Sample records for professor mechanical engineering

  1. Engineering science and mechanics department head named


    Nystrom, Lynn A.


    Ishwar K. Puri, professor of mechanical engineering and executive associate dean of engineering at the University of Illinois at Chicago, will become the head of Virginia Tech•À_ó»s Department of Engineering Science and Mechanics Aug. 1.

  2. Head of Department of Mechanical Engineering appointed


    Nystrom, Lynn A.


    Kenneth S. Ball, professor of mechanical engineering at the University of Texas at Austin, will become the head of the Department of Mechanical Engineering in Virginia Tech's College of Engineering Aug. 1.

  3. Categorization of Quantum Mechanics Problems by Professors and Students (United States)

    Lin, Shih-Yin; Singh, Chandralekha


    We discuss the categorization of 20 quantum mechanics problems by physics professors and undergraduate students from two honours-level quantum mechanics courses. Professors and students were asked to categorize the problems based upon similarity of solution. We also had individual discussions with professors who categorized the problems. Faculty…

  4. Mechanical engineering

    CERN Document Server

    Darbyshire, Alan


    Alan Darbyshire's best-selling text book provides five-star high quality content to a potential audience of 13,000 engineering students. It explains the most popular specialist units of the Mechanical Engineering, Manufacturing Engineering and Operations & Maintenance Engineering pathways of the new 2010 BTEC National Engineering syllabus. This challenging textbook also features contributions from specialist lecturers, ensuring that no stone is left unturned.

  5. Engineering mechanics

    CERN Document Server

    Gross, Dietmar; Schröder, Jörg; Wall, Wolfgang A; Rajapakse, Nimal

    Statics is the first volume of a three-volume textbook on Engineering Mechanics. The authors, using a time-honoured straightforward and flexible approach, present the basic concepts and principles of mechanics in the clearest and simplest form possible to advanced undergraduate engineering students of various disciplines and different educational backgrounds. An important objective of this book is to develop problem solving skills in a systematic manner. Another aim of this volume is to provide engineering students as well as practising engineers with a solid foundation to help them bridge the gap between undergraduate studies on the one hand and advanced courses on mechanics and/or practical engineering problems on the other. The book contains numerous examples, along with their complete solutions. Emphasis is placed upon student participation in problem solving. The contents of the book correspond to the topics normally covered in courses on basic engineering mechanics at universities and colleges. Now in i...

  6. Yue Joseph Wang named Grant A. Dove Professor of Electrical and Computer Engineering


    Owczarski, Mark


    Yue Joseph Wang, professor of electrical and computer engineering in the College of Engineering at Virginia Tech, has been named the Grant A. Dove Professor of Electrical and Computer Engineering by the Virginia Tech Board of Visitors.

  7. Maury Nussbaum reappointed as Hal G. Prillaman Professor Fellow in Industrial and Systems Engineering


    Owczarski, Mark


    Maury Nussbaum, professor of industrial and systems engineering in the College of Engineering at Virginia Tech, has been reappointed as the Hal G. Prillaman Professor Fellow in Industrial and Systems Engineering by the Virginia Tech Board of Visitors.

  8. Brian M. Kleiner receives Ralph H. Bogle Professor Fellowship in Industrial and Systems Engineering


    Owczarski, Mark


    Brian M. Kleiner, professor of industrial and systems engineering in the College of Engineering at Virginia Tech, has been named the Ralph H. Bogle Professor Fellow in Industrial and Systems Engineering by the Virginia Tech Board of Visitors.

  9. 19 January 2011 - British University of Manchester, Vice-President and Dean for the Faculty of Engineering and Physical Sciences Professor of Structural Engineering School of Mechanical, Aerospace and Civil Engineering C. Bailey in CERN Control Centre with Department Head P. Collier; at LHCb with R. Lindner and ATLAS underground experimental area with Deputy Spokesperson D. Charlton, througout accompanied by . Collier with R. Appleby and F. Loebinger

    CERN Multimedia

    Maximilien Brice


    19 January 2011 - British University of Manchester, Vice-President and Dean for the Faculty of Engineering and Physical Sciences Professor of Structural Engineering School of Mechanical, Aerospace and Civil Engineering C. Bailey in CERN Control Centre with Department Head P. Collier; at LHCb with R. Lindner and ATLAS underground experimental area with Deputy Spokesperson D. Charlton, througout accompanied by . Collier with R. Appleby and F. Loebinger

  10. Categorization of Quantum Mechanics Problems by Professors and Students

    CERN Document Server

    Lin, Shih-Yin


    We discuss the categorization of 20 quantum mechanics problems by physics professors and undergraduate students from two honors-level quantum mechanics courses. Professors and students were asked to categorize the problems based upon similarity of solution. We also had individual discussions with professors who categorized the problems. Faculty members' categorizations were overall rated higher than those of students by three faculty members who evaluated all of the categorizations. The categories created by faculty members were more diverse compared to the categories they created for a set of introductory mechanics problems. Some faculty members noted that the categorization of introductory physics problems often involves identifying fundamental principles relevant for the problem, whereas in upper-level undergraduate quantum mechanics problems, it mainly involves identifying concepts and procedures required to solve the problem. Moreover, physics faculty members who evaluated others' categorizations express...

  11. Mechanical engineer's handbook

    CERN Document Server

    Marghitu, Dan B


    The Mechanical Engineer's Handbook was developed and written specifically to fill a need for mechanical engineers and mechanical engineering students throughout the world. With over 1000 pages, 550 illustrations, and 26 tables the Mechanical Engineer's Handbook is very comprehensive, yet affordable, compact, and durable. The Handbook covers all major areas of mechanical engineering with succinct coverage of the definitions, formulas, examples, theory, proofs, and explanations of all principle subject areas. The Handbook is an essential, practical companion for all mechanic

  12. Mechanical engineering education

    CERN Document Server

    Davim, J Paulo


    Mechanical Engineering is defined nowadays as a discipline "which involves the application of principles of physics, design, manufacturing and maintenance of mechanical systems". Recently, mechanical engineering has also focused on some cutting-edge subjects such as nanomechanics and nanotechnology, mechatronics and robotics, computational mechanics, biomechanics, alternative energies, as well as aspects related to sustainable mechanical engineering.This book covers mechanical engineering higher education with a particular emphasis on quality assurance and the improvement of academic

  13. Tokamak engineering mechanics

    CERN Document Server

    Song, Yuntao; Du, Shijun


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

  14. Quantum mechanical Carnot engine


    Bender, C.M.; Brody, D. C.; Meister, B. K.


    A cyclic thermodynamic heat engine runs most efficiently if it is reversible. Carnot constructed such a reversible heat engine by combining adiabatic and isothermal processes for a system containing an ideal gas. Here, we present an example of a cyclic engine based on a single quantum-mechanical particle confined to a potential well. The efficiency of this engine is shown to equal the Carnot efficiency because quantum dynamics is reversible. The quantum heat engine has a cycle consisting of a...

  15. Mechanical engineers' handbook, materials and engineering mechanics

    CERN Document Server

    Kutz, Myer


    Full coverage of materials and mechanical design inengineering Mechanical Engineers' Handbook, Fourth Edition provides aquick guide to specialized areas you may encounter in your work,giving you access to the basics of each and pointing you towardtrusted resources for further reading, if needed. The accessibleinformation inside offers discussions, examples, and analyses ofthe topics covered. This first volume covers materials and mechanical design, givingyou accessible and in-depth access to the most common topics you'llencounter in the discipline: carbon and alloy steels, stainlesssteels, a

  16. Mechanical engineers data handbook

    CERN Document Server

    Carvill, James


    This text provides the student and professional mechanical engineer with a reference text of an essentially practical nature. It is uncluttered by text, and extensive use of illustrations and tables provide quick and clear access to information. It alsoincludes examples of detailed calculations on many of the applications of technology used by mechanical and production engineers, draughtsmen and engineering designers.Although mainly intended for those studying and practising mechanical engineering, a glance at the contents will show that it is also useful to those in related br

  17. Mechanical design engineering handbook

    CERN Document Server

    Childs, Peter R N


    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

  18. Engineering quantum mechanics

    CERN Document Server

    Ahn, Doyeol


    A clear introduction to quantum mechanics concepts Quantum mechanics has become an essential tool for modern engineering, particularly due to the recent developments in quantum computing as well as the rapid progress in optoelectronic devices. Engineering Quantum Mechanics explains the fundamentals of this exciting field, providing broad coverage of both traditional areas such as semiconductor and laser physics as well as relatively new yet fast-growing areas such as quantum computation and quantum information technology. The book begins with basic quantum mechanics, reviewing measurements and probability, Dirac formulation, the uncertainty principle, harmonic oscillator, angular momentum eigenstates, and perturbation theory. Then, quantum statistical mechanics is explored, from second quantization and density operators to coherent and squeezed states, coherent interactions between atoms and fields, and the Jaynes-Cummings model. From there, the book moves into elementary and modern applications, discussing s...

  19. Mechanical engineer's reference book

    CERN Document Server

    Parrish, A


    Mechanical Engineer's Reference Book: 11th Edition presents a comprehensive examination of the use of Systéme International d' Unités (SI) metrication. It discusses the effectiveness of such a system when used in the field of engineering. It addresses the basic concepts involved in thermodynamics and heat transfer. Some of the topics covered in the book are the metallurgy of iron and steel; screw threads and fasteners; hole basis and shaft basis fits; an introduction to geometrical tolerancing; mechanical working of steel; high strength alloy steels; advantages of making components as castings

  20. Mechanical engineering principles

    CERN Document Server

    Bird, John


    A student-friendly introduction to core engineering topicsThis book introduces mechanical principles and technology through examples and applications, enabling students to develop a sound understanding of both engineering principles and their use in practice. These theoretical concepts are supported by 400 fully worked problems, 700 further problems with answers, and 300 multiple-choice questions, all of which add up to give the reader a firm grounding on each topic.The new edition is up to date with the latest BTEC National specifications and can also be used on undergraduate courses in mecha

  1. Engineering fluid mechanics

    CERN Document Server

    Yamaguchi, Hiroshi


    This book is intended to serve as a unique and comprehensive textbook for scientists and engineers as well as advanced students in thermo-fluid courses. It provides an intensive monograph essential for understanding dynamics of ideal fluid, Newtonian fluid, non-Newtonian fluid and magnetic fluid. These distinct, yet intertwined subjects are addressed in an integrated manner. It starts with coherent treatment of fundamental continuum mechanics, with an emphasis on the intrinsic angular momentum, by which the concepts of ferrohydrodynamics are progressively built up, and serve as a foundation for later development. Flows of ideal and Newtonian fluids are followed by a detailed presentation of basic continuum equations for applications of fluid engineering, which cover the design and operations of various turbomachines, heat exchangers and flow elements. The study of the deformation and flow of matter, namely rheology, is discussed primarily with regard to the stresses generated during the flow of complex materi...

  2. Game mechanics engine


    Magnusson, Lars V


    Game logic and game rules exists in all computer games, but they are created di erently for all game engines. This game engine dependency exists because of how the internal object model is implemented in the engine, as a place where game logic data is intermingled with the data needed by the low- level subsystems. This thesis propose a game object model design, based on existing theory, that removes this dependency and establish a general game logic framework. The thesis the...

  3. Diesel Engine Mechanics. (United States)

    Foutes, William A.

    Written in student performance terms, this curriculum guide on diesel engine repair is divided into the following eight sections: an orientation to the occupational field and instructional program; instruction in operating principles; instruction in engine components; instruction in auxiliary systems; instruction in fuel systems; instruction in…

  4. System dynamics for mechanical engineers

    CERN Document Server

    Davies, Matthew


    This textbook is ideal for mechanical engineering students preparing to enter the workforce during a time of rapidly accelerating technology, where they will be challenged to join interdisciplinary teams. It explains system dynamics using analogies familiar to the mechanical engineer while introducing new content in an intuitive fashion. The fundamentals provided in this book prepare the mechanical engineer to adapt to continuous technological advances with topics outside traditional mechanical engineering curricula by preparing them to apply basic principles and established approaches to new problems. This book also: ·         Reinforces the connection between the subject matter and engineering reality ·         Includes an instructor pack with the online publication that describes in-class experiments with minimal preparation requirements ·         Provides content dedicated to the modeling of modern interdisciplinary technological subjects, including opto-mechanical systems, high...

  5. Mechanical Engineering Department Technical Review

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.B.; Denney, R.M. (eds.)


    The Mechanical Engineering Department Technical Review is published to inform readers of various technical activities within the Department, promote exchange of ideas, and give credit to personnel who are achieving the results. The report is presented in two parts: technical achievements and publication abstracts. The first is divided into seven sections, each of which reports on an engineering division and its specific activities related to nuclear tests, nuclear explosives, weapons, energy systems, engineering sciences, magnetic fusion, and materials fabrication.

  6. Mechanical Engineering Department technical abstracts

    Energy Technology Data Exchange (ETDEWEB)


    The Mechanical Engineering Department publishes abstracts twice a year to inform readers of the broad range of technical activities in the Department, and to promote an exchange of ideas. Details of the work covered by an abstract may be obtained by contacting the author(s). General information about the current role and activities of each of the Department's seven divisions precedes the technical abstracts. Further information about a division's work may be obtained from the division leader, whose name is given at the end of each divisional summary. The Department's seven divisions are as follows: Nuclear Test Engineering Division, Nuclear Explosives Engineering Division, Weapons Engineering Division, Energy Systems Engineering Division, Engineering Sciences Division, Magnetic Fusion Engineering Division and Materials Fabrication Division.

  7. Handbook of mechanical engineering terms

    CERN Document Server

    Ramalingam, KK


    About the Book: The Handbook of Mechanical Engineering terms contains short, precise definitions of about four thousand terms. These terms have been collected from different sources, edited and grouped under twenty six parts and given alphabetically under each part for easy reference. The book will be a source of guidance and help to the students, staff and practising engineers in understanding and updating the subject matter. Contents: The Handbook of Mechanical Engineering terms contains short, precise definitions of about four thousand terms. These terms have been collected from differ

  8. The Stirling engine mechanism optimization

    Directory of Open Access Journals (Sweden)

    Jiří Podešva


    Full Text Available A special type of the gas engine with external combustion is called Stirling engine. The mechanism has two pistons with two volumes inside. The pistons are connected together through cooler, regenerator and warmer. The engine effectivity depends on the piston movement behaviour. The usual sinusoidal time curve leads to low effectiveness. The quick movement from lower to upper position with a certain delay in both top and bottom dead centres is more effective. The paper deals with three types of mechanisms, analyzing the piston movement, and their behavior. Special emphasize is taken to the piston movement regime.

  9. Basic Mechanics with Engineering Applications

    CERN Document Server

    Jones, J; Fawcett, J N


    This book gives a sufficient grounding in mechanics for engineers to tackle a significant range of problems encountered in the design and specification of simple structures and machines. It also provides an excellent background for students wishing to progress to more advanced studies in three-dimensional mechanics.

  10. Continuum mechanics for engineers

    CERN Document Server

    Mase, G Thomas; Mase, George E


    Continuum TheoryContinuum MechanicsStarting OverNotationEssential MathematicsScalars, Vectors and Cartesian TensorsTensor Algebra in Symbolic Notation - Summation ConventionIndicial NotationMatrices and DeterminantsTransformations of Cartesian TensorsPrincipal Values and Principal DirectionsTensor Fields, Tensor CalculusIntegral Theorems of Gauss and StokesStress PrinciplesBody and Surface Forces, Mass DensityCauchy Stress PrincipleThe Stress TensorForce and Moment Equilibrium; Stress Tensor SymmetryStress Transformation LawsPrincipal Stresses; Principal Stress DirectionsMaximum and Minimum Stress ValuesMohr's Circles For Stress Plane StressDeviator and Spherical Stress StatesOctahedral Shear StressKinematics of Deformation and MotionParticles, Configurations, Deformations and MotionMaterial and Spatial CoordinatesLangrangian and Eulerian DescriptionsThe Displacement FieldThe Material DerivativeDeformation Gradients, Finite Strain TensorsInfinitesimal Deformation TheoryCompatibility EquationsStretch RatiosRot...

  11. Hamiltonian mechanics limits microscopic engines (United States)

    Anglin, James; Gilz, Lukas; Thesing, Eike


    We propose a definition of fully microscopic engines (micro-engines) in terms of pure mechanics, without reference to thermodynamics, equilibrium, or cycles imposed by external control, and without invoking ergodic theory. This definition is pragmatically based on the observation that what makes engines useful is energy transport across a large ratio of dynamical time scales. We then prove that classical and quantum mechanics set non-trivial limits-of different kinds-on how much of the energy that a micro-engine extracts from its fuel can be converted into work. Our results are not merely formal; they imply manageable design constraints on micro-engines. They also suggest the novel possibility that thermodynamics does not emerge from mechanics in macroscopic regimes, but rather represents the macroscopic limit of a generalized theory, valid on all scales, which governs the important phenomenon of energy transport across large time scale ratios. We propose experimental realizations of the dynamical mechanisms we identify, with trapped ions and in Bose-Einstein condensates (``motorized bright solitons'').

  12. Modern mechanical engineering research, development and education

    CERN Document Server


    This book covers modern subjects of mechanical engineering such as nanomechanics and nanotechnology, mechatronics and robotics, computational mechanics, biomechanics, alternative energies, sustainability as well as all aspects related with mechanical engineering education. The chapters help enhance the understanding of both the fundamentals of mechanical engineering and its application to the solution of problems in modern industry. This book is suitable for students, both in final undergraduate mechanical engineering courses or at the graduate level. It also serves as a useful reference for academics, mechanical engineering researchers, mechanical, materials and manufacturing engineers, professionals in related with mechanical engineering.

  13. Quantum Mechanics for Electrical Engineers

    CERN Document Server

    Sullivan, Dennis M


    The main topic of this book is quantum mechanics, as the title indicates.  It specifically targets those topics within quantum mechanics that are needed to understand modern semiconductor theory.   It begins with the motivation for quantum mechanics and why classical physics fails when dealing with very small particles and small dimensions.  Two key features make this book different from others on quantum mechanics, even those usually intended for engineers:   First, after a brief introduction, much of the development is through Fourier theory, a topic that is at

  14. Perspectives of ukrainian mechanical engineering development


    Dyrda, E.; Schepetkova, A.; Galushko, O.


    Theses are devoted to problems and perspectives of Ukrainian mechanical engineering development. Role of mechanical engineering in national economy is described. Problems of mechanical engineering, such as losing the cometetive advantages, production decreasing, debts growing, ineffective assets structure, are investigated. Influence of European integration process on mechanical engineering enterprises is discussed.

  15. Timoshenko: Father of Engineering Mechanics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 10. Timoshenko: Father of Engineering Mechanics. K R Y Simha. Article-in-a-Box Volume 7 Issue 10 October 2002 pp 2-3. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  16. 1st International Conference on Engineering and Applied Sciences Optimization : Dedicated to the Memory of Professor M.G. Karlaftis

    CERN Document Server

    Papadrakakis, Manolis; OPT-i


    The chapters which appear in this volume are selected studies presented at the First International Conference on Engineering and Applied Sciences Optimization (OPT-i), Kos, Greece, 4-6 June 2014,  and works written by friends, former colleagues and students of the late Professor M. G. Karlaftis; all in the area of optimization that he loved and published so much in himself. The subject areas represented here range from structural optimization, logistics, transportation, traffic and telecommunication networks to operational research, metaheuristics, multidisciplinary and multiphysics design optimization, etc.  This volume is dedicated to the life and the memory of Professor Matthew G. Karlaftis, who passed away a few hours before he was to give the opening speech at OPT-i. All contributions reflect the warmth and genuine friendship which he enjoyed from his associates and show how much his scientific contribution has been appreciated. He will be greatly missed and it is hoped that this volume will be receive...

  17. Mechanical Autonomous Stochastic Heat Engine. (United States)

    Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara


    Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

  18. Mechanical engineering department technical review

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.B. Denney, R.M. (eds.)


    The Mechanical Engineering Department Technical Review is published to: (1) inform the readers of various technical activities within the department, (2) promote exchange of ideas, and (3) give credit to the personnel who are achieving the results. The report is formatted into two parts: technical acievements and publication abstracts. The first is divided into eight sections, one for each division in the department providing the reader with the names of the personnel and the division accomplishing the work.

  19. A brief history of mechanical engineering

    CERN Document Server

    Dixit, Uday Shanker; Davim, J Paulo


    What is mechanical engineering? What a mechanical engineering does? How did the mechanical engineering change through ages? What is the future of mechanical engineering? This book answers these questions in a lucid manner. It also provides a brief chronological history of landmark events and answers questions such as: When was steam engine invented? Where was first CNC machine developed? When did the era of additive manufacturing start? When did the marriage of mechanical and electronics give birth to discipline of mechatronics? This book informs and create interest on mechanical engineering in the general public and particular in students. It also helps to sensitize the engineering fraternity about the historical aspects of engineering. At the same time, it provides a common sense knowledge of mechanical engineering in a handy manner.

  20. Expose Mechanical Engineering Students to Biomechanics Topics (United States)

    Shen, Hui


    To adapt the focus of engineering education to emerging new industries and technologies nationwide and in the local area, a biomechanics module has been developed and incorporated into a mechanical engineering technical elective course to expose mechanical engineering students at ONU (Ohio Northern University) to the biomedical engineering topics.…

  1. Standardized Curriculum for Diesel Engine Mechanics. (United States)

    Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

    Standardized curricula are provided for two courses for the secondary vocational education program in Mississippi: diesel engine mechanics I and II. The eight units in diesel engine mechanics I are as follows: orientation; shop safety; basic shop tools; fasteners; measurement; engine operating principles; engine components; and basic auxiliary…

  2. Innovative Mechanical Engineering Technologies, Equipment and Materials-2013 (United States)

    Ilnaz Izailovich, Fayrushin; Nail Faikovich, Kashapov; Mahmut Mashutovich, Ganiev


    In the period from 25 to 27 September 2013 the city of Kazan hosted the International Scientific Conference "Innovative mechanical engineering technologies, equipment and materials - 2013" (IRTC "IMETEM - 2013"). The conference was held on the grounds of "Kazanskaya Yarmarka" (Kazan). The conference plenary meeting was held with the participation of the Republic of Tatarstan, breakout sessions, forum "Improving the competitiveness and efficiency of engineering enterprises in the WTO" and a number of round tables. Traditionally, the event was followed by the 13th International specialized exhibition "Engineering. Metalworking. Kazan ", in which were presented the development of innovative enterprises in the interests of the Russian Federation of Industry of Republic of Tatarstan, to support the "Foundation for Assistance to Small Innovative Enterprises in Science and Technology" and the 8th specialized exhibition "TechnoWelding". Kashapov Nail, D.Sc., professor (Kazan Federal University)

  3. SMAP Instrument Mechanical System Engineering (United States)

    Slimko, Eric; French, Richard; Riggs, Benjamin


    The Soil Moisture Active Passive (SMAP) mission, scheduled for launch by the end of 2014, is being developed to measure the soil moisture and soil freeze/thaw state on a global scale over a three-year period. The accuracy, resolution, and global coverage of SMAP measurements are invaluable across many science and applications disciplines including hydrology, climate, carbon cycle, and the meteorological, environment, and ecology applications communities. The SMAP observatory is composed of a despun bus and a spinning instrument platform that includes both a deployable 6 meter aperture low structural frequency Astromesh reflector and a spin control system. The instrument section has engendered challenging mechanical system issues associated with the antenna deployment, flexible antenna pointing in the context of a multitude of disturbances, spun section mass properties, spin control system development, and overall integration with the flight system on both mechanical and control system levels. Moreover, the multitude of organizations involved, including two major vendors providing the spin subsystem and reflector boom assembly plus the flight system mechanical and guidance, navigation, and control teams, has led to several unique system engineering challenges. Capturing the key physics associated with the function of the flight system has been challenging due to the many different domains that are applicable. Key interfaces and operational concepts have led to complex negotiations because of the large number of organizations that integrate with the instrument mechanical system. Additionally, the verification and validation concerns associated with the mechanical system have had required far-reaching involvement from both the flight system and other subsystems. The SMAP instrument mechanical systems engineering issues and their solutions are described in this paper.

  4. Mechanical Engineering Department technical review

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.B.; Abrahamson, L.; Denney, R.M.; Dubois, B.E (eds.)


    Technical achievements and publication abstracts related to research in the following Divisions of Lawrence Livermore Laboratory are reported in this biannual review: Nuclear Fuel Engineering; Nuclear Explosives Engineering; Weapons Engineering; Energy Systems Engineering; Engineering Sciences; Magnetic Fusion Engineering; and Material Fabrication. (LCL)

  5. Technical abstracts: Mechanical engineering, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Broesius, J.Y. (comp.)


    This document is a compilation of the published, unclassified abstracts produced by mechanical engineers at Lawrence Livermore National Laboratory (LLNL) during the calendar year 1990. Many abstracts summarize work completed and published in report form. These are UCRL-JC series documents, which include the full text of articles to be published in journals and of papers to be presented at meetings, and UCID reports, which are informal documents. Not all UCIDs contain abstracts: short summaries were generated when abstracts were not included. Technical Abstracts also provides descriptions of those documents assigned to the UCRL-MI (miscellaneous) category. These are generally viewgraphs or photographs presented at meetings. An author index is provided at the back of this volume for cross referencing.

  6. Engineering

    National Research Council Canada - National Science Library

    Includes papers in the following fields: Aerospace Engineering, Agricultural Engineering, Chemical Engineering, Civil Engineering, Electrical Engineering, Environmental Engineering, Industrial Engineering, Materials Engineering, Mechanical...

  7. An introduction to mechanical engineering, pt.1

    CERN Document Server

    Clifford, Michael; Shipway, Philip


    An Introduction to Mechanical Engineering is an essential text for all first-year undergraduate students as well as those studying for foundation degrees and HNDs. The text gives a thorough grounding in the following core engineering topics: thermodynamics, fluid mechanics, solid mechanics, dynamics, electricals and electronics, and materials science. As well as mechanical engineers, the text will be highly relevant to civil, automotive, aeronautical/aerospace and general engineering students.The text is written by an experienced team of first-year lecturers at the internationally renowned Uni

  8. Deformation and fracture mechanics of engineering materials

    National Research Council Canada - National Science Library

    Hertzberg, Richard W; Vinci, Richard Paul; Hertzberg, Jason L


    "Hertzberg's 5th edition of Deformation & Fracture Mechanics of Engineering Materials offers several new features including a greater number and variety of homework problems using more computational software...

  9. Teaching Continuum Mechanics in a Mechanical Engineering Program (United States)

    Liu, Yucheng


    This paper introduces a graduate course, continuum mechanics, which is designed for and taught to graduate students in a Mechanical Engineering (ME) program. The significance of continuum mechanics in engineering education is demonstrated and the course structure is described. Methods used in teaching this course such as topics, class…

  10. Mechanical engineering science in SI units

    CERN Document Server

    Gwyther, J L; Williams, G


    0.1 Mechanical Engineering Science covers various fundamental concepts that are essential in the practice of mechanical engineering. The title is comprised of 19 chapters that detail various topics, including chemical and physical laws. The coverage of the book includes Newtonian laws, mechanical energy, friction, stress, and gravity. The text also discusses the chemical aspects of mechanical engineering, which include gas laws, states of matter, and fuel combustion. The last chapter tackles concerns in laboratory experiments. The book will be of great use to students of mechanical eng

  11. Gasoline Engine Mechanics. Florida Vocational Program Guide. (United States)

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This vocational program guide is intended to assist in the organization, operation, and evaluation of a program in gasoline engine mechanics in school districts, area vocational centers, and community colleges. The following topics are covered: job duties of small-engine mechanics; program content (curriculum framework and student performance…

  12. Work Sampling Study of an Engineering Professor during a Regular Contract Period (United States)

    Brink, Jan; McDonald, Dale B.


    Work sampling is a technique that has been employed in industry and fields such as healthcare for some time. It is a powerful technique, and an alternative to conventional stop watch time studies, used by industrial engineers to focus upon random work sampling observations. This study applies work sampling to the duties performed by an individual…

  13. Professional Development of English Professors in Indian Engineering Colleges: The Need of the Hour (United States)

    Clement, A.; Murugavel, T.


    English has become the language of international business and in this age of globalization, communication skills in the English language are of supreme importance in the professional success of individuals. In India, the percentage of engineering graduates who remain unemployed after graduation steadily increases due to lack of soft skills…

  14. Selection of software for mechanical engineering undergraduates

    Energy Technology Data Exchange (ETDEWEB)

    Cheah, C. T.; Yin, C. S.; Halim, T.; Naser, J.; Blicblau, A. S., E-mail: [Swinburne University of Technology, Faculty of Science Engineering and Technology, PO Box 218 Hawthorn, Victoria, Australia, 3122 (Australia)


    A major problem with the undergraduate mechanical course is the limited exposure of students to software packages coupled with the long learning curve on the existing software packages. This work proposes the use of appropriate software packages for the entire mechanical engineering curriculum to ensure students get sufficient exposure real life design problems. A variety of software packages are highlighted as being suitable for undergraduate work in mechanical engineering, e.g. simultaneous non-linear equations; uncertainty analysis; 3-D modeling software with the FEA; analysis tools for the solution of problems in thermodynamics, fluid mechanics, mechanical system design, and solid mechanics.

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

    CERN Document Server

    Kutz, Myer


    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

  16. The characteristics of mechanical engineering systems

    CERN Document Server

    Holmes, R


    The Characteristics of Mechanical Engineering Systems focuses on the characteristics that must be considered when designing a mechanical engineering system. Mechanical systems are presented on the basis of component input-output relationships, paying particular attention to lumped-parameter problems and the interrelationships between lumped components or """"black-boxes"""" in an engineering system. Electric motors and generators are treated in an elementary manner, and the principles involved are explained as far as possible from physical and qualitative reasoning. This book is comprised of

  17. PREFACE: Special section on Computational Fluid Dynamics—in memory of Professor Kunio Kuwahara Special section on Computational Fluid Dynamics—in memory of Professor Kunio Kuwahara (United States)

    Ishii, Katsuya


    This issue includes a special section on computational fluid dynamics (CFD) in memory of the late Professor Kunio Kuwahara, who passed away on 15 September 2008, at the age of 66. In this special section, five articles are included that are based on the lectures and discussions at `The 7th International Nobeyama Workshop on CFD: To the Memory of Professor Kuwahara' held in Tokyo on 23 and 24 September 2009. Professor Kuwahara started his research in fluid dynamics under Professor Imai at the University of Tokyo. His first paper was published in 1969 with the title 'Steady Viscous Flow within Circular Boundary', with Professor Imai. In this paper, he combined theoretical and numerical methods in fluid dynamics. Since that time, he made significant and seminal contributions to computational fluid dynamics. He undertook pioneering numerical studies on the vortex method in 1970s. From then to the early nineties, he developed numerical analyses on a variety of three-dimensional unsteady phenomena of incompressible and compressible fluid flows and/or complex fluid flows using his own supercomputers with academic and industrial co-workers and members of his private research institute, ICFD in Tokyo. In addition, a number of senior and young researchers of fluid mechanics around the world were invited to ICFD and the Nobeyama workshops, which were held near his villa, and they intensively discussed new frontier problems of fluid physics and fluid engineering at Professor Kuwahara's kind hospitality. At the memorial Nobeyama workshop held in 2009, 24 overseas speakers presented their papers, including the talks of Dr J P Boris (Naval Research Laboratory), Dr E S Oran (Naval Research Laboratory), Professor Z J Wang (Iowa State University), Dr M Meinke (RWTH Aachen), Professor K Ghia (University of Cincinnati), Professor U Ghia (University of Cincinnati), Professor F Hussain (University of Houston), Professor M Farge (École Normale Superieure), Professor J Y Yong (National

  18. Activities of the Institute for Mechanical Engineering (United States)

    The Institute of Mechanical Engineering (IME) is part of Canada's National Research Council. Its mission is to undertake, support, promote, and disseminate research and development in the mechanical engineering aspects of three vital sectors of the Canadian economy: transportation, resource industries, and manufacturing. The IME achieves its mission by performing research and development in its own facilities; by developing, providing, and transferring expertise and knowledge; by making its research facilities available to collaborators and clients; and by participating in international liaison and collaborative research activities. Six research programs are conducted in the IME: Advanced Manufacturing Technology; Coastal Zone Engineering; Cold Regions Engineering; Combustion and Fluids Engineering; Ground Transportation Technology; and Machinery and Engine Technology. The rationale and major research thrusts of each program are described, and specific achievements in 1991-92 are reviewed. Lists of technical reports and papers presented by IME personnel are also included.

  19. Engineering Change Management Method Framework in Mechanical Engineering (United States)

    Stekolschik, Alexander


    Engineering changes make an impact on different process chains in and outside the company, and lead to most error costs and time shifts. In fact, 30 to 50 per cent of development costs result from technical changes. Controlling engineering change processes can help us to avoid errors and risks, and contribute to cost optimization and a shorter time to market. This paper presents a method framework for controlling engineering changes at mechanical engineering companies. The developed classification of engineering changes and accordingly process requirements build the basis for the method framework. The developed method framework comprises two main areas: special data objects managed in different engineering IT tools and process framework. Objects from both areas are building blocks that can be selected to the overall business process based on the engineering process type and change classification. The process framework contains steps for the creation of change objects (both for overall change and for parts), change implementation, and release. Companies can select singleprocess building blocks from the framework, depending on the product development process and change impact. The developed change framework has been implemented at a division (10,000 employees) of a big German mechanical engineering company.


    National Research Council Canada - National Science Library

    SCURTU Iacob Liviu; BODEA Sanda Mariana; JURCO Ancuta Nadia


    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...

  1. Os professores e seus mecanismos de fuga e enfrentamento Teachers and their escape and coping mechanisms

    Directory of Open Access Journals (Sweden)

    Gideon Borges dos Santos


    Full Text Available A partir de exemplos concretos reunidos ao longo de dois anos de estudo sobre a saúde docente, este artigo propõe uma discussão sobre as estratégias que professores constroem para enfrentar as adversidades do cotidiano escolar. Com a utilização dos conceitos de saúde e da psicodinâmica do trabalho, busca-se refletir de que modo os docentes enfrentam adversidades como a não aprendizagem, o comportamento indisciplinado dos alunos, a falta de material didático-pedagógico e o cansaço ou a indisposição para ministrar as aulas. Essas estratégias - denominadas de enfrentamento e de fuga - que seriam, aparentemente, promotoras de aprendizagens, também são atividades que reduzem o desgaste dos professores, o que leva à banalização do processo educacional.Taken from concrete examples gathered over two years of study on the health of teachers, this article proposes a discussion about the strategies that teachers create to face the adversities of everyday school life. With the use of concepts of health and psychodynamics of work, we try to reflect on how teachers deal with adversities such as learning difficulties, the undisciplined behavior of students, the lack of teaching resources, and the teachers fatigue or unwillingness to teach the classes. These strategies - known as coping and escape strategies - which would apparently enhance learning, are also activities that reduce the teacher's burnout, which leads to the trivialization of the educational process.

  2. Mechanical engineers' handbook, energy and power

    CERN Document Server

    Kutz, Myer


    The engineer's ready reference for mechanical power and heat Mechanical Engineer's Handbook provides the mostcomprehensive coverage of the entire discipline, with a focus onexplanation and analysis. Packaged as a modular approach, thesebooks are designed to be used either individually or as a set,providing engineers with a thorough, detailed, ready reference ontopics that may fall outside their scope of expertise. Each bookprovides discussion and examples as opposed to straight data andcalculations, giving readers the immediate background they needwhile pointing them toward more in-depth infor

  3. Mechanical technology for higher engineering technicians

    CERN Document Server

    Black, Peter


    Mechanical Technology for Higher Engineering Technicians deals with the mechanics of machines, thermodynamics, and mechanics of fluids. This book presents discussions and examples that deal with the strength of materials, technology of machines, and techniques used by professional engineers. The book explains the strain energy of torsion, coil springs, and the effects of axial load. The author also discusses the forces that produce bending, shearing, and bending combined with direct stress, as well as beams subjected to a uniform bending moment or simply supported beams with concentrated non-c

  4. Computational structural mechanics for engine structures (United States)

    Chamis, C. C.


    The computational structural mechanics (CSM) program at Lewis encompasses: (1) fundamental aspects for formulating and solving structural mechanics problems, and (2) development of integrated software systems to computationally simulate the performance/durability/life of engine structures. It is structured to mainly supplement, complement, and whenever possible replace, costly experimental efforts which are unavoidable during engineering research and development programs. Specific objectives include: investigate unique advantages of parallel and multiprocesses for: reformulating/solving structural mechanics and formulating/solving multidisciplinary mechanics and develop integrated structural system computational simulators for: predicting structural performances, evaluating newly developed methods, and for identifying and prioritizing improved/missing methods needed. Herein the CSM program is summarized with emphasis on the Engine Structures Computational Simulator (ESCS). Typical results obtained using ESCS are described to illustrate its versatility.

  5. Mechanical engineers' handbook, manufacturing and management

    CERN Document Server

    Kutz, Myer


    Full coverage of manufacturing and management in mechanicalengineering Mechanical Engineers' Handbook, Fourth Edition provides aquick guide to specialized areas that engineers may encounter intheir work, providing access to the basics of each and pointingtoward trusted resources for further reading, if needed. The book'saccessible information offers discussions, examples, and analysesof the topics covered, rather than the straight data, formulas, andcalculations found in other handbooks. No single engineer can be aspecialist in all areas that they are called upon to work in. It'sa discipline

  6. 7 March 2013 -Stanford University Professor N. McKeown FREng, Electrical Engineering and Computer Science and B. Leslie, Creative Labs visiting CERN Control Centre and the LHC tunnel with Director for Accelerators and Technology S. Myers.

    CERN Multimedia

    Anna Pantelia


    7 March 2013 -Stanford University Professor N. McKeown FREng, Electrical Engineering and Computer Science and B. Leslie, Creative Labs visiting CERN Control Centre and the LHC tunnel with Director for Accelerators and Technology S. Myers.

  7. Professor Sir Mark Walport Government Chief Scientific Adviser Head of Government Science and Engineering Profession Chief Executive Designate of UK Research and Innovation United Kingdom of Great Britain and Northern Ireland

    CERN Multimedia

    Bennett, Sophia Elizabeth


    Professor Sir Mark Walport Government Chief Scientific Adviser Head of Government Science and Engineering Profession Chief Executive Designate of UK Research and Innovation United Kingdom of Great Britain and Northern Ireland

  8. Micro electromechanical systems (MEMS) for mechanical engineers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A. P., LLNL


    The ongoing advances in Microelectromechanical Systems (MEMS) are providing man-kind the freedom to travel to dimensional spaces never before conceivable. Advances include new fabrication processes, new materials, tailored modeling tools, new fabrication machines, systems integration, and more detailed studies of physics and surface chemistry as applied to the micro scale. In the ten years since its inauguration, MEMS technology is penetrating industries of automobile, healthcare, biotechnology, sports/entertainment, measurement systems, data storage, photonics/optics, computer, aerospace, precision instruments/robotics, and environment monitoring. It is projected that by the turn of the century, MEMS will impact every individual in the industrial world, totaling sales up to $14 billion (source: System Planning Corp.). MEMS programs in major universities have spawned up all over the United States, preparing the brain-power and expertise for the next wave of MEMS breakthroughs. It should be pointed out that although MEMS has been initiated by electrical engineering researchers through the involvement of IC fabrication techniques, today it has evolved such that it requires a totally multi-disciplinary team to develop useful devices. Mechanical engineers are especially crucial to the success of MEMS development, since 90% of the physical realm involved is mechanical. Mechanical engineers are needed for the design of MEMS, the analysis of the mechanical system, the design of testing apparatus, the implementation of analytical tools, and the packaging process. Every single aspect of mechanical engineering is being utilized in the MEMS field today, however, the impact could be more substantial if more mechanical engineers are involved in the systems level designing. In this paper, an attempt is made to create the pathways for a mechanical engineer to enter in the MEMS field. Examples of application in optics and medical devices will be used to illustrate how mechanical

  9. International Conference on Mechanical Engineering and Technology

    CERN Document Server

    Mechanical Engineering and Technology


    The volume includes a set of selected papers extended and revised from the 2011 International Conference on Mechanical Engineering and Technology, held on London, UK, November 24-25, 2011.   Mechanical engineering technology is the application of physical principles and current technological developments to the creation of useful machinery and operation design. Technologies such as solid models may be used as the basis for finite element analysis (FEA) and / or computational fluid dynamics (CFD) of the design. Through the application of computer-aided manufacturing (CAM), the models may also be used directly by software to create "instructions" for the manufacture of objects represented by the models, through computer numerically controlled (CNC) machining or other automated processes, without the need for intermediate drawings.   This volume covers the subject areas of mechanical engineering and technology, and also covers interdisciplinary subject areas of computers, communications, control and automation...

  10. 46 CFR 12.15-13 - Deck engine mechanic. (United States)


    ... 46 Shipping 1 2010-10-01 2010-10-01 false Deck engine mechanic. 12.15-13 Section 12.15-13 Shipping... ENDORSEMENTS Qualified Member of the Engine Department § 12.15-13 Deck engine mechanic. (a) An applicant for an endorsement as deck engine mechanic shall be a person holding an MMC or MMD endorsed as junior engineer. The...

  11. Mechanics of materials formulas and problems : engineering mechanics 2

    CERN Document Server

    Gross, Dietmar; Wriggers, Peter; Schröder, Jörg; Müller, Ralf


    This book contains the most important formulas and more than 140 completely solved problems from Mechanics of Materials and Hydrostatics. It provides engineering students material to improve their skills and helps to gain experience in solving engineering problems. Particular emphasis is placed on finding the solution path and formulating the basic equations. Topics include: - Stress - Strain - Hooke’s Law - Tension and Compression in Bars - Bending of Beams - Torsion - Energy Methods - Buckling of Bars - Hydrostatics .

  12. Mechanics, Models and Methods in Civil Engineering

    CERN Document Server

    Maceri, Franco


    Mechanics, Models and Methods in Civil Engineering” collects leading papers dealing with actual Civil Engineering problems. The approach is in the line of the Italian-French school and therefore deeply couples mechanics and mathematics creating new predictive theories, enhancing clarity in understanding, and improving effectiveness in applications. The authors of the contributions collected here belong to the Lagrange Laboratory, an European Research Network active since many years. This book will be of a major interest for the reader aware of modern Civil Engineering.

  13. Elements of theoretical mechanics for electronic engineers

    CERN Document Server

    Bultot, Franz


    Elements of Theoretical Mechanics for Electronic Engineers deals with theoretical mechanics, which is considered one of the fundamental branches of instruction essential to training an engineer. This book discusses the oscillatory motions and their counterparts in electrical circuits and radio, and provides an introduction to differential operators of vector field theory. Other topics covered include systems and functions of vectors; dynamics of a free point; vibrations and waves; and statics. Worked examples and many notes on the application of most sections of the theories to electrical deve

  14. Mechanical engineering capstone senior design textbook (United States)

    Barrett, Rolin Farrar, Jr.

    This textbook is intended to bridge the gap between mechanical engineering equations and mechanical engineering design. To that end, real-world examples are used throughout the book. Also, the material is presented in an order that follows the chronological sequence of coursework that must be performed by a student in the typical capstone senior design course in mechanical engineering. In the process of writing this book, the author surveyed the fifty largest engineering schools (as ranked by the American Society of Engineering Education, or ASEE) to determine what engineering instructors are looking for in a textbook. The survey results revealed a clear need for a textbook written expressly for the capstone senior design course as taught throughout the nation. This book is designed to meet that need. This text was written using an organizational method that the author calls the General Topics Format. The format gives the student reader rapid access to the information contained in the text. All manufacturing methods, and some other material presented in this text, have been presented using the General Topics Format. The text uses examples to explain the importance of understanding the environment in which the product will be used and to discuss product abuse. The safety content contained in this text is unique. The Safety chapter teaches engineering ethics and includes a step-by-step guide to resolving ethical conflicts. The chapter includes explanations of rules, recommendations, standards, consensus standards, key safety concepts, and the legal implications of product failure. Key design principles have been listed and explained. The text provides easy-to-follow design steps, helpful for both the student and new engineer. Prototyping is presented as consisting of three phases: organization, building, and refining. A chapter on common manufacturing methods is included for reference.

  15. Thermal integrity in mechanics and engineering

    CERN Document Server

    Shorr, Boris F


    The book is targeted at engineers, university lecturers, postgraduates, and final year undergraduate students involved in computational modelling and experimental and theoretical analysis of the high-temperature behavior of engineering structures. It will also be of interest to researchers developing the thermal strength theory as a branch of continuum mechanics. Thermal integrity is a multidisciplinary field combining the expertise of mechanical engineers, material scientists and applied mathematicians, each approaching the problem from their specific viewpoint. This monograph draws on the research of a broad scientific community including the author’s contribution. The scope of thermal strength analysis was considerably extended thanks to modern computers and the implementation of FEM codes. However, the author believes that some material models adopted in the advanced high-performance software, are not sufficiently justificated due to lack of easy-to-follow books on the theoretical and experimental aspec...

  16. Gasoline Engine Mechanics. Performance Objectives. Intermediate Course. (United States)

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives presented in this curriculum guide for an intermediate gasoline engine mechanics course at the secondary level. (For the beginning course guide see CE 010 947.) The materials were developed for a two-semester (2 hour…

  17. Auto Mechanics. Heavy Equipment. Small Engines. (United States)

    Finnerty, Kathy

    Developed for use in auto mechanics, Heavy Equipment Repair and Operation (HERO), and small engines programs, these study guides and supplemental worksheets cover operating principles, lubrication, cooling system, ignition circuit and electrical system, and fuel system. The worksheets and guide questions are phrased to emphasize key points…

  18. Euclides Roxo: engineer, teacher, intellectual, and mathematics educator Euclides Roxo: engenheiro, professor, intelectual e educador matemático

    Directory of Open Access Journals (Sweden)

    Bruno Alves Dassie


    Full Text Available This paper presents Euclides Roxo’s professional life, taking into account his past experiences before he became an educational reformer. We describe the work possibilities for engineers in Brazil at the beginning of the 20th Century to show that Roxo’s option for a teaching career was influenced by the society in which he lived. On the other hand, his years as a teacher at the Instituto de Educação in Rio de Janeiro are essential to study the evolution of Roxo’s educational ideas, since this institution provided him with the necessary stimulus for the development of his ideas. We also briefly present some of his other educational activities. We think we can justly claim that Euclides Roxo was an intellectual working as a mathematics teacher, indeed a mathematics educator. Keywords: Euclides Roxo. History of mathematics education. mathematics educator. Institutionalization of mathematics teachers.Este artigo apresenta a trajetória profissional de Euclides Roxo considerando fatos que precederam sua atuação como reformador educacional. São apresentadas considerações sobre o mercado de trabalho do engenheiro no início do século XX, para mostrar que a opção de Euclides Roxo pelo magistério não foi autônoma em relação ao quadro da sociedade da época. Por outro lado, sua atuação no Instituto de Educação do Rio de Janeiro, antiga Escola Normal, é essencial para analisar a gênese de suas idéias, pois esta instituição apresentou um ambiente educacional propício. Por fim, apresentamos de forma breve outras instâncias de atuação de Euclides Roxo. Dessa forma, podemos considerar Euclides Roxo como um intelectual atuante no ensino da matemática, ou seja, um educador matemático. Palavras-chave: Euclides Roxo. História da Educação Matemática. Institucionalização do professor de matemática. Educador Matemático.

  19. Quantum mechanics for applied physics and engineering

    CERN Document Server

    Fromhold, Albert T


    This excellent text, directed to upper-level undergraduates and graduate students in engineering and applied physics, introduces the fundamentals of quantum mechanics, emphasizing those aspects of quantum mechanics and quantum statistics essential to an understanding of solid-state theory. A heavy background in mathematics and physics is not required beyond basic courses in calculus, differential equations, and calculus-based elementary physics.The first three chapters introduce quantum mechanics (using the Schrödinger equations), quantum statistics, and the free-electron theory of metals. Ch

  20. Mathematical formulas for industrial and mechanical engineering

    CERN Document Server

    Kadry, Seifedine


    Mathematical Formulas For Industrial and Mechanical Engineering serves the needs of students and teachers as well as professional workers in engineering who use mathematics. The contents and size make it especially convenient and portable. The widespread availability and low price of scientific calculators have greatly reduced the need for many numerical tables that make most handbooks bulky. However, most calculators do not give integrals, derivatives, series and other mathematical formulas and figures that are often needed. Accordingly, this book contains that information in an easy way to

  1. Mechanical Engineering Department engineering research: Annual report, FY 1986

    Energy Technology Data Exchange (ETDEWEB)

    Denney, R.M.; Essary, K.L.; Genin, M.S.; Highstone, H.H.; Hymer, J.D.; Taft, S.O. (eds.)


    This report provides information on the five areas of research interest in LLNL's Mechanical Engineering Department. In Computer Code Development, a solid geometric modeling program is described. In Dynamic Systems and Control, structure control and structure dynamics are discussed. Fabrication technology involves machine cutting, interferometry, and automated optical component manufacturing. Materials engineering reports on composite material research and measurement of molten metal surface properties. In Nondestructive Evaluation, NMR, CAT, and ultrasound machines are applied to manufacturing processes. A model for underground collapse is developed. Finally, an alternative heat exchanger is investigated for use in a fusion power plant. Separate abstracts were prepared for each of the 13 reports in this publication. (JDH)

  2. The Clean Development Mechanism Re-engineered

    DEFF Research Database (Denmark)

    Lütken, Søren


    has shown that unless someone guarantees the result – in CDM the 'emissions reduction outcome' – the market will adopt a ‘wait-and-see’ approach and abstain from participating financially on the basis of prospective cash flows. New mechanisms, like the CDM, that deliver new and untried benefits...... for engineering such mechanism, or indeed reengineering the CDM itself, to make it a viable mitigation financing tool, providing receipts for payments in the form of certified emission reductions (CER). Two solutions are presented, both of which secure new financing for projects that deliver real and measurable...... in tracking GHGs mitigation outcomes. This working paper takes an essential look at the CDM and proposes a way to transform it into a true climate finance instrument based on its prospective cash flow. Two elementary solutionsto improving the CDM are offered: 1) a 're-engineered CDM' with an securitization...

  3. Research Skills Enhancement in Future Mechanical Engineers

    Directory of Open Access Journals (Sweden)

    Jorge Lino Alves


    Full Text Available Nowadays, the Web is a common tool for students searching information about the subjects taught in the different university courses. Although this is a good tool for the first rapid knowledge, a deeper study is usually demanded.

    After many years of teaching a course about ceramic and composite materials in the Integrated Master in Mechanical Engineering of Faculty of Engineering of University of Porto, Portugal, the authors used the Bologna reformulation of the mechanical engineering course to introduce new teaching methodologies based on a project based learning methodology.

    One of the main innovations is a practical work that comprises the study of a recent ceramic scientific paper, using all the actual available tools, elaboration of a scientific report, work presentation and participation in a debate.

    With this innovative teaching method the enrolment of the students was enhanced with a better knowledge about the ceramics subject and the skills related with the CDIO competences.

    This paper presents the reasons for this implementation and explains the teaching methodology adopted as well as the changes obtained in the students’ final results.

  4. Mechanical Engineering Practice – using a simple Stirling engine as case

    DEFF Research Database (Denmark)

    Meyer, Knud Erik


    The first technical course that students in mechanical engineering take at the Technical University of Denmark is called “Mechanical Engineering Practice”. We have used a simple Stirling engine as a design-implement project. Students were asked to design and build a heat engine using materials....... The Stirling engine worked well in the drawing assignments. The Stirling engine also served as illustration of coming courses in mechanical engineering. The resulting engines had large variations in their design and most groups succeeded in building a functioning engine. However, achieved efficiencies were...

  5. Essays on the history of mechanical engineering

    CERN Document Server

    Genchi, Giuseppe


    This book treats several subjects from the History of Mechanism and Machine Science, and also contains an illustrative presentation of the Museum of Engines and Mechanisms of the University of Palermo, Italy, which houses a collection of various pieces of machinery from the last 150 years. The various sections deal with some eminent scientists of the past, with the history of industrial installations, machinery and transport, with the human inventiveness for mechanical and scientific devices, and with robots and human-driven automata. All chapters have been written by experts in their fields. The volume shows a wide-ranging panorama on the historical progress of scientific and technical knowledge in the past centuries. It will stimulate new research and ideas for those involved in the history of Science and Technology.

  6. PREFACE: International Scientific and Technical Conference ''Innovative Mechanical Engineering Technologies, Equipment and Materials-2014'' (United States)

    Nail, K.


    In the period from 3 to 5 December 2014 the city of Kazan hosted the International Scientific Conference ''Innovative mechanical engineering technologies, equipment and materials - 2014'' (ISC ''vIMETEM - 2014''). The event was followed by the 14th International specialized exhibition ''Engineering. Metalworking. Kazan'' The main objective of the annual conference was for participants to discuss scientific and technical achievements in the design and manufacture of engineering products, the expansion of cooperation between scientific organizations and enterprises of machine-building complex and the definition of perspective ways of creation and development of new techniques, technologies and materials. The conference ''IMETEM'' was devoted to the 90th anniversary of Fayzrahman Salahovich Yunusov, who made a great contribution in the field of aviation technology. Kashapov Nail, D.Sc., professor (Kazan Federal University)

  7. Simulation based engineering in solid mechanics

    CERN Document Server

    Rao, J S


    This book begins with a brief historical perspective of the advent of rotating machinery in 20th century Solid Mechanics and the development of the discipline of the Strength of Materials. High Performance Computing (HPC) and Simulation Based Engineering Science (SBES) have gradually replaced the conventional approach in Design bringing science directly into engineering without approximations. A recap of the required mathematical principles is given. The science of deformation, strain and stress at a point under the application of external traction loads is next presented. Only one-dimensional structures classified as Bars (axial loads), Rods (twisting loads) and Beams (bending loads) are considered in this book. The principal stresses and strains and von Mises stress and strain that used in design of structures are next presented. Lagrangian solution was used to derive the governing differential equations consistent with assumed deformation field and solution for deformations, strains and stresses were obtai...

  8. Handbook of air pollution from internal combustion engines: pollutant formation and control

    National Research Council Canada - National Science Library

    Sher, Eran


    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix PART I OVERViEW . 1. Motor Vehicle Emissions Control: Achievements, Future Prospects Past 3 John B. Heywood Sun Jae Professor of Mechanical Engineering...


    Directory of Open Access Journals (Sweden)

    Alina-Andreea Dragoescu


    Full Text Available The latest political positioning of Serbia has caused many changes in the society with the most dramatic economic shift on the market. The market requires young educated employees with special additional "soft skills". This has resulted in the need to change the Serbian educational system with the Bologna process implemented. Therefore, the syllabus of ESP in Mechanical Engineering must be adjusted to the demands as regards needs analysis so that it can meet the requirements of the rapidly growing market. This paper offers an outline of ESP syllabus which can be regularly updated with respect to technological and other changes on the market.

  10. Mechanics of materials an introduction to engineering technology

    CERN Document Server

    Ghavami, Parviz


    This book, framed in the processes of engineering analysis and design, presents concepts in mechanics of materials for students in two-year or four-year programs in engineering technology, architecture, and building construction, as well as for students in vocational schools and technical institutes. Using the principles and laws of mechanics, physics, and the fundamentals of engineering, Mechanics of Materials: An Introduction for Engineering Technology will help aspiring and practicing engineers and engineering technicians from across disciplines—mechanical, civil, chemical, and electrical—apply concepts of engineering mechanics for analysis and design of materials, structures, and machine components. The book is ideal for those seeking a rigorous, algebra/trigonometry-based text on the mechanics of materials. This book also: ·       Elucidates concepts of engineering mechanics in materials, including stress and strain, force systems on structures, moment of inertia, and shear and bending moments...

  11. Geometry of surfaces a practical guide for mechanical engineers

    CERN Document Server

    Radzevich, Stephen P


    Presents an in-depth analysis of geometry of part surfaces and provides the tools for solving complex engineering problems Geometry of Surfaces: A Practical Guide for Mechanical Engineers is a comprehensive guide to applied geometry of surfaces with focus on practical applications in various areas of mechanical engineering. The book is divided into three parts on Part Surfaces, Geometry of Contact of Part Surfaces and Mapping of the Contacting Part Surfaces. Geometry of Surfaces: A Practical Guide for Mechanical Engineers combines differential geometry and gearing theory and presents new developments in the elementary theory of enveloping surfaces. Written by a leading expert of the field, this book also provides the reader with the tools for solving complex engineering problems in the field of mechanical engineering. Presents an in-depth analysis of geometry of part surfaces Provides tools for solving complex engineering problems in the field of mechanical engineering Combines differential geometry an...

  12. International Conference on Research and Innovations in Mechanical Engineering

    CERN Document Server

    Singh, Paramjit; Singh, Harwinder; Brar, Gurinder


    This book comprises the proceedings of International Conference on Research and Innovations in Mechanical Engineering (ICRIME 2013) organized by Guru Nanak Dev Engineering College, Ludhiana with support from AICTE, TEQIP, DST and PTU, Jalandhar. This international conference served as a premier forum for communication of new advances and research results in the fields of mechanical engineering. The proceedings reflect the conference’s emphasis on strong methodological approaches and focus on applications within the domain of mechanical engineering. The contents of this volume aim to highlight new theoretical and experimental findings in the fields of mechanical engineering and closely related fields, including interdisciplinary fields such as robotics and mechatronics.

  13. Latest progress of soft rock mechanics and engineering in China


    He, Manchao


    The progress of soft rock mechanics and associated technology in China is basically accompanied by the development of mining engineering and the increasing disasters of large rock deformation during construction of underground engineering. In this regard, Chinese scholars proposed various concepts and classification methods for soft rocks in terms of engineering practices. The large deformation mechanism of engineering soft rocks is to be understood through numerous experiments; and thus a co...

  14. On models and methods of mechanics of pneumatic tires and rubber-cord shells. Development of the ideas due to Professor V. L. Biderman (United States)

    Belkin, A. E.; Mukhin, O. N.; Sorokin, F. D.


    A survey of work of Professor V. L. Biderman's scientific school concerned with the mechanics of tires and rubber-cord shells is presented. Analytical models of diagonal and radial tires aimed at analyzing their stress-strain state, calculating the critical rolling speed, and determining their operating characteristics are discussed. The theory of pneumatic lattice shells is presented in detail, and its new technical applications are considered. The equations of lattice shells of revolution are generalized to the case of nonsymmetric cord placement.

  15. Professor Igor Yevseyev: In Memoriam Professor Igor Yevseyev: In Memoriam (United States)


    Dear readers and authors, June 3, 2012 will mark five months since Professor Igor Yevseyev, Deputy Editor-in-Chief of both journals Laser Physics and Laser Physics Letters passed away, suddenly and unexpectedly. He was 67. Born in Moscow, he entered one of the world's best schools of physics, Moscow Engineering Physics Institute (MEPhI). With this renowned educational and research institution he bonded an alliance for his entire life, starting as an undergraduate student in the Department of Theoretical Physics and later continued as graduate student, assistant professor, associated professor, and full professor in the same department, a rare accomplishment of a person. All those years he retained the love of his life—the love for physics. He worked tirelessly as a teacher and scholar in this captivating field of knowledge. Professor Yevseyev was one of the founders of the international journal of Laser Physics in 1990, the first academic English language journal published in the former USSR. Later, in 2004, the second journal, Laser Physics Letters was brought to the forum of global laser physics community. The idea behind this new title was Professor Yevseyev's initiative to reach the readers and participants with new pioneering and break-through research results more rapidly. His leadership and indefatigable dedication to the quality of published materials made it possible that this journal reached international recognition in a few short years. Still, in order to attract even more attention of potential contributors and readers, Professor Yevseyev originally proposed to conduct the International Laser Physics Workshop (LPHYS) on the annual basis. Since 1992 the Workshop has been conducted every year, each year in a different country. As in all previous years, Professor Yevseyev was the key organizer of this year's workshop in Calgary, Canada. Sadly, this workshop will take place without him. Editorial Board

  16. Selected Aspects of Hydraulic Engineering : Liber Amicorum dedicated to Johannes Theodoor Thijsse, on occasion of his retirement as professor

    NARCIS (Netherlands)

    Thijsse, J.T.; Van Douwen, A.A.


    - Biography of Johannes Theodoor Thijsse - British Hydraulic Engineering and Research - Probleme der Donau in Österreich - Évolution, depuis trente ans, de la Normalisation Internationale des Mesures de Débits en Conduite - L' Association Internationale d'Hydrologie Scientifique - Activities of

  17. Trends in the Education and Training of Professional Mechanical Engineers. (United States)

    Institution of Mechanical Engineers, London (England).

    Twelve papers discussing problems encountered and solutions to them were presented at a symposium which brought together persons concerned with the training of professional mechanical engineers. At Session I, papers covered the need for broadly-based training and engineering practice, training requirements for engineers in the process industries,…

  18. Engineering Mechanics and Design Applications Transdisciplinary Engineering Fundamentals

    CERN Document Server

    Ertas, Atila


    In the last decade, the number of complex problems facing engineers has increased, and the technical knowledge required to address and mitigate them continues to evolve rapidly. These problems include not only the design of engineering systems with numerous components and subsystems, but also the design, redesign, and interaction of social, political, managerial, commercial, biological, medical, and other systems. These systems are likely to be dynamic and adaptive in nature. Finding creative solutions to such large-scale, unstructured problems requires activities that cut across traditional d

  19. A real CDIO mechanical engineering project in 4th semester

    DEFF Research Database (Denmark)

    Lauritsen, Aage Birkkjær

    In the past 6 years at the mechanical engineering study at the Engineering College of Aarhus we have been practicing project work on 4th Semester in the design of energy technology systems. In my presentation, I will give a description of the project, and the thoughts behind; pedagogic-didactic a......In the past 6 years at the mechanical engineering study at the Engineering College of Aarhus we have been practicing project work on 4th Semester in the design of energy technology systems. In my presentation, I will give a description of the project, and the thoughts behind; pedagogic...

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

    CERN Document Server

    Altenbach, Holm


    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.

  1. Teaching professional development of science and engineering professors at a research-extensive university: Motivations, meaningfulness, obstacles, and effects (United States)

    Bouwma-Gearhart, Jana

    There is a national movement to improve undergraduate science, technology, engineering, and mathematics (STEM) education. Given the percentage of academics teaching and training at research institutions, there is a parallel movement to improve the quality of teaching-focused professional development for practicing and future STEM educators at these institutions. While research into the effectiveness of teaching professional development at the postsecondary level has increased over the last 40 years, little attention has been paid to understanding faculty perceptions regarding what constitutes effective teaching professional development. Less is known about how to best meet the needs of STEM faculty at research universities and why, given that they are seldom required to engage in teaching professional development, they bother to participate at all. The higher education research community must develop theory grounded in the knowledge and practical experiences of the faculty engaged in teaching professional development. I have studied what motivates twelve research university science and engineering faculty to engage in teaching professional development in light of local supports and barriers and the resulting value of their participation. I have interpreted the experiences of my research participants to indicate that they were motivated to engage in teaching professional development to fulfill a need to bring their teaching competencies in better concordance with their professional strengths as researchers. Once engaged, my research participants increased their teaching competence and achieved more autonomy with respect to their professional practice. As they continued to engage, they internalized the values and practices associated with effective teaching professional development and adopted the commitment to continually problematize their teaching practice as more of their own. My research participants attempted to transfer their revised stance regarding teaching

  2. PREFACE: 1st International Conference on Mechanical Engineering Research 2011 (ICMER2011) (United States)

    Abu Bakar, Rosli


    thanks to the expert reviewers who have spared their time reviewing the papers. We also highly appreciate the assistance offered by many volunteers in the preparation of the conference proceedings. All papers in ICMER 2011 have the opportunity to be published in IOP Conference Series: Materials Science and Engineering, (indexed by Scopus, Ei Compendex, Inspec), International Journal of Automotive and Mechanical Engineering (IJAME) and Journal of Mechanical Engineering and Sciences (JMES). Professor Dr Hj Rosli Abu Bakar Chairman ICMER 2011

  3. Mathematical Building-Blocks in Engineering Mechanics (United States)

    Boyajian, David M.


    A gamut of mathematical subjects and concepts are taught within a handful of courses formally required of the typical engineering student who so often questions the relevancy of being bound to certain lower-division prerequisites. Basic classes at the undergraduate level, in this context, include: Integral and Differential Calculus, Differential…

  4. Marine Engine Mechanics. Performance Objectives. Basic Course. (United States)

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are presented for each of six terminal objectives for a two-semester course (2 hours daily) which provides training in the terminology, construction, and function of both two- and four-cycle fuel-air mixture internal combustion engines with emphasis on outboard marine…

  5. Healthcare Technology Management (HTM) of mechanical ventilators by clinical engineers. (United States)

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki


    Mechanical ventilator failures expose patients to unacceptable risks, and maintaining mechanical ventilator safety is an important issue. We examined the usefulness of maintaining mechanical ventilators by clinical engineers (CEs) using a specialized calibrator. These evaluations and the ability to make in-house repairs proved useful for obviating the need to rent ventilators which, in turn, might prove faulty themselves. The CEs' involvement in maintaining mechanical ventilators is desirable, ensures prompt service, and, most importantly, enhances safe management of mechanical ventilators.

  6. Schnabel Engineering Lecture


    Cording, Edward


    Schnabel Engineering is pleased to bring you Dr. Edward J. Cording as our eighth lecturer of this series. Dr. Cording is Professor Emeritus of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign where he has taught and performed research in geotechnical engineering, focusing on rock mechanics, soil-structure interaction, and underground construction. The field has been his laboratory, on engineering projects; beginning in the 1960's with large deep caverns ...

  7. The development and application of CFD technology in mechanical engineering (United States)

    Wei, Yufeng


    Computational Fluid Dynamics (CFD) is an analysis of the physical phenomena involved in fluid flow and heat conduction by computer numerical calculation and graphical display. The numerical method simulates the complexity of the physical problem and the precision of the numerical solution, which is directly related to the hardware speed of the computer and the hardware such as memory. With the continuous improvement of computer performance and CFD technology, it has been widely applied to the field of water conservancy engineering, environmental engineering and industrial engineering. This paper summarizes the development process of CFD, the theoretical basis, the governing equations of fluid mechanics, and introduces the various methods of numerical calculation and the related development of CFD technology. Finally, CFD technology in the mechanical engineering related applications are summarized. It is hoped that this review will help researchers in the field of mechanical engineering.

  8. 2012 International Conference on Mechanical and Electronic Engineering

    CERN Document Server

    Lin, Sally; ICMEE2012; Advances in Mechanical and Electronic Engineering v.2


    This book includes the volume 2 of the proceedings of the 2012 International Conference on Mechanical and Electronic Engineering(ICMEE2012), held at June 23-24,2012 in Hefei, China. The conference provided a rare opportunity to bring together worldwide researchers who are working in the fields. This volume 2 is focusing on Mechatronic Engineering and Technology,  Electronic Engineering and Electronic Information Technology .

  9. Formula Student as Part of a Mechanical Engineering Curriculum (United States)

    Davies, Huw Charles


    Formula Student (FS) is a multi-university student design competition managed by the UK Institution of Mechanical Engineers. Students are required to demonstrate and prove their creativity and engineering skills through the design, manufacture and financing of a small formula style race car. This paper seeks to explore the educational value that…

  10. Roles of emeriti professors


    Thody, Angela


    Emeritus Professor Angela Thody commenced a study of emeriti professors in 2006 when she herself had become an emeritus in 2003 and was seeking to establish an Association for emeriti at her university at Lincoln. By 2008, the literature review was finished and a pilot study of emeriti professors at Leicester University was underway. This presentation was one of several to the University of Lincoln's College of Professors to encourage their support for the formation of the association and to ...


    African Journals Online (AJOL)


    Aug 14, 2016 ... University, Sweden in 1990. Although still very young, Professor Ensermu Kelbessa joined the Addis Ababa. University's Biology Department as a graduate assistant in 1979. He then went on to serve the university in various positions including: Lecturer, Assistant Professor, Associate. Professor and, finally ...

  12. Welcoming speech from Dean Faculty of Mechanical Engineering, UMP (United States)

    Taha, Zahari


    In the Name of Allah, the Most Beneficent, the Most Merciful. It is with great pleasure that I welcome the participants of the International Conference of Mechanical Engineering Research 2011. The Prophet Muhammad (peace be upon him) said 'Acquire knowledge and impart it to the people.' (Al Tirmidhi). The quest for knowledge has been from the beginning of time but knowledge only becomes valuable when it is disseminated and applied to benefit humankind. It is hoped that ICMER 2011 will be a platform to gather and disseminate the latest knowledge in mechanical engineering. Academicians, Scientist, Researchers and practitioners of mechanical engineering will be able to share and discuss new findings and applications of mechanical engineering. It is envisaged that the intellectual discourse will result in future collaborations between universities, research institutions and industry both locally and internationally. In particular it is expected that focus will be given to issues on environmental and energy sustainability. Researchers in the mechanical engineering faculty at UMP have a keen interest in technology to harness energy from the ocean. Lowering vehicle emissions has been a primary goal of researchers in the mechanical engineering faculty and the automotive engineering centre as well including developing vehicles using alternative fuels such as biodiesel and renewable sources such as solar driven electric vehicles. Finally I would like to congratulate the organizing committee for their tremendous efforts in organizing the conference. As I wrote this in the Holy Land of Makkah, I pray to Allah swt that the conference will be a success. Prof. Dr. Zahari Taha CEng, MIED, FASc Dean, Faculty of Mechanical Engineering Universiti Malaysia Pahang

  13. Making objective decisions in mechanical engineering problems (United States)

    Raicu, A.; Oanta, E.; Sabau, A.


    Decision making process has a great influence in the development of a given project, the goal being to select an optimal choice in a given context. Because of its great importance, the decision making was studied using various science methods, finally being conceived the game theory that is considered the background for the science of logical decision making in various fields. The paper presents some basic ideas regarding the game theory in order to offer the necessary information to understand the multiple-criteria decision making (MCDM) problems in engineering. The solution is to transform the multiple-criteria problem in a one-criterion decision problem, using the notion of utility, together with the weighting sum model or the weighting product model. The weighted importance of the criteria is computed using the so-called Step method applied to a relation of preferences between the criteria. Two relevant examples from engineering are also presented. The future directions of research consist of the use of other types of criteria, the development of computer based instruments for decision making general problems and to conceive a software module based on expert system principles to be included in the Wiki software applications for polymeric materials that are already operational.

  14. Latest progress of soft rock mechanics and engineering in China

    Directory of Open Access Journals (Sweden)

    Manchao He


    Full Text Available The progress of soft rock mechanics and associated technology in China is basically accompanied by the development of mining engineering and the increasing disasters of large rock deformation during construction of underground engineering. In this regard, Chinese scholars proposed various concepts and classification methods for soft rocks in terms of engineering practices. The large deformation mechanism of engineering soft rocks is to be understood through numerous experiments; and thus a coupled support theory for soft rock roadways is established, followed by the development of a new support material, i.e. the constant resistance and large deformation bolt/anchor with negative Poisson's ratio effect, and associated control technology. Field results show that large deformation problems related to numbers of engineering cases can be well addressed with this new technology, an effective way for similar soft rock deformation control.

  15. System dynamics an introduction for mechanical engineers

    CERN Document Server

    Seeler, Karl A


    This essential textbook takes the student from the initial steps in modeling a dynamic system through development of the mathematical models needed for feedback control.  The generously-illustrated, student-friendly text focuses on fundamental theoretical development rather than the application of commercial software.  Practical details of machine design are included to motivate the non-mathematically inclined student. This book also: Emphasizes the linear graph method for modeling dynamic systems Offers a systematic approach for creating an engineering model, extracting information, and formulating mathematical analyses Adopts a unifying theme of power flow as the dynamic agent that eases analysis of hybrid systems, such as machinery Presents differential equations as dynamic operators and stresses input/output relationships Introduces Mathcad and programming in MATLAB Allows for use of Open Source Computational Software (R or C) Features over 1000 illustrations

  16. Learning mathematics in students of Mechanical Engineering

    Directory of Open Access Journals (Sweden)

    Raquel Ramírez-Pedroso


    Full Text Available Mathematical discipline contributes to the development of logical and algorithmic thinking and provides the basics of a specialist in Technical Sciences, as every engineer considers technical and scientific representations in mathematical terms, with which reflects the quantitative and qualitative features of the phenomena studied . His goal is to make the engineer master the mathematical apparatus to do so able to model and analyze the technical, economic, productive and scientific processes using both, analytical methods and numerical. Interdisciplinarity is a current educational trend that puts in the center the comprehensive treatment of the complex processes of reality from the contribution of different disciplines and meet common objectives. It is necessary to address the issue of interdisciplinarity, from different points of view. Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  17. Engineering a General Education Program: Designing Mechanical Engineering General Education Courses (United States)

    Fagette, Paul; Chen, Shih-Jiun; Baran, George R.; Samuel, Solomon P.; Kiani, Mohammad F.


    The Department of Mechanical Engineering at our institution created two engineering courses for the General Education Program that count towards second level general science credit (traditional science courses are first level). The courses were designed for the general student population based upon the requirements of our General Education Program…

  18. Control Engineering as a Part of Undergraduate Curriculum for Mechanical Engineering in India (United States)

    Akhtar, Shagil; Iqbal, Syed Muneeb; Bajpai, Shrish


    In this present study we have traced the genesis of control engineering in the scope of mechanical engineering and then some analysis on its recent developments, their increasing need and how this particular subject has evolved machines functioning nowadays specifically its standard of education in India. We have probed this field right from its…

  19. Deconstructing Engineering Education Programmes: The DEEP Project to Reform the Mechanical Engineering Curriculum (United States)

    Busch-Vishniac, Ilene; Kibler, Tom; Campbell, Patricia B.; Patterson, Eann; Guillaume, Darrell; Jarosz, Jeffrey; Chassapis, Constantin; Emery, Ashley; Ellis, Glenn; Whitworth, Horace; Metz, Susan; Brainard, Suzanne; Ray, Pradosh


    The goal of the Deconstructing Engineering Education Programmes project is to revise the mechanical engineering undergraduate curriculum to make the discipline more able to attract and retain a diverse community of students. The project seeks to reduce and reorder the prerequisite structure linking courses to offer greater flexibility for…

  20. Proper body mechanics from an engineering perspective. (United States)

    Mohr, Edward G


    The economic viability of the manual therapy practitioner depends on the number of massages/treatments that can be given in a day or week. Fatigue or injuries can have a major impact on the income potential and could ultimately reach the point which causes the practitioner to quit the profession, and seek other, less physically demanding, employment. Manual therapy practitioners in general, and massage therapists in particular, can utilize a large variety of body postures while giving treatment to a client. The hypothesis of this paper is that there is an optimal method for applying force to the client, which maximizes the benefit to the client, and at the same time minimizes the strain and effort required by the practitioner. Two methods were used to quantifiably determine the effect of using "poor" body mechanics (Improper method) and "best" body mechanics (Proper/correct method). The first approach uses computer modeling to compare the two methods. Both postures were modeled, such that the biomechanical effects on the practitioner's elbow, shoulder, hip, knee and ankle joints could be calculated. The force applied to the client, along with the height and angle of application of the force, was held constant for the comparison. The second approach was a field study of massage practitioners (n=18) to determine their maximal force capability, again comparing methods using "Improper and Proper body mechanics". Five application methods were tested at three different application heights, using a digital palm force gauge. Results showed that there was a definite difference between the two methods, and that the use of correct body mechanics can have a large impact on the health and well being of the massage practitioner over both the short and long term. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. Engineering mechanical microenvironment of macrophage and its biomedical applications. (United States)

    Li, Jing; Li, Yuhui; Gao, Bin; Qin, Chuanguang; He, Yining; Xu, Feng; Yang, Hui; Lin, Min


    Macrophages are the most plastic cells in the hematopoietic system and can be widely found in almost all tissues. Recently studies have shown that mechanical cues (e.g., matrix stiffness and stress/strain) can significantly affect macrophage behaviors. Although existing reviews on the physical and mechanical cues that regulate the macrophage's phenotype are available, engineering mechanical microenvironment of macrophages in vitro as well as a comprehensive overview and prospects for their biomedical applications (e.g., tissue engineering and immunotherapy) has yet to be summarized. Thus, this review provides an overview on the existing methods for engineering mechanical microenvironment of macrophages in vitro and then a section on their biomedical applications and further perspectives are presented.

  2. A Math Knowledge Inevitable for Bachelor Engineer, Enlightened Through Teaching at Mechanical Engineering Department (United States)

    Harada, Shoji

    Inspite efforts of rebirthing engineering education degradation of student achievement is progressing due to several reasons. In particular, introducing accrediting system in each university has actually contributed to improve engineering education. However, math achievement of student having different study path is unclear. Taking into account the math knowledge inevitable for bachelor engineer, present author proposes a concrete desirable math knowledge on differentiation, integral, ordinal and extraordinal differential equation, vector, tensor and complex variables at graduation, derived from his teaching career at department of mechanical engineering.

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

    CERN Document Server

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


    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...

  4. Sputtering. [as deposition technique in mechanical engineering (United States)

    Spalvins, T.


    This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

  5. Fuel supply mechanism for an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    San Filipo, F.J.


    This patent describes a fuel supply mechanism for an internal combustion engine having a plurality of combustion chambers. It comprises: a remote reservoir adapted to contain a primary supply of fuel; means, located in said remote reservoir, for evaporating fuel in said remote reservoir into an air stream moving therethrough; and means for transporting said air stream containing such evaporated fuel from said remote reservoir directly into said combustion chambers of said internal combustion engine.

  6. The Mechanics of Mechanical Watches and Clocks

    CERN Document Server

    Du, Ruxu


    "The Mechanics of Mechanical Watches and Clocks" presents historical views and mathematical models of mechanical watches and clocks. Although now over six hundred years old, mechanical watches and clocks are still popular luxury items that fascinate many people around the world. However few have examined the theory of how they work as presented in this book. The illustrations and computer animations are unique and have never been published before. It will be of significant interest to researchers in mechanical engineering, watchmakers and clockmakers, as well as people who have an engineering background and are interested in mechanical watches and clocks. It will also inspire people in other fields of science and technology, such as mechanical engineering and electronics engineering, to advance their designs. Professor Ruxu Du works at the Chinese University of Hong Kong, China. Assistant Professor Longhan Xie works at the South China University of Technology, China.

  7. A Concise Introduction to Mechanics of Rigid Bodies Multidisciplinary Engineering

    CERN Document Server

    Huang, L


    A Concise Introduction to Mechanics of Rigid Bodies: Multidisciplinary Engineering presents concise, key concepts of kinematics and dynamics of rigid bodies. This compact volume bridges the steep gap between  introductory texts on engineering mechanics, which focus on one and two dimensional motions of particles and rigid bodies, and advanced texts on multi-body dynamics in high dimension spaces  found in multidisciplinary areas like mechatronics, robotics and biomechanics. In the book, rigid body motions in the spaces with different dimensions are described in addition to studies in a uniform framework supported by vector and matrix operations. Rigorous mathematic tools and explanations are provided to clarify the most complex concepts. This book also: Provides practical examples from different engineering areas, offering a link between theoretical fundamentals and everyday applications Offers simplified mathematical equations to clearly present essential theories in robotics and mechanics Presents statics...

  8. Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms

    CERN Document Server

    Williams, J J


    Modern design methods of Automotive Cam Design require the computation of a range of parameters. This book provides a logical sequence of steps for the derivation of the relevant equations from first principles, for the more widely used cam mechanisms. Although originally derived for use in high performance engines, this work is equally applicable to the design of mass produced automotive and other internal combustion engines.   Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms provides the equations necessary for the design of cam lift curves with an associated smooth acceleration curve. The equations are derived for the kinematics and kinetics of all the mechanisms considered, together with those for cam curvature and oil entrainment velocity. This permits the cam shape, all loads, and contact stresses to be evaluated, and the relevant tribology to be assessed. The effects of asymmetry on the manufacture of cams for finger follower and offset translating curved followers is ...

  9. Engineering three-dimensional cell mechanical microenvironment with hydrogels. (United States)

    Huang, Guoyou; Wang, Lin; Wang, Shuqi; Han, Yulong; Wu, Jinhui; Zhang, Qiancheng; Xu, Feng; Lu, Tian Jian


    Cell mechanical microenvironment (CMM) significantly affects cell behaviors such as spreading, migration, proliferation and differentiation. However, most studies on cell response to mechanical stimulation are based on two-dimensional (2D) planar substrates, which cannot mimic native three-dimensional (3D) CMM. Accumulating evidence has shown that there is a significant difference in cell behavior in 2D and 3D microenvironments. Among the materials used for engineering 3D CMM, hydrogels have gained increasing attention due to their tunable properties (e.g. chemical and mechanical properties). In this paper, we provide an overview of recent advances in engineering hydrogel-based 3D CMM. Effects of mechanical cues (e.g. hydrogel stiffness and externally induced stress/strain in hydrogels) on cell behaviors are described. A variety of approaches to load mechanical stimuli in 3D hydrogel-based constructs are also discussed.

  10. Developing economic and managerial competencies of bachelors in mechanical engineering

    Directory of Open Access Journals (Sweden)

    Lizunkov Vladislav G.


    Full Text Available The paper deals with the development problems of economic and managerial competencies of bachelors after graduating from engineering higher schools to meet employers’ requirements, through implementing the Federal State Education Standards (FSES of the third generation. The case study is conducted on the basis of training programs for the bachelor’s degree in Mechanical Engineering at Yurga Institute of Technology (Affiliate of National Research Tomsk Polytechnic University. The list of economic and managerial competencies for bachelors in mechanical engineering is specified according to the third generation FSES, enlarged with new competences based on surveys and analyses after questioning employers. The criteria and indicators are described to identify maturity levels in terms of economic and managerial competencies for bachelors. A structural and functional model for training mechanical engineering bachelors has been tested in the implementation of the bachelor’s degree courses in "Mechanical engineering" at Yurga Institute of Technology (Affiliate of National Research Tomsk Polytechnic University, in the period from 2011 to 2015.

  11. Professor Volker Claus: vom o. Professor zum e-Professor (United States)

    Gunzenhäuser, Rul; Taras, Christiane; Wörner, Michael

    Der Beitrag würdigt das Wirken von Professor Claus auf Gebieten des rechnerunterstützten Lehrens. Dabei wird ein Bogen von den frühen Systemen des rechnerunterstützten Lehrens über moderne Lernplattformen im Internet zu neuen Anwendungen web-basierter Systeme für das lebenslange Lehren und Lernen gespannt.

  12. 46 CFR 113.35-15 - Mechanical engine order telegraph systems; application. (United States)


    ... 46 Shipping 4 2010-10-01 2010-10-01 false Mechanical engine order telegraph systems; application...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-15 Mechanical engine order telegraph systems; application. If a mechanical engine order telegraph...

  13. Control Engineering as a Part of Undergraduate Curriculum for Mechanical Engineering in India

    Directory of Open Access Journals (Sweden)

    Akhtar Shagil


    Full Text Available In this present study we have traced the genesis of control engineering in the scope of mechanical engineering and then some analysis on its recent developments, their increasing need and how this particular subject has evolved machines functioning nowadays specifically its standard of education in India. We have probed this field right from its starting. We have examined how it is required as a proper course for mechanical engineering students and in which order the evolution in this field is expanding and, at the same time, its level of education in India and where we are in confronting the business need in terms of quality and quantity of students. The point is that it holds significance in near future. Over the years control engineering has been expanding its perimeter in various branches such mechanics, electronics, instrumentation, electrics, chemistry, aeronautics, mechatronics, etc. As a result, numerous interactive feedback structure from the output and the ability to alter the input accordingly have given the world a new era of equipment commonly termed as “smart devices” which have changed the lifestyle of common people. Furthermore, its various applications in different industry have also favored its development. So, some views from the industry prospective have been included to find out about the skills that are required for aspiring and practicing control engineers having mechanical engineering background.

  14. Mechanism of Intellectual Property Management in Engineering Companies


    Pukhalskaya Anastasiya P.


    The article offers a mechanism of intellectual property management in engineering companies, which envisages synthesis of a system of opinions upon provision of management with existing objects of intellectual property (IP) in a company with the aim to attract them into economic turnover and increase efficiency of their use. Application of the described mechanism of IP management would provide a company with realisation of monopoly rights on results of intellectual activity and would facilita...

  15. Kinematics and Load Formulation of Engine Crank Mechanism


    Nigus, Hailemariam


    International audience; This paper presents the kinematics formulation of an internal combustion engine crank mechanism. The kinematics formulation of the crank mechanism is done using vector loop method and cosine rule are applied to describe the position of the piston. Following the velocity of piston and connecting rod is performed by differentiating the position in terms of the crank angle and connecting rod angle respectively. The acceleration equation with brief form is derived from the...

  16. A Plastic Damage Mechanics Model for Engineered Cementitious Composites

    DEFF Research Database (Denmark)

    Dick-Nielsen, Lars; Stang, Henrik; Poulsen, Peter Noe


    This paper discusses the establishment of a plasticity-based damage mechanics model for Engineered Cementitious Composites (ECC). The present model differs from existing models by combining a matrix and fiber description in order to describe the behavior of the ECC material. The model provides...

  17. Basic Gasoline Engine Mechanics. Florida Vocational Program Guide. (United States)

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This packet contains a program guide and Career Merit Achievement Plan (Career MAP) for the implementation of a basic gasoline engine mechanics program in Florida secondary and postsecondary schools. The program guide describes the program content and structure, provides a program description, lists job titles under the program, and includes a…

  18. Alternative evaluation of innovations’ effectiveness in mechanical engineering (United States)

    Puryaev, A. S.


    The aim of present work is approbation of the developed technique for assessing innovations’ effectiveness. We demonstrate an alternative assessment of innovations’ effectiveness (innovation projects) in mechanical engineering on illustrative example. It is proposed as an alternative to the traditional method technique based on the value concept and the method of “Cash flow”.

  19. Evaluating Risk Awareness in Undergraduate Students Studying Mechanical Engineering (United States)

    Langdon, G. S.; Balchin, K.; Mufamadi, P.


    This paper examines the development of risk awareness among undergraduate students studying mechanical engineering at a South African university. A questionnaire developed at the University of Liverpool was modified and used on students from the first, second and third year cohorts to assess their awareness in the areas of professional…

  20. A Professor's Work. (United States)

    Melko, Matthew

    This book describes a year-long participant-observer case study of the professorship as a profession. Following an introductory chapter, each chapter examines one aspect of the professor's occupation by recounting the specific experiences of the author, a sociology professor at Wright State University (Ohio). Chapter 2 looks at the department as…

  1. Mechanical stimulation in the engineering of heart muscle. (United States)

    Liaw, Norman Yu; Zimmermann, Wolfram-Hubertus


    Recreating the beating heart in the laboratory continues to be a formidable bioengineering challenge. The fundamental feature of the heart is its pumping action, requiring considerable mechanical forces to compress a blood filled chamber with a defined in- and outlet. Ventricular output crucially depends on venous loading of the ventricles (preload) and on the force generated by the preloaded ventricles to overcome arterial blood pressure (afterload). The rate of contraction is controlled by the spontaneously active sinus node and transmission of its electrical impulses into the ventricles. The underlying principles for these physiological processes are described by the Frank-Starling mechanism and Bowditch phenomenon. It is essential to consider these principles in the design and evaluation of tissue engineered myocardium. This review focuses on current strategies to evoke mechanical loading in hydrogel-based heart muscle engineering. Copyright © 2015. Published by Elsevier B.V.

  2. International Stand of Ukrainian Mechanical Engineering in the European Economy

    Directory of Open Access Journals (Sweden)

    Anastasia A. Goncharova


    Full Text Available The article analyses the significant changes in the society that have taken place in Ukraine for the past twenty-five years that considerably influenced the structure and dynamics of mechanical engineering, which, due to objective and subjective reasons, is not ready for large-scale transformational actions. The author has also investigated the dynamics of changes, taking place in the machine-building complex of Ukraine. There have been identified structural changes of the industrial complex that occurred during the crisis and post-crisis period. The article has identified the position of Ukrainian engineering in the European economy.

  3. 2014 Joint Conference on Mechanical Design Engineering and Advanced Manufacturing

    CERN Document Server

    Daidie, Alain; Eynard, Benoit; Paredes, Manuel


    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.

  4. Contact mechanics of reverse engineered distal humeral hemiarthroplasty implants. (United States)

    Willing, Ryan; King, Graham J W; Johnson, James A


    Erosion of articular cartilage is a concern following distal humeral hemiarthroplasty, because native cartilage surfaces are placed in contact with stiff metallic implant components, which causes decreases in contact area and increases in contact stresses. Recently, reverse engineered implants have been proposed which are intended to promote more natural contact mechanics by reproducing the native bone or cartilage shape. In this study, finite element modeling is used in order to calculate changes in cartilage contact areas and stresses following distal humeral hemiarthroplasty with commercially available and reverse engineered implant designs. At the ulna, decreases in contact area were -34±3% (p=0.002), -27±1% (pengineered and cartilage reverse engineered designs, respectively. Peak contact stresses increased by 461±57% (p=0.008), 387±127% (p=0.229) and 165±16% (p=0.003). At the radius, decreases in contact area were -21±3% (p=0.013), -13±2% (p0.999), 241±32% (p=0.010) and 61±10% (p=0.021). Between the three different implant designs, the cartilage reverse engineered design yielded the largest contact areas and lowest contact stresses, but was still unable to reproduce the contact mechanics of the native joint. These findings align with a growing body of evidence indicating that although reverse engineered hemiarthroplasty implants can provide small improvements in contact mechanics when compared with commercially available designs, further optimization of shape and material properties is required in order reproduce native joint contact mechanics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A high throughput mechanical screening device for cartilage tissue engineering. (United States)

    Mohanraj, Bhavana; Hou, Chieh; Meloni, Gregory R; Cosgrove, Brian D; Dodge, George R; Mauck, Robert L


    Articular cartilage enables efficient and near-frictionless load transmission, but suffers from poor inherent healing capacity. As such, cartilage tissue engineering strategies have focused on mimicking both compositional and mechanical properties of native tissue in order to provide effective repair materials for the treatment of damaged or degenerated joint surfaces. However, given the large number design parameters available (e.g. cell sources, scaffold designs, and growth factors), it is difficult to conduct combinatorial experiments of engineered cartilage. This is particularly exacerbated when mechanical properties are a primary outcome, given the long time required for testing of individual samples. High throughput screening is utilized widely in the pharmaceutical industry to rapidly and cost-effectively assess the effects of thousands of compounds for therapeutic discovery. Here we adapted this approach to develop a high throughput mechanical screening (HTMS) system capable of measuring the mechanical properties of up to 48 materials simultaneously. The HTMS device was validated by testing various biomaterials and engineered cartilage constructs and by comparing the HTMS results to those derived from conventional single sample compression tests. Further evaluation showed that the HTMS system was capable of distinguishing and identifying 'hits', or factors that influence the degree of tissue maturation. Future iterations of this device will focus on reducing data variability, increasing force sensitivity and range, as well as scaling-up to even larger (96-well) formats. This HTMS device provides a novel tool for cartilage tissue engineering, freeing experimental design from the limitations of mechanical testing throughput. © 2013 Published by Elsevier Ltd.

  6. Combination of biochemical and mechanical cues for tendon tissue engineering. (United States)

    Testa, Stefano; Costantini, Marco; Fornetti, Ersilia; Bernardini, Sergio; Trombetta, Marcella; Seliktar, Dror; Cannata, Stefano; Rainer, Alberto; Gargioli, Cesare


    Tendinopathies negatively affect the life quality of millions of people in occupational and athletic settings, as well as the general population. Tendon healing is a slow process, often with insufficient results to restore complete endurance and functionality of the tissue. Tissue engineering, using tendon progenitors, artificial matrices and bioreactors for mechanical stimulation, could be an important approach for treating rips, fraying and tissue rupture. In our work, C3H10T1/2 murine fibroblast cell line was exposed to a combination of stimuli: a biochemical stimulus provided by Transforming Growth Factor Beta (TGF-β) and Ascorbic Acid (AA); a three-dimensional environment represented by PEGylated-Fibrinogen (PEG-Fibrinogen) biomimetic matrix; and a mechanical induction exploiting a custom bioreactor applying uniaxial stretching. In vitro analyses by immunofluorescence and mechanical testing revealed that the proposed combined approach favours the organization of a three-dimensional tissue-like structure promoting a remarkable arrangement of the cells and the neo-extracellular matrix, reflecting into enhanced mechanical strength. The proposed method represents a novel approach for tendon tissue engineering, demonstrating how the combined effect of biochemical and mechanical stimuli ameliorates biological and mechanical properties of the artificial tissue compared to those obtained with single inducement. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  7. Something Old, Something New: Integrating Engineering Practice into the Teaching of Engineering Mechanics. (United States)

    Miller, Gregory R.; Cooper, Stephen C.


    Presents a multifaceted method for teaching engineering mechanics to satisfy several desiderata. This approach includes design projects, group work, basic competency exams, computational environments for simulating and visualizing phenomena, multimedia instructional tools, hands-on experiences, and student presentations. Describes the materials…

  8. Thermodynamic Optimization of Flow Geometry in Mechanical and Civil Engineering (United States)

    Bejan, Adrian; Lorente, Sylvie


    Recent developments in thermodynamic optimization are reviewed by focusing on the generation of optimal geometric form (shape, structure, topology) in flow systems. The flow configuration is free to vary. The principle that generates geometric form is the pursuit of maximum global performance (e.g., minimum flow resistance, minimum irreversibility) subject to global finiteness constraints (volume, weight, time). The resulting structures constructed in this manner have been named constructal designs. The thought that the same objective and constraints principle accounts for the optimally shaped flow paths that occur in natural systems (animate and inanimate) has been named constructal theory. Examples of large classes of applications are drawn from various sectors of mechanical and civil engineering: the distribution of heat transfer area in power plants, optimal sizing and shaping of flow channels and fins, optimal aspect ratios of heat exchanger core structures, aerodynamic and hydrodynamic shapes, tree-shaped assemblies of convective fins, treeshaped networks for fluid flow and other currents, optimal configurations for streams that undergo bifurcation or pairing, insulated pipe networks for the distribution of hot water and exergy over a fixed territory, and distribution networks for virtually everything that moves in society (goods, currency, information). The principle-based generation of flow geometry unites the thermodynamic optimization developments known in mechanical engineering with lesser known applications in civil engineering and social organization. This review extends thermodynamics, because it shows how thermodynamic principles of design optimization account for the development of optimal configurations in civil engineering and social organization.

  9. Integration of Social Sciences and Humanities into Mechanical Engineering Curriculum

    Directory of Open Access Journals (Sweden)

    Nikša Dubreta


    Full Text Available Article deals with ways in which social sciences and humanities have been integrated from the 1980s to the present day into curriculum of Faculty of Mechanical Engineering and Naval Architecture at University of Zagreb, Croatia. After a brief review and summary of selected research and theoretical contributions to the subject theme, a specific research setting is indicated and contextualized. Elements of socio-historical approach are established primarily through analysis of corresponding documents: curriculums from the 1980s, 1990s and 2000s and from key documents on strategic development of the Faculty. It is stressed that social sciences and humanities topics are continually represented in mechanical engineering study program as legitimate, but separate unit, poorly integrated in the main engineering courses. Together with more or less expressed orientation toward micro-social and micro-economical issues in industry and business, it points to the main features in continuity of establishing the field of social sciences and humanities. Finally, it is shown that chances to widen and enrich aforementioned field are in close relation to the character of engineering and its social contextualization expressed in a key Faculty’s strategic documents.

  10. Formula student as part of a mechanical engineering curriculum (United States)

    Davies, Huw Charles


    Formula Student (FS) is a multi-university student design competition managed by the UK Institution of Mechanical Engineers. Students are required to demonstrate and prove their creativity and engineering skills through the design, manufacture and financing of a small formula style race car. This paper seeks to explore the educational value that derives from the FS activity through a series of semi-structured interviews with key stakeholders. Through the analysis of the interview data, it was found that the FS activity supported development of student skills and competencies in the following areas: use of engineering knowledge to support the application of existing and emerging technology; application of theoretical and practical knowledge to the solution of engineering problems; development of technical and commercial management skills; development of effective interpersonal skills, including communication skills; and demonstration of personal commitment to professional development. In addition, a number of areas for implementing 'good practise' have been identified. The information herein supports educators in their responsibility to help meet the needs of the engineering industry for high quality graduates.

  11. Microcontrollers for Mechanical Engineers: From Assembly Language to Controller Implementation


    Salzman, Noah; Meckl, Peter H.


    This paper describes the evolution of a graduate and advanced undergraduate mechanical engineering course on microcontrollers and electromechanical control systems. The course begins with developing an understanding of the architecture of the microcontroller, and low-level programming in assembly language. It then proceeds to working with various functions of the microcontroller, including serial communications, interrupts, analog to digital conversion, and digital to analog conversion. Final...

  12. Channeled Scaffolds for Engineering Myocardium with Mechanical Stimulation (United States)

    Zhang, Ting; Wan, Leo Q.; Xiong, Zhuo; Marsano, Anna; Maidhof, Robert; Park, Miri; Yan, Yongnian; Vunjak-Novakovic, Gordana


    The characteristics of the matrix (composition, structure, mechanical properties) and external culture environment (pulsatile perfusion, physical stimulation) are critically important for engineering functional myocardial tissue. We report the development of chitosan-collagen scaffolds with micro-pores and an array of parallel channels (~200 μm in diameter) that were specifically designed for cardiac tissue engineering with mechanical stimulation. The scaffolds were designed to have the structural and mechanical properties similar to those of the native human heart matrix. Scaffolds were seeded with neonatal rat heart cells and subjected to dynamic tensile stretch using a custom-designed bioreactor. The channels enhanced oxygen transport and facilitated the establishment of cell connections within the construct. The myocardial patches (14 mm in diameter, 1–2 mm thick) consisted of metabolically active cells and started to contract synchronously after 3 days of culture. Mechanical stimulation with high tensile stresses promoted cell alignment, elongation, and the expression of connexin-43 (Cx-43). This study confirms the importance of scaffold design and mechanical stimulation for the formation of contractile cardiac constructs. PMID:22081518

  13. Channelled scaffolds for engineering myocardium with mechanical stimulation. (United States)

    Zhang, Ting; Wan, Leo Q; Xiong, Zhuo; Marsano, Anna; Maidhof, Robert; Park, Miri; Yan, Yongnian; Vunjak-Novakovic, Gordana


    The characteristics of the matrix (composition, structure, mechanical properties) and external culture environment (pulsatile perfusion, physical stimulation) of the heart are important characteristics in the engineering of functional myocardial tissue. This study reports on the development of chitosan-collagen scaffolds with micropores and an array of parallel channels (~ 200 µm in diameter) that were specifically designed for cardiac tissue engineering using mechanical stimulation. The scaffolds were designed to have similar structural and mechanical properties of those of native heart matrix. Scaffolds were seeded with neonatal rat heart cells and subjected to dynamic tensile stretch using a custom designed bioreactor. The channels enhanced oxygen transport and facilitated the establishment of cell connections within the construct. The myocardial patches (14 mm in diameter, 1-2 mm thick) consisted of metabolically active cells that began to contract synchronously after 3 days of culture. Mechanical stimulation with high tensile stress promoted cell alignment, elongation, and expression of connexin-43 (Cx-43). This study confirms the importance of scaffold design and mechanical stimulation for the formation of contractile cardiac constructs. Copyright © 2011 John Wiley & Sons, Ltd.

  14. Professor Martin Hairer

    Directory of Open Access Journals (Sweden)

    Martine Barons


    Full Text Available Professor Martin Hairer was one of four recipients of the 2014 Fields Medal, widely viewed as the highest honour a mathematician can receive. He is currently Regius Professor of Mathematics in the Mathematics Department at the University of Warwick. Professor Hairer has contributed significantly to the field of stochastic partial differential equations (SPDEs, which engages with interdisciplinary approaches to mathematics and physics. He has enjoyed great success communicating mathematics to a range of audiences and has also developed music editing software.In this interview, early career mathematicians, Dr Martine Barons (MJB and Dr Paul Chleboun ask Professor Hairer (MH about how his interest in mathematics developed; the awards ceremony where he received the Fields Medal; Amadeus Pro, the music software he developed and continues to maintain; and the challenges of engaging a sceptical and sometimes critical public as a mathematician.

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

    CERN Document Server

    Woo, Seongwoo


    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...

  16. Development of an integrated engine-hydro-mechanical transmission control algorithm for a tractor


    Sunghyun Ahn; Jingyu Choi; Suchul Kim; Jinwoong Lee; Changhyun Choi; Hyunsoo Kim


    This article presents an integrated engine-hydro-mechanical transmission control algorithm for a tractor considering the engine-hydro-mechanical transmission efficiency. First, the hydro-mechanical transmission efficiency was obtained by network analysis based on the hydrostatic unit efficiency constructed from the test. Using the hydro-mechanical transmission efficiency map and the thermal efficiency of the engine, an engine-hydro-mechanical transmission optimal operating line was obtained, ...

  17. Mechanical stimulation improves tissue-engineered human skeletal muscle (United States)

    Powell, Courtney A.; Smiley, Beth L.; Mills, John; Vandenburgh, Herman H.


    Human bioartificial muscles (HBAMs) are tissue engineered by suspending muscle cells in collagen/MATRIGEL, casting in a silicone mold containing end attachment sites, and allowing the cells to differentiate for 8 to 16 days. The resulting HBAMs are representative of skeletal muscle in that they contain parallel arrays of postmitotic myofibers; however, they differ in many other morphological characteristics. To engineer improved HBAMs, i.e., more in vivo-like, we developed Mechanical Cell Stimulator (MCS) hardware to apply in vivo-like forces directly to the engineered tissue. A sensitive force transducer attached to the HBAM measured real-time, internally generated, as well as externally applied, forces. The muscle cells generated increasing internal forces during formation which were inhibitable with a cytoskeleton depolymerizer. Repetitive stretch/relaxation for 8 days increased the HBAM elasticity two- to threefold, mean myofiber diameter 12%, and myofiber area percent 40%. This system allows engineering of improved skeletal muscle analogs as well as a nondestructive method to determine passive force and viscoelastic properties of the resulting tissue.

  18. Protein-hydrogel interactions in tissue engineering: mechanisms and applications. (United States)

    Zustiak, Silviya P; Wei, Yunqian; Leach, Jennie B


    Recent advances in our understanding of the sophistication of the cellular microenvironment and the dynamics of tissue remodeling during development, disease, and regeneration have increased our appreciation of the current challenges facing tissue engineering. As this appreciation advances, we are better equipped to approach problems in the biology and therapeutics of even more complex fields, such as stem cells and cancer. To aid in these studies, as well as the established areas of tissue engineering, including cardiovascular, musculoskeletal, and neural applications, biomaterials scientists have developed an extensive array of materials with specifically designed chemical, mechanical, and biological properties. Herein, we highlight an important topic within this area of biomaterials research, protein-hydrogel interactions. Due to inherent advantages of hydrated scaffolds for soft tissue engineering as well as specialized bioactivity of proteins and peptides, this field is well-posed to tackle major needs within emerging areas of tissue engineering. We provide an overview of the major modes of interactions between hydrogels and proteins (e.g., weak forces, covalent binding, affinity binding), examples of applications within growth factor delivery and three-dimensional scaffolds, and finally future directions within the area of hydrogel-protein interactions that will advance our ability to control the cell-biomaterial interface.

  19. Protein–Hydrogel Interactions in Tissue Engineering: Mechanisms and Applications (United States)

    Zustiak, Silviya P.; Wei, Yunqian


    Recent advances in our understanding of the sophistication of the cellular microenvironment and the dynamics of tissue remodeling during development, disease, and regeneration have increased our appreciation of the current challenges facing tissue engineering. As this appreciation advances, we are better equipped to approach problems in the biology and therapeutics of even more complex fields, such as stem cells and cancer. To aid in these studies, as well as the established areas of tissue engineering, including cardiovascular, musculoskeletal, and neural applications, biomaterials scientists have developed an extensive array of materials with specifically designed chemical, mechanical, and biological properties. Herein, we highlight an important topic within this area of biomaterials research, protein–hydrogel interactions. Due to inherent advantages of hydrated scaffolds for soft tissue engineering as well as specialized bioactivity of proteins and peptides, this field is well-posed to tackle major needs within emerging areas of tissue engineering. We provide an overview of the major modes of interactions between hydrogels and proteins (e.g., weak forces, covalent binding, affinity binding), examples of applications within growth factor delivery and three-dimensional scaffolds, and finally future directions within the area of hydrogel–protein interactions that will advance our ability to control the cell–biomaterial interface. PMID:23150926

  20. Mechanics and model-based control of advanced engineering systems

    CERN Document Server

    Irschik, Hans; Krommer, Michael


    Mechanics and Model-Based Control of Advanced Engineering Systems collects 32 contributions presented at the International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines, which took place in St. Petersburg, Russia in July 2012. The workshop continued a series of international workshops, which started with a Japan-Austria Joint Workshop on Mechanics and Model Based Control of Smart Materials and Structures and a Russia-Austria Joint Workshop on Advanced Dynamics and Model Based Control of Structures and Machines. In the present volume, 10 full-length papers based on presentations from Russia, 9 from Austria, 8 from Japan, 3 from Italy, one from Germany and one from Taiwan are included, which represent the state of the art in the field of mechanics and model based control, with particular emphasis on the application of advanced structures and machines.

  1. 49 CFR 176.905 - Motor vehicles or mechanical equipment powered by internal combustion engines. (United States)


    ... internal combustion engines. 176.905 Section 176.905 Transportation Other Regulations Relating to... engines. (a) A motor vehicle or any mechanized equipment powered by an internal combustion engine is... met: (1) The motor vehicle or mechanical equipment has an internal combustion engine using liquid fuel...

  2. 46 CFR 113.35-9 - Mechanical engine order telegraph systems. (United States)


    ... 46 Shipping 4 2010-10-01 2010-10-01 false Mechanical engine order telegraph systems. 113.35-9 Section 113.35-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-9 Mechanical engine order...

  3. 46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation. (United States)


    ... 46 Shipping 4 2010-10-01 2010-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

  4. Influence of internship toward entrepreneurship interest for mechanical engineering students (United States)

    Sunyoto, Nugroho, Agus; Ulum, Miftakhul


    This study was aimed to determine the influence of internship toward students' entrepreneurship interest. Mechanical Engineering Education students from 2013 Batch who had the internship from Engineering Faculty at Semarang State University are the subject of this study. Data was collected through questionnaire and analyzed by simple regression analysis method. The internship subject score and entrepreneurship are categorized in very good level in which the average is 87.08% and 85.61%. However, the influence of internship toward students' interest is categorized in low level in which the average score is 7.9%. Internship section shall encourage students to study entrepreneurship aspects during the internship for entrepreneurship interest improvement and the students' preparation once they graduated. Description scoring standard is needed for scoring the students although they conduct their internship at different locations and companies. The students are highly recommended to conduct an an internship at entrepreneurship-based companies.

  5. Mechanical cues in orofacial tissue engineering and regenerative medicine. (United States)

    Brouwer, Katrien M; Lundvig, Ditte M S; Middelkoop, Esther; Wagener, Frank A D T G; Von den Hoff, Johannes W


    Cleft lip and palate patients suffer from functional, aesthetical, and psychosocial problems due to suboptimal regeneration of skin, mucosa, and skeletal muscle after restorative cleft surgery. The field of tissue engineering and regenerative medicine (TE/RM) aims to restore the normal physiology of tissues and organs in conditions such as birth defects or after injury. A crucial factor in cell differentiation, tissue formation, and tissue function is mechanical strain. Regardless of this, mechanical cues are not yet widely used in TE/RM. The effects of mechanical stimulation on cells are not straight-forward in vitro as cellular responses may differ with cell type and loading regime, complicating the translation to a therapeutic protocol. We here give an overview of the different types of mechanical strain that act on cells and tissues and discuss the effects on muscle, and skin and mucosa. We conclude that presently, sufficient knowledge is lacking to reproducibly implement external mechanical loading in TE/RM approaches. Mechanical cues can be applied in TE/RM by fine-tuning the stiffness and architecture of the constructs to guide the differentiation of the seeded cells or the invading surrounding cells. This may already improve the treatment of orofacial clefts and other disorders affecting soft tissues. © 2015 by the Wound Healing Society.

  6. Engineering the mechanical and biological properties of nanofibrous vascular grafts for in situ vascular tissue engineering. (United States)

    Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song


    Synthetic small diameter vascular grafts have a high failure rate, and endothelialization is critical for preventing thrombosis and graft occlusion. A promising approach is in situ tissue engineering, whereby an acellular scaffold is implanted and provides stimulatory cues to guide the in situ remodeling into a functional blood vessel. An ideal scaffold should have sufficient binding sites for biomolecule immobilization and a mechanical property similar to native tissue. Here we developed a novel method to blend low molecular weight (LMW) elastic polymer during electrospinning process to increase conjugation sites and to improve the mechanical property of vascular grafts. LMW elastic polymer improved the elasticity of the scaffolds, and significantly increased the amount of heparin conjugated to the micro/nanofibrous scaffolds, which in turn increased the loading capacity of vascular endothelial growth factor (VEGF) and prolonged the release of VEGF. Vascular grafts were implanted into the carotid artery of rats to evaluate the in vivo performance. VEGF treatment significantly enhanced endothelium formation and the overall patency of vascular grafts. Heparin coating also increased cell infiltration into the electrospun grafts, thus increasing the production of collagen and elastin within the graft wall. This work demonstrates that LMW elastic polymer blending is an approach to engineer the mechanical and biological property of micro/nanofibrous vascular grafts for in situ vascular tissue engineering.

  7. Mechanisms Engineering Test Loop - Phase 1 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Kultgen, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Hvasta, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lisowski, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Toter, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Borowski, A. [Argonne National Lab. (ANL), Argonne, IL (United States)


    This report documents the current status of the Mechanisms Engineering Test Loop (METL) as of the end of FY2016. Currently, METL is in Phase I of its design and construction. Once operational, the METL facility will test small to intermediate-scale components and systems in order to develop advanced liquid metal technologies. Testing different components in METL is essential for the future of advanced fast reactors as it will provide invaluable performance data and reduce the risk of failures during plant operation.

  8. Quantitative ultrasonic evaluation of mechanical properties of engineering materials (United States)

    Vary, A.


    Current progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength properties of engineering materials is reviewed. Even where conventional NDE techniques have shown that a part is free of overt defects, advanced NDE techniques should be available to confirm the material properties assumed in the part's design. There are many instances where metallic, composite, or ceramic parts may be free of critical defects while still being susceptible to failure under design loads due to inadequate or degraded mechanical strength. This must be considered in any failure prevention scheme that relies on fracture analysis. This review will discuss the availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions.

  9. Professor Michael Levitt

    Directory of Open Access Journals (Sweden)

    Gemma-Louise Davies


    Full Text Available Professor Michael Levitt (Stanford University, USA won the 2013 Nobel Prize in Chemistry for the development of multiscale models for complex chemical systems—computational tools which can calculate the course of chemical reactions. Professor Levitt was born in Pretoria, South Africa; he came to the UK on a summer vacation aged 16, where he decided to stay and study for his A‑levels. His interest in the physics of living systems drove him to study biophysics at King’s College London, before securing a PhD position at the Laboratory of Molecular Biology in Cambridge. In the interim year between his degree and beginning his PhD, Professor Levitt worked at the Weizmann Institute of Science in Israel, where he met his future wife. They married later that year and moved to Cambridge, where their three children were born. After completing his PhD, he spent time working in Israel, Cambridge, the Salk Institute and Stanford (both California. Since 1986, he has split his time between Israel and California. Outside of science, he is a keen hiker and he is well-known to have attended the eclectic ‘Burning Man’ Festival in California.[1]Professor Levitt visited the University of Warwick to speak at the Computational Molecular Science Annual Conference in March 2015. In this interview, Dr Gemma-Louise Davies, an Institute of Advanced Study Global Research Fellow, spoke to Professor Levitt about the importance of Interdisciplinarity in his field, role models in Academia, and his plans for the future.Image: Professor Michael Levitt (left with Dr Scott Habershon (right, organiser of the 2015 Computational Molecular Science Annual Conference during his visit to the University of Warwick in March 2015.[1] ‘Burning Man’ is a unique annual festival dedicated to community, art, music, self-expression and self-reliance. Tens of thousands of people flock to this temporary metropolis built in the Californian desert.

  10. Design of a biaxial mechanical loading bioreactor for tissue engineering. (United States)

    Bilgen, Bahar; Chu, Danielle; Stefani, Robert; Aaron, Roy K


    We designed a loading device that is capable of applying uniaxial or biaxial mechanical strain to a tissue engineered biocomposites fabricated for transplantation. While the device primarily functions as a bioreactor that mimics the native mechanical strains, it is also outfitted with a load cell for providing force feedback or mechanical testing of the constructs. The device subjects engineered cartilage constructs to biaxial mechanical loading with great precision of loading dose (amplitude and frequency) and is compact enough to fit inside a standard tissue culture incubator. It loads samples directly in a tissue culture plate, and multiple plate sizes are compatible with the system. The device has been designed using components manufactured for precision-guided laser applications. Bi-axial loading is accomplished by two orthogonal stages. The stages have a 50 mm travel range and are driven independently by stepper motor actuators, controlled by a closed-loop stepper motor driver that features micro-stepping capabilities, enabling step sizes of less than 50 nm. A polysulfone loading platen is coupled to the bi-axial moving platform. Movements of the stages are controlled by Thor-labs Advanced Positioning Technology (APT) software. The stepper motor driver is used with the software to adjust load parameters of frequency and amplitude of both shear and compression independently and simultaneously. Positional feedback is provided by linear optical encoders that have a bidirectional repeatability of 0.1 μm and a resolution of 20 nm, translating to a positional accuracy of less than 3 μm over the full 50 mm of travel. These encoders provide the necessary position feedback to the drive electronics to ensure true nanopositioning capabilities. In order to provide the force feedback to detect contact and evaluate loading responses, a precision miniature load cell is positioned between the loading platen and the moving platform. The load cell has high accuracies of 0

  11. Interactive simulations as teaching tools for engineering mechanics courses (United States)

    Carbonell, Victoria; Romero, Carlos; Martínez, Elvira; Flórez, Mercedes


    This study aimed to gauge the effect of interactive simulations in class as an active teaching strategy for a mechanics course. Engineering analysis and design often use the properties of planar sections in calculations. In the stress analysis of a beam under bending and torsional loads, cross-sectional properties are used to determine stress and displacement distributions in the beam cross section. The centroid, moments and products of inertia of an area made up of several common shapes (rectangles usually) may thus be obtained by adding the moments of inertia of the component areas (U-shape, L-shape, C-shape, etc). This procedure is used to calculate the second moments of structural shapes in engineering practice because the determination of their moments of inertia is necessary for the design of structural components. This paper presents examples of interactive simulations developed for teaching the ‘Mechanics and mechanisms’ course at the Universidad Politecnica de Madrid, Spain. The simulations focus on fundamental topics such as centroids, the properties of the moment of inertia, second moments of inertia with respect to two axes, principal moments of inertia and Mohr's Circle for plane stress, and were composed using Geogebra software. These learning tools feature animations, graphics and interactivity and were designed to encourage student participation and engagement in active learning activities, to effectively explain and illustrate course topics, and to build student problem-solving skills.

  12. The Effects of Professors' Race and Gender on Student Evaluations and Performance (United States)

    Basow, Susan A.; Codos, Stephanie; Martin, Julie L.


    This experimental study examined the effects of professor gender, professor race, and student gender on student ratings of teaching effectiveness and amount learned. After watching a three-minute engineering lecture presented by a computer-animated professor who varied by gender and race (African American, White), female and male undergraduates…

  13. 23rd June 2010 - University of Bristol Head of the Aerospace Engineering Department and Professor of Aerospace Dynamics N. Lieven visiting CERN control centre with Beams Department Head P. Collier, visiting the LHC superconducting magnet test hall with R. Veness and CMS control centre with Collaboration Spokesperson G. Tonelli and CMS User J. Goldstein.

    CERN Multimedia

    Jean-Claude Gadmer


    23rd June 2010 - University of Bristol Head of the Aerospace Engineering Department and Professor of Aerospace Dynamics N. Lieven visiting CERN control centre with Beams Department Head P. Collier, visiting the LHC superconducting magnet test hall with R. Veness and CMS control centre with Collaboration Spokesperson G. Tonelli and CMS User J. Goldstein.

  14. 27 August 2013 - Signature of an Agreement between KTO Karatay University in Turkey represented by the Dean of Engineering Professor Ali Okatan, CERN represented by Director for Research and Computing Dr Sergio Bertolucci and ALICE Collaboration represented by ALICE Collaboration Spokesperson Dr Paolo Giubellino.

    CERN Multimedia

    Maximilien Brice


    27 August 2013 - Signature of an Agreement between KTO Karatay University in Turkey represented by the Dean of Engineering Professor Ali Okatan, CERN represented by Director for Research and Computing Dr Sergio Bertolucci and ALICE Collaboration represented by ALICE Collaboration Spokesperson Dr Paolo Giubellino.

  15. Professor Kalkman retires

    NARCIS (Netherlands)

    Baas, Pieter


    On 13 December 1990 Prof. Dr. Cornelis (Kees) Kalkman retired from the positions of Professor of Plant Systematics and Scientific Director of the Rijksherbarium/ Hortus Botanicus by presenting his valedictory lecture to the academic community of Leiden University and the assembled Dutch Botanical

  16. Professor Wolfgang Panofsky

    CERN Multimedia


    "Professor Wolfgang panofsky, who died on September 24 aged 88, was a particle physicists and director of the Stanford Linear Accelerator Centre (SLAC) in California; with Jack Steinberger, he was the first to isolate the neutral pi meson, one of the subatomic particles which had been predicted by theoretical scientists to account for the strng force which binds the nuclei of atoms." (1 page)

  17. Professor Tiina Tasmuth Helsingis

    Index Scriptorium Estoniae


    Tervisekasvatuse õppetooli professor Tiina Tasmuth osales 11.-14. juunini Helsingis toimunud rahvusvahelise konverentsi "2nd Psycho-Social Impacts of Breast Cancer" töös ning esines ettekandega teemal "Chronic post-treatment symptoms in patients with breast cancer" : [täistekst

  18. Professor og DMI

    DEFF Research Database (Denmark)

    Kaas, Eigil


    oplever meget lave temperaturer - og for Danmarks vedkommende en usædvanlig lang periode med vintervejr. Forklaringen kommer fra professor Eigil Kaas fra Niels Bohr Instituttet ved Københavns Universitet. Han forklarer til, at vintervejret dog er betinget af den mere eller mindre tilfældige måde...

  19. Tunable engineered skin mechanics via coaxial electrospun fiber core diameter. (United States)

    Blackstone, Britani Nicole; Drexler, Jason William; Powell, Heather Megan


    Autologous engineered skin (ES) offers promise as a treatment for massive full thickness burns. Unfortunately, ES is orders of magnitude weaker than normal human skin causing it to be difficult to apply surgically and subject to damage by mechanical shear in the early phases of engraftment. In addition, no manufacturing strategy has been developed to tune ES biomechanics to approximate the native biomechanics at different anatomic locations. To enhance and tune ES biomechanics, a coaxial (CoA) electrospun scaffold platform was developed from polycaprolactone (PCL, core) and gelatin (shell). The ability of the coaxial fiber core diameter to control both scaffold and tissue mechanics was investigated along with the ability of the gelatin shell to facilitate cell adhesion and skin development compared to pure gelatin, pure PCL, and a gelatin-PCL blended fiber scaffold. CoA ES exhibited increased cellular adhesion and metabolism versus PCL alone or gelatin-PCL blend and promoted the development of well stratified skin with a dense dermal layer and a differentiated epidermal layer. Biomechanics of the scaffold and ES scaled linearly with core diameter suggesting that this scaffold platform could be utilized to tailor ES mechanics for their intended grafting site and reduce graft damage in vitro and in vivo.

  20. Integrating Technical Communication in the Mechanical Engineering Curriculum (United States)

    Norberg, Seth; Ashcraft, Timothy; van Poppel, Bret


    Technical communication is essential to engineering practice, but these skills can be challenging to teach and assess in the classroom. Instructors in the Mechanical Engineering (ME) program at the United States Military Academy are developing new learning exercises to prepare students for success in their capstone design course and beyond. In this paper we highlight the recent successes and lessons learned from two courses: junior-level Thermal-Fluid Systems and the senior-level ME Seminar. Both courses support the newly implemented West Point Writing Program (WPWP), an institutional, writing-across-the-curriculum program. The junior course incorporates four hands-on experiments, which provide an abundance of data for students to analyze, assess, and present. In the senior course the majority of the content that students present is from their ongoing capstone design projects. Between the two courses, students craft essays, lab reports, short summaries, posters, quad charts, and technical presentations. Both courses include peer evaluation, revision exercises, and timed (on demand) writing assignments. The junior course includes assignments co-authored by a group as well as an individual report. An overview of both courses' assignments with course-end feedback from the students and the faculty is provided. Strengths and weaknesses are identified and recommendations for instructors seeking to implement similar technical communications assignments in their own courses are presented.

  1. 49 CFR 173.220 - Internal combustion engines, self-propelled vehicles, mechanical equipment containing internal... (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Internal combustion engines, self-propelled vehicles, mechanical equipment containing internal combustion engines, and battery powered vehicles or... Than Class 1 and Class 7 § 173.220 Internal combustion engines, self-propelled vehicles, mechanical...

  2. A concise introduction to mechanics of rigid bodies multidisciplinary engineering

    CERN Document Server

    Huang, L


    This updated second edition broadens the explanation of rotational kinematics and dynamics — the most important aspect of rigid body motion in three-dimensional space and a topic of much greater complexity than linear motion. It expands treatment of vector and matrix, and includes quaternion operations to describe and analyze rigid body motion which are found in robot control, trajectory planning, 3D vision system calibration, and hand-eye coordination of robots in assembly work, etc. It features updated treatments of concepts in all chapters and case studies. The textbook retains its comprehensiveness in coverage and compactness in size, which make it easily accessible to the readers from multidisciplinary areas who want to grasp the key concepts of rigid body mechanics which are usually scattered in multiple volumes of traditional textbooks. Theoretical concepts are explained through examples taken from across engineering disciplines and links to applications and more advanced courses (e.g. industrial rob...

  3. Incorporating a Product Archaeology Paradigm across the Mechanical Engineering Curriculum (United States)

    Moore-Russo, Deborah; Cormier, Phillip; Lewis, Kemper; Devendorf, Erich


    Historically, the teaching of design theory in an engineering curriculum has been relegated to a senior capstone design experience. Presently, however, engineering design concepts and courses can be found through the entirety of most engineering programs. Educators have recognized that engineering design provides a foundational platform that can…

  4. Professors' Observations on Their Work. (United States)

    Myers, Betty; Mager, Gerald M.

    Previous studies of professors of education have noted what activities comprised the work of being a professor, how professors allocated time to the various work tasks, how they would have preferred to allocate time, and insights they had about their work. In this study, parallel data were gathered on the broader education professoriate. Survey…

  5. Positivistas e republicanos: os professores da Escola de Engenharia de Porto Alegre entre a atividade política e a administração pública (1896-1930 Positivists and Republicans: the professors of the School of Engineering in Porto Alegre between political activity and public administration (1896-1930

    Directory of Open Access Journals (Sweden)

    Flavio M. Heinz


    Full Text Available A história da administração pública no sul do Brasil durante a Primeira República põe em evidência uma instituição de formação superior, a Escola de Engenharia de Porto Alegre, que, fundada em 1896, forneceu parte significativa dos quadros técnicos das secretarias e agências do estado nas décadas seguintes, notadamente da Secretaria dos Negócios de Obras Públicas (SOP. Neste artigo (1 faremos uma breve exposição do cenário político-institucional no sul do Brasil na transição do século XIX para o XX; (2 apresentaremos as linhas gerais do processo de organização da Escola de Engenharia de Porto Alegre; e (3 discutiremos alguns aspectos do percurso profissional, administrativo e político de seu grupo original de docentes e de seus primeiros diplomados.The history of public administration in Southern Brazil during the so-called "First Republic" includes an institution of higher education, the School of Engineering in Porto Alegre, that was founded in 1896 and provided a major part of the cadre of technicians of state departments and agencies in the following decades, particularly of the state's Department of Public Works. In this paper the author (1 briefly discusses the political-institutional scenario in Southern Brazil during the transition from the 19th to the 20th century, then (2 sketches the process of organization of the School of Engineering in Porto Alegre, and finally (3 presents some aspects of the professional, administrative and political career of the School's original group of professors and its first graduates.

  6. Engineering and Design: Reliability Analysis of Navigation Lock and Dam Mechanical and Electrical Equipment

    National Research Council Canada - National Science Library

    Beranek, Dwight


    This engineer technical letter (ETL) provides guidance for assessing the reliability of mechanical and electrical systems of navigation locks and dams and for establishing an engineering basis for major rehabilitation investment decisions...

  7. A Novel bioreactor with mechanical stimulation for skeletal tissue engineering

    Directory of Open Access Journals (Sweden)

    M. Petrović


    Full Text Available The provision of mechanical stimulation is believed to be necessary for the functional assembly of skeletal tissues, which are normally exposed to a variety of biomechanical signals in vivo. In this paper, we present a development and validation of a novel bioreactor aimed for skeletal tissue engineering that provides dynamic compression and perfusion of cultivated tissues. Dynamic compression can be applied at frequencies up to 67.5 Hz and displacements down to 5 m thus suitable for the simulation of physiological conditions in a native cartilage tissue (0.1-1 Hz, 5-10 % strain. The bioreactor also includes a load sensor that was calibrated so to measure average loads imposed on tissue samples. Regimes of the mechanical stimulation and acquisition of load sensor outputs are directed by an automatic control system using applications developed within the LabView platform. In addition, perfusion of tissue samples at physiological velocities (10–100 m/s provides efficient mass transfer, as well as the possibilities to expose the cells to hydrodynamic shear and simulate the conditions in a native bone tissue. Thus, the novel bioreactor is suited for studies of the effects of different biomechanical signals on in vitro regeneration of skeletal tissues, as well as for the studies of newly formulated biomaterials and cell biomaterial interactions under in vivo-like settings.

  8. Dynamics and control of mechanical systems in offshore engineering

    CERN Document Server

    He, Wei; How, Bernard Voon Ee; Choo, Yoo Sang


    Dynamics and Control of Mechanical Systems in Offshore Engineering is a comprehensive treatment of marine mechanical systems (MMS) involved in processes of great importance such as oil drilling and mineral recovery. Ranging from nonlinear dynamic modeling and stability analysis of flexible riser systems, through advanced control design for an installation system with a single rigid payload attached by thrusters, to robust adaptive control for mooring systems, it is an authoritative reference on the dynamics and control of MMS. Readers will gain not only a complete picture of MMS at the system level, but also a better understanding of the technical considerations involved and solutions to problems that commonly arise from dealing with them. The text provides:                                                                                                                                 ...


    Human Engineering Inst., Cleveland, OH.


  10. A Systems Engineering Approach to Electro-Mechanical Actuator Diagnostic and Prognostic Development (United States)

    National Aeronautics and Space Administration — The authors have formulated a Comprehensive Systems Engineering approach to Electro-Mechanical Actuator (EMA) Prognostics and Health Management (PHM) system...

  11. Mechanical Design Engineering Enabler Project wheel and wheel drives (United States)

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


    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.

  12. Sex and Science: How Professor Gender Perpetuates the Gender Gap


    Scott E. Carrell; Marianne E. Page; West, James E.


    Why aren't there more women in science? Female college students are currently 37 percent less likely than males to obtain a bachelor's degree in science, technology, engineering, and math (STEM), and comprise only 25 percent of the STEM workforce. This paper begins to shed light on this issue by exploiting a unique dataset of college students who have been randomly assigned to professors over a wide variety of mandatory standardized courses. We focus on the role of professor gender. Our resul...

  13. H.E. Professor Dragoljub Popovic, Ambassador to Switzerland of the Federal Republic of Yugoslavia

    CERN Multimedia

    Patrice Loïez


    H. E. Professor Dragoljub Popovic, Ambassador of the Federal Republic of Yugoslavia to Switzerland, visiting the ATLAS cavern. From left to right: Dr Torsten Akesson, Deputy Spokesman of the ATLAS experiment; H. E. Professor Dragoljub Popovic; Mrs Simone Hajos, Project Engineer, LHC civil engineering; Dr Peter Adzic, Chairman of the Committee of the Republic of Serbia for relations with CERN.

  14. Professor Stewart's incredible numbers

    CERN Document Server

    Stewart, Ian


    Ian Stewart explores the astonishing properties of numbers from 1 to10 to zero and infinity, including one figure that, if you wrote it out, would span the universe. He looks at every kind of number you can think of - real, imaginary, rational, irrational, positive and negative - along with several you might have thought you couldn't think of. He explains the insights of the ancient mathematicians, shows how numbers have evolved through the ages, and reveals the way numerical theory enables everyday life. Under Professor Stewart's guidance you will discover the mathematics of codes,

  15. Morphologic and mechanical characteristics of engineered bovine arteries

    National Research Council Canada - National Science Library

    Niklason, Laura E; Abbott, William; Gao, Jinming; Klagges, Brian; Hirschi, Karen K; Ulubayram, Kezban; Conroy, Nancy; Jones, Rosemary; Vasanawala, Ami; Sanzgiri, Seema; Langer, Robert


    .... Engineered vessels were cultured from bovine aortic smooth muscle cells (SMCs) and endothelial cells that were seeded onto biodegradable polymer scaffolds and cultured under physiologically pulsatile conditions...

  16. First VBI Fellows Accepted From Virginia Tech's College Of Engineering


    Call, Neysa


    The Virginia Bioinformatics Institute (VBI) at Virginia Tech has awarded fellowships to four faculty in the College of Engineering--professor Peter Athanas, associate professor Amy Bell and assistant professor Mark Jones of electrical and computer engineering; and associate professor Joe Wang of aerospace and ocean engineering.

  17. A dual flow bioreactor with controlled mechanical stimulation for cartilage tissue engineering

    NARCIS (Netherlands)

    Spitters, Tim; Leijten, Jeroen Christianus Hermanus; Deus, F.D.; Costa, I.B.F.; van Apeldoorn, Aart A.; van Blitterswijk, Clemens; Karperien, Hermanus Bernardus Johannes


    In cartilage tissue engineering bioreactors can create a controlled environment to study chondrocyte behavior under mechanical stimulation or produce chondrogenic grafts of clinically relevant size. Here we present a novel bioreactor, which combines mechanical stimulation with a two compartment

  18. NASA GSFC Mechanical Engineering Latest Inputs for Verification Standards (GEVS) Updates (United States)

    Kaufman, Daniel


    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.

  19. Professor Alex Callinicos

    Directory of Open Access Journals (Sweden)

    Ali Saqer


    Full Text Available Professor Alex Callinicos is a renowned social theorist and scholar of international political economy. He conducts research on Marx and Marxism, European social and political theory, contemporary political philosophy, critical theory, historiography, and international political economy. His work provides invaluable insights on issues of race and racism, social justice, the Third Way, imperialism, austerity, and EU politics, among many other fascinating contemporary issues. Alex studied Philosophy, Politics, and Economics at Balliol College, Oxford, and Philosophy of Science at the London School of Economics before writing a DPhil on Marx's Capital, also at Balliol. He was a Junior Research Fellow in Contemporary Social Thought at St Peter's College, Oxford from 1979 to 1981, after which he taught social and political theory at the Department of Politics at the University of York until 2005, when he moved to King's College London. Alex is currently the Professor of European Studies at King's and editor of International Socialism. Alex has been an active contributor to the development of the movement for another globalization, participating in the World Social Forum and an animator of the European Social Forum. Among his best known books are The Revolutionary Ideas of Karl Marx (1983, Against Postmodernism (1990, Social Theory (1999, An Anti-Capitalist Manifesto (2003, The Resources of Critique (2006, Imperialism and Global Political Economy (2009. His most recent book is entitled Deciphering Capital: Marx’s Capital and its Destiny (2014.

  20. Mechanical behavior of materials engineering methods for deformation, fracture, and fatigue

    CERN Document Server

    Dowling, Norman E


    For upper-level undergraduate engineering courses in Mechanical Behavior of Materials. Mechanical Behavior of Materials, 4/e introduces the spectrum of mechanical behavior of materials, emphasizing practical engineering methods for testing structural materials to obtain their properties, and predicting their strength and life when used for machines, vehicles, and structures. With its logical treatment and ready-to-use format, it is ideal for upper-level undergraduate students who have completed elementary mechanics of materials courses.

  1. Embarked diagnosis applied to a mechanical system "diesel engine ...

    African Journals Online (AJOL)

    The implementation of OBD (on-board diagnostic) systems for diesel engines has become an unavoidable necessity. From the models described in the literature, the latest generation diesel engine models as well as defects affecting it were established. A board diagnostic system based on the use of fuzzy pattern ...

  2. Development of an integrated engine-hydro-mechanical transmission control algorithm for a tractor

    Directory of Open Access Journals (Sweden)

    Sunghyun Ahn


    Full Text Available This article presents an integrated engine-hydro-mechanical transmission control algorithm for a tractor considering the engine-hydro-mechanical transmission efficiency. First, the hydro-mechanical transmission efficiency was obtained by network analysis based on the hydrostatic unit efficiency constructed from the test. Using the hydro-mechanical transmission efficiency map and the thermal efficiency of the engine, an engine-hydro-mechanical transmission optimal operating line was obtained, which provides higher total system efficiency. Based on the optimal operating line, an integrated engine-hydro-mechanical transmission control algorithm was proposed, which provides higher total powertrain system efficiency. To evaluate the performance of the proposed control algorithm, an AMESim-MATLAB/Simulink-based co-simulator was developed. From the simulation results for the plow working, it was found that the integrated engine-hydro-mechanical transmission control provides improved fuel economy by 7.5% compared with the existing engine optimal operating line control. The performance of the integrated engine-hydro-mechanical transmission control was also validated using the test bench.

  3. Reducing barriers to energy efficiency in the German mechanical engineering sector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schleich, J.; Boede, U.


    This report describes the empirical research into barriers to energy efficiency in the German mechanical engineering (ME) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of four case studies of energy management in German companies in the ME sector. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the ME sector may be improved. The results of the study for the ME sector in Germany are summarised in this executive summary under the following headings: - Characterising the mechanical engineering sector; - Case studies of energy management in the German mechanical engineering sector; - Evidence of barriers in the German mechanical engineering sector; - The role of energy service companies in the mechanical engineering sector; - Policy implications. (orig.)

  4. Reducing barriers to energy efficiency in the German mechanical engineering sector. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Schleich, J.; Boede, U.


    This report describes the empirical research into barriers to energy efficiency in the German mechanical engineering (ME) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of four case studies of energy management in German companies in the ME sector. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the ME sector may be improved. The results of the study for the ME sector in Germany are summarised in this executive summary under the following headings: - Characterising the mechanical engineering sector; - Case studies of energy management in the German mechanical engineering sector; - Evidence of barriers in the German mechanical engineering sector; - The role of energy service companies in the mechanical engineering sector; - Policy implications. (orig.)

  5. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P


    This third volume completes the Work Mechanical Systems, Classical Models. The first two volumes dealt with particle dynamics and with discrete and continuous mechanical systems. The present volume studies analytical mechanics. Topics like Lagrangian and Hamiltonian mechanics, the Hamilton-Jacobi method, and a study of systems with separate variables are thoroughly discussed. Also included are variational principles and canonical transformations, integral invariants and exterior differential calculus, and particular attention is given to non-holonomic mechanical systems. The author explains in detail all important aspects of the science of mechanics, regarded as a natural science, and shows how they are useful in understanding important natural phenomena and solving problems of interest in applied and engineering sciences. Professor Teodorescu has spent more than fifty years as a Professor of Mechanics at the University of Bucharest and this book relies on the extensive literature on the subject as well as th...

  6. A Cloverleaf of Software Engineering

    DEFF Research Database (Denmark)

    Bjørner, Dines


    by senior academic staff. Professors of medicine daily perform specialized surgery and treatments at hospitals. Professors of architecture design new, daring buildings for industry, and professors of civil engineering head the engineering structural design of new, daring bridges. So we speculate what...

  7. Voorwoord: Professor Andrzej Borowski

    Directory of Open Access Journals (Sweden)

    Koch Jerzy


    Full Text Available Professor Andrzej Borowski from the Jagiellonian University, whose 70th anniversary we celebrate this year, is a very well known scholar and literature historian, specialised in Old Polish Literature (Middle Ages, Renaissance and Baroque - and with a background from Classical studies. A lesser known fact is that he also is a scholar active in the field of the Netherlandish (Dutch and Flemish literature and culture: as author of numerous books and articles about (South Netherlandish figures from the 16th and 17th century, as supervisor of numerous dissertations or habilitations in the field of the Netherlandish literature and as an inspiring personality in the field of the Netherlandish studies at Polish universities. He can indeed be seen as the Spiritus Litterarum Neerlandicorum in Poland.

  8. Study of nozzle deposit formation mechanism for direct injection gasoline engines; Chokufun gasoline engine yo nozzle no deposit seisei kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, M.; Saito, A. [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsushita, S. [Toyota Motor Corp., Aichi (Japan); Shibata, H. [Nippon Soken, Inc., Tokyo (Japan); Niwa, Y. [Denso Corp., Aichi (Japan)


    Nozzles in fuel injectors for direct injection gasoline engines are exposed to high temperature combustion gases and soot. In such a rigorous environment, it is a fear that fuel flow rate changes in injectors by deposit formation on nozzles. Fundamental factors of nozzle deposit formation were investigated through injector bench tests and engine dynamometer tests. Deposit formation processes were observed by SEM through engine dynamometer tests. The investigation results reveal nozzle deposit formation mechanism and how to suppress the deposit. 4 refs., 8 figs., 3 tabs.

  9. Comparative study on the mechanical mechanism of confined concrete supporting arches in underground engineering. (United States)

    Lv, Zhijin; Qin, Qian; Jiang, Bei; Luan, Yingcheng; Yu, Hengchang


    In order to solve the supporting problem in underground engineering with high stress, square steel confined concrete (SQCC) supporting method is adopted to enhance the control on surrounding rocks, and the control effect is remarkable. The commonly used cross section shapes of confined concrete arch are square and circular. At present, designers have no consensus on which kind is more proper. To search for the answer, this paper makes an analysis on the mechanical properties of the two shapes of the cross-sections. A full-scale indoor comparative test was carried out on the commonly used straight-wall semi-circular SQCC arch and circular steel confined concrete arch (CCC arch). This test is based on self-developed full-scale test system for confined concrete arch. Our research, combining with the numerical analysis, shows: (1) SQCC arch is consistent with CCC arch in the deformation and failure mode. The largest damages parts are at the legs of both of them. (2) The SQCC arch's bearing capability is 1286.9 kN, and the CCC arch's ultimate bearing capability is 1072.4kN. Thus, the SQCC arch's bearing capability is 1.2 times that of the CCC arch. (3) The arches are subjected to combined compression and bending, bending moment is the main reason for the arch failure. The section moment of inertia of SQCC arch is 1.26 times of that of CCC arch, and the former is better than the latter in bending performance. The ultimate bearing capacity is positively correlated with the size of the moment of inertia. Based on the above research, the engineering suggestions are as follows: (1) To improve the bearing capacity of the arch, the cross-sectional shape of the chamber should be optimized and the arch bearing mode changed accordingly. (2) The key damaged positions, such as the arch leg, should be reinforced, optimizing the state of force on the arch. SQCC arches should be used for supporting in underground engineering, which is under stronger influence of the bending moment and

  10. Fracture mechanics of piezoelectric and ferroelectric solids

    CERN Document Server

    Fang, Daining


    Fracture Mechanics of Piezoelectric and Ferroelectric Solids presents a systematic and comprehensive coverage of the fracture mechanics of piezoelectric/ferroelectric materials, which includes the theoretical analysis, numerical computations and experimental observations. The main emphasis is placed on the mechanics description of various crack problems such static, dynamic and interface fractures as well as the physical explanations for the mechanism of electrically induced fracture. The book is intended for postgraduate students, researchers and engineers in the fields of solid mechanics, applied physics, material science and mechanical engineering. Dr. Daining Fang is a professor at the School of Aerospace, Tsinghua University, China; Dr. Jinxi Liu is a professor at the Department of Engineering Mechanics, Shijiazhuang Railway Institute, China.

  11. Respiratory Mechanics


    Martin R. Miller


    Respiratory Mechanics by Theodore Wilson is a slim paperback volume (64 pages) describing three aspects of the way the lungs work: 1) pressure?volume relationships with regard to the lungs, 2) chest wall and muscles with regard to how the respiratory pump works, and 3) gas flow and transport. Relevant details about the author are missing, which I think is a loss. He is Emeritus Professor of Aerospace Engineering and Mechanics and this background and his expertise was a perfect fit for the inv...

  12. Mechanics of oriented electrospun nanofibrous scaffolds for annulus fibrosus tissue engineering. (United States)

    Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L


    Engineering a functional replacement for the annulus fibrosus (AF) of the intervertebral disc is contingent upon recapitulation of AF structure, composition, and mechanical properties. In this study, we propose a new paradigm for AF tissue engineering that focuses on the reconstitution of anatomic fiber architecture and uses constitutive modeling to evaluate construct function. A modified electrospinning technique was utilized to generate aligned nanofibrous polymer scaffolds for engineering the basic functional unit of the AF, a single lamella. Scaffolds were tested in uniaxial tension at multiple fiber orientations, demonstrating a nonlinear dependence of modulus on fiber angle that mimicked the nonlinearity and anisotropy of native AF. A homogenization model previously applied to native AF successfully described scaffold mechanical response, and parametric studies demonstrated that nonfibrillar matrix, along with fiber connectivity, are key contributors to tensile mechanics for engineered AF. We demonstrated that AF cells orient themselves along the aligned scaffolds and deposit matrix that contributes to construct mechanics under loading conditions relevant to the in vivo environment. The homogenization model was applied to cell-seeded constructs and provided quantitative measures for the evolution of matrix and interfibrillar interactions. Finally, the model demonstrated that at fiber angles of the AF (28 degrees -44 degrees ), engineered material behaved much like native tissue, suggesting that engineered constructs replicate the physiologic behavior of the single AF lamella. Constitutive modeling provides a powerful tool for analysis of engineered AF neo-tissue and native AF tissue alike, highlighting key mechanical design criteria for functional AF tissue engineering.

  13. A Comparison of the mechanical engineering and safety engineering student’s ICT attitudes at the Obuda University

    Directory of Open Access Journals (Sweden)

    Kiss Gabor


    Full Text Available Communication and technology are critical to education. However, using technology in education is not an easy task as communication barriers emerge. The aim of this research is to analyze the ICT attitudes from different faculties at the Obuda University that is between the mechanical engineering students and safety engineering students from the Donát Bánki Mechanical Safety Engineer Faculty. The students from these two groups will use different ICT tool at work after their graduation; the mechanical engineering students will work mostly with designer ICT tools, the safety engineering students will use security systems. It would be important to know whether instructors, when using ICT, have to follow different teaching methods and approaches in these two different groups or not. We measured the ICT attitude with a tool consisting of 23 items (Likert scaled. We worked with 361 students. The data analysis was performed with SPSS software using descriptive statistics and Mann-Whitney test. The results show both groups having the same positive ICT attitude however with one difference.

  14. Mechanical Engineering Department quarterly review, April--June 1978

    Energy Technology Data Exchange (ETDEWEB)

    Stone, R.G.; Bathgate, M.B. (eds.)


    The review is presented in sections on x-ray spectrograph development, sampling of gases in a post shot cavity, oil shale retort heat losses, development of an automated thermocouple, seismic engineering, testing fuel rod casks, and nuclear materials control. A separate abstract was prepared for each section. (JRD)

  15. Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering. (United States)

    Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won


    Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration-culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch.

  16. Automatic compression adjusting mechanism for internal combustion engines (United States)

    Akkerman, J. W. (Inventor)


    Means for controlling the compression pressure in an internal combustion engine having one or more cylinders and subject to widely varying power output requirements are provided. Received between each crank pin and connecting rod is an eccentric sleeve selectively capable of rotation about the crank pin and/or inside the rod and for latching with the rod to vary the effective length of the connecting rod and thereby the clearance volume of the engine. The eccentric normally rotates inside the connecting rod during the exhaust and intake strokes but a latching pawl carried by the eccentric is movable radially outwardly to latch the rod and eccentric together during the compression and power strokes. A control valve responds to intake manifold pressure to time the supply of hydraulic fluid to move the latch-pawl outwardly, varying the effective rod length to maintain a substantially optimum firing chamber pressure at all intake manifold pressures.

  17. Use of Concept Maps as an Assessment Tool in Mechanical Engineering Education (United States)

    Tembe, B. L.; Kamble, S. K.


    The purpose of this study to investigate, how third year mechanical engineering students are able to use their knowledge of concept maps in their study of the topic of "Introduction to the Internal Combustion Engines (IICE)". 41 students participated in this study. Firstly, the students were taught about concept maps and then asked to…

  18. Curriculum Development Based on the Big Picture Assessment of the Mechanical Engineering Program (United States)

    Sabri, Mohd Anas Mohd; Khamis, Nor Kamaliana; Tahir, Mohd Faizal Mat; Wahid, Zaliha; Kamal, Ahmad; Ihsan, Ariffin Mohd; Sulong, Abu Bakar; Abdullah, Shahrum


    One of the major concerns of the Engineering Accreditation Council (EAC) is the need for an effective monitoring and evaluation of program outcome domains that can be associated with courses taught under the Mechanical Engineering program. However, an effective monitoring method that can determine the results of each program outcome using Bloom's…

  19. Mechanisms of mechanosensing - mechanosensitive channels, function and re-engineering

    NARCIS (Netherlands)

    Kocer, Armagan


    Sensing and responding to mechanical stimuli is an ancient behavior and ubiquitous to all forms of life. One of its players 'mechanosensitive ion channels' are involved in processes from osmosensing in bacteria to pain in humans. However, the mechanism of mechanosensing is yet to be elucidated. This

  20. Prior Knowledge of Mechanics amongst First Year Engineering Students (United States)

    Clements, Dick


    In the last 25 years, A-level Mathematics syllabi have changed very considerably, introducing a broader range of application areas but reducing the previous emphasis on classical mechanics. This article describes a baseline survey undertaken to establish in detail the entry levels in mechanics for the cohort of students entering Engineering…

  1. Profiles of Automotive Suppliers Industries--Engineered Mechanical Components and Systems : Volume II, Appendices. (United States)


    The profile describes and analyzes that segment of the automotive supplier industry which provides engineered mechanical components/assemblies/systems to the prime auto manufacturers. It presents an overview of the role and structure of this industry...

  2. Profiles of Automotive Suppliers Industries--Engineered Mechanical Components and Systems : Volume I, Text. (United States)


    This profile describes and analyzes that segment of the automotive supplier industry which provides engineered mechanical components/assemblies/systems to the prime auto manufacturers. It presents an overview of the role and structure of this industr...

  3. A new bioreactor for the controlled application of complex mechanical stimuli for cartilage tissue engineering. (United States)

    Laganà, K; Moretti, M; Dubini, G; Raimondi, M T


    Mechanical stimuli have been shown to enhance chondrogenesis on both animal and human chondrocytes cultured in vitro. Different mechanical stimuli act simultaneously in vivo in cartilage tissue and their effects have been extensively studied in vitro, although often in a separated manner. A new bioreactor is described where different mechanical stimuli, i.e. shear stress and hydrostatic pressure, can be combined in different ways to study the mechanobiology of tissue engineered cartilage. Shear stress is imposed on cells by forcing the culture medium through the scaffolds, whereas a high hydrostatic pressure up to 15 MPa is generated by pressurizing the culture medium. Fluid-dynamic experimental tests have been performed and successful validation of the bioreactor has been carried out by dynamic culture of tissue-engineered cartilage constructs. The bioreactor system allows the investigation of the combined effects of different mechanical stimuli on the development of engineered cartilage, as well as other possible three-dimensional tissue-engineered constructs.

  4. Rise in accuracy of gas stream spectral analysis in mechanical engineering technology (United States)

    Mukhametzyanova, G. F.; Karikh, F. G.; Mukhametzyanov, I. R.


    The submitted method of rise in accuracy of gas stream spectral analysis in mechanical engineering technology by controlling the chemical composition of the exhaust gas streams by means of a six-jet electric-arc plasmatron is available.

  5. A dual flow bioreactor with controlled mechanical stimulation for cartilage tissue engineering


    Spitters, Tim; Leijten, Jeroen Christianus Hermanus; Deus, F.D.; Costa, I.B.F.; van Apeldoorn, Aart A.; van Blitterswijk, Clemens; Karperien, Hermanus Bernardus Johannes


    In cartilage tissue engineering bioreactors can create a controlled environment to study chondrocyte behavior under mechanical stimulation or produce chondrogenic grafts of clinically relevant size. Here we present a novel bioreactor, which combines mechanical stimulation with a two compartment system through which nutrients can be supplied solely by diffusion from opposite sides of a tissue engineered construct. This design is based on the hypothesis that creating gradients of nutrients, gro...

  6. Computational Quantum Mechanics for Materials Engineers The EMTO Method and Applications

    CERN Document Server

    Vitos, L


    Traditionally, new materials have been developed by empirically correlating their chemical composition, and the manufacturing processes used to form them, with their properties. Until recently, metallurgists have not used quantum theory for practical purposes. However, the development of modern density functional methods means that today, computational quantum mechanics can help engineers to identify and develop novel materials. Computational Quantum Mechanics for Materials Engineers describes new approaches to the modelling of disordered alloys that combine the most efficient quantum-level th

  7. Particular mechanism for continuously varying the compression ratio for an internal combustion engine (United States)

    Raţiu, S.; Cătălinoiu, R.; Alexa, V.; Miklos, I.; Cioată, V.


    Variable compression ratio (VCR) is a technology to adjust the compression ratio of an internal combustion engine while the engine is in operation. The paper proposes the presentation of a particular mechanism allowing the position of the top dead centre to be changed, while the position of the bottom dead centre remains fixed. The kinematics of the mechanism is studied and its trajectories are graphically represented for different positions of operation.

  8. A Model for Implementing Practical Design in the Education of Mechanical Engineers

    DEFF Research Database (Denmark)

    Hansen, Michael Rygaard; Mouritsen, Ole Ø.; Andersen, Torben Ole


    In this paper the PBL model used at Aalborg University in the mechanical engineering is shortly presented. A specific semester with a both theoretical and practical content that allow the students to is presented in detail. It is then used as a reference project for a subsequent discussion on three...... potential concerns with respect to the continued succes of problem and project based learning in mechanical and mechatronics engineering namely: individual assessment, bologna (student exchange) model and research based teaching....

  9. The Profession and the Professors. (United States)

    Dain, Phyllis


    Speculates on why graduate library schools have not, in the persons of their professors, produced theoretical leadership in Library Science. The ideals of professional ethical standards are contrasted with present practice. (RAA)

  10. Mechanical testing of hydrogels in cartilage tissue engineering: beyond the compressive modulus. (United States)

    Xiao, Yinghua; Friis, Elizabeth A; Gehrke, Stevin H; Detamore, Michael S


    Injuries to articular cartilage result in significant pain to patients and high medical costs. Unfortunately, cartilage repair strategies have been notoriously unreliable and/or complex. Biomaterial-based tissue-engineering strategies offer great promise, including the use of hydrogels to regenerate articular cartilage. Mechanical integrity is arguably the most important functional outcome of engineered cartilage, although mechanical testing of hydrogel-based constructs to date has focused primarily on deformation rather than failure properties. In addition to deformation testing, as the field of cartilage tissue engineering matures, this community will benefit from the addition of mechanical failure testing to outcome analyses, given the crucial clinical importance of the success of engineered constructs. However, there is a tremendous disparity in the methods used to evaluate mechanical failure of hydrogels and articular cartilage. In an effort to bridge the gap in mechanical testing methods of articular cartilage and hydrogels in cartilage regeneration, this review classifies the different toughness measurements for each. The urgency for identifying the common ground between these two disparate fields is high, as mechanical failure is ready to stand alongside stiffness as a functional design requirement. In comparing toughness measurement methods between hydrogels and cartilage, we recommend that the best option for evaluating mechanical failure of hydrogel-based constructs for cartilage tissue engineering may be tensile testing based on the single edge notch test, in part because specimen preparation is more straightforward and a related American Society for Testing and Materials (ASTM) standard can be adopted in a fracture mechanics context.

  11. Response to Professor Jean Guichard


    Kargulowa, Alicja; Czerkawska, Alicja; Kłodkowska, Joanna; Siarkiewicz, Elżbieta; Zielińska-Pękał, Daria; Zierkiewicz, Edyta


    The article recounts a discussion inspired by Professor Jean Guichard’s letter to Professor Alicja Kargulowa. Its participants – a group of female counsellogists – are engaged in an e-mail exchange that freely unfolds in the symbolic space of the on-line discourse. Embedded in their own specific research, their contributions depart from a conventional, structured line of argumentation, spontaneously, and at the same time insightfully, reflecting on various facets of purification and translati...

  12. Analysis of engineering cycles thermodynamics and fluid mechanics series

    CERN Document Server

    Haywood, R W


    Analysis of Engineering Cycles, Third Edition, deals principally with an analysis of the overall performance, under design conditions, of work-producing power plants and work-absorbing refrigerating and gas-liquefaction plants, most of which are either cyclic or closely related thereto. The book is organized into two parts, dealing first with simple power and refrigerating plants and then moving on to more complex plants. The principal modifications in this Third Edition arise from the updating and expansion of material on nuclear plants and on combined and binary plants. In view of increased

  13. Robert Beichner joins university as American Council of Education Fellow and visiting professor of physics


    Owczarski, Mark


    Robert Beichner, Alumni Distinguished Professor of Physics and director of the Science, Technology, Engineering and Mathematics Education Initiative at North Carolina State University, will spend the fall semester as the American Council of Education Fellow and visiting professor of physics in the College of Science.

  14. Engineering Mathematics I : Electromagnetics, Fluid Mechanics, Material Physics and Financial Engineering

    CERN Document Server

    Rančić, Milica


    This book highlights the latest advances in engineering mathematics with a main focus on the mathematical models, structures, concepts, problems and computational methods and algorithms most relevant for applications in modern technologies and engineering. In particular, it features mathematical methods and models of applied analysis, probability theory, differential equations, tensor analysis and computational modelling used in applications to important problems concerning electromagnetics, antenna technologies, fluid dynamics, material and continuum physics and financial engineering. The individual chapters cover both theory and applications, and include a wealth of figures, schemes, algorithms, tables and results of data analysis and simulation. Presenting new methods and results, reviews of cutting-edge research, and open problems for future research, they equip readers to develop new mathematical methods and concepts of their own, and to further compare and analyse the methods and results discussed. The ...

  15. The International Congress of Mechanical Engineering and Agricultural Sciences - CIIMCA 2013 (United States)

    Remolina-Millán, Aduljay; Hernández-Arroyo, Emil


    The organizing committee of The International Congress of Mechanical Engineering and Agricultural Sciences - CIIMCA 2013 - are pleased to present CIIMCA-2013: the first international conference focused on subjects of materials science, mechanical engineering and renewable energy organized by Mechanical Engineering Faculty of the ''Universidad Pontificia Bolivariana'' in Bucaramanga, Colombia. This conference aims to be a place to produce discussions on whole topics of the congress, between the scientists of Colombia and the world. We strongly believe that knowledge is fundamental to the development of our countries. For that reason this multidisciplinary conference is looking forward to integrate engineering, agricultural science and nanoscience and nanotechnology to produce a synergy of this area of knowledge and to achieve scientific and technological developments. Agriculture is a very important topic for our conference; in Colombia, agricultural science needs more attention from the scientific community and the government. In the Faculty of Mechanical Engineering we are beginning to work on these issues to produce knowledge and improve the conditions in our country. The CIIMCA conference is a great opportunity to create interpersonal relationships and networks between scientists around the world. The interaction between scientists is very important in the process of the construction of knowledge. The general chairman encourages and invites you to make friends, relationships and participate strongly in the symposia and all program activities. PhD Aduljay Remolina-Millán Principal Chairman, International Mechanical Engineering and Agricultural Sciences Congress - CIIMCA Msc Emil Hernández-Arroyo Principal Chairman, International Mechanical Engineering and Agricultural Sciences Congress - CIIMCA Conference photograph Conference photograph 'Universidad Pontificia Bolivariana seccional Bucaramanga' host of the first International Mechanical Engineering and


    DEFF Research Database (Denmark)

    Houbak, Niels; Klit, Peder


    of Manufacturing Engineering and Management and the Department of Mechanical Engineering deliver the technical courses for the Bachelor education (called Production and Engineering Design, P&E). In cooperation the two departments gives an introductory ‘Engineering Work’ course with much emphasis on the CDIO...... CDIO skills, group work, team work, report writing, communication etc. To a large extend this reduces the effort that we usually put directly into teaching those topics and allow us to put more emphasis on developing their technical skills and only make sure that their proficiency in personal......-up of new 3 years Bachelors and 2 years Masters Educations. Though special attention has been paid to not making too many drastic changes, a lot of effort has gone into a re-thinking of study plans, goals, possibilities and inappropriate situations. In the mechanical engineering area the Department...

  17. Efficiency and education in mechanical engineering.; Cultural anthropological perspective

    Energy Technology Data Exchange (ETDEWEB)

    Ushijima, F. [Kyushu Women`s Univ., Kitakyushu (Japan). Faculty of Literature


    Regarding cultural anthropology, interviews with and observations on a targeted social group are used as its central techniques and an ethnography is created using what has been obtained by its techniques as material. In the process of its description, culture and society are never separated for investigation. When mechanical technique is contained in this culture, it must be depicted vividly as a social creation. The author of this article points out that there has been a measure similar to efficiency as a criterion for comparing its merits and demerits, since the inception of mechanical technique, but as an industrial society progresses, that measure has been applied to a man. It was in 1920`s that efficiency improvement and aptitude tests were gradually adopted in Japan, but the essence of mechanization is not the introduction of mechanical power, but is the mechanization of a man and a person must be reborn to be a manhood capable for being measured by a measure called efficiency. Also the agricultural changes in Northern Kyushu are shown by its examination in a cultural anthropological perspective. 1 ref.

  18. A novel tissue-engineered trachea with a mechanical behavior similar to native trachea. (United States)

    Park, Jeong Hun; Hong, Jung Min; Ju, Young Min; Jung, Jin Woo; Kang, Hyun-Wook; Lee, Sang Jin; Yoo, James J; Kim, Sung Won; Kim, Soo Hyun; Cho, Dong-Woo


    A novel tissue-engineered trachea was developed with appropriate mechanical behavior and substantial regeneration of tracheal cartilage. We designed hollow bellows scaffold as a framework of a tissue-engineered trachea and demonstrated a reliable method for three-dimensional (3D) printing of monolithic bellows scaffold. We also functionalized gelatin sponge to allow sustained release of TGF-β1 for stimulating tracheal cartilage regeneration and confirmed that functionalized gelatin sponge induces cartilaginous tissue formation in vitro. A tissue-engineered trachea was then created by assembling chondrocytes-seeded functionalized gelatin sponges into the grooves of bellows scaffold and it showed very similar mechanical behavior to that of native trachea along with substantial regeneration of tracheal cartilage in vivo. The tissue-engineered trachea developed here represents a novel concept of tracheal substitute with appropriate mechanical behavior similar to native trachea for use in reconstruction of tracheal stenosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. A Blended Learning Approach to Teach Fluid Mechanics in Engineering (United States)

    Rahman, Ataur


    This paper presents a case study on the teaching and learning of fluid mechanics at the University of Western Sydney (UWS), Australia, by applying a blended learning approach (BLA). In the adopted BLA, various flexible learning materials have been made available to the students such as online recorded lectures, online recorded tutorials, hand…

  20. Intermediate eXperimental Vehicle Jettison Mechanism Engineering and Test (United States)

    Caldirola, L.; Schmid, B.


    The IXV (Intermediate eXperimental Vehicle) is a project of the European Space Agency that aims to develop an autonomous atmospheric re-entry system. A flight model has been launched on a Vega rocket on the 11th of February 2015 and after descending from an altitude of 420km splashed down in the Pacific Ocean. In the frame of this project RUAG space has developed the entire cold structure and the mechanisms able to eject the panels closing the parachute and floatation balloons bays. Panels ejection allows respectively parachutes deployment, reducing the IXV re-entry speed from Mach 1.5 to few meters per second just before the splash down, and buoyancy balloons inflation which let the vehicle float on the sea surface until arrival of the recovery ship.Such panels and the relevant mechanisms had to be designed not only to guarantee the correct external aerodynamic shape needed for the flight performance, but also to provide enough stiffness and strength to the IXV structure, being capable of transfer high shear loads.Moreover the floatation doors design enclosed both the hold down and release mechanism, based on a non- explosive separation nut, and the jettison springs, therefore particular attention had to be put to prevent any damage to the panel during the release which could have potentially led to jamming of the panel itself which jeopardise the floatation balloon deployment. The chosen design was therefore based on a spherical joint, so that shear load can be withstand and bending moment on the jettison-able panels limited at the same time.Test activities have been performed at mechanism level for environmental and preliminary functional qualification, subsystem level, including dummy panel jettison and full scale IXV drop test, to complete the functional qualification and system level test to close qualification campaign.The purpose of this paper is to present the mechanism design and the activities performed to qualify at component and sub-system level the


    Directory of Open Access Journals (Sweden)

    KIRALY Andrei


    Full Text Available Not a long time ago in “Eastern Economies”, especially in the mechanical design domain, words like costing or sustainability were practical neglected. Their importance is raising nowadays more and more and the author explains how it introduced them in mechanical engineers curriculum at the computer aided design discipline, because good habits must be implemented from young ages.

  2. Dynamic model of Stirling engine crank mechanism with connected electric generator

    Directory of Open Access Journals (Sweden)

    Vlach R.


    Full Text Available This paper treats of a numerical dynamic model of Stirling engine crank mechanism. The model is included in the complex model of combined heat and power unit. The unit is composed of the Stirling engine and of attached three-phase synchronous generator. This generator should start the Stirling engine in motor mode as well. It is necessary to combine the crank shaft dynamic model and the complete thermal model of Stirling engine for simulations and analyses of engine run. Our aim is to create a dynamics model which takes into account the parameters of crankshaft, piston rods, pistons, and attached generator. For unit working, the electro-mechanical behaviour of generator is also important. That is why we experimentally verified the parameters of generator. The measured characteristics are used in a complex model of heat and power unit. Moreover, it is also possible to determine the Stirling engine torque by the help of these electro-mechanical characteristics. These values can be used e. g. for determination of optimal engine working point or for unit control.

  3. Chemical Engineering Education Revisited. (United States)

    Theodore, Louis


    The opinion is presented that chemical engineering education seems to emphasize the professor's research and/or professional interests with little regard for the real needs of the student who intends to become a practicing engineer. (BB)

  4. Start Up Research Effort in Fluid Mechanics. Advanced Methods for Acoustic and Thrust Benefits for Aircraft Engine Nozzle (United States)

    White, Samuel G.; Gilinsky, Mikhail M.


    In accordance with the project plan for the report period in the proposal titled above, HU and FML teams investigated two sets of concepts for reduction of noise and improvement in efficiency for jet exhaust nozzles of aircraft engines and screws for mixers, fans, propellers and boats. The main achievements in the report period are: (a) Publication of the paper in the AIAA Journal, which described our concepts and some results. (b) The Award in the Civil Research and Development Foundation (CRDF) competition. This 2 year grant for Hampton University (HU) and Central AeroHydrodynamic Institute (TSAGI, Moscow, Russia) supports the research implementation under the current NASA FAR grant. (c) Selection for funding by NASA HQ review panel of the Partnership Awards Concept Paper. This two year grant also will support our current FAR grant. (d) Publication of a Mobius Strip concept in NASA Technical Briefs, June, 1996, and a great interest of many industrial companies in this invention. Successful experimental results with the Mobius shaped screw for mixers, which save more than 30% of the electric power by comparison with the standard screws. Creation of the scientific-popular video-film which can be used for commercial and educational purposes. (e) Organization work, joint meetings and discussions of the NASA LARC JNL Team and HU professors and administration for the solution of actual problems and effective work of the Fluid Mechanics Laboratory at Hampton University. In this report the main designs are enumerated. It also contains for both concept sets: (1) the statement of the problem for each design, some results, publications, inventions, patents, our vision for continuation of this research, and (2) present and expected problems in the future.

  5. Effects of mechanical loading on human mesenchymal stem cells for cartilage tissue engineering. (United States)

    Choi, Jane Ru; Yong, Kar Wey; Choi, Jean Yu


    Today, articular cartilage damage is a major health problem, affecting people of all ages. The existing conventional articular cartilage repair techniques, such as autologous chondrocyte implantation (ACI), microfracture, and mosaicplasty, have many shortcomings which negatively affect their clinical outcomes. Therefore, it is essential to develop an alternative and efficient articular repair technique that can address those shortcomings. Cartilage tissue engineering, which aims to create a tissue-engineered cartilage derived from human mesenchymal stem cells (MSCs), shows great promise for improving articular cartilage defect therapy. However, the use of tissue-engineered cartilage for the clinical therapy of articular cartilage defect still remains challenging. Despite the importance of mechanical loading to create a functional cartilage has been well demonstrated, the specific type of mechanical loading and its optimal loading regime is still under investigation. This review summarizes the most recent advances in the effects of mechanical loading on human MSCs. First, the existing conventional articular repair techniques and their shortcomings are highlighted. The important parameters for the evaluation of the tissue-engineered cartilage, including chondrogenic and hypertrophic differentiation of human MSCs are briefly discussed. The influence of mechanical loading on human MSCs is subsequently reviewed and the possible mechanotransduction signaling is highlighted. The development of non-hypertrophic chondrogenesis in response to the changing mechanical microenvironment will aid in the establishment of a tissue-engineered cartilage for efficient articular cartilage repair. © 2017 Wiley Periodicals, Inc.

  6. Introducing New Engineering Students to Mechanical Concepts through an “Energy Cube” Project


    Chance, Shannon; O'Flaherty, Micheal; Farrell, Fionnuala; Montague, Christopher


    The objective of this paper is to describe a problem based learning module, called the “Energy Cube”, offered by Dublin Institute of Technology that is designed to teach mechanical, building services and manufacturing engineering concepts to first year engineering students. The Energy Cube project gives students hands-on experience in areas ranging from heat transfer, lighting and energy efficiency to industrial and product design. In the Energy Cube, students design and construct (using c...

  7. Assessment of the Use of AutoCAD in Mechanical Engineering Technical Drawing Education


    Akyürek, Turgut


    AutoCAD is one of the widely used software tools in engineering education. In this study, ageneral assessment of AutoCAD for the usage in the mechanical engineering technical drawing educationis made. AutoCAD is assessed in terms of the fulfilment of the requirements defined for the main twotechnical drawing courses. AutoCAD is assessed in terms of its capability in meeting the requirements ofthe technical drawing courses.

  8. Il professor Mitja Skubic ottuagenario

    Directory of Open Access Journals (Sweden)

    Martina Ožbot


    Full Text Available Incredibile ma vero: il professor Mitja Skubic si trova, questa volta lui stesso, al centro dell’attenzione anziché essere il motore, il perno dell’attività. La ragione per questo attimo di respiro è il suo ottantesimo compleanno, a dire il vero passato già da tempo. È pressoché una contingenza aneddotica quella per cui il volume dedicatogli per l’occasione viene pubblicato così tardi: il professore ha continuato a tener d’occhio la nostra rivista ben dopo aver nominato i nuovi direttori tanto che sarebbe stato impossibile sorprenderlo con una miscellanea di contributi in suo onore.

  9. Professor@s e Eros Teachers and Eros

    Directory of Open Access Journals (Sweden)

    Deborah P. Britzman


    Full Text Available Professores/as são testemunhas do fantástico mundo da sexualidade. Esse artigo explora a centralidade de Eros para a educação e estabelece uma relação entre o desejo do/a professor/a e os acontecimentos emocionais da relação própria relação aluno/professor. Eu proponho que o aprendizado deva envolver nosso "eu" erótico, além das nossas fantasias. Mas esta perspectiva requer que professores/as considerem uma psicologia do amor como um caminho principal para a as situações emocionais de Eros. Na sua conclusão este trabalho sugere uma pedagogia que dê as boas vindas tanto à homossexualidade como a heterossexualidade como expressões humanas do amor.Teachers bear witness to the wondrous world of sexuality. This essay explores the centrality of Eros to education and links the teacher's desire to the emotional situation of the student/teacher relationship. I propose that learning involves our erotic selves and our fantasy life. But such a view requires that teachers consider a psychology of love as lending insight into the emotional situation of Eros. The paper concludes by suggesting a pedagogy that welcomes homosexuality and heterosexuality as human expressions of love.

  10. Mechanical Objects and the Engineering Learner: An Experimental Study of How the Presence of Objects Affects Students' Performance on Engineering Related Tasks (United States)

    Bairaktarova, Diana N.


    People display varying levels of interaction with the mechanical objects in their environment; engineers in particular as makers and users of these objects display a higher level of interaction with them. Investigating the educational potential of mechanical objects in stimulating and supporting learning in engineering is warranted by the fact…

  11. Engineering a Place for Women: A Study of How Departmental Climate Influences the Career Satisfaction of Female Mechanical Engineering Faculty Members (United States)

    Young, Monica J.


    The purpose of this mixed-methods study was to better understand how female mechanical engineering faculty members' career experiences in academia affect their satisfaction. Specifically, the research considered differences in satisfaction reported by female and male mechanical engineering faculty members in terms of: (a) departmental…

  12. Stability of the lumbar spine. A study in mechanical engineering. (United States)

    Bergmark, A


    From the mechanical point of view the spinal system is highly complex, containing a multitude of components, passive and active. In fact, even if the active components (the muscles) were exchanged by passive springs, the total number of elements considerably exceeds the minimum needed to maintain static equilibrium. In other words, the system is statically highly indeterminate. The particular role of the active components at static equilibrium is to enable a virtually arbitrary choice of posture, independent of the distribution and magnitude of the outer load albeit within physiological limits. Simultaneously this implies that ordinary procedures known from the analysis of mechanical systems with passive components cannot be applied. Hence the distribution of the forces over the different elements is not uniquely determined. Consequently nervous control of the force distribution over the muscles is needed, but little is known about how this achieved. This lack of knowledge implies great difficulties at numerical simulation of equilibrium states of the spinal system. These difficulties remain even if considerable reductions are made, such as the assumption that the thoracic cage behaves like a rigid body. A particularly useful point of view about the main principles of the force distributions appears to be the distinction between a local and a global system of muscles engaged in the equilibrium of the lumbar spine. The local system consists of muscles with insertion or origin (or both) at lumbar vertebrae, whereas the global system consists of muscles with origin on the pelvis and insertions on the thoracic cage. Given the posture of the lumbar spine, the force distribution over the local system appears to be essentially independent of the outer load of the body (though the force magnitudes are, of course, dependent on the magnitude of this load). Instead different distributions of the outer load on the body are met by different distributions of the forces in the

  13. Metric-driven Robust Design – Robustness Quantification of Complex Engineering Systems

    DEFF Research Database (Denmark)

    Göhler, Simon Moritz


    This PhD dissertation was carried out at the Technical University of Denmark in the Department of Mechanical Engineering and has been supervised by Associate Professor Anders Ivarsson and co-supervised by Professor Jesper Schramm. The project has been a part of the RADIADE project funded by the D......This PhD dissertation was carried out at the Technical University of Denmark in the Department of Mechanical Engineering and has been supervised by Associate Professor Anders Ivarsson and co-supervised by Professor Jesper Schramm. The project has been a part of the RADIADE project funded...... by the Danish Council for Strategic Research. Other supporters of the project have been MAN Diesel & Turbo A/S, DTU Mechanical Engineering, DTU Chemical Engineering, Sandia National Laboratories USA, Norwegian University of Science & Technology (NTNU) and University of Nottingham, Malaysia Campus....... The continuing stringency of emission regulations for marine diesel engines forces a deeper understanding of the complex physical processes occurring inside the engine cylinder. A deeper understanding can lead to higher accuracy of predictive numerical models, thereby enabling evaluation of multiple engine...

  14. The main problems in the mechanical engineering sector and some possible directions of their solution (United States)

    Strizhakova, E.


    The article shows the problems of the sector of mechanical engineering in the industrial system in Russia. The author's method of estimating the relative level of risk and the method of determining the de-industrialization degree of the sector based on the aggregated level of adaptability are given. According to them we have analysed the key indicators, such as basic, developed and advanced technologies, and investments in an old or new technology of industrial sectors. The main directions of the impact of industrial policy allowing a change in the current situation in mechanical engineering are given. The results can be applied in practice in formation of directions and actual control actions to improve the overall efficiency of mechanical engineering industry.

  15. Robot-based Learning : Toward Cultivation of Information Technology Skills for Mechanical Engineering Students (United States)

    Hanajima, Naohiko; Yamashita, Mitsuhisa; Kazama, Toshiharu; Yuasa, Tomonori; Niida, Yoichi; Aizu, Yoshihisa; Hikita, Hiromitsu

    Today there is increasing development of products in which embedded microprocessors are installed in a wide variety of industrial fields including mechanical industries. Mechanical engineers will be asked to develop such embedded systems in the future. To educate mechanical engineering students who possess information technology skills, for five years we have offered practical classes in which the students build a mobile robot with an embedded microprocessor and compete in a robot-triathlon race. The students have an incentive to program their robot to finish the race. We call this style of learning “robot-based learning.” In this paper, we discuss the efficiency of and problems in our practical classes as derived from information gained in surveys. In addition, we verify how the engineering design abilities of the students are improved through their participation in these classes.

  16. Crystal Engineering for Mechanical Strength at Nano-Scale Dimensions

    Directory of Open Access Journals (Sweden)

    Ronald W. Armstrong


    Full Text Available The mechanical strengths of nano-scale individual crystal or nanopolycrystalline metals, and other dimensionally-related materials are increased by an order of magnitude or more as compared to those values measured at conventional crystal or polycrystal grain dimensions. An explanation for the result is attributed to the constraint provided at the surface of the crystals or, more importantly, at interfacial boundaries within or between crystals. The effect is most often described in terms either of two size dependencies: an inverse dependence on crystal size because of single dislocation behavior or, within a polycrystalline material, in terms of a reciprocal square root of grain size dependence, designated as a Hall-Petch relationship for the researchers first pointing to the effect for steel and who provided an enduring dislocation pile-up interpretation for the relationship. The current report provides an updated description of such strength properties for iron and steel materials, and describes applications of the relationship to a wider range of materials, including non-ferrous metals, nano-twinned, polyphase, and composite materials. At limiting small nm grain sizes, there is a generally minor strength reversal that is accompanied by an additional order-of-magnitude elevation of an increased strength dependence on deformation rate, thus giving an important emphasis to the strain rate sensitivity property of materials at nano-scale dimensions.

  17. Effect of a mechanical stimulation bioreactor on tissue engineered, scaffold-free cartilage. (United States)

    Tran, Scott C; Cooley, Avery J; Elder, Steven H


    Achieving sufficient functional properties prior to implantation remains a significant challenge for the development of tissue engineered cartilage. Many studies have shown chondrocytes respond well to various mechanical stimuli, resulting in the development of bioreactors capable of transmitting forces to articular cartilage in vitro. In this study, we describe the production of sizeable, tissue engineered cartilage using a novel scaffold-free approach, and determine the effect of perfusion and mechanical stimulation from a C9-x Cartigen bioreactor on the properties of the tissue engineered cartilage. We created sizable tissue engineered cartilage from porcine chondrocytes using a scaffold-free approach by centrifuging a high-density chondrocyte cell-suspension onto an agarose layer in a 50 mL tube. The gross and histological appearances, biochemical content, and mechanical properties of constructs cultured in the bioreactor for 4 weeks were compared to constructs cultured statically. Mechanical properties were determined from unconfined uniaxial compression tests. Constructs cultured in the bioreactor exhibited an increase in total GAG content, equilibrium compressive modulus, and dynamic modulus versus static constructs. Our study demonstrates the C9-x CartiGen bioreactor is able to enhance the biomechanical and biochemical properties of scaffold-free tissue engineered cartilage; however, no additional enhancement was seen between loaded and perfused groups. Copyright © 2011 Wiley Periodicals, Inc.


    Directory of Open Access Journals (Sweden)

    N.A. Malyh


    Full Text Available The experience of FGUP PO "Uralvagonzavod" development is shown in the article, the analysis of mechanical engineering development in our country on modern stage is given. The authors’ approach upon the possibility, necessity and inevitability of a single right perspective decision of such economical problem in short period by the native financial, scientific-technical and people resources of Russia is proven. The position of seeing defensive enterprises as modern integrated scientific-manufacturing complexes, which are a real basis for creation of qualitatively new technique and technology of mechanical engineering and other country’s industry sectors.

  19. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P


    This second volume of Mechanical Systems, Classical Models, deals with the dynamics of systems consisting of discrete particles as well as continuous systems. While differences between these models are highlighted, the generality of the proofs and corresponding computations yields results that are expressed in a common form for both discrete and continuous systems. The author explains in detail all important aspects of the science of mechanics, regarded as a natural science, and shows how they are useful in understanding important natural phenomena and solving problems of interest in applied and engineering sciences. A large variety of problems are analyzed, from the traditional to more recent ones, such as the dynamics of rigid solids with variable mass. Professor Teodorescu has spent more that fifty years as a Professor of Mechanics at the University of Bucharest and this book relies on the extensive literature on the subject as well as the author's original contributions. Audience: students and researchers...

  20. Mechanical stretching for tissue engineering: two-dimensional and three-dimensional constructs. (United States)

    Riehl, Brandon D; Park, Jae-Hong; Kwon, Il Keun; Lim, Jung Yul


    Mechanical cell stretching may be an attractive strategy for the tissue engineering of mechanically functional tissues. It has been demonstrated that cell growth and differentiation can be guided by cell stretch with minimal help from soluble factors and engineered tissues that are mechanically stretched in bioreactors may have superior organization, functionality, and strength compared with unstretched counterparts. This review explores recent studies on cell stretching in both two-dimensional (2D) and three-dimensional (3D) setups focusing on the applications of stretch stimulation as a tool for controlling cell orientation, growth, gene expression, lineage commitment, and differentiation and for achieving successful tissue engineering of mechanically functional tissues, including cardiac, muscle, vasculature, ligament, tendon, bone, and so on. Custom stretching devices and lab-specific mechanical bioreactors are described with a discussion on capabilities and limitations. While stretch mechanotransduction pathways have been examined using 2D stretch, studying such pathways in physiologically relevant 3D environments may be required to understand how cells direct tissue development under stretch. Cell stretch study using 3D milieus may also help to develop tissue-specific stretch regimens optimized with biochemical feedback, which once developed will provide optimal tissue engineering protocols.

  1. Professors of the New Economy. (United States)

    Wilson, Robin


    Profiles four professors who epitomize the increasing influence of academe on new technology-driven Internet business: a start-up maven, Steven Kaplan; a social psychologist, Michael Ray; a cyberlawyer, David Post; and an e-commerce expert, Andrew B. Whinston. (DB)

  2. Advances in Application of Mechanical Stimuli in Bioreactors for Cartilage Tissue Engineering. (United States)

    Li, Ke; Zhang, Chunqiu; Qiu, Lulu; Gao, Lilan; Zhang, Xizheng


    Articular cartilage (AC) is the weight-bearing tissue in diarthroses. It lacks the capacity for self-healing once there are injuries or diseases due to its avascularity. With the development of tissue engineering, repairing cartilage defects through transplantation of engineered cartilage that closely matches properties of native cartilage has become a new option for curing cartilage diseases. The main hurdle for clinical application of engineered cartilage is how to develop functional cartilage constructs for mass production in a credible way. Recently, impressive hyaline cartilage that may have the potential to provide capabilities for treating large cartilage lesions in the future has been produced in laboratories. The key to functional cartilage construction in vitro is to identify appropriate mechanical stimuli. First, they should ensure the function of metabolism because mechanical stimuli play the role of blood vessels in the metabolism of AC, for example, acquiring nutrition and removing wastes. Second, they should mimic the movement of synovial joints and produce phenotypically correct tissues to achieve the adaptive development between the micro- and macrostructure and function. In this article, we divide mechanical stimuli into three types according to forces transmitted by different media in bioreactors, namely forces transmitted through the liquid medium, solid medium, or other media, then we review and summarize the research status of bioreactors for cartilage tissue engineering (CTE), mainly focusing on the effects of diverse mechanical stimuli on engineered cartilage. Based on current researches, there are several motion patterns in knee joints; but compression, tension, shear, fluid shear, or hydrostatic pressure each only partially reflects the mechanical condition in vivo. In this study, we propose that rolling-sliding-compression load consists of various stimuli that will represent better mechanical environment in CTE. In addition, engineers

  3. Microfabrication of a platform to measure and manipulate the mechanics of engineered microtissues. (United States)

    Ramade, Alexandre; Legant, Wesley R; Picart, Catherine; Chen, Christopher S; Boudou, Thomas


    Engineered tissues can be used to understand fundamental features of biology, develop organotypic in vitro model systems, and as engineered tissue constructs for replacing damaged tissue in vivo. However, a key limitation is an inability to test the wide range of parameters that might impact the engineered tissue in a high-throughput manner and in an environment that mimics the three-dimensional (3D) native architecture. We developed a microfabricated platform to generate arrays of microtissues embedded within 3D micropatterned matrices. Microcantilevers simultaneously constrain microtissue formation and report forces generated by the microtissues in real time, opening the possibility to use high-throughput, low-volume screening for studies on engineered tissues. Thanks to the micrometer scale of the microtissues, this platform is also suitable for high-throughput monitoring of drug-induced effect on architecture and contractility in engineered tissues. Moreover, independent variations of the mechanical stiffness of the cantilevers and collagen matrix allow the measurement and manipulation of the mechanics of the microtissues. Thus, our approach will likely provide valuable opportunities to elucidate how biomechanical, electrical, biochemical, and genetic/epigenetic cues modulate the formation and maturation of 3D engineered tissues. In this chapter, we describe the microfabrication, preparation, and experimental use of such microfabricated tissue gauges. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. An engineering approach to dry friction behaviour of numerous engineering plastics with respect to the mechanical properties

    Directory of Open Access Journals (Sweden)

    G. Kalacska


    Full Text Available Twenty-one different commercial-grade engineering polymers, including virgin and composite types, were selected for testing, based on mechanical engineering practices. Three groups were formed according to typical applications: 1 Sliding machine element materials; 2 Mechanically load-carrying machine element materials that are often subjected to friction and wear effects; and 3 Additional two amorphous materials used as chemically resistant materials that have rare sliding load properties. The friction running-in state was tested using a dynamic pin-on-plate test rig. During steady-state friction tests, two pv regimes (0.8 and 2 MPa"ms–1 were analysed by a pin-on-disc test system. Based on the measured forces on ground structural steel, surface friction coefficients were calculated and analysed with respect to the mechanical effects of friction. The friction results were evaluated by the measured mechanical properties: yield stress, Shore D hardness, Young’s modulus and elongation at the break. The three material groups exhibited different trends in friction with respect to changing mechanical properties. Linear (with varying positive and negative slopes, logarithmic and exponential relationships were observed, and occasionally there were no effects observed. At steady-state friction, the elongation at the break had less effect on the friction coefficients. The dynamic sliding model, which correlates better to real machine element applications, showed that increasing hardness and yield stress decreases friction. During steady-state friction, an increase in pv regime often changed the sign of the linear relationship between the material property and the friction, which agrees with the frictional theory of polymer/steel sliding pairs.

  5. Mechatronics: the future of mechanical engineering; past, present, and a vision for the future (United States)

    Ramasubramanian, M. K.


    Mechatronics is the synergistic integration of precision mechanical engineering, electronics, computational hardware and software in the design of products and processes. Mechatronics, the term coined in Japan in the '70s, has evolved to symbolize what mechanical design engineers do today worldwide. The revolutionary introduction of the microprocessor (or microcontroller) in the early '80s and ever increasing performance-cost ratio has changed the paradigm of mechanical design forever, and has broadened the original definition of mechatronics to include intelligent control and autonomous decision-making. Today, increasing number of new products is being developed at the intersection between traditional disciplines of Engineering, and Computer and Material Sciences. New developments in these traditional disciplines are being absorbed into mechatronics design at an ever-increasing pace. In this paper, a brief history of mechatronics, and several examples of this rapid adaptation of technologies into product design is presented. With the ongoing information technology revolution, especially in wireless communication, smart sensors design (enabled by MEMS technology), and embedded systems engineering, mechatronics design is going through another step change in capabilities and scope. The implications of these developments in mechatronics design in the near future are discussed. Finally, deficiencies in our engineering curriculum to address the needs of the industry to cope up with these rapid changes, and proposed remedies, will also be discussed.

  6. Multi-scale mechanical characterization of scaffolds for heart valve tissue engineering. (United States)

    Argento, G; Simonet, M; Oomens, C W J; Baaijens, F P T


    Electrospinning is a promising technology to produce scaffolds for cardiovascular tissue engineering. Each electrospun scaffold is characterized by a complex micro-scale structure that is responsible for its macroscopic mechanical behavior. In this study, we focus on the development and the validation of a computational micro-scale model that takes into account the structural features of the electrospun material, and is suitable for studying the multi-scale scaffold mechanics. We show that the computational tool developed is able to describe and predict the mechanical behavior of electrospun scaffolds characterized by different microstructures. Moreover, we explore the global mechanical properties of valve-shaped scaffolds with different microstructural features, and compare the deformation of these scaffolds when submitted to diastolic pressures with a tissue engineered and a native valve. It is shown that a pronounced degree of anisotropy is necessary to reproduce the deformation patterns observed in the native heart valve. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    CERN Document Server

    Bertsche, Bernd


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

  8. NOTES ON CONTRIBUTORS H. Johnson Nenty, Professor ...

    African Journals Online (AJOL)


    NOTES ON CONTRIBUTORS. H. Johnson Nenty, Professor, Educational Research, Measurement and Evaluation, Department of Educational. Foundations, University of Botswana Idowu Biao, Professor of Lifelong learning, Department of Adult Education,. University of Botswana. Cletus K. Mbowura, Lecturer, Department of ...

  9. Cam Design Projects in an Advanced CAD Course for Mechanical Engineers (United States)

    Ault, H. K.


    The objective of this paper is to present applications of solid modeling aimed at modeling of complex geometries such as splines and blended surfaces in advanced CAD courses. These projects, in CAD-based Mechanical Engineering courses, are focused on the use of the CAD system to solve design problems for applications in machine design, namely the…

  10. Student Motivation in Low-Stakes Assessment Contexts: An Exploratory Analysis in Engineering Mechanics (United States)

    Musekamp, Frank; Pearce, Jacob


    The goal of this paper is to examine the relationship of student motivation and achievement in low-stakes assessment contexts. Using Pearson product-moment correlations and hierarchical linear regression modelling to analyse data on 794 tertiary students who undertook a low-stakes engineering mechanics assessment (along with the questionnaire of…

  11. Identifying and Investigating Difficult Concepts in Engineering Mechanics and Electric Circuits. Research Brief (United States)

    Streveler, Ruth; Geist, Monica; Ammerman, Ravel; Sulzbach, Candace; Miller, Ronald; Olds, Barbara; Nelson, Mary


    This study extends ongoing work to identify difficult concepts in thermal and transport science and measure students' understanding of those concepts via a concept inventory. Two research questions provided the focal point: "What important concepts in electric circuits and engineering mechanics do students find difficult to learn?" and…

  12. Preliminary Assessment of the Emporium Model in a Redesigned Engineering Mechanics Course (United States)

    Rais-Rohani, Masoud; Walters, Andrew


    A lecture-based engineering mechanics course (Statics) is redesigned using the Emporium model. Whereas students study the material outside of class via asynchronous online delivery of the content and instructional videos, they do all the other activities (e.g., assignments, tests) either individually or in groups inside the classroom. Computer-…

  13. How Students Use Their Knowledge of Calculus in an Engineering Mechanics Course. (United States)

    Roddick, Cheryl Stitt

    This study investigated students' conceptual and procedural understanding of calculus within the context of an engineering mechanics course. Four traditional calculus students were compared with three students from one of the calculus reform projects, Calculus & Mathematica. Task-based interviews were conducted with each participant throughout…

  14. Marine Engine Mechanic. Apprenticeship Training Standards = Mecanicien de bateaux a moteur. Normes de formation en apprentissage. (United States)

    Ontario Ministry of Skills Development, Toronto.

    These training standards for marine engine mechanics are intended to be used by apprentice/trainees, instructors, and companies in Ontario, Canada, as a blueprint for training or as a prerequisite for accreditation/certification. The training standards identify skills required for this occupation and its related training program. They are designed…

  15. Engine Performance (Section C: Emission Control Systems). Auto Mechanics Curriculum Guide. Module 3. Instructor's Guide. (United States)

    Rains, Larry

    This engine performance (emission control systems) module is one of a series of competency-based modules in the Missouri Auto Mechanics Curriculum Guide. Topics of this module's five units are: positive crankcase ventilation (PCV) and evaporative emission control systems; exhaust gas recirculation (EGR); air injection and catalytic converters;…

  16. Engine Tune-up Service. Unit 6: Emission Control Systems. Student Guide. Automotive Mechanics Curriculum. (United States)

    Bacon, E. Miles

    This student guide is for Unit 6, Emission Control Systems, in the Engine Tune-Up Service portion of the Automotive Mechanics Curriculum. It deals with inspecting, testing, and servicing an emission control system. A companion review exercise book and posttests are available separately as CE 031 221-222. An introduction tells how this unit fits…

  17. Assessing Cognitive Load Theory to Improve Student Learning for Mechanical Engineers (United States)

    Impelluso, Thomas J.


    A computer programming class for students of mechanical engineering was redesigned and assessed: Cognitive Load Theory was used to redesign the content; online technologies were used to redesign the delivery. Student learning improved and the dropout rate was reduced. This article reports on both attitudinal and objective assessment: comparing…

  18. The Faculty Perspective on Holistic and Systems Thinking in American and Australian Mechanical Engineering Programmes (United States)

    Kellam, N. N.; Maher, M. A.; Peters, W. H.


    This research effort examined current mechanical engineering educational programmes in America and Australia to determine the degree of holistic, systems thinking of each programme. Faculty from ten American universities and ten Australian universities participated in online surveys and interviews. Resulting data analysis and interpretation…

  19. Effectiveness of Using a Video Game to Teach a Course in Mechanical Engineering (United States)

    Coller, B. D.; Scott, M. J.


    One of the core courses in the undergraduate mechanical engineering curriculum has been completely redesigned. In the new numerical methods course, all assignments and learning experiences are built around a video/computer game. Students are given the task of writing computer programs to race a simulated car around a track. In doing so, students…

  20. PREFACE: 3rd International Conference of Mechanical Engineering Research (ICMER 2015) (United States)

    Mamat, Riazalman; Rahman, Mustafizur; Mohd. Zuki Nik Mohamed, Nik; Che Ghani, Saiful Anwar; Harun, Wan Sharuzi Wan


    The 3rd ICMER2015 is the continuity of the NCMER2010. The year 2010 represents a significant milestone in the history for Faculty of Mechanical Engineering, Universiti Malaysia Pahang (UMP) Malaysia with the organization of the first and second national level conferences (1st and 2nd NCMER) at UMP on May 26-27 and Dec 3-4 2010. The Faculty then changed the name from National Conference on Mechanical Engineering Research (NCMER) to International Conference on Mechanical Engineering Research (ICMER) in 2011 and this year, 2015 is our 3rd ICMER. These proceedings contain the selected scientific manuscripts submitted to the conference. It is with great pleasure to welcome you to the "International Conference on Mechanical Engineering Research (ICMER2015)" that is held at Zenith Hotel, Kuantan, Malaysia. The call for papers attracted submissions of over two hundred abstracts from twelve different countries including Japan, Iran, China, Kuwait, Indonesia, Norway, Philippines, Morocco, Germany, UAE and more. The scientific papers published in these proceedings have been revised and approved by the technical committee of the 3rd ICMER2015. All of the papers exhibit clear, concise, and precise expositions that appeal to a broad international readership interested in mechanical engineering, combustion, metallurgy, materials science as well as in manufacturing and biomechanics. The reports present original ideas or results of general significance supported by clear reasoning and compelling evidence, and employ methods, theories and practices relevant to the research. The authors clearly state the questions and the significance of their research to theory and practice, describe how the research contributes to new knowledge, and provide tables and figures that meaningfully add to the narrative. In this edition of ICMER representatives attending are from academia, industry, governmental and private sectors. The plenary and invited speakers will present, discuss, promote and

  1. ICT Use by Journalism Professors in Colombia (United States)

    Hung, Elias Said


    This article analyses how journalism professors at Colombian universities use information and communications technologies (ICT) in their teaching. Survey data was obtained during the first trimester of 2009 from 63 professors in journalism departments and from a total of 865 professors who are affiliated with journalism departments at 29…

  2. Erratum: Professor J. H. S. Gear

    African Journals Online (AJOL)

    s short of their. Lesley, a nd their amily a proper Wake on 15 November 1994. Erratum: Professor J. H. S. Gear. The name of Professor B. D. Schoub, Director of the. National Institute for Virology, was inadvertently omitted as the author of the obituary of Professor J. H. S. Gear published in the September 1994 SAMJ. Books.

  3. Comparison of automatically generated reaction mechanism for oxidation of simple hydrocarbons in IC engine

    Directory of Open Access Journals (Sweden)

    Muhammad Mansha


    Full Text Available In this work, a detailed kinetic reaction mechanism, consisting of 208 reactions and 79 species, has been developed todescribe the oxidation of simple hydrocarbon fuel (natural gas in IC engine. The performance of the proposed mechanismis tested using simulation, tool CHEMKIN 4.1.1, and experimental measurements. The simulation results of the proposedreaction scheme were compared with those of reference mechanisms (GRI v3.0 and Konnov 0.5 version as well as experimentaldata. Based upon simulation results, it can be concluded that the proposed mechanism shows good concordanceswith GR I3.0 mechanism especially in the prediction of temperature, pressure, and major product species (H2O, CO2 profilesat stoichiometric conditions (= 1.0. Although, there are some discrepancies among each predicted profile, the proposeddetailed mechanism is good to describe the oxidation of natural gas in IC engine. The experimental data also showed favorableresults for prediction of major product species (CO2, H2O & CO at various engine operating speeds in idle mode.

  4. The history of theoretical, material and computational mechanics mathematics meets mechanics and engineering

    CERN Document Server


    This collection of 23 articles is the output of lectures in special sessions on “The History of Theoretical, Material and Computational Mechanics” within the yearly conferences of the GAMM in the years 2010 in Karlsruhe, Germany, 2011 in Graz, Austria, and in 2012 in Darmstadt, Germany; GAMM is the “Association for Applied Mathematics and Mechanics”, founded in 1922 by Ludwig Prandtl and Richard von Mises. The contributions in this volume discuss different aspects of mechanics. They are related to solid and fluid mechanics in general and to specific problems in these areas including the development of numerical solution techniques. In the first part the origins and developments of conservation principles in mechanics and related variational methods are treated together with challenging applications from the 17th to the 20th century. Part II treats general and more specific aspects of material theories of deforming solid continua and porous soils. and Part III presents important theoretical and enginee...

  5. Design considerations and challenges for mechanical stretch bioreactors in tissue engineering. (United States)

    Lei, Ying; Ferdous, Zannatul


    With the increase in average life expectancy and growing aging population, lack of functional grafts for replacement surgeries has become a severe problem. Engineered tissues are a promising alternative to this problem because they can mimic the physiological function of the native tissues and be cultured on demand. Cyclic stretch is important for developing many engineered tissues such as hearts, heart valves, muscles, and bones. Thus a variety of stretch bioreactors and corresponding scaffolds have been designed and tested to study the underlying mechanism of tissue formation and to optimize the mechanical conditions applied to the engineered tissues. In this review, we look at various designs of stretch bioreactors and common scaffolds and offer insights for future improvements in tissue engineering applications. First, we summarize the requirements and common configuration of stretch bioreactors. Next, we present the features of different actuating and motion transforming systems and their applications. Since most bioreactors must measure detailed distributions of loads and deformations on engineered tissues, techniques with high accuracy, precision, and frequency have been developed. We also cover the key points in designing culture chambers, nutrition exchanging systems, and regimens used for specific tissues. Since scaffolds are essential for providing biophysical microenvironments for residing cells, we discuss materials and technologies used in fabricating scaffolds to mimic anisotropic native tissues, including decellularized tissues, hydrogels, biocompatible polymers, electrospinning, and 3D bioprinting techniques. Finally, we present the potential future directions for improving stretch bioreactors and scaffolds. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:543-553, 2016. © 2016 American Institute of Chemical Engineers.

  6. Gelatin Scaffolds with Controlled Pore Structure and Mechanical Property for Cartilage Tissue Engineering. (United States)

    Chen, Shangwu; Zhang, Qin; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping


    Engineering of cartilage tissue in vitro using porous scaffolds and chondrocytes provides a promising approach for cartilage repair. However, nonuniform cell distribution and heterogeneous tissue formation together with weak mechanical property of in vitro engineered cartilage limit their clinical application. In this study, gelatin porous scaffolds with homogeneous and open pores were prepared using ice particulates and freeze-drying. The scaffolds were used to culture bovine articular chondrocytes to engineer cartilage tissue in vitro. The pore structure and mechanical property of gelatin scaffolds could be well controlled by using different ratios of ice particulates to gelatin solution and different concentrations of gelatin. Gelatin scaffolds prepared from ≥70% ice particulates enabled homogeneous seeding of bovine articular chondrocytes throughout the scaffolds and formation of homogeneous cartilage extracellular matrix. While soft scaffolds underwent cellular contraction, stiff scaffolds resisted cellular contraction and had significantly higher cell proliferation and synthesis of sulfated glycosaminoglycan. Compared with the gelatin scaffolds prepared without ice particulates, the gelatin scaffolds prepared with ice particulates facilitated formation of homogeneous cartilage tissue with significantly higher compressive modulus. The gelatin scaffolds with highly open pore structure and good mechanical property can be used to improve in vitro tissue-engineered cartilage.

  7. Mathematical Modeling of Uniaxial Mechanical Properties of Collagen Gel Scaffolds for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Ramiro M. Irastorza


    Full Text Available Small diameter tissue-engineered arteries improve their mechanical and functional properties when they are mechanically stimulated. Applying a suitable stress and/or strain with or without a cycle to the scaffolds and cells during the culturing process resides in our ability to generate a suitable mechanical model. Collagen gel is one of the most used scaffolds in vascular tissue engineering, mainly because it is the principal constituent of the extracellular matrix for vascular cells in human. The mechanical modeling of such a material is not a trivial task, mainly for its viscoelastic nature. Computational and experimental methods for developing a suitable model for collagen gels are of primary importance for the field. In this research, we focused on mechanical properties of collagen gels under unconfined compression. First, mechanical viscoelastic models are discussed and framed in the control system theory. Second, models are fitted using system identification. Several models are evaluated and two nonlinear models are proposed: Mooney-Rivlin inspired and Hammerstein models. The results suggest that Mooney-Rivlin and Hammerstein models succeed in describing the mechanical behavior of collagen gels for cyclic tests on scaffolds (with best fitting parameters 58.3% and 75.8%, resp.. When Akaike criterion is used, the best is the Mooney-Rivlin inspired model.

  8. Mathematical modeling of uniaxial mechanical properties of collagen gel scaffolds for vascular tissue engineering. (United States)

    Irastorza, Ramiro M; Drouin, Bernard; Blangino, Eugenia; Mantovani, Diego


    Small diameter tissue-engineered arteries improve their mechanical and functional properties when they are mechanically stimulated. Applying a suitable stress and/or strain with or without a cycle to the scaffolds and cells during the culturing process resides in our ability to generate a suitable mechanical model. Collagen gel is one of the most used scaffolds in vascular tissue engineering, mainly because it is the principal constituent of the extracellular matrix for vascular cells in human. The mechanical modeling of such a material is not a trivial task, mainly for its viscoelastic nature. Computational and experimental methods for developing a suitable model for collagen gels are of primary importance for the field. In this research, we focused on mechanical properties of collagen gels under unconfined compression. First, mechanical viscoelastic models are discussed and framed in the control system theory. Second, models are fitted using system identification. Several models are evaluated and two nonlinear models are proposed: Mooney-Rivlin inspired and Hammerstein models. The results suggest that Mooney-Rivlin and Hammerstein models succeed in describing the mechanical behavior of collagen gels for cyclic tests on scaffolds (with best fitting parameters 58.3% and 75.8%, resp.). When Akaike criterion is used, the best is the Mooney-Rivlin inspired model.

  9. 77 FR 39996 - Department of Mechanical Engineering, Texas A&M University, Notice of Decision on Application for... (United States)


    ... International Trade Administration Department of Mechanical Engineering, Texas A&M University, Notice of...., Washington, D.C. Docket Number: 12-024. Applicant: Department of Mechanical Engineering, Texas A&M University..., 2012. Gregory W. Campbell, Director, Subsidies Enforcement Office, Import Administration. BILLING CODE...

  10. 75 FR 24323 - American Society of Mechanical Engineers (ASME) Codes and New and Revised ASME Code Cases (United States)


    ... Regulatory Commission 10 CFR Part 50 American Society of Mechanical Engineers (ASME) Codes and New and Revised ASME Code Cases; Proposed Rule #0;#0;Federal Register / Vol. 75 , No. 85 / Tuesday, May 4, 2010... Mechanical Engineers (ASME) Codes and New and Revised ASME Code Cases AGENCY: Nuclear Regulatory Commission...

  11. Professor Dragutin M. Drazic - On the occasion of his 70th birthday

    Directory of Open Access Journals (Sweden)

    Aleksandar Despic


    Full Text Available Professor Dragutin Drazic was born on May 5, 1930, in Belgrade. His father, Milan Drazic, was a professor at the Faculty of Civil Engineering of the University of Belgrade, while his mother, Zorka, was also a civil engineer working for the City of Belgrade. These facts, as well as the entire intellectual entourage in the “Professors’ Colony” in Belgrade, predetermined his orientation to natural sciences and engineering. Thus, after finishing elementary school before WWII and secondary school by 1949, he entered the Faculty of Science and Mathematics (Department of Chemistry of the University of Belgrade. After his first year of study, he changed the school, enlisting in the faculty of Chemical Engineering (“Faculty of Technology” of the same University. He graduated from the Department of Chemical Technology with the highest grade in 1956. After graduation, he joined the teaching staff of the same school, in the Department of Physical Chemistry and Electrochemistry, in which he spent his entire career, commencing as an assistant lecturer and becoming a full professor. His affinity for science was supported by his wife Vera (b. Kuharic who was in the same profession and also became a university professor in physical chemistry. The family tradition continued with their two sons, Milan and Dusan, who also joined the academic world, becoming capable mathematician and computer scientists. Profesor Drazic taught very successfully a variety of subjects, such as Electrode Kinetics, Corrosion, Electrochemical Double Layer and Adsorption (postgraduate and finally, Physical Chemistry – a General Course. At the height of his professional career he was the Head of the Chair and Department of Physical Chemistry and Electrochemistry for several years. In July 1959 he went to the USA, to join the Electrochemistry Laboratory of the University of Pennsylvania in Philadelphia, led by Professor John O’Mara Bockris, which at the time was the leading

  12. Chondroprotective supplementation promotes the mechanical properties of injectable scaffold for human nucleus pulposus tissue engineering. (United States)

    Foss, Berit L; Maxwell, Thomas W; Deng, Ying


    A result of intervertebral disc (IVD) degeneration, the nucleus pulposus (NP) is no longer able to withstand applied load leading to pain and disability. The objective of this study is to fabricate a tissue-engineered injectable scaffold with chondroprotective supplementation in vitro to improve the mechanical properties of a degenerative NP. Tissue-engineered scaffolds were fabricated using different concentrations of alginate and calcium chloride and mechanically evaluated. Fabrication conditions were based on structural and mechanical resemblance to the native NP. Chondroprotective supplementation, glucosamine (GCSN) and chondroitin sulfate (CS), were added to scaffolds at concentrations of 0:0µg/mL (0:0-S), 125:100µg/mL (125:100-S), 250:200µg/mL (250:200-S), and 500:400µg/mL (500:400-S), GCSN and CS, respectively. Scaffolds were used to fabricate tissue-engineered constructs through encapsulation of human nucleus pulposus cells (HNPCs). The tissue-engineered constructs were collected at days 1, 14, and 28 for biochemical and biomechanical evaluations. Confocal microscopy showed HNPC viability and rounded morphology over the 28 day period. MTT analysis resulted in significant increases in cell proliferation for each group. Collagen type II ELISA quantification and compressive aggregate moduli (HA) showed increasing trends for both 250:200-S and the 500:400-S groups on Day 28 with significantly greater HA compared to 0:0-S group. Glycosaminoglycan and water content decreased for all groups. Results indicate the increased mechanical properties of the 250:200-S and the 500:400-S was due to production of a functional matrix. This study demonstrated potential for a chondroprotective supplemented injectable scaffold to restore biomechanical function of a degenerative disc through the production of a mechanically functional matrix. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. ExoMars 2016 EDM SM Mechanical Test Campaign Engineering Results Evaluation (United States)

    Luison, Dario; Tenore, Amedeo Giancarlo


    This paper describes the analytical engineering activities done in the frame of ExoMars Descent Module (EDM) Structural Model (SM) Mechanical Test Campaign performed in ESTEC (for Sinusoidal Test) and in Thales Alenia Space Turin (Italy) laboratories (for Static Test) in the period from February and July 2013.The main results of Sine and Static Tests are described, as well as the updating of the Mathematical Model based on the results of the Base Excitation Vibration Modal Parameters Extraction. The engineering test evaluation activity was concentrated in particular on the simulation of the failure occurred during the sine test. This failure represented a serious issues never encountered in previous tests. Despite the gravity of the phenomenon, in a short time, the engineering was able to prove the structural integrity and to conclude successfully the test.


    Directory of Open Access Journals (Sweden)



    Full Text Available MechanicaJ properties of high performance ceramics have been improved to the point where their use in heat engines is possible. The high temperature strength and low thermal expansion properties of bigh performance ceramics offer an advantage over metals in the development of non-water cooling engine. However, because bard environment in diesel engine combustion chamber, solving the problem of durabiUty of TBC is important. DurabiUty of thermal barrier coatings(TBC is liınited by two main failure mechanisms: Therınal expansion nlİsmatch betwcen bond coat and top coat and bond coat oxidation. Both of these can cause failure of the ceramic top coat. Developments of recent years sholv that bond coats \\Vith higher oxidation resistance tend to have better coating system cyclic lives

  15. Atomic force microscopy studies of bioprocess engineering surfaces - imaging, interactions and mechanical properties mediating bacterial adhesion. (United States)

    James, Sean A; Hilal, Nidal; Wright, Chris J


    The detrimental effect of bacterial biofilms on process engineering surfaces is well documented. Thus, interest in the early stages of bacterial biofilm formation; in particular bacterial adhesion and the production of anti-fouling coatings has grown exponentially as a field. During this time, Atomic force microscopy (AFM) has emerged as a critical tool for the evaluation of bacterial adhesion. Due to its versatility AFM offers not only insight into the topographical landscape and mechanical properties of the engineering surfaces, but elucidates, through direct quantification the topographical and biomechnical properties of the foulants The aim of this review is to collate the current research on bacterial adhesion, both theoretical and practical, and outline how AFM as a technique is uniquely equipped to provide further insight into the nanoscale world at the bioprocess engineering surface. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Engineering manual. A practical reference of design methods and data in building systems, chemical, civil, electrical, mechanical, and environmental engineering and energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Perry, R.H. (ed.)


    Following 3 chapters of general reference information for engineers which include mathematics and mathematical tables, heat transfer, fluid flow, and basic thermodynamics, and data on the chemical, mechanical, and physical properties of materials, 7 chapters of data and design methods for specific engineering fields, i.e., architectural or building systems, chemical, civil, electrical, mechanical, environmental, and for energy conversion are presented. A subject index is included. (LCL)

  17. Methods for automated semantic definition of manufacturing structures (mBOM) in mechanical engineering companies (United States)

    Stekolschik, Alexander, Prof.


    The bill of materials (BOM), which involves all parts and assemblies of the product, is the core of any mechanical or electronic product. The flexible and integrated management of engineering (Engineering Bill of Materials [eBOM]) and manufacturing (Manufacturing Bill of Materials [mBOM]) structures is the key to the creation of modern products in mechanical engineering companies. This paper presents a method framework for the creation and control of e- and, especially, mBOM. The requirements, resulting from the process of differentiation between companies that produce serialized or engineered-to-order products, are considered in the analysis phase. The main part of the paper describes different approaches to fully or partly automated creation of mBOM. The first approach is the definition of part selection rules in the generic mBOM templates. The mBOM can be derived from the eBOM for partly standardized products by using this method. Another approach is the simultaneous use of semantic rules, options, and parameters in both structures. The implementation of the method framework (selection of use cases) in a standard product lifecycle management (PLM) system is part of the research.

  18. Thermo-mechanical concepts applied to modeling liquid propellant rocket engine stability (United States)

    Kassoy, David R.; Norris, Adam


    The response of a gas to transient, spatially distributed energy addition can be quantified mathematically using thermo-mechanical concepts available in the literature. The modeling demonstrates that the ratio of the energy addition time scale to the acoustic time scale of the affected volume, and the quantity of energy added to that volume during the former determine the whether the responses to heating can be described as occurring at nearly constant volume, fully compressible or nearly constant pressure. Each of these categories is characterized by significantly different mechanical responses. Application to idealized configurations of liquid propellant rocket engines provides an opportunity to identify physical conditions compatible with gasdynamic disturbances that are sources of engine instability. Air Force Office of Scientific Research.

  19. 2nd International Conference on Mechanical, Manufacturing and Process Plant Engineering

    CERN Document Server


    This volume presents selected papers from the 2nd International Conference on Mechanical, Manufacturing and Process Plant Engineering (ICMMPE 2016) which was held from 23rd to 24th November, 2016 in Kuala Lumpur, Malaysia. The proceedings discuss genuine problems of joining technologies that are heart of manufacturing sectors. It discusses the findings of experimental and numerical works from soldering, arc welding to solid state joining technology that faced by current industry. .

  20. Definition of design criteria of mechanical transfer: an interaction between engineering and health areas. (United States)

    Luz, Taciana Ramos; Echternacht, Eliza Helena de Oliveira


    This study aims to analyze the factors that justify the low use of a mechanical transfer in the context of a long-term institution. It is a device intended for internal transportation of individuals who have mobility problems. The analysis involves researchers from the fields of health and engineering in order to generate design criteria that consider the needs of caregivers and patients of this institution. To understand the reality of this site and their specificities, was used Ergonomic Work Analysis.

  1. Mechanical and thermal analysis of the internal combustion engine piston using Ansys (United States)

    Cioată, V. G.; Kiss, I.; Alexa, V.; Raţiu, S. A.


    The piston is one of the most important components of the internal combustion engine. Piston fail mainly due to mechanical stresses and thermal stresses. In this paper is determined by using the finite element method, stress and displacement distribution due the flue gas pressure and temperature, separately and combined. The FEA is performed by CAD and CAE software. The results are compared with those obtained by the analytical method and conclusions have been drawn.

  2. The role of a clinical engineer within a mechanical circulatory support device program: a single center's experience. (United States)

    Princer, Kathleen


    With the rapidly growing world of mechanical circulatory support device programs, a variety of multidisciplinary team models have been successful. Most include nurses, nurse practitioners, perfusionists, and/or clinical engineers, with patient care and education primarily directed by nurses. At Aurora St Luke's Medical Center, the team includes transplant surgeons, transplant cardiologists, nurse practitioners, clinical engineers, perfusionists, and nurses who serve as transplant coordinators and research coordinators, but the team is unique in having clinical engineers at the center of patient care. The clinical engineers and the transplant coordinators split many of the duties of a typical ventricular assist device coordinator. The role of the clinical engineer within the program is elucidated by discussing the history of the program, the structure of the clinical engineering team, the duties related to mechanical circulatory support devices and the additional responsibilities of the clinical engineers.

  3. Analytical expression for an optimised link bar mechanism for a beta-type Stirling engine

    DEFF Research Database (Denmark)

    Carlsen, Henrik; Bovin, Jonas Kabell


    The design of a mechanism for kinematic beta-type Stirling engines, where the displacer piston and the working piston share the same cylinder, is complicated. A well-known solution is the rhombic drive, but this solution depends on oil lubrication because of the gear wheels connecting the two...... pointing downwards is connected to the displacer piston. In the paper, an analytical analysis of an optimised link bar mechanism is presented, which can be used for determination of the geometry, the phase angle between the pistons and the in-accuracy of the straight line movement. Furthermore, the design...

  4. A dual flow bioreactor with controlled mechanical stimulation for cartilage tissue engineering. (United States)

    Spitters, Tim W G M; Leijten, Jeroen C H; Deus, Filipe D; Costa, Ines B F; van Apeldoorn, Aart A; van Blitterswijk, Clemens A; Karperien, Marcel


    In cartilage, tissue engineering bioreactors can create a controlled environment to study chondrocyte behavior under mechanical stimulation or produce chondrogenic grafts of clinically relevant size. Here we present a novel bioreactor that combines mechanical stimulation with a two compartment system through which nutrients can be supplied solely by diffusion from opposite sides of a tissue-engineered construct. This design is based on the hypothesis that creating gradients of nutrients, growth factors, and growth factor antagonists can aid in the generation of zonal tissue-engineered cartilage. Computational modeling predicted that the design facilitates the creation of a biologically relevant glucose gradient. This was confirmed by quantitative glucose measurements in cartilage explants. In this system, it is not only possible to create gradients of nutrients, but also of anabolic or catabolic factors. Therefore, the bioreactor design allows control over nutrient supply and mechanical stimulation useful for in vitro generation of cartilage constructs that can be used for the resurfacing of articulated joints or as a model for studying osteoarthritis disease progression.

  5. Development of Chitosan Scaffolds with Enhanced Mechanical Properties for Intestinal Tissue Engineering Applications. (United States)

    Zakhem, Elie; Bitar, Khalil N


    Massive resections of segments of the gastrointestinal (GI) tract lead to intestinal discontinuity. Functional tubular replacements are needed. Different scaffolds were designed for intestinal tissue engineering application. However, none of the studies have evaluated the mechanical properties of the scaffolds. We have previously shown the biocompatibility of chitosan as a natural material in intestinal tissue engineering. Our scaffolds demonstrated weak mechanical properties. In this study, we enhanced the mechanical strength of the scaffolds with the use of chitosan fibers. Chitosan fibers were circumferentially-aligned around the tubular chitosan scaffolds either from the luminal side or from the outer side or both. Tensile strength, tensile strain, and Young's modulus were significantly increased in the scaffolds with fibers when compared with scaffolds without fibers. Burst pressure was also increased. The biocompatibility of the scaffolds was maintained as demonstrated by the adhesion of smooth muscle cells around the different kinds of scaffolds. The chitosan scaffolds with fibers provided a better candidate for intestinal tissue engineering. The novelty of this study was in the design of the fibers in a specific alignment and their incorporation within the scaffolds.

  6. A novel bioreactor to simulate urinary bladder mechanical properties and compliance for bladder functional tissue engineering. (United States)

    Wei, Xin; Li, Dao-bing; Xu, Feng; Wang, Yan; Zhu, Yu-chun; Li, Hong; Wang, Kun-jie


    Bioreactors are pivotal tools for generating mechanical stimulation in functional tissue engineering study. This study aimed to create a bioreactor that can simulate urinary bladder mechanical properties, and to investigate the effects of a mechanically stimulated culture on urothelial cells and bladder smooth muscle cells. We designed a bioreactor to simulate the mechanical properties of bladder. A pressure-record system was used to evaluate the mechanical properties of the bioreactor by measuring the pressure in culture chambers. To test the biocompatibility of the bioreactor, viabilities of urothelial cells and smooth muscle cells cultured in the bioreactor under static and mechanically changed conditions were measured after 7-day culture. To evaluate the effect of mechanical stimulations on the vital cells, urethral cells and smooth muscle cells were cultured in the simulated mechanical conditions. After that, the viability and the distribution pattern of the cells were observed and compared with cells cultured in non-mechanical stimulated condition. The bioreactor system successfully generated waveforms similar to the intended programmed model while maintaining a cell-seeded elastic membrane between the chambers. There were no differences between viabilities of urothelial cells ((91.90 ± 1.22)% vs. (93.14 ± 1.78)%, P > 0.05) and bladder smooth muscle cells ((93.41 ± 1.49)% vs. (92.61 ± 1.34)%, P > 0.05). The viability of cells and tissue structure observation after cultured in simulated condition showed that mechanical stimulation was the only factor affected cells in the bioreactor and improved the arrangement of cells on silastic membrane. This bioreactor can effectively simulate the physiological and mechanical properties of the bladder. Mechanical stimulation is the only factor that affected the viability of cells cultured in the bioreactor. The bioreactor can change the growth behavior of urothelial cells and bladder smooth muscle cells, resulting in

  7. Compaction enhances extracellular matrix content and mechanical properties of tissue-engineered cartilaginous constructs. (United States)

    Han, EunHee; Ge, Chenghao; Chen, Albert C; Schumacher, Barbara L; Sah, Robert L


    Many cell-based tissue-engineered cartilaginous constructs are mechanically softer than native tissue and have low content and abnormal proportions of extracellular matrix (ECM) constituents. We hypothesized that the load-bearing mechanical properties of cartilaginous constructs improve with the inclusion of collagen (COL) and proteoglycan (PG) during assembly. The objectives of this work were to determine (1) the effect of addition of PG, COL, or COL+PG on compressive properties of 2% agarose constructs and (2) the ability of mechanical compaction to concentrate matrix content and improve the compressive properties of such constructs. The inclusion of COL+PG improved the compressive properties of hydrogel constructs compared with PG or COL alone. Mechanical compaction increased the PG and COL concentrations in and compressive stiffness of the constructs. Chondrocytes included in the constructs maintained high viability after compaction. These results support the concepts that the assembly of cartilaginous constructs with COL+PG and application of mechanical compaction enhance the ECM content and compressive properties of engineered cartilaginous constructs.

  8. Enabling Robotic Social Intelligence by Engineering Human Social-Cognitive Mechanisms

    DEFF Research Database (Denmark)

    Wiltshire, Travis; Warta, Samantha F.; Barber, Daniel


    For effective human-robot interaction, we argue that robots must gain social-cognitive mechanisms that allow them to function naturally and intuitively in social interactions with humans. However, a lack of consensus on social cognitive processes poses a challenge for how to design such mechanisms...... for artificial cognitive systems. We discuss a recent integrative perspective of social cognition to provide a systematic theoretical underpinning for computational instantiations of these mechanisms. We highlight several commitments of our approach that we refer to as Engineering Human Social Cognition. We...... then provide a series of recommendations to facilitate the development of the perceptual, motor, and cognitive architecture for this proposed artificial cognitive system in future work. For each recommendation, we highlight their relation to the discussed social-cognitive mechanisms, provide the rationale...

  9. Design and fabrication of a cryostat for low temperature mechanical testing for the Mechanical and Materials Engineering group at CERN

    CERN Document Server

    Aviles Santillana, I; Gerardin, A; Guinchard, M; Langeslag, S A E; Sgobba, S


    Mechanical testing of materials at low temperatures is one of the cornerstones of the Mechanical and Materials Engineering (MME) group at CERN. A long tradition of more than 20 years and a unique know - how of such tests has been developed with an 18 kN double-walled cryostat. Large campaigns of material qualification have been carried out and the mechanical behaviour of materials at 4 K has been vastly studied in sub - size samples for projects like LEP, LHC and its experiments. With the aim of assessing the mechanical properties of materials of higher strength and/or issued from heavy gauge products for which testing standardized specimens of larger cross section might be more adapted, a new 100 kN cryostat capable of hosting different shapes of normalized samples has been carefully designed and fabricated inhouse together with the associated tooling and measurement instrumentation. It has been conceived to be able to adapt to different test frames both dynamic and static, which will be of paramount importa...

  10. Mechanical Characterization of Tissue-Engineered Cartilage Using Microscopic Magnetic Resonance Elastography (United States)

    Yin, Ziying; Schmid, Thomas M.; Yasar, Temel K.; Liu, Yifei; Royston, Thomas J.


    Knowledge of mechanical properties of tissue-engineered cartilage is essential for the optimization of cartilage tissue engineering strategies. Microscopic magnetic resonance elastography (μMRE) is a recently developed MR-based technique that can nondestructively visualize shear wave motion. From the observed wave pattern in MR phase images the tissue mechanical properties (e.g., shear modulus or stiffness) can be extracted. For quantification of the dynamic shear properties of small and stiff tissue-engineered cartilage, μMRE needs to be performed at frequencies in the kilohertz range. However, at frequencies greater than 1 kHz shear waves are rapidly attenuated in soft tissues. In this study μMRE, with geometric focusing, was used to overcome the rapid wave attenuation at high frequencies, enabling the measurement of the shear modulus of tissue-engineered cartilage. This methodology was first tested at a frequency of 5 kHz using a model system composed of alginate beads embedded in agarose, and then applied to evaluate extracellular matrix development in a chondrocyte pellet over a 3-week culture period. The shear stiffness in the pellet was found to increase over time (from 6.4 to 16.4 kPa), and the increase was correlated with both the proteoglycan content and the collagen content of the chondrocyte pellets (R2=0.776 and 0.724, respectively). Our study demonstrates that μMRE when performed with geometric focusing can be used to calculate and map the shear properties within tissue-engineered cartilage during its development. PMID:24266395

  11. Mechanical modulation of nascent stem cell lineage commitment in tissue engineering scaffolds. (United States)

    Song, Min Jae; Dean, David; Knothe Tate, Melissa L


    Taking inspiration from tissue morphogenesis in utero, this study tests the concept of using tissue engineering scaffolds as delivery devices to modulate emergent structure-function relationships at early stages of tissue genesis. We report on the use of a combined computational fluid dynamics (CFD) modeling, advanced manufacturing methods, and experimental fluid mechanics (micro-piv and strain mapping) for the prospective design of tissue engineering scaffold geometries that deliver spatially resolved mechanical cues to stem cells seeded within. When subjected to a constant magnitude global flow regime, the local scaffold geometry dictates the magnitudes of mechanical stresses and strains experienced by a given cell, and in a spatially resolved fashion, similar to patterning during morphogenesis. In addition, early markers of mesenchymal stem cell lineage commitment relate significantly to the local mechanical environment of the cell. Finally, by plotting the range of stress-strain states for all data corresponding to nascent cell lineage commitment (95% CI), we begin to "map the mechanome", defining stress-strain states most conducive to targeted cell fates. In sum, we provide a library of reference mechanical cues that can be delivered to cells seeded on tissue engineering scaffolds to guide target tissue phenotypes in a temporally and spatially resolved manner. Knowledge of these effects allows for prospective scaffold design optimization using virtual models prior to prototyping and clinical implementation. Finally, this approach enables the development of next generation scaffolds cum delivery devices for genesis of complex tissues with heterogenous properties, e.g., organs, joints or interface tissues such as growth plates. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Estrogen inhibits lysyl oxidase and decreases mechanical function in engineered ligaments. (United States)

    Lee, Cassandra A; Lee-Barthel, Ann; Marquino, Louise; Sandoval, Natalie; Marcotte, George R; Baar, Keith


    Women are more likely to suffer an anterior cruciate ligament (ACL) rupture than men, and the incidence of ACL rupture in women rises with increasing estrogen levels. We used an engineered ligament model to determine how an acute rise in estrogen decreases the mechanical properties of ligaments. Using fibroblasts isolated from human ACLs from male or female donors, we engineered ligaments and determined that ligaments made from female ACL cells had more collagen and were equal in strength to those made from male ACL cells. We then treated engineered ligaments for 14 days with low (5 pg/ml), medium (50 pg/ml), or high (500 pg/ml) estrogen, corresponding to the range of in vivo serum estrogen concentrations and found that collagen within the grafts increased without a commensurate increase in mechanical strength. Mimicking the menstrual cycle, with 12 days of low estrogen followed by 2 days of physiologically high estrogen, resulted in a decrease in engineered ligament mechanical function with no change in the amount of collagen in the graft. The decrease in mechanical stiffness corresponded with a 61.7 and 76.9% decrease in the activity of collagen cross-linker lysyl oxidase with 24 and 48 h of high estrogen, respectively. Similarly, grafts treated with the lysyl oxidase inhibitor β-aminoproprionitrile (BAPN) for 24 h showed a significant decrease in ligament mechanical strength [control (CON) = 1.58 ± 0.06 N; BAPN = 1.06 ± 0.13 N] and stiffness (CON = 7.7 ± 0.46 MPa; BAPN = 6.1 ± 0.71 MPa) without changing overall collagen levels (CON = 396 ± 11.5 μg; BAPN = 382 ± 11.6 μg). Together, these data suggest that the rise in estrogen during the follicular phase decreases lysyl oxidase activity in our engineered ligament model and if this occurs in vivo may decrease the stiffness of ligaments and contribute to the elevated rate of ACL rupture in women. Copyright © 2015 the American Physiological Society.

  13. Interview with Professor Mark Wilcox. (United States)

    Wilcox, Mark


    Mark Wilcox speaks to Georgia Patey, Commissioning Editor: Professor Mark Wilcox is a Consultant Microbiologist and Head of Microbiology at the Leeds Teaching Hospitals (Leeds, UK), the Professor of Medical Microbiology at the University of Leeds (Leeds, UK), and is the Lead on Clostridium difficile and the Head of the UK C. difficile Reference Laboratory for Public Health England (PHE). He was the Director of Infection Prevention (4 years), Infection Control Doctor (8 years) and Clinical Director of Pathology (6 years) at the Leeds Teaching Hospitals. He is Chair of PHE's Rapid Review Panel (reviews utility of infection prevention and control products for National Health Service), Deputy Chair of the UK Department of Health's Antimicrobial Resistance and Healthcare Associated Infection Committee and a member of PHE's HCAI/AR Programme Board. He is a member of UK/European/US working groups on C. difficile infection. He has provided clinical advice as part of the FDA/EMA submissions for the approval of multiple novel antimicrobial agents. He heads a healthcare-associated infection research team at University of Leeds, comprising approximately 30 doctors, scientists and nurses; projects include multiple aspects of C. difficile infection, diagnostics, antimicrobial resistance and the clinical development of new antimicrobial agents. He has authored more than 400 publications, and is the coeditor of Antimicrobial Chemotherapy (5th/6th/7th Editions, 15 December 2007).

  14. Chitosan fibers with improved biological and mechanical properties for tissue engineering applications. (United States)

    Albanna, Mohammad Z; Bou-Akl, Therese H; Blowytsky, Oksana; Walters, Henry L; Matthew, Howard W T


    The low mechanical properties of hydrogel materials such as chitosan hinder their broad utility for tissue engineering applications. Previous research efforts improved the mechanical properties of chitosan fiber through chemical and physical modifications; however, unfavorable toxicity effects on cells were reported. In this paper, we report the preparation of chitosan fibers with improved mechanical and biocompatibility properties. The structure-property relationships of extruded chitosan fibers were explored by varying acetic acid (AA) concentration, ammonia concentration, annealing temperature and degree of heparin crosslinking. Results showed that optimizing AA concentration to 2vol% improved fiber strength and stiffness by 2-fold. Extruding chitosan solution into 25wt% of ammonia solution reduced fiber diameters and improved fiber strength by 2-fold and stiffness by 3-fold, due to an increase in crystallinity as confirmed by XRD. Fiber annealing further reduced fiber diameter and improved fiber strength and stiffness as temperature increased. Chitosan fibers crosslinked with heparin had increased diameter but lower strength and stiffness properties and higher breaking strain values. When individual parameters were combined, further improvement in fiber mechanical properties was achieved. All mechanically improved fibers and heparin crosslinked fibers promoted valvular interstitial cells (VIC) attachment and growth over 10 day cultures. Our results demonstrate the ability to substantially improve the mechanical properties of chitosan fibers without adversely affecting their biological properties. The investigated treatments offer numerous advantages over previous physical/chemical modifications and thus are expected to expand the utility of chitosan fibers with tunable mechanical properties in various tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. From the interview with professor Jan Derksen: "There are no emotions in brain images"

    NARCIS (Netherlands)

    Derksen, J.J.L.


    We present an interview of professor Jan Derksen (Radboud Universiteit Nijmegen) about the importance of psychological theories of mental processes. He also considered the dangers of narrow biological interpretations in psychological research and practice based solely on neurobiological mechanisms

  16. A Novel Pulsatile Bioreactor for Mechanical Stimulation of Tissue Engineered Cardiac Constructs

    Directory of Open Access Journals (Sweden)

    Günther Eissner


    Full Text Available After myocardial infarction, the implantation of stem cell seeded scaffolds on the ischemic zone represents a promising strategy for restoration of heart function. However, mechanical integrity and functionality of tissue engineered constructs need to be determined prior to implantation. Therefore, in this study a novel pulsatile bioreactor mimicking the myocardial contraction was developed to analyze the behavior of mesenchymal stem cells derived from umbilical cord tissue (UCMSC colonized on titanium-coated polytetrafluorethylene scaffolds to friction stress. The design of the bioreactor enables a simple handling and defined mechanical forces on three seeded scaffolds at physiological conditions. The compact system made of acrylic glass, Teflon®, silicone, and stainless steel allows the comparison of different media, cells and scaffolds. The bioreactor can be gas sterilized and actuated in a standard incubator. Macroscopic observations and pressure-measurements showed a uniformly sinusoidal pulsation, indicating that the bioreactor performed well. Preliminary experiments to determine the adherence rate and morphology of UCMSC after mechanical loadings showed an almost confluent cellular coating without damage on the cell surface. In summary, the bioreactor is an adequate tool for the mechanical stress of seeded scaffolds and offers dynamic stimuli for pre-conditioning of cardiac tissue engineered constructs in vitro.

  17. Photoresponsive Polysaccharide-Based Hydrogels with Tunable Mechanical Properties for Cartilage Tissue Engineering. (United States)

    Giammanco, Giuseppe E; Carrion, Bita; Coleman, Rhima M; Ostrowski, Alexis D


    Photoresponsive hydrogels were obtained by coordination of alginate-acrylamide hybrid gels (AlgAam) with ferric ions. The photochemistry of Fe(III)-alginate was used to tune the chemical composition, mechanical properties, and microstructure of the materials upon visible light irradiation. The photochemical treatment also induced changes in the swelling properties and transport mechanism in the gels due to the changes in material composition and microstructure. The AlgAam gels were biocompatible and could easily be dried and rehydrated with no change in mechanical properties. These gels showed promise as scaffolds for cartilage tissue engineering, where the photochemical treatment could be used to tune the properties of the material and ultimately change the growth and extracellular matrix production of chondrogenic cells. ATDC5 cells cultured on the hydrogels showed a greater than 2-fold increase in the production of sulfated glycosaminoglycans (sGAG) in the gels irradiated for 90 min compared to the dark controls. Our method provides a simple photochemical tool to postsynthetically control and adjust the chemical and mechanical environment in these gels, as well as the pore microstructure and transport properties. By changing these properties, we could easily access different levels of performance of these materials as substrates for tissue engineering.

  18. Multi-scale mechanical response of freeze-dried collagen scaffolds for tissue engineering applications. (United States)

    Offeddu, Giovanni S; Ashworth, Jennifer C; Cameron, Ruth E; Oyen, Michelle L


    Tissue engineering has grown in the past two decades as a promising solution to unresolved clinical problems such as osteoarthritis. The mechanical response of tissue engineering scaffolds is one of the factors determining their use in applications such as cartilage and bone repair. The relationship between the structural and intrinsic mechanical properties of the scaffolds was the object of this study, with the ultimate aim of understanding the stiffness of the substrate that adhered cells experience, and its link to the bulk mechanical properties. Freeze-dried type I collagen porous scaffolds made with varying slurry concentrations and pore sizes were tested in a viscoelastic framework by macroindentation. Membranes made up of stacks of pore walls were indented using colloidal probe atomic force microscopy. It was found that the bulk scaffold mechanical response varied with collagen concentration in the slurry consistent with previous studies on these materials. Hydration of the scaffolds resulted in a more compliant response, yet lesser viscoelastic relaxation. Indentation of the membranes suggested that the material making up the pore walls remains unchanged between conditions, so that the stiffness of the scaffolds at the scale of seeded cells is unchanged; rather, it is suggested that thicker pore walls or more of these result in the increased moduli for the greater slurry concentration conditions. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering. (United States)

    Jahnavi, S; Saravanan, U; Arthi, N; Bhuvaneshwar, G S; Kumary, T V; Rajan, S; Verma, R S


    Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44+, αSMA+, Vimentin+ and CD105- human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Mini-Symposium on Micromechanics at the CSME Mechanical Engineering Forum

    CERN Document Server

    Muschik, W


    This volume contains the lectures presented at the mini-symposium on "Micromechanics" held in conjunction with the CSME Mechanical Engineer­ ing Forum 1990 between the 3rd and 8th June, 1990 at the University of Toronto, Canada. The expressed purpose of this symposium was to discuss some recent developments in the Micromechanics of Materials and how ad­ vances in this field now relate to the solution of practical engineer­ ing problems. Due to the time limit set for this section of the Engineer­ ing Forum as well as the restriction on the number of papers to be pre­ sented, it was not possible to cover a much wider range of topics. How­ ever, an attempt was made to include the most important advances asso­ ciated with the progress made in micromechanics in its application to material science and engineering over the past decade. Thus, the topics are concerned with: the fundamental aspects of the thermodynamics of structured solids (part I), - the micromechanical behaviour of alloys (part II), - the mod...

  1. Design and fabrication of a cryostat for low temperature mechanical testing for the Mechanical and Materials Engineering group at CERN (United States)

    Aviles Santillana, I.; Betemps, R.; Gerardin, A.; Guinchard, M.; Langeslag, S. A. E.; Sgobba, S.


    Mechanical testing of materials at low temperatures is one of the cornerstones of the Mechanical and Materials Engineering (MME) group at CERN. A long tradition of more than 20 years and a unique know - how of such tests has been developed with an 18 kN double-walled cryostat. Large campaigns of material qualification have been carried out and the mechanical behaviour of materials at 4 K has been vastly studied in sub - size samples for projects like LEP, LHC and its experiments. With the aim of assessing the mechanical properties of materials of higher strength and/or issued from heavy gauge products for which testing standardized specimens of larger cross section might be more adapted, a new 100 kN cryostat capable of hosting different shapes of normalized samples has been carefully designed and fabricated inhouse together with the associated tooling and measurement instrumentation. It has been conceived to be able to adapt to different test frames both dynamic and static, which will be of paramount importance for future studies of fracture mechanics at low temperatures. The cryostat features a double-walled vessel consisting of a central cylindrical section with a convex lower end and a flat top end closure. The transmission of the load is guaranteed by a 4 column system and its precise monitoring is assured by an internal load cell positioned next to the sample in the load train. This innovative approach will be discussed together with other nonconventional instrumentation solutions. A validation of the whole system has been carried out, where bending efforts on instrumented samples have been measured. Additionally, dedicated tooling has been fabricated for the device's optimization. The preliminary results obtained confirm an excellent performance of the system and enhance the analysis of materials under extreme conditions with state of the art instrumentation.

  2. Mapping of Mechanical Strains and Stresses around Quiescent Engineered Three-Dimensional Epithelial Tissues (United States)

    Gjorevski, Nikolce; Nelson, Celeste M.


    Understanding how physical signals guide biological processes requires qualitative and quantitative knowledge of the mechanical forces generated and sensed by cells in a physiologically realistic three-dimensional (3D) context. Here, we used computational modeling and engineered epithelial tissues of precise geometry to define the experimental parameters that are required to measure directly the mechanical stress profile of 3D tissues embedded within native type I collagen. We found that to calculate the stresses accurately in these settings, we had to account for mechanical heterogeneities within the matrix, which we visualized and quantified using confocal reflectance and atomic force microscopy. Using this technique, we were able to obtain traction forces at the epithelium-matrix interface, and to resolve and quantify patterns of mechanical stress throughout the surrounding matrix. We discovered that whereas single cells generate tension by contracting and pulling on the matrix, the contraction of multicellular tissues can also push against the matrix, causing emergent compression. Furthermore, tissue geometry defines the spatial distribution of mechanical stress across the epithelium, which communicates mechanically over distances spanning hundreds of micrometers. Spatially resolved mechanical maps can provide insight into the types and magnitudes of physical parameters that are sensed and interpreted by multicellular tissues during normal and pathological processes. PMID:22828342

  3. Cell-Biomaterial Mechanical Interaction in the Framework of Tissue Engineering: Insights, Computational Modeling and Perspectives (United States)

    Sanz-Herrera, Jose A.; Reina-Romo, Esther


    Tissue engineering is an emerging field of research which combines the use of cell-seeded biomaterials both in vitro and/or in vivo with the aim of promoting new tissue formation or regeneration. In this context, how cells colonize and interact with the biomaterial is critical in order to get a functional tissue engineering product. Cell-biomaterial interaction is referred to here as the phenomenon involved in adherent cells attachment to the biomaterial surface, and their related cell functions such as growth, differentiation, migration or apoptosis. This process is inherently complex in nature involving many physico-chemical events which take place at different scales ranging from molecular to cell body (organelle) levels. Moreover, it has been demonstrated that the mechanical environment at the cell-biomaterial location may play an important role in the subsequent cell function, which remains to be elucidated. In this paper, the state-of-the-art research in the physics and mechanics of cell-biomaterial interaction is reviewed with an emphasis on focal adhesions. The paper is focused on the different models developed at different scales available to simulate certain features of cell-biomaterial interaction. A proper understanding of cell-biomaterial interaction, as well as the development of predictive models in this sense, may add some light in tissue engineering and regenerative medicine fields. PMID:22174660

  4. Manufacturing of hydrogel biomaterials with controlled mechanical properties for tissue engineering applications. (United States)

    Vedadghavami, Armin; Minooei, Farnaz; Mohammadi, Mohammad Hossein; Khetani, Sultan; Rezaei Kolahchi, Ahmad; Mashayekhan, Shohreh; Sanati-Nezhad, Amir


    Hydrogels have been recognized as crucial biomaterials in the field of tissue engineering, regenerative medicine, and drug delivery applications due to their specific characteristics. These biomaterials benefit from retaining a large amount of water, effective mass transfer, similarity to natural tissues and the ability to form different shapes. However, having relatively poor mechanical properties is a limiting factor associated with hydrogel biomaterials. Controlling the biomechanical properties of hydrogels is of paramount importance. In this work, firstly, mechanical characteristics of hydrogels and methods employed for characterizing these properties are explored. Subsequently, the most common approaches used for tuning mechanical properties of hydrogels including but are not limited to, interpenetrating polymer networks, nanocomposites, self-assembly techniques, and co-polymerization are discussed. The performance of different techniques used for tuning biomechanical properties of hydrogels is further compared. Such techniques involve lithography techniques for replication of tissues with complex mechanical profiles; microfluidic techniques applicable for generating gradients of mechanical properties in hydrogel biomaterials for engineering complex human tissues like intervertebral discs, osteochondral tissues, blood vessels and skin layers; and electrospinning techniques for synthesis of hybrid hydrogels and highly ordered fibers with tunable mechanical and biological properties. We finally discuss future perspectives and challenges for controlling biomimetic hydrogel materials possessing proper biomechanical properties. Hydrogels biomaterials are essential constituting components of engineered tissues with the applications in regenerative medicine and drug delivery. The mechanical properties of hydrogels play crucial roles in regulating the interactions between cells and extracellular matrix and directing the cells phenotype and genotype. Despite

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

    Directory of Open Access Journals (Sweden)

    Laixiang Wen


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

  6. Mechanical Stimulation Protocols of Human Derived Cells in Articular Cartilage Tissue Engineering - A Systematic Review. (United States)

    Khozoee, Baktash; Mafi, Pouya; Mafi, Reza; Khan, Wasim S


    Mechanical stimulation is a key factor in articular cartilage generation and maintenance. Bioreactor systems have been designed and built in order to deliver specific types of mechanical stimulation. The focus has been twofold, applying a type of preconditioning in order to stimulate cell differentiation, and to simulate in vivo conditions in order to gain further insight into how cells respond to different stimulatory patterns. Due to the complex forces at work within joints, it is difficult to simulate mechanical conditions using a bioreactor. The aim of this review is to gain a deeper understanding of the complexities of mechanical stimulation protocols by comparing those employed in bioreactors in the context of tissue engineering for articular cartilage, and to consider their effects on cultured cells. Allied and Complementary Medicine 1985 to 2016, Ovid MEDLINE[R] 1946 to 2016, and Embase 1974 to 2016 were searched using key terms. Results were subject to inclusion and exclusion criteria, key findings summarised into a table and subsequently discussed. Based on this review it is overwhelmingly clear that mechanical stimulation leads to increased chondrogenic properties in the context of bioreactor articular cartilage tissue engineering using human cells. However, given the variability and lack of controlled factors between research articles, results are difficult to compare, and a standardised method of evaluating stimulation protocols proved challenging. With improved standardisation in mechanical stimulation protocol reporting, bioreactor design and building processes, along with a better understanding of joint behaviours, we hope to perform a meta-analysis on stimulation protocols and methods. Copyright© Bentham Science Publishers; For any queries, please email at

  7. A systemic analysis of cheating in an undergraduate engineering mechanics course. (United States)

    Bertram Gallant, Tricia; Van Den Einde, Lelli; Ouellette, Scott; Lee, Sam


    Cheating in the undergraduate classroom is not a new problem, and it is recognized as one that is endemic to the education system. This paper examines the highly normative behavior of using unauthorized assistance (e.g., a solutions manual or a friend) on an individual assignment within the context of an upper division undergraduate course in engineering mechanics. The findings indicate that there are varying levels of accepting responsibility among the students (from denial to tempered to full) and that acceptance of responsibility can lead to identification of learning and necessary behavioral changes. The findings have implications for institutions and engineering faculty, in particular the need for consistent academic integrity education and the teaching of professional integrity and ethics.

  8. Tensor Algebra and Tensor Analysis for Engineers With Applications to Continuum Mechanics

    CERN Document Server

    Itskov, Mikhail


    There is a large gap between the engineering course in tensor algebra on the one hand and the treatment of linear transformations within classical linear algebra on the other hand. The aim of this modern textbook is to bridge this gap by means of the consequent and fundamental exposition. The book primarily addresses engineering students with some initial knowledge of matrix algebra. Thereby the mathematical formalism is applied as far as it is absolutely necessary. Numerous exercises are provided in the book and are accompanied by solutions, enabling self-study. The last chapters of the book deal with modern developments in the theory of isotropic and anisotropic tensor functions and their applications to continuum mechanics and are therefore of high interest for PhD-students and scientists working in this area. This third edition is completed by a number of additional figures, examples and exercises. The text and formulae have been revised and improved where necessary.

  9. Critical review on the physical and mechanical factors involved in tissue engineering of cartilage. (United States)

    Gaut, Carrie; Sugaya, Kiminobu


    Articular cartilage defects often progress to osteoarthritis, which negatively impacts quality of life for millions of people worldwide and leads to high healthcare expenditures. Tissue engineering approaches to osteoarthritis have concentrated on proliferation and differentiation of stem cells by activation and suppression of signaling pathways, and by using a variety of scaffolding techniques. Recent studies indicate a key role of environmental factors in the differentiation of mesenchymal stem cells to mature cartilage-producing chondrocytes. Therapeutic approaches that consider environmental regulation could optimize chondrogenesis protocols for regeneration of articular cartilage. This review focuses on the effect of scaffold structure and composition, mechanical stress and hypoxia in modulating mesenchymal stem cell fate and the current use of these environmental factors in tissue engineering research.

  10. Reverse engineering the mechanical and molecular pathways in stem cell morphogenesis. (United States)

    Lu, Kai; Gordon, Richard; Cao, Tong


    The formation of relevant biological structures poses a challenge for regenerative medicine. During embryogenesis, embryonic cells differentiate into somatic tissues and undergo morphogenesis to produce three-dimensional organs. Using stem cells, we can recapitulate this process and create biological constructs for therapeutic transplantation. However, imperfect imitation of nature sometimes results in in vitro artifacts that fail to recapitulate the function of native organs. It has been hypothesized that developing cells may self-organize into tissue-specific structures given a correct in vitro environment. This proposition is supported by the generation of neo-organoids from stem cells. We suggest that morphogenesis may be reverse engineered to uncover its interacting mechanical pathway and molecular circuitry. By harnessing the latent architecture of stem cells, novel tissue-engineering strategies may be conceptualized for generating self-organizing transplants. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Methodology for Developing Teaching Activities and Materials for Use in Fluid Mechanics Courses in Undergraduate Engineering Programs (United States)

    Gamez-Montero, P. Javier; Raush, Gustavo; Domènech, Lluis; Castilla, Robert; García-Vílchez, Mercedes; Moreno, Hipòlit; Carbó, Albert


    "Mechanics" and "Fluids" are familiar concepts for any newly-registered engineering student. However, when combined into the term "Fluid Mechanics", students are thrust into the great unknown. The present article demonstrates the process of adaptation employed by the Fluid Mechanics course in the undergraduate…

  12. Professor Gender, Age, and "Hotness" in Influencing College Students' Generation and Interpretation of Professor Ratings (United States)

    Sohr-Preston, Sara L.; Boswell, Stefanie S.; McCaleb, Kayla; Robertson, Deanna


    A sample of 230 undergraduate psychology students rated their expectations of a bogus professor (who was randomly designated a man or woman and "hot" versus "not hot") based on ratings and comments found on Five professor qualities were derived using principal components analysis: dedication,…

  13. Engineering the Mechanical Properties of Polymer Networks with Precise Doping of Primary Defects. (United States)

    Chan, Doreen; Ding, Yichuan; Dauskardt, Reinhold H; Appel, Eric A


    Polymer networks are extensively utilized across numerous applications ranging from commodity superabsorbent polymers and coatings to high-performance microelectronics and biomaterials. For many applications, desirable properties are known; however, achieving them has been challenging. Additionally, the accurate prediction of elastic modulus has been a long-standing difficulty owing to the presence of loops. By tuning the prepolymer formulation through precise doping of monomers, specific primary network defects can be programmed into an elastomeric scaffold, without alteration of their resulting chemistry. The addition of these monomers that respond mechanically as primary defects is used both to understand their impact on the resulting mechanical properties of the materials and as a method to engineer the mechanical properties. Indeed, these materials exhibit identical bulk and surface chemistry, yet vastly different mechanical properties. Further, we have adapted the real elastic network theory (RENT) to the case of primary defects in the absence of loops, thus providing new insights into the mechanism for material strength and failure in polymer networks arising from primary network defects, and to accurately predict the elastic modulus of the polymer system. The versatility of the approach we describe and the fundamental knowledge gained from this study can lead to new advancements in the development of novel materials with precisely defined and predictable chemical, physical, and mechanical properties.

  14. Improvement of mechanical properties and biocompatibility of forsterite bioceramic addressed to bone tissue engineering materials. (United States)

    Kharaziha, M; Fathi, M H


    This work deals with the fabrication and characterization of nanostructured forsterite bulk. This material may have better biocompatibility and mechanical properties than coarse grain forsterite for the development of bone tissue engineering materials. Nanostructured forsterite bulks were prepared by two step sintering of sol-gel derived forsterite nanopowder. Their sinterability and mechanical properties were then studied. Biocompatibility of the nanostructured forsterite bulk was also evaluated by cell attachment and proliferation experiments. In addition, the effects of ionic products from forsterite nanopowder dissolution on osteoblasts were studied. Results show that dense nanostructured forsterite bulk was prepared with hardness and fracture toughness of about 1102 Hv and 4.3 MPa m(1/2), respectively. Nanostructured forsterite was biocompatible and the MTT test confirmed that the products from forsterite nanopowder dissolution significantly promoted osteoblast proliferation within a certain concentration range. In addition, cells attached to and spread on the surface of nanostructured forsterite bulks. Mechanical properties of the nanostructured forsterite were much higher than that of hydroxyapatite. It was concluded that nanostructured forsterite is a bioactive ceramic with good biocompatibility that can be used as a bone tissue engineering material. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  15. The Chlamydomonas CO2 -concentrating mechanism and its potential for engineering photosynthesis in plants. (United States)

    Mackinder, Luke C M


    Contents Summary I. Introduction 54 II. Recent advances in our understanding of the Chlamydomonas CCM 55 III. Current gaps in our understanding of the Chlamydomonas CCM 58 IV. Approaches to rapidly advance our understanding of the Chlamydomonas CCM 58 V. Engineering a CCM into higher plants 58 VI. Conclusion and outlook 59 Acknowledgements 60 References 60 SUMMARY: To meet the food demands of a rising global population, innovative strategies are required to increase crop yields. Improvements in plant photosynthesis by genetic engineering show considerable potential towards this goal. One prospective approach is to introduce a CO2 -concentrating mechanism into crop plants to increase carbon fixation by supplying the central carbon-fixing enzyme, Rubisco, with a higher concentration of its substrate, CO2 . A promising donor organism for the molecular machinery of this mechanism is the eukaryotic alga Chlamydomonas reinhardtii. This review summarizes the recent advances in our understanding of carbon concentration in Chlamydomonas, outlines the most pressing gaps in our knowledge and discusses strategies to transfer a CO2 -concentrating mechanism into higher plants to increase photosynthetic performance. © 2017 The Author. New Phytologist © 2017 New Phytologist Trust.

  16. Detergent-enzymatic decellularization of swine blood vessels: insight on mechanical properties for vascular tissue engineering. (United States)

    Pellegata, Alessandro F; Asnaghi, M Adelaide; Stefani, Ilaria; Maestroni, Anna; Maestroni, Silvia; Dominioni, Tommaso; Zonta, Sandro; Zerbini, Gianpaolo; Mantero, Sara


    Small caliber vessels substitutes still remain an unmet clinical need; few autologous substitutes are available, while synthetic grafts show insufficient patency in the long term. Decellularization is the complete removal of all cellular and nuclear matters from a tissue while leaving a preserved extracellular matrix representing a promising tool for the generation of acellular scaffolds for tissue engineering, already used for various tissues with positive outcomes. The aim of this work is to investigate the effect of a detergent-enzymatic decellularization protocol on swine arteries in terms of cell removal, extracellular matrix preservation, and mechanical properties. Furthermore, the effect of storage at -80°C on the mechanical properties of the tissue is evaluated. Swine arteries were harvested, frozen, and decellularized; histological analysis revealed complete cell removal and preserved extracellular matrix. Furthermore, the residual DNA content in decellularized tissues was far low compared to native one. Mechanical testings were performed on native, defrozen, and decellularized tissues; no statistically significant differences were reported for Young's modulus, ultimate stress, compliance, burst pressure, and suture retention strength, while ultimate strain and stress relaxation of decellularized vessels were significantly different from the native ones. Considering the overall results, the process was confirmed to be suitable for the generation of acellular scaffolds for vascular tissue engineering.

  17. Detergent-Enzymatic Decellularization of Swine Blood Vessels: Insight on Mechanical Properties for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Alessandro F. Pellegata


    Full Text Available Small caliber vessels substitutes still remain an unmet clinical need; few autologous substitutes are available, while synthetic grafts show insufficient patency in the long term. Decellularization is the complete removal of all cellular and nuclear matters from a tissue while leaving a preserved extracellular matrix representing a promising tool for the generation of acellular scaffolds for tissue engineering, already used for various tissues with positive outcomes. The aim of this work is to investigate the effect of a detergent-enzymatic decellularization protocol on swine arteries in terms of cell removal, extracellular matrix preservation, and mechanical properties. Furthermore, the effect of storage at −80°C on the mechanical properties of the tissue is evaluated. Swine arteries were harvested, frozen, and decellularized; histological analysis revealed complete cell removal and preserved extracellular matrix. Furthermore, the residual DNA content in decellularized tissues was far low compared to native one. Mechanical testings were performed on native, defrozen, and decellularized tissues; no statistically significant differences were reported for Young’s modulus, ultimate stress, compliance, burst pressure, and suture retention strength, while ultimate strain and stress relaxation of decellularized vessels were significantly different from the native ones. Considering the overall results, the process was confirmed to be suitable for the generation of acellular scaffolds for vascular tissue engineering.

  18. 76 FR 36231 - American Society of Mechanical Engineers (ASME) Codes and New and Revised ASME Code Cases (United States)


    ... Engineers (ASME) Codes and New and Revised ASME Code Cases; Final Rule #0;#0;Federal Register / Vol. 76 , No... 50 RIN 3150-AI35 American Society of Mechanical Engineers (ASME) Codes and New and Revised ASME Code... 2004 ASME Boiler and Pressure Vessel Code, Section III, Division 1; 2007 ASME Boiler and Pressure...

  19. 'Supermentoring' of assistant professors' teaching

    DEFF Research Database (Denmark)

    Lauridsen, Ole

    Aarhus University offers a mandatory pedagogical training program for assistant professors, required in order to obtain tenure at a Danish university. At Business and Social Sciences, this program is supplemented by voluntary observation and (first of all formative) supervision of the assistant...... professors’ teaching practice. This offer is given is (i) because many young university teachers face problems putting pedagogical theory into practice – even though the program mentioned is practice-oriented, and (ii) because many of them (partly due to (i)) lack self-confidence as to teaching....... The presentation will discuss the theoretical framework of the supervision given and compare it to other supervision models. Furthermore it will address the need of working with supervision in a SOTL context. Attendees will be activated through discussion of short prototypical cases. A possible – and desired...

  20. Observations on Professor Hayek's Plan

    Directory of Open Access Journals (Sweden)

    Ludwig von Mises


    Full Text Available This memorandum was written at the request of Henry Hazlitt to provide Mises’s comments on and concerns about F.A. Hayek’s initial proposals for what became the Mont Pèlerin Society. Mises stresses that those who favor liberty and freedom and oppose totalitarianism must also oppose interventionism. The memo argues that those who fought and lost against the rising tide of totalitarianism at the turn of the 20th Century lost their battles because they settled for middle-of-the-road policies that conceded considerable ground to the socialists. The weak point in Professor Hayek’s plan is that it relies upon the cooperation of many men who are today’s middle-of-the-roaders. As interventionists, they may not be the hoped-for intellectual pioneers to inspire people to build a freer world.

  1. Professor Camillo Negro's Neuropathological Films. (United States)

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella


    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease.

  2. Mechanical behavior of a cellulose-reinforced scaffold in vascular tissue engineering. (United States)

    Pooyan, Parisa; Tannenbaum, Rina; Garmestani, Hamid


    Scaffolds constitute an essential structural component in tissue engineering of a vascular substitute for small grafts by playing a significant role in integrating the overall tissue constructs. The microstructure and mechanical properties of such scaffolds are important parameters to promote further cellular activities and neo-tissue development. Cellulose nanowhiskers (CNWs), an abundant, biocompatible material, could potentially constitute an acceptable candidate in scaffolding of a tissue-engineered vessel. Inspired by the advantages of cellulose and its derivatives, we have designed a biomaterial comprising CNWs embedded in a matrix of cellulose acetate propionate to fabricate a fully bio-based scaffold. To ensure uniform distribution, CNWs were delicately extracted from a multi-stage process and dispersed in an acetone suspension prior to the composite fabrication. Comparable to carbon nanotubes or kevlar, CNWs impart significant strength and directional rigidity even at 0.2 wt% and almost double that at only 3.0 wt%. To ensure the accuracy of our experimental data and to predict the unusual reinforcing effect of CNWs in a cellulose-based composite, homogenization schemes such as the mean field approach and the percolation technique were also investigated. Based on these comparisons, the tendency of CNWs to interconnect with one another through strong hydrogen bonding confirmed the formation of a three-dimensional rigid percolating network, fact which imparted an excellent mechanical stability to the entire structure at such low filler contents. Hence, our fibrous porous microstructure with improved mechanical properties could introduce a potential scaffold to withstand the physiological pressure and to mimic the profile features of native extracellular matrix in a human vessel. We believe that our nanohybrid design not only could expand the biomedical applications of renewable cellulose-based materials but also could provide a potential scaffold candidate

  3. Matrix production and organization by endothelial colony forming cells in mechanically strained engineered tissue constructs.

    Directory of Open Access Journals (Sweden)

    Nicky de Jonge

    Full Text Available AIMS: Tissue engineering is an innovative method to restore cardiovascular tissue function by implanting either an in vitro cultured tissue or a degradable, mechanically functional scaffold that gradually transforms into a living neo-tissue by recruiting tissue forming cells at the site of implantation. Circulating endothelial colony forming cells (ECFCs are capable of differentiating into endothelial cells as well as a mesenchymal ECM-producing phenotype, undergoing Endothelial-to-Mesenchymal-transition (EndoMT. We investigated the potential of ECFCs to produce and organize ECM under the influence of static and cyclic mechanical strain, as well as stimulation with transforming growth factor β1 (TGFβ1. METHODS AND RESULTS: A fibrin-based 3D tissue model was used to simulate neo-tissue formation. Extracellular matrix organization was monitored using confocal laser-scanning microscopy. ECFCs produced collagen and also elastin, but did not form an organized matrix, except when cultured with TGFβ1 under static strain. Here, collagen was aligned more parallel to the strain direction, similar to Human Vena Saphena Cell-seeded controls. Priming ECFC with TGFβ1 before exposing them to strain led to more homogenous matrix production. CONCLUSIONS: Biochemical and mechanical cues can induce extracellular matrix formation by ECFCs in tissue models that mimic early tissue formation. Our findings suggest that priming with bioactives may be required to optimize neo-tissue development with ECFCs and has important consequences for the timing of stimuli applied to scaffold designs for both in vitro and in situ cardiovascular tissue engineering. The results obtained with ECFCs differ from those obtained with other cell sources, such as vena saphena-derived myofibroblasts, underlining the need for experimental models like ours to test novel cell sources for cardiovascular tissue engineering.

  4. Multiaxial mechanical response and constitutive modeling of esophageal tissues: Impact on esophageal tissue engineering. (United States)

    Sommer, Gerhard; Schriefl, Andreas; Zeindlinger, Georg; Katzensteiner, Andreas; Ainödhofer, Herwig; Saxena, Amulya; Holzapfel, Gerhard A


    Congenital defects of the esophagus are relatively frequent, with 1 out of 2500 babies suffering from such a defect. A new method of treatment by implanting tissue engineered esophagi into newborns is currently being developed and tested using ovine esophagi. For the reconstruction of the biological function of native tissues with engineered esophagi, their cellular structure as well as their mechanical properties must be considered. Since very limited mechanical and structural data for the esophagus are available, the aim of this study was to investigate the multiaxial mechanical behavior of the ovine esophagus and the underlying microstructure. Therefore, uniaxial tensile, biaxial tensile and extension-inflation tests on esophagi were performed. The underlying microstructure was examined in stained histological sections through standard optical microscopy techniques. Moreover, the uniaxial ultimate tensile strength and residual deformations of the tissue were determined. Both the mucosa-submucosa and the muscle layers showed nonlinear and anisotropic mechanical behavior during uniaxial, biaxial and inflation testing. Cyclical inflation of the intact esophageal tube caused marked softening of the passive esophagi in the circumferential direction. The rupture strength of the mucosa-submucosa layer was much higher than that of the muscle layer. Overall, the ovine esophagus showed a heterogeneous and anisotropic behavior with different mechanical properties for the individual layers. The intact and layer-specific multiaxial properties were characterized using a well-known three-dimensional microstructurally based strain-energy function. This novel and complete set of data serves the basis for a better understanding of tissue remodeling in diseased esophagi and can be used to perform computer simulations of surgical interventions or medical-device applications. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. An Approximate Solution for Boundary Value Problems in Structural Engineering and Fluid Mechanics

    Directory of Open Access Journals (Sweden)

    A. Barari


    Full Text Available Variational iteration method (VIM is applied to solve linear and nonlinear boundary value problems with particular significance in structural engineering and fluid mechanics. These problems are used as mathematical models in viscoelastic and inelastic flows, deformation of beams, and plate deflection theory. Comparison is made between the exact solutions and the results of the variational iteration method (VIM. The results reveal that this method is very effective and simple, and that it yields the exact solutions. It was shown that this method can be used effectively for solving linear and nonlinear boundary value problems.

  6. Concepts of supporting math courses for mechanical engineers during the first semesters (United States)

    Wallenta, Daniel


    The heterogeneity of students studying mechanical engineering at the University of Kassel causes some difficulties in mathematical education. More precisely, students start with very different levels of knowledge and practice in basic and advanced calculation methods and concepts. Due to this effect the classical mathematical education, consisting of main lecture, lecture hall instructions and exercises, has been extended by additional courses during the last couple of years. In the present paper we give an overview of these courses and other supporting arrangements. We explain their structure and interaction and discuss first positive effects.

  7. How College Students View a Professor's Role (United States)

    Gadzella, Bernadette M.


    Views of 3,670 students from six colleges and universities on most and least important traits of an ideal professor were analyzed. All data were collected with the same instrument. Data revealed students selected similar MOST and LEAST important traits of a quality professor. (Author)

  8. Finnish Students' Perceptions of a Visiting Professor. (United States)

    Haussler, Susan C.; Paavilainen, Eija; Astedt-Kurki, Paivi


    Finnish nursing students (n=31) evaluated their experience with a visiting Fulbright professor. Students were satisfied with course content, teaching methods, and information about the U.S. health care system. They thought the professor should have been more knowledgeable about Finnish culture, education, and health care. (Contains 15 references.)…

  9. Professor Delight: Cultivating Organizational Citizenship Behavior (United States)

    Mazen, Abdelmagid; Herman, Susan; Ornstein, Suzyn


    This article describes the rationale for and use of a class innovation the authors call "professor delight." This inexpensive, high-yield concept allows students and professors to enact their understanding of citizenship throughout the term, and often beyond. The authors explain the concept, describe its implementation in class, and link it to the…

  10. Program Guide for Diesel Engine Mechanics 8742000 (IN47.060500) and Heavy Duty Truck and Bus Mechanics DIM0991 (IN47.060501). (United States)

    University of South Florida, Tampa. Coll. of Education.

    This competency-based program guide provides course content information and procedures for secondary schools, postsecondary vocational schools, and community colleges in Florida that conduct programs in diesel engine mechanics and heavy duty truck and bus mechanics. The first section is on legal authority, which applies to all vocational education…

  11. Nitrite-induced cross-linking alters remodeling and mechanical properties of collagenous engineered tissues. (United States)

    Paik, David C; Saito, Lynne Y; Sugirtharaj, Dorcas D; Holmes, Jeffrey W


    Cumulative damage to long-lived connective tissue proteins play a key role in the development of age-related human diseases such as cardiovascular stiffening and age-related macular degeneration. The processes that result in the accumulation of increasingly insoluble, undigestible damaged collagen are only partially known. Nonenzymatic glycation (NEG) is one such process and has been linked to the development of diabetic-related complications and aging. An additional novel mechanism particularly relevant to smoking- and inflammation-related diseases involves the nonenzymatic nitrite (NEN) modification of connective tissue proteins. The present study was undertaken to examine the effects of NEN of fibrillar type I collagen on cell-mediated remodeling and mechanical properties of collagenous tissues. Using a modification of an in vitro fibroblast-populated collagen gel model system developed in our laboratory, we tested two hypotheses: NEN reduces the ability of primary adult cardiac fibroblasts to remodel type I collagen gels; NEN reduces the deformability of type I collagen gels subjected to mechanical testing. The results show that NEN impairs both cell-mediated remodeling and mechanical deformability in collagenous engineered tissues. Furthermore, these mechanical changes correlate with the degree of cross-linking as determined by SDS-PAGE. Thus, we concluded that NEN reactions may contribute to alterations in the biomechanical properties of collagen-containing tissues consistent with the age-related functional decline observed in human disease.

  12. Mechanical properties of native and tissue-engineered cartilage depend on carrier permeability: a bioreactor study. (United States)

    Hoenig, Elisa; Leicht, Uta; Winkler, Thomas; Mielke, Gabriela; Beck, Katharina; Peters, Fabian; Schilling, Arndt F; Morlock, Michael M


    The implantation of osteochondral constructs-tissue-engineered (TE) cartilage on a bone substitute carrier-is a promising method to treat defects in articular cartilage. Currently, however, the TE cartilage's mechanical properties are clearly inferior to those of native cartilage. Their improvement has been the subject of various studies, mainly focusing on growth factors and physical loading during cultivation. With the approach of osteochondral constructs another aspect arises: the permeability of the carrier materials. The purpose of this study was to investigate whether and how the permeability of the subchondral bone influences the properties of native cartilage and whether the bone substitute carrier's permeability influences the TE cartilage of osteochondral constructs accordingly. Consequently, the influence of the subchondral bone's permeability on native cartilage was determined: Native porcine cartilage-bone cylinders were cultivated for 2 weeks in a bioreactor under mechanical loading with and without restricted permeability of the bone. For the TE cartilage these two permeability conditions were investigated using permeable and impermeable tricalciumphosphate carriers under equivalent cultivation conditions. All specimens were evaluated mechanically, biochemically, and histologically. The restriction of the bone's permeability significantly decreased the Young's modulus of native cartilage in vitro. No biochemical differences were found. This finding was confirmed for TE cartilage: While the biochemical parameters were not affected, a permeable carrier improved the cell morphology and mechanical properties in comparison to an impermeable one. In conclusion, the carrier permeability was identified as a determining factor for the mechanical properties of TE cartilage of osteochondral constructs.

  13. A Model for the Molecular Mechanism of an Engineered Light-Driven Protein Machine. (United States)

    Hoersch, Daniel; Kortemme, Tanja


    Controllable protein-based machines and materials are of considerable interest for diverse biotechnological applications. We previously re-engineered an ATP-driven protein machine, a group II chaperonin, to function as a light-gated nanocage. Here we develop and test a model for the molecular mechanism of the re-engineered chaperonin, which undergoes a large-scale closed to open conformational change triggered by reversible photo-isomerization of a site-specifically attached azobenzene crosslinker. In silico experiments using all-atom simulations suggest that rigid body motions of protein subdomains couple the length changes of the crosslinker to rearrangements of the nucleotide-binding pocket, leading to cage opening. We tested this model by designing a mutant for which the orientation of the two protein subdomains forming the nucleotide-binding pocket is directly controlled by the crosslinker, and confirmed successful reversible photoswitching in vitro. The model probes the conformational cycle of group II chaperonins and offers a design principle for engineering other light-driven protein-based molecular machines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Implementation of the TRIZ innovation methodology: experience from a mechanical engineering company

    Directory of Open Access Journals (Sweden)

    Michal Jirásek


    Full Text Available In the rapidly changing world, an innovation process needs to become an efficient and consistent supply of innovative ideas – functioning despite growing the complexity of the products companies make and the shortening time frame between innovation and its deployment. Creativity and engineering solely are no longer able to handle the just-in-time stream of innovations required to keep the competitive advantage of a particular company, and for this reason, innovative methods structuring the process and bringing new ideas are needed. The TRIZ (the Theory of Inventive Problem Solving innovation methodology is proposed as a possible solution for the mechanical engineering company researched in this case study. The company manufactures products that have already been developed for decades and, therefore, struggle to bring a sufficient amount of innovations to keep up with the pace of its competitors. TRIZ provides engineers a structured approach to innovations and shows them possible principles used in the past to solve similar innovative problems. The case study follows the initial implementation of the methodology in the company and points out the difficulties faced during a two-day training of employees in using TRIZ. The selection of only some of the basic methods of TRIZ and an emphasis on their practical handling are proposed as a better way to begin the training of the methodology, rather than trying to give a participant a broad view of all the possibilities TRIZ offers.

  15. Combining mechanical foaming and thermally induced phase separation to generate chitosan scaffolds for soft tissue engineering. (United States)

    Biswas, D P; Tran, P A; Tallon, C; O'Connor, A J


    In this paper, a novel foaming methodology consisting of turbulent mixing and thermally induced phase separation (TIPS) was used to generate scaffolds for tissue engineering. Air bubbles were mechanically introduced into a chitosan solution which forms the continuous polymer/liquid phase in the foam created. The air bubbles entrained in the foam act as a template for the macroporous architecture of the final scaffolds. Wet foams were crosslinked via glutaraldehyde and frozen at -20 °C to induce TIPS in order to limit film drainage, bubble coalescence and Ostwald ripening. The effects of production parameters, including mixing speed, surfactant concentration and chitosan concentration, on foaming are explored. Using this method, hydrogel scaffolds were successfully produced with up to 80% porosity, average pore sizes of 120 μm and readily tuneable compressive modulus in the range of 2.6 to 25 kPa relevant to soft tissue engineering applications. These scaffolds supported 3T3 fibroblast cell proliferation and penetration and therefore show significant potential for application in soft tissue engineering.

  16. Multifaceted Learning Objective Assessment in a Mechanical Engineering Capstone Design Course (United States)

    Baker, Nicholas S.

    This thesis details multi method research approaches that have been used to study student learning objective instruction and assessment in the mechanical engineering (ME) capstone course at the University of Nevada, Reno (UNR). A primary focus of the research is to evaluate the pilot implementation of a Writing Fellows (WF) program in the ME capstone course, which has been assessed using a variety of techniques. The assessment generally indicates positive results. In particular, students favor the continuation of the program and find it more helpful than group consultations within the University Writing Center (UWC) alone. Self-assessment by the students indicates higher confidence in their communication skills, while preliminary analysis suggests that the writing fellow improved the scores of graded assignments by approximately one-third of a letter grade overall. Assessment efforts also highlight the need for deeper interaction between the WF and engineering faculty. A secondary focus of this research presents a methodology that has been developed and used to analyze how the Accreditation Board for Engineering and Technology's (ABET's) current Criterion 3 Student Outcomes (SOs) have been assessed in UNR's ME capstone class over several academic years. The methodology generally finds levels of ABET SO assessment in agreement with departmental and industry-held expectations for capstone courses at large. Finally, an analysis of student grades in the capstone course finds significant differences across semesters and identifies several potential causes.

  17. Quantitatively probing propensity for structural transitions in engineered virus nanoparticles by single-molecule mechanical analysis (United States)

    Castellanos, Milagros; Carrillo, Pablo J. P.; Mateu, Mauricio G.


    Viruses are increasingly being studied from the perspective of fundamental physics at the nanoscale as biologically evolved nanodevices with many technological applications. In viral particles of the minute virus of mice (MVM), folded segments of the single-stranded DNA genome are bound to the capsid inner wall and act as molecular buttresses that increase locally the mechanical stiffness of the particle. We have explored whether a quantitative linkage exists in MVM particles between their DNA-mediated stiffening and impairment of a heat-induced, virus-inactivating structural change. A series of structurally modified virus particles with disrupted capsid-DNA interactions and/or distorted capsid cavities close to the DNA-binding sites were engineered and characterized, both in classic kinetics assays and by single-molecule mechanical analysis using atomic force microscopy. The rate constant of the virus inactivation reaction was found to decrease exponentially with the increase in elastic constant (stiffness) of the regions closer to DNA-binding sites. The application of transition state theory suggests that the height of the free energy barrier of the virus-inactivating structural transition increases linearly with local mechanical stiffness. From a virological perspective, the results indicate that infectious MVM particles may have acquired the biological advantage of increased survival under thermal stress by evolving architectural elements that rigidify the particle and impair non-productive structural changes. From a nanotechnological perspective, this study provides proof of principle that determination of mechanical stiffness and its manipulation by protein engineering may be applied for quantitatively probing and tuning the conformational dynamics of virus-based and other protein-based nanoassemblies.Viruses are increasingly being studied from the perspective of fundamental physics at the nanoscale as biologically evolved nanodevices with many technological

  18. Interface Optoelectronics Engineering for Mechanically Stacked Tandem Solar Cells Based on Perovskite and Silicon. (United States)

    Kanda, Hiroyuki; Uzum, Abdullah; Nishino, Hitoshi; Umeyama, Tomokazu; Imahori, Hiroshi; Ishikawa, Yasuaki; Uraoka, Yukiharu; Ito, Seigo


    Engineering of photonics for antireflection and electronics for extraction of the hole using 2.5 nm of a thin Au layer have been performed for two- and four-terminal tandem solar cells using CH 3 NH 3 PbI 3 perovskite (top cell) and p-type single crystal silicon (c-Si) (bottom cell) by mechanically stacking. Highly transparent connection multilayers of evaporated-Au and sputtered-ITO films were fabricated at the interface to be a point-contact tunneling junction between the rough perovskite and flat silicon solar cells. The mechanically stacked tandem solar cell with an optimized tunneling junction structure was ⟨perovskite for the top cell/Au (2.5 nm)/ITO (154 nm) stacked-on ITO (108 nm)/c-Si for the bottom cell⟩. It was confirmed the best efficiency of 13.7% and 14.4% as two- and four-terminal devices, respectively.

  19. Grain Boundary Engineering the Mechanical Properties of Allvac 718Plus(Trademark) Superalloy (United States)

    Gabb, Timothy P.; Telesman, Jack; Garg, Anita; Lin, Peter; Provenzano, virgil; Heard, Robert; Miller, Herbert M.


    Grain Boundary Engineering can enhance the population of structurally-ordered "low S" Coincidence Site Lattice (CSL) grain boundaries in the microstructure. In some alloys, these "special" grain boundaries have been reported to improve overall resistance to corrosion, oxidation, and creep resistance. Such improvements could be quite beneficial for superalloys, especially in conditions which encourage damage and cracking at grain boundaries. Therefore, the effects of GBE processing on high-temperature mechanical properties of the cast and wrought superalloy Allvac 718Plus (Allvac ATI) were screened. Bar sections were subjected to varied GBE processing, and then consistently heat treated, machined, and tested at 650 C. Creep, tensile stress relaxation, and dwell fatigue crack growth tests were performed. The influences of GBE processing on microstructure, mechanical properties, and associated failure modes are discussed.

  20. Shear stress magnitude and duration modulates matrix composition and tensile mechanical properties in engineered cartilaginous tissue. (United States)

    Gemmiti, Christopher V; Guldberg, Robert E


    Cartilage tissue-engineering strategies aim to produce a functional extracellular matrix similar to that of the native tissue. However, none of the myriad approaches taken have successfully generated a construct possessing the structure, composition, and mechanical properties of healthy articular cartilage. One possible approach to modulating the matrix composition and mechanical properties of engineered tissues is through the use of bioreactor-driven mechanical stimulation. In this study, we hypothesized that exposing scaffold-free cartilaginous tissue constructs to 7 days of continuous shear stress at 0.001 or 0.1 Pa would increase collagen deposition and tensile mechanical properties compared to that of static controls. Histologically, type II collagen staining was evident in all construct groups, while a surface layer of type I collagen increased in thickness with increasing shear stress magnitude. The areal fraction of type I collagen was higher in the 0.1-Pa group (25.2 +/- 2.2%) than either the 0.001-Pa (13.6 +/- 3.8%) or the static (7.9 +/- 1.5%) group. Type II collagen content, as assessed by ELISA, was also higher in the 0.1-Pa group (7.5 +/- 2.1%) compared to the 0.001-Pa (3.0 +/- 2.25%) or static groups (3.7 +/- 3.2%). Temporal gene expression analysis showed a flow-induced increase in type I and type II collagen expression within 24 h of exposure. Interestingly, while the 0.1-Pa group showed higher collagen content, this group retained less sulfated glycosaminoglycans in the matrix over time in bioreactor culture. Increases in both tensile Young's modulus and ultimate strength were observed with increasing shear stress, yielding constructs possessing a modulus of nearly 5 MPa and strength of 1.3 MPa. This study demonstrates that shear stress is a potent modulator of both the amount and type of synthesized extracellular matrix constituents in engineered cartilaginous tissue with corresponding effects on mechanical function. Copyright 2009 Wiley

  1. Mechanical enhancement and in vitro biocompatibility of nanofibrous collagen-chitosan scaffolds for tissue engineering. (United States)

    Zou, Fengjuan; Li, Runrun; Jiang, Jianjun; Mo, Xiumei; Gu, Guofeng; Guo, Zhongwu; Chen, Zonggang


    The collagen-chitosan complex with a three-dimensional nanofiber structure was fabricated to mimic native ECM for tissue repair and biomedical applications. Though the three-dimensional hierarchical fibrous structures of collagen-chitosan composites could provide more adequate stimulus to facilitate cell adhesion, migrate and proliferation, and thus have the potential as tissue engineering scaffolding, there are still limitations in their applications due to the insufficient mechanical properties of natural materials. Because poly (vinyl alcohol) (PVA) and thermoplastic polyurethane (TPU) as biocompatible synthetic polymers can offer excellent mechanical properties, they were introduced into the collagen-chitosan composites to fabricate the mixed collagen/chitosan/PVA fibers and a sandwich structure (collagen/chitosan-TPU-collagen/chitosan) of nanofiber in order to enhance the mechanical properties of the nanofibrous collagen-chitosan scaffold. The results showed that the tensile behavior of materials was enhanced to different degrees with the difference of collagen content in the fibers. Besides the Young's modulus had no obvious changes, both the break strength and the break elongation of materials were heightened after reinforced by PVA. For the collagen-chitosan nanofiber reinforced by TPU, both the break strength and the Young's modulus of materials were heightened in different degrees with the variety of collagen content in the fibers despite the decrease of the break elongation of materials to some extent. In vitro cell test demonstrated that the materials could provide adequate environment for cell adhesion and proliferation. All these indicated that the reinforced collagen-chitosan nanofiber could be as potential scaffold for tissue engineering according to the different mechanical requirements in clinic.

  2. Efficiency of Mergers of Mechanical Engineering Companies in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Režňáková Mária


    Full Text Available This paper presents the research results in the field of the efficiency of mergers and acquisitions in the mechanical engineering industry of the Czech Republic. The aim of this paper is to determine whether mergers taking place in mechanical engineering are successful, or possibly to identify factors which may be deemed as synergies sources. In our research, the success rate of mergers is identified on the basis of the increasing revenues and operating profit. It has been established that out of mergers completed in 2004 - 2011, success has been achieved in approximately half of them. For this reason, we have focused on identifying the factors which may serve as the reasons for such a difference. The selected indicators of the cost-to-revenue ratio and utilization of fixed assets, investments, and net working capital we analysed before and after the mergers in both groups of successful and unsuccessful mergers. The Mann-Whitney U test was used to test the results. The research results have demonstrated that synergies are not achieved due to the change in the market power of the merged companied but owing to operational efficiency which is reflected in a drop in labour costs and depreciation to revenues ratios and increasing asset utilization.

  3. Virtual reality as a new trend in mechanical and electrical engineering education (United States)

    Kamińska, Dorota; Sapiński, Tomasz; Aitken, Nicola; Rocca, Andreas Della; Barańska, Maja; Wietsma, Remco


    In their daily practice, academics frequently face lack of access to modern equipment and devices, which are currently in use on the market. Moreover, many students have problems with understanding issues connected to mechanical and electrical engineering due to the complexity, necessity of abstract thinking and the fact that those concepts are not fully tangible. Many studies indicate that virtual reality can be successfully used as a training tool in various domains, such as development, health-care, the military or school education. In this paper, an interactive training strategy for mechanical and electrical engineering education shall be proposed. The prototype of the software consists of a simple interface, meaning it is easy for comprehension and use. Additionally, the main part of the prototype allows the user to virtually manipulate a 3D object that should be analyzed and studied. Initial studies indicate that the use of virtual reality can contribute to improving the quality and efficiency of higher education, as well as qualifications, competencies and the skills of graduates, and increase their competitiveness in the labour market.

  4. Proposal for the award of a contract for mechanical engineering design work at CERN

    CERN Document Server


    This document concerns the award of a contract for mechanical engineering design work at CERN. Following a market survey carried out among 54 firms in fourteen Member States, a call for tenders (IT-2879/EST) was sent on 13 August 2001 to eight firms and three consortia, each consisting of two firms, in eight Member States. By the closing date, CERN had received four tenders from two firms and two consortia in four Member States. The Finance Committee is invited to agree to the negotiation of a contract with the consortium KRAFTANLAGEN (DE) - THALES (FR), the lowest bidder, for mechanical engineering design work at CERN for an initial period of three years from 1 January 2003 for a total amount not exceeding 14 500 000 Swiss francs, subject to revision for inflation from 1 January 2005. The contract will include an option for two further one-year extensions beyond the initial three-year period. The consortium has indicated the following distribution by country of the contract values covered by this adjudicatio...

  5. Osmotic Engine: Translating Osmotic Pressure into Macroscopic Mechanical Force via Poly(Acrylic Acid) Based Hydrogels (United States)

    Arens, Lukas; Weißenfeld, Felix; Klein, Christopher O.; Schlag, Karin


    Poly(acrylic acid)‐based hydrogels can swell up to 100–1000 times their own weight in desalinated water due to osmotic forces. As the swelling is about a factor of 2–12 lower in seawater‐like saline solutions (4.3 wt% NaCl) than in deionized water, cyclic swelling, and shrinking can potentially be used to move a piston in an osmotic motor. Consequently, chemical energy is translated into mechanical energy. This conversion is driven by differences in chemical potential and by changes in entropy. This is special, as most thermodynamic engines rely instead on the conversion of heat into mechanical energy. To optimize the efficiency of this process, the degree of neutralization, the degree of crosslinking, and the particle size of the hydrogels are varied. Additionally, different osmotic engine prototypes are constructed. The maximum mean power of 0.23 W kg−1 dry hydrogel is found by using an external load of 6 kPa, a polymer with 1.7 mol% crosslinking, a degree of neutralization of 10 mol%, and a particle size of 370–670 µm. As this is achieved only in the first round of optimization, higher values of the maximum power average over one cycle seem realistic. PMID:28932675

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

    Directory of Open Access Journals (Sweden)

    Enrico Lertora


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

  7. Improving the mechanical properties of collagen-based membranes using silk fibroin for corneal tissue engineering. (United States)

    Long, Kai; Liu, Yang; Li, Weichang; Wang, Lin; Liu, Sa; Wang, Yingjun; Wang, Zhichong; Ren, Li


    Although collagen with outstanding biocompatibility has promising application in corneal tissue engineering, the mechanical properties of collagen-based scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This article describes a toughness reinforced collagen-based membrane using silk fibroin. The collagen-silk fibroin membranes based on collagen [silk fibroin (w/w) ratios of 100:5, 100:10, and 100:20] were prepared by using silk fibroin and cross-linking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These membranes were analyzed by scanning electron microscopy and their optical property, and NaCl and tryptophan diffusivity had been tested. The water content was found to be dependent on the content of silk fibroin, and CS10 membrane (loading 10 wt % of silk fibroin) performed the optimal mechanical properties. Also the suture experiments have proved CS10 has high suture retention strength, which can be sutured in rabbit eyes integrally. Moreover, the composite membrane proved good biocompatibility for the proliferation of human corneal epithelial cells in vitro. Lamellar keratoplasty shows that CS10 membrane promoted complete epithelialization in 35 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization, and keratoconus are not observed. The composite films show potential for use in the field of corneal tissue engineering. © 2014 Wiley Periodicals, Inc.

  8. Fabrication and mechanical characterization of a polyvinyl alcohol sponge for tissue engineering applications. (United States)

    Karimi, A; Navidbakhsh, M; Faghihi, S


    Polyvinyl alcohol (PVA) sponges are widely used for clinical applications, including ophthalmic surgical treatments, wound healing and tissue engineering. There is, however, a lack of sufficient data on the mechanical properties of PVA sponges. In this study, a biomechanical method is used to characterize the elastic modulus, maximum stress and strain as well as the swelling ratio of a fabricated PVA sponge (P-sponge) and it is compared with two commercially available PVA sponges (CENEFOM and EYETEC). The results indicate that the elastic modulus of the P-sponge is 5.32% and 13.45% lower than that of the CENEFOM and EYETEC sponges, while it bears 4.11% more and 10.37% less stress compared to the CENEFOM and EYETEC sponges, respectively. The P-sponge shows a maximum strain of 32% more than the EYETEC sponge as well as a 26.78% higher swelling ratio, which is a significantly higher absorbency compared to the CENEFOM. It is believed that the results of this study would help for a better understanding of the extension, rupture and swelling mechanism of PVA sponges, which could lead to crucial improvement in the design and application of PVA-based materials in ophthalmic and plastic surgeries as well as wound healing and tissue engineering.

  9. An Interview with Professor Melquíades de Dios Leyva, December 2008 (United States)

    Arias de Fuentes, Olimpia

    When writing about the history of physics in Cuba, this remarkable professor of quantum mechanics must be mentioned, for he embodies a most genuine example of the turn taken by national educational policy after 1959: Education for all, at all levels, with no discrimination or elitism. The following is an interview granted by Dr. Melquíades de Dios Leyva, Outstanding Full Professor of the Physics Faculty of the University of Havana, to Dr. Olimpia Arias de Fuentes, Associate Professor at the same, and Senior Researcher of the Institute of Materials Science and Technology (IMRE) of the University of Havana.

  10. Memorial to Professor Antonio Barone (United States)

    Tafuri, Francesco; Pepe, Giampiero; Vaglio, Ruggero


    Antonio Barone prematurely passed away on 4 December 2011 at the age of 72, after a one-year battle with cancer. He left behind his wife Sveva and his two sons, Alberto and Livio. Antonio was Professor Emeritus at the University of Napoli Federico II, where he had been teaching for about 40 years. The initial research activity of Antonio was in the field of nuclear physics. In this context, almost 45 years ago, the Ge 'Lithium drift' semiconductor detectors represented a novelty, due to the high energy resolution enabled by those devices. Superconductors stimulated new approaches to radiation detection and this motivated Antonio's interest towards superconductivity. Following the birth of the Laboratorio di Cibernetica of the CNR in 1967 he was given the opportunity to work on a joint USA-Italy project (University of Wisconsin, Madison and CNR Naples) in the field of superconductivity on the peculiar subject of the superconductive 'Neuristors'. His research activity on Josephson junctions opened up a wide variety of very stimulating subjects in which he was deeply involved, ranging from the soliton propagation in 'long' Josephson structures to fluctuations phenomena, from light-sensitive junctions and proximity effect to the development of innovative superconducting devices. The strong interaction of Antonio with the Landau Institute for Theoretical Physics of the Academy of Sciences in Moscow, characterizes a long period of his research activity with a precious merging of theoretical and experimental aspects. This body of work converged into the famous monograph on the 'Physics and Applications of the Josephson Effect', written in collaboration with Gianfranco Paternò in 1982. This rapidly became the reference text for the Josephson effect, as documented by thousands of citations and the fact that it was translated into Russian, Japanese and Chinese. In 1983 Antonio was awarded the highest academic title of 'Doctor of the Physical-Mathematical Sciences' by the

  11. Viscoelastic behaviour of hydrogel-based composites for tissue engineering under mechanical load. (United States)

    Kocen, Rok; Gasik, Michael; Gantar, Ana; Novak, Saša


    Along with biocompatibility, bioinductivity and appropriate biodegradation, mechanical properties are also of crucial importance for tissue engineering scaffolds. Hydrogels, such as gellan gum (GG), are usually soft materials, which may benefit from the incorporation of inorganic particles, e.g. bioactive glass, not only due to the acquired bioactivity, but also due to improved mechanical properties. They exhibit complex viscoelastic properties, which can be evaluated in various ways. In this work, to reliably evaluate the effect of the bioactive glass (BAG) addition on viscoelastic properties of the composite hydrogel, we employed and compared the three most commonly used techniques, analyzing their advantages and limitations: monotonic uniaxial unconfined compression, small amplitude oscillatory shear (SAOS) rheology and dynamic mechanical analysis (DMA). Creep and small amplitude dynamic strain-controlled tests in DMA are suggested as the best ways for the characterization of mechanical properties of hydrogel composites, whereas the SAOS rheology is more useful for studying the hydrogel's processing kinetics, as it does not induce volumetric changes even at very high strains. Overall, the results confirmed a beneficial effect of BAG (nano)particles on the elastic modulus of the GG-BAG composite hydrogel. The Young's modulus of 6.6 ± 0.8 kPa for the GG hydrogel increased by two orders of magnitude after the addition of 2 wt.% BAG particles (500-800 kPa).

  12. Mechanical loading regulates human MSC differentiation in a multi-layer hydrogel for osteochondral tissue engineering. (United States)

    Steinmetz, Neven J; Aisenbrey, Elizabeth A; Westbrook, Kristofer K; Qi, H Jerry; Bryant, Stephanie J


    A bioinspired multi-layer hydrogel was developed for the encapsulation of human mesenchymal stem cells (hMSCs) as a platform for osteochondral tissue engineering. The spatial presentation of biochemical cues, via incorporation of extracellular matrix analogs, and mechanical cues, via both hydrogel crosslink density and externally applied mechanical loads, were characterized in each layer. A simple sequential photopolymerization method was employed to form stable poly(ethylene glycol)-based hydrogels with a soft cartilage-like layer of chondroitin sulfate and low RGD concentrations, a stiff bone-like layer with high RGD concentrations, and an intermediate interfacial layer. Under a compressive load, the variation in hydrogel stiffness within each layer produced high strains in the soft cartilage-like layer, low strains in the stiff bone-like layer, and moderate strains in the interfacial layer. When hMSC-laden hydrogels were cultured statically in osteochondral differentiation media, the local biochemical and matrix stiffness cues were not sufficient to spatially guide hMSC differentiation after 21 days. However dynamic mechanical stimulation led to differentially high expression of collagens with collagen II in the cartilage-like layer, collagen X in the interfacial layer and collagen I in the bone-like layer and mineral deposits localized to the bone layer. Overall, these findings point to external mechanical stimulation as a potent regulator of hMSC differentiation toward osteochondral cellular phenotypes. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)

    L. O. Neduzha


    Full Text Available Purpose.To conduct the research at all stages of design, development, operation, residual operation life determination, namely, preliminary study, action principle choice, design of draft and technical projects, their optimization, preparation of design documentation and control information for automated production, comprehensive engineering analysis, it is required to use the latest computer technologies. Their use can not only present data and information in some way, but also gives the opportunity to effectively and directly interact with the information object that is created or demonstrated. Methodology.To perform engineering calculations associated with the analysis of the strength of machines, mechanisms, constructions one uses both analytical and numerical methods in practice.The most common method for analysing the stress-strain state of object models, obtaining their dynamic and stability characteristics at constant and variable modes of external load is the finite element method, which is implemented in many famous and widespread software products, providing strength calculation of models of machines, mechanisms and structures. Findings.The use of modern software for designing machine parts and various types of their joints and for strength analysis of structures is justified. Colour charts for distribution of stresses, displacement, internal efforts, safety factor and others allow accurate and quick identification of the most dangerous places in the structure. The program also provides an opportunity to «look» inside the elements and see the resulting distribution of internal force factors. Originality.The paper considered the aspects, which are unexplored at present, associated with the current state and prospects of development of industrial production, the use of software package for design and calculations in the mechanical industry. The result of the work is the justification of software application for solving problems that

  14. Engineering tissue constructs to mimic native aortic and pulmonary valve leaflets' structures and mechanics (United States)

    Masoumi, Nafiseh

    There are several disadvantages correlated with current heart valve replacement, including anticoagulation therapy for patients with mechanical valves and the low durability of bioprosthetic valves. The non-viable nature of such devices is a critical drawback especially for pediatric cases due to the inability of the graft to grow in vivo with the patients. A tissue engineered heart valve (TEHV) with remodeling and growth ability, is conceptually appealing to use in the surgical repair and could serve as a permanent replacements when operating for pediatric valvular lesions. It is critical that scaffolds for functional heart valve tissue engineering, be capable of mimicking the native leaflet's structure and mechanical properties at the time of implantation. Meanwhile, the scaffolds should be able to support cellular proliferation and native-like tissue formation as the TEHV remodels toward a scaffold-free state. Our overall hypothesis is that an "ideal" engineered construct, designed based on native leaflet's structure and mechanics, will complement a native heart valve leaflet in providing benchmarks for use in the design of clinically-applicable TEHV. This hypothesis was addressed through several experiments conducted in the present study. To establish a functional biomimetic TEHV, we developed scaffolds capable of matching the anisotropic stiffness of native leaflet while promoting native-like cell and collagen content and supporting the ECM generation. Scaffolds with various polymer contents (e.g., poly (glycerol sebacate) (PGS) and poly (epsilon-caprolactone) (PCL)) and structural designs (e.g., microfabricated and microfibrous scaffolds), were fabricated based on native leaflet's structure and mechanics. It was found that the tri-layered scaffold, designed with assembly of microfabricated PGS and microfibrous PGS/PCL was a functional leaflet capable of promoting tissue formation. Furthermore, to investigate the effect of cyclic stress and flexure

  15. Tomorrow's Professor, Preparing for an Academic/Research Career (United States)

    Reis, R. M.


    Richard M. Reis, author of Tomorrow's Professor: Preparing for Academic Careers in Science and Engineering, and a former executive officer of the Astronomical Society of the Pacific, will discuss the essential elements in preparing for, finding, and succeeding at academic careers in today's higher education environment. He will begin with a no-hold-barred look at the academic enterprise and the important ways it differs for all other institutions in society. The unique nature engineering and science - with a particular emphasis on astronomy and astrophysics - in higher education and the special problems facing new professors in these fields will be looked at next. Dr. Reis will then describe a powerful preparation strategy to make graduate students and postdocs competitive for academic positions while maintaining their options for worthwhile careers in government and industry. He will then explain how to get the offer you want and the start-up package you need to ensure success in your first critical years on the job. Finally, Dr. Reis will summarize essential insights from experienced faculty in all areas of science and engineering on how to develop a rewarding academic career and a quality of life that is both balanced and fulfilling. Plenty of time will be set aside for active interaction and discussion.

  16. Dynamic Mechanical Compression of Chondrocytes for Tissue Engineering: A Critical Review

    Directory of Open Access Journals (Sweden)

    Devon E. Anderson


    derived from different species, and complex loading regimes, did not necessarily corroborate prior positive results. These studies report positive results with respect to very specific conditions for cellular responses to dynamic load but fail to consistently achieve significant positive changes in relevant tissue engineering parameters, particularly collagen content and stiffness. There is a need for standardized methods and analyses of dynamic mechanical loading systems to guide the field of tissue engineering toward building cartilaginous implants that meet the goal of regenerating articular cartilage.

  17. Dynamic Mechanical Compression of Chondrocytes for Tissue Engineering: A Critical Review. (United States)

    Anderson, Devon E; Johnstone, Brian


    species, and complex loading regimes, did not necessarily corroborate prior positive results. These studies report positive results with respect to very specific conditions for cellular responses to dynamic load but fail to consistently achieve significant positive changes in relevant tissue engineering parameters, particularly collagen content and stiffness. There is a need for standardized methods and analyses of dynamic mechanical loading systems to guide the field of tissue engineering toward building cartilaginous implants that meet the goal of regenerating articular cartilage.


    Directory of Open Access Journals (Sweden)

    Maitê Alves Bezerra


    Full Text Available Ao observar a comunidade portuguesa que busca compreender a historicidade das formas e dos processos de escolarização por meio do estabelecimento de intenso diálogo com outras comunidades, é impossível não dar destaque à figura de António Manuel Seixas Nóvoa. Nascido em Lisboa no ano de 1954, aos 18 anos inicia o curso de Ciências da Educação na Universidade de Lisboa. Após lecionar em importantes universidades tais como Paris V, Oxford e Columbia University, atualmente acumula as posições de reitor da Universidade de Lisboa e professor catedrático da Faculdade de Psicologia e de Ciências da Educação na Instituição. Nóvoa tem se destacado à frente de debates internacionais a respeito da história da educação e educação comparada.

  19. Example of Good Practice of a Learning Environment with a Classroom Response System in a Mechanical Engineering Bachelor Course (United States)

    Arteaga, Ines Lopez; Vinken, Esther


    Results of a successful pilot study are presented, in which quizzes are introduced in a second year bachelor course for mechanical engineering students. The pilot study course entailed the basic concepts of mechanical vibrations in complex, realistic structures. The quiz is held weekly using a SharePoint application. The purpose of the quizzes is…

  20. Infusion of Emerging Technologies and New Teaching Methods into the Mechanical Engineering Curriculum at the City College of New York (United States)

    Delale, Feridun; Liaw, Benjamin M.; Jiji, Latif M.; Voiculescu, Ioana; Yu, Honghui


    From October 2003 to April 2008 a systemic reform of the Mechanical Engineering program at The City College of New York was undertaken with the goal of incorporating emerging technologies (such as nanotechnology, biotechnology, Micro-Electro-Mechanical Systems (MEMS), intelligent systems) and new teaching methodologies (such as project based…

  1. Cyanobacterial defense mechanisms against foreign DNA transfer and their impact on genetic engineering

    Directory of Open Access Journals (Sweden)

    Karina Stucken


    Full Text Available Cyanobacteria display a large diversity of cellular forms ranging from unicellular to complex multicellular filaments or aggregates. Species in the group present a wide range of metabolic characteristics including the fixation of atmospheric nitrogen, resistance to extreme environments, production of hydrogen, secondary metabolites and exopolysaccharides. These characteristics led to the growing interest in cyanobacteria across the fields of ecology, evolution, cell biology and biotechnology. The number of available cyanobacterial genome sequences has increased considerably in recent years, with more than 140 fully sequenced genomes to date. Genetic engineering of cyanobacteria is widely applied to the model unicellular strains Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942. However the establishment of transformation protocols in many other cyanobacterial strains is challenging. One obstacle to the development of these novel model organisms is that many species have doubling times of 48 h or more, much longer than the bacterial models E. coli or B. subtilis. Furthermore, cyanobacterial defense mechanisms against foreign DNA pose a physical and biochemical barrier to DNA insertion in most strains. Here we review the various barriers to DNA uptake in the context of lateral gene transfer among microbes and the various mechanisms for DNA acquisition within the prokaryotic domain. Understanding the cyanobacterial defense mechanisms is expected to assist in the development and establishment of novel transformation protocols that are specifically suitable for this group.

  2. Additively Manufactured Scaffolds for Bone Tissue Engineering and the Prediction of their Mechanical Behavior: A Review. (United States)

    Zhang, Xiang-Yu; Fang, Gang; Zhou, Jie


    Additive manufacturing (AM), nowadays commonly known as 3D printing, is a revolutionary materials processing technology, particularly suitable for the production of low-volume parts with high shape complexities and often with multiple functions. As such, it holds great promise for the fabrication of patient-specific implants. In recent years, remarkable progress has been made in implementing AM in the bio-fabrication field. This paper presents an overview on the state-of-the-art AM technology for bone tissue engineering (BTE) scaffolds, with a particular focus on the AM scaffolds made of metallic biomaterials. It starts with a brief description of architecture design strategies to meet the biological and mechanical property requirements of scaffolds. Then, it summarizes the working principles, advantages and limitations of each of AM methods suitable for creating porous structures and manufacturing scaffolds from powdered materials. It elaborates on the finite-element (FE) analysis applied to predict the mechanical behavior of AM scaffolds, as well as the effect of the architectural design of porous structure on its mechanical properties. The review ends up with the authors' view on the current challenges and further research directions.

  3. Mechanisms relevant to the enhanced virulence of a dihydroxynaphthalene-melanin metabolically engineered entomopathogen.

    Directory of Open Access Journals (Sweden)

    Min-Nan Tseng

    Full Text Available The entomopathogenic fungus Metarhizium anisopliae MA05-169 is a transformant strain that has been metabolically engineered to express dihydroxynaphthalene-melanin biosynthesis genes. In contrast to the wild type strain, the transformant displays a greater resistance to environmental stress and a higher virulence toward target insect host. However, the underlying mechanisms for these characteristics remain unclear; hence experiments were initiated to explore the possible mechanism(s through physiological and molecular approaches. Although both transformant and wild type strains could infect and share the same insect host range, the former germinated faster and produced more appressoria than the latter, both in vivo and in vitro. The transformant showed a significantly shorter median lethal time (LT50 when infecting the diamondback moth (Plutella xylostella and the striped flea beetle (Phyllotreta striolata, than the wild type. Additionally, the transformant was more tolerant to reactive oxygen species (ROS, produced 40-fold more orthosporin and notably overexpressed the transcripts of the pathogenicity-relevant hydrolytic enzymes (chitinase, protease, and phospholipase genes in vivo. In contrast, appressorium turgor pressure and destruxin A content were slightly decreased compared to the wild type. The transformant's high anti-stress tolerance, its high virulence against five important insect pests (cowpea aphid Aphis craccivora, diamondback moth Pl. xylostella, striped flea beetle Ph. striolata, and silverleaf whitefly Bemisia argentifolii and its capacity to colonize the root system are key properties for its potential bio-control field application.

  4. Enhanced mechanical properties of thermosensitive chitosan hydrogel by silk fibers for cartilage tissue engineering. (United States)

    Mirahmadi, Fereshteh; Tafazzoli-Shadpour, Mohammad; Shokrgozar, Mohammad Ali; Bonakdar, Shahin


    Articular cartilage has limited repair capability following traumatic injuries and current methods of treatment remain inefficient. Reconstructing cartilage provides a new way for cartilage repair and natural polymers are often used as scaffold because of their biocompatibility and biofunctionality. In this study, we added degummed chopped silk fibers and electrospun silk fibers to the thermosensitive chitosan/glycerophosphate hydrogels to reinforce two hydrogel constructs which were used as scaffold for hyaline cartilage regeneration. The gelation temperature and gelation time of hydrogel were analyzed by the rheometer and vial tilting method. Mechanical characterization was measured by uniaxial compression, indentation and dynamic mechanical analysis assay. Chondrocytes were then harvested from the knee joint of the New Zealand white rabbits and cultured in constructs. The cell proliferation, viability, production of glycosaminoglycans and collagen type II were assessed. The results showed that mechanical properties of the hydrogel were significantly enhanced when a hybrid with two layers of electrospun silk fibers was made. The results of GAG and collagen type II in cell-seeded scaffolds indicate support of the chondrogenic phenotype for chondrocytes with a significant increase in degummed silk fiber-hydrogel composite for GAG content and in two-layer electrospun fiber-hydrogel composite for Col II. It was concluded that these two modified scaffolds could be employed for cartilage tissue engineering. © 2013.

  5. Mechanically activated fly ash as a high performance binder for civil engineering (United States)

    Rieger, D.; Kullová, L.; Čekalová, M.; Novotný, P.; Pola, M.


    This study is aimed for investigation of fly ash binder with suitable properties for civil engineering needs. The fly ash from Czech brown coal power plant Prunerov II was used and mechanically activated to achieve suitable particle size for alkaline activation of hardening process. This process is driven by dissolution of aluminosilicate content of fly ash and by subsequent development of inorganic polymeric network called geopolymer. Hardening kinetics at 25 and 30 °C were measured by strain controlled small amplitude oscillatory rheometry with strain of 0.01 % and microstructure of hardened binder was evaluated by scanning electron microscopy. Strength development of hardened binder was investigated according to compressional and flexural strength for a period of 180 days. Our investigation finds out, that mechanically activated fly ash can be comparable to metakaolin geopolymers, according to setting time and mechanical parameters even at room temperature curing. Moreover, on the bases of long time strength development, achieved compressional strength of 134.5 after 180 days is comparable to performance of high grade Portland cement concretes.

  6. Evading Quantum Mechanics: Engineering a Classical Subsystem within a Quantum Environment

    Directory of Open Access Journals (Sweden)

    Mankei Tsang


    Full Text Available Quantum mechanics is potentially advantageous for certain information-processing tasks, but its probabilistic nature and requirement of measurement backaction often limit the precision of conventional classical information-processing devices, such as sensors and atomic clocks. Here we show that, by engineering the dynamics of coupled quantum systems, it is possible to construct a subsystem that evades the measurement backaction of quantum mechanics, at all times of interest, and obeys any classical dynamics, linear or nonlinear, that we choose. We call such a system a quantum-mechanics-free subsystem (QMFS. All of the observables of a QMFS are quantum-nondemolition (QND observables; moreover, they are dynamical QND observables, thus demolishing the widely held belief that QND observables are constants of motion. QMFSs point to a new strategy for designing classical information-processing devices in regimes where quantum noise is detrimental, unifying previous approaches that employ QND observables, backaction evasion, and quantum noise cancellation. Potential applications include gravitational-wave detection, optomechanical-force sensing, atomic magnetometry, and classical computing. Demonstrations of dynamical QMFSs include the generation of broadband squeezed light for use in interferometric gravitational-wave detection, experiments using entangled atomic-spin ensembles, and implementations of the quantum Toffoli gate.

  7. Development and Validation of a Reduced DME Mechanism Applicable to Various Combustion Modes in Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Gregory T. Chin


    Full Text Available A 28-species reduced chemistry mechanism for Dimethyl Ether (DME combustion is developed on the basis of a recent detailed mechanism by Zhao et al. (2008. The construction of reduced chemistry was carried out with automatic algorithms incorporating newly developed strategies. The performance of the reduced mechanism is assessed over a wide range of combustion conditions anticipated to occur in future advanced piston internal combustion engines, such as HCCI, SAHCCI, and PCCI. Overall, the reduced chemistry gives results in good agreement with those from the detailed mechanism for all the combustion modes tested. While the detailed mechanism by Zhao et al. (2008 shows reasonable agreement with the shock tube autoignition delay data, the detailed mechanism requires further improvement in order to better predict HCCI combustion under engine conditions.

  8. Engineering mechanical gradients in next generation biomaterials - Lessons learned from medical textile design. (United States)

    Ng, Joanna L; Collins, Ciara E; Knothe Tate, Melissa L


    facilitate transport of molecules and cells during tissue genesis within tissue defects (surgical membranes). External and internal biomaterial membranes prescribe boundary conditions for treatment of medical disorders, from oedema to tissue defects. Studies are needed to guide the design of next generation biomaterials and devices that incorporate gradient engineering approaches, which offer great potential to enhance function in a dynamic and physiological context. Mechanical gradients intrinsic to currently implemented biomaterials such as medical textiles and surgical interface membranes are poorly understood. Here we characterise quantitatively the mechanics of textile and nonwoven biomaterial membranes for external and internal use. The lack of seamless gradients in compression medical textiles contrasts with the graded mechanical effects achieved by elastomeric exercise bands, which are designed to deliver controlled, incremental increases in loading to facilitate healing as injured tissues return to normal structure and function. Engineering textiles with a prescient choice of fibre composition/size, type of knit/weave and inlay fibres, and weave density/anisotropy will enable creation of fabrics that can deliver spatially and temporally controlled mechanical gradients to maintain force balances at tissue boundaries, e.g. to treat oedema or tissue defects. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. The use of mechanically activated micronized coal in thermal power engineering

    Directory of Open Access Journals (Sweden)

    Burdukov Anatoliy P.


    Full Text Available Coal is one of the main energy resources and development of new promising technologies on its basis is certainly topical. This article discusses the use of new technology of gas and fuel oil replacement by mechanically activated micronized coal in power engineering: ignition and stabilization of pulverized coal flame combustion, as well as gasification of micronized coal in the flow. The new technology coal combustion with two stages of grinding is suggested. Optimization of the scheme of two-stage combustion is calculated. The first experimental data on the combustion process are obtained. The first demonstration tests on gas and heavy oil replacement by micronized coal during boiler ignition were carried out in the real power boiler with the capacity of 320 tons of steam per hour.

  10. Electro-Mechanical Response and Engineering Properties of Piezocomposite with Imperfect Interface

    Directory of Open Access Journals (Sweden)

    Tippayaphalapholgul Rattanan


    Full Text Available Composites of piezoelectric materials are widely use in practical applications such as nondestructive testing devices, smart adaptive structures and medical devices. A thorough understanding of coupled electro-elastic response and properties of piezocomposite are crucial for the development and design of piezoelectric composite materials used in advanced applications. The micromechanics analysis is employed in this paper to determine the response and engineering properties of the piezocomposite. A mechanical imperfect interface bonding between piezoelectric inclusion and polymer matrix is taken into consideration in the analysis. The micromechanics analysis is based on the Boundary Element Method (BEM together with the periodic micro-field micromechanics theory. A selected set of numerical results is presented to investigate the influence of volume ratio and interface bonding condition on effective piezocomposite material coefficients and portray basic features of coupled electroelastic response within the domain of piezocomposite unit cell.

  11. Outsourcing neural active control to passive composite mechanics: a tissue engineered cyborg ray (United States)

    Gazzola, Mattia; Park, Sung Jin; Park, Kyung Soo; Park, Shirley; di Santo, Valentina; Deisseroth, Karl; Lauder, George V.; Mahadevan, L.; Parker, Kevin Kit


    Translating the blueprint that stingrays and skates provide, we create a cyborg swimming ray capable of orchestrating adaptive maneuvering and phototactic navigation. The impossibility of replicating the neural system of batoids fish is bypassed by outsourcing algorithmic functionalities to the body composite mechanics, hence casting the active control problem into a design, passive one. We present a first step in engineering multilevel "brain-body-flow" systems that couple sensory information to motor coordination and movement, leading to behavior. This work paves the way for the development of autonomous and adaptive artificial creatures able to process multiple sensory inputs and produce complex behaviors in distributed systems and may represent a path toward soft-robotic "embodied cognition".

  12. Crosslinkable Graphene Oxide Embedded Nanocomposite Hydrogel with Enhanced Mechanics and Cytocompatibility for Tissue Engineering. (United States)

    Liu, Xifeng; Miller, Alan L; Waletzki, Brian E; Lu, Lichun


    Graphene oxide (GO) is an attractive material that can be utilized to enhance the modulus and conductivities of substrates and hydrogels. To covalently crosslink graphene oxide sheets into hydrogels, abundant crosslinkable double bonds were introduced to synthesize the graphene-oxide-tris-acrylate sheet (GO-TrisA). Polyacrylamide (PAM) nanocomposite hydrogels were then fabricated with inherent covalently and permanently crosslinked GO-TrisA sheets. Results showed the covalently crosslinked GO-TrisA/PAM nanocomposite hydrogel had enhanced mechanical strength, thermo stability compared with GO/PAM hydrogel maintained mainly by hydrogen bonding between PAM chains and GO sheets. In vitro cell study showed the covalently crosslinked rGO-TrisA/PAM nanocomposite hydrogel had excellent cytocompatibility after in situ reduction. These results suggest that rGO-TrisA/PAM nanocomposite hydrogel holds great potential for tissue engineering applications. This article is protected by copyright. All rights reserved. © 2017 Wiley Periodicals, Inc.

  13. Distortions and gender-related differences in the perception of mechanical engineering in high school students. (United States)

    Ferrando Piera, Pere Joan; Gutiérrez-Colón Plana, Mar; Paleo Cageao, Paloma; de la Flor López, Silvia; Ferrando Piera, Francesc


    The reason for this study was the low interest that high school students, particularly females, show for the subject of mechanical engineering (ME). We assumed that this problem was partly due to: (a) lack of understanding of the tasks involved in ME, and (b) a distorted and negative perception of the professional environment and working conditions. To assess these two assumptions, two measurement instruments (tasks and perceptions) were developed and administered in a sample of 496 high school students. A multiple-group design was used and data was analyzed by using an extended item response theory model. In general terms, the results agreed with our expectations. However, no significant gender differences were found. The implications of the results for future improvements are discussed.

  14. Preparation and mechanical property of a novel 3D porous magnesium scaffold for bone tissue engineering. (United States)

    Zhang, Xue; Li, Xiao-Wu; Li, Ji-Guang; Sun, Xu-Dong


    Porous magnesium has been recently recognized as a biodegradable metal for bone substitute applications. A novel porous Mg scaffold with three-dimensional (3D) interconnected pores and with a porosity of 33-54% was produced by the fiber deposition hot pressing (FDHP) technology. The microstructure and morphologies of the porous Mg scaffold were characterized by scanning electron microscopy (SEM), and the effects of porosities on the microstructure and mechanical properties of the porous Mg were investigated. Experimental results indicate that the measured Young's modulus and compressive strength of the Mg scaffold are ranged in 0.10-0.37 GPa, and 11.1-30.3 MPa, respectively, which are fairly comparable to those of cancellous bone. Such a porous Mg scaffold having a 3D interconnected network structure has the potential to be used in bone tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Effects of mechanical loading on the magnetic and dynamic properties of engineering materials (United States)

    Scherthan, L.; Auerbach, H.; Deldar, S.; Jenni, K.; Wolny, J. A.; Herlitschke, M.; Wille, H.-C.; Mutter, A.; Meiser, J.; Umstätter, P.; Urbassek, H. M.; Beck, T.; Smaga, M.; Schünemann, V.


    The influence of strain on the magnetic and dynamic properties of ARMCO iron has been characterized by Mössbauer spectroscopy and by Nuclear Inelastic Scattering of synchrotron radiation. The Mössbauer spectra, taken in backscattering geometry, reveal that the magnetic texture in these materials is depending on the type of mechanical loading, monotonic or cyclic, respectively. The applicability of Nuclear Inelastic Scattering for the investigation of the dynamic properties of these macroscopic bulk-engineering materials is shown. The so obtained phonon density of states of a monotonically loaded specimen shows slight differences in its shape and spectral features in comparison to the initial state. An influence of dislocations is also reflected in theoretically calculated phonon density of states based on classical molecular dynamics simulations.

  16. Effect of Kettlebell Lifting on Physical Condition of Future Mechanical Engineers

    Directory of Open Access Journals (Sweden)

    А. П. Конох


    Full Text Available The objective of the paper is to study the effect of exercises with kettlebell lifting elements on the physical condition of future mechanical engineers. Materials and methods. To address the tasks set, the study used the following research methods: theoretical analysis and collation of literary sources; implementation of a pilot program of physical education through kettlebell lifting in higher agricultural educational institutions; methods of mathematical statistics. Research results. The paper focuses on the relevant issue of theoretical and methodological support of the process of improving students' physical condition. The study has determined the effect of kettlebell lifting on the physical condition of the future mechanical engineers involved in maintenance and repair of agricultural equipment and machinery. Kettlebell lifting proves to provide good physical training, has a positive effect on the human body, and strengthens health in general. The research conducted gave grounds to determine that the level of the physical condition of the test group students is satisfactory on all indicators. This meets the requirements set before the future specialists. Conclusions. The study of the effectiveness of kettlebell lifting influence on the physical condition of the test group students yielded positive results. As a result, the training improves the performance of the students’ respiratory and cardiovascular systems, decreases their heart rate and blood pressure, enhances economization of the body systems performance at rest and at load, boosts the reserve capacity of these systems, reduces the recovery period after load, and improves the metabolic processes, which contributes to enhancing the organism tolerance to the unfavorable factors of the profession-related activity.

  17. Professor dr hab. Anna Maria Bujakiewicz

    Directory of Open Access Journals (Sweden)

    Anna Kujawa


    Full Text Available The article presents the biography and scientific achievements of Professor Anna Bujakiewicz. After receiving her master’s degree and doctorate in biology and mycology from Adam Mickiewicz University in Poznań, Professor Bujakiewicz continued her exciting research and teaching on mycology at her Alma Mater Posnaniensis for more than 50 years. Her publications in this field include many books, articles, and other scholarly reports.

  18. Torque and power characteristics of a helium charged Stirling engine with a lever controlled displacer driving mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Karabulut, H.; Cinar, C.; Oztuerk, E.; Yuecesu, H.S. [Department of Mechanical Technology, Faculty of Technical Education, Gazi University, 06500 Teknikokullar, Ankara (Turkey)


    This study presents test results of a Stirling engine with a lever controlled displacer driving mechanism. Tests were conducted with helium and the working fluid was charged into the engine block. The engine was loaded by means of a prony type micro dynamometer. The heat was supplied by a liquefied petroleum gas (LPG) burner. The engine started to run at 118 C hot end temperature and the systematic tests of the engine were conducted at 180 C, 220 C and 260 C hot end external surface temperatures. During the test, cold end temperature was kept at 27 C by means of water circulation. Variation of the shaft torque and power with respect to the charge pressure and hot end temperature were examined. The maximum torque and power were measured as 3.99 Nm and 183 W at 4 bars charge pressure and 260 C hot end temperature. Maximum power corresponded to 600 rpm speed. (author)

  19. A structural model for the flexural mechanics of nonwoven tissue engineering scaffolds. (United States)

    Engelmayr, George C; Sacks, Michael S


    The development of methods to predict the strength and stiffness of biomaterials used in tissue engineering is critical for load-bearing applications in which the essential functional requirements are primarily mechanical. We previously quantified changes in the effective stiffness (E) of needled nonwoven polyglycolic acid (PGA) and poly-L-lactic acid (PLLA) scaffolds due to tissue formation and scaffold degradation under three-point bending. Toward predicting these changes, we present a structural model for E of a needled nonwoven scaffold in flexure. The model accounted for the number and orientation of fibers within a representative volume element of the scaffold demarcated by the needling process. The spring-like effective stiffness of the curved fibers was calculated using the sinusoidal fiber shapes. Structural and mechanical properties of PGA and PLLA fibers and PGA, PLLA, and 50:50 PGA/PLLA scaffolds were measured and compared with model predictions. To verify the general predictive capability, the predicted dependence of E on fiber diameter was compared with experimental measurements. Needled nonwoven scaffolds were found to exhibit distinct preferred (PD) and cross-preferred (XD) fiber directions, with an E ratio (PD/XD) of approximately 3:1. The good agreement between the predicted and experimental dependence of E on fiber diameter (R2 = 0.987) suggests that the structural model can be used to design scaffolds with E values more similar to native soft tissues. A comparison with previous results for cell-seeded scaffolds (Engelmayr, G. C., Jr., et al., 2005, Biomaterials, 26(2), pp. 175-187) suggests, for the first time, that the primary mechanical effect of collagen deposition is an increase in the number of fiber-fiber bond points yielding effectively stiffer scaffold fibers. This finding indicated that the effects of tissue deposition on needled nonwoven scaffold mechanics do not follow a rule-of-mixtures behavior. These important results underscore

  20. Methodology for developing teaching activities and materials for use in fluid mechanics courses in undergraduate engineering programs

    Directory of Open Access Journals (Sweden)

    Pedro Javier Gamez-Montero


    Full Text Available “Mechanics” and “Fluids” are familiar concepts for any newly-registered engineering student. However, when combined into the term “Fluid Mechanics”, students are thrust into the great unknown. The present article demonstrates the process of adaptation employed by the Fluid Mechanics course in the undergraduate engineering program, along with the teaching methodology, teaching materials and results obtained, evaluating the final objective in terms of student satsfaction and level of learning.

  1. The use of physical and virtual manipulatives in an undergraduate mechanical engineering (Dynamics) course (United States)

    Pan, Edward A.

    Science, technology, engineering, and mathematics (STEM) education is a national focus. Engineering education, as part of STEM education, needs to adapt to meet the needs of the nation in a rapidly changing world. Using computer-based visualization tools and corresponding 3D printed physical objects may help nontraditional students succeed in engineering classes. This dissertation investigated how adding physical or virtual learning objects (called manipulatives) to courses that require mental visualization of mechanical systems can aid student performance. Dynamics is one such course, and tends to be taught using lecture and textbooks with static diagrams of moving systems. Students often fail to solve the problems correctly and an inability to mentally visualize the system can contribute to student difficulties. This study found no differences between treatment groups on quantitative measures of spatial ability and conceptual knowledge. There were differences between treatments on measures of mechanical reasoning ability, in favor of the use of physical and virtual manipulatives over static diagrams alone. There were no major differences in student performance between the use of physical and virtual manipulatives. Students used the physical and virtual manipulatives to test their theories about how the machines worked, however their actual time handling the manipulatives was extremely limited relative to the amount of time they spent working on the problems. Students used the physical and virtual manipulatives as visual aids when communicating about the problem with their partners, and this behavior was also seen with Traditional group students who had to use the static diagrams and gesture instead. The explanations students gave for how the machines worked provided evidence of mental simulation; however, their causal chain analyses were often flawed, probably due to attempts to decrease cognitive load. Student opinions about the static diagrams and dynamic

  2. Cell-matrix mechanical interaction in electrospun polymeric scaffolds for tissue engineering: Implications for scaffold design and performance. (United States)

    Kennedy, Kelsey M; Bhaw-Luximon, Archana; Jhurry, Dhanjay


    Engineered scaffolds produced by electrospinning of biodegradable polymers offer a 3D, nanofibrous environment with controllable structural, chemical, and mechanical properties that mimic the extracellular matrix of native tissues and have shown promise for a number of tissue engineering applications. The microscale mechanical interactions between cells and electrospun matrices drive cell behaviors including migration and differentiation that are critical to promote tissue regeneration. Recent developments in understanding these mechanical interactions in electrospun environments are reviewed, with emphasis on how fiber geometry and polymer structure impact on the local mechanical properties of scaffolds, how altering the micromechanics cues cell behaviors, and how, in turn, cellular and extrinsic forces exerted on the matrix mechanically remodel an electrospun scaffold throughout tissue development. Techniques used to measure and visualize these mechanical interactions are described. We provide a critical outlook on technological gaps that must be overcome to advance the ability to design, assess, and manipulate the mechanical environment in electrospun scaffolds toward constructs that may be successfully applied in tissue engineering and regenerative medicine. Tissue engineering requires design of scaffolds that interact with cells to promote tissue development. Electrospinning is a promising technique for fabricating fibrous, biomimetic scaffolds. Effects of electrospun matrix microstructure and biochemical properties on cell behavior have been extensively reviewed previously; here, we consider cell-matrix interaction from a mechanical perspective. Micromechanical properties as a driver of cell behavior has been well established in planar substrates, but more recently, many studies have provided new insights into mechanical interaction in fibrillar, electrospun environments. This review provides readers with an overview of how electrospun scaffold mechanics and

  3. Assistant professor's National Science Foundation CAREER grant will help understand cell cycle model


    Mackay, Steven D.


    Yang Cao, an assistant professor in the computer science department at Virginia Tech's College of Engineering, has won a $550,000 National Science Foundation Faculty Early Career Development (CAREER) award to develop computer simulation methods that will better understand the complex, discrete, and stochastic cell cycle model.

  4. Engineering on the straight and narrow: the mechanics of nanofibrous assemblies for fiber-reinforced tissue regeneration. (United States)

    Mauck, Robert L; Baker, Brendon M; Nerurkar, Nandan L; Burdick, Jason A; Li, Wan-Ju; Tuan, Rocky S; Elliott, Dawn M


    Tissue engineering of fibrous tissues of the musculoskeletal system represents a considerable challenge because of the complex architecture and mechanical properties of the component structures. Natural healing processes in these dense tissues are limited as a result of the mechanically challenging environment of the damaged tissue and the hypocellularity and avascular nature of the extracellular matrix. When healing does occur, the ordered structure of the native tissue is replaced with a disorganized fibrous scar with inferior mechanical properties, engendering sites that are prone to re-injury. To address the engineering of such tissues, we and others have adopted a structurally motivated approach based on organized nanofibrous assemblies. These scaffolds are composed of ultrafine polymeric fibers that can be fabricated in such a way to recreate the structural anisotropy typical of fiber-reinforced tissues. This straight-and-narrow topography not only provides tailored mechanical properties, but also serves as a 3D biomimetic micropattern for directed tissue formation. This review describes the underlying technology of nanofiber production and focuses specifically on the mechanical evaluation and theoretical modeling of these structures as it relates to native tissue structure and function. Applying the same mechanical framework for understanding native and engineered fiber-reinforced tissues provides a functional method for evaluating the utility and maturation of these unique engineered constructs. We further describe several case examples where these principles have been put to test, and discuss the remaining challenges and opportunities in forwarding this technology toward clinical implementation.

  5. Engineering on the Straight and Narrow: The Mechanics of Nanofibrous Assemblies for Fiber-Reinforced Tissue Regeneration (United States)

    Baker, Brendon M.; Nerurkar, Nandan L.; Burdick, Jason A.; Li, Wan-Ju; Tuan, Rocky S.; Elliott, Dawn M.


    Tissue engineering of fibrous tissues of the musculoskeletal system represents a considerable challenge because of the complex architecture and mechanical properties of the component structures. Natural healing processes in these dense tissues are limited as a result of the mechanically challenging environment of the damaged tissue and the hypocellularity and avascular nature of the extracellular matrix. When healing does occur, the ordered structure of the native tissue is replaced with a disorganized fibrous scar with inferior mechanical properties, engendering sites that are prone to re-injury. To address the engineering of such tissues, we and others have adopted a structurally motivated approach based on organized nanofibrous assemblies. These scaffolds are composed of ultrafine polymeric fibers that can be fabricated in such a way to recreate the structural anisotropy typical of fiber-reinforced tissues. This straight-and-narrow topography not only provides tailored mechanical properties, but also serves as a 3D biomimetic micropattern for directed tissue formation. This review describes the underlying technology of nanofiber production and focuses specifically on the mechanical evaluation and theoretical modeling of these structures as it relates to native tissue structure and function. Applying the same mechanical framework for understanding native and engineered fiber-reinforced tissues provides a functional method for evaluating the utility and maturation of these unique engineered constructs. We further describe several case examples where these principles have been put to test, and discuss the remaining challenges and opportunities in forwarding this technology toward clinical implementation. PMID:19207040

  6. Differences between Male Students' and Female Students' Perception of Professors (United States)

    Tomkiewicz, Joseph; Bass, Kenneth


    This study is an empirical examination of possible differences between female and male college seniors' perceptions between male and female college professors. Subjects were presented with three variations of a scale designed to measure students' perceptions of university professors in general, female professors, and male professors. These…

  7. Improvements in Mechanical Properties of 319 Al Alloy Engine Blocks Through Cost-Effective Solution Heat Treatment (United States)

    Lombardi, A.; Ravindran, C.; MacKay, R.


    The use of Al engine blocks has increased significantly to improve vehicle fuel efficiency. However, the gray cast iron cylinder liners cause the development of large tensile residual stress along the cylinder bores which necessitates the optimization of mechanical properties in this region to prevent premature engine failure. This study compared the microstructure of T4-treated Al billet castings of varying cooling rate to that of the cylinder region of T4-treated (current production schedule) Al engine blocks. The aim of this study was to develop a cost-effective small scale heat treatment optimization method for engine block production. Comparisons in microstructure between the engine block and the billet castings were carried out using optical and scanning electron microscopy. The results suggest that the microstructure and hardness at the top, middle, and bottom of the cylinder were similar to those of each representative billet casting, indicating that heat treatment resulted in successful replication of the engine block locations. In addition, tensile testing revealed that the YS and UTS increased slightly following T4 treatment for all billet castings, which was also observed at the middle of the engine block cylinder bridge. As such, this method can be an effective forerunner for future heat treatment optimization in Al engine block production.

  8. Mechanisms Underlying Cytotoxicity Induced by Engineered Nanomaterials: A Review of In Vitro Studies (United States)

    Nogueira, Daniele R.; Mitjans, Montserrat; Rolim, Clarice M. B.; Vinardell, M. Pilar


    Engineered nanomaterials are emerging functional materials with technologically interesting properties and a wide range of promising applications, such as drug delivery devices, medical imaging and diagnostics, and various other industrial products. However, concerns have been expressed about the risks of such materials and whether they can cause adverse effects. Studies of the potential hazards of nanomaterials have been widely performed using cell models and a range of in vitro approaches. In the present review, we provide a comprehensive and critical literature overview on current in vitro toxicity test methods that have been applied to determine the mechanisms underlying the cytotoxic effects induced by the nanostructures. The small size, surface charge, hydrophobicity and high adsorption capacity of nanomaterial allow for specific interactions within cell membrane and subcellular organelles, which in turn could lead to cytotoxicity through a range of different mechanisms. Finally, aggregating the given information on the relationships of nanomaterial cytotoxic responses with an understanding of its structure and physicochemical properties may promote the design of biologically safe nanostructures. PMID:28344232

  9. Continuum theory of fibrous tissue damage mechanics using bond kinetics: application to cartilage tissue engineering. (United States)

    Nims, Robert J; Durney, Krista M; Cigan, Alexander D; Dusséaux, Antoine; Hung, Clark T; Ateshian, Gerard A


    This study presents a damage mechanics framework that employs observable state variables to describe damage in isotropic or anisotropic fibrous tissues. In this mixture theory framework, damage is tracked by the mass fraction of bonds that have broken. Anisotropic damage is subsumed in the assumption that multiple bond species may coexist in a material, each having its own damage behaviour. This approach recovers the classical damage mechanics formulation for isotropic materials, but does not appeal to a tensorial damage measure for anisotropic materials. In contrast with the classical approach, the use of observable state variables for damage allows direct comparison of model predictions to experimental damage measures, such as biochemical assays or Raman spectroscopy. Investigations of damage in discrete fibre distributions demonstrate that the resilience to damage increases with the number of fibre bundles; idealizing fibrous tissues using continuous fibre distribution models precludes the modelling of damage. This damage framework was used to test and validate the hypothesis that growth of cartilage constructs can lead to damage of the synthesized collagen matrix due to excessive swelling caused by synthesized glycosaminoglycans. Therefore, alternative strategies must be implemented in tissue engineering studies to prevent collagen damage during the growth process.

  10. Polyphenols modulate calcium-independent mechanisms in human arterial tissue-engineered vascular media. (United States)

    Diebolt, Myriam; Laflamme, Karina; Labbé, Raymond; Auger, François A; Germain, Lucie; Andriantsitohaina, Ramaroson


    In the present study, an arterial tissue-engineered vascular media (TEVM) was produced from cultured human smooth muscle cells of the umbilical artery and we took advantage of this model to evaluate the regulation of contraction and the signalling pathways of polyphenols in arteries. Cultured human smooth muscle cells of the umbilical artery were used to produce arterial TEVMs. Contraction experiments were performed to determine intracellular targets involved in the modulation of contraction by polyphenols extract from red wine, Provinols (SEPPIC Groupe Air Liquide, Paris, France). Smooth muscle cells in arterial TEVM displayed a differentiated phenotype as demonstrated by the expression of alpha-smooth muscle actin, a vascular smooth muscle-specific marker, and tissue contraction in response to vasoconstrictor and vasodilator agents. Contractions caused by histamine were associated with an increase in [Ca(2+)](i) and a Ca(2+)-independent signalling pathway. The latter pathway involved mechanisms sensitive to protein kinase C, myosin light chain kinase, and Rho-associated protein kinase inhibitors. The regulation of contraction induced by Provinols shows that treatment of arterial TEVM with this compound significantly decreased histamine-induced contraction. This effect was associated with the inhibition of the Rho-associated protein kinase pathway and the decrease in alpha-smooth muscle actin expression. The use of arterial TEVM, brings new insights into the mechanisms by which polyphenols regulate vascular contraction in the human artery.

  11. Mechanics

    CERN Document Server

    Hartog, J P Den


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

  12. Biochemical, mechanical, and spectroscopic analyses of genetically engineered flax fibers producing bioplastic (poly-beta-hydroxybutyrate). (United States)

    Wróbel-Kwiatkowska, Magdalena; Skórkowska-Telichowska, Katarzyna; Dymińska, Lucyna; Maczka, Mirosław; Hanuza, Jerzy; Szopa, Jan


    The interest in biofibers has grown in recent years due to their expanding range of applications in fields as diverse as biomedical science and the automotive industry. Their low production costs, biodegradability, physical properties, and perceived eco-friendliness allow for their extensive use as composite components, a role in which they could replace petroleum-based synthetic polymers. We performed biochemical, mechanical, and structural analyses of flax stems and fibers derived from field-grown transgenic flax enriched with PHB (poly-beta-hydroxybutyrate). The analyses of the plant stems revealed an increase in the cellulose content and a decrease in the lignin and pectin contents relative to the control plants. However, the contents of the fibers' major components (cellulose, lignin, pectin) remain unchanged. An FT-IR study confirmed the results of the biochemical analyses of the flax fibers. However, the arrangement of the cellulose polymer in the transgenic fibers differed from that in the control, and a significant increase in the number of hydrogen bonds was detected. The mechanical properties of the transgenic flax stems were significantly improved, reflecting the cellulose content increase. However, the mechanical properties of the fibers did not change in comparison with the control, with the exception of the fibers from transgenic line M13. The generated transgenic flax plants, which produce both components of the flax/PHB composites (i.e., fibers and thermoplastic matrix in the same plant organ) are a source of an attractive and ecologically safe material for industry and medicine. 2009 American Institute of Chemical Engineers Biotechnol.

  13. Mechanical properties and in vitro behavior of nanofiber-hydrogel composites for tissue engineering applications. (United States)

    Kai, Dan; Prabhakaran, Molamma P; Stahl, Benjamin; Eblenkamp, Markus; Wintermantel, Erich; Ramakrishna, Seeram


    Hydrogel-based biomaterial systems have great potential for tissue reconstruction by serving as temporary scaffolds and cell delivery vehicles for tissue engineering (TE). Hydrogels have poor mechanical properties and their rapid degradation limits the development and application of hydrogels in TE. In this study, nanofiber reinforced composite hydrogels were fabricated by incorporating electrospun poly(ε-caprolactone) (PCL)/gelatin 'blend' or 'coaxial' nanofibers into gelatin hydrogels. The morphological, mechanical, swelling and biodegradation properties of the nanocomposite hydrogels were evaluated and the results indicated that the moduli and compressive strengths of the nanofiber reinforced hydrogels were remarkably higher than those of pure gelatin hydrogels. By increasing the amount of incorporated nanofibers into the hydrogel, the Young's modulus of the composite hydrogels increased from 3.29 ± 1.02 kPa to 20.30 ± 1.79 kPa, while the strain at break decreased from 66.0 ± 1.1% to 52.0 ± 3.0%. Compared to composite hydrogels with coaxial nanofibers, those with blend nanofibers showed higher compressive strength and strain at break, but with lower modulus and energy dissipation properties. Biocompatibility evaluations of the nanofiber reinforced hydrogels were carried out using bone marrow mesenchymal stem cells (BM-MSCs) by cell proliferation assay and immunostaining analysis. The nanocomposite hydrogel with 25 mg ml(-1) PCL/gelatin 'blend' nanofibers (PGB25) was found to enhance cell proliferation, indicating that the 'nanocomposite hydrogels' might provide the necessary mechanical support and could be promising cell delivery systems for tissue regeneration.

  14. Relationship between micro-porosity, water permeability and mechanical behavior in scaffolds for cartilage engineering. (United States)

    Vikingsson, L; Claessens, B; Gómez-Tejedor, J A; Gallego Ferrer, G; Gómez Ribelles, J L


    In tissue engineering the design and optimization of biodegradable polymeric scaffolds with a 3D-structure is an important field. The porous scaffold provide the cells with an adequate biomechanical environment that allows mechanotransduction signals for cell differentiation and the scaffolds also protect the cells from initial compressive loading. The scaffold have interconnected macro-pores that host the cells and newly formed tissue, while the pore walls should be micro-porous to transport nutrients and waste products. Polycaprolactone (PCL) scaffolds with a double micro- and macro-pore architecture have been proposed for cartilage regeneration. This work explores the influence of the micro-porosity of the pore walls on water permeability and scaffold compliance. A Poly(Vinyl Alcohol) with tailored mechanical properties has been used to simulate the growing cartilage tissue inside the scaffold pores. Unconfined and confined compression tests were performed to characterize both the water permeability and the mechanical response of scaffolds with varying size of micro-porosity while volume fraction of the macro-pores remains constant. The stress relaxation tests show that the stress response of the scaffold/hydrogel construct is a synergic effect determined by the performance of the both components. This is interesting since it suggests that the in vivo outcome of the scaffold is not only dependent upon the material architecture but also the growing tissue inside the scaffold׳s pores. On the other hand, confined compression results show that compliance of the scaffold is mainly controlled by the micro-porosity of the scaffold and less by hydrogel density in the scaffold pores. These conclusions bring together valuable information for customizing the optimal scaffold and to predict the in vivo mechanical behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Effective management of engineering know how. A pragmatic approach to knowledge management for special mechanical engineering; Ingenieurwissen effektiv managen. Ein pragmatischer Ansatz zum Wissensmanagement im Sondermaschinenbau

    Energy Technology Data Exchange (ETDEWEB)

    Wappler, D. [Bosch Packaging Technology, Crailsheim (Germany)


    In the special mechanical engineering known physical effects are often put together for solutions. A crucial factor in this business is to include existing experiences and ''best practices'' in the realization and to make this knowledge not only accessible to a wide number of associates but applicable. This article focuses on the requirements from the practice of the special mechanical engineering industry. The path from the message to the information and from the information to become knowledge is presented, and the following success factors are discussed: Organization: develop methods - monitor compliance, Content: from the practice - for the practice, Tools: integrated ''knowledge management'' into the tools of the technical designer, easy to add and maintain, - simply to use. Realized examples from the design manual at Bosch Packaging or the integration of knowledge in the CAD system as well as from the guideline organization provide a reference to the practice. (orig.)

  16. Manipulation of mechanical compliance of elastomeric PGS by incorporation of halloysite nanotubes for soft tissue engineering applications. (United States)

    Chen, Qi-Zhi; Liang, Shu-Ling; Wang, Jiang; Simon, George P


    Poly (glycerol sebacate) (PGS) is a promising elastomer for use in soft tissue engineering. However, it is difficult to achieve with PGS a satisfactory balance of mechanical compliance and degradation rate that meet the requirements of soft tissue engineering. In this work, we have synthesised a new PGS nanocomposite system filled with halloysite nanotubes, and mechanical properties, as well as related chemical characters, of the nanocomposites were investigated. It was found that the addition of nanotubular halloysite did not compromise the extensibility of material, compared with the pure PGS counterpart; instead the elongation at rupture was increased from 110 (in the pure PGS) to 225% (in the 20 wt% composite). Second, Young's modulus and resilience of 3-5 wt% composites were ∼0.8 MPa and >94% respectively, remaining close to the level of pure PGS which is desired for applications in soft tissue engineering. Third, an important feature of the 1-5 wt% composites was their stable mechanical properties over an extended period, which could allow the provision of reliable mechanical support to damaged tissues during the lag phase of the healing process. Finally, the in vitro study indicated that the addition of halloysite slowed down the degradation rate of the composites. In conclusion, the good compliance, enhanced stretchability, stable mechanical behavior over an extended period, and reduced degradation rates make the 3-5 wt% composites promising candidates for application in soft tissue engineering. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Accounting Professor Qualification in Digital Age: A Perception Study on Brazilian Professors (United States)

    Vendruscolo, Maria Ivanice; Behar, Patrícia Alejandra


    This papers aims at analyzing the perception of Accounting professors about the necessary qualifications in Accounting undergraduate courses. The contribution of this study is to theoretically discuss the education of Accounting professors, with empirical data, because Accounting teaching requires specific competencies in the digital area. The…

  18. A novel bioreactor system for biaxial mechanical loading enhances the properties of tissue-engineered human cartilage. (United States)

    Meinert, Christoph; Schrobback, Karsten; Hutmacher, Dietmar W; Klein, Travis J


    The ex vivo engineering of autologous cartilage tissues has the potential to revolutionize the clinical management of joint disorders. Yet, high manufacturing costs and variable outcomes associated with tissue-engineered implants are still limiting their application. To improve clinical outcomes and facilitate a wider use of engineered tissues, automated bioreactor systems capable of enhancing and monitoring neotissues are required. Here, we developed an innovative system capable of applying precise uni- or biaxial mechanical stimulation to developing cartilage neotissues in a tightly controlled and automated fashion. The bioreactor allows for simple control over the loading parameters with a user-friendly graphical interface and is equipped with a load cell for monitoring tissue maturation. Applying our bioreactor, we demonstrate that human articular chondrocytes encapsulated in hydrogels composed of gelatin methacryloyl (GelMA) and hyaluronic acid methacrylate (HAMA) respond to uni- and biaxial mechanical stimulation by upregulation of hyaline cartilage-specific marker genes. We further demonstrate that intermittent biaxial mechanostimulation enhances accumulation of hyaline cartilage-specific extracellular matrix. Our study underlines the stimulatory effects of mechanical loading on the biosynthetic activity of human chondrocytes in engineered constructs and the need for easy-to-use, automated bioreactor systems in cartilage tissue engineering.

  19. The housekeeper and the professor a novel

    CERN Document Server

    Ogawa, Yoko


    He is a brilliant math Professor with a peculiar problem—ever since a traumatic head injury, he has lived with only eighty minutes of short-term memory. She is an astute young Housekeeper—with a ten-year-old son—who is hired to care for the Professor. And every morning, as the Professor and the Housekeeper are introduced to each other anew, a strange and beautiful relationship blossoms between them. Though he cannot hold memories for long (his brain is like a tape that begins to erase itself every eighty minutes), the Professor's mind is still alive with elegant equations from the past. And the numbers, in all of their articulate order, reveal a sheltering and poetic world to both the Housekeeper and her young son. The Professor is capable of discovering connections between the simplest of quantities—like the Housekeeper's shoe size—and the universe at large, drawing their lives ever closer and more profoundly together, even as his memory slips away. Yoko Ogawa's The Housekeeper and the Professo...

  20. Investigation of Deposit Formation Mechanisms for Engine In-cylinder Combustion and Exhaust Systems Using Quantitative Analysis and Sustainability Study (United States)

    Ye, Z.; Meng, Q.; Mohamadian, H. P.; Wang, J. T.; Chen, L.; Zhu, L.


    The formation of SI engine combustion deposits is a complex phenomenon which depends on various factors of fuel, oil, additives, and engine. The goal of this study is to examine the effects of operating conditions, gasoline, lubricating oil, and additives on deposit formation. Both an experimental investigation and theoretical analysis are conducted on a single cylinder engine. As a result, the impact of deposits on engine performance and exhaust emissions (HC, NO x ) has been indicated. Using samples from a cylinder head and exhaust pipe as well as switching gases via the dual-gas method (N2, O2), the deposit formation mechanism is thoroughly investigated via the thermogravity analysis approach, where the roles of organic, inorganic, and volatile components of fuel, additives, and oil on deposit formation are identified from thermogravity curves. Sustainable feedback control design is then proposed for potential emission control and performance optimization

  1. Physics of Mechanical, Gaseous, and Fluid Systems. A Study Guide of the Science and Engineering Technician Curriculum. (United States)

    Dixon, Peggy; And Others

    This study guide is part of a program of studies entitled Science and Engineering Technician (SET) Curriculum. The SET Curriculum integrates elements from the disciplines of chemistry, physics, mathematics, mechanical technology, and electronic technology. The objective of this curriculum development project is to train technicians in the use of…

  2. Development and Validation of Mechanical Engineering Trade Skills Assessment Instrument for Sustainable Job Security in Yobe State (United States)

    Adamu, Gishua Garba; Dawha, Josphine Musa; Kamar, Tiamiyu Salihu


    Mechanical Engineering Trade Skills Assessment Instrument (METSAI) is aimed at determining the extent to which students have acquired practical skills before graduation that will enable them get employment for sustainable job security in Yobe state. The study employed instrumentation research design. The populations of the study were 23 mechanical…

  3. 77 FR 3073 - American Society of Mechanical Engineers (ASME) Codes and New and Revised ASME Code Cases... (United States)


    ...-AI35 American Society of Mechanical Engineers (ASME) Codes and New and Revised ASME Code Cases... addenda to the ASME Boiler and Pressure Vessel (B&PV) Code, and the ASME Code for Operation and... on their use) ASME B&PV Code Cases N-722-1 and N-770-1. This document is necessary to correct...

  4. Mississippi Curriculum Framework for Diesel Equipment Repair & Service (Program CIP: 47.0605--Diesel Engine Mechanic & Repairer). Secondary Programs. (United States)

    Mississippi Research and Curriculum Unit for Vocational and Technical Education, State College.

    This document, which reflects Mississippi's statutory requirement that instructional programs be based on core curricula and performance-based assessment, contains outlines of the instructional units required in local instructional management plans and daily lesson plans for diesel engine mechanics I and II. Presented first are a program…

  5. Mechanical Engineering at KSC: 'How I spend My Hours from 9 to 5 and Draw a Paycheck' (United States)

    Randazzo, John; Steinrock. Todd (Technical Monitor)


    This viewgraph presentation provides an overview of a senior mechanical engineer's role in designing and testing sensors to fly aboard the shuttle Discovery during STS-95 and STS-98. Topics covered include: software development tools, computation fluid dynamics, structural analysis, housing design, and systems integration.

  6. The Influence of Bioreactor Geometry and the Mechanical Environment on Engineered Tissues

    KAUST Repository

    Osborne, J. M.


    A three phase model for the growth of a tissue construct within a perfusion bioreactor is examined. The cell population (and attendant extracellular matrix), culture medium, and porous scaffold are treated as distinct phases. The bioreactor system is represented by a two-dimensional channel containing a cell-seeded rigid porous scaffold (tissue construct), which is perfused with a culture medium. Through the prescription of appropriate functional forms for cell proliferation and extracellular matrix deposition rates, the model is used to compare the influence of cell density-, pressure-, and culture medium shear stress-regulated growth on the composition of the engineered tissue. The governing equations are derived in O\\'Dea et al. "A Three Phase Model for Tissue Construct Growth in a Perfusion Bioreactor," Math. Med. Biol., in which the long-wavelength limit was exploited to aid analysis; here, finite element methods are used to construct two-dimensional solutions to the governing equations and to investigate thoroughly their behavior. Comparison of the total tissue yield and averaged pressures, velocities, and shear stress demonstrates that quantitative agreement between the two-dimensional and long-wavelength approximation solutions is obtained for channel aspect ratios of order 10 -2 and that much of the qualitative behavior of the model is captured in the long-wavelength limit, even for relatively large channel aspect ratios. However, we demonstrate that in order to capture accurately the effect of mechanotransduction mechanisms on tissue construct growth, spatial effects in at least two dimensions must be included due to the inherent spatial variation of mechanical stimuli relevant to perfusion bioreactors, most notably, fluid shear stress, a feature not captured in the long-wavelength limit. Copyright © 2010 by ASME.

  7. Training mechanical engineering students to utilize biological inspiration during product development. (United States)

    Bruck, Hugh A; Gershon, Alan L; Golden, Ira; Gupta, Satyandra K; Gyger, Lawrence S; Magrab, Edward B; Spranklin, Brent W


    The use of bio-inspiration for the development of new products and devices requires new educational tools for students consisting of appropriate design and manufacturing technologies, as well as curriculum. At the University of Maryland, new educational tools have been developed that introduce bio-inspired product realization to undergraduate mechanical engineering students. These tools include the development of a bio-inspired design repository, a concurrent fabrication and assembly manufacturing technology, a series of undergraduate curriculum modules and a new senior elective in the bio-inspired robotics area. This paper first presents an overview of the two new design and manufacturing technologies that enable students to realize bio-inspired products, and describes how these technologies are integrated into the undergraduate educational experience. Then, the undergraduate curriculum modules are presented, which provide students with the fundamental design and manufacturing principles needed to support bio-inspired product and device development. Finally, an elective bio-inspired robotics project course is present, which provides undergraduates with the opportunity to demonstrate the application of the knowledge acquired through the curriculum modules in their senior year using the new design and manufacturing technologies.

  8. Aerosol in selected laboratories at Faculty of Mechanical Engineering, Opole University of Technology (United States)

    Olszowski, Tomasz


    The paper contains the results of a study into mass concentration of the dispersed aerosol fraction with the aerodynamic diameter of up to 2.5 and 10 micrometers. The study was conducted during classes with students participating in them in two laboratories located at Faculty of Mechanical Engineering, Opole University of Technology as well as outdoor outside the building. It was demonstrated that the values of the mass concentration of PM2.5 and PM10 measured in the laboratories differ considerably from the levels measured in the ambient air in the outdoor areas surrounding the faculty building. It was concluded that the diversity of PM2.5/PM10 ratio was greater in the laboratories. Direct correlation was not established between the concentrations of the particular PM fractions in the two investigated environments. It was demonstrated that there is a statistically significant relation between the concentration of PM2.5 and PM10 and the number of people present in the laboratory. The conducted cluster analysis led to the detection of the existence of dominant structures determining air quality parameters. For the analyzed case, endogenic factors are responsible for the aerosanitary condition. The study demonstrated that the evaluation of air quality needs to be performed individually for the specific rooms.

  9. Mechanical properties and biocompatibility of porous titanium scaffolds for bone tissue engineering. (United States)

    Chen, Yunhui; Frith, Jessica Ellen; Dehghan-Manshadi, Ali; Attar, Hooyar; Kent, Damon; Soro, Nicolas Dominique Mathieu; Bermingham, Michael J; Dargusch, Matthew S


    Synthetic scaffolds are a highly promising new approach to replace both autografts and allografts to repair and remodel damaged bone tissue. Biocompatible porous titanium scaffold was manufactured through a powder metallurgy approach. Magnesium powder was used as space holder material which was compacted with titanium powder and removed during sintering. Evaluation of the porosity and mechanical properties showed a high level of compatibility with human cortical bone. Interconnectivity between pores is higher than 95% for porosity as low as 30%. The elastic moduli are 44.2GPa, 24.7GPa and 15.4GPa for 30%, 40% and 50% porosity samples which match well to that of natural bone (4-30GPa). The yield strengths for 30% and 40% porosity samples of 221.7MPa and 117MPa are superior to that of human cortical bone (130-180MPa). In-vitro cell culture tests on the scaffold samples using Human Mesenchymal Stem Cells (hMSCs) demonstrated their biocompatibility and indicated osseointegration potential. The scaffolds allowed cells to adhere and spread both on the surface and inside the pore structures. With increasing levels of porosity/interconnectivity, improved cell proliferation is obtained within the pores. It is concluded that samples with 30% porosity exhibit the best biocompatibility. The results suggest that porous titanium scaffolds generated using this manufacturing route have excellent potential for hard tissue engineering applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Aerosol in selected laboratories at Faculty of Mechanical Engineering, Opole University of Technology

    Directory of Open Access Journals (Sweden)

    Olszowski Tomasz


    Full Text Available The paper contains the results of a study into mass concentration of the dispersed aerosol fraction with the aerodynamic diameter of up to 2.5 and 10 micrometers. The study was conducted during classes with students participating in them in two laboratories located at Faculty of Mechanical Engineering, Opole University of Technology as well as outdoor outside the building. It was demonstrated that the values of the mass concentration of PM2.5 and PM10 measured in the laboratories differ considerably from the levels measured in the ambient air in the outdoor areas surrounding the faculty building. It was concluded that the diversity of PM2.5/PM10 ratio was greater in the laboratories. Direct correlation was not established between the concentrations of the particular PM fractions in the two investigated environments. It was demonstrated that there is a statistically significant relation between the concentration of PM2.5 and PM10 and the number of people present in the laboratory. The conducted cluster analysis led to the detection of the existence of dominant structures determining air quality parameters. For the analyzed case, endogenic factors are responsible for the aerosanitary condition. The study demonstrated that the evaluation of air quality needs to be performed individually for the specific rooms.

  11. Mechanical properties of electrospun bilayer fibrous membranes as potential scaffolds for tissue engineering. (United States)

    Pu, Juan; Komvopoulos, Kyriakos


    Bilayer fibrous membranes of poly(l-lactic acid) (PLLA) were fabricated by electrospinning, using a parallel-disk mandrel configuration that resulted in the sequential deposition of a layer with fibers aligned across the two parallel disks and a layer with randomly oriented fibers, both layers deposited in a single process step. Membrane structure and fiber alignment were characterized by scanning electron microscopy and two-dimensional fast Fourier transform. Because of the intricacies of the generated electric field, bilayer membranes exhibited higher porosity than single-layer membranes consisting of randomly oriented fibers fabricated with a solid-drum collector. However, despite their higher porosity, bilayer membranes demonstrated generally higher elastic modulus, yield strength and toughness than single-layer membranes with random fibers. Bilayer membrane deformation at relatively high strain rates comprised multiple abrupt microfracture events characterized by discontinuous fiber breakage. Bilayer membrane elongation yielded excessive necking of the layer with random fibers and remarkable fiber stretching (on the order of 400%) in the layer with fibers aligned in the stress direction. In addition, fibers in both layers exhibited multiple localized necking, attributed to the nonuniform distribution of crystalline phases in the fibrillar structure. The high membrane porosity, good mechanical properties, and good biocompatibility and biodegradability of PLLA (demonstrated in previous studies) make the present bilayer membranes good scaffold candidates for a wide range of tissue engineering applications. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. Understanding dental CAD/CAM for restorations--accuracy from a mechanical engineering viewpoint. (United States)

    Tapie, Laurent; Lebon, Nicolas; Mawussi, Bernardin; Fron-Chabouis, Hélène; Duret, Francois; Attal, Jean-Pierre


    As is the case in the field of medicine, as well as in most areas of daily life, digital technology is increasingly being introduced into dental practice. Computer-aided design/ computer-aided manufacturing (CAD/CAM) solutions are available not only for chairside practice but also for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental practice can be considered as the handling of devices and software processing for the almost automatic design and creation of dental restorations. However, dentists who want to use dental CAD/CAM systems often do not have enough information to understand the variations offered by such technology practice. Knowledge of the random and systematic errors in accuracy with CAD/CAM systems can help to achieve successful restorations with this technology, and help with the purchasing of a CAD/CAM system that meets the clinical needs of restoration. This article provides a mechanical engineering viewpoint of the accuracy of CAD/ CAM systems, to help dentists understand the impact of this technology on restoration accuracy.

  13. Internal combustion engines. Mechanics, calculation and design of piston engines; Verbrennungsmotoren. Motormechanik, Berechnung und Auslegung des Hubkolbenmotors

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, E.


    The book starts by discussing the main dimenstions of piston engines for passenger cars and industrial vehicles and then proceeds to look into components, i.e. connecting rod, piston, piston rings, crankshafts, cylinder block and crankcase, cylinder head and cylinder head gasket, and valve gear components. Instead of the well-documented field of crankshaft drives, the book contains a section on the relatively new subject area of engine acoustics as illustrated by the cylinder block and crankcase. The book addresses a wide variety of readers and requires no prior theoretical knowledge. Rather than a strictly methodical textbook, it is an information source for practictians and advanced students. [Deutsch] Am Anfang steht eine Auseinandersetzung mit den Hauptabmessungen des Hubkolbenmotors (Pkw- und Nkw-Motoren). Daran schliesst sich die Behandlung der Bauteile Pleuel, Kolben, Kolbenringe, Kurbelwelle, Zylinderkurbelgehaeuse, Zylinderkopf und -dichtung sowie der Baugruppe Ventiltrieb an. Ausfuehrungen zum relativ neuen Fachgebiet Motorakustik, im wesentlichen am Beispiel des Zylinderkurbelgehaeuses, sind hier solchen zur von vielen Seiten umfangreich behandelten Dynamik der Baugruppe Kurbeltrieb vorgezogen worden. Das Buch wendet sich an eine breite Leserschaft. Es setzt keine besonderen theoretischen Vorkenntnisse voraus. Dennoch ist es eher eine Informationsquelle fuer den Berufspraktiker als ein streng methodisch aufbereitetes Lehrbuch. Es eignet sich jedoch gut als ergaenzende Fachliteratur im zweiten Studienabschnitt. (orig.)

  14. Professor Karel Oštir zum andenken

    Directory of Open Access Journals (Sweden)

    Bojan Čop


    Full Text Available Die Redaktion der Zeitschrift tinguistica beschloss am Anfang des Jahres 1973, den XIII.Jg. der Vollendung des fünfundachtzigsten Lebensjahres, die Professor Karel Oštir am 13. Oktober feiern sollte, zu widmen. Da sich aber das Sammeln des Materials für diesen Jahrgang sowie der Druck des XII. Jahrganges allzusehr in die Länge gezogen hatten, ist uns das unerbittliche Schicksal zuvorgekommen: am 27. Dezember 1973 ist Professor Karel Oštir sanft entschlafen. Das Leben eines der eigenartigsten Sprachwissenschaftler aller Zei ten hat sich so erfüllt. Aus einer Festschrift musste nun eine Gedenkschrift werden.

  15. Professor Stewart's casebook of mathematical mysteries

    CERN Document Server

    Stewart, Ian


    Like its wildly popular predecessors Cabinet of Mathematical Curiosities and Hoard of Mathematical Treasures, Professor Stewart's brand-new book is a miscellany of over 150 mathematical curios and conundrums, packed with trademark humour and numerous illustrations. In addition to the fascinating formulae and thrilling theorems familiar to Professor Stewart's fans, the Casebook follows the adventures of the not-so-great detective Hemlock Soames and his sidekick Dr John Watsup (immortalised in the phrase 'Watsup, Doc?'). By a remarkable coincidence they live at 222B Baker Street, just a

  16. Supplementation of exogenous adenosine 5'-triphosphate enhances mechanical properties of 3D cell-agarose constructs for cartilage tissue engineering. (United States)

    Gadjanski, Ivana; Yodmuang, Supansa; Spiller, Kara; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana


    Formation of tissue-engineered cartilage is greatly enhanced by mechanical stimulation. However, direct mechanical stimulation is not always a suitable method, and the utilization of mechanisms underlying mechanotransduction might allow for a highly effective and less aggressive alternate means of stimulation. In particular, the purinergic, adenosine 5'-triphosphate (ATP)-mediated signaling pathway is strongly implicated in mechanotransduction within the articular cartilage. We investigated the effects of transient and continuous exogenous ATP supplementation on mechanical properties of cartilaginous constructs engineered using bovine chondrocytes and human mesenchymal stem cells (hMSCs) encapsulated in an agarose hydrogel. For both cell types, we have observed significant increases in equilibrium and dynamic compressive moduli after transient ATP treatment applied in the fourth week of cultivation. Continuous ATP treatment over 4 weeks of culture only slightly improved the mechanical properties of the constructs, without major changes in the total glycosaminoglycan (GAG) and collagen content. Structure-function analyses showed that transiently ATP-treated constructs, and in particular those based on hMSCs, had the highest level of correlation between compositional and mechanical properties. Transiently treated groups showed intense staining of the territorial matrix for GAGs and collagen type II. These results indicate that transient ATP treatment can improve functional mechanical properties of cartilaginous constructs based on chondrogenic cells and agarose hydrogels, possibly by improving the structural organization of the bulk phase and territorial extracellular matrix (ECM), that is, by increasing correlation slopes between the content of the ECM components (GAG, collagen) and mechanical properties of the construct.

  17. Forensic engineering: applying materials and mechanics principles to the investigation of product failures. (United States)

    Hainsworth, S V; Fitzpatrick, M E


    Forensic engineering is the application of engineering principles or techniques to the investigation of materials, products, structures or components that fail or do not perform as intended. In particular, forensic engineering can involve providing solutions to forensic problems by the application of engineering science. A criminal aspect may be involved in the investigation but often the problems are related to negligence, breach of contract, or providing information needed in the redesign of a product to eliminate future failures. Forensic engineering may include the investigation of the physical causes of accidents or other sources of claims and litigation (for example, patent disputes). It involves the preparation of technical engineering reports, and may require giving testimony and providing advice to assist in the resolution of disputes affecting life or property.This paper reviews the principal methods available for the analysis of failed components and then gives examples of different component failure modes through selected case studies.

  18. Development of Kinetic Mechanisms for Next-Generation Fuels and CFD Simulation of Advanced Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McNenly, Matt J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whitesides, Russell [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Killingsworth, Nick J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    Predictive chemical kinetic models are needed to represent next-generation fuel components and their mixtures with conventional gasoline and diesel fuels. These kinetic models will allow the prediction of the effect of alternative fuel blends in CFD simulations of advanced spark-ignition and compression-ignition engines. Enabled by kinetic models, CFD simulations can be used to optimize fuel formulations for advanced combustion engines so that maximum engine efficiency, fossil fuel displacement goals, and low pollutant emission goals can be achieved.

  19. Possible role of mechanical force in regulating regeneration of the vascularized fat flap inside a tissue engineering chamber. (United States)

    Ye, Yuan; Yuan, Yi; Lu, Feng; Gao, Jianhua


    In plastic and reconstructive surgery, adipose tissue is widely used as effective filler for tissue defects. Strategies for treating soft tissue deficiency, which include free adipose tissue grafts, use of hyaluronic acid, collagen injections, and implantation of synthetic materials, have several clinical limitations. With the aim of overcoming these limitations, researchers have recently utilized tissue engineering chambers to produce large volumes of engineered vascularized fat tissue. However, the process of growing fat tissue in a chamber is still relatively limited, and can result in unpredictable or dissatisfactory final tissue volumes. Therefore, detailed understanding of the process is both necessary and urgent. Many studies have shown that mechanical force can change the function of cells via mechanotransduction. Here, we hypothesized that, besides the inflammatory response, one of the key factors to control the regeneration of vascularized fat flap inside a tissue engineering chamber might be the balance of mechanical forces. To test our hypothesis, we intend to change the balance of forces by means of measures in order to make the equilibrium point in favor of the direction of regeneration. If those measures proved to be feasible, they could be applied in clinical practice to engineer vascularized adipose tissue of predictable size and shape, which would in turn help in the advancement of tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Simulation of biodiesel combustion in a light-duty diesel engine using integrated compact biodiesel–diesel reaction mechanism

    DEFF Research Database (Denmark)

    Ng, Hoon Kiat; Gan, Suyin; Ng, Jo-Han


    This computational fluid dynamics (CFD) study is performed to investigate the combustion characteristics and emissions formation processes of biodiesel fuels in a light-duty diesel engine. A compact reaction mechanism with 80 species and 303 reactions is used to account for the effects of chemical......-component surrogate fuel mechanism with CFD to elucidate the in-cylinder combustion and emissions characteristics of biodiesel fuels. The knowledge acquired here is useful for the development of biodiesel usage strategies in light-duty diesel engines for mass adoption....... kinetics. Here, the mechanism is capable of emulating biodiesel–diesel mixture of different blending levels and biodiesel produced from different feedstock. The integrated CFD-kinetic model was validated against a test matrix which covers the entire saturated–unsaturated methyl ester range typical...

  1. Near-Infrared Spectroscopy Predicts Compositional and Mechanical Properties of Hyaluronic Acid-Based Engineered Cartilage Constructs. (United States)

    Yousefi, Farzad; Kim, Minwook; Nahri, Syeda Yusra; Mauck, Robert L; Pleshko, Nancy


    Hyaluronic acid (HA) has been widely used for cartilage tissue engineering applications. However, the optimal time point to harvest HA-based engineered constructs for cartilage repair is still under investigation. In this study, we investigated the ability of a nondestructive modality, near-infrared spectroscopic (NIR) analysis, to predict compositional and mechanical properties of HA-based engineered cartilage constructs. NIR spectral data were collected from control, unseeded constructs, and twice per week by fiber optic from constructs seeded with chondrocytes during their development over an 8-week period. Constructs were harvested at 2, 4, 6, and 8 weeks, collagen and sulfated glycosaminoglycan content measured using biochemical assays, and the mechanical properties of the constructs evaluated using unconfined compression tests. NIR absorbances associated with the scaffold material, water, and engineered cartilage matrix, were identified. The NIR-determined matrix absorbance plateaued after 4 weeks of culture, which was in agreement with the biochemical assay results. Similarly, the mechanical properties of the constructs also plateaued at 4 weeks. A multivariate partial least square model based on NIR spectral input was developed to predict the moduli of the constructs, which resulted in a prediction error of 10% and R value of 0.88 for predicted versus actual values of dynamic modulus. Furthermore, the maximum increase in moduli was calculated from the first derivative of the curve fit of NIR-predicted and actual moduli values over time, and both occurred at ∼2 weeks. Collectively, these data suggest that NIR spectral data analysis could be an alternative to destructive biochemical and mechanical methods for evaluation of HA-based engineered cartilage construct properties.

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

    NARCIS (Netherlands)

    Ghodrat, S.


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

  3. Using the van Hiele K-12 Geometry Learning Theory to Modify Engineering Mechanics Instruction (United States)

    Sharp, Janet M.; Zachary, Loren W.


    Engineering students use spatial thinking when examining diagrams or models to study structure design. It is expected that most engineering students have solidified spatial thinking skills during K-12 schooling. However, according to what we know about geometry learning and teaching, spatial thinking probably needs to be explicitly taught within…

  4. The Use of Physical and Virtual Manipulatives in an Undergraduate Mechanical Engineering (Dynamics) Course (United States)

    Pan, Edward A.


    Science, technology, engineering, and mathematics (STEM) education is a national focus. Engineering education, as part of STEM education, needs to adapt to meet the needs of the nation in a rapidly changing world. Using computer-based visualization tools and corresponding 3D printed physical objects may help nontraditional students succeed in…

  5. Computational mechanics in civil engineering (CMC). Fire - Heat transfer - Stress analysis

    NARCIS (Netherlands)

    Hendriks, M.A.N.; H¢iseth, K.V.; Hynne, T.; ¥verli, J.A.


    engineering, especially related to integrated analysis [1]. That is, analysis where two or more interacting effects or phenomena are analysed either staggered or simultaneously. CMC contains five main projects where frequently encountered problems in civil engineering will be treated by an

  6. A Case for the Need of Using Scaffolding Methods in Teaching Introductory, Fundamental Engineering Mechanics Classes (United States)

    Boylan-Ashraf, Peggy C.; Freeman, Steven A.; Shelley, Mack C.


    In the past ten years, engineering classrooms have seen an exponential growth in the use of technology, more than during any other previous decade. Unprecedented advancements, such as the advent of innovative gadgets and fundamental instructional alterations in engineering classrooms, have introduced changes in both teaching and learning. Student…

  7. Direct Measurement and Evaluation for Mechanical Engineering Programme Outcomes: Impact on Continuous Improvement (United States)

    Tahir, Mohd Faizal Mat; Khamis, Nor Kamaliana; Wahid, Zaliha; Ihsan, Ahmad Kamal Ariffin Mohd; Ghani, Jaharah Ab; Sabri, Mohd Anas Mohd; Sajuri, Zainuddin; Abdullah, Shahrum; Sulong, Abu Bakar


    Universiti Kebangsaan Malaysia (UKM) is a research university that continuously undergoes an audit and accreditation process for the management of its courses. The Faculty of Engineering and the Built Environment (FKAB) is subjected to such processes, one of them is the auditing conducted by the Engineering Accreditation Council (EAC), which gives…

  8. Redox Pioneer: Professor Joseph Loscalzo


    Leopold, Jane A.


    Dr. Joseph Loscalzo (M.D., 1978; Ph.D., 1977) is recognized here as a Redox Pioneer because he has published two articles in the field of antioxidant/redox biology that have been cited more than 1,000 times and 22 articles that have been cited more than 100 times. Dr. Loscalzo is known for his seminal contributions to our understanding of the vascular biology of nitric oxide. His initial discovery that the antiplatelet effects of organic nitrates are potentiated by thiols through a mechanism ...

  9. Kai Adolf Jensen, professor i almindelig patologi

    DEFF Research Database (Denmark)

    Høiby, Niels


    for the Bacillus Calmette-Guérin vaccine production and supervised many young scientists’ doctoral theses on the aspects of tuberculosis. He became internationally recognized, and he revealed an important scientific fraud in the laboratory of the Austrian professor Ernst Löwenstein (1878-1950), who claimed that he...

  10. String theorist takes over as Lucasian Professor (United States)

    Banks, Michael


    String theorist Michael Green will be the next Lucasian Professor of Mathematics at Cambridge University. Green, 63, will succeed Stephen Hawking, who held the chair from 1980 before retiring last month at the age of 67 and taking up a distinguished research chair at the Perimeter Institute for Theoretical Physics in Canada (see above).

  11. Epistemology Shock: English Professors Confront Science (United States)

    Barnard, Ian; Osborn, Jan


    This article raises questions and concerns regarding students from the sciences working with faculty in the humanities in interdisciplinary settings. It explores the experience of two English professors facing the privileging of "facts" and a science-based understanding of the world in their own classrooms. It poses both questions and…

  12. Understanding Asperger Syndrome: A Professor's Guide [DVD (United States)

    Organization for Autism Research (NJ3), 2011


    College can be a trying time in any individual's life. For adults with Asperger Syndrome this experience can be overwhelming. This title in the new DVD series Asperger Syndrome and Adulthood focuses on educating professors, teaching assistants, and others on what it means to be a college student on the spectrum and how they might best be able to…

  13. Professor Brand Advocacy: Do Brand Relationships Matter? (United States)

    Jillapalli, Ravi K.; Wilcox, James B.


    The trend among students to advocate their professors online continues to generate interest within marketing academia. Brand advocacy in products and services has played a vital role in marketing. However, no known research to date has embraced the idea of brand advocacy in marketing education. This research builds on the recent human brand…

  14. Forestry professors and students receive national recognition


    Davis, Lynn


    Two Virginia Tech professors in the College of Natural Resources and the university's Society of American Foresters student chapter received awards for their accomplishments at the Society of American Foresters 2005 national convention held in Fort Worth, Texas, earlier this month.

  15. Two business professors receive Fulbright Scholar awards


    Ho, Sookhan


    Virginia Tech Pamplin College of Business professors Larry French and Mahmood A. Khan have received Fulbright Scholar Awards to teach and conduct research abroad next year. Both faculty members teach in the MBA program at the university's Northern Virginia Center in metro Washington, D.C.

  16. The Supervisor Is Not the Professor (United States)

    Johnson, G. Stewart; Shafer, Carl


    College educational exposure does not prepare the graduate for the human relations demands of teamwork in industry, and may not prepare the graduate for the relationship with his supervisor. Five major dimensions of difference for the student between his interaction with his professors and his new relationships with his supervisor are: degree of…

  17. "Dear Professor: I Hate You"--Anonymous (United States)

    Bartlett, Thomas


    Flip through a stack of anonymous student evaluations of professors and the mild comments, even the compliments, tend to blend together. But often, hidden among them, is a dagger. Then there are the out-and-out insults. Students' comments can be more than simply mean. Sometimes student comments aren't cruel, just weird. In this article, some…

  18. Africa's New Crisis: A Dearth of Professors (United States)

    Lindow, Megan


    With many professors approaching retirement. a shortage of qualified academics has reached crisis proportions at a number of African universities. The shortfall is a consequence of decades of neglect of African higher education, as donors and governments concentrated limited resources on primary and secondary schools, and young scholars who manage…

  19. Professor Jacques Cortes prantsuse keele lektoraadis

    Index Scriptorium Estoniae


    Juuni alguses külastas filoloogiateaduskonna romaani-germaani filoloogia osakonda Roueni ülikooli professor Jacques Cortes (Prantsusmaa). Ta korraldas 4. õa üliõpilastele prantsuse keele intensiivkursuse ja võttis vastu eksami ning kohtus prantsuse keele lektoraadi õppejõududega : [täistekst

  20. Microcomputing Competencies for Special Education Professors. (United States)

    Blackhurst, A. Edward; And Others


    A list of microcomputing competencies associated with functions that special education professors typically perform was assessed by 148 special education faculty who use microcomputers. Word processing was rated as the single most useful competency, along with the category of providing instruction about microcomputer applications in special…

  1. Veterinary medicine professor receives national honor


    Douglas, Jeffrey S.


    Marie-Suthers-McCabe, of Riner, Va., associate professor of small animal clinical sciences at the Virginia-Maryland Regional College of Veterinary Medicine, has been awarded the highest honor in the nation for work in the area of the "human/animal bond."

  2. CFA or CFP: A Guide for Professors (United States)

    Moy, Ronald L.


    The CFA Institute and the CFP Board of Standards provide professional certifications in the field of finance. In this paper, I provide my experience with the CFA and CFP programs in order to give other professors some insight into the process of attaining the designations. I hope to provide answers to some of the questions that other faculty…

  3. Family Law and Family Studies: Professor's Views (United States)

    Hicks, Mary W.; And Others


    The results of a survey of family studies faculty concerning the inclusion of family law topics in family studies courses are discussed. The professor's needs for training and resources in the area of family and the law are identified and recommendations for meeting these needs are suggested. (Author)

  4. Modeling of heat release and emissions from droplet combustion of multi component fuels in compression ignition engines

    DEFF Research Database (Denmark)

    Ivarsson, Anders

    emissions from the compression ignition engines (CI engines or diesel engines) are continuously increased. To comply with this, better modeling tools for the diesel combustion process are desired from the engine developers. The complex combustion process of a compression ignition engine may be divided......-mixed flat flame burner at atmospheric pressure. The fundamental mechanisms of this laboratory flame are identical with those of an IC engine. The high control of the laboratory flame and the easy access to it makes it valuable for model validation. Modeling of the pre-mixed flat flame was performed......This PhD dissertation was carried out at the Technical University of Denmark in Department of Mechanical Engineering and supervised by Associate Professor Jesper Schramm. The PhD project was funded by the Technical University of Denmark. Demands on reducing the fuel consumption and harmful...

  5. Professor Attitudes and Beliefs about Teaching Evolution (United States)

    Barnes, Maryann Elizabeth

    Teaching evolution has been shown to be a challenge for faculty, in both K-12 and postsecondary education. Many of these challenges stem from perceived conflicts not only between religion and evolution, but also faculty beliefs about religion, it's compatibility with evolutionary theory, and it's proper role in classroom curriculum. Studies suggest that if educators engage with students' religious beliefs and identity, this may help students have positive attitudes towards evolution. The aim of this study was to reveal attitudes and beliefs professors have about addressing religion and providing religious scientist role models to students when teaching evolution. 15 semi-structured interviews of tenured biology professors were conducted at a large Midwestern universiy regarding their beliefs, experiences, and strategies teaching evolution and particularly, their willingness to address religion in a class section on evolution. Following a qualitative analysis of transcripts, professors did not agree on whether or not it is their job to help students accept evolution (although the majority said it is not), nor did they agree on a definition of "acceptance of evolution". Professors are willing to engage in students' religious beliefs, if this would help their students accept evolution. Finally, professors perceived many challenges to engaging students' religious beliefs in a science classroom such as the appropriateness of the material for a science class, large class sizes, and time constraints. Given the results of this study, the author concludes that instructors must come to a consensus about their goals as biology educators as well as what "acceptance of evolution" means, before they can realistically apply the engagement of student's religious beliefs and identity as an educational strategy.

  6. Optics for engineers

    CERN Document Server

    DiMarzio, Charles A


    This book is an excellent resource for teaching any student or scientist who needs to use optical systems. I particularly like the addition of MATLAB scripts and functions. Highly recommended.-Professor James C. Wyant, Dean of College of Optical Sciences, University of ArizonaHis book is clear, concise and highly readable. This is an excellent text.-Professor Changhuei Yang, California Institute of TechnologyAt last, a book on optics that is written with the practising engineer in mind. I have been teaching optics to engineers for many years and have often longed for a text aimed at my student

  7. Integrin β1 Gene Therapy Enhances in Vitro Creation of Tissue-Engineered Cartilage Under Periodic Mechanical Stress

    Directory of Open Access Journals (Sweden)

    Wenwei Liang


    Full Text Available Background/Aims: Periodic mechanical stress activates integrin β1-initiated signal pathways to promote chondrocyte proliferation and matrix synthesis. Integrin β1 overexpression has been demonstrated to play important roles in improving the activities and functions of several non-chondrocytic cell types. Therefore, in the current study, we evaluated the effects of integrin β1 up-regulation on periodic mechanical stress-induced chondrocyte proliferation, matrix synthesis and ERK1/2 phosphorylation in chondrocyte monolayer culture, and evaluated the quality of tissue-engineered cartilage constructed in vitro under periodic mechanical stress combined with integrin β1 up-regulation. Methods and Results: Our results revealed that under periodic mechanical stress, pre-treatment with integrin β1-wild type vector significantly enhanced chondrocyte proliferation and matrix synthesis and promoted ERK1/2 phosphorylation in comparison to mock transfectants. Furthermore, when chondrocytes were seeded in PLGA scaffolds, more accumulated GAG and type II collagen tissue were detected after Lv-integrin β1 transfection compared with sham controls exposed to periodic mechanical stress. In contrast, in the Lv-shRNA-integrin β1 group, the opposite results were observed. Conclusion: Our findings collectively suggest that in addition to periodic mechanical stress, integrin β1 up-regulation in chondrocytes could further improve the quality of tissue-engineered cartilage.

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


    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.

  9. Yuriko and Michael Renardy reappointed Class of 1950 Professors


    Owczarski, Mark


    Yuriko and Michael Renardy, professors of mathematics in the College of Science at Virginia Tech, have been reappointed as the Virginia Tech Class of 1950 Professors by the Virginia Tech Board of Visitors.

  10. Greentech in mechanical engineering and plant engineering of Baden-Wuerttemberg. Potentials in the future fields energy efficiency, renewable energy, electro mobility; Greentech im Maschinen- und Anlagenbau Baden-Wuerttembergs. Potenziale in den Zukunftsfeldern Energieeffizienz, Erneuerbare Energien, Elektromobilitaet

    Energy Technology Data Exchange (ETDEWEB)

    Dispan, Juergen


    The author of the contribution under consideration reports on the chances of some key topics for green-tech mechanical engineering and plant engineering in Baden-Wuerttemberg (Federal Republic of Germany). From the broad green-tech spectrum, in the connection with 'energy' future fields are selected for a more detailed analysis: energy efficiency, renewable energy and electric mobility. Framework conditions such as the EU regulation and EU funding will find special consideration. Operational case studies are described based on publicly available information. Fields of activity for a sustainable industrial policy in Baden-Wuerttemberg are described in terms of key mechanical engineering and plant engineering.

  11. Understanding dental CAD/CAM for restorations - dental milling machines from a mechanical engineering viewpoint. Part A: chairside milling machines. (United States)

    Lebon, Nicolas; Tapie, Laurent; Duret, Francois; Attal, Jean-Pierre


    The dental milling machine is an important device in the dental CAD/CAM chain. Nowadays, dental numerical controlled (NC) milling machines are available for dental surgeries (chairside solution). This article provides a mechanical engineering approach to NC milling machines to help dentists understand the involvement of technology in digital dentistry practice. First, some technical concepts and definitions associated with NC milling machines are described from a mechanical engineering viewpoint. The technical and economic criteria of four chairside dental NC milling machines that are available on the market are then described. The technical criteria are focused on the capacities of the embedded technologies of these milling machines to mill both prosthetic materials and types of shape restorations. The economic criteria are focused on investment costs and interoperability with third-party software. The clinical relevance of the technology is assessed in terms of the accuracy and integrity of the restoration.

  12. Impacts and Opportunities for Engineering in the Era of Cloud Computing Systems (United States)


    massive cloud-based infrastructure (particularly around Siri ) promises revolutionary changes in human computer (spoken-language) interaction. Radio...users’ agreement) to assist in the repair process. Similar mechanisms can be employed for cloud-based systems, although they must be further adapted...University of Maryland College Park. Email: MDiep@fc- Dr. LiGuo Huang is an Assistant Professor in the Dept. of Computer Science and Engineering

  13. Fault mechanism analysis and simulation for continuity resistance test of electrical components in aircraft engine (United States)

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


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

  14. Scuffing resistance testing of piston ring materials for marine two-stroke diesel engines and mapping of the operating mechanisms


    Olander, Petra; Jacobson, Staffan


    The incentive is strong for optimising sliding materials to reduce the risk for scuffing. In this study, scuffing tests were performed aiming towards finding new piston ring materials for greener marine diesel engines and also towards understanding scuffing mechanisms better. The tested ring materials where grey iron, Stellite 6, plasma sprayed cermet and high velocity oxy fuel (HVOF) cermet (both cermets with the same compounds: Cr-carbide, Ni, Cr, Mo). The Stellite 6 and HVOF cermet perform...

  15. Enhancing vehicle’s engine warm up using integrated mechanical approach (United States)

    Ibrahim, T. M.; Syahir, A. Z.; Zulkifli, N. W. M.; Masjuki, H. H.; Osman, A.


    Transportation sector covers a large portion of the total energy consumption shares and is highly associated to global warming. Growing concern over the harmful gases being emitted from vehicles and their environmental implications has urged the need for pollutant reduction through more efficient engines. Good engine thermal management especially during cold-start warm up phase has been proven to enhance the engine efficiency in terms of fuel economy and greenhouse emissions specifically. In this study, the viability engine split cooling system was tested in two separate test. The parameters of interest include coolant and transmission temperature as these both parameters indicate the internal engine condition and highly associated with engine efficiency. In the first idle test, coolant temperature within the modified cooling configuration reached the optimum coolant temperature of 60 °C about 41.28% faster when compared to baseline configuration. The modified configuration also heat up the transmission oil around 4 times faster. In the second NEDC test which simulates the real time driving condition, the coolant of the modified vehicle reached the optimum temperature around 28.26% compared to the baseline.

  16. E-Mail from Professor Enhances Student Motivation and Attitudes (United States)

    Legg, Angela M.; Wilson, Janie H.


    Traditionally, professors use the first day of class to build rapport. However, current technology allows professors to contact students prior to the first day of class. This study assessed how the receipt of a welcoming e-mail from a female professor 1 week before the first day of class affected student motivation and attitudes toward the…

  17. Connect and Thrive: Perspectives from a Newly Tenured Professor (United States)

    Ciocchetti, Corey A.


    This essay encapsulates the author's perspective on how average professors can become highly effective professors. The author asserts that the secret rests in the ability to genuinely connect with students. Connecting really matters--even if it takes some personality adaptation and thrusts academics out of their comfort zones. Many professors fail…

  18. Anti-Fat Bias by Professors Teaching Physical Education Majors (United States)

    Fontana, Fabio; Furtado, Ovande, Jr.; Mazzardo, Oldemar, Jr.; Hong, Deockki; de Campos, Wagner


    Anti-fat bias by professors in physical education departments may interfere with the training provided to pre-service teachers. The purpose of this study was to evaluate the attitudes of professors in physical education departments toward obese individuals. Professors from randomly selected institutions across all four US regions participated in…

  19. 26 CFR 509.115 - Visiting professors or teachers. (United States)


    ... 26 Internal Revenue 19 2010-04-01 2010-04-01 false Visiting professors or teachers. 509.115...) REGULATIONS UNDER TAX CONVENTIONS SWITZERLAND General Income Tax § 509.115 Visiting professors or teachers. (a) General. Pursuant to Article XII of the convention, a professor or teacher, a nonresident alien who is a...

  20. Variables That Can Affect Student Ratings of Their Professors (United States)

    Gotlieb, Jerry


    Attribution theory was applied to help predict the results of an experiment that examined the effects of three independent variables on students' ratings of their professors. The dependent variables were students' perceptions of whether the professor caused the students' grades and student satisfaction with their professor. The results suggest…

  1. Development of transport mechanical engineering as the condition of maintenance of social and economic security of region

    Directory of Open Access Journals (Sweden)

    Vsevolod Petrovich Babushkin


    Full Text Available In the article, the transport role in the decision of problems of innovative and scientifically-technological development of territory is defined. Dependence of quality, completeness and timeliness of granting of transport services on replenishment and updating of park of locomotives, cars, i.e. from a level of development of domestic transport mechanical engineering is shown. The basic problems of development given branches –low competitiveness of made production are revealed. The basic accent in the course of such analysis is made on research of competitive possibilities of the enterprises of railway mechanical engineering of Sverdlovsk area. Such enterprises play the increasing role, become points of development of region’s economy and maintenance of its social and economic safety. The cooperation communications, which have developed in an industrial complex of Sverdlovsk area on the basis of development of modern manufacture on building of electric locomotives, have allowed to generate in region cluster railway mechanical engineering. The structure cluster is shown, development prospects, the estimation of its influence on the economy of Sverdlovsk area and maintenance of its social and economic security is given

  2. Development of the mechanical engineering complex on the basis of the improvement of large and small businesses relations

    Directory of Open Access Journals (Sweden)

    Sokolova Svetlana


    Full Text Available Condition, pace and character of the development of the mechanical engineering complex is in many aspects a crucial factor for the social and economic situation of any country. The development of market relations, changes of the conditions of doing business encourage the enterprises to search new managerial methods and to improve the interaction forms. In this respect the display of the peculiarities of the interaction of large machine engineering enterprises and small business in this sphere and also the assessment of the relationship of their development is an important and crucial issue under modern conditions. The most widely spread forms of the cooperation of large scale mechanical engineering enterprises and small businesses of the industry are: outsourcing, franchising, leasing, subcontracting, venture financing, creation of regional forms of the cooperation of large and small firms. However cooperation processes of large scale and small entrepreneurship in Russia are not properly developed. The authors determine the factors hindering the growth of the machine building industry, suggest the recommendations for the development of the large scale enterprises and small business in the industry, substantiate the role of the government in this process. Besides the mechanism of the state support of the development of small business is described.

  3. Assessment of the mechanics of a tissue-engineered rat trachea in an image-processing environment. (United States)

    Silva, Thiago Henrique Gomes da; Pazetti, Rogerio; Aoki, Fabio Gava; Cardoso, Paulo Francisco Guerreiro; Valenga, Marcelo Henrique; Deffune, Elenice; Evaristo, Thaiane; Pêgo-Fernandes, Paulo Manuel; Moriya, Henrique Takachi


    Despite the recent success regarding the transplantation of tissue-engineered airways, the mechanical properties of these grafts are not well understood. Mechanical assessment of a tissue-engineered airway graft before implantation may be used in the future as a predictor of function. The aim of this preliminary work was to develop a noninvasive image-processing environment for the assessment of airway mechanics. Decellularized, recellularized and normal tracheas (groups DECEL, RECEL, and CONTROL, respectively) immersed in Krebs-Henseleit solution were ventilated by a small-animal ventilator connected to a Fleisch pneumotachograph and two pressure transducers (differential and gauge). A camera connected to a stereomicroscope captured images of the pulsation of the trachea before instillation of saline solution and after instillation of Krebs-Henseleit solution, followed by instillation with Krebs-Henseleit with methacholine 0.1 M (protocols A, K and KMCh, respectively). The data were post-processed with computer software and statistical comparisons between groups and protocols were performed. There were statistically significant variations in the image measurements of the medial region of the trachea between the groups (two-way analysis of variance [ANOVA], pmechanical assessment of engineered tracheal grafts that will enable evaluation of the viscoelastic properties of neo-tracheas prior to transplantation.

  4. Mechanical properties and cellular response of novel electrospun nanofibers for ligament tissue engineering: Effects of orientation and geometry. (United States)

    Pauly, Hannah M; Kelly, Daniel J; Popat, Ketul C; Trujillo, Nathan A; Dunne, Nicholas J; McCarthy, Helen O; Haut Donahue, Tammy L


    Electrospun nanofibers are a promising material for ligamentous tissue engineering, however weak mechanical properties of fibers to date have limited their clinical usage. The goal of this work was to modify electrospun nanofibers to create a robust structure that mimics the complex hierarchy of native tendons and ligaments. The scaffolds that were fabricated in this study consisted of either random or aligned nanofibers in flat sheets or rolled nanofiber bundles that mimic the size scale of fascicle units in primarily tensile load bearing soft musculoskeletal tissues. Altering nanofiber orientation and geometry significantly affected mechanical properties; most notably aligned nanofiber sheets had the greatest modulus; 125% higher than that of random nanofiber sheets; and 45% higher than aligned nanofiber bundles. Modifying aligned nanofiber sheets to form aligned nanofiber bundles also resulted in approximately 107% higher yield stresses and 140% higher yield strains. The mechanical properties of aligned nanofiber bundles were in the range of the mechanical properties of the native ACL: modulus=158±32MPa, yield stress=57±23MPa and yield strain=0.38±0.08. Adipose derived stem cells cultured on all surfaces remained viable and proliferated extensively over a 7 day culture period and cells elongated on nanofiber bundles. The results of the study suggest that aligned nanofiber bundles may be useful for ligament and tendon tissue engineering based on their mechanical properties and ability to support cell adhesion, proliferation, and elongation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Carbon nanotubes reinforced chitosan films: mechanical properties and cell response of a novel biomaterial for cardiovascular tissue engineering. (United States)

    Kroustalli, A; Zisimopoulou, A E; Koch, S; Rongen, L; Deligianni, D; Diamantouros, S; Athanassiou, G; Kokozidou, M; Mavrilas, D; Jockenhoevel, S


    Carbon nanotubes have been proposed as fillers to reinforce polymeric biomaterials for the strengthening of their structural integrity to achieve better biomechanical properties. In this study, a new polymeric composite material was introduced by incorporating various low concentrations of multiwalled carbon nanotubes (MWCNTs) into chitosan (CS), aiming at achieving a novel composite biomaterial with superior mechanical and biological properties compared to neat CS, in order to be used in cardiovascular tissue engineering applications. Both mechanical and biological characteristics in contact with the two relevant cell types (endothelial cells and vascular myofibroblasts) were studied. Regarding the mechanical behavior of MWCNT reinforced CS (MWCNT/CS), 5 and 10 % concentrations of MWCNTs enhanced the mechanical behavior of CS, with that of 5 % exhibiting a superior mechanical strength compared to 10 % concentration and neat CS. Regarding biological properties, MWCNT/CS best supported proliferation of endothelial and myofibroblast cells, MWCNTs and MWCNT/CS caused no apoptosis and were not toxic of the examined cell types. Conclusively, the new material could be suitable for tissue engineering (TE) and particularly for cardiovascular TE applications.

  6. EDITORIAL: 65th Birthday of Professor Hauptmann 65th Birthday of Professor Hauptmann (United States)

    Lucklum, Ralf


    The papers in this special feature have been contributed by scientific partners in international research projects and from former PhD students of the Editor-in-Chief of this journal, Professor Dr Peter Hauptmann. The motivation for this feature is the occasion of Peter Hauptmann's 65th birthday on 24 July 2009 and his retirement from his chair at the Otto-von-Guericke-University, Magdeburg, Germany this autumn. Peter graduated in Physics at the Technical University Dresden and received his PhD from the Technical University Leuna-Merseburg in 1973. He habilitated in 1979. With his appointment at the Faculty of Electrical Engineering and Information Technology in 1985 the Chair of Measurement Science extended its profile to the fast growing area of sensors. Peter was one of the very early developers of ultrasonic sensor systems for process monitoring and quality assurance. The working style here was characteristic of all his future activities. He combined his background in theory and experiment on ultrasonic wave propagation and its application to material science with the advantages of rapidly developing capabilities in microelectronics and data processing. The results have meanwhile found their way into products that are now on the market worldwide. Germany's reunification opened the door to the international sensor community and the most challenging sensor research areas. Peter Hauptmann very soon became a well respected colleague and was consequently appointed as member of the Technical Program Committee of the most important sensor conferences, elected member and head of expert groups of research associations and funding organizations, and of course reviewer of many scientific journals. Nowadays Peter Hauptmann can rightly be called one of the key players in the area of sensors. Professor Hauptmann's research interests combine fundamental aspects of the sensor transduction scheme with application issues up to the use of the sensor system in the industrial world

  7. Spotlight on CERN : Professor Michel Spiro

    CERN Multimedia

    CERN video productions


    20 Member states throughout Europe. A geographical expansion underway. A worldwide, international collaboration and a scientific challenge on a scale second to none. In view of this complexity, how is CERN managed? This is the remit of the CERN council, which notably defines the strategic programmes, annual objectives, approves the annual budget and nominates the directorate. I am pleased to welcome Professor Michel Spiro, scientific director of the CNRS in France and CERN Council presdient since 2010. On today’s agenda: Expansion, innovation and communication. Hello and welcome Professor.. François et Stéphan are of course with me today to discuss such matters as antimatter, press and we will also be talking water and towers… I will say no more. It’s good to see you both ! And welcome to you all for this latest edition of Spotlight on CERN.

  8. Nonlinear approaches in engineering applications applied mechanics, vibration control, and numerical analysis

    CERN Document Server

    Jazar, Reza


    This book focuses on the latest applications of nonlinear approaches in different disciplines of engineering. For each selected topic, detailed concept development, derivations, and relevant knowledge are provided for the convenience of the readers. The topics range from dynamic systems and control to optimal approaches in nonlinear dynamics. The volume includes invited chapters from world class experts in the field. The selected topics are of great interest in the fields of engineering and physics and this book is ideal for engineers and researchers working in a broad range of practical topics and approaches. This book also: ·         Explores the most up-to-date applications and underlying principles of nonlinear approaches to problems in engineering and physics, including sections on analytic nonlinearity and practical nonlinearity ·         Enlightens readers to the conceptual significance of nonlinear approaches with examples of applications in scientific and engineering problems from v...

  9. 31 July 2014 - Professor M. Kastner

    CERN Multimedia

    Egli, Laurent


    MIT Faculty Member Donner Professor of Physics Massachusetts Institute of Technology United States of America, Prof. M. Kastner visiting the LHC tunnel at Point 5 with Beams Department M. Solfaroli Camillocci, LHC superconducting magnet assembly hall visit with L. Rossi and R. Principe, LHC Computing Grid Project presentation and computer centre visit with I. Bird and signing the guest book with CERN Director-General R. Heuer.

  10. [Homage to Professor Dr. Nicasio Etchepareborda]. (United States)


    During a solemn academic act, de Main Classroom of the Facultad de Odontologia de Buenos Aires was named after Prof. Dr. Nicasio Etchepareborda. He has been the first professor at the Escuela de Odontologia and its organizer, after having obtained his Dentistry degree at the Dental School of Paris, in 1882. The new school was founded in 1891, and its activities began the following year.

  11. In memory of Professor Paolo Talamucci

    Directory of Open Access Journals (Sweden)

    Cantiani M


    Full Text Available Paolo Talamucci, Full Professor of Range Management at the Università degli Studi in Florence from 1975 to 2001, passed away on 27th November 2009, after a brief and unrelenting illness. Professor Talamucci spent many long years in the field of research, in both Mediterranean and Alpine regions. His research, profoundly rooted in the territory he was studying, holistic in its approach and rigorously scientific, was characterized by a strong interdisciplinary element, seeking always to take into account the totality of the components of the ecosystem. Professor Talamucci was one of the first scholars of the pastoral system to highlight the problems related to the abandonment of traditional animal husbandry in mountainous zones and to look for ways to counteract the undesirable transformation of the landscape and the consequent loss of biodiversity. His curriculum and his numerous scientific publications bear testimony not only to the prestigious research institutes, world-wide, with which he was associated, but also to the important international dimension of his research.

  12. APOSENTADORIA: como professores vivenciam este momento?

    Directory of Open Access Journals (Sweden)

    Cristiane Nervis Conrado Machado


    Full Text Available O presente artigo buscou compreender as implicações que a aposentadoria causa na vida de professores, levando em conta o significado que a aposentadoria representa à estes, considerando os pontos de maior mudança após a aposentadoria, bem como os aspectos positivos e negativos causados pela aposentadoria na percepção dos sujeitos da pesquisa. Para tanto, foi realizada uma pesquisa qualitativa caracterizada como exploratória e descritiva com professores aposentados por mais de dois anos, com idade entre 58 e 66 anos, através de entrevistas individuais, com roteiros semiestruturados. A análise dos dados foi por meio da análise de conteúdo de Bardin (2011. Entre os principais resultados, destaca-se o significado de “liberdade” que a aposentadoria representa, a rotina como maior mudança e flexibilidade de horários dentre os pontos positivos e a falta dos alunos como aspecto negativo, contudo, pode-se perceber que a aposentadoria possibilitou e contribuiu para que os professores pudessem desfrutar de momentos de lazer, dedicando cuidado à família e realizando seus anseios e vontades.

  13. Direct Observation of Oil Consumption Mechanisms in a Production Spark Ignition Engine Using Fluorescence Techniques (United States)


    Test Matrices .......... ................ .. 58 4.4 Engine/ Dynamometer Operating Procedures . . 66 4.5 Radiotracer Method Validation Procedures . 66 the cylinder coordinates z = 40mm and e = 900, referenced respectively from 44 the fire deck of the engine and from the forward wrist -pin axis...Company, Inc. 46 CYLNDER P4 WRIST •UOMCM INCIDEN7 UGHiT UGH7 Figure 3-3: Quartz LIF Window (Top View) at a wavelength of 495 nm. Fluorescence Subsystem The

  14. Lung stress, strain, and energy load: engineering concepts to understand the mechanism of ventilator-induced lung injury (VILI). (United States)

    Nieman, Gary F; Satalin, Joshua; Andrews, Penny; Habashi, Nader M; Gatto, Louis A


    It was recently shown that acute respiratory distress syndrome (ARDS) mortality has not been reduced in over 15 years and remains ~40 %, even with protective low tidal volume (LVt) ventilation. Thus, there is a critical need to develop novel ventilation strategies that will protect the lung and reduce ARDS mortality. Protti et al. have begun to analyze the impact of mechanical ventilation on lung tissue using engineering methods in normal pigs ventilated for 54 h. They used these methods to assess the impact of a mechanical breath on dynamic and static global lung strain and energy load. Strain is the change in lung volume in response to an applied stress (i.e., Tidal Volume-Vt). This study has yielded a number of exciting new concepts including the following: (1) Individual mechanical breath parameters (e.g., Vt or Plateau Pressure) are not directly correlated with VILI but rather any combination of parameters that subject the lung to excessive dynamic strain and energy/power load will cause VILI; (2) all strain is not equal; dynamic strain resulting in a dynamic energy load (i.e., kinetic energy) is more damaging to lung tissue than static strain and energy load (i.e., potential energy); and (3) a critical consideration is not just the size of the Vt but the size of the lung that is being ventilated by this Vt. This key concept merits attention since our current protective ventilation strategies are fixated on the priority of keeping the Vt low. If the lung is fully inflated, a large Vt is not necessarily injurious. In conclusion, using engineering concepts to analyze the impact of the mechanical breath on the lung is a novel new approach to investigate VILI mechanisms and to help design the optimally protective breath. Data generated using these methods have challenged some of the current dogma surrounding the mechanisms of VILI and of the components in the mechanical breath necessary for lung protection.

  15. ATS-6 engineering performance report. Volume:Program and systems summaries: Mechanical and thermal details (United States)

    Wales, R. O. (Editor)


    The overall mission and spacecraft systems, testing, and operations are summarized. The mechanical subsystems are reviewed, encompassing mechanical design requirements; separation and deployment mechanisms; design and performance evaluation; and the television camera reflector monitor. Thermal control and contamination are discussed in terms of thermal control subsystems, design validation, subsystems performance, the advanced flight experiment, and the quartz-crystal microbalance contamination monitor.

  16. Basic flight mechanics a simple approach without equations

    CERN Document Server

    Tewari, Ashish


    This book presents flight mechanics of aircraft, spacecraft, and rockets to technical and non-technical readers in simple terms and based purely on physical principles. Adapting an accessible and lucid writing style, the book retains the scientific authority and conceptual substance of an engineering textbook without requiring a background in physics or engineering mathematics. Professor Tewari explains relevant physical principles of flight by straightforward examples and meticulous diagrams and figures. Important aspects of both atmospheric and space flight mechanics are covered, including performance, stability and control, aeroelasticity, orbital mechanics, and altitude control. The book describes airplanes, gliders, rotary wing and flapping wing flight vehicles, rockets, and spacecraft and visualizes the essential principles using detailed illustration. It is an ideal resource for managers and technicians in the aerospace industry without engineering degrees, pilots, and anyone interested in the mechanic...

  17. Emergence of Form from Function - Mechanical Engineering Approaches to Probe the Role of Stem Cell Mechanoadaptation in Sealing Cell Fate. (United States)

    Knothe Tate, Melissa L; Gunning, Peter W; Sansalone, Vittorio


    Stem cell "mechanomics" refers to the effect of mechanical cues on stem cell and matrix biology, where cell shape and fate are intrinsic manifestations of form and function. Before specialization, the stem cell itself serves as a sensor and actuator; its structure emerges from its local mechanical milieu as the cell adapts over time. Coupling of novel spatiotemporal imaging and computational methods allows for linking of the energy of adaptation to the structure, biology and mechanical function of the cell. Cutting edge imaging methods enable probing of mechanisms by which stem cells' emergent anisotropic architecture and fate commitment occurs. A novel cell-scale model provides a mechanistic framework to describe stem cell growth and remodeling through mechanical feedback; making use of a generalized virtual power principle, the model accounts for the rate of doing work or the rate of using energy to effect the work. This coupled approach provides a basis to elucidate mechanisms underlying the stem cell's innate capacity to adapt to mechanical stimuli as well as the role of mechanoadaptation in lineage commitment. An understanding of stem cell mechanoadaptation is key to deciphering lineage commitment, during prenatal development, postnatal wound healing, and engineering of tissues.

  18. Mechanical behaviour of a fibrous scaffold for ligament tissue engineering: finite elements analysis vs. X-ray tomography imaging. (United States)

    Laurent, Cédric P; Latil, Pierre; Durville, Damien; Rahouadj, Rachid; Geindreau, Christian; Orgéas, Laurent; Ganghoffer, Jean-François


    The use of biodegradable scaffolds seeded with cells in order to regenerate functional tissue-engineered substitutes offers interesting alternative to common medical approaches for ligament repair. Particularly, finite element (FE) method enables the ability to predict and optimise both the macroscopic behaviour of these scaffolds and the local mechanic signals that control the cell activity. In this study, we investigate the ability of a dedicated FE code to predict the geometrical evolution of a new braided and biodegradable polymer scaffold for ligament tissue engineering by comparing scaffold geometries issued from FE simulations and from X-ray tomographic imaging during a tensile test. Moreover, we compare two types of FE simulations the initial geometries of which are issued either from X-ray imaging or from a computed idealised configuration. We report that the dedicated FE simulations from an idealised reference configuration can be reasonably used in the future to predict the global and local mechanical behaviour of the braided scaffold. A valuable and original dialog between the fields of experimental and numerical characterisation of such fibrous media is thus achieved. In the future, this approach should enable to improve accurate characterisation of local and global behaviour of tissue-engineering scaffolds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Determining the Mechanism of In-Service Cylinder Distortion in Aluminum Engine Blocks with Cast-In Gray Iron Liners (United States)

    Lombardi, Anthony; Ravindran, Comondore; Sediako, Dimitry; MacKay, Robert


    In recent years, stringent government legislation on vehicle fuel efficiency has pushed the automotive industry to replace steel and cast iron power train components with light weight Al alloys. However, unlike their ferrous-based equivalents, Al-Si alloy engine blocks are prone to permanent dimensional distortion in critical locations such as the cylinder bore regions. Understanding the mechanisms that cause distortion will promote the use of Al alloys over ferrous alloys for power train applications and enable automotive manufacturers to meet emission standards and reduce fuel consumption. In this study, neutron diffraction was used to evaluate residual stress along the Al cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. Microstructural analysis was carried out using OM, SEM, and TEM, while mechanical testing was accomplished via ambient and elevated temperature [~453 K (180 °C)] tensile testing. The results suggest that the distorted engine block had high tensile residual stress in the Al cylinder bridge, reaching a maximum of 170 MPa in the hoop direction, which triggered permanent dimensional distortion in the cylinders when exposed to service conditions. In addition, the middle of the cylinder had the highest magnitude of distortion since this region had a combination of high tensile residual stress (hoop stress of 150 MPa) and reduced strength compared with the bottom of the cylinder.

  20. Flipping Core Courses in the Undergraduate Mechanical Engineering Curriculum: Heat Transfer (United States)

    Schrlau, Michael G.; Stevens, Robert J.; Schley, Sara


    Flipped classrooms support learner-centered approaches to improve conceptualization, comprehension, and problem solving skills by delivering content outside the classroom and actively engaging students inside the classroom. While literature in engineering and science education supports and encourages the use of inverted instruction, many core…