WorldWideScience

Sample records for mechanical design update

  1. PDX, mechanical design update and assembly

    International Nuclear Information System (INIS)

    Knutson, D.; Cavalluzzo, S.; Davenport, J.; Kaminsky, E.; Perry, E.; Willard, J.

    1977-01-01

    Mechanical design changes and refinements have occurred since the Sixth Symposium on Engineering Problems of Fusion Research. Particular attention is focused on the area of the toroidal field coil lap joint. Preassembly of major components and final assembly and alignment of the toroidal and poloidal field coils is discussed

  2. HYLIFE-II reactor chamber mechanical design: Update

    International Nuclear Information System (INIS)

    House, P.A.

    1992-01-01

    Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li 2 BeF 4 ) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (17 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GW e and 2 GW e reactor chamber are presented

  3. 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

  4. SSC design update

    International Nuclear Information System (INIS)

    Syphers, M.J.

    1992-11-01

    Recent developments in the design and construction of the SSC are presented. Topics include status of the 20 TeV Collider rings, including interaction regions, utility regions, and main arcs, plus some remarks on the injector accelerators. Remaining issues facing the design of the colliding beams synchrotron and its injectors are discussed

  5. Update heat exchanger designing principles

    International Nuclear Information System (INIS)

    Lipets, A.U.; Yampol'skij, A.E.

    1985-01-01

    Update heat exchanger design principles are analysed. Different coolant pattern in a heat exchanger are considered. It is suggested to rationally organize flow rates irregularity in it. Applying on heat exchanger designing measures on using really existing temperature and flow rate irregularities will permit to improve heat exchanger efficiency. It is expedient in some cases to artificially produce irregularities. In this connection some heat exchanger design principles must be reviewed now

  6. 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...

  7. Mechanical Design

    Energy Technology Data Exchange (ETDEWEB)

    Shook, Richard; /Marquette U. /SLAC

    2010-08-25

    The particle beam of the SXR (soft x-ray) beam line in the LCLS (Linac Coherent Light Source) has a high intensity in order to penetrate through samples at the atomic level. However, the intensity is so high that many experiments fail because of severe damage. To correct this issue, attenuators are put into the beam line to reduce this intensity to a level suitable for experimentation. Attenuation is defined as 'the gradual loss in intensity of any flux through a medium' by [1]. It is found that Beryllium and Boron Carbide can survive the intensity of the beam. At very thin films, both of these materials work very well as filters for reducing the beam intensity. Using a total of 12 filters, the first 9 being made of Beryllium and the rest made of Boron Carbide, the beam's energy range of photons can be attenuated between 800 eV and 9000 eV. The design of the filters allows attenuation for different beam intensities so that experiments can obtain different intensities from the beam if desired. The step of attenuation varies, but is relative to the thickness of the filter as a power function of 2. A relationship for this is f(n) = x{sub 0}2{sup n} where n is the step of attenuation desired and x{sub 0} is the initial thickness of the material. To allow for this desired variation, a mechanism must be designed within the test chamber. This is visualized using a 3D computer aided design modeling tool known as Solid Edge.

  8. Mechanical Design

    International Nuclear Information System (INIS)

    2010-01-01

    The particle beam of the SXR (soft x-ray) beam line in the LCLS (Linac Coherent Light Source) has a high intensity in order to penetrate through samples at the atomic level. However, the intensity is so high that many experiments fail because of severe damage. To correct this issue, attenuators are put into the beam line to reduce this intensity to a level suitable for experimentation. Attenuation is defined as 'the gradual loss in intensity of any flux through a medium' by (1). It is found that Beryllium and Boron Carbide can survive the intensity of the beam. At very thin films, both of these materials work very well as filters for reducing the beam intensity. Using a total of 12 filters, the first 9 being made of Beryllium and the rest made of Boron Carbide, the beam's energy range of photons can be attenuated between 800 eV and 9000 eV. The design of the filters allows attenuation for different beam intensities so that experiments can obtain different intensities from the beam if desired. The step of attenuation varies, but is relative to the thickness of the filter as a power function of 2. A relationship for this is f(n) = x 0 2 n where n is the step of attenuation desired and x 0 is the initial thickness of the material. To allow for this desired variation, a mechanism must be designed within the test chamber. This is visualized using a 3D computer aided design modeling tool known as Solid Edge.

  9. Mechanical design

    Science.gov (United States)

    1976-01-01

    Design concepts for a 1000 mw thermal stationary power plant employing the UF6 fueled gas core breeder reactor are examined. Three design combinations-gaseous UF6 core with a solid matrix blanket, gaseous UF6 core with a liquid blanket, and gaseous UF6 core with a circulating blanket were considered. Results show the gaseous UF6 core with a circulating blanket was best suited to the power plant concept.

  10. Mechanical design of machine components

    CERN Document Server

    Ugural, Ansel C

    2015-01-01

    Mechanical Design of Machine Components, Second Edition strikes a balance between theory and application, and prepares students for more advanced study or professional practice. It outlines the basic concepts in the design and analysis of machine elements using traditional methods, based on the principles of mechanics of materials. The text combines the theory needed to gain insight into mechanics with numerical methods in design. It presents real-world engineering applications, and reveals the link between basic mechanics and the specific design of machine components and machines. Divided into three parts, this revised text presents basic background topics, deals with failure prevention in a variety of machine elements and covers applications in design of machine components as well as entire machines. Optional sections treating special and advanced topics are also included.Key Features of the Second Edition:Incorporates material that has been completely updated with new chapters, problems, practical examples...

  11. Design of mechanical joints

    CERN Document Server

    Blake, Alexander

    2018-01-01

    A cornerstone publication that covers the basic principles and practical considerations of design methodology for joints held by rivets, bolts, weld seams, and adhesive materials, Design of Mechanical Joints gives engineers the practical results and formulas they need for the preliminary design of mechanical joints, combining the essential topics of joint mechanics...strength of materials...and fracture control to provide a complete treatment of problems pertinent to the field of mechanical connections.

  12. a Bottom-Up Geosptial Data Update Mechanism for Spatial Data Infrastructure Updating

    Science.gov (United States)

    Tian, W.; Zhu, X.; Liu, Y.

    2012-08-01

    Currently, the top-down spatial data update mechanism has made a big progress and it is wildly applied in many SDI (spatial data infrastructure). However, this mechanism still has some issues. For example, the update schedule is limited by the professional department's project, usually which is too long for the end-user; the data form collection to public cost too much time and energy for professional department; the details of geospatial information does not provide sufficient attribute, etc. Thus, how to deal with the problems has become the effective shortcut. Emerging Internet technology, 3S technique and geographic information knowledge which is popular in the public promote the booming development of geoscience in volunteered geospatial information. Volunteered geospatial information is the current "hotspot", which attracts many researchers to study its data quality and credibility, accuracy, sustainability, social benefit, application and so on. In addition to this, a few scholars also pay attention to the value of VGI to support the SDI updating. And on that basis, this paper presents a bottom-up update mechanism form VGI to SDI, which includes the processes of match homonymous elements between VGI and SDI vector data , change data detection, SDI spatial database update and new data product publication to end-users. Then, the proposed updating cycle is deeply discussed about the feasibility of which can detect the changed elements in time and shorten the update period, provide more accurate geometry and attribute data for spatial data infrastructure and support update propagation.

  13. BWR mechanics and materials technology update

    International Nuclear Information System (INIS)

    Kiss, E.

    1983-01-01

    This paper discusses technical results obtained from a variety of important programs underway at General Electric's Nuclear Engineering Division. The principal objective of these programs is to qualify and improve BWR product related technologies that fall broadly under the disciplines of Applied Mechanics and Materials Engineering. The paper identifies and deals with current technical issues that are of general importance to the LWR industry albeit the specific focus is directed to the development and qualification of analytical predictive methods and criteria, and improved materials for use in the design of the BWR. In this paper, specific results and accomplishments are summarized to provide a braod perspective of technology advances. Results are presented in sections which discuss: dynamic analysis and modeling; fatigue and fracture evaluation; materials engineering advances; and flow induced vibration. (orig.)

  14. Mechanical design engineering handbook

    CERN Document Server

    Childs, Peter R N

    2013-01-01

    Mechanical Design Engineering Handbook is a straight-talking and forward-thinking reference covering the design, specification, selection, use and integration of machine elements fundamental to a wide range of engineering applications. Develop or refresh your mechanical design skills in the areas of bearings, shafts, gears, seals, belts and chains, clutches and brakes, springs, fasteners, pneumatics and hydraulics, amongst other core mechanical elements, and dip in for principles, data and calculations as needed to inform and evaluate your on-the-job decisions. Covering the full spectrum

  15. Design principles for precision mechanisms

    CERN Document Server

    Soemers, Herman

    2011-01-01

    The successful design of mechanisms for products, tools and equipment relies on excellent concepts and properly designed details. Both are covered in this book. Many of the examples presented have been realised in practice and properly evaluated, giving the reader/designer a high level of confidence. Every example comes with the considerations underlying the application and the limitations of the particular idea. This book is based on the work started in the 1960s by W. van der Hoek at Philips in Eindhoven, the Netherlands, and subsequently continued by M.P. Koster, culminating in the Dutch-language book “Constructieprincipes” [Design principles for accurate movement and positioning]. The core of their design approach has been preserved, while theory and examples were updated and the English language was adopted to reach a broad audience within the Netherlands as well as abroad. Herman (H.M.J.R.) Soemers is associated with the University of Twente, Enschede, the Netherlands. He also works as a technolog...

  16. Mechanical Drawing and Design.

    Science.gov (United States)

    Mikulsky, Marilyn; McEnaney, Walter K.

    A syllabus is provided for a comprehensive foundation course in mechanical drawing and design for grades 9, 10, 11, or 12 that is prerequisite to advanced elective courses. Introductory materials include course objectives, an overview of basic concepts, and guidelines for implementation. Brief discussions of and suggestions for the areas of design…

  17. Mechanical Design of Spacecraft

    Science.gov (United States)

    1962-01-01

    In the spring of 1962, engineers from the Engineering Mechanics Division of the Jet Propulsion Laboratory gave a series of lectures on spacecraft design at the Engineering Design seminars conducted at the California Institute of Technology. Several of these lectures were subsequently given at Stanford University as part of the Space Technology seminar series sponsored by the Department of Aeronautics and Astronautics. Presented here are notes taken from these lectures. The lectures were conceived with the intent of providing the audience with a glimpse of the activities of a few mechanical engineers who are involved in designing, building, and testing spacecraft. Engineering courses generally consist of heavily idealized problems in order to allow the more efficient teaching of mathematical technique. Students, therefore, receive a somewhat limited exposure to actual engineering problems, which are typified by more unknowns than equations. For this reason it was considered valuable to demonstrate some of the problems faced by spacecraft designers, the processes used to arrive at solutions, and the interactions between the engineer and the remainder of the organization in which he is constrained to operate. These lecture notes are not so much a compilation of sophisticated techniques of analysis as they are a collection of examples of spacecraft hardware and associated problems. They will be of interest not so much to the experienced spacecraft designer as to those who wonder what part the mechanical engineer plays in an effort such as the exploration of space.

  18. IRIS design overview and status update

    International Nuclear Information System (INIS)

    Carelli, M.D.; Petrovic, B.; Conway, L.E.; Oriani, L.; Kling, C.L.; Miller, K.; Lombardi, C.V.; Ricotti, M.E.; Barroso, A.C.O.; Collado, J.M.; Cinotti, L.; Storai, S.; Berra, F.; Todreas, N.E.; Ninokata, H.; Cavlina, N.; Grgic, D.; Oriolo, F.; Moraes, M.M.; Frederico, C.; Henning, F.; Griffith, W.; Love, J.; Ingersoll, D.T.; Wood, R.; Alonso, G.; Kodochigov, N.; Polunichev, V.; Augutis, J.; Alzbutas, R.; Boroughs, R.D.; Naviglio, A.; Panella, B.

    2005-01-01

    The International Reactor Innovative and Secure (IRIS) is an advanced, integral, light-water cooled reactor of medium generating capacity (1000 MWt, or ∼335 MWe), geared at near term deployment (2012- 2015). It has been under development since the turn of the century by an international consortium--led by Westinghouse--that includes 21 organizations from 10 countries, and it is currently in the pre-application licensing process with the U.S. Nuclear Regulatory Commission (NRC). This paper describes its integral design (i.e., steam generators, pumps, pressurizer and control rod drive mechanisms are all included inside the reactor vessel, together with the core, control rods, and neutron reflector/shield) and discusses the unique ('safety-by-design') TM IRIS philosophy. This approach, by eliminating accidents at the design stage, or decreasing their consequences and probabilities when outright elimination is not possible, provides a very powerful first level of defense in depth. The ('safety by- design') TM allows a significant reduction and simplification of the passive safety systems, which not only improves safety but simultaneously reduces the overall cost. Moreover, it supports licensing the power plant without the need for off-site emergency response planning--an objective which is part of the pre-application with NRC and is also pursued within an international research project coordinated by the International Atomic Energy Agency (IAEA). This would allow IRIS to be treated as any other industrial facility, located closer to population centers, and enable its effective dual-purpose use for electricity production and co-generation (district heating, desalination, industrial steam). The modular IRIS--with each module rated at ∼335 MWe--is an ideal size for developing countries as it allows to easily introducing single modules in regions only requiring a few hundred MWs, or a moderate amount of power on limited electric grids. IRIS can be also deployed in

  19. Updating design information questionnaire (DIQ) experiences

    International Nuclear Information System (INIS)

    Palafox-Garcia, P.

    2001-01-01

    Full text: 1. Introduction - Once the State signed with the International Atomic Energy Agency the Non-Proliferation Treaty (NPT), the State has to declare to the IAEA their facilities where they handle Nuclear Material. Each facility will have their own Safeguards Agreement and these are called Subsidiary Arrangements. In order to have a good control and accountability of this material, each facility is named Material Balance Area (MBA). Based on the Subsidiary Arrangements each MBA has to fill a proper IAEA format named DIQ in order to get the Facility Attachment. The DIQ format varies, relying on the kind of facility. 2. Facility - In the NNRI, we have two MBA's and the experiences that we have had to fill the DIQ formats had been, that it takes quite a time to get the proper Facility Attachment, because first you have to have the proper format, then you fill it properly with all their respective annexes and once it is reviewed and approved by the people involved, this is signed and sent to the IAEA, this first step took six months. Once the format is reviewed by the IAEA, they send it back to the facility, asking for proper comments in order to clarify it properly, this took three months. The facility update the comments and send it back, this took three months. With this format the IAEA prepares the Facility Attachment of the MBA and send it to the facility for its approval or comments, this took five months. The facility reviewed it and sent it back with some comments or doubts after tree months. The IAEA clarifies the comments and doubts and send to the facility the approved Facility Attachment, four months later. So in order to get the proper Facility Attachments for each of our MBA's, it has been taken 24 months (two years) at least. 3. Actual situation - At present, now that the nuclear activities have been diminished and consequently the nuclear material movements, because the Fuel Fabrication Pilot Plant (FFPP) we have, was stopped for financial reasons

  20. Reliability and mechanical design

    International Nuclear Information System (INIS)

    Lemaire, Maurice

    1997-01-01

    A lot of results in mechanical design are obtained from a modelisation of physical reality and from a numerical solution which would lead to the evaluation of needs and resources. The goal of the reliability analysis is to evaluate the confidence which it is possible to grant to the chosen design through the calculation of a probability of failure linked to the retained scenario. Two types of analysis are proposed: the sensitivity analysis and the reliability analysis. Approximate methods are applicable to problems related to reliability, availability, maintainability and safety (RAMS)

  1. Update formulas for split-plot and block designs

    NARCIS (Netherlands)

    H. Arnouts (Heidi); P.P. Goos (Peter)

    2009-01-01

    textabstractFor the algorithmic construction of optimal experimental designs, it is important to be able to evaluate small modifications of given designs in terms of the optimality criteria at a low computational cost. This can be achieved by using powerful update formulas for the optimality

  2. Update of bridge design standards in Alabama for AASHTO LRFD seismic design requirements.

    Science.gov (United States)

    2013-11-01

    The Alabama Department of Transportation (ALDOT) has been required to update their bridge design to the LRFD Bridge Design Specifications. This transition has resulted in changes to the seismic design standards of bridges in the state. Multiple bridg...

  3. Game mechanics : advanced game design

    NARCIS (Netherlands)

    Adams, Ernest; Dormans, Joris

    2012-01-01

    Game Mechanics is aimed at game design students and industry professionals who want to improve their understanding of how to design, build, and test the mechanics of a game. Game Mechanics will show you how to design, test, and tune the core mechanics of a game—any game, from a huge role-playing

  4. An Updated Point Design for Heavy Ion Fusion

    International Nuclear Information System (INIS)

    Yu, S.S.; Meier, W.R.; Abbott, R.B.; Barnard, J.J.; Brown, T.; Callahan, D.A.; Heitzenroeder, P.; Latkowski, J.F.; Logan, B.G.; Pemberton, S.J.; Peterson, P.F.; Rose, D.V.; Sabbi, G.L.; Sharp, W.M.; Welch, D.R.

    2002-01-01

    An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant

  5. Mechanizing Exploratory Game Design

    OpenAIRE

    Smith, Adam Marshall

    2012-01-01

    Game design is an art form that deals with inherently interactive artifacts. Game designers craft games (assembled from rule systems and content), but they really seek to manipulate play: the interaction between games and players. When developing new games that are similar to past games, a designer may rely on previous experience with related designs and relatively easy access to players familiar with conventional design choices. When exploratorily venturing into uncharted territory, uncoveri...

  6. TMX magnets: mechanical design

    International Nuclear Information System (INIS)

    Hinkle, R.E.; Harvey, A.R.; Calderon, M.O.; Chargin, A.K.; Chen, F.F.K.; Denhoy, B.S.; Horvath, J.A.; Reed, J.R.; Waugh, A.F.

    1977-01-01

    The Tandem Mirror Experiment (TMX) system, part of the Lawrence Livermore Laboratory magnetic mirror program incorporates in its design various types of coils or magnets. This paper describes the physical construction of each coil within the system as well as the structural design required for their support and installation

  7. Mechanism of action of recombinant activated factor VII: an update.

    Science.gov (United States)

    Hedner, Ulla

    2006-01-01

    Bleeding episodes in patients with hemophilia and inhibitors must be managed using agents that are hemostatically active in the absence of factor VIII or IX. Activated prothrombin complex concentrates have long been used in this context. However, the search for safer and more effective agents has led to the development of recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark). This paper presents an update on the mechanism of action of rFVIIa, and describes how pharmacologic doses of this agent enhance thrombin production and thus contribute to the development of a stable, lysis-resistant fibrin plug at the site of vessel damage. This mechanism explains the reported efficacy of rFVIIa in a range of clinical situations characterized by impaired thrombin generation.

  8. Mechanical Design Science

    International Nuclear Information System (INIS)

    Jung, Sun Mo

    1969-04-01

    This book contains element of machine and machine design, machine standard, a safety factor, fatigue limit like notch, creep, limits and fits for engineering, design of shaft system machine, shaft coupling and clutch, journal and roller bearing such as needle bearing, flexible roller bearing and miniature ball bearing and sliding bearing. It also deals with brake like band brake, spring such as coil spring, torsion bar spring, ring spring and fly wheel, design of pipe system machine like pipe types, joint pipes, check valve, reductive valve and escape valve.

  9. Mechanical design in arteries.

    Science.gov (United States)

    Shadwick, R E

    1999-12-01

    The most important mechanical property of the artery wall is its non-linear elasticity. Over the last century, this has been well-documented in vessels in many animals, from humans to lobsters. Arteries must be distensible to provide capacitance and pulse-smoothing in the circulation, but they must also be stable to inflation over a range of pressure. These mechanical requirements are met by strain-dependent increases in the elastic modulus of the vascular wall, manifest by a J-shaped stress-strain curve, as typically exhibited by other soft biological tissues. All vertebrates and invertebrates with closed circulatory systems have arteries with this non-linear behaviour, but specific tissue properties vary to give correct function for the physiological pressure range of each species. In all cases, the non-linear elasticity is a product of the parallel arrangement of rubbery and stiff connective tissue elements in the artery wall, and differences in composition and tissue architecture can account for the observed variations in mechanical properties. This phenomenon is most pronounced in large whales, in which very high compliance in the aortic arch and exceptionally low compliance in the descending aorta occur, and is correlated with specific modifications in the arterial structure.

  10. Robust Design of Sounds in Mechanical Mechanisms

    DEFF Research Database (Denmark)

    Boegedal Jensen, Annemette; Munch, Natasja; Howard, Thomas J.

    2015-01-01

    mechanism consisting of a toothed rack and a click arm. First several geometries of the teeth and the click arm’s head were investigated to identify the most robust and repeatable design. It was found that a flat surface in the valleys between the teeth is very beneficial in relation to repeatability...

  11. Shape Synthesis in Mechanical Design

    OpenAIRE

    C. P. Teng; S. Bai; J. Angeles

    2007-01-01

    The shaping of structural elements in the area of mechanical design is a recurrent problem. The mechanical designer, as a rule, chooses what is believed to be the “simplest” shapes, such as the geometric primitives: lines, circles and, occasionally, conics. The use of higher-order curves is usually not even considered, not to speak of other curves than polynomials. However, the simplest geometric shapes are not necessarily the most suitable when the designed element must withstand loads that ...

  12. Design considerations for mechanical snubbers

    International Nuclear Information System (INIS)

    Severud, L.K.; Summers, G.D.

    1980-03-01

    The use of mechanical snubbers to restrain piping during an earthquake event is becoming more common in design of nuclear power plants. The design considerations and qualification procedures for mechanical snubbers used on the Fast Flux Test Facility will be presented. Design precautions and requirements for both normal operation and seismic operation are necessary. Effects of environmental vibration (nonseismic) induced through the piping by pump shaft imbalance and fluid flow oscillations will be addressed. Also, the snubber dynamic characteristics of interest to design and snubber design application considerations will be discussed

  13. Mechanical design of DNA nanostructures

    Science.gov (United States)

    Castro, Carlos E.; Su, Hai-Jun; Marras, Alexander E.; Zhou, Lifeng; Johnson, Joshua

    2015-03-01

    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.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. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07153k

  14. Analyses for designing objects in mechanical design

    International Nuclear Information System (INIS)

    Nakajima, Norihiro; Miyamura, Hiroko N.; Kawakami, Yoshiaki; Kawamura, Takuma

    2015-01-01

    Defining factors to induce the damage that can be assumed in the mechanical structures, it is a loaded work to analyze a damage possibility point derived by the assumption phenomenon that can occur is, but it is the important designing process. Taking factors caused by the earthquake as an example, and simulating the phenomenon that can be assumed, the computational result was analyzed with information visualization. A damage possibility point by analyzing the result mathematically. The illustration of analytical results may give points to designers as means for a designer to recognize a damage possibility point from the sensitivity of the designer. (author)

  15. Strategy update in a design and consulting company

    OpenAIRE

    Kiviniemi, Juha

    2017-01-01

    The target company of the present thesis is a small engineering company specialising in electrical design. The company’s current development stage and changes in its operating environment call for a strategy up-date. The objective of this study was to formulate key conclusions based on an analysis of the company’s current strategy and its operating environment which will later act as an input to the company’s strategy process. The strategy process itself is left outside the scope of this...

  16. Mechanical Design Handbook for Elastomers

    Science.gov (United States)

    Darlow, M.; Zorzi, E.

    1986-01-01

    Mechanical Design Handbook for Elastomers reviews state of art in elastomer-damper technology with particular emphasis on applications of highspeed rotor dampers. Self-contained reference but includes some theoretical discussion to help reader understand how and why dampers used for rotating machines. Handbook presents step-by-step procedure for design of elastomer dampers and detailed examples of actual elastomer damper applications.

  17. Shape Synthesis in Mechanical Design

    Directory of Open Access Journals (Sweden)

    C. P. Teng

    2007-01-01

    Full Text Available The shaping of structural elements in the area of mechanical design is a recurrent problem. The mechanical designer, as a rule, chooses what is believed to be the “simplest” shapes, such as the geometric primitives: lines, circles and, occasionally, conics. The use of higher-order curves is usually not even considered, not to speak of other curves than polynomials. However, the simplest geometric shapes are not necessarily the most suitable when the designed element must withstand loads that can lead to failure-prone stress concentrations. Indeed, as mechanical designers have known for a while, stress concentrations occur, first and foremost, by virtue of either dramatic changes in curvature or extremely high values thereof. As an alternative, we propose here the use of smooth curves that can be simply generated using standard concepts such as non-parametric cubic splines. These curves can be readily used to produce either extruded surfaces or surfaces of revolution. 

  18. CHEMICAL OIL SPILL DISPERSANTS: UPDATE STATE-OF-THE- ART ON MECHANISM OF ACTION AND LABORATORY TESTING FOR PERFORMANCE

    Science.gov (United States)

    Chemical dispersants are formulations designed to facilitate dispersion of an oil slick into small droplets that disperse to non-problematic concentrations in an underlying water column. This project had two primary objectives: (1) update information on mechanisms of action of ...

  19. IRIS project update: status of the design and licensing activities

    International Nuclear Information System (INIS)

    Petrovic, B.; Carelli, M.

    2004-01-01

    This paper presents an overview of the current status of the IRIS (International Reactor Innovative and Secure) project, focusing on the design and licensing activities. An update relative to the previous presentation at the 4th HND Conference is provided, highlighting some of the main accomplishments over the past two years. After successfully completing the conceptual design phase, IRIS is now finalizing the preliminary design as well. The pre-application licensing review with the U.S. NRC has been initiated in October of 2002. The safety-by-design approach and PRA-guided design open the possibility to aim for licensing not requiring off-site emergency response planning. Multiple single-unit and twin-unit site layouts have been developed within the ESP (Early Site Permit) program currently pursued by three U.S. power utilities. Desalination and district heating options have recently been added to the base design. Staggered construction schedules of multiple units may be applied to optimize cash-flow and minimize the required investment, making IRIS a financially attractive option, even for economies with limited investment capabilities. Because of its modularity, compatibility with smaller/medium grids, and enabling gradual build of new generating capacity matching the needs, IRIS has a large potential in the worldwide market.(author)

  20. Mechanical design of electric motors

    CERN Document Server

    Tong, Wei

    2014-01-01

    Rapid increases in energy consumption and emphasis on environmental protection have posed challenges for the motor industry, as has the design and manufacture of highly efficient, reliable, cost-effective, energy-saving, quiet, precisely controlled, and long-lasting electric motors.Suitable for motor designers, engineers, and manufacturers, as well as maintenance personnel, undergraduate and graduate students, and academic researchers, Mechanical Design of Electric Motors provides in-depth knowledge of state-of-the-art design methods and developments of electric motors. From motor classificati

  1. IVVS probe mechanical concept design

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Paolo, E-mail: paolo.rossi@enea.it; Neri, Carlo; De Collibus, Mario Ferri; Mugnaini, Giampiero; Pollastrone, Fabio; Crescenzi, Fabio

    2015-10-15

    Highlights: • ENEA designed, developed and tested a laser based In Vessel Viewing System (IVVS). • IVVS mechanical design has been revised from 2011 to 2013 to meet ITER requirements. • Main improvements are piezoceramic actuators and a step focus system. • Successful qualification activities validated the concept design for ITER environment. - Abstract: ENEA has been deeply involved in the design, development and testing of a laser based In Vessel Viewing System (IVVS) required for the inspection of ITER plasma-facing components. The IVVS probe shall be deployed into the vacuum vessel, providing high resolution images and metrology measurements to detect damages and possible erosion. ENEA already designed and manufactured an IVVS probe prototype based on a rad-hard concept and driven by commercial micro-step motors, which demonstrated satisfying viewing and metrology performances at room conditions. The probe sends a laser beam through a reflective rotating prism. By rotating the axes of the prism, the probe can scan all the environment points except those present in a shadow cone and the backscattered light signal is then processed to measure the intensity level (viewing) and the distance from the probe (metrology). During the last years, in order to meet all the ITER environmental conditions, such as high vacuum, gamma radiation lifetime dose up to 5 MGy, cumulative neutron fluence of about 2.3 × 10{sup 17} n/cm{sup 2}, temperature of 120 °C and magnetic field of 8 T, the probe mechanical design was significantly revised introducing a new actuating system based on piezo-ceramic actuators and improved with a new step focus system. The optical and mechanical schemes have been then modified and refined to meet also the geometrical constraints. The paper describes the mechanical concept design solutions adopted in order to fulfill IVVS probe functional performance requirements considering ITER working environment and geometrical constraints.

  2. STAR PIXEL detector mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Wieman, H H; Anderssen, E; Greiner, L; Matis, H S; Ritter, H G; Sun, X; Szelezniak, M [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: hhwieman@lbl.gov

    2009-05-15

    A high resolution pixel detector is being designed for the STAR [1] experiment at RHIC. This device will use MAPS as the detector element and will have a pointing accuracy of {approx}25 microns. We will be reporting on the mechanical design required to support this resolution. The radiation length of the first layer ({approx}0.3% X{sub 0}) and its distance from the interaction point (2.5 cm) determines the resolution. The design makes use of air cooling and thin carbon composite structures to limit the radiation length. The mechanics are being developed to achieve spatial calibrations and stability to 20 microns and to permit rapid detector replacement in event of radiation damage or other potential failures from operation near the beam.

  3. Neural Mechanisms of Updating under Reducible and Irreducible Uncertainty.

    Science.gov (United States)

    Kobayashi, Kenji; Hsu, Ming

    2017-07-19

    Adaptive decision making depends on an agent's ability to use environmental signals to reduce uncertainty. However, because of multiple types of uncertainty, agents must take into account not only the extent to which signals violate prior expectations but also whether uncertainty can be reduced in the first place. Here we studied how human brains of both sexes respond to signals under conditions of reducible and irreducible uncertainty. We show behaviorally that subjects' value updating was sensitive to the reducibility of uncertainty, and could be quantitatively characterized by a Bayesian model where agents ignore expectancy violations that do not update beliefs or values. Using fMRI, we found that neural processes underlying belief and value updating were separable from responses to expectancy violation, and that reducibility of uncertainty in value modulated connections from belief-updating regions to value-updating regions. Together, these results provide insights into how agents use knowledge about uncertainty to make better decisions while ignoring mere expectancy violation. SIGNIFICANCE STATEMENT To make good decisions, a person must observe the environment carefully, and use these observations to reduce uncertainty about consequences of actions. Importantly, uncertainty should not be reduced purely based on how surprising the observations are, particularly because in some cases uncertainty is not reducible. Here we show that the human brain indeed reduces uncertainty adaptively by taking into account the nature of uncertainty and ignoring mere surprise. Behaviorally, we show that human subjects reduce uncertainty in a quasioptimal Bayesian manner. Using fMRI, we characterize brain regions that may be involved in uncertainty reduction, as well as the network they constitute, and dissociate them from brain regions that respond to mere surprise. Copyright © 2017 the authors 0270-6474/17/376972-11$15.00/0.

  4. Mechanical design of ORPUS-3

    International Nuclear Information System (INIS)

    Schwall, R.E.; Gray, W.H.; Long, C.J.

    1977-01-01

    ORPUS-3 is the third in a series of pulsed superconducting solenoids built to test construction techniques applicable to tokamak poloidal field coils. The present coil is designed to be charged to a maximum field of 7 T in 1 sec. Stored energy is approximately 300 kJ. The conductor is a high copper-superconductor ratio mixed matrix material developed for this application. In this paper we present a mechanical design which uses distributed reinforcement to support a self-ventilating braid conductor. Using this design, it has been possible to obtain a high overall current density and a low heat flux in a fully normal zone. In order for the stress to be kept within acceptable limits in the reinforcing material, a programmed winding tension schedule has been calculated. The deflection, stress, and strain of the windings are predicted using the STANSOL-II computer code

  5. Cyclic mechanical fatigue in ceramic-ceramic composites: an update

    International Nuclear Information System (INIS)

    Lewis, D. III

    1983-01-01

    Attention is given to cyclic mechanical fatigue effects in a number of ceramics and ceramic composites, including several monolithic ceramics in which significant residual stresses should be present as a result of thermal expansion mismatches and anisotropy. Fatigue is also noted in several BN-containing ceramic matrix-particulate composites and in SiC fiber-ceramic matrix composites. These results suggest that fatigue testing is imperative for ceramics and ceramic composites that are to be used in applications subject to cyclic loading. Fatigue process models are proposed which provide a rationale for fatigue effect observations, but do not as yet provide quantitative results. Fiber composite fatigue damage models indicate that design stresses in these materials may have to be maintained below the level at which fiber pullout occurs

  6. Mechanical flexible joint design document

    Science.gov (United States)

    Daily, Vic

    1993-01-01

    The purpose of this report is to document the status of the Mechanical Flexible Joint (MFJ) Design Subtask with the intent of halting work on the design. Recommendations for future work is included in the case that the task is to be resumed. The MFJ is designed to eliminate two failure points from the current flex joint configuration, the inner 'tripod configuration' and the outer containment jacket. The MFJ will also be designed to flex 13.5 degrees and have three degrees of freedom. By having three degrees of freedom, the MFJ will allow the Low Pressure Fuel Duct to twist and remove the necessity to angulate the full 11 degrees currently required. The current flex joints are very labor intensive and very costly and a simple alternative is being sought. The MFJ is designed with a greater angular displacement, with three degrees of freedom, to reside in the same overall envelope, to meet weight constraints of the current bellows, to be compatible with cryogenic fuel and oxidizers, and also to be man-rated.

  7. Mechanical engineers' handbook, design, instrumentation, and controls

    CERN Document Server

    Kutz, Myer

    2015-01-01

    Full coverage of electronics, MEMS, and instrumentation andcontrol in mechanical engineering This second volume of Mechanical Engineers' Handbookcovers electronics, MEMS, and instrumentation and control, givingyou accessible and in-depth access to the topics you'll encounterin the discipline: computer-aided design, product design formanufacturing and assembly, design optimization, total qualitymanagement in mechanical system design, reliability in themechanical design process for sustainability, life-cycle design,design for remanufacturing processes, signal processing, dataacquisition and dis

  8. Neural mechanisms of reactivation-induced updating that enhance and distort memory

    OpenAIRE

    St. Jacques, Peggy L.; Olm, Christopher; Schacter, Daniel L.

    2013-01-01

    We remember a considerable number of personal experiences because we are frequently reminded of them, a process known as memory reactivation. Although memory reactivation helps to stabilize and update memories, reactivation may also introduce distortions if novel information becomes incorporated with memory. Here we used functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms mediating reactivation-induced updating in memory for events experienced during a museum tou...

  9. Fermilab D-0 Experimental Facility: Energy conservation report and mechanical systems design optimization and cost analysis study

    International Nuclear Information System (INIS)

    Krstulovich, S.F.

    1987-01-01

    This report is developed as part of the Fermilab D-0 Experimental Facility Project Title II Design Documentation Update. As such, it concentrates primarily on HVAC mechanical systems design optimization and cost analysis

  10. Microgel mechanics in biomaterial design.

    Science.gov (United States)

    Saxena, Shalini; Hansen, Caroline E; Lyon, L Andrew

    2014-08-19

    The field of polymeric biomaterials has received much attention in recent years due to its potential for enhancing the biocompatibility of systems and devices applied to drug delivery and tissue engineering. Such applications continually push the definition of biocompatibility from relatively straightforward issues such as cytotoxicity to significantly more complex processes such as reducing foreign body responses or even promoting/recapitulating natural body functions. Hydrogels and their colloidal analogues, microgels, have been and continue to be heavily investigated as viable materials for biological applications because they offer numerous, facile avenues in tailoring chemical and physical properties to approach biologically harmonious integration. Mechanical properties in particular are recently coming into focus as an important manner in which biological responses can be altered. In this Account, we trace how mechanical properties of microgels have moved into the spotlight of research efforts with the realization of their potential impact in biologically integrative systems. We discuss early experiments in our lab and in others focused on synthetic modulation of particle structure at a rudimentary level for fundamental drug delivery studies. These experiments elucidated that microgel mechanics are a consequence of polymer network distribution, which can be controlled by chemical composition or particle architecture. The degree of deformability designed into the microgel allows for a defined response to an imposed external force. We have studied deformation in packed colloidal phases and in translocation events through confined pores; in all circumstances, microgels exhibit impressive deformability in response to their environmental constraints. Microgels further translate their mechanical properties when assembled in films to the properties of the bulk material. In particular, microgel films have been a large focus in our lab as building blocks for self

  11. Understanding Mechanical Design with Respect to Manufacturability

    Science.gov (United States)

    Mondell, Skyler

    2010-01-01

    At the NASA Prototype Development Laboratory in Kennedy Space Center, Fl, several projects concerning different areas of mechanical design were undertaken in order to better understand the relationship between mechanical design and manufacturabiIity. The assigned projects pertained specifically to the NASA Space Shuttle, Constellation, and Expendable Launch Vehicle programs. During the work term, mechanical design practices relating to manufacturing processes were learned and utilized in order to obtain an understanding of mechanical design with respect to manufacturability.

  12. Myositis non-inflammatory mechanisms: An up-dated review.

    Science.gov (United States)

    Manole, Emilia; Bastian, Alexandra E; Butoianu, Niculina; Goebel, Hans H

    2017-01-01

    Idiopathic inflammatory myopathies (IIM) represent a heterogeneous group of rare muscular diseases, with no clearly known causes. IIM frequently have an incomplete response to treatment due to the difficulty in distinguishing between IIM forms, and due to neglect their non-inflammatory causes. Important data concerning non-immune mechanisms in IIM pathology have been recently accumulated. There is a correlation between inflammatory and non-inflammatory mechanisms, but their involvement in IIM pathogenesis is still unknown. Here we review some of the most important data regarding the non-immune IIM pathology, highlighting possible future therapeutic targets: endoplasmic reticulum stress, ATP metabolism, ROS generation, autophagy, and microRNAs disturbances.

  13. Lithium- an update on the mechanisms of action

    African Journals Online (AJOL)

    Adele

    2004-05-20

    May 20, 2004 ... rotransmitter effects as well as the impact on G proteins. Lithium's influence .... the binding of neurotransmitters to receptors, located on the .... be elucidated. The role ..... A molecular mechanism for the action of lithum on develop- ment. ... municate with one another on an on-going and dynamic basis, con-.

  14. An Update on Design Tools for Optimization of CMC 3D Fiber Architectures

    Science.gov (United States)

    Lang, J.; DiCarlo, J.

    2012-01-01

    Objective: Describe and up-date progress for NASA's efforts to develop 3D architectural design tools for CMC in general and for SIC/SiC composites in particular. Describe past and current sequential work efforts aimed at: Understanding key fiber and tow physical characteristics in conventional 2D and 3D woven architectures as revealed by microstructures in the literature. Developing an Excel program for down-selecting and predicting key geometric properties and resulting key fiber-controlled properties for various conventional 3D architectures. Developing a software tool for accurately visualizing all the key geometric details of conventional 3D architectures. Validating tools by visualizing and predicting the Internal geometry and key mechanical properties of a NASA SIC/SIC panel with a 3D orthogonal architecture. Applying the predictive and visualization tools toward advanced 3D orthogonal SiC/SIC composites, and combining them into a user-friendly software program.

  15. Routine Design for Mechanical Engineering

    OpenAIRE

    Brinkop, Axel; Laudwein, Norbert; Maasen, Rudiger

    1995-01-01

    COMIX (configuration of mixing machines) is a system that assists members of the EKATO Sales Department in designing a mixing machine that fulfills the requirements of a customer. It is used to help the engineer design the requested machine and prepare an offer that's to be submitted to the customer. comix integrates more traditional software techniques with explicit knowledge representation and constraint propagation. During the process of routine design, some design decisions have to be mad...

  16. Problems of structural mechanics in nuclear design

    International Nuclear Information System (INIS)

    Patwardhan, V.M.; Kakodkar, Anil

    1975-01-01

    A very careful and detailed stress analysis of nuclear presure vessels and components is essential for ensuring the safety and integrity of nuclear power plants. The nuclear designer, therefore, relies heavily on structural mechanics for application of the most advanced stress analysis techniques to practical design problems. The paper reviews the inter-relation between structural mechanics and nuclear design and discusses a few of the specific structural mechanics problems faced by the nuclear designers in the Department of Atomic Energy, India. (author)

  17. PEP-II design update and R ampersand D results

    International Nuclear Information System (INIS)

    Zisman, M.S.

    1993-01-01

    We describe the present status of the PEP-II asymmetric β factory design undertaken by SLAC, LBL, and LLNL. Design optimization during the past year and changes from the original CDR design are described. R ampersand D activities have focused primarily on the key technology areas of vacuum, RF, and feedback system design. Recent progress in these areas is described. The R ampersand D results have verified our design assumptions and provide further confidence in the design of PEP-II

  18. Immune evasion mechanisms of human papillomavirus: An update.

    Science.gov (United States)

    Steinbach, Alina; Riemer, Angelika B

    2018-01-15

    Human papillomavirus (HPV) is the most frequently sexually transmitted agent in the world. It can cause cervical and other anogenital malignancies, and oropharyngeal cancer. HPV has the unique ability to persist in the host's epithelium for a long time-longer than most viruses do-which is necessary to complete its replication cycle. To this end, HPV has developed a variety of immune evasion mechanisms, which unfortunately also favor the progression of the disease from infection to chronic dysplasia and eventually to cancer. This article summarizes the current knowledge about HPV immune evasion strategies. A special emphasis lies in HPV-mediated changes of the antigen processing machinery, which is generating epitopes for T cells and contributes to the detectability of infected cells. © 2017 UICC.

  19. Design and development for updating national 1:50,000 topographic databases in China

    Directory of Open Access Journals (Sweden)

    CHEN Jun

    2010-02-01

    Full Text Available 1.1 Objective Map databases are irreplaceable national treasure of immense importance. Their currency referring to its consistency with respect to the real world plays a critical role in its value and applications. The continuous updating of map databases at 1:50,000 scales is a massive and difficult task for larger countries of the size of more than several million’s kilometer squares. This paper presents the research and technological development to support the national map updating at 1:50,000 scales in China, including the development of updating models and methods, production tools and systems for large-scale and rapid updating, as well as the design and implementation of the continuous updating workflow. 1.2 Methodology The updating of map databases is different than its original creation, and a number of new problems should be solved, such as change detection using latest multi-source data, incremental object revision and relation amendment. The methodology of this paper consists of the following three parts: 1 Examine the four key aspects of map database updating and develop basic updating models/methods, such as currentness-oriented integration of multi-resource data, completeness-based incremental change detection in the context of existing datasets, consistency-aware processing of updated data sets, and user-friendly propagation and services of updates. 2 Design and develop specific software tools and packages to support the large-scale updating production with high resolution imagery and large-scale data generalization, such as map generalization, GIS-supported change interpretation from imagery, DEM interpolation, image matching-based orthophoto generation, data control at different levels. 3 Design a national 1:50,000 databases updating strategy and its production workflow, including a full coverage updating pattern characterized by all element topographic data modeling, change detection in all related areas, and whole process

  20. Norm-based mechanism design

    NARCIS (Netherlands)

    Bulling, Nils; Dastani, Mehdi

    2016-01-01

    The increasing presence of autonomous (software) systems in open environments in general, and the complex interactions taking place among them in particular, require flexible control and coordination mechanisms to guarantee desirable overall system level properties without limiting the autonomy of

  1. An Updated Review of the Molecular Mechanisms in Drug Hypersensitivity

    Directory of Open Access Journals (Sweden)

    Chun-Bing Chen

    2018-01-01

    Full Text Available Drug hypersensitivity may manifest ranging from milder skin reactions (e.g., maculopapular exanthema and urticaria to severe systemic reactions, such as anaphylaxis, drug reactions with eosinophilia and systemic symptoms (DRESS/drug-induced hypersensitivity syndrome (DIHS, or Stevens–Johnson syndrome (SJS/toxic epidermal necrolysis (TEN. Current pharmacogenomic studies have made important strides in the prevention of some drug hypersensitivity through the identification of relevant genetic variants, particularly for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs. The associations identified by these studies are usually drug, phenotype, and ethnic specific. The drug presentation models that explain how small drug antigens might interact with HLA and T cell receptor (TCR molecules in drug hypersensitivity include the hapten theory, the p-i concept, the altered peptide repertoire model, and the altered TCR repertoire model. The broad spectrum of clinical manifestations of drug hypersensitivity involving different drugs, as well as the various pathomechanisms involved, makes the diagnosis and management of it more challenging. This review highlights recent advances in our understanding of the predisposing factors, immune mechanisms, pathogenesis, diagnostic tools, and therapeutic approaches for drug hypersensitivity.

  2. An Updated Review of the Molecular Mechanisms in Drug Hypersensitivity

    Science.gov (United States)

    Abe, Riichiro; Pan, Ren-You; Wang, Chuang-Wei

    2018-01-01

    Drug hypersensitivity may manifest ranging from milder skin reactions (e.g., maculopapular exanthema and urticaria) to severe systemic reactions, such as anaphylaxis, drug reactions with eosinophilia and systemic symptoms (DRESS)/drug-induced hypersensitivity syndrome (DIHS), or Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Current pharmacogenomic studies have made important strides in the prevention of some drug hypersensitivity through the identification of relevant genetic variants, particularly for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs). The associations identified by these studies are usually drug, phenotype, and ethnic specific. The drug presentation models that explain how small drug antigens might interact with HLA and T cell receptor (TCR) molecules in drug hypersensitivity include the hapten theory, the p-i concept, the altered peptide repertoire model, and the altered TCR repertoire model. The broad spectrum of clinical manifestations of drug hypersensitivity involving different drugs, as well as the various pathomechanisms involved, makes the diagnosis and management of it more challenging. This review highlights recent advances in our understanding of the predisposing factors, immune mechanisms, pathogenesis, diagnostic tools, and therapeutic approaches for drug hypersensitivity. PMID:29651444

  3. Polymyxin susceptibility testing, interpretative breakpoints and resistance mechanisms: An update.

    Science.gov (United States)

    Bakthavatchalam, Yamuna Devi; Pragasam, Agila Kumari; Biswas, Indranil; Veeraraghavan, Balaji

    2018-03-01

    Emerging multidrug-resistant (MDR) nosocomial pathogens are a great threat. Polymyxins, an old class of cationic polypeptide antibiotic, are considered as last-resort drugs in treating infections caused by MDR Gram-negative bacteria. Increased use of polymyxins in treating critically ill patients necessitates routine polymyxin susceptibility testing. However, susceptibility testing both of colistin and polymyxin B (PMB) is challenging. In this review, currently available susceptibility testing methods are briefly discussed. The multicomponent composition of colistin and PMB significantly influences susceptibility testing. In addition, poor diffusion in the agar medium, adsorption to microtitre plates and the synergistic effect of the surfactant polysorbate 80 with polymyxins have a great impact on the performance of susceptibility testing methods This review also describes recently identified chromosomal resistance mechanisms, including modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose (L-Ara4-N) and phosphoethanolamine (pEtN) resulting in alteration of the negative charge, as well as the plasmid-mediated colistin resistance determinants mcr-1, mcr-1.2, mcr-2 and mcr-3. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  4. Space reactor preliminary mechanical design

    International Nuclear Information System (INIS)

    Meier, K.L.

    1983-01-01

    An analysis was performed on the SABRE reactor space power system to determine the effect of the number and size of heat pipes on the design parameters of the nuclear subsystem. Small numbers of thin walled heat pipes were found to give a lower subsystem mass, but excessive fuel swelling resulted. The SP-100 preliminary design uses 120 heat pipes because of acceptable fuel swelling and a minimum nuclear subsystem mass of 1875 kg. Salient features of the reactor preliminary design are: individual fuel modules, ZrO 2 block core mounts, bolted collar fuel module restraints, and a BeO central plug

  5. SANGUINATE (PEGylated Carboxyhemoglobin Bovine): Mechanism of Action and Clinical Update.

    Science.gov (United States)

    Abuchowski, Abraham

    2017-04-01

    Historically, blood substitutes were under development that would provide oxygen carrying capacity as well as fluid replacement for both trauma and surgical indications. Their development was halted by the inability of the products to deliver therapeutic amounts of oxygen targeted to hypoxic tissue as well as from the inherent toxicity of the molecules. This led to the concept of an oxygen therapeutic that would be targeted for indications caused by anemia/ischemia/hypoxia but would not exhibit the toxicity that plagued earlier products. The complex pathophysiology of diseases such as sickle cell and hemorrhagic stroke not only has hypoxia as a pivotal event but also includes inflammation and vasoconstriction that perpetuate the oxygen deprivation. There is a need for an effective therapeutic that addresses the multiple events of inflammation and oxygen deprivation. SANGUINATE acts as a dual mode carbon monoxide (CO) and oxygen delivery therapeutic. SANGUINATE is designed not only to treat hypoxia but also to act on concurrent pathologies such as inflammation and reperfusion injury. This expands the potential therapeutic utility of SANGUINATE beyond anemia into indications such as early brain injury and delayed kidney graft function, where inflammation plays a pivotal pathological role as well as in indications such as sickle cell disease where the inflammation and hypoxia contribute to the development of comorbidities such as vaso-occlusive crisis. Clinical trials in multiple indications are underway. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  6. Suanzaoren Formulae for Insomnia: Updated Clinical Evidence and Possible Mechanisms

    Directory of Open Access Journals (Sweden)

    Qi-Hui Zhou

    2018-02-01

    Full Text Available Insomnia disorder is a widespread and refractory disease. Semen Ziziphi Spinosae, Suanzaoren, a well-known Chinese herbal medicine, has been used for treating insomnia for thousands of years. Here, we aimed to assess the available evidence of Chinese herbal formulae that contains Suanzaoren (FSZR for insomnia according to high-quality randomized controlled trials (RCTs and reviewed their possible mechanisms based on animal-based studies. Electronic searches were performed in eight databases from inception to November 2016. The primary outcome measures were polysomnography index and Pittsburgh sleep quality index. The secondary outcome measures were clinical effective rate and adverse events. The methodological quality of RCTs was assessed by Cochrane's collaboration tool, and only RCTs with positive for 4 out of 7 for the Cochrane risk of bias domains were included in analyses. Thirteen eligible studies with 1,454 patients were identified. Meta-analysis of high-quality RCTs showed that FSZR monotherapy was superior to placebo (P < 0.01; FSZR plus Diazepam was superior to Diazepam alone (P < 0.05; there were mixed results comparing FSZR with Diazepam (P > 0.05 or P < 0.05. Furthermore, FSZR caused fewer side effects than that of Diazepam. Suanzaoren contains complex mixtures of phytochemicals including sanjoinine A, Jujuboside A, spinosin and other flavonoids, which has sedative and hypnotic functions primarily mediated by the GABAergic and serotonergic system. In conclusion, the findings of present study supported that FSZR could be an alternative treatment for insomnia in clinic. FSZR exerted sedative and hypnotic actions mainly through the GABAergic and serotonergic system.

  7. Small Satellite Mechanical Design Experience

    OpenAIRE

    Meyers, Stewart

    1993-01-01

    The design approach used and the experience gained in the building of four small satellite payloads is explained. Specific recommendations are made and the lessons learned on the SAMPEX program are detailed.

  8. Mechanical considerations and design skills.

    Energy Technology Data Exchange (ETDEWEB)

    Alvis, Robert L.

    2008-03-01

    The purpose of the report is to provide experienced-based insights into design processes that will benefit designers beginning their employment at Sandia National Laboratories or those assuming new design responsibilities. The main purpose of this document is to provide engineers with the practical aspects of system design. The material discussed here may not be new to some readers, but some of it was to me. Transforming an idea to a design to solve a problem is a skill, and skills are similar to history lessons. We gain these skills from experience, and many of us have not been fortunate enough to grow in an environment that provided the skills that we now need. I was fortunate to grow up on a farm where we had to learn how to maintain and operate several different kinds of engines and machines. If you are like me, my formal experience is partially based upon the two universities from which I graduated, where few practical applications of the technologies were taught. What was taught was mainly theoretical, and few instructors had practical experience to offer the students. I understand this, as students have their hands full just to learn the theoretical. The practical part was mainly left up to 'on the job experience'. However, I believe it is better to learn the practical applications early and apply them quickly 'on the job'. System design engineers need to know several technical things, both in and out of their field of expertise. An engineer is not expected to know everything, but he should know when to ask an expert for assistance. This 'expert' can be in any field, whether it is in analyses, drafting, machining, material properties, testing, etc. The best expert is a person who has practical experience in the area of needed information, and consulting with that individual can be the best and quickest way for one to learn. If the information provided here can improve your design skills and save one design from having a problem

  9. Review of updated design of SPWR with PSA methodology

    International Nuclear Information System (INIS)

    Oikawa, Tetsukuni; Muramatsu, Ken

    1995-01-01

    This paper presents the procedures and results of a PSA (Probabilistic Safety Assessment) of the SPWR (System-Integrated PWR), which is being developed at the Japan Atomic Energy Research Institute (JAERI) as a medium sized innovative passive safe reactor, to assist in the design improvement of the SPWR at the basic or conceptual design phase by reviewing the design and identifying the design vulnerability. The first phase PSA, which was carried out in 1991, was a scoping analysis in order to understand overall plant characteristics and to search for general design weakness. After discussing the results of the first phase PSA, the SPWR designer group changed some designs of the SPWR. The second phase PSA of the SPWR was performed for the modified design in order to identify the design vulnerability as well as to grasp its overall safety level. Special items of these PSAs are as follows: (1) systematic identification of initiating events related to newly designed systems by the failure mode effect analysis (FMEA), (2) delineation of accident sequences for the internal initiating events using accident progression flow charts which is cost effective for conceptual design phase, (3) quantification of event trees based on many engineering judgement, and (4) lots of sensitivity analyses to examine applicability of data assignment. Qualitative and quantitative results of PSA provided very useful information for decision makings of design improvement and recommendations for further consideration in the process of detailed design. (author)

  10. Updated Design Standards and Guidance from the What Works Clearinghouse: Regression Discontinuity Designs and Cluster Designs

    Science.gov (United States)

    Cole, Russell; Deke, John; Seftor, Neil

    2016-01-01

    The What Works Clearinghouse (WWC) maintains design standards to identify rigorous, internally valid education research. As education researchers advance new methodologies, the WWC must revise its standards to include an assessment of the new designs. Recently, the WWC has revised standards for two emerging study designs: regression discontinuity…

  11. Updated conceptual design of helium cooling ceramic blanket for HCCB-DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Suhao [University of Science and Technology of China, Hefei, Anhui (China); Southwestern Institute of Physics, Chengdu, Sichuan (China); Cao, Qixiang; Wu, Xinghua; Wang, Xiaoyu; Zhang, Guoshu [Southwestern Institute of Physics, Chengdu, Sichuan (China); Feng, Kaiming, E-mail: fengkm@swip.ac.cn [Southwestern Institute of Physics, Chengdu, Sichuan (China)

    2016-11-15

    Highlights: • An updated design of Helium Cooled Ceramic breeder Blanket (HCCB) for HCCB-DEMO is proposed in this paper. • The Breeder Unit is transformed to TBM-like sub-modules, with double “banana” shape tritium breeder. Each sub-module is inserted in space formed by Stiffen Grids (SGs). • The performance analysis is performed based on the R&D development of material, fabrication technology and safety assessment in CN ITER TBM program. • Hot spots will be located at the FW bend side. - Abstract: The basic definition of the HCCB-DEMO plant and preliminary blanket designed by Southwestern Institution of Physics was proposed in 2009. The DEMO fusion power is 2550 MW and electric power is 800 MW. Based on development of R&D in breeding blanket, a conceptual design of helium cooled blanket with ceramic breeder in HCCB-DEMO was presented. The main design features of the HCCB-DEMO blanket were: (1) CLF-1 structure materials, Be multiplier and Li{sub 4}SiO{sub 4} breeder; (2) neutronic wall load is 2.3 MW/m{sup 2} and surface heat flux is 0.43 MW/m{sup 2} (2) TBR ≈ 1.15; (3) geometry of breeding units is ITER TBM-like segmentation; (4)Pressure of helium is 8 MPa and inlet/outlet temperature is 300/500 °C. On the basis of these design, some important analytical results are presented in aspects of (i) neutronic behavior of the blanket; (ii) design of 3D structure and thermal-hydraulic lay-out for breeding blanket module; (iii) structural-mechanical behavior of the blanket under pressurization. All of these assessments proved current stucture fulfill the design requirements.

  12. Mechanical design of walking machines.

    Science.gov (United States)

    Arikawa, Keisuke; Hirose, Shigeo

    2007-01-15

    The performance of existing actuators, such as electric motors, is very limited, be it power-weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control.

  13. Conceptual Design of the ITER ECE Diagnostic – An Update

    Directory of Open Access Journals (Sweden)

    Ouroua A.

    2012-09-01

    Full Text Available The ITER ECE diagnostic has recently been through a conceptual design review for the entire system including front end optics, transmission line, and back-end instruments. The basic design of two viewing lines, each with a single ellipsoidal mirror focussing into the plasma near the midplane of the typical operating scenarios is agreed upon. The location and design of the hot calibration source and the design of the shutter that directs its radiation to the transmission line are issues that need further investigation. In light of recent measurements and discussion, the design of the broadband transmission line is being revisited and new options contemplated. For the instruments, current systems for millimeter wave radiometers and broad-band spectrometers will be adequate for ITER, but the option for employing new state-of-the-art techniques will be left open.

  14. Conceptual Design of the ITER ECE Diagnostic - An Update

    Science.gov (United States)

    Austin, M. E.; Pandya, H. K. B.; Beno, J.; Bryant, A. D.; Danani, S.; Ellis, R. F.; Feder, R.; Hubbard, A. E.; Kumar, S.; Ouroua, A.; Phillips, P. E.; Rowan, W. L.

    2012-09-01

    The ITER ECE diagnostic has recently been through a conceptual design review for the entire system including front end optics, transmission line, and back-end instruments. The basic design of two viewing lines, each with a single ellipsoidal mirror focussing into the plasma near the midplane of the typical operating scenarios is agreed upon. The location and design of the hot calibration source and the design of the shutter that directs its radiation to the transmission line are issues that need further investigation. In light of recent measurements and discussion, the design of the broadband transmission line is being revisited and new options contemplated. For the instruments, current systems for millimeter wave radiometers and broad-band spectrometers will be adequate for ITER, but the option for employing new state-of-the-art techniques will be left open.

  15. ARGOS laser system mechanical design

    Science.gov (United States)

    Deysenroth, M.; Honsberg, M.; Gemperlein, H.; Ziegleder, J.; Raab, W.; Rabien, S.; Barl, L.; Gässler, W.; Borelli, J. L.

    2014-07-01

    ARGOS, a multi-star adaptive optics system is designed for the wide-field imager and multi-object spectrograph LUCI on the LBT (Large Binocular Telescope). Based on Rayleigh scattering the laser constellation images 3 artificial stars (at 532 nm) per each of the 2 eyes of the LBT, focused at a height of 12 km (Ground Layer Adaptive Optics). The stars are nominally positioned on a circle 2' in radius, but each star can be moved by up to 0.5' in any direction. For all of these needs are following main subsystems necessary: 1. A laser system with its 3 Lasers (Nd:YAG ~18W each) for delivering strong collimated light as for LGS indispensable. 2. The Launch system to project 3 beams per main mirror as a 40 cm telescope to the sky. 3. The Wave Front Sensor with a dichroic mirror. 4. The dichroic mirror unit to grab and interpret the data. 5. A Calibration Unit to adjust the system independently also during day time. 6. Racks + platforms for the WFS units. 7. Platforms and ladders for a secure access. This paper should mainly demonstrate how the ARGOS Laser System is configured and designed to support all other systems.

  16. Stiffness and damping in mechanical design

    National Research Council Canada - National Science Library

    Rivin, Eugene I

    1999-01-01

    ... important conceptual issues are stiffness of mechanical structures and their components and damping in mechanical systems sensitive to and/or generating vibrations. Stiffness and strength are the most important criteria for many mechanical designs. However, although there are hundreds of books on various aspects of strength, and strength issues ar...

  17. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    Energy Technology Data Exchange (ETDEWEB)

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.; Gromada, R.J.; McCarville, T.J.; Moir, R.W.; Lee, J.D.; Bandini, B.R.; Fulton, F.J.; Wong, C.P.C.; Maya, I.; Hoot, C.G.; Schultz, K.R.; Miller, L.G.; Beeston, J.M.; Harris, B.L.; Westman, R.A.; Ghoniem, N.M.; Orient, G.; Wolfer, M.; DeVan, J.H.; Torterelli, P.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future.

  18. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    International Nuclear Information System (INIS)

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future

  19. Gas-cooled fast-breeder reactor. Helium Circulator Test Facility updated design cost estimate

    International Nuclear Information System (INIS)

    1979-04-01

    Costs which are included in the cost estimate are: Titles I, II, and III Architect-Engineering Services; Titles I, II, and III General Atomic Services; site clearing, grading, and excavation; bulk materials and labor of installation; mechanical and electrical equipment with installation; allowance for contractors' overhead, profit, and insurance; escalation on materials and labor; a contingency; and installation of GAC supplied equipment and materials. The total estimated cost of the facility in As Spent Dollars is $27,700,000. Also included is a cost comparison of the updated design and the previous conceptual design. There would be a considerable penalty for the direct-cooled system over the indirect-cooled system due to the excessive cost of the large diameter helium loop piping to an outdoor heat exchanger. The indirect cooled system which utilizes a helium/Dowtherm G heat exchanger and correspondingly smaller and lower pressure piping to its outdoor air cooler proved to be the more economical of the two systems

  20. Present opto-mechanical design status of NFIRAOS

    Science.gov (United States)

    Byrnes, Peter W. G.; Atwood, Jenny; Boucher, Marc-André; Fitzsimmons, Joeleff; Hill, Alexis; Herriot, Glen; Spanò, Paolo; Szeto, Kei; Wevers, Ivan

    2014-07-01

    This paper describes the current opto-mechanical design of NFIRAOS (Narrow Field InfraRed Adaptive Optics System) for the Thirty Meter Telescope (TMT). The preliminary design update review for NFIRAOS was successfully held in December 2011, and incremental design progress has since occurred on several fronts. The majority of NFIRAOS is housed within an insulated and cooled enclosure, and operates at -30 C to reduce background emissivity. The cold optomechanics are attached to a space-frame structure, kinematically supported by bipods that penetrate the insulated enclosure. The bipods are attached to an exo-structure at ambient temperature, which also supports up to three client science instruments and a science calibration unit.

  1. WAG (water-alternating-gas) process design: an update review

    Energy Technology Data Exchange (ETDEWEB)

    Zahoor, M.K. [University of Engineering and Technology, Lahore (Pakistan). Dept. of Petroleum and Gas Engineering], e-mail: mkzahoor@uet.edu.pk; Derahman, M.N.; Yunan, M.H. [Universiti Teknologi Malaysia, Johor (Malaysia). Dept. of Petroleum Engineering

    2011-04-15

    The design and implementation of water-alternating-gas (WAG) process in an improved and cost-effective way are still under process. Due to the complexities involved in implementing the process and the lack of information regarding fluid and reservoir properties, the water-alternating-gas process has not yet been as successful as initially expected. This situation can be overcome by better understanding the fluid distribution and flow behavior within the reservoir. The ultimate purpose can be achieved with improved knowledge on wettability and its influence on fluid distribution, capillary pressure, relative permeability, and other design parameters. This paper gives an insight on the WAG process design and the recently developed correlations which are helpful in incorporating the effects of wettability variations on fluid dynamics within the reservoir. (author)

  2. Update of the ITER MELCOR model for the validation of the Cryostat design

    Energy Technology Data Exchange (ETDEWEB)

    Martínez, M.; Labarta, C.; Terrón, S.; Izquierdo, J.; Perlado, J.M.

    2015-07-01

    Some transients can compromise the vacuum in the Cryostat of ITER and cause significant loads. A MELCOR model has been updated in order to assess this loads. Transients have been run with this model and its result will be used in the mechanical assessment of the cryostat. (Author)

  3. Mechanism design visual and programmable approaches

    CERN Document Server

    Russell, Kevin; Sodhi, Raj S

    2013-01-01

    "… the book provides a lot of MATLAB® and SimMechanics examples. Students could benefit from the experience of solving the complex spatial synthesis problems using computer tools. The mathematics software tools are very efficient to do the displacement analysis, too."-Wen-Tzong Lee, National Pingtung University of Science and Technology, Neipu, Taiwan"The book covers a vast range of mechanism kinematics and design. The algorithm covering the topics presented is useful for mechanism design in class and homework assignments. The book provides an alternative modern tool, as compared to kinematics analysis methods based on Fortran or QuickBasic algorithms, covering all topics for mechanism design."-Thomas G. Chondros, University of Patras, Greece"… well elaborated for students at their first approach to the subject of mechanism design and its computation with MATLAB®."-Marco Ceccarelli, University of Cassino and South Latium, Italy.

  4. How to update design floods after the construction of small ...

    Indian Academy of Sciences (India)

    Several small reservoirs and a large number of check dams had been constructed in theWangkuai reservoirwatershed after 1970s, and flood time series lacked stationarity, which affected the original design floodhydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of thelarge ...

  5. Update on quadruple suspension design for Advanced LIGO

    International Nuclear Information System (INIS)

    Aston, S M; Carbone, L; Cutler, R M; Hoyland, D; Barton, M A; Bland, B; Bell, A S; Beveridge, N; Cagnoli, G; Cantley, C A; Cumming, A V; Cunningham, L; Hammond, G D; Haughian, K; Hough, J; Brummitt, A J; Greenhalgh, R J S; Hayler, T M; Heptonstall, A; Heefner, J

    2012-01-01

    We describe the design of the suspension systems for the major optics for Advanced LIGO, the upgrade to LIGO—the Laser Interferometric Gravitational-Wave Observatory. The design is based on that used in GEO600—the German/UK interferometric gravitational wave detector, with further development to meet the more stringent noise requirements for Advanced LIGO. The test mass suspensions consist of a four-stage or quadruple pendulum for enhanced seismic isolation. To minimize suspension thermal noise, the final stage consists of a silica mirror, 40 kg in mass, suspended from another silica mass by four silica fibres welded to silica ears attached to the sides of the masses using hydroxide-catalysis bonding. The design is chosen to achieve a displacement noise level for each of the seismic and thermal noise contributions of 10 −19 m/√Hz at 10 Hz, for each test mass. We discuss features of the design which has been developed as a result of experience with prototypes and associated investigations. (paper)

  6. Update on the status of the ITER ECE diagnostic design

    Directory of Open Access Journals (Sweden)

    Taylor G.

    2017-01-01

    Full Text Available Considerable progress has been made on the design of the ITER electron cyclotron emission (ECE diagnostic over the past two years. Radial and oblique views are still included in the design in order to measure distortions in the electron momentum distribution, but the oblique view has been redirected to reduce stray millimeter radiation from the electron cyclotron heating system. A major challenge has been designing the 1000 K calibration sources and remotely activated mirrors located in the ECE diagnostic shield module (DSM in the equatorial port plug #09. These critical systems are being modeled and prototypes are being developed. Providing adequate neutron shielding in the DSM while allowing sufficient space for optical components is also a significant challenge. Four 45-meter long low-loss transmission lines transport the 70–1000 GHz ECE from the DSM to the ECE instrumentation room. Prototype transmission lines are being tested, as are the polarization splitter modules that separate O-mode and X-mode polarized ECE. A highly integrated prototype 200–300 GHz radiometer is being tested on the DIII-D tokamak in the USA. Design activities also include integration of ECE signals into the ITER plasma control system and determining the hardware and software architecture needed to control and calibrate the ECE instruments.

  7. The Mechanical Design for the LHC Collimators

    CERN Document Server

    Bertarelli, A; Assmann, R W; Chiaveri, Enrico; Kurtyka, T; Mayer, M; Perret, R; Sievers, P

    2004-01-01

    The design of the LHC collimators must comply with the very demanding specifications entailed by the highly energetic beam handled in the LHC: these requirements impose a temperature on the collimating jaws not exceeding 50ºC in steady operations and an unparalleled overall geometrical stability of 25 micro-m on a 1200 mm span. At the same time, the design phase must meet the challenging deadlines required by the general time schedule. To respond to these tough and sometimes conflicting constraints, the chosen design appeals to a mixture of traditional and innovative technologies, largely drawing from LEP collimator experience. The specifications impose a low-Z material for the collimator jaws, directing the design towards such graphite or such novel materials as 3-d Carbon/carbon composites. An accurate mechanical design has allowed to considerably reduce mechanical play and optimize geometrical stability. Finally, all mechanical studies were supported by in-depth thermo-mechanical analysis concerning tempe...

  8. Mechanical Design of Superconducting Accelerator Magnets

    International Nuclear Information System (INIS)

    Toral, F

    2014-01-01

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques

  9. Mechanical Design of Superconducting Accelerator Magnets

    CERN Document Server

    Toral, Fernando

    2014-07-17

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques.

  10. Mechanical Design of Superconducting Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Toral, F [Madrid, CIEMAT (Spain)

    2014-07-01

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques.

  11. Mechanical design and protection of superconducting magnets

    CERN Document Server

    Asner, Alfred M

    1978-01-01

    The principles of the mechanical design of superconducting magnets of concentric configuration, with iron low-temperature and room- temperature screening, are outlined. Measures for protection of such magnets against quench forces, are considered. (4 refs).

  12. Emerging Dynamic Design Techniques for Mechanical and ...

    Indian Academy of Sciences (India)

    Emerging Dynamic Design Techniques for Mechanical ... through this school to bring about an awareness of the state-of-art of the software and ... those mentioned above, cannot be ensured on the basis of approaches involving numerical.

  13. Mechanical Design Optimization Using Advanced Optimization Techniques

    CERN Document Server

    Rao, R Venkata

    2012-01-01

    Mechanical design includes an optimization process in which designers always consider objectives such as strength, deflection, weight, wear, corrosion, etc. depending on the requirements. However, design optimization for a complete mechanical assembly leads to a complicated objective function with a large number of design variables. It is a good practice to apply optimization techniques for individual components or intermediate assemblies than a complete assembly. Analytical or numerical methods for calculating the extreme values of a function may perform well in many practical cases, but may fail in more complex design situations. In real design problems, the number of design parameters can be very large and their influence on the value to be optimized (the goal function) can be very complicated, having nonlinear character. In these complex cases, advanced optimization algorithms offer solutions to the problems, because they find a solution near to the global optimum within reasonable time and computational ...

  14. Mechanical design of the Mars Pathfinder mission

    Science.gov (United States)

    Eisen, Howard Jay; Buck, Carl W.; Gillis-Smith, Greg R.; Umland, Jeffrey W.

    1997-01-01

    The Mars Pathfinder mission and the Sojourner rover is reported on, with emphasis on the various mission steps and the performance of the technologies involved. The mechanical design of mission hardware was critical to the success of the entry sequence and the landing operations. The various mechanisms employed are considered.

  15. Algorithmic Mechanism Design of Evolutionary Computation.

    Science.gov (United States)

    Pei, Yan

    2015-01-01

    We consider algorithmic design, enhancement, and improvement of evolutionary computation as a mechanism design problem. All individuals or several groups of individuals can be considered as self-interested agents. The individuals in evolutionary computation can manipulate parameter settings and operations by satisfying their own preferences, which are defined by an evolutionary computation algorithm designer, rather than by following a fixed algorithm rule. Evolutionary computation algorithm designers or self-adaptive methods should construct proper rules and mechanisms for all agents (individuals) to conduct their evolution behaviour correctly in order to definitely achieve the desired and preset objective(s). As a case study, we propose a formal framework on parameter setting, strategy selection, and algorithmic design of evolutionary computation by considering the Nash strategy equilibrium of a mechanism design in the search process. The evaluation results present the efficiency of the framework. This primary principle can be implemented in any evolutionary computation algorithm that needs to consider strategy selection issues in its optimization process. The final objective of our work is to solve evolutionary computation design as an algorithmic mechanism design problem and establish its fundamental aspect by taking this perspective. This paper is the first step towards achieving this objective by implementing a strategy equilibrium solution (such as Nash equilibrium) in evolutionary computation algorithm.

  16. Mechanical and thermal design of hybrid blankets

    International Nuclear Information System (INIS)

    Schultz, K.R.

    1978-01-01

    The thermal and mechanical aspects of hybrid reactor blanket design considerations are discussed. This paper is intended as a companion to that of J. D. Lee of Lawrence Livermore Laboratory on the nuclear aspects of hybrid reactor blanket design. The major design characteristics of hybrid reactor blankets are discussed with emphasis on the areas of difference between hybrid reactors and standard fusion or fission reactors. Specific examples are used to illustrate the design tradeoffs and choices that must be made in hybrid reactor design. These examples are drawn from the work on the Mirror Hybrid Reactor

  17. SSC collider dipole magnet end mechanical design

    International Nuclear Information System (INIS)

    Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, M.; Leung, K.K.

    1991-01-01

    This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described

  18. Design of compliant mechanisms with selective compliance

    International Nuclear Information System (INIS)

    Hasse, Alexander; Campanile, Lucio Flavio

    2009-01-01

    Conventional mechanisms provide a defined mobility, which expresses the number of degrees of freedom of the mechanism. This allows the system to be driven by a low number of control outputs. This property is virtually retained in the case of compliant mechanisms with lumped compliance, which are obtained by replacing the conventional hinges by solid-state ones. Compliant mechanisms with distributed compliance have, in general, an infinite number of degrees of freedom and therefore cannot guarantee defined kinematics. In this paper the concept of compliant mechanisms with selective compliance is introduced. This special class of compliant mechanisms combines the advantages of distributed compliance with the easy controllability of systems with defined kinematics. The task is accomplished by introducing a new design criterion based on a modal formulation. After this design criterion has been implemented in an optimization formulation for a formal optimization procedure, mechanisms are obtained in which a freely chosen deformation pattern is associated with a low deformation energy while other deformation patterns are considerably stiffer. Besides the description of the modal design criterion and the associated objective function, the sensitivity analysis of the objective function is presented and an application example is shown

  19. Mechanical Cushion Design Influence on Cylinder Dynamics

    DEFF Research Database (Denmark)

    Borghi, Massimo; Milani, Massimo; Conrad, Finn

    2005-01-01

    The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow....... experimental comparison, involving the piston velocity and the cylinder chambers pressure. After, with the aim of highlighting the effect of mechanical cushions design on a two effect linear actuator dynamic performances, the characteristics modulation of four alternative cushioning systems are determined...

  20. Thermal hydraulics and mechanics core design programs

    International Nuclear Information System (INIS)

    Heinecke, J.

    1992-10-01

    The report documents the work performed within the Research and Development Task T hermal hydraulics and mechanics core design programs , funded by the German government. It contains the development of new codes, the extension of existing codes, the qualification and verification of codes and the development of a code library. The overall goal of this work was to adapt the system of thermal hydraulics and mechanics codes to the permanently growing requirements of the status of science and technology

  1. HYLIFE-II reactor chamber mechanical design

    International Nuclear Information System (INIS)

    House, P.A.

    1992-01-01

    Mechanical design features of the reactor chamber for the HYLIFE-11 inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams are used for shielding and blast protection. The system is designed for an 8 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (20 m/s) salt streams and also recover up to half of the dynamic head

  2. Self-repair networks a mechanism design

    CERN Document Server

    Ishida, Yoshiteru

    2015-01-01

    This book describes the struggle to introduce a mechanism that enables next-generation information systems to maintain themselves. Our generation observed the birth and growth of information systems, and the Internet in particular. Surprisingly information systems are quite different from conventional (energy, material-intensive) artificial systems, and rather resemble biological systems (information-intensive systems). Many artificial systems are designed based on (Newtonian) physics assuming that every element obeys simple and static rules; however, the experience of the Internet suggests a different way of designing where growth cannot be controlled but self-organized with autonomous and selfish agents. This book suggests using game theory, a mechanism design in particular, for designing next-generation information systems which will be self-organized by collective acts with autonomous components. The challenge of mapping a probability to time appears repeatedly in many forms throughout this book. The book...

  3. High mechanical advantage design of six-bar Stephenson mechanism for servo mechanical presses

    Directory of Open Access Journals (Sweden)

    Jianguo Hu

    2016-06-01

    Full Text Available This article proposed a two-phase design scheme of Stephenson six-bar working mechanisms for servo mechanical presses with high mechanical advantage. In the qualitative design phase, first, a Stephenson six-bar mechanism with a slide was derived from Stephenson six-bar kinematic chains. Second, based on the instant center analysis method, the relationship between mechanical advantage and some special instant centers was founded, and accordingly a primary mechanism configuration with high mechanical advantage was designed qualitatively. Then, a parameterized prototype model was established, and the influences of design parameters toward slide kinematical characteristics were analyzed. In the quantitative design phase, a multi-objective optimization model, aiming at high mechanical advantage and dwelling characteristics, was built, and a case design was done to find optimal dimensions. Finally, simulations based on the software ADAMS were conducted to compare the transmission characteristics of the optimized working mechanism with that of slide-crank mechanism and symmetrical toggle mechanism, and an experimental press was made to validate the design scheme. The simulation and experiment results show that, compared with general working mechanisms, the Stephenson six-bar working mechanism has higher mechanical advantage and better dwelling characteristics, reducing capacities and costs of servo motors effectively.

  4. Mechanical Design Features of PGSFR NSSS

    International Nuclear Information System (INIS)

    Park, Chang-Gyu; Koo, Gyeong-Hoi; Cho, Jae-Hun; Kim, Sung-Kyun

    2016-01-01

    The NSSS(Nuclear Steam Supply System) is composed of PHTS(Primary Heat Transport System), IHTS (Intermediate Heat Transport System), and SGS(Steam Generation System). And, DHRS(Decay Heat Removal System) adopts both the active and passive systems for diversity. The structures including components and piping should be designed to ensure the structural integrity for their design life against mechanical and operational loads. In this study, the mechanical design features for the structures and components that make up PGSFR NSSS are described. The mechanical design features of structures and components for a PGSFR NSSS are described. The structures are being designed to maintain the structural integrity for their design lifetime by considering the high temperature operating condition. The decay heat removal system(DHRS) removes all reactor decay heat in two ways; active type(ADHRS) and passive type(PDHRS). ADHRS consists of DHX, blower, FHX, circulation pump, and expansion tank. But PDHRS consists of DHX, AHX, and expansion tank. FHX is a finned-tube-type sodium-to-air heat exchanger whereas AHX is a helical-type sodium-to-air heat exchanger

  5. Mechanical Design Features of PGSFR NSSS

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang-Gyu; Koo, Gyeong-Hoi; Cho, Jae-Hun; Kim, Sung-Kyun [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The NSSS(Nuclear Steam Supply System) is composed of PHTS(Primary Heat Transport System), IHTS (Intermediate Heat Transport System), and SGS(Steam Generation System). And, DHRS(Decay Heat Removal System) adopts both the active and passive systems for diversity. The structures including components and piping should be designed to ensure the structural integrity for their design life against mechanical and operational loads. In this study, the mechanical design features for the structures and components that make up PGSFR NSSS are described. The mechanical design features of structures and components for a PGSFR NSSS are described. The structures are being designed to maintain the structural integrity for their design lifetime by considering the high temperature operating condition. The decay heat removal system(DHRS) removes all reactor decay heat in two ways; active type(ADHRS) and passive type(PDHRS). ADHRS consists of DHX, blower, FHX, circulation pump, and expansion tank. But PDHRS consists of DHX, AHX, and expansion tank. FHX is a finned-tube-type sodium-to-air heat exchanger whereas AHX is a helical-type sodium-to-air heat exchanger.

  6. Neural mechanisms of reactivation-induced updating that enhance and distort memory.

    Science.gov (United States)

    St Jacques, Peggy L; Olm, Christopher; Schacter, Daniel L

    2013-12-03

    We remember a considerable number of personal experiences because we are frequently reminded of them, a process known as memory reactivation. Although memory reactivation helps to stabilize and update memories, reactivation may also introduce distortions if novel information becomes incorporated with memory. Here we used functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms mediating reactivation-induced updating in memory for events experienced during a museum tour. During scanning, participants were shown target photographs to reactivate memories from the museum tour followed by a novel lure photograph from an alternate tour. Later, participants were presented with target and lure photographs and asked to determine whether the photographs showed a stop they visited during the tour. We used a subsequent memory analysis to examine neural recruitment during reactivation that was associated with later true and false memories. We predicted that the quality of reactivation, as determined by online ratings of subjective recollection, would increase subsequent true memories but also facilitate incorporation of the lure photograph, thereby increasing subsequent false memories. The fMRI results revealed that the quality of reactivation modulated subsequent true and false memories via recruitment of left posterior parahippocampal, bilateral retrosplenial, and bilateral posterior inferior parietal cortices. However, the timing of neural recruitment and the way in which memories were reactivated contributed to differences in whether memory reactivation led to distortions or not. These data reveal the neural mechanisms recruited during memory reactivation that modify how memories will be subsequently retrieved, supporting the flexible and dynamic aspects of memory.

  7. Mechanisms of change in psychotherapy for depression: An empirical update and evaluation of research aimed at identifying psychological mediators.

    Science.gov (United States)

    Lemmens, Lotte H J M; Müller, Viola N L S; Arntz, Arnoud; Huibers, Marcus J H

    2016-12-01

    We present a systematic empirical update and critical evaluation of the current status of research aimed at identifying a variety of psychological mediators in various forms of psychotherapy for depression. We summarize study characteristics and results of 35 relevant studies, and discuss the extent to which these studies meet several important requirements for mechanism research. Our review indicates that in spite of increased attention for the topic, advances in theoretical consensus about necessities for mechanism research, and sophistication of study designs, research in this field is still heterogeneous and unsatisfactory in methodological respect. Probably the biggest challenge in the field is demonstrating the causal relation between change in the mediator and change in depressive symptoms. The field would benefit from a further refinement of research methods to identify processes of therapeutic change. Recommendations for future research are discussed. However, even in the most optimal research designs, explaining psychotherapeutic change remains a challenge. Psychotherapy is a multi-dimensional phenomenon that might work through interplay of multiple mechanisms at several levels. As a result, it might be too complex to be explained in relatively simple causal models of psychological change. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. SSC collider dipole magnet end mechanical design

    International Nuclear Information System (INIS)

    Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, S.M.; Leung, K.K.

    1991-05-01

    This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described. 8 refs., 3 figs

  9. Design considerations for mechanical face seals

    Science.gov (United States)

    Ludwig, L. P.; Greiner, H. F.

    1980-01-01

    Two companion reports deal with design considerations for improving performance of mechanical face seals, one of family of devices used in general area of fluid sealing of rotating shafts. One report deals with basic seal configuration and other with lubrication of seal.

  10. Design definition of a mechanical capacitor

    Science.gov (United States)

    Michaelis, T. D.; Schlieban, E. W.; Scott, R. D.

    1977-01-01

    A design study and analyses of a 10 kW-hr, 15 kW mechanical capacitor system was studied. It was determined that magnetically supported wheels constructed of advanced composites have the potential for high energy density and high power density. Structural concepts are analyzed that yield the highest energy density of any structural design yet reported. Particular attention was paid to the problem of 'friction' caused by magnetic and I to the second power R losses in the suspension and motor-generator subsystems, and low design friction levels have been achieved. The potentially long shelf life of this system, and the absence of wearing parts, provide superior performance over conventional flywheels supported with mechanical bearings. Costs and economies of energy storage wheels were reviewed briefly.

  11. AHTR Mechanical, Structural, And Neutronic Preconceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Varma, Venugopal Koikal [ORNL; Holcomb, David Eugene [ORNL; Peretz, Fred J [ORNL; Bradley, Eric Craig [ORNL; Ilas, Dan [ORNL; Qualls, A L [ORNL; Zaharia, Nathaniel M [ORNL

    2012-10-01

    This report provides an overview of the mechanical, structural, and neutronic aspects of the Advanced High Temperature Reactor (AHTR) design concept. The AHTR is a design concept for a large output Fluoride salt cooled High-temperature Reactor (FHR) that is being developed to enable evaluation of the technology hurdles remaining to be overcome prior to FHRs becoming a commercial reactor class. This report documents the incremental AHTR design maturation performed over the past year and is focused on advancing the design concept to a level of a functional, self-consistent system. The AHTR employs plate type coated particle fuel assemblies with rapid, off-line refueling. Neutronic analysis of the core has confirmed the viability of a 6-month 2-batch cycle with 9 weight-percent enriched uranium fuel. Refueling is intended to be performed automatically under visual guidance using dedicated robotic manipulators. The present design intent is for used fuel to be stored inside of containment for at least 6 months and then transferred to local dry wells for intermediate term, on-site storage. The mechanical and structural concept development effort has included an emphasis on transportation and constructability to minimize construction costs and schedule. The design intent is that all components be factory fabricated into rail transportable modules that are assembled into subsystems at an on-site workshop prior to being lifted into position using a heavy-lift crane in an open-top style construction. While detailed accident identification and response sequence analysis has yet to be performed, the design concept incorporates multiple levels of radioactive material containment including fully passive responses to all identified design basis or non-very-low frequency beyond design basis accidents. Key building design elements include: 1) below grade siting to minimize vulnerability to aircraft impact, 2) multiple natural circulation decay heat rejection chimneys, 3) seismic

  12. Staged Optimization Design for Updating Urban Drainage Systems in a City of China

    Directory of Open Access Journals (Sweden)

    Kui Xu

    2018-01-01

    Full Text Available Flooding has been reported more often than in the past in most cities of China in recent years. In response, China’s State Council has urged the 36 largest cities to update the preparedness to handle the 50-year rainfall, which would be a massive project with large investments. We propose a staged optimization design for updating urban drainage that is not only a flexible option against environmental changes, but also an effective way to reduce the cost of the project. The staged cost optimization model involving the hydraulic model was developed in Fuzhou City, China. This model was established to minimize the total present costs, including intervention costs and flooding costs, with full consideration of the constraints of specific local conditions. The results show that considerable financial savings could be achieved by a staged design rather than the implement-once scheme. The model’s sensitivities to four data parameters were analyzed, including rainfall increase rate, flood unit cost, storage unit cost, and discount rate. The results confirm the applicability and robustness of the model for updating drainage systems to meet the requirements. The findings of this study may have important implications on urban flood management in the cities of developing countries with limited construction investments.

  13. Computational Design of Animated Mechanical Characters

    Science.gov (United States)

    Coros, Stelian; Thomaszewski, Bernhard; DRZ Team Team

    2014-03-01

    A factor key to the appeal of modern CG movies and video-games is that the virtual worlds they portray place no bounds on what can be imagined. Rapid manufacturing devices hold the promise of bringing this type of freedom to our own world, by enabling the fabrication of physical objects whose appearance, deformation behaviors and motions can be precisely specified. In order to unleash the full potential of this technology however, computational design methods that create digital content suitable for fabrication need to be developed. In recent work, we presented a computational design system that allows casual users to create animated mechanical characters. Given an articulated character as input, the user designs the animated character by sketching motion curves indicating how they should move. For each motion curve, our framework creates an optimized mechanism that reproduces it as closely as possible. The resulting mechanisms are attached to the character and then connected to each other using gear trains, which are created in a semi-automated fashion. The mechanical assemblies generated with our system can be driven with a single input driver, such as a hand-operated crank or an electric motor, and they can be fabricated using rapid prototyping devices.

  14. Small Sized Drone Fall Recover Mechanism Design

    Science.gov (United States)

    LIU, Tzu-Heng; CHAO, Fang-Lin; LIOU, Jhen-Yuan

    2017-12-01

    Drones uses four motors to rotate clockwise, counter-clockwise, or change in rotational speed to change its status of motion. The problem of Unmanned Aerial Vehicle turnover causes personal loses and harm local environment. Designs of devices that can let falling drones recover are discussed. The models attempt to change the orientation, so that the drone may be able to improve to the point where it can take off again. The design flow included looking for functional elements, using simplify model to estimate primary functional characteristics, and find the appropriate design parameters. For reducing the complexity, we adopted the simple rotate mechanism with rotating arms to change the fuselage angle and reduce the dependence on the extra-components. A rough model was built to verify structure, and then the concept drawing and prototype were constructed. We made the prototype through the integration of mechanical part and the electronic control circuit. The electronic control module that selected is Arduino-mini pro. Through the Bluetooth modules, user can start the rebound mechanism by the motor control signal. Protections frames are added around each propeller to improve the body rotate problem. Limited by current size of Arduino module, motor and rebound mechanism make the main chassis more massive than the commercial product. However, built-in sensor and circuit miniaturization will improve it in future.

  15. DESIGN QUALITY IN MECHANICAL ENGINEERING APPLICATION

    Directory of Open Access Journals (Sweden)

    Ayşegül Akdogan Eker

    2010-09-01

    Full Text Available There is a close relationship between material chose and quality in mechanical engineering application like there is in all the other engineering applications. If this relation is balanced then engineering success increases. Material chose comes to fore in the design process most of the time. The two most important responsibilities of the design engineer in here is to chose suitable material and to know the production processes about design. The chose of material of a design that will fulfill the needs all through its life has great importance. It is needed to limit the material applicants by choosing the most suitable ones among variable material. Choosing materials that were examined before and whose behavior is well known provides the designer to feel confident. However since using highly successful materials would increase the competitive power of the designs; designers should follow the developments in materials and know the features of new materials. The description of these features can be interpreted within quality. Quality from the point of engineer is the total fulfillment of expectations.Engineer today are faced with very important problems such as fast technological innovations, a dynamic socio-economical environment, global rivalry. One of the life buoys they stick while trying to solve these problems is total method of quality control. Total Quality model which can provide higher competitive power compared to classical management model brings success only when applied with its whole components. "Approach toward prevention" and "measurement and statistics" have an important place among these elements. The first step of the approach toward prevention composes of design quality and Quality Function Deployment (QFD, or in other words The House of Quality method that will provide this. In this paper; considering the quality function deployment, how the chose of material are done in mechanical engineering applications will be explained.

  16. Mechanical design of SERT 2 thruster system

    Science.gov (United States)

    Zavesky, R. J.; Hurst, E. B.

    1972-01-01

    The mechanical design of the mercury bombardment thruster that was tested on SERT is described. The report shows how the structural, thermal, electrical, material compatibility, and neutral mercury coating considerations affected the design and integration of the subsystems and components. The SERT 2 spacecraft with two thrusters was launched on February 3, 1970. One thruster operated for 3782 hours and the other for 2011 hours. A high voltage short resulting from buildup of loose eroded material was believed to be the cause of failure.

  17. AHTR Mechanical, Structural, and Neutronic Preconceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Varma, V.K.; Holcomb, D.E.; Peretz, F.J.; Bradley, E.C.; Ilas, D.; Qualls, A.L.; Zaharia, N.M.

    2012-09-15

    This report provides an overview of the mechanical, structural, and neutronic aspects of the Advanced High Temperature Reactor (AHTR) design concept. The AHTR is a design concept for a large output Fluoride salt cooled High-temperature Reactor (FHR) that is being developed to enable evaluation of the technology hurdles remaining to be overcome prior to FHRs becoming an option for commercial reactor deployment. This report documents the incremental AHTR design maturation performed over the past year and is focused on advancing the design concept to a level of a functional, self-consistent system. The reactor concept development remains at a preconceptual level of maturity. While the overall appearance of an AHTR design is anticipated to be similar to the current concept, optimized dimensions will differ from those presented here. The AHTR employs plate type coated particle fuel assemblies with rapid, off-line refueling. Neutronic analysis of the core has confirmed the viability of a 6-month two-batch cycle with 9 wt. % enriched uranium fuel. Refueling is intended to be performed automatically under visual guidance using dedicated robotic manipulators. The report includes a preconceptual design of the manipulators, the fuel transfer system, and the used fuel storage system. The present design intent is for used fuel to be stored inside of containment for at least six months and then transferred to local dry wells for intermediate term, on-site storage. The mechanical and structural concept development effort has included an emphasis on transportation and constructability to minimize construction costs and schedule. The design intent is that all components be factory fabricated into rail transportable modules that are assembled into subsystems at an on-site workshop prior to being lifted into position using a heavy-lift crane in an open-top style construction. While detailed accident identification and response sequence analysis has yet to be performed, the design

  18. Mechanical Cushion Design Influence on Cylinder Dynamics

    DEFF Research Database (Denmark)

    Borghi, Massimo; Milani, Massimo; Conrad, Finn

    2005-01-01

    . experimental comparison, involving the piston velocity and the cylinder chambers pressure. After, with the aim of highlighting the effect of mechanical cushions design on a two effect linear actuator dynamic performances, the characteristics modulation of four alternative cushioning systems are determined......The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow......-rate (and of the correspondent discharging orifice design) on the cushioning characteristics variation is firstly introduced. Then, with respect to the case of the cylindrical cushioning engagement, both the reliability and the limits of the numerical approach are highlighted through a numerical vs...

  19. Premium quality for a mechanical design department

    OpenAIRE

    Rofín Serrà, Guillem

    2009-01-01

    This Thesis has been carried out in a market which is expected to grow rapidly in the next decade. Because of this, actors in the market like Alpha want to strengthen their business position through refining the quality of their products and processes. One of the internal targets of MD, a mechanical design department within Alpha, referred to “premium product quality parameters” although these were not defined. Hence, this Thesis intends to contribute in the definition and understanding that ...

  20. Surface mechanics design by cavitation peening

    OpenAIRE

    Hitoshi Soyama

    2015-01-01

    Although impacts at cavitation bubble collapses cause severe damage in hydraulic machineries, the cavitation impacts can be utilised for surface mechanics design such as introduction of compressive residual stress and/or improvement of fatigue strength. The peening method using the cavitation impacts was called as cavitation peening. In order to reveal the peening intensity of hydrodynamic cavitation and laser cavitation, the arc height of Almen strip and duralumin plate were measured. In the...

  1. Mechanism Design for Incentivizing Social Media Contributions

    Science.gov (United States)

    Singh, Vivek K.; Jain, Ramesh; Kankanhalli, Mohan

    Despite recent advancements in user-driven social media platforms, tools for studying user behavior patterns and motivations remain primitive. We highlight the voluntary nature of user contributions and that users can choose when (and when not) to contribute to the common media pool. A Game theoretic framework is proposed to study the dynamics of social media networks where contribution costs are individual but gains are common. We model users as rational selfish agents, and consider domain attributes like voluntary participation, virtual reward structure, network effect, and public-sharing to model the dynamics of this interaction. The created model describes the most appropriate contribution strategy from each user's perspective and also highlights issues like 'free-rider' problem and individual rationality leading to irrational (i.e. sub-optimal) group behavior. We also consider the perspective of the system designer who is interested in finding the best incentive mechanisms to influence the selfish end-users so that the overall system utility is maximized. We propose and compare multiple mechanisms (based on optimal bonus payment, social incentive leveraging, and second price auction) to study how a system designer can exploit the selfishness of its users, to design incentive mechanisms which improve the overall task-completion probability and system performance, while possibly still benefiting the individual users.

  2. The results of the investigations on rock mechanics in HDB-9-11 boreholes and update of the rock mechanical model around the Horonobe URL construction area

    International Nuclear Information System (INIS)

    Sanada, Hiroyuki; Niunoya, Sumio; Matsui, Hiroya

    2008-09-01

    Horonobe URL (Underground Research Laboratory) Project is conducted at Horonobe-cho, Teshio-gun, Hokkaido. This research report shows the result of the rock mechanical investigations which have been carried out from 2004 to 2005 as a part of the project. The objectives of the rock mechanical investigation are as follows: To obtain the data which were necessary for construction design of URL. To confirm the distribution of rock mechanical properties in and around URL construction area. The results of the investigations are summarized as follows: 1) Variation and values of depth direction of physical and mechanical properties in the laboratory construction area corresponded approximately to the results obtained from the rock mechanical investigations of HDB-1-8. 2) The major redesign had been not had about physical and mechanical properties in the laboratory construction area being able to divide into three zones and length of its own zone in updating rock mechanical model. 3) From the results of initial stress measured by hydraulic fracturing, the results that the direction of the maximum principle stress is E-W was no different from results obtained from the investigations of HDB-1-8, but the magnitude correlation among maximum, minimum principle stress and overburden pressure measured around G.L.-927 m showed different trends compared with the results of HDB-1-8. 4) Diatomaceous mudstone was yielded under isotropic compression. Cam-clay model as constitutive law of diatomaceous mudstone should be used for tunnel excavation analysis. 5) Uniaxial compression strength of rock saturated under saline water is larger than that of saturated under freshwater. Poisson's ratio of rock saturated under saline water is smaller than that of saturated under saline water. 6) The effective confining pressure increases with the equivalent opening width and permeability decreases. 7) The value of principle stress obtained from DSCA method is larger than that obtained from hydraulic

  3. Quantum mechanical design of enzyme active sites.

    Science.gov (United States)

    Zhang, Xiyun; DeChancie, Jason; Gunaydin, Hakan; Chowdry, Arnab B; Clemente, Fernando R; Smith, Adam J T; Handel, T M; Houk, K N

    2008-02-01

    The design of active sites has been carried out using quantum mechanical calculations to predict the rate-determining transition state of a desired reaction in presence of the optimal arrangement of catalytic functional groups (theozyme). Eleven versatile reaction targets were chosen, including hydrolysis, dehydration, isomerization, aldol, and Diels-Alder reactions. For each of the targets, the predicted mechanism and the rate-determining transition state (TS) of the uncatalyzed reaction in water is presented. For the rate-determining TS, a catalytic site was designed using naturalistic catalytic units followed by an estimation of the rate acceleration provided by a reoptimization of the catalytic site. Finally, the geometries of the sites were compared to the X-ray structures of related natural enzymes. Recent advances in computational algorithms and power, coupled with successes in computational protein design, have provided a powerful context for undertaking such an endeavor. We propose that theozymes are excellent candidates to serve as the active site models for design processes.

  4. Mechanical Design of Carbon Ion Optics

    Science.gov (United States)

    Haag, Thomas

    2005-01-01

    Carbon Ion Optics are expected to provide much longer thruster life due to their resistance to sputter erosion. There are a number of different forms of carbon that have been used for fabricating ion thruster optics. The mechanical behavior of carbon is much different than that of most metals, and poses unique design challenges. In order to minimize mission risk, the behavior of carbon must be well understood, and components designed within material limitations. Thermal expansion of the thruster structure must be compatible with thermal expansion of the carbon ion optics. Specially designed interfaces may be needed so that grid gap and aperture alignment are not adversely affected by dissimilar material properties within the thruster. The assembled thruster must be robust and tolerant of launch vibration. The following paper lists some of the characteristics of various carbon materials. Several past ion optics designs are discussed, identifying strengths and weaknesses. Electrostatics and material science are not emphasized so much as the mechanical behavior and integration of grid electrodes into an ion thruster.

  5. Design and update of a classification system: the UCSD map of science.

    Directory of Open Access Journals (Sweden)

    Katy Börner

    Full Text Available Global maps of science can be used as a reference system to chart career trajectories, the location of emerging research frontiers, or the expertise profiles of institutes or nations. This paper details data preparation, analysis, and layout performed when designing and subsequently updating the UCSD map of science and classification system. The original classification and map use 7.2 million papers and their references from Elsevier's Scopus (about 15,000 source titles, 2001-2005 and Thomson Reuters' Web of Science (WoS Science, Social Science, Arts & Humanities Citation Indexes (about 9,000 source titles, 2001-2004-about 16,000 unique source titles. The updated map and classification adds six years (2005-2010 of WoS data and three years (2006-2008 from Scopus to the existing category structure-increasing the number of source titles to about 25,000. To our knowledge, this is the first time that a widely used map of science was updated. A comparison of the original 5-year and the new 10-year maps and classification system show (i an increase in the total number of journals that can be mapped by 9,409 journals (social sciences had a 80% increase, humanities a 119% increase, medical (32% and natural science (74%, (ii a simplification of the map by assigning all but five highly interdisciplinary journals to exactly one discipline, (iii a more even distribution of journals over the 554 subdisciplines and 13 disciplines when calculating the coefficient of variation, and (iv a better reflection of journal clusters when compared with paper-level citation data. When evaluating the map with a listing of desirable features for maps of science, the updated map is shown to have higher mapping accuracy, easier understandability as fewer journals are multiply classified, and higher usability for the generation of data overlays, among others.

  6. Topical glucocorticoids and the skin-mechanisms of action: an update

    Directory of Open Access Journals (Sweden)

    A. Ahluwalia

    1998-01-01

    Full Text Available The topical glucocorticoids (GCs represent the treatment of choice for many types of inflammatory dermatoses. Despite the extensive use of this class of drugs as first line therapy the mechanism of their action is uncertain. It is clear that the multiplicity of actions of the topical GCs is an important facet of their scope in the treatment of dermal disorders. The aim of this update is to review past and current theories regarding how these agents might work. Current understanding of the molecular mechanism s of GC action has advanced significantly over the past decade with the realisation that multiple systems are responsible for transduction of GC effects at a molecular level. The two primary modes of action are via interaction directly with DNA or indirectly through modulation of specific transcription factors: the endpoint in both cases being modulation of specific protein synthesis. Both of these mechanisms will be discussed. In particular this review will concentrate on the possibility that a GC-inducible protein, termed lipocortin 1, may have a significant role to play in the anti-inflammatory actions of these drugs. Additionally it has become apparent that several inflammatory enzymes induced in inflamm ation are sites of inhibitory action of the GCs, and the possibility that this occurs in the skin will be discussed paying particular attention to the inducible phospholipase A2, nitric oxide synthase and cyclooxygenase systems.

  7. Mechanical components design for PWR - control rod drive mechanism

    International Nuclear Information System (INIS)

    Leme, Francisco Louzano; Mattar Neto, Miguel

    2002-01-01

    The Control Rod Drive Mechanism (CRDM) is usually - a high precision - equipment incorporating mechanical and electrical components designed to move the control rods. The 'control rods' refer to all rods or assemblies that are moved to assess the performance of the reactor. The CRDM here presented is the Nut and Lead Screw type. This type is basically a power screw type magnetically coupled to a slow speed reluctance electric motor that provides a means of axially positioning the movable fuel assemblies in the reactor core for purpose of controlling core reactivity. A helically threaded lead screw assembly, comprising one element of power screw, is attached to a movable fuel assemblies. The CRDM usually has closer and more consistent contact with environment peculiar to the reactor than has only other machinery component. This environment includes not only the radiation field of the reactor, but also the temperature, pressure and chemical properties associated with the material used as the coolant for reactor fuel. Specific and special materials are needed because of the above mentioned application. Due to the importance of the above described CRDM functions, this paper will also consider the nuclear functions and their safety classes as well as the CRDM nuclear design criteria. (author)

  8. Mechanical design of translocating motor proteins.

    Science.gov (United States)

    Hwang, Wonmuk; Lang, Matthew J

    2009-01-01

    Translocating motors generate force and move along a biofilament track to achieve diverse functions including gene transcription, translation, intracellular cargo transport, protein degradation, and muscle contraction. Advances in single molecule manipulation experiments, structural biology, and computational analysis are making it possible to consider common mechanical design principles of these diverse families of motors. Here, we propose a mechanical parts list that include track, energy conversion machinery, and moving parts. Energy is supplied not just by burning of a fuel molecule, but there are other sources or sinks of free energy, by binding and release of a fuel or products, or similarly between the motor and the track. Dynamic conformational changes of the motor domain can be regarded as controlling the flow of free energy to and from the surrounding heat reservoir. Multiple motor domains are organized in distinct ways to achieve motility under imposed physical constraints. Transcending amino acid sequence and structure, physically and functionally similar mechanical parts may have evolved as nature's design strategy for these molecular engines.

  9. Lansce Wire Scanning Diagnostics Device Mechanical Design

    International Nuclear Information System (INIS)

    Rodriguez Esparza, Sergio; Batygin, Yuri K.; Gilpatrick, John D.; Gruchalla, Michael E.; Maestas, Alfred J.; Pillai, Chandra; Raybun, Joseph L.; Sattler, F.D.; Sedillo, James Daniel; Smith, Brian G.

    2011-01-01

    The Accelerator Operations and Technology Division at Los Alamos National Laboratory operates a linear particle accelerator which utilizes 110 wire scanning diagnostics devices to gain position and intensity information of the proton beam. In the upcoming LANSCE improvements, 51 of these wire scanners are to be replaced with a new design, up-to-date technology and off-the-shelf components. This document outlines the requirements for the mechanical design of the LANSCE wire scanner and presents the recently developed linac wire scanner prototype. Additionally, this document presents the design modifications that have been implemented into the fabrication and assembly of this first linac wire scanner prototype. Also, this document will present the design for the second, third, and fourth wire scanner prototypes being developed. Prototypes 2 and 3 belong to a different section of the particle accelerator and therefore have slightly different design specifications. Prototype 4 is a modification of a previously used wire scanner in our facility. Lastly, the paper concludes with a plan for future work on the wire scanner development.

  10. Lansce Wire Scanning Diagnostics Device Mechanical Design

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gilpatrick, John D. [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Maestas, Alfred J. [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Raybun, Joseph L. [Los Alamos National Laboratory; Sattler, F. D. [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2011-01-01

    The Accelerator Operations & Technology Division at Los Alamos National Laboratory operates a linear particle accelerator which utilizes 110 wire scanning diagnostics devices to gain position and intensity information of the proton beam. In the upcoming LANSCE improvements, 51 of these wire scanners are to be replaced with a new design, up-to-date technology and off-the-shelf components. This document outlines the requirements for the mechanical design of the LANSCE wire scanner and presents the recently developed linac wire scanner prototype. Additionally, this document presents the design modifications that have been implemented into the fabrication and assembly of this first linac wire scanner prototype. Also, this document will present the design for the second, third, and fourth wire scanner prototypes being developed. Prototypes 2 and 3 belong to a different section of the particle accelerator and therefore have slightly different design specifications. Prototype 4 is a modification of a previously used wire scanner in our facility. Lastly, the paper concludes with a plan for future work on the wire scanner development.

  11. A Commentary on "Updating the Duplex Design for Test-Based Accountability in the Twenty-First Century"

    Science.gov (United States)

    Brandt, Steffen

    2010-01-01

    This article presents the author's commentary on "Updating the Duplex Design for Test-Based Accountability in the Twenty-First Century," in which Isaac I. Bejar and E. Aurora Graf propose the application of a test design--the duplex design (which was proposed in 1988 by Bock and Mislevy) for application in current accountability assessments.…

  12. Habitable Exoplanet Imager Optical-Mechanical Design and Analysis

    Science.gov (United States)

    Gaskins, Jonathan; Stahl, H. Philip

    2017-01-01

    The Habitable Exoplanet Imager (HabEx) is a space telescope currently in development whose mission includes finding and spectroscopically characterizing exoplanets. Effective high-contrast imaging requires tight stability requirements of the mirrors to prevent issues such as line of sight and wavefront errors. PATRAN and NASTRAN were used to model updates in the design of the HabEx telescope and find how those updates affected stability. Most of the structural modifications increased first mode frequencies and improved line of sight errors. These studies will be used to help define the baseline HabEx telescope design.

  13. Mechanical design for TMX injector system

    International Nuclear Information System (INIS)

    Calderon, M.O.; Chen, F.F.K.; Denhoy, B.S.

    1977-01-01

    The injector system for the Tandem Mirror Experiment (TMX) contains the components required to create and maintain a high-temperature, high-density plasma. These components include a streaming-plasma gun in each of the plug tanks to form the target-plasma, 24 neutral-beam source modules for injecting neutral deuterium atoms to heat and replace losses from the plasma, and a gas box system that applies a streaming cold gas to the plasma to stabilize it. This paper discusses the mechanical design problems and solutions for this injector system

  14. Mechanical design of the SNS MEBT

    International Nuclear Information System (INIS)

    Oshatz, D.; DeMello, A.; Doolittle, L.; Luft, P.; Staples, J.; Zachoszcz, A.

    2001-01-01

    The Lawrence Berkeley National Laboratory (LBNL) is presently designing and building the 2.5 MeV front end for the Spallation Neutron Source (SNS). The front end includes a medium-energy beam transport (MEBT) that carries the 2.5 MeV, 38 mA peak current, H - beam from the radio frequency quadrupole (RFQ) to the drift tube linac (DTL) through a series of 14 electromagnetic quadrupoles, four rebuncher cavities, and a fast traveling wave chopping system. The beamline contains numerous diagnostic devices, including stripline beam position and phase monitors (BPM), toroid beam current monitors (BCM), and beam profile monitors. Components are mounted on three rafts that are separately supported and aligned. The large number of beam transport and diagnostic components in the 3.6 meter-long beamline necessitates an unusually compact mechanical design

  15. Mechanical design of a RF electron gun

    International Nuclear Information System (INIS)

    Woodle, M.H.; Batchelor, K.; Sheehan, J.

    1989-01-01

    Brookhaven National Laboratory is building an Accelerator Test Facility at which we plan to study laser acceleration of electrons, inverse free electron lasers and the production of X-rays by non-linear Compton scattering. The facility contains an electron gun, linac, lasers and ancillary systems which will enable the production of 6 ps duration pulses of 50-100 MeV electrons. The electron source is an one and one half cell RF Electron gun which utilizes either a thermionic or photoemissive cathode to produce 5 MeV electrons. This paper discusses how gun mechanical design considerations such as material, vacuum maintenance, surface finish, fabrication methods, cavity tuning, and cathode replacement were reconciled to arrive at the final design. 9 refs., 2 figs., 2 tabs

  16. Mechanical design of a rf electron gun

    International Nuclear Information System (INIS)

    Woodle, M.H.; Batchelor, K.; Sheehan, J.

    1988-01-01

    Brookhaven National Laboratory is building an Accelerator Test Facility at which we plan to study laser acceleration of electrons inverse free electron lasers and the production of X-rays by non- linear Compton scattering. The facility contains an electron gun, linac, lasers and ancillary systems which will enable the production of 6 ps duration pulses of 50--100 MeV electrons. The electron source is an one and one half cell RF Electron gun which utilizes either a thermionic or photoemissive cathode to produce 5 MeV electrons. This paper discusses how gun mechanical design considerations such as material, vacuum maintenance, surface finish, fabrication methods, cavity tuning, and cathode replacement were reconciled to arrive at the final design. 9 refs., 2 figs., 2 tabs

  17. Mechanical design of a PERMCAT reactor module

    Energy Technology Data Exchange (ETDEWEB)

    Tosti, S. [Associazione ENEA Euratom sulla Fusione, C.R. ENEA Frascati, Via E. Fermi 45, Frascati, Roma I-00044 (Italy)], E-mail: tosti@frascati.enea.it; Bettinali, L. [Associazione ENEA Euratom sulla Fusione, C.R. ENEA Frascati, Via E. Fermi 45, Frascati, Roma I-00044 (Italy); Borgognoni, F. [Tesi Sas, Via Bolzano 28, Rome (Italy); Murdoch, D.K. [EFDA CSU, Boltzmannstr. 2, D-85748 Garching bei Munchen (Germany)

    2007-02-15

    The PERMCAT is a membrane reactor proposed for processing fusion reactor plasma exhaust gas: tritium removal is obtained by isotopic swamping operating in counter-current mode. In this work, a membrane reactor using a permeator tube of length about 500 mm produced via diffusion welding of Pd-Ag thin foils is described. An appropriate mechanical design of the membrane module has been developed in order to avoid any significant compressive and bending stresses on the very long and thin wall permeator tube: two expanded bellows have been applied to the Pd-Ag tube, so that it has been pre-tensioned before operating. The elongation of the metal permeator under hydrogenation has been theoretically estimated and experimentally verified for properly designing the membrane reactor.

  18. Bioinspiration: applying mechanical design to experimental biology.

    Science.gov (United States)

    Flammang, Brooke E; Porter, Marianne E

    2011-07-01

    The production of bioinspired and biomimetic constructs has fostered much collaboration between biologists and engineers, although the extent of biological accuracy employed in the designs produced has not always been a priority. Even the exact definitions of "bioinspired" and "biomimetic" differ among biologists, engineers, and industrial designers, leading to confusion regarding the level of integration and replication of biological principles and physiology. By any name, biologically-inspired mechanical constructs have become an increasingly important research tool in experimental biology, offering the opportunity to focus research by creating model organisms that can be easily manipulated to fill a desired parameter space of structural and functional repertoires. Innovative researchers with both biological and engineering backgrounds have found ways to use bioinspired models to explore the biomechanics of organisms from all kingdoms to answer a variety of different questions. Bringing together these biologists and engineers will hopefully result in an open discourse of techniques and fruitful collaborations for experimental and industrial endeavors.

  19. Update on infections caused by Stenotrophomonas maltophilia with particular attention to resistance mechanisms and therapeutic options

    Directory of Open Access Journals (Sweden)

    Ya Ting eChang

    2015-09-01

    Full Text Available Stenotrophomonas maltophilia is a Gram-negative, biofilm-forming bacterium. Although generally regarded as an organism of low virulence, S. maltophilia is an emerging multi-drug resistant opportunistic pathogen in hospital and community settings, especially among immunocompromised hosts. Risk factors associated with S. maltophilia infection include underlying malignancy, cystic fibrosis, corticosteroid or immunosuppressant therapy, the presence of an indwelling central venous catheter and exposure to broad spectrum antibiotics. In this review, we provide a synthesis of information on current global trends in S. maltophilia pathogenicity as well as updated information on the molecular mechanisms contributing to its resistance to an array of antimicrobial agents. The prevalence of S. maltophilia infection in the general population increased from 0.8%-1.4% during 1997-2003 to 1.3%-1.68% during 2007-2012. The most important molecular mechanisms contributing to its resistance to antibiotics include β-lactamase production, the expression of Qnr genes, and the presence of class 1 integrons and efflux pumps. Trimethoprim/sulfamethoxazole (TMP/SMX is the antimicrobial drug of choice. Although a few studies have reported increased resistance to TMP/SMX, the majority of studies worldwide show that S. maltophilia continues to be highly susceptible. Drugs with historically good susceptibility results include ceftazidime, ticarcillin-clavulanate, and fluoroquinolones; however, a number of studies show an alarming trend

  20. Mechanism design for refunding emissions payment

    Energy Technology Data Exchange (ETDEWEB)

    Hagem, Cathrine; Holtsmark, Bjart; Sterner, Thomas

    2012-07-01

    We analyze two mechanism designs for refunding emission payments to polluting firms; Output Based (OB) and Expenditure Based (EB) refunding. In both instruments, emissions fees are returned to the polluting industry, possibly making the policy more easily accepted by policymakers than a standard tax. The crucial difference between OB and EB is that the fees are refunded in proportion to output in the former, but in proportion to the firms' expenditure on abatement equipment in the latter. We show that to achieve a given abatement target, the fee level in the OB design exceeds the standard tax rate, whereas the fee level in the EB design is lower. Furthermore, the use of OB and EB refunding may lead to large differences in the distribution of costs across firms. Both designs do, strictly speaking, imply a cost-ineffective provision of abatement as firms put relatively too much effort into reducing emissions through abatement technology compared with emission reductions through reduced output. However, this may be seen as an advantage by policymakers if they seek to avoid activity reduction in the regulated sector. We provide some numerical illustrations based on abatement cost information from the Norwegian NOx fund.(Author)

  1. Experimental validation of a new heterogeneous mechanical test design

    Science.gov (United States)

    Aquino, J.; Campos, A. Andrade; Souto, N.; Thuillier, S.

    2018-05-01

    Standard material parameters identification strategies generally use an extensive number of classical tests for collecting the required experimental data. However, a great effort has been made recently by the scientific and industrial communities to support this experimental database on heterogeneous tests. These tests can provide richer information on the material behavior allowing the identification of a more complete set of material parameters. This is a result of the recent development of full-field measurements techniques, like digital image correlation (DIC), that can capture the heterogeneous deformation fields on the specimen surface during the test. Recently, new specimen geometries were designed to enhance the richness of the strain field and capture supplementary strain states. The butterfly specimen is an example of these new geometries, designed through a numerical optimization procedure where an indicator capable of evaluating the heterogeneity and the richness of strain information. However, no experimental validation was yet performed. The aim of this work is to experimentally validate the heterogeneous butterfly mechanical test in the parameter identification framework. For this aim, DIC technique and a Finite Element Model Up-date inverse strategy are used together for the parameter identification of a DC04 steel, as well as the calculation of the indicator. The experimental tests are carried out in a universal testing machine with the ARAMIS measuring system to provide the strain states on the specimen surface. The identification strategy is accomplished with the data obtained from the experimental tests and the results are compared to a reference numerical solution.

  2. Analogous Mechanisms of Selection and Updating in Declarative and Procedural Working Memory: Experiments and a Computational Model

    Science.gov (United States)

    Oberauer, Klaus; Souza, Alessandra S.; Druey, Michel D.; Gade, Miriam

    2013-01-01

    The article investigates the mechanisms of selecting and updating representations in declarative and procedural working memory (WM). Declarative WM holds the objects of thought available, whereas procedural WM holds representations of what to do with these objects. Both systems consist of three embedded components: activated long-term memory, a…

  3. Controller design for flexible, distributed parameter mechanical arms via combined state space and frequency domain techniques

    Science.gov (United States)

    Book, W. J.; Majett, M.

    1982-01-01

    The potential benefits of the ability to control more flexible mechanical arms are discussed. A justification is made in terms of speed of movement. A new controller design procedure is then developed to provide this capability. It uses both a frequency domain representation and a state variable representation of the arm model. The frequency domain model is used to update the modal state variable model to insure decoupled states. The technique is applied to a simple example with encouraging results.

  4. Designs for mechanical circulatory support device studies.

    Science.gov (United States)

    Neaton, James D; Normand, Sharon-Lise; Gelijns, Annetine; Starling, Randall C; Mann, Douglas L; Konstam, Marvin A

    2007-02-01

    There is increased interest in mechanical circulatory support devices (MCSDs), such as implantable left ventricular assist devices (LVADs), as "destination" therapy for patients with advanced heart failure. Because patient availability to evaluate these devices is limited and randomized trials have been slow in enrolling patients, a workshop was convened to consider designs for MCSD development including alternatives to randomized trials. A workshop was jointly planned by the Heart Failure Society of America and the US Food and Drug Administration and was convened in March 2006. One of the panels was asked to review different designs for evaluating new MCSDs. Randomized trials have many advantages over studies with no controls or with nonrandomized concurrent or historical controls. These advantages include the elimination of bias in the assignment of treatments and the balancing, on average, of known and unknown baseline covariates that influence response. These advantages of randomization are particularly important for studies in which the treatments may not differ from one another by a large amount (eg, a head-to-head study of an approved LVAD with a new LVAD). However, researchers have found it difficult to recruit patients to randomized studies because the number of clinical sites that can carry out the studies is not large. Also, there is a reluctance to randomize patients when the control device is considered technologically inferior. Thus ways of improving the design of randomized trials were discussed, and the advantages and disadvantages of alternative designs were considered. The panel concluded that designs should include a randomized component. Randomized designs might be improved by allowing the control device to be chosen before randomization, by first conducting smaller vanguard studies, and by allowing crossovers in trials with optimal medical management controls. With use of data from completed trials, other databases, and registries, alternative

  5. 400-MWe consolidated nuclear steam system (CNSS). 1255 MWt CNSS design/cost update

    International Nuclear Information System (INIS)

    1984-07-01

    Since 1976 Babcock and Wilcox (B and W) has been extensively involved in the development of a medium-sized (1255 MWt/400 MWe) reactor. Under the sponsorship of the U.S. Department of Energy (DOE) and through a contract with Oak Ridge National Laboratories (ORNL), B and W investigated the feasibility of the concept for utility power generation and cogenerated process heat. The potential benefits of the design, called the Consolidated Nuclear Steam System (CNSS), were also identified. This study provides an update of the CNSS design and cost reflecting current regulatory requirements and operating reactor experience. The study was funded by DOE through ORNL and was performed by B and W and UE and C

  6. Mechanical design aspects of the HYVAX railgun

    International Nuclear Information System (INIS)

    Fox, W.E.; Cummings, C.E.

    1984-01-01

    The hypervelocity experiment (HYVAX) railgun is designed to produce projectile velocities greater than 15 km/s in a 13-m-long, round bore gun. The HYVAX gun incorporates a modular design enabling it to operate in either a distributed energy-storage mode or a single-stage mode. The gun is composed of seven 0.3-m-long power input modules and nine 1.2-mlong accelerating modules. The gun is designed for a 100-shot life. To accommodate this, the bore may be enlarged from an initial diameter of 10.8 mm to a final diameter of 12.7 mm. This will allow the bore to be refinished several times during the life of the gun. To minimize mechanical and arc damage to the gun between bore refinishing operations, the gun will incorporate a low pressure helium projectile injector. Projectiles will be injected under vacuum at 350 m/s. The gun will be operated at a peak current and voltage of 600 kA and 6 kV respectively. The gun will undergo three phases of testing. The first phase will be the characterization of the gun's performance using a 3.0-m-long section of the gun comprising two power modules and two accelerating modules

  7. Computer Game Play Reduces Intrusive Memories of Experimental Trauma via Reconsolidation-Update Mechanisms.

    Science.gov (United States)

    James, Ella L; Bonsall, Michael B; Hoppitt, Laura; Tunbridge, Elizabeth M; Geddes, John R; Milton, Amy L; Holmes, Emily A

    2015-08-01

    Memory of a traumatic event becomes consolidated within hours. Intrusive memories can then flash back repeatedly into the mind's eye and cause distress. We investigated whether reconsolidation-the process during which memories become malleable when recalled-can be blocked using a cognitive task and whether such an approach can reduce these unbidden intrusions. We predicted that reconsolidation of a reactivated visual memory of experimental trauma could be disrupted by engaging in a visuospatial task that would compete for visual working memory resources. We showed that intrusive memories were virtually abolished by playing the computer game Tetris following a memory-reactivation task 24 hr after initial exposure to experimental trauma. Furthermore, both memory reactivation and playing Tetris were required to reduce subsequent intrusions (Experiment 2), consistent with reconsolidation-update mechanisms. A simple, noninvasive cognitive-task procedure administered after emotional memory has already consolidated (i.e., > 24 hours after exposure to experimental trauma) may prevent the recurrence of intrusive memories of those emotional events. © The Author(s) 2015.

  8. DESIGN OPTIMIZATION METHOD USED IN MECHANICAL ENGINEERING

    Directory of Open Access Journals (Sweden)

    SCURTU Iacob Liviu

    2016-11-01

    Full Text Available This paper presents an optimization study in mechanical engineering. First part of the research describe the structural optimization method used, followed by the presentation of several optimization studies conducted in recent years. The second part of the paper presents the CAD modelling of an agricultural plough component. The beam of the plough is analysed using finite element method. The plough component is meshed in solid elements, and the load case which mimics the working conditions of agricultural equipment of this are created. The model is prepared to find the optimal structural design, after the FEA study of the model is done. The mass reduction of part is the criterion applied for this optimization study. The end of this research presents the final results and the model optimized shape.

  9. Design Features of Modern Mechanical Ventilators.

    Science.gov (United States)

    MacIntyre, Neil

    2016-12-01

    A positive-pressure breath ideally should provide a V T that is adequate for gas exchange and appropriate muscle unloading while minimizing any risk for injury or discomfort. The latest generation of ventilators uses sophisticated feedback systems to sculpt positive-pressure breaths according to patient effort and respiratory system mechanics. Currently, however, these new control strategies are not totally closed-loop systems. This is because the automatic input variables remain limited, some clinician settings are still required, and the specific features of the perfect breath design still are not entirely clear. Despite these limitations, there are some rationale for many of these newer feedback features. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Transcatheter Mitral Valve Devices - Functional Mechanical Designs.

    Science.gov (United States)

    Kliger, Chad

    2014-03-01

    Mitral regurgitation is a complex disorder involving a multitude of components of the mitral apparatus. With the desire for less invasive treatment approaches, transcatheter mitral valve therapies (TMVT) are directed at these components and available at varying stages of development. Therapeutic advancements and the potential to combine technologies may further improve their efficacy and safety. Transcatheter mitral valve replacement, while preserving the mitral apparatus, may emerge as an alternative or even a more suitable treatment option. In addition, early data on transcatheter mitral valve-in-valve and valve-in-ring implantation are encouraging and this approach may be an alternative to reoperation in the high-risk patient. This review details the expanding functional mechanical designs of current active TMVT.

  11. Recombination rate plasticity: revealing mechanisms by design

    Science.gov (United States)

    Sefick, Stephen; Rushton, Chase

    2017-01-01

    For over a century, scientists have known that meiotic recombination rates can vary considerably among individuals, and that environmental conditions can modify recombination rates relative to the background. A variety of external and intrinsic factors such as temperature, age, sex and starvation can elicit ‘plastic’ responses in recombination rate. The influence of recombination rate plasticity on genetic diversity of the next generation has interesting and important implications for how populations evolve. Further, many questions remain regarding the mechanisms and molecular processes that contribute to recombination rate plasticity. Here, we review 100 years of experimental work on recombination rate plasticity conducted in Drosophila melanogaster. We categorize this work into four major classes of experimental designs, which we describe via classic studies in D. melanogaster. Based on these studies, we highlight molecular mechanisms that are supported by experimental results and relate these findings to studies in other systems. We synthesize lessons learned from this model system into experimental guidelines for using recent advances in genotyping technologies, to study recombination rate plasticity in non-model organisms. Specifically, we recommend (1) using fine-scale genome-wide markers, (2) collecting time-course data, (3) including crossover distribution measurements, and (4) using mixed effects models to analyse results. To illustrate this approach, we present an application adhering to these guidelines from empirical work we conducted in Drosophila pseudoobscura. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109222

  12. ACCESS: Thermal Mechanical Design, Performance, and Status

    Science.gov (United States)

    Kaiser, Mary Elizabeth; Morris, M. J.; McCandliss, S. R.; Rauscher, B. J.; Kimble, R. A.; Kruk, J. W.; Wright, E. L.; Bohlin, R.; Kurucz, R. L.; Riess, A. G.; Pelton, R.; Deustua, S. E.; Dixon, W. V.; Sahnow, D. J.; Benford, D. J.; Gardner, J. P.; Feldman, P. D.; Moos, H. W.; Lampton, M.; Perlmutter, S.; Woodgate, B. E.

    2014-01-01

    Systematic errors associated with astrophysical data used to probe fundamental astrophysical questions, such as SNeIa observations used to constrain dark energy theories, are now rivaling and exceeding the statistical errors associated with these measurements. ACCESS: Absolute Color Calibration Experiment for Standard Stars is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 - 1.7μm bandpass. Achieving this level of accuracy requires characterization and stability of the instrument and detector including a thermal background that contributes less than 1% to the flux per resolution element in the NIR. We will present the instrument and calibration status with a focus on the thermal mechanical design and associated performance data. The detector control and performance will be presented in a companion poster (Morris, et al). NASA APRA sounding rocket grant NNX08AI65G supports this work.

  13. LANSCE wire scanning diagnostics device mechanical design

    International Nuclear Information System (INIS)

    Rodriguez Esparza, Sergio

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) is one of the major experimental science facilities at the Los Alamos National Laboratory (LANL). The core of LANSCE's work lies in the operation of a powerful linear accelerator, which accelerates protons up to 84% the speed oflight. These protons are used for a variety of purposes, including materials testing, weapons research and isotopes production. To assist in guiding the proton beam, a series of over one hundred wire scanners are used to measure the beam profile at various locations along the half-mile length of the particle accelerator. A wire scanner is an electro-mechanical device that moves a set of wires through a particle beam and measures the secondary emissions from the resulting beam-wire interaction to obtain beam intensity information. When supplemented with data from a position sensor, this information is used to determine the cross-sectional profile of the beam. This measurement allows beam operators to adjust parameters such as acceleration, beam steering, and focus to ensure that the beam reaches its destination as effectively as possible. Some of the current wire scanners are nearly forty years old and are becoming obsolete. The problem with current wire scanners comes in the difficulty of maintenance and reliability. The designs of these wire scanners vary making it difficult to keep spare parts that would work on all designs. Also many of the components are custom built or out-dated technology and are no longer in production.

  14. LANSCE wire scanning diagnostics device mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Esparza, Sergio [Los Alamos National Laboratory

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) is one of the major experimental science facilities at the Los Alamos National Laboratory (LANL). The core of LANSCE's work lies in the operation of a powerful linear accelerator, which accelerates protons up to 84% the speed oflight. These protons are used for a variety of purposes, including materials testing, weapons research and isotopes production. To assist in guiding the proton beam, a series of over one hundred wire scanners are used to measure the beam profile at various locations along the half-mile length of the particle accelerator. A wire scanner is an electro-mechanical device that moves a set of wires through a particle beam and measures the secondary emissions from the resulting beam-wire interaction to obtain beam intensity information. When supplemented with data from a position sensor, this information is used to determine the cross-sectional profile of the beam. This measurement allows beam operators to adjust parameters such as acceleration, beam steering, and focus to ensure that the beam reaches its destination as effectively as possible. Some of the current wire scanners are nearly forty years old and are becoming obsolete. The problem with current wire scanners comes in the difficulty of maintenance and reliability. The designs of these wire scanners vary making it difficult to keep spare parts that would work on all designs. Also many of the components are custom built or out-dated technology and are no longer in production.

  15. Preliminary Mechanical Design of FHX for PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Jinyup; Koo, G. H.; Kim, S. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, more specific data from analysis and mechanical method of approach to design will be addressed. Especially, frame of tube bundle and housing of FHX. Heretofore, it is concept design by mechanical basic knowledge and research of various structures that are activating in realities. Especially, to reduce thermal stress, we have planning to attach insulations inside the housing. In as much as FHX is as important on SFR as the other part, hereafter, we will develop FEM to check feasibility of the FHX's housing design in order to perform static and thermal analysis as well as bucking, seismic and so on. The Forced-draft sodium-to-air Heat Exchanger system (FHX) (employed in the Active Decay Heat Removal System (ADHRS) is a shell-and-tube type counter-current flow heat exchanger with serpentine finned-tube arrangement. Liquid sodium flows over the finned tubes. The unit is placed above the reactor building and has function of dumping the system heat load into the final heat sink, i. e., the atmosphere. Heat is transmitted from the primary hot sodium pool into the ADHRS sodium loop via Decay Heat Exchanger (DHX), and a direct heat exchange occurs between the tube-side sodium and the shell-side air through the FHX sodium tube wall. Cold atmospheric air is introduced into the air inlet duct at the lower part of the unit by using an electrically driven air blower. Air flows across the finned tube bank rising upward direction to make uniform air flow with perfect mixing across the tubes. The finned tube bundle is placed inside a well-insulated casing. The air heated at the tube bank region is collected at the top of the unit and then is discharged through the air stack above the unit. Although a blower supplies atmospheric air into the FHX unit, a tall air stack is also provided to secure natural draft head of natural circulation air flow against a loss power supply. The stack also has rain protecting structures to prevent inflow of rain drops or undesired

  16. The impact of safety standards updating for design purposes in nuclear power plants licensing

    International Nuclear Information System (INIS)

    Alvarenga, Marco Antonio Bayout; Rabello, Sidney Luiz

    2009-01-01

    The Brazilian experience of nuclear power plants licensing was consolidated by the use of the Brazilian, American, German and IAEA standards. Independently of the set of norms, standards or guides to be used, this set should be in consonance with the state-of-art or the current state of knowledge in science and technology. In the general design criteria of US NRC or German BMI, or in the Brazilian norms (CNEN) or even, in the IAEA standards, this aspect is always emphasized. On the other hand, the international operational experience of nuclear reactors (for example, TMI accident) also contributes to the updating of norms and standards. The use of new technologies (for example, digital technology) impels the norms and standards to adopt new design criteria related to the new technological context. Moreover, we must add the particular vision that each country can have concerning to specific topics in nuclear safety. This work discusses how the norms, standards and guides used in the nuclear licensing are being reviewed to cope with the requirement of the state-of-art. In order to accomplish this aim we took some general design criteria to exemplify how they are fulfilled, mainly those related directly with the protection of the defense-in-depth barriers: primary coolant system, containment vessel and containment systems, including external events and severe accidents. In complement to the deterministic analysis, it is also discussed the design criteria related to the human factors engineering and probabilistic safety analysis, including severe accidents aspects. (author)

  17. Design of planar articulated mechanisms using branch and bound

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Kawamoto, Atsushi

    2004-01-01

    This paper considers an optimization model and a solution method for the design of two-dimensional mechanical mechanisms. The mechanism design problem is modeled as a nonconvex mixed integer program which allows the optimal topology and geometry of the mechanism to be determined simultaneously...... and that buckling is prevented. The feasible set of the design problem is described by nonlinear differentiable and non-differentiable constraints as well as nonlinear matrix inequalities. To solve the mechanism design problem a branch and bound method based on convex relaxations is developed. To guarantee...... mechanism design problems of realistic size to global optimality....

  18. Planar articulated mechanism design by graph theoretical enumeration

    DEFF Research Database (Denmark)

    Kawamoto, A; Bendsøe, Martin P.; Sigmund, Ole

    2004-01-01

    This paper deals with design of articulated mechanisms using a truss-based ground-structure representation. By applying a graph theoretical enumeration approach we can perform an exhaustive analysis of all possible topologies for a test example for which we seek a symmetric mechanism. This guaran....... This guarantees that one can identify the global optimum solution. The result underlines the importance of mechanism topology and gives insight into the issues specific to articulated mechanism designs compared to compliant mechanism designs....

  19. Surface mechanics design by cavitation peening

    Directory of Open Access Journals (Sweden)

    Hitoshi Soyama

    2015-07-01

    Full Text Available Although impacts at cavitation bubble collapses cause severe damage in hydraulic machineries, the cavitation impacts can be utilised for surface mechanics design such as introduction of compressive residual stress and/or improvement of fatigue strength. The peening method using the cavitation impacts was called as cavitation peening. In order to reveal the peening intensity of hydrodynamic cavitation and laser cavitation, the arc height of Almen strip and duralumin plate were measured. In the case of hydrodynamic cavitation, cavitation was generated by injecting a high speed water jet into water with a pressurised chamber and an open chamber, and the cavitating jet in air was also examined. The laser cavitation was produced by a pulse laser, and a high speed observation using a high speed video camera was carried out to clarify laser abrasion and laser cavitation with detecting noise by a hydrophone. It was concluded that the peening intensity by using the cavitating jet in water with the pressurized chamber was most aggressive, and the impact induced by the laser cavitation was larger than that of the laser abrasion at the present condition.

  20. Design Mechanism as Territorial Strategic Capability

    Directory of Open Access Journals (Sweden)

    Gianita BLEOJU

    2009-01-01

    Full Text Available The current exigencies that a territory must faced in order to its’ optimalpositioning in future regional competition requires the ability to design theappropriate mechanism which better valorize the territory capability. Such aconstruct is vital for territorial sustainable development and supposes thecreation of a specific body of knowledge from distinctive local resourceexploitation and unique value creation and allocation. Territorial mechanismdesign is a typical management decision about identification, ownership andcontrol of specific strategic capabilities and their combination in a distinctiveterritorial portfolio. The most difficult responsibility is to allocate the territorialvalue added which is a source of conflict among territorial components. Ourcurrent paper research covers the basics of two complementary territorialpillars-rural and tourism potential and proves the lack of specific designmechanisms which explain the current diminishing value of Galati Brailaregion. The proposed management system, relying upon territorial controlmechanism, will ensure knowledge sharing process via collaborative learning,with the final role of appropriate territorial attractivity signals, reinforcingidentity as key factor of territorial attractability. Our paper is fully documentedon there years of data analyzing from territorial area of interest. This offers usthe necessary empiric contrasting for our proposed solution.

  1. Design of planar articulated mechanisms using branch and bound

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Kawamoto, Atsushi

    2005-01-01

    This paper considers an optimization model and a solution method for the design of two-dimensional mechanical mechanisms. The mechanism design problem is modeled as a nonconvex mixed integer program which allows the optimal topology and geometry of the mechanism to be determined simultaneously...

  2. Design review of the INTOR mechanical configuration

    International Nuclear Information System (INIS)

    Brown, T.G.

    1981-01-01

    The INTOR conceptual design has been carried out by design teams working in the home countries with periodic workshop sessions in Vienna to review the ongoing work and to make decisions on the evolving design. The decisions taken at each workshop session were then incorporated into each national design activity, so that the four national design contributions would progressively converge toward a single design with increasingly greater detail. This paper defines the final INTOR configuration that has evolved during the conceptual design phase, defining the major system design alternatives that were considered and the rationale for selecting the final system configuration

  3. Finite element model updating in structural dynamics using design sensitivity and optimisation

    OpenAIRE

    Calvi, Adriano

    1998-01-01

    Model updating is an important issue in engineering. In fact a well-correlated model provides for accurate evaluation of the structure loads and responses. The main objectives of the study were to exploit available optimisation programs to create an error localisation and updating procedure of nite element models that minimises the "error" between experimental and analytical modal data, addressing in particular the updating of large scale nite element models with se...

  4. Thermostructural and mechanical aspects of the TFTR plasma limiter design

    International Nuclear Information System (INIS)

    Condolff, R.; Fixler, S.

    1977-01-01

    This paper presents the preliminary mechanical and thermostructural aspects of the TFTR (TOKAMAK Fusion Test Reactor) plasma limiter design. The evolution of the limiter design is traced through the various stages from conceptual design to the present state. Results of parametric limiter blade studies are presented. Design criteria, requirements, design loads (mechanical and thermal), material considerations, and remote handling problems are described. The design approach used to achieve a satisfactory plasma limiter and blade is discussed

  5. Thermostructural and mechanical aspects of the TFTR plasma limiter design

    International Nuclear Information System (INIS)

    Condolff, R.; Fixler, S.

    1978-01-01

    This paper presents the preliminary mechanical and thermostructural aspects of the TFTR (TOKAMAK Fusion Test Reactor) plasma limiter design. The evolution of the limiter design is traced through the various stages from conceptual design to the present state. Results of parametric limiter blade studies are presented. Design criteria, requirements, design loads (mechanical and thermal), material considerations, and remote handling problems are described. The design approach used to achieve a satisfactory plasma limiter and blade is discussed

  6. Mechanical design in embryos: mechanical signalling, robustness and developmental defects.

    Science.gov (United States)

    Davidson, Lance A

    2017-05-19

    Embryos are shaped by the precise application of force against the resistant structures of multicellular tissues. Forces may be generated, guided and resisted by cells, extracellular matrix, interstitial fluids, and how they are organized and bound within the tissue's architecture. In this review, we summarize our current thoughts on the multiple roles of mechanics in direct shaping, mechanical signalling and robustness of development. Genetic programmes of development interact with environmental cues to direct the composition of the early embryo and endow cells with active force production. Biophysical advances now provide experimental tools to measure mechanical resistance and collective forces during morphogenesis and are allowing integration of this field with studies of signalling and patterning during development. We focus this review on concepts that highlight this integration, and how the unique contributions of mechanical cues and gradients might be tested side by side with conventional signalling systems. We conclude with speculation on the integration of large-scale programmes of development, and how mechanical responses may ensure robust development and serve as constraints on programmes of tissue self-assembly.This article is part of the themed issue 'Systems morphodynamics: understanding the development of tissue hardware'. © 2017 The Author(s).

  7. Alloy design through mechanical equation of state

    International Nuclear Information System (INIS)

    Li, C.Yu.; Ellis, F.V.; Huang, F.H.

    1975-01-01

    The concept of plastic equation of state and the experimental results which are used to support this approach are introduced. It is shown that considerable savings in mechanical testing are possible in using this approach to establish the constitutive relationships for plastic deformation for a material. Advantages in data correlation and data extrapolation are also described. Examples are given to suggest that the constitutive relationships for plastic deformation obtained may be used as a useful basis for correlating the effects of composition and microstructure changes on mechanical properties and therefore serve as a guide for alloy selection. The savings in mechanical testing suggest also that the approach of plastic equation of state may be adopted for evaluating and assessing the mechanical properties of candidate alloys

  8. Designing Online Marketplaces: Trust and Reputation Mechanisms

    OpenAIRE

    Luca, Michael

    2017-01-01

    Online marketplaces have proliferated over the past decade, creating new markets where none existed. By reducing transaction costs, online marketplaces facilitate transactions that otherwise would not have occurred and enable easier entry of small sellers. One central challenge faced by designers of online marketplaces is how to build enough trust to facilitate transactions between strangers. This paper provides an economist’s toolkit for designing online marketplaces, focusing on trust and r...

  9. On the design of compliant mechanisms using topology optimization

    DEFF Research Database (Denmark)

    Sigmund, Ole

    1997-01-01

    This paper presents a method for optimal design of compliant mechanism topologies. The method is based on continuum-type topology optimization techniques and finds the optimal compliant mechanism topology within a given design domain and a given position and direction of input and output forces....... By constraining the allowed displacement at the input port, it is possible to control the maximum stress level in the compliant mechanism. The ability of the design method to find a mechanism with complex output behavior is demonstrated by several examples. Some of the optimal mechanism topologies have been...... manufactured, both in macroscale (hand-size) made in Nylon, and in microscale (

  10. Deformation mechanisms in ferritic/martensitic steels and the impact on mechanical design

    International Nuclear Information System (INIS)

    Ghoniem, Nasr M.; Po, Giacomo; Sharafat, Shahram

    2013-01-01

    Structural steels for nuclear applications have undergone rapid development during the past few decades, thanks to a combination of trial-and-error, mechanism-based optimization, and multiscale modeling approaches. Deformation mechanisms are shown to be intimately related to mechanical design via dominant plastic deformation modes. Because mechanical design rules are mostly based on failure modes associated with plastic strain damage accumulation, we present here the fundamental deformation mechanisms for Ferritic/Martensitic (F/M) steels, and delineate their operational range of temperature and stress. The connection between deformation mechanisms, failure modes, and mechanical design is shown through application of design rules. A specific example is given for the alloy F82H utilized in the design of a Test Blanket Module (TBM) in the International Thermonuclear Experimental Reactor (ITER), where several constitutive equations are developed for design-related mechanical properties

  11. Deformation mechanisms in ferritic/martensitic steels and the impact on mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Ghoniem, Nasr M., E-mail: ghoniem@seas.ucla.edu; Po, Giacomo; Sharafat, Shahram

    2013-10-15

    Structural steels for nuclear applications have undergone rapid development during the past few decades, thanks to a combination of trial-and-error, mechanism-based optimization, and multiscale modeling approaches. Deformation mechanisms are shown to be intimately related to mechanical design via dominant plastic deformation modes. Because mechanical design rules are mostly based on failure modes associated with plastic strain damage accumulation, we present here the fundamental deformation mechanisms for Ferritic/Martensitic (F/M) steels, and delineate their operational range of temperature and stress. The connection between deformation mechanisms, failure modes, and mechanical design is shown through application of design rules. A specific example is given for the alloy F82H utilized in the design of a Test Blanket Module (TBM) in the International Thermonuclear Experimental Reactor (ITER), where several constitutive equations are developed for design-related mechanical properties.

  12. Mathematical concepts for mechanical engineering design

    CERN Document Server

    Asli, Kaveh Hariri; Aliyev, Soltan Ali Ogli

    2013-01-01

    PrefaceIntroductionHeat Flow: From Theory to PracticeDispersed Fluid and Ideal Fluid MechanicsModeling for Pressure Wave into Water PipelineHeat Transfer and Vapor BubbleMathematical Concepts and Computational Approaches on Hydrodynamics InstabilityMathematical Concepts and Dynamic ModelingModeling for Predictions of Air Entrance into Water PipelineIndex

  13. Neural correlates of informational cascades: brain mechanisms of social influence on belief updating.

    Science.gov (United States)

    Huber, Rafael E; Klucharev, Vasily; Rieskamp, Jörg

    2015-04-01

    Informational cascades can occur when rationally acting individuals decide independently of their private information and follow the decisions of preceding decision-makers. In the process of updating beliefs, differences in the weighting of private and publicly available social information may modulate the probability that a cascade starts in a decisive way. By using functional magnetic resonance imaging, we examined neural activity while participants updated their beliefs based on the decisions of two fictitious stock market traders and their own private information, which led to a final decision of buying one of two stocks. Computational modeling of the behavioral data showed that a majority of participants overweighted private information. Overweighting was negatively correlated with the probability of starting an informational cascade in trials especially prone to conformity. Belief updating by private information was related to activity in the inferior frontal gyrus/anterior insula, the dorsolateral prefrontal cortex and the parietal cortex; the more a participant overweighted private information, the higher the activity in the inferior frontal gyrus/anterior insula and the lower in the parietal-temporal cortex. This study explores the neural correlates of overweighting of private information, which underlies the tendency to start an informational cascade. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  14. Mechanical design and engineering calculation of the SMCAMS magnet

    International Nuclear Information System (INIS)

    Chen Guosheng

    2001-01-01

    The basis of the mechanical design of the SMCAMS magnet, and the structure characters of the magnet and its coils are introduced. Finally, the engineering design of other parts, including deflectors, probes and accelerating electrodes are described

  15. Infrastructure Retrofit Design via Composite Mechanics

    Science.gov (United States)

    Chamis, Christos, C.; Gotsis,Pascal K.

    1998-01-01

    Select applications are described to illustrate the concept for retrofitting reinforced concrete infrastructure with fiber reinforced plastic laminates. The concept is first illustrated by using an axially loaded reinforced concrete column. A reinforced concrete arch and a dome are then used to illustrate the versatility of the concept. Advanced methods such as finite element structural analysis and progressive structural fracture are then used to evaluate the retrofitting laminate adequacy. Results obtains show that retrofits can be designed to double and even triple the as-designed load of the select reinforced concrete infrastructures.

  16. Design methodology for wing trailing edge device mechanisms

    OpenAIRE

    Martins Pires, Rui Miguel

    2007-01-01

    Over the last few decades the design of high lift devices has become a very important part of the total aircraft design process. Reviews of the design process are performed on a regular basis, with the intent to improve and optimize the design process. This thesis describes a new and innovative methodology for the design and evaluation of mechanisms for Trailing Edge High-Lift devices. The initial research reviewed existing High-Lift device design methodologies and current f...

  17. Design and application of chitosan microspheres as oral and nasal vaccine carriers: an updated review

    Directory of Open Access Journals (Sweden)

    Islam MA

    2012-12-01

    Full Text Available Mohammad Ariful Islam,1–3,* Jannatul Firdous,1–3,* Yun-Jaie Choi,1 Cheol-Heui Yun,1–4 Chong-Su Cho1,21Department of Agricultural Biotechnology, 2Research Institute for Agriculture and Life Sciences, 3Center for Food and Bioconvergence, 4World Class University Biomodulation Program, Seoul National University, Seoul, South Korea*These authors contributed equally to this workAbstract: Chitosan, a natural biodegradable polymer, is of great interest in biomedical research due to its excellent properties including bioavailability, nontoxicity, high charge density, and mucoadhesivity, which creates immense potential for various pharmaceutical applications. It has gelling properties when it interacts with counterions such as sulfates or polyphosphates and when it crosslinks with glutaraldehyde. This characteristic facilitates its usefulness in the coating or entrapment of biochemicals, drugs, antigenic molecules as a vaccine candidate, and microorganisms. Therefore, chitosan together with the advance of nanotechnology can be effectively applied as a carrier system for vaccine delivery. In fact, chitosan microspheres have been studied as a promising carrier system for mucosal vaccination, especially via the oral and nasal route to induce enhanced immune responses. Moreover, the thiolated form of chitosan is of considerable interest due to its improved mucoadhesivity, permeability, stability, and controlled/extended release profile. This review describes the various methods used to design and synthesize chitosan microspheres and recent updates on their potential applications for oral and nasal delivery of vaccines. The potential use of thiolated chitosan microspheres as next-generation mucosal vaccine carriers is also discussed.Keywords: chitosan microspheres, oral, nasal, vaccine delivery, mucosal and systemic immune responses

  18. The Large UV/Optical/Infrared Surveyor (LUVOIR): Decadal Mission concept design update

    Science.gov (United States)

    Bolcar, Matthew R.; Aloezos, Steve; Bly, Vincent T.; Collins, Christine; Crooke, Julie; Dressing, Courtney D.; Fantano, Lou; Feinberg, Lee D.; France, Kevin; Gochar, Gene; Gong, Qian; Hylan, Jason E.; Jones, Andrew; Linares, Irving; Postman, Marc; Pueyo, Laurent; Roberge, Aki; Sacks, Lia; Tompkins, Steven; West, Garrett

    2017-09-01

    In preparation for the 2020 Astrophysics Decadal Survey, NASA has commissioned the study of four large mission concepts, including the Large Ultraviolet / Optical / Infrared (LUVOIR) Surveyor. The LUVOIR Science and Technology Definition Team (STDT) has identified a broad range of science objectives including the direct imaging and spectral characterization of habitable exoplanets around sun-like stars, the study of galaxy formation and evolution, the epoch of reionization, star and planet formation, and the remote sensing of Solar System bodies. NASA's Goddard Space Flight Center (GSFC) is providing the design and engineering support to develop executable and feasible mission concepts that are capable of the identified science objectives. We present an update on the first of two architectures being studied: a 15- meter-diameter segmented-aperture telescope with a suite of serviceable instruments operating over a range of wavelengths between 100 nm to 2.5 μm. Four instruments are being developed for this architecture: an optical / near-infrared coronagraph capable of 10-10 contrast at inner working angles as small as 2 λ/D the LUVOIR UV Multi-object Spectrograph (LUMOS), which will provide low- and medium-resolution UV (100 - 400 nm) multi-object imaging spectroscopy in addition to far-UV imaging; the High Definition Imager (HDI), a high-resolution wide-field-of-view NUV-Optical-IR imager; and a UV spectro-polarimeter being contributed by Centre National d'Etudes Spatiales (CNES). A fifth instrument, a multi-resolution optical-NIR spectrograph, is planned as part of a second architecture to be studied in late 2017.

  19. Mechanical design of ISABELLE magnet cryostats

    International Nuclear Information System (INIS)

    Kassner, D.

    1977-01-01

    It has been proposed to construct an intersecting storage ring accelerator, ISABELLE, at BNL, consisting of two concentric rings of magnets containing counter-rotating beams of charged particles. Each ring contains 216 dipole magnets and 138 quadrupoles. All magnets are superconducting and operate at a temperature of 4.3 K. A description of the design of the cryostats, including the internal supports, heat shield superinsulation system and the vacuum vessel is given. Details of fabrication techniques are also included

  20. Design and mechanical properties of insect cuticle.

    Science.gov (United States)

    Vincent, Julian F V; Wegst, Ulrike G K

    2004-07-01

    Since nearly all adult insects fly, the cuticle has to provide a very efficient and lightweight skeleton. Information is available about the mechanical properties of cuticle-Young's modulus of resilin is about 1 MPa, of soft cuticles about 1 kPa to 50 MPa, of sclerotised cuticles 1-20 GPa; Vicker's Hardness of sclerotised cuticle ranges between 25 and 80 kgf mm(-2); density is 1-1.3 kg m(-3)-and one of its components, chitin nanofibres, the Young's modulus of which is more than 150 GPa. Experiments based on fracture mechanics have not been performed although the layered structure probably provides some toughening. The structural performance of wings and legs has been measured, but our understanding of the importance of buckling is lacking: it can stiffen the structure (by elastic postbuckling in wings, for example) or be a failure mode. We know nothing of fatigue properties (yet, for instance, the insect wing must undergo millions of cycles, flexing or buckling on each cycle). The remarkable mechanical performance and efficiency of cuticle can be analysed and compared with those of other materials using material property charts and material indices. Presented in this paper are four: Young's modulus-density (stiffness per unit weight), specific Young's modulus-specific strength (elastic hinges, elastic energy storage per unit weight), toughness-Young's modulus (fracture resistance under various loading conditions), and hardness (wear resistance). In conjunction with a structural analysis of cuticle these charts help to understand the relevance of microstructure (fibre orientation effects in tendons, joints and sense organs, for example) and shape (including surface structure) of this fibrous composite for a given function. With modern techniques for analysis of structure and material, and emphasis on nanocomposites and self-assembly, insect cuticle should be the archetype for composites at all levels of scale.

  1. NIF/LMJ prototype amplifier mechanical design

    International Nuclear Information System (INIS)

    Horvath, J.

    1996-10-01

    Amplifier prototypes for the National Ignition Facility and the Laser Megajoule will be tested at Lawrence Livermore National Laboratory. The prototype amplifier, which is an ensemble of modules from LLNL and Centre d'Etudes de Limeil-Valenton, is cassette-based with bottom access for maintenance. A sealed maintenance transfer vehicle which moves optical cassettes between the amplifier and the assembly cleanroom, and a vacuum gripper which holds laser slabs during cassette assembly will also be tested. The prototype amplifier will be used to verify amplifier optical performance, thermal recovery time, and cleanliness of mechanical operations

  2. Diclofenac: an update on its mechanism of action and safety profile.

    Science.gov (United States)

    Gan, Tong J

    2010-07-01

    Diclofenac is a proven, commonly prescribed nonsteroidal anti-inflammatory drug (NSAID) that has analgesic, anti-inflammatory, and antipyretic properties, and has been shown to be effective in treating a variety of acute and chronic pain and inflammatory conditions. As with all NSAIDs, diclofenac exerts its action via inhibition of prostaglandin synthesis by inhibiting cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) with relative equipotency. However, extensive research shows the pharmacologic activity of diclofenac goes beyond COX inhibition, and includes multimodal and, in some instances, novel mechanisms of action (MOA). Literature retrieval was performed through PubMed/MEDLINE (through May 2009) using combinations of the terms diclofenac, NSAID, mechanism of action, COX-1, COX-2, and pharmacology. Reference citations resulting from publications identified in the literature search were reviewed when appropriate. This article reviews the established, putative, and emerging MOAs of diclofenac; compares the drug's pharmacologic and pharmacodynamic properties with other NSAIDs to delineate its potentially unique qualities; hypothesizes why it has been chosen for further recent formulation enhancement; and evaluates the potential effect of its MOA characteristics on safety. Research suggests diclofenac can inhibit the thromboxane-prostanoid receptor, affect arachidonic acid release and uptake, inhibit lipoxygenase enzymes, and activate the nitric oxide-cGMP antinociceptive pathway. Other novel MOAs may include the inhibition of substrate P, inhibition of peroxisome proliferator activated receptor gamma (PPARgamma), blockage of acid-sensing ion channels, alteration of interleukin-6 production, and inhibition of N-methyl-D-aspartate (NMDA) receptor hyperalgesia. The review was not designed to compare MOAs of diclofenac with other NSAIDs. Additionally, as the highlighted putative and emerging MOAs do not have clinical data to demonstrate that these models are

  3. A Fractual Mechanical Testing and Design Strategy for FRC Structures

    DEFF Research Database (Denmark)

    Stang, Henrik; Olesen, John Forbes

    1999-01-01

    A unified testing and design strategy for fibre reinforced concrete structures is summarised. The strategy is based on fracture mechanical concepts. Emphasis is placed on material characterisation and testing specifications.......A unified testing and design strategy for fibre reinforced concrete structures is summarised. The strategy is based on fracture mechanical concepts. Emphasis is placed on material characterisation and testing specifications....

  4. Game Theoretic Problems in Network Economics and Mechanism Design Solutions

    CERN Document Server

    Narahari, Y; Narayanam, Ramasuri; Prakash, Hastagiri

    2009-01-01

    Explores game theoretic modeling and mechanism design for problem solving in Internet and network economics. This monograph contains an exposition of representative game theoretic problems in three different network economics situations and a systematic exploration of mechanism design solutions to these problems.

  5. Mechanical design of the TIBER breeding shield

    Energy Technology Data Exchange (ETDEWEB)

    Rathke, J.; Deutsch, L. (Grumman Corp., Bethpage, NY (USA). Space Systems Div.)

    1989-04-01

    TIBER features a segmented shield assembly that provides the nuclear shielding for the superconducting toroidal field coils. In addition to its primary function, the shield also provides tritium breeding through the use of water coolant that contains 16 wt% dissolved lithium nitrate. Because the TIBER reactor need not provide electrical power, the coolant is maintained at low pressure (0.2 MPa) and low temperature (75/sup 0/C). The shield is made in several segments to facilitate assembly and allow for replacement of high heat flux components (divertor blades). The segments are designated as inboard, outboard, upper, lower, and divertor modules. In total, there are 96 separate modules in the machine, consisting of six different types. The design features of the different modules vary primarily depending on the thickness of the shield in a given location. The very thick outboard shield has a breeding zone in the inboard portion of the module, with a shielding zone behind it. The breeding zone consists of a stainless steel casing filled with beryllium spheres. The shielding zone consists of the same casing filled with steel spheres. Both of these zones have lithiated water circulated throughout to provide cooling and breeding. In zones with minimal thickness, tungsten alloys are used to achieve the required shielding. These alloys are incoprorated in subassemblies utilizing stainless steel casings surrounding blocks of tungsten heavy metal alloy. These are infiltrated with lead on final assembly to form a thermally continuous panel. Several of these panels are then assembled into an outer stainless steel case to form an inboard module. These modules also use the lithiated coolant. The details of the design are presented and discussed. (orig.).

  6. Update and Improve Subsection NH - Alternative Simplified Creep-Fatigue Design Methods

    International Nuclear Information System (INIS)

    Asayama, Tai

    2009-01-01

    This report described the results of investigation on Task 10 of DOE/ASME Materials NGNP/Generation IV Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 10 is to Update and Improve Subsection NH -- Alternative Simplified Creep-Fatigue Design Methods. Five newly proposed promising creep-fatigue evaluation methods were investigated. Those are (1) modified ductility exhaustion method, (2) strain range separation method, (3) approach for pressure vessel application, (4) hybrid method of time fraction and ductility exhaustion, and (5) simplified model test approach. The outlines of those methods are presented first, and predictability of experimental results of these methods is demonstrated using the creep-fatigue data collected in previous Tasks 3 and 5. All the methods (except the simplified model test approach which is not ready for application) predicted experimental results fairly accurately. On the other hand, predicted creep-fatigue life in long-term regions showed considerable differences among the methodologies. These differences come from the concepts each method is based on. All the new methods investigated in this report have advantages over the currently employed time fraction rule and offer technical insights that should be thought much of in the improvement of creep-fatigue evaluation procedures. The main points of the modified ductility exhaustion method, the strain range separation method, the approach for pressure vessel application and the hybrid method can be reflected in the improvement of the current time fraction rule. The simplified mode test approach would offer a whole new advantage including robustness and simplicity which are definitely attractive but this approach is yet to be validated for implementation at this point. Therefore, this report recommends the following two steps as a course of improvement of NH based on newly proposed creep-fatigue evaluation

  7. Technologies and mechanisms for safety control of ready-to-eat muscle foods: an updated review.

    Science.gov (United States)

    Jiang, Jiang; Xiong, Youling L

    2015-01-01

    Ready-to-eat (RTE) muscle foods refer to a general category of meat and poultry products that are fully cooked and consumable without reheating. These products, including whole and sliced pork, beef, turkey, chicken, and variety of meats, in the forms of ham, roast, rolls, sausage, and frankfurter, are widely available in the delicatessen section of retail stores or various food service outlets. However, difficulties in avoidance of contamination by foodborne pathogens, notably Listeria monocytogenes, during product postlethality repackaging render RTE meats labile to outbreaks. Accordingly, the USDA-FSIS has established processing guidelines and regulations, which are constantly updated, to minimize foodborne pathogens in RTE products. Technologies that complement good manufacturing practice have been developed to control RTE meat safety. Among them, various antimicrobial product formulations, postpackaging pasteurization (thermal and nonthermal), and antimicrobial packaging are being used. Through these efforts, outbreaks linked to RTE meat consumption have substantially reduced in recent years. However, the pervasive and virulent nature of L. monocytogenes and the possible presence of other cold-tolerant pathogens entail continuing developments of new intervention technologies. This review updates existing and emerging physical and chemical methods and their mode of action to inactivate or inhibit threatening microorganisms in RTE muscle foods.

  8. Mechanical design of injection line for VEC

    International Nuclear Information System (INIS)

    Nandi, C.; Bandopadhyay, D.K.; Pal, G.; Sharma, R.N.; Mallik, C.; Chaudhuri, J.; Bhandari, R.K.

    2003-01-01

    A 14.5 GHz ECR ion source along with its analyzing section was earlier installed at VECC for injecting multiply charged gaseous and metallic ions into the existing K 130 cyclotron. The injection line from this ECR ion source was connected to the vertical section of the existing injection line for integrating it with the K 130 cyclotron. The injection line comprises two solenoid magnets, a steering magnet, and a bending magnet. In between the solenoid magnets a length about 1.5 metres has been provided for future atomic physics experimental applications. Two gate valves are used to isolate this area. For beam diagnostics, two Faraday cups, designed and fabricated in this centre, have been installed

  9. Mechanical Design of the LSST Camera

    Energy Technology Data Exchange (ETDEWEB)

    Nordby, Martin; Bowden, Gordon; Foss, Mike; Guiffre, Gary; /SLAC; Ku, John; /Unlisted; Schindler, Rafe; /SLAC

    2008-06-13

    The LSST camera is a tightly packaged, hermetically-sealed system that is cantilevered into the main beam of the LSST telescope. It is comprised of three refractive lenses, on-board storage for five large filters, a high-precision shutter, and a cryostat that houses the 3.2 giga-pixel CCD focal plane along with its support electronics. The physically large optics and focal plane demand large structural elements to support them, but the overall size of the camera and its components must be minimized to reduce impact on the image stability. Also, focal plane and optics motions must be minimized to reduce systematic errors in image reconstruction. Design and analysis for the camera body and cryostat will be detailed.

  10. Quantum-mechanical designed terahertz laser

    International Nuclear Information System (INIS)

    Benz, A.; Fasching, G.; Unterrainer, K.; Zobl, R.; Andrews, M.A.; Roch, T.; Schrenk, W.; Strasser, G.

    2005-01-01

    Full text: The terahertz-frequency region (1 THz=10 12 Hz) lies between RF-electronics and the photonics. Due to the large demand of coherent sources in this spectral range for applications liKEX medical imaging, chemical sensing and security applications large effort is put into the development of the THz-technology to close the THz-gap. The RF-electronics is able to generate frequencies up to around 0.1 THz, limited by the RC-time-constant of the system. The photonics on the other hand generates frequencies down to around 100 THz, defined by the bandgap of the used semiconducting material. Changing the wavelength requires the selection of a new material or of a new material composition. A new concept for coherent light sources is the quantum cascade laser (QCL), which was developed for the mid-infrared spectral region. The major advantage of the QCL-structure is the possibility to design the emission wavelength by band structure engineering. The wavelength is defined by the energy difference of quantized states in the conduction band. Here, we present a QCL working in the THz spectral region at 3 THz. The design is based on optical transitions between subbands of an AlGaAs/GaAs heterostructure. The thickness of the GaAs and AlGaAs layers were calculated to obtain quantized transitions at the desired THz-frequency. The wavefunctions were optimized to achieve the largest possible matrix element. 271 cascades were grown by molecular beam epitaxy to increase the optical gain and to achieve a waveguide thickness comparable to the THz-wavelength. We report lasing from conventional ridge waveguide and microcavity devices. (author)

  11. Agricultural robot designed for seeding mechanism

    Science.gov (United States)

    Sunitha, K. A., Dr.; Suraj, G. S. G. S.; Sowrya, CH P. N.; Atchyut Sriram, G.; Shreyas, D.; Srinivas, T.

    2017-05-01

    In the field of agriculture, plantation begins with ploughing the land and sowing seeds. The old traditional method plough attached to an OX and tractors needs human involvement to carry the process. The driving force behind this work is to reduce the human interference in the field of agriculture and to make it cost effective. In this work, apart of the land is taken into consideration and the robot introduced localizes the path and can navigate itself without human action. For ploughing, this robot is provided with tentacles attached with saw blades. The sowing mechanism initiates with long toothed gears actuated with motors. The complete body is divided into two parts the tail part acts as a container for seeds. The successor holds on all the electronics used for automating and actuation. The locomotion is provided with wheels covered under conveyor belts. Gears at the back of the robot rotate in equal speed with respect to each other with the saw blades. For each rotation every tooth on gear will take seeds and will drop them on field. Camera at the front end tracks the path for every fixed distance and at the minimum distance it takes the path pre-programmed.

  12. NASA GSFC Mechanical Engineering Latest Inputs for Verification Standards (GEVS) Updates

    Science.gov (United States)

    Kaufman, Daniel

    2003-01-01

    This viewgraph presentation provides information on quality control standards in mechanical engineering. The presentation addresses safety, structural loads, nonmetallic composite structural elements, bonded structural joints, externally induced shock, random vibration, acoustic tests, and mechanical function.

  13. Integrating Thermal Tools Into the Mechanical Design Process

    Science.gov (United States)

    Tsuyuki, Glenn T.; Siebes, Georg; Novak, Keith S.; Kinsella, Gary M.

    1999-01-01

    The intent of mechanical design is to deliver a hardware product that meets or exceeds customer expectations, while reducing cycle time and cost. To this end, an integrated mechanical design process enables the idea of parallel development (concurrent engineering). This represents a shift from the traditional mechanical design process. With such a concurrent process, there are significant issues that have to be identified and addressed before re-engineering the mechanical design process to facilitate concurrent engineering. These issues also assist in the integration and re-engineering of the thermal design sub-process since it resides within the entire mechanical design process. With these issues in mind, a thermal design sub-process can be re-defined in a manner that has a higher probability of acceptance, thus enabling an integrated mechanical design process. However, the actual implementation is not always problem-free. Experience in applying the thermal design sub-process to actual situations provides the evidence for improvement, but more importantly, for judging the viability and feasibility of the sub-process.

  14. Application of green concept in mechanical design and manufacture

    Science.gov (United States)

    Liu, Xing ping

    2017-11-01

    With the development of productive forces, the relationship between human and nature is becoming tight increasingly, especially environmental pollution and resource consumption that comes from equipment manufacturing industry mainly. Green development concept is a new concept which can solve the current ecological environment. The philosophical foundation and theoretical basis of green idea are expounded through the study of scientific development and green concept. The difference between the traditional design and the green design is analyzed; the meaning and content of the mechanical design for green concept are discussed. And the evaluation method of green design is discussed too. The significance of green development concept in the mechanical design and manufacturing science is pinpointed clearly. The results show that the implementation of green design under the mechanical design, from the source of pollution control to achieve green manufacturing, is the only way to achieve sustainable development.

  15. Mechanical Design of an Alternate Structure for LARP Nb$_{3}$Sn Quadrupole Magnets for LHC

    CERN Document Server

    Anerella, M; Kovach, P; Schmalzle, J; Wanderer, P; Ambrosio, G; Lamm, M J; Caspi, S; Felice, H; Ferracin, P; Sabbi, G L

    2011-01-01

    An alternative structure for the 120 mm Nb$_{3}$Sn quadrupole magnet is presently under development for use in the upgrade for LHC at CERN. The design aims to build existing technology developed in LARP with the LQ and HQ magnets and to further optimize the features required for operation in the accelerator. The structure includes features for maintaining mechanical alignment of the coils to achieve the required field quality. It also includes a helium containment vessel and provisions for cooling with 1.9 K helium. The development effort includes the assembly of a six inch model to verify required coil load is achieved. Status of the R&D effort and an update on the magnet design, including its incorporation into the design of a complete one meter cold mass is presented.

  16. Quality and rules for mechanical aspects of tangible interaction design

    NARCIS (Netherlands)

    Broekhuijsen, M.J.; Delbressine, F.L.M.; Feijs, L.M.G.

    2011-01-01

    This paper describes the application of Exact Kinematic Constraint Design to designs meant for tangible interaction with users. The paper gives rules for generating high quality mechanical designs for tangible interactions. Each rule is explained using examples made in LEGO and real world examples.

  17. Mechanical Design of Metal Dome for Industrial Application

    Science.gov (United States)

    Jin-Chee Liu, Thomas; Chen, Li-Wei; Lin, Nai-Pin

    2018-02-01

    In this paper, the mechanical design of metal domes is studied using finite element analysis. The snap-through behavior of a practical button design that uses a metal dome is found. In addition, the individual click ratio and maximum force for a variety of metal domes are determined. This paper provides guidance on button design for industrial engineers.

  18. Preliminary Opto-Mechanical Design for the X2000 Transceiver

    Science.gov (United States)

    Hemmati, H.; Page, N. A.

    2000-01-01

    Preliminary optical design and mechanical conceptual design for a 30 cm aperture transceiver are described. A common aperture is used for both transmit and receive. Special attention was given to off-axis and scattered light rejection and isolation of the receive channel from the transmit channel. Requirements, details of the design and preliminary performance analysis of the transceiver are provided.

  19. Electromagnetic design calculation of the control rod drive mechanism

    International Nuclear Information System (INIS)

    Zhu Qirong; Zhu Jingchang

    1991-01-01

    Electromagnetic design calculation of the step-by-step magnetic jacking control rod drive mechanism includes magnetic field force calculation and design calculation of magnetomotive force for three electromagnetic iron and their coilds. The basic principle and method of electromagnetic design calculation had been expounded to take the lift magnet and lift coil for example

  20. A Proposed Multimedia Cone of Abstraction: Updating a Classic Instructional Design Theory

    Science.gov (United States)

    Baukal, Charles E.; Ausburn, Floyd B.; Ausburn, Lynna J.

    2013-01-01

    Advanced multimedia techniques offer significant learning potential for students. Dale (1946, 1954, 1969) developed a Cone of Experience (CoE) which is a hierarchy of learning experiences ranging from direct participation to abstract symbolic expression. This paper updates the CoE for today's technology and learning context, specifically focused…

  1. Updating polytechnic teachers' knowledge and skills through teacher design teams in Ghana

    NARCIS (Netherlands)

    Bakah, M.A.B.; Voogt, Joke; Pieters, Julius Marie

    2012-01-01

    While teachers and administrators in polytechnics in Ghana have categorically expressed the growing need for the former’s knowledge and skills to be updated in the era of polytechnic transformation, little attention has been paid to the subject. This study reports a professional development

  2. Mechanical Designs for Inorganic Stretchable Circuits in Soft Electronics.

    Science.gov (United States)

    Wang, Shuodao; Huang, Yonggang; Rogers, John A

    2015-09-01

    Mechanical concepts and designs in inorganic circuits for different levels of stretchability are reviewed in this paper, through discussions of the underlying mechanics and material theories, fabrication procedures for the constituent microscale/nanoscale devices, and experimental characterization. All of the designs reported here adopt heterogeneous structures of rigid and brittle inorganic materials on soft and elastic elastomeric substrates, with mechanical design layouts that isolate large deformations to the elastomer, thereby avoiding potentially destructive plastic strains in the brittle materials. The overall stiffnesses of the electronics, their stretchability, and curvilinear shapes can be designed to match the mechanical properties of biological tissues. The result is a class of soft stretchable electronic systems that are compatible with traditional high-performance inorganic semiconductor technologies. These systems afford promising options for applications in portable biomedical and health-monitoring devices. Mechanics theories and modeling play a key role in understanding the underlining physics and optimization of these systems.

  3. The design of disengaging mechanism of radix pseudostellariae and soil

    Science.gov (United States)

    Xiao, Shungen; Song, Mengmeng; Chen, Chanwei

    2017-12-01

    With the continuous development of the scale of the cultivation of the radix pseudostellariae, the traditional separation mode cannot adapt to the mass production of the crown prince, and the existing manual separation mode is of great labor intensity and low degree of mechanization. Therefore, it is necessary to design a disengaging mechanism of radix pseudostellariae and soil on the basis of the design principle of modern agricultural machinery. According to the physical characteristics and growing environment of radix pseudostellariae, a drum-type separating component is presented, and the drum screen separating mechanism and vibration mechanism of the disengaging mechanism are designed. In this paper, the movement rule and time of the mixture of radix pseudostellariae and soil are determined in the drum screen. Rotation speed of the drum screen is calculated, and the operation rules of the eccentric wheel in the vibration mechanism are summarized.

  4. Reliability design of mechanical systems a guide for mechanical and civil engineers

    CERN Document Server

    Woo, Seongwoo

    2017-01-01

    This book describes basic reliability concepts – parametric ALT plan, failure mechanism and design, and reliability testing with acceleration factor and sample size equation. A generalized life-stress failure model with a new effort concept has been derived and recommended to calculate the acceleration factor of the mechanical system. The new sample size equation with the acceleration factor has also been derived to carry out the parametric ALT. This new parametric ALT should help a mechanical/civil engineer to uncover the design parameters affecting reliability during the design process of the mechanical system. Consequently, it should help companies to improve product reliability and avoid recalls due to the product/structure failures in the field. As the improper or missing design parameters in the design phase are experimentally identified by this new reliability design method - parametric ALT, the mechanical/civil engineering system might improve in reliability by the increase in lifetime and the reduc...

  5. Development of mechanical structure design technology for LMR

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Bong; Lee, Jae Han; Joo, Young Sang [and others

    2000-05-01

    In this project, fundamentals for conceptual design of mechanical structure system for LMR are independently established. The research contents are as follow; at first, conceptual design for SSC, design integration of interfaces, design consistency to keep functions and interfaces by developing arrangement of reactor system and 3 dimensional concept drawings, development and revision of preliminary design requirements and structural design basis, and evaluation of structural integrity for SSC following structural design criteria to check the conceptual design to be proper, at second, development of high temperature structure design and analysis technology and establishment of high temperature structural analysis codes and scheme, development of seismic isolation design concept to reduce seismic design loads to SCC and establishment of seismic analysis codes and scheme.

  6. Development of mechanical structure design technology for LMR

    International Nuclear Information System (INIS)

    Yoo, Bong; Lee, Jae Han; Joo, Young Sang

    2000-05-01

    In this project, fundamentals for conceptual design of mechanical structure system for LMR are independently established. The research contents are as follow; at first, conceptual design for SSC, design integration of interfaces, design consistency to keep functions and interfaces by developing arrangement of reactor system and 3 dimensional concept drawings, development and revision of preliminary design requirements and structural design basis, and evaluation of structural integrity for SSC following structural design criteria to check the conceptual design to be proper, at second, development of high temperature structure design and analysis technology and establishment of high temperature structural analysis codes and scheme, development of seismic isolation design concept to reduce seismic design loads to SCC and establishment of seismic analysis codes and scheme

  7. Mechanical design of a power-adjustable spectacle lens frame.

    Science.gov (United States)

    Zapata, Asuncion; Barbero, Sergio

    2011-05-01

    Power-adjustable spectacle lenses, based on the Alvarez-Lohmann principle, can be used to provide affordable spectacles for subjective refractive errors measurement and its correction. A new mechanical frame has been designed to maximize the advantages of this technology. The design includes a mechanism to match the interpupillary distance with that of the optical centers of the lenses. The frame can be manufactured using low cost plastic injection molding techniques. A prototype has been built to test the functioning of this mechanical design.

  8. Mechanical design of a magnetic fusion production reactor

    International Nuclear Information System (INIS)

    Neef, W.S.; Jassby, D.L.

    1986-01-01

    The mechanical aspects of a tandem mirror and tokamak concepts for the tritium production mission are compared, and a proposed breeding blanket configuration for each type of reactor is presented in detail, along with a design outline of the complete fusion reaction system. In both cases, the reactor design is developed sufficiently to permit preliminary cost estimates of all components. A qualitative comparison is drawn between both concepts from the view of mechanical design and serviceability, and suggestions are made for technology proof tests on unique mechanical features. Detailed cost breakdowns indicate less than 10% difference in the overall costs of the two reactors

  9. Basic considerations for the mechanical design of heating reactors

    International Nuclear Information System (INIS)

    Rau, P.

    1997-01-01

    The paper discusses the principal aspects of the mechanical design of the reactor unit for a nuclear district heating plant. It is reasoned that the design must be specifically tailored to the characteristics of the applications, and that the experience gained with the design practice of big nuclear power stations must also be incorporated. Some examples of the design solutions for the SIEMENS NRH-200 are presented for illustration. (author). 7 refs, 10 figs

  10. Basic considerations for the mechanical design of heating reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rau, P [Siemens AG, Unternehmensbereich KWU, Erlangen (Germany)

    1997-09-01

    The paper discusses the principal aspects of the mechanical design of the reactor unit for a nuclear district heating plant. It is reasoned that the design must be specifically tailored to the characteristics of the applications, and that the experience gained with the design practice of big nuclear power stations must also be incorporated. Some examples of the design solutions for the SIEMENS NRH-200 are presented for illustration. (author). 7 refs, 10 figs.

  11. Low-cost satellite mechanical design and construction

    Science.gov (United States)

    Boisjolie-Gair, Nathaniel; Straub, Jeremy

    2017-05-01

    This paper presents a discussion of techniques for low-cost design and construction of a CubeSat mechanical structure that can serve as a basis for academic programs and a starting point for government, military and commercial large-scale sensing networks, where the cost of each node must be minimized to facilitate system affordability and lower the cost and associated risk of losing any node. Spacecraft Design plays a large role in manufacturability. An intentionally simplified mechanical design is presented which reduces machining costs, as compared to more intricate designs that were considered. Several fabrication approaches are evaluated relative to the low-cost goal.

  12. Small-break loss-of-coolant accidents in the updated PIUS 600 advanced reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Boyack, B.E.; Steiner, J.L.; Harmony, S.C. [Los Alamos National Lab., Albuquerque, NM (United States)] [and others

    1995-09-01

    The PIUS advanced reactor is a 640-MWe pressurized water reactor developed by Asea Brown Boveri (ABB). A unique feature of the PIUS concept is the absence of mechanical control and shutdown rods. Reactivity is normally controlled by coolant boron concentration and the temperature of the moderator coolant. ABB submitted the PIUS design to the US Nuclear Regulatory Commission (NRC) for preapplication review, and Los Alamos supported the NRC`s review effort. Baseline analyses of small-break initiators at two locations were performed with the system neutronic and thermal-hydraulic analysis code TRAC-PF1/MOD2. In addition, sensitivity studies were performed to explore the robustness of the PIUS concept to severe off-normal conditions having a very low probability of occurrence.

  13. 6th Conference on Design and Modeling of Mechanical Systems

    CERN Document Server

    Fakhfakh, Tahar; Daly, Hachmi; Aifaoui, Nizar; Chaari, Fakher

    2015-01-01

    This book offers a collection of original peer-reviewed contributions presented at the 6th International Congress on Design and Modeling of Mechanical Systems (CMSM’2015), held in Hammamet, Tunisia, from the 23rd to the 25th of March 2015. It reports on both recent research findings and innovative industrial applications in the fields of mechatronics and robotics, dynamics of mechanical systems, fluid structure interaction and vibroacoustics, modeling and analysis of materials and structures, and design and manufacturing of mechanical systems. Since its first edition in 2005, the CMSM Congress has been held every two years with the aim of bringing together specialists from universities and industry to present the state-of-the-art in research and applications, discuss the most recent findings and exchange and develop expertise in the field of design and modeling of mechanical systems. The CMSM Congress is jointly organized by three Tunisian research laboratories: the Mechanical Engineering Laboratory of th...

  14. Arc plasma devices: Evolving mechanical design from numerical

    Indian Academy of Sciences (India)

    A recipe for obtaining mechanical design of arc plasma devices from numerical ... to the plasma of the mixture of molecular gases like nitrogen and oxygen. ... Temperature field, associated fluid dynamics and electrical characteristics of a ...

  15. Arts and design as translational mechanisms for academic entrepreneurship

    DEFF Research Database (Denmark)

    Simeone, Luca; Secundo, Giustina; Schiuma, Giovanni

    2018-01-01

    This paper proposes arts and design as translational mechanisms to connect and align stakeholders, particularly in the context of academic entrepreneurship where multiple stakeholders with different expertise and interests work together in joint endeavors. Insights gathered from an ethnographic...

  16. The Potential Role of Cache Mechanism for Complicated Design Optimization

    International Nuclear Information System (INIS)

    Noriyasu, Hirokawa; Fujita, Kikuo

    2002-01-01

    This paper discusses the potential role of cache mechanism for complicated design optimization While design optimization is an application of mathematical programming techniques to engineering design problems over numerical computation, its progress has been coevolutionary. The trend in such progress indicates that more complicated applications become the next target of design optimization beyond growth of computational resources. As the progress in the past two decades had required response surface techniques, decomposition techniques, etc., any new framework must be introduced for the future of design optimization methods. This paper proposes a possibility of what we call cache mechanism for mediating the coming challenge and briefly demonstrates some promises in the idea of Voronoi diagram based cumulative approximation as an example of its implementation, development of strict robust design, extension of design optimization for product variety

  17. Robust design of large-displacement compliant mechanisms

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Schevenels, M.; Sigmund, Ole

    2011-01-01

    The aim of this article is to introduce a new topology optimisation formulation for optimal robust design of Micro Electro Mechanical Systems. Mesh independence in topology optimisation is most often ensured by using filtering techniques, which result in transition grey regions difficult to inter...... in nearly black and white mechanism designs, robust with respect to uncertainties in the production process, i.e. without any hinges or small details which can create manufacturing difficulties....

  18. Computations Underlying Social Hierarchy Learning: Distinct Neural Mechanisms for Updating and Representing Self-Relevant Information.

    Science.gov (United States)

    Kumaran, Dharshan; Banino, Andrea; Blundell, Charles; Hassabis, Demis; Dayan, Peter

    2016-12-07

    Knowledge about social hierarchies organizes human behavior, yet we understand little about the underlying computations. Here we show that a Bayesian inference scheme, which tracks the power of individuals, better captures behavioral and neural data compared with a reinforcement learning model inspired by rating systems used in games such as chess. We provide evidence that the medial prefrontal cortex (MPFC) selectively mediates the updating of knowledge about one's own hierarchy, as opposed to that of another individual, a process that underpinned successful performance and involved functional interactions with the amygdala and hippocampus. In contrast, we observed domain-general coding of rank in the amygdala and hippocampus, even when the task did not require it. Our findings reveal the computations underlying a core aspect of social cognition and provide new evidence that self-relevant information may indeed be afforded a unique representational status in the brain. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. A macro-directive mechanism that facilitates automatic updating and processing of the contents of Electronic Healthcare Records: an extension to the CEN architecture.

    Science.gov (United States)

    Deftereos, S; Lambrinoudakis, C; Gritzalis, S; Georgonikou, D; Andriopoulos, P; Aessopos, A

    2003-03-01

    Facilitating data entry, eliminating redundant effort and providing decision support are some of the factors upon which the successful uptake of Electronic Healthcare Record (EHCR) technology is dependent. The European Standardization Committee (CEN), on the other hand, has proposed a standard EHCR architecture, which allows patient record contents to be highly diverse, customized to individual user needs; this makes their processing a challenging task and poses a demand for specially designed mechanisms. We describe the requirements for a macro-directive mechanism, pertaining to CEN-compatible EHCR software that can automate updating and processing of patient records, thus enhancing the functionality of the software. We have implemented the above-mentioned mechanism in an EHCR application that has been customized for use in the care process of patients suffering from beta-Thalassemia. The application is being used during the last two years in the Thalassemia units of four Greek hospitals, as part of their every day practice. We report on the experience we have acquired so far.

  20. Design and Validation of the Quantum Mechanics Conceptual Survey

    Science.gov (United States)

    McKagan, S. B.; Perkins, K. K.; Wieman, C. E.

    2010-01-01

    The Quantum Mechanics Conceptual Survey (QMCS) is a 12-question survey of students' conceptual understanding of quantum mechanics. It is intended to be used to measure the relative effectiveness of different instructional methods in modern physics courses. In this paper, we describe the design and validation of the survey, a process that included…

  1. Review on Molecular Mechanisms of Antifouling Compounds: An Update since 2012.

    Science.gov (United States)

    Chen, Lianguo; Qian, Pei-Yuan

    2017-08-28

    Better understanding of the mechanisms of antifouling compounds is recognized to be of high value in establishing sensitive biomarkers, allowing the targeted optimization of antifouling compounds and guaranteeing environmental safety. Despite vigorous efforts to find new antifouling compounds, information about the mechanisms of antifouling is still scarce. This review summarizes the progress into understanding the molecular mechanisms underlying antifouling activity since 2012. Non-toxic mechanisms aimed at specific targets, including inhibitors of transmembrane transport, quorum sensing inhibitors, neurotransmission blockers, adhesive production/release inhibitors and enzyme/protein inhibitors, are put forward for natural antifouling products or shelf-stable chemicals. Several molecular targets show good potential for use as biomarkers in future mechanistic screening, such as acetylcholine esterase for neurotransmission, phenoloxidase/tyrosinase for the formation of adhesive plaques, N -acyl homoserine lactone for quorum sensing and intracellular Ca 2+ levels as second messenger. The studies on overall responses to challenges by antifoulants can be categorized as general targets, including protein expression/metabolic activity regulators, oxidative stress inducers, neurotransmission blockers, surface modifiers, biofilm inhibitors, adhesive production/release inhibitors and toxic killing. Given the current situation and the knowledge gaps regarding the development of alternative antifoulants, a basic workflow is proposed that covers the indispensable steps, including preliminary mechanism- or bioassay-guided screening, evaluation of environmental risks, field antifouling performance, clarification of antifouling mechanisms and the establishment of sensitive biomarkers, which are combined to construct a positive feedback loop.

  2. Research Update: Mechanical properties of metal-organic frameworks – Influence of structure and chemical bonding

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-12-01

    Full Text Available Metal-organic frameworks (MOFs, a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  3. Research Update: Mechanical properties of metal-organic frameworks - Influence of structure and chemical bonding

    Science.gov (United States)

    Li, Wei; Henke, Sebastian; Cheetham, Anthony K.

    2014-12-01

    Metal-organic frameworks (MOFs), a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  4. Design and manufacturing of mechanical steering system for ...

    African Journals Online (AJOL)

    Design and manufacturing of mechanical steering system for parallel parking, zero turning radius, minimum turning radius with traditional turning. ... of the steering system are designed so as to meet all the configuration of steering system and to be well-matched to the power train, suspension system and body of the car.

  5. Mechanical design of NASA Ames Research Center vertical motion simulator

    Science.gov (United States)

    Engelbert, D. F.; Bakke, A. P.; Chargin, M. K.; Vallotton, W. C.

    1976-01-01

    NASA has designed and is constructing a new flight simulator with large vertical travel. Several aspects of the mechanical design of this Vertical Motion Simulator (VMS) are discussed, including the multiple rack and pinion vertical drive, a pneumatic equilibration system, and the friction-damped rigid link catenaries used as cable supports.

  6. Updated TRAC analysis of an 80% double-ended cold-leg break for the AP600 design

    International Nuclear Information System (INIS)

    Lime, J.F.; Boyack, B.E.

    1995-01-01

    An updated TRAC 80% large-break loss-of-coolant accident (LBLOCA) has been calculated for the Westinghouse AP600 advanced reactor design, The updated calculation incorporates major code error corrections, model corrections, and plant design changes. The 80% break size was calculated by Westinghouse to be the most severe large-break size for the AP600 design. The LBLOCA transient was calculated to 144 s. Peak cladding temperatures (PCTS) were well below the Appendix K limit of 1,478 K (2,200 F), but very near the cladding oxidation temperature of 1,200 K (1,700 F). Transient event times and PCT for the TRAC calculation were in reasonable agreement with those calculated by Westinghouse using their WCOBRA/TRAC code. However, there were significant differences in the detailed phenomena calculated by the two codes, particularly during the blowdown phase. The reasons for these differences are still being investigated. Additional break sizes and break locations need to be analyzed to confirm the most severe break postulated by Westinghouse

  7. Mechanical design features and challenges for the ITER ICRH antenna

    Energy Technology Data Exchange (ETDEWEB)

    Borthwick, A. [UKAEA/Euratom Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)], E-mail: andy.borthwick@yahoo.co.uk; Agarici, G. [Fusion for Energy, Barcelona (Spain); Davis, A. [UKAEA/Euratom Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Dumortier, P.; Durodie, F. [LPP-ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Fanthome, J.; Hamlyn-Harris, C.; Hancock, A.D.; Lockley, D. [UKAEA/Euratom Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Mitteau, R. [Euratom-CEA Association, DSM/IRFM, CEA-Cadarache, 13108 St Paul lez Durance (France); Nightingale, M. [UKAEA/Euratom Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Sartori, R. [Fusion for Energy, Barcelona (Spain); Vulliez, K. [Euratom-CEA Association, DSM/IRFM, CEA-Cadarache, 13108 St Paul lez Durance (France)

    2009-06-15

    The ITER Ion Cyclotron Resonant Heating (ICRH) antenna provides plasma heating at a power of 20 MW. Operation in the ITER environment imposes significant thermal power handling capability, structural integrity, shielding and operations requirements. The design will require a step change over any predecessor in terms of power, scale and complexity. This paper reports the main mechanical design features that address the challenges and often conflicting requirements during the conceptual design phase.

  8. Mechanical Design and Fabrication Studies for SPL Superconducting RF Cavities

    CERN Document Server

    Atieh, S; Aviles Santillana, I; Capatina, O; Renaglia, T; Tardy, T; Valverde Alonso, N; Weingarten, W

    2011-01-01

    CERN’s R&D programme on the Superconducting Proton Linac’s (SPL) superconducting radio frequency (SRF) elliptical cavities made from niobium sheets explores new mechanical design and consequently new fabrication methods, where several opportunities for improved optimization were identified. A stainless steel helium vessel is under design rather than a titanium helium vessel using an integrated brazed transition between Nb and the SS helium vessel. Different design and fabrication aspects were proposed and the results are discussed hereafter.

  9. Process Improvement Through Tool Integration in Aero-Mechanical Design

    Science.gov (United States)

    Briggs, Clark

    2010-01-01

    Emerging capabilities in commercial design tools promise to significantly improve the multi-disciplinary and inter-disciplinary design and analysis coverage for aerospace mechanical engineers. This paper explores the analysis process for two example problems of a wing and flap mechanical drive system and an aircraft landing gear door panel. The examples begin with the design solid models and include various analysis disciplines such as structural stress and aerodynamic loads. Analytical methods include CFD, multi-body dynamics with flexible bodies and structural analysis. Elements of analysis data management, data visualization and collaboration are also included.

  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. Light water reactors fuel assembly mechanical design and evaluation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This standard establishes a procedure for performing an evaluation of the mechanical design of fuel assemblies for light water-cooled commercial power reactors. It does not address the various aspects of neutronic or thermalhydraulic performance except where these factors impose loads or constraints on the mechanical design of the fuel assemblies. This standard also includes a set of specific requirements for design, various potential performance problems and criteria aimed specifically at averting them. This standard replaces ANSI/ANS-57.5-1978

  12. Stress-constrained topology optimization for compliant mechanism design

    DEFF Research Database (Denmark)

    de Leon, Daniel M.; Alexandersen, Joe; Jun, Jun S.

    2015-01-01

    This article presents an application of stress-constrained topology optimization to compliant mechanism design. An output displacement maximization formulation is used, together with the SIMP approach and a projection method to ensure convergence to nearly discrete designs. The maximum stress...... is approximated using a normalized version of the commonly-used p-norm of the effective von Mises stresses. The usual problems associated with topology optimization for compliant mechanism design: one-node and/or intermediate density hinges are alleviated by the stress constraint. However, it is also shown...

  13. Bone biopsy needles. Mechanical properties, needle design and specimen quality

    International Nuclear Information System (INIS)

    Keulers, Annika; Penzkofer, T.; Cunha-Cruz, V.C.; Bruners, P.; Helmholtz Inst. fuer biomedizinische Technik, Aachen; Braunschweig, T.; Schmitz-Rode, T.; Mahnken, A.; Helmholtz Inst. fuer biomedizinische Technik, Aachen

    2011-01-01

    To quantitatively analyze differences in mechanical properties, needle design including signs of wear, subjective handling and specimen quality of bone biopsy needles. Materials and Methods: In this study 19 different bone biopsy systems (total 38; 2 /type) were examined. With each biopsy needle five consecutive samples were obtained from vertebral bodies of swine. During puncture a force-torques sensor measured the mechanical properties and subjective handling was assessed. Before and after each biopsy the needles were investigated using a profile projector and signs of wear were recorded. Afterwards, a pathologist semi-quantitatively examined the specimen regarding sample quality. The overall evaluation considered mechanical properties, needle wear, subjective handling and sample quality. Differences were assessed for statistical significance using ANOVA and t-test. Results: Needle diameter (p = 0.003) as well as needle design (p = 0.008) affect the mechanical properties significantly. Franseen design is significantly superior to other needle designs. Besides, length reduction recorded by the profile projector, as a quality criterion showed notable distinctions in between the needle designs. Conclusion: Bone biopsy needles vary significantly in performance. Needle design has an important influence on mechanical properties, handling and specimen quality. Detailed knowledge of those parameters would improve selecting the appropriate bone biopsy needle. (orig.)

  14. The Process of Optimizing Mechanical Sound Quality in Product Design

    DEFF Research Database (Denmark)

    Eriksen, Kaare; Holst, Thomas

    2011-01-01

    The research field concerning optimizing product sound quality is a relatively unexplored area, and may become difficult for designers to operate in. To some degree, sound is a highly subjective parameter, which is normally targeted sound specialists. This paper describes the theoretical...... and practical background for managing a process of optimizing the mechanical sound quality in a product design by using simple tools and workshops systematically. The procedure is illustrated by a case study of a computer navigation tool (computer mouse or mouse). The process is divided into 4 phases, which...... clarify the importance of product sound, defining perceptive demands identified by users, and, finally, how to suggest mechanical principles for modification of an existing sound design. The optimized mechanical sound design is followed by tests on users of the product in its use context. The result...

  15. Rationally designed synthetic protein hydrogels with predictable mechanical properties.

    Science.gov (United States)

    Wu, Junhua; Li, Pengfei; Dong, Chenling; Jiang, Heting; Bin Xue; Gao, Xiang; Qin, Meng; Wang, Wei; Bin Chen; Cao, Yi

    2018-02-12

    Designing synthetic protein hydrogels with tailored mechanical properties similar to naturally occurring tissues is an eternal pursuit in tissue engineering and stem cell and cancer research. However, it remains challenging to correlate the mechanical properties of protein hydrogels with the nanomechanics of individual building blocks. Here we use single-molecule force spectroscopy, protein engineering and theoretical modeling to prove that the mechanical properties of protein hydrogels are predictable based on the mechanical hierarchy of the cross-linkers and the load-bearing modules at the molecular level. These findings provide a framework for rationally designing protein hydrogels with independently tunable elasticity, extensibility, toughness and self-healing. Using this principle, we demonstrate the engineering of self-healable muscle-mimicking hydrogels that can significantly dissipate energy through protein unfolding. We expect that this principle can be generalized for the construction of protein hydrogels with customized mechanical properties for biomedical applications.

  16. The Components of Smile Design: New York University Smile Evaluation Form Revisited, Update 2015.

    Science.gov (United States)

    Calamia, John R; Wolff, Mark S

    2015-07-01

    This article updates a simple checklist of foundational knowledge in aesthetic dental concepts that allows clinicians to organize their thoughts, to record the concerns of the patient, and to map out those improvements that must be addressed. This adjunct is called a Smile Evaluation Form. Along with other adjuncts such as radiographs, study casts, and diagnostic wax-ups, the Smile Evaluation Form allows clinicians to form a conceptual visualization of the expected end point. It provides a checklist for discussions with other disciplines in the team, to provide a logical sequence of treatment with a mutually agreed-on end point. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Up-date on neuro-immune mechanisms involved in allergic and non-allergic rhinitis

    NARCIS (Netherlands)

    van Gerven, L.; Boeckxstaens, G.; Hellings, P.

    2012-01-01

    Non-allergic rhinitis (NAR) is a common disorder, which can be defined as chronic nasal inflammation, independent of systemic IgE-mediated mechanisms. Symptoms of NAR patients mimic those of allergic rhinitis (AR) patients. However, AR patients can easily be diagnosed with skin prick test or

  18. Heterogeneous update mechanisms in evolutionary games: Mixing innovative and imitative dynamics

    Science.gov (United States)

    Amaral, Marco Antonio; Javarone, Marco Alberto

    2018-04-01

    Innovation and evolution are two processes of paramount relevance for social and biological systems. In general, the former allows the introduction of elements of novelty, while the latter is responsible for the motion of a system in its phase space. Often, these processes are strongly related, since an innovation can trigger the evolution, and the latter can provide the optimal conditions for the emergence of innovations. Both processes can be studied by using the framework of evolutionary game theory, where evolution constitutes an intrinsic mechanism. At the same time, the concept of innovation requires an opportune mathematical representation. Notably, innovation can be modeled as a strategy, or it can constitute the underlying mechanism that allows agents to change strategy. Here, we analyze the second case, investigating the behavior of a heterogeneous population, composed of imitative and innovative agents. Imitative agents change strategy only by imitating that of their neighbors, whereas innovative ones change strategy without the need for a copying source. The proposed model is analyzed by means of analytical calculations and numerical simulations in different topologies. Remarkably, results indicate that the mixing of mechanisms can be detrimental to cooperation near phase transitions. In those regions, the spatial reciprocity from imitative mechanisms is destroyed by innovative agents, leading to the downfall of cooperation. Our investigation sheds some light on the complex dynamics emerging from the heterogeneity of strategy revision methods, highlighting the role of innovation in evolutionary games.

  19. Decentralized Consistent Network Updates in SDN with ez-Segway

    KAUST Repository

    Nguyen, Thanh Dang; Chiesa, Marco; Canini, Marco

    2017-01-01

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and black-holes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes

  20. Metal complexes in cancer therapy – an update from drug design perspective

    Directory of Open Access Journals (Sweden)

    Ndagi U

    2017-03-01

    Full Text Available Umar Ndagi, Ndumiso Mhlongo, Mahmoud E Soliman Molecular Modelling and Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal, Westville, Durban, South Africa Abstract: In the past, metal-based compounds were widely used in the treatment of disease conditions, but the lack of clear distinction between the therapeutic and toxic doses was a major challenge. With the discovery of cisplatin by Barnett Rosenberg in 1960, a milestone in the history of metal-based compounds used in the treatment of cancers was witnessed. This forms the foundation for the modern era of the metal-based anticancer drugs. Platinum drugs, such as cisplatin, carboplatin and oxaliplatin, are the mainstay of the metal-based compounds in the treatment of cancer, but the delay in the therapeutic accomplishment of other metal-based compounds hampered the progress of research in this field. Recently, however, there has been an upsurge of activities relying on the structural information, aimed at improving and developing other forms of metal-based compounds and nonclassical platinum complexes whose mechanism of action is distinct from known drugs such as cisplatin. In line with this, many more metal-based compounds have been synthesized by redesigning the existing chemical structure through ligand substitution or building the entire new compound with enhanced safety and cytotoxic profile. However, because of increased emphasis on the clinical relevance of metal-based complexes, a few of these drugs are currently on clinical trial and many more are awaiting ethical approval to join the trial. In this review, we seek to give an overview of previous reviews on the cytotoxic effect of metal-based complexes while focusing more on newly designed metal-based complexes and their cytotoxic effect on the cancer cell lines, as well as on new approach to metal-based drug design and molecular target in cancer therapy. We are optimistic that the concept of selective

  1. Mechanical design of a high field common coil magnet

    CERN Document Server

    Caspi, S; Dietderich, D R; Gourlay, S A; Gupta, R; McInturff, A; Millos, G; Scanlan, R M

    1999-01-01

    A common coil design for high field 2-in-1 accelerator magnets has been previously presented as a "conductor-friendly" option for high field magnets applicable for a Very Large Hadron Collider. This paper presents the mechanical design for a 14 tesla 2-in-1 dipole based on the common coil design approach. The magnet will use a high current density Nb/sub 3/Sn conductor. The design addresses mechanical issues particular to the common coil geometry: horizontal support against coil edges, vertical preload on coil faces, end loading and support, and coil stresses and strains. The magnet is the second in a series of racetrack coil magnets that will provide experimental verification of the common coil design approach. (9 refs).

  2. Integrating rock mechanics issues with repository design through design process principles and methodology

    International Nuclear Information System (INIS)

    Bieniawski, Z.T.

    1996-01-01

    A good designer needs not only knowledge for designing (technical know-how that is used to generate alternative design solutions) but also must have knowledge about designing (appropriate principles and systematic methodology to follow). Concepts such as open-quotes design for manufactureclose quotes or open-quotes concurrent engineeringclose quotes are widely used in the industry. In the field of rock engineering, only limited attention has been paid to the design process because design of structures in rock masses presents unique challenges to the designers as a result of the uncertainties inherent in characterization of geologic media. However, a stage has now been reached where we are be able to sufficiently characterize rock masses for engineering purposes and identify the rock mechanics issues involved but are still lacking engineering design principles and methodology to maximize our design performance. This paper discusses the principles and methodology of the engineering design process directed to integrating site characterization activities with design, construction and performance of an underground repository. Using the latest information from the Yucca Mountain Project on geology, rock mechanics and starter tunnel design, the current lack of integration is pointed out and it is shown how rock mechanics issues can be effectively interwoven with repository design through a systematic design process methodology leading to improved repository performance. In essence, the design process is seen as the use of design principles within an integrating design methodology, leading to innovative problem solving. In particular, a new concept of open-quotes Design for Constructibility and Performanceclose quotes is introduced. This is discussed with respect to ten rock mechanics issues identified for repository design and performance

  3. Design and analysis of shutdown mechanisms of PFBR

    International Nuclear Information System (INIS)

    Vijayashree, R.; Rajan Babu, V.; Puthiyavinayagam, P.; Chellapandi, P.; Chetal, S.C.

    2009-01-01

    Prototype Fast Breeder Reactor (PFBR) is equipped with two independent, fast acting and diverse shutdown systems. The absorber rod of the first system is called Control and Safety Rod (CSR) and that of the second system is called Diverse Safety Rod (DSR). The respective drive mechanisms are called Control and Safety Rod Drive Mechanism (CSRDM) and Diverse Safety Rod Drive Mechanism (DSRDM). The conceptual features of the Absorber Rods (ARs) and Absorber Rod Drive Mechanisms (ARDMs) are given in the figures. The functions and design specifications of the ARDMs are listed. The theoretical results of the performance of the shutdown systems during scram are presented. The design was always backed up with testing and design validation. The individual subassemblies testing and the design have proceeded side by side, the efforts finally culminated into the manufacturing of 1:1 scale prototype ARDMs and ARs. The prototypes were extensively tested in air, water and sodium to qualify them for reactor application. A companion paper in this conference gives the details of design validation by testing. This paper gives a brief account of the design of ARDMs and ARs. (author)

  4. Multiaxial pedicle screw designs: static and dynamic mechanical testing.

    Science.gov (United States)

    Stanford, Ralph Edward; Loefler, Andreas Herman; Stanford, Philip Mark; Walsh, William R

    2004-02-15

    Randomized investigation of multiaxial pedicle screw mechanical properties. Measure static yield and ultimate strengths, yield stiffness, and fatigue resistance according to an established model. Compare these measured properties with expected loads in vivo. Multiaxial pedicle screws provide surgical versatility, but the complexity of their design may reduce their strength and fatigue resistance. There is no published data on the mechanical properties of such screws. Screws were assembled according to a vertebrectomy model for destructive mechanical testing. Groups of five assemblies were tested in static tension and compression and subject to three cyclical loads. Modes of failure, yield, and ultimate strength, yield stiffness, and cycles to failure were determined for six designs of screw. Static compression yield loads ranged from 217.1 to 388.0 N and yield stiffness from 23.7 to 38.0 N/mm. Cycles to failure ranged from 42 x 10(3) to 4,719 x 10(3) at 75% of static ultimate load. There were significant differences between designs in all modes of testing. Failure occurred at the multiaxial link in static and cyclical compression. Bending yield strengths just exceeded loads expected in vivo. Multiaxial designs had lower static bending yield strength than fixed screw designs. Five out of six multiaxial screw designs achieved one million cycles at 200 N in compression bending. "Ball-in-cup" multiaxial locking mechanisms were vulnerable to fatigue failure. Smooth surfaces and thicker material appeared to be protective against fatigue failure.

  5. Parametric Design and Mechanical Analysis of Beams based on SINOVATION

    Science.gov (United States)

    Xu, Z. G.; Shen, W. D.; Yang, D. Y.; Liu, W. M.

    2017-07-01

    In engineering practice, engineer needs to carry out complicated calculation when the loads on the beam are complex. The processes of analysis and calculation take a lot of time and the results are unreliable. So VS2005 and ADK are used to develop a software for beams design based on the 3D CAD software SINOVATION with C ++ programming language. The software can realize the mechanical analysis and parameterized design of various types of beams and output the report of design in HTML format. Efficiency and reliability of design of beams are improved.

  6. Optical telescope refocussing mechanism concept design on remote sensing satellite

    Science.gov (United States)

    Kuo, Jen-Chueh; Ling, Jer

    2017-09-01

    The optical telescope system in remote sensing satellite must be precisely aligned to obtain high quality images during its mission life. In practical, because the telescope mirrors could be misaligned due to launch loads, thermal distortion on supporting structures or hygroscopic distortion effect in some composite materials, the optical telescope system is often equipped with refocussing mechanism to re-align the optical elements while optical element positions are out of range during image acquisition. This paper is to introduce satellite Refocussing mechanism function model design development process and the engineering models. The design concept of the refocussing mechanism can be applied on either cassegrain type telescope or korsch type telescope, and the refocussing mechanism is located at the rear of the secondary mirror in this paper. The purpose to put the refocussing mechanism on the secondary mirror is due to its higher sensitivity on MTF degradation than other optical elements. There are two types of refocussing mechanism model to be introduced: linear type model and rotation type model. For the linear refocussing mechanism function model, the model is composed of ceramic piezoelectric linear step motor, optical rule as well as controller. The secondary mirror is designed to be precisely moved in telescope despace direction through refocussing mechanism. For the rotation refocussing mechanism function model, the model is assembled with two ceramic piezoelectric rotational motors around two orthogonal directions in order to adjust the secondary mirror attitude in tilt angle and yaw angle. From the validation test results, the linear type refocussing mechanism function model can be operated to adjust the secondary mirror position with minimum 500 nm resolution with close loop control. For the rotation type model, the attitude angle of the secondary mirror can be adjusted with the minimum 6 sec of arc resolution and 5°/sec of angle velocity.

  7. An update on potential molecular mechanisms underlying the actions of snake venom L-amino acid oxidases (LAAOs).

    Science.gov (United States)

    Paloschi, Mauro Valentino; Pontes, Adriana Silva; Soares, Andreimar Martins; Zuliani, Juliana Pavan

    2017-11-08

    LAAOs (EC 1.4.3.2) are found in concentrations that vary according to each species of snakes; Viperidae, Crotalidae and Elapidae contain 1-9% of this enzyme in their venoms. This review focuses on an update on molecular mechanisms, platelet activities, antimicrobial, antiprotozoal, induction of apoptosis and inflammatory potential underlying the actions of SV-LAAOs. Snake venom LAAOs (SV-LAAOs) have become an interesting subject for pharmacological, structural and molecular studies. Although the mechanisms of action of these enzymes are not well understood they are a subject of a variety of studies, because LAAOs are multifunctional enzymes exhibiting a wide range of pharmacological effects, including the inhibition or induction of platelet aggregation, hemolysis and hemorrhage, in addition to the stimulation of apoptosis, the activation of leukocytes and the formation of edema. Moreover, SV-LAAOs play an important role in bactericidal, cytotoxic, anti-parasitic, anti-tumor, and antiviral activities. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Pathogenesis of myasthenia gravis: update on disease types, models, and mechanisms

    Science.gov (United States)

    Phillips, William D.; Vincent, Angela

    2016-01-01

    Myasthenia gravis is an autoimmune disease of the neuromuscular junction (NMJ) caused by antibodies that attack components of the postsynaptic membrane, impair neuromuscular transmission, and lead to weakness and fatigue of skeletal muscle. This can be generalised or localised to certain muscle groups, and involvement of the bulbar and respiratory muscles can be life threatening. The pathogenesis of myasthenia gravis depends upon the target and isotype of the autoantibodies. Most cases are caused by immunoglobulin (Ig)G1 and IgG3 antibodies to the acetylcholine receptor (AChR). They produce complement-mediated damage and increase the rate of AChR turnover, both mechanisms causing loss of AChR from the postsynaptic membrane. The thymus gland is involved in many patients, and there are experimental and genetic approaches to understand the failure of immune tolerance to the AChR. In a proportion of those patients without AChR antibodies, antibodies to muscle-specific kinase (MuSK), or related proteins such as agrin and low-density lipoprotein receptor-related protein 4 (LRP4), are present. MuSK antibodies are predominantly IgG4 and cause disassembly of the neuromuscular junction by disrupting the physiological function of MuSK in synapse maintenance and adaptation. Here we discuss how knowledge of neuromuscular junction structure and function has fed into understanding the mechanisms of AChR and MuSK antibodies. Myasthenia gravis remains a paradigm for autoantibody-mediated conditions and these observations show how much there is still to learn about synaptic function and pathological mechanisms. PMID:27408701

  9. Pathogenesis of myasthenia gravis: update on disease types, models, and mechanisms.

    Science.gov (United States)

    Phillips, William D; Vincent, Angela

    2016-01-01

    Myasthenia gravis is an autoimmune disease of the neuromuscular junction (NMJ) caused by antibodies that attack components of the postsynaptic membrane, impair neuromuscular transmission, and lead to weakness and fatigue of skeletal muscle. This can be generalised or localised to certain muscle groups, and involvement of the bulbar and respiratory muscles can be life threatening. The pathogenesis of myasthenia gravis depends upon the target and isotype of the autoantibodies. Most cases are caused by immunoglobulin (Ig)G1 and IgG3 antibodies to the acetylcholine receptor (AChR). They produce complement-mediated damage and increase the rate of AChR turnover, both mechanisms causing loss of AChR from the postsynaptic membrane. The thymus gland is involved in many patients, and there are experimental and genetic approaches to understand the failure of immune tolerance to the AChR. In a proportion of those patients without AChR antibodies, antibodies to muscle-specific kinase (MuSK), or related proteins such as agrin and low-density lipoprotein receptor-related protein 4 (LRP4), are present. MuSK antibodies are predominantly IgG4 and cause disassembly of the neuromuscular junction by disrupting the physiological function of MuSK in synapse maintenance and adaptation. Here we discuss how knowledge of neuromuscular junction structure and function has fed into understanding the mechanisms of AChR and MuSK antibodies. Myasthenia gravis remains a paradigm for autoantibody-mediated conditions and these observations show how much there is still to learn about synaptic function and pathological mechanisms.

  10. Pathogenesis of myasthenia gravis: update on disease types, models, and mechanisms [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    William D. Phillips

    2016-06-01

    Full Text Available Myasthenia gravis is an autoimmune disease of the neuromuscular junction (NMJ caused by antibodies that attack components of the postsynaptic membrane, impair neuromuscular transmission, and lead to weakness and fatigue of skeletal muscle. This can be generalised or localised to certain muscle groups, and involvement of the bulbar and respiratory muscles can be life threatening. The pathogenesis of myasthenia gravis depends upon the target and isotype of the autoantibodies. Most cases are caused by immunoglobulin (IgG1 and IgG3 antibodies to the acetylcholine receptor (AChR. They produce complement-mediated damage and increase the rate of AChR turnover, both mechanisms causing loss of AChR from the postsynaptic membrane. The thymus gland is involved in many patients, and there are experimental and genetic approaches to understand the failure of immune tolerance to the AChR. In a proportion of those patients without AChR antibodies, antibodies to muscle-specific kinase (MuSK, or related proteins such as agrin and low-density lipoprotein receptor-related protein 4 (LRP4, are present. MuSK antibodies are predominantly IgG4 and cause disassembly of the neuromuscular junction by disrupting the physiological function of MuSK in synapse maintenance and adaptation. Here we discuss how knowledge of neuromuscular junction structure and function has fed into understanding the mechanisms of AChR and MuSK antibodies. Myasthenia gravis remains a paradigm for autoantibody-mediated conditions and these observations show how much there is still to learn about synaptic function and pathological mechanisms.

  11. Decentralized Consistent Updates in SDN

    KAUST Repository

    Nguyen, Thanh Dang

    2017-04-10

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and blackholes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes information needed by the switches during the update execution. This information is distributed to the switches, which use partial knowledge and direct message passing to efficiently realize the update. This separation of concerns has the key benefit of improving update performance as the communication and computation bottlenecks at the controller are removed. Our evaluations via network emulations and large-scale simulations demonstrate the efficiency of ez-Segway, which compared to a centralized approach, improves network update times by up to 45% and 57% at the median and the 99th percentile, respectively. A deployment of a system prototype in a real OpenFlow switch and an implementation in P4 demonstrate the feasibility and low overhead of implementing simple network update functionality within switches.

  12. [Research update of effectiveness and mechanism of essential fatty acids in treating dry eye].

    Science.gov (United States)

    Liu, Y; Liang, Q F

    2017-03-11

    Topical anti-inflammatory therapy has become the significant way of treating dry eye so far. However, as the long-term use of routine anti-inflammatory medications are restricted from their side effects, it is inevitable to explore safer and more effective alternatives. Essential fatty acids have proven to be anti-inflammatory systemically, which makes it possible to treat dry eye. Clinical trials have demonstrated that supplementation with either ω-3 or ω-6 essential fatty acids or both has multifactorial efficacies including improvement of subjective symptoms, alleviation of inflammation of ocular surface and eyelid margin, prolongation of tear break-up time and increase of tear flow secretion. Besides anti-inflammation effects, several basic researches have revealed that other mechanisms of essential fatty acids treating dry eye might lie in the corneal epithelial healing and tear secretion promotion. This review puts emphasis on the effectiveness, feasibility and mechanism of treating dry eye with essential fatty acids. (Chin J Ophthalmol, 2017, 53: 225-229) .

  13. Fruit-Derived Polysaccharides and Terpenoids: Recent Update on the Gastroprotective Effects and Mechanisms

    Directory of Open Access Journals (Sweden)

    Mohammed Safwan Ali Khan

    2018-06-01

    Full Text Available Ulceration in the stomach develops in peptic ulcer disease when there is a loss of protective mucosal layers, particularly in Helicobacter pylori infection. Antibiotic therapy has failed to eradicate and impede the colonization of H. pylori. Despite given treatment, recurrent bleeding can occur and lead to death in the affected individual. The disease progression is also related to the non-steroidal inflammatory drug and stress. There are extensive research efforts to identify the gastroprotective property from various alkaloids, flavonoids, and tannins compounds from plants and marine. These natural products are believed to be safe for consumption. However, not much attention was given to summarize the carbohydrate and terpenoidal anti-ulcer compounds. Hence, this review will cover the possible mechanisms and information about acidic hydroxylans, arabinogalactan and rhamnogalacturon; and limonene, pinene, lupeol, citral, ursolic acid and nomilin to exemplify on the gastroprotective properties of polysaccharides and terpenoid, respectively, obtained from fruits. These compounds could act as a prebiotic to prevent the inhabitation of H. pylori, modulate the inflammation, suppress gastric cancer growth, and capable of stimulating the reparative mechanisms on the affected regions. Finally, this review provides the future research prospects of these natural compounds in an effort to develop new therapy for gastrointestinal tissue healing.

  14. THE STIRLING GAS REFRIGERATING MACHINE MECHANICAL DESIGN IMPROVING

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2016-06-01

    Full Text Available To improve the mechanical design of the piston Stirling gas refrigeration machine the structural optimization of rotary vane Stirling gas refrigeration machine is carried out. This paper presents the results of theoretical research. Analysis and prospects of rotary vane Stirling gas refrigeration machine for domestic and industrial refrigeration purpose are represented. The results of a patent search by mechanisms of transformation of rotary vane machines are discussed.

  15. THE STIRLING GAS REFRIGERATING MACHINE MECHANICAL DESIGN IMPROVING

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2016-02-01

    Full Text Available To improve the mechanical design of the piston Stirling gas refrigeration machine the structural optimization of rotary vane Stirling gas refrigeration machine is carried out. This paper presents the results of theoretical research. Analysis and prospects of rotary vane Stirling gas refrigeration machine for domestic and industrial refrigeration purpose are represented. The results of a patent search by mechanisms of transformation of rotary vane machines are discussed

  16. The Design of Wheelchair Lifting Mechanism and Control System

    Institute of Scientific and Technical Information of China (English)

    ZHAO Cong; WANG Zheng-xing; JIANG Shi-hong; ZHANG Li; LIU Zheng-yu

    2014-01-01

    In order to achieve a wheelchair lift function, this paper designs a tri-scissors mechanism. Through the so-called H-type transmission and L-type swing rod, the three scissors mechanisms lift in the same rate with only one liner motor while ensuring the stability of the lift. Finite element analysis in ANSYS is performed to verify the material strength. The control system with Sunplus SCM achieves the voice control of wheelchair walking and lifting.

  17. Novel Design Aspects of the Space Technology 5 Mechanical Subsystem

    Science.gov (United States)

    Rossoni, Peter; McGill, William

    2003-01-01

    This paper describes several novel design elements of the Space Technology 5 (ST5) spacecraft mechanical subsystem. The spacecraft structure itself takes a significant step in integrating electronics into the primary structure. The deployment system restrains the spacecraft during launch and imparts a predetermined spin rate upon release from its secondary payload accommodations. The deployable instrument boom incorporates some traditional as well as new techniques for lightweight and stiffness. Analysis and test techniques used to validate these technologies are described. Numerous design choices were necessitated due to the compact spacecraft size and strict mechanical subsystem requirements.

  18. Molecular and cellular mechanisms of hexavalent chromium-induced lung cancer: an updated perspective.

    Science.gov (United States)

    Urbano, A M; Ferreira, L M R; Alpoim, M C

    2012-03-01

    For over a century, chromium (Cr) has found widespread industrial and commercial use, namely as a pigment, in the production of stainless steel and in chrome plating. The adverse health effects to the skin and respiratory tract of prolonged exposure to Cr have been known or suspected for a long time, but it was much more recently that the toxicity of this element was unequivocally attributed to its hexavalent state. Based on the combined results of extensive epidemiological studies, animal carcinogenicity studies and several types of other relevant data, authoritative regulatory agencies have found sufficient evidence to classify hexavalent chromium [Cr(VI)] compounds as encountered in the chromate production, chromate pigment production and chromium plating industries as carcinogenic to humans. Crucial for the development of novel strategies to prevent, detect and/or treat Cr(VI)-induced cancers is a detailed knowledge of the molecular and cellular mechanisms underlying these pathologies. Unfortunately, in spite of a considerable research effort, crucial facets of these mechanisms remain essentially unknown. This review is intended to provide a concise, integrated and critical perspective of the current state of knowledge concerning multiple aspects of Cr(VI) carcinogenesis. It will present recent theories of Cr(VI)-induced carcinogenesis and will include aspects not traditionally covered in other reviews, such as the possible involvement of the energy metabolism in this process. A brief discussion on the models that have been used in the studies of Cr(VI)-induced carcinogenicity will also be included, due to the impact of this parameter on the relevance of the results obtained.

  19. Stress relaxation insensitive designs for metal compliant mechanism threshold accelerometers

    Directory of Open Access Journals (Sweden)

    Carlos Vilorio

    2015-12-01

    Full Text Available We present two designs for metal compliant mechanisms for use as threshold accelerometers which require zero external power. Both designs rely on long, thin flexures positioned orthogonally to a flat body. The first design involves cutting or stamping a thin spring-steel sheet and then bending elements to form the necessary thin flexors. The second design uses precut spring-steel flexure elements mounted into a mold which is then filled with molten tin to form a bimetallic device. Accelerations necessary to switch the devices between bistable states were measured using a centrifuge. Both designs showed very little variation in threshold acceleration due to stress relaxation over a period of several weeks. Relatively large variations in threshold acceleration were observed for devices of the same design, most likely due to variations in the angle of the flexor elements relative to the main body of the devices. Keywords: Structural health monitoring, Sensor, Accelerometer, Zero power, Shock, Threshold

  20. International Joint Conference on Mechanics, Design Engineering & Advanced Manufacturing

    CERN Document Server

    Nigrelli, Vincenzo; Oliveri, Salvatore; Peris-Fajarnes, Guillermo; Rizzuti, Sergio

    2017-01-01

    This book gathers papers presented at the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM 2016), held on 14-16 September, 2016, in Catania, Italy. It reports on cutting-edge topics in product design and manufacturing, such as industrial methods for integrated product and process design; innovative design; and computer-aided design. Further topics covered include virtual simulation and reverse engineering; additive manufacturing; product manufacturing; engineering methods in medicine and education; representation techniques; and nautical, aeronautics and aerospace design and modeling. The book is divided into eight main sections, reflecting the focus and primary themes of the conference. The contributions presented here will not only provide researchers, engineers and experts in a range of industrial engineering subfields with extensive information to support their daily work; they are also intended to stimulate new research directions, advanced applications of t...

  1. Mechanical design of a sodium heated steam generator

    International Nuclear Information System (INIS)

    Chetal, S.C.

    1975-01-01

    FBTR steam generator is a once through type unit consisting of four 12.5 MW thermal modules generating a total of 74 tons per hour of steam at 125 bar and 480 0 C. This paper outlines the mechanical design of such type of steam generator with emphasis on special design problems associated with this type of sodium to water steam heat exchanger, namely, thermal cycling of transition zone where nucleate boiling changes over to film boiling, application of pressure vessel design criteria for transient pressures, thermal stress evaluation resulting from differential expansion between shell and tube in this typical configuration, sodium headers support design, thermal sleeve, design, thermal shock analysis in thick tubes, thermal stress resulting from stratification and stability of expansion bends against vibration. Some of the possible design changes for the future large size steam generator are outlined. (author)

  2. MECHANICAL CAVITY DESIGN FOR 100MV UPGRADE CRYOMODULE

    International Nuclear Information System (INIS)

    K.M. Wilson; G. Ciovati; E. F. Daly; J. Henry; R. Hicks; J. Hogan; D. Machie; P. Kneisel; C. Reece; J. Sekutowicz; T. Whitlatch

    2003-01-01

    To achieve up to 6 GeV, each cryomodule in the CEBAF accelerator currently provides about 30 MV of acceleration. To raise the accelerator energy to 12 GeV, ten additional cryomodules capable of providing over 100 MV of acceleration are required. A prototype of the 100 MV cryomodule has been designed, is presently under construction, and will be completed in 2004. This prototype cryomodule comprises two new cavity designs, four cavities of the low loss design and four cavities of the high gradient design. Although the cavity shapes were designed for their RF properties, the mechanical implications must be considered. In addition to the new cavity shapes, changes have also been made to the cavity end dish assemblies, weld joints, and stiffening rings. This paper will present the results of the stress and vibration analyses used for designing the cryomodule

  3. The opto-mechanical design process: from vision to reality

    Science.gov (United States)

    Kvamme, E. Todd; Stubbs, David M.; Jacoby, Michael S.

    2017-08-01

    The design process for an opto-mechanical sub-system is discussed from requirements development through test. The process begins with a proper mission understanding and the development of requirements for the system. Preliminary design activities are then discussed with iterative analysis and design work being shared between the design, thermal, and structural engineering personnel. Readiness for preliminary review and the path to a final design review are considered. The value of prototyping and risk mitigation testing is examined with a focus on when it makes sense to execute a prototype test program. System level margin is discussed in general terms, and the practice of trading margin in one area of performance to meet another area is reviewed. Requirements verification and validation is briefly considered. Testing and its relationship to requirements verification concludes the design process.

  4. Thermo-mechanical design aspects of mercury bombardment ion thrusters.

    Science.gov (United States)

    Schnelker, D. E.; Kami, S.

    1972-01-01

    The mechanical design criteria are presented as background considerations for solving problems associated with the thermomechanical design of mercury ion bombardment thrusters. Various analytical procedures are used to aid in the development of thruster subassemblies and components in the fields of heat transfer, vibration, and stress analysis. Examples of these techniques which provide computer solutions to predict and control stress levels encountered during launch and operation of thruster systems are discussed. Computer models of specific examples are presented.

  5. Organic nitrates: update on mechanisms underlying vasodilation, tolerance and endothelial dysfunction.

    Science.gov (United States)

    Münzel, Thomas; Steven, Sebastian; Daiber, Andreas

    2014-12-01

    Given acutely, organic nitrates, such as nitroglycerin (GTN), isosorbide mono- and dinitrates (ISMN, ISDN), and pentaerythrityl tetranitrate (PETN), have potent vasodilator and anti-ischemic effects in patients with acute coronary syndromes, acute and chronic congestive heart failure and arterial hypertension. During long-term treatment, however, side effects such as nitrate tolerance and endothelial dysfunction occur, and therapeutic efficacy of these drugs rapidly vanishes. Recent experimental and clinical studies have revealed that organic nitrates per se are not just nitric oxide (NO) donors, but rather a quite heterogeneous group of drugs considerably differing for mechanisms underlying vasodilation and the development of endothelial dysfunction and tolerance. Based on this, we propose that the term nitrate tolerance should be avoided and more specifically the terms of GTN, ISMN and ISDN tolerance should be used. The present review summarizes preclinical and clinical data concerning organic nitrates. Here we also emphasize the consequences of chronic nitrate therapy on the supersensitivity of the vasculature to vasoconstriction and on the increased autocrine expression of endothelin. We believe that these so far rather neglected and underestimated side effects of chronic therapy with at least GTN and ISMN are clinically important. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Update of green tea interactions with cardiovascular drugs and putative mechanisms

    Directory of Open Access Journals (Sweden)

    José Pablo Werba

    2018-04-01

    Full Text Available Many patients treated with cardiovascular (CV drugs drink green tea (GT, either as a cultural tradition or persuaded of its putative beneficial effects for health. Yet, GT may affect the pharmacokinetics and pharmacodynamics of CV compounds. Novel GT-CV drug interactions were reported for rosuvastatin, sildenafil and tacrolimus. Putative mechanisms involve inhibitory effects of GT catechins at the intestinal level on influx transporters OATP1A2 or OATP2B1 for rosuvastatin, on CYP3A for sildenafil and on both CYP3A and the efflux transporter p-glycoprotein for tacrolimus. These interactions, which add to those previously described with simvastatin, nadolol and warfarin, might lead, in some cases, to reduced drug efficacy or risk of drug toxicity. Oddly, available data on GT interaction with CV compounds with a narrow therapeutic index, such as warfarin and tacrolimus, derive from single case reports. Conversely, GT interactions with simvastatin, rosuvastatin, nadolol and sildenafil were documented through pharmacokinetic studies. In these, the effect of GT or GT derivatives on drug exposure was mild to moderate, but a high inter-individual variability was observed. Further investigations, including studies on the effect of the dose and the time of GT intake are necessary to understand more in depth the clinical relevance of GT-CV drug interactions. Keywords: Cardiovascular drugs, Green tea, Herb–drug interactions

  7. Mechanical Design of Military Communication Satellite X-band PCM

    Directory of Open Access Journals (Sweden)

    Hyung Je Woo

    1998-12-01

    Full Text Available Before an actual military communications satellite is designed and constructed, a feasibility study should take place. The basic functions of such system can be observed and demonstrated in an X-Band payload simulator. For this purpose a Payload Concept Model (PCM for X-Band payload subsystem has been developed to simulate the workings of an actual military communications payload. This paper explains and illustrates the mechanical design, manufacture, and integration of the PCM. Basic RF tests also have been performed in order to verify the design requirement of the system. The results demonstrate successful development of the PCM and operation without RF losses.

  8. 2014 Joint Conference on Mechanical Design Engineering and Advanced Manufacturing

    CERN Document Server

    Daidie, Alain; Eynard, Benoit; Paredes, Manuel

    2016-01-01

    Covering key topics in the field such as technological innovation, human-centered sustainable engineering and manufacturing, and manufacture at a global scale in a virtual world, this book addresses both advanced techniques and industrial applications of key research in interactive design and manufacturing. Featuring the full papers presented at the 2014 Joint Conference on Mechanical Design Engineering and Advanced Manufacturing, which took place in June 2014 in Toulouse, France, it presents recent research and industrial success stories related to implementing interactive design and manufacturing solutions.

  9. Design and structural calculation of nuclear power plant mechanical components

    International Nuclear Information System (INIS)

    Amaral, J.A.R. do

    1986-01-01

    The mechanical components of a nuclear power plant must show high quality and safety due to the presence of radioactivity. Besides the perfect functioning during the rigid operating conditions, some postulated loadings are foreseen, like earthquake and loss of coolant accidents, which must be also considered in the design. In this paper, it is intended to describe the design and structural calculations concept and development, the interactions with the piping and civil designs, as well as their influences in the licensing process with the authorities. (Author) [pt

  10. The Hierarchical Specification and Mechanical Verification of the SIFT Design

    Science.gov (United States)

    1983-01-01

    The formal specification and proof methodology employed to demonstrate that the SIFT computer system meets its requirements are described. The hierarchy of design specifications is shown, from very abstract descriptions of system function down to the implementation. The most abstract design specifications are simple and easy to understand, almost all details of the realization were abstracted out, and are used to ensure that the system functions reliably and as intended. A succession of lower level specifications refines these specifications into more detailed, and more complex, views of the system design, culminating in the Pascal implementation. The section describes the rigorous mechanical proof that the abstract specifications are satisfied by the actual implementation.

  11. Update on Mechanisms of Renal Tubule Injury Caused by Advanced Glycation End Products

    Directory of Open Access Journals (Sweden)

    Hong Sun

    2016-01-01

    Full Text Available Diabetic nephropathy (DN caused by advanced glycation end products (AGEs may be associated with lipid accumulation in the kidneys. This study was designed to investigate whether Nε-(carboxymethyl lysine (CML, a member of the AGEs family increases lipid accumulation in a human renal tubular epithelial cell line (HK-2 via increasing cholesterol synthesis and uptake and reducing cholesterol efflux through endoplasmic reticulum stress (ERS. Our results showed that CML disrupts cholesterol metabolism in HK-2 cells by activating sterol regulatory element-binding protein 2 (SREBP-2 and liver X receptor (LXR, followed by an increase in 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR mediated cholesterol synthesis and low density lipoprotein receptor (LDLr mediated cholesterol uptake and a reduction in ATP-binding cassette transporter A1 (ABCA1 mediated cholesterol efflux, ultimately causing lipid accumulation in HK-2 cells. All of these responses could be suppressed by an ERS inhibitor, which suggests that CML causes lipid accumulation in renal tubule cells through ERS and that the inhibition of ERS is a potential novel approach to treating CML-induced renal tubular foam cell formation.

  12. An update on CRF mechanisms underlying alcohol use disorders and dependence.

    Directory of Open Access Journals (Sweden)

    Isabel Marian Hartmann Quadros

    2016-10-01

    Full Text Available Alcohol is the most commonly used and abused substance worldwide. The emergence of alcohol use disorders, and alcohol dependence in particular, is accompanied by functional changes in brain reward and stress systems, which contribute to escalated alcohol drinking and seeking. Corticotropin Releasing Factor (CRF systems have been critically implied in the transition towards problematic alcohol drinking and alcohol dependence. This review will discuss how dysregulation of CRF function contributes to the vulnerability for escalated alcohol drinking and other consequences of alcohol consumption, based on preclinical evidence. CRF signaling, mostly via CRF1 receptors, seems to be particularly important in conditions of excessive alcohol taking and seeking, including during early and protracted withdrawal, relapse, as well as during withdrawal-induced anxiety and escalated aggression promoted by alcohol. Modulation of CRF1 function seems to exert a less prominent role over low to moderate alcohol intake, or to species-typical behaviors. While CRF mechanisms in the hypothalamic-pituitary-adrenal axis have some contribution to the neurobiology of alcohol abuse and dependence, a pivotal role for extra-hypothalamic CRF pathways, particularly in the extended amygdala, is well characterized. More recent studies further suggest a direct modulation of brain reward function by CRF signaling in the ventral tegmental area, nucleus accumbens and the prefrontal cortex, among other structures. This review will further discuss a putative role for other components of the CRF system that contribute for the overall balance of CRF function in reward and stress pathways, including CRF2 receptors, CRF binding protein and Urocortins, a family of CRF-related peptides.

  13. Mechanical Design of Downhole Tractor Based on Two-Way Self-locking Mechanism

    Science.gov (United States)

    Fang, Delei; Shang, Jianzhong; Luo, Zirong; Wu, Guoheng; Liu, Yiying

    2018-03-01

    Based on the technology of horizontal well tractor, a kind of downhole tractor was developed which can realize Two-Way self-locking function. Aiming at the needs of horizontal well logging to realize the target of small size, high traction and high reliability, the tractor selects unique heart-shaped CAM as the locking mechanism. The motion principle of telescopic downhole tractor, the design of mechanical structure and locking principle of the locking mechanism are all analyzed. The mathematical expressions of traction are obtained by mechanical analysis of parallel support rod in the locking mechanism. The force analysis and contour design of the heart-shaped CAM are performed, which can lay the foundation for the development of tractor prototype.

  14. Optimal design of nuclear mechanical dampers with analytical hierarchy process

    International Nuclear Information System (INIS)

    Zou Yuehua; Wen Bo; Xu Hongxiang; Qin Yonglie

    2000-01-01

    An optimal design with analytical hierarchy process on nuclear mechanical dampers manufactured by authors' university was described. By using fuzzy judgement matrix the coincidence was automatically satisfied without the need of coincidence test. The results obtained by this method have been put into the production practices

  15. A System for Distributed Mechanisms: Design, Implementation and Applications

    NARCIS (Netherlands)

    K.R. Apt (Krzysztof); F. Arbab (Farhad); H. Ma (Huiye)

    2007-01-01

    htmlabstractWe describe here a structured system for distributed mechanism design. In our approach the players dynamically form a network in which they know neither their neighbours nor the size of the network and interact to jointly take decisions. The only assumption concerning the underlying

  16. SPICA/SAFARI fourier transform spectrometer mechanism evolutionary design

    NARCIS (Netherlands)

    Dool, T.C. van den; Kruizinga, B.; Braam, B.C.; Hamelinck, R.F.M.M.; Loix, N.; Loon, D. van; Dams, J.

    2012-01-01

    TNO, together with its partners, have designed a cryogenic scanning mechanism for use in the SAFARI Fourier Transform Spectrometer (FTS) on board of the SPICA mission. SPICA is one of the M-class missions competing to be launched in ESA's Cosmic Vision Programme in 2022. JAXA leads the development

  17. Mechanical design for a large fusion laser system

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1979-01-01

    The Nova Mechanical Systems Group at LLL is responsible for the design, fabrication, and installation of all laser chain components, for the stable support structure that holds them, and for the beam lines that transport the laser beam to the target system. This paper is an overview of the group's engineering effort, emphasizing new developments

  18. Mechanical Design of a Manipulation System for Unmanned Aerial Vehicles

    NARCIS (Netherlands)

    Keemink, A.Q.L.; Fumagalli, M.; Stramigioli, S.; Carloni, R.

    In this paper, we present the mechanical design and modeling of a manipulation system for unmanned aerial vehicles, which have to physically interact with environments and perform ultrasonic non-destructive testing experiments and other versatile tasks at unreachable locations for humans. The

  19. Mechanical design of epithermal neutron diagnostic for TFTR

    International Nuclear Information System (INIS)

    Groo, R.C.

    1981-01-01

    The mechanical design of the Epithermal Neutron Diagnostic for TFTR is described. This fission detector system measures the time resolution of the neutron flux for folding into the Neutron Activation system and also provides continuous, wide range coverage of all expected fusion reaction rates

  20. Mechanical design and control of a new myoelectric hand prosthesis

    NARCIS (Netherlands)

    Peerdeman, B.; Stramigioli, Stefano; Hekman, Edsko E.G.; Brouwer, Dannis Michel; Misra, Sarthak

    2011-01-01

    The development of modern, myoelectrically controlled hand prostheses can be difficult, due to the many requirements its mechanical design and control system need to fulfill [1]. The hand should be controllable with few input signals, while being able to perform a wide range of motions. It should be

  1. Computer-based mechanical design of overhead lines

    Science.gov (United States)

    Rusinaru, D.; Bratu, C.; Dinu, R. C.; Manescu, L. G.

    2016-02-01

    Beside the performance, the safety level according to the actual standards is a compulsory condition for distribution grids’ operation. Some of the measures leading to improvement of the overhead lines reliability ask for installations’ modernization. The constraints imposed to the new lines components refer to the technical aspects as thermal stress or voltage drop, and look for economic efficiency, too. The mechanical sizing of the overhead lines is after all an optimization problem. More precisely, the task in designing of the overhead line profile is to size poles, cross-arms and stays and locate poles along a line route so that the total costs of the line's structure to be minimized and the technical and safety constraints to be fulfilled.The authors present in this paper an application for the Computer-Based Mechanical Design of the Overhead Lines and the features of the corresponding Visual Basic program, adjusted to the distribution lines. The constraints of the optimization problem are adjusted to the existing weather and loading conditions of Romania. The outputs of the software application for mechanical design of overhead lines are: the list of components chosen for the line: poles, cross-arms, stays; the list of conductor tension and forces for each pole, cross-arm and stay for different weather conditions; the line profile drawings.The main features of the mechanical overhead lines design software are interactivity, local optimization function and high-level user-interface

  2. Mechanical design and fabrication of pure-permanent magnet undulator

    International Nuclear Information System (INIS)

    Chouksey, Sanjay; Vinit Kumar; Abhay Kumar; Krishnagopal, Srinivas

    2003-01-01

    A 50 mm period, 2.5 m long (50 periods), pure permanent magnet, variable gap undulator using NdFeB magnets is being built in two sections, each 1.25 m long. We present details of the mechanical design, fabrication experience, assembly and inspection of the undulator. (author)

  3. Physiological evaluation of a newly designed lever mechanism for wheelchairs

    NARCIS (Netherlands)

    van der Woude, L H; Veeger, DirkJan (H. E. J.); de Boer, Y; Rozendal, R H

    1993-01-01

    Lever-propelled wheelchairs have been described as more efficient and less physically demanding than hand-rim-propelled wheelchairs. To evaluate a newly designed lever mechanism (MARC) in both one- and two-arm use, a series of wheelchair exercise tests were performed on a motor-driven treadmill.

  4. Multispectral linear array (MLA) focal plane mechanical and thermal design

    Science.gov (United States)

    Mitchell, A. S.; Kaminski, E. F.

    1982-01-01

    The mechanical and thermal design of an integrated focal plane subsystem of a Multispectral Linear Array (MLA) instrument is discussed in terms of focal-plane alignment, thermoelastic performance, and thermal requirements. The modular construction and thermal control of the focal plane array are discussed.

  5. Detailed mechanical design of the LIPAc beam dump radiological shielding

    Energy Technology Data Exchange (ETDEWEB)

    Nomen, Oriol, E-mail: onomen@irec.cat [IREC, Barcelona, Catalonia (Spain); CDEI-UPC, Barcelona, Catalonia (Spain); Martínez, José I.; Arranz, Fernando; Iglesias, Daniel; Barrera, Germán; Brañas, Beatriz [CIEMAT, Madrid (Spain); Ogando, Francisco [UNED, Madrid (Spain); Molla, Joaquín [CIEMAT, Madrid (Spain); Sanmartí, Manel [IREC, Barcelona, Catalonia (Spain)

    2013-10-15

    Highlights: ► Mechanical design of the IFMIF LIPAc beam dump shielding has been performed. ► Lead shutter design performed to shield radiation from beam dump when LIPAc is off. ► External loads, working and dismantling conditions, included as design constraints. -- Abstract: The LIPAc is a 9 MeV, D{sup +} linear prototype accelerator for the validation of the IFMIF accelerator design. The high intensity, 125 mA CW beam is stopped in a copper cone involving a high production of neutrons and gamma radiation and activation of its surface. The beam stopper is surrounded by a shielding to attenuate the resulting radiation so that dose rate values comply with the limits at the different zones of the installation. The shielding includes for that purpose polyethylene rings, water tanks and gray cast iron rings. A lead shutter has also been designed to shield the gamma radiation that comes through the beam tube when the linear accelerator is not in operation, in order to allow access inside the building for maintenance tasks. The present work summarizes the detailed mechanical design of the beam dump shielding and the lead shutter taking into account the design constraints, such as working conditions and other external loads, as well as including provisions for dismantling.

  6. Updated design for a low-noise, wideband transimpedance photodiode amplifier

    International Nuclear Information System (INIS)

    Paul, S. F.; Marsala, R.

    2006-01-01

    The high-speed rotation diagnostic developed for Columbia's HBT-EP tokamak requires a high quantum efficiency, very low drift detector/amplifier combination. An updated version of the circuit developed originally for the beam emission spectroscopy experiment on TFTR is being used. A low dark current (2 nA at 15 V bias), low input source capacitance (2 pF) FFD-040 N-type Si photodiode is operated in photoconductive mode. It has a quantum efficiency of 40% at the 468.6 nm (He II line that is being observed). A low-noise field-effect transistor (InterFET IFN152 with e Na =1.2 nV/√Hz) is used to reduce the noise in the transimpedance preamplifier (A250 AMPTEK op-amp) and a very high speed (unity-gain bandwidth=200 MHz) voltage feedback amplifier (LM7171) is used to restore the frequency response up to 100 kHz. This type of detector/amplifier is photon-noise limited at this bandwidth for incident light with a power of >∼2 nW. The circuit has been optimized using SIMETRIX 4.0 SPICE software and a prototype circuit has been tested successfully. Though photomultipliers and avalanche photodiodes can detect much lower light levels, for light levels >2 nW and a 10 kHz bandwidth, this detector/amplifier combination is more sensitive because of the absence of excess (internally generated) noise

  7. Mechanical design of a shape memory alloy actuated prosthetic hand.

    Science.gov (United States)

    De Laurentis, Kathryn J; Mavroidis, Constantinos

    2002-01-01

    This paper presents the mechanical design for a new five fingered, twenty degree-of-freedom dexterous hand patterned after human anatomy and actuated by Shape Memory Alloy artificial muscles. Two experimental prototypes of a finger, one fabricated by traditional means and another fabricated by rapid prototyping techniques, are described and used to evaluate the design. An important aspect of the Rapid Prototype technique used here is that this multi-articulated hand will be fabricated in one step, without requiring assembly, while maintaining its desired mobility. The use of Shape Memory Alloy actuators combined with the rapid fabrication of the non-assembly type hand, reduce considerably its weight and fabrication time. Therefore, the focus of this paper is the mechanical design of a dexterous hand that combines Rapid Prototype techniques and smart actuators. The type of robotic hand described in this paper can be utilized for applications requiring low weight, compactness, and dexterity such as prosthetic devices, space and planetary exploration.

  8. Global and Local Mechanical Responses for Necking of Rectangular Bars Using Updated and Total Lagrangian Finite Element Formulations

    Directory of Open Access Journals (Sweden)

    Claudio A. Careglio

    2016-01-01

    Full Text Available In simulations of forged and stamping processes using the finite element method, load displacement paths and three-dimensional stress and strains states should be well and reliably represented. The simple tension test is a suitable and economical tool to calibrate constitutive equations with finite strains and plasticity for those simulations. A complex three-dimensional stress and strain states are developed when this test is done on rectangular bars and the necking phenomenon appears. In this work, global and local numerical results of the mechanical response of rectangular bars subjected to simple tension test obtained from two different finite element formulations are compared and discussed. To this end, Updated and Total Lagrangian formulations are used in order to get the three-dimensional stress and strain states. Geometric changes together with strain and stress distributions at the cross section where necking occurs are assessed. In particular, a detailed analysis of the effective plastic strain, stress components in axial and transverse directions and pressure, and deviatoric stress components is presented. Specific numerical results are also validated with experimental measurements comparing, in turn, the performance of the two numerical approaches used in this study.

  9. Priors engaged in long-latency responses to mechanical perturbations suggest a rapid update in state estimation.

    Directory of Open Access Journals (Sweden)

    Frédéric Crevecoeur

    Full Text Available In every motor task, our brain must handle external forces acting on the body. For example, riding a bike on cobblestones or skating on irregular surface requires us to appropriately respond to external perturbations. In these situations, motor predictions cannot help anticipate the motion of the body induced by external factors, and direct use of delayed sensory feedback will tend to generate instability. Here, we show that to solve this problem the motor system uses a rapid sensory prediction to correct the estimated state of the limb. We used a postural task with mechanical perturbations to address whether sensory predictions were engaged in upper-limb corrective movements. Subjects altered their initial motor response in ∼60 ms, depending on the expected perturbation profile, suggesting the use of an internal model, or prior, in this corrective process. Further, we found trial-to-trial changes in corrective responses indicating a rapid update of these perturbation priors. We used a computational model based on Kalman filtering to show that the response modulation was compatible with a rapid correction of the estimated state engaged in the feedback response. Such a process may allow us to handle external disturbances encountered in virtually every physical activity, which is likely an important feature of skilled motor behaviour.

  10. A preliminary design of mechanical device on industrial digital radiography equipment design

    International Nuclear Information System (INIS)

    Nur Khasan; Samuel Praptoyo

    2015-01-01

    A preliminary design of mechanical device on industrial digital radiography equipment has been done. this design is intended as a basis for the manufacture of complete facilities for the realization a prototype on industrial digital radiography equipment. the design and construction were carried out by paying attention to the general configuration of the basic design in which its mechanical design has several components with specific dimensions and heavy mass. this design consist of a main frame holder, flat panel detector support and hydraulic hand stacker for mounting the x-ray machine. this mechanical device design will then be fabricated to facilitate and assist work of digital radiographic retrieval. computer application programs sketch-up is used to draw this design and the analysis stress of autodesk inventor to analysis the strength construction design. the results of this design are the configuration drawing, sketch drawings of construction and the safety factor of construction design with a minimum value of 2.39 as well as a maximum value of 15 when to be simulated by the load 500 Kg which is 4 times of total workload. (author)

  11. PATIENT-CENTRED SCREENING FOR PRIMARY IMMUNODEFICIENCY, A MULTI-STAGE DIAGNOSTIC PROTOCOL DESIGNED FOR NONIMMUNOLOGISTS: 2011 UPDATE

    Directory of Open Access Journals (Sweden)

    E. de Vries

    2013-01-01

    Full Text Available Abstract. Members of the European Society for Immunodeficiencies (ESID and other colleagues have updated themulti-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs. The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage.

  12. Design optimization and fatigue testing of an electronically-driven mechanically-resonant cantilever spring mechanism

    International Nuclear Information System (INIS)

    Kheng, Lim Boon; Kean, Koay Loke; Gitano-Briggs, Horizon

    2010-01-01

    A light scanning device consisting of an electronically-driven mechanically-resonant cantilever spring-mirror system has been developed for innovative lighting applications. The repeated flexing of the cantilever spring during operation can lead to premature fatigue failure. A model was created to optimize the spring design. The optimized spring design can reduce stress by approximately one-third from the initial design. Fatigue testing showed that the optimized spring design can operate continuously for over 1 month without failure. Analysis of failures indicates surface cracks near the root of the spring are responsible for the failures.

  13. Task-Based Method for Designing Underactuated Mechanisms

    Directory of Open Access Journals (Sweden)

    Shoichiro Kamada

    2012-03-01

    Full Text Available In this paper we introduce a task-based method for designing underactuated multi-joint prosthetic hands for specific grasping tasks. The designed robotic hands or prosthetic hands contain fewer independent actuators than joints. We chose a few specific grasping tasks that are frequently repeated in everyday life and analysed joint motions of the hand during the completion of each task and the level of participation of each joint. The information was used for the synthesis of dedicated underactuated mechanisms that can operate in a low dimensional task coordinate space. We propose two methods for reducing the actuators' number. The kinematic parameters of the synthesized mechanism are determined by using a numerical approach. In this study the joint angles of the synthesized hand are considered as linearly dependent on the displacements of the actuators. We introduced a special error index that allowed us to compare the original trajectory and the trajectory performed by the synthesized mechanism, and to select the kinematic parameters of the new kinematic structure as a way to reduce the error. The approach allows the design of simple gripper mechanisms with good accuracy for the preliminary defined tasks.

  14. Mechanical Design Technology--Modified. (Computer Assisted Drafting, Computer Aided Design). Curriculum Grant 84/85.

    Science.gov (United States)

    Schoolcraft Coll., Livonia, MI.

    This document is a curriculum guide for a program in mechanical design technology (computer-assisted drafting and design developed at Schoolcraft College, Livonia, Michigan). The program helps students to acquire the skills of drafters and to interact with electronic equipment, with the option of becoming efficient in the computer-aided…

  15. New design for a space cryo-mechanism

    Science.gov (United States)

    Durand, Gilles; Amiaux, Jérôme; Augueres, Jean-Louis; Carty, Michael; Barrière, Jean Christophe; Bouzat, Marylène; Duboué, Bruno; Lagage, Pierre Olivier; Lebeuf, Didier; Lepage, Erwan; Lemer, Isabelle; Marlaguey, Nathalie Peydrol; Poupar, Sébastien

    2008-07-01

    Based on its experience of space application instrument and its development of cryomechanism for astronomical ground based instrument VLT / VISIR, CEA Saclay is proposing a new concept of Space Cryomechanism. This design is based on VLT/VISIR cryo-mechanism design adapted to space requirements taking into account all the specification of space environment (vibrations at launch, cryogenic vacuum, materials, radiations, ...). The original concept of the design is based on the association of the key elements: a dog-clutch with Hirth teeth jaws coupled to a step-by-step space qualified cryo-motor, a bellows that allows for separation of indexing and rotating functions, and enlarged bearings design in "O" arrangement that increase robustness to vibration. The actuator has 360 steady positions that can be reached within les than a second with repeatability of 5 arcsec peak to peak. After a presentation of the details of the concept and of its benefits to robustness to space environment, the paper describes the thoroughly qualification program of the cryo-mechanism with respect to space requirements (cryo-cycling, indexing accuracy, power consumption, heat dissipation, motorisation margins, vibrations). This cryo-mechanism may be built in 3 different sizes for wheels up to 10 kg.

  16. Some mechanical design aspects of the European Robotic Arm

    Science.gov (United States)

    Lambooy, Peter J.; Mandersloot, Wart M.; Bentall, Richard H.

    1995-01-01

    The European Robotic Arm (ERA) is a contribution to the Russian Segment of the International Space Station Alpha. It will start operating on the Russian Segment during the assembly phase. ERA is designed and produced by a large industrial consortium spread over Europe with Fokker Space & Systems as prime contractor. In this paper, we will describe some of the overall design aspects and focus on the development of several mechanisms within ERA. The operation of ERA during the approach of its end effector towards the grapple interface and the grapple operation is discussed, with a focus on mechanisms. This includes the geometry of the end effector leading edge, which is carefully designed to provide the correct and complete tactile information to a torque-force sensor (TFS). The data from this TFS are used to steer the arm such that forces and moments are kept below 20 N and 20 N.m respectively during the grappling operation. Two hardware models of the end effector are built. The problems encountered are described as well as their solutions. The joints in the wrists and the elbow initially used a harmonic drive lubricated by MoS2. During development testing, this combination showed an insufficient lifetime in air to survive the acceptance test program. The switch-over to a system comprising planetary gearboxes with grease lubrication is described. From these development efforts, conclusions are drawn and recommendations are given for the design of complex space mechanisms.

  17. Advances in mechanisms, robotics and design education and research

    CERN Document Server

    Schmiedeler, James; Sreenivasan, S; Su, Hai-Jun

    2013-01-01

    This book contains papers on a wide range of topics in the area of kinematics, mechanisms, robotics, and design, addressing new research advances and innovations in design education. The content is divided into  five main categories headed ‘Historical Perspectives’, ‘Kinematics and Mechanisms’, ‘Robotic Systems’, ‘Legged Locomotion’, and ‘Design Engineering Education’. Contributions take the form of survey articles, historical perspectives, commentaries on trends on education or research, original research contributions, and papers on design education.   This volume celebrates the achievements of Professor Kenneth Waldron who has made innumerable and invaluable contributions to these fields in the last fifty years. His leadership and his pioneering work have influenced thousands of people in this discipline.

  18. Optical and mechanical design of beam-target coupling sensor

    International Nuclear Information System (INIS)

    Wang Liquan; Li Tian'en; Feng Bin; Xiang Yong; Li Keyu; Zhong Wei; Liu Guodong

    2012-01-01

    A sensor based on conjugate principle has been designed for matching the light beams and the target in inertial confinement fusion. It can avoid the direct illumination of the simulation collimating light on the target under test in targeting processes. This paper introduces the optical and mechanical design of the sensor, according to its design functions and working principle. The resolution of the optical images obtained in experiments reaches 6 μm and the beam-target matching accuracy is 8.8 μm. The sensor has been successfully applied to the Shenguang-Ⅲ facility. Statistical analyses of the four-hole CH target images derived with pinhole camera shows that the targeting accuracy of the facility is better than 25 μm, satisfying the design requirements. (authors)

  19. Mechanism design and optimization of a bionic kangaroo jumping robot

    Science.gov (United States)

    Zhang, Y. H.; Zheng, L.; Ge, W. J.; Zou, Z. H.

    2018-03-01

    Hopping robots have broad application prospects in the fields of military reconnaissance, field search or life rescue. However, current hopping robots still face the problems of weak jumping ability and load bearing. Inspired by the jumping of kangaroo, we design a Kangaroo hopping robot “Zbot”, which has two degrees of freedom and three joints. The geared five-bar mechanism is used to decouple the knee and ankle joints of the robot. In order to get a bionic performance, the coupling mechanism parameters are optimized. The simulation and experiments show that the robot has an excellent jumping ability and load capacity.

  20. Mechanical thrombectomy in acute ischemic stroke: Consensus statement by ESO-Karolinska Stroke Update 2014/2015, supported by ESO, ESMINT, ESNR and EAN.

    Science.gov (United States)

    Wahlgren, Nils; Moreira, Tiago; Michel, Patrik; Steiner, Thorsten; Jansen, Olav; Cognard, Christophe; Mattle, Heinrich P; van Zwam, Wim; Holmin, Staffan; Tatlisumak, Turgut; Petersson, Jesper; Caso, Valeria; Hacke, Werner; Mazighi, Mikael; Arnold, Marcel; Fischer, Urs; Szikora, Istvan; Pierot, Laurent; Fiehler, Jens; Gralla, Jan; Fazekas, Franz; Lees, Kennedy R

    2016-01-01

    The original version of this consensus statement on mechanical thrombectomy was approved at the European Stroke Organisation (ESO)-Karolinska Stroke Update conference in Stockholm, 16-18 November 2014. The statement has later, during 2015, been updated with new clinical trials data in accordance with a decision made at the conference. Revisions have been made at a face-to-face meeting during the ESO Winter School in Berne in February, through email exchanges and the final version has then been approved by each society. The recommendations are identical to the original version with evidence level upgraded by 20 February 2015 and confirmed by 15 May 2015. The purpose of the ESO-Karolinska Stroke Update meetings is to provide updates on recent stroke therapy research and to discuss how the results may be implemented into clinical routine. Selected topics are discussed at consensus sessions, for which a consensus statement is prepared and discussed by the participants at the meeting. The statements are advisory to the ESO guidelines committee. This consensus statement includes recommendations on mechanical thrombectomy after acute stroke. The statement is supported by ESO, European Society of Minimally Invasive Neurological Therapy (ESMINT), European Society of Neuroradiology (ESNR), and European Academy of Neurology (EAN). © 2016 World Stroke Organization.

  1. Development of mechanical design technology for integral reactor

    International Nuclear Information System (INIS)

    Park, Keun Bae; Choi, Suhn; Kim, Kang Soo; Kim, Tae Wan; Jeong, Kyeong Hoon; Lee, Gyu Mahn; Kim, Jong Wook; Choi, Woo Seok

    2002-03-01

    This report is the final documentation of the 'Development of Mechanical Design Technology for Integral Reactor' which describes the design activities including reactor vessel assembly structural modelling, normal operation and transient analysis, preparation of design specification, major component stress analysis, evaluation of structural integrity, review of fabricability, maintenance and repair scheme, etc. To establish the design requirements and applicable codes and standards, each GDC criterion was reviewed regarding the SMART structural characteristics and design status, and then the applicability and point of issues were evaluated. To accomodate the result of the core optimization program, modification of pressure vessel and reactor internal components were carried out. SG nozzles were rearranged to penetrate the pressure vessel wall instead of the annular cover. Coolant flow path through the MCP impeller was revised and the adjacent structures were modified. Dynamic analysis model was developed reflecting all the structural changes to perform the seismic and BLPB analysis. Fracture mechanics evaluation on the structural integrity of the reactor pressure vessel was also conducted. Besides, equipment maintenance and replacement plan including the refueling scheme was discussed to confirm the embodiment of SMART through construction and operation

  2. The optical-mechanical design of DMD modulation imaging device

    Science.gov (United States)

    Li, Tianting; Xu, Xiping; Qiao, Yang; Li, Lei; Pan, Yue

    2014-09-01

    In order to avoid the phenomenon of some image information were lost, which is due to the jamming signals, such as incident laser, make the pixels dot on CCD saturated. In this article a device of optical-mechanical structure was designed, which utilized the DMD (Digital Micro mirror Device) to modulate the image. The DMD reflection imaging optical system adopts the telecentric light path. However, because the design is not only required to guarantee a 66° angle between the optical axis of the relay optics and the DMD, but also to ensure that the optical axis of the projection system keeps parallel with the perpendicular bisector of the micro-mirror which is in the "flat" state, so the TIR prism is introduced,and making the relay optics and the DMD satisfy the optical institution's requirements. In this paper, a mechanical structure of the imaging optical system was designed and at the meanwhile the lens assembly has been well connected and fixed and fine-tuned by detailed structural design, which included the tilt decentered lens, wedge flanges, prisms. By optimizing the design, the issues of mutual restraint between the inverting optical system and the projecting system were well resolved, and prevented the blocking of the two systems. In addition, the structure size of the whole DMD reflection imaging optical system was minimized; it reduced the energy loss and ensured the image quality.

  3. Design and use of an engineering simulator for power plant and training simulator updates

    International Nuclear Information System (INIS)

    Sharawy, P.S.; Kennard, J.R.; Chou, Q.B.

    1990-01-01

    The advancement in real-time simulators has been facilitated by the availability of increasingly powerful computing devices at reduced costs for use in conjunction with high-fidelity simulation software. Ontario Hydro's commitment to the safe and reliable operation of its nuclear power plants was one of the factors which influenced its decision to build a plant-replica operator training simulator for each of its nuclear generating stations. This investment soon proved to have advantages beyond those originally envisaged. It become apparent that because the software developed for these simulators met rigorous acceptance criteria, it could be used on an engineering simulator to effectively investigate problems occurring at the stations. It could also serve as a design aid for station modifications. Encouraged by the success of early experimentation in the use of its training simulators for concept validation and verification, Ontario Hydro is developing a low-cost central facility - the Instrumentation and Control Engineering Simulator (ICES) - for use in its design work. This facility incorporates the software of its training simulators and includes a user-friendly generic interface which enables designers to configure and operate it. Inclusion of the engineering simulator in all phases of the design process, from the original concept to implementation and verification, will make it possible to shorten the design period significantly while achieving a high level of quality. It will also facilitate the rapid retrofit of simulators to reflect station modifications. This paper will recount Ontario Hydro's experience in the use of simulators for design work and will specifically discuss the design features and system performance of its engineering simulator

  4. The Mechanical Design Optimization of a High Field HTS Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Lalitha, SL; Gupta, RC

    2015-06-01

    This paper describes the conceptual design optimization of a large aperture, high field (24 T at 4 K) solenoid for a 1.7 MJ superconducting magnetic energy storage device. The magnet is designed to be built entirely of second generation (2G) high temperature superconductor tape with excellent electrical and mechanical properties at the cryogenic temperatures. The critical parameters that govern the magnet performance are examined in detail through a multiphysics approach using ANSYS software. The analysis results formed the basis for the performance specification as well as the construction of the magnet.

  5. Mechanical testing - designers need: a view at component design and operations stages

    International Nuclear Information System (INIS)

    Shrivastava, S.K.

    2007-01-01

    Mechanical design of any component requires knowledge of values of various material properties which designer(s) make(s) use in designing the component. In design of nuclear power plant components, it assumes even greater importance in view of degree of precision and accuracy with which the values of various properties are required. This is in turn demands, high accuracy in testing machines and measuring methods. In this paper, attempt has been made to bring out that even from conventional tension test, how designer today looks for availability of engineering stress-strain diagram preferably through digitally acquired data points during the test from which he can derive values of Ramberg-Osgood parameters for use in fracture mechanics based analysis. Attempt has been also made to provide account of some of important fracture mechanics related tests which have been evolved in last two decades and designers need for evolution of simple test techniques to measure many more fracture mechanics related parameters as well as cater to constraints such as shape and size of material available from the components. Nuclear power plant has been primarily kept in view and ASME. Section III NB, ASME Section XI and relevant ASTM Standards have been taken as standard references. Further pressure retaining materials of pressure vessels/Reactor Pressure Vessels have been kept in view. (author)

  6. Mechanical Design for Robustness of the LHC Collimators

    CERN Document Server

    Bertarelli, Alessandro; Assmann, R W; Calatroni, Sergio; Dallocchio, Alessandro; Kurtyka, Tadeusz; Mayer, Manfred; Perret, Roger; Redaelli, Stefano; Robert-Demolaize, Guillaume

    2005-01-01

    The functional specification of the LHC Collimators requires, for the start-up of the machine and the initial luminosity runs (Phase 1), a collimation system with maximum robustness against abnormal beam operating conditions. The most severe cases to be considered in the mechanical design are the asynchronous beam dump at 7 TeV and the 450 GeV injection error. To ensure that the collimator jaws survive such accident scenarios, low-Z materials were chosen, driving the design towards Graphite or Carbon/Carbon composites. Furthermore, in-depth thermo-mechanical simulations, both static and dynamic, were necessary.This paper presents the results of the numerical analyses performed for the 450 GeV accident case, along with the experimental results of the tests conducted on a collimator prototype in Cern TT40 transfer line, impacted by a 450 GeV beam of 3.1·1013

  7. Mechanical Design of a Second Generation LHC IR Quadrupole

    International Nuclear Information System (INIS)

    Caspi, S.; Bartlett, S.E.; Dietderich, D.R.; Ferracin, P.; Gourlay, S.A.; Hafalia, R.R.; Hannaford, C.R.; Lietzke, A.F.; McInturff, A.D.; Sabbi, G.; Scanlan, R.M.

    2003-01-01

    One of the proposed options to increase the LHC luminosity is the replacement of the existing inner triplets at the Interaction Regions with new low-beta larger aperture quadrupoles operating at the same gradient. Lawrence Berkeley National Laboratory (LBNL) is carrying out preliminary studies of a large-bore Nb 3 Sn quadrupole. The mechanical design presents a support structure based on the use of keys and bladders without self-supporting collars. This technology has been proven effective in several successful common coil Nb 3 Sn dipoles built at LBNL, and it is for the first time applied to a cos(2(var t heta)) design. In this paper we present a detailed analysis of the quadrupole mechanical behavior, demonstrating the possibility of delivering, through this method, well-controlled coil precompression during assembly, cool-down and excitation. The study has been performed with the finite element program ANSYS

  8. Mechanical Design of the HER Synchrotron Light Monitor Primary Mirror

    Energy Technology Data Exchange (ETDEWEB)

    Daly, Edward F.; /SLAC; Fisher, Alan S.; Kurita, Nadine R.; Langton, J.; /SLAC

    2011-09-14

    This paper describes the mechanical design of the primary mirror that images the visible portion of the synchrotron radiation (SR) extracted from the High Energy Ring (HER) of the PEP-II B-Factory. During off-axis operation, the water-cooled GlidCop mirror is subjected to a heat flux in excess of 2000 W/cm2. When on-axis imaging occurs, the heat flux due to scattered SR, resistive wall losses and Higher-Order-Mode (HOM) heating is estimated at 1 W/cm2. The imaging surface is plated with Electroless Nickel to improve its optical characteristics. The design requirements for the primary mirror are listed and discussed. Calculated mechanical distortions and stresses experienced by the mirror during on-axis and off-axis operation will be presented.

  9. POMM: design of rotating mechanism and hexapod structure

    Science.gov (United States)

    Côté, Patrice; Leclerc, Mélanie; Demers, Mathieu; Bastien, Pierre; Hernandez, Olivier

    2014-08-01

    The new high precision polarimeter for the "Observatoire du Mont Mégantic" (POMM) is an instrument designed to observe exoplanets and other targets in the visible and near infrared wavebands. The requirements to achieve these observation goals are posing unusual challenges to structural and mechanical designers. In this paper, the detailed design, analysis and laboratory results of the key mechanical structure and sub-systems are presented. First, to study extremely low polarization, the birefringence effect due to stresses in the optical elements must be kept to the lowest possible values. The double-wedge Wollaston custom prism assembly that splits the incoming optical beam is made of bonded α-BBO to N-BK-7 glass lenses. Because of the large mismatch of coefficients of thermal expansion and temperatures as low as -40°C that can be encountered at Mont-Mégantic observatory, a finite element analysis (FEA) model is developed to find the best adhesive system to minimize stresses. Another critical aspect discussed in details is the implementation of the cascaded rotating elements and the twin rotating stages. Special attention is given to the drive mechanism and encoding technology. The objective was to reach high absolute positional accuracy in rotation without any mechanical backlash. As for many other instruments, mass, size and dimensional stability are important critera for the supporting structure. For a cantilevered device, such as POMM, a static hexapod is an attractive solution because of the high stiffness to weight ratio. However, the mechanical analysis revealed that the specific geometry of the dual channel optical layout also added an off-axis counterbalancing problem. To reach an X-Y displacement error on the detector smaller than 35μm for 0-45° zenith angle, further structural optimization was done using FEA. An imaging camera was placed at the detector plane during assembly to measure the actual optical beam shift under varying gravitational

  10. Mechanical design of the CDF SVX II silicon vertex detector

    International Nuclear Information System (INIS)

    Skarha, J.E.

    1994-08-01

    A next generation silicon vertex detector is planned at CDF for the 1998 Tevatron collider run with the Main Injector. The SVX II silicon vertex detector will allow high luminosity data-taking, enable online triggering of secondary vertex production, and greatly increase the acceptance for heavy flavor physics at CDF. The design specifications, geometric layout, and early mechanical prototyping work for this detector are discussed

  11. Designing incentive market mechanisms for improving restructured power system reliabilities

    DEFF Research Database (Denmark)

    Ding, Yi; Østergaard, Jacob; Wu, Qiuwei

    2011-01-01

    state. The reliability management of producers usually cannot be directly controlled by the system operators in a restructured power system. Producers may have no motivation to improve their reliabilities, which can result in serious system unreliability issues in the new environment. Incentive market...... mechanisms for improving the restructured power system reliabilities have been designed in this paper. In the proposed incentive mechanisms, penalty will be implemented on a producer if the failures of its generator(s) result in the variation of electricity prices. Incentive market mechanisms can motivate......In a restructured power system, the monopoly generation utility is replaced by different electricity producers. There exists extreme price volatility caused by random failures by generation or/and transmission systems. In these cases, producers' profits can be much higher than those in the normal...

  12. Design and Dynamic Modeling of Flexible Rehabilitation Mechanical Glove

    Science.gov (United States)

    Lin, M. X.; Ma, G. Y.; Liu, F. Q.; Sun, Q. S.; Song, A. Q.

    2018-03-01

    Rehabilitation gloves are equipment that helps rehabilitation doctors perform finger rehabilitation training, which can greatly reduce the labour intensity of rehabilitation doctors and make more people receive finger rehabilitation training. In the light of the defects of the existing rehabilitation gloves such as complicated structure and stiff movement, a rehabilitation mechanical glove is designed, which provides driving force by using the air cylinder and adopts a rope-spring mechanism to ensure the flexibility of the movement. In order to fit the size of different hands, the bandage ring which can adjust size is used to make the mechanism fixed. In the interest of solve the complex problem of dynamic equation, dynamic simulation is carried out by using Adams to obtain the motion curve, which is easy to optimize the structure of ring position.

  13. Conceptual Design of Bottom-mounted Control Rod Drive Mechanism

    International Nuclear Information System (INIS)

    Lee, Jin Haeng; Kim, Sanghaun; Yoo, Yeonsik; Cho, Yeonggarp; Kim, Dongmin; Kim, Jong In

    2013-01-01

    The arrangement of the BMCRDMs and irradiation holes in the core is therefore easier than that of the top-mounted CRDM. Hence, many foreign research reactors, such as JRR-3M, JMTR, OPAL, and CARR, have adopted the BMCRDM concept. The purpose of this paper is to introduce the basic design concept on the BMCRDM. The major differences of the CRDMs between HANARO and KJRR are compared, and the design features and individual system of the BMCRDM for the KJRR are described. The Control Rod Drive Mechanism (CRDM) is a device to regulate the reactor power by changing the position of a Control Absorber Rod (CAR) and to shut down the reactor by fully inserting the CAR into the core within a specified time. The Bottom-Mounted CRDM (BMCRDM) for the KiJang Research Reactor (KJRR) is a quite different design concept compared to the top-mounted CRDM such as HANARO and JRTR. The main drive mechanism of the BMCRDM is located in a Reactivity Control Mechanism (RCM) room under the reactor pool bottom, which makes the interference with equipment in the reactor pool reduced

  14. Convergent evolution in mechanical design of lamnid sharks and tunas.

    Science.gov (United States)

    Donley, Jeanine M; Sepulveda, Chugey A; Konstantinidis, Peter; Gemballa, Sven; Shadwick, Robert E

    2004-05-06

    The evolution of 'thunniform' body shapes in several different groups of vertebrates, including whales, ichthyosaurs and several species of large pelagic fishes supports the view that physical and hydromechanical demands provided important selection pressures to optimize body design for locomotion during vertebrate evolution. Recognition of morphological similarities between lamnid sharks (the most well known being the great white and the mako) and tunas has led to a general expectation that they also have converged in their functional design; however, no quantitative data exist on the mechanical performance of the locomotor system in lamnid sharks. Here we examine the swimming kinematics, in vivo muscle dynamics and functional morphology of the force-transmission system in a lamnid shark, and show that the evolutionary convergence in body shape and mechanical design between the distantly related lamnids and tunas is much more than skin deep; it extends to the depths of the myotendinous architecture and the mechanical basis for propulsive movements. We demonstrate that not only have lamnids and tunas converged to a much greater extent than previously known, but they have also developed morphological and functional adaptations in their locomotor systems that are unlike virtually all other fishes.

  15. Conceptual Design of Bottom-mounted Control Rod Drive Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Haeng; Kim, Sanghaun; Yoo, Yeonsik; Cho, Yeonggarp; Kim, Dongmin; Kim, Jong In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The arrangement of the BMCRDMs and irradiation holes in the core is therefore easier than that of the top-mounted CRDM. Hence, many foreign research reactors, such as JRR-3M, JMTR, OPAL, and CARR, have adopted the BMCRDM concept. The purpose of this paper is to introduce the basic design concept on the BMCRDM. The major differences of the CRDMs between HANARO and KJRR are compared, and the design features and individual system of the BMCRDM for the KJRR are described. The Control Rod Drive Mechanism (CRDM) is a device to regulate the reactor power by changing the position of a Control Absorber Rod (CAR) and to shut down the reactor by fully inserting the CAR into the core within a specified time. The Bottom-Mounted CRDM (BMCRDM) for the KiJang Research Reactor (KJRR) is a quite different design concept compared to the top-mounted CRDM such as HANARO and JRTR. The main drive mechanism of the BMCRDM is located in a Reactivity Control Mechanism (RCM) room under the reactor pool bottom, which makes the interference with equipment in the reactor pool reduced.

  16. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    Science.gov (United States)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approx.10 cm x 20 cm x 30 cm) cubesat Near Earth Asteroid (NEA) Scout1, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System, will utilize a solar sail as its main method of propulsion throughout its approx.3-year mission to a Near Earth Asteroid. Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems, advance solutions, and build confidence in the final design product. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  17. Mechanical design and optimal control of humanoid robot (TPinokio

    Directory of Open Access Journals (Sweden)

    Teck Chew Wee

    2014-04-01

    Full Text Available The mechanical structure and the control of the locomotion of bipedal humanoid is an important and challenging domain of research in bipedal robots. Accurate models of the kinematics and dynamics of the robot are essential to achieve bipedal locomotion. Toe-foot walking produces a more natural and faster walking speed and it is even possible to perform stretch knee walking. This study presents the mechanical design of a toe-feet bipedal, TPinokio and the implementation of some optimal walking gait generation methods. The optimality in the gait trajectory is achieved by applying augmented model predictive control method and the pole-zero cancellation method, taken into consideration of a trade-off between walking speed and stability. The mechanism of the TPinokio robot is designed in modular form, so that its kinematics can be modelled accurately into a multiple point-mass system, its dynamics is modelled using the single and double mass inverted pendulum model and zero-moment-point concept. The effectiveness of the design and control technique is validated by simulation testing with the robot walking on flat surface and climbing stairs.

  18. Effects of pore design on mechanical properties of nanoporous silicon

    International Nuclear Information System (INIS)

    Winter, Nicholas; Becton, Matthew; Zhang, Liuyang; Wang, Xianqiao

    2017-01-01

    Nanoporous silicon has been emerging as a powerful building block for next-generation sensors, catalysts, transistors, and tissue scaffolds. The capability to design novel devices with desired mechanical properties is paramount to their reliability and serviceability. In order to bring further resolution to the highly variable mechanical characteristics of nanoporous silicon, here we perform molecular dynamics simulations to study the effects of ligament thickness, relative density, and pore geometry/orientation on the mechanical properties of nanoporous silicon, thereby determining its Young's modulus, ultimate strength, and toughness as well as the scaling laws versus the features of interior ligaments. Results show that pore shape and pattern dictate stress accumulation inside the designed structure, leading to the corresponding failure signature, such as stretching-dominated, bending-dominated, or stochastic failure signatures, in nanoporous silicon. The nanostructure of the material is also seen to drive or mute size effects such as “smaller is stronger” and “smaller is ductile”. This investigation provides useful insight into the behavior of nanoporous silicon and how one might leverage its promising applications. - Graphical abstract: Molecular dynamics simulations are performed to study the effects of ligament thickness, relative density, and pore geometry/orientation on the mechanical properties of nanoporous silicon, thereby determining its Young's modulus, ultimate strength, and toughness as well as the scaling trends versus the features of interior ligaments.

  19. Design of a new type synchronous focusing mechanism

    Science.gov (United States)

    Zhang, Jintao; Tan, Ruijun; Chen, Zhou; Zhang, Yongqi; Fu, Panlong; Qu, Yachen

    2018-05-01

    Aiming at the dual channel telescopic imaging system composed of infrared imaging system, low-light-level imaging system and image fusion module, In the fusion of low-light-level images and infrared images, it is obvious that using clear source images is easier to obtain high definition fused images. When the target is imaged at 15m to infinity, focusing is needed to ensure the imaging quality of the dual channel imaging system; therefore, a new type of synchronous focusing mechanism is designed. The synchronous focusing mechanism realizes the focusing function through the synchronous translational imaging devices, mainly including the structure of the screw rod nut, the shaft hole coordination structure and the spring steel ball eliminating clearance structure, etc. Starting from the synchronous focusing function of two imaging devices, the structure characteristics of the synchronous focusing mechanism are introduced in detail, and the focusing range is analyzed. The experimental results show that the synchronous focusing mechanism has the advantages of ingenious design, high focusing accuracy and stable and reliable operation.

  20. Mechanical design of an intracranial stent for treating cerebral aneurysms.

    Science.gov (United States)

    Shobayashi, Yasuhiro; Tanoue, Tetsuya; Tateshima, Satoshi; Tanishita, Kazuo

    2010-11-01

    Endovascular treatment of cerebral aneurysms using stents has advanced markedly in recent years. Mechanically, a cerebrovascular stent must be very flexible longitudinally and have low radial stiffness. However, no study has examined the stress distribution and deformation of cerebrovascular stents using the finite element method (FEM) and experiments. Stents can have open- and closed-cell structures, and open-cell stents are used clinically in the cerebrovasculature because of their high flexibility. However, the open-cell structure confers a risk of in-stent stenosis due to protrusion of stent struts into the normal parent artery. Therefore, a flexible stent with a closed-cell structure is required. To design a clinically useful, highly flexible, closed-cell stent, one must examine the mechanical properties of the closed-cell structure. In this study, we investigated the relationship between mesh patterns and the mechanical properties of closed-cell stents. Several mesh patterns were designed and their characteristics were studied using numerical simulation. The results showed that the bending stiffness of a closed-cell stent depends on the geometric configuration of the stent cell. It decreases when the stent cell is stretched in the circumferential direction. Mechanical flexibility equal to an open-cell structure was obtained in a closed-cell structure by varying the geometric configuration of the stent cell. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

  1. Differential evolution and simulated annealing algorithms for mechanical systems design

    Directory of Open Access Journals (Sweden)

    H. Saruhan

    2014-09-01

    Full Text Available In this study, nature inspired algorithms – the Differential Evolution (DE and the Simulated Annealing (SA – are utilized to seek a global optimum solution for ball bearings link system assembly weight with constraints and mixed design variables. The Genetic Algorithm (GA and the Evolution Strategy (ES will be a reference for the examination and validation of the DE and the SA. The main purpose is to minimize the weight of an assembly system composed of a shaft and two ball bearings. Ball bearings link system is used extensively in many machinery applications. Among mechanical systems, designers pay great attention to the ball bearings link system because of its significant industrial importance. The problem is complex and a time consuming process due to mixed design variables and inequality constraints imposed on the objective function. The results showed that the DE and the SA performed and obtained convergence reliability on the global optimum solution. So the contribution of the DE and the SA application to the mechanical system design can be very useful in many real-world mechanical system design problems. Beside, the comparison confirms the effectiveness and the superiority of the DE over the others algorithms – the SA, the GA, and the ES – in terms of solution quality. The ball bearings link system assembly weight of 634,099 gr was obtained using the DE while 671,616 gr, 728213.8 gr, and 729445.5 gr were obtained using the SA, the ES, and the GA respectively.

  2. A Curriculum Model: Engineering Design Graphics Course Updates Based on Industrial and Academic Institution Requirements

    Science.gov (United States)

    Meznarich, R. A.; Shava, R. C.; Lightner, S. L.

    2009-01-01

    Engineering design graphics courses taught in colleges or universities should provide and equip students preparing for employment with the basic occupational graphics skill competences required by engineering and technology disciplines. Academic institutions should introduce and include topics that cover the newer and more efficient graphics…

  3. PEP-II asymmetric B Factory: Design update and R ampersand D results

    International Nuclear Information System (INIS)

    Zisman, M.S.; Bell, R.A.; Dorfan, J.; Schwarz, H.; Barletta, W.A.; Calderon, M.

    1992-07-01

    PEP-II, a 9 GeV x 3.1 GeV e + e - collider with a design luminosity of 3 x 10 33 cm -2 s -1 , was proposed jointly by SLAC, LBL, and LLNL. Recent efforts have continued towards an optimized design. In addition, an aggressive R ampersand D program is under way to validate our design choices. Fabrication of a low-power prototype RF cavity is complete, and impedance measurements are beginning. A 500-kW, 476-MHz klystron has been completed; it will be used for testing both high-power RF windows and a prototype high-power cavity (now under design in collaboration with Chalk River Laboratory). Vacuum studies have demonstrated that chambers with suitable photodesorption properties can be fabricated. A mockup of the two-ring arc area has been completed and used to investigate alignment and stability issues. The PEP-II project is ready to begin construction as soon as funds become available

  4. Updating the Duplex Design for Test-Based Accountability in the Twenty-First Century

    Science.gov (United States)

    Bejar, Isaac I.; Graf, E. Aurora

    2010-01-01

    The duplex design by Bock and Mislevy for school-based testing is revisited and evaluated as a potential platform in test-based accountability assessments today. We conclude that the model could be useful in meeting the many competing demands of today's test-based accountability assessments, although many research questions will need to be…

  5. Design update, thermal and fluid dynamic analyses of the EU-HCPB TBM in vertical arrangement

    International Nuclear Information System (INIS)

    Cismondi, F.; Kecskes, S.; Ilic, M.; Legradi, G.; Kiss, B.; Bitz, O.; Dolensky, B.; Neuberger, H.; Boccaccini, L.V.; Ihli, T.

    2009-01-01

    In the frame of the activities of the EU Breeder Blanket Programme and of the Test Blanket Working Group of ITER, the Helium Cooled Pebble Bed Test Blanket Module (HCPB TBM) is developed in Forschungszentrum Karlsruhe (FZK) to investigate DEMO relevant concepts for blanket modules. The three main functions of a blanket module (removing heat, breeding tritium and shielding sensitive components from radiation) will be tested in ITER using a series of four TBMs, which are irradiated successively during different test campaigns. Each HCPB TBM will be installed, with a vertical orientation, into the vacuum vessel connected to one equatorial port. As the studies performed up to 2006 in FZK concerned a horizontal orientation of the HCPB TBM, a global review of the design is necessary to match with the new ITER specifications. A preliminary version of the new vertical design is proposed extrapolating the neutronic analysis performed for the horizontal HCPB TBM. An overview of the new HCPB TBM vertical designs, as well as the preliminary thermal and fluid dynamic analyses performed for the validation of the design, are presented in this paper. A critical review of the results obtained allows us, in the conclusion, to prepare a plan for the future detailed analyses of the vertical HCPB TBM.

  6. Repeat-swap homology modeling of secondary active transporters: updated protocol and prediction of elevator-type mechanisms.

    Science.gov (United States)

    Vergara-Jaque, Ariela; Fenollar-Ferrer, Cristina; Kaufmann, Desirée; Forrest, Lucy R

    2015-01-01

    Secondary active transporters are critical for neurotransmitter clearance and recycling during synaptic transmission and uptake of nutrients. These proteins mediate the movement of solutes against their concentration gradients, by using the energy released in the movement of ions down pre-existing concentration gradients. To achieve this, transporters conform to the so-called alternating-access hypothesis, whereby the protein adopts at least two conformations in which the substrate binding sites are exposed to one or other side of the membrane, but not both simultaneously. Structures of a bacterial homolog of neuronal glutamate transporters, GltPh, in several different conformational states have revealed that the protein structure is asymmetric in the outward- and inward-open states, and that the conformational change connecting them involves a elevator-like movement of a substrate binding domain across the membrane. The structural asymmetry is created by inverted-topology repeats, i.e., structural repeats with similar overall folds whose transmembrane topologies are related to each other by two-fold pseudo-symmetry around an axis parallel to the membrane plane. Inverted repeats have been found in around three-quarters of secondary transporter folds. Moreover, the (a)symmetry of these systems has been successfully used as a bioinformatic tool, called "repeat-swap modeling" to predict structural models of a transporter in one conformation using the known structure of the transporter in the complementary conformation as a template. Here, we describe an updated repeat-swap homology modeling protocol, and calibrate the accuracy of the method using GltPh, for which both inward- and outward-facing conformations are known. We then apply this repeat-swap homology modeling procedure to a concentrative nucleoside transporter, VcCNT, which has a three-dimensional arrangement related to that of GltPh. The repeat-swapped model of VcCNT predicts that nucleoside transport also

  7. Repeat-swap homology modeling of secondary active transporters: updated protocol and prediction of elevator-type mechanisms

    Directory of Open Access Journals (Sweden)

    Cristina eFenollar Ferrer

    2015-09-01

    Full Text Available Secondary active transporters are critical for neurotransmitter clearance and recycling during synaptic transmission and uptake of nutrients. These proteins mediate the movement of solutes against their concentration gradients, by using the energy released in the movement of ions down pre-existing concentration gradients. To achieve this, transporters conform to the so-called alternating-access hypothesis, whereby the protein adopts at least two conformations in which the substrate binding sites are exposed to either the outside or inside of the membrane, but not both simultaneously. Structures of a bacterial homolog of neuronal glutamate transporters, GltPh, in several different conformational states have revealed that the protein structure is asymmetric in the outward- and inward-open states, and that the conformational change connecting them involves a elevator-like movement of a substrate binding domain across the membrane. The structural asymmetry is created by inverted-topology repeats, i.e., structural repeats with similar overall folds whose transmembrane topologies are related to each other by two-fold pseudo-symmetry around an axis parallel to the membrane plane. Inverted repeats have been found in around three-quarters of secondary transporter folds. Moreover, the (asymmetry of these systems has been successfully used as a bioinformatic tool, called repeat-swap modeling to predict structural models of a transporter in one conformation using the known structure of the transporter in the complementary conformation as a template. Here, we describe an updated repeat-swap homology modeling protocol, and calibrate the accuracy of the method using GltPh, for which both inward- and outward-facing conformations are known. We then apply this repeat-swap homology modeling procedure to a concentrative nucleoside transporter, VcCNT, which has a three-dimensional arrangement related to that of GltPh. The repeat-swapped model of VcCNT predicts that

  8. Fuel Element Mechanical Design for CAREM-25 Reactor

    International Nuclear Information System (INIS)

    Estevez, Esteban; Markiewicz, Mario; Gerding, Jose

    2000-01-01

    The Fuel Element mechanical design and spider-control reactivity and security rods assembly for the CAREM-25 reactor is introduced. The CAREM-25 Fuel Element has a hexagonal cross section with 127 positions, in a triangular arrangement.There are 108 positions for the fuel rods while the guide tubes and instrumentation tube occupy the 19 remaining positions.From the structural point of view, the fuel element is being composed by a framework formed by the guides and instrumentation tubes, 4 spacer grids and the upper and lower coupling pieces.The spider is a plane piece, with a central body and six radial branches in T form, which has holes where the absorber rods are fitted.The central body ends in a joint in the upper side, which allows connect the assembly whit the reactor control mechanisms.The absorber rods are made of a neutron absorber material (Ag-In-Cd) hermetically closed in a stainless steel cladding. In this work are determined, in addition to the basic design, the operational conditions, the functional requirements to be satisfied and in agreement with those, the adopted criteria and limits to avoid systematics failure during normal operation conditions. The proposed program for the verification and evaluation of design is detailed.To consolidate the design, a prototype was manufactures, based on drawings and specifications needed for its construction

  9. Mechanical design problems associated with turbopump fluid film bearings

    Science.gov (United States)

    Evces, Charles R.

    1990-01-01

    Most high speed cryogenic turbopumps for liquid propulsion rocket engines currently use ball or roller contact bearings for rotor support. The operating speeds, loads, clearances, and environments of these pumps combine to make bearing wear a limiting factor on turbopump life. An example is the high pressure oxygen turbopump (HPOTP) used in the Space Shuttle Main Engine (SSME). Although the HPOTP design life is 27,000 seconds at 30,000 rpms, or approximately 50 missions, bearings must currently be replaced after 2 missions. One solution to the bearing wear problem in the HPOTP, as well as in future turbopump designs, is the utilization of fluid film bearings in lieu of continuous contact bearings. Hydrostatic, hydrodynamic, and damping seal bearings are all replacement candidates for contact bearings in rocket engine high speed turbomachinery. These three types of fluid film bearings have different operating characteristics, but they share a common set of mechanical design opportunities and difficulties. Results of research to define some of the mechanical design issues are given. Problems considered include transient strat/stop rub, non-operational rotor support, bearing wear inspection and measurement, and bearing fluid supply route. Emphasis is given to the HPOTP preburner pump (PBP) bearing, but the results are pertinent to high-speed cryogenic turbomachinery in general.

  10. Design and Experimental Investigation of Pneumatic Movement Mechanism Supported by Mechanic Cam and Crank Shaft

    Directory of Open Access Journals (Sweden)

    Salih KORUCU

    2015-02-01

    Full Text Available The pressurized air is applied to many sectors required purity and velocity. One of these sectors is to use of air as impulsive force in the moving mechanisms. In this study, the movement mechanism prototype worked with compressed air was designed and produced forlight vehicle engine as motorbike and ATV (All-Terrain Vehicle. In developed mechanisms, pneumatic artificial muscles were used for a given movement of crankshaft. A cam system was also designed for synchronization pneumatic muscles. In this way, these muscles transmit the synchronous movement to crankshaft. At the end of the study, the developed mechanism was mounted on an ATV vehicle(110 cc/ Cubic Centimeter, engine displacement capacityand its performance was tested using the four different weights (50, 75, 100 and 150 kg, three different pressures (4, 5 and 6 bar and two different hoses (Ø 6 and Ø 8 mm. By considering experimental results and design criteria, power of the movement mechanism was obtained as 886 Watt. With this study, minimization of energy consumption for movement of passenger cars, and using clean and cheap energy as ATV which can be alternative for single or two passenger vehicles.

  11. Mechanical design of the small-scale experimental ADS: MYRRHA

    Energy Technology Data Exchange (ETDEWEB)

    Maes, Dirk [SCKCEN, Reactor Physics and MYRRHA Department, Boeretang 200, B-2400 Mol (Belgium)

    2006-10-15

    Since 1998, SCK*CEN, in partnership with IBA s.a. and many European research laboratories, is designing a multipurpose Accelerator Driven System (ADS) - MYRRHA - and is conducting an associated R and D support programme. MYRRHA aims to serve as a basis for the European experimental ADS to provide protons and neutrons for various R and D applications. Besides an overall configuration of the MYRRHA reactor internals, the description in this paper is limited to the mechanical design of the main components of the Primary System and Associated Equipment (vessel and cover, diaphragm, spallation loop, sub-critical core, primary cooling system, emergency cooling system, in-vessel fuel storage and fuel transfer machine), the conceptual design of the robotics for In-Service Inspection and Repair (ISIR), together with the remote handling for operation and maintenance (O and M). (author)

  12. Mechanical Design Engineering Enabler Project wheel and wheel drives

    Science.gov (United States)

    Nutt, Richard E.; Couch, Britt K.; Holley, John L., Jr.; Garris, Eric S.; Staut, Paul V.

    1992-01-01

    Our group was assigned the responsibility of designing the wheel and wheel drive system for a proof-of-concept model of the lunar-based ENABLER. ENABLER is a multi-purpose, six wheeled vehicle designed to lift and transport heavy objects associated with the construction of a lunar base. The resulting design was based on the performance criteria of the ENABLER. The drive system was designed to enable the vehicle to achieve a speed of 7 mph on a level surface, climb a 30 percent grade, and surpass a one meter high object and one meter wide crevice. The wheel assemblies were designed to support the entire weight of the vehicle on two wheels. The wheels were designed to serve as the main component of the vehicle's suspension and will provide suitable traction for lunar-type surfaces. The expected performance of the drive system for the ENABLER was influenced by many mechanical factors. The expected top speed on a level sandy surface is 4 mph instead of the desired 7 mph. This is due to a lack of necessary power at the wheels. The lack of power resulted from dimension considerations that allowed only an eight horsepower engine and also from mechanical inefficiencies of the hydraulic system. However, the vehicle will be able to climb a 30 percent grade, surpass a one meter high object and one meter wide crevice. The wheel assemblies will be able to support the entire weight of the vehicle on two wheels. The wheels will also provide adequate suspension for the vehicle and sufficient traction for lunar-type surfaces.

  13. SBWR design update: Passively safe, nuclear power generation for the twenty first century

    International Nuclear Information System (INIS)

    Upton, H.A.; Torbeck, J.E.; Billig, P.F.; Duncan, J.D.; Herzog, M.

    1996-01-01

    This paper describes the current state of design, development and testing of a new generation of Boiling Water Reactors, the SBWR. The SBWR is a plant that will be significantly simpler to build, operate and maintain compared to operating plants. In this paper, the design and performance of the reference 670 MWe SBWR is summarized, the economics of SBWR power generation is addressed and the current developments in component testing and integrated system testing are given. This paper specifically discusses the current innovations and key reference design features of the SBWR including the RPV, depressurization system, pressure suppression system, flammability control system (based on passive autocatalytic recombiners), gravity driven cooling system, the passive containment cooling system, isolation condenser system and other unique engineered safety features that rely on gravity or stored energy to ensure core cooling, decay heat removal, and ATWS mitigation. The component and integrated system development testing summarized includes key results of recently concluded PANTHERS condenser tests conducted at SIET in Italy, GIRAFFE non-condensable gas testing by Toshiba in Japan, and the ongoing testing at the PANDA facility at PSI in Switzerland

  14. Updated Assessment of an Open Rotor Airplane Using an Advanced Blade Design

    Science.gov (United States)

    Hendricks, Eric S.; Berton, Jeffrey J.; Haller, William J.; Tong, Michael T.; Guynn, Mark D.

    2013-01-01

    Application of open rotor propulsion systems (historically referred to as "advanced turboprops" or "propfans") to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation's environmental impact have renewed interest in open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Over the last few years, NASA has revived and developed analysis capabilities to assess aircraft designs with open rotor propulsion systems. These efforts have been described in several previous papers along with initial results from applying these capabilities. The initial results indicated that open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicated that current noise regulations can be met with modern baseline blade designs. Improved blades incorporating low-noise features are expected to result in even lower noise levels. This paper describes improvements to the initial assessment, plus a follow-on study using a more advanced open rotor blade design to power the advanced singleaisle transport. The predicted performance and environmental results of these two advanced open rotor concepts are presented and compared.

  15. Updating the Design of the Poloidal Field Coils for the ITER Magnet System

    International Nuclear Information System (INIS)

    Yoshida, K.; Takahashi, Y.; Mitchell, N.; Jong, C.; Bessette, D.

    2006-01-01

    The ITER superconducting coil system consists of 18 Toroidal Field coils, six Poloidal Field (PF) coils, six Central Solenoid (CS) modules, 18 Correction Coils and their feeders. The six PF coils are attached to the TF coil cases through flexible plates or sliding supports allowing radial displacements. The PF coils and CS modules provide suitable magnetic fields for plasma shaping and position control. The PF coils use NbTi superconductor, cooled by supercritical helium. This gives a substantial cost saving compared to Nb 3 Sn and the elimination of a reaction heat treatment greatly simplifies the insulation of such large diameter coils. The cable configuration is 6 sub-cables arranged around a central cooling space. The conductors have a heavy square walled stainless steel jacket. The latest parameters of conductor design are evaluated by analysis of the minimum quench energy and hotspot temperature. The PF coils are self supporting as regards the radial magnetic loads. The vertical loads on each PF coil are transmitted to the TF coil cases. Load transmission is through flexible plates for the PF2 to PF5 coils or sliding supports for the PF1 and PF6 coils with fibreslip bearing surfaces. The supports for the PF winding consist of a set of clamping plates and stud bolts. The shape of the clamping plates has been designed to minimize stresses in the winding pack insulation. Bolts are pre-tensioned to keep pressure between the winding pack and clamping plate. Because of the difficulties in replacing the PF coils, the most unreliable component (the coil insulation) is designed with extra redundancy. There are two insulation layers with a thin metal screen in between. By monitoring the voltage of the intermediate screen, it is possible to detect an incipient short, defined as a short in only one of the two insulation layers. Adjustment of the screen voltage level may allow the shot growth to the stopped once it is detected. Alternately the faulty double pancake must

  16. Fragment informatics and computational fragment-based drug design: an overview and update.

    Science.gov (United States)

    Sheng, Chunquan; Zhang, Wannian

    2013-05-01

    Fragment-based drug design (FBDD) is a promising approach for the discovery and optimization of lead compounds. Despite its successes, FBDD also faces some internal limitations and challenges. FBDD requires a high quality of target protein and good solubility of fragments. Biophysical techniques for fragment screening necessitate expensive detection equipment and the strategies for evolving fragment hits to leads remain to be improved. Regardless, FBDD is necessary for investigating larger chemical space and can be applied to challenging biological targets. In this scenario, cheminformatics and computational chemistry can be used as alternative approaches that can significantly improve the efficiency and success rate of lead discovery and optimization. Cheminformatics and computational tools assist FBDD in a very flexible manner. Computational FBDD can be used independently or in parallel with experimental FBDD for efficiently generating and optimizing leads. Computational FBDD can also be integrated into each step of experimental FBDD and help to play a synergistic role by maximizing its performance. This review will provide critical analysis of the complementarity between computational and experimental FBDD and highlight recent advances in new algorithms and successful examples of their applications. In particular, fragment-based cheminformatics tools, high-throughput fragment docking, and fragment-based de novo drug design will provide the focus of this review. We will also discuss the advantages and limitations of different methods and the trends in new developments that should inspire future research. © 2012 Wiley Periodicals, Inc.

  17. Design and validation of the Quantum Mechanics Conceptual Survey

    Directory of Open Access Journals (Sweden)

    S. B. McKagan

    2010-11-01

    Full Text Available The Quantum Mechanics Conceptual Survey (QMCS is a 12-question survey of students’ conceptual understanding of quantum mechanics. It is intended to be used to measure the relative effectiveness of different instructional methods in modern physics courses. In this paper, we describe the design and validation of the survey, a process that included observations of students, a review of previous literature and textbooks and syllabi, faculty and student interviews, and statistical analysis. We also discuss issues in the development of specific questions, which may be useful both for instructors who wish to use the QMCS in their classes and for researchers who wish to conduct further research of student understanding of quantum mechanics. The QMCS has been most thoroughly tested in, and is most appropriate for assessment of (as a posttest only, sophomore-level modern physics courses. We also describe testing with students in junior quantum courses and graduate quantum courses, from which we conclude that the QMCS may be appropriate for assessing junior quantum courses, but is not appropriate for assessing graduate courses. One surprising result of our faculty interviews is a lack of faculty consensus on what topics should be taught in modern physics, which has made designing a test that is valued by a majority of physics faculty more difficult than expected.

  18. Mechanical Design of the Intensity Measurement Devices for the LHC

    CERN Document Server

    Belorhad, D; Odier, P; Thoulet, S

    2008-01-01

    The intensity measurement for the LHC ring is provided by eight current transformers (2×DCCT, 2×FBCT per beam). The measurement resolution of 1?Arms at 1s average for the DCCTs and ±10^9p in 25ns for the FBCTs is required. Such constraints call for low noise electronics and a compact magnetically shielded mechanical design. Correct integration of these devices into the vacuum system also requires the vacuum chambers equipped with the non-evaporable getter (NEG) film. The NEG is activated by heating the vacuum chamber to 200?C and more. Such temperatures affect the structure of the magnetic materials, which form the base part of the intensity measurement devices, and degrade their performace. A cooling circuit is needed. Due to the mechanical constraints, the cooling circuit, as well as heating element must form an integral part of the design. The aim of this paper is to present the solutions to these problems and discuss the mechanical construction of the DCCTs and FBCTs currently being installed in the LH...

  19. Post design evaluation (ageing mechanisms, effects, management, monitoring, PSR, ISI)

    International Nuclear Information System (INIS)

    Ichikawa, Toshio

    2001-01-01

    Although the nuclear plant was designed for the purpose of the 30-year life the early stages of construction, it also already has the plant abolished by passing in 30 years. There is a plant under operation and a plant that is employed variously, extends the original life and continues operation now, and the plant that is going to be abolished politically is before a life. By using a nuclear plant for a long period of time, damage. by the influence of irradiation, wear of slipping, corrosion, etc. appears. When this degradation is left, the serious accident is caused. In this lecture, refer to Assessment and management of ageing of major nuclear power plant components important to safety, Oct. 1999 of IAEA. A point of view from guide is introduced about management of the mechanism in the secular degradation mode expected by operating for a long period of time, the influence of secular degradation, and influence, monitoring technology, periodical safe evaluation, and a periodic inspection. And raises and explains the correspondence situation of secular degradation, and the example of evaluation of PSR and ISI equipment. The aging mechanism for reactor vessel internal components considered are related to embrittlement, fatigue, corrosion, radiation induced creep, relaxation and swelling, and mechanical wear. This lecture includes; monitoring methods, a description of periodic safety reviews and a sample of seismic design periodic safety report for the reactor internals

  20. Development of mechanical design technology for integral reactor

    International Nuclear Information System (INIS)

    Park, Keun Bae; Choi, Suhn; Kim, Kang Soo; Kim, Tae Wan; Jeong, Kyeong Hoon; Lee, Gyu Mahn

    1999-03-01

    While Korean nuclear reactor strategy seems to remain focused on the large capacity power generation, it is expected that demand of small and medium size reactor will arise for multi-purpose application such as small capacity power generation, co-generation and sea water desalination. With this in mind, an integral reactor SMART is under development. Design concepts, system layout and types of equipment of integral reactor are significantly different from those of loop type reactor. Conceptual design development of mechanical structures of integral reactor SMART is completed through the first stage of the project. Efforts were endeavored for the establishment of design basis and evaluation of applicable codes and standards. Design and functional requirements of major structural components were set up, and three dimensional structural modelling of SMART reactor vessel assembly was prepared. Also, maintenance and repair scheme as well as preliminary fabricability evaluation were carried out. Since small integral reactor technology includes sensitive technologies and know-how's, it is hard to achieve systematic and comprehensive technology transfer from nuclear-advanced countries. Thus, it is necessary to develop the related design technology and to verify the adopted methodologies through test and experiments in order to assure the structural integrity of reactor system. (author)

  1. Development of mechanical design technology for integral reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keun Bae; Choi, Suhn; Kim, Kang Soo; Kim, Tae Wan; Jeong, Kyeong Hoon; Lee, Gyu Mahn

    1999-03-01

    While Korean nuclear reactor strategy seems to remain focused on the large capacity power generation, it is expected that demand of small and medium size reactor will arise for multi-purpose application such as small capacity power generation, co-generation and sea water desalination. With this in mind, an integral reactor SMART is under development. Design concepts, system layout and types of equipment of integral reactor are significantly different from those of loop type reactor. Conceptual design development of mechanical structures of integral reactor SMART is completed through the first stage of the project. Efforts were endeavored for the establishment of design basis and evaluation of applicable codes and standards. Design and functional requirements of major structural components were setup, and three dimensional structural modelling of SMART reactor vessel assembly was prepared. Also, maintenance and repair scheme as well as preliminary fabricability evaluation were carried out. Since small integral reactor technology includes sensitive technologies and know-how's, it is hard to achieve systematic and comprehensive technology transfer from nuclear-advanced countries. Thus, it is necessary to develop the related design technology and to verify the adopted methodologies through test and experiments in order to assure the structural integrity of reactor system. (author)

  2. Mechanical design optimization of bioabsorbable fixation devices for bone fractures.

    Science.gov (United States)

    Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret

    2009-03-01

    Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

  3. Statistical methods in the mechanical design of fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Radsak, C.; Streit, D.; Muench, C.J. [AREVA NP GmbH, Erlangen (Germany)

    2013-07-01

    The mechanical design of a fuel assembly is still being mainly performed in a de terministic way. This conservative approach is however not suitable to provide a realistic quantification of the design margins with respect to licensing criter ia for more and more demanding operating conditions (power upgrades, burnup increase,..). This quantification can be provided by statistical methods utilizing all available information (e.g. from manufacturing, experience feedback etc.) of the topic under consideration. During optimization e.g. of the holddown system certain objectives in the mechanical design of a fuel assembly (FA) can contradict each other, such as sufficient holddown forces enough to prevent fuel assembly lift-off and reducing the holddown forces to minimize axial loads on the fuel assembly structure to ensure no negative effect on the control rod movement.By u sing a statistical method the fuel assembly design can be optimized much better with respect to these objectives than it would be possible based on a deterministic approach. This leads to a more realistic assessment and safer way of operating fuel assemblies. Statistical models are defined on the one hand by the quanti le that has to be maintained concerning the design limit requirements (e.g. one FA quantile) and on the other hand by the confidence level which has to be met. Using the above example of the holddown force, a feasible quantile can be define d based on the requirement that less than one fuel assembly (quantile > 192/19 3 [%] = 99.5 %) in the core violates the holddown force limit w ith a confidence of 95%. (orig.)

  4. Mechanical Design of the SMC (Short Model Coil) Dipole Magnet

    International Nuclear Information System (INIS)

    Regis, F.; Fessia, P.; Bajko, M.; Rijk, G. de; Manil, P.

    2010-01-01

    The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb 3 Sn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm 2 Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb 3 Sn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (FEM) models have been implemented in ANSYS and in CAST3M, aiming at setting the mechanical parameters of the dipole magnet structure, thus fulfilling the design constraints imposed by the materials. (authors)

  5. Mechanical Design of the SMC (Short Model Coil) Dipole Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Regis, F.; Fessia, P.; Bajko, M.; Rijk, G. de [European Organization for Nuclear Research - CERN, CH-1211, Geneve 23 (Switzerland); Manil, P. [CEA/Saclay, IRFU/SIS, 91191 Gif-sur-Yvette (France)

    2010-06-15

    The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb{sub 3}Sn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm{sup 2} Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb{sub 3}Sn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (FEM) models have been implemented in ANSYS and in CAST3M, aiming at setting the mechanical parameters of the dipole magnet structure, thus fulfilling the design constraints imposed by the materials. (authors)

  6. Opto-mechanical design of small infrared cloud measuring device

    Science.gov (United States)

    Zhang, Jiao; Yu, Xun; Tao, Yu; Jiang, Xu

    2018-01-01

    In order to make small infrared cloud measuring device can be well in a wide temperature range and day-night environment, a design idea using catadioptric infrared panoramic imaging optical system and simple mechanical structure for realizing observation clode under all-weather conditions was proposed. Firstly, the optical system of cloud measuring device was designed. An easy-to-use numerical method was proposed to acquire the profile of a catadioptric mirror, which brought the property of equidistance projection and played the most important role in a catadioptric panoramic lens. Secondly, the mechanical structure was studied in detail. Overcoming the limitations of traditional primary mirror support structure, integrative design was used for refractor and mirror support structure. Lastly, temperature adaptability and modes of the mirror support structure were analyzed. Results show that the observation range of the cloud measuring device is wide and the structure is simple, the fundamental frequency of the structure is greater than 100 Hz, the surface precision of the system reflector reaches PV of λ/10 and RMS of λ/40under the load of temperature range - 40 60°C, it can meet the needs of existing meteorological observation.

  7. How the RRR neutronic characteristics impact on the mechanical design

    International Nuclear Information System (INIS)

    Villarino, E.; Coquibus, K.

    2005-01-01

    This paper describes how the neutronic characteristics of a very demanding research reactor facility impact on the mechanical design of the reactor core. The Replacement Research Reactor (RRR) for the Australian Nuclear Science and Technology Organization is described making emphasis in the mechanical solutions to improve the core performance. The compact core is located inside a chimney, surrounded by heavy water contained in the Reflector Vessel. The whole assembly is at the bottom of the Reactor Pool, which is full of de-mineralized light water acting as coolant and moderator and biological shielding. The core is an array of sixteen plate-type Fuel Assemblies (FAs) and five absorber plates, which are called Control Plates (CP). The coolant is light water, which flows upwards. The final design of the core layout and control guide boxes was adopted to minimize the flux and PPF perturbation during the normal operation. The four lateral control plates are used mainly to shutdown the reactor and to compensate large reactivity transients. The central and cruciform regulating plate is used to compensate the reactivity change during the cycle operation. The regulating plate does minimize perturbation on PPF and irradiation fluxes. The design of the reflector tank fulfills all the flux requirements for the irradiation facilities and also the flux perturbation between irradiation facilities. (authors)

  8. Panel discussion on rock mechanics issues in repository design

    International Nuclear Information System (INIS)

    Bieniawski, Z.T.; Kim, K.S.; Nataraja, M.

    1996-01-01

    The panel discussion was introduced by Mr. Z.T.(Richard) Bieniawski and then continued with five additional speakers. The topics covered in the discussion included rock mechanics pertaining to the design of underground facilities for the disposal of radioactive wastes and the safety of such facilities. The speakers included: Mr. Kun-Soo Kim who is a specialist in the area of rock mechanics testing during the Basalt Waste Isolation Project; Dr. Mysore Nataraja who is the senior project manager with the NRC; Dr. Michael Voegele who is the project manager for Science Applications International Corporation (SAIC) on the Yucca Mountain Project; Dr. Edward Cording who is a member of the Nuclear Waste Technical Review Board; and Dr. Hemendra Kalia who is employed by Los Alamos National Laboratory and coordinates various activities of testing programs at the Yucca Mountain Site

  9. SPICA/SAFARI Fourier transform spectrometer mechanism evolutionary design

    Science.gov (United States)

    van den Dool, Teun C.; Kruizinga, Bob; Braam, Ben C.; Hamelinck, Roger F. M. M.; Loix, Nicolas; Van Loon, Dennis; Dams, Johan

    2012-09-01

    TNO, together with its partners, have designed a cryogenic scanning mechanism for use in the SAFARI1 Fourier Transform Spectrometer (FTS) on board of the SPICA mission. SPICA is one of the M-class missions competing to be launched in ESA's Cosmic Vision Programme2 in 2022. JAXA3 leads the development of the SPICA satellite and SRON is the prime investigator of the Safari instrument. The FTS scanning mechanism (FTSM) has to meet a 35 mm stroke requirement with an Optical Path Difference resolution of less then 15 nm and must fit in a small volume. It consists of two back-to-back roof-top mirrors mounted on a small carriage, which is moved using a magnetic bearing linear guiding system in combination with a magnetic linear motor serving as the OPD actuator. The FTSM will be used at cryogenic temperatures of 4 Kelvin inducing challenging requirements on the thermal power dissipation and heat leak. The magnetic bearing enables movements over a scanning stroke of 35.5 mm in a small volume. It supports the optics in a free-floating way with no friction, or other non-linearities, with sub-nanometer accuracy. This solution is based on the design of the breadboard ODL (Optical Delay Line) developed for the ESA Darwin mission4 and the MABE mechanism developed by Micromega Dynamics. During the last couple of years the initial design of the SAFARI instrument, as described in an earlier SPIE 2010 paper5, was adapted by the SAFARI team in an evolutionary way to meet the changing requirements of the SPICA payload module. This presentation will focus on the evolution of the FTSM to meet these changing requirements. This work is supported by the Netherlands Space Office (NSO).

  10. Self-Stabilising Quadrupedal Running by Mechanical Design

    Directory of Open Access Journals (Sweden)

    Panagiotis Chatzakos

    2009-01-01

    Full Text Available Dynamic stability allows running animals to maintain preferred speed during locomotion over rough terrain. It appears that rapid disturbance rejection is an emergent property of the mechanical system. In running robots, simple motor control seems to be effective in the negotiation of rough terrain when used in concert with a mechanical system that stabilises passively. Spring-like legs are a means for providing self-stabilising characteristics against external perturbations. In this paper, we show that a quadruped robot could be able to perform self-stable running behaviour in significantly broader ranges of forward speed and pitch rate with a suitable mechanical design, which is not limited to choosing legs spring stiffness only. The results presented here are derived by studying the stability of the passive dynamics of a quadruped robot running in the sagittal plane in a dimensionless context and might explain the success of simple, open loop running controllers on existing experimental quadruped robots. These can be summarised in (a the self-stabilised behaviour of a quadruped robot for a particular gait is greatly related to the magnitude of its dimensionless body inertia, (b the values of hip separation, normalised to rest leg length, and leg relative stiffness of a quadruped robot affect the stability of its motion and should be in inverse proportion to its dimensionless body inertia, and (c the self-stable regime of quadruped running robots is enlarged at relatively high forward speeds. We anticipate the proposed guidelines to assist in the design of new, and modifications of existing, quadruped robots. As an example, specific design changes for the Scout II quadruped robot that might improve its performance are proposed.

  11. Update and Improve Subsection NH - Simplified Elastic and Inelastic Design Analysis Methods

    Energy Technology Data Exchange (ETDEWEB)

    Jeries J. Abou-Hanna; Douglas L. Marriott; Timothy E. McGreevy

    2009-06-27

    The objective of this subtask is to develop a template for the 'Ideal' high temperature design Code, in which individual topics can be identified and worked on separately in order to provide the detail necessary to comprise a comprehensive Code. Like all ideals, this one may not be attainable as a practical matter. The purpose is to set a goal for what is believed the 'Ideal' design Code should address, recognizing that some elements are not mutually exclusive and that the same objectives can be achieved in different way. Most, if not all existing Codes may therefore be found to be lacking in some respects, but this does not mean necessarily that they are not comprehensive. While this subtask does attempt to list the elements which individually or in combination are considered essential in such a Code, the authors do not presume to recommend how these elements should be implemented or even, that they should all be implemented at all. The scope of this subtask is limited to compiling the list of elements thought to be necessary or at minimum, useful in such an 'Ideal' Code; suggestions are provided as to their relationship to one another. Except for brief descriptions, where these are needed for clarification, neither this repot, nor Task 9 as a whole, attempts to address details of the contents of all these elements. Some, namely primary load limits (elastic, limit load, reference stress), and ratcheting (elastic, e-p, reference stress) are dealt with specifically in other subtasks of Task 9. All others are merely listed; the expectation is that they will either be the focus of attention of other active DOE-ASME GenIV Materials Tasks, e.g. creep-fatigue, or to be considered in future DOE-ASME GenIV Materials Tasks. Since the focus of this Task is specifically approximate methods, the authors have deemed it necessary to include some discussion on what is meant by 'approximate'. However, the topic will be addressed in one or

  12. Update and Improve Subsection NH - Simplified Elastic and Inelastic Design Analysis Methods

    International Nuclear Information System (INIS)

    Abou-Hanna, Jeries J.; Marriott, Douglas L.; McGreevy, Timothy E.

    2009-01-01

    The objective of this subtask is to develop a template for the 'Ideal' high temperature design Code, in which individual topics can be identified and worked on separately in order to provide the detail necessary to comprise a comprehensive Code. Like all ideals, this one may not be attainable as a practical matter. The purpose is to set a goal for what is believed the 'Ideal' design Code should address, recognizing that some elements are not mutually exclusive and that the same objectives can be achieved in different way. Most, if not all existing Codes may therefore be found to be lacking in some respects, but this does not mean necessarily that they are not comprehensive. While this subtask does attempt to list the elements which individually or in combination are considered essential in such a Code, the authors do not presume to recommend how these elements should be implemented or even, that they should all be implemented at all. The scope of this subtask is limited to compiling the list of elements thought to be necessary or at minimum, useful in such an 'Ideal' Code; suggestions are provided as to their relationship to one another. Except for brief descriptions, where these are needed for clarification, neither this repot, nor Task 9 as a whole, attempts to address details of the contents of all these elements. Some, namely primary load limits (elastic, limit load, reference stress), and ratcheting (elastic, e-p, reference stress) are dealt with specifically in other subtasks of Task 9. All others are merely listed; the expectation is that they will either be the focus of attention of other active DOE-ASME GenIV Materials Tasks, e.g. creep-fatigue, or to be considered in future DOE-ASME GenIV Materials Tasks. Since the focus of this Task is specifically approximate methods, the authors have deemed it necessary to include some discussion on what is meant by 'approximate'. However, the topic will be addressed in one or more later subtasks. This report describes

  13. Mechanical design of a 250 kilogauss solenoidal magnet

    International Nuclear Information System (INIS)

    Bonanos, P.

    1975-12-01

    The mechanical design and construction of a 5 cm bore, 23 cm long solenoidal magnet operated at 250 kilogauss is described. The magnet provides confining field for a plasma heated by a CO 2 laser. Radial diagnostic ports with a clear aperture of 0.41 cm allow viewing access near the magnet midplane. The on-axis field homogeneity is within 5 percent over a central length of 12 cm. The magnet sustained 500 to 1000 pulses at the highest field levels before catastrophic failure

  14. Social Welfare in Algorithmic Mechanism Design Without Money

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris

    Social choice theory is concerned with collective decision making under different, possibly contrasting opinions and has been part of the core of society since ancient times. The goal is to implement some socially desired objective while at the same time accounting for the fact that people will act...... strategically, in order to manipulate the outcomes in their favor. In this thesis, we consider the well-known objective of social welfare, i.e. the sum of individual utilities as the social objective and following the agenda of algorithmic mechanism design, we study how well our objectives can be approximated...

  15. Beta II plasma-gun mechanical design and construction

    International Nuclear Information System (INIS)

    Pedrotti, L.; Deis, G.; Wong, R.; Calderon, M.; Chargin, A.; Garner, D.

    1979-01-01

    The magnetized coaxial plasma gun (located on the east end of the Beta II facility at the Lawrence Livermore Laboratory) will be used to test a new method of initiating a field reversed mirror plasma. The field-reversed mirror is expected to improve the mirror-fusion reactor by enhancing the ratio of fusion power to injected power. This paper concentrates on the mechanical design and construction of the magnetized coaxial plasma gun and also discusses the diagnostic devices necessary to demonstrate the formation of field-reversed rings

  16. PGT: A Statistical Approach to Prediction and Mechanism Design

    Science.gov (United States)

    Wolpert, David H.; Bono, James W.

    One of the biggest challenges facing behavioral economics is the lack of a single theoretical framework that is capable of directly utilizing all types of behavioral data. One of the biggest challenges of game theory is the lack of a framework for making predictions and designing markets in a manner that is consistent with the axioms of decision theory. An approach in which solution concepts are distribution-valued rather than set-valued (i.e. equilibrium theory) has both capabilities. We call this approach Predictive Game Theory (or PGT). This paper outlines a general Bayesian approach to PGT. It also presents one simple example to illustrate the way in which this approach differs from equilibrium approaches in both prediction and mechanism design settings.

  17. Enclosed mechanical seal face design for brittle materials copyright

    International Nuclear Information System (INIS)

    Marsi, J.A.

    1994-01-01

    Metal carbides are widely used as seal face material due to their hardness and wear resistance. Silicon carbide (SiC) has excellent performance as a seal face material, but it is relatively brittle and may break due to accidental overloads outside the boundary of normal operating conditions. In mechanical seals for nuclear primary coolant pumps, the shattered SiC pieces can get into the reactor system and cause serious damage. The conventional method of containing an SiC seal face is to shrink-fit it in a holder, which may lead the seal designer to contend with unwanted seal face deflections. This paper presents a successful, tested design which does not rely on shrink-fits. 5 refs., 9 figs., 4 tabs

  18. Updated pipe break analysis for Advanced Neutron Source Reactor conceptual design

    International Nuclear Information System (INIS)

    Wendel, M.W.; Chen, N.C.J.; Yoder, G.L.

    1994-01-01

    The Advanced Neutron Source Reactor (ANSR) is a research reactor to be built at the Oak Ridge National Laboratory that will supply the highest continuous neutron flux levels of any reactor in the world. It uses plate-type fuel with high-mass-flux and highly subcooled heavy water as the primary coolant. The Conceptual Safety Analysis for the ANSR was completed in June 1992. The thermal-hydraulic pipe-break safety analysis (performed with a specialized version of RELAP5/MOD3) focused primarily on double-ended guillotine breaks of the primary piping and some core-damage mitigation options for such an event. Smaller, instantaneous pipe breaks in the cold- and hot-leg piping were also analyzed to a limited extent. Since the initial analysis for the conceptual design was completed, several important changes to the RELAP5 input model have been made reflecting improvements in the fuel grading and changes in the elevation of the primary coolant pumps. Also, a new philosophy for pipe-break safety analysis (similar to that adopted for the New Production Reactor) accentuates instantaneous, limited flow area pipe-break accidents in addition to finite-opening-time, double-ended guillotine breaks of the major coolant piping. This paper discloses the results of the most recent instantaneous pipe-break calculations

  19. Mechanical Design of Innovative Electromagnetic Linear Actuators for Marine Applications

    Science.gov (United States)

    Muscia, Roberto

    2017-11-01

    We describe an engineering solution to manufacture electromagnetic linear actuators for moving rudders and fin stabilizers of military shipsItalian Ministry of Defence, General Direction of Naval Equipments (NAVARM), Projects ISO (2012-2014) and EDDA (2015-2017). . The solution defines the transition from the conceptual design of the device initially studied from an electromagnetic point of view to mechanical configurations that really work. The structural problems that have been resolved with the proposed configuration are described. In order to validate the design choices discussed we illustrate some results of the numerical simulations performed by the structural finite elements method. These results quantitatively justify the suggested mechanical solution by evaluating stresses and deformations in a virtual prototype of the structure during its functioning. The parts of the device that have been studied are the most critical because in cases of excessive deformation/stress, they can irreparably compromise the actuator operation. These parts are the pole piece-base set and the retention cages of the permanent magnets. The FEM analysis has allowed us to identify the most stressed areas of the previous elements whose shape has been appropriately designed so as to reduce the maximum stresses and deformations. Moreover, the FEM analysis helped to find the most convenient solution to join the pole pieces to the respective bases. The good results obtained by the suggested engineering solution have been experimentally confirmed by tests on a small prototype actuator purposely manufactured. Finally, a qualitative analysis of the engineering problems that have to be considered to design electromagnetic linear actuators bigger than the one already manufactured is illustrated.

  20. Mechanical Design of Innovative Electromagnetic Linear Actuators for Marine Applications

    Directory of Open Access Journals (Sweden)

    Muscia Roberto

    2017-11-01

    Full Text Available We describe an engineering solution to manufacture electromagnetic linear actuators for moving rudders and fin stabilizers of military shipsItalian Ministry of Defence, General Direction of Naval Equipments (NAVARM, Projects ISO (2012-2014 and EDDA (2015-2017.. The solution defines the transition from the conceptual design of the device initially studied from an electromagnetic point of view to mechanical configurations that really work. The structural problems that have been resolved with the proposed configuration are described. In order to validate the design choices discussed we illustrate some results of the numerical simulations performed by the structural finite elements method. These results quantitatively justify the suggested mechanical solution by evaluating stresses and deformations in a virtual prototype of the structure during its functioning. The parts of the device that have been studied are the most critical because in cases of excessive deformation/stress, they can irreparably compromise the actuator operation. These parts are the pole piece-base set and the retention cages of the permanent magnets. The FEM analysis has allowed us to identify the most stressed areas of the previous elements whose shape has been appropriately designed so as to reduce the maximum stresses and deformations. Moreover, the FEM analysis helped to find the most convenient solution to join the pole pieces to the respective bases. The good results obtained by the suggested engineering solution have been experimentally confirmed by tests on a small prototype actuator purposely manufactured. Finally, a qualitative analysis of the engineering problems that have to be considered to design electromagnetic linear actuators bigger than the one already manufactured is illustrated.

  1. Mechanisms and coherences of robust design methodology: a robust design process proposal

    DEFF Research Database (Denmark)

    Göhler, Simon Moritz; Christensen, Martin Ebro; Howard, Thomas J.

    2016-01-01

    Although robust design (RD) methods are recognised as a way of developing mechanical products with consistent and predictable performance and quality, they do not experience widespread success in industry. One reason being the lack of a coherent RD process (RDP). In this contribution we analyse...

  2. Mechanical Design of the NSTX Liquid Lithium Divertor

    Energy Technology Data Exchange (ETDEWEB)

    R. Ellis, R. Kaita, H. Kugel, G. Paluzzi, M. Viola and R. Nygren

    2009-02-19

    The Liquid Lithium Divertor (LLD) on NSTX will be the first test of a fully-toroidal liquid lithium divertor in a high-power magnetic confinement device. It will replace part of the lower outboard divertor between a specified inside and outside radius, and ultimately provide a lithium surface exposed to the plasma with enough depth to absorb a significant particle flux. There are numerous technical challenges involved in the design. The lithium layer must be as thin as possible, and maintained at a temperature between 200 and 400 degrees Celsius to minimize lithium evaporation. This requirement leads to the use of a thick copper substrate, with a thin stainless steel layer bonded to the plasma-facing surface. A porous molybdenum layer is then plasma-sprayed onto the stainless steel, to provide a coating that facilitates full wetting of the surface by the liquid lithium. Other challenges include the design of a robust, vacuumcompatible heating and cooling system for the LLD. Replacement graphite tiles that provided the proper interface between the existing outer divertor and the LLD also had to be designed, as well as accommodation for special LLD diagnostics. This paper describes the mechanical design of the LLD, and presents analyses showing the performance limits of the LLD.

  3. The mechanical design for the WEAVE prime focus corrector system

    Science.gov (United States)

    Abrams, Don Carlos; Dee, Kevin; Agócs, Tibor; Lhome, Emilie; Peñate, José; Jaskó, Attila; Bányai, Evelin; Burgal, José A.; Dalton, Gavin; Middleton, Kevin; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; Trager, S. C.; Balcells, Marc

    2014-08-01

    WEAVE is the next-generation, wide-field, optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. The WHT will undergo a significant adaptation to accommodate this facility. A two- degree Prime Focus Corrector (PFC), that includes an Atmospheric Dispersion Compensator, is being planned and is currently in its final design phase. To compensate for the effects of temperature-induced image degradation, the entire PFC system will be translated along the telescope optical axis. The optical system comprises six lenses, the largest of which will have a diameter of 1.1m. Now that the optical elements are in production, the designs for the lens cells and the mounting arrangements are being analysed to ensure that the image quality of the complete system is better than 1.0 arcsec (80% encircled energy diameter) over the full field of view. The new PFC system is designed to be routinely interchanged with the existing top-end ring. This will maximise the versatility of the WHT and allow the two top-end systems to be interchanged as dictated by the scientific needs of the astronomers that will use WEAVE and other instruments on the telescope. This manuscript describes the work that has been carried out in developing the designs for the mechanical subsystems and the plans for mounting the lenses to attain an optical performance that is commensurate with the requirements derived from planning the WEAVE surveys.

  4. Mechanical Design of the NSTX Liquid Lithium Divertor

    International Nuclear Information System (INIS)

    Ellis, R.; Kaita, R.; Kugel, H.; Paluzzi, G.; Viola, M.; Nygren, R.

    2009-01-01

    The Liquid Lithium Divertor (LLD) on NSTX will be the first test of a fully-toroidal liquid lithium divertor in a high-power magnetic confinement device. It will replace part of the lower outboard divertor between a specified inside and outside radius, and ultimately provide a lithium surface exposed to the plasma with enough depth to absorb a significant particle flux. There are numerous technical challenges involved in the design. The lithium layer must be as thin as possible, and maintained at a temperature between 200 and 400 degrees Celsius to minimize lithium evaporation. This requirement leads to the use of a thick copper substrate, with a thin stainless steel layer bonded to the plasma-facing surface. A porous molybdenum layer is then plasma-sprayed onto the stainless steel, to provide a coating that facilitates full wetting of the surface by the liquid lithium. Other challenges include the design of a robust, vacuum compatible heating and cooling system for the LLD. Replacement graphite tiles that provided the proper interface between the existing outer divertor and the LLD also had to be designed, as well as accommodation for special LLD diagnostics. This paper describes the mechanical design of the LLD, and presents analyses showing the performance limits of the LLD.

  5. Refuge alternatives relief valve testing and design with updated test stand.

    Science.gov (United States)

    Lutz, T J; Bissert, P T; Homce, G T; Yonkey, J A

    2018-03-01

    Underground refuge alternatives require an air source to supply breathable air to the occupants. This requires pressure relief valves to prevent unsafe pressures from building up within the refuge alternative. The U.S. Mine Safety and Health Administration (MSHA) mandates that pressure relief valves prevent pressure from exceeding 1.25 kPa (0.18 psi), or as specified by the manufacturer, above mine atmospheric pressure when a fan or compressor is used for the air supply. The U.S. National Institute for Occupational Safety and Health (NIOSH) tested a variety of pressure relief valves using an instrumented test fixture consisting of data acquisition equipment, a centrifugal blower, ductwork and various sensors to determine if the subject pressure relief valves meet the MSHA requirement. Relief pressures and flow characteristics, including opening pressure and flow rate, were measured for five different pressure relief valves under a variety of conditions. The subject pressure relief valves included two off-the-shelf modified check valves, two check valves used in MSHA-approved built-in-place refuge alternatives, and a commercially available valve that was designed for a steel refuge alternative and is currently being used in some built-in-place refuge alternatives. The test results showed relief pressures ranging from 0.20 to 1.53 kPa (0.03 to 0.22 psi) and flow rates up to 19.3 m 3 /min (683 scfm). As tested, some of the pressure relief valves did not meet the 1.25 kPa (0.18 psi) relief specification.

  6. Mechanical system design in the engineering design of digital x-ray

    International Nuclear Information System (INIS)

    Muhammad Awwaluddin; I Putu Susila; Edy Purwanta; Abdul Jalil; Ahmad H

    2014-01-01

    Has been designed a mechanical system design to hold and moving the x-ray tube, detector films, and a place the holder control box. The design was conducted on the frame foundation, frame columns and frame arms in order to operate the device as well SS304 hollow measuring 40 x 60 x mm with thickness of 2 mm long 4.1 m, size 100 x 100 mm and 2 mm thick along the 2 m, and the size of 40 x 80 mm thickness 2 mm long 1.8 m is needed to reactive the design the linear guide way models HGW20HB 3 m. With the proposed design, the operation of the digital x-rays can be completed as well. (author)

  7. Intelligent design of mechanical parameters of the joint in vehicle body concept design model

    Science.gov (United States)

    Hou, Wen-bin; Zhang, Hong-zhe; Hou, Da-jun; Hu, Ping

    2013-05-01

    In order to estimate the mechanical properties of the overall structure of the body accurately and quickly in conceptual design phase of the body, the beam and shell mixing elements was used to build simplified finite element model of the body. Through the BP neural network algorithm, the parameters of the mechanical property of joints element which had more affection on calculation accuracy were calculated and the joint finite element model based on the parameters was also constructed. The case shown that the method can improve the accuracy of the vehicle simulation results, while not too many design details were needed, which was fit to the demand in the vehicle body conceptual design phase.

  8. Fracture mechanics in new designed power module under thermo-mechanical loads

    Directory of Open Access Journals (Sweden)

    Durand Camille

    2014-06-01

    Full Text Available Thermo-mechanically induced failure is a major reliability issue in the microelectronic industry. On this account, a new type of Assembly Interconnected Technology used to connect MOSFETs in power modules has been developed. The reliability is increased by using a copper clip soldered on the top side of the chip, avoiding the use of aluminium wire bonds, often responsible for the failure of the device. Thus the new designed MOSFET package does not follow the same failure mechanisms as standard modules. Thermal and power cycling tests were performed on these new packages and resulting failures were analyzed. Thermo-mechanical simulations including cracks in the aluminium metallization and intermetallics (IMC were performed using Finite Element Analysis in order to better understand crack propagation and module behaviour.

  9. Mechanisms of change in psychotherapy for depression : An empirical update and evaluation of research aimed at identifying psychological mediators

    NARCIS (Netherlands)

    Lemmens, L.H.J.M.; Müller, V.N.L.S.; Arntz, A.; Huibers, M.J.H.

    2016-01-01

    We present a systematic empirical update and critical evaluation of the current status of research aimed at identifying a variety of psychological mediators in various forms of psychotherapy for depression. We summarize study characteristics and results of 35 relevant studies, and discuss the extent

  10. Dynamic Financial Constraints: Distinguishing Mechanism Design from Exogenously Incomplete Regimes.

    Science.gov (United States)

    Karaivanov, Alexander; Townsend, Robert M

    2014-05-01

    We formulate and solve a range of dynamic models of constrained credit/insurance that allow for moral hazard and limited commitment. We compare them to full insurance and exogenously incomplete financial regimes (autarky, saving only, borrowing and lending in a single asset). We develop computational methods based on mechanism design, linear programming, and maximum likelihood to estimate, compare, and statistically test these alternative dynamic models with financial/information constraints. Our methods can use both cross-sectional and panel data and allow for measurement error and unobserved heterogeneity. We estimate the models using data on Thai households running small businesses from two separate samples. We find that in the rural sample, the exogenously incomplete saving only and borrowing regimes provide the best fit using data on consumption, business assets, investment, and income. Family and other networks help consumption smoothing there, as in a moral hazard constrained regime. In contrast, in urban areas, we find mechanism design financial/information regimes that are decidedly less constrained, with the moral hazard model fitting best combined business and consumption data. We perform numerous robustness checks in both the Thai data and in Monte Carlo simulations and compare our maximum likelihood criterion with results from other metrics and data not used in the estimation. A prototypical counterfactual policy evaluation exercise using the estimation results is also featured.

  11. Integrated design of castings: effect of porosity on mechanical performance

    International Nuclear Information System (INIS)

    Hardin, R A; Beckermann, C

    2012-01-01

    Porosity can significantly reduce the strength and durability of castings in service. An integrated design approach has been developed where casting simulation is combined with mechanical performance simulations. Predictions of the porosity distribution from the casting process simulation are transferred to and used in stress and fatigue life simulations. Thus, the effect of casting quality on service performance can be evaluated. Results of a study are presented where the measured porosity distribution in cast steel specimens is transferred to an elasto-plastic finite-element stress analysis model. Methods are developed to locally reduce the mechanical properties according to the porosity present, without having to resolve individual pores. Plastic deformation is modeled using porous metal plasticity theory. The predictions are compared to tensile measurements performed on the specimens. The complex deformations and the reductions in the ductility of the specimens due to porosity are predicted well. The predicted stresses are transferred to a fatigue analysis code that takes the porosity distribution into account as well. The measured and predicted fatigue lives are also in good agreement. Finally, the results of a case study are presented that illustrate the utility of the present integrated approach in optimizing the design of a steel casting.

  12. Processing test of an upgraded mechanical design for PERMCAT reactor

    International Nuclear Information System (INIS)

    Borgognoni, Fabio; Demange, David; Doerr, Lothar; Tosti, Silvano; Welte, Stefan

    2010-01-01

    The PERMCAT membrane reactor is a coaxial combination of a Pd/Ag permeator membrane and a catalyst bed. This device has been proposed for processing fusion reactor plasma exhaust gas. A stream containing tritium (up to 1% of tritium in different chemical forms such as water, methane or molecular hydrogen) is decontaminated in the PERMCAT by counter-current isotopic swamping with protium. Different mechanical designs of the membrane reactor have been proposed to improve robustness and lifetime. The ENEA membrane reactor uses a permeator tube with a length of about 500 mm produced via cold-rolling and diffusion welding of Pd/Ag thin foils: two stainless steel pre-tensioned bellows have been applied to the Pd/Ag tube in order to avoid any significant compressive and bending stresses due to the permeator tube elongation consequent to the hydrogen uptake. An experimental test campaign has been performed using this reactor in order to assess the influence of different operating parameters and to evaluate the overall performance (decontamination factor). Tests have been carried out on two reactor prototypes: a defect-free membrane with complete (infinite) hydrogen selectivity and not perm-selective membrane. In this last case, the study has been aimed at verifying the behaviour of the PERMCAT devices under non-normal (accidental) conditions in the view of providing information for future safety analysis. The paper will present the specific mechanical design and the experimental results of tests based on isotopic exchange between H 2 O and D 2 .

  13. Design and construction of a planar motion mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Tanasovici, Gilberto [Protemaq Engenharia e Projetos, Santo Andre, SP (Brazil); Fucatu, Carlos H. [Technomar Engenharia Ltda., Sao Paulo, SP (Brazil); Tannuri, Eduardo A. [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecatronica; Umeda, Carlos H. [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2008-07-01

    This paper describes the design and construction of a PMM (Planar Motion Mechanism) towed by the IPT-SP main carriage. The IPT towing tank no. 2 is 220 m length and 6.6 m wide. The PMM provides a forced sway and/or yaw oscillation on a ship or other marine structure scaled model.. The maximum sway amplitude (transversal motion) is {+-}1 m, and the maximum sway velocity is 1.0 m/s, with a maximum carrying load of 1000 N. The maximum yaw velocity (rotation motion) is 36 deg/s. High-precision components were used in the construction, and the final estimated accuracy in the sway axis is 0.02 mm and approximately 0.1 deg for yaw motions. Finite Element Analysis and Structural Optimization techniques were used during the design stage. The PMM structure total mass is less than 1 ton, lighter than similar mechanisms in other institutions. A Man-Machine Interface was developed, and the operator is able to define the period and amplitude of sway and yaw motions, as well as the fade-in and fade-out time. An integral 3-component force load cell is installed in the end of the support axis, which measures the hydrodynamic loads on the captive model at low speed tests. This novel laboratorial facility allows the IPT to execute new kinds of experimental procedures, related to evaluation of hydrodynamic loads acting on ship hulls and offshore structures. (author)

  14. Maintainability design and evaluation of mechanical systems based on tribology

    International Nuclear Information System (INIS)

    Wani, M.F.; Gandhi, O.P.

    2002-01-01

    Maintainability of mechanical systems based on tribology is suggested and evaluated in this paper. Tribo-features of mechanical systems, which characterise maintainability are identified and are modelled in terms of tribo-maintainability digraph. The nodes in the digraph represent the tribo-features and edges represent the degree of influence among the features. A matrix, one to one representation of the digraph, is defined to develop system maintainability expression (SPF-t) based on the tribology. It is also useful in comparing the various design alternatives from tribo-maintainability point of view. Maintainability is evaluated from the tribo-maintainability index, obtained from SPF-t (i.e. permanent of the matrix) by substituting the numerical values of the features and their interdependence. A higher value of the index implies better maintainability of the systems. The proposed methodology also guides designers in enhancing the maintainability of a system by appropriately incorporating tribo-features. An example to illustrate the methodology is also presented

  15. Mechanical design of the second ICRF antenna for EAST

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.Q., E-mail: yangqx@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Song, Y.T.; Wu, S.T.; Zhao, Y.P.; Zhang, J.X.; Wang, Z.W. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer The second ICRF antenna of EAST is capable of coupling higher power than the former ICRF antenna due to it has been designed with four current straps. Black-Right-Pointing-Pointer Many cooling channels have been designed for the key components of faraday shied, current strap, baffles and transmission lines, which can remove the dissipated RF loss power and incoming heat loads on them and make ICRF antenna being capable of coupling higher power in constant wave operation. Black-Right-Pointing-Pointer Extra structure via cantilever support beam has been designed to support the forepart of the ICRF antenna. Black-Right-Pointing-Pointer Numerical analysis by applying the thermo-mechanical coupling method have been applied to analyze for the key components of ICRF antenna. - Abstract: In order to satisfy the requirements of heating plasma on EAST project, 3 MW ion cyclotron range of frequency (ICRF) heating system will be available at the second stage. Based on this requirement, the second ICRF antenna, has been designed for EAST. The antenna which is planned to operate with a frequency ranging from 30 MHz to 110 MHz, comprises four poloidal current straps. The antenna has many cooling channels inside the current straps, faraday shield and baffle to remove the dissipated RF loss power and incoming plasma heat loads. The antenna is supported via a cantilever support box to the external support structure. Its assembly is plugged in the port and fixed on the support box. External slideway and bellows allow the antenna to be able to move in the radial direction. The key components of the second ICRF antenna has been designed together with structural and thermal analysis presented.

  16. The avian egg exhibits general allometric invariances in mechanical design.

    Science.gov (United States)

    Juang, Jia-Yang; Chen, Pin-Yi; Yang, Da-Chang; Wu, Shang-Ping; Yen, An; Hsieh, Hsin-I

    2017-10-27

    The avian egg exhibits extraordinary diversity in size, shape and color, and has a key role in avian adaptive radiations. Despite extensive work, our understanding of the underlying principles that guide the "design" of the egg as a load-bearing structure remains incomplete, especially over broad taxonomic scales. Here we define a dimensionless number C, a function of egg weight, stiffness and dimensions, to quantify how stiff an egg is with respect to its weight after removing geometry-induced rigidity. We analyze eggs of 463 bird species in 36 orders across five orders of magnitude in body mass, and find that C number is nearly invariant for most species, including tiny hummingbirds and giant elephant birds. This invariance or "design guideline" dictates that evolutionary changes in shell thickness and Young's modulus, both contributing to shell stiffness, are constrained by changes in egg weight. Our analysis illuminates unique reproductive strategies of brood parasites, kiwis, and megapodes, and quantifies the loss of safety margin for contact incubation due to artificial selection and environmental toxins. Our approach provides a mechanistic framework for a better understanding of the mechanical design of the avian egg, and may provide clues to the evolutionary origin of contact incubation of amniote eggs.

  17. Computer-based Creativity Enhanced Conceptual Design Model for Non-routine Design of Mechanical Systems

    Institute of Scientific and Technical Information of China (English)

    LI Yutong; WANG Yuxin; DUFFY Alex H B

    2014-01-01

    Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure(FBS) model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model(CECD) for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions(BOA), and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

  18. Computer-based creativity enhanced conceptual design model for non-routine design of mechanical systems

    Science.gov (United States)

    Li, Yutong; Wang, Yuxin; Duffy, Alex H. B.

    2014-11-01

    Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure(FBS) model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model(CECD) for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions(BOA), and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

  19. Mechanical Design of Odin, an Extendable Heterogeneous Deformable Modular Robot

    DEFF Research Database (Denmark)

    Lyder, Andreas; Garcia, Ricardo Franco Mendoza; Støy, Kasper

    2008-01-01

    Highly sophisticated animals consist of a set of heterogenous modules decided by nature so that they can survive in a complex environment. In this paper we present a new modular robot inspired by biology called Odin. The Odin robot is based on a deformable lattice and consists of an extendable se...... of heterogeneous modules. We present the design and implementation of a cubic closed-packed (CCP) joint module, a telescoping link, and a flexible connection mechanism. The developed robot is highly versatile and opens up for a wide range of new research in modular robotics.......Highly sophisticated animals consist of a set of heterogenous modules decided by nature so that they can survive in a complex environment. In this paper we present a new modular robot inspired by biology called Odin. The Odin robot is based on a deformable lattice and consists of an extendable set...

  20. Current Total Knee Designs: Does Baseplate Roughness or Locking Mechanism Design Affect Polyethylene Backside Wear?

    Science.gov (United States)

    Sisko, Zachary W; Teeter, Matthew G; Lanting, Brent A; Howard, James L; McCalden, Richard W; Naudie, Douglas D; MacDonald, Steven J; Vasarhelyi, Edward M

    2017-12-01

    Tibial baseplate roughness and polyethylene-insert micromotion resulting from locking-mechanism loosening can lead to polyethylene backside wear in TKAs. However, many retrieval studies examining these variables have evaluated only older TKA implant designs. We used implant-retrieval analysis to examine if there were differences in: (1) backside damage scores, (2) backside damage modes, and (3) backside linear wear rates in five TKA implant designs owing to differing baseplate surface roughness and locking mechanisms. Additionally, we examined if (4) patient demographics influence backside damage and wear. Five TKA implant models (four modern and one historical design) were selected with different tibial baseplate and/or locking mechanism designs. Six tibial inserts retrieved at the time of revision from each TKA model were matched for time in vivo, age of the patient at TKA revision, BMI, sex, revision number, and revision reason. Each insert backside was analyzed for: (1) visual total damage score and (2) individual visual damage modes, both by two observers and with an intraclass correlation coefficient of 0.66 (95% CI, 0.39-0.92), and (3) linear wear rate measured by micro-CT. Median primary outcomes were compared among the five designs. For our given sample size among five groups we could detect with 80% power a 10-point difference in damage score and an 0.11-mm per year difference in wear rate. The polished tibial design with a partial peripheral capture locking mechanism and anterior constraint showed a lower total damage score compared with the nonpolished tibial design with only a complete peripheral-rim locking mechanism (median, 12.5; range, 9.5-18.0; 95% CI, 9.58-16.42 versus median, 22.3; range, 15.5-27.0; 95% CI, 17.5-26.5; p = 0.019). The polished baseplate with a tongue-in-groove locking mechanism showed more abrasions than the nonpolished baseplate with a peripheral-rim capture and antirotational island (median, 7.25; range, 0.5-8.0; 95% CI, 2

  1. Processing test of an upgraded mechanical design for PERMCAT reactor

    Energy Technology Data Exchange (ETDEWEB)

    Borgognoni, Fabio, E-mail: fabio.borgognoni@enea.i [Associazione ENEA-Euratom sulla Fusione, C.R. ENEA Frascati, Via E. Fermi 45, Frascati, Roma I-00044 (Italy); Demange, David; Doerr, Lothar [Forschungszentrum Karlsruhe GmbH, Institute for Technical Physics, Tritium Laboratory Karlsruhe, Postfach 3640, D-76021 Karlsruhe (Germany); Tosti, Silvano [Associazione ENEA-Euratom sulla Fusione, C.R. ENEA Frascati, Via E. Fermi 45, Frascati, Roma I-00044 (Italy); Welte, Stefan [Forschungszentrum Karlsruhe GmbH, Institute for Technical Physics, Tritium Laboratory Karlsruhe, Postfach 3640, D-76021 Karlsruhe (Germany)

    2010-12-15

    The PERMCAT membrane reactor is a coaxial combination of a Pd/Ag permeator membrane and a catalyst bed. This device has been proposed for processing fusion reactor plasma exhaust gas. A stream containing tritium (up to 1% of tritium in different chemical forms such as water, methane or molecular hydrogen) is decontaminated in the PERMCAT by counter-current isotopic swamping with protium. Different mechanical designs of the membrane reactor have been proposed to improve robustness and lifetime. The ENEA membrane reactor uses a permeator tube with a length of about 500 mm produced via cold-rolling and diffusion welding of Pd/Ag thin foils: two stainless steel pre-tensioned bellows have been applied to the Pd/Ag tube in order to avoid any significant compressive and bending stresses due to the permeator tube elongation consequent to the hydrogen uptake. An experimental test campaign has been performed using this reactor in order to assess the influence of different operating parameters and to evaluate the overall performance (decontamination factor). Tests have been carried out on two reactor prototypes: a defect-free membrane with complete (infinite) hydrogen selectivity and not perm-selective membrane. In this last case, the study has been aimed at verifying the behaviour of the PERMCAT devices under non-normal (accidental) conditions in the view of providing information for future safety analysis. The paper will present the specific mechanical design and the experimental results of tests based on isotopic exchange between H{sub 2}O and D{sub 2}.

  2. Mechanism Design for Single Leader Stackelberg Problems and Application to Procurement Auction Design

    OpenAIRE

    Garg, Dinesh; Narahari, Y

    2008-01-01

    In this paper, we focus on mechanism design for single leader Stackelberg problems, which are a special case of hierarchical decision making problems in which a distinguished agent, known as the leader, makes the first move and this action is followed by the actions of the remaining agents, which are known as the followers. These problems are also known as single leader rest follower (SLRF) problems. There are many examples of such problems in the areas of electronic commerce, supply chain ma...

  3. Mechanical and thermal design of the Cascade reactor

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1983-01-01

    We present an improved Cascade fusion reaction chamber that is optimized with respect to chamber radius, wall thickness, and pebble blanket outlet temperature. We show results of a parameter study where we varied chamber radius from 3 to 6 m, wall thickness from 15 to 80 mm, and blanket outlet temperature from 900 to 1400 K. Based on these studies, we achieved an optimized chamber with 50% the volume of the original design and 60% of its blanket. Chamber radius is only 4.4 m and its half length is only 5.9 m, decreased from the original 5-m radius and 8-m half-length. In our optimization method, we calculate both thermal and mechanical stresses resulting from x-ray, fusion-pellet-debris, and neutron-generated momentum, pressure from ablated material, centrifugal action, vacuum inside the chamber, and gravity. We add the mechanical stresses to thermal stresses and keep the total less than the yield stress. Further, we require that fluctuations in these stresses be less than that which would produce creep-fatigue failure within the chamber 30-year lifetime

  4. Design of synchromesh mechanism to optimization manual transmission's electric vehicle

    Science.gov (United States)

    Zainuri, Fuad; Sumarsono, Danardono A.; Adhitya, Muhammad; Siregar, Rolan

    2017-03-01

    Significant research has been attempted on a vehicle that lead to the development of transmission that can reduce energy consumption and improve vehicle efficiency. Consumers also expect safety, convenience, and competitive prices. Automatic transmission (AT), continuously variable transmission (CVT), and dual clutch transmission (DCT) is the latest transmission developed for road vehicle. From literature reviews that have been done that this transmission is less effective on electric cars which use batteries as a power source compared to type manual transmission, this is due to the large power losses when making gear changes. Zeroshift system is the transmission can do shift gears with no time (zero time). It was developed for the automatic manual transmission, and this transmission has been used on racing vehicles to eliminate deceleration when gear shift. Zeroshift transmission still use the clutch to change gear in which electromechanical be used to replace the clutch pedal. Therefore, the transmission is too complex for the transmission of electric vehicles, but its mechanism is considered very suitable to increase the transmission efficiency. From this idea, a new innovation design transmission will be created to electric car. The combination synchromesh with zeroshift mechanism for the manual transmission is a transmission that is ideal for improving the transmission efficiency. Installation synchromesh on zeroshift mechanism is expected to replace the function of the clutch MT, and assisted with the motor torque setting when to change gear. Additionally to consider is the weight of the transmission, ease of manufacturing, ease of installation with an electric motor, as well as ease of use by drivers is a matter that must be done to obtain a new transmission system that is suitable for electric cars.

  5. Silicon-based tracking system: Mechanical engineering and design

    International Nuclear Information System (INIS)

    Miller, W.O.; Gamble, M.T.; Thompson, T.C.; Woloshun, K.A.; Reid, R.S.; Hanlon, J.A.; Michaud, F.D.; Dransfield, G.D.; Ziock, H.J.; Palounek, A.P.

    1992-01-01

    The Silicon Tracking System (STS) is composed of silicon strip detectors arranged by both in a cylindrical array and an array of flat panels about the interaction region. The cylindrical array is denoted the central region and the flat panel arrays, which are normal to the beam axis, we denoted the forward regions. The overall length of the silicon array is 5.16 m and the maximum diameter is 0.93 m. The Silicon Tracking System Conceptual Design Report, should be consulted for the body of analysis performed to quantify the present design concept. For the STS to achieve its physics goals, the mechanical structures and services must support 17 m 2 of silicon detectors and stabilize their positions to within 5 μm, uniformly cool the detector the system to O degrees C and at the same time potentially remove up to 13 kW of waste heat generated by the detector electronics, provide up to 3400 A of current to supply the 6.5 million electronics channels, and supply of control and data transmission lines for those channels. These objectives must be achieved in a high ionizing radiation environment, using virtually no structural mass and only low-Z materials. The system must be maintainable during its 10 year operating life

  6. Basic MR relaxation mechanisms and contrast agent design.

    Science.gov (United States)

    De León-Rodríguez, Luis M; Martins, André F; Pinho, Marco C; Rofsky, Neil M; Sherry, A Dean

    2015-09-01

    The diagnostic capabilities of magnetic resonance imaging (MRI) have undergone continuous and substantial evolution by virtue of hardware and software innovations and the development and implementation of exogenous contrast media. Thirty years since the first MRI contrast agent was approved for clinical use, a reliance on MR contrast media persists, largely to improve image quality with higher contrast resolution and to provide additional functional characterization of normal and abnormal tissues. Further development of MR contrast media is an important component in the quest for continued augmentation of diagnostic capabilities. In this review we detail the many important considerations when pursuing the design and use of MR contrast media. We offer a perspective on the importance of chemical stability, particularly kinetic stability, and how this influences one's thinking about the safety of metal-ligand-based contrast agents. We discuss the mechanisms involved in MR relaxation in the context of probe design strategies. A brief description of currently available contrast agents is accompanied by an in-depth discussion that highlights promising MRI contrast agents in the development of future clinical and research applications. Our intention is to give a diverse audience an improved understanding of the factors involved in developing new types of safe and highly efficient MR contrast agents and, at the same time, provide an appreciation of the insights into physiology and disease that newer types of responsive agents can provide. © 2015 Wiley Periodicals, Inc.

  7. Mechanical Design of the SMC (Short Model Coil) Dipole Magnet

    CERN Document Server

    Regis, F; Fessia, P; Bajko, M; de Rijk, G

    2010-01-01

    The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb$_{3}$Sn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm2 Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb$_{3}$Sn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (...

  8. Advances in Mechanisms Design : Proceedings of TMM 2012

    CERN Document Server

    Bílek, Martin; Hejnova, Monika; Zabka, Petr; Advances in Mechanisms Design

    2012-01-01

    The International Conference on the Theory of Machines and Mechanisms is organized every four years, under the auspices of the International Federation for the Promotion of Mechanism and Machine Science (IFToMM) and the Czech Society for Mechanics. This eleventh edition of the conference took place at the Technical University of Liberec, Czech Republic, 4-6 September 2012. This volume offers an international selection of the most important new results and developments, in 73 papers, grouped in seven different parts, representing a well-balanced overview, and spanning the general theory of machines and mechanisms, through analysis and synthesis of planar and spatial mechanisms, dynamics of machines and mechanisms, linkages and cams, computational mechanics, rotor dynamics, biomechanics, mechatronics, vibration and noise in machines, optimization of mechanisms and machines, control and monitoring systems of machines, accuracy and reliability of machines and mechanisms, robots and manipulators to the mechanisms ...

  9. The mechanical design of a transfemoral prosthesis using computational tools and design methodology

    Directory of Open Access Journals (Sweden)

    John Sánchez Otero

    2012-09-01

    Full Text Available Artificial limb replacement with lower limb prostheses has been widely reported in current scientific literature. There are many lower limb prosthetic designs ranging from a single-axis knee mechanism to complex mechanisms involving microcontrollers, made from many materials ranging from lightweight, high specific strength ones (e.g., carbon fibre to traditional forms (e.g., stainless steel. However, the challenge is to design prostheses whose movement resembles the human body’s natural movement as closely as possible. Advances in prosthetics have enabled many amputees to return to their everyday activities; however, such prostheses are expensive, some costing as much as $60,000. Many of the affected population in Colombia have scarce economic resources; there is therefore a need to develop affordable functional prostheses.The Universidad del Norte’s Materials, Processes and Design Research Group and the Robotics and Intelligent Systems Group have been working on this line of research to develop modular prostheses which can be adjusted to each patient’s requirements. This research represents an initial methodological approach to developing a prosthesis in which software tools have been used (the finite element method with a criteria relationship matrix for selecting the best alternative while considering different aspects such as mod-ularity, cost, stiffness and weight.

  10. Mechanical design engineering. NASA/university advanced design program: Lunar Bulk Material Transport Vehicle

    Science.gov (United States)

    Daugherty, Paul; Griner, Stewart; Hendrix, Alan; Makarov, Chris; Martiny, Stephen; Meyhoefer, Douglas Ralph; Platt, Cody Claxton; Sivak, John; Wheeler, Elizabeth Fitch

    1988-01-01

    The design of a Lunar Bulk Material Transport Vehicle (LBMTV) is discussed. Goals set in the project include a payload of 50 cubic feet of lunar soil with a lunar of approximately 800 moon-pounds, a speed of 15 mph, and the ability to handle a grade of 20 percent. Thermal control, an articulated steering mechanism, a dump mechanism, a self-righting mechanism, viable power sources, and a probable control panel are analyzed. The thermal control system involves the use of small strip heaters to heat the housing of electronic equipment in the absence of sufficient solar radiation and multi-layer insulation during periods of intense solar radiation. The entire system uses only 10 W and weighs about 60 pounds, or 10 moon-pounds. The steering mechanism is an articulated steering joint at the center of the vehicle. It utilizes two actuators and yields a turning radius of 10.3 feet. The dump mechanism rotates the bulk material container through an angle of 100 degree using one actuator. The self-righting mechanism consists of two four bar linkages, each of which is powered by the same size actuator as the other linkages. The LBMTV is powered by rechargeable batteries. A running time of at least two hours is attained under a worst case analysis. The weight of the batteries is 100 pounds. A control panel consisting of feedback and control instruments is described. The panel includes all critical information necessary to control the vehicle remotely. The LBMTV is capable of handling many types of cargo. It is able to interface with many types of removable bulk material containers. These containers are made to interface with the three-legged walker, SKITTER. The overall vehicle is about 15 feet in length and has a weight of about 1000 pounds, or 170 lunar pounds.

  11. Quiet Clean Short-haul Experimental Engine (QCSEE). Ball spline pitch change mechanism design report

    Science.gov (United States)

    1978-01-01

    Detailed design parameters are presented for a variable-pitch change mechanism. The mechanism is a mechanical system containing a ball screw/spline driving two counteracting master bevel gears meshing pinion gears attached to each of 18 fan blades.

  12. Mechanical design and fabrication of a 425-MHz H- buncher

    International Nuclear Information System (INIS)

    Wilson, N.G.; Precechtel, D.

    1987-01-01

    A beam buncher has been designed, fabricated, and installed on the accelerator test stand (ATS) to match the 2-MeV output beam of a 425-MHz H - radio-frequency quadrupole (RFQ) into a 425-MHz drift-tube linac (DTL). The buncher configuration provides integral-matching permanent-magnet quadrupoles (PMQ) at the exit of the RFQ and one βλ across the buncher accelerating gap; a third PMQ is the first DTL half-cell magnet. Located between the second and third PMQs is a 50-Ω, capacitively coupled, beam-sensing pickup loop. Cooling channels are provided in each of the brazed OFHC copper wall sections. Vacuum pumping of the buncher is provided by a cryogenic refrigerator vacuum pump through an array of small-diameter holes in the buncher cavity wall. Mechanical features of the buncher, the brazing and electron-beam welding of the solid-copper buncher structure, and the beam pickup loop are described in this paper. The buncher has been tuned, installed, and operated at full power on the ATS

  13. Pricing Mechanism Design for Centralized Pollutant Treatment with SME Alliances

    Directory of Open Access Journals (Sweden)

    Yuyu Li

    2016-06-01

    Full Text Available In this paper, we assume that a professional pollutant treatment enterprise treats all of the pollutants emitted by multiple small and medium-sized enterprises (SMEs. In order to determine the treatment price, SMEs can bargain with the pollutant treatment enterprise individually, or through forming alliances. We propose a bargaining game model of centralized pollutant treatment to study how the pollutant treatment price is determined through negotiation. Then, we consider that there is a moral hazard from SMEs in centralized pollutant treatment; in other words, they may break their agreement concerning their quantities of production and pollutant emissions with the pollutant treatment enterprise. We study how the pollutant treatment enterprise can prevent this by pricing mechanism design. It is found that the pollutant treatment enterprise can prevent SMEs’ moral hazard through tiered pricing. If the marginal treatment cost of the pollutant treatment enterprise is a constant, SMEs could bargain with the pollutant treatment enterprise individually, otherwise, they should form a grand alliance to bargain with it as a whole.

  14. Pricing Mechanism Design for Centralized Pollutant Treatment with SME Alliances.

    Science.gov (United States)

    Li, Yuyu; Huang, Bo; Tao, Fengming

    2016-06-22

    In this paper, we assume that a professional pollutant treatment enterprise treats all of the pollutants emitted by multiple small and medium-sized enterprises (SMEs). In order to determine the treatment price, SMEs can bargain with the pollutant treatment enterprise individually, or through forming alliances. We propose a bargaining game model of centralized pollutant treatment to study how the pollutant treatment price is determined through negotiation. Then, we consider that there is a moral hazard from SMEs in centralized pollutant treatment; in other words, they may break their agreement concerning their quantities of production and pollutant emissions with the pollutant treatment enterprise. We study how the pollutant treatment enterprise can prevent this by pricing mechanism design. It is found that the pollutant treatment enterprise can prevent SMEs' moral hazard through tiered pricing. If the marginal treatment cost of the pollutant treatment enterprise is a constant, SMEs could bargain with the pollutant treatment enterprise individually, otherwise, they should form a grand alliance to bargain with it as a whole.

  15. Intelligent Test Mechanism Design of Worn Big Gear

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. The measure equations transformations were made on involute straight gear. Original polar coordinate equations were transformed into rectangular coordinate equations. Big gear abrasion measure principle was introduced. Detection principle diagram was given. Detection route realization method was introduced. OADM12 laser sensor was selected. Detection on big gear abrasion area was realized by detection mechanism. Tested data of unworn gear and worn gear were led in designed calculation program written by Visual Basic language. Big gear abrasion quantity can be obtained. It provides a feasible method for intelligent test and intelligent repair welding on worn big gear.

  16. Nuclear power plant performance and mechanical design - French experience

    International Nuclear Information System (INIS)

    Leclercq, J.

    1986-01-01

    The fact that users of nuclear boilers of proved types are no longer troubled by the mechanical structure behaviour of reactors is due to the sustained efforts of construction engineers during the past ten or twenty years to perfect, and incorporate in their equipment studies, the latest developments which have emerged from the expert engineering community of the world, which you represent here today. The presentation is divided into five parts. Firstly, two parts will be devoted to showing how and why the past twenty years have enabled us to achieve our present results which can objectively be regarded as excellent. Thirdly, it is explained why we believe that it is reasonable to assume that our power stations will have an effective life of up to 40 years. In the fourth part I shall revert to more immediate preoccupations and tackle the subject of the desirable optimisation of in service inspection programmes in the light of what we have learnt from modern design studies. (orig./GL)

  17. Plasmonic Solar Cells: From Rational Design to Mechanism Overview.

    Science.gov (United States)

    Jang, Yoon Hee; Jang, Yu Jin; Kim, Seokhyoung; Quan, Li Na; Chung, Kyungwha; Kim, Dong Ha

    2016-12-28

    Plasmonic effects have been proposed as a solution to overcome the limited light absorption in thin-film photovoltaic devices, and various types of plasmonic solar cells have been developed. This review provides a comprehensive overview of the state-of-the-art progress on the design and fabrication of plasmonic solar cells and their enhancement mechanism. The working principle is first addressed in terms of the combined effects of plasmon decay, scattering, near-field enhancement, and plasmonic energy transfer, including direct hot electron transfer and resonant energy transfer. Then, we summarize recent developments for various types of plasmonic solar cells based on silicon, dye-sensitized, organic photovoltaic, and other types of solar cells, including quantum dot and perovskite variants. We also address several issues regarding the limitations of plasmonic nanostructures, including their electrical, chemical, and physical stability, charge recombination, narrowband absorption, and high cost. Next, we propose a few potentially useful approaches that can improve the performance of plasmonic cells, such as the inclusion of graphene plasmonics, plasmon-upconversion coupling, and coupling between fluorescence resonance energy transfer and plasmon resonance energy transfer. This review is concluded with remarks on future prospects for plasmonic solar cell use.

  18. Mechanical design of a light water breeder reactor

    International Nuclear Information System (INIS)

    Fauth, W.L. Jr.; Jones, D.S.; Kolsun, G.J.; Erbes, J.G.; Brennan, J.J.; Weissburg, J.A.; Sharbaugh, J.E.

    1976-01-01

    In a light water reactor system using the thorium-232--uranium-233 fuel system in a seed-blanket modular core configuration having the modules arranged in a symmetrical array surrounded by a reflector blanket region, the seed regions are disposed for a longitudinal movement between the fixed or stationary blanket region which surrounds each seed region. Control of the reactor is obtained by moving the inner seed region thus changing the geometry of the reactor, and thereby changing the leakage of neutrons from the relatively small seed region into the blanket region. The mechanical design of the Light Water Breeder Reactor (LWBR) core includes means for axially positioning of movable fuel assemblies to achieve the neutron economy required of a breeder reactor, a structure necessary to adequately support the fuel modules without imposing penalties on the breeding capability, a structure necessary to support fuel rods in a closely packed array and a structure necessary to direct and control the flow of coolant to regions in the core in accordance with the heat transfer requirements. 4 claims, 24 drawing figures

  19. Superconducting Super Collider Laboratory coupled-cavity linac mechanical design

    International Nuclear Information System (INIS)

    Starling, W.J.; Cain, T.

    1992-01-01

    A collaboration between the Superconducting Super Collider Laboratory (SSCL) and the Los Alamos National Laboratory (LANL) for the engineering and mechanical design of the SSCL Coupled-Cavity Linac (CCL) has yielded an innovative example of the well known side coupled-cavity type of linear accelerator. The SSCL CCL accelerates an H - beam from 70 MeV to 600 MeV with an rf cavity structure consisting of eight tanks in each of nine modules for a total length of about 112 meters. Magnetically-coupled bridge couplers transfer power from tank to tank within a module. A single rf power input is located at the center bridge coupler of each module. The bridge couplers permit placement along the beam line of combined function focusing/steering electromagnets and diagnostic pods for beam instrumentation. Each tank and bridge coupler is rf frequency stabilized, nominally to 1,283 MHz, by water pumped through integral water passages. Air isolation grooves surround the water passages at each braze joint so that water-to-vacuum interfaces are avoided. Each tank is supported by adjustable spherical bearing rod end struts to permit alignment and accommodate thermal expansion and contraction of the rf structure. Tank struts, electromagnet/diagnostic pod support frames, vacuum manifolds and utilities are all mounted to a girder-and-leg support stand running the full length of the CCL. (Author) tab., fig

  20. Design for the Structure and the Mechanics of Moballs

    Science.gov (United States)

    Davoodi, Faranak; Davoudi, Farhooman

    2012-01-01

    The moball is envisioned to be a round, self-powered, and wind-driven multifunctioning sensor used in the Gone with the Wind ON-Mars (GOWON) [http://www.lpi.usra.edu/meetings/ marsconcepts2012/pdf/4238.pdf]: A Wind-Driven Networked System of Mobile sensors on Mars. The moballs would have sensing, processing, and communication capabilities. The moballs would perform in situ detection of key environmental elements such as vaporized water, trace gases, wind, dust, clouds, light and UV exposure, temperature, as well as minerals of interest, possible biosignatures, surface magnetic and electric fields, etc. The embedded various low-power micro instruments could include a Multispectral Microscopic Imager (to detect various minerals), a compact curved focal plane array camera (UV/Vis/NIR) with a large field of view, a compact UV/Visible spectrometer, a micro-weather station, etc. The moballs could communicate with each other and an orbiter. Their wind- or gravity-driven rolling movement could be used to harvest and store electric energy. They could also generate and store energy using the sunlight, when available, and the diurnal temperature variations on Mars. The moballs would be self-aware of their (and their neighbors ) positions, energy storage, and memory availability; they would have processing power and could intelligently cooperate with neighboring moballs by distributing tasks, sharing data, and fusing information. The major advantages of using the wind-driven and spherical moball network over rovers or other fixed sensor webs to explore Mars would be: (1) moballs could explore a much larger expanse of Mars in a much faster fashion, (2) they could explore the difficult terrains such as steep slopes and sand dunes, and (3) they would be self-energy- generating and could work together and move around autonomously. The challenge in designing the structure and the mechanics of the moball would be that it should be sturdy enough to withstand the impact of its initial

  1. ON THE TOPOLOGY OF MECHANISMS DESIGNED FOR CURVES GENERATION

    Directory of Open Access Journals (Sweden)

    MEREUTA Elena

    2008-07-01

    Full Text Available The paper presents some mechanisms used for generating simple or complex curves. The mechanisms are shown in different positions and for some special curves the demonstrations are performed.

  2. Opto-mechanical subsystem with temperature compensation through isothemal design

    Science.gov (United States)

    Goodwin, F. E. (Inventor)

    1977-01-01

    An opto-mechanical subsystem for supporting a laser structure which minimizes changes in the alignment of the laser optics in response to temperature variations is described. Both optical and mechanical structural components of the system are formed of the same material, preferably beryllium, which is selected for high mechanical strength and good thermal conducting qualities. All mechanical and optical components are mounted and assembled to provide thorough thermal coupling throughout the subsystem to prevent the development of temperature gradients.

  3. A recoil resilient lumen support, design, fabrication and mechanical evaluation

    Science.gov (United States)

    Mehdizadeh, Arash; Ali, Mohamed Sultan Mohamed; Takahata, Kenichi; Al-Sarawi, Said; Abbott, Derek

    2013-06-01

    Stents are artificial implants that provide scaffolding to a cavity inside the body. This paper presents a new luminal device for reducing the mechanical failure of stents due to recoil, which is one of the most important issues in stenting. This device, which we call a recoil-resilient ring (RRR), is utilized standalone or potentially integrated with existing stents to address the problem of recoil. The proposed structure aims to minimize the need for high-pressure overexpansion that can induce intra-luminal trauma and excess growth of vascular tissue causing later restenosis. The RRR is an overlapped open ring with asymmetrical sawtooth structures that are intermeshed. These teeth can slide on top of each other, while the ring is radially expanded, but interlock step-by-step so as to keep the final expanded state against compressional forces that normally cause recoil. The RRRs thus deliver balloon expandability and, when integrated with a stent, bring both radial rigidity and longitudinal flexibility to the stent. The design of the RRR is investigated through finite element analysis (FEA), and then the devices are fabricated using micro-electro-discharge machining of 200-µm-thick Nitinol sheet. The standalone RRR is balloon expandable in vitro by 5-7 Atm in pressure, which is well within the recommended in vivo pressure ranges for stenting procedures. FEA compression tests indicate 13× less reduction of the cross-sectional area of the RRR compared with a typical stainless steel stent. These results also show perfect elastic recovery of the RRR after removal of the pressure compared to the remaining plastic deformations of the stainless steel stent. On the other hand, experimental loading tests show that the fabricated RRRs have 2.8× radial stiffness compared to a two-column section of a commercial stent while exhibiting comparable elastic recovery. Furthermore, testing of in vitro expansion in a mock artery tube shows around 2.9% recoil, approximately 5-11

  4. A recoil resilient lumen support, design, fabrication and mechanical evaluation

    International Nuclear Information System (INIS)

    Mehdizadeh, Arash; Al-Sarawi, Said; Abbott, Derek; Ali, Mohamed Sultan Mohamed; Takahata, Kenichi

    2013-01-01

    Stents are artificial implants that provide scaffolding to a cavity inside the body. This paper presents a new luminal device for reducing the mechanical failure of stents due to recoil, which is one of the most important issues in stenting. This device, which we call a recoil-resilient ring (RRR), is utilized standalone or potentially integrated with existing stents to address the problem of recoil. The proposed structure aims to minimize the need for high-pressure overexpansion that can induce intra-luminal trauma and excess growth of vascular tissue causing later restenosis. The RRR is an overlapped open ring with asymmetrical sawtooth structures that are intermeshed. These teeth can slide on top of each other, while the ring is radially expanded, but interlock step-by-step so as to keep the final expanded state against compressional forces that normally cause recoil. The RRRs thus deliver balloon expandability and, when integrated with a stent, bring both radial rigidity and longitudinal flexibility to the stent. The design of the RRR is investigated through finite element analysis (FEA), and then the devices are fabricated using micro-electro-discharge machining of 200-µm-thick Nitinol sheet. The standalone RRR is balloon expandable in vitro by 5–7 Atm in pressure, which is well within the recommended in vivo pressure ranges for stenting procedures. FEA compression tests indicate 13× less reduction of the cross-sectional area of the RRR compared with a typical stainless steel stent. These results also show perfect elastic recovery of the RRR after removal of the pressure compared to the remaining plastic deformations of the stainless steel stent. On the other hand, experimental loading tests show that the fabricated RRRs have 2.8× radial stiffness compared to a two-column section of a commercial stent while exhibiting comparable elastic recovery. Furthermore, testing of in vitro expansion in a mock artery tube shows around 2.9% recoil, approximately 5

  5. Mechanical design of mussel byssus: material yield enhances attachment strength

    Science.gov (United States)

    Bell; Gosline

    1996-01-01

    The competitive dominance of mussels in the wave-swept rocky intertidal zone is in part due to their ability to maintain a secure attachment. Mussels are tethered to the substratum by a byssus composed of numerous extracellular, collagenous threads secreted by the foot. Each byssal thread has three serially arranged parts: a corrugated proximal region, a smooth distal region and an adhesive plaque. This study examines the material and structural properties of the byssal threads of three mussel species: Mytilus californianus, M. trossulus, and M. galloprovincialis. Tensile tests in general reveal similar material properties among species: the proximal region has a lower initial modulus, a lower ultimate stress and a higher ultimate strain than the distal region. The distal region also yields at a stress well below its ultimate value. In whole thread tests, the proximal region and adhesive plaque are common sites of structural failure and are closely matched in strength, while the distal region appears to be excessively strong. We propose that the high strength of the distal region is the byproduct of a material designed to yield and extend before structural failure occurs. Experimental and theoretical evidence is presented suggesting that thread yield and extensibility provide two important mechanisms for increasing the overall attachment strength of the mussel: (1) the reorientation of threads towards the direction of applied load, and (2) the 'recruitment' of more threads into tension and the consequent distribution of applied load over a larger cross-sectional area, thereby reducing the stress on each thread. This distal region yield behavior is most striking for M. californianus and may be a key to its success in extreme wave-swept environments.

  6. Triple vacuum glazing: Heat transfer and basic mechanical design constraints

    Energy Technology Data Exchange (ETDEWEB)

    Manz, H.; Brunner, S.; Wullschleger, L. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Laboratory for Applied Physics in Building, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

    2006-12-15

    Given the major role played by windows with regard to energy losses from buildings in cold climates, low thermal transmittance is an indispensable property of glazing in low-energy buildings. Evacuation offers the only means of achieving negligible gaseous conduction in glazing cavities. Application of low-emittance coatings to glass sheet surfaces inside the cavity reduces the radiative heat transfer. The feasibility of double vacuum glazing using arrays of support pillars between the glass sheets has been shown by other authors. This type of glazing is commercially manufactured today. Based on these achievements, our study set out to investigate heat transfer in triple vacuum glazing by means of (i) an analytical thermal network model and (ii) a numerical finite difference model. The study focused on the impact of the following parameters on thermal transmittance: emittances of glass sheet surfaces inside the cavity, support pillar radius, support pillar separation and thermal conductivity of support pillar material. The design procedure for triple vacuum glazing taking into account not only thermal but also mechanical stresses due to atmospheric pressure, i.e., to enable identification of favourable parameter sets, is presented. Our findings suggest that use of the triple vacuum glazing concept can significantly reduce the thermal transmittances achieved by the best insulation glazing units currently on the market. E.g., a centre-of-glazing thermal transmittance of less than 0.2Wm{sup -2}K{sup -1} is achievable using stainless steel support pillars, 6mm/4mm/6mm sheets of untempered soda-lime glass and four low-emittance coatings ({epsilon}=0.03). (author)

  7. Road Edge of Pavement, Pavement Condition Ratings and Maintenance Designations per Street Centerline. Updated frequently by Public Works Streets Division, Published in 2006, 1:1200 (1in=100ft) scale, City of Asheville Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Road Edge of Pavement dataset current as of 2006. Pavement Condition Ratings and Maintenance Designations per Street Centerline. Updated frequently by Public Works...

  8. A Compliant Bistable Mechanism Design Incorporating Elastica Buckling Beam Theory and Pseudo-Rigid-Body Model

    DEFF Research Database (Denmark)

    Sönmez, Ümit; Tutum, Cem Celal

    2008-01-01

    In this work, a new compliant bistable mechanism design is introduced. The combined use of pseudo-rigid-body model (PRBM) and the Elastica buckling theory is presented for the first time to analyze the new design. This mechanism consists of the large deflecting straight beams, buckling beams...... and the buckling Elastica solution for an original compliant mechanism kinematic analysis. New compliant mechanism designs are presented to highlight where such combined kinematic analysis is required....

  9. The mechanical Design of the LHCb Silicon Trigger Tracker

    CERN Document Server

    Gassner, J; Steiner, S

    2010-01-01

    In this note, we describe the design of the Silicon Trigger Tracker for the LHCb experiment. We emphasize on detector module and station design and characterize the layout of all relevant parts and components.

  10. FRMAC Updates

    International Nuclear Information System (INIS)

    Mueller, P.

    1995-01-01

    This talks describes updates in the following updates in FRMAC publications concerning radiation emergencies: Monitoring and Analysis Manual; Evaluation and Assessment Manual; Handshake Series (Biannual) including exercises participated in; environmental Data and Instrument Transmission System (EDITS); Plume in a Box with all radiological data stored onto a hand-held computer; and courses given

  11. Mechanical design of a lidar system for space applications - LITE

    Science.gov (United States)

    Crockett, Sharon K.

    1990-01-01

    The Lidar In-Space Technology Experiment (LITE) is a Shuttle experiment that will demonstrate the first use of a lidar system in space. Its design process must take into account not only the system design but also the unique design requirements for spaceborne experiment.

  12. Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen flight cells - An update

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  13. Thermal and mechanical design of WITAMIR-I blanket

    International Nuclear Information System (INIS)

    Sze, D.K.; Sviatoslavsky, I.N.

    1980-10-01

    The design philosophy of WITAMIR-I, a Wisconsin Tandem Mirror Reactor design study, uses the experience obtained from our previous tokamak studies and combines it with the unique features of the tandem mirror to obtain an attractive design of a TM power reactor. It is aimed at maximizing the strengths of the tandem mirror while mitigating its weaknesses. The end product should be a safe, reliable, maintainable and a relatively economic power reactor. The general description of the reactor, the plasma calculations, the magnet design, the neutronic calculations and the maintenance considerations are presented elsewhere. This paper presents the blanket design of this reactor study

  14. Mechanism-Based Design of Green Oxidation Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rybak-Akimova, Elena [Tufts Univ., Medford, MA (United States)

    2015-03-16

    In modern era of scarce resources, developing chemical processes that can eventually generate useful materials and fuels from readily available, simple, cheap, renewable starting materials is of paramount importance. Small molecules, such as dioxygen, dinitrogen, water, or carbon dioxide, can be viewed as ideal sources of oxygen, nitrogen, or carbon atoms in synthetic applications. Living organisms perfected the art of utilizing small molecules in biosynthesis and in generating energy; photosynthesis, which couples carbohydrate synthesis from carbon dioxide with photocatalytic water splitting, is but one impressive example of possible catalytic processes. Small molecule activation in synthetic systems remains challenging, and current efforts are focused on developing catalytic reactions that can convert small molecules into useful building blocks for generating more complicated organic molecules, including fuels. Modeling nature is attractive in many respects, including the possibility to use non-toxic, earth-abundant metals in catalysis. Specific systems investigated in our work include biomimetic catalytic oxidations with dioxygen, hydrogen peroxide, and related oxygen atom donors. More recently, a new direction was been also pursued in the group, fixation of carbon dioxide with transition metal complexes. Mechanistic understanding of biomimetic metal-catalyzed oxidations is critical for the design of functional models of metalloenzymes, and ultimately for the rational synthesis of useful, selective and efficient oxidation catalysts utilizing dioxygen and hydrogen peroxide as terminal oxidants. All iron oxidases and oxygenases (both mononuclear and dinuclear) utilize metal-centered intermediates as reactive species in selective substrate oxidation. In contrast, free radical pathways (Fenton chemistry) are common for traditional inorganic iron compounds, producing hydroxyl radicals as very active, non-selective oxidants. Recent developments, however, changed this

  15. Studies Regarding Design and Optimization of Mechanisms Using Modern Techniques of CAD and CAE

    Directory of Open Access Journals (Sweden)

    Marius Tufoi

    2010-01-01

    Full Text Available The paper presents applications of modern techniques of CAD (Computer Aided Design and CAE (Computer Aided Engineering to design and optimize the mechanisms used in mechanical engineering. The use exemplification of these techniques was achieved by designing and optimizing parts of a drawing installation for horizontal continuous casting of metals. By applying these design methods and using finite element method at simulations on designed mechanisms results a number of advantages over traditional methods of drawing and design: speed in drawing, design and optimization of parts and mechanisms, kinematic analysis option, kinetostatic and dynamic through simulation, without requiring physical realization of the part or mechanism, the determination by finite element method of tension, elongations, travel and safety factor and the possibility of optimization for these sizes to ensure the mechanical strength of each piece separately. Achieving these studies was possible using SolidWorks 2009 software suite.

  16. 3rd IFToMM Symposium on Mechanism Design for Robotics

    CERN Document Server

    Ceccarelli, Marco

    2015-01-01

    This volume contains the Proceedings of the 3rd IFToMM Symposium on Mechanism Design for Robotics, held in Aalborg, Denmark, 2-4 June, 2015. The book contains papers on recent advances in the design of mechanisms and their robotic applications. It treats the following topics: mechanism design, mechanics of robots, parallel manipulators, actuators and their control, linkage and industrial manipulators, innovative mechanisms/robots and their applications, among others. The book can be used by researchers and engineers in the relevant areas of mechanisms, machines and robotics.

  17. Design of articulated mechanisms with a degree of freedom constraint using global optimization

    DEFF Research Database (Denmark)

    Kawamoto, Atsushi; Stolpe, Mathias

    2004-01-01

    This paper deals with design of articulated mechanisms using a truss ground structure representation. The considered mechanism design problem is to maximize the output displacement for a given input force by choosing a prescribed number of truss elements out of all the available elements, so...... that the resultant mechanism has one mechanical degree of freedom when supported in a statically determinate manner. The mechanical degree of freedom constraint is included since it is essential for obtaining a proper articulated mechanism design. The Green-Lagrange strain measure is used to accommodate for large...

  18. Stochastic modelling in design of mechanical properties of nanometals

    International Nuclear Information System (INIS)

    Tengen, T.B.; Wejrzanowski, T.; Iwankiewicz, R.; Kurzydlowski, K.J.

    2010-01-01

    Polycrystalline nanometals are being fabricated through different processing routes and conditions. The consequence is that nanometals having the same mean grain size may have different grain size dispersion and, hence, may have different material properties. This has often led to conflicting reports from both theoretical and experimental findings about the evolutions of the mechanical properties of nanomaterials. The present paper employs stochastic model to study the impact of microstructure evolution during grain growth on the mechanical properties of polycrystalline nanometals. The stochastic model for grain growth and the stochastic model for changes in mechanical properties of nanomaterials are proposed. The model for the mechanical properties developed is tested on aluminium samples.Many salient features of the mechanical properties of the aluminium samples are revealed. The results show that the different mechanisms of grain growth impart different nature of response to the material mechanical properties. The conventional, homologous and anomalous temperature dependences of the yield stress have also been revealed to be due to different nature of interactions of the microstructures during evolution.

  19. General Description of the Mechanic Design of the Pressure Vessel and the Internal Mechanical Component of the CAREM Reactor

    International Nuclear Information System (INIS)

    Diez, F.; Horro, R.

    2000-01-01

    This paper presents a brief description of the CAREM reactor pressure vessel and its main internal mechanical components and summarizes the functional requirements and approaches applied for their design, together with a review of the normative applicable in each case

  20. Mechanical and electromagnetic analysis of 50 millimeter designs for the SSC dipole

    International Nuclear Information System (INIS)

    Jayakumar, J.; Leung, K.; Nobrega, F.; Orrell, D.; Sanger, P.; Snitchler, G.; Spigo, G.; Turner, J.; Goodzeit, C.; Gupta, R.; Kahn, S.; Morgan, G.; Willen, E.; Kerby, J.; Strait, J.; Schermer, R.

    1990-09-01

    Several designs for the Superconducting Super Collider dipole magnet have been analyzed. This note discusses the mechanical and electromagnetic features of each design. Electromagnetic and Mechanical analyses were performed using hand, computer programs and finite element techniques to evaluate the design. 10 refs., 6 figs., 3 tabs

  1. A unified approach to the analysis and design of elasto-plastic structures with mechanical contact

    Science.gov (United States)

    Bendsoe, Martin P.; Olhoff, Niels; Taylor, John E.

    1990-01-01

    With structural design in mind, a new unified variational model has been developed which represents the mechanics of deformation elasto-plasticity with unilateral contact conditions. For a design problem formulated as maximization of the load carrying capacity of a structure under certain constraints, the unified model allows for a simultaneous analysis and design synthesis for a whole range of mechanical behavior.

  2. Commentary on fair, effective and efficient REDD mechanism design

    CSIR Research Space (South Africa)

    Obersteiner, M

    2009-11-01

    Full Text Available two key requirements of any potential REDD mechanism: first, the generation of measurable, reportable and verifiable (MRV) REDD credits; and secondly, the sustainable and efficient provision of emission reductions under a robust financing regime...

  3. On fair, effective and efficient REDD mechanism design

    CSIR Research Space (South Africa)

    Obersteiner, M

    2009-11-01

    Full Text Available two key requirements of any potential REDD mechanism: first, the generation of measurable, reportable and verifiable (MRV) REDD credits; and secondly, the sustainable and efficient provision of emission reductions under a robust financing regime...

  4. Design of Electrostatic Directional Dry Adhesives for Robotic Attachment Mechanisms

    Data.gov (United States)

    National Aeronautics and Space Administration — Attachment mechanisms that are effective over a wide range of material types and surface conditions can be used for a variety of applications including manipulator...

  5. Parametric fuselage design : Integration of mechanics and acoustic & thermal insulation

    NARCIS (Netherlands)

    Krakers, L.A.

    2009-01-01

    Designing a fuselage is a very complex process, which involves many different aspects like strength and stability, fatigue, damage tolerance, fire resistance, thermal and acoustic insulation but also inspection, maintenance, production and repair aspects. It is difficult to include all design

  6. Mechanical design of the recirculating, terminal pumping in the Lund ...

    Indian Academy of Sciences (India)

    An extremly limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass spectrometry, will be ...

  7. Mechanical Design of a Performance Test Rig for the Turbine Air-Flow Task (TAFT)

    Science.gov (United States)

    Forbes, John C.; Xenofos, George D.; Farrow, John L.; Tyler, Tom; Williams, Robert; Sargent, Scott; Moharos, Jozsef

    2004-01-01

    To support development of the Boeing-Rocketdyne RS84 rocket engine, a full-flow, reaction turbine geometry was integrated into the NASA-MSFC turbine air-flow test facility. A mechanical design was generated which minimized the amount of new hardware while incorporating all test and instrumentation requirements. This paper provides details of the mechanical design for this Turbine Air-Flow Task (TAFT) test rig. The mechanical design process utilized for this task included the following basic stages: Conceptual Design. Preliminary Design. Detailed Design. Baseline of Design (including Configuration Control and Drawing Revision). Fabrication. Assembly. During the design process, many lessons were learned that should benefit future test rig design projects. Of primary importance are well-defined requirements early in the design process, a thorough detailed design package, and effective communication with both the customer and the fabrication contractors.

  8. Two-Stage Fan I: Aerodynamic and Mechanical Design

    Science.gov (United States)

    Messenger, H. E.; Kennedy, E. E.

    1972-01-01

    A two-stage, highly-loaded fan was designed to deliver an overall pressure ratio of 2.8 with an adiabatic efficiency of 83.9 percent. At the first rotor inlet, design flow per unit annulus area is 42 lbm/sec/sq ft (205 kg/sec/sq m), hub/tip ratio is 0.4 with a tip diameter of 31 inches (0.787 m), and design tip speed is 1450 ft/sec (441.96 m/sec). Other features include use of multiple-circular-arc airfoils, resettable stators, and split casings over the rotor tip sections for casing treatment tests.

  9. Electromagnetic and mechanical design of RFX Magnetizing Winding

    International Nuclear Information System (INIS)

    Guarnieri, M.; Modena, C.; Schrefler, B.A.; Stella, A.

    1985-01-01

    This paper presents the RFX Magnetizing Winding design and describes its most significant features. Two numerical codes have been used for the magnetic design and a number of solutions, complying with the design specifications, have been obtained. The most attractive of them have been studied in detail from the electromagnetic point of view and a comparison is given here together with an analysis of the stress states. The finite element procedure used is discussed in the paper and the results of the comparison indicated above are presented together with the main electromagnetic parameters and winding features

  10. Hybrid controller design and verification for the METIS Cold Chopper Mechanism

    NARCIS (Netherlands)

    Huisman, Robert; Jayawardhana, Bayu; Scherpen, Jacquelien M.A.

    2014-01-01

    We discuss the design and validation of a hybrid controller for the METIS Cold Chopper Mechanism (MCCD)(1). The described control strategy has been chosen to meet the stringent performance requirements of the mechanism subject to constraints on the input.

  11. Geologic, stratigraphic, thermal, and mechanical factors which influence repository design in the bedded salt environment

    International Nuclear Information System (INIS)

    Ashby, J.P.; Nair, O.; Ortman, D.; Rowe, J.

    1979-12-01

    This report describes the geologic, stratigraphic, thermal, and mechanical considerations applicable to repository design. The topics discussed in the report include: tectonic activity; geologic structure; stratigraphy; rock mechanical properties; and hydrologic properties

  12. Design of reinforced concrete members based on structural mechanics

    International Nuclear Information System (INIS)

    Diaz, B.E.; Schulz, M.

    1984-01-01

    Up to now the design of reinforced concrete linear members is performed with the help of an inconsistent design theory, which nevertherless is sufficiently safe and simple to be used in the practice. The purpose of this paper is to present a rational reinforced concrete design method which is not too dissimilar to the present design rules, but is capable of defining consistently internal stresses along a reinforced concrete section. The present status of the completed computer procedures allows the analysis of linear reinforced concrete members formed by laminar reinforced concrete plates presenting variable thickness. A practical approach is presented for which the concrete and steel section is constant along the member axis. In this case, the concept of the equivalent section is introduced, which allows a simple analysis of the stress pattern along the member section. (Author) [pt

  13. Mechanical design aspects of a tandem mirror fusion reactor

    International Nuclear Information System (INIS)

    Neef, W.S. Jr.

    1977-01-01

    Two ''plugs'' of dense plasma at either end of a central solenoid cell form the basis of a new mirror fusion power plant concept. A central cell blanket design is presented. Modules on crawler tracks serviced by remote welding and handling machines of very simple design are important features resulting from linear axisymmetric geometry. Three blanket designs are considered and the best one presented in some detail. It has lithium as the breeder material, helium cooled. ''Plug'' magnet field strengths must be high. A novel magnet is presented to satisfy the physics of the end plugs. Beam sources at 1,200 KV present special problems. Methods of voltage standoff, arc damage control, and neutralization are discussed. New secondary containment ideas are presented to allow removable roof sections of balanced design

  14. Teacher collaboration in curriculum design teams : Effects, mechanisms and conditions

    NARCIS (Netherlands)

    Voogt, J.M.; Pieters, J.M.; Handelzalts, A.

    2016-01-01

    Collaborative design positively affects both professional development and the implementation of curriculum change, because teachers develop competencies and practice and develop ownership of the change. The current study was aimed to explore what empirical evidence is available about processes that

  15. Teacher collaboration in curriculum design teams : effects, mechanisms, and conditions

    NARCIS (Netherlands)

    Voogt, Joke M.; Pieters, Jules M.; Handelzalts, Adam

    2016-01-01

    Collaborative design positively affects both professional development and the implementation of curriculum change, because teachers develop competencies and practice and develop ownership of the change. The current study was aimed to explore what empirical evidence is available about processes that

  16. Circular Updates

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Circular Updates are periodic sequentially numbered instructions to debriefing staff and observers informing them of changes or additions to scientific and specimen...

  17. Email Updates

    Science.gov (United States)

    ... of this page: https://medlineplus.gov/listserv.html Email Updates To use the sharing features on this ... view your email history or unsubscribe. Prevent MedlinePlus emails from being marked as "spam" or "junk" To ...

  18. An application of interactive computer graphics technology to the design of dispersal mechanisms

    Science.gov (United States)

    Richter, B. J.; Welch, B. H.

    1977-01-01

    Interactive computer graphics technology is combined with a general purpose mechanisms computer code to study the operational behavior of three guided bomb dispersal mechanism designs. These studies illustrate the use of computer graphics techniques to discover operational anomalies, to assess the effectiveness of design improvements, to reduce the time and cost of the modeling effort, and to provide the mechanism designer with a visual understanding of the physical operation of such systems.

  19. NREL Next Generation Drivetrain: Mechanical Design and Test Plan (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; Halse, C.

    2014-05-01

    The Department of Energy and industry partners are sponsoring a $3m project for design and testing of a 'Next Generation' wind turbine drivetrain at the National Renewable Energy Laboratory (NREL). This poster focuses on innovative aspects of the gearbox design, completed as part of an end-to-end systems engineering approach incorporating innovations that increase drivetrain reliability, efficiency, torque density and minimize capital cost.

  20. Mechanical Engineering Design Project report: Enabler control systems

    Science.gov (United States)

    Cullen, Christian; Delvecchio, Dave; Scarborough, Alan; Havics, Andrew A.

    1992-01-01

    The Controls Group was assigned the responsibility for designing the Enabler's control system. The requirement for the design was that the control system must provide a simple user interface to control the boom articulation joints, chassis articulation joints, and the wheel drive. The system required controlling hydraulic motors on the Enabler by implementing 8-bit microprocessor boards. In addition, feedback to evaluate positions and velocities must be interfaced to provide the operator with confirmation as well as control.

  1. Mechanical Engineering Senior Design Project Final Presentations | College

    Science.gov (United States)

    Engineering Research Computational Mechanics Laboratory Environmental Engineering Laboratory Geotechnical of Engineering & Applied Science A B C D E F G H I J K L M N O P Q R S T U V W X Y Z D2L Programs Concentration in Biomedical Engineering Concentration on Ergonomics M.S. Program in Computer

  2. Design of a deployment rotation mechanism for microsatellite

    NARCIS (Netherlands)

    Abdelal, G.F.; Bakr Elhady, A.; Kassab, M.

    2009-01-01

    Solar array rotation mechanism provides a hinged joint between the solar panel and satellite body, smooth rotation of the solar array into deployed position and its fixation in this position. After unlocking of solar panel (while in orbit), rotation bracket turns towards ready-to-work position under

  3. Designing Competency-Based Materials for the Automotive Mechanics Curriculum

    Science.gov (United States)

    Richardson, Roger L.

    1977-01-01

    Describes the Career Education Center's (Florida State University) development of the "Automotive Mechanics Catalog" (a job inventory noting performance objectives for specific occupational programs), using the Vocational-Technical Education Consortium of States (V-TECS) model. Also describes the development of curriculum materials using…

  4. How (not) to design procurement mechanisms: A laboratory experiment

    NARCIS (Netherlands)

    Onderstal, S.; van de Meerendonk, A.

    2008-01-01

    In this paper, we examine the relative performance of three commonly used procurement mechanisms: price-only auctions, scoring auctions, and benchmarking. We do so both in theory and in a laboratory experiment. We find that the auctions yield the same level of welfare, and welfare dominate

  5. Designing remote web-based mechanical-volumetric flow meter ...

    African Journals Online (AJOL)

    Today, in water and wastewater industry a lot of mechanical-volumetric flow meters are used for the navigation of the produced water and the data of these flow meters, due to use in a wide geographical range, is done physically and by in person presence. All this makes reading the data costly and, in some cases, due to ...

  6. Partial Linearization of Mechanical Systems with Application to Observer Design

    NARCIS (Netherlands)

    Sarras, Ioannis; Venkatraman, Aneesh; Ortega, Romeo; Schaft, Arjan van der

    2008-01-01

    We consider general mechanical systems and establish a necessary and sufficient condition for the existence of a suitable change in the generalized momentum coordinates such that the new dynamics become linear in the transformed momenta. The class of systems which can be (partially) linearized by

  7. Preliminary study of an expert system for mechanical design of a pressure vessel

    International Nuclear Information System (INIS)

    Kasmuri, N.H.; Md Som, A.

    2006-01-01

    This paper describes a preliminary study of an expert system for mechanical design of a pressure vessel. The system supports the framework for the conceptual mechanical design from the initial stages within the design procedures. ASME Boiler and Pressure Vessel Code Section VIII Division 1 were applied as a design rule. The proposed methodology facilitates the development of knowledge base acquisition, knowledge base construction and the prototype implementation. This study characterizes a knowledge base (procedure) of mechanical design of a pressure vessel subjected to internal pressure including all design parameters; i.e. temperature, shell thickness, selection of materials of constructions, stress analysis procedure, support and ancillary items. The rationalization of the mechanical design is shown in the form of a schematic flow diagram. A Kappa PC expert system shell is used as a tool to develop the prototype software. It provides graphical representation for creating objects, hierarchies and rules for knowledge base used in pressure vessel design. (Author)

  8. Parametric mechanical design of new insertion devices at the APS.

    Energy Technology Data Exchange (ETDEWEB)

    Grimmer, J.; Kmak, R.

    2005-01-01

    Three permanent-magnet, planar, hybrid insertion device (ID) designs have recently been completed at the APS. The periods of these undulators are 2.7 cm, 3.0 cm and 3.5 cm with nominal lengths of 2.4 m. Several design studies were performed for the initial 2.7-cm-period device. Then a parametric solid model for the initial device was developed and value engineered to minimize manufacturing, assembly and tuning costs. The model allowed the very rapid design of subsequent devices of similar periods and allowed commonality of several components of the IDs. This design family incorporates a low-cost method of pole retention and registration. Poles are secured by screws in two holes tapped into each pole. Pole location is registered by means of two small dowel pins in mating holes reamed into each pole and a 'divider' plate common to the poles and magnets. This divider plate is flexible along its length so shimming behind it can be used to accurately change the height of a pair of poles for tuning. Another feature of the design is modular construction to allow each device to be used full length or shortened to a nominal 2.1 m length for use in APS 'canted undulator' sectors.

  9. Parametric Mechanical Design of New Insertion Devices at the APS

    CERN Document Server

    Grimmer, John H

    2005-01-01

    Three permanent-magnet, planar, hybrid ID designs have recently been completed at the APS. The periods of the devices are 2.7 cm, 3.0 cm and 3.5 cm with nominal lengths of 2.4 m. Several design studies were performed for the initial 2.7 cm period device to investigate the utility of various design features. Then a parametric solid model for the initial device was developed and value engineered to minimize manufacturing, assembly and tuning costs. The model allowed the very rapid design of subsequent devices of similar periods and allowed commonality of several components of the IDs. This design family incorporates a low-cost method of pole retention and registration. Poles are secured by screws in two holes tapped into each pole. Pole location is registered by means of two small dowel pins for each pole in mating holes reamed into each pole and a base plate common to the poles and magnets. This base plate is flexible in bending along its length so shimming behind it can be used to accurately change the height...

  10. Mechanical design of an electronic control unit using axiomatic principles

    Directory of Open Access Journals (Sweden)

    Cazacu Vlad

    2017-01-01

    Full Text Available If the engine of the car can be considered as the heart, then the E.C.U’s represents the brain of the car. Electronic control units (E.C.U’s are electronic devices which control the way different components of a car (engine, windows, airbags, etc. react in some situations (overheating, button pressed by a passenger, crash, etc.. Axiomatic design is a set of principles that theorizes the act of conceiving a new project. Based on two axiom this method comes into designers help, giving them the option to reach in a short period of time a fully functional and compliant product without supporting the design of the product on chance, past experiences or “try and fail” principle.

  11. Mechanical System Analysis/Design Tool (MSAT) Quick Guide

    Science.gov (United States)

    Lee, HauHua; Kolb, Mark; Madelone, Jack

    1998-01-01

    MSAT is a unique multi-component multi-disciplinary tool that organizes design analysis tasks around object-oriented representations of configuration components, analysis programs and modules, and data transfer links between them. This creative modular architecture enables rapid generation of input stream for trade-off studies of various engine configurations. The data transfer links automatically transport output from one application as relevant input to the next application once the sequence is set up by the user. The computations are managed via constraint propagation - the constraints supplied by the user as part of any optimization module. The software can be used in the preliminary design stage as well as during the detail design of product development process.

  12. Design and Development of Mechanical Structure and Control System for Tracked Trailing Mobile Robot

    OpenAIRE

    Hongchuan Xu; Jianxing Ren; Rui Zhu; Zhiwei Chen

    2013-01-01

    Along with the science and technology unceasing progress, the uses of tracing robots become more and more widely. Tracked tracing robot was adopted as the research object in this paper, mechanical structure and control system of robot was designed and developmented. In mechanical structure design part, structure designed and positioned  were completed, including design of robot body, wheel, underpan, transmission structure and the positioning of batteries, control panel, sensors, etc, and the...

  13. Mechanical design and simulation of an automatized sample exchanger

    International Nuclear Information System (INIS)

    Lopez, Yon; Gora, Jimmy; Bedregal, Patricia; Hernandez, Yuri; Baltuano, Oscar; Gago, Javier

    2013-01-01

    The design of a turntable type sample exchanger for irradiation and with a capacity for up to 20 capsules was performed. Its function is the automatic sending of samples contained in polyethylene capsules, for irradiation in the grid position of the reactor core, using a pneumatic system and further analysis by neutron activation. This study shows the structural design analysis and calculations in selecting motors and actuators. This development will improve efficiency in the analysis, reducing the contribution of the workers and also the radiation exposure time. (authors).

  14. Updated questions and research on mechanisms which control release in nuclear power plants. Solubility or other effects?

    International Nuclear Information System (INIS)

    Guinard, L.; Noel, D.; Kerrec, O.

    1997-01-01

    There are many computer codes, based on mass transfer in the liquid phase, which have been developed to help in predicting emission and transport of corrosion products. Their limit for the release is discussed and, through two new studies, it is investigated how new mechanisms can be taken into account. Models based on the transfer of electronic or ionic charges in the solid phase should be developed. (K.A.)

  15. Updated questions and research on mechanisms which control release in nuclear power plants. Solubility or other effects?

    Energy Technology Data Exchange (ETDEWEB)

    Guinard, L.; Noel, D.; Kerrec, O.

    1997-01-01

    There are many computer codes, based on mass transfer in the liquid phase, which have been developed to help in predicting emission and transport of corrosion products. Their limit for the release is discussed and, through two new studies, it is investigated how new mechanisms can be taken into account. Models based on the transfer of electronic or ionic charges in the solid phase should be developed. (K.A.). 29 refs.

  16. Updated constraints on the light-neutrino exchange mechanisms of the 0νββ-decay

    Energy Technology Data Exchange (ETDEWEB)

    Štefánik, Dušan, E-mail: dus.stefanik@gmail.com [Comenius University, Mlynská dolina F1, SK-842 48 Bratislava (Slovakia); Dvornický, Rastislav [Comenius University, Mlynská dolina F1, SK-842 48 Bratislava (Slovakia); Dzhelepov Laboratory of Nuclear Problems, JINR 141980 Dubna (Russian Federation); Šimkovic, Fedor [Comenius University, Mlynská dolina F1, SK-842 48 Bratislava (Slovakia); Boboliubov Laboratory of Theoretical Physics, JINR 141980 Dubna (Russian Federation); Czech Technical University in Prague, 128-00 Prague (Czech Republic)

    2015-10-28

    The neutrinoless double-beta (0νββ) decay associated with light neutrino exchange mechanisms, which are due to both left-handed V-A and right-handed V+A leptonic and hadronic currents, is discussed by using the recent progress achieved by the GERDA, EXO and KamlandZen experiments. The upper limits for effective neutrino mass m{sub ββ} and the parameters 〈λ〉 and 〈η〉 characterizing the right handed current mechanisms are deduced from the data on the 0νββ-decay of {sup 76}Ge and {sup 136}Xe using nuclear matrix elements calculated within the nuclear shell model and quasiparticle random phase approximation and phase-space factors calculated with exact Dirac wave functions with finite nuclear size and electron screening. The careful analysis of upper constraints on effective lepton number violating parameters assumes a competition of the above mechanisms and arbitrary values of involved CP violating phases.

  17. Mechanical Design of AM Fabricated Prismatic Rods under Torsion

    Directory of Open Access Journals (Sweden)

    Manzhirov Alexander V.

    2017-01-01

    Full Text Available We study the stress-strain state of viscoelastic prismatic rods fabricated or repaired by additive manufacturing technologies under torsion. An adequate description of the processes involved is given by methods of a new scientific field, mechanics of growing solids. Three main stages of the deformation process (before the beginning of growth, in the course of growth, and after the termination of growth are studied. Two versions of statement of two problems are given: (i given the torque, find the stresses, displacements, and torsion; (ii given the torsion, find the stresses, displacements, and torque. Solution methods using techniques of complex analysis are presented. The results can be used in mechanical and instrument engineering.

  18. Mechanical design of the recirculating, terminal pumping in the Lund ...

    Indian Academy of Sciences (India)

    ory effect are essential. For the injector .... Copco oil-free rotating compressors, capacity 4.2 l/s at 1 MPa air, model Scroll-SF4-10) are fed with gas of a ... The expanding gas leaves the motors and enters the accelerator tank. 2.3 Design of the ...

  19. Development of Mechanical Structure Design Technology for LMR

    International Nuclear Information System (INIS)

    Lee, Jae Han; Joo, Young Sang; Lee, Hyeong Yeon

    2007-03-01

    Structural integrity and design simplifications were secured on reactor core support system, upper internal structure and core catcher of KALIMER-600. The evaluation on the suitability of high temperature and seismic design of reactor structures, and the structural integrity evaluation on reactor components and high temperature pipings are performed. The interfaces between the components and ISI accessibility are checked. Lightening of reactor building by 7%, the seismic design for 0.3g seismic loads and improvement of reactor structural design concept for KALIMER-600 have been carried out. Remote inspection technique using ultrasonic wave guide sensor was acquired as a visualization method for reactor internals under opaque sodium environments. The basic guideline on high temperature structure assessment as an assessment procedure on high temperature inelastic behaviour has been completed. In high temperature creep-fatigue test, totally 500 cycles (totally 700 hold time) were carried on cylindrical test and IHTS co-axial pipe test models. The behaviors of creep-fatigue damage and creep-fatigue crack behaviour were investigated, and the DB on the structural test were established. The seismic response tests on 19-sub assembly validation test model in air and in water were carried out, and its multi-purpose characteristics and reliability on the SAC-CORE3.0 code developed for core seismic response analysis were validated

  20. Arc plasma devices: Evolving mechanical design from numerical ...

    Indian Academy of Sciences (India)

    feeds power into the system for sustained operation. Depending ... distribution, velocity profiles, device efficiency, spatial concentration of nascent active species .... where V is the arc voltage and ϕ is the work function of the anode material. The first .... to predict correct potential drop within the device in a number of designs.

  1. Mechanism design for mobile geo-location advertising

    OpenAIRE

    Gatti, Nicola; Rocco, Marco; Ceppi, Sofia; Gerding, Enrico H.

    2014-01-01

    Mobile geo–location advertising, where mobile ads are targeted based on a user’s location, has been identified as a key growth factor for the mobile market. As with online advertising, a crucial ingredient for their success is the development of effective economic mechanisms. An important difference is that mobile ads are shown sequentially over time and information about the user can be learned based on their movements. Furthermore, ads need to be shown selectively to prevent ad fatigue. To ...

  2. Mechanical design criteria for intervertebral disc tissue engineering.

    Science.gov (United States)

    Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L

    2010-04-19

    Due to the inability of current clinical practices to restore function to degenerated intervertebral discs, the arena of disc tissue engineering has received substantial attention in recent years. Despite tremendous growth and progress in this field, translation to clinical implementation has been hindered by a lack of well-defined functional benchmarks. Because successful replacement of the disc is contingent upon replication of some or all of its complex mechanical behaviors, it is critically important that disc mechanics be well characterized in order to establish discrete functional goals for tissue engineering. In this review, the key functional signatures of the intervertebral disc are discussed and used to propose a series of native tissue benchmarks to guide the development of engineered replacement tissues. These benchmarks include measures of mechanical function under tensile, compressive, and shear deformations for the disc and its substructures. In some cases, important functional measures are identified that have yet to be measured in the native tissue. Ultimately, native tissue benchmark values are compared to measurements that have been made on engineered disc tissues, identifying where functional equivalence was achieved, and where there remain opportunities for advancement. Several excellent reviews exist regarding disc composition and structure, as well as recent tissue engineering strategies; therefore this review will remain focused on the functional aspects of disc tissue engineering. Copyright 2009 Elsevier Ltd. All rights reserved.

  3. Determining the Optimal Design for a New ADR Mechanical Support

    Science.gov (United States)

    Waldvogel, Kelly; Stacey, Gordon; Nikola, Thomas; Parshley, Stephen

    2018-01-01

    ZEUS-2 is a grating spectrometer that is used to observe emission lines in submillimeter wavelengths. It is capable of detecting redshifted fine structure lines of galaxies over a wide redshift range. ZEUS-2 can observe carbon, nitrogen, and oxygen lines, which will in turn allow for modeling of optically thick molecular clouds, provide information about star temperatures, and help gain insight about the interstellar medium and gases from which stars form. The detections collected by ZEUS-2 can provide a glimpse into star formation in the early universe and improve the current understanding of the star formation process.ZEUS-2 utilizes an Adiabatic Demagnetization Refrigerator (ADR) to cool its detectors to around 100 mK. Copper rods connect the salt pills within the ADR and the mechanical supports. These supports are comprised of three main pieces: a base member, an inner member, and a guard member. On two separate mechanical supports, the Kevlar strands have broken. This led to thermal contact between the three members, preventing the detector from reaching its final operating temperature. It is clear that a replacement mechanical support system is necessary for operation.

  4. On fair, effective and efficient REDD mechanism design

    Directory of Open Access Journals (Sweden)

    Gusti Mykola

    2009-11-01

    Full Text Available Abstract The issues surrounding 'Reduced Emissions from Deforestation and Forest Degradation' (REDD have become a major component of continuing negotiations under the United Nations Framework Convention on Climate Change (UNFCCC. This paper aims to address two key requirements of any potential REDD mechanism: first, the generation of measurable, reportable and verifiable (MRV REDD credits; and secondly, the sustainable and efficient provision of emission reductions under a robust financing regime. To ensure the supply of MRV credits, we advocate the establishment of an 'International Emission Reference Scenario Coordination Centre' (IERSCC. The IERSCC would act as a global clearing house for harmonized data to be used in implementing reference level methodologies. It would be tasked with the collection, reporting and subsequent processing of earth observation, deforestation- and degradation driver information in a globally consistent manner. The IERSCC would also assist, coordinate and supervise the computation of national reference scenarios according to rules negotiated under the UNFCCC. To overcome the threats of "market flooding" on the one hand and insufficient economic incentives for REDD on the other hand, we suggest an 'International Investment Reserve' (IIR as REDD financing framework. In order to distribute the resources of the IIR we propose adopting an auctioning mechanism. Auctioning not only reveals the true emission reduction costs, but might also allow for incentivizing the protection of biodiversity and socio-economic values. The introduced concepts will be vital to ensure robustness, environmental integrity and economic efficiency of the future REDD mechanism.

  5. The iSAT Project Mechanical properties and designs

    KAUST Repository

    Llewellyn, Gareth

    2011-08-08

    The whale shark Rhincodon typus is the largest fish in the world. The global population of R.typus is unknown however the International Union for Conservation of Nature (IUNC) classified it as Vulnerable in 2005. To ensure a population of R.typus is maintained protection from direct fishing, by-catch and collision damage is required. To be able to enact successful protection the habitat and range of R.typus must be known. Many authors have conducted studies of R.typus in a variety of different locations and many more have reported sightings. In many locations R.typus consistently appear annually and many authors have hypothesised reasons for their appearance. What is not known however is whether these populations are isolated or inter-linked, and where these populations go when they are not at known sites. The aim of this thesis was to design the body of a vessel that could house the electronics and components designed to track an acoustic tag, survive in open ocean, and travel fast enough to keep up with R.typus allowing a long-term and high resolution track to be compiled. In order to design such a vessel many factors needed to be known. A large part of this thesis is a review of literature to conclude the most appropriate type of vessel, the average speed of R.typus, hence the required speed of the vessel, and the sea state of the Red Sea, hence the conditions the vessel would be required to survive in. It was concluded that the average speed of R.typus is 1.2 knots; the Red Sea reaches Sea State 5-6; and the most appropriate hull type for this project was a Small Waterplane Area Twin Hull (SWATH). After following a design iteration process, a final design was completed that it is believed will achieve all the required objectives.

  6. Design of mechanical arm for an automatic sorting system of recyclable cans

    Science.gov (United States)

    Resti, Y.; Mohruni, A. S.; Burlian, F.; Yani, I.; Amran, A.

    2018-04-01

    The use of a mechanical arm for an automatic sorting system of used cans should be designed carefully. The right design will result in a high precision sorting rate and a short sorting time. The design includes first; design manipulator,second; determine link and joint specifications, and third; build mechanical systems and control systems. This study aims to design the mechanical arm as a hardware system for automatic cans sorting system. The material used for the manipulator is the aluminum plate. The manipulator is designed using 6 links and 6 join where the 6th link is the end effectorand the 6th join is the gripper. As a driving motor used servo motor, while as a microcontroller used Arduino Uno which is connected with Matlab programming language. Based on testing, a mechanical arm designed for this recyclable canned recycling system has a precision sorting rate at 93%, where the average total time required for sorting is 10.82 seconds.

  7. A new preconditioner update strategy for the solution of sequences of linear systems in structural mechanics: application to saddle point problems in elasticity

    Science.gov (United States)

    Mercier, Sylvain; Gratton, Serge; Tardieu, Nicolas; Vasseur, Xavier

    2017-12-01

    Many applications in structural mechanics require the numerical solution of sequences of linear systems typically issued from a finite element discretization of the governing equations on fine meshes. The method of Lagrange multipliers is often used to take into account mechanical constraints. The resulting matrices then exhibit a saddle point structure and the iterative solution of such preconditioned linear systems is considered as challenging. A popular strategy is then to combine preconditioning and deflation to yield an efficient method. We propose an alternative that is applicable to the general case and not only to matrices with a saddle point structure. In this approach, we consider to update an existing algebraic or application-based preconditioner, using specific available information exploiting the knowledge of an approximate invariant subspace or of matrix-vector products. The resulting preconditioner has the form of a limited memory quasi-Newton matrix and requires a small number of linearly independent vectors. Numerical experiments performed on three large-scale applications in elasticity highlight the relevance of the new approach. We show that the proposed method outperforms the deflation method when considering sequences of linear systems with varying matrices.

  8. Improving Tools and Processes in Mechanical Design Collaboration

    Science.gov (United States)

    Briggs, Clark

    2009-01-01

    Cooperative product development projects in the aerospace and defense industry are held hostage to high cost and risk due to poor alignment of collaborative design tools and processes. This impasse can be broken if companies will jointly develop implementation approaches and practices in support of high value working arrangements. The current tools can be used to better advantage in many situations and there is reason for optimism that tool vendors will provide significant support.

  9. Design principles and developmental mechanisms underlying retinal mosaics.

    Science.gov (United States)

    Reese, Benjamin E; Keeley, Patrick W

    2015-08-01

    Most structures within the central nervous system (CNS) are composed of different types of neuron that vary in both number and morphology, but relatively little is known about the interplay between these two features, i.e. about the population dynamics of a given cell type. How such arrays of neurons are distributed within a structure, and how they differentiate their dendrites relative to each other, are issues that have recently drawn attention in the invertebrate nervous system, where the genetic and molecular underpinnings of these organizing principles are being revealed in exquisite detail. The retina is one of the few locations where these principles have been extensively studied in the vertebrate CNS, indeed, where the design principles of 'mosaic regularity' and 'uniformity of coverage' were first explicitly defined, quantified, and related to each other. Recent studies have revealed a number of genes that influence the formation of these histotypical features in the retina, including homologues of those invertebrate genes, although close inspection reveals that they do not always mediate comparable developmental processes nor elucidate fundamental design principles. The present review considers just how pervasive these features of 'mosaic regularity' and 'uniform dendritic coverage' are within the mammalian retina, discussing the means by which such features can be assessed in the mature and developing nervous system and examining the limitations associated with those assessments. We then address the extent to which these two design principles co-exist within different populations of neurons, and how they are achieved during development. Finally, we consider the neural phenotypes obtained in mutant nervous systems, to address whether a prospective gene of interest underlies those very design principles. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  10. Core compressor exit stage study. 1: Aerodynamic and mechanical design

    Science.gov (United States)

    Burdsall, E. A.; Canal, E., Jr.; Lyons, K. A.

    1979-01-01

    The effect of aspect ratio on the performance of core compressor exit stages was demonstrated using two three stage, highly loaded, core compressors. Aspect ratio was identified as having a strong influence on compressors endwall loss. Both compressors simulated the last three stages of an advanced eight stage core compressor and were designed with the same 0.915 hub/tip ratio, 4.30 kg/sec (9.47 1bm/sec) inlet corrected flow, and 167 m/sec (547 ft/sec) corrected mean wheel speed. The first compressor had an aspect ratio of 0.81 and an overall pressure ratio of 1.357 at a design adiabatic efficiency of 88.3% with an average diffusion factor or 0.529. The aspect ratio of the second compressor was 1.22 with an overall pressure ratio of 1.324 at a design adiabatic efficiency of 88.7% with an average diffusion factor of 0.491.

  11. Graphite structure and its relation to mechanical engineering design

    International Nuclear Information System (INIS)

    Brocklehurst, J.E.; Kelly, B.T.

    1980-01-01

    The inhomogeneous nature of polycrystalline graphite requires property measurements to be made over dimensions large enough to average the local variations in the structure. This is particularly true for mechanical integrity, and experimental data are presented which illustrate the importance of the real aggregate structure of graphite and the difficulties of interpreting strength data from different tests. The classical statistical treatments do not hold generally, and the problem of defining a failure criterion for graphite is discussed. It is suggested that the stress conditions in graphite components might be classified in terms of the dimensions and stress gradients related to the characteristic flaw size of the material as determined experimentally. (author)

  12. Chemotherapeutics-resistance "arms" race: An update on mechanisms involved in resistance limiting EGFR inhibitors in lung cancer.

    Science.gov (United States)

    Singh, Pankaj Kumar; Silakari, Om

    2017-10-01

    Clinical reports suggest that EGFR-mutated lung cancer usually respond significantly towards small molecule tyrosine kinase inhibitors. Same studies also report the eventual development of acquired resistance within a median time interval of 9 to 14months. One of the major mechanisms involved in this acquired resistance was found to be a secondary point mutation at gate-keeper residue, EGFR T790M. However, there are other recent studies which disclose the role of few other novel key players such as, ZEB1, TOPK etc., in the development of tolerance towards the EGFR TKI's, along with other commonly known mechanisms, such as amplification of signalling pathways such as, c-MET, Erbb2, AXL, additional acquired secondary mutations (PIK3CA, BRAF), or phenotypic transformation (small cell or epithelial to mesenchymal transitions). Interestingly, a recent study showed development of resistance via another point mutation, C797S, in case of tumors which were previously resistant and were administered agents capable of overcoming T790M gatekeeper mutation based resistance. Thus, raising serious concern over the direction of drug development involving tyrosine kinases such as EGFR. Current approaches focussing on development of third generation inhibitors, dual inhibitors or inhibitors of HSP90 have shown significant activity but do not answer the long term question of resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Mechanism Design for Task Procurement with Flexible Quality of Service

    Science.gov (United States)

    Gerding, Enrico H.; Larson, Kate; Rogers, Alex; Jennings, Nicholas R.

    In this paper, we consider the problem where an agent wishes to complete a single computational task, but lacks the required resources. Instead, it must contract self-interested service providers, who are able to flexibly manipulate the quality of service they deliver, in order to maximise their own utility. We extend an existing model to allow for multiple such service providers to be contracted for the same task, and derive optimal task procurement mechanisms in the setting where the agent has full knowledge of the cost functions of these service providers (considering both simultaneous and sequential procurement). We then extend these results to the incomplete information setting where the agent must elicit cost information from the service providers, and we characterise a family of incentive-compatible and individually-rational mechanisms. We show empirically that sequential procurement always generates greater utility for the agent compared to simultaneous procurement, and that over a range of settings, contracting multiple providers is preferable to contracting just one.

  14. Examples of Mechanism Design : From King Solomon to eBay

    NARCIS (Netherlands)

    De Weerdt, M.M.

    2007-01-01

    The judgment of king Solomon is an early example of mechanism design. Mechanism design attempts to achieve desired outcomes in situations with self-interested players by setting the rules of the game in a specific way. We will see that the game Solomon proposed would not have worked if the women

  15. Teaching Reform of Course Group Regarding Theory and Design of Mechanisms Based on MATLAB Technology

    Science.gov (United States)

    Shen, Yi; Yuan, Mingxin; Wang, Mingqiang

    2013-01-01

    Considering that the course group regarding theory and design of mechanisms is characterized by strong engineering application background and the students generally feel very boring and tedious during the learning process, some teaching reforms for the theory and design of mechanisms are carried out to improve the teaching effectiveness in this…

  16. Design and characteristics of the drive mechanism for movable limiters of JT-60, (1)

    International Nuclear Information System (INIS)

    Takashima, Tetsuo; Morishita, Osamu; Yamamoto, Masahiro; Shimizu, Masatsugu; Ohta, Mitsuru

    1976-10-01

    Two fast-acting movable rail limiters will be installed in a large Tokamak JT-60 being designed in JAERI. The movable limiter consists of a drive mechanism, a vacuum seal, a bearing, and a molybdenum rail limiter. Design of the drive mechanism for the movable limiter and experimental results on the driving characteristics in full scale are described. (auth.)

  17. Generation and application of tri-dimensional animation in mechanical design

    International Nuclear Information System (INIS)

    Liu Li

    2003-01-01

    The mechanical design can be understood vividly and accurately and can be improved in time when there is any mistake if it is made in tri-dimensional animation. The author introduces the generation process and methods for animation in mechanical design with an example

  18. Mechanism design: theory and application to welfare-to-work programs

    NARCIS (Netherlands)

    Onderstal, S.

    2008-01-01

    In October 2007, Leonid Hurwicz , Eric Maskin, and Roger Myerson won the Nobel Prize in Economic Sciences "for having laid the foundations of mechanism design theory". My aim is to give you a flavor of what mechanism design theory is and how we can apply it in practice. More in particular, I will

  19. Design of a high speed rotating mechanical shutter

    International Nuclear Information System (INIS)

    Stowers, I.F.; Merritt, B.T.; McFann, C.B.

    1979-01-01

    A high-speed rotating shutter was designed to operate in a 10 -6 Torr vacuum at the optical focus of a laser spatial filter. The shutter is basically a wheel, with a single 3 x 10-mm slot at the perimeter, which rotates with a peripheral speed of 1 km/s. The motor to drive the rotating wheel is magnetically suspended and synchronously wound. The wheel achieves a 4 μs opening time and a timing accuracy of better than 0.2 μs

  20. Thermal and Mechanical Design Aspects of the LIFE Engine

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, R P; Gerhard, M A; Latkowski, J F; Kramer, K J; Morris, K R; Peterson, P F; Seifried, J E

    2008-10-25

    The Laser Inertial confinement fusion - Fission Energy (LIFE) engine encompasses the components of a LIFE power plant responsible for converting the thermal energy of fusion and fission reactions into electricity. The design and integration of these components must satisfy a challenging set of requirements driven by nuclear, thermal, geometric, structural, and materials considerations. This paper details a self-consistent configuration for the LIFE engine along with the methods and technologies selected to meet these stringent requirements. Included is discussion of plant layout, coolant flow dynamics, fuel temperatures, expected structural stresses, power cycle efficiencies, and first wall survival threats. Further research and to understand and resolve outstanding issues is also outlined.

  1. Design of transplanting mechanism for system of rice intensification (SRI) transplanter in Kedah, Malaysia

    Science.gov (United States)

    Imran, M. S.; Manan, M. S. Abdul; Khalil, A. N. M.; MdNaim, M. K.; Ahmad, R. N.

    2017-08-01

    There is a demand to develop transplanter specifically for system of rice intensification (SRI) cultivation in Malaysia. This SRI transplanter is different from conventional transplanter as it is required special requirements for transplanting. The work focused on transplanting mechanism design which can be later attached to SRI transplanter. The mechanical design was established using linkage mechanism, having a wheel that act as timing wheel that will control the distance between transplanted seedlings. The linkage mechanism also control the opening of the flapper that allow the seedling together with its nursery soil to be dropped, and control the stopper to prevent next seedling from sliding down the tray. The use of simple mechanism will have low cost for fabrication. The design was analysed using motion analysis software. Results show the design is perfectly good and can be fabricated without any problem. The animation successfully shows the perfect movement of the mechanism and transplanting process.

  2. Ameliorative design for CARR safety rod drive mechanism

    International Nuclear Information System (INIS)

    Zhu Xuewei; Luo Zhong; Zhen Jianxiao; Wang Yulin

    2014-01-01

    The problem of safety rod accident dropped during C commissioning phase for China Advanced Research Reactor (CARR) was analyzed, and the reason was that the solenoid valve in safety rod drive mechanism (SRDM) driven loop was breakdown because of long-playing work. To solve this safe hidden trouble, SRDM was redesigned, and a new type of 'hydro lifting-hydro and electromagnetic holding' SRDM was presented, using Ansoft Maxwell to make a finite element analysis on new SRDM, working out electromagnetic field distribution and electromagnetic force of new SRDM. The results show that the value of electromagnetic force produced by electromagnetic force holding unit reaches 2.12 times about the weight of safety rod drive line, and it has some margins. (authors)

  3. System Topology Optimization - An Approach to System Design of Electro-Hydraulic-Mechanical Systems

    DEFF Research Database (Denmark)

    Andersen, T. O.; Hansen, M. R.; Conrad, Finn

    2003-01-01

    The current paper presents an approach to system design of combined electro-hydraulic-mechanical systems. The approach is based on the concurrent handling of the topology as well as the design parameters of the mechanical, hydraulic and controller sub- systems, respectively. Based on an initial...... design the procedure attempts to find the optimal topology and the related parameters. The topology considerations comprise the type of hydraulic pump, the employment of knee linkages or not as well as the type of hydraulic actuators. The design variables also include the signals to the proportional...... valve in a number of predefined load cases as well as the hydraulic and mechanical parameters....

  4. Mixed reality temporal bone surgical dissector: mechanical design.

    Science.gov (United States)

    Hochman, Jordan Brent; Sepehri, Nariman; Rampersad, Vivek; Kraut, Jay; Khazraee, Milad; Pisa, Justyn; Unger, Bertram

    2014-08-08

    The Development of a Novel Mixed Reality (MR) Simulation. An evolving training environment emphasizes the importance of simulation. Current haptic temporal bone simulators have difficulty representing realistic contact forces and while 3D printed models convincingly represent vibrational properties of bone, they cannot reproduce soft tissue. This paper introduces a mixed reality model, where the effective elements of both simulations are combined; haptic rendering of soft tissue directly interacts with a printed bone model. This paper addresses one aspect in a series of challenges, specifically the mechanical merger of a haptic device with an otic drill. This further necessitates gravity cancelation of the work assembly gripper mechanism. In this system, the haptic end-effector is replaced by a high-speed drill and the virtual contact forces need to be repositioned to the drill tip from the mid wand. Previous publications detail generation of both the requisite printed and haptic simulations. Custom software was developed to reposition the haptic interaction point to the drill tip. A custom fitting, to hold the otic drill, was developed and its weight was offset using the haptic device. The robustness of the system to disturbances and its stable performance during drilling were tested. The experiments were performed on a mixed reality model consisting of two drillable rapid-prototyped layers separated by a free-space. Within the free-space, a linear virtual force model is applied to simulate drill contact with soft tissue. Testing illustrated the effectiveness of gravity cancellation. Additionally, the system exhibited excellent performance given random inputs and during the drill's passage between real and virtual components of the model. No issues with registration at model boundaries were encountered. These tests provide a proof of concept for the initial stages in the development of a novel mixed-reality temporal bone simulator.

  5. Robust design of microelectronics assemblies against mechanical shock, temperature and moisture effects of temperature, moisture and mechanical driving forces

    CERN Document Server

    Wong, E-H

    2015-01-01

    Robust Design of Microelectronics Assemblies Against Mechanical Shock, Temperature and Moisture discusses how the reliability of packaging components is a prime concern to electronics manufacturers. The text presents a thorough review of this important field of research, providing users with a practical guide that discusses theoretical aspects, experimental results, and modeling techniques. The authors use their extensive experience to produce detailed chapters covering temperature, moisture, and mechanical shock induced failure, adhesive interconnects, and viscoelasticity. Useful progr

  6. Design and fabrication of a eccentric wheels based motorised alignment mechanism for cylindrical accelerator components

    International Nuclear Information System (INIS)

    Mundra, G.; Jain, V.; Karmarkar, Mangesh; Kotaiah, S.

    2006-01-01

    Precision alignment mechanisms with long term stability are required for accelerator components. For some of the components motorised and remotely operable alignment mechanism are required. An eccentric wheel mechanism based alignment system is very much suitable for such application. One such alignment system is designed, a prototype is machined/fabricated for SFDTL type accelerating structure and preliminary trial experiments have been done. (author)

  7. Designing a software for systematic registration of oral and maxillofacial diseases based on the latest update of the World Health Organization ICD-10 classification system in 2010

    Directory of Open Access Journals (Sweden)

    Arash Mansorian

    2014-04-01

    Full Text Available   Background and Aims: Classification is a fundamental issue in quantitative studies of any phenomenon and has been known as a necessity for the advancement of science. Using a standard record system for diseases is critical for research purposes and also could improve the quality of medical health services. In this study, after evaluating current codding systems in oral medicine, we designed a software for systematic coding and registration of Oral and Maxillofacial diseases based on the latest update of the World Health Organization ICD-10 classification system in 2010.   Materials and Methods: Based on the latest WHO ICD-10 update in 2010 and by using software s as: vb.net, net framework, SQL Server and Microsoft Visual Studio, standard coding software for recording patient's data at the department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences was designed. Data from all patients were codded by standard ICD-10 codes and registered by the software. Also an online portal for recording patient's data which could be used nationwide was designed. By d esigning this software the process of forming and registering patient's records, and their treatment process is facilitated . An archive of patient data was also stablished .   Conclusion: As a result , this software in addition to maintaining patient data , facilitate studies and research projects greatly. It’s recommended that the Iranian Ministry of Health and Medical Education as the concessioner of this software, improves codding and registration systems of oral diseases at the dental schools by developing this software.

  8. The design and testing of a memory metal actuated boom release mechanism

    Science.gov (United States)

    Powley, D. G.; Brook, G. B.

    1979-01-01

    A boom latch and release mechanism was designed, manufactured and tested, based on a specification for the ISEE-B satellite mechanism. From experimental results obtained, it is possible to calculate the energy available and the operating torques which can be achieved from a torsional shape memory element in terms of the reversible strain induced by prior working. Some guidelines to be followed when designing mechanisms actuated by shape memory elements are included.

  9. An update on the mechanisms and pathophysiological consequences of genomic instability with a focus on ionizing radiation

    Directory of Open Access Journals (Sweden)

    Streffer C

    2015-12-01

    Full Text Available Christian Streffer Institute for Medical Radiobiology, University Clinics Essen, Essen, Germany Abstract: The genome of eukaryotic cells is generally instable. DNA damage occurs by endogenous processes and exogenous toxic agents. The efficient DNA repair pathways conserve the genetic information to a large extent throughout the life. However, exposure to genotoxic agents can increase the genomic instability. This phenomenon develops in a delayed manner after approximately 20 and more cell generations. It is comparatively thoroughly investigated after the exposure to ionizing radiation. The increase of genomic instability has been observed after exposures to ionizing radiation in vitro and in vivo as well as with many different types of radiation. The effect is induced over a wide dose range, and it has been found with cell death, chromosomal damage, cell transformations, mutations, double-strand breaks, malformations, and cancers. No specific chromosomes or genomic sites have been observed for such events. The increased genomic instability can be transmitted to the next generation. Possible mechanisms such as oxidative stress (mitochondria may be involved, reduced DNA repair, changes in telomeres, epigenetic effects are discussed. A second wave of oxidative stress has been observed after radiation exposures with considerably high doses as well as with cytotoxic agents at time periods when an increased genomic instability was seen. However, the increase of genomic instability also happens to much lower radiation doses. Hypoxia induces an increase of genomic instability. This effect is apparently connected with a reduction of DNA repair. Changes of telomeres appear as the most probable mechanisms for the increase of genomic instability. Syndromes have been described with a genetic predisposition for high radiosensitivity. These individuals show an increase of cancer, a deficient DNA repair, a disturbed regulation of the cell cycle, and an

  10. Mechanical Engineering and Design of the LHC Phase II Collimators

    CERN Document Server

    Bertarelli, A; Gentini, L; Mariani, N; Perret, R; Timmins, M A

    2010-01-01

    Phase II collimators will complement the existing system to improve the expected high RF impedance and limited efficiency of Phase I jaws. An international collaborative effort has been launched to identify novel advanced materials responding to the very challenging requirements of the new collimators. Complex numerical calculations simulating extreme conditions and experimental tests are in progress. In parallel, an innovative modular design concept of the jaw assembly is being developed to allow fitting in alternative materials, minimizing the thermally induced deformations, withstanding accidents and accepting high radiation doses. Phase II jaw assembly is made up of a molybdenum back-stiffener ensuring high geometrical stability and a modular jaw split in threes sectors. Each sector is equipped with a high-efficiency independent cooling circuit. Beam position monitors (BPM) are embedded in the jaws to fasten setup time and improve beam monitoring. An adjustment system will permit to fine-tune the jaw flat...

  11. Direct numerical methods of mathematical modeling in mechanical structural design

    International Nuclear Information System (INIS)

    Sahili, Jihad; Verchery, Georges; Ghaddar, Ahmad; Zoaeter, Mohamed

    2002-01-01

    Full text.Structural design and numerical methods are generally interactive; requiring optimization procedures as the structure is analyzed. This analysis leads to define some mathematical terms, as the stiffness matrix, which are resulting from the modeling and then used in numerical techniques during the dimensioning procedure. These techniques and many others involve the calculation of the generalized inverse of the stiffness matrix, called also the 'compliance matrix'. The aim of this paper is to introduce first, some different existing mathematical procedures, used to calculate the compliance matrix from the stiffness matrix, then apply direct numerical methods to solve the obtained system with the lowest computational time, and to compare the obtained results. The results show a big difference of the computational time between the different procedures

  12. Misfits in Organization Design: Information Processing as a Compensatory Mechanism

    Directory of Open Access Journals (Sweden)

    Ben Nanfeng Luo

    2013-04-01

    Full Text Available We propose a compensatory misfits theory which holds that an “over-fitting” organization structure can compensate for an “under-fitting” structure, thereby reducing the total misfit. In organizations, over-fit occurs when structural features misfit the core contingencies because the structural level is too high to fit the contingencies. An under-fit occurs when structural features misfit the contingencies because the structural level is too low. When an under-fit is compensated by an over-fit, the combination can produce performance outcomes that approximate those from fit. The reason inheres in information processing being a higher level factor that cuts across different contingencies and structural features that are mis-fitted to each other, so that compensation is possible. We identify the specific conditions that must be fulfilled for compensation to occur, and we discuss implications for organization design theory and practice.

  13. Market Mechanism Design for Renewable Energy based on Risk Theory

    Science.gov (United States)

    Yang, Wu; Bo, Wang; Jichun, Liu; Wenjiao, Zai; Pingliang, Zeng; Haobo, Shi

    2018-02-01

    Generation trading between renewable energy and thermal power is an efficient market means for transforming supply structure of electric power into sustainable development pattern. But the trading is hampered by the output fluctuations of renewable energy and the cost differences between renewable energy and thermal power at present. In this paper, the external environmental cost (EEC) is defined and the EEC is introduced into the generation cost. At same time, the incentive functions of renewable energy and low-emission thermal power are designed, which are decreasing functions of EEC. On these bases, for the market risks caused by the random variability of EEC, the decision-making model of generation trading between renewable energy and thermal power is constructed according to the risk theory. The feasibility and effectiveness of the proposed model are verified by simulation results.

  14. Designing behavior in interaction : using aesthetic experience as a mechanism for design

    NARCIS (Netherlands)

    Ross, P.R.; Wensveen, S.A.G.

    2010-01-01

    As design moves into the realm of intelligent products and systems, interactive product behavior becomes an ever more prominent aspect of design, raising the question of how to design the aesthetics of such interactive behavior. To address this challenge, we developed a conception of aesthetics

  15. The Molecular Mechanisms of Anesthetic Action: Updates and Cutting Edge Developments from the Field of Molecular Modeling

    Directory of Open Access Journals (Sweden)

    Edward J. Bertaccini

    2010-07-01

    Full Text Available For over 160 years, general anesthetics have been given for the relief of pain and suffering. While many theories of anesthetic action have been purported, it has become increasingly apparent that a significant molecular focus of anesthetic action lies within the family of ligand-gated ion channels (LGIC’s. These protein channels have a transmembrane region that is composed of a pentamer of four helix bundles, symmetrically arranged around a central pore for ion passage. While initial and some current models suggest a possible cavity for binding within this four helix bundle, newer calculations postulate that the actual cavity for anesthetic binding may exist between four helix bundles. In either scenario, these cavities have a transmembrane mode of access and may be partially bordered by lipid moieties. Their physicochemical nature is amphiphilic. Anesthetic binding may alter the overall motion of a ligand-gated ion channel by a “foot-in-door” motif, resulting in the higher likelihood of and greater time spent in a specific channel state. The overall gating motion of these channels is consistent with that shown in normal mode analyses carried out both in vacuo as well as in explicitly hydrated lipid bilayer models. Molecular docking and large scale molecular dynamics calculations may now begin to show a more exact mode by which anesthetic molecules actually localize themselves and bind to specific protein sites within LGIC’s, making the design of future improvements to anesthetic ligands a more realizable possibility.

  16. Design of a Single Motor Based Leg Structure with the Consideration of Inherent Mechanical Stability

    Science.gov (United States)

    Taha Manzoor, Muhammad; Sohail, Umer; Noor-e-Mustafa; Nizami, Muhammad Hamza Asif; Ayaz, Yasar

    2017-07-01

    The fundamental aspect of designing a legged robot is constructing a leg design that is robust and presents a simple control problem. In this paper, we have successfully designed a robotic leg based on a unique four bar mechanism with only one motor per leg. The leg design parameters used in our platform are extracted from design principles used in biological systems, multiple iterations and previous research findings. These principles guide a robotic leg to have minimal mechanical passive impedance, low leg mass and inertia, a suitable foot trajectory utilizing a practical balance between leg kinematics and robot usage, and the resultant inherent mechanical stability. The designed platform also exhibits the key feature of self-locking. Theoretical tools and software iterations were used to derive these practical features and yield an intuitive sense of the required leg design parameters.

  17. Radial basis function (RBF) neural network control for mechanical systems design, analysis and Matlab simulation

    CERN Document Server

    Liu, Jinkun

    2013-01-01

    Radial Basis Function (RBF) Neural Network Control for Mechanical Systems is motivated by the need for systematic design approaches to stable adaptive control system design using neural network approximation-based techniques. The main objectives of the book are to introduce the concrete design methods and MATLAB simulation of stable adaptive RBF neural control strategies. In this book, a broad range of implementable neural network control design methods for mechanical systems are presented, such as robot manipulators, inverted pendulums, single link flexible joint robots, motors, etc. Advanced neural network controller design methods and their stability analysis are explored. The book provides readers with the fundamentals of neural network control system design.   This book is intended for the researchers in the fields of neural adaptive control, mechanical systems, Matlab simulation, engineering design, robotics and automation. Jinkun Liu is a professor at Beijing University of Aeronautics and Astronauti...

  18. Mechanically and electrically robust metal-mask design for organic CMOS circuits

    Science.gov (United States)

    Shintani, Michihiro; Qin, Zhaoxing; Kuribara, Kazunori; Ogasahara, Yasuhiro; Hiromoto, Masayuki; Sato, Takashi

    2018-04-01

    The design of metal masks for fabricating organic CMOS circuits requires the consideration of not only the electrical property of the circuits, but also the mechanical strength of the masks. In this paper, we propose a new design flow for metal masks that realizes coanalysis of the mechanical and electrical properties and enables design exploration considering the trade-off between the two properties. As a case study, we apply a “stitching technique” to the mask design of a ring oscillator and explore the best design. With this technique, mask patterns are divided into separate parts using multiple mask layers to improve the mechanical strength at the cost of high resistance of the vias. By a numerical experiment, the design trade-off of the stitching technique is quantitatively analyzed, and it is demonstrated that the proposed flow is useful for the exploration of the designs of metal masks.

  19. Using Vector Projection Method to evaluate maintainability of mechanical system in design review

    International Nuclear Information System (INIS)

    Chen Lu; Cai Jianguo

    2003-01-01

    Maintainability of a mechanical system is one of the system design parameters that has a great impact in terms of ease of maintenance. In this article, based on the definition of the terms of maintenance and maintainability, an important tool of Design for Maintenance is developed as a way to improve maintainability through design. A set of standard and organized guidelines is provided and maintainability factors in terms of physical design, logistics support and ergonomics are identified. As a specific application of design review, a methodology so called Vector Projection Method is developed to evaluate the maintainability of the mechanical system. Lastly, an example is discussed

  20. Analysis and optimal design of an underactuated finger mechanism for LARM hand

    Science.gov (United States)

    Yao, Shuangji; Ceccarelli, Marco; Carbone, Giuseppe; Zhan, Qiang; Lu, Zhen

    2011-09-01

    This paper aims to present general design considerations and optimality criteria for underactuated mechanisms in finger designs. Design issues related to grasping task of robotic fingers are discussed. Performance characteristics are outlined as referring to several aspects of finger mechanisms. Optimality criteria of the finger performances are formulated after careful analysis. A general design algorithm is summarized and formulated as a suitable multi-objective optimization problem. A numerical case of an underactuated robot finger design for Laboratory of Robotics and Mechatronics (LARM) hand is illustrated with the aim to show the practical feasibility of the proposed concepts and computations.