, in the sense that the integration of fully conformant components is

  13. DOE fundamentals handbook: Mechanical science. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    The Mechanical Science Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mechanical components and mechanical science. The handbook includes information diesel engines, heat exchangers, pumps, valves, and miscellaneous mechanical components. This information will provide personnel with a foundation for understanding the construction and operation of mechanical components that are associated with various DOE nuclear facility operations and maintenance.

  14. Food Components and Supplements

    DEFF Research Database (Denmark)

    Parlesak, Alexandr

    2012-01-01

    The major part of food consists of chemical compounds that can be used for energy production, biological synthesis, or maintenance of metabolic processes by the host. These components are defined as nutrients, and can be categorized into macronutrients (proteins, carbohydrates, triglycerides......, and alcohol), minerals, and micronutrients. The latter category comprises 13 vitamins and a hand full of trace elements. Many micronutrients are used as food supplements and are ingested at doses exceeding the amounts that can be consumed along with food by a factor of 10–100. Both macro- and micronutrients....... The supplements and contaminants can compete directly with drug oxidation, induce or suppress the expression of xenobiotic-metabolizing enzymes, change the bioavailability of drugs, and, in the case of live bacteria, bring in their own xenobiotic metabolism, including cytochrome P450 (CYP) activity. In numerous...

  15. Impedance and component heating

    CERN Document Server

    Métral, E; Mounet, N; Pieloni, T; Salvant, B

    2015-01-01

    The impedance is a complex function of frequency, which represents, for the plane under consideration (longitudinal, horizontal or vertical), the force integrated over the length of an element, from a “source” to a “test” wave, normalized by their charges. In general, the impedance in a given plane is a nonlinear function of the test and source transverse coordinates, but it is most of the time sufficient to consider only the first few linear terms. Impedances can influence the motion of trailing particles, in the longitudinal and in one or both transverse directions, leading to energy loss, beam instabilities, or producing undesirable secondary effects such as excessive heating of sensitive components at or near the chamber wall, called beam-induced RF heating. The LHC performance limitations linked to impedances encountered during the 2010-2012 run are reviewed and the currently expected situation during the HL-LHC era is discussed.

  16. Distributed and Parallel Component Library

    Institute of Scientific and Technical Information of China (English)

    XU Zheng-quan; XU Yang; YAN Ai-ping

    2005-01-01

    Software component library is the essential part of reuse-based software development. It is shown that making use of a single component library to store all kinds of components and from which components are searched is very inefficient. We construct multi-libraries to support software reuse and use PVM as development environments to imitate largescale computer, which is expected to fulfill distributed storage and parallel search of components efficiently and improve software reuse.

  17. Sensitivity Analysis of Component Reliability

    Institute of Scientific and Technical Information of China (English)

    ZhenhuaGe

    2004-01-01

    In a system, Every component has its unique position within system and its unique failure characteristics. When a component's reliability is changed, its effect on system reliability is not equal. Component reliability sensitivity is a measure of effect on system reliability while a component's reliability is changed. In this paper, the definition and relative matrix of component reliability sensitivity is proposed, and some of their characteristics are analyzed. All these will help us to analyse or improve the system reliability.

  18. A Systematic Approach to Composing Heterogeneous Components

    Institute of Scientific and Technical Information of China (English)

    HUANGGang; MEIHong; WANGQianxiang; YANGFuqing

    2003-01-01

    As the Component-based software development (CBSD) becomes the prevalent approach to building large-scale distributed systems, the infrastructure of CBSD - middleware - is proliferating. Not only is the existing middleware evolving, but also new middleware has emerged. At the same time, the proliferation of middleware brings a new challenge to CBSD, i.e., how to compose heterogeneous components deployed in different middleware. This issue has received increasing attention from the academia and industry, but the existing solutions lack a systematic view of the CBSD processes and do not provide an open way to extend new mechanisms for interacting with new types of heterogeneous components. In this paper, a systematic approach to composing heterogeneous components is presented. The composition can occur at different lifecycle phases and is automated via a set of CASE (Computer aided software engineering) tools and runtime mechanisms. The feasibility and applicability of the systematic approach are shown by the implementation and case study of composing EJBs (Enterprise JavaBeans) with other heterogeneous components.

  19. Autoignition Chemistry of Surrogate Fuel Components in an Engine Environment

    Science.gov (United States)

    2015-08-21

    Environment David L. Miller and Nicholas P. Cernansky Mechanical Engineering and Mechanics Drexel University, Philadelphia, Pennsylvania, 19104... Engineering and Mechanics Department at Drexel University, and utilized an existing single cylinder research engine facility. The facility...a single-cylinder, variable compression ratio research engine . The program objectives were to determine the branching pathways of JP-8 components at

  20. The incompatibility mechanism based on the interaction of multiple-components for Flos Genkwa and Radix et Rhizoma Glycyrrhizae%基于化学成分相互作用探讨芫花与甘草配伍禁忌的机制

    Institute of Scientific and Technical Information of China (English)

    陈艳琰; 钱大玮; 尚尔鑫; 钱叶飞; 刘培; 宿树兰; 郭建明; 唐于平; 段金廒

    2012-01-01

    通过研究芫花与甘草合煎液中化学成分相互作用及其变化特点,揭示其“反”的可能特征与机制.以中药“十八反”中芫花/醋芫花-甘草多个不同配比组合为研究对象,采用超高效液相色谱串联四级杆飞行时间质谱(UPLC-Q-TOF/MS)及超高效液相色谱串联三重四级杆质谱(UPLC-TQ/MS)联用集成技术,分析其化学成分相互作用及其变化特点.结果表明,芫花/醋芫花-甘草不同配比合煎对其中化学物质的溶出具有一定的规律性,芫花不论醋炙与否,与甘草合煎时,随甘草比例升高,芫花中二萜类等毒性成分溶出明显提高,尤其对芫花酯甲、芫花酯乙及芫花酯已的溶出影响最为显著.从反药合煎过程化学物质相互作用促使毒性成分的溶出释放增加导致配伍禁忌的角度,揭示了甘草所含化学成分促使芫花中二萜类等毒性物质的溶出释放增加是芫花与甘草配伍禁忌的物质基础和可能机制之一.%By investigating the interaction between components from Flos Genkwa (FG) and Radix et Rhizoma Glycyrrhizae (RRG) and the dissolution profile of toxic components in co-decoction, the characteristics and possible mechanism of incompatibility were revealed. Ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and ultra-high performance liquid chromatography triple-quadrupole mass spectrometry (UPLC-TQ/MS) were used to analyze multi-components in different herb extractions prepared by different ratios of FG/FG processed by vinegar (FGV) and RRG, which reflect the interaction and characteristics of multiple components in incompatibility combinations. The results showed that the components dissolution was influenced by compatibility ratio with certain regularity. Whether FG processed by vinegar or not, with the increase of RRG in co-decoction, the dissolution of diterpenes, especially for yuanhuacine, yuanhuadine and yuanhuajine, the

  1. Component Composition Using Feature Models

    DEFF Research Database (Denmark)

    Eichberg, Michael; Klose, Karl; Mitschke, Ralf;

    2010-01-01

    In general, components provide and require services and two components are bound if the first component provides a service required by the second component. However, certain variability in services - w.r.t. how and which functionality is provided or required - cannot be described using standard...... interface description languages. If this variability is relevant when selecting a matching component then human interaction is required to decide which components can be bound. We propose to use feature models for making this variability explicit and (re-)enabling automatic component binding. In our...... approach, feature models are one part of service specifications. This enables to declaratively specify which service variant is provided by a component. By referring to a service's variation points, a component that requires a specific service can list the requirements on the desired variant. Using...

  2. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    to breakage without any warning or ductility, which can be catastrophic if no precautions are taken. One aspect of this issue is treated here by looking at the possibility of mechanically reinforcing glass beams in order to obtain ductile failure for such a structural component. A mechanically reinforced...... the mechanical behavior of the beam is explained. Finally, some design criterions for reinforced glass beams are discussed....

  3. Surface Active Components: Review

    Directory of Open Access Journals (Sweden)

    Z. Shafiei

    2014-03-01

    Full Text Available Biosurfactant or surface active components are produced by many different microorganisms. Biosurfactants are amphiphilic molecules with both hydrophilic and hydrophobic (generally hydrocarbon moieties that partition preferentially a within the interface between fluid phases with some other degrees of polarity and hydrogen bonding including oil/water or air/water interfaces. These properties render surfactants able to reducing surface and interfacial tension and forming microemulsion where hydrocarbons can solubilize in water or where water can solubilize in hydrocarbons, the majority of surfactants have gained importance in the fields of enhanced oil recovery, environmental bioremediation, food processing and pharmaceuticals. However, large-scale production of these molecules has not been realized as a result of low yields in production processes and high recovery and purification costs. This review article represents a classification of biosurfactant in addition to their microbial origin and effect of some nutrition and environmental factor for high production of biosurfactant. The nitrogen, carbon sources and environmental factors can make a difference key to the regulating biosurfactants synthesis Fascination with microbial surfactants have been steadily increasing recently because of advantages over the chemical surfactants for example environmentally friendly nature, lower toxicity, higher biodegradability, higher selectivity and specific gravity at extreme temperature, pH and salinity. For this reason the demand of biosurfactant are increasing day by day.

  4. Local Component Analysis

    CERN Document Server

    Roux, Nicolas Le

    2011-01-01

    Kernel density estimation, a.k.a. Parzen windows, is a popular density estimation method, which can be used for outlier detection or clustering. With multivariate data, its performance is heavily reliant on the metric used within the kernel. Most earlier work has focused on learning only the bandwidth of the kernel (i.e., a scalar multiplicative factor). In this paper, we propose to learn a full Euclidean metric through an expectation-minimization (EM) procedure, which can be seen as an unsupervised counterpart to neighbourhood component analysis (NCA). In order to avoid overfitting with a fully nonparametric density estimator in high dimensions, we also consider a semi-parametric Gaussian-Parzen density model, where some of the variables are modelled through a jointly Gaussian density, while others are modelled through Parzen windows. For these two models, EM leads to simple closed-form updates based on matrix inversions and eigenvalue decompositions. We show empirically that our method leads to density esti...

  5. Mechanisms and Components of the DNA Damage Checkpoint

    Science.gov (United States)

    2002-09-01

    Saccharomyces cerevisiae DNA damage checkpoint. Molecular Cell 9: 1055-1065. (reprint included as Appendix 2) "* Schwartz, M.F., Duong, J.K., Sun, Z., Pradhan...phosphorylation sites couple Rad53 to the Saccharomyces cerevisiae DNA damage checkpoint. Molecular Cell 9, 1055-1065. 13 Molecular Cell , Vol. 9,1055-1065...Cambridge, Massachusetts 02139. 1999), and mutation of conserved amino acids in the Molecular Cell 1056 A Rad9 B ,•o 0, 1 sitesN NC -T6 RVTQSA o- 0~ --T240

  6. [Origin, components and mechanisms of action of the Mediterranean diet].

    Science.gov (United States)

    Urquiaga, Inés; Echeverría, Guadalupe; Dussaillant, Catalina; Rigotti, Attilio

    2017-01-01

    The Mediterranean diet is currently considered a healthy dietary pattern. It includes a great variety of foods, which are eaten in moderation and within a positive social environment. The generic term "Mediterranean diet" was born after the "Seven Countries Study" led by Ancel Keys around 1960. This dietary pattern is characterized by a high intake of fruits and vegetables, whole grains, legumes, nuts, fish, white meats and olive oil. It also includes moderate consumption of fermented dairy products, low intake of red meat and drinking wine with moderation during meals. Nutritionally, this diet is low in saturated fats and animal protein, high in antioxidants, fiber and monounsaturated fats, and exhibits an adequate omega-6/omega-3 fatty acid balance. The main bioactive compounds, which explain the health benefits of this dietary pattern, are antioxidants, fiber, monounsaturated and omega-3 fatty acids, phytosterols and probiotics. This diet is not exclusively confined to the Mediterranean Basin. Central Chile has a Mediterranean climate and our agriculture and culinary traditions are similar to those found in Mediterranean countries. Therefore, it is fundamental to increase awareness about the richness of our natural produce as well as our culinary culture, which may bring many health benefits and improve the quality of life in our population.

  7. Mechanical Behaviour of Masonry Components, Monitored by Elastic Wave Method

    OpenAIRE

    Garrido Bernal, Jaime

    2016-01-01

    El mundo de la construcción en un campo que no se detiene nunca, que está en continuo proceso de innovación día tras día y en el que están involucrados muchísimos ámbitos, tanto de la ingeniería como de la vida cotidiana en general. A parte de los nuevas construcciones y edificios, se llevan siglos creando infraestructuras usadas por todos los hombres así como por vehículos. El paso del tiempo y la influencia de la erosión y desgaste pasan factura a todas estas infraestructuras, con lo que es...

  8. Thermophysical Properties of 60-NITINOL for Mechanical Component Applications

    Science.gov (United States)

    Stanford, Malcolm K.

    2012-01-01

    The linear thermal expansion coefficient, specific heat capacity, electrical resistivity and thermal conductivity of 60- NITINOL were studied over a range of temperatures representing the operating environment of an oil-lubricated bearing. The behavior of this material appears to follow wellestablished theories applicable to either metal alloys, in general, or to intermetallic compounds, more specifically and the measured data were found to be comparable to those for conventional bearing alloys.

  9. Towards Prognostics for Electronics Components

    Data.gov (United States)

    National Aeronautics and Space Administration — Electronics components have an increasingly critical role in avionics systems and in the development of future aircraft systems. Prognostics of such components is...

  10. Formalization in Component Based Development

    DEFF Research Database (Denmark)

    Holmegaard, Jens Peter; Knudsen, John; Makowski, Piotr;

    2006-01-01

    We present a unifying conceptual framework for components, component interfaces, contracts and composition of components by focusing on the collection of properties or qualities that they must share. A specific property, such as signature, functionality behaviour or timing is an aspect. Each aspe...... by small examples, using UML as concrete syntax for various aspects, and is illustrated by one larger case study based on an industrial prototype of a complex component based system....

  11. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2016-05-17

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  12. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2015-12-15

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  13. Multilevel Contracts for Trusted Components

    CERN Document Server

    Messabihi, Mohamed; Attiogbé, Christian; 10.4204/EPTCS.37.6

    2010-01-01

    This article contributes to the design and the verification of trusted components and services. The contracts are declined at several levels to cover then different facets, such as component consistency, compatibility or correctness. The article introduces multilevel contracts and a design+verification process for handling and analysing these contracts in component models. The approach is implemented with the COSTO platform that supports the Kmelia component model. A case study illustrates the overall approach.

  14. Formalization in Component Based Development

    DEFF Research Database (Denmark)

    Holmegaard, Jens Peter; Knudsen, John; Makowski, Piotr

    2006-01-01

    We present a unifying conceptual framework for components, component interfaces, contracts and composition of components by focusing on the collection of properties or qualities that they must share. A specific property, such as signature, functionality behaviour or timing is an aspect. Each aspect...

  15. Key optical components for spaceborne lasers

    Science.gov (United States)

    Löhring, J.; Winzen, M.; Faidel, H.; Miesner, J.; Plum, D.; Klein, J.; Fitzau, O.; Giesberts, M.; Brandenburg, W.; Seidel, A.; Schwanen, N.; Riesters, D.; Hengesbach, S.; Hoffmann, H.-D.

    2016-03-01

    Spaceborne lidar (light detection and ranging) systems have a large potential to become powerful instruments in the field of atmospheric research. Obviously, they have to be in operation for about three years without any maintenance like readjusting. Furthermore, they have to withstand strong temperature cycles typically in the range of -30 to +50 °C as well as mechanical shocks and vibrations, especially during launch. Additionally, the avoidance of any organic material inside the laser box is required, particularly in UV lasers. For atmospheric research pulses of about several 10 mJ at repetition rates of several 10 Hz are required in many cases. Those parameters are typically addressed by DPSSL that comprise components like: laser crystals, nonlinear crystals in pockels cells, faraday isolators and frequency converters, passive fibers, diode lasers and of course a lot of mirrors and lenses. In particular, some components have strong requirements regarding their tilt stability that is often in the 10 μrad range. In most of the cases components and packages that are used for industrial lasers do not fulfil all those requirements. Thus, the packaging of all these key components has been developed to meet those specifications only making use of metal and ceramics beside the optical component itself. All joints between the optical component and the laser baseplate are soldered or screwed. No clamps or adhesives are used. Most of the critical properties like tilting after temperature cycling have been proven in several tests. Currently, these components are used to build up first prototypes for spaceborne systems.

  16. Component-specific modeling. [jet engine hot section components

    Science.gov (United States)

    Mcknight, R. L.; Maffeo, R. J.; Tipton, M. T.; Weber, G.

    1992-01-01

    Accomplishments are described for a 3 year program to develop methodology for component-specific modeling of aircraft hot section components (turbine blades, turbine vanes, and burner liners). These accomplishments include: (1) engine thermodynamic and mission models, (2) geometry model generators, (3) remeshing, (4) specialty three-dimensional inelastic structural analysis, (5) computationally efficient solvers, (6) adaptive solution strategies, (7) engine performance parameters/component response variables decomposition and synthesis, (8) integrated software architecture and development, and (9) validation cases for software developed.

  17. SBA Network Components & Software Inventory

    Data.gov (United States)

    Small Business Administration — SBA’s Network Components & Software Inventory contains a complete inventory of all devices connected to SBA’s network including workstations, servers, routers,...

  18. Connected Component Labeling Using Components Neighbors-Scan Labeling Approach

    Directory of Open Access Journals (Sweden)

    Akmal Rakhmadi

    2010-01-01

    Full Text Available Problem statement: Many approaches have been proposed in previous such as the classic sequential connected components labeling algorithm which is relies on two subsequent raster-scans of a binary image. This method produced good performance in terms of accuracy, but because of the implementation of the image processing systems now requires faster process of the computer, the speed of this technique’s process has become an important issue. Approach: A computational approach, called components neighbors-scan labeling algorithm for connected component labeling was presented in this study. This algorithm required scanning through an image only once to label connected components. The algorithm started by scanning from the head of the component’s group, before tracing all the components neighbors by using the main component’s information. This algorithm had desirable characteristics, it is simple while promoted accuracy and low time consuming. By using a table of components, this approach also gave other advantages as the information for the next higher process. Results: The approach had been tested with a collection of binary images. In practically all cases, the technique had successfully given the desired result. Averagely, from the results the algorithm increased the speed around 67.4% from the two times scanning method. Conclusion: Conclusion from the comparison with the previous method, the approach of components neighbors-scan for connected component labeling promoted speed, accuracy and simplicity. The results showed that the approach has a good performance in terms of accuracy, the time consumed and the simplicity of the algorithm.

  19. Outcome and complications of constrained acetabular components.

    Science.gov (United States)

    Yang, Cao; Goodman, Stuart B

    2009-02-01

    Constrained acetabular liners were developed for the surgical treatment of recurrent instability by holding the femoral head captive within the socket. This article summarizes the data describing constrained component designs, indications, outcome, and complications. Different designs accept head sizes of varying diameter and have differing amounts of rim elevation and offset, allowing slight variations in the range of movement allowed. Complications of constrained acetabular components can be divided into three categories. The first category is directly related to the constraining mechanism such as dislocation, head dissociation from the stem, liner dissociation from the acetabular device, and impingement with or without locking ring breakage. The second category is related to increased constraint such as aseptic component loosening and osteolysis and periprosthetic fracture. The third category includes those cases not associated with increased constraint such as infection, deep vein thrombosis, and periprosthetic fracture. This device is effective at achieving hip stability, but the complications related to the constraining mechanism and increased constraint are of concern. These devices should be used as a salvage measure for the treatment of severe instability.

  20. High Temperature Electromechanical Components for Control Rod Drive Assemblies

    Science.gov (United States)

    Gleason, Thomas E.; Lazarus, Jonathan D.; Yaspo, Robert; Cole, Allan R.; Otwell, Robert L.; Schuster, Gary B.; Jaing, Thomas J.; Meyer, Raymond A.; Shukla, Jaikaran N.; Maldonado, Jerry

    1994-07-01

    The SP-100 power system converts heat generated within a compact fast spectrum nuclear reactor directly to electricity for spacecraft applications. The reactor control system contains the only moving mechanical and electromechanical components in the entire electrical generating system. The high temperature, vacuum environment presents unique challenges for these reactor control system components. This paper describes the environmental testing of these components that has been completed and that is in progress. The specific components and assemblies include electromagnetic (EM) coils, stepper motors, EM clutches, EM brakes, ball bearings, ball screw assemblies, constant torque spring motors, gear sets, position sensors, and very high temperature sliding bearings.

  1. Pressure and compressibility in a quantum one-component plasma

    NARCIS (Netherlands)

    John, P.; Suttorp, L.G.

    1994-01-01

    With the help of scaling methods, a general relation is established between the thermodynamic pressure and the mechanical pressure tensor of an equilibrium one-component plasma in a magnetic field. The mechanical pressure tenser is shown to be anisotropic. A general proof of the compressibility sum

  2. Unblockable Compositions of Software Components

    DEFF Research Database (Denmark)

    Dong, Ruzhen; Faber, Johannes; Liu, Zhiming

    2012-01-01

    . To this end, we develop an algorithm to compute the unblockable interaction behavior, called the interface model of a component, from its execution model. Based on this model, we introduce composition operators for the components and prove important compositionality results, showing the conditions under which...

  3. Secure coupling of hardware components

    NARCIS (Netherlands)

    Knobbe, J.W.; Hoepman, J.H.; Joosten, H.J.M.

    2011-01-01

    A method and a system for securing communication between at least a first and a second hardware components of a mobile device is described. The method includes establishing a first shared secret between the first and the second hardware components during an initialization of the mobile device and, f

  4. Active components in food supplements

    NARCIS (Netherlands)

    Siemelink M; Jansen EHJM; Piersma AH; Opperhuizen A; LEO

    2000-01-01

    The growing food supplement market, where supplements are both more diverse and more easily available (e.g. through Internet) formed the backdrop to the inventory of the active components in food supplements. The safety of an increased intake of food components via supplements was also at issue her

  5. Regularized Generalized Structured Component Analysis

    Science.gov (United States)

    Hwang, Heungsun

    2009-01-01

    Generalized structured component analysis (GSCA) has been proposed as a component-based approach to structural equation modeling. In practice, GSCA may suffer from multi-collinearity, i.e., high correlations among exogenous variables. GSCA has yet no remedy for this problem. Thus, a regularized extension of GSCA is proposed that integrates a ridge…

  6. Statistical inference on variance components

    NARCIS (Netherlands)

    Verdooren, L.R.

    1988-01-01

    In several sciences but especially in animal and plant breeding, the general mixed model with fixed and random effects plays a great role. Statistical inference on variance components means tests of hypotheses about variance components, constructing confidence intervals for them, estimating them,

  7. Components of Successful Magnet Schools.

    Science.gov (United States)

    Bryant, Faye B.

    This paper identifies and discusses components of successful magnet programs. It is based on a review of existing research literature and information gathered directly from school districts. First, the paper discusses separately the following elements, which are considered "core components": (1) leadership; (2) organizational structure; (3)…

  8. Semantic Annotation of Computational Components

    Science.gov (United States)

    Vanderbilt, Peter; Mehrotra, Piyush

    2004-01-01

    This paper describes a methodology to specify machine-processable semantic descriptions of computational components to enable them to be shared and reused. A particular focus of this scheme is to enable automatic compositon of such components into simple work-flows.

  9. Oxygen Compatibility Assessment of Components and Systems

    Science.gov (United States)

    Stoltzfus, Joel; Sparks, Kyle

    2010-01-01

    Fire hazards are inherent in oxygen systems and a storied history of fires in rocket engine propulsion components exists. To detect and mitigate these fire hazards requires careful, detailed, and thorough analyses applied during the design process. The oxygen compatibility assessment (OCA) process designed by NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) can be used to determine the presence of fire hazards in oxygen systems and the likelihood of a fire. This process may be used as both a design guide and during the approval process to ensure proper design features and material selection. The procedure for performing an OCA is a structured step-by-step process to determine the most severe operating conditions; assess the flammability of the system materials at the use conditions; evaluate the presence and efficacy of ignition mechanisms; assess the potential for a fire to breach the system; and determine the reaction effect (the potential loss of life, mission, and system functionality as the result of a fire). This process should be performed for each component in a system. The results of each component assessment, and the overall system assessment, should be recorded in a report that can be used in the short term to communicate hazards and their mitigation and to aid in system/component development and, in the long term, to solve anomalies that occur during engine testing and operation.

  10. The integrity concept and its implementation; Das Integritaetskonzept und seine praktische Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    Roos, E.; Herter, K.H.; Schuler, X. [Stuttgart Univ. (Germany). MPA; Koenig, G. [EnBW Kernkraft GmbH, Neckarwestheim (Germany)

    2008-07-01

    The safety of nuclear power plants is mainly based on the assumption that operational and accidental loads on mechanical components and systems that must not fail due to their safety relevant importance can be controlled. This implies that the respective quality is available and assured over the complete projected lifetime. In this context the term ''break preclusion'' is often used which is commonly defined as the ''leak-before-break'' demonstration based on fracture mechanical analysis in connection with fulfilled basic safety for design and manufacture. Usually it is not taken into account that for guaranteed break preclusion the controllability of any possible operational damage mechanism is of crucial importance. On the contrary, the integrity concept as implementation of the basic safety concept taking into account the particular plant-specific preconditions constitutes a closed master plan that accommodates for the necessity of a multi-level safeguarding and continuous actualization. The integrity concept is part of the aging management for mechanical components and systems. The practical implementation of this concept for integrity confirmation is demonstrated for the case of the feed water lines within the containment of the NPP GKN1. [German] Die Sicherheit von Kernkraftwerken basiert wesentlichen darauf, dass die aus betrieblichen Belastungen und aus postulierten Stoerfallen resultierenden Beanspruchungen mechanischer Komponenten und Systeme, die entsprechend ihrer sicherheitstechnischen Bedeutung nicht versagen duerfen, sicher beherrscht werden koennen. Dies setzt voraus, dass die hierzu erforderliche Qualitaet ueber die gesamte Betriebszeit zur Verfuegung steht. Oft wird in diesem Zusammenhang der Begriff ''Bruchausschluss'' verwendet, unter dem haeufig ausschliesslich der ''Leck-vor-Bruch''-Nachweis durch eine bruchmechanische Analyse in Verbindung mit einer basissicheren Auslegung und Herstellung verstanden wird. Dabei wird nicht beruecksichtigt

  11. A potent dauer pheromone component in Caenorhabditis elegans that acts synergistically with other components.

    Science.gov (United States)

    Butcher, Rebecca A; Ragains, Justin R; Kim, Edward; Clardy, Jon

    2008-09-23

    In the model organism Caenorhabditis elegans, the dauer pheromone is the primary cue for entry into the developmentally arrested, dauer larval stage. The dauer is specialized for survival under harsh environmental conditions and is considered "nonaging" because larvae that exit dauer have a normal life span. C. elegans constitutively secretes the dauer pheromone into its environment, enabling it to sense its population density. Several components of the dauer pheromone have been identified as derivatives of the dideoxy sugar ascarylose, but additional unidentified components of the dauer pheromone contribute to its activity. Here, we show that an ascaroside with a 3-hydroxypropionate side chain is a highly potent component of the dauer pheromone that acts synergistically with previously identified components. Furthermore, we show that the active dauer pheromone components that are produced by C. elegans vary depending on cultivation conditions. Identifying the active components of the dauer pheromone, the conditions under which they are produced, and their mechanisms of action will greatly extend our understanding of how chemosensory cues from the environment can influence such fundamental processes as development, metabolism, and aging in nematodes and in higher organisms.

  12. Component reliability for electronic systems

    CERN Document Server

    Bajenescu, Titu-Marius I

    2010-01-01

    The main reason for the premature breakdown of today's electronic products (computers, cars, tools, appliances, etc.) is the failure of the components used to build these products. Today professionals are looking for effective ways to minimize the degradation of electronic components to help ensure longer-lasting, more technically sound products and systems. This practical book offers engineers specific guidance on how to design more reliable components and build more reliable electronic systems. Professionals learn how to optimize a virtual component prototype, accurately monitor product reliability during the entire production process, and add the burn-in and selection procedures that are the most appropriate for the intended applications. Moreover, the book helps system designers ensure that all components are correctly applied, margins are adequate, wear-out failure modes are prevented during the expected duration of life, and system interfaces cannot lead to failure.

  13. Phylogenetic Co-Occurrence of ExoR, ExoS, and ChvI, Components of the RSI Bacterial Invasion Switch, Suggests a Key Adaptive Mechanism Regulating the Transition between Free-Living and Host-Invading Phases in Rhizobiales.

    Directory of Open Access Journals (Sweden)

    Mary Ellen Heavner

    Full Text Available Both bacterial symbionts and pathogens rely on their host-sensing mechanisms to activate the biosynthetic pathways necessary for their invasion into host cells. The Gram-negative bacterium Sinorhizobium meliloti relies on its RSI (ExoR-ExoS-ChvI Invasion Switch to turn on the production of succinoglycan, an exopolysaccharide required for its host invasion. Recent whole-genome sequencing efforts have uncovered putative components of RSI-like invasion switches in many other symbiotic and pathogenic bacteria. To explore the possibility of the existence of a common invasion switch, we have conducted a phylogenomic survey of orthologous ExoR, ExoS, and ChvI tripartite sets in more than ninety proteobacterial genomes. Our analyses suggest that functional orthologs of the RSI invasion switch co-exist in Rhizobiales, an order characterized by numerous invasive species, but not in the order's close relatives. Phylogenomic analyses and reconstruction of orthologous sets of the three proteins in Alphaproteobacteria confirm Rhizobiales-specific gene synteny and congruent RSI evolutionary histories. Evolutionary analyses further revealed site-specific substitutions correlated specifically to either animal-bacteria or plant-bacteria associations. Lineage restricted conservation of any one specialized gene is in itself an indication of species adaptation. However, the orthologous phylogenetic co-occurrence of all interacting partners within this single signaling pathway strongly suggests that the development of the RSI switch was a key adaptive mechanism. The RSI invasion switch, originally found in S. meliloti, is a characteristic of the Rhizobiales, and potentially a conserved crucial activation step that may be targeted to control host invasion by pathogenic bacterial species.

  14. Durability Improvements Through Degradation Mechanism Studies

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baker, Andrew M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lujan, Roger W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Langlois, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahluwalia, Rajesh [Argonne National Lab. (ANL), Argonne, IL (United States); Papadia, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Weber, Adam Z. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kusoglu, Ahmet [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shi, Shouwnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); More, K. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Grot, Steve [Ion Power, New Castle, DE (United States)

    2015-08-03

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. By investigating cell component degradation modes and defining the fundamental degradation mechanisms of components and component interactions, new materials can be designed to improve durability. To achieve a deeper understanding of PEM fuel cell durability and component degradation mechanisms, we utilize a multi-institutional and multi-disciplinary team with significant experience investigating these phenomena.

  15. Air-Conditioning Mechanic.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by air conditioning mechanics. Addressed in the four chapters, or lessons, of the manual are the following topics: principles of air conditioning, refrigeration components as…

  16. Mechanical Measurements Laboratory

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    The CERN mechanical measurements team check the sensors on one of the ATLAS inner detector end-caps using high precision measurement equipment. Remote checks like this must be made on these sensitive detector components before they can be transported to make sure that all systems are working correctly.

  17. Vacuum Brazing of Accelerator Components

    Science.gov (United States)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  18. Progress in research on possible role of progesterone receptor membrane component 1 (PGRMC1) in the mechanism of breast cancer development%孕激素受体膜组分1在乳腺癌发生机制中作用的研究进展

    Institute of Scientific and Technical Information of China (English)

    张颖; 阮祥燕; Alfred O. Mueck

    2015-01-01

    Breast cancer is one of the most common leading cause of cancers death in women world-wide. But the mechanism of breast cancer development is still unclear. The only placebo-controlled study, the Women’s Health Initiative(WHI) demonstrated that breast cancer risk mainly is dependent on the progestogen component since only in the combined estrogen/progestogen arm, but not in the estrogen-only arm this risk was seen to increase the risk. According to this finding, our previous investigation point towards an important role of progesterone receptor membrane component 1 ( PGRMC1 ) in hormone related breast cancer risk. This finding got great attention from the related field in the world. An editorial published in the journal Menopause raised the following questions: “Can the increase in breast cancer observed in the estrogen plus progestin arm of the Women’ s Health Initiative trial be explained by progesterone receptor membrane component 1? Can the PGRMC1 become to be a potential marker in the future? Will the women with high expression of PGRMC1 be breast cancer susceptible people?” We will review the results of related researches.%乳腺癌是导致女性死亡的主要癌症之一,但目前为止关于乳腺癌的发生机制尚未完全明确。唯一一项全球大型安慰剂对照研究,妇女健康启动项目(Women’s Health Initiative,WHI)指出,雌孕激素联合治疗组乳腺癌风险增高,单一雌激素治疗组妇女的乳腺癌风险没有增加,反而有降低,说明在激素补充治疗( hormone replacement therapy,HRT)治疗中孕激素对乳腺癌风险具有负面影响。针对此结论开展了很多体外研究,发现雌孕激素联合治疗可以明显促进孕激素受体膜组分1( progesterone receptor membrane component 1,PGRMC1)表达阳性的乳腺癌细胞的增生。针对此结论,北美绝经学会官方科学杂志Menopause对此给予特别的编者按:“WHI研究中雌孕激素联合治疗组妇女乳腺癌

  19. Puzzling Mechanisms

    Science.gov (United States)

    van Deventer, M. Oskar

    2009-01-01

    The basis of a good mechanical puzzle is often a puzzling mechanism. This article will introduce some new puzzling mechanisms, like two knots that engage like gears, a chain whose links can be interchanged, and flat gears that do not come apart. It illustrates how puzzling mechanisms can be transformed into real mechanical puzzles, e.g., by…

  20. Electronic components, tubes and transistors

    CERN Document Server

    Dummer, G W A

    1965-01-01

    Electronic Components, Tubes and Transistors aims to bridge the gap between the basic measurement theory of resistance, capacitance, and inductance and the practical application of electronic components in equipments. The more practical or usage aspect of electron tubes and semiconductors is given emphasis over theory. The essential characteristics of each main type of component, tube, and transistor are summarized. This book is comprised of six chapters and begins with a discussion on the essential characteristics in terms of the parameters usually required in choosing a resistor, including s

  1. Component Based Electronic Voting Systems

    Science.gov (United States)

    Lundin, David

    An electronic voting system may be said to be composed of a number of components, each of which has a number of properties. One of the most attractive effects of this way of thinking is that each component may have an attached in-depth threat analysis and verification strategy. Furthermore, the need to include the full system when making changes to a component is minimised and a model at this level can be turned into a lower-level implementation model where changes can cascade to as few parts of the implementation as possible.

  2. Electrical Components Library for HAWC2

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos A.; Larsen, Torben J.; Sørensen, Poul

    and Aalborg University. In this project, the focus is on the development of a simulation platform for wind turbine systems using different simulation tools. This report presents the electric component library developed for use in the aeroelastic code HAWC2. The developed library includes both steady state...... was developed. The model includes the dynamics of the rotor fluxes. The model is suitable for a more detailed investigation of the mechanical - electrical interaction, both under normal and fault operation. For the variable speed wind turbine, a steadystate model, typically used in aeroelastic design...

  3. Electrical components library for HAWC2

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Larsen, Torben J.; Sørensen, Poul Ejnar

    and Aalborg University. In this project, the focus is on the development of a simulation platform for wind turbine systems using different simulation tools. This report presents the electric component library developed for use in the aeroelastic code HAWC2. The developed library includes both steady state...... was developed. The model includes the dynamics of the rotor fluxes. The model is suitable for a more detailed investigation of the mechanical – electrical interaction, both under normal and fault operation. For the variable speed wind turbine, a steadystate model, typically used in aeroelastic design...

  4. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    State-of-the-art microwave systems always require higher performance and lower cost microwave components. Constantly growing demands and performance requirements of industrial and scientific applications often make employing traditionally designed components impractical. For that reason, the design...... and development process remains a great challenge today. This problem motivated intensive research efforts in microwave design and technology, which is responsible for a great number of recently appeared alternative approaches to analysis and design of microwave components and antennas. This book highlights...... techniques. Modelling and computations in electromagnetics is a quite fast-growing research area. The recent interest in this field is caused by the increased demand for designing complex microwave components, modeling electromagnetic materials, and rapid increase in computational power for calculation...

  5. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    techniques. Modelling and computations in electromagnetics is a quite fast-growing research area. The recent interest in this field is caused by the increased demand for designing complex microwave components, modeling electromagnetic materials, and rapid increase in computational power for calculation......State-of-the-art microwave systems always require higher performance and lower cost microwave components. Constantly growing demands and performance requirements of industrial and scientific applications often make employing traditionally designed components impractical. For that reason, the design...... and development process remains a great challenge today. This problem motivated intensive research efforts in microwave design and technology, which is responsible for a great number of recently appeared alternative approaches to analysis and design of microwave components and antennas. This book highlights...

  6. Plasmonic components fabrication via nanoimprint

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra

    2009-01-01

    A review report on nanoimprinted plasmonic components is given. The fabrication of different metal–dielectric geometries and nanostructured surfaces that support either propagating or localized surface plasmon modes is discussed. The main characteristics and advantages of the nanoimprint technolo...

  7. Metallurgical Laboratory and Components Testing

    Data.gov (United States)

    Federal Laboratory Consortium — In the field of metallurgy, TTC is equipped to run laboratory tests on track and rolling stock components and materials. The testing lab contains scanning-electron,...

  8. Formal aspects of component software

    OpenAIRE

    Sun, Meng; Schatz, B.

    2014-01-01

    This issue includes extended versions of selected best papers from the 7th International Workshop on Formal Aspects of Component Software (FACS 2010) held in Guimarães, Portugal on October 14–16, 2010. The component-based software development approach has emerged as a promising paradigm to cope with an ever increasing complexity of present-day software solutions by bringing sound production and engineering principles into software engineering. However, many conceptual and technological iss...

  9. Multiview Bayesian Correlated Component Analysis

    DEFF Research Database (Denmark)

    Kamronn, Simon Due; Poulsen, Andreas Trier; Hansen, Lars Kai

    2015-01-01

    we denote Bayesian correlated component analysis, evaluates favorably against three relevant algorithms in simulated data. A well-established benchmark EEG data set is used to further validate the new model and infer the variability of spatial representations across multiple subjects....... are identical. Here we propose a hierarchical probabilistic model that can infer the level of universality in such multiview data, from completely unrelated representations, corresponding to canonical correlation analysis, to identical representations as in correlated component analysis. This new model, which...

  10. Enabling Technologies for Ceramic Hot Section Components

    Energy Technology Data Exchange (ETDEWEB)

    Venkat Vedula; Tania Bhatia

    2009-04-30

    Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navy applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section

  11. Turbine component, turbine blade, and turbine component fabrication process

    Energy Technology Data Exchange (ETDEWEB)

    Delvaux, John McConnell; Cairo, Ronald Ralph; Parolini, Jason Robert

    2017-05-30

    A turbine component, a turbine blade, and a turbine component fabrication process are disclosed. The turbine component includes ceramic matrix composite plies and a feature configured for preventing interlaminar tension of the ceramic matrix composite plies. The feature is selected from the group consisting of ceramic matrix composite tows or precast insert tows extending through at least a portion of the ceramic matrix composite plies, a woven fabric having fiber tows or a precast insert preventing contact between a first set of the ceramic matrix composite plies and a second set of the ceramic matrix composite plies, and combinations thereof. The process includes laying up ceramic matrix composite plies in a preselected arrangement and securing a feature configured for interlaminar tension.

  12. Creep fatigue assessment for EUROFER components

    Energy Technology Data Exchange (ETDEWEB)

    Özkan, Furkan, E-mail: oezkan.furkan@partner.kit.edu; Aktaa, Jarir

    2015-11-15

    Highlights: • Design rules for creep fatigue assessment are developed to EUROFER components. • Creep fatigue assessment tool is developed in FORTRAN code with coupling MAPDL. • Durability of the HCPB-TBM design is discussed under typical fusion reactor loads. - Abstract: Creep-fatigue of test blanket module (TBM) components built from EUROFER is evaluated based on the elastic analysis approach in ASME Boiler Pressure Vessel Code (BPVC). The required allowable number of cycles design fatigue curve and stress-to-rupture curve to estimate the creep-fatigue damage are used from the literature. Local stress, strain and temperature inputs for the analysis of creep-fatigue damage are delivered by the finite element code ANSYS utilizing the Mechanical ANSYS Parametric Design Language (MAPDL). A developed external FORTRAN code used as a post processor is coupled with MAPDL. Influences of different pulse durations (hold-times) and irradiation on creep-fatigue damage for the preliminary design of the Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM) are discussed for the First Wall component of the TBM box.

  13. Effect of main components of environmental-friendly no-clean flux on its corrosivity and its mechanism%环保型免清洗助焊剂组分对其腐蚀性能的影响及其机理

    Institute of Scientific and Technical Information of China (English)

    郝志峰; 吴青青; 郭奕鹏; 饶耀; 孙明; 余坚

    2012-01-01

    主要研究活化剂、表面活性剂和缓蚀剂3种组分对环保型免清洗助焊剂腐蚀性能的影响.采用交流阻抗法研究了各组分对铜电极缓蚀性能的影响;通过扫描电镜观察测试了各组分对梳形试件的腐蚀;借助热分析研究了组分残留及相互作用.结果表明,随活化剂酸性的减弱,助焊剂体系的腐蚀性逐渐减弱;壬基酚聚氧乙烯醚系列的非离子表面活性剂有助于降低体系的腐蚀性能;缓蚀剂苯并三氮唑(BTA)的添加能显著改善助焊剂体系的缓蚀性能.用壬基酚聚氧乙烯(50)醚(w-0.2%)作表面活性剂、丁二酸和苹果酸复配(w=1.6%)作活化剂,BTA作缓蚀剂(w=0.06%)制备的助焊剂体系的膜电阻最大,在湿热条件下助焊剂对梳形试件的腐蚀明显降低,缓蚀性能最佳.热分析结果表明,体系缓蚀性能的改善可能是有机酸与丙三醇发生的酯化反应所致.%The influence of three main components of environmental-friendly no-clean flux (activator, surfactant and inhibitor) on its corrosivity was studied. The effect of different components on the copper electrode inhibition performance was studied by using alternating current (AC) impedance. The surface corrosion of three main components on comb patterns was also observed with scanning electron microscope! and the residue of flux and interaction were tested by thermal analysis. The results showed that the structure and acidity of the activator had some effect on the corrosivity of the flux. The weaker the acid, the weaker the corrosivity of the flux. The corrosion inhibition of the flux could be improved by the addition of polyoxyethylene nonyl phenyl ether as nonionic surfactant. With benzotriazole (BTA) as inhibitor, the corrosion inhibition performance of the flux was promoted effectively. The results showed that the no-clean flux, using polyoxyethylene nonyl phenyl ether (50)(wj=0. 2%) as surfactant, showed lower surface tension and better

  14. The acoustic effects of guitar components

    Science.gov (United States)

    Inta, Ra; Gilet, Gerard; Smith, John; Wolfe, Joe

    2002-11-01

    The guitar is a complex oscillatory system made up of many vibrating components. Because of the variable mechanical properties of wood, it is not easy for makers to reproduce good instruments. Reproducibility can be improved if we know how the mechanical properties of the components interact to produce the sound of the completed instrument. Three steel-string acoustic guitars were constructed, in parallel and as similarly as possible, the only design difference being the timber used for the top-plates. Prior to construction, the Young's moduli, densities, and moisture contents of a selection of top-plate brace, neck, and bridge materials were measured and the most similar were retained for creating the three instruments. Transfer functions and Chladni modes of the top-plates were measured at seven stages of construction, and the radiation patterns and acoustic efficiencies of the finished instruments measured. The effects of brace scalloping and neck attachment systems are reported. These results, and the behavior of some simple systems, are compared with finite element simulations that include scalloped bracing and glue bonding. [Work supported by the Australian Research Council and Gilet Guitars, Australia.

  15. Imaging Cytoskeleton Components by Electron Microscopy

    Science.gov (United States)

    Svitkina, Tatyana

    2016-01-01

    The cytoskeleton is a complex of detergent-insoluble components of the cytoplasm playing critical roles in cell motility, shape generation, and mechanical properties of a cell. Fibrillar polymers—actin filaments, microtubules, and intermediate filaments—are major constituents of the cytoskeleton, which constantly change their organization during cellular activities. The actin cytoskeleton is especially polymorphic, as actin filaments can form multiple higher order assemblies performing different functions. Structural information about cytoskeleton organization is critical for understanding its functions and mechanisms underlying various forms of cellular activity. Because of the nanometer-scale thickness of cytoskeletal fibers, electron microscopy (EM) is a key tool to determine the structure of the cytoskeleton. This article describes application of rotary shadowing (or metal replica) EM for visualization of the cytoskeleton. The procedure is applicable to thin cultured cells growing on glass coverslips and consists of detergent extraction of cells to expose their cytoskeleton, chemical fixation to provide stability, ethanol dehydration and critical point drying to preserve three-dimensionality, rotary shadowing with platinum to create contrast, and carbon coating to stabilize replicas. This technique provides easily interpretable three-dimensional images, in which individual cytoskeletal fibers are clearly resolved, and individual proteins can be identified by immunogold labeling. More importantly, replica EM is easily compatible with live cell imaging, so that one can correlate the dynamics of a cell or its components, e.g., expressed fluorescent proteins, with high resolution structural organization of the cytoskeleton in the same cell. PMID:26498781

  16. Beta-钛与镍钛、不锈钢正畸弓丝合金成分、表面形貌以及力学性能的对比研究%A comparison study of elemental components, surface characteristics and mechanical properties of beta-titanium alloy wires, nitinol wires and stainless steel wires

    Institute of Scientific and Technical Information of China (English)

    李兴; 杨凯; 张颖; 尤力; 宋西平

    2012-01-01

    目的:比较Beta-钛丝与正畸临床常用的超弹性镍钛丝及不锈钢丝的合金成分、表面形貌以及力学性能,为临床应用提供参考.方法:选取Beta-钛丝、超弹性镍钛丝及不锈钢丝,弓丝尺寸均为0.43 mm×0.64 mm.选用EDAX X-射线能谱分析仪联合SUPRATM 55热场发射扫描电子显微镜分析弓丝的合金成分,观察其表面形貌.使用Nano Indenter XP纳米压痕测试机测定弓丝弹性模量及硬度,使用Instron 5848微力材料试验机,三点弯曲测定弓丝的负荷-形变曲线.结果:Beta-钛丝合金成分中含有Ti、Zr、Mo、Sn 4种元素,不锈钢丝含有Fe、Mn、Cr、Si,超弹性镍钛丝含有Ni、Ti 2种元素.不锈钢丝表面比Beta-钛丝及镍钛丝光滑.Beta-钛丝的弹性模量及硬度明显小于不锈钢丝,略大于超弹性镍钛丝.当形变3 mm的负荷完全去除时,Beta-钛丝及不锈钢丝均有残余形变,超弹性镍钛丝形变完全恢复.结论:Beta-钛丝、超弹性镍钛丝及不锈钢丝依据其性能适用于正畸治疗的不同阶段.%Objective:To compare the differences of Beta-titanium alloy wires, superelastic nitinol wires and stainless steel wires (SSW) in elemental components, surface characteristics and mechanical properties for clinical orthodontic use. Methods; Beta-titanium alloy wires, superelastic nitinol wires and SSW were used. All the wires were in the same size of 0.43 mm×0.64 mm. ED AX and SUPRATM 55 SEM were used to analyze the components and surface characteristics. Nano Indenter XP was used to test elasticity modulus and hardness of the wires. Three-Bending Test was performed to compare the mechanical properties in Instron 5848 equipment. Results: Ti, Zr, Mo, Sn were contained in Beta- titanium wire, Ni and Ti in superelstic nitinol wire, Fe, Mn, Cr and Si in SSW. The surface of SSW was the smoothest. The value of elasticity modulus and hardness in Beta-titanium was much lower than in SSW and a little higher than in superelastic

  17. Continuum mechanics

    CERN Document Server

    Spencer, A J M

    2004-01-01

    The mechanics of fluids and the mechanics of solids represent the two major areas of physics and applied mathematics that meet in continuum mechanics, a field that forms the foundation of civil and mechanical engineering. This unified approach to the teaching of fluid and solid mechanics focuses on the general mechanical principles that apply to all materials. Students who have familiarized themselves with the basic principles can go on to specialize in any of the different branches of continuum mechanics. This text opens with introductory chapters on matrix algebra, vectors and Cartesian ten

  18. Efeito da adição de componentes inorgânicos na resistência mecânica de moldes de areia para fundição Effect of addition of inorganic components on the mechanical strength of sand molds for casting

    Directory of Open Access Journals (Sweden)

    M. S. Cilla

    2012-03-01

    tratamentos térmicos foi comprovada por testes de resistência mecânica a compressão e análise de fotomicrografias das composições estudadas, conforme previsto nos respectivos diagramas de fases.The casting process faster, economical and conventional is to green sand molding, where the main ligand is a moist clay (bentonite. However, due to technological requirements, are also used as binders toxic furan resin, phenolic or urethane. New technologies have been developed for the recovery and blanketing the sands, but the resins currently available are limited by its chemical origin. After use these molds are discarded, and thus the toxic binders become an environmental problem. Thus, the replacement of these binders by organic compounds derived from renewable sources such as polyurethane resin derived from castor oil minimizes environmental impacts, leading the casting process towards sustainability, necessary because of the increasing stringency of environmental legislation. Because of the thermal behavior of vegetable polyurethane, which decompose in a more pronounced when exposed to high temperatures compared to traditional organic binders the addition of inorganic components is required as a facilitator of the link between the grains sand and consequent cohesion of the molds during stage of fusion. In this sense, the use of phase diagrams to predict the appearance of liquid phase by the addition of inorganic components to the mix sand / resin in sand molds for casting and its effect on mechanical strength at high temperatures of the mold serves as a theoretical tool in helping to determining the composition of the molds according to its thermal stress during melting. Initial tests of molding and mechanical strength at room temperature showed that the polyurethane resin derived from castor oil produces results comparable to those of commercial resins. Also the addition of inorganic components and its effect when subjected to heat treatment is tested for mechanical

  19. Towards Prognostics for Electronics Components

    Science.gov (United States)

    Saha, Bhaskar; Celaya, Jose R.; Wysocki, Philip F.; Goebel, Kai F.

    2013-01-01

    Electronics components have an increasingly critical role in avionics systems and in the development of future aircraft systems. Prognostics of such components is becoming a very important research field as a result of the need to provide aircraft systems with system level health management information. This paper focuses on a prognostics application for electronics components within avionics systems, and in particular its application to an Isolated Gate Bipolar Transistor (IGBT). This application utilizes the remaining useful life prediction, accomplished by employing the particle filter framework, leveraging data from accelerated aging tests on IGBTs. These tests induced thermal-electrical overstresses by applying thermal cycling to the IGBT devices. In-situ state monitoring, including measurements of steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.

  20. Mechanics of materials model

    Science.gov (United States)

    Meister, Jeffrey P.

    1987-01-01

    The Mechanics of Materials Model (MOMM) is a three-dimensional inelastic structural analysis code for use as an early design stage tool for hot section components. MOMM is a stiffness method finite element code that uses a network of beams to characterize component behavior. The MOMM contains three material models to account for inelastic material behavior. These include the simplified material model, which assumes a bilinear stress-strain response; the state-of-the-art model, which utilizes the classical elastic-plastic-creep strain decomposition; and Walker's viscoplastic model, which accounts for the interaction between creep and plasticity that occurs under cyclic loading conditions.

  1. Two component systems: physiological effect of a third component.

    Directory of Open Access Journals (Sweden)

    Baldiri Salvado

    Full Text Available Signal transduction systems mediate the response and adaptation of organisms to environmental changes. In prokaryotes, this signal transduction is often done through Two Component Systems (TCS. These TCS are phosphotransfer protein cascades, and in their prototypical form they are composed by a kinase that senses the environmental signals (SK and by a response regulator (RR that regulates the cellular response. This basic motif can be modified by the addition of a third protein that interacts either with the SK or the RR in a way that could change the dynamic response of the TCS module. In this work we aim at understanding the effect of such an additional protein (which we call "third component" on the functional properties of a prototypical TCS. To do so we build mathematical models of TCS with alternative designs for their interaction with that third component. These mathematical models are analyzed in order to identify the differences in dynamic behavior inherent to each design, with respect to functionally relevant properties such as sensitivity to changes in either the parameter values or the molecular concentrations, temporal responsiveness, possibility of multiple steady states, or stochastic fluctuations in the system. The differences are then correlated to the physiological requirements that impinge on the functioning of the TCS. This analysis sheds light on both, the dynamic behavior of synthetically designed TCS, and the conditions under which natural selection might favor each of the designs. We find that a third component that modulates SK activity increases the parameter space where a bistable response of the TCS module to signals is possible, if SK is monofunctional, but decreases it when the SK is bifunctional. The presence of a third component that modulates RR activity decreases the parameter space where a bistable response of the TCS module to signals is possible.

  2. Formal Component-Based Semantics

    CERN Document Server

    Madlener, Ken; van Eekelen, Marko; 10.4204/EPTCS.62.2

    2011-01-01

    One of the proposed solutions for improving the scalability of semantics of programming languages is Component-Based Semantics, introduced by Peter D. Mosses. It is expected that this framework can also be used effectively for modular meta theoretic reasoning. This paper presents a formalization of Component-Based Semantics in the theorem prover Coq. It is based on Modular SOS, a variant of SOS, and makes essential use of dependent types, while profiting from type classes. This formalization constitutes a contribution towards modular meta theoretic formalizations in theorem provers. As a small example, a modular proof of determinism of a mini-language is developed.

  3. Feedback Control of Two-Component Regulatory Systems.

    Science.gov (United States)

    Groisman, Eduardo A

    2016-09-08

    Two-component systems are a dominant form of bacterial signal transduction. The prototypical two-component system consists of a sensor that responds to a specific input(s) by modifying the output of a cognate regulator. Because the output of a two-component system is the amount of phosphorylated regulator, feedback mechanisms may alter the amount of regulator, and/or modify the ability of a sensor or other proteins to alter the phosphorylation state of the regulator. Two-component systems may display intrinsic feedback whereby the amount of phosphorylated regulator changes under constant inducing conditions and without the participation of additional proteins. Feedback control allows a two-component system to achieve particular steady-state levels, to reach a given steady state with distinct dynamics, to express coregulated genes in a given order, and to activate a regulator to different extents, depending on the signal acting on the sensor.

  4. Reliability Analysis of Fatigue Fracture of Wind Turbine Drivetrain Components

    DEFF Research Database (Denmark)

    Berzonskis, Arvydas; Sørensen, John Dalsgaard

    2016-01-01

    in the volume of the casted ductile iron main shaft, on the reliability of the component. The probabilistic reliability analysis conducted is based on fracture mechanics models. Additionally, the utilization of the probabilistic reliability for operation and maintenance planning and quality control is discussed....... of operation and maintenance. The manufacturing of casted drivetrain components, like the main shaft of the wind turbine, commonly result in many smaller defects through the volume of the component with sizes that depend on the manufacturing method. This paper considers the effect of the initial defect present...

  5. Spacecraft redesign to reduce microphonic response of a VCO component

    Science.gov (United States)

    Strain, J. C.; Mittal, S.

    1988-01-01

    Reaction wheel vibration was found to induce out of specification sidebands on the carrier frequencies of some spacecraft components containing mechanical voltage control oscillators (VCOs). Concurrent investigations were performed to redesign the VCOs to reduce their response to the wheel vibration, and to design a reaction wheel isolation system to reduce the vibration input to the affected components. Component level tests indicated that both efforts provided viable solutions. The redesigned VCO will be incorporated into future spacecraft in the series, while affected spacecraft already in production will be retrofitted with the reaction wheel isolation system.

  6. Experimental study on hollow structural component by explosive welding

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Mianjun, E-mail: dmjwl@163.com [PLA University of Science and Technology, Nanjing 210007 (China); Wei, Ling, E-mail: 386006087@qq.com [Tongda College, Nanjing University of Posts and Telecommunication, Nanjing 210007 (China); Hong, Jin [PLA University of Science and Technology, Nanjing 210007 (China); Ran, Hong [Southwestern Institute of Physics, Chengdu 610041 (China); Ma, Rui; Wang, Yaohua [PLA University of Science and Technology, Nanjing 210007 (China)

    2014-12-15

    Highlights: • This paper relates to a study on a thin double-layers hollow structural component by using an explosive welding technology. • This thin double-layer hollow structural component is an indispensable component required for certain core equipment of thermonuclear experimental reactor. • An adjusted explosive welding technology for manufacturing an inconel625 hollow structural component was developed which cannot be made by common technology. • The result shows that a metallurgical bonding was realized by the ribs and slabs of the hollow sheet. • The shearing strength of bonding interface exceeds that of the parent metal. - Abstract: A large thin-walled hollow structural component with sealed channels is required for the vacuum chamber of a thermonuclear experimental reactor, with inconel625 as its fabrication material. This hollow structural component is rarely manufactured by normal machining method, and its manufacture is also problematic in the field of explosive welding. With this in mind, we developed an adjusted explosive welding technology which involves a two-step design, setting and annealing technology. The joints were evaluated using optical microscope and scanning electron microscope, and a mechanical experiment was conducted, involving micro-hardness test, cold helium leak test and hydraulic pressure test. The results showed that a metallurgical bonding was realized by the ribs and slabs, and the shearing strength of the bonding interface exceeded that of the parent metal. Hence, the hollow structural component has a good comprehensive mechanical performance and sealing property.

  7. Pulmonary mechanics during mechanical ventilation.

    Science.gov (United States)

    Henderson, William R; Sheel, A William

    2012-03-15

    The use of mechanical ventilation has become widespread in the management of hypoxic respiratory failure. Investigations of pulmonary mechanics in this clinical scenario have demonstrated that there are significant differences in compliance, resistance and gas flow when compared with normal subjects. This paper will review the mechanisms by which pulmonary mechanics are assessed in mechanically ventilated patients and will review how the data can be used for investigative research purposes as well as to inform rational ventilator management.

  8. Components of dynamic digital maps

    Science.gov (United States)

    Condit, Christopher D.

    1999-05-01

    The core of a dynamic digital map (DDM) is a program created to display a digital geologic map and its associated data set as a single integrated package. This DDM program core is authored using a high-level object oriented graphical programming environment, SuperCard, a Macintosh `xTalk' language. Some of the major philosophical underpinnings relevant to the job of creating DDMs in this programming environment include taking advantage of specific object's attributes, how to organize data structure effectively for this job and keeping applicable code as transportable (generalized) as possible between objects. The core components of DDMs are parts of a SuperCard `template' or map display `container' into which the various externally created digital pieces (e.g. CAD produced geologic maps, spread sheet data, digital images, text files, movies) can be inserted for integrated display and digital publication. Components of DDMs consist of windows, cards within these windows, card fields (text and data containers) and a menu structure. The paper discusses each of these major components and how they fit into a DDM and gives examples of each topic in programs whose components demonstrate the concept. These programs are available from Web (see Appendix A); readers can refer to them as they examine these examples.

  9. Opinions about Component Energetic Security

    OpenAIRE

    Elena GOLUMBEANU (GEORGESCU)

    2012-01-01

    Collective security (international) represent the morphological expression of individual security components. According to the Report presented at the United Nations Development Programme, collective security (international) as well as national security, is the expression of seven synergistic dimensions as follows: economic security, food security, environmental security, personal security, community security, political security and individual security. As part of economic security, energy an...

  10. Carcinogenicity of hair dye components.

    Science.gov (United States)

    Van Duuren, B L

    1980-03-01

    The available animal carcinogenicity data on hair dye components was reviewed. From this review it became clear that certain hair dye components, some of which are still in hair dye formulations now on the market, are animal carcinogens. The compounds of concern that are still in use are: 3-amino-4-methoxyaniline, 2-nitro-4-aminoaniline and 3-nitro-4-hydroxyaniline. Certain azo dyes formerly used, and related compounds still in use, contain the benzidine moiety. Two of these compounds, Direct Blue 6 and Direct Black 38, have been shown to be metabolized in animals to the human carcinogen benzidine. Furthermore, skin absorption studies carried out with radiolabeled hair dye components applied to animal or human skin have conclusively shown that these compounds are systemically absorbed and excreted. Known cocarcinogens such as catechol and pyrogallol, which enhance benzo(a)pyrene carcinogenicity on mouse skin, are used as hair dye components. It is not known whether such compounds will enhance the carcinogenicity of substituted aniline hair dye chemicals. The available epidemiologic data are not sufficient to link hair dye use with an increased incidence in human cancer.

  11. COMPONENT ELEMENTS OF MARKETING COMMUNICATIONS

    Directory of Open Access Journals (Sweden)

    G. I. Tamoshina

    2012-01-01

    Full Text Available Marketing communications are the specific communication program of the company. It consists of: advertising, which is intended for informing about commodity and accommodations (services; encouragement of marketing- sales augmentation for acceleration of marketing; straight marketing, that provide with personal contacts, flexibility and ability to make a bargain; public relations - all that components are promoting and uphold the image of the firm.

  12. Mechanical sensitivity reveals evolutionary dynamics of mechanical systems.

    Science.gov (United States)

    Anderson, P S L; Patek, S N

    2015-04-07

    A classic question in evolutionary biology is how form-function relationships promote or limit diversification. Mechanical metrics, such as kinematic transmission (KT) in linkage systems, are useful tools for examining the evolution of form and function in a comparative context. The convergence of disparate systems on equivalent metric values (mechanical equivalence) has been highlighted as a source of potential morphological diversity under the assumption that morphology can evolve with minimal impact on function. However, this assumption does not account for mechanical sensitivity-the sensitivity of the metric to morphological changes in individual components of a structure. We examined the diversification of a four-bar linkage system in mantis shrimp (Stomatopoda), and found evidence for both mechanical equivalence and differential mechanical sensitivity. KT exhibited variable correlations with individual linkage components, highlighting the components that influence KT evolution, and the components that are free to evolve independently from KT and thereby contribute to the observed pattern of mechanical equivalence. Determining the mechanical sensitivity in a system leads to a deeper understanding of both functional convergence and morphological diversification. This study illustrates the importance of multi-level analyses in delineating the factors that limit and promote diversification in form-function systems. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  13. Materials Characterization of Additively Manufactured Components for Rocket Propulsion

    Science.gov (United States)

    Carter, Robert; Draper, Susan; Locci, Ivan; Lerch, Bradley; Ellis, David; Senick, Paul; Meyer, Michael; Free, James; Cooper, Ken; Jones, Zachary

    2015-01-01

    To advance Additive Manufacturing (AM) technologies for production of rocket propulsion components the NASA Glenn Research Center (GRC) is applying state of the art characterization techniques to interrogate microstructure and mechanical properties of AM materials and components at various steps in their processing. The materials being investigated for upper stage rocket engines include titanium, copper, and nickel alloys. Additive manufacturing processes include laser powder bed, electron beam powder bed, and electron beam wire fed processes. Various post build thermal treatments, including Hot Isostatic Pressure (HIP), have been studied to understand their influence on microstructure, mechanical properties, and build density. Micro-computed tomography, electron microscopy, and mechanical testing in relevant temperature environments has been performed to develop relationships between build quality, microstructure, and mechanical performance at temperature. A summary of GRC's Additive Manufacturing roles and experimental findings will be presented.

  14. Material Characterization of Additively Manufactured Components for Rocket Propulsion

    Science.gov (United States)

    Carter, Robert; Draper, Susan; Locci, Ivan; Lerch, Bradley; Ellis, David; Senick, Paul; Meyer, Michael; Free, James; Cooper, Ken; Jones, Zachary

    2015-01-01

    To advance Additive Manufacturing (AM) technologies for production of rocket propulsion components the NASA Glenn Research Center (GRC) is applying state of the art characterization techniques to interrogate microstructure and mechanical properties of AM materials and components at various steps in their processing. The materials being investigated for upper stage rocket engines include titanium, copper, and nickel alloys. Additive manufacturing processes include laser powder bed, electron beam powder bed, and electron beam wire fed processes. Various post build thermal treatments, including Hot Isostatic Pressure (HIP), have been studied to understand their influence on microstructure, mechanical properties, and build density. Micro-computed tomography, electron microscopy, and mechanical testing in relevant temperature environments has been performed to develop relationships between build quality, microstructure, and mechanical performance at temperature. A summary of GRCs Additive Manufacturing roles and experimental findings will be presented.

  15. Mechanical Kinesiology.

    Science.gov (United States)

    Barham, Jerry N.

    Mechanical kinesiology is defined as a study of the mechanical factors affecting human movement, i.e., applying the physical laws of mechanics to the study of human motor behavior. This textbook on the subject is divided into thirty lessons. Each lesson is organized into three parts: a part on the text proper; a part entitled "study…

  16. Mechanisms Design

    DEFF Research Database (Denmark)

    Restrepo-Giraldo, John Dairo

    2006-01-01

    Most products and machines involve some kind of controlled movement. From window casements to DVD players, from harbor cranes to the shears to prune your garden, all these machines require mechanisms to move. This course intends to provide the analytical and conceptual tools to design such mechan......Most products and machines involve some kind of controlled movement. From window casements to DVD players, from harbor cranes to the shears to prune your garden, all these machines require mechanisms to move. This course intends to provide the analytical and conceptual tools to design...... using criteria such as size, performance parameters, operation environment, etc. Content: Understanding Mechanisms Design (2 weeks) Definitions, mechanisms representations, kinematic diagrams, the four bar linkage, mobility, applications of mechanisms, types of mechanisms, special mechanisms, the design......: equations for various mechanisms. At the end of this module you will be able to analyze existing mechanisms and to describe their movement. Designing mechanisms (7 weeks) Type synthesis and dimensional synthesis, function generation, path generation, three precision points in multi-loop mechanisms...

  17. Component Dependency in object-Oriented Software

    Institute of Scientific and Technical Information of China (English)

    Li-Guo Yu; Srini Ramaswamy

    2007-01-01

    Component dependency is an important software measure. It is directly related to software understandability,maintainability, and reusability. Two important parameters in describing component dependency are the type of couplingbetween two components and the type of the dependent component. Depending upon the different types of coupling and thetype of the dependent components, there can be different effects on component maintenance and component reuse. In thispaper, we divide dependent components into three types. We then classify various component dependencies and analyzetheir effects on maintenance and reuse. Based on the classification, we present a dependency metric and validate it on 11open-source Java components. Our study shows that a strong correlation exists between the measurement of the dependencyof the component and the effort to reuse the component. This indicates that the classification of component dependencyand the suggested metric could be further used to represent other external software quality factors.

  18. Mechanical engineer's reference book

    CERN Document Server

    Parrish, A

    1973-01-01

    Mechanical Engineer's Reference Book: 11th Edition presents a comprehensive examination of the use of Systéme International d' Unités (SI) metrication. It discusses the effectiveness of such a system when used in the field of engineering. It addresses the basic concepts involved in thermodynamics and heat transfer. Some of the topics covered in the book are the metallurgy of iron and steel; screw threads and fasteners; hole basis and shaft basis fits; an introduction to geometrical tolerancing; mechanical working of steel; high strength alloy steels; advantages of making components as castings

  19. Noncommutative quantum mechanics

    Science.gov (United States)

    Gamboa, J.; Loewe, M.; Rojas, J. C.

    2001-09-01

    A general noncommutative quantum mechanical system in a central potential V=V(r) in two dimensions is considered. The spectrum is bounded from below and, for large values of the anticommutative parameter θ, we find an explicit expression for the eigenvalues. In fact, any quantum mechanical system with these characteristics is equivalent to a commutative one in such a way that the interaction V(r) is replaced by V=V(HHO,Lz), where HHO is the Hamiltonian of the two-dimensional harmonic oscillator and Lz is the z component of the angular momentum. For other finite values of θ the model can be solved by using perturbation theory.

  20. Frequency-agile microwave components using ferroelectric materials

    Science.gov (United States)

    Colom-Ustariz, Jose G.; Rodriguez-Solis, Rafael; Velez, Salmir; Rodriguez-Acosta, Snaider

    2003-04-01

    The non-linear electric field dependence of ferroelectric thin films can be used to design frequency and phase agile components. Tunable components have traditionally been developed using mechanically tuned resonant structures, ferrite components, or semiconductor-based voltage controlled electronics, but they are limited by their frequency performance, high cost, hgih losses, and integration into larger systems. In contrast, the ferroelectric-based tunable microwave component can easily be integrated into conventional microstrip circuits and attributes such as small size, light weight, and low-loss make these components attractive for broadband and multi-frequency applications. Components that are essential elements in the design of a microwave sensor can be fabricated with ferroelectric materials to achieve tunability over a broad frequency range. It has been reported that with a thin ferroelectric film placed between the top conductor layer and the dielectric material of a microstrip structure, and the proper DC bias scheme, tunable components above the Ku band can be fabricated. Components such as phase shifters, coupled line filters, and Lange couplers have been reported in the literature using this technique. In this wokr, simulated results from a full wave electromagnetic simulator are obtained to show the tunability of a matching netowrk typically used in the design of microwave amplifiers and antennas. In addition, simulated results of a multilayer Lange coupler, and a patch antenna are also presented. The results show that typical microstrip structures can be easily modified to provide frequency agile capabilities.

  1. Discrete mechanics

    CERN Document Server

    Caltagirone, Jean-Paul

    2014-01-01

    This book presents the fundamental principles of mechanics to re-establish the equations of Discrete Mechanics. It introduces physics and thermodynamics associated to the physical modeling.  The development and the complementarity of sciences lead to review today the old concepts that were the basis for the development of continuum mechanics. The differential geometry is used to review the conservation laws of mechanics. For instance, this formalism requires a different location of vector and scalar quantities in space. The equations of Discrete Mechanics form a system of equations where the H

  2. Component Reconnexion at the Heliopause

    Science.gov (United States)

    Moore, T. E.; Alouani-Bibi, F.; Opher, M.; Toth, G.; McComas, D. J.

    2010-12-01

    Extended X lines of component reconnection at the heliopause are derived from 3D MHD simulations of the steady state heliosphere (Alouani-Bibi et al 2010, Opher et al 2009). A similar study established this technique to describe the extended shape of reconnection X-lines at the magnetosphere, as result of its interaction with the interplanetary field of varying orientation (Moore et al., 2002). At the heliopause, reconnection X-line candidates are derived on the basis of geometrical criteria, allowing for shear angles between the interacting fields of less than 180 degree (Cowley 1976) and properties of the magnetic fields and flows outside (interstellar medium) and inside (interplanetary space beyond the termination shock) the heliopause. Kinetic effects addressed by Swisdak et al. (2009) and Opher et al. (2010) can inhibit large scale component reconnection, leading to more localized and nearly anti-parallel reconnection, possibly accounting for the persistent hot spot in IBEX heliopause ribbon.

  3. Components of Attention in Synesthesia

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik; Nordfang, Maria; Pedersen, Michael Nygaard

    2013-01-01

    One of the most common forms of synesthesia is between colors and graphemes (Colizoli, Murre, & Rouw, 2012). Numerous studies have investigated different aspects of attention and synesthesia, e.g. effects of Stroop-like interference by colors that are incongruent with the synesthetic experience....... Here we attempt to isolate how speci¿ c components of attention are affected by grapheme-color synesthesia. Eight carefully screened healthy participants with synesthesia reported the letters in brie¿ y presented, post-masked arrays of letters and digits. On half the trials, the letters and digits were...... presented in colors congruent with the synesthetic experience. On the other half of the trials, the letters and digits were presented in colors that were incongruent with the synesthetic experience. Components of attention were estimated separately for congruent and incongruent trials by ¿ tting the data...

  4. COMPONENTS OF SUSTAINABLE HUMAN DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Neyda Ibañez

    2017-03-01

    Full Text Available The present research aimed to propose new components of measurement of sustainable human development based on the historical-theoretical trajectory of development. The research assumes a ontoepistemological posture based on positivism, addressing the technique of the survey and the written questionnaire instrument applied to thirty-one (31 experts in the area of knowledge, whose analysis allowed to conclude that the traditional models to measure the Insufficient to demonstrate the reality of nations. Therefore, the proposal of measurement is derived in seven components: ethical, spiritual and cultural, in addition to those formally established by Munasinghe (1993, 2011 and the UN (2012: economic, social, environmental, institutional , In total, by the selection of one hundred and fifty-five (155 variables, whose index is denominated ISIDEHUS.

  5. Information component of hybrid war

    OpenAIRE

    Bohdanov, Aleksander

    2015-01-01

    A hybrid warfare in the three-dimensional coordinate system «Matter-Information-measure» is considering. In particular, the information component is highlighted and analyzed. The factors of preparation of information operations is defined, which are disclosed as an example of experience of volunteer group information warfare of Institute of special communication and information security of NTUU «KPI».Keywords: coordinate system «Matter-Information-Measure» hybrid warfare, information componen...

  6. The Risk Components of Liquidity

    OpenAIRE

    Chollete, Lorán; Næs, Randi; Johannes A. Skjeltorp

    2008-01-01

    Does liquidity risk differ depending on our choice of liquidity proxy? Unlike literature that considers common liquidity variation, we focus on identifying different components of liquidity, statistically and economically, using more than a decade of US transaction data. We identify three main statistical liquidity factors which are utilized in a linear asset pricing framework. We motivate a correspondence of the statistical factors to traditional dimensions of liquidity as well as the notion...

  7. Feasibility and Testing of Additive Manufactured Components

    Energy Technology Data Exchange (ETDEWEB)

    Dehoff, Ryan R [ORNL; Hummelt, Ed [Eaton Corporation; Solovyeva, Lyudmila [Eaton Corporation

    2016-09-01

    This project focused on demonstrating the ability to fabricate two parts with different geometry: an arc flash interrupter and a hydraulic manifold. Eaton Corporation provided ORNL solid models, information related to tolerances and sensitive parameters of the parts and provided testing and evaluation. ORNL successfully manufactured both components, provided cost models of the manufacturing (materials, labor, time and post processing) and delivered test components for Eaton evaluation. The arc flash suppressor was fabricated using the Renishaw laser powder bed technology in CoCrMo while the manifold was produced from Ti-6Al-4V using the Arcam electron beam melting technology. These manufacturing techniques were selected based on the design and geometrical tolerances required. A full-scale manifold was produced on the Arcam A2 system (nearly 12 inches tall). A portion of the manifold was also produced in the Arcam Q10 system. Although a full scale manifold could not be produced in the system, a full scale manifold is expected to have similar material properties, geometric accuracy, and surface finish as could be fabricated on an Arcam Q20 system that is capable of producing four full scale manifolds in a production environment. In addition to the manifold, mechanical test specimens, geometric tolerance artifacts, and microstructure samples were produced alongside the manifold. The development and demonstration of these two key components helped Eaton understand the impact additive manufacturing can have on many of their existing products. By working within the MDF and leveraging ORNL’s manufacturing and characterization capabilities, the work will ensure the rapid insertion and commercialization of this technology.

  8. Elution of leachable components from composites.

    Science.gov (United States)

    Ferracane, J L

    1994-07-01

    A significant amount of residual monomer or short chain polymers remain unbound in set composite material. Due to its potential impact on both the biocompatibility and the structural stability of the restoration, many investigators have studied the elution of these unbound molecules into aqueous media. The results of these studies suggest that elution of leachable components from composites is rapid, with the majority being released within a matter of hours. Weight losses of up to 2% of the mass of the composite have been reported under certain conditions. The studies have also shown that the extent and rate of elution of components from composites is dependent upon several factors. The quantity of leachables has been correlated to the degree of cure of the polymer network. The composition and solubility characteristics of the extraction solvent influence the kinetics and mechanism of the elution process. Elution is generally thought to occur via diffusion of molecules through the resin matrix, and is therefore dependent upon the size and chemical characteristics of the leachable species.

  9. Identification of Telomerase Components and Telomerase Regulating Factors in Yeast

    Science.gov (United States)

    1998-07-01

    required for telomere function. To further explore the mechanism of telomere replication, I identified CDCl3 and EST2 interacting proteins via yeast two...hybrid screens. Characterization of the EST2 interacting proteins may reveal additional telomerase components or regulators. STNl, a high-copy

  10. Control of relaxation cracking in austenitic high temperature components

    NARCIS (Netherlands)

    Wortel, J.C. van

    2007-01-01

    The degradation mechanism "relaxation cracking" is acting in austenitic components operating between 550°C (1020°F) and 750°C (1380°F). The brittle failures are always located in cold formed areas or in welded joints and are mostly addressed within 1 year service. More than 10 different names can be

  11. Nominal and Structural Subtyping in Component-Based Programming

    DEFF Research Database (Denmark)

    Ostermann, Klaus

    2007-01-01

    type. We analyze structural and different flavors of nominal subtyping from the perspective of component-based programming, where issues such as blame assignment and modular extensibility are important. Our analysis puts various existing subtyping mechanisms into a common frame of reference...

  12. Two Component Injection Moulding for Moulded Interconnect Devices

    DEFF Research Database (Denmark)

    Islam, Aminul

    The moulded interconnect devices (MIDs) contain huge possibilities for many applications in micro electro-mechanical-systems because of their potential in reducing the number of components, process steps and finally in miniaturization of the product. Among the available MID process chains, two...

  13. Control of relaxation cracking in austenitic high temperature components

    NARCIS (Netherlands)

    Wortel, J.C. van

    2007-01-01

    The degradation mechanism "relaxation cracking" is acting in austenitic components operating between 550°C (1020°F) and 750°C (1380°F). The brittle failures are always located in cold formed areas or in welded joints and are mostly addressed within 1 year service. More than 10 different names can be

  14. Harmonic component detection: Optimized Spectral Kurtosis for operational modal analysis

    Science.gov (United States)

    Dion, J.-L.; Tawfiq, I.; Chevallier, G.

    2012-01-01

    This work is a contribution in the field of Operational Modal Analysis to identify the modal parameters of mechanical structures using only measured responses. The study deals with structural responses coupled with harmonic components amplitude and frequency modulated in a short range, a common combination for mechanical systems with engines and other rotating machines in operation. These harmonic components generate misleading data interpreted erroneously by the classical methods used in OMA. The present work attempts to differentiate maxima in spectra stemming from harmonic components and structural modes. The detection method proposed is based on the so-called Optimized Spectral Kurtosis and compared with others definitions of Spectral Kurtosis described in the literature. After a parametric study of the method, a critical study is performed on numerical simulations and then on an experimental structure in operation in order to assess the method's performance.

  15. Mechanical Testing of MLCCs

    Science.gov (United States)

    Teverovsky, Alexander A.

    2016-01-01

    Cracking of multilayer ceramic capacitors, MLCCs, remains a serious problem for space systems. This problem increases substantially for large size capacitors and in cases when manual soldering is involved or the system experiences mechanical shock or vibration. In any case, a fracture occurs when the sum of external and internal mechanical stresses exceeds the strength of the part. To reduce the probability of cracking, the level of stress should be reduced, e.g. by optimizing the assembly workmanship and rules for board design, and the strength of the parts increased by selecting the most mechanically robust capacitors. The latter might possibly be achieved by selecting MLCCs based on the in-situ measurements of mechanical characteristics using four types of tests: flexural strength, hardness, fracture toughness, and flex bend testing. Note that military specifications MIL-PRF-123 and MIL-PRF-55681 do not have requirements for mechanical testing of the parts. However, specifications for automotive industry components employ two types of mechanical tests: beam load (break strength) test per AEC-Q200-003 and board flex test per AEC-Q200-005. A recent military specification for thin dielectric capacitors, MIL-PRF-32535, has one mechanical test, board flex testing, that is similar to AEC-Q200-005. The purpose of this report was assessment of the efficiency of different mechanical tests for selection robust capacitors and comparison of mechanical characteristics of Base Metal Electrode (BME) and Precious Metal Electrode (PME) capacitors. The report has three parts related to the first three mechanical tests mentioned above.

  16. Mechanical science

    CERN Document Server

    Bolton, W C

    2013-01-01

    This book gives comprehensive coverage of mechanical science for HNC/HND students taking mechanical engineering courses, including all topics likely to be covered in both years of such courses, as well as for first year undergraduate courses in mechanical engineering. It features 500 problems with answers and 200 worked examples. The third edition includes a new section on power transmission and an appendix on mathematics to help students with the basic notation of calculus and solution of differential equations.

  17. A Finite Element Method for Cracked Components of Structures

    Institute of Scientific and Technical Information of China (English)

    刘立名; 段梦兰; 秦太验; 刘玉标; 柳春图; 余建星

    2003-01-01

    In this paper, a method is developed for determining the effective stiffness of the cracked component. The stiffness matrix of the cracked component is integrated into the global stiffness matrix of the finite element model of the global platform for the FE calculation of the structure in any environmental conditions. The stiffness matrix equation of the cracked component is derived by use of the finite variation principle and fracture mechanics. The equivalent parameters defining the element that simulates the cracked component are mathematically presented, and can be easily used for the FE calculation of large scale cracked structures together with any finite element program. The theories developed are validated by both lab tests and numerical calculations, and applied to the evaluation of crack effect on the strength of a fixed platform and a self-elevating drilling rig.

  18. Nondestructive Measurements for Diagnostics of Advanced Reactor Passive Components

    Energy Technology Data Exchange (ETDEWEB)

    Prowant, Matthew S.; Dib, Gerges; Roy, Surajit; Luzi, Lorenzo; Ramuhalli, Pradeep

    2016-09-20

    Information on advanced reactor (AdvRx) component condition and failure probability is necessary to maintaining adequate safety margins and avoiding unplanned shutdowns, both of which have regulatory and economic consequences. Prognostic health management (PHM) technologies provide one approach to addressing these needs by providing the technical means for lifetime management of significant passive components and reactor internals. However, such systems require measurement data that are sensitive to degradation of the component. This paper describes results to date of ongoing research on nondestructive measurements of component condition for degradation mechanisms of relevance to AdvRx concepts. The focus of this paper is on in-situ ultrasonic measurements during high-temperature creep degradation. The data were analyzed to assess the sensitivity of the measurements to creep degradation, with the specific objective of assessing the suitability of the resulting correlations for remaining life prediction. The details of the measurements, results of data analysis, and ongoing research in this area are discussed.

  19. Integrating and Processing XML Documents with JavaBeans Components

    Directory of Open Access Journals (Sweden)

    Yin-Wah Chiou

    2003-02-01

    Full Text Available The eXtensible Markup Language (XML and JavaBeans component model have gained wide popularity in the Object Web computing. This paper explores how JavaBeans components can be used to integrate and process the XML documents. It covers Bean Markup Language (BML, XML BeanMaker, XML Bean Suite, and Xbeans. The most powerful JavaBeans connection language is BML, which represents an integration of XML and JavaBeans components to provide a mechanism for implementing active content. XML BeanMaker is used to generate JavaBeans from XML DTD files. XML Bean Suite is a toolkit of JavaBeans components to provide a comprehensive set of functionality to manipulate XML content. The Xbean is a powerful paradigm to process XML-based distributed applications.

  20. Nanolubrication of sliding components in adaptive optics used in microprojectors

    Science.gov (United States)

    Bhushan, Bharat; Lee, Hyungoo; Chaparala, Satish C.; Bhatia, Vikram

    2010-10-01

    Integrated microprojectors are being developed to project a large image on any surface chosen by the users. For a laser-based microprojector, a piezo-electric based adaptive optics unit is adopted in the green laser architecture. The operation of this unit depends on stick-slip motion between the sliding components. Nanolubrication of adaptive optics sliding components is needed to reduce wear and for smooth operation. In this study, a methodology to measure lubricant thickness distribution with a nanoscale resolution is developed. Friction, adhesion, and wear mechanisms of lubricant on the sliding components are studied. Effect of actual composite components, scan direction, scale effect, temperature, and humidity to correlate AFM data with the microscale device performance is studied.

  1. Geometric mechanics

    CERN Document Server

    Muniz Oliva, Waldyr

    2002-01-01

    Geometric Mechanics here means mechanics on a pseudo-riemannian manifold and the main goal is the study of some mechanical models and concepts, with emphasis on the intrinsic and geometric aspects arising in classical problems. The first seven chapters are written in the spirit of Newtonian Mechanics while the last two ones as well as two of the four appendices describe the foundations and some aspects of Special and General Relativity. All the material has a coordinate free presentation but, for the sake of motivation, many examples and exercises are included in order to exhibit the desirable flavor of physical applications.

  2. High-frequency magnetic components

    CERN Document Server

    Kazimierczuk, Marian K

    2009-01-01

    If you are looking for a complete study of the fundamental concepts in magnetic theory, read this book. No other textbook covers magnetic components of inductors and transformers for high-frequency applications in detail. This unique text examines design techniques of the major types of inductors and transformers used for a wide variety of high-frequency applications including switching-mode power supplies (SMPS) and resonant circuits. It describes skin effect and proximity effect in detail to provide you with a sound understanding of high-frequency phenomena. As well as this, you will disco

  3. Fast Steerable Principal Component Analysis

    OpenAIRE

    Zhao, Zhizhen; Shkolnisky, Yoel; Singer, Amit

    2016-01-01

    Cryo-electron microscopy nowadays often requires the analysis of hundreds of thousands of 2D images as large as a few hundred pixels in each direction. Here we introduce an algorithm that efficiently and accurately performs principal component analysis (PCA) for a large set of two-dimensional images, and, for each image, the set of its uniform rotations in the plane and their reflections. For a dataset consisting of $n$ images of size $L \\times L$ pixels, the computational complexity of our a...

  4. Astrophysical components from Planck maps

    CERN Document Server

    Burigana, Carlo; Paoletti, Daniela; Mandolesi, Nazzareno; Natoli, Paolo

    2016-01-01

    The Planck Collaboration has recently released maps of the microwave sky in both temperature and polarization. Diffuse astrophysical components (including Galactic emissions, cosmic far infrared (IR) background, y-maps of the thermal Sunyaev-Zeldovich (SZ) effect) and catalogs of many thousands of Galactic and extragalactic radio and far-IR sources, and galaxy clusters detected through the SZ effect are the main astrophysical products of the mission. A concise overview of these results and of astrophysical studies based on Planck data is presented.

  5. Components of Co-creation

    DEFF Research Database (Denmark)

    Tanev, Stoyan

    2009-01-01

    . However, these typically focus on the study, discussion and analysis of a small number of cases using deep, ethnographic description of their practices aiming at conceptualization and categorization of the different types of interactions between end users, the firm and the value network. Although useful...... and end customers based on the application of web search and Principal Component Analysis (PCA) techniques. The analysis of these preliminary results is then used as an opportunity to identify a number of research questions to be addressed in future research. The emerging research questions follow...

  6. The cyclical component factor model

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Hansen, Henrik; Smidt, John

    Forecasting using factor models based on large data sets have received ample attention due to the models' ability to increase forecast accuracy with respect to a range of key macroeconomic variables in the US and the UK. However, forecasts based on such factor models do not uniformly outperform...... the simple autoregressive model when using data from other countries. In this paper we propose to estimate the factors based on the pure cyclical components of the series entering the large data set. Monte Carlo evidence and an empirical illustration using Danish data shows that this procedure can indeed...

  7. Anthropological Component of Descartes’ Ontology

    Directory of Open Access Journals (Sweden)

    Anatolii M. Malivskyi

    2014-06-01

    Full Text Available The purpose of the article is to outline and comprehend the Descartes’ theory about anthropological component of ontology as the most important part of his philosophy. The accomplishment of this purpose covers the successive solution of the following tasks: 1 review of the research literature concerning the problem of human’s presence and the individual nature of truth; 2 emphasize the ambivalence of the basic intention of his legacy; 3 justify the thesis about constitutivity of human’s presence and comprehend passions as the form of disclosure of ontology’s anthropological component. Methodology. The use of the euristic potential of phenomenology, postpositivism and postmodernism makes it possible to emphasize the multiple-layer and multiple-meaning classical philosophy works, to comprehend the limitation and scarcity of the naïve-enlightening vision of human nature and to look for a new reception of European classics that provides the overcoming of established nihilism and pessimism concerning the interpretation of human nature. Scientific novelty. It is the first time that anthropological component of Descartes’ ontology became an object of particular attention. It previously lacked attention because of following main reasons: 1 traditional underestimating of the fact of Descartes’ legacy incompleteness as an unrealized anthropological project and 2 lack of proper attention to the individual nature of truth. The premise for its constructive overcoming is the attention to ambivalence of the basic intention and the significance of ethics in the philosopher’s legacy. His texts and research literature allow confirming the constitutive nature of human’s presence and passions as the key form of disclosure of the ontology anthropological component. Conclusions. The established tradition of interpretation the Descartes’ philosophizing nature as the filiation process of impersonal knowledge loses its cogency these days. The

  8. Parallel Assembly of LIGA Components

    Energy Technology Data Exchange (ETDEWEB)

    Christenson, T.R.; Feddema, J.T.

    1999-03-04

    In this paper, a prototype robotic workcell for the parallel assembly of LIGA components is described. A Cartesian robot is used to press 386 and 485 micron diameter pins into a LIGA substrate and then place a 3-inch diameter wafer with LIGA gears onto the pins. Upward and downward looking microscopes are used to locate holes in the LIGA substrate, pins to be pressed in the holes, and gears to be placed on the pins. This vision system can locate parts within 3 microns, while the Cartesian manipulator can place the parts within 0.4 microns.

  9. Components of Co-creation

    DEFF Research Database (Denmark)

    Allen, Stephen; Bailetti, Tony; Tanev, Stoyan

    2013-01-01

    There is a growing body of literature dedicated to the discussion of value co -creation frameworks, mechanisms and processes. However , these typically focus on the study, discussion and analysis of a small number of cases using deep, ethnographic description of their practices aiming at conceptu...

  10. Black Component of Dark Matter

    Directory of Open Access Journals (Sweden)

    A. V. Grobov

    2014-01-01

    Full Text Available A mechanism of primordial black hole formation with specific mass spectrum is discussed. It is shown that these black holes could contribute to the energy density of dark matter. Our approach is elaborated in the framework of universal extra dimensions.

  11. Damage modelling in Plasma Facing Components

    Energy Technology Data Exchange (ETDEWEB)

    Martin, E.; Camus, G. [Bordeaux-1 Univ. des Sciences et Technologies-3, LCTS, Lab. des Composites Thermostructuraux, CNRS-UMR 5801, 33 - Pessac, (France); Schlosser, J. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2007-07-01

    Full text of publication follows: The plasma facing components (PFC) of controlled fusion devices are submitted to high heat fluxes in operating conditions (10 MW/m2 for Tore Supra and up to 20 MW/m{sup 2} for ITER, Cadarache, France). Active cooling is required to maintain a reasonable surface temperature and to avoid critical heat flux and melting of the components. The PFC developed for Tore Supra are made of a carbon/carbon (C/C) composite flat tile bonded to a copper alloy heat sink. Under operating conditions, because of the thermal expansion mismatch existing between the C/C composite and the copper alloy, these components withstand significant stresses which induce damage in the C/C material as well as at the copper/composite interface. Design tools are thus required in order to analyse the initiation and the propagation of damage in thermally loaded PFC. The present study describes a modelling approach aimed at predicting damage in actively cooled PFC. For this purpose, dedicated experimental procedures have been developed and sound constitutive laws taking into account the damage related non linear behaviour of both the C/C material and the Cu-C/C joint have been established. Various tests have first been performed on C/C samples in tension and compression, within the fibre axis and off-axis, as well as in shear using a Iosipescu type device, in order to carefully analyse the non-linear mechanical behaviour of this material. A constitutive law able to handle complex multiaxial loadings, established within a classical thermodynamical framework and using scalar damage variables, was then identified. Tensile and shear tests were also performed on C/C-Cu samples in order to identify a cohesive zone model representative of the damageable behaviour of the joint. These constitutive laws were then introduced in a numerical model representative of a PFC. Obtained results have evidenced the progressive development of damage which takes place in the assembly when

  12. Neem components as potential agents for cancer prevention and treatment.

    Science.gov (United States)

    Hao, Fang; Kumar, Sandeep; Yadav, Neelu; Chandra, Dhyan

    2014-08-01

    Azadirachta indica, also known as neem, is commonly found in many semi-tropical and tropical countries including India, Pakistan, and Bangladesh. The components extracted from neem plant have been used in traditional medicine for the cure of multiple diseases including cancer for centuries. The extracts of seeds, leaves, flowers, and fruits of neem have consistently shown chemopreventive and antitumor effects in different types of cancer. Azadirachtin and nimbolide are among the few bioactive components in neem that have been studied extensively, but research on a great number of additional bioactive components is warranted. The key anticancer effects of neem components on malignant cells include inhibition of cell proliferation, induction of cell death, suppression of cancer angiogenesis, restoration of cellular reduction/oxidation (redox) balance, and enhancement of the host immune responses against tumor cells. While the underlying mechanisms of these effects are mostly unclear, the suppression of NF-κB signaling pathway is, at least partially, involved in the anticancer functions of neem components. Importantly, the anti-proliferative and apoptosis-inducing effects of neem components are tumor selective as the effects on normal cells are significantly weaker. In addition, neem extracts sensitize cancer cells to immunotherapy and radiotherapy, and enhance the efficacy of certain cancer chemotherapeutic agents. This review summarizes the current updates on the anticancer effects of neem components and their possible impact on managing cancer incidence and treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Components of Adenovirus Genome Packaging

    Science.gov (United States)

    Ahi, Yadvinder S.; Mittal, Suresh K.

    2016-01-01

    Adenoviruses (AdVs) are icosahedral viruses with double-stranded DNA (dsDNA) genomes. Genome packaging in AdV is thought to be similar to that seen in dsDNA containing icosahedral bacteriophages and herpesviruses. Specific recognition of the AdV genome is mediated by a packaging domain located close to the left end of the viral genome and is mediated by the viral packaging machinery. Our understanding of the role of various components of the viral packaging machinery in AdV genome packaging has greatly advanced in recent years. Characterization of empty capsids assembled in the absence of one or more components involved in packaging, identification of the unique vertex, and demonstration of the role of IVa2, the putative packaging ATPase, in genome packaging have provided compelling evidence that AdVs follow a sequential assembly pathway. This review provides a detailed discussion on the functions of the various viral and cellular factors involved in AdV genome packaging. We conclude by briefly discussing the roles of the empty capsids, assembly intermediates, scaffolding proteins, portal vertex and DNA encapsidating enzymes in AdV assembly and packaging. PMID:27721809

  14. Food components with anticaries activity.

    Science.gov (United States)

    Gazzani, Gabriella; Daglia, Maria; Papetti, Adele

    2012-04-01

    Caries is the most common oral infectious disease in the world. Its development is influenced also by diet components that interfere with pathogen mutans group Streptococci (MGS) activity. A very active research to identify functional foods and their components that are generally recognised as safe has been ongoing, with the aim of developing alternative approaches, to the use of synthetic chlorhexidine, and at the reduction or prevention of caries. Until now convincing evidence exists only for green tea as a functional food for oral health, partly owing to its high content of catechins, especially epigallocatechin-gallate. A number of other foods showed potential anticaries activity. Some other foods able to act against MGS growth and/or their virulence factors in in vitro tests are: apple, red grape seeds, red wine (proanthocyanidins), nutmeg (macelignan), ajowan caraway (nafthalen-derivative), coffee (trigonelline, nicotinic and chlorogenic acids, melanoidins), barley coffee (melanoidins), chicory and mushroom (quinic acid). In vivo anticaries activity has been shown by cranberry (procyanidins), glycyrrhiza root (glycyrrhizol-A), myrtus ethanolic extract, garlic aqueous extract, cocoa extracts (procyanidins), and propolis (apigenin, tt-farnesol). Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Bioactive Components in Fish Venoms

    Science.gov (United States)

    Ziegman, Rebekah; Alewood, Paul

    2015-01-01

    Animal venoms are widely recognized excellent resources for the discovery of novel drug leads and physiological tools. Most are comprised of a large number of components, of which the enzymes, small peptides, and proteins are studied for their important bioactivities. However, in spite of there being over 2000 venomous fish species, piscine venoms have been relatively underrepresented in the literature thus far. Most studies have explored whole or partially fractioned venom, revealing broad pharmacology, which includes cardiovascular, neuromuscular, cytotoxic, inflammatory, and nociceptive activities. Several large proteinaceous toxins, such as stonustoxin, verrucotoxin, and Sp-CTx, have been isolated from scorpaenoid fish. These form pores in cell membranes, resulting in cell death and creating a cascade of reactions that result in many, but not all, of the physiological symptoms observed from envenomation. Additionally, Natterins, a novel family of toxins possessing kininogenase activity have been found in toadfish venom. A variety of smaller protein toxins, as well as a small number of peptides, enzymes, and non-proteinaceous molecules have also been isolated from a range of fish venoms, but most remain poorly characterized. Many other bioactive fish venom components remain to be discovered and investigated. These represent an untapped treasure of potentially useful molecules. PMID:25941767

  16. Parametric functional principal component analysis.

    Science.gov (United States)

    Sang, Peijun; Wang, Liangliang; Cao, Jiguo

    2017-03-10

    Functional principal component analysis (FPCA) is a popular approach in functional data analysis to explore major sources of variation in a sample of random curves. These major sources of variation are represented by functional principal components (FPCs). Most existing FPCA approaches use a set of flexible basis functions such as B-spline basis to represent the FPCs, and control the smoothness of the FPCs by adding roughness penalties. However, the flexible representations pose difficulties for users to understand and interpret the FPCs. In this article, we consider a variety of applications of FPCA and find that, in many situations, the shapes of top FPCs are simple enough to be approximated using simple parametric functions. We propose a parametric approach to estimate the top FPCs to enhance their interpretability for users. Our parametric approach can also circumvent the smoothing parameter selecting process in conventional nonparametric FPCA methods. In addition, our simulation study shows that the proposed parametric FPCA is more robust when outlier curves exist. The parametric FPCA method is demonstrated by analyzing several datasets from a variety of applications. © 2017, The International Biometric Society.

  17. Interpretable functional principal component analysis.

    Science.gov (United States)

    Lin, Zhenhua; Wang, Liangliang; Cao, Jiguo

    2016-09-01

    Functional principal component analysis (FPCA) is a popular approach to explore major sources of variation in a sample of random curves. These major sources of variation are represented by functional principal components (FPCs). The intervals where the values of FPCs are significant are interpreted as where sample curves have major variations. However, these intervals are often hard for naïve users to identify, because of the vague definition of "significant values". In this article, we develop a novel penalty-based method to derive FPCs that are only nonzero precisely in the intervals where the values of FPCs are significant, whence the derived FPCs possess better interpretability than the FPCs derived from existing methods. To compute the proposed FPCs, we devise an efficient algorithm based on projection deflation techniques. We show that the proposed interpretable FPCs are strongly consistent and asymptotically normal under mild conditions. Simulation studies confirm that with a competitive performance in explaining variations of sample curves, the proposed FPCs are more interpretable than the traditional counterparts. This advantage is demonstrated by analyzing two real datasets, namely, electroencephalography data and Canadian weather data.

  18. Respiratory mechanics

    CERN Document Server

    Wilson, Theodore A

    2016-01-01

    This book thoroughly covers each subfield of respiratory mechanics: pulmonary mechanics, the respiratory pump, and flow. It presents the current understanding of the field and serves as a guide to the scientific literature from the golden age of respiratory mechanics, 1960 - 2010. Specific topics covered include the contributions of surface tension and tissue forces to lung recoil, the gravitational deformation of the lung, and the interdependence forces that act on pulmonary airways and blood vessels. The geometry and kinematics of the ribs is also covered in detail, as well as the respiratory action of the external and internal intercostal muscles, the mechanics of the diaphragm, and the quantitative compartmental models of the chest wall is also described. Additionally, flow in the airways is covered thoroughly, including the wave-speed and viscous expiratory flow-limiting mechanisms; convection, diffusion and the stationary front; and the distribution of ventilation. This is an ideal book for respiratory ...

  19. Fracture Mechanics

    CERN Document Server

    Zehnder, Alan T

    2012-01-01

    Fracture mechanics is a vast and growing field. This book develops the basic elements needed for both fracture research and engineering practice. The emphasis is on continuum mechanics models for energy flows and crack-tip stress- and deformation fields in elastic and elastic-plastic materials. In addition to a brief discussion of computational fracture methods, the text includes practical sections on fracture criteria, fracture toughness testing, and methods for measuring stress intensity factors and energy release rates. Class-tested at Cornell, this book is designed for students, researchers and practitioners interested in understanding and contributing to a diverse and vital field of knowledge. Alan Zehnder joined the faculty at Cornell University in 1988. Since then he has served in a number of leadership roles including Chair of the Department of Theoretical and Applied Mechanics, and Director of the Sibley School of Mechanical and Aerospace Engineering.  He teaches applied mechanics and his research t...

  20. College mechanics

    CERN Document Server

    Şengül, Caner

    2016-01-01

    College Mechanics QueBank has been designed to be different, enthusiastic, interesting and helpful to you. Therefore, it is not just a test bank about mechanics but also it is like a compass in order to find your way in mechanics Each chapter in this book is put in an order to follow a hierarchy of the mechanics topics; from vectors to simple harmonic motion. Throughout the book there are many multiple choice and long answer questions for you to solve. They have been created for YGS, LYS, SAT, IB or other standardized exams in the world because mechanics has no boundaries and so Physics has no country. Learn the main principle of each chapter and explore the daily life applications. Then you can start to solve the questions by planning a problem solving method carefully. Finally, enjoy solving the questions and discover the meachanics of the universe once more.

  1. Quantum mechanics

    CERN Document Server

    Rae, Alastair I M

    2016-01-01

    A Thorough Update of One of the Most Highly Regarded Textbooks on Quantum Mechanics Continuing to offer an exceptionally clear, up-to-date treatment of the subject, Quantum Mechanics, Sixth Edition explains the concepts of quantum mechanics for undergraduate students in physics and related disciplines and provides the foundation necessary for other specialized courses. This sixth edition builds on its highly praised predecessors to make the text even more accessible to a wider audience. It is now divided into five parts that separately cover broad topics suitable for any general course on quantum mechanics. New to the Sixth Edition * Three chapters that review prerequisite physics and mathematics, laying out the notation, formalism, and physical basis necessary for the rest of the book * Short descriptions of numerous applications relevant to the physics discussed, giving students a brief look at what quantum mechanics has made possible industrially and scientifically * Additional end-of-chapter problems with...

  2. Mechanical design of DNA nanostructures.

    Science.gov (United States)

    Castro, Carlos E; Su, Hai-Jun; Marras, Alexander E; Zhou, Lifeng; Johnson, Joshua

    2015-04-14

    Structural DNA nanotechnology is a rapidly emerging field that has demonstrated great potential for applications such as single molecule sensing, drug delivery, and templating molecular components. As the applications of DNA nanotechnology expand, a consideration of their mechanical behavior is becoming essential to understand how these structures will respond to physical interactions. This review considers three major avenues of recent progress in this area: (1) measuring and designing mechanical properties of DNA nanostructures, (2) designing complex nanostructures based on imposed mechanical stresses, and (3) designing and controlling structurally dynamic nanostructures. This work has laid the foundation for mechanically active nanomachines that can generate, transmit, and respond to physical cues in molecular systems.

  3. Absorption Of Dietary Lipid Components

    OpenAIRE

    Abdulkadir Hurşit

    2015-01-01

    Although the digestion and absorption of lipids that are necessary for the survival of living organisms are well known in general terms, nevertheless how different lipids to be digested, how it is distributed into the bloodstream, and how to be used by the cells, are unknown issues by most non specialist people. In recent years, knowledge of lipid digestion and absorption has expanded considerably. More insight has been gained in the mechanism of action of H + pump as a transport system in fa...

  4. Theoretical physics 2 analytical mechanics

    CERN Document Server

    Nolting, Wolfgang

    2016-01-01

    This textbook offers a clear and comprehensive introduction to analytical mechanics, one of the core components of undergraduate physics courses.It follows on naturally from the previous volumes in this series, thus expanding the knowledge in classical mechanics. The book starts with a thorough introduction into Lagrangian mechanics, detailing the d’Alembert principle, Hamilton’s principle and conservation laws. It continues with an in-depth explanation of Hamiltonian mechanics, illustrated by canonical and Legendre transformation, the generalization to quantum mechanics through Poisson brackets and all relevant variational principles. Finally, the Hamilton-Jacobi theory and the transition to wave mechanics are presented in detail. Ideally suited to undergraduate students with some grounding in classical mechanics, the book is enhanced throughout with learning features such as boxed inserts and chapter summaries, with key mathematical derivations highlighted to aid understanding. The text is supported by ...

  5. Understanding symmetrical components for power system modeling

    CERN Document Server

    Das, J C

    2017-01-01

    This book utilizes symmetrical components for analyzing unbalanced three-phase electrical systems, by applying single-phase analysis tools. The author covers two approaches for studying symmetrical components; the physical approach, avoiding many mathematical matrix algebra equations, and a mathematical approach, using matrix theory. Divided into seven sections, topics include: symmetrical components using matrix methods, fundamental concepts of symmetrical components, symmetrical components –transmission lines and cables, sequence components of rotating equipment and static load, three-phase models of transformers and conductors, unsymmetrical fault calculations, and some limitations of symmetrical components.

  6. Bioactivity of Minor Milk Components

    DEFF Research Database (Denmark)

    Nguyen, Duc Ninh

    . In particular, 3-15% of very low birth weight preterm infants suffer from the most servere form of intestinal inflammation, known as necrotizing enterocolitis (NEC). This disease is incurable with a high mortality rate of 15-30%. Mother’s breast milk consists of different bioactive constituents...... several steps of thermal processing, which are known to decrease/abolish bioactivity of milk constituents. This may explain for high NEC incidence in formula-fed preterm infants. We therefore in this PhD project investigated whether gentle thermal processing conditions increase the bioavailability...... of infant formula. Thereafter, bioactive milk components which were preserved in gently-processed infant formula were selected for further investigation of their immunomodulatory activity in cell and preterm pig models. We hope this project will contribute to the research on the development of new...

  7. Fast Steerable Principal Component Analysis.

    Science.gov (United States)

    Zhao, Zhizhen; Shkolnisky, Yoel; Singer, Amit

    2016-03-01

    Cryo-electron microscopy nowadays often requires the analysis of hundreds of thousands of 2-D images as large as a few hundred pixels in each direction. Here, we introduce an algorithm that efficiently and accurately performs principal component analysis (PCA) for a large set of 2-D images, and, for each image, the set of its uniform rotations in the plane and their reflections. For a dataset consisting of n images of size L × L pixels, the computational complexity of our algorithm is O(nL(3) + L(4)), while existing algorithms take O(nL(4)). The new algorithm computes the expansion coefficients of the images in a Fourier-Bessel basis efficiently using the nonuniform fast Fourier transform. We compare the accuracy and efficiency of the new algorithm with traditional PCA and existing algorithms for steerable PCA.

  8. Latent semantics as cognitive components

    DEFF Research Database (Denmark)

    Petersen, Michael Kai; Mørup, Morten; Hansen, Lars Kai

    2010-01-01

    Cognitive component analysis, defined as an unsupervised learning of features resembling human comprehension, suggests that the sensory structures we perceive might often be modeled by reducing dimensionality and treating objects in space and time as linear mixtures incorporating sparsity...... and independence. In music as well as language the patterns we come across become part of our mental workspace when the bottom-up sensory input raises above the background noise of core affect, and top-down trigger distinct feelings reflecting a shift of our attention. And as both low-level semantics and our...... emotional responses can be encoded in words, we propose a simplified cognitive approach to model how we perceive media. Representing song lyrics in a vector space of reduced dimensionality using LSA, we combine bottom-up defined term distances with affective adjectives, that top-down constrain the latent...

  9. Components of Co-creation

    DEFF Research Database (Denmark)

    Tanev, Stoyan

    2009-01-01

    , such an approach misses the advantages of an empirically driven quantitative approach that benefits from larger size samples and is more appropriate for theory building through the development and testing of hypotheses. It is important, therefore, to seek the development of a research methodology that combines...... the benefits of both qualitative and quantitative research approaches for studying the nature of value co-creation. The article provides a first attempt to identify the main research steps of such a methodology. It provides some preliminary results on the key components of value co-creation between firms...... of both qualitative and quantitative techniques. One of the main contributions of this article is to suggest and explore the possibility for using the QCA technique in future research on value co-creation....

  10. Bioactivity of Minor Milk Components

    DEFF Research Database (Denmark)

    Nguyen, Duc Ninh

    . In particular, 3-15% of very low birth weight preterm infants suffer from the most servere form of intestinal inflammation, known as necrotizing enterocolitis (NEC). This disease is incurable with a high mortality rate of 15-30%. Mother’s breast milk consists of different bioactive constituents...... several steps of thermal processing, which are known to decrease/abolish bioactivity of milk constituents. This may explain for high NEC incidence in formula-fed preterm infants. We therefore in this PhD project investigated whether gentle thermal processing conditions increase the bioavailability...... of infant formula. Thereafter, bioactive milk components which were preserved in gently-processed infant formula were selected for further investigation of their immunomodulatory activity in cell and preterm pig models. We hope this project will contribute to the research on the development of new...

  11. Rosin components identified in diapers.

    Science.gov (United States)

    Karlberg, A T; Magnusson, K

    1996-03-01

    As part of the investigation of sources of exposure to rosin allergens, disposable diapers (napkins) common on the Swedish market were analyzed, using gas chromatography, to detect the main rosin compounds. Rosin components were detected in all diapers, the highest amounts in those from the 2 major producers. In these diapers, more rosin was found in the top layer, which is in close contact with the skin than in the fluff. Despite the possibly minimal risk of induction of sensitization to rosin allergens in diapers, there is a real risk of elicitation of dermatitis in sensitive individuals, especially since penetration is enhanced by occlusion and irritation. Such material is not only used for infant diapers, but also for adult incontinence products and feminine hygiene products.

  12. The magnet components database system

    Energy Technology Data Exchange (ETDEWEB)

    Baggett, M.J. (Brookhaven National Lab., Upton, NY (USA)); Leedy, R.; Saltmarsh, C.; Tompkins, J.C. (Superconducting Supercollider Lab., Dallas, TX (USA))

    1990-01-01

    The philosophy, structure, and usage MagCom, the SSC magnet components database, are described. The database has been implemented in Sybase (a powerful relational database management system) on a UNIX-based workstation at the Superconducting Super Collider Laboratory (SSCL); magnet project collaborators can access the database via network connections. The database was designed to contain the specifications and measured values of important properties for major materials, plus configuration information (specifying which individual items were used in each cable, coil, and magnet) and the test results on completed magnets. These data will facilitate the tracking and control of the production process as well as the correlation of magnet performance with the properties of its constituents. 3 refs., 10 figs.

  13. Characteristic test technology for PWR fuel and its components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Ho; Lee, Chan Bock; Bang, Je Gun; Jung, Yeon Ho; Jeong, Yong Hwan; Park, Sang Yoon; Kim, Kyeng Ho; Nam, Cheol; Baek, Jong Hyuk; Lee, Myung Ho; Choi, Byoung Kwon; Song, Kun Woo; Kang, Ki Won; Kim, Keon Sik; Kim, Jong Hun; Kim, Young Min; Yang, Jae Ho; Song, Kee Nam; Kim, Hyung Kyu; Kang, Heung Seok; Yoon, Kyung Ho; Chun, Tae Hyun; In, Wang Kee; Oh, Dong Seok [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-01-01

    Characteristic tests of fuel assembly and its components being developed in the Advanced LWR Fuel Development Project supported by the mid-long term nuclear R and D program are described in this report. Performance verification of fuel and its components by the characteristic tests are essential to their development. Fuel components being developed in the Advanced LWR Fuel Development Project are zirconium alloy cladding, UO{sub 2} and burnable absorber pellets, spacer grid and top and bottom end pieces. Detailed test plans for those fuel components are described in this report, and test procedures of cladding and pellet are also described in the Appendix. Examples of the described tests are in- and out-of- pile corrosion and mechanical tests such as creep and burst tests for the cladding, in-pile capsule and ramp tests for the pellet, mechanical tests such as strength and vibration, and thermal-hydraulic tests such as pressure drop and critical heat flux for the spacer grid and top and bottom end pieces. It is expected that this report could be used as the standard reference for the performance verification tests in the development of LWR fuel and its components. 11 refs., 9 figs., 2 tabs. (Author)

  14. Quantum mechanics

    CERN Document Server

    Powell, John L

    2015-01-01

    Suitable for advanced undergraduates, this thorough text focuses on the role of symmetry operations and the essentially algebraic structure of quantum-mechanical theory. Based on courses in quantum mechanics taught by the authors, the treatment provides numerous problems that require applications of theory and serve to supplement the textual material.Starting with a historical introduction to the origins of quantum theory, the book advances to discussions of the foundations of wave mechanics, wave packets and the uncertainty principle, and an examination of the Schrödinger equation that includ

  15. Robot Mechanisms

    CERN Document Server

    Lenarcic, Jadran; Stanišić, Michael M

    2013-01-01

    This book provides a comprehensive introduction to the area of robot mechanisms, primarily considering industrial manipulators and humanoid arms. The book is intended for both teaching and self-study. Emphasis is given to the fundamentals of kinematic analysis and the design of robot mechanisms. The coverage of topics is untypical. The focus is on robot kinematics. The book creates a balance between theoretical and practical aspects in the development and application of robot mechanisms, and includes the latest achievements and trends in robot science and technology.

  16. Fluid mechanics

    CERN Document Server

    Kundu, Pijush K; Dowling, David R

    2011-01-01

    Fluid mechanics, the study of how fluids behave and interact under various forces and in various applied situations-whether in the liquid or gaseous state or both-is introduced and comprehensively covered in this widely adopted text. Revised and updated by Dr. David Dowling, Fluid Mechanics, 5e is suitable for both a first or second course in fluid mechanics at the graduate or advanced undergraduate level. Along with more than 100 new figures, the text has been reorganized and consolidated to provide a better flow and more cohesion of topics.Changes made to the

  17. Gauge mechanics

    CERN Document Server

    Mangiarotti, L

    1998-01-01

    This book presents in a unified way modern geometric methods in analytical mechanics based on the application of fibre bundles, jet manifold formalism and the related concept of connection. Non-relativistic mechanics is seen as a particular field theory over a one-dimensional base. In fact, the concept of connection is the major link throughout the book. In the gauge scheme of mechanics, connections appear as reference frames, dynamic equations, and in Lagrangian and Hamiltonian formalisms. Inertial forces, energy conservation laws and other phenomena related to reference frames are analyzed;

  18. Fracture mechanics

    CERN Document Server

    Perez, Nestor

    2017-01-01

    The second edition of this textbook includes a refined presentation of concepts in each chapter, additional examples; new problems and sections, such as conformal mapping and mechanical behavior of wood; while retaining all the features of the original book. The material included in this book is based upon the development of analytical and numerical procedures pertinent to particular fields of linear elastic fracture mechanics (LEFM) and plastic fracture mechanics (PFM), including mixed-mode-loading interaction. The mathematical approach undertaken herein is coupled with a brief review of several fracture theories available in cited references, along with many color images and figures. Dynamic fracture mechanics is included through the field of fatigue and Charpy impact testing. Explains computational and engineering approaches for solving crack-related problems using straightforward mathematics that facilitate comprehension of the physical meaning of crack growth processes; Expands computational understandin...

  19. Engineering mechanics

    CERN Document Server

    Gross, Dietmar; Schröder, Jörg; Wall, Wolfgang A; Rajapakse, Nimal

    Statics is the first volume of a three-volume textbook on Engineering Mechanics. The authors, using a time-honoured straightforward and flexible approach, present the basic concepts and principles of mechanics in the clearest and simplest form possible to advanced undergraduate engineering students of various disciplines and different educational backgrounds. An important objective of this book is to develop problem solving skills in a systematic manner. Another aim of this volume is to provide engineering students as well as practising engineers with a solid foundation to help them bridge the gap between undergraduate studies on the one hand and advanced courses on mechanics and/or practical engineering problems on the other. The book contains numerous examples, along with their complete solutions. Emphasis is placed upon student participation in problem solving. The contents of the book correspond to the topics normally covered in courses on basic engineering mechanics at universities and colleges. Now in i...

  20. Detection of incorrect manufacturer labelling of hip components.

    Science.gov (United States)

    Durand-Hill, Matthieu; Henckel, Johann; Burwell, Matthew; Skinner, John; Hart, Alister

    2017-01-01

    We describe the case of a 53-year-old man who underwent a left metal-on-metal hip resurfacing in 2015. Component size mismatch (CSM) was suspected because of the patient's immediate post-operative mechanical symptoms and high metal ion levels. Surgical notes indicated the appropriate combinations of implants were used. However, we detected a mismatch using computed tomography. Revision was performed and subsequent measurements of explanted components confirmed the mismatch. To our knowledge, this case is the first report of a CT method being used in a patient to pre-operatively identify CSM.