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Sample records for bioinspired engineering study

  1. Bioinspired Hydrogels to Engineer Cancer Microenvironments.

    Science.gov (United States)

    Park, Kyung Min; Lewis, Daniel; Gerecht, Sharon

    2017-06-21

    Recent research has demonstrated that tumor microenvironments play pivotal roles in tumor development and metastasis through various physical, chemical, and biological factors, including extracellular matrix (ECM) composition, matrix remodeling, oxygen tension, pH, cytokines, and matrix stiffness. An emerging trend in cancer research involves the creation of engineered three-dimensional tumor models using bioinspired hydrogels that accurately recapitulate the native tumor microenvironment. With recent advances in materials engineering, many researchers are developing engineered tumor models, which are promising platforms for the study of cancer biology and for screening of therapeutic agents for better clinical outcomes. In this review, we discuss the development and use of polymeric hydrogel materials to engineer native tumor ECMs for cancer research, focusing on emerging technologies in cancer engineering that aim to accelerate clinical outcomes.

  2. Vorticella: A Protozoan for Bio-Inspired Engineering

    Directory of Open Access Journals (Sweden)

    Sangjin Ryu

    2016-12-01

    Full Text Available In this review, we introduce Vorticella as a model biological micromachine for microscale engineering systems. Vorticella has two motile organelles: the oral cilia of the zooid and the contractile spasmoneme in the stalk. The oral cilia beat periodically, generating a water flow that translates food particles toward the animal at speeds in the order of 0.1–1 mm/s. The ciliary flow of Vorticella has been characterized by experimental measurement and theoretical modeling, and tested for flow control and mixing in microfluidic systems. The spasmoneme contracts in a few milliseconds, coiling the stalk and moving the zooid at 15–90 mm/s. Because the spasmoneme generates tension in the order of 10–100 nN, powered by calcium ion binding, it serves as a model system for biomimetic actuators in microscale engineering systems. The spasmonemal contraction of Vorticella has been characterized by experimental measurement of its dynamics and energetics, and both live and extracted Vorticellae have been tested for moving microscale objects. We describe past work to elucidate the contraction mechanism of the spasmoneme, recognizing that past and continuing efforts will increase the possibilities of using the spasmoneme as a microscale actuator as well as leading towards bioinspired actuators mimicking the spasmoneme.

  3. Tissue-Engineered Fibrin-Based Heart Valve with Bio-Inspired Textile Reinforcement.

    Science.gov (United States)

    Moreira, Ricardo; Neusser, Christine; Kruse, Magnus; Mulderrig, Shane; Wolf, Frederic; Spillner, Jan; Schmitz-Rode, Thomas; Jockenhoevel, Stefan; Mela, Petra

    2016-08-01

    The mechanical properties of tissue-engineered heart valves still need to be improved to enable their implantation in the systemic circulation. The aim of this study is to develop a tissue-engineered valve for the aortic position - the BioTexValve - by exploiting a bio-inspired composite textile scaffold to confer native-like mechanical strength and anisotropy to the leaflets. This is achieved by multifilament fibers arranged similarly to the collagen bundles in the native aortic leaflet, fixed by a thin electrospun layer directly deposited on the pattern. The textile-based leaflets are positioned into a 3D mould where the components to form a fibrin gel containing human vascular smooth muscle cells are introduced. Upon fibrin polymerization, a complete valve is obtained. After 21 d of maturation by static and dynamic stimulation in a custom-made bioreactor, the valve shows excellent functionality under aortic pressure and flow conditions, as demonstrated by hydrodynamic tests performed according to ISO standards in a mock circulation system. The leaflets possess remarkable burst strength (1086 mmHg) while remaining pliable; pronounced extracellular matrix production is revealed by immunohistochemistry and biochemical assay. This study demonstrates the potential of bio-inspired textile-reinforcement for the fabrication of functional tissue-engineered heart valves for the aortic position. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Engineered bio-inspired coating for passive flow control.

    Science.gov (United States)

    Bocanegra Evans, Humberto; Hamed, Ali M; Gorumlu, Serdar; Doosttalab, Ali; Aksak, Burak; Chamorro, Leonardo P; Castillo, Luciano

    2018-02-06

    Flow separation and vortex shedding are some of the most common phenomena experienced by bluff bodies under relative motion with the surrounding medium. They often result in a recirculation bubble in regions with adverse pressure gradient, which typically reduces efficiency in vehicles and increases loading on structures. Here, the ability of an engineered coating to manipulate the large-scale recirculation region was tested in a separated flow at moderate momentum thickness Reynolds number, [Formula: see text] We show that the coating, composed of uniformly distributed cylindrical pillars with diverging tips, successfully reduces the size of, and shifts downstream, the separation bubble. Despite the so-called roughness parameter, [Formula: see text], falling within the hydrodynamic smooth regime, the coating is able to modulate the large-scale recirculating motion. Remarkably, this modulation does not induce noticeable changes in the near-wall turbulence levels. Supported with experimental data and theoretical arguments based on the averaged equations of motion, we suggest that the inherent mechanism responsible for the bubble modulation is essentially unsteady suction and blowing controlled by the increasing cross-section of the tips. The coating can be easily fabricated and installed and works under dry and wet conditions, increasing its potential impact on a diverse range of applications. Copyright © 2018 the Author(s). Published by PNAS.

  5. Bioinspired Engineering of Exploration Systems (BEES) - its Impact on Future Missions

    Science.gov (United States)

    Thakoor, Sarita; Hine, Butler; Zornetzer, Steve

    2004-01-01

    This paper describes an overview of our "Bioinspired Engineering of Exploration Systems for Mars" ( "BEES for Mars") project. The BEES approach distills selected biologically inspired strategies utilizing motion cues/optic flow, bioinspired pattern recognition, biological visual and neural control systems, bioinspired sensing and communication techniques, and birds of prey inspired search and track algorithmic systems. Unique capabilities so enabled, provide potential solutions to future autonomous robotic space and planetary mission applications. With the first series of tests performed in September 2003, August 2004 and September 2004, we have demonstrated the BEES technologies at the El Mirage Dry Lakebed site in the Mojave Desert using Delta Wing experimental prototypes. We call these test flyers the "BEES flyer", since we are developing them as dedicated test platform for the newly developed bioinspired sensors, processors and algorithmic strategies. The Delta Wing offers a robust airframe that can sustain high G launches and offers ease of compact stowability and packaging along with scaling to small size and low ReynOld's number performance for a potential Mars deployment. Our approach to developing light weight, low power autonomous flight systems using concepts distilled from biology promises to enable new applications, of dual use to NASA and DoD needs. Small in size (0.5 -5 Kg) BEES Flyers are demonstrating capabilities for autonomous flight and sensor operability in Mars analog conditions. The BEES project team spans JPL, NASA Ames, Australian National University (ANU), Brigham Young University(BYU), DC Berkeiey, Analogic Computers Inc. and other institutions. The highlights from our recent flight demonstrations exhibiting new Mission enabling capabilities are described. Further, this paper describes two classes of potential new missions for Mars exploration: (1) the long range exploration missions, and (2) observation missions, for real time imaging of

  6. An FEA study on impact resistance of bio-inspired CAD models

    OpenAIRE

    Page, T; Thorsteinsson, G

    2017-01-01

    The purpose of this paper is to explore the use of biomimetic methods in the design of armour systems. It focusses on biological structures found in nature that feature both rigid and flexible armours, analysing their structures and determining which are the most widely successful. A study was conducted on three bio-inspired structures built in Creo Parametric and tested using Finite Element Analysis (FEA) software to determine which structure had the best impact resistance. The study was con...

  7. Bio-inspired nanotechnology from surface analysis to applications

    CERN Document Server

    Walsh, Tiffany

    2014-01-01

    This book focuses on the use of bio-inspired and biomimetic methods for the fabrication and activation of nanomaterials. This includes studies concerning the binding of the biomolecules to the surface of inorganic structures, structure/function relationships of the final materials, and extensive discussions on the final applications of such biomimetic materials in unique applications including energy harvesting/storage, biomedical diagnostics, and materials assembly. This book also: ·          Covers the sustainable features of bio-inspired nanotechnology ·          Includes studies on the unique applications of biomimetic materials, such as energy harvesting and biomedical diagnostics Bio-Inspired Nanotechnology: From Surface Analysis to Applications is an ideal book for researchers, students, nanomaterials engineers, bioengineers, chemists, biologists, physicists, and medical researchers.

  8. A Comparative Numerical Study on the Performances and Vortical Patterns of Two Bioinspired Oscillatory Mechanisms: Undulating and Pure Heaving

    Directory of Open Access Journals (Sweden)

    Mohsen Ebrahimi

    2015-01-01

    Full Text Available The hydrodynamics and energetics of bioinspired oscillating mechanisms have received significant attentions by engineers and biologists to develop the underwater and air vehicles. Undulating and pure heaving (or plunging motions are two significant mechanisms which are utilized in nature to provide propulsive, maneuvering, and stabilization forces. This study aims to elucidate and compare the propulsive vortical signature and performance of these two important natural mechanisms through a systematic numerical study. Navier-Stokes equations are solved, by a pressure-based finite volume method solver, in an arbitrary Lagrangian-Eulerian (ALE framework domain containing a 2D NACA0012 foil moving with prescribed kinematics. Some of the important findings are (1 the thrust production of the heaving foil begins at lower St and has a greater growing slope with respect to the St; (2 the undulating mechanism has some limitations to produce high thrust forces; (3 the undulating foil shows a lower power consumption and higher efficiency; (4 changing the Reynolds number (Re in a constant St affects the performance of the oscillations; and (5 there is a distinguishable appearance of leading edge vortices in the wake of the heaving foil without observable ones in the wake of the undulating foil, especially at higher St.

  9. Bio-inspired mineralization of hydroxyapatite in 3D silk fibroin hydrogel for bone tissue engineering.

    Science.gov (United States)

    Jin, Yashi; Kundu, Banani; Cai, Yurong; Kundu, Subhas C; Yao, Juming

    2015-10-01

    To fabricate hard tissue implants with bone-like structure using a biomimetic mineralization method is drawing much more attentions in bone tissue engineering. The present work focuses in designing 3D silk fibroin hydrogel to modulate the nucleation and growth of hydroxyapatite crystals via a simple ion diffusion method. The study indicates that Ca(2+) incorporation within the hydrogel provides the nucleation sites for hydroxyapatite crystals and subsequently regulates their oriented growth. The mineralization process is regulated in a Ca(2+) concentration- and minerlization time-dependent way. Further, the compressive strength of the mineralized hydrogels is directly proportional with the mineral content in hydrogel. The orchestrated organic/inorganic composite supports well the viability and proliferation of human osteoblast cells; improved cyto-compatibility with increased mineral content. Together, the present investigation reports a simple and biomimetic process to fabricate 3D bone-like biomaterial with desired efficacy to repair bone defects. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Bio-inspired design of a magnetically active trilayered scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Brady, Mariea A; Talvard, Lucien; Vella, Alain; Ethier, C Ross

    2017-04-01

    An important topic in cartilage tissue engineering is the development of biomimetic scaffolds which mimic the depth-dependent material properties of the native tissue. We describe an advanced trilayered nanocomposite hydrogel (ferrogel) with a gradient in compressive modulus from the top to the bottom layers (p elastic, depth-dependent strain gradient. When bovine chondrocytes were seeded into the ferrogels and cultured for up to 14 days, there was good cell viability and a biochemical gradient was measured with sulphated glycosaminoglycan increasing with depth from the surface. This novel construct provides tremendous scope for tailoring location-specific cartilage replacement tissue; by varying the density of magnetic nanoparticles, concentration of base hydrogel and number of cells, physiologically relevant depth-dependent gradients may be attained. © 2015 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. © 2015 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.

  11. A bioinspired autonomous swimming robot as a tool for studying goal-directed locomotion.

    Science.gov (United States)

    Manfredi, L; Assaf, T; Mintchev, S; Marrazza, S; Capantini, L; Orofino, S; Ascari, L; Grillner, S; Wallén, P; Ekeberg, O; Stefanini, C; Dario, P

    2013-10-01

    The bioinspired approach has been key in combining the disciplines of robotics with neuroscience in an effective and promising fashion. Indeed, certain aspects in the field of neuroscience, such as goal-directed locomotion and behaviour selection, can be validated through robotic artefacts. In particular, swimming is a functionally important behaviour where neuromuscular structures, neural control architecture and operation can be replicated artificially following models from biology and neuroscience. In this article, we present a biomimetic system inspired by the lamprey, an early vertebrate that locomotes using anguilliform swimming. The artefact possesses extra- and proprioceptive sensory receptors, muscle-like actuation, distributed embedded control and a vision system. Experiments on optimised swimming and on goal-directed locomotion are reported, as well as the assessment of the performance of the system, which shows high energy efficiency and adaptive behaviour. While the focus is on providing a robotic platform for testing biological models, the reported system can also be of major relevance for the development of engineering system applications.

  12. Bio-Inspired Design Approach Analysis: A Case Study of Antoni Gaudi and Santiago Calatrava

    OpenAIRE

    Marzieh Imani

    2017-01-01

    Antoni Gaudi and Santiago Calatrava have reputation for designing bio-inspired creative and technical buildings. Even though they have followed different independent approaches towards design, the source of bio-inspiration seems to be common. Taking a closer look at their projects reveals that Calatrava has been influenced by Gaudi in terms of interpreting nature and applying natural principles into the design process. This research firstly discusses the dialogue between Biomimicry and archit...

  13. Bio-inspired computation in telecommunications

    CERN Document Server

    Yang, Xin-She; Ting, TO

    2015-01-01

    Bio-inspired computation, especially those based on swarm intelligence, has become increasingly popular in the last decade. Bio-Inspired Computation in Telecommunications reviews the latest developments in bio-inspired computation from both theory and application as they relate to telecommunications and image processing, providing a complete resource that analyzes and discusses the latest and future trends in research directions. Written by recognized experts, this is a must-have guide for researchers, telecommunication engineers, computer scientists and PhD students.

  14. Bio-inspired engineering of cell- and virus-like nanoparticles for drug delivery.

    Science.gov (United States)

    Parodi, Alessandro; Molinaro, Roberto; Sushnitha, Manuela; Evangelopoulos, Michael; Martinez, Jonathan O; Arrighetti, Noemi; Corbo, Claudia; Tasciotti, Ennio

    2017-12-01

    The engineering of future generations of nanodelivery systems aims at the creation of multifunctional vectors endowed with improved circulation, enhanced targeting and responsiveness to the biological environment. Moving past purely bio-inert systems, researchers have begun to create nanoparticles capable of proactively interacting with the biology of the body. Nature offers a wide-range of sources of inspiration for the synthesis of more effective drug delivery platforms. Because the nano-bio-interface is the key driver of nanoparticle behavior and function, the modification of nanoparticles' surfaces allows the transfer of biological properties to synthetic carriers by imparting them with a biological identity. Modulation of these surface characteristics governs nanoparticle interactions with the biological barriers they encounter. Building off these observations, we provide here an overview of virus- and cell-derived biomimetic delivery systems that combine the intrinsic hallmarks of biological membranes with the delivery capabilities of synthetic carriers. We describe the features and properties of biomimetic delivery systems, recapitulating the distinctive traits and functions of viruses, exosomes, platelets, red and white blood cells. By mimicking these biological entities, we will learn how to more efficiently interact with the human body and refine our ability to negotiate with the biological barriers that impair the therapeutic efficacy of nanoparticles. Copyright © 2017. Published by Elsevier Ltd.

  15. Bioinspired Sensor Systems

    Directory of Open Access Journals (Sweden)

    Manel del Valle

    2011-10-01

    Full Text Available This editorial summarizes and classifies the contributions presented by different authors to the special issue of the journal Sensors dedicated to Bioinspired Sensor Systems. From the coupling of sensor arrays or networks, plus computer processing abilities, new applications to mimic or to complement human senses are arising in the context of ambient intelligence. Principles used, and illustrative study cases have been presented permitting readers to grasp the current status of the field.

  16. A comparative study of bio-inspired protective scales using 3D printing and mechanical testing.

    Science.gov (United States)

    Martini, Roberto; Balit, Yanis; Barthelat, Francois

    2017-06-01

    Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention for their unique combinations of hardness, flexibility and light weight. The extreme contrast of stiffness between hard scales and surrounding soft tissues gives rise to unusual and attractive mechanisms, which now serve as models for the design of bio-inspired armors. Despite this growing interest, there is little guideline for the choice of materials, optimum thickness, size, shape and arrangement for the protective scales. In this work, we explore how the geometry and arrangement of hard scales can be tailored to promote scale-scale interactions. We use 3D printing to fabricate arrays of scales with increasingly complex geometries and arrangements, from simple squares with no overlap to complex ganoid-scales with overlaps and interlocking features. We performed puncture tests and flexural tests on each of the 3D printed materials, and we report the puncture resistance - compliance characteristics of each design on an Ashby chart. The interactions between the scales can significantly increase the resistance to puncture, and these interactions can be maximized by tuning the geometry and arrangement of the scales. Interestingly, the designs that offer the best combinations of puncture resistance and flexural compliance are similar to the geometry and arrangement of natural teleost and ganoid scales, which suggests that natural evolution has shaped these systems to maximize flexible protection. This study yields new insights into the mechanisms of natural dermal armor, and also suggests new designs for personal protective systems. Flexible natural armors from fishes, alligators or armadillos are attracting an increasing amount of attention for their unique and attractive combinations of hardness, flexibility and low weight. Despite a growing interest in bio-inspired flexible protection, there is still little guideline for the choice of materials, optimum

  17. Combinatorial cell-3D biomaterials cytocompatibility screening for tissue engineering using bioinspired superhydrophobic substrates.

    Science.gov (United States)

    Salgado, Christiane L; Oliveira, Mariana B; Mano, João F

    2012-03-01

    We report on the development of a new array-based screening flat platform with the potential to be used as a high-throughput device based on biomimetic polymeric substrates for combinatorial cell/3D biomaterials screening assays in the context of tissue engineering. Polystyrene was used to produce superhydrophobic surfaces based on the so-called lotus effect. Arrays of hydrophilic regions could be patterned in such surfaces using UV/ozone radiation, generating devices onto which combinatorial hydrogel spots were deposited. The biological performance of encapsulated cells in hydrogels could be tested in an in vitro 3D environment assuming that each site was isolated from the others due to the high contrast of wettability between the patterned spots and the superhydrophobic surroundings. Three different polymers-chitosan, collagen and hyaluronic acid-were combined with alginate in different proportions in order to obtain combinatorial binary alginate-based polymeric arrays. The effect of the addition of gelatin to the binary structures was also tested. The gels were chemically analyzed by FTIR microscopic mapping. Cell culture results varied according to the hydrogel composition and encapsulated cell types (L929 fibroblast cells and MC3T3-E1 pre-osteoblast cells). Cell viability and number could be assessed by conventional methods, such as MTS reduction test and dsDNA quantification. Non-destructive image analysis was performed using cytoskeleton and nuclei staining agents and the results were consistent with the ones obtained by conventional sample-destructive techniques. Briefly, L929 cells showed higher number and viability for higher alginate-content and collagen-containing hydrogels, while MC3T3-E1 showed higher cell viability and cell number in lower alginate-content and chitosan containing hydrogels. The addition of gelatin did not influence significantly cell metabolic activity or cell number in any of the encapsulated cell types. This journal is © The Royal

  18. Improving mechanical properties of maxillary complete dentures through a bioinspired engineering design.

    Science.gov (United States)

    White, James A P; Bond, Ian P; Jagger, Daryll C

    2011-01-01

    This study investigated how ribbed design features, including palatal rugae, may be used to significantly improve the structural performance of a maxillary denture under load. A computer-aided design model of a generic maxillary denture, incorporating various rib features, was created and imported into a finite element analysis program. The denture and ribbed features were assigned the material properties of standard denture acrylic resin, and load was applied in two different ways: the first simulating a three-point flexural bend of the posterior section and the second simulating loading of the entire palatal region. To investigate the combined use of ribbing and reinforcement, the same simulations were repeated with the ribbed features having a Young modulus two orders of magnitude greater than denture acrylic resin. For a prescribed load, total displacements of tracking nodes were compared to those of a control denture (without ribbing) to assess relative denture rigidity. When subjected to flexural loading, an increase in rib depth was seen to result in a reduction of both the transverse displacement of the last molar and vertical displacement at the centerline. However, ribbed features assigned the material properties of denture acrylic resin require a depth that may impose on speech and bolus propulsion before significant improvements are observed. The use of ribbed features, when made from a significantly stiffer material (eg, fiber-reinforced polymer) and designed to mimic palatal rugae, offer an acceptable method of providing significant improvements in rigidity to a maxillary denture under flexural load.

  19. Feasibility Study of a Bio-inspired Artificial Pancreas in Adults with Type 1 Diabetes

    Science.gov (United States)

    Herrero, Pau; El Sharkawy, Mohamed; Pesl, Peter; Jugnee, Narvada; Thomson, Hazel; Pavitt, Darrell; Toumazou, Christofer; Johnston, Desmond; Georgiou, Pantelis; Oliver, Nick

    2014-01-01

    Abstract Background: This study assesses proof of concept and safety of a novel bio-inspired artificial pancreas (BiAP) system in adults with type 1 diabetes during fasting, overnight, and postprandial conditions. In contrast to existing glucose controllers in artificial pancreas systems, the BiAP uses a control algorithm based on a mathematical model of β-cell physiology. The algorithm is implemented on a miniature silicon microchip within a portable hand-held device that interfaces the components of the artificial pancreas. Materials and Methods: In this nonrandomized open-label study each subject attended for a 6-h fasting study followed by a 13-h overnight and post-breakfast study on a separate occasion. During both study sessions the BiAP system was used, and microboluses of insulin were recommended every 5 min by the control algorithm according to subcutaneous sensor glucose levels. The primary outcome was percentage time spent in the glucose target range (3.9–10.0 mmol/L). Results: Twenty subjects (55% male; mean [SD] age, 44 [10] years; duration of diabetes, 22 [12] years; glycosylated hemoglobin, 7.4% [0.7%] [57 (7) mmol/mol]; body mass index, 25 [4] kg/m2) participated in the fasting study, and the median (interquartile range) percentage time in target range was 98.0% (90.8–100.0%). Seventeen of these subjects then participated in the overnight/postprandial study, where 70.7% (63.9–77.4%) of time was spent in the target range and, reassuringly, 0.0% (0.0–2.3%) of time was spent in hypoglycemia (<3.9 mmol/L). Conclusions: The BiAP achieves safe glycemic control during fasting, overnight, and postprandial conditions. PMID:24801544

  20. Studying Engineering Practice

    DEFF Research Database (Denmark)

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However......, engineering studies have not given much attention to conceptually clarifying what should be understood by 'engineering practices' and more precisely account for the composition and organization of the entities and phenomena that make up the practices. This chapter investigates and discusses how a 'practice...... will draw out some methodological consequences and discuss the ramifications of a practice theoretical approach for Engineering Studies....

  1. Bio-Inspired Sustainability Assessment for Building Product Development—Concept and Case Study

    Directory of Open Access Journals (Sweden)

    Rafael Horn

    2018-01-01

    Full Text Available Technological advancement culminating in a globalized economy has brought tremendous improvements for mankind in manifold respects but comes at the cost of alienation from nature. Human activities nowadays are unsustainable and cause severe damage especially in terms of global depletion and destabilization of natural systems but also harm its own social resources. In this paper, a sustainability assessment method is developed based on a bio-inspired sustainability framework that has been developed in the project TRR 141-C01 “The biomimetic promise.” It is aims at regaining the advantages of societal embeddedness in its environment through biological inspiration. The method is developed using a structured approach including requirement specification, description of the inventory models on bio-inspiration and sustainability assessment, creation of a bio-inspired sustainability assessment model and its validation. It is defined as an accompanying assessment for decision support, using a six-fold two-dimensional structure of social, economic and environmental functions and burdens. The method is applied and validated in 6 projects of TRR 141 and its applicability is exemplarily shown by the assessment of “Bio-flexi”, a biobased and biodegradable natural fiber reinforced plastic composite for indoor cladding applications. Based on the findings of the application the assessment method itself is proposed to be advanced towards an adaptive structure and a consequent outlook is provided.

  2. In Situ Atomic Force Microscopy Studies on Nucleation and Self-Assembly of Biogenic and Bio-Inspired Materials

    Directory of Open Access Journals (Sweden)

    Cheng Zeng

    2017-08-01

    Full Text Available Through billions of years of evolution, nature has been able to create highly sophisticated and ordered structures in living systems, including cells, cellular components and viruses. The formation of these structures involves nucleation and self-assembly, which are fundamental physical processes associated with the formation of any ordered structure. It is important to understand how biogenic materials self-assemble into functional and highly ordered structures in order to determine the mechanisms of biological systems, as well as design and produce new classes of materials which are inspired by nature but equipped with better physiochemical properties for our purposes. An ideal tool for the study of nucleation and self-assembly is in situ atomic force microscopy (AFM, which has been widely used in this field and further developed for different applications in recent years. The main aim of this work is to review the latest contributions that have been reported on studies of nucleation and self-assembly of biogenic and bio-inspired materials using in situ AFM. We will address this topic by introducing the background of AFM, and discussing recent in situ AFM studies on nucleation and self-assembly of soft biogenic, soft bioinspired and hard materials.

  3. Bioinspired spring origami

    Science.gov (United States)

    Faber, Jakob A.; Arrieta, Andres F.; Studart, André R.

    2018-03-01

    Origami enables folding of objects into a variety of shapes in arts, engineering, and biological systems. In contrast to well-known paper-folded objects, the wing of the earwig has an exquisite natural folding system that cannot be sufficiently described by current origami models. Such an unusual biological system displays incompatible folding patterns, remains open by a bistable locking mechanism during flight, and self-folds rapidly without muscular actuation. We show that these notable functionalities arise from the protein-rich joints of the earwig wing, which work as extensional and rotational springs between facets. Inspired by this biological wing, we establish a spring origami model that broadens the folding design space of traditional origami and allows for the fabrication of precisely tunable, four-dimensional–printed objects with programmable bioinspired morphing functionalities.

  4. Bioinspired spring origami.

    Science.gov (United States)

    Faber, Jakob A; Arrieta, Andres F; Studart, André R

    2018-03-23

    Origami enables folding of objects into a variety of shapes in arts, engineering, and biological systems. In contrast to well-known paper-folded objects, the wing of the earwig has an exquisite natural folding system that cannot be sufficiently described by current origami models. Such an unusual biological system displays incompatible folding patterns, remains open by a bistable locking mechanism during flight, and self-folds rapidly without muscular actuation. We show that these notable functionalities arise from the protein-rich joints of the earwig wing, which work as extensional and rotational springs between facets. Inspired by this biological wing, we establish a spring origami model that broadens the folding design space of traditional origami and allows for the fabrication of precisely tunable, four-dimensional-printed objects with programmable bioinspired morphing functionalities. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  5. Bioinspired Mechanical Gradients in Cellulose Nanofibril/Polymer Nanopapers.

    Science.gov (United States)

    Wang, Baochun; Benitez, Alejandro J; Lossada, Francisco; Merindol, Remi; Walther, Andreas

    2016-05-10

    Mechanical gradients are important as tough joints, for strain field engineering in printable electronics, for actuators, and for biological studies, yet they are difficult to prepare and quantitatively characterize. We demonstrate the additive fabrication of gradient bioinspired nanocomposites based on stiff, renewable cellulose nanofibrils that are bottom-up toughened via a tailor-made copolymer. Direct filament writing of different nanocomposite hydrogels in patterns, and subsequent healing of the filaments into continuous films while drying leads to a variety of linear, parabolic and striped bulk gradients. In situ digital image correlation under tensile deformation reveals important differences in the strain fields regarding asymmetry and step heights of the patterns. We envisage that merging top-down and bottom-up structuring of nanocellulose hybrids opens avenues for aperiodic and multiscale, bioinspired nanocomposites with optimized combinations of stiffness and toughness. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Bioinspired coupled helical coils for soft tissue engineering of tubular structures - Improved mechanical behavior of tubular collagen type I templates.

    Science.gov (United States)

    Janke, H P; Bohlin, J; Lomme, R M L M; Mihaila, S M; Hilborn, J; Feitz, W F J; Oosterwijk, E

    2017-09-01

    The design of constructs for tubular tissue engineering is challenging. Most biomaterials need to be reinforced with supporting structures such as knittings, meshes or electrospun material to comply with the mechanical demands of native tissues. In this study, coupled helical coils (CHCs) were manufactured to mimic collagen fiber orientation as found in nature. Monofilaments of different commercially available biodegradable polymers were wound and subsequently fused, resulting in right-handed and left-handed polymer helices fused together in joints where the filaments cross. CHCs of different polymer composition were tested to determine the tensile strength, strain recovery, hysteresis, compressive strength and degradation of CHCs of different composition. Subsequently, seamless and stable hybrid constructs consisting of PDSII® USP 2-0 CHCs embedded in porous collagen type I were produced. Compared to collagen alone, this hybrid showed superior strain recovery (93.5±0.9% vs 71.1±12.6% in longitudinal direction; 87.1±6.6% vs 57.2±4.6% in circumferential direction) and hysteresis (18.9±2.7% vs 51.1±12.0% in longitudinal direction; 11.5±4.6% vs 46.3±6.3% in circumferential direction). Furthermore, this hybrid construct showed an improved Young's modulus in both longitudinal (0.5±0.1MPavs 0.2±0.1MPa; 2.5-fold) and circumferential (1.65±0.07MPavs (2.9±0.3)×10 -2 MPa; 57-fold) direction, respectively, compared to templates created from collagen alone. Moreover, hybrid template characteristics could be modified by changing the CHC composition and CHCs were produced showing a mechanical behavior similar to the native ureter. CHC-enforced templates, which are easily tunable to meet different demands may be promising for tubular tissue engineering. Most tubular constructs lack sufficient strength and tunability to comply with the mechanical demands of native tissues. Therefore, we embedded coupled helical coils (CHCs) produced from biodegradable polymers - to

  7. Bio-inspired networking

    CERN Document Server

    Câmara, Daniel

    2015-01-01

    Bio-inspired techniques are based on principles, or models, of biological systems. In general, natural systems present remarkable capabilities of resilience and adaptability. In this book, we explore how bio-inspired methods can solve different problems linked to computer networks. Future networks are expected to be autonomous, scalable and adaptive. During millions of years of evolution, nature has developed a number of different systems that present these and other characteristics required for the next generation networks. Indeed, a series of bio-inspired methods have been successfully used to solve the most diverse problems linked to computer networks. This book presents some of these techniques from a theoretical and practical point of view. Discusses the key concepts of bio-inspired networking to aid you in finding efficient networking solutions Delivers examples of techniques both in theoretical concepts and practical applications Helps you apply nature's dynamic resource and task management to your co...

  8. Bioinspired Poly(2-oxazolines

    Directory of Open Access Journals (Sweden)

    Helmut Schlaad

    2011-02-01

    Full Text Available Poly(2-oxazolines are regarded as pseudopeptides, thus bioinspired polymers, due to their structural relationship to polypeptides. Materials and solution properties can be tuned by varying the side-chain (hydrophilic-hydrophobic, chiral, bioorganic, etc., opening the way to advanced stimulus-responsive materials and complex colloidal structures. The bioinspired “smart” solution and aggregation behavior of poly(2-oxazolines in aqueous environments are discussed in this review.

  9. Parallel Architectures and Bioinspired Algorithms

    CERN Document Server

    Pérez, José; Lanchares, Juan

    2012-01-01

    This monograph presents examples of best practices when combining bioinspired algorithms with parallel architectures. The book includes recent work by leading researchers in the field and offers a map with the main paths already explored and new ways towards the future. Parallel Architectures and Bioinspired Algorithms will be of value to both specialists in Bioinspired Algorithms, Parallel and Distributed Computing, as well as computer science students trying to understand the present and the future of Parallel Architectures and Bioinspired Algorithms.

  10. High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation.

    Science.gov (United States)

    Diaz, Alfredo J; Noh, Hanaul; Meier, Tobias; Solares, Santiago D

    2017-01-01

    Bioinspired design has been central in the development of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties, as well as gas-barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has also been utilized in sensing devices. Here we extend the multifunctionality of nacre-mimetics by designing an optically transparent and electron conductive coating based on PEDOT:PSS and nanoclays Laponite RD and Cloisite Na + . We carry out extensive characterization of the nanocomposite using transmittance spectra (transparency), conductive atomic force microscopy (conductivity), contact-resonance force microscopy (mechanical properties), and SEM combined with a variety of stress-strain AFM experiments and AFM numerical simulations (internal structure). We further study the nanoclay's response to the application of pressure with multifrequency AFM and conductive AFM, whereby increases and decreases in conductivity can occur for the Laponite RD composites. We offer a possible mechanism to explain the changes in conductivity by modeling the coating as a 1-dimensional multibarrier potential for electron transport, and show that conductivity can change when the separation between the barriers changes under the application of pressure, and that the direction of the change depends on the energy of the electrons. We did not observe changes in conductivity under the application of pressure with AFM for the Cloisite Na + nanocomposite, which has a large platelet size compared with the AFM probe diameter. No pressure-induced changes in conductivity were observed in the clay-free polymer either.

  11. Introducing Students to Bio-Inspiration and Biomimetic Design: A Workshop Experience

    Science.gov (United States)

    Santulli, Carlo; Langella, Carla

    2011-01-01

    In recent years, bio-inspired approach to design has gained considerable interest between designers, engineers and end-users. However, there are difficulties in introducing bio-inspiration concepts in the university curriculum in that they involve multi-disciplinary work, which can only possibly be successfully delivered by a team with integrated…

  12. Hybrid metal-coordinate transient networks: using bio-inspired building blocks to engineer the mechanical properties of physical hydrogels

    Science.gov (United States)

    Grindy, Scott; Barrett, Devin; Messersmith, Phillip; Holten-Andersen, Niels

    2014-03-01

    Recently, metal-coordinate complex crosslinks have been suggested to contribute to the self-healing properties of mussel byssi. Two specific amino acid derivatives - 3,4 dihydroxy-L-phenylalanine (dopa) and histidine (his) - are known to form coordinate complexes with trivalent and divalent ions (respectively) in aqueous solutions. We show here that, by functionalizing poly(ethylene glycol) polymers with dopa and his we are (1) able to characterize the fundamental kinetics and energetics of each specific metal-ligand pair using small amplitude oscillatory shear rheology and (2) create hybrid networks using various mixtures of metals and ligands. From this information, we can design gels with specific target mechanical properties by tailoring the amounts and types of metal-ligand crosslinks present in the gel network, resulting in the ability to engineer the mechanical relaxation spectrum. This work provides basic understanding necessary to intelligently design materials which incorporate metal-ligand crosslinks in more complex architectures.

  13. Bio-inspired vision

    International Nuclear Information System (INIS)

    Posch, C

    2012-01-01

    Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980's, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ''neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems

  14. Fast nastic motion of plants and bioinspired structures.

    Science.gov (United States)

    Guo, Q; Dai, E; Han, X; Xie, S; Chao, E; Chen, Z

    2015-09-06

    The capability to sense and respond to external mechanical stimuli at various timescales is essential to many physiological aspects in plants, including self-protection, intake of nutrients and reproduction. Remarkably, some plants have evolved the ability to react to mechanical stimuli within a few seconds despite a lack of muscles and nerves. The fast movements of plants in response to mechanical stimuli have long captured the curiosity of scientists and engineers, but the mechanisms behind these rapid thigmonastic movements are still not understood completely. In this article, we provide an overview of such thigmonastic movements in several representative plants, including Dionaea, Utricularia, Aldrovanda, Drosera and Mimosa. In addition, we review a series of studies that present biomimetic structures inspired by fast-moving plants. We hope that this article will shed light on the current status of research on the fast movements of plants and bioinspired structures and also promote interdisciplinary studies on both the fundamental mechanisms of plants' fast movements and biomimetic structures for engineering applications, such as artificial muscles, multi-stable structures and bioinspired robots. © 2015 The Author(s).

  15. High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

    Directory of Open Access Journals (Sweden)

    Alfredo J. Diaz

    2017-10-01

    Full Text Available Bioinspired design has been central in the development of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties, as well as gas-barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has also been utilized in sensing devices. Here we extend the multifunctionality of nacre-mimetics by designing an optically transparent and electron conductive coating based on PEDOT:PSS and nanoclays Laponite RD and Cloisite Na+. We carry out extensive characterization of the nanocomposite using transmittance spectra (transparency, conductive atomic force microscopy (conductivity, contact-resonance force microscopy (mechanical properties, and SEM combined with a variety of stress-strain AFM experiments and AFM numerical simulations (internal structure. We further study the nanoclay’s response to the application of pressure with multifrequency AFM and conductive AFM, whereby increases and decreases in conductivity can occur for the Laponite RD composites. We offer a possible mechanism to explain the changes in conductivity by modeling the coating as a 1-dimensional multibarrier potential for electron transport, and show that conductivity can change when the separation between the barriers changes under the application of pressure, and that the direction of the change depends on the energy of the electrons. We did not observe changes in conductivity under the application of pressure with AFM for the Cloisite Na+ nanocomposite, which has a large platelet size compared with the AFM probe diameter. No pressure-induced changes in conductivity were observed in the clay-free polymer either.

  16. Bioinspired polarization navigation sensor for autonomous munitions systems

    Science.gov (United States)

    Giakos, G. C.; Quang, T.; Farrahi, T.; Deshpande, A.; Narayan, C.; Shrestha, S.; Li, Y.; Agarwal, M.

    2013-05-01

    Small unmanned aerial vehicles UAVs (SUAVs), micro air vehicles (MAVs), Automated Target Recognition (ATR), and munitions guidance, require extreme operational agility and robustness which can be partially offset by efficient bioinspired imaging sensor designs capable to provide enhanced guidance, navigation and control capabilities (GNC). Bioinspired-based imaging technology can be proved useful either for long-distance surveillance of targets in a cluttered environment, or at close distances limited by space surroundings and obstructions. The purpose of this study is to explore the phenomenology of image formation by different insect eye architectures, which would directly benefit the areas of defense and security, on the following four distinct areas: a) fabrication of the bioinspired sensor b) optical architecture, c) topology, and d) artificial intelligence. The outcome of this study indicates that bioinspired imaging can impact the areas of defense and security significantly by dedicated designs fitting into different combat scenarios and applications.

  17. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1990-01-01

    The main focus of the work by the Fusion Plasma Engineering Group at the University during the prior contract year involved a study of fusion ash (helium) effects on burn efficiency and on potential ways to control ash buildup. This work has wide application to a variety of fusion reactor concepts, but the immediate application for the present work is in the ARIES tokamak reactor design study now being undertaken by a national design team headed by the UCLA. The examples presented here largely deal with the ARIES-I design which is a D-T device operating in the first instability regime

  18. Combining Bio-inspired Sensing with Bio-inspired Locomotion

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    In this paper we present a preliminary Braitenberg vehicle–like approach to combine bio-inspired audition with bio-inspired quadruped locomotion in simulation. Locomotion gaits of the salamander–like robot Salamandra robotica are modified by a lizard’s peripheral auditory system model...

  19. Bioarchitecture: bioinspired art and architecture--a perspective.

    Science.gov (United States)

    Ripley, Renee L; Bhushan, Bharat

    2016-08-06

    Art and architecture can be an obvious choice to pair with science though historically this has not always been the case. This paper is an attempt to interact across disciplines, define a new genre, bioarchitecture, and present opportunities for further research, collaboration and professional cooperation. Biomimetics, or the copying of living nature, is a field that is highly interdisciplinary, involving the understanding of biological functions, structures and principles of various objects found in nature by scientists. Biomimetics can lead to biologically inspired design, adaptation or derivation from living nature. As applied to engineering, bioinspiration is a more appropriate term, involving interpretation, rather than direct copying. Art involves the creation of discrete visual objects intended by their creators to be appreciated by others. Architecture is a design practice that makes a theoretical argument and contributes to the discourse of the discipline. Bioarchitecture is a blending of art/architecture and biomimetics/bioinspiration, and incorporates a bioinspired design from the outset in all parts of the work at all scales. Herein, we examine various attempts to date of art and architecture to incorporate bioinspired design into their practice, and provide an outlook and provocation to encourage collaboration among scientists and designers, with the aim of achieving bioarchitecture.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  20. Green processes for nanotechnology from inorganic to bioinspired nanomaterials

    CERN Document Server

    Basiuk, Elena

    2015-01-01

    This book provides the state-of-the-art survey of green techniques in preparation of different classes of nanomaterials, with an emphasis on the use of renewable sources. Key topics covered include fabrication of nanomaterials using green techniques as well as their properties and applications, the use of renewable sources to obtain nanomaterials of different classes, from simple metal and metal oxide nanoparticles to complex bioinspired nanomaterials, economic contributions of nanotechnology to green and sustainable growth, and more. This is an ideal book for students, lecturers, researchers and engineers dealing with versatile (mainly chemical, biological, and medical) aspects of nanotechnology, including fabrication of nanomaterials using green techniques and their properties and applications. This book also: Maximizes reader insights into the design and fabrication of bioinspired nanomaterials and the design of complex bio-nanohybrids Covers many different applications for nanomaterials, bioinspired nanom...

  1. Numerical study on the hydrodynamics of thunniform bio-inspired swimming under self-propulsion.

    Directory of Open Access Journals (Sweden)

    Ningyu Li

    Full Text Available Numerical simulations are employed to study the hydrodynamics of self-propelled thunniform swimming. The swimmer is modeled as a tuna-like flexible body undulating with kinematics of thunniform type. The wake evolution follows the vortex structures arranged nearly vertical to the forward direction, vortex dipole formation resulting in the propulsion motion, and finally a reverse Kármán vortex street. We also carry out a systematic parametric study of various aspects of the fluid dynamics behind the freely swimming behavior, including the swimming speed, hydrodynamic forces, power requirement and wake vortices. The present results show that the fin thrust as well as swimming velocity is an increasing function of both tail undulating amplitude Ap and oscillating amplitude of the caudal fin θm. Whereas change on the propulsive performance with Ap is associated with the strength of wake vortices and the area of suction region on the fin, the swimming performance improves with θm due to the favorable tilting of the fin that make the pressure difference force more oriented toward the thrust direction. Moreover, the energy loss in the transverse direction and the power requirement increase with Ap but decrease with θm, and this indicates that for achieving a desired swimming speed increasing θm seems more efficiently than increasing Ap. Furthermore, we have compared the current simulations with the published experimental studies on undulatory swimming. Comparisons show that our work tackles the flow regime of natural thunniform swimmers and follows the principal scaling law of undulatory locomotion reported. Finally, this study enables a detailed quantitative analysis, which is difficult to obtain by experiments, of the force production of the thunniform mode as well as its connection to the self-propelled swimming kinematics and vortex wake structure. The current findings help provide insights into the swimming performance and mechanisms of self

  2. Bioinspired Principles for Large-Scale Networked Sensor Systems: An Overview

    Directory of Open Access Journals (Sweden)

    Thomas Skjødeberg Toftegaard

    2011-04-01

    Full Text Available Biology has often been used as a source of inspiration in computer science and engineering. Bioinspired principles have found their way into network node design and research due to the appealing analogies between biological systems and large networks of small sensors. This paper provides an overview of bioinspired principles and methods such as swarm intelligence, natural time synchronization, artificial immune system and intercellular information exchange applicable for sensor network design. Bioinspired principles and methods are discussed in the context of routing, clustering, time synchronization, optimal node deployment, localization and security and privacy.

  3. A bio-inspired study on tidal energy extraction with flexible flapping wings.

    Science.gov (United States)

    Liu, Wendi; Xiao, Qing; Cheng, Fai

    2013-09-01

    Previous research on the flexible structure of flapping wings has shown an improved propulsion performance in comparison to rigid wings. However, not much is known about this function in terms of power efficiency modification for flapping wing energy devices. In order to study the role of the flexible wing deformation in the hydrodynamics of flapping wing energy devices, we computationally model the two-dimensional flexible single and twin flapping wings in operation under the energy extraction conditions with a large Reynolds number of 106. The flexible motion for the present study is predetermined based on a priori structural result which is different from a passive flexibility solution. Four different models are investigated with additional potential local distortions near the leading and trailing edges. Our simulation results show that the flexible structure of a wing is beneficial to enhance power efficiency by increasing the peaks of lift force over a flapping cycle, and tuning the phase shift between force and velocity to a favourable trend. Moreover, the impact of wing flexibility on efficiency is more profound at a low nominal effective angle of attack (AoA). At a typical flapping frequency f * = 0.15 and nominal effective AoA of 10°, a flexible integrated wing generates 7.68% higher efficiency than a rigid wing. An even higher increase, around six times that of a rigid wing, is achievable if the nominal effective AoA is reduced to zero degrees at feathering condition. This is very attractive for a semi-actuated flapping energy system, where energy input is needed to activate the pitching motion. The results from our dual-wing study found that a parallel twin-wing device can produce more power compared to a single wing due to the strong flow interaction between the two wings.

  4. Bio-inspired computational heuristics to study Lane-Emden systems arising in astrophysics model.

    Science.gov (United States)

    Ahmad, Iftikhar; Raja, Muhammad Asif Zahoor; Bilal, Muhammad; Ashraf, Farooq

    2016-01-01

    This study reports novel hybrid computational methods for the solutions of nonlinear singular Lane-Emden type differential equation arising in astrophysics models by exploiting the strength of unsupervised neural network models and stochastic optimization techniques. In the scheme the neural network, sub-part of large field called soft computing, is exploited for modelling of the equation in an unsupervised manner. The proposed approximated solutions of higher order ordinary differential equation are calculated with the weights of neural networks trained with genetic algorithm, and pattern search hybrid with sequential quadratic programming for rapid local convergence. The results of proposed solvers for solving the nonlinear singular systems are in good agreements with the standard solutions. Accuracy and convergence the design schemes are demonstrated by the results of statistical performance measures based on the sufficient large number of independent runs.

  5. Bio-inspired variable structural color materials.

    Science.gov (United States)

    Zhao, Yuanjin; Xie, Zhuoying; Gu, Hongcheng; Zhu, Cun; Gu, Zhongze

    2012-04-21

    Natural structural color materials, especially those that can undergo reversible changes, are attracting increasing interest in a wide variety of research fields. Inspired by the natural creatures, many elaborately nanostructured photonic materials with variable structural colors were developed. These materials have found important applications in switches, display devices, sensors, and so on. In this critical review, we will provide up-to-date research concerning the natural and bio-inspired photonic materials with variable structural colors. After introducing the variable structural colors in natural creatures, we will focus on the studies of artificial variable structural color photonic materials, including their bio-inspired designs, fabrications and applications. The prospects for the future development of these fantastic variable structural color materials will also be presented. We believe this review will promote the communications among biology, bionics, chemistry, optical physics, and material science (196 references). This journal is © The Royal Society of Chemistry 2012

  6. Mechanics of bioinspired imaging systems

    OpenAIRE

    Zhengwei Li; Yu Wang; Jianliang Xiao

    2016-01-01

    Imaging systems in nature have attracted a lot of research interest due to their superior optical and imaging characteristics. Recent advancements in materials science, mechanics, and stretchable electronics have led to successful development of bioinspired cameras that resemble the structures and functions of biological light-sensing organs. In this review, we discuss some recent progresses in mechanics of bioinspired imaging systems, including tunable hemispherical eyeball camera and artifi...

  7. Insertion mechanics of bioinspired needles into soft tissues.

    Science.gov (United States)

    Sahlabadi, Mohammad; Khodaei, Seyedvahid; Jezler, Kyle; Hutapea, Parsaoran

    2017-12-22

    Most studies to date confirm that any increase in the needle insertion force increases the damage to the tissue. When it comes to brain tissue, even minor damage can cause a long-lasting traumatic brain injury. Thus there is a great demand for innovative minimally invasive needles among the medical community. In our previous studies a novel bioinspired needle design with specially designed barbs was used to perform insertion tests into Polyvinyl chloride (PVC) tissue-mimicking gels, in which it decreased the insertion force by as much as 25%. In this work, bioinspired needles were designed using a CAD software, and were then manufactured using a 3 D printer. The insertion tests into bovine brain and liver were then performed to further investigate the performance of our bioinspired needles in real tissues. Our results show that there was a 10-25% decrease in the insertion force for insertions into bovine brain, and a 35-45% reduction in the insertion force for insertions into bovine liver using the proposed bioinspired needles. The reduction in the insertion force is due to the decrease in the friction force of the bioinspired needle with the bovine tissues, and its results are consistent with our previous results.

  8. 2012 Gordon Research Conference on Bioinspired Materials - Formal Schedule and Speaker/Poster Program

    Energy Technology Data Exchange (ETDEWEB)

    Chilkoti, Ashutosk [Duke Univ., Durham, NC (United States)

    2012-06-29

    The emerging, interdisciplinary field of Bioinspired Materials focuses on developing a fundamental understanding of the synthesis, directed self-assembly and hierarchical organization of natural occurring materials, and uses this understanding to engineer new bioinspired artificial materials for diverse applications. The inaugural 2012 Gordon Conference on Bioinspired Materials seeks to capture the excitement of this burgeoning field by a cutting-edge scientific program and roster of distinguished invited speakers and discussion leaders who will address the key issues in the field. The Conference will feature a wide range of topics, such as materials and devices from DNA, reprogramming the genetic code for design of new materials, peptide, protein and carbohydrate based materials, biomimetic systems, complexity in self-assembly, and biomedical applications of bioinspired materials.

  9. Understanding Toughness in Bioinspired Cellulose Nanofibril/Polymer Nanocomposites.

    Science.gov (United States)

    Benítez, Alejandro J; Lossada, Francisco; Zhu, Baolei; Rudolph, Tobias; Walther, Andreas

    2016-07-11

    Cellulose nanofibrils (CNFs) are considered next generation, renewable reinforcements for sustainable, high-performance bioinspired nanocomposites uniting high stiffness, strength and toughness. However, the challenges associated with making well-defined CNF/polymer nanopaper hybrid structures with well-controlled polymer properties have so far hampered to deduce a quantitative picture of the mechanical properties space and deformation mechanisms, and limits the ability to tune and control the mechanical properties by rational design criteria. Here, we discuss detailed insights on how the thermo-mechanical properties of tailor-made copolymers govern the tensile properties in bioinspired CNF/polymer settings, hence at high fractions of reinforcements and under nanoconfinement conditions for the polymers. To this end, we synthesize a series of fully water-soluble and nonionic copolymers, whose glass transition temperatures (Tg) are varied from -60 to 130 °C. We demonstrate that well-defined polymer-coated core/shell nanofibrils form at intermediate stages and that well-defined nanopaper structures with tunable nanostructure arise. The systematic correlation between the thermal transitions in the (co)polymers, as well as its fraction, on the mechanical properties and deformation mechanisms of the nanocomposites is underscored by tensile tests, SEM imaging of fracture surfaces and dynamic mechanical analysis. An optimum toughness is obtained for copolymers with a Tg close to the testing temperature, where the soft phase possesses the best combination of high molecular mobility and cohesive strength. New deformation modes are activated for the toughest compositions. Our study establishes quantitative structure/property relationships in CNF/(co)polymer nanopapers and opens the design space for future, rational molecular engineering using reversible supramolecular bonds or covalent cross-linking.

  10. Utilizing the cochlea as a bio-inspired compressive sensing technique

    International Nuclear Information System (INIS)

    Peckens, C A; Lynch, J P

    2013-01-01

    Structural monitoring for civil infrastructure is a rapidly developing field that has made significant advancements over the last decade. However, a number of performance bottlenecks remain including challenges with cost-effectively scaling monitoring systems up to large nodal counts. Due to the many parallels between biological sensory systems and engineered sensing systems, the biological nervous system can offer potential solutions to the current deficiencies of structural monitoring systems. The nervous system is capable of real-time processing and data transmission of external stimuli through an extremely condensed format with very basic processing units. This study explores the mammalian auditory system for inspiration because it achieves efficient data acquisition processes that outperform existing engineered sensing systems. Specifically, the auditory system realizes this through three steps: (1) real-time decomposition of a convoluted time-based signal into frequency components, (2) information compression for each component, and (3) efficient high-speed data transmission to the auditory cortex. In this paper, these three main mechanisms are explored and a bio-inspired structural monitoring system is proposed. The functionality of the proposed system is compared to traditional data compression techniques (wavelet transforms and compressed sensing) on various vibratory signals. While the wavelet transform is able to outperform the proposed sensor by minimizing signal reconstruction errors, the proposed bio-inspired sensor achieves similar compression rates but, unlike the others, does so using real-time processing. (paper)

  11. Mechanics of bioinspired imaging systems

    Directory of Open Access Journals (Sweden)

    Zhengwei Li

    2016-01-01

    Full Text Available Imaging systems in nature have attracted a lot of research interest due to their superior optical and imaging characteristics. Recent advancements in materials science, mechanics, and stretchable electronics have led to successful development of bioinspired cameras that resemble the structures and functions of biological light-sensing organs. In this review, we discuss some recent progresses in mechanics of bioinspired imaging systems, including tunable hemispherical eyeball camera and artificial compound eye camera. The mechanics models and results reviewed in this article can provide efficient tools for design and optimization of such systems, as well as other related optoelectronic systems that combine rigid elements with soft substrates.

  12. Marine Bioinspired Underwater Contact Adhesion.

    Science.gov (United States)

    Clancy, Sean K; Sodano, Antonio; Cunningham, Dylan J; Huang, Sharon S; Zalicki, Piotr J; Shin, Seunghan; Ahn, B Kollbe

    2016-05-09

    Marine mussels and barnacles are sessile biofouling organisms that adhere to a number of surfaces in wet environments and maintain remarkably strong bonds. Previous synthetic approaches to mimic biological wet adhesive properties have focused mainly on the catechol moiety, present in mussel foot proteins (mfps), and especially rich in the interfacial mfps, for example, mfp-3 and -5, found at the interface between the mussel plaque and substrate. Barnacles, however, do not use Dopa for their wet adhesion, but are instead rich in noncatecholic aromatic residues. Due to this anomaly, we were intrigued to study the initial contact adhesion properties of copolymerized acrylate films containing the key functionalities of barnacle cement proteins and interfacial mfps, for example, aromatic (catecholic or noncatecholic), cationic, anionic, and nonpolar residues. The initial wet contact adhesion of the copolymers was measured using a probe tack testing apparatus with a flat-punch contact geometry. The wet contact adhesion of an optimized, bioinspired copolymer film was ∼15.0 N/cm(2) in deionized water and ∼9.0 N/cm(2) in artificial seawater, up to 150 times greater than commercial pressure-sensitive adhesive (PSA) tapes (∼0.1 N/cm(2)). Furthermore, maximum wet contact adhesion was obtained at ∼pH 7, suggesting viability for biomedical applications.

  13. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1991-01-01

    Ash (e.g. thermalized helium from D-T) buildup in a tokamak can potentially prevent ignition and seriously degrade the fusion energy gain from driven system. This problem is most pronounced as the ratio of particle/energy confinement time increases towards the neoclassical limit. Yet much improved confinement of the fuel ions is desirable for a fusion reactor. The goals of the work described here were two fold: to study the effect of helium buildup on the energy balance for a tokamak, and consider methods of active control that might be employed to alleviate the problem. We examine ash buildup effect for both D-T and D- 3 He systems. Most examples used apply to the ARIES 1 D-T reactor design and to the ARIES 3 D- 3 He design since part of this was in support of these two designs. Then we report on brief studies of two potentially attractive control methods, namely controlled sawtooth and fishbone instabilities. The concept is that sawteeth or fishbones would be used on purpose periodically in order to ''flush'' out excess ash from the fusion core. Both methods are shown to feasible and attractive. More study is needed, however, since the phenomenona in which are physically complex. Still the pay off, namely, reduced ash buildup, is exceedingly important so that such studies desires strong attention

  14. Experimental study on the effects of trailing edge geometry on the propulsive performance and wake structure of bio-inspired pitching panels

    Science.gov (United States)

    King, Justin; Green, Melissa

    2017-11-01

    Force measurements and stereoscopic particle image velocimetry (SPIV) were used to characterize the propulsive performance and three-dimensional wake structure of rigid, acrylic pitching panels with various trailing edge geometries. Experiments were carried out on multiple panels with bio-inspired planforms that were pitched about their leading edge. A trapezoidal panel geometry with a straight trailing edge was chosen as a baseline case, and deviations from a trapezoid were studied using panels with either a concave or convex trailing edge Previous work by van Buren et al. (Physical Review Fluids, 2017) has established that parameters such as coefficient of thrust and propulsive efficiency can be affected by changes in the trailing edge shape of pitching panels. In the current work, SPIV data were collected across the spanwise extent of the wake, and it is demonstrated that spanwise vortices are organized to form a reverse von Karman vortex street across much of the spanwise extent of the wake. The spanwise vortices are oriented in accordance with the trailing edge shape, i.e. a concave trailing edge sheds spanwise vortices that are bent inwards while a convex trailing edge sheds spanwise vortices that are bent outwards. The SPIV results also provide further insight into the three-dimensional wake behavior and structure as it relates to propulsive performance. This work was supported by the Office of Naval Research under ONR Award No. N00014-14-1-0418.

  15. High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods

    Science.gov (United States)

    Diaz Gonzalez, Alfredo J.

    Bioinspired design has been crucial in the development of new types of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties as well as gas barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has been designed to serve as sensing devices. Here we expand the multi-functionality of nacre-mimetics by designing an optically transparent and electron conductive coating that reacts to high-pressure based on PEDOT:PSS and nanoclay. The main objectives of this project are: (i) to develop a multifunctional nanocomposite and evaluate the effect of high-pressure applied at the surface and (ii) to establish protocols for the morphological and structural characterization, and electro-mechanical testing of the nanocomposites based on a combination of atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmittance spectroscopy. The synthesis of the nanocomposite, containing PEDOT:PSS (conductive polymer) and nanoclay, was achieved using the self-assembly of core/shell platelets. Two different types of nanoclay, Cloisite Na+ and Laponite RD, are used and their properties compared. The reduction of thickness in PEDOT:PSS has been shown to increase the light transmittance across a film. Similarly, the thickness of the nanocomposite was reduced and compared to PEDOT:PSS. The measured optical transmittance for both nanocomposites is comparable to the bare polymer, demonstrating that the addition of the nanoclay does not affect the transparency of PEDOT:PSS significantly. The layered structure of the nanocomposites is investigated by imaging the fracture surface with SEM. The fracture surface of the Laponite RD based nanocomposite is much flatter than the Cloisite Na+ nanocomposite, since the particle size in Cloisite Na+ is about 10 times larger than Laponite RD. The characterization of electro-mechanical properties of the nanocomposites

  16. An experimental study of an airfoil with a bio-inspired leading edge device at high angles of attack

    Science.gov (United States)

    Mandadzhiev, Boris A.; Lynch, Michael K.; Chamorro, Leonardo P.; Wissa, Aimy A.

    2017-09-01

    Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces from the wing leading or trailing edges are often used to extend the aerodynamic envelope (e.g. slats and flaps). Birds have also evolved feathers at the leading edge (LE) of their wings, known as the alula, which enables them to perform high angles of attack maneuvers. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like LE device on the aerodynamic performance of a cambered airfoil (S1223) at stall and post stall conditions. The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection angle is varied to modulate the distance between the tip vortex and the wing surface. Integrated lift force measurements were collected at various alula-inspired device configurations. The effect of the alula-inspired device on the boundary layer velocity profile and turbulence intensity were investigated through hot-wire anemometer measurements. Results show that as alula deflection angle increases, the lift coefficient also increase especially at lower alula relative angles of attack. Moreover, at post stall wing angles of attack, the wake velocity deficit is reduced in the presence of alula device, confirming the mitigation of the wing adverse pressure gradient. The results are in strong agreement with measurements taken on bird wings showing delayed flow reversal and extended range of operational angles of attack. An engineered alula-inspired device has the potential to improve mission adaptability in small unmanned air vehicles during low Reynolds number flight.

  17. Material requirements for bio-inspired sensing systems

    Science.gov (United States)

    Biggins, Peter; Lloyd, Peter; Salmond, David; Kusterbeck, Anne

    2008-10-01

    The aim of developing bio-inspired sensing systems is to try and emulate the amazing sensitivity and specificity observed in the natural world. These capabilities have evolved, often for specific tasks, which provide the organism with an advantage in its fight to survive and prosper. Capabilities cover a wide range of sensing functions including vision, temperature, hearing, touch, taste and smell. For some functions, the capabilities of natural systems are still greater than that achieved by traditional engineering solutions; a good example being a dog's sense of smell. Furthermore, attempting to emulate aspects of biological optics, processing and guidance may lead to more simple and effective devices. A bio-inspired sensing system is much more than the sensory mechanism. A system will need to collect samples, especially if pathogens or chemicals are of interest. Other functions could include the provision of power, surfaces and receptors, structure, locomotion and control. In fact it is possible to conceive of a complete bio-inspired system concept which is likely to be radically different from more conventional approaches. This concept will be described and individual component technologies considered.

  18. Protein Engineering: Case Studies of Commercialized Engineered Products

    Science.gov (United States)

    Walsh, Gary

    2007-01-01

    Programs in biochemistry invariably encompass the principles of protein engineering. Students often display increased understanding and enthusiasm when theoretical concepts are underpinned by practical example. Herein are presented five case studies, each focusing upon a commercial protein product engineered to enhance its application-relevant…

  19. NASA Software Engineering Benchmarking Study

    Science.gov (United States)

    Rarick, Heather L.; Godfrey, Sara H.; Kelly, John C.; Crumbley, Robert T.; Wifl, Joel M.

    2013-01-01

    To identify best practices for the improvement of software engineering on projects, NASA's Offices of Chief Engineer (OCE) and Safety and Mission Assurance (OSMA) formed a team led by Heather Rarick and Sally Godfrey to conduct this benchmarking study. The primary goals of the study are to identify best practices that: Improve the management and technical development of software intensive systems; Have a track record of successful deployment by aerospace industries, universities [including research and development (R&D) laboratories], and defense services, as well as NASA's own component Centers; and Identify candidate solutions for NASA's software issues. Beginning in the late fall of 2010, focus topics were chosen and interview questions were developed, based on the NASA top software challenges. Between February 2011 and November 2011, the Benchmark Team interviewed a total of 18 organizations, consisting of five NASA Centers, five industry organizations, four defense services organizations, and four university or university R and D laboratory organizations. A software assurance representative also participated in each of the interviews to focus on assurance and software safety best practices. Interviewees provided a wealth of information on each topic area that included: software policy, software acquisition, software assurance, testing, training, maintaining rigor in small projects, metrics, and use of the Capability Maturity Model Integration (CMMI) framework, as well as a number of special topics that came up in the discussions. NASA's software engineering practices compared favorably with the external organizations in most benchmark areas, but in every topic, there were ways in which NASA could improve its practices. Compared to defense services organizations and some of the industry organizations, one of NASA's notable weaknesses involved communication with contractors regarding its policies and requirements for acquired software. One of NASA's strengths

  20. Bio-Inspired Self-Cleaning Surfaces

    Science.gov (United States)

    Liu, Kesong; Jiang, Lei

    2012-08-01

    Self-cleaning surfaces have drawn a lot of interest for both fundamental research and practical applications. This review focuses on the recent progress in mechanism, preparation, and application of self-cleaning surfaces. To date, self-cleaning has been demonstrated by the following four conceptual approaches: (a) TiO2-based superhydrophilic self-cleaning, (b) lotus effect self-cleaning (superhydrophobicity with a small sliding angle), (c) gecko setae-inspired self-cleaning, and (d) underwater organisms-inspired antifouling self-cleaning. Although a number of self-cleaning products have been commercialized, the remaining challenges and future outlook of self-cleaning surfaces are also briefly addressed. Through evolution, nature, which has long been a source of inspiration for scientists and engineers, has arrived at what is optimal. We hope this review will stimulate interdisciplinary collaboration among material science, chemistry, biology, physics, nanoscience, engineering, etc., which is essential for the rational design and reproducible construction of bio-inspired multifunctional self-cleaning surfaces in practical applications.

  1. Bioinspired computation in combinatorial optimization: algorithms and their computational complexity

    DEFF Research Database (Denmark)

    Neumann, Frank; Witt, Carsten

    2012-01-01

    Bioinspired computation methods, such as evolutionary algorithms and ant colony optimization, are being applied successfully to complex engineering and combinatorial optimization problems, and it is very important that we understand the computational complexity of these algorithms. This tutorials...... explains the most important results achieved in this area. The presenters show how runtime behavior can be analyzed in a rigorous way, in particular for combinatorial optimization. They present well-known problems such as minimum spanning trees, shortest paths, maximum matching, and covering and scheduling...

  2. Flexible heat pipes with integrated bioinspired design

    OpenAIRE

    Chao Yang; Chengyi Song; Wen Shang; Peng Tao; Tao Deng

    2015-01-01

    In this work we report the facile fabrication and performance evaluation of flexible heat pipes that have integrated bioinspired wick structures and flexible polyurethane polymer connector design between the copper condenser and evaporator. Inside the heat pipe, a bioinspired superhydrophilic strong-base-oxidized copper mesh with multi-scale micro/nano-structures was used as the wicking material and deionized water was selected as working fluid. Thermal resistances of the fabricated flexible ...

  3. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Science.gov (United States)

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-04

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.

  4. Bioinspired synthesis of magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    David, Anand [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The synthesis of magnetic nanoparticles has long been an area of active research. Magnetic nanoparticles can be used in a wide variety of applications such as magnetic inks, magnetic memory devices, drug delivery, magnetic resonance imaging (MRI) contrast agents, and pathogen detection in foods. In applications such as MRI, particle uniformity is particularly crucial, as is the magnetic response of the particles. Uniform magnetic particles with good magnetic properties are therefore required. One particularly effective technique for synthesizing nanoparticles involves biomineralization, which is a naturally occurring process that can produce highly complex nanostructures. Also, the technique involves mild conditions (ambient temperature and close to neutral pH) that make this approach suitable for a wide variety of materials. The term 'bioinspired' is important because biomineralization research is inspired by the naturally occurring process, which occurs in certain microorganisms called 'magnetotactic bacteria'. Magnetotactic bacteria use biomineralization proteins to produce magnetite crystals having very good uniformity in size and morphology. The bacteria use these magnetic particles to navigate according to external magnetic fields. Because these bacteria synthesize high quality crystals, research has focused on imitating aspects of this biomineralization in vitro. In particular, a biomineralization iron-binding protein found in a certain species of magnetotactic bacteria, magnetospirillum magneticum, AMB-1, has been extracted and used for in vitro magnetite synthesis; Pluronic F127 gel was used to increase the viscosity of the reaction medium to better mimic the conditions in the bacteria. It was shown that the biomineralization protein mms6 was able to facilitate uniform magnetite synthesis. In addition, a similar biomineralization process using mms6 and a shorter version of this protein, C25, has been used to synthesize cobalt ferrite

  5. Parametric studies for the fusion engineering device

    International Nuclear Information System (INIS)

    Reid, R.L.; Steiner, D.

    1983-01-01

    Parametric studies were conducted using the Fusion Engineering Design Center (FEDC) systems code to investigate the cost, performance, and engineering sensitivity of variations within the fusion engineering device (FED) design space. Candidate FED missions and the associated fusion devices required to achieve the missions are compared. A brief description of the FEDC systems code and the results of the parametric studies that helped to define the FED baseline design are presented

  6. Switchable bio-inspired adhesives

    Science.gov (United States)

    Kroner, Elmar

    2015-03-01

    Geckos have astonishing climbing abilities. They can adhere to almost any surface and can run on walls and even stick to ceilings. The extraordinary adhesion performance is caused by a combination of a complex surface pattern on their toes and the biomechanics of its movement. These biological dry adhesives have been intensely investigated during recent years because of the unique combination of adhesive properties. They provide high adhesion, allow for easy detachment, can be removed residue-free, and have self-cleaning properties. Many aspects have been successfully mimicked, leading to artificial, bio-inspired, patterned dry adhesives, and were addressed and in some aspects they even outperform the adhesion capabilities of geckos. However, designing artificial patterned adhesion systems with switchable adhesion remains a big challenge; the gecko's adhesion system is based on a complex hierarchical surface structure and on advanced biomechanics, which are both difficult to mimic. In this paper, two approaches are presented to achieve switchable adhesion. The first approach is based on a patterned polydimethylsiloxane (PDMS) polymer, where adhesion can be switched on and off by applying a low and a high compressive preload. The switch in adhesion is caused by a reversible mechanical instability of the adhesive silicone structures. The second approach is based on a composite material consisting of a Nickel- Titanium (NiTi) shape memory alloy and a patterned adhesive PDMS layer. The NiTi alloy is trained to change its surface topography as a function of temperature, which results in a change of the contact area and of alignment of the adhesive pattern towards a substrate, leading to switchable adhesion. These examples show that the unique properties of bio-inspired adhesives can be greatly improved by new concepts such as mechanical instability or by the use of active materials which react to external stimuli.

  7. Bioinspired Haircell Receptive Sensors

    Science.gov (United States)

    2009-07-23

    Bonn Friedrich Barth, University of Vienna Rajesh Naik, Air Force Research Laboratory Agreement Number: FA 9550-05-1-0459 7oUO(i\\^o\\0...HAIRCELL SENSORS (Co-PI Rajesh Naik, Air Force Research Laboratory ) Objectives Development of multi-layered haircell to improve its resilience, and... hydroacoustic principles and empirical studies have shown that vibratory dipole sources are also a potent stimulus to the inner ear of fishes. Responses to

  8. Makerspaces in Engineering Education: A Case Study

    DEFF Research Database (Denmark)

    Jensen, Lasse Skovgaard; Özkil, Ali Gürcan; Mougaard, Krestine

    2016-01-01

    it by opening makerspaces and adopting elements of the Maker Movement in their offerings. This paper investigates how university driven makerspaces can affect engineering design and product development education trough a case study. We provide our findings based on interviews and data collected from educators...... engineering design education....

  9. KE Basin water dispositioning engineering study

    International Nuclear Information System (INIS)

    Hunacek, G.S.; Gahir, S.S.

    1994-01-01

    This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation

  10. Impact of an Engineering Case Study in a High School Pre-Engineering Course

    Science.gov (United States)

    Rutz, Eugene; Shafer, Michelle

    2011-01-01

    Students at an all-girls high school who were enrolled in an introduction to engineering course were presented an engineering case study to determine if the case study affected their attitudes toward engineering and their abilities to solve engineering problems. A case study on power plants was implemented during a unit on electrical engineering.…

  11. Bioinspired, dynamic, structured surfaces for biofilm prevention

    Science.gov (United States)

    Epstein, Alexander K.

    Bacteria primarily exist in robust, surface-associated communities known as biofilms, ubiquitous in both natural and anthropogenic environments. Mature biofilms resist a wide range of biocidal treatments and pose persistent pathogenic threats. Treatment of adherent biofilm is difficult, costly, and, in medical systems such as catheters, frequently impossible. Adding to the challenge, we have discovered that biofilm can be both impenetrable to vapors and extremely nonwetting, repelling even low surface tension commercial antimicrobials. Our study shows multiple contributing factors, including biochemical components and multiscale reentrant topography. Reliant on surface chemistry, conventional strategies for preventing biofilm only transiently affect attachment and/or are environmentally toxic. In this work, we look to Nature's antifouling solutions, such as the dynamic spiny skin of the echinoderm, and we develop a versatile surface nanofabrication platform. Our benchtop approach unites soft lithography, electrodeposition, mold deformation, and material selection to enable many degrees of freedom—material, geometric, mechanical, dynamic—that can be programmed starting from a single master structure. The mechanical properties of the bio-inspired nanostructures, verified by AFM, are precisely and rationally tunable. We examine how synthetic dynamic nanostructured surfaces control the attachment of pathogenic biofilms. The parameters governing long-range patterning of bacteria on high-aspect-ratio (HAR) nanoarrays are combinatorially elucidated, and we discover that sufficiently low effective stiffness of these HAR arrays mechanoselectively inhibits ˜40% of Pseudomonas aeruginosa biofilm attachment. Inspired by the active echinoderm skin, we design and fabricate externally actuated dynamic elastomer surfaces with active surface microtopography. We extract from a large parameter space the critical topographic length scales and actuation time scales for achieving

  12. Bio-inspired solutions in design for manufacturing of micro fuel cell

    DEFF Research Database (Denmark)

    Omidvarnia, Farzaneh; Hansen, Hans Nørgaard

    2014-01-01

    In this paper the application of biomimetic principles in design for micro manufacturing is investigated. A micro direct methanol fuel cell (μDMFC) for power generation in hearing aid devices is considered as the case study in which the bioinspired functions are replicated. The focus in design of μ......DMFC is mainly on solving the problem of fuel delivery to the anode in the fuel chamber. Two different biological phenomena are suggested, and based on them different bioinspired solutions are proposed and modeled in CAD software. Considering the manufacturing constraints and design specifications...

  13. Bioinspiration From Nano to Micro Scales

    CERN Document Server

    2012-01-01

    Methods in bioinspiration and biomimicking have been around for a long time. However, due to current advances in modern physical, biological sciences, and technologies, our understanding of the methods have evolved to a new level. This is due not only to the identification of mysterious and fascinating phenomena but also to the understandings of the correlation between the structural factors and the performance based on the latest theoretical, modeling, and experimental technologies. Bioinspiration: From Nano to Micro Scale provides readers with a broad view of the frontiers of research in the area of bioinspiration from the nano to macroscopic scales, particularly in the areas of biomineralization, antifreeze protein, and antifreeze effect. It also covers such methods as the lotus effect and superhydrophobicity, structural colors in animal kingdom and beyond, as well as behavior in ion channels. A number of international experts in related fields have contributed to this book, which offers a comprehensive an...

  14. 7th International Conference on Bio-Inspired Computing : Theories and Applications

    CERN Document Server

    Singh, Pramod; Deep, Kusum; Pant, Millie; Nagar, Atulya

    2013-01-01

    The book is a collection of high quality peer reviewed research papers presented in Seventh International Conference on Bio-Inspired Computing (BIC-TA 2012) held at ABV-IIITM Gwalior, India. These research papers provide the latest developments in the broad area of "Computational Intelligence". The book discusses wide variety of industrial, engineering and scientific applications of nature/bio-inspired computing and presents invited papers from the inventors/originators of novel computational techniques.

  15. Bioinspired, Ultrastrong, Highly Biocompatible, and Bioactive Natural Polymer/Graphene Oxide Nanocomposite Films.

    Science.gov (United States)

    Zhu, Wen-Kun; Cong, Huai-Ping; Yao, Hong-Bin; Mao, Li-Bo; Asiri, Abdullah M; Alamry, Khalid A; Marwani, Hadi M; Yu, Shu-Hong

    2015-09-09

    Tough and biocompatible nanocomposite films: A new type of bioinspired ultrastrong, highly biocompatible, and bioactive konjac glucomannan (KGM)/graphene oxide (GO) nanocomposite film is fabricated on a large scale by a simple solution-casting method. Such KGM-GO composite films exhibit much enhanced mechanical properties under the strong hydrogen-bonding interactions, showing great potential in the fields of tissue engineering and food package. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Bioinspired Materials for Water Purification

    Directory of Open Access Journals (Sweden)

    Alfredo Gonzalez-Perez

    2016-06-01

    Full Text Available Water scarcity issues associated with inadequate access to clean water and sanitation is a ubiquitous problem occurring globally. Addressing future challenges will require a combination of new technological development in water purification and environmental remediation technology with suitable conservation policies. In this scenario, new bioinspired materials will play a pivotal role in the development of more efficient and environmentally friendly solutions. The role of amphiphilic self-assembly on the fabrication of new biomimetic membranes for membrane separation like reverse osmosis is emphasized. Mesoporous support materials for semiconductor growth in the photocatalytic degradation of pollutants and new carriers for immobilization of bacteria in bioreactors are used in the removal and processing of different kind of water pollutants like heavy metals. Obstacles to improve and optimize the fabrication as well as a better understanding of their performance in small-scale and pilot purification systems need to be addressed. However, it is expected that these new biomimetic materials will find their way into the current water purification technologies to improve their purification/removal performance in a cost-effective and environmentally friendly way.

  17. Bioinspired synthesis of new silica structures.

    Science.gov (United States)

    Patwardhan, Siddharth V; Mukherjee, Niloy; Steintz-Kannan, Miriam; Clarson, Stephen J

    2003-05-21

    Silicon and oxygen are the two most abundant elements in the Earth's crust but despite the vast scientific literature on crystalline and amorphous silica, new chemistries, structures and applications continue to be discovered for compounds formed from these elements--thus we present here for the first time the formation of new amorphous silica structures that were uniquely synthesized by a bioinspired synthetic system.

  18. Study Strategies for Engineering Students at DTU

    DEFF Research Database (Denmark)

    Christensen, Hans Peter

    2002-01-01

    The study strategies of first year Master students are investigated at DTU fall 1999 - spring 2002. The results show that the students study less than their teachers expect. And they spend most time on activities not leading to deep understanding and engineering competencies. The students spend...... activated the students, but not significantly increased their independent studying....

  19. FED baseline engineering studies report

    Energy Technology Data Exchange (ETDEWEB)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept.

  20. FED baseline engineering studies report

    International Nuclear Information System (INIS)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept

  1. TNS engineering trade study analysis

    International Nuclear Information System (INIS)

    Chapin, D.L.; Gibson, G.

    1977-01-01

    The computer code, ground rules, and plasma scalings used in the trade studies are briefly discussed. The results of these analyses are presented in detail. The results are summarized and pertinent conclusions and recommendations regarding the TNS design options are discussed

  2. Identifying Relevant Studies in Software Engineering

    DEFF Research Database (Denmark)

    Zhang, He; Ali Babar, Muhammad; Tell, Paolo

    2011-01-01

    Context: Systematic literature review (SLR) has become an important research methodology in software engineering since the introduction of evidence-based software engineering (EBSE) in 2004. One critical step in applying this methodology is to design and execute appropriate and effective search....... Objective: The main objective of the research reported in this paper is to improve the search step of undertaking SLRs in software engineering (SE) by devising and evaluating systematic and practical approaches to identifying relevant studies in SE. Method: We have systematically selected and analytically...... serve as a supplement to the guidelines for SLRs in EBSE. We plan to further evaluate the proposed approach using a series of case studies on varying research topics in SE....

  3. Photonic engineering for biological study

    Science.gov (United States)

    Wu, Fei

    My dissertation focuses on designing and developing prototypes of optical tools in the laboratory that can facilitate practical medical therapies. More specifically, this dissertation examines two novel biophotonic techniques: (1) a frequency multiplexed confocal microscope with the potential to provide rational therapy of congestive heart failure (CHF), and (2) the "optical comb" with the potential to improve results of retina reattachment surgery and accelerate post surgical recovery. Next, I will discuss the background, design and initial experimental results of each study individually. Part I: The Frequency Multiplexed Confocal Microscope. To overcome the limitations of existing confocal microscope technology, this dissertation proposes a non-scanning, real-time, high resolution technique (a multi-point frequency multiplexed confocal microscope) to measure 3-D intracellular calcium ion concentration in a living cardiac myocyte. This method can be also applied to measure the intracellular sodium ion concentration, or other ions in which high quantum-yield fluorescent probes are available. The novelty of the proposed research lies in the introduction of carrier frequency multiplexing techniques which can differentiate fluorescence emitted at different spatial locations in cardiac myocyte by their modulated frequency. It therefore opens the possibility to visualize the transient dynamics of intracellular dynamics at multiple locations in cells simultaneously, which will shine a new light on our understanding of CHF. The procedure for frequency multiplexing proposed is described below. Multiple incident laser beams are focused onto different locations in an isolated rat cardiac myocyte with each beam modulated at a different carrier frequency. The fluorescence emission at each location therefore bears the same modulated frequency as the stimulation laser beam. Each fluorescence signal is sent to the photo multiplier tube (PMT) after being spatially filtered by a

  4. Exploring Creativity in the Bio-Inspired Design Process

    DEFF Research Database (Denmark)

    Anggakara, K.; Aksdal, T.; Onarheim, Balder

    2015-01-01

    The growing interest in the of field bio-inspired design has been driven by the acknowledgement that inspiration from nature can serve as a valuable source of innovation. As an emerging approach, there has been a focus on building a principled methodology to address the challenges that arise...... in the application of the practice. This article investigates ways in which the understanding of creativity can support the application of bio-inspired design. By observing the bio-inspired design approach using a macro-orientational framework of creativity, we identify the role of creativity in bio-inspired design...

  5. Tokamak Engineering Technology Facility scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, W.M. Jr.; Abdou, M.A.; Bolta, C.C.

    1976-03-01

    A scoping study for a Tokamak Engineering Technology Facility (TETF) is presented. The TETF is a tokamak with R = 3 m and I/sub p/ = 1.4 MA based on the counterstreaming-ion torus mode of operation. The primary purpose of TETF is to demonstrate fusion technologies for the Experimental Power Reactor (EPR), but it will also serve as an engineering and radiation test facility. TETF has several technological systems (e.g., superconducting toroidal-field coil, tritium fuel cycle, impurity control, first wall) that are prototypical of EPR.

  6. Guided extracellular matrix formation from fibroblast cells cultured on bio-inspired configurable multiscale substrata

    Directory of Open Access Journals (Sweden)

    Won-Gyu Bae

    2015-12-01

    Full Text Available Engineering complex extracellular matrix (ECM is an important challenge for cell and tissue engineering applications as well as for understanding fundamental cell biology. We developed the methodology for fabrication of precisely controllable multiscale hierarchical structures using capillary force lithography in combination with original wrinkling technique for the generation of well-defined native ECM-like platforms by culturing fibroblast cells on the multiscale substrata [1]. This paper provides information on detailed characteristics of polyethylene glycol-diacrylate multiscale substrata. In addition, a possible model for guided extracellular matrix formation from fibroblast cells cultured on bio-inspired configurable multiscale substrata is proposed.

  7. Diesel engine emission deterioration - a preliminary study

    CSIR Research Space (South Africa)

    Pretorius, Cecilia J

    2016-04-01

    Full Text Available The objective of this study was to find a parameter in diesel and oil analysis of underground mining vehicles that can be correlated with personal diesel particulate matter (DPM) exposure and used as part of an engine maintenance programme. A number...

  8. Studying Design Engineers Use Of Information Systems

    DEFF Research Database (Denmark)

    Restrepo-Giraldo, John Dairo

    2006-01-01

    Studying information usage by design engineers involves considering technical, social, cognitive and volitional factors. This makes it challenging, especially for researchers without a cognitive psychology background. This paper presents a summary of key findings in researching information use...... and processing in design, discusses important issues on the selection of a research strategy and sums up the important variables that need to be controlled for....

  9. Global Hawk Systems Engineering. Case Study

    Science.gov (United States)

    2010-01-01

    Charles Garland, whose support was integral in guiding me throughout this case study. Bill Kinzig Global Hawk Systems Engineering Case Study...necessary to characterize the system’s utility. 3.2.3.2 First Flight AV-1 rolled out of the TRA facility on February 20, 1997. While at Lindbergh Field... Lindbergh Field, but its delivery to Edwards AFB, California, was already late. Thus, the air vehicle was disassembled and trucked to Edwards AFB on

  10. Conceptual study of advanced VTOL transport aircraft engine

    OpenAIRE

    Saito, Yoshio; Endo, Masanori; Matsuda, Yukio; Sugiyama, Nanahisa; Watanabe, Minoru; Sugahara, Noboru; Yamamoto, Kazuomi; 齊藤 喜夫; 遠藤 征紀; 松田 幸雄; 杉山 七契; 渡辺 実; 菅原 昇; 山本 一臣

    1996-01-01

    A new concept for a quiet engine for high subsonic VTOL transport aircraft is studied and presented. The concept engine, which is called the separated core turbofan engine, is effectively applied. It is composed of three core engines, two cruise fan engines and six lift fan engines. The cruise fan engines are optimized for high subsonic cruise, and the lift fan engines produce about 98 kN (10,000 kgf) of thrust and can realize highly quiet operation. In this study, no technical problems have ...

  11. Bio-Inspired Innovation and National Security

    Science.gov (United States)

    2010-01-01

    of Weapons of Mass Destruction: Assessing the Risks (Washington, DC: U.S. Government Printing Office, August 1993). 11 Jim Monke , Agroterrorism...Six Legs,” The Boston Globe, October 21, 2007. 15 Monke . 50 Bio-inspired innovation and national security1 BioloGical WarFare: a WarFiGHtinG...Scientists and Tibetan Buddhists Examine Human Nature (New York: Oxford University Press, 2002). 50 L. Tickle-Degnan and R. Rosenthal, “The Nature of

  12. A two-dimensional iterative panel method and boundary layer model for bio-inspired multi-body wings

    Science.gov (United States)

    Blower, Christopher J.; Dhruv, Akash; Wickenheiser, Adam M.

    2014-03-01

    The increased use of Unmanned Aerial Vehicles (UAVs) has created a continuous demand for improved flight capabilities and range of use. During the last decade, engineers have turned to bio-inspiration for new and innovative flow control methods for gust alleviation, maneuverability, and stability improvement using morphing aircraft wings. The bio-inspired wing design considered in this study mimics the flow manipulation techniques performed by birds to extend the operating envelope of UAVs through the installation of an array of feather-like panels across the airfoil's upper and lower surfaces while replacing the trailing edge flap. Each flap has the ability to deflect into both the airfoil and the inbound airflow using hinge points with a single degree-of-freedom, situated at 20%, 40%, 60% and 80% of the chord. The installation of the surface flaps offers configurations that enable advantageous maneuvers while alleviating gust disturbances. Due to the number of possible permutations available for the flap configurations, an iterative constant-strength doublet/source panel method has been developed with an integrated boundary layer model to calculate the pressure distribution and viscous drag over the wing's surface. As a result, the lift, drag and moment coefficients for each airfoil configuration can be calculated. The flight coefficients of this numerical method are validated using experimental data from a low speed suction wind tunnel operating at a Reynolds Number 300,000. This method enables the aerodynamic assessment of a morphing wing profile to be performed accurately and efficiently in comparison to Computational Fluid Dynamics methods and experiments as discussed herein.

  13. Temperature-tunable wettability on a bioinspired structured graphene surface for fog collection and unidirectional transport.

    Science.gov (United States)

    Song, Yun-Yun; Liu, Yan; Jiang, Hao-Bo; Li, Shu-Yi; Kaya, Cigdem; Stegmaier, Thomas; Han, Zhi-Wu; Ren, Lu-Quan

    2018-02-22

    We designed a type of smart bioinspired wettable surface with tip-shaped patterns by combining polydimethylsiloxane (PDMS) and graphene (PDMS/G). The laser etched porous graphene surface can produce an obvious wettability change between 200 °C and 0 °C due to a change in aperture size and chemical components. We demonstrate that the cooperation of the geometrical structure and the controllable wettability play an important role in water gathering, and surfaces with tip-shaped wettability patterns can quickly drive tiny water droplets toward more wettable regions, so making a great contribution to the improvement of water collection efficiency. In addition, due to the effective cooperation between super hydrophobic and hydrophilic regions of the special tip-shaped pattern, unidirectional water transport on the 200 °C heated PDMS/G surface can be realized. This study offers a novel insight into the design of temperature-tunable materials with interphase wettability that may enhance fog collection efficiency in engineering liquid harvesting equipment, and realize unidirectional liquid transport, which could potentially be applied to the realms of microfluidics, medical devices and condenser design.

  14. Bio-inspired adaptive feedback error learning architecture for motor control.

    Science.gov (United States)

    Tolu, Silvia; Vanegas, Mauricio; Luque, Niceto R; Garrido, Jesús A; Ros, Eduardo

    2012-10-01

    This study proposes an adaptive control architecture based on an accurate regression method called Locally Weighted Projection Regression (LWPR) and on a bio-inspired module, such as a cerebellar-like engine. This hybrid architecture takes full advantage of the machine learning module (LWPR kernel) to abstract an optimized representation of the sensorimotor space while the cerebellar component integrates this to generate corrective terms in the framework of a control task. Furthermore, we illustrate how the use of a simple adaptive error feedback term allows to use the proposed architecture even in the absence of an accurate analytic reference model. The presented approach achieves an accurate control with low gain corrective terms (for compliant control schemes). We evaluate the contribution of the different components of the proposed scheme comparing the obtained performance with alternative approaches. Then, we show that the presented architecture can be used for accurate manipulation of different objects when their physical properties are not directly known by the controller. We evaluate how the scheme scales for simulated plants of high Degrees of Freedom (7-DOFs).

  15. Bio-inspired composites with functionally graded platelets exhibit enhanced stiffness.

    Science.gov (United States)

    Tapse, Sanjay; S, Anup

    2017-11-09

    Unidirectional composites inspired from biological materials such as nacre, are composed of stiff platelets arranged in a staggered manner within a soft matrix. Elaborate analyses have been conducted on the aforementioned composites and they are found to have excellent mechanical properties like stiffness, strength and fracture toughness. The superior properties exhibited by these composites have been proved to be the result of its unique structure. An emerging development in the field of composite structures is Functionally Graded Composites(FGC), whose properties vary spatially and possess enhanced thermo-mechanical properties. In this paper, the platelets are functionally graded with its Young's Modulus varying parabolically along the length. Two different models - namely, Tension Shear Chain Model and Minimisation of Complementary Energy Model have been employed to obtain the stiffness of the overall composite analytically. The effect of various parameters that define the composite model such as overlapping length between any two neighbouring platelets, different gradation parameters and platelet aspect ratio on the overall mechanical properties have been studied. Composites with functionally graded platelets are found to possess enhanced stiffness (upto 14% higher) for certain values of these parameters. The obtained solutions have been validated using Finite Element Analysis. Bio-inspired composites with functionally graded platelets can be engineered for structural applications, such as in automobile, aerospace and aircraft industry, where stiffness plays a crucial role. © 2017 IOP Publishing Ltd.

  16. Biomimicry as an approach for bio-inspired structure with the aid of compu

    Directory of Open Access Journals (Sweden)

    Moheb Sabry Aziz

    2016-03-01

    Full Text Available Biomimicry is the study of emulating and mimicking nature, where it has been used by designers to help in solving human problems. From centuries ago designers and architects looked at nature as a huge source of inspiration. Biomimicry argues that nature is the best, most influencing and the guaranteed source of innovation for the designers as a result of nature’s 3.85 billion years of evolution, as it holds a gigantic experience of solving problems of the environment and its inhabitants. The biomimicry emerging field deals with new technologies honed from bio-inspired engineering at the micro and macro scale levels. Architects have been searching for answers from nature to their complex questions about different kinds of structures, and they have mimicked a lot of forms from nature to create better and more efficient structures for different architectural purposes. Without computers these complex ways and forms of structures couldn’t been mimicked and thus using computers had risen the way of mimicking and taking inspiration from nature because it is considered a very sophisticated and accurate tool for simulation and computing, as a result designers can imitate different nature’s models in spite of its complexity.

  17. Theoretical and experimental study of thermoacoustic engines

    Science.gov (United States)

    Raspet, Richard; Bass, Henry E.; Arnott, W. P.

    1992-12-01

    A three year study of thermoacoustic engines operating as prime movers and refrigerators was completed. The major thrust of this effort was the use and theoretical description of ceramic honeycomb structures as the active element in thermoacoustic engines. An air-filled demonstration prime mover was constructed and demonstrated at Acoustical Society of America and IEE meetings. A helium-filled test prime mover was designed and built an is being employed in studies of the threshold of oscillation as a function of temperature difference and pressure. In addition, acoustically based theories of the thermoacoustic engine have been developed and tested for a parallel plate stack at the Naval Postgraduate School and for a honeycomb stack at the University of Mississippi. Most of this work is described in detail in the attached publications. In this report we will give an overview of the research completed to date and its relationship to work performed at the Naval Postgraduate School and to future work at the University of Mississippi.

  18. Nuclear thermal propulsion engine cost trade studies

    International Nuclear Information System (INIS)

    Paschall, R.K.

    1993-01-01

    The NASA transportation strategy for the Mars Exploration architecture includes the use of nuclear thermal propulsion as the primary propulsion system for Mars transits. It is anticipated that the outgrowth of the NERVA/ROVER programs will be a nuclear thermal propulsion (NTP) system capable of providing the propulsion for missions to Mars. The specific impulse (Isp) for such a system is expected to be in the 870 s range. Trade studies were conducted to investigate whether or not it may be cost effective to invest in a higher performance (Isp>870 s) engine for nuclear thermal propulsion for missions to Mars. The basic cost trades revolved around the amount of mass that must be transported to low-earth orbit prior to each Mars flight and the cost to launch that mass. The mass required depended on the assumptions made for Mars missions scenarios including piloted/cargo flights, number of Mars missions, and transit time to Mars. Cost parameters included launch cost, program schedule for development and operations, and net discount rate. The results were very dependent on the assumptions that were made. Under some assumptions, higher performance engines showed cost savings in the billions of dollars; under other assumptions, the additional cost to develop higher performance engines was not justified

  19. Bioinspiring an Interest in STEM

    Science.gov (United States)

    Laut, Jeffrey; Bartolini, Tiziana; Porfiri, Maurizio

    2015-01-01

    Attracting K-12 students to pursue careers in science, technology, engineering, and mathematics (STEM) is viewed as a critical element for benefiting both the economy and society. This paper describes an outreach program, conducted in a Brooklyn, New York, USA, public middle school, aimed at educating students in mechatronics, biology, and…

  20. Bioinspired design and interfacial failure of biomedical systems

    Science.gov (United States)

    Rahbar, Nima

    The deformation mechanism of nacre as a model biological material is studied in this project. A numerical model is presented which consists of tensile pillars, shear pillars, asperities and aragonite platelets. It has been shown that the tensile pillars are the main elements that control the global stiffness of the nacre structure. Meanwhile, ultimate strength of the nacre structure is controlled by asperities and their behavior and the ratio of L/2D which is itself a function of the geometry of the platelets. Protein/shear pillars provide the glue which holds the assembly of entire system together, particularly in the direction normal to the platelets main axis. This dissertation also presents the results of a combined theoretical/computational and experimental effort to develop crack resistant dental multilayers that are inspired by the functionally graded dento-enamel junction (DEJ) structure that occurs between dentin and enamel in natural teeth. The complex structures of natural teeth and ceramic crowns are idealized using at layered configurations. The potential effects of occlusal contact are then modeled using finite element simulations of Hertzian contact. The resulting stress distributions are compared for a range of possible bioinspired, functionally graded architecture. The computed stress distributions show that the highest stress concentrations in the top ceramic layer of crown structures are reduced significantly by the use of bioinspired functionally graded architectures. The reduced stresses are shown to be associated with significant improvements (30%) in the pop-in loads over a wide range of clinically-relevant loading rates. The implications of the results are discussed for the design of bioinspired dental ceramic crown structures. The results of a combined experimental and computational study of mixed mode fracture in glass/cement and zirconia/cement interfaces that are relevant to dental restorations is also presented. The interfacial fracture

  1. Aquarius study - engineering and economic considerations

    International Nuclear Information System (INIS)

    Griffin, Roger F.

    1970-01-01

    The two previous papers described the scope of the Aquarius Study and the various applications considered in evaluating the use of nuclear explosives for the development of water resources in Arizona. Surface storage behind a dam created with the use of nuclear explosives was selected for the major effort, primarily because it could afford the most valid direct comparison between nuclear and conventional methods. In this paper I will focus on the engineering and economic considerations involved in developing and evaluating three concepts for constructing a rockfill dam using nuclear explosives. Engineering development and economic evaluation of the concepts was the principal responsibility of Bechtel Corporation as a consultant in the study to the Arizona Atomic Energy Commission. We depended heavily on information supplied by the Federal participants, notably the U.S. Bureau of Reclamation for site data and the U.S. AEC*s Lawrence Radiation Laboratory for information on nuclear explosives effects. Since the study report has not yet been published and additional material is still forthcoming, some of the information I will present, such as the cost estimates, may be subject to change and should be considered preliminary. (author)

  2. Freeze Casting for Assembling Bioinspired Structural Materials.

    Science.gov (United States)

    Cheng, Qunfeng; Huang, Chuanjin; Tomsia, Antoni P

    2017-12-01

    Nature is very successful in designing strong and tough, lightweight materials. Examples include seashells, bone, teeth, fish scales, wood, bamboo, silk, and many others. A distinctive feature of all these materials is that their properties are far superior to those of their constituent phases. Many of these natural materials are lamellar or layered in nature. With its "brick and mortar" structure, nacre is an example of a layered material that exhibits extraordinary physical properties. Finding inspiration in living organisms to create bioinspired materials is the subject of intensive research. Several processing techniques have been proposed to design materials mimicking natural materials, such as layer-by-layer deposition, self-assembly, electrophoretic deposition, hydrogel casting, doctor blading, and many others. Freeze casting, also known as ice-templating, is a technique that has received considerable attention in recent years to produce bioinspired bulk materials. Here, recent advances in the freeze-casting technique are reviewed for fabricating lamellar scaffolds by assembling different dimensional building blocks, including nanoparticles, polymer chains, nanofibers, and nanosheets. These lamellar scaffolds are often infiltrated by a second phase, typically a soft polymer matrix, a hard ceramic matrix, or a metal matrix. The unique architecture of the resultant bioinspired structural materials displays excellent mechanical properties. The challenges of the current research in using the freeze-casting technique to create materials large enough to be useful are also discussed, and the technique's promise for fabricating high-performance nacre-inspired structural materials in the future is reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Copper removal using bio-inspired polydopamine coated natural zeolites

    International Nuclear Information System (INIS)

    Yu, Yang; Shapter, Joseph G.; Popelka-Filcoff, Rachel; Bennett, John W.; Ellis, Amanda V.

    2014-01-01

    Highlights: • Natural zeolites were modified with bio-inspired polydopamine. • A 91.4% increase in Cu(II) ion adsorption capacity was observed. • Atomic absorption and neutron activation analysis gave corroborative results. • Neutron activation analysis was used to provide accurate information on 30+ elements. • Approximately 90% of the adsorbed copper could be recovered by 0.1 M HCl treatment. - Abstract: Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2–5.5), PDA treatment time (3–24 h), contact time (0 to 24 h) and initial Cu(II) ion concentrations (1 to 500 mg dm −3 ) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93 mg g −1 for pristine natural zeolite and 28.58 mg g −1 for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01 M or 0.1 M) of either acid or base

  4. Enhanced adhesion of bioinspired nanopatterned elastomers via colloidal surface assembly

    Science.gov (United States)

    Akerboom, Sabine; Appel, Jeroen; Labonte, David; Federle, Walter; Sprakel, Joris; Kamperman, Marleen

    2015-01-01

    We describe a scalable method to fabricate nanopatterned bioinspired dry adhesives using colloidal lithography. Close-packed monolayers of polystyrene particles were formed at the air/water interface, on which polydimethylsiloxane (PDMS) was applied. The order of the colloidal monolayer and the immersion depth of the particles were tuned by altering the pH and ionic strength of the water. Initially, PDMS completely wetted the air/water interface outside the monolayer, thereby compressing the monolayer as in a Langmuir trough; further application of PDMS subsequently covered the colloidal monolayers. PDMS curing and particle extraction resulted in elastomers patterned with nanodimples. Adhesion and friction of these nanopatterned surfaces with varying dimple depth were studied using a spherical probe as a counter-surface. Compared with smooth surfaces, adhesion of nanopatterned surfaces was enhanced, which is attributed to an energy-dissipating mechanism during pull-off. All nanopatterned surfaces showed a significant decrease in friction compared with smooth surfaces. PMID:25392404

  5. Advances in bio-inspired computing for combinatorial optimization problems

    CERN Document Server

    Pintea, Camelia-Mihaela

    2013-01-01

    Advances in Bio-inspired Combinatorial Optimization Problems' illustrates several recent bio-inspired efficient algorithms for solving NP-hard problems.Theoretical bio-inspired concepts and models, in particular for agents, ants and virtual robots are described. Large-scale optimization problems, for example: the Generalized Traveling Salesman Problem and the Railway Traveling Salesman Problem, are solved and their results are discussed.Some of the main concepts and models described in this book are: inner rule to guide ant search - a recent model in ant optimization, heterogeneous sensitive a

  6. Aerodynamic efficiency of a bio-inspired flapping wing rotor at low Reynolds number

    OpenAIRE

    Li, Hao; Guo, Shijun

    2018-01-01

    This study investigates the aerodynamic efficiency of a bioinspired flapping wing rotor kinematics which combines an active vertical flapping motion and a passive horizontal rotation induced by aerodynamic thrust. The aerodynamic efficiencies for producing both vertical lift and horizontal thrust of the wing are obtained using a quasi-steady aerodynamic model and two-dimensional (2D) CFD analysis at Reynolds number of 2500. The calculated efficiency data show that both efficiencies (propulsiv...

  7. Elementary teachers' perceptions of engineering, engineering design, and their abilities to teach engineering: A mixed methods study

    Science.gov (United States)

    Hammack, Rebekah Jane

    This explanatory sequential mixed methods study explores elementary teachers' preparedness to teach engineering and engineering design as prescribed by the Next Generation Science Standards (NGSS). The data analyzed included the NGSS document, responses to an online survey that was completed by 542 Oklahoma K-5 teachers responsible for the science instruction of their students, and interview and focus group transcripts from a subset of survey participants. The results are organized into three distinct manuscripts, each devoted to a specific set of research questions. As a whole, the dissertation findings indicate that elementary teachers are not prepared to incorporate engineering practices into their classrooms. Study participants were found to have limited understanding of engineering and engineering design, as well as low engineering self-efficacy and engineering teaching efficacy related to pedagogical content knowledge. While participants recognized the benefits of including engineering activities in their classrooms, they reported that barriers such as lack of time, lack of training, lack of materials, and lack of support inhibited their abilities to infuse engineering into their curriculum.

  8. Multibody system dynamics for bio-inspired locomotion: from geometric structures to computational aspects.

    Science.gov (United States)

    Boyer, Frédéric; Porez, Mathieu

    2015-03-26

    This article presents a set of generic tools for multibody system dynamics devoted to the study of bio-inspired locomotion in robotics. First, archetypal examples from the field of bio-inspired robot locomotion are presented to prepare the ground for further discussion. The general problem of locomotion is then stated. In considering this problem, we progressively draw a unified geometric picture of locomotion dynamics. For that purpose, we start from the model of discrete mobile multibody systems (MMSs) that we progressively extend to the case of continuous and finally soft systems. Beyond these theoretical aspects, we address the practical problem of the efficient computation of these models by proposing a Newton-Euler-based approach to efficient locomotion dynamics with a few illustrations of creeping, swimming, and flying.

  9. Flexible heat pipes with integrated bioinspired design

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2015-02-01

    Full Text Available In this work we report the facile fabrication and performance evaluation of flexible heat pipes that have integrated bioinspired wick structures and flexible polyurethane polymer connector design between the copper condenser and evaporator. Inside the heat pipe, a bioinspired superhydrophilic strong-base-oxidized copper mesh with multi-scale micro/nano-structures was used as the wicking material and deionized water was selected as working fluid. Thermal resistances of the fabricated flexible heat pipes charged with different filling ratios were measured under thermal power inputs ranging from 2 W to 12 W while the device was bent at different angles. The fabricated heat pipes with a 30% filling ratio demonstrated a low thermal resistance less than 0.01 K/W. Compared with the vertically oriented straight heat pipes, bending from 30° up to 120° has negligible influence on the heat-transfer performance. Furthermore, repeated heating tests indicated that the fabricated flexible heat pipes have consistent and reliable heat-transfer performance, thus would have important applications for advanced thermal management in three dimensional and flexible electronic devices.

  10. Climbing plants: attachment adaptations and bioinspired innovations.

    Science.gov (United States)

    Burris, Jason N; Lenaghan, Scott C; Stewart, C Neal

    2018-04-01

    Climbing plants have unique adaptations to enable them to compete for sunlight, for which they invest minimal resources for vertical growth. Indeed, their stems bear relatively little weight, as they traverse their host substrates skyward. Climbers possess high tensile strength and flexibility, which allows them to utilize natural and manmade structures for support and growth. The climbing strategies of plants have intrigued scientists for centuries, yet our understanding about biochemical adaptations and their molecular undergirding is still in the early stages of research. Nonetheless, recent discoveries are promising, not only from a basic knowledge perspective, but also for bioinspired product development. Several adaptations, including nanoparticle and adhesive production will be reviewed, as well as practical translation of these adaptations to commercial applications. We will review the botanical literature on the modes of adaptation to climb, as well as specialized organs-and cellular innovations. Finally, recent molecular and biochemical data will be reviewed to assess the future needs and new directions for potential practical products that may be bioinspired by climbing plants.

  11. Bio-inspired computation in unmanned aerial vehicles

    CERN Document Server

    Duan, Haibin

    2014-01-01

    Bio-inspired Computation in Unmanned Aerial Vehicles focuses on the aspects of path planning, formation control, heterogeneous cooperative control and vision-based surveillance and navigation in Unmanned Aerial Vehicles (UAVs) from the perspective of bio-inspired computation. It helps readers to gain a comprehensive understanding of control-related problems in UAVs, presenting the latest advances in bio-inspired computation. By combining bio-inspired computation and UAV control problems, key questions are explored in depth, and each piece is content-rich while remaining accessible. With abundant illustrations of simulation work, this book links theory, algorithms and implementation procedures, demonstrating the simulation results with graphics that are intuitive without sacrificing academic rigor. Further, it pays due attention to both the conceptual framework and the implementation procedures. The book offers a valuable resource for scientists, researchers and graduate students in the field of Control, Aeros...

  12. Perspectives and Plans for Graduate Studies. 11, Engineering 1974-75; F. Civil Engineering.

    Science.gov (United States)

    Ontario Council on Graduate Studies, Toronto. Advisory Committee on Academic Planning.

    A series of studies carried out by the Advisory Committee on Academic Planning (ACAP) published by the Council of Ontario Universities (COU) dealt with a planning study of doctoral work in engineering that was conducted in several parts corresponding to the various disciplines within engineering. This document, which is one part of that study,…

  13. A prediction study of a spark ignition supercharged hydrogen engine

    International Nuclear Information System (INIS)

    Al-Baghdadi, Maher A.R. Sadiq.; Al-Janabi, Haroun A.K. Shahad

    2003-01-01

    Hydrogen is found to be a suitable alternative fuel for spark ignition engines with certain drawbacks, such as high NO x emission and small power output. However, supercharging may solve such problems. In this study, the effects of equivalence ratio, compression ratio and inlet pressure on the performance and NO x emission of a four stroke supercharged hydrogen engine have been analyzed using a specially developed computer program. The results are verified and compared with experimental data obtained from tests on a Ricardo E6/US engine. A chart specifying the safe operation zone of the hydrogen engine has been produced. The safe operation zone means no pre-ignition, acceptable NO x emission, high engine efficiency and lower specific fuel consumption in comparison with the gasoline engine. The study also shows that supercharging is a more effective method to increase the output of a hydrogen engine rather than increasing the compression ratio of the engine at the knock limited equivalence ratio

  14. Structure property relations and finite element analysis of ram horns: A pathway to energy absorbent bio-inspired designs

    Science.gov (United States)

    Trim, Michael Wesley

    2011-12-01

    A recently emerging engineering design approach entails studying the brilliant design solutions found in nature with an aim to develop design strategies that mimic the remarkable efficiency found in biological systems. This novel engineering approach is referred to as bio-inspired design. In this context, the present study quantifies the structure-property relations in bighorn sheep (Ovis canadensis) horn keratin, qualitatively characterizes the effects of a tapered spiral geometry (the same form as in a ram's horn) on pressure wave and impulse mitigation, describes the stress attenuation capabilities and features of a ram's head, and compares the structures and mechanical properties of some energy absorbent natural materials. The results and ideas presented herein can be used in the development of lightweight, energy absorbent, bio-inspired material designs. Among the most notable conclusions garnered from this research include: (1) Horn keratin behaves in an anisotropic manner similar to a long fiber composite. (2) Moisture content dominates the material behavior of horn keratin more than anisotropy, age, and stress-state. This makes moisture content the most influential parameter on the mechanical behavior of horn keratin. (3) Tapered geometries mitigate the impulse generated by a stress wave due to the convergent boundary and a continually decreasing cross sectional area such that greater uniaxial stresses and subsequent axial deformation arises. Furthermore, the tapered geometry introduces small shear stresses that further decrease the impulse. (4) Spiral geometries attenuate the impulse generated by a stress wave by the introduction of shear stresses along the length of the spiral. These shear stresses introduce transverse displacements that function to lessen the impulse. (5) When both a taper and spiral geometry are used in a design, their synergistic effects multiplicatively reduce the impulse (6) Tough natural materials have a high porosity, which makes

  15. Small nonroad engine and equipment industry study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The purpose of the report is to describe and analyze the structure, conduct, and performance of the small nonroad engine and equipment industry and to assess the technologies represented by the most common engines and equipment. The small nonroad engine and equipment industry is defined as the market or markets, in which engines under 50 horsepower are produced and/or incorporated into new or used nonroad equipment. Examples of the types of equipment in which utility engines are installed include lawnmowers, cement mixers, 2-wheel tractors, generator sets, all terrain vehicles, and many other types of equipment used in various applications. Engine below 50 horsepower are also found in many marine applications, such as outboard sailboat auxiliary engines. However, marine engines are excluded from the study.

  16. A Review on Development and Applications of Bio-Inspired Superhydrophobic Textiles.

    Science.gov (United States)

    Ahmad, Ishaq; Kan, Chi-Wai

    2016-11-03

    Bio-inspired engineering has been envisioned in a wide array of applications. All living bodies on Earth, including animals and plants, have well organized functional systems developed by nature. These naturally designed functional systems inspire scientists and engineers worldwide to mimic the system for practical applications by human beings. Researchers in the academic world and industries have been trying, for hundreds of years, to demonstrate how these natural phenomena could be translated into the real world to save lives, money and time. One of the most fascinating natural phenomena is the resistance of living bodies to contamination by dust and other pollutants, thus termed as self-cleaning phenomenon. This phenomenon has been observed in many plants, animals and insects and is termed as the Lotus Effect. With advancement in research and technology, attention has been given to the exploration of the underlying mechanisms of water repellency and self-cleaning. As a result, various concepts have been developed including Young's equation, and Wenzel and Cassie-Baxter theories. The more we unravel this process, the more we get access to its implications and applications. A similar pursuit is emphasized in this review to explain the fundamental principles, mechanisms, past experimental approaches and ongoing research in the development of bio-inspired superhydrophobic textiles.

  17. A Review on Development and Applications of Bio-Inspired Superhydrophobic Textiles

    Directory of Open Access Journals (Sweden)

    Ishaq Ahmad

    2016-11-01

    Full Text Available Bio-inspired engineering has been envisioned in a wide array of applications. All living bodies on Earth, including animals and plants, have well organized functional systems developed by nature. These naturally designed functional systems inspire scientists and engineers worldwide to mimic the system for practical applications by human beings. Researchers in the academic world and industries have been trying, for hundreds of years, to demonstrate how these natural phenomena could be translated into the real world to save lives, money and time. One of the most fascinating natural phenomena is the resistance of living bodies to contamination by dust and other pollutants, thus termed as self-cleaning phenomenon. This phenomenon has been observed in many plants, animals and insects and is termed as the Lotus Effect. With advancement in research and technology, attention has been given to the exploration of the underlying mechanisms of water repellency and self-cleaning. As a result, various concepts have been developed including Young’s equation, and Wenzel and Cassie–Baxter theories. The more we unravel this process, the more we get access to its implications and applications. A similar pursuit is emphasized in this review to explain the fundamental principles, mechanisms, past experimental approaches and ongoing research in the development of bio-inspired superhydrophobic textiles.

  18. A Review on Development and Applications of Bio-Inspired Superhydrophobic Textiles

    Science.gov (United States)

    Ahmad, Ishaq; Kan, Chi-wai

    2016-01-01

    Bio-inspired engineering has been envisioned in a wide array of applications. All living bodies on Earth, including animals and plants, have well organized functional systems developed by nature. These naturally designed functional systems inspire scientists and engineers worldwide to mimic the system for practical applications by human beings. Researchers in the academic world and industries have been trying, for hundreds of years, to demonstrate how these natural phenomena could be translated into the real world to save lives, money and time. One of the most fascinating natural phenomena is the resistance of living bodies to contamination by dust and other pollutants, thus termed as self-cleaning phenomenon. This phenomenon has been observed in many plants, animals and insects and is termed as the Lotus Effect. With advancement in research and technology, attention has been given to the exploration of the underlying mechanisms of water repellency and self-cleaning. As a result, various concepts have been developed including Young’s equation, and Wenzel and Cassie–Baxter theories. The more we unravel this process, the more we get access to its implications and applications. A similar pursuit is emphasized in this review to explain the fundamental principles, mechanisms, past experimental approaches and ongoing research in the development of bio-inspired superhydrophobic textiles. PMID:28774012

  19. Experimental study of dual fuel engine performance using variable LPG composition and engine parameters

    International Nuclear Information System (INIS)

    Elnajjar, Emad; Selim, Mohamed Y.E.; Hamdan, Mohammad O.

    2013-01-01

    Highlights: • The effect of using variable LPG is studied. • Five fuels with propane to butane % volume ratio are: 100-70-55-25-0. • 100% Propane composition shows the highest noise levels with similar performance. • At 45° BTDC injection timing 55% Propane LPG the only fuel experience knocking. • LPG fuels gave similar engine performance, with differences in levels of noise. - Abstract: The present work investigates experimentally the effect of LPG fuel with different composition and engine parameters on the performance of a dual compression engine. Five different blends of LPG fuels are used with Propane to Butane volume ratio of 100:0, 70:30, 55:45, 25:75, and 0:100. A single cylinder, naturally aspirated, four strokes, indirectly injected, water cooled modified Ricardo E6 engine, is used in this study. The study is carried out by measuring the cylinder pressure, engine load, engine speed, crank angle, and the fuel’s flow rate. The engine performance under variable LPG fuel composition, engine load, pilot fuel injection timing, compression ratio, pilot fuel mass and engine speed, are estimated by comparing the following engine parameters: the cylinder maximum pressure, the indicated mean effective pressure, the maximum rate of pressure rise, and the thermal efficiency. The experimental data indicates that the engine parameters are playing a major role on the engine’s performance. Different LPG fuel composition did not show a major effect on the engine efficiency but directly impacted the levels of generated combustion noise

  20. A study of coupled thermoacoustic engines

    Science.gov (United States)

    Gillman, Brenna Jane

    In the development of thermoacoustic energy conversion from heat to electricity, an array configuration of heat engines can yield high acoustic power output. Arrays consisting of multiple thermoacoustic engines have been constructed in such a way that the heat driven acoustic engines radiate sound into a common cavity where a piezoelectric transducer is used to convert acoustic power into electrical signal. Coupling effects between two or more self-sustaining thermoacoustic engines, operating near 2.5 kHz, have been observed and considered in terms of synchronization. Two types of coupling were observed to be present in the system: mass coupling and acoustic coupling. It was found that for a weaker mass coupling, in the absence of acoustic coupling, anti-phase synchronization was observed. In-phase synchronization was observed for stronger mass coupling. To vary the acoustic coupling present in this system, the volume of the cavity, and the separation distance between engines were varied. In-phase synchronization was observed for each combination of two engines tested at every cavity volume and separation distance, however the average phase difference measured between oscillators was not the same for each cavity volume tested. It was found that the cavity volume with 228 cm3 was the only cavity tested to result in synchronization with an average phase difference of approximately zero degrees, and also maintain oscillations in a stable acoustic cavity mode for each array tested. Acoustic pressure amplitude was measured to be proportional to the number of engines in the array when scaled by the amplitude of each single engine operating alone for arrays up to four engines. Since an array consisting of four engines was shown to synchronize and produce coherent sound, the coupling between engines was identified as global coupling. To determine the threshold of frequency difference for synchronization, two coupled engines were detuned. It was found that the threshold

  1. Study on the evolution of nuclear engineering professions

    International Nuclear Information System (INIS)

    2008-01-01

    Based on interviews of experts belonging to different companies and institutions (EDF, AREVA, CEA, ASN, IRSN, INSTN), subcontractors, engineers and technicians of the nuclear sector, persons in charge of education, pupils and students, this study gives a synthetic vision of the general context of the needs for nuclear engineering professionals, at the world scale, in the French context, the perceived difficulties faced by this sector, the use of subcontracting, the recruitment needs, the educational profile of engineers and technicians, their revenues, their opinion about their work, the adequacy between education and employment in this sector. It gives estimated figures for engineer and technician recruitment needs for different abilities in the French nuclear engineering

  2. Study Regarding the Identification of an Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Ioan Ruja

    2016-10-01

    Full Text Available The paper presents the results of the scientific investigations performed on an Otto engine. One conducted surveys on the analytic and experimental modelling of the internal combustion engine, considered as automated system element. The results of the analytical study are concretised in the mathematical model of the engine, expressed in the operational. The experimental results are concretised in the indicial response in rotating speed, as well as in the determination of the constants of interest. The investigation methods used in conducting the survey were: experimental identification based on the indicial response of the engine and the analytical identification based on the mathematical models of diverse engine subsystems.

  3. Researching primary engineering education: UK perspectives, an exploratory study

    Science.gov (United States)

    Clark, Robin; Andrews, Jane

    2010-10-01

    This paper draws attention to the findings of an exploratory study that critically identified and analysed relevant perceptions of elementary level engineering education within the UK. Utilising an approach based upon grounded theory methodology, 30 participants including teachers, representatives of government bodies and non-profit providers of primary level engineering initiatives were interviewed. Three main concepts were identified during the analysis of findings, each relevant to primary engineering education. These were pedagogic issues, exposure to engineering within the curriculum and children's interest. The paper concludes that the opportunity to make a real difference to children's education by stimulating their engineering imagination suggests this subject area is of particular value.

  4. Molecular machines with bio-inspired mechanisms.

    Science.gov (United States)

    Zhang, Liang; Marcos, Vanesa; Leigh, David A

    2018-02-26

    The widespread use of molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular machines-which by and large function as switches-and the machines of the macroscopic world, which utilize the synchronized behavior of integrated components to perform more sophisticated tasks than is possible with any individual switch. Should we try to make molecular machines of greater complexity by trying to mimic machines from the macroscopic world or instead apply unfamiliar (and no doubt have to discover or invent currently unknown) mechanisms utilized by biological machines? Here we try to answer that question by exploring some of the advances made to date using bio-inspired machine mechanisms.

  5. Bioinspired Chemical Communication between Synthetic Nanomotors.

    Science.gov (United States)

    Chen, Chuanrui; Chang, Xiaocong; Teymourian, Hazhir; Ramírez-Herrera, Doris E; Esteban-Fernández de Ávila, Berta; Lu, Xiaolong; Li, Jinxing; He, Sha; Fang, Chengcheng; Liang, Yuyan; Mou, Fangzhi; Guan, Jianguo; Wang, Joseph

    2018-01-02

    While chemical communication plays a key role in diverse natural processes, the intelligent chemical communication between synthetic nanomotors remains unexplored. The design and operation of bioinspired synthetic nanomotors is presented. Chemical communication between nanomotors is possible and has an influence on propulsion behavior. A chemical "message" is sent from a moving activator motor to a nearby activated (receiver) motor by release of Ag + ions from a Janus polystyrene/Ni/Au/Ag activator motor to the activated Janus SiO 2 /Pt nanomotor. The transmitted silver signal is translated rapidly into a dramatic speed change associated with the enhanced catalytic activity of activated motors. Selective and successive activation of multiple nanomotors is achieved by sequential localized chemical communications. The concept of establishing chemical communication between different synthetic nanomotors paves the way to intelligent nanoscale robotic systems that are capable of cooperating with each other. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Bio-inspired photonic crystals with superwettability.

    Science.gov (United States)

    Kuang, Minxuan; Wang, Jingxia; Jiang, Lei

    2016-12-21

    Photonic crystals (PCs) have attracted enormous research interest due to their unique light manipulation and potential applications in sensing, catalysts, detection, displays, solar cells and other fields. In particular, many novel applications of PCs are derived from their surface wettability. Generally, the wettability of PCs is determined by a combination of its surface geometrical structures and surface chemical compositions. This review focuses on the recent developments in the mechanism, fabrication and application of bio-inspired PCs with superwettability. It includes information on constructing superwetting PCs based on designing the topographical structure and regulating the surface chemical composition, and information on extending the practical applications of superwetting PCs in humidity/oil/solvent sensing, actuating, anti-fouling and liquid-impermeable surface, chemical detection, etc.

  7. Tough, bio-inspired hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Munch, Etienne; Launey, Maximimilan E.; Alsem, Daan H.; Saiz, Eduardo; Tomsia, Antoni P.; Ritchie, Robert O.

    2008-10-06

    The notion of mimicking natural structures in the synthesis of new structural materials has generated enormous interest but has yielded few practical advances. Natural composites achieve strength and toughness through complex hierarchical designs extremely difficult to replicate synthetically. Here we emulate Nature's toughening mechanisms through the combination of two ordinary compounds, aluminum oxide and polymethylmethacrylate, into ice-templated structures whose toughness can be over 300 times (in energy terms) that of their constituents. The final product is a bulk hybrid ceramic material whose high yield strength and fracture toughness ({approx}200 MPa and {approx}30 MPa{radical}m) provide specific properties comparable to aluminum alloys. These model materials can be used to identify the key microstructural features that should guide the synthesis of bio-inspired ceramic-based composites with unique strength and toughness.

  8. Case Study Research in Software Engineering Guidelines and Examples

    CERN Document Server

    Runeson, Per; Rainer, Austen; Regnell, Bjorn

    2012-01-01

    Based on their own experiences of in-depth case studies of software projects in international corporations, in this book the authors present detailed practical guidelines on the preparation, conduct, design and reporting of case studies of software engineering.  This is the first software engineering specific book on the case study research method.

  9. Progress on bioinspired, biomimetic, and bioreplication routes to harvest solar energy

    Science.gov (United States)

    Martín-Palma, Raúl J.; Lakhtakia, Akhlesh

    2017-06-01

    Although humans have long been imitating biological structures to serve their particular purposes, only a few decades ago engineered biomimicry began to be considered a technoscientific discipline with a great problem-solving potential. The three methodologies of engineered biomimicry-viz., bioinspiration, biomimetic, and bioreplication-employ and impact numerous technoscientific fields. For producing fuels and electricity by artificial photosynthesis, both processes and porous surfaces inspired by plants and certain marine animals are under active investigation. Biomimetically textured surfaces on the subwavelength scale have been shown to reduce the reflectance of photovoltaic solar cells over the visible and the near-infrared regimes. Lenticular compound lenses bioreplicated from insect eyes by an industrially scalable technique offer a similar promise.

  10. A Historical Systems Study of Liquid Rocket Engine Throttling Capabilities

    Science.gov (United States)

    Betts, Erin M.; Frederick, Robert A., Jr.

    2010-01-01

    This is a comprehensive systems study to examine and evaluate throttling capabilities of liquid rocket engines. The focus of this study is on engine components, and how the interactions of these components are considered for throttling applications. First, an assessment of space mission requirements is performed to determine what applications require engine throttling. A background on liquid rocket engine throttling is provided, along with the basic equations that are used to predict performance. Three engines are discussed that have successfully demonstrated throttling. Next, the engine system is broken down into components to discuss special considerations that need to be made for engine throttling. This study focuses on liquid rocket engines that have demonstrated operational capability on American space launch vehicles, starting with the Apollo vehicle engines and ending with current technology demonstrations. Both deep throttling and shallow throttling engines are discussed. Boost and sustainer engines have demonstrated throttling from 17% to 100% thrust, while upper stage and lunar lander engines have demonstrated throttling in excess of 10% to 100% thrust. The key difficulty in throttling liquid rocket engines is maintaining an adequate pressure drop across the injector, which is necessary to provide propellant atomization and mixing. For the combustion chamber, cooling can be an issue at low thrust levels. For turbomachinery, the primary considerations are to avoid cavitation, stall, surge, and to consider bearing leakage flows, rotordynamics, and structural dynamics. For valves, it is necessary to design valves and actuators that can achieve accurate flow control at all thrust levels. It is also important to assess the amount of nozzle flow separation that can be tolerated at low thrust levels for ground testing.

  11. Bioinspired orientation-dependent friction.

    Science.gov (United States)

    Xue, Longjian; Iturri, Jagoba; Kappl, Michael; Butt, Hans-Jürgen; del Campo, Aránzazu

    2014-09-23

    Spatular terminals on the toe pads of a gecko play an important role in directional adhesion and friction required for reversible attachment. Inspired by the toe pad design of a gecko, we study friction of polydimethylsiloxane (PDMS) micropillars terminated with asymmetric (spatular-shaped) overhangs. Friction forces in the direction of and against the spatular end were evaluated and compared to friction forces on symmetric T-shaped pillars and pillars without overhangs. The shape of friction curves and the values of friction forces on spatula-terminated pillars were orientation-dependent. Kinetic friction forces were enhanced when shearing against the spatular end, while static friction was stronger in the direction toward the spatular end. The overall friction force was higher in the direction against the spatula end. The maximum value was limited by the mechanical stability of the overhangs during shear. The aspect ratio of the pillar had a strong influence on the magnitude of the friction force, and its contribution surpassed and masked that of the spatular tip for aspect ratios of >2.

  12. Orbit Transfer Vehicle Engine Study. Phase A, extension 1: Study plan update

    Science.gov (United States)

    Mellish, J. A.

    1979-01-01

    The updated study plan for the Space Transportation System orbit transfer vehicle (OTV) engine study is presented. The study program consists of engine system, programmatic, cost, and risk analyses of OTV engine concepts. Detailed task descriptions for the advanced expander cycle engine optimization, alternate low thrust capability, and safety, reliability, and cost comparisons are given.

  13. K Basin sludge dissolution engineering study

    International Nuclear Information System (INIS)

    Westra, A.G.

    1998-01-01

    The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel

  14. Quality engineering as a discipline of study.

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, Rachel R.; Hoover, Marcey L.

    2012-12-01

    The current framework for quality scholarship in the United States ranges from the training and education of future quality engineers, managers, and professionals to focused and sustained research initiatives that, through academic institutions and other organizations, aim to improve the knowledge and application of quality across a variety of sectors. Numerous quality journals also provide a forum for professional dissemination of information.

  15. Case Study: A Bio-Inspired Control Algorithm for a Robotic Foot-Ankle Prosthesis Provides Adaptive Control of Level Walking and Stair Ascent

    Directory of Open Access Journals (Sweden)

    Uzma Tahir

    2018-04-01

    Full Text Available Powered ankle-foot prostheses assist users through plantarflexion during stance and dorsiflexion during swing. Provision of motor power permits faster preferred walking speeds than passive devices, but use of active motor power raises the issue of control. While several commercially available algorithms provide torque control for many intended activities and variations of terrain, control approaches typically exhibit no inherent adaptation. In contrast, muscles adapt instantaneously to changes in load without sensory feedback due to the intrinsic property that their stiffness changes with length and velocity. We previously developed a “winding filament” hypothesis (WFH for muscle contraction that accounts for intrinsic muscle properties by incorporating the giant titin protein. The goals of this study were to develop a WFH-based control algorithm for a powered prosthesis and to test its robustness during level walking and stair ascent in a case study of two subjects with 4–5 years of experience using a powered prosthesis. In the WFH algorithm, ankle moments produced by virtual muscles are calculated based on muscle length and activation. Net ankle moment determines the current applied to the motor. Using this algorithm implemented in a BiOM T2 prosthesis, we tested subjects during level walking and stair ascent. During level walking at variable speeds, the WFH algorithm produced plantarflexion angles (range = −8 to −19° and ankle moments (range = 1 to 1.5 Nm/kg similar to those produced by the BiOM T2 stock controller and to people with no amputation. During stair ascent, the WFH algorithm produced plantarflexion angles (range −15 to −19° that were similar to persons with no amputation and were ~5 times larger on average at 80 steps/min than those produced by the stock controller. This case study provides proof-of-concept that, by emulating muscle properties, the WFH algorithm provides robust, adaptive control of level walking at

  16. New bioactive bone-like microspheres with intrinsic magnetic properties obtained by bio-inspired mineralisation process.

    Science.gov (United States)

    Fernandes Patrício, Tatiana Marisa; Panseri, Silvia; Sandri, Monica; Tampieri, Anna; Sprio, Simone

    2017-08-01

    A bio-inspired mineralisation process was investigated and applied to develop novel hybrid magnetic materials by heterogeneous nucleation of Fe 2+ /Fe 3+ -doped hydroxyapatite nanocrystals onto a biopolymeric matrix made of a Type I collagen-based recombinant peptide (RCP). The effect of the synthesis temperature on the phase composition, crystallinity and magnetic properties of the nucleated inorganic phase was studied. The as-obtained magnetic materials were then engineered, by using a water-in-oil emulsification process, into hybrid magnetic microspheres, which were stabilized by de-hydrothermal treatment yielding cross-linking of the macromolecular matrix. Thorough investigation of the physicochemical, morphological and biological properties of the new hybrid microspheres, as induced by the presence of the inorganic nanophase and controlled iron substitution into hydroxyapatite lattice, revealed bone-like composition, good cytocompatibility, designed shape and size, and tailored magnetization. Such features are interesting and promising for application as new biomaterials with ability of remote activation and control by using external magnetic fields, for smart and personalized applications in medicine, particularly in bone tissue regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Engineering geophysical study of the convocation square, Kaduna ...

    African Journals Online (AJOL)

    Geophysical investigation for engineering studies was carried out at the convocation square of Kaduna State University (KASU) main campus, Kaduna state, which falls within the Basement Complex of North-Western Nigeria. The study is aimed at assisting in the planning and development process of civil engineering ...

  18. Oxidation Catalyst Studies on a Diesel Engine

    OpenAIRE

    Ye, Shifei

    2010-01-01

    In this thesis, the experimental test facilities consisted of a well instrumented live Ford 2.0 litre turbocharged diesel engine connected to a specially made exhaust can, which contained a diesel oxidation catalyst (DOC). Experiments were performed on DOCs, which were specially prepared by Johnson Matthey, and had thermocouples mounted in their walls to measure axial temperature profiles. These DOCs consisted of a Pt catalyst dispersed in an alumina washcoat on a cordierite monolith supports...

  19. Three-Dimensional-Printing of Bio-Inspired Composites.

    Science.gov (United States)

    Xiang Gu, Grace; Su, Isabelle; Sharma, Shruti; Voros, Jamie L; Qin, Zhao; Buehler, Markus J

    2016-02-01

    Optimized for millions of years, natural materials often outperform synthetic materials due to their hierarchical structures and multifunctional abilities. They usually feature a complex architecture that consists of simple building blocks. Indeed, many natural materials such as bone, nacre, hair, and spider silk, have outstanding material properties, making them applicable to engineering applications that may require both mechanical resilience and environmental compatibility. However, such natural materials are very difficult to harvest in bulk, and may be toxic in the way they occur naturally, and therefore, it is critical to use alternative methods to fabricate materials that have material functions similar to material function as their natural counterparts for large-scale applications. Recent progress in additive manufacturing, especially the ability to print multiple materials at upper micrometer resolution, has given researchers an excellent instrument to design and reconstruct natural-inspired materials. The most advanced 3D-printer can now be used to manufacture samples to emulate their geometry and material composition with high fidelity. Its capabilities, in combination with computational modeling, have provided us even more opportunities for designing, optimizing, and testing the function of composite materials, in order to achieve composites of high mechanical resilience and reliability. In this review article, we focus on the advanced material properties of several multifunctional biological materials and discuss how the advanced 3D-printing techniques can be used to mimic their architectures and functions. Lastly, we discuss the limitations of 3D-printing, suggest possible future developments, and discuss applications using bio-inspired materials as a tool in bioengineering and other fields.

  20. Three-Dimensional-Printing of Bio-Inspired Composites

    Science.gov (United States)

    Xiang Gu, Grace; Su, Isabelle; Sharma, Shruti; Voros, Jamie L.; Qin, Zhao; Buehler, Markus J.

    2016-01-01

    Optimized for millions of years, natural materials often outperform synthetic materials due to their hierarchical structures and multifunctional abilities. They usually feature a complex architecture that consists of simple building blocks. Indeed, many natural materials such as bone, nacre, hair, and spider silk, have outstanding material properties, making them applicable to engineering applications that may require both mechanical resilience and environmental compatibility. However, such natural materials are very difficult to harvest in bulk, and may be toxic in the way they occur naturally, and therefore, it is critical to use alternative methods to fabricate materials that have material functions similar to material function as their natural counterparts for large-scale applications. Recent progress in additive manufacturing, especially the ability to print multiple materials at upper micrometer resolution, has given researchers an excellent instrument to design and reconstruct natural-inspired materials. The most advanced 3D-printer can now be used to manufacture samples to emulate their geometry and material composition with high fidelity. Its capabilities, in combination with computational modeling, have provided us even more opportunities for designing, optimizing, and testing the function of composite materials, in order to achieve composites of high mechanical resilience and reliability. In this review article, we focus on the advanced material properties of several multifunctional biological materials and discuss how the advanced 3D-printing techniques can be used to mimic their architectures and functions. Lastly, we discuss the limitations of 3D-printing, suggest possible future developments, and discuss applications using bio-inspired materials as a tool in bioengineering and other fields. PMID:26747791

  1. Computational studies of an intake manifold for restricted engine application

    Science.gov (United States)

    Prasetyo, Bagus Dwi; Ubaidillah, Maharani, Elliza Tri; Setyohandoko, Gabriel; Idris, Muhammad Idzdihar

    2018-02-01

    The Formula Society of Automotive Engineer (FSAE) student competition is an international contest for a vehicle that entirely designed and built by students from various universities. The engine design in the Formula SAE competition has to comply a tight regulation. Concerning the engine intake line, an air restrictor of circular cross-section less than 20 mm must be fitted between the throttle valve and the engine inlet. The throat is aimed to limit the engine air flow rate as it strongly influences the volumetric efficiency and then the maximum power. This article focuses on the design of the engine intake system of the Bengawan FSAE team vehicle to optimize the engine power output and its stability. The performance of engine intake system is studied through computational fluid dynamics (CFD). The objective of CFD is to know the pressure, velocity, and airflow of the air intake manifold for the best performance of the engine. The three-dimensional drawing of the intake manifold was made, and CFD simulation was conducted using ANSYS FLUENT. Two models were studied. The result shows that the different design produces a different value of the velocity of airflow and the kind of flow type.

  2. Copper removal using bio-inspired polydopamine coated natural zeolites.

    Science.gov (United States)

    Yu, Yang; Shapter, Joseph G; Popelka-Filcoff, Rachel; Bennett, John W; Ellis, Amanda V

    2014-05-30

    Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2-5.5), PDA treatment time (3-24h), contact time (0 to 24h) and initial Cu(II) ion concentrations (1 to 500mgdm(-3)) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93mgg(-1) for pristine natural zeolite and 28.58mgg(-1) for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01M or 0.1M) of either acid or base. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Double Compression Expansion Engine: A Parametric Study on a High-Efficiency Engine Concept

    KAUST Repository

    Bhavani Shankar, Vijai Shankar

    2018-04-03

    The Double compression expansion engine (DCEE) concept has exhibited a potential for achieving high brake thermal efficiencies (BTE). The effect of different engine components on system efficiency was evaluated in this work using GT Power simulations. A parametric study on piston insulation, convection heat transfer multiplier, expander head insulation, insulation of connecting pipes, ports and tanks, and the expander intake valve lift profiles was conducted to understand the critical parameters that affected engine efficiency. The simulations were constrained to a constant peak cylinder pressure of 300 bar, and a fixed combustion phasing. The results from this study would be useful in making technology choices that will help realise the potential of this engine concept.

  4. Engineering Students' Views of Corporate Social Responsibility: A Case Study from Petroleum Engineering.

    Science.gov (United States)

    Smith, Jessica M; McClelland, Carrie J; Smith, Nicole M

    2017-12-01

    The mining and energy industries present unique challenges to engineers, who must navigate sometimes competing responsibilities and codes of conduct, such as personal senses of right and wrong, professional ethics codes, and their employers' corporate social responsibility (CSR) policies. Corporate social responsibility (CSR) is the current dominant framework used by industry to conceptualize firms' responsibilities to their stakeholders, yet has it plays a relatively minor role in engineering ethics education. In this article, we report on an interdisciplinary pedagogical intervention in a petroleum engineering seminar that sought to better prepare engineering undergraduate students to critically appraise the strengths and limitations of CSR as an approach to reconciling the interests of industry and communities. We find that as a result of the curricular interventions, engineering students were able to expand their knowledge of the social, rather than simply environmental and economic dimensions of CSR. They remained hesitant, however, in identifying the links between those social aspects of CSR and their actual engineering work. The study suggests that CSR may be a fruitful arena from which to illustrate the profoundly sociotechnical dimensions of the engineering challenges relevant to students' future careers.

  5. Ultrastrong Bioinspired Graphene-Based Fibers via Synergistic Toughening.

    Science.gov (United States)

    Zhang, Yuanyuan; Li, Yuchen; Ming, Peng; Zhang, Qi; Liu, Tianxi; Jiang, Lei; Cheng, Qunfeng

    2016-04-13

    Ultrastrong bioinspired graphene-based fibers are designed and prepared via synergistic toughening of ionic and covalent bonding. The tensile strength reaches up to 842.6 MPa and is superior to all other reported graphene-based fibers. In addition, its electrical conductivity is as high as 292.4 S cm(-1). This bioinspired synergistic toughening strategy supplies new insight toward the construction of integrated high-performance graphene-based fibers in the near future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Natural and bioinspired nanostructured bactericidal surfaces.

    Science.gov (United States)

    Tripathy, Abinash; Sen, Prosenjit; Su, Bo; Briscoe, Wuge H

    2017-10-01

    Bacterial antibiotic resistance is becoming more widespread due to excessive use of antibiotics in healthcare and agriculture. At the same time the development of new antibiotics has effectively ground to a hold. Chemical modifications of material surfaces have poor long-term performance in preventing bacterial build-up and hence approaches for realising bactericidal action through physical surface topography have become increasingly important in recent years. The complex nature of the bacteria cell wall interactions with nanostructured surfaces represents many challenges while the design of nanostructured bactericidal surfaces is considered. Here we present a brief overview of the bactericidal behaviour of naturally occurring and bio-inspired nanostructured surfaces against different bacteria through the physico-mechanical rupture of the cell wall. Many parameters affect this process including the size, shape, density, rigidity/flexibility and surface chemistry of the surface nanotextures as well as factors such as bacteria specificity (e.g. gram positive and gram negative) and motility. Different fabrication methods for such bactericidal nanostructured surfaces are summarised. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Bioinspired sensory systems for local flow characterization

    Science.gov (United States)

    Colvert, Brendan; Chen, Kevin; Kanso, Eva

    2016-11-01

    Empirical evidence suggests that many aquatic organisms sense differential hydrodynamic signals.This sensory information is decoded to extract relevant flow properties. This task is challenging because it relies on local and partial measurements, whereas classical flow characterization methods depend on an external observer to reconstruct global flow fields. Here, we introduce a mathematical model in which a bioinspired sensory array measuring differences in local flow velocities characterizes the flow type and intensity. We linearize the flow field around the sensory array and express the velocity gradient tensor in terms of frame-independent parameters. We develop decoding algorithms that allow the sensory system to characterize the local flow and discuss the conditions under which this is possible. We apply this framework to the canonical problem of a circular cylinder in uniform flow, finding excellent agreement between sensed and actual properties. Our results imply that combining suitable velocity sensors with physics-based methods for decoding sensory measurements leads to a powerful approach for understanding and developing underwater sensory systems.

  8. Soft Dielectric Elastomer Oscillators Driving Bioinspired Robots.

    Science.gov (United States)

    Henke, E-F Markus; Schlatter, Samuel; Anderson, Iain A

    2017-12-01

    Entirely soft robots with animal-like behavior and integrated artificial nervous systems will open up totally new perspectives and applications. To produce them, we must integrate control and actuation in the same soft structure. Soft actuators (e.g., pneumatic and hydraulic) exist but electronics are hard and stiff and remotely located. We present novel soft, electronics-free dielectric elastomer oscillators, which are able to drive bioinspired robots. As a demonstrator, we present a robot that mimics the crawling motion of the caterpillar, with an integrated artificial nervous system, soft actuators and without any conventional stiff electronic parts. Supplied with an external DC voltage, the robot autonomously generates all signals that are necessary to drive its dielectric elastomer actuators, and it translates an in-plane electromechanical oscillation into a crawling locomotion movement. Therefore, all functional and supporting parts are made of polymer materials and carbon. Besides the basic design of this first electronic-free, biomimetic robot, we present prospects to control the general behavior of such robots. The absence of conventional stiff electronics and the exclusive use of polymeric materials will provide a large step toward real animal-like robots, compliant human machine interfaces, and a new class of distributed, neuron-like internal control for robotic systems.

  9. Bioinspired Heterogeneous Structural Color Stripes from Capillaries.

    Science.gov (United States)

    Zhao, Ze; Wang, Huan; Shang, Luoran; Yu, Yunru; Fu, Fanfan; Zhao, Yuanjin; Gu, Zhongze

    2017-12-01

    As an important characteristic of many creatures, structural colors play a crucial role in the survival of organisms. Inspired by these features, an intelligent structural color material with a heterogeneous striped pattern and stimuli-responsivity by fast self-assembly of colloidal nanoparticles in capillaries with a certain diameter range are presented here. The width, spacing, color, and even combination of the structural color stripe patterns can be precisely tailored by adjusting the self-assembly parameters. Attractively, with the integration of a near-infrared (NIR) light responsive graphene hydrogel into the structural color stripe pattern, the materials are endowed with light-controlled reversible bending behavior with self-reporting color indication. It is demonstrated that the striped structural color materials can be used as NIR-light-triggered dynamic barcode labels for the anti-counterfeiting of different products. These features of the bioinspired structural color stripe pattern materials indicate their potential values for mimicking structural color organisms, which will find important applications in constructing intelligent sensors, anti-counterfeiting devices, and so on. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Enhancing Systems Engineering Education Through Case Study Writing

    Science.gov (United States)

    Stevens, Jennifer Stenger

    2016-01-01

    Developing and refining methods for teaching systems engineering is part of Systems Engineering grand challenges and agenda for research in the SE research community. Retention of systems engineering knowledge is a growing concern in the United States as the baby boom generation continues to retire and the faster pace of technology development does not allow for younger generations to gain experiential knowledge through years of practice. Government agencies, including the National Aeronautics and Space Administration (NASA), develop their own curricula and SE leadership development programs to "grow their own" systems engineers. Marshall Space Flight Center (MSFC) conducts its own Center-focused Marshall Systems Engineering Leadership Development Program (MSELDP), a competitive program consisting of coursework, a guest lecture series, and a rotational assignment into an unfamiliar organization engaged in systems engineering. Independently, MSFC developed two courses to address knowledge retention and sharing concerns: Real World Marshall Mission Success course and its Case Study Writers Workshop and Writers Experience. Teaching case study writing and leading students through a hands-on experience at writing a case study on an SE topic can enhance SE training and has the potential to accelerate the transfer of experiential knowledge. This paper is an overview of the pilot experiences with teaching case study writing, its application in case study-based learning, and identifies potential areas of research and application for case study writing in systems engineering education.

  11. Bio-inspired color sketch for eco-friendly printing

    Science.gov (United States)

    Safonov, Ilia V.; Tolstaya, Ekaterina V.; Rychagov, Michael N.; Lee, Hokeun; Kim, Sang Ho; Choi, Donchul

    2012-01-01

    Saving of toner/ink consumption is an important task in modern printing devices. It has a positive ecological and social impact. We propose technique for converting print-job pictures to a recognizable and pleasant color sketches. Drawing a "pencil sketch" from a photo relates to a special area in image processing and computer graphics - non-photorealistic rendering. We describe a new approach for automatic sketch generation which allows to create well-recognizable sketches and to preserve partly colors of the initial picture. Our sketches contain significantly less color dots then initial images and this helps to save toner/ink. Our bio-inspired approach is based on sophisticated edge detection technique for a mask creation and multiplication of source image with increased contrast by this mask. To construct the mask we use DoG edge detection, which is a result of blending of initial image with its blurred copy through the alpha-channel, which is created from Saliency Map according to Pre-attentive Human Vision model. Measurement of percentage of saved toner and user study proves effectiveness of proposed technique for toner saving in eco-friendly printing mode.

  12. In-plane crashworthiness of bio-inspired hierarchical honeycombs

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Hanfeng; Huang, Xiaofei; Scarpa, Fabrizio; Wen, Guilin; Chen, Yanyu; Zhang, Chao

    2018-05-01

    Biological tissues like bone, wood, and sponge possess hierarchical cellular topologies, which are lightweight and feature an excellent energy absorption capability. Here we present a system of bio-inspired hierarchical honeycomb structures based on hexagonal, Kagome, and triangular tessellations. The hierarchical designs and a reference regular honeycomb configuration are subjected to simulated in-plane impact using the nonlinear finite element code LS-DYNA. The numerical simulation results show that the triangular hierarchical honeycomb provides the best performance compared to the other two hierarchical honeycombs, and features more than twice the energy absorbed by the regular honeycomb under similar loading conditions. We also propose a parametric study correlating the microstructure parameters (hierarchical length ratio r and the number of sub cells N) to the energy absorption capacity of these hierarchical honeycombs. The triangular hierarchical honeycomb with N = 2 and r = 1/8 shows the highest energy absorption capacity among all the investigated cases, and this configuration could be employed as a benchmark for the design of future safety protective systems.

  13. CDIO Projects in Civil Engineering Study Program at DTU

    DEFF Research Database (Denmark)

    Krogsbøll, Anette; Simonsen, Claus; Christensen, Jørgen Erik

    2011-01-01

    In 2008 all Bachelor of engineering study programs at the Technical University of Denmark (DTU) have been adopted to the “Conceive – Design – Implement – Operate” approach. As part of the necessary changes it was decided that all seven study programs should have a cross disciplinary project...... or a design build project on each of the first four semesters. In this paper the four projects in the civil engineering study program are described along with a brief description of the entire study program. The aim is to provide additional information and documentation to accompany an exposition where...... students present their projects. Learning outcomes, training and assessment of personal, professional and social engineering skills are described from a project point of view. Progression of engineering skills is discussed from a study program perspective. The interrelation between the various elements...

  14. A bio-inspired approach for in situ synthesis of tunable adhesive

    International Nuclear Information System (INIS)

    Sun, Leming; Yi, Sijia; Wang, Yongzhong; Pan, Kang; Zhong, Qixin; Zhang, Mingjun

    2014-01-01

    Inspired by the strong adhesive produced by English ivy, this paper proposes an in situ synthesis approach for fabricating tunable nanoparticle enhanced adhesives. Special attention was given to tunable features of the adhesive produced by the biological process. Parameters that may be used to tune properties of the adhesive will be proposed. To illustrate and validate the proposed approach, an experimental platform was presented for fabricating tunable chitosan adhesive enhanced by Au nanoparticles synthesized in situ. This study contributes to a bio-inspired approach for in situ synthesis of tunable nanocomposite adhesives by mimicking the natural biological processes of ivy adhesive synthesis. (paper)

  15. Study of temperature distribution in a Stirling engine regenerator

    International Nuclear Information System (INIS)

    Gheith, R.; Aloui, F.; Ben Nasrallah, S.

    2014-01-01

    Highlights: • A Gamma-Stirling engine is experimented to determine the optimal operation parameters. • A set of experiment reveals a difference of temperature between regenerator sides. • A phenomenon which consumes a part of the produced energy by the engine is highlighted. • A multi-objectif study based on experimental design methodology is developed. • The optimal set of operation parameters maximizing the engine power is proposed. - Abstract: A gamma Stirling engine is studied in this paper. A special care was accorded to the instrumentation of this engine and especially the instrumentation of the regenerator. A preliminarily set of experimental measurement reveals a difference of temperature between both regenerator sides. A second set of experiments was proposed to detect the influence of this phenomenon on Stirling engine performances. The asymmetry of heat transfer inside the Stirling engine regenerator’s is one of the important phenomenons which consume a part of the produced energy. Two experiments are made to find out the causes of this asymmetry. In order to know the influence of the different operation parameters on this new phenomenon the experimental design method is adopted. The experimental design is an alternative to identify the parameters sets allowing optimal Stirling engine performances. A central composite rotatable design was adopted for minimizing the asymmetry of temperature between both regenerator sides and maximizes the engine brake power. The selected four independent parameters are: heating temperature (300 °C–500 °C), initial filling pressure (3 bar–8 bar), cooling water flow rate (0.2 l/m–3 l/min) and operation time (4–20 min after study regime). The four adopted factors are experimentally varied. The results show that the heating temperature is the most significant factor for the studied phenomenon. The major damages caused by this phenomenon will be presented too

  16. Multi-Locomotion Robotic Systems New Concepts of Bio-inspired Robotics

    CERN Document Server

    Fukuda, Toshio; Sekiyama, Kosuke; Aoyama, Tadayoshi

    2012-01-01

    Nowadays, multiple attention have been paid on a robot working in the human living environment, such as in the field of medical, welfare, entertainment and so on. Various types of researches are being conducted actively in a variety of fields such as artificial intelligence, cognitive engineering, sensor- technology, interfaces and motion control. In the future, it is expected to realize super high functional human-like robot by integrating technologies in various fields including these types of researches. The book represents new developments and advances in the field of bio-inspired robotics research introducing the state of the art, the idea of multi-locomotion robotic system to implement the diversity of animal motion. It covers theoretical and computational aspects of Passive Dynamic Autonomous Control (PDAC), robot motion control, multi legged walking and climbing as well as brachiation focusing concrete robot systems, components and applications. In addition, gorilla type robot systems are described as...

  17. Ethical Considerations in Tissue Engineering Research: Case Studies in Translation

    Science.gov (United States)

    Baker, Hannah B.; McQuilling, John P.

    2016-01-01

    Tissue engineering research is a complex process that requires investigators to focus on the relationship between their research and anticipated gains in both knowledge and treatment improvements. The ethical considerations arising from tissue engineering research are similarly complex when addressing the translational progression from bench to bedside, and investigators in the field of tissue engineering act as moral agents at each step of their research along the translational pathway, from early benchwork and preclinical studies to clinical research. This review highlights the ethical considerations and challenges at each stage of research, by comparing issues surrounding two translational tissue engineering technologies: the bioartificial pancreas and a tissue engineered skeletal muscle construct. We present relevant ethical issues and questions to consider at each step along the translational pathway, from the basic science bench to preclinical research to first-in-human clinical trials. Topics at the bench level include maintaining data integrity, appropriate reporting and dissemination of results, and ensuring that studies are designed to yield results suitable for advancing research. Topics in preclinical research include the principle of “modest translational distance” and appropriate animal models. Topics in clinical research include key issues that arise in early-stage clinical trials, including selection of patient-subjects, disclosure of uncertainty, and defining success. The comparison of these two technologies and their ethical issues brings to light many challenges for translational tissue engineering research and provides guidance for investigators engaged in development of any tissue engineering technology. PMID:26282436

  18. Bioinspired catalytic materials for energy-relevant conversions

    Science.gov (United States)

    Artero, Vincent

    2017-09-01

    The structure of active sites of enzymes involved in bioenergetic processes can inspire design of active, stable and cost-effective catalysts for renewable-energy technologies. For these materials to reach maturity, the benefits of bioinspired systems must be combined with practical technological requirements.

  19. Bio-inspired hair-based inertial sensors

    NARCIS (Netherlands)

    Droogendijk, H.; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2015-01-01

    In biology, hair-based sensor systems are used regularly for measurement of physical quantities like acceleration, flow, rotational rate, and IR light. In this chapter, two different types of bio-inspired sensors for inertial measurement are discussed, which have been developed using surface

  20. Bioinspired Nanocarriers Designed to Enhance Intracellular Delivery of Biotherapeutics

    Science.gov (United States)

    2001-10-25

    therapeutic and vaccine development. Keywords - gene therapy, vaccine, bioinspired, biotherapeutic I. INTRODUCTION The efficacy of many protein and DNA...DNA, RNA and proteins . While these therapeutics have tremendous potential, effectively formulating and delivering them has also been a widely...intracellular trafficking that is inspired by biological polymers, i.e. proteins , that are involved in controlling vesicular trafficking pathways. For

  1. Swimming, swarming and sensing. Bio-inspired underwater robotics

    NARCIS (Netherlands)

    Henrion, S.; Vercruyssen, T.; Müller, U.K.

    2014-01-01

    For operations in complex underwater environments, bio-inspired robots offer manoeuvrability, stealth and autonomy. They integrate propulsion and control systems into one multi-purpose undulatory propeller. By generating large counteracting forces, undulating fins generate a wide range of net

  2. Tissue-Engineering for the Study of Cardiac Biomechanics

    Science.gov (United States)

    Ma, Stephen P.; Vunjak-Novakovic, Gordana

    2016-01-01

    The notion that both adaptive and maladaptive cardiac remodeling occurs in response to mechanical loading has informed recent progress in cardiac tissue engineering. Today, human cardiac tissues engineered in vitro offer complementary knowledge to that currently provided by animal models, with profound implications to personalized medicine. We review here recent advances in the understanding of the roles of mechanical signals in normal and pathological cardiac function, and their application in clinical translation of tissue engineering strategies to regenerative medicine and in vitro study of disease. PMID:26720588

  3. A bio-inspired glucose controller based on pancreatic β-cell physiology.

    Science.gov (United States)

    Herrero, Pau; Georgiou, Pantelis; Oliver, Nick; Johnston, Desmond G; Toumazou, Christofer

    2012-05-01

    Control algorithms for closed-loop insulin delivery in type 1 diabetes have been mainly based on control engineering or artificial intelligence techniques. These, however, are not based on the physiology of the pancreas but seek to implement engineering solutions to biology. Developments in mathematical models of the β-cell physiology of the pancreas have described the glucose-induced insulin release from pancreatic β cells at a molecular level. This has facilitated development of a new class of bio-inspired glucose control algorithms that replicate the functionality of the biological pancreas. However, technologies for sensing glucose levels and delivering insulin use the subcutaneous route, which is nonphysiological and introduces some challenges. In this article, a novel glucose controller is presented as part of a bio-inspired artificial pancreas. A mathematical model of β-cell physiology was used as the core of the proposed controller. In order to deal with delays and lack of accuracy introduced by the subcutaneous route, insulin feedback and a gain scheduling strategy were employed. A United States Food and Drug Administration-accepted type 1 diabetes mellitus virtual population was used to validate the presented controller. Premeal and postmeal mean ± standard deviation blood glucose levels for the adult and adolescent populations were well within the target range set for the controller [(70, 180) mg/dl], with a percent time in range of 92.8 ± 7.3% for the adults and 83.5 ± 14% for the adolescents. This article shows for the first time very good glucose control in a virtual population with type 1 diabetes mellitus using a controller based on a subcellular β-cell model. © 2012 Diabetes Technology Society.

  4. Development of a bio-inspired UAV perching system

    Science.gov (United States)

    Xie, Pu

    Although technologies of unmanned aerial vehicles (UAVs) including micro air vehicles (MAVs) have been greatly advanced in the recent years, it is still very difficult for a UAV to perform some very challenging tasks such as perching to any desired spot reliably and agilely like a bird. Unlike the UAVs, the biological control mechanism of birds has been optimized through millions of year evolution and hence, they can perform many extremely maneuverability tasks, such as perching or grasping accurately and robustly. Therefore, we have good reason to learn from the nature in order to significantly improve the capabilities of UAVs. The development of a UAV perching system is becoming feasible, especially after a lot of research contributions in ornithology which involve the analysis of the bird's functionalities. Meanwhile, as technology advances in many engineering fields, such as airframes, propulsion, sensors, batteries, micro-electromechanical-system (MEMS), and UAV technology is also advancing rapidly. All of these research efforts in ornithology and the fast growing development technologies in UAV applications are motivating further interests and development in the area of UAV perching and grasping research. During the last decade, the research contributions about UAV perching and grasping were mainly based on fixed-wing, flapping-wing, and rotorcraft UAVs. However, most of the current researches in UAV systems with perching and grasping capability are focusing on either active (powered) grasping and perching or passive (unpowered) perching. Although birds do have both active and passive perching capabilities depending on their needs, there is no UAV perching system with both capabilities. In this project, we focused on filling this gap. Inspired by the anatomy analysis of bird legs and feet, a novel perching system has been developed to implement the bionics action for both active grasping and passive perching. In addition, for developing a robust and

  5. Training mechanical engineering students to utilize biological inspiration during product development.

    Science.gov (United States)

    Bruck, Hugh A; Gershon, Alan L; Golden, Ira; Gupta, Satyandra K; Gyger, Lawrence S; Magrab, Edward B; Spranklin, Brent W

    2007-12-01

    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.

  6. Space engineering modeling and optimization with case studies

    CERN Document Server

    Pintér, János

    2016-01-01

    This book presents a selection of advanced case studies that cover a substantial range of issues and real-world challenges and applications in space engineering. Vital mathematical modeling, optimization methodologies and numerical solution aspects of each application case study are presented in detail, with discussions of a range of advanced model development and solution techniques and tools. Space engineering challenges are discussed in the following contexts: •Advanced Space Vehicle Design •Computation of Optimal Low Thrust Transfers •Indirect Optimization of Spacecraft Trajectories •Resource-Constrained Scheduling, •Packing Problems in Space •Design of Complex Interplanetary Trajectories •Satellite Constellation Image Acquisition •Re-entry Test Vehicle Configuration Selection •Collision Risk Assessment on Perturbed Orbits •Optimal Robust Design of Hybrid Rocket Engines •Nonlinear Regression Analysis in Space Engineering< •Regression-Based Sensitivity Analysis and Robust Design ...

  7. Initial trade and design studies for the fusion engineering device

    International Nuclear Information System (INIS)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-06-01

    The Magnetic Fusion Energy Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. The Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), initiated a program of trade and design studies in October 1980 to support the selection of the FED concept. This document presents the results of these initial trade and design studies. Based on these results, a baseline configuration has been identified and the Design Center effort for the remainder of the fiscal year will be devoted to the development of a self-consistent FED design description

  8. Initial trade and design studies for the fusion engineering device

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-06-01

    The Magnetic Fusion Energy Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. The Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), initiated a program of trade and design studies in October 1980 to support the selection of the FED concept. This document presents the results of these initial trade and design studies. Based on these results, a baseline configuration has been identified and the Design Center effort for the remainder of the fiscal year will be devoted to the development of a self-consistent FED design description.

  9. A PRELIMINARY STUDY OF HUMOUR IN ENGINEERING EDUCATION

    Directory of Open Access Journals (Sweden)

    SIOW C. LIM

    2017-01-01

    Full Text Available It is commonly known that humour has an implication on the process of teaching and learning. However, there is still limited study done on the implication of humour in teaching and learning engineering courses. This paper studies the perception and experience of engineering lecturers and students towards the incorporation of sense of humour in the teaching and learning of engineering courses. Online and offline surveys were conducted on the students and lecturers from the school of engineering, Taylors’ University respectively. Several interesting insights were drawn from the responses with the general consensus from both students and lecturers that humour helps in enhancing the teaching and learning process. Real case examples of how the lecturers deliver their lectures with humour were also presented.

  10. A case study of technology transfer: Rehabilitative engineering at Rancho Los Amigos Hospital. [prosthetic devices engineering

    Science.gov (United States)

    Hildred, W.

    1973-01-01

    The transfer of NASA technolgy to rehabilitative applications of artificial limbs is studied. Human factors engineering activities range from orthotic manipulators to tiny dc motors and transducers to detect and transmit voluntary control signals. It is found that bicarbon implant devices are suitable for medical equipment and artificial limbs because of their biological compatibility with human body fluids and tissues.

  11. Hybrid vehicle system studies and optimized hydrogen engine design

    Science.gov (United States)

    Smith, J. R.; Aceves, S.

    1995-04-01

    We have done system studies of series hydrogen hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. We have evaluated the impact of various on-board storage options on fuel economy. Experiments in an available engine at the Sandia CRF demonstrated NO(x) emissions of 10 to 20 ppM at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppM to meet the 0.2 g/mile ULEV or Federal Tier II emissions regulations. LLNL has designed and fabricated a first generation optimized hydrogen engine head for use on an existing Onan engine. This head features 15:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses. Initial testing shows promise of achieving an indicated efficiency of nearly 50% and emissions of less than 100 ppM NO(x). Hydrocarbons and CO are to be measured, but are expected to be very low since their only source is engine lubricating oil. A successful friction reduction program on the Onan engine should result in a brake thermal efficiency of about 42% compared to today's gasoline engines of 32%. Based on system studies requirements, the next generation engine will be about 2 liter displacement and is projected to achieve 46% brake thermal efficiency with outputs of 15 kW for cruise and 40 kW for hill climb.

  12. The Role of Ethnographic Studies in Empirical Software Engineering

    DEFF Research Database (Denmark)

    Sharp, Helen; Dittrich, Yvonne; Souza, Cleidson R. B. de

    2016-01-01

    Ethnography is a qualitative research method used to study people and cultures. It is largely adopted in disciplines outside software engineering, including different areas of computer science. Ethnography can provide an in-depth understanding of the socio-technological realities surrounding...... everyday software development practice, i.e., it can help to uncover not only what practitioners do, but also why they do it. Despite its potential, ethnography has not been widely adopted by empirical software engineering researchers, and receives little attention in the related literature. The main goal...... of this paper is to explain how empirical software engineering researchers would benefit from adopting ethnography. This is achieved by explicating four roles that ethnography can play in furthering the goals of empirical software engineering: to strengthen investigations into the social and human aspects...

  13. An Industrial Case Study: Identification of Competencies of Design Engineers

    DEFF Research Database (Denmark)

    Ahmed, Saeema

    2007-01-01

    This paper describes the findings from an empirical study carried out with engineers in senior roles within a large company manufacturing complex products. This research aimed to identify the types of knowledge that are important for design engineers. Twenty-four knowledge categories were...... identified and the importance of these for design engineers in industry was investigated. In addition, the number of years of relevant experience required to become an expert in these types of knowledge was investigated. Knowledge related to the process was perceived as more important to those related...... to the product. However, the number of years to become an expert in process knowledge was found to be lower than for product knowledge, despite process knowledge being perceived as more important. The findings of this research contribute to the education and training of design engineers....

  14. Motivational Factors of Professional Engineers and Non-Professional Engineers in Applying for License as Professional Engineer: A Comparative Study

    Science.gov (United States)

    Khamis, Nor Kamaliana; Harun, Zambri; Tahir, Mohd Faizal Mat; Wahid, Zaliha; Sabri, Mohd Anas Mohd

    2013-01-01

    All engineering faculties in Malaysia are required to have at least three academics who have engineering competency for each program. Having an engineering competency means academics has obtained the compulsory endorsements from the Boards of Engineers, Malaysia, BEM. Upon approval, academics seeking such competency could carry the suffix Ir. to…

  15. Application of quercetin and its bio-inspired nanoparticles as anti-adhesive agents against Bacillus subtilis attachment to surface.

    Science.gov (United States)

    Raie, Diana S; Mhatre, Eisha; Thiele, Matthias; Labena, A; El-Ghannam, Gamal; Farahat, Laila A; Youssef, Tareq; Fritzsche, Wolfgang; Kovács, Ákos T

    2017-01-01

    The aim of this study was directed to reveal the repulsive effect of coated glass slides by quercetin and its bio-inspired titanium oxide and tungsten oxide nanoparticles on physical surface attachment of Bacillus subtilis as an ab-initio step of biofilm formation. Nanoparticles were successfully synthesized using sol-gel and acid precipitation methods for titanium oxide and tungsten oxide, respectively (in the absence or presence of quercetin). The anti-adhesive impact of the coated-slides was tested through the physical attachment of B. subtilis after 24h using Confocal Laser Scanning Microscopy (CLSM). Here, quercetin was presented as a bio-route for the synthesis of tungsten mixed oxides nano-plates at room temperature. In addition, quercetin had an impact on zeta potential and adsorption capacity of both bio-inspired amorphous titanium oxide and tungsten oxide nano-plates. Interestingly, our experiments indicated a contrary effect of quercetin as an anti-adhesive agent than previously reported. However, its bio-inspired metal oxide proved their repulsive efficiency. In addition, quercetin-mediated nano-tungsten and quercetin-mediated amorphous titanium showed anti-adhesive activity against B. subtilis biofilm. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. EAP artificial muscle actuators for bio-inspired intelligent social robotics (Conference Presentation)

    Science.gov (United States)

    Hanson, David F.

    2017-04-01

    Bio-inspired intelligent robots are coming of age in both research and industry, propelling market growth for robots and A.I. However, conventional motors limit bio-inspired robotics. EAP actuators and sensors could improve the simplicity, compliance, physical scaling, and offer bio-inspired advantages in robotic locomotion, grasping and manipulation, and social expressions. For EAP actuators to realize their transformative potential, further innovations are needed: the actuators must be robust, fast, powerful, manufacturable, and affordable. This presentation surveys progress, opportunities, and challenges in the author's latest work in social robots and EAP actuators, and proposes a roadmap for EAP actuators in bio-inspired intelligent robotics.

  17. Bio-Inspired Trajectory Generation for UAV Perching Movement Based on Tau Theory

    Directory of Open Access Journals (Sweden)

    Zhen Zhang

    2014-09-01

    Full Text Available This paper offers a bio-inspired trajectory generation method for UAV/MAV perching (i.e., the final approach to, and landing on, a target. The method is based on tau theory, which was established based on the study of the natural motion patterns of animals (including humans when they approach a fixed or moving object for perching or capturing prey. In our research, tau theory is applied to the trajectory generation problem of an air vehicle for perching on a target object. Three bio-inspired strategies, namely the tau in the action gap strategy, the tau coupling strategy and the intrinsic tau gravity strategy are studied for perching tasks. A key parameter of the method inspired by biological systems is discussed. Two perching scenarios, one from a flight state (with non-zero initial velocity and one from a hovering state (with zero initial velocity, are studied. Numerical simulations with a rotary vehicle are presented as examples to demonstrate the performance of the proposed approach. The simulation results show that the resulting flight trajectories meet all the desired requirements for the vehicle in perching on an object.

  18. Guidelines for using empirical studies in software engineering education

    Directory of Open Access Journals (Sweden)

    Fabian Fagerholm

    2017-09-01

    Full Text Available Software engineering education is under constant pressure to provide students with industry-relevant knowledge and skills. Educators must address issues beyond exercises and theories that can be directly rehearsed in small settings. Industry training has similar requirements of relevance as companies seek to keep their workforce up to date with technological advances. Real-life software development often deals with large, software-intensive systems and is influenced by the complex effects of teamwork and distributed software development, which are hard to demonstrate in an educational environment. A way to experience such effects and to increase the relevance of software engineering education is to apply empirical studies in teaching. In this paper, we show how different types of empirical studies can be used for educational purposes in software engineering. We give examples illustrating how to utilize empirical studies, discuss challenges, and derive an initial guideline that supports teachers to include empirical studies in software engineering courses. Furthermore, we give examples that show how empirical studies contribute to high-quality learning outcomes, to student motivation, and to the awareness of the advantages of applying software engineering principles. Having awareness, experience, and understanding of the actions required, students are more likely to apply such principles under real-life constraints in their working life.

  19. Adoption of value engineering: an attribute study for construction

    International Nuclear Information System (INIS)

    Shaikh, P.

    2015-01-01

    For economic reasons, engineers are compelled to explore low cost methods in construction industry to reduce the overall cost of a project. Research studies have been conducted in this regard throughout the world and value engineering is one of such approaches. Its effective use and applications reduces the project cost without compromising the project quality. Project cost, and efficient design alternatives can be identified using this technique, which will ultimately reduce the overall project cost. Client satisfaction, project reliability and quality can also be improved by the application of value engineering. It is also used for improving managerial performance, project schedule and reduced risks in a project. It is a powerful tool used to identify problems and recommend solutions. This paper highlights the importance of value engineering in general and with specific perspective of Construction Industry in Pakistan. Questionnaire based survey has been conducted by construction managers (i.e. project engineers, construction engineers, project managers, architects, etc.) through online web based system, as a result, random data sampling is achieved. The attributes are mapped to obtain goals for the project. The data has been analyzed through reliability and linear regression using SPSS while Z-Score and Average Index are conducted using MS Excel. The results showed that there is ample need to apply such techniques in initial phases of any project to get project benefits. (author)

  20. Cryostat design case studies, principles and engineering

    CERN Document Server

    2016-01-01

    This book enables the reader to learn the fundamental and applied aspects of practical cryostat design by examining previous design choices and resulting cryostat performance. Through a series of extended case studies the book presents an overview of existing cryostat design covering a wide range of cryostat types and applications, including the magnet cryostats that comprise the majority of the Large Hadron Collider at CERN, space-borne cryostats containing sensors operating below 1 K, and large cryogenic liquid storage vessels. It starts with an introductory section on the principles of cryostat design including practical data and equations. This section is followed by a series of case studies on existing cryostats, describing the specific requirements of the cryostat, the challenges involved and the design choices made along with the resulting performance of the cryostat. The cryostat examples used in the studies are chosen to cover a broad range of cryostat applications and the authors of each case are ...

  1. Assessing Bioinspired Topographies for their Antifouling Potential Control Using Computational Fluid Dynamics (CFD

    Directory of Open Access Journals (Sweden)

    Ling Jacky

    2018-01-01

    Full Text Available Biofouling is the accumulation of unwanted material on surfaces submerged or semi submerged over an extended period. This study investigates the antifouling performance of a new bioinspired topography design. A shark riblets inspired topography was designed with Solidworks and CFD simulations were antifouling performance. The study focuses on the fluid flow velocity, the wall shear stress and the appearance of vortices are to be noted to determine the possible locations biofouling would most probably occur. The inlet mass flow rate is 0.01 kgs-1 and a no-slip boundary condition was applied to the walls of the fluid domain. Simulations indicate that Velocity around the topography averaged at 7.213 x 10-3 ms-1. However, vortices were observed between the gaps. High wall shear stress is observed at the peak of each topography. In contrast, wall shear stress is significantly low at the bed of the topography. This suggests the potential location for the accumulation of biofouling. Results show that bioinspired antifouling topography can be improved by reducing the frequency of gaps between features. Linear surfaces on the topography should also be minimized. This increases the avenues of flow for the fluid, thus potentially increasing shear stresses with surrounding fluid leading to better antifouling performance.

  2. Filtration engineering study to upgrade the ETF

    International Nuclear Information System (INIS)

    McDonald, F.N.N.

    1995-01-01

    Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal

  3. Analytical Study of Component Based Software Engineering

    OpenAIRE

    Iqbaldeep Kaur; Parvinder S. Sandhu; Hardeep Singh; Vandana Saini

    2009-01-01

    This paper is a survey of current component-based software technologies and the description of promotion and inhibition factors in CBSE. The features that software components inherit are also discussed. Quality Assurance issues in componentbased software are also catered to. The feat research on the quality model of component based system starts with the study of what the components are, CBSE, its development life cycle and the pro & cons of CBSE. Various attributes are s...

  4. Engineering study for ISSTRS design concept

    Energy Technology Data Exchange (ETDEWEB)

    Hertzel, J.S.

    1997-01-31

    Los Alamos Technical Associates, Inc., is pleased to transmit the attached Conceptual Design Package for the Initial Single Shell Tank Retrieval System (ISSTRS), 90% Conceptual Design Review. The package includes the following: (1) ISSTRS Trade Studies: (a) Retrieval Facility Cooling Requirements; (b) Equipment Re-usability between Project W-320 and Tanks 241-C-103 and 241-C-1 05; (c) Sluice Line Options; and (d) Options for the Location of Tanks AX-103 and A-1 02 HVAC Equipment; (2) Drawings; (3) Risk Management Plan; (4) 0850 Interface Control Document; (5) Requirements Traceability Report; and (6) Project Design Specification.

  5. Mined salt storage feasibility: Engineering study report

    International Nuclear Information System (INIS)

    1987-07-01

    This study addresses a method of eliminating the surface storage of mined salt at the Deaf Smith repository site. It provides rough estimates of the logistics and costs of transporting 3.7 million tons of salt from the repository to the salt disposal site near Carlsbad, New Mexico and returning it to the repository for decommissioning backfill. The study assumes that a railcar/truck system will be installed and that the excavated salt will be transported from the repository to an existing potash mine located near Carlsbad, New Mexico approximately 300 miles from the repository. The 3.7 million tons of salt required for repository decommissioning backfill can be stored in the potash mines along with the excess salt, with no additional capital costs required for either a railcar or a truck transportation system. The capital cost for facilities to reclaim the 3.7 million tons of salt from the potash mine is estimated to be $4,400,000 with either a rail or truck transportation system. Segregating the 3.7 million tons of backfill salt in a surface storage area at the potash mine requires a capital cost of $13,900,000 with a rail system or $11,400,000 with a truck system. Transportation costs are estimated at $0.08/ton-mile for rail and $0.13/ton-mile for truck. 2 figs., 5 tabs

  6. Gas barrier properties of bio-inspired Laponite-LC polymer hybrid films.

    Science.gov (United States)

    Tritschler, Ulrich; Zlotnikov, Igor; Fratzl, Peter; Schlaad, Helmut; Grüner, Simon; Cölfen, Helmut

    2016-05-26

    Bio-inspired Laponite (clay)-liquid crystal (LC) polymer composite materials with high clay fractions (>80%) and a high level of orientation of the clay platelets, i.e. with structural features similar to the ones found in natural nacre, have been shown to exhibit a promising behavior in the context of reduced oxygen transmission. Key characteristics of these bio-inspired composite materials are their high inorganic content, high level of exfoliation and orientation of the clay platelets, and the use of a LC polymer forming the organic matrix in between the Laponite particles. Each single feature may be beneficial to increase the materials gas barrier property rendering this composite a promising system with advantageous barrier capacities. In this detailed study, Laponite/LC polymer composite coatings with different clay loadings were investigated regarding their oxygen transmission rate. The obtained gas barrier performance was linked to the quality, respective Laponite content and the underlying composite micro- and nanostructure of the coatings. Most efficient oxygen barrier properties were observed for composite coatings with 83% Laponite loading that exhibit a structure similar to sheet-like nacre. Further on, advantageous mechanical properties of these Laponite/LC polymer composites reported previously give rise to a multifunctional composite system.

  7. A Study Of Internet Search Engines Usage By Undergraduate ...

    African Journals Online (AJOL)

    The purpose of this study is to investigate students' ability to use different Internet search engines (ISEs) in Universities in the Niger Delta Region of Nigeria. To reveal the types of ISEs used, and identify the source through which students acquire the skills. The study adopted a descriptive survey method. Questionnaire and ...

  8. On the Pragmatic Design of Literature Studies in Software Engineering

    DEFF Research Database (Denmark)

    Kuhrmann, Marco; Méndez Fernández, Daniel; Daneva, Maya

    2017-01-01

    Systematic literature studies have received much attention in empirical software engineering in recent years. They have become a powerful tool to collect and structure reported knowledge in a systematic and reproducible way. We distinguish systematic literature reviews to systematically analyze...... reported evidence in depth, and systematic mapping studies to structure a field of interest in a broader, usually quantified manner. Due to the rapidly increasing body of knowledge in software engineering, researchers who want to capture the published work in a domain often face an extensive amount...

  9. Engineering Lipid Bilayer Membranes for Protein Studies

    Science.gov (United States)

    Khan, Muhammad Shuja; Dosoky, Noura Sayed; Williams, John Dalton

    2013-01-01

    Lipid membranes regulate the flow of nutrients and communication signaling between cells and protect the sub-cellular structures. Recent attempts to fabricate artificial systems using nanostructures that mimic the physiological properties of natural lipid bilayer membranes (LBM) fused with transmembrane proteins have helped demonstrate the importance of temperature, pH, ionic strength, adsorption behavior, conformational reorientation and surface density in cellular membranes which all affect the incorporation of proteins on solid surfaces. Much of this work is performed on artificial templates made of polymer sponges or porous materials based on alumina, mica, and porous silicon (PSi) surfaces. For example, porous silicon materials have high biocompatibility, biodegradability, and photoluminescence, which allow them to be used both as a support structure for lipid bilayers or a template to measure the electrochemical functionality of living cells grown over the surface as in vivo. The variety of these media, coupled with the complex physiological conditions present in living systems, warrant a summary and prospectus detailing which artificial systems provide the most promise for different biological conditions. This study summarizes the use of electrochemical impedance spectroscopy (EIS) data on artificial biological membranes that are closely matched with previously published biological systems using both black lipid membrane and patch clamp techniques. PMID:24185908

  10. Fluid design studies of integrated modular engine system

    Science.gov (United States)

    Frankenfield, Bruce; Carek, Jerry

    1993-01-01

    A study was performed to develop a fluid system design and show the feasibility of constructing an integrated modular engine (IME) configuration, using an expander cycle engine. The primary design goal of the IME configuration was to improve the propulsion system reliability. The IME fluid system was designed as a single fault tolerant system, while minimizing the required fluid components. This study addresses the design of the high pressure manifolds, turbopumps and thrust chambers for the IME configuration. A physical layout drawing was made, which located each of the fluid system components, manifolds and thrust chambers. Finally, a comparison was made between the fluid system designs of an IME system and a non-network (clustered) engine system.

  11. Web Search Studies: Multidisciplinary Perspectives on Web Search Engines

    Science.gov (United States)

    Zimmer, Michael

    Perhaps the most significant tool of our internet age is the web search engine, providing a powerful interface for accessing the vast amount of information available on the world wide web and beyond. While still in its infancy compared to the knowledge tools that precede it - such as the dictionary or encyclopedia - the impact of web search engines on society and culture has already received considerable attention from a variety of academic disciplines and perspectives. This article aims to organize a meta-discipline of “web search studies,” centered around a nucleus of major research on web search engines from five key perspectives: technical foundations and evaluations; transaction log analyses; user studies; political, ethical, and cultural critiques; and legal and policy analyses.

  12. A phenomenographic study of students' experiences with transition from pre-college engineering programs to first-year engineering

    Science.gov (United States)

    Salzman, Noah

    Recent national dialogues on the importance of preparing more students for careers in Science, Technology, Engineering, and Mathematics has driven the development of formal and informal learning opportunities for children and adolescents to explore engineering. Despite the growth of these programs, relatively little research exists on how participation in these programs affects students who choose to pursue further study in engineering. The present study addressed this gap through an exploration of the different ways that First-Year Engineering students experience the transition from pre-college engineering to undergraduate engineering studies. Given the focus of this research on students' experiences, phenomenography was chosen to explore the phenomenon of transition from pre-college to first-year engineering at a large, public Midwestern university. This facilitated understanding the range of variation in the ways that students experienced this transition. Twenty-two students with different amounts of participation in a variety of different engineering programs were selected to be interviewed using a purposeful maximum variation sampling strategy. The interviews were guided by a semi-structured interview protocol that encouraged the participants to reflect on their pre-college engineering experiences, their experiences in First-Year Engineering, and the transition between the two domains. The interviews were analyzed using phenomenographic methods to develop an outcome space consisting of five qualitatively different but related ways of experiencing the transition from pre-college to First-Year Engineering. These categories of description included Foreclosure, Frustration, Tedium, Connection, and Engaging Others. With the exception of the first category which was characterized by a lack of passion and commitment to engineering, the remaining four categories formed a hierarchical relationship representing increasing integration in First-Year Engineering. The

  13. Mechatronics and Bioinspiration in Actuator Design and Control

    Directory of Open Access Journals (Sweden)

    J. L. Pons

    2008-01-01

    Full Text Available Actuators are components of motion control systems in which mechatronics plays a crucial role. They can be regarded as a paradigmatic case in which this mechatronic approach is required. Furthermore, actuator technologies can get new sources of inspiration from nature (bioinspiration. Biological systems are the result of an evolutionary process and show excellent levels of performance. In this paper, we analyse the actuator as a bioinspired mechatronic system through analogies between mechatronics and biological actuating mechanisms that include hierarchical control of actuators, switched control of power flow and some transduction principles. Firstly, some biological models are introduced as a source of inspiration for setting up both actuation principles and control technologies. Secondly, a particular actuator technology, the travelling wave ultrasonic motor, is taken to illustrate this approach. Eventually, the last section draws some conclusions and points out future directions.

  14. Engine Power Turbine and Propulsion Pod Arrangement Study

    Science.gov (United States)

    Robuck, Mark; Zhang, Yiyi

    2014-01-01

    A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing

  15. Bio-inspired Self-Adaptive Agents in Distributed Systems

    OpenAIRE

    Ichiro SATOH

    2013-01-01

    This paper proposes a bio-inspired middleware for selfadaptive software agents on distributed systems. It is unique to other existing approaches for software adaptation because it introduces the notions of differentiation, dedifferentiation, and cellular division in cellular slime molds, e.g., dictyostelium discoideum, into real distributed systems. When an agent delegates a function to another agent coordinating with it, if the former has the function, this function becomes lessdeveloped ...

  16. Bio-Inspired Distributed Decision Algorithms for Anomaly Detection

    Science.gov (United States)

    2017-03-01

    which purposefully and maliciously masquerade as ‘normal network behavior.’ Social insects in the natural world routinely need to make classification...thereby reduce the collateral damage to minimum. 4.1.4 Minimal and Marginal Deployment Gain. Deployment of networked services across administrative ...BIO-INSPIRED DISTRIBUTED DECISION ALGORITHMS FOR ANOMALY DETECTION RUTGERS UNIVERSITY MARCH 2017 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC

  17. Experimental studies of the air hybrid engine charging operation

    OpenAIRE

    Zhao, H; Ma, T; Lee, CY

    2014-01-01

    Over the last few years, theoretical and modelling studies have been carried out on the feasibility and potential of novel mild air hybrid engine concepts based on production components. These mild air hybrid concepts are able to convert vehicle brake energy into pneumatic energy in the form of compressed air stored in the air tank. The compressed air can then be used to crank-start the engine by either injecting and expanding in the cylinder or driving a production air starter. Thus, the reg...

  18. The experiences of women engineers who have completed one to five years of professional engineering employment: A phenomenological study

    Science.gov (United States)

    White, Susan M.

    Women engineers remain underrepresented in employment in engineering fields in the United States. Feminist theory views this gender disparity beyond equity in numbers for women engineers and looks at structural issues of women's access, opportunities, and quality of experience in the workplace. Research on women's success and persistence in engineering education is diverse; however, there are few studies that focus on the early years of women's careers in engineering and less using a phenomenological research design. Experiences of women engineers who have completed one to five years of professional engineering employment are presented using a phenomenological research design. Research questions explored the individual and composite experiences for the co-researchers of the study as well as challenges and advantages of the phenomenon of having completed one to five years of professional engineering employment. Themes that emanated from the data were a feeling that engineering is a positive profession, liking math and science from an early age, having experiences of attending math and science camps or learning and practicing engineering interests with their fathers for some co-researchers. Other themes included a feeling of being different as a woman in the engineering workplace, taking advantage of opportunities for training, education, and advancement to further their careers, and the role of informal and formal mentoring in developing workplace networks and engineering expertise. Co-researchers negotiated issues of management quality and support, experiences of gender discrimination in the workplace, and having to make decisions balancing their careers and family responsibilities. Finally, the women engineers for this research study expressed intentions to persist in their careers while pursuing expertise and experience in their individual engineering fields.

  19. Breathing Life into Engineering: A Lesson Study Life Science Lesson

    Science.gov (United States)

    Lawrence, Maria; Yang, Li-Ling; Briggs, May; Hession, Alicia; Koussa, Anita; Wagoner, Lisa

    2016-01-01

    A fifth grade life science lesson was implemented through a lesson study approach in two fifth grade classrooms. The research lesson was designed by a team of four elementary school teachers with the goal of emphasizing engineering practices consistent with the "Next Generation Science Standards" (NGSS) (Achieve Inc. 2013). The fifth…

  20. Engineering study for closure of 209E facility

    International Nuclear Information System (INIS)

    Brevick, C.H.; Heys, W.H.; Johnson, E.D.

    1997-01-01

    This document is an engineering study for evaluating alternatives to determine the most cost effective closure plan for the 209E Facility, Critical Mass Laboratory. This laboratory is located in the 200 East Area of the Hanford Site and contains a Critical Assembly Room and a Mix room were criticality experiments were once performed

  1. Elements of Motivational Structure for Studying Mechanical Engineering

    Science.gov (United States)

    Dubreta, Nikša; Miloš, Damir

    2017-01-01

    The article presents the findings on students' reasons for studying mechanical engineering. These reasons were covered in terms of extrinsic and intrinsic motivation additionally related to selected independent variables of the sample--students' secondary school Grade Point Average, their gender and the socio-economic status. The research was…

  2. Evaluating Risk Awareness in Undergraduate Students Studying Mechanical Engineering

    Science.gov (United States)

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

    2010-01-01

    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…

  3. Engineering study for closure of 209E facility

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.; Heys, W.H.; Johnson, E.D.

    1997-07-07

    This document is an engineering study for evaluating alternatives to determine the most cost effective closure plan for the 209E Facility, Critical Mass Laboratory. This laboratory is located in the 200 East Area of the Hanford Site and contains a Critical Assembly Room and a Mix room were criticality experiments were once performed.

  4. A Study on Semantic Searching, Semantic Search Engines and Technologies Used for Semantic Search Engines

    OpenAIRE

    Junaid Rashid; Muhammad Wasif Nisar

    2016-01-01

    Semantic search engines(SSE) are more efficient than other web engines because in this era of busy life everyone wants an exact answer to his question which only semantic engines can provide. The immense increase in the volume of data, traditional search engines has increased the number of answers to satisfy the user. This creates the problem to search for the desired answer. To solve this problem, the trend of developing semantic search engines is increasing day by da...

  5. Review of marine animals and bioinspired robotic vehicles: Classifications and characteristics

    Science.gov (United States)

    Zimmerman, S.; Abdelkefi, A.

    2017-08-01

    Marine robots are a developing topic for military, scientific, and environmental missions. However, most existing marine robots are either limited to flight or limited to swimming. Therefore, the combination of both provides endless possibilities for tasks, such as espionage, pollution and marine wildlife surveillance, and border protection. Applying bioinspiration and biomimetics not only camouflages the robot, but also increases the efficiency of already perfected designs. Because bioinspiration and aerial-aquatic locomotion are the main attraction for this article, this review gathers the characteristics of aerial-aquatic animals useful for such designs. These animals are diving birds and flying fish, specifically plunge-diving birds, surface-diving birds, both plunge- and surface-diving birds, two-winger flying fish, and four-winger flying fish. The overview of the current marine bioinspired and non-bioinspired robots that are both aerial and aquatic are also presented, followed by the limitations and recommendations of the bioinspired robots. It is shown by a comparison between the bioinspired robot and its corresponding animal that the existing robotic systems are not truly bioinspired. The main traits these systems are missing are replicating the exact weight, size, muscle movement, and skin texture of the biological animal. In order to have efficient robots, bioinspiration needs to be perfected. Doing so requires not only the basic design to be replicated, but every detail of the system to be imitated.

  6. Conceptual study of advanced VTOL transport aircraft engine; Kosoku VTOL kiyo engine no gainen kento

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y.; Endo, M.; Matsuda, Y.; Sugiyama, N.; Watanabe, M.; Sugahara, N.; Yamamoto, K. [National Aerospace Laboratory, Tokyo (Japan)

    1996-04-01

    This report proposes the concept of an ultra-low noise engine for advanced high subsonic VTOL transport aircraft, and discusses its technological feasibility. As one of the applications of the previously reported `separated core turbofan engine,` the conceptual engine is composed of 3 core engines, 2 cruise fan engines for high subsonic cruising and 6 lift fan engines producing thrust of 98kN (10000kgf)/engine. The core turbojet engine bleeds a large amount of air at the outlet of a compressor to supply driving high-pressure air for fans to other engines. The lift fan engine is composed of a lift fan, driving combustor, turbine and speed reduction gear, and is featured by not only high operation stability and thin fan engine like a separated core engine but also ultra-low noise operation. The cruise fan engine adopts the same configuration as the lift fan engine. Since this engine configuration has no technological problems difficult to be overcome, its high technological feasibility is expected. 6 refs., 7 figs., 5 tabs.

  7. Study of occupational stress among railway engine pilots

    Science.gov (United States)

    Kumar, Devesh; Singh, Jai Vir; Kharwar, Poonam S.

    2011-01-01

    Background: Traffic volume and speed is going to be increased in Indian Railways successively, leading to higher stress in staff connected with train operations. The jobs of railway engine pilots come under the category of high-strain jobs, necessitating a need to conduct multicentric study to unfold the factors associated with occupational stress and organizational strategies. Materials and Methods: Present study covered 185 railway engine pilots and office clerks working in various railway zones by incidental method. Occupational Stress Index (OSI) test developed by Srivastva and Singh, questionnaire of specific stressors constructed by authors and laboratory test battery for psychological screening of high-speed train pilots were used as tools. Results: Means of OSI and all the 12 occupational stressors of railway engine pilots were found significantly higher to that of office clerks. Means of OSI and occupational stressors of goods train pilots were significantly higher in comparison to high-speed train pilots and passenger train pilots. Study revealed positive correlation of speed perception and complex reaction time tests and negative correlation of other constituent tests of laboratory test battery to OSI test. Highest subgroup of stressor observedwas role overload followed by role conflict. Conclusions: These findings provide a prima facie evidence of higher occupational stress among railway engine pilots because of identified specific stressors prevalent in their job and explore the possible intervention strategies for its reduction. Significant correlation is noticed between OSI and laboratory test results, indicating its relevant utility in preliminary psychological screening. PMID:21808497

  8. Antimisting kerosene JT3 engine fuel system integration study

    Science.gov (United States)

    Fiorentino, A.

    1987-01-01

    An analytical study and laboratory tests were conducted to assist NASA in determining the safety and mission suitability of the modified fuel system and flight tests for the Full-Scale Transport Controlled Impact Demonstration (CID) program. This twelve-month study reviewed and analyzed both the use of antimisting kerosene (AMK) fuel and the incorporation of a fuel degrader on the operational and performance characteristics of the engines tested. Potential deficiencies and/or failures were identified and approaches to accommodate these deficiencies were recommended to NASA Ames -Dryden Flight Research Facility. The result of flow characterization tests on degraded AMK fuel samples indicated levels of degradation satisfactory for the planned missions of the B-720 aircraft. The operability and performance with the AMK in a ground test engine and in the aircraft engines during the test flights were comparable to those with unmodified Jet A. For the final CID test, the JT-3C-7 engines performed satisfactorily while operating on AMK right up to impact.

  9. Reverse Engineering of Gene Regulatory Networks: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Hendrik Hache

    2009-01-01

    Full Text Available Reverse engineering of gene regulatory networks has been an intensively studied topic in bioinformatics since it constitutes an intermediate step from explorative to causative gene expression analysis. Many methods have been proposed through recent years leading to a wide range of mathematical approaches. In practice, different mathematical approaches will generate different resulting network structures, thus, it is very important for users to assess the performance of these algorithms. We have conducted a comparative study with six different reverse engineering methods, including relevance networks, neural networks, and Bayesian networks. Our approach consists of the generation of defined benchmark data, the analysis of these data with the different methods, and the assessment of algorithmic performances by statistical analyses. Performance was judged by network size and noise levels. The results of the comparative study highlight the neural network approach as best performing method among those under study.

  10. A Review of Natural Joint Systems and Numerical Investigation of Bio-Inspired GFRP-to-Steel Joints

    Directory of Open Access Journals (Sweden)

    Evangelos I. Avgoulas

    2016-07-01

    Full Text Available There are a great variety of joint types used in nature which can inspire engineering joints. In order to design such biomimetic joints, it is at first important to understand how biological joints work. A comprehensive literature review, considering natural joints from a mechanical point of view, was undertaken. This was used to develop a taxonomy based on the different methods/functions that nature successfully uses to attach dissimilar tissues. One of the key methods that nature uses to join dissimilar materials is a transitional zone of stiffness at the insertion site. This method was used to propose bio-inspired solutions with a transitional zone of stiffness at the joint site for several glass fibre reinforced plastic (GFRP to steel adhesively bonded joint configurations. The transition zone was used to reduce the material stiffness mismatch of the joint parts. A numerical finite element model was used to identify the optimum variation in material stiffness that minimises potential failure of the joint. The best bio-inspired joints showed a 118% increase of joint strength compared to the standard joints.

  11. Engineering education research: Impacts of an international network of female engineers on the persistence of Liberian undergraduate women studying engineering

    Science.gov (United States)

    Rimer, Sara; Reddivari, Sahithya; Cotel, Aline

    2015-11-01

    As international efforts to educate and empower women continue to rise, engineering educators are in a unique position to be a part of these efforts by encouraging and supporting women across the world at the university level through STEM education and outreach. For the past two years, the University of Michigan has been a part of a grassroots effort to encourage and support the persistence of engineering female students at University of Liberia. This effort has led to the implementation of a leadership camp this past August for Liberian engineering undergraduate women, meant to: (i) to empower engineering students with the skills, support, and inspiration necessary to become successful and well-rounded engineering professionals in a global engineering market; and (ii) to strengthen the community of Liberian female engineers by building cross-cultural partnerships among students resulting in a international network of women engineers. This session will present qualitative research findings on the impact of this grassroots effort on Liberian female students? persistence in engineering, and the future directions of this work.

  12. Study on the morals of nuclear power engineers

    International Nuclear Information System (INIS)

    Kosaka, Takashi; Kotani, Fumio; Morikawa, Shin'ichi; Hiramoto, Mitsuru; Koya, Masahiko

    2000-01-01

    Regarding the incident that occurred in October 1998 in which records of containers for transporting spent fuel were altered, the morals of engineers was pointed out as one reason for the problem. Since then, much effort has been exerted to prevent the re-occurrence of such an incident and to reform the corporate climate at electric power companies. From an objective point of view the Institute of Nuclear Safety Systems, inc., the Institute of Social Research conducted an analysis regarding of the conditions faced by that engineers are faced with and discussing how the engineers should deal with the issue of morals as professionals under such circumstances. In this research, teaching materials were compiled, such as a checklist and examples of case studies, to be used for morals education/training and others. This will be useful for engineers who are working for an organization and are in a number of complicated relationships, in dealing with a wide variety of moral issues in their day-to-day activities. (author)

  13. Bio-inspired synthesis and characterization of superparamagnetic particles; Sintese e caracterizacao bioinspirada de particulas superparamagneticas

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Vinicius F., E-mail: vfc_mg@yahoo.com.br [Universidade Federal de Itajuba (UNIFEI), MG (Brazil); Queiroz, Alvaro A.A. [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Centro de Estudos e Inovacao em Materiais Biofuncionais Avancados

    2012-08-15

    This paper discusses the bio-inspired synthesis of type YFeAl ferrites encapsulated into polyglycerol dendrimers (PGLD) generation 3. The structure and morphological properties of the system YFeAl/PGLD was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The magnetic properties were studied through the techniques of Moessbauer spectroscopy and magnetization. The cytotoxicity of the nanoparticles encapsulated in dendrimers PGLD G3 at the cell membrane was studied against mammalian cell line CHO.K1 measuring the amount of lactate dehydrogenase (LDH) released by the cell damage. Microscopy TEM and XRD analysis indicate that spherical nanoparticles were obtained highly crystalline and monodisperse with size 20 nmstudy of magnetization of the nanoparticles compared to a magnetic field indicated superparamagnetic behavior of the system YFeAl/PGLD. The cytotoxicity results indicated that YFeAl / PGLD nano system is suitable for use in nano medicine. (author)

  14. Natural and bio-inspired underwater adhesives: Current progress and new perspectives

    Science.gov (United States)

    Cui, Mengkui; Ren, Susu; Wei, Shicao; Sun, Chengjun; Zhong, Chao

    2017-11-01

    Many marine organisms harness diverse protein molecules as underwater adhesives to achieve strong and robust interfacial adhesion under dynamic and turbulent environments. Natural underwater adhesion phenomena thus provide inspiration for engineering adhesive materials that can perform in water or high-moisture settings for biomedical and industrial applications. Here we review examples of biological adhesives to show the molecular features of natural adhesives and discuss how such knowledge serves as a heuristic guideline for the rational design of biologically inspired underwater adhesives. In view of future bio-inspired research, we propose several potential opportunities, either in improving upon current L-3, 4-dihydroxyphenylalanine-based and coacervates-enabled adhesives with new features or engineering conceptually new types of adhesives that recapitulate important characteristics of biological adhesives. We underline the importance of viewing natural adhesives as dynamic materials, which owe their outstanding performance to the cellular coordination of protein expression, delivery, deposition, assembly, and curing of corresponding components with spatiotemporal control. We envision that the emerging synthetic biology techniques will provide great opportunities for advancing both fundamental and application aspects of underwater adhesives.

  15. Bioinspired fabrication and characterization of a synthetic fish skin for the protection of soft materials.

    Science.gov (United States)

    Funk, Natasha; Vera, Marc; Szewciw, Lawrence J; Barthelat, Francois; Stoykovich, Mark P; Vernerey, Franck J

    2015-03-18

    The scaled skin of fish is a high-performance natural armor that represents a source of inspiration for novel engineering designs. In this paper, we present a biomimetic fish skin material, fabricated with a design and components that are simple, that achieves many of the advantageous attributes of natural materials, including the unique combination of flexibility and mechanical robustness. The bioinspired fish skin material is designed to replicate the structural, mechanical, and functional aspects of a natural teleost fish skin comprised of leptoid-like scales, similar to that of the striped red mullet Mullus surmuletus. The man-made fish skin material consists of a low-modulus elastic mesh or "dermis" layer that holds rigid, plastic scales. The mechanics of the synthetic material is characterized under in-plane, bending, and indentation modes of deformation and is successfully described by theoretical deformation models that have been developed. This combined experimental and modeling approach elucidates the critical mechanisms by which the composite material achieves its unique properties and provides design rules that allow for the engineering of scaled skins. Such artificial scaled skins that are flexible, lightweight, transparent, and robust under mechanical deformation may thus have potential as thin protective coatings for soft materials.

  16. A Wireless Fatigue Monitoring System Utilizing a Bio-Inspired Tree Ring Data Tracking Technique

    Directory of Open Access Journals (Sweden)

    Shi Bai

    2014-03-01

    Full Text Available Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

  17. A wireless fatigue monitoring system utilizing a bio-inspired tree ring data tracking technique.

    Science.gov (United States)

    Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

    2014-03-05

    Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC) method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP) is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF) sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

  18. Study of hydrogeological and engineering-geological conditions of deposits

    International Nuclear Information System (INIS)

    1985-01-01

    Methods for hydrogeological and engineering-geological studies are considered as a part of the complex works dUring eXploration of hydrogenic uranium deposits to develop them by Underground ieaching (UL). Problems are enumerated and peculiarities Of hydrogeologic and engipeering-geological works at different stages are outlined (prospeccing - evaluating works, preliminary and detailed survey). Attention is paid to boring and equipment for hydrogeological and engineering - geological boreholes. Testing-filtering works are described, the latter includes: evacuations, fulnesses ( forcings), and tests of fulness-evacuation. The problem on steady-state observations in boreholes and laboratory studies of rocks and underground waters is discussed. Geological and geophysical methods for evaluation of rock and ore filtering properties are presented. Necessity of hydrogeological zonation of deposits as applied to UL is marked

  19. Separation of organic ion exchange resins from sludge -- engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.

    1998-08-25

    This engineering study evaluates the use of physical separation technologies to separate organic ion exchange resin from KE Basin sludge prior to nitric acid dissolution. This separation is necessitate to prevent nitration of the organics in the acid dissolver. The technologies under consideration are: screening, sedimentation, elutriation. The recommended approach is to first screen the Sludge and resin 300 microns then subject the 300 microns plus material to elutriation.

  20. Visual study of capabilities of managing IC engine filling degree vs engine ecological indicators

    Science.gov (United States)

    Kołodziej, Szymon; Ligus, Grzegorz

    2017-10-01

    The operation of an internal combustion engine in a transient state is related to constant changes in cylinder filling degree. Managing a steady course of engine torque demands constant corrections in the volume of air delivered to the engine. In this work, different engine throttle management strategies were analyzed. The effect of throttle velocity on emissions was depicted. The research has shown that the greatest value of work density is reached by the IC engine for relatively low values of throttle angle. For shown values, disturbances in air flow in engine intake which may adversely affect emissions due to uneven cylinder filling were researched with the use of Digital Particle Image Velocimetry. The conducted research has shown significant unevennes in air supply to individual cylinders in the engine. This effect may cause discrepancies in air excess ratio for each cylinder, and result in heightened harmful substance emission.

  1. Biophysiochemical properties of endothelial cells cultured on bio-inspired collagen films.

    Science.gov (United States)

    Seo, Eunseok; Seo, Kyung Won; Gil, Jung-Eun; Ha, Young-Ran; Yeom, Eunseop; Lee, Seungchul; Lee, Sang Joon

    2014-07-02

    In this study, we investigated the effect of the extracellular matrix on endothelial dysfunction by careful observation of human umbilical vein endothelial cells (HUVECs) cultured on denatured collagen film. HUVECs on denatured collagen film showed relatively high surface roughness compared with normal HUVECs. The expression levels of MMP-1, MMP-2 and CD146 increased in the ECs on denatured collagen film. In addition, we examined the accumulation of fluorescent beads on HUVEC layers subjected to circulatory flow. The number of accumulated fluorescent beads increased on the disorganized HUVEC layers. The proposed in vitro study using bio-inspired collagen films could potentially be used in the size- and ligand-based design of drugs to treat endothelial dysfunction caused by circulatory vascular diseases.

  2. Consolidated View on Space Software Engineering Problems - An Empirical Study

    Science.gov (United States)

    Silva, N.; Vieira, M.; Ricci, D.; Cotroneo, D.

    2015-09-01

    Independent software verification and validation (ISVV) has been a key process for engineering quality assessment for decades, and is considered in several international standards. The “European Space Agency (ESA) ISVV Guide” is used for the European Space market to drive the ISVV tasks and plans, and to select applicable tasks and techniques. Software artefacts have room for improvement due to the amount if issues found during ISVV tasks. This article presents the analysis of the results of a large set of ISVV issues originated from three different ESA missions-amounting to more than 1000 issues. The study presents the main types, triggers and impacts related to the ISVV issues found and sets the path for a global software engineering improvement based on the most common deficiencies identified for space projects.

  3. Promoting Active Learning in Electrical Engineering Basic Studies

    Directory of Open Access Journals (Sweden)

    Anu Lehtovuori

    2013-05-01

    Full Text Available Active learning, project-based teaching, and student collaboration are current trends in engineering education. Incorporating these have also been the goal of the basic studies development project EPOP started at the Aalto University School of Electrical Engineering in 2011. In the project, two obligatory basic courses in circuit analysis and electromagnetic field theory have been taught using interactive engagement during the spring of 2012. This paper presents the implementation of the teaching, including methods and evaluation with several concrete examples. As a result of the novel teaching, motivation and the engagement of students were at a high level during the whole course and learning results were better than those of the students participating the traditional lecture course.

  4. Energy Efficient Engine program advanced turbofan nacelle definition study

    Science.gov (United States)

    Howe, David C.; Wynosky, T. A.

    1985-01-01

    Advanced, low drag, nacelle configurations were defined for some of the more promising propulsion systems identified in the earlier Benefit/Cost Study, to assess the benefits associated with these advanced technology nacelles and formulate programs for developing these nacelles and low volume thrust reversers/spoilers to a state of technology readiness in the early 1990's. The study results established the design feasibility of advanced technology, slim line nacelles applicable to advanced technology, high bypass ratio turbofan engines. Design feasibility was also established for two low volume thrust reverse/spoiler concepts that meet or exceed the required effectiveness for these engines. These nacelle and thrust reverse/spoiler designs were shown to be applicable in engines with takeoff thrust sizes ranging from 24,000 to 60,000 pounds. The reduced weight, drag, and cost of the advanced technology nacelle installations relative to current technology nacelles offer a mission fuel burn savings ranging from 3.0 to 4.5 percent and direct operating cost plus interest improvements from 1.6 to 2.2 percent.

  5. Introducing Knowledge Management in Study Program of Nuclear Engineering

    International Nuclear Information System (INIS)

    Pleslic, S.

    2012-01-01

    Nuclear engineering is the branch of engineering concerning application of the fission as well as the fusion of atomic nuclei, and the application of other sub-atomic physics, based on the principles of nuclear physics. In the sub-field of nuclear fission there are many investigations of interactions and maintaining of systems and components like nuclear reactors and nuclear power plants. The field also includes the study of different applications of ionizing radiation (medicine, agriculture...), nuclear safety, the problems of thermodynamics transport, nuclear materials and nuclear fuels, and other related technologies like radioactive waste management. In the area of nuclear science and engineering a big amount of knowledge has been accumulated over the last decades. Different levels of nuclear knowledge were considered in different ways and they were taught to different parts of population as a general human culture and as a general scientific-technical-technological culture (high schools, nuclear information centres, training centres, universities...). An advanced level of nuclear knowledge has been accumulated by many experienced workers, specialists and experts in all nuclear and nuclear-related fields and applications. In the last 20 years knowledge management has established itself as a discipline of enabling individuals, teams and whole organizations to create, share and apply knowledge collectively and systematically, with goal to better achieve their objectives. Also, knowledge management became key strategic approach for management of intellectual assets and knowledge that can improve safety, efficiency and innovation, and lead to preserve and enhance current knowledge. Knowledge management could be applied in education, training, networking, human resource development and capacity building, sharing, pooling and transferring knowledge form centres of knowledge to centres of growth. Considering the critical importance of nuclear knowledge it is important

  6. Design studies of lift fan engines suitable for use in civilian VTOL aircraft.

    Science.gov (United States)

    Roelke, R. J.; Zigan, S.

    1972-01-01

    Preliminary engine design studies have been made of two general types of low-pressure-ratio lift fan engines that are receiving increasing attention as a means to provide low-speed lift for large civilian VTOL transports. The two engine types are integral fans and remote powered fans. A portion of the results of these design studies is summarized, including the crucial engine requirements, and some of the characteristics of the emerging engine designs of each type.

  7. Women withdrawers in engineering studies : identity formation and learning culture as gendered barriers for persistence?

    OpenAIRE

    Wolffram, Andrea; Derboven, Wibke; Winker, Gabriele

    2009-01-01

    Scholarship on women in engineering education mainly focuses on the question of how to attract more women to this subject. The topic concerning women in engineering education is here guided by the question of why women leave engineering studies. The paper aims to examine the main conflicts women encounter in engineering education and to derive implications for interventions suited for strengthening institutional bonding forces.

  8. The preparation of Nepenthes Bio-inspired superhydrophobic surface primary microstructure

    Science.gov (United States)

    Lin, Jieqiong; Ma, Mingwei; Jing, Xian

    2017-12-01

    4Wetting phenomenon is an important phenomenon in nature, and it is related to our daily life closely. Therefore, it is of great practical significance to study wettability surface. Recently, based on the observation and measurement of Nepenthes surface, we realized the liquid or insects will roll down from the surface almost without resistance resulted from the lunate-shaped microstructure and its composite microstructure, which can make the surface possess superhydrophobic properties. Nepenthes Bio-inspired superhydrophobic primary microstructure was fabricated by the two-photon polymerization using femtosecond laser and characterized by developering are still stable after washing observed by Zygo. The lunate are still intact after washing, so the character of hydrophobicity can be maintained. We demonstrate that our approach provide a novel way to fabricate such primary microstructures on the glass using femtosecond laser two-photon polymerization for practical applications in related area. 97714025@qq.com

  9. Geometric mechanics for modelling bioinspired robots locomotion: from rigid to continuous (soft) systems

    Science.gov (United States)

    Boyer, Frederic; Porez, Mathieu; Renda, Federico

    This talk presents recent geometric tools developed to model the locomotion dynamics of bio-inspired robots. Starting from the model of discrete rigid multibody systems we will rapidly shift to the case of continuous systems inspired from snakes and fish. To that end, we will build on the model of Cosserat media. This extended picture of geometric locomotion dynamics (inspired from fields' theory) will allow us to introduce models of swimming recently used in biorobotics. We will show how modeling a fish as a one-dimensional Cosserat medium allows to recover and extend the Large Amplitude Elongated Body theory of J. Lighthill and to apply it to an eel-like robot. In the same vein, modeling the mantle of cephalopods as a two dimensional Cosserat medium will build a basis for studying the jet propelling of a soft octopus like robot.

  10. A bio-inspired approach for the reduction of left ventricular workload.

    Directory of Open Access Journals (Sweden)

    Niema M Pahlevan

    Full Text Available Previous studies have demonstrated the existence of optimization criteria in the design and development of mammalians cardiovascular systems. Similarities in mammalian arterial wave reflection suggest there are certain design criteria for the optimization of arterial wave dynamics. Inspired by these natural optimization criteria, we investigated the feasibility of optimizing the aortic waves by modifying wave reflection sites. A hydraulic model that has physical and dynamical properties similar to a human aorta and left ventricle was used for a series of in-vitro experiments. The results indicate that placing an artificial reflection site (a ring at a specific location along the aorta may create a constructive wave dynamic that could reduce LV pulsatile workload. This simple bio-inspired approach may have important implications for the future of treatment strategies for diseased aorta.

  11. Bioinspired self-healing of advanced composite structures using hollow glass fibres.

    Science.gov (United States)

    Trask, R S; Williams, G J; Bond, I P

    2007-04-22

    Self-healing is receiving an increasing amount of worldwide interest as a method to autonomously address damage in materials. The incorporation of a self-healing capability within fibre-reinforced polymers has been investigated by a number of workers previously. The use of functional repair components stored inside hollow glass fibres (HGF) is one such bioinspired approach being considered. This paper considers the placement of self-healing HGF plies within both glass fibre/epoxy and carbon fibre/epoxy laminates to mitigate damage occurrence and restore mechanical strength. The study investigates the effect of embedded HGF on the host laminates mechanical properties and also the healing efficiency of the laminates after they were subjected to quasi-static impact damage. The results of flexural testing have shown that a significant fraction of flexural strength can be restored by the self-repairing effect of a healing resin stored within hollow fibres.

  12. Microneedle, bio-microneedle and bio-inspired microneedle: A review.

    Science.gov (United States)

    Ma, Guojun; Wu, Chengwei

    2017-04-10

    Microneedles (MNs) are micro-scale needles used for drug delivery and other targets. Micro-scale size endows them with many advantages over hypodermic needles, including painlessness, minimal invasiveness and convenient operation, but it may also lead to risk of mechanical failures, which should be prevented in the clinical applications of MNs. The objective of this review is mainly to introduce studies on the mechanics problems with respect to MNs. Firstly, the basic knowledge of MNs is introduced in brief, so that readers can understand the basic characteristics of MNs. Secondly, researches on inserting behavior and mechanical performances of MNs are discussed. Thirdly, literatures on the drug delivery and the pain resulted from the insertion of MNs are overviewed. Finally, some bio-microneedles and bio-inspired MNs are introduced. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Role of cellulose functionality in bio-inspired synthesis of nano bioactive glass.

    Science.gov (United States)

    Gupta, Nidhi; Santhiya, Deenan

    2017-06-01

    In search of abundant cheaper natural polymer for bio-inspired bioactive glass nanoparticles synthesis, cellulose and its derivatives have been considered as a template. Different templates explored in the present studies are pure cellulose, methyl cellulose and amine grafted cellulose. To the best of our knowledge, for the first time of the considered templates, pure cellulose and amine grafted cellulose results in in situ nano particulate composite formation while interestingly methyl cellulose proves to be an excellent sacrificial template for the synthesis of uniform bioglass nanoparticles of diameter in the range of 55nm. Further, viscoelastic measurements were carried out using dynamic mechanical analyzer. Herein, an attempt has been made to establish structure-mechanical relationship based on the templates. Moreover, in vitro bioactivity is also observed to be affected by the nature of the template molecule used for the synthesis of bioactive glass. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Real cases study through computer applications for futures Agricultural Engineers

    Science.gov (United States)

    Moratiel, R.; Durán, J. M.; Tarquis, A. M.

    2010-05-01

    One of the huge concerns on the higher engineer education is the lag of real cases study that the future professionals need in the work and corporation market. This concern was reflected in Bologna higher education system including recommendations in this respect. The knowhow as why this or other methodology is one of the keys to resolve this problem. In the last courses given in Department of Crop Production, at the Agronomy Engineer School of Madrid (Escuela Técnica Superior de Ingenieros Agrónomos, UPM) we have developed more than one hundred applications in Microsoft Excel®. Our aim was to show different real scenarios which the future Agronomic Engineers can be found in their professional life and with items related to crop production field. In order to achieve our target, each application in Excel presents a file text in which is explained the theoretical concepts and the objectives, as well as some resources used from Excel syntax. In this way, the student can understand and use of such application, even they can modify and customize it for a real case presented in their context and/or master project. This electronic monograph gives an answer to the need to manage data in several real scenarios showed in lectures, calculus resolution, information analysis and manage worksheets in a professional and student level.

  15. RAIN: A Bio-Inspired Communication and Data Storage Infrastructure.

    Science.gov (United States)

    Monti, Matteo; Rasmussen, Steen

    2017-01-01

    We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized cloud storage, has privacy by design, is open source, is more secure, is scalable, is more sustainable, has community ownership, is inexpensive, and is potentially faster, more efficient, and more reliable. We propose that a RAIN-style architecture could form the backbone of the Internet of Things that likely will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration.

  16. Bioinspired silica as drug delivery systems and their biocompatibility

    DEFF Research Database (Denmark)

    Steven, Christopher R.; Busby, Grahame A.; Mather, Craig

    2014-01-01

    Silica nanoparticles have been shown to have great potential as drug delivery systems (DDS), however, their fabrication often involves harsh chemicals and energy intensive laborious methods. This work details the employment of a bioinspired "green" method for the controlled synthesis of silica, use...... to identify the key synthetic parameters and quantify their effects on silica formation, drug loading and drug release. The observation that these new DDS are considerably less cytotoxic than their current counterparts, and exhibit additional benefits such as green synthesis and ease of functionalization...

  17. Student employment and study effort for engineering students

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Harder, D. E.

    2015-01-01

    to answer if the full-time student is under demise in these settings as opposed to settings without financial support [1, 2]. The research consisted of a web-based survey amongst all students at the Technical University of Denmark (DTU). The students in this survey had fewer employment hours and studied......The aim of this paper is to examine which factors effect student employment and study effort in a setting where engineering students are financially supported, such that their education is free of cost and that they receive financial support for living costs while studying. In addition, we wish...... more than those in studies from e.g. UK and US [3, 4, 5]. A similar trend was seen in a study from Norway [6]. Government financial support seems to limit the amount of hours spent on paid work but not the percentage of students who take on paid work. Thus, full-time studies with benefits of increased...

  18. Study on the joint training mode of optical engineering master

    Science.gov (United States)

    Wang, Jicheng; Hu, Zheng-Da; Sang, Tian; Gao, Shumei; Chen, Guoqing

    2017-08-01

    We study on the joint training mode of optical engineering (OE) master in the ways of teaching, scientific research and practice cooperation. Our goal is to enhance the abilities and research level of OE graduate students by establishing the joint training cooperation with the domestic or foreign high level universities, the top research institutes and the famous enterprises, and to let more and more graduate students enter the high level universities and companies. In addition, we want to create the training quality evaluation index and evaluation system of the OE master students to evaluate this joint training mode.

  19. Working conditions in the engine department - A qualitative study among engine room personnel on board Swedish merchant ships.

    Science.gov (United States)

    Lundh, Monica; Lützhöft, Margareta; Rydstedt, Leif; Dahlman, Joakim

    2011-01-01

    The specific problems associated with the work on board within the merchant fleet are well known and have over the years been a topic of discussion. The work conditions in the engine room (ER) are demanding due to, e.g. the thermal climate, noise and awkward working postures. The work in the engine control room (ECR) has over recent years undergone major changes, mainly due to the introduction of computers on board. In order to capture the impact these changes had implied, and also to investigate how the work situation has developed, a total of 20 engine officers and engine ratings were interviewed. The interviews were semi-structured and Grounded Theory was used for the data analysis. The aim of the present study was to describe how the engine crew perceive their work situation and working environment on board. Further, the aim was to identify areas for improvements which the engine crew consider especially important for a safe and effective work environment. The result of the study shows that the design of the ECR and ER is crucial for how different tasks are performed. Design which does not support operational procedures and how tasks are performed risk inducing inappropriate behaviour as the crew members' are compelled to find alternative ways to perform their tasks in order to get the job done. These types of behaviour can induce an increased risk of exposure to hazardous substances and the engine crew members becoming injured. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  20. Effects of curriculum organisation on study progress in engineering studies

    NARCIS (Netherlands)

    van der Hulst, M.; Jansen, E.P.W.A.

    Procrastination and time investment are important issues in the study of student performance and progress. Previous research on these issues has mainly concentrated upon individual differences between students in personality and time management skills. However, study progress depends not only on

  1. Biomimetic and Bioinspired Synthesis of Nanomaterials/Nanostructures.

    Science.gov (United States)

    Zan, Guangtao; Wu, Qingsheng

    2016-03-16

    In recent years, due to its unparalleled advantages, the biomimetic and bioinspired synthesis of nanomaterials/nanostructures has drawn increasing interest and attention. Generally, biomimetic synthesis can be conducted either by mimicking the functions of natural materials/structures or by mimicking the biological processes that organisms employ to produce substances or materials. Biomimetic synthesis is therefore divided here into "functional biomimetic synthesis" and "process biomimetic synthesis". Process biomimetic synthesis is the focus of this review. First, the above two terms are defined and their relationship is discussed. Next different levels of biological processes that can be used for process biomimetic synthesis are compiled. Then the current progress of process biomimetic synthesis is systematically summarized and reviewed from the following five perspectives: i) elementary biomimetic system via biomass templates, ii) high-level biomimetic system via soft/hard-combined films, iii) intelligent biomimetic systems via liquid membranes, iv) living-organism biomimetic systems, and v) macromolecular bioinspired systems. Moreover, for these five biomimetic systems, the synthesis procedures, basic principles, and relationships are discussed, and the challenges that are encountered and directions for further development are considered. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Armours for soft bodies: How far can bioinspiration take us?

    Science.gov (United States)

    White, Zachary; Vernerey, Franck

    2018-03-29

    The development of armour is as old as the dawn of civilization. Early man looked to natural structures to harvest or replicate for protection, leaning on millennia of evolutionary developments in natural protection. Since the advent of more modern weaponry, Armor development has seemingly been driven more by materials research than bio-inspiration. However, parallels can still be drawn between modern bullet-protective armours and natural defensive structures. Soft armour for handgun and fragmentation threats can be likened to mammalian skin, and similarly, hard armour can be compared with exoskeletons and turtle shells. Via bio-inspiration, it may be possible to develop structures previously un-researched for ballistic protection. This review will cover current modern ballistic protective structures focusing on energy dissipation and absorption methods, and their natural analogues. As all armour is a compromise between weight, flexibility and protection, the imbricated structure of scaled skin will be presented as a better balance between these factors. © 2018 IOP Publishing Ltd.

  3. Bioinspired assembly of small molecules in cell milieu.

    Science.gov (United States)

    Wang, Huaimin; Feng, Zhaoqianqi; Xu, Bing

    2017-05-09

    Self-assembly, the autonomous organization of components to form patterns or structures, is a prevalent process in nature at all scales. Particularly, biological systems offer remarkable examples of diverse structures (as well as building blocks) and processes resulting from self-assembly. The exploration of bioinspired assemblies not only allows for mimicking the structures of living systems, but it also leads to functions for applications in different fields that benefit humans. In the last several decades, efforts on understanding and controlling self-assembly of small molecules have produced a large library of candidates for developing the biomedical applications of assemblies of small molecules. Moreover, recent findings in biology have provided new insights on the assemblies of small molecules to modulate essential cellular processes (such as apoptosis). These observations indicate that the self-assembly of small molecules, as multifaceted entities and processes to interact with multiple proteins, can have profound biological impacts on cells. In this review, we illustrate that the generation of assemblies of small molecules in cell milieu with their interactions with multiple cellular proteins for regulating cellular processes can result in primary phenotypes, thus providing a fundamentally new molecular approach for controlling cell behavior. By discussing the correlation between molecular assemblies in nature and the assemblies of small molecules in cell milieu, illustrating the functions of the assemblies of small molecules, and summarizing some guiding principles, we hope this review will stimulate more molecular scientists to explore the bioinspired self-assembly of small molecules in cell milieu.

  4. Bio-Inspired Cyber Security for Smart Grid Deployments

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, Archibald D.; Thompson, Seth R.; Doroshchuk, Ruslan A.; Fink, Glenn A.; Fulp, Errin W.

    2013-05-01

    mart grid technologies are transforming the electric power grid into a grid with bi-directional flows of both power and information. Operating millions of new smart meters and smart appliances will significantly impact electric distribution systems resulting in greater efficiency. However, the scale of the grid and the new types of information transmitted will potentially introduce several security risks that cannot be addressed by traditional, centralized security techniques. We propose a new bio-inspired cyber security approach. Social insects, such as ants and bees, have developed complex-adaptive systems that emerge from the collective application of simple, light-weight behaviors. The Digital Ants framework is a bio-inspired framework that uses mobile light-weight agents. Sensors within the framework use digital pheromones to communicate with each other and to alert each other of possible cyber security issues. All communication and coordination is both localized and decentralized thereby allowing the framework to scale across the large numbers of devices that will exist in the smart grid. Furthermore, the sensors are light-weight and therefore suitable for implementation on devices with limited computational resources. This paper will provide a brief overview of the Digital Ants framework and then present results from test bed-based demonstrations that show that Digital Ants can identify a cyber attack scenario against smart meter deployments.

  5. Self-shaping composites with programmable bioinspired microstructures

    Science.gov (United States)

    Erb, Randall M.; Sander, Jonathan S.; Grisch, Roman; Studart, André R.

    2013-04-01

    Shape change is a prevalent function apparent in a diverse set of natural structures, including seed dispersal units, climbing plants and carnivorous plants. Many of these natural materials change shape by using cellulose microfibrils at specific orientations to anisotropically restrict the swelling/shrinkage of their organic matrices upon external stimuli. This is in contrast to the material-specific mechanisms found in synthetic shape-memory systems. Here we propose a robust and universal method to replicate this unusual shape-changing mechanism of natural systems in artificial bioinspired composites. The technique is based upon the remote control of the orientation of reinforcing inorganic particles within the composite using a weak external magnetic field. Combining this reinforcement orientational control with swellable/shrinkable polymer matrices enables the creation of composites whose shape change can be programmed into the material’s microstructure rather than externally imposed. Such bioinspired approach can generate composites with unusual reversibility, twisting effects and site-specific programmable shape changes.

  6. Report on the TESLA engineering study/review

    Energy Technology Data Exchange (ETDEWEB)

    C. Boffo et al.

    2002-07-18

    A team from Argonne National Lab, Cornell, Fermilab, Jefferson Lab, and SLAC has studied the TESLA TDR and its associated cost and manpower estimates, concentrating on the five largest cost sub-systems (Main Linac Modules, Main Linac RF Systems, Civil Engineering, Machine Infrastructure, and XFEL Incremental). These elements were concerned mainly with providing energy reach. We did not study the lower cost, but still technically challenging elements providing luminosity and physics capability, namely damping rings, beam delivery system, beam injection system, positron production, polarized beams, etc. The study did not attempt to validate the TDR cost estimates, but rather its purpose was to understand the technology and status of the large cost items, and the methodology by which their estimated cost was determined. In addition, topics of project oversight were studied.

  7. Case Study: Meeting the Demand for Skilled Precision Engineers

    Science.gov (United States)

    Sansom, Chris; Shore, Paul

    2008-01-01

    Purpose: This paper aims to demonstrate how science and engineering graduates can be recruited and trained to Masters level in precision engineering as an aid to reducing the skills shortage of mechanical engineers in UK industry. Design/methodology/approach: The paper describes a partnership between three UK academic institutions and industry,…

  8. Bioinspired synthesis of multifunctional inorganic and bio-organic hybrid materials.

    Science.gov (United States)

    Andre, Rute; Tahir, Muhammad N; Natalio, Filipe; Tremel, Wolfgang

    2012-05-01

    Owing to their physical and chemical properties, inorganic functional materials have tremendous impacts on key technologies such as energy generation and storage, information, medicine, and automotive engineering. Nature, on the other hand, provides evolution-optimized processes, which lead to multifunctional inorganic-bio-organic materials with complex structures. Their formation occurs under physiological conditions, and is goverened by a combination of highly regulated biological processes and intrinsic chemical properties. Nevertheless, insights into the molecular mechanisms of biomineralization open up promising perspectives for bioinspired and biomimetic design and the development of inorganic-bio-organic multifunctional hybrids. Therefore, biomimetic approaches may disclose new synthetic routes under ambient conditions by integrating the concept of gene-regulated biomineralization principles. The skeletal structures of marine sponges provide an interesting example of biosilicification via enzymatically controlled and gene-regulated silica metabolism. Spicule formation is initiated intracellularly by a fine-tuned genetic mechanism, which involves silica deposition in vesicles (silicassomes) under the control of the enzyme silicatein, which has both catalytic and templating functions. In this review, we place an emphasis on the fabrication of biologically inspired materials with silicatein as a biocatalyst. © 2012 The Authors Journal compilation © 2012 FEBS.

  9. Fifth International Conference on Innovations in Bio-Inspired Computing and Applications

    CERN Document Server

    Abraham, Ajith; Snášel, Václav

    2014-01-01

    This volume of Advances in Intelligent Systems and Computing contains accepted papers presented at IBICA2014, the 5th International Conference on Innovations in Bio-inspired Computing and Applications. The aim of IBICA 2014 was to provide a platform for world research leaders and practitioners, to discuss the full spectrum of current theoretical developments, emerging technologies, and innovative applications of Bio-inspired Computing. Bio-inspired Computing remains to be one of the most exciting research areas, and it is continuously demonstrating exceptional strength in solving complex real life problems. The main driving force of the conference was to further explore the intriguing potential of Bio-inspired Computing. IBICA 2014 was held in Ostrava, Czech Republic and hosted by the VSB - Technical University of Ostrava.

  10. 4th International Conference on Innovations in Bio-Inspired Computing and Applications

    CERN Document Server

    Krömer, Pavel; Snášel, Václav

    2014-01-01

    This volume of Advances in Intelligent Systems and Computing contains accepted papers presented at IBICA2013, the 4th International Conference on Innovations in Bio-inspired Computing and Applications. The aim of IBICA 2013 was to provide a platform for world research leaders and practitioners, to discuss the full spectrum of current theoretical developments, emerging technologies, and innovative applications of Bio-inspired Computing. Bio-inspired Computing is currently one of the most exciting research areas, and it is continuously demonstrating exceptional strength in solving complex real life problems. The main driving force of the conference is to further explore the intriguing potential of Bio-inspired Computing. IBICA 2013 was held in Ostrava, Czech Republic and hosted by the VSB - Technical University of Ostrava.

  11. Robust, Self-Contained and Bio-Inspired Shear Sensor Array, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a robust, bio-inspired, and self-contained sensor array for the measurement of shear stress. The proposed system uses commercially...

  12. Bio-Inspired Autonomous Communications Systems with Anomaly Detection Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and demonstrate BioComm, a bio-inspired autonomous communications system (ACS) aimed at dynamically reconfiguring and redeploying autonomous...

  13. Viscous-Inviscid Methods in Unsteady Aerodynamic Analysis of Bio-Inspired Morphing Wings

    Science.gov (United States)

    Dhruv, Akash V.

    Flight has been one of the greatest realizations of human imagination, revolutionizing communication and transportation over the years. This has greatly influenced the growth of technology itself, enabling researchers to communicate and share their ideas more effectively, extending the human potential to create more sophisticated systems. While the end product of a sophisticated technology makes our lives easier, its development process presents an array of challenges in itself. In last decade, scientists and engineers have turned towards bio-inspiration to design more efficient and robust aerodynamic systems to enhance the ability of Unmanned Aerial Vehicles (UAVs) to be operated in cluttered environments, where tight maneuverability and controllability are necessary. Effective use of UAVs in domestic airspace will mark the beginning of a new age in communication and transportation. The design of such complex systems necessitates the need for faster and more effective tools to perform preliminary investigations in design, thereby streamlining the design process. This thesis explores the implementation of numerical panel methods for aerodynamic analysis of bio-inspired morphing wings. Numerical panel methods have been one of the earliest forms of computational methods for aerodynamic analysis to be developed. Although the early editions of this method performed only inviscid analysis, the algorithm has matured over the years as a result of contributions made by prominent aerodynamicists. The method discussed in this thesis is influenced by recent advancements in panel methods and incorporates both viscous and inviscid analysis of multi-flap wings. The surface calculation of aerodynamic coefficients makes this method less computationally expensive than traditional Computational Fluid Dynamics (CFD) solvers available, and thus is effective when both speed and accuracy are desired. The morphing wing design, which consists of sequential feather-like flaps installed

  14. Engineered Barrier System performance requirements systems study report. Revision 02

    International Nuclear Information System (INIS)

    Balady, M.A.

    1997-01-01

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken

  15. Engineered Barrier System performance requirements systems study report. Revision 02

    Energy Technology Data Exchange (ETDEWEB)

    Balady, M.A.

    1997-01-14

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.

  16. Tissue-Engineered Heart Valves: A Call for Mechanistic Studies.

    Science.gov (United States)

    Blum, Kevin M; Drews, Joseph D; Breuer, Christopher K

    2018-02-13

    Heart valve disease carries a substantial risk of morbidity and mortality. Outcomes are significantly improved by valve replacement, but currently available mechanical and biological replacement valves are associated with complications of their own. Mechanical valves have a high rate of thromboembolism and require lifelong anticoagulation. Biological prosthetic valves have a much shorter lifespan, and they are prone to tearing and degradation. Both types of valves lack the capacity for growth, making them particularly problematic in pediatric patients. Tissue engineering has the potential to overcome these challenges by creating a neovalve composed of native tissue that is capable of growth and remodeling. The first tissue-engineered heart valve (TEHV) was created more than 20 years ago in an ovine model, and the technology has been advanced to clinical trials in the intervening decades. Some TEHVs have had clinical success, whereas others have failed, with structural degeneration resulting in patient deaths. The etiologies of these complications are poorly understood because much of the research in this field has been performed in large animals and humans, and, therefore, there are few studies of the mechanisms of neotissue formation. This review examines the need for a TEHV to treat pediatric patients with valve disease, the history of TEHVs, and a future that would benefit from extension of the reverse translational trend in this field to include small animal studies.

  17. Variable Cycle Engine Technology Program Planning and Definition Study

    Science.gov (United States)

    Westmoreland, J. S.; Stern, A. M.

    1978-01-01

    The variable stream control engine, VSCE-502B, was selected as the base engine, with the inverted flow engine concept selected as a backup. Critical component technologies were identified, and technology programs were formulated. Several engine configurations were defined on a preliminary basis to serve as demonstration vehicles for the various technologies. The different configurations present compromises in cost, technical risk, and technology return. Plans for possible variably cycle engine technology programs were formulated by synthesizing the technology requirements with the different demonstrator configurations.

  18. Diving Deep: A Comparative Study of Educator Undergraduate and Graduate Backgrounds and Their Effect on Student Understanding of Engineering and Engineering Careers, Utilizing an Underwater Robotics Program

    Science.gov (United States)

    Scribner, J. Adam

    Numerous studies have demonstrated that educators having degrees in their subjects significantly enhances student achievement, particularly in secondary mathematics and science (Chaney, 1995; Goe, 2007; Rowan, Chiang, & Miller, 1997; Wenglinsky, 2000). Yet, science teachers in states that adopt the Next Generation Science Standards will be facilitating classroom engineering activities despite the fact that few have backgrounds in engineering. This quantitative study analyzed ex-post facto WaterBotics (an innovative underwater robotics curriculum for middle and high school students) data to determine if educators having backgrounds in engineering (i.e., undergraduate and graduate degrees in engineering) positively affected student learning on two engineering outcomes: 1) the engineering design process, and 2) understanding of careers in engineering (who engineers are and what engineers do). The results indicated that educators having backgrounds in engineering did not significantly affect student understanding of the engineering design process or careers in engineering when compared to educators having backgrounds in science, mathematics, technology education, or other disciplines. There were, however, statistically significant differences between the groups of educators. Students of educators with backgrounds in technology education had the highest mean score on assessments pertaining to the engineering design process while students of educators with disciplines outside of STEM had the highest mean scores on instruments that assess for student understanding of careers in engineering. This might be due to the fact that educators who lack degrees in engineering but who teach engineering do a better job of "sticking to the script" of engineering curricula.

  19. Learning intervention and the approach to study of engineering undergraduates

    Science.gov (United States)

    Solomonides, Ian Paul

    The aim of the research was to: investigate the effect of a learning intervention on the Approach to Study of first year engineering degree students. The learning intervention was a local programme of learning to learn' workshops designed and facilitated by the author. The primary aim of these was to develop students' Approaches to Study. Fifty-three first year engineering undergraduates at The Nottingham Trent University participated in the workshops. Approaches to Study were quantified using data obtained from the Revised Approach to Study Inventory (RASI) which was also subjected to a validity and reliability study using local data. Quantitative outcomes were supplemented using a qualitative analysis of essays written by students during the workshops. These were analysed for detail regarding student Approach to Study. It was intended that any findings would inform the local system of Engineering Education, although more general findings also emerged, in particular in relation to the utility of the research instrument. It was concluded that the intervention did not promote the preferential Deep Approach and did not affect Approaches to Study generally as measured by the RASI. This concurred with previous attempts to change student Approaches to Study at the group level. It was also established that subsequent years of the Integrated Engineering degree course are associated with progressively deteriorating Approaches to Study. Students who were exposed to the intervention followed a similar pattern of deteriorating Approaches suggesting that the local course context and its demands had a greater influence over the Approach of students than the intervention did. It was found that academic outcomes were unrelated to the extent to which students took a Deep Approach to the local assessment demands. There appeared therefore to be a mis-match between the Approach students adopted to pass examinations and those that are required for high quality learning outcomes. It is

  20. STUDY OF TRENDS AND PERSPECTIVES OF INDUSTRIAL ENGINEERING RESEARCH

    Directory of Open Access Journals (Sweden)

    H. Dastkhan

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Industrial engineering is an engineering discipline which, because of its multi-disciplinary nature, has played an important role in the development and optimization of different systems at macro and micro levels. In this paper, the results of a research to study the position and trend of Industrial Engineering research in recent years are described. The data from a sample of 7 114 IE-related articles from international journals during the last 27 years were used for the analysis. The results showed that the development of IE in many countries has a strong correlation with their industrial and economic development. However, IE research topics are spreading in other management and engineering departments and so there is a need to redefine the discipline and its specific areas of interest. According to the prediction made using time series analysis, the most favorite fields of IE research in future will be on subjects related to information technology, intelligent systems, optimization, quality, and supply chain management.

    AFRIKAANSE OPSOMMING: Bedryfsingenieurswese is 'n ingenieursdissipline wat vanweë die multi-dissiplinêre aard daarvan 'n belangrike rol gespeel het in die optimisering van verskillende sisteme op makroen mikrovlak. Hierdie artikel hou die resultate voor van 'n navorsingsprojek wat onderneem is om die posisie en rigting van Bedryfsingenieursnavorsing in onlangse jare te bepaal. Die data van 'n monster van 7 114 Bedryfsingenieursverwante artikels wat verskyn het in internasionale joernale oor die afgelope 27 jaar is gebruik vir die ontleding. Die resultate toon dat die groei van Bedryfsingenieurswese in verskeie lande sterk korreleer met industriële en ekonomiese ontwikkeling. Tog blyk dit dat die navorsingsonderwerpe van Bedryfsingenieurswese sprei na ander bestuurs- en ingenieursdepartemente en dus bestaan daar ‘n nodigheid om die dissipline en die spesifieke belangstellingsvelde te herdefinieer

  1. Study of Second Generation Biofuels in Internal Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Dhandapani

    2012-07-01

    This research focused on the fuel modification approach to emissions reduction. In order to address the food-fuel-fiber conflicts, the alternative fuel has to have its source preferably from non-food crops. Therefore, non-food-crop-based blends of biomass-derived bio diesel (BD), derived from Jatropha curcus, is considered a good choice. However this bio-diesel has a high viscosity and thereby problems associated with its spray characteristics. In order to tide over these challenges, it is blended with low-viscosity fuels such as ethanol or Fischer-Tropsch (FT) synthetic diesel. This research studied the feasibility and usage of bio-fuels in IC engines to address the aforesaid concerns, understand what the fundamentally acceptable emission levels are and also determine the optimal blending limits of bio-fuels. In this context, the experimental works are carried out as two cases. First, the experimental investigations on blends of Fischer-Tropsch (FT) synthetic diesel and Jatropha methyl ester (JME), as fuel in a diesel engine, are carried out. The JME was produced by the trans-esterification process and the blends are tested against EN14214, or in some cases, ASTM standards. The volumetric blending percentages of BD to FT fuel are 0:100, 25:75, 50:50, 75:25 and 100:0 respectively. Fourier Transform Infra-Red (FTIR) spectroscopy results indicate that the BD and FT fuels are mainly aliphatic and ester compounds. The gas chromatography (GC) result shows that the neat BD (B100) contains more than 97% ester. The experiment was conducted with a four-stroke, six-cylinder, turbo-charged, direct injection (DI) diesel engine with an optimum engine speed of 1450 rpm and a dynamic fuel injection timing of 20 crank angle degrees (CAD) before the top dead centre (TDC). The experimental results showed that the exhaust emissions including carbon monoxide (CO), total unburnt hydrocarbon (THC), smoke, total particulate matter (TPM) and oxides of nitrogen (NOx) were reduced with FT

  2. Cross Functional Working and Concurrent Engineering – a UK Study

    Directory of Open Access Journals (Sweden)

    H. Williams

    2000-01-01

    Full Text Available This paper reports on the preliminary results of an investigative study into the implementation of concurrent engineering applied to new product development. Concurrent (or Simultaneous engineering is the term commonly given to creating new products using multi-disciplined teams of marketing, design, manufacturing and support functions together with supplier and customers. Such techniques have produced robust, low cost quality products in short concept to market times compared to traditional ones. The research investigated design management practice and performance in a number of organisations across a range of industrial sectors in the UK by means of a questionnaire survey. The results identify the current use of a variety of design practices and methodologies such as different organisational structures, the extent of cross-functional working, the use of design and phase reviews and the use of different technologies. They indicate that companies implementing CE are more successful in time to market performance than those who don’t implement CE. Factors most influencing the successful adoption of CE are design and phase reviews, and, to a lesser extent, the use of multifunctional teams and supplier partnerships.

  3. Evaluating risk awareness in undergraduate students studying mechanical engineering

    Science.gov (United States)

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

    2010-10-01

    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 responsibility, risk assessment, techniques for reducing risk and potential exposure to hazards and risk in the workplace. Students performed best in hazard identification in the workplace. The student performance was similar in the first and second years, but a significant improvement was evident towards the end of the third year. This was attributed to the third year design curriculum, which formally covers certain aspects of risk awareness, including the ones showing improved performance. The results were compared to those obtained from the University of Liverpool - the UK students outperformed their South African counterparts. It is recommended that teaching interventions regarding health and safety be introduced earlier in the South African Mechanical Engineering curriculum to address this deficiency.

  4. Civil Engineering Feasibility Studies for Future Ring Colliders at CERN

    CERN Document Server

    Bruning, O; Myers, S; Osborne, J; Rossi, L; Waaijer, C; Zimmermann, F

    2013-01-01

    CERN civil engineers are studying the feasibility of several potential ring colliders to complement the LHC: an 80km circular tunnel to house the TLEP and VHE-LHC, and the ring-ring and linac-ring options for the LHeC. The feasibility of these projects is largely dependent on civil design and geotechnical and environmental risks. As civil infrastructure works typically represent one third of the cost of major physics projects, it is critical that the construction costs are well understood from the conceptual stage. This proceeding presents the first results of the feasibility studies for the 80km tunnel and the linac-ring LHeC. Presented at IPAC'13 Shanghai, 12-17 May 2013

  5. VHTR engineering design study: intermediate heat exchanger program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-11-01

    The work reported is the result of a follow-on program to earlier Very High Temperature Reactor (VHTR) studies. The primary use of the VHTR is to provide heat for various industrial processes, such as hydrocarbon reforming and coal gasification. For many processes the use of an intermediate heat transfer barrier between the reactor coolant and the process is desirable; for some processes it is mandatory. Various intermediate heat exchanger (IHX) concepts for the VHTR were investigated with respect to safety, cost, and engineering design considerations. The reference processes chosen were steam-hydrocarbon reforming, with emphasis on the chemical heat pipe, and steam gasification of coal. The study investigates the critically important area of heat transfer between the reactor coolant, helium, and the various chemical processes.

  6. In-situ Study on the Performance of Engineered Barriers

    International Nuclear Information System (INIS)

    Cho, Won Jin; Park, J. H.; Lee, J. O.

    2010-04-01

    An engineering scale experiment, KENTEX was conducted to investigate THM behavior in the buffer, and the computer modelling and simulation technique was developed. In the study on the thermal behavior of near-field rock, various studies for the in situ heater test, which is for the investigation of the thermo-mechanical behavior in rock mass, were carried out. The geophysics exploration and in-situ field tests were carried out to investigate the range of EDZ and its effects on the mechanical properties of rock. The discontinuities in rock mass and dynamic material properties were also measured. The mechanical properties of buffer block are investigated regarding the fabrication, compression, and degradation of the buffer blocks. The experiments are carried out to investigate the resaturation processes. The material properties of low-pH and high-pH cement grouts were evaluated

  7. Study the impact of internship on improving engineering students' competency

    Science.gov (United States)

    Marsono, Sugandi, Machmud; Tuwoso, Purnomo

    2017-09-01

    An effort to improve human resources quality in higher education can be done through an internship program. This program is important for the graduate student to enhance their self-development and entrepreneurship ability. This study aims to evaluate the effectiveness of internship course on the student's achievement, particularly of their professional competencies. Furthermore, this research was conducted to identify the type of industries that are suitable for internship program of the engineering students. The results showed that the investigation information related to data collection and assignment, lodging, suitability of expertise and some matters correlated to the process students' internship in industry. This study also found the method to improve the services of industries and university.

  8. VHTR engineering design study: intermediate heat exchanger program. Final report

    International Nuclear Information System (INIS)

    1976-11-01

    The work reported is the result of a follow-on program to earlier Very High Temperature Reactor (VHTR) studies. The primary use of the VHTR is to provide heat for various industrial processes, such as hydrocarbon reforming and coal gasification. For many processes the use of an intermediate heat transfer barrier between the reactor coolant and the process is desirable; for some processes it is mandatory. Various intermediate heat exchanger (IHX) concepts for the VHTR were investigated with respect to safety, cost, and engineering design considerations. The reference processes chosen were steam-hydrocarbon reforming, with emphasis on the chemical heat pipe, and steam gasification of coal. The study investigates the critically important area of heat transfer between the reactor coolant, helium, and the various chemical processes

  9. A Case Study: Problem-Based Learning for Civil Engineering Students in Transportation Courses

    Science.gov (United States)

    Ahern, A. A.

    2010-01-01

    This paper describes two case studies where problem-based learning (PBL) has been introduced to undergraduate civil engineering students in University College Dublin. PBL has recently been put in place in the penultimate and final year transport engineering classes in the civil engineering degree in University College Dublin. In this case study,…

  10. Health effects engineering: Perspectives for environmental health and environmental engineering studies-domestic biomass combustion as an example

    International Nuclear Information System (INIS)

    Gao Xiang; Yu Qi; Chen Limin

    2007-01-01

    Health effects engineering (HEE) is a newly developed research field, which involves collaboration with environmental scientists, engineering researchers, and toxicologists. By employing the methods of HEE, one can not only confirm which attributes of the project are likely to contribute to certain health effects, but can also get rid of the adverse health effects by engineering technologies. HEE is thought to be particularly important to domestic projects in which there is a lack of environmental assessment. This paper presented the authors' viewpoints of the principles of HEE in the field of the environmental health and engineering studies by using programs of domestic biomass combustion as an example. The authors showed that there are three sub-fields of HEE, which are as follows: engineering behavior, the pollution characteristics, and the health effects. The authors conclude that the principles of HEE compose a helix with the studies in the fields of environmental science, health, and engineering, and give suggestions on how to perform HEE in a practical field

  11. Performance and efficiency evaluation and heat release study of a direct-injection stratified-charge rotary engine

    Science.gov (United States)

    Nguyen, H. L.; Addy, H. E.; Bond, T. H.; Lee, C. M.; Chun, K. S.

    1987-01-01

    A computer simulation which models engine performance of the Direct Injection Stratified Charge (DISC) rotary engines was used to study the effect of variations in engine design and operating parameters on engine performance and efficiency of an Outboard Marine Corporation (OMC) experimental rotary combustion engine. Engine pressure data were used in a heat release analysis to study the effects of heat transfer, leakage, and crevice flows. Predicted engine data were compared with experimental test data over a range of engine speeds and loads. An examination of methods to improve the performance of the rotary engine using advanced heat engine concepts such as faster combustion, reduced leakage, and turbocharging is also presented.

  12. Mathematics for physicists and engineers fundamentals and interactive study guide

    CERN Document Server

    Weltner, Klaus; Grosjean, Jean; Schuster, Peter

    2009-01-01

    Mathematics is the basic language in physics and engineering. It is an essential tool which first and second year students have to master as soon as possible. A lack of competence in mathematics is the main reason for failure and drop out in the beginning periods of study. This textbook offers an accessible and highly approved approach which is characterized by the combination of the textbook with a detailed study guide available online at extras.springer.com. This study guide divides the whole learning task into small units which the student is very likely to master successfully. Thus he or she is asked to read and study a limited section of the textbook and to return to the study guide afterwards. Working with the study guide his or her learning results are controlled, monitored and deepened by graded questions, exercises, repetitions and finally by problems and applications of the content studied. Since the degree of difficulties is slowly rising the students gain confidence and experience their own progre...

  13. Study, optimization, and design of a laser heat engine

    Science.gov (United States)

    1978-01-01

    Laser heat engine concepts, proposed for satellite applications, were analyzed to determine which engine concepts best meet the requirements of high efficiency (50 percent or better) continuous operation in space. The best laser heat engine for a near-term experimental demonstration, selected on the basis of high overall operating efficiency, high power-to-weight characteristics, and availability of the required technology, is an Otto/Diesel cycle piston engine using a diamond window to admit CO2 laser radiation. The technology with the greatest promise of scaling to megawatt power levels in the long term is the energy exchanger/gas turbine combination.

  14. Reservoir engineering studies of the Cerro Prieto geothermal field

    Science.gov (United States)

    Goyal, K. P.; Lippmann, M. J.; Tsang, C. F.

    1982-09-01

    Reservoir engineering studies of the Cerro Prieto geothermal field began in 1978 under a five-year cooperative agreement between the US Department of Energy and the Comision Federal de Electricidad de Mexico, with the ultimate objective of simulating the reservoir to forecast its production capacity, energy longevity, and recharge capability under various production and injection scenarios. During the fiscal year 1981, attempts were made to collect information on the evolution history of the field since exploitation began; the information is to be used later to validate the reservoir model. To this end, wellhead production data were analyzed for heat and mass flow and also for changes in reservoir pressures, temperatures, and saturations for the period from March 1973 to November 1980.

  15. Plutonium Finishing Plant. Interim plutonium stabilization engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Sevigny, G.J.; Gallucci, R.H.; Garrett, S.M.K.; Geeting, J.G.H.; Goheen, R.S.; Molton, P.M.; Templeton, K.J.; Villegas, A.J. [Pacific Northwest Lab., Richland, WA (United States); Nass, R. [Nuclear Fuel Services, Inc. (United States)

    1995-08-01

    This report provides the results of an engineering study that evaluated the available technologies for stabilizing the plutonium stored at the Plutonium Finishing Plant located at the hanford Site in southeastern Washington. Further processing of the plutonium may be required to prepare the plutonium for interim (<50 years) storage. Specifically this document provides the current plutonium inventory and characterization, the initial screening process, and the process descriptions and flowsheets of the technologies that passed the initial screening. The conclusions and recommendations also are provided. The information contained in this report will be used to assist in the preparation of the environmental impact statement and to help decision makers determine which is the preferred technology to process the plutonium for interim storage.

  16. Communication Problems in Requirements Engineering: A Field Study

    Science.gov (United States)

    Al-Rawas, Amer; Easterbrook, Steve

    1996-01-01

    The requirements engineering phase of software development projects is characterized by the intensity and importance of communication activities. During this phase, the various stakeholders must be able to communicate their requirements to the analysts, and the analysts need to be able to communicate the specifications they generate back to the stakeholders for validation. This paper describes a field investigation into the problems of communication between disparate communities involved in the requirements specification activities. The results of this study are discussed in terms of their relation to three major communication barriers: (1) ineffectiveness of the current communication channels; (2) restrictions on expressiveness imposed by notations; and (3) social and organizational barriers. The results confirm that organizational and social issues have great influence on the effectiveness of communication. They also show that in general, end-users find the notations used by software practitioners to model their requirements difficult to understand and validate.

  17. Plutonium Finishing Plant. Interim plutonium stabilization engineering study

    International Nuclear Information System (INIS)

    Sevigny, G.J.; Gallucci, R.H.; Garrett, S.M.K.; Geeting, J.G.H.; Goheen, R.S.; Molton, P.M.; Templeton, K.J.; Villegas, A.J.; Nass, R.

    1995-08-01

    This report provides the results of an engineering study that evaluated the available technologies for stabilizing the plutonium stored at the Plutonium Finishing Plant located at the hanford Site in southeastern Washington. Further processing of the plutonium may be required to prepare the plutonium for interim (<50 years) storage. Specifically this document provides the current plutonium inventory and characterization, the initial screening process, and the process descriptions and flowsheets of the technologies that passed the initial screening. The conclusions and recommendations also are provided. The information contained in this report will be used to assist in the preparation of the environmental impact statement and to help decision makers determine which is the preferred technology to process the plutonium for interim storage

  18. Process engineering versus product engineering - A case study on volatile organic compounds removal

    DEFF Research Database (Denmark)

    Coutinho, João A.P.; Vilela, T.; Pereira, P.

    2005-01-01

    to the problem-need specified in the beginning of the project, but producing a novel formulation (chemical product design) represents a method that results to a completely xylene-free process which is environmentally and economically more interesting than those generated via the more traditional process......Three solutions for removing the dangerous volatile organic compound (VOC) xylene from an industrial coating process are presented and compared. Two of them are based on classical process engineering principles, i.e., development of separation-cleaning methods such as incineration and adsorption....... The last approach is somewhat different and is based on the so-called product engineering concept, i.e., in this case, a change of the formulation so that xylene is entirely eliminated from the process. It is shown that both the process and the product engineering approaches yield viable solutions...

  19. Systems study on engineered barriers: barrier performance analysis

    International Nuclear Information System (INIS)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed

  20. Systems study on engineered barriers: barrier performance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed.

  1. Gender in Engineering Studies at Brazilian Technical University

    Directory of Open Access Journals (Sweden)

    de Lima Sobreira, Josimeire

    2008-10-01

    Full Text Available The research on a Technological University of Brazil, among students in Engineering, revealed that women occupy no more than 12 % (in general of the places at the Institution. The university study that the girls most prefer is the Engineering of Buildings and the other one, where there are the least number of women, is Mechanics Engineering. The qualitative research with the students, made by interviews, showed that there is a gender discrimination among them. The boys do not consider their schoolmates competents for the exact sciences. The girls have to do a greater effort than the boys to success and to be respected by them. But even so they recognize that will not have the same opportunities of work that the men will. However, gender changes among the students are evidences that women have reached important places at the technological field.La investigación en una Universidad Tecnológica de Brasil entre estudiantes de los cursos de ingeniería ha mostrado que las mujeres no ocupan más que 12 % (en general de las plazas de la Institución. El curso con más estudiantes es el de Ingeniería Civil, mientras el curso con el más pequeño número de mujeres es el de Mecánica. La metodología de la investigación ha sido cualitativa. Las entrevistas con chicas-chicos de los cursos investigados revelaron que hay discriminación entre los estudiantes que no consideran a sus compañeras de curso competentes para los estudios de ciencias exactas. Para que sean respetadas ellas tienen que estudiar mucho más que ellos, pero, aunque logren muy buenas evaluaciones, reconocen que en el mercado laboral tendrán menos oportunidades de trabajo que sus colegas. Entretanto, los cambios de género entre los y las estudiantes evidencian que las mujeres están conquistando espacios importantes.

  2. Bioinspired Design of Alcohol Dehydrogenase@nano TiO2 Microreactors for Sustainable Cycling of NAD+/NADH Coenzyme

    Directory of Open Access Journals (Sweden)

    Sen Lin

    2018-02-01

    Full Text Available The bioinspired design and construction of enzyme@capsule microreactors with specific cell-like functionality has generated tremendous interest in recent years. Inspired by their fascinating complexity, scientists have endeavored to understand the essential aspects of a natural cell and create biomimicking microreactors so as to immobilize enzymes within the hierarchical structure of a microcapsule. In this study, simultaneous encapsulation of alcohol dehydrogenase (ADH was achieved during the preparation of microcapsules by the Pickering emulsion method using amphiphilic modified TiO2 nanoparticles (NPs as building blocks for assembling the photocatalytic microcapsule membrane. The ADH@TiO2 NP microreactors exhibited dual catalytic functions, i.e., spatially confined enzymatic catalysis and the membrane-associated photocatalytic oxidation under visible light. The sustainable cycling of nicotinamide adenine dinucleotide (NAD coenzyme between NADH and NAD+ was realized by enzymatic regeneration of NADH from NAD+ reduction, and was provided in a form that enabled further photocatalytic oxidation to NAD+ under visible light. This bioinspired ADH@TiO2 NP microreactor allowed the linking of a semiconductor mineral-based inorganic photosystem to enzymatic reactions. This is a first step toward the realization of sustainable biological cycling of NAD+/NADH coenzyme in synthetic functional microsystems operating under visible light irradiation.

  3. Long-term decontamination engineering study. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Geuther, W.J.

    1995-04-03

    This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site.

  4. Long-term decontamination engineering study. Volume 1

    International Nuclear Information System (INIS)

    Geuther, W.J.

    1995-01-01

    This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site

  5. Learning from Engineering Failures: A Case Study of the Deepwater Horizon

    Science.gov (United States)

    Rose, Mary Annette; Hunt, Brian

    2012-01-01

    Natural catastrophes and engineering failures provide timely, motivating, and conceptually rich backdrops for learning. Engineering educators have long embraced case studies of engineering failures as a sound pedagogical strategy for meeting several learning standards, such as "design within realistic constraints", and teaching failure…

  6. Engineering Students Learning Preferences in UNITEN: Comparative Study and Patterns of Learning Styles

    Science.gov (United States)

    Lee, Chen Kang; Sidhu, Manjit Singh

    2015-01-01

    Engineering educators have been increasingly taking the learning style theories into serious consideration as part of their efforts to enhance the teaching and learning in engineering. This paper presents a research study to investigate the learning style preference of the mechanical engineering students in Universiti Tenaga Nasional (UNITEN),…

  7. Bioinspired nanocoatings for biofouling prevention by photocatalytic redox reactions.

    Science.gov (United States)

    Sathe, Priyanka; Laxman, Karthik; Myint, Myo Tay Zar; Dobretsov, Sergey; Richter, Jutta; Dutta, Joydeep

    2017-06-15

    Aquaculture is a billion dollar industry and biofouling of aquaculture installations has heavy economic penalties. The natural antifouling (AF) defence mechanism of some seaweed that inhibits biofouling by production of reactive oxygen species (ROS) inspired us to mimic this process by fabricating ZnO photocatalytic nanocoating. AF activity of fishing nets modified with ZnO nanocoating was compared with uncoated nets (control) and nets painted with copper-based AF paint. One month experiment in tropical waters showed that nanocoatings reduce abundances of microfouling organisms by 3-fold compared to the control and had higher antifouling performance over AF paint. Metagenomic analysis of prokaryotic and eukaryotic fouling organisms using next generation sequencing platform proved that nanocoatings compared to AF paint were not selectively enriching communities with the resistant and pathogenic species. The proposed bio-inspired nanocoating is an important contribution towards environmentally friendly AF technologies for aquaculture.

  8. Self-organizing bioinspired oligothiophene–oligopeptide hybrids

    Directory of Open Access Journals (Sweden)

    Alexey K. Shaytan

    2011-09-01

    Full Text Available In this minireview, we survey recent advances in the synthesis, characterization, and modeling of new oligothiophene–oligopeptide hybrids capable of forming nanostructured fibrillar aggregates in solution and on solid substrates. Compounds of this class are promising for applications because their self-assembly and stimuli-responsive properties, provided by the peptide moieties combined with the semiconducting properties of the thiophene blocks, can result in novel opportunities for the design of advanced smart materials. These bio-inspired molecular hybrids are experimentally shown to form stable fibrils as visualized by AFM and TEM. While the experimental evidence alone is not sufficient to reveal the exact molecular organization of the fibrils, theoretical approaches based on quantum chemistry calculations and large-scale atomistic molecular dynamics simulations are attempted in an effort to reveal the structure of the fibrils at the nanoscale. Based on the combined theoretical and experimental analysis, the most likely models of fibril formation and aggregation are suggested.

  9. Bio-Inspired Optimization of Sustainable Energy Systems: A Review

    Directory of Open Access Journals (Sweden)

    Yu-Jun Zheng

    2013-01-01

    Full Text Available Sustainable energy development always involves complex optimization problems of design, planning, and control, which are often computationally difficult for conventional optimization methods. Fortunately, the continuous advances in artificial intelligence have resulted in an increasing number of heuristic optimization methods for effectively handling those complicated problems. Particularly, algorithms that are inspired by the principles of natural biological evolution and/or collective behavior of social colonies have shown a promising performance and are becoming more and more popular nowadays. In this paper we summarize the recent advances in bio-inspired optimization methods, including artificial neural networks, evolutionary algorithms, swarm intelligence, and their hybridizations, which are applied to the field of sustainable energy development. Literature reviewed in this paper shows the current state of the art and discusses the potential future research trends.

  10. Flow over bio-inspired 3D herringbone wall riblets

    Science.gov (United States)

    Chen, Huawei; Rao, Fugang; Shang, Xiaopeng; Zhang, Deyuan; Hagiwara, Ichiro

    2014-03-01

    Under the inspiration of small riblets of shark skin, the microgroove drag reduction riblets whose direction set along fluid flow have been widely investigated. Herringbone-type riblets of bird flight feather are seldom exploited although bird also has excellent flight performance. Inspired from the flight feather, novel bio-inspired plane-3D (p-3D) and spatial-3D (s-3D) herringbone wall riblets are proposed. Through experiment measurement of drag reduction in water tunnel, maximum drag reduction of p-3D and s-3D herringbone riblets was about 17 and 20 %, higher than traditional microgroove riblets. Moreover, significant change of drag reduction was also found by change of the angle between herringbone riblets. In particular, maximum drag reduction occurred as angle between herringbone riblets was about 60° close to real flight feather, which indicates that microstructure of bird flight feather has great impact on flight performance.

  11. Visual Flight Control of a Quadrotor Using Bioinspired Motion Detector

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2012-01-01

    Full Text Available Motion detection in the fly is extremely fast with low computational requirements. Inspired from the fly's vision system, we focus on a real-time flight control on a miniquadrotor with fast visual feedback. In this work, an elaborated elementary motion detector (EMD is utilized to detect local optical flow. Combined with novel receptive field templates, the yaw rate of the quadrotor is estimated through a lookup table established with this bioinspired visual sensor. A closed-loop control system with the feedback of yaw rate estimated by EMD is designed. With the motion of the other degrees of freedom stabilized by a camera tracking system, the yaw-rate of the quadrotor during hovering is controlled based on EMD feedback under real-world scenario. The control performance of the proposed approach is compared with that of conventional approach. The experimental results demonstrate the effectiveness of utilizing EMD for quadrotor control.

  12. Optimal Design of a Bio-Inspired Anthropocentric Shoulder Rehabilitator

    Directory of Open Access Journals (Sweden)

    S. K. Mustafa

    2006-01-01

    Full Text Available This paper presents the design of a bio-inspired anthropocentric 7-DOF wearable robotic arm for the purpose of stroke rehabilitation. The proposed arm rehabilitator synergistically utilizes the human arm structure with non-invasive kinematically under-deterministic cable-driven mechanisms to form a completely deterministic structure. It offers the advantages of being lightweight and having high dexterity. Adopting an anthropocentric design concept also allows it to conform to the human anatomical structure. The focus of this paper is on the analysis and design of the 3-DOF-shoulder module, called the shoulder rehabilitator. The design methodology is divided into three main steps: (1 performance evaluation of the cable-driven shoulder rehabilitator, (2 performance requirements of the shoulder joint based on its physiological characteristics and (3 design optimization of the shoulder rehabilitator based on shoulder joint physiological limitations. The aim is to determine a suitable configuration for the development of a shoulder rehabilitator prototype.

  13. Tissue engineering and surgery: from translational studies to human trials

    Directory of Open Access Journals (Sweden)

    Vranckx Jan Jeroen

    2017-06-01

    Full Text Available Tissue engineering was introduced as an innovative and promising field in the mid-1980s. The capacity of cells to migrate and proliferate in growth-inducing medium induced great expectancies on generating custom-shaped bioconstructs for tissue regeneration. Tissue engineering represents a unique multidisciplinary translational forum where the principles of biomaterial engineering, the molecular biology of cells and genes, and the clinical sciences of reconstruction would interact intensively through the combined efforts of scientists, engineers, and clinicians. The anticipated possibilities of cell engineering, matrix development, and growth factor therapies are extensive and would largely expand our clinical reconstructive armamentarium. Application of proangiogenic proteins may stimulate wound repair, restore avascular wound beds, or reverse hypoxia in flaps. Autologous cells procured from biopsies may generate an ‘autologous’ dermal and epidermal laminated cover on extensive burn wounds. Three-dimensional printing may generate ‘custom-made’ preshaped scaffolds – shaped as a nose, an ear, or a mandible – in which these cells can be seeded. The paucity of optimal donor tissues may be solved with off-the-shelf tissues using tissue engineering strategies. However, despite the expectations, the speed of translation of in vitro tissue engineering sciences into clinical reality is very slow due to the intrinsic complexity of human tissues. This review focuses on the transition from translational protocols towards current clinical applications of tissue engineering strategies in surgery.

  14. Comparative Study on Three Major Internet Search Engines ...

    African Journals Online (AJOL)

    , Google and ask.com search engines. Experimental method was used with ten reference questions which were used to query each of the search engines . Yahoo obtained the highest results (521,801,043) among the three Web search ...

  15. Numerical Study on the Performance Characteristics of Hydrogen Fueled Port Injection Internal Combustion Engine

    OpenAIRE

    Rosli A. Bakar; Mohammed K. Mohammed; M. M. Rahman

    2009-01-01

    This study was focused on the engine performance of single cylinder hydrogen fueled port injection internal combustion engine. GT-Power was utilized to develop the model for port injection engine. One dimensional gas dynamics was represented the flow and heat transfer in the components of the engine model. The governing equations were introduced first, followed by the performance parameters and model description. Air-fuel ratio was varied from stoichiometric limit to a lean limit and the rota...

  16. Bio-inspired Autonomic Structures: a middleware for Telecommunications Ecosystems

    Science.gov (United States)

    Manzalini, Antonio; Minerva, Roberto; Moiso, Corrado

    Today, people are making use of several devices for communications, for accessing multi-media content services, for data/information retrieving, for processing, computing, etc.: examples are laptops, PDAs, mobile phones, digital cameras, mp3 players, smart cards and smart appliances. One of the most attracting service scenarios for future Telecommunications and Internet is the one where people will be able to browse any object in the environment they live: communications, sensing and processing of data and services will be highly pervasive. In this vision, people, machines, artifacts and the surrounding space will create a kind of computational environment and, at the same time, the interfaces to the network resources. A challenging technological issue will be interconnection and management of heterogeneous systems and a huge amount of small devices tied together in networks of networks. Moreover, future network and service infrastructures should be able to provide Users and Application Developers (at different levels, e.g., residential Users but also SMEs, LEs, ASPs/Web2.0 Service roviders, ISPs, Content Providers, etc.) with the most appropriate "environment" according to their context and specific needs. Operators must be ready to manage such level of complication enabling their latforms with technological advanced allowing network and services self-supervision and self-adaptation capabilities. Autonomic software solutions, enhanced with innovative bio-inspired mechanisms and algorithms, are promising areas of long term research to face such challenges. This chapter proposes a bio-inspired autonomic middleware capable of leveraging the assets of the underlying network infrastructure whilst, at the same time, supporting the development of future Telecommunications and Internet Ecosystems.

  17. First-Hand Experience with Engineering Design and Career Interest in Engineering: An Informal STEM Education Case Study

    Science.gov (United States)

    Ayar, Mehmet C.

    2015-01-01

    The purpose of this study is to present students' experiences, interest in engineering, and personal narratives while participating in a robotics summer camp in a metropolitan city in Turkey. In this study, I used qualitative data collection methods such as interviews, field notes, and observations. I used the four principles of Engle and Conant…

  18. Study for Agricultural Engineering Development in Brazil. Summary Report of Joint Study Group on Agricultural Engineering in Brazil (July 24-August 12, 1972).

    Science.gov (United States)

    National Academy of Sciences, Washington, DC.

    The joint study group was established to identify the most urgent research and training needs in agricultural engineering in Brazil and to recommend how best to meet those needs. Specific recommendations are given for a long-term program to establish quality programs in education and research in agricultural engineering in Brazil and means to gain…

  19. Third cycle university studies in Europe in the field of agricultural engineering and in the emerging discipline of biosystems engineering.

    Science.gov (United States)

    Ayuga, F; Briassoulis, D; Aguado, P; Farkas, I; Griepentrog, H; Lorencowicz, E

    2010-01-01

    The main objectives of European Thematic Network entitled 'Education and Research in Agricultural for Biosystems Engineering in Europe (ERABEE-TN)' is to initiate and contribute to the structural development and the assurance of the quality assessment of the emerging discipline of Biosystems Engineering in Europe. ERABEE is co-financed by the European Community in the framework of the LLP Programme. The partnership consists of 35 participants from 27 Erasmus countries, out of which 33 are Higher Education Area Institutions (EDU) and 2 are Student Associations (ASS). 13 Erasmus participants (e.g. Thematic Networks, Professional Associations, and Institutions from Brazil, Croatia, Russia and Serbia) are also involved in the Thematic Network through synergies. To date, very few Biosystems Engineering programs exist in Europe and those that are initiated are at a very primitive stage of development. The innovative and novel goal of the Thematic Network is to promote this critical transition, which requires major restructuring in Europe, exploiting along this direction the outcomes accomplished by its predecessor; the USAEE-TN (University Studies in Agricultural Engineering in Europe). It also aims at enhancing the compatibility among the new programmes of Biosystems Engineering, aiding their recognition and accreditation at European and International level and facilitating greater mobility of skilled personnel, researchers and students. One of the technical objectives of ERABEE is dealing with mapping and promoting the third cycle studies (including European PhDs) and supporting the integration of research at the 1st and 2nd cycle regarding European Biosystems Engineering university studies. During the winter 2008 - spring 2009 period, members of ERABEE conducted a survey on the contemporary status of doctoral studies in Europe, and on a possible scheme for promotion of cooperation and synergies in the framework of the third cycle of studies and the European Doctorate

  20. Engineering support for magnetohydrodynamic power plant analysis and design studies

    Science.gov (United States)

    Carlson, A. W.; Chait, I. L.; Marchmont, G.; Rogali, R.; Shikar, D.

    1980-01-01

    The major factors which influence the economic engineering selection of stack inlet temperatures in combined cycle MHD powerplants are identified and the range of suitable stack inlet temperatures under typical operating conditions is indicated. Engineering data and cost estimates are provided for four separately fired high temperature air heater (HTAH) system designs for HTAH system thermal capacity levels of 100, 250, 500 and 1000 MWt. An engineering survey of coal drying and pulverizing equipment for MHD powerplant application is presented as well as capital and operating cost estimates for varying degrees of coal pulverization.

  1. Orbital Transfer Rocket Engine Technology. Advanced Engine Study, Task D.6 Final Report

    Science.gov (United States)

    1992-06-01

    development using expert systems and artificial * intelligence techniques. 3.1.2 Power Balance I A rocket engine power balance is an energy and mass balnce com...the whitish, new-copper penny appearance. Blanched surfaces are commonly interconnected by subsurface " wormholing ," severe interconnected porosity, and...In particular, some techniques of artificial intelligence decision making should be adapted to handle this propulsion system. RPT/OOfl?. a/,.o..o 194

  2. Engineering study of tank fill options for landfill closure

    Energy Technology Data Exchange (ETDEWEB)

    Skelly, W.A.

    1996-09-27

    To prepare single-shell tanks for closure, it will be necessary to piece some type of load- bearing fill material inside the tanks to support the domes. Provision of internal support permits the simplifying assumption that the combined weight of the dome, the existing operational soil cover, and the surface barrier will eventually transfer to and be carried by the fill. This engineering study provides descriptions and evaluations of four alternative concepts for fitting and stabilizing nominally empty SSTs with fill materials. For this study it is assumed that 99 percent (or more) of tank wastes will be retrieved before closure is undertaken. The alternatives are: Gravel: tanks would be fitted with crushed aggregate using a rotating stinger apparatus installed in the central riser; Grout: tanks would be fitted with a pumpable, ex-situ mixed grout formulation; Hybrid: tanks would be fitted first with coarse aggregate, then with grout, producing a pre-placed aggregate concrete material; or Concrete: tank. would be filled with a highly-flowable, ex-situ mixed concrete formulation.

  3. Aqueous Ethanol Ignition and Engine Studies, Phase I

    Science.gov (United States)

    2010-09-01

    Our objectives were to design a micro-dilution tunnel for monitoring engine emissions, measure ignition temperature and heat release from ethanol-water-air mixtures on platinum, and initiate a computational fluid dynamics model of a catalytic igniter...

  4. Oxford engineering students to study new solutions for vacuum chambers

    CERN Multimedia

    Department of Engineering Science - University of Oxford

    2012-01-01

    In April, eleven engineering science students in their third year at Oxford University were invited here to present their design ideas for new vacuum chamber materials to be used in accelerators. We publish below an abstract of the article that the University of Oxford featured on its website.   The 11 Oxford students who worked at CERN on alternatives to beryllium in vacuum chambers. (Photo courtesy of the Department of Engineering Science, University of Oxford.) Engineering Science students invited to design for CERN’s Large Hadron Collider In April, eleven Engineering Science students in their third year were invited to the CERN laboratory in Geneva to present their ideas for new vacuum chamber designs for the experiments of the Large Hadron Collider (LHC). Their design objectives were to propose alternatives to beryllium – the material used for some of the existing experimental vacuum chambers. Beryllium (chemical element with the symbol Be and atomic number 4) is to...

  5. "Genetic Engineering" Gains Momentum (Science/Society Case Study).

    Science.gov (United States)

    Moore, John W.; Moore, Elizabeth A., Eds.

    1980-01-01

    Reviews the benefits and hazards of genetic engineering, or "recombinant-DNA" research. Recent federal safety rules issued by NIH which ease the strict prohibitions on recombinant-DNA research are explained. (CS)

  6. Holographic aids for internal combustion engine flow studies

    Science.gov (United States)

    Regan, C.

    1984-01-01

    Worldwide interest in improving the fuel efficiency of internal combustion (I.C.) engines has sparked research efforts designed to learn more about the flow processes of these engines. The flow fields must be understood prior to fuel injection in order to design efficient valves, piston geometries, and fuel injectors. Knowledge of the flow field is also necessary to determine the heat transfer to combustion chamber surfaces. Computational codes can predict velocity and turbulence patterns, but experimental verification is mandatory to justify their basic assumptions. Due to their nonintrusive nature, optical methods are ideally suited to provide the necessary velocity verification data. Optical sytems such as Schlieren photography, laser velocimetry, and illuminated particle visualization are used in I.C. engines, and now their versatility is improved by employing holography. These holographically enhanced optical techniques are described with emphasis on their applications in I.C. engines.

  7. Numerical Study on Fan Spray for Gasoline Direct Injection Engines

    OpenAIRE

    Shirabe, Naotaka; Sato, Takaaki; Murase, Eiichi

    2003-01-01

    In gasoline direct injection engines, it is important to optimize fuel spray characteristics, which strongly affect stratified combustion process. Spray simulation is expected as a tool for optimizing the nozzle design. Conventional simulation method, how

  8. Mean Value SI Engine Model for Control Studies

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Sorenson, Spencer C

    1990-01-01

    This paper presents a mathematically simple nonlinear three state (three differential equation) dynamic model of an SI engine which has the same steady state accuracy as a typical dynamometer measurement of the engine over its entire speed/load operating range (± 2.0%). The model's accuracy for l....... The model can easily be run on a Personal Computer (PC) using a ordinary differential equation (ODE) integrating routine or package. This makes the model is useful for control system design and evaluation....

  9. Review on study of multi-physics in environment engineering

    International Nuclear Information System (INIS)

    Liu Shanli; Zhao Jian; Sheng Jinchang

    2006-01-01

    This paper analyzes some problems on multi-field coupling ones between seepage mechanics and other physical and chemical processes (such as temperature field. stress field, solute transport. chemical action and so on) in environment engineering, it explains the research theory of multi-field coupling, it summarizes the abroad and domestic research about the model of multi-field problem and finally it looks into the future of research tendency in environment engineering. (authors)

  10. Thermographic study of the preheating plugs in diesel engines

    OpenAIRE

    Royo Pastor, Rafael; Albertos Arranz, M.A.; CÁRCEL CUBAS, JUAN ANTONIO; Payá Herrero, Jorge

    2012-01-01

    The use of direct injection diesel engines has been widely applied during the past ten years. In such engines, the preheating plugs are a key element which has a significant contribution in the pollutant emissions. In this paper, two different plug designs from Renault are analyzed. The new plug reduces substantially the required electrical consumption. Nevertheless, the pollutant emissions are higher (fundamentally CO and HCs) and hereby a thorough analysis is required to underst...

  11. Study of Scientists and Engineers in DoD Laboratories

    Science.gov (United States)

    1982-09-01

    other conzerns. Final.y, in February 1982, Dr. Robert He’-ann’s report for the Under Secretary of Defe.,sc for Research and Engineering presentee his...insufficient preparation Academy of ing neering in mathematics and the physical bcxences. inadequate Sciences 1977 motivation toward engineering as a...Among Univer- tempred by outside offers are not motivated solely by sity Officials the prospects of higher salaries While in virtually by Malcolm G

  12. Leadership preparation in engineering: A study of perceptions of leadership attributes, preparedness, and policy implications

    Science.gov (United States)

    Latorre, Julia Talarico

    Perceptions of engineers and leaders in the field of engineering regarding leadership preparation for engineers were evaluated in this dissertation. More specifically, engineers' and leaders' perceptions of leadership preparation and the necessary skills of leaders in technical fields were studied. The design and analyses of the study were divided into two parts: (1) Data for employment and college enrollment for engineers in New York State (NYS) were plotted using Geographic Information Systems (GIS) in order to evaluate recent data regarding employment and college enrollment for engineers in order to better understand the relevance of leadership preparation in engineering, (2) Perceptions regarding engineering leadership preparedness were analyzed using descriptive statistical methods and inferential statistical methods and engineers' perceptions regarding the importance of chosen leadership attributes were analyzed using inferential statistics and Generalizability Theory (G-theory). Responses to open-ended questions regarding the importance of leadership or management training for engineers, and responses discussing possible implications of increasing leadership or management training for engineers were also examined. Possible implications of the study, and suggestions for future research, were also included.

  13. A global study of undergraduate environmental engineering programs

    International Nuclear Information System (INIS)

    Abro, Q.M.

    2005-01-01

    Recent analyses of environmental engineering and management (EE and M) field has highlighted its rapidly expanding size and increasingly diverse nature (Hart and Nolan, 1999). The last 30 years have seen growing international recognition that the challenges associated with environmental degradation and sustainable development have important implications for, and connections with, education and research (IUCN, 1970; UNCED, 1992). The concept of environmental education is now widespread in national educational policies, curriculum documents, curriculum development initiatives, and conservation strategies. Reflecting this trend, several universities throughout the world offer a wide range of graduate as well as undergraduate programs in environment. These programs have originated from various academic schools and disciplines (engineering, public policy, business, management, etc) creating considerable diversity of focus, themes emphasized, courses and methods of offerings. The rise of these programs, in part, reflects the growing need for engineers, technologists as well as managers, who are able to understand, contribute to, and manage a wide variety of technology-based programs and organizations. In addition, the large number of environmental engineering research journals, professional associations and international/national conferences point to the rapid growth of this field. This paper will examine the trends in provision, type of program, major curriculum focus of undergraduate environmental engineering and management education and then compare these trends with the emerging trends in the environmental engineering and management research journals of the last decade. (author)

  14. TWRS privatization phase 1 monitoring wells engineering study

    International Nuclear Information System (INIS)

    Williams, B.A.; Newcomer, D.R.

    1998-04-01

    This engineering study provides an evaluation of existing wells and boreholes (wells) within the proposed location for the Tank Waste Remediation System (TWRS) Privatization Phase 1 demonstration site. Phase 1 is part of the TWRS program that was established to manage, retrieve, treat, immobilize, and dispose of high-level waste stored in underground tanks at the Hanford Site. This evaluation is to determine which wells will remain active within the demonstration site based on regulatory, programmatic, or other beneficial use requirements. An initial evaluation of wells within the demonstration site was conducted in 1996. However, changes in construction plans and expansion of the demonstration site necessitated a reevaluation and reclassification of the wells that are within the expanded site. Impacted wells include many of those previously evaluated as well as additional wells identified in or near the expansion areas. Thirty-three wells exist within and immediately adjacent to the identified boundary of the proposed demonstration site. The wells identified for decommissioning will be abandoned according to the well decommissioning plan. Future well requirements within the site include replacement wells for those wells impacted by construction activities, replacements for Resource Conservation and Recovery Act of 1976 (RCRA) wells going dry, and a new characterization well installed to support a TWRS Phase 2 site assessment

  15. A Multimodal Search Engine for Medical Imaging Studies.

    Science.gov (United States)

    Pinho, Eduardo; Godinho, Tiago; Valente, Frederico; Costa, Carlos

    2017-02-01

    The use of digital medical imaging systems in healthcare institutions has increased significantly, and the large amounts of data in these systems have led to the conception of powerful support tools: recent studies on content-based image retrieval (CBIR) and multimodal information retrieval in the field hold great potential in decision support, as well as for addressing multiple challenges in healthcare systems, such as computer-aided diagnosis (CAD). However, the subject is still under heavy research, and very few solutions have become part of Picture Archiving and Communication Systems (PACS) in hospitals and clinics. This paper proposes an extensible platform for multimodal medical image retrieval, integrated in an open-source PACS software with profile-based CBIR capabilities. In this article, we detail a technical approach to the problem by describing its main architecture and each sub-component, as well as the available web interfaces and the multimodal query techniques applied. Finally, we assess our implementation of the engine with computational performance benchmarks.

  16. Challenges in the flow measurement engineering study phases

    Energy Technology Data Exchange (ETDEWEB)

    Henne, Liv Marit; Monnet, Jean

    2005-07-01

    Offshore development of marginal Oil and Gas fields can often be economically profitable if they can be tied in to existing platforms. This usually requires execution of comprehensive feasibility studies, which can often be a long and costly process. Close cooperation in a multi discipline engineering team is necessary to assure that all possibilities and aspects of the design task have been evaluated. Integration of a new flow measurement module on an existing installation is often the simplest solution, yielding low total cost as the module can be assembled and fully tested on shore. However on many installations one is required to integrate the new equipment in existing modules. Flow measurement is a crucial element in the development of marginal fields which has to be evaluated, taking into consideration all critical aspects such as: available space, weight, location accessibility, maintenance and integration to existing metering systems. In particular, special attention should be given to the possible use of new flow measurement technologies and principles. (author) (tk)

  17. Study of applying reverse engineering to turbine blade manufacture

    International Nuclear Information System (INIS)

    She, Chen Hua; Chang, Chun Chi

    2007-01-01

    A turbine blade has complex shaped free-form surfaces that can be modelled as surfaces with variable curvature by high-degree polynomials. Industry typically utilizes a turnkey system and special-purpose machine tool to manufacture turbine blades. A turkey system is a closed form design. Users need only input relevant data to this system to manufacture the product directly. However, users are unaware of the internal operation of the system. With rapidly advances in computing technology, commercial CAD/CAM systems can be utilized to design freeform surfaces and generate a tool path for the designed surfaces. This study uses a reverse engineering technology that is used to reconstruct the CAD model for a turbine blade. The prototype is measured by a coordinate measuring machine to obtain the geometrical control data points that are used to generate the CAD model in the UniGraphics (UG) CAD/CAM system. The UG/GRIP (GRaphics interactive Programming) language is used to generate the cutter location data rather than using the default UG CAM module. A five-axis NC code is acquired by the developed postprocessor and verified by the solid cutting simulation software VERICUT. Real turbine blade machining is performed on a table/spindle tilting five-axis machine tool, demonstrating the effectiveness of the proposed approach

  18. Expansion to 4.0 capacity factor: Purex Engineering Study

    Energy Technology Data Exchange (ETDEWEB)

    Doud, E.

    1960-10-28

    The Purex Plant was originally designed to operate at a instantaneous rate of 8-1/3 tons of uranium per 24-hour day on a three-cycle flowsheet. Subsequently, the rate was increased to 26-2/3 T/day and the process changed to a two-cycle flowsheet. Recently, flowsheet changes made for neptunium recovery and replacements of certain critical equipment items have altered the plant`s capacity. The status of the plant is discussed in the Continuity of Operations, Plant Improvement Program, Reference 1; wherein, the need for expansion to a capacity factor of 4.0 by January 1, 1962, was envisioned. Reference 2 was prepared to implement that program. A new chemical flowsheet, Reference 3, was prepared to serve as a basis for the Purex Expansion Program. The purpose of this engineering study was to determine the changes and capital expenditure needed to obtain a 33-1/3 T/day instantaneous production rate through the Purex Plant. This report discusses equipment additions and modifications that are required for the Purex Plant to operate at an instantaneous rate of 33-1/3 tons of uranium per day on the flowsheet, as described in Reference 3.

  19. Women Studies in Engineering Education: Content Analysis in Three Referred Journals

    Science.gov (United States)

    Chou, Pao-Nan

    2013-01-01

    Little is known about the research characteristics of past women studies in engineering education. In order to add knowledge base about the advanced development of women studies in current engineering education research, the purpose of the study is to investigate research characteristics of past women studies published in three referred…

  20. Bio-inspired passive actuator simulating an abalone shell mechanism for structural control

    International Nuclear Information System (INIS)

    Yang, Henry T Y; Lin, Chun-Hung; Bridges, Daniel; Randall, Connor J; Hansma, Paul K

    2010-01-01

    An energy dispersion mechanism called 'sacrificial bonds and hidden length', which is found in some biological systems, such as abalone shells and bones, is the inspiration for new strategies for structural control. Sacrificial bonds and hidden length can substantially increase the stiffness and enhance energy dissipation in the constituent molecules of abalone shells and bone. Having been inspired by the usefulness and effectiveness of such a mechanism, which has evolved over millions of years and countless cycles of evolutions, the authors employ the conceptual underpinnings of this mechanism to develop a bio-inspired passive actuator. This paper presents a fundamental method for optimally designing such bio-inspired passive actuators for structural control. To optimize the bio-inspired passive actuator, a simple method utilizing the force–displacement–velocity (FDV) plots based on LQR control is proposed. A linear regression approach is adopted in this research to find the initial values of the desired parameters for the bio-inspired passive actuator. The illustrative examples, conducted by numerical simulation with experimental validation, suggest that the bio-inspired passive actuator based on sacrificial bonds and hidden length may be comparable in performance to state-of-the-art semi-active actuators

  1. Developing Generic Skills through University Study: A Study of Arts, Science and Engineering in Australia

    Science.gov (United States)

    Badcock, Paul B. T.; Pattison, Philippa E.; Harris, Kerri-Lee

    2010-01-01

    This study examined relationships between important aspects of a university education and the assessment and development of generic skills. A sample of 323 students enrolled in single or double arts, engineering and/or science degrees from a research-intensive university in Australia were administered the Graduate Skills Assessment to measure four…

  2. A Three-Year Feedback Study of a Remote Laboratory Used in Control Engineering Studies

    Science.gov (United States)

    Chevalier, Amélie; Copot, Cosmin; Ionescu, Clara; De Keyser, Robin

    2017-01-01

    This paper discusses the results of a feedback study for a remote laboratory used in the education of control engineering students. The goal is to show the effectiveness of the remote laboratory on examination results. To provide an overview, the two applications of the remote laboratory are addressed: 1) the Stewart platform, and 2) the quadruple…

  3. Analytical design and performance studies of the nuclear light bulb engine

    Science.gov (United States)

    Rodgers, R. J.; Latham, T. S.

    1972-01-01

    Analytical studies were conducted to investigate in detail the heat balance characteristics of the nuclear light bulb engine. Distributions of energy deposition to all engine components from the fission process, conduction and convection, and thermal radiation were considered. Where uncertainties in basic data or heat transfer characteristics were encountered, ranges of heat loads were calculated and reference values were selected. The influence of these heat loads on engine performance, space radiator requirements, and cooling sequence and cooling circuit designs was determined. The analyses resulted in revisions to the previously reported reference engine characteristics, principally in the heat loads to some engine components and in the cooling sequence. These revisions were incorporated in the engine dynamics digital computer simulation program. No significant changes occurred in the dynamic response of the engine to perturbations in fuel injection rate, reactivity or exhaust nozzle area.

  4. Virtual Reference Services through Web Search Engines: Study of Academic Libraries in Pakistan

    Directory of Open Access Journals (Sweden)

    Rubia Khan

    2017-03-01

    Full Text Available Web search engines (WSE are powerful and popular tools in the field of information service management. This study is an attempt to examine the impact and usefulness of web search engines in providing virtual reference services (VRS within academic libraries in Pakistan. The study also attempts to investigate the relevant expertise and skills of library professionals in providing digital reference services (DRS efficiently using web search engines. Methodology used in this study is quantitative in nature. The data was collected from fifty public and private sector universities in Pakistan using a structured questionnaire. Microsoft Excel and SPSS were used for data analysis. The study concludes that web search engines are commonly used by librarians to help users (especially research scholars by providing digital reference services. The study also finds a positive correlation between use of web search engines and quality of digital reference services provided to library users. It is concluded that although search engines have increased the expectations of users and are really big competitors to a library’s reference desk, they are however not an alternative to reference service. Findings reveal that search engines pose numerous challenges for librarians and the study also attempts to bring together possible remedial measures. This study is useful for library professionals to understand the importance of search engines in providing VRS. The study also provides an intellectual comparison among different search engines, their capabilities, limitations, challenges and opportunities to provide VRS effectively in libraries.

  5. Waste Receiving and Processing (WRAP) facility engineering study

    International Nuclear Information System (INIS)

    Christie, M.A.; Cammann, J.W.; McBeath, R.S.; Rode, H.H.

    1985-01-01

    A new Hanford waste management facility, the Waste Receiving and Processing (WRAP) facility (planned to be operational by FY 1994) will receive, inspect, process, and repackage contact-handled transuranic (CH-TRU) contaminated solid wastes. The wastes will be certified according to the waste acceptance criteria for disposal at the Waste Isolation Pilot Plant (WIPP) geologic repository in southeast New Mexico. Three alternatives which could cost effectively be applied to certify Hanford CH-TRU waste to the WIPP Waste Acceptance Criteria (WIPP-WAC) have been examined in this updated engineering study. The alternatives differed primarily in the reference processing systems used to transform nonconforming waste into an acceptable, certified waste form. It is recommended to include the alternative of shredding and immobilizing nonconforming wastes in cement (shred/grout processing) in the WRAP facility. Preliminary capital costs for WRAP in mid-point-of-construction (FY 1991) dollars were estimated at $45 million for new construction and $37 million for modification and installation in an existing Hanford surplus facility (231-Z Building). Operating, shipping, and decommissioning costs in FY 1986 dollars were estimated at $126 million, based on a 23-y WRAP life cycle (1994 to 2017). During this period, the WRAP facility will receive an estimated 38,000 m 3 (1.3 million ft 3 ) of solid CH-TRU waste. The study recommends pilot-scale testing and evaluation of the processing systems planned for WRAP and advises further investigation of the 231-Z Building as an alternative to new facility construction

  6. Model Based Systems Engineering on the Europa Mission Concept Study

    Science.gov (United States)

    Bayer, Todd J.; Chung, Seung; Cole, Bjorn; Cooke, Brian; Dekens, Frank; Delp, Chris; Gontijo, I.; Lewis, Kari; Moshir, Mehrdad; Rasmussen, Robert; hide

    2012-01-01

    At the start of 2011, the proposed Jupiter Europa Orbiter (JEO) mission was staffing up in expectation of becoming an official project later in the year for a launch in 2020. A unique aspect of the pre-project work was a strong emphasis and investment on the foundations of Model-Based Systems Engineering (MBSE). As so often happens in this business, plans changed: NASA's budget and science priorities were released and together fundamentally changed the course of JEO. As a result, it returned to being a study task whose objective is to propose more affordable ways to accomplish the science. As part of this transition, the question arose as to whether it could continue to afford the investment in MBSE. In short, the MBSE infusion has survived and is providing clear value to the study effort. By leveraging the existing infrastructure and a modest additional investment, striking advances in the capture and analysis of designs using MBSE were achieved. In the process, the need to remain relevant in the new environment has brought about a wave of innovation and progress. The effort has reaffirmed the importance of architecting. It has successfully harnessed the synergistic relationship of architecting to system modeling. We have found that MBSE can provide greater agility than traditional methods. We have also found that a diverse 'ecosystem' of modeling tools and languages (SysML, Mathematica, even Excel) is not only viable, but an important enabler of agility and adaptability. This paper will describe the successful application of MBSE in the dynamic environment of early mission formulation, the significant results produced and lessons learned in the process.

  7. Epidemiological study of health hazards among workers handling engineered nanomaterials

    Science.gov (United States)

    Liou, Saou-Hsing; Tsou, Tsui-Chun; Wang, Shu-Li; Li, Lih-Ann; Chiang, Hung-Che; Li, Wan-Fen; Lin, Pin-Pin; Lai, Ching-Huang; Lee, Hui-Ling; Lin, Ming-Hsiu; Hsu, Jin-Huei; Chen, Chiou-Rong; Shih, Tung-Sheng; Liao, Hui-Yi; Chung, Yu-Teh

    2012-08-01

    The aim of this study was to establish and identify the health effect markers of workers with potential exposure to nanoparticles (20-100 nm) during manufacturing and/or application of nanomaterials. For this cross-sectional study, we recruited 227 workers who handled nanomaterials and 137 workers for comparison who did not from 14 plants in Taiwan. A questionnaire was used to collect data on exposure status, demographics, and potential confounders. The health effect markers were measured in the medical laboratory. Control banding from the Nanotool Risk Level Matrix was used to categorize the exposure risk levels of the workers. The results showed that the antioxidant enzyme, superoxide dismutase (SOD) in risk level 1 (RL1) and risk level 2 (RL2) workers was significantly ( p RL1 > RL2). Another antioxidant, glutathione peroxidase (GPX), was significantly lower only in RL1 workers than in the control workers. The cardiovascular markers, fibrinogen and ICAM (intercellular adhesion molecule), were significantly higher in RL2 workers than in controls and a significant dose-response with an increasing trend was found for these two cardiovascular markers. Another cardiovascular marker, interleukin-6, was significantly increased among RL1 workers, but not among RL2 workers. The accuracy rate for remembering 7-digits and reciting them backwards was significantly lower in RL2 workers (OR = 0.48) than in controls and a significantly reversed gradient was also found for the correct rate of backward memory (OR = 0.90 for RL1, OR = 0.48 for RL2, p Depression of antioxidant enzymes and increased expression of cardiovascular markers were found among workers handling nanomaterials. Antioxidant enzymes, such as SOD and GPX, and cardiovascular markers, such as fibrinogen, ICAM, and interluekin-6, are possible biomarkers for medical surveillance of workers handling engineered nanomaterials.

  8. Epidemiological study of health hazards among workers handling engineered nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Saou-Hsing, E-mail: shliou@nhri.org.tw; Tsou, Tsui-Chun; Wang, Shu-Li; Li, Lih-Ann; Chiang, Hung-Che; Li, Wan-Fen; Lin, Pin-Pin [National Health Research Institutes, Division of Environmental Health and Occupational Medicine, Taiwan (China); Lai, Ching-Huang [National Defense Medical Center, Department of Public Health, Taiwan (China); Lee, Hui-Ling [Fu Jen Catholic University, Department of Chemistry, Taiwan (China); Lin, Ming-Hsiu; Hsu, Jin-Huei; Chen, Chiou-Rong [Council of Labor Affairs, Institute of Occupational Safety and Health, Taiwan (China); Shih, Tung-Sheng [College of Public Health, China Medical University and Hospital, Institute of Environmental Health, Taiwan (China); Liao, Hui-Yi; Chung, Yu-Teh [National Health Research Institutes, Division of Environmental Health and Occupational Medicine, Taiwan (China)

    2012-08-15

    The aim of this study was to establish and identify the health effect markers of workers with potential exposure to nanoparticles (20-100 nm) during manufacturing and/or application of nanomaterials. For this cross-sectional study, we recruited 227 workers who handled nanomaterials and 137 workers for comparison who did not from 14 plants in Taiwan. A questionnaire was used to collect data on exposure status, demographics, and potential confounders. The health effect markers were measured in the medical laboratory. Control banding from the Nanotool Risk Level Matrix was used to categorize the exposure risk levels of the workers. The results showed that the antioxidant enzyme, superoxide dismutase (SOD) in risk level 1 (RL1) and risk level 2 (RL2) workers was significantly (p < 0.05) lower than in control workers. A significantly decreasing gradient was found for SOD (control > RL1 > RL2). Another antioxidant, glutathione peroxidase (GPX), was significantly lower only in RL1 workers than in the control workers. The cardiovascular markers, fibrinogen and ICAM (intercellular adhesion molecule), were significantly higher in RL2 workers than in controls and a significant dose-response with an increasing trend was found for these two cardiovascular markers. Another cardiovascular marker, interleukin-6, was significantly increased among RL1 workers, but not among RL2 workers. The accuracy rate for remembering 7-digits and reciting them backwards was significantly lower in RL2 workers (OR = 0.48) than in controls and a significantly reversed gradient was also found for the correct rate of backward memory (OR = 0.90 for RL1, OR = 0.48 for RL2, p < 0.05 in test for trend). Depression of antioxidant enzymes and increased expression of cardiovascular markers were found among workers handling nanomaterials. Antioxidant enzymes, such as SOD and GPX, and cardiovascular markers, such as fibrinogen, ICAM, and interluekin-6, are possible biomarkers for medical surveillance of

  9. Epidemiological study of health hazards among workers handling engineered nanomaterials

    International Nuclear Information System (INIS)

    Liou, Saou-Hsing; Tsou, Tsui-Chun; Wang, Shu-Li; Li, Lih-Ann; Chiang, Hung-Che; Li, Wan-Fen; Lin, Pin-Pin; Lai, Ching-Huang; Lee, Hui-Ling; Lin, Ming-Hsiu; Hsu, Jin-Huei; Chen, Chiou-Rong; Shih, Tung-Sheng; Liao, Hui-Yi; Chung, Yu-Teh

    2012-01-01

    The aim of this study was to establish and identify the health effect markers of workers with potential exposure to nanoparticles (20–100 nm) during manufacturing and/or application of nanomaterials. For this cross-sectional study, we recruited 227 workers who handled nanomaterials and 137 workers for comparison who did not from 14 plants in Taiwan. A questionnaire was used to collect data on exposure status, demographics, and potential confounders. The health effect markers were measured in the medical laboratory. Control banding from the Nanotool Risk Level Matrix was used to categorize the exposure risk levels of the workers. The results showed that the antioxidant enzyme, superoxide dismutase (SOD) in risk level 1 (RL1) and risk level 2 (RL2) workers was significantly (p RL1 > RL2). Another antioxidant, glutathione peroxidase (GPX), was significantly lower only in RL1 workers than in the control workers. The cardiovascular markers, fibrinogen and ICAM (intercellular adhesion molecule), were significantly higher in RL2 workers than in controls and a significant dose–response with an increasing trend was found for these two cardiovascular markers. Another cardiovascular marker, interleukin-6, was significantly increased among RL1 workers, but not among RL2 workers. The accuracy rate for remembering 7-digits and reciting them backwards was significantly lower in RL2 workers (OR = 0.48) than in controls and a significantly reversed gradient was also found for the correct rate of backward memory (OR = 0.90 for RL1, OR = 0.48 for RL2, p < 0.05 in test for trend). Depression of antioxidant enzymes and increased expression of cardiovascular markers were found among workers handling nanomaterials. Antioxidant enzymes, such as SOD and GPX, and cardiovascular markers, such as fibrinogen, ICAM, and interluekin-6, are possible biomarkers for medical surveillance of workers handling engineered nanomaterials.

  10. Study on the Modifications Required to Re-Engine the Lockheed D-21 Drone

    Science.gov (United States)

    1999-01-01

    This report was prepared by Lockheed Martin (LM). The purpose of this 45 day study contract was to investigate the feasibility of using the D-21 as a Rocket Based Combined Cycle engine test-bed. The new NASA engine is entitled "Demonstration of Rocket Combined Cycle Operations (DRACO)". Four objectives were defined and modification study provide an estimation of the: (1) mudified vehicle performance; (2) required engine performance; (3) required vehicle modification; and (4) modification cost and schedule.

  11. Study on vibration behaviors of engineered barrier system

    International Nuclear Information System (INIS)

    Mikoshiba, Tadashi; Ogawa, Nobuyuki; Minowa, Chikahiro

    1998-01-01

    High-level radioactive wastes have been buried underground by packing into a strong sealed container made from carbon steel (over-pack) with buffer material (bentonite). The engineered barrier system constructed with an overpack and buffer materials must be resistant to earthquakes as well as invasion of groundwater for a long period. Therefore, seismic evaluation of barrier system for earthquakes is indispensable especially in Japan to keep its structural safety. Here, the effects of earthquake vibration on the engineered barrier systems were investigated experimentally. Random-wave vibration and practical seismic wave one were loaded for the systems and fundamental data were obtained. For the former vibration the response characteristics of both engineered barrier models constructed with overpack and bentonite were non-linear. For the latter one, the stress in bentonite was increased in proportion to the vibration level. (M.N.)

  12. A bioinspired elastin-based protein for a cytocompatible underwater adhesive.

    Science.gov (United States)

    Brennan, M Jane; Kilbride, Bridget F; Wilker, Jonathan J; Liu, Julie C

    2017-04-01

    The development of adhesives that can be applied and create strong bonds underwater is a significant challenge for materials engineering. When the adhesive is intended for biomedical applications, further criteria, such as biocompatibility, must be met. Current biomedical adhesive technologies do not meet these needs. In response, we designed a bioinspired protein system that shows promise to achieve biocompatible underwater adhesion coupled with environmentally responsive behavior that is "smart" - that is, it can be tuned to suit a specific application. The material, ELY 16 , is constructed from an elastin-like polypeptide (ELP) that can be produced in high yields from Escherichia coli and can coacervate in response to environmental factors such as temperature, pH, and salinity. To confer wet adhesion, we utilized design principles from marine organisms such as mussels and sandcastle worms. When expressed, ELY 16 is rich in tyrosine. Upon modification with the tyrosinase enzyme to form mELY 16 , the tyrosine residues are converted to 3,4-dihydroxyphenylalanine (DOPA). Both ELY 16 and mELY 16 exhibit cytocompatibility and significant dry adhesion strength (>2 MPa). Modification with DOPA increases protein adsorption to glass and provides moderate adhesion strength (∼240 kPa) in a highly humid environment. Furthermore, this ELP exhibits a tunable phase transition behavior that can be formulated to coacervate in physiological conditions and provides a convenient mechanism for application underwater. Finally, mELY 16 possesses significantly higher adhesion strength in dry, humid, and underwater environments compared with a commercially available fibrin sealant. To our knowledge, mELY 16 provides the strongest bonds of any rationally designed protein when used completely underwater, and its high yields make it more viable for commercial application compared to natural adhesive proteins. In conclusion, this ELP shows great potential to be a new "smart" underwater

  13. Systems Engineering Education Development(SEED)Case Study

    Science.gov (United States)

    Bagg, Thomas C., III; Brumfield, Mark D.; Jamison, Donald E.; Granata, Raymond L.; Casey, Carolyn A.

    2003-01-01

    The Systems Engineering Development Program (SEED) was initiated to help Goddard resolve a Systems Engineering skill shortage. The chronology of events and the experiences of the pilot program are outlined to describe the development of the present program. The program goals are included in order to give a focus on what the developers saw as the program drivers. Lessons learned from a pilot program were incorporated into the present program. This program is constantly learning from its past efforts and looks for continuous improvement. We list several future ideas for improvement and change.

  14. An Ethical Study on the Uses of Enhancement Genetic Engineering

    Science.gov (United States)

    Kawakita, Koji

    A variety of biomedical technologies are being developed that can be used for purposes other than treating diseases. Such “enhancement technologies” can be used to improve our own and future generation's life-chances. While these technologies can help people in many ways, their use raises important ethical issues. Some arguments for anti-enhancement as well as pro-enhancement seem to rest, however, on shaky foundation. Both company engineers and the general public had better learn more from technological, economical and philosophical histories. For such subjects may provide engineers with less opportunities of technological misuses and more powers of self-esteem in addition to self-control.

  15. Study of compressor systems for a gas-generator engine

    Science.gov (United States)

    Sather, Bernard I; Tauschek, Max J

    1950-01-01

    Various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes from sea level to 50,000 feet are presented. The analytical results indicate that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. The constant-speed second stage could be either a mixed-flow rotary compressor or a piston-type compressor. A variable-area turbine nozzle is shown to be unnecessary for cruising operation of the engine.

  16. Space Power Free-Piston Stirling Engine Scaling Study

    Science.gov (United States)

    Jones, D.

    1989-01-01

    The design feasibility study is documented of a single cylinder, free piston Stirling engine/linear alternator (FPSE/LA) power module generating 150 kW-electric (kW sub e), and the determination of the module's maximum feasible power level. The power module configuration was specified to be a single cylinder (single piston, single displacer) FPSE/LA, with tuning capacitors if required. The design requirements were as follows: (1) Maximum electrical power output; (2) Power module thermal efficiency equal to or greater than 20 percent at a specific mass of 5 to 8 kg/kW(sub e); (3) Heater wall temperature/cooler wall temperature = 1050 K/525 K; (4) Sodium heat-pipe heat transport system, pumped loop NaK (sodium-potassium eutectic mixture) rejection system; (5) Maximum power module vibration amplitude = 0.0038 cm; and (6) Design life = 7 years (60,000 hr). The results show that a single cylinder FPSE/LA is capable of meeting program goals and has attractive scaling attributes over the power range from 25 to 150 kW(sub e). Scaling beyond the 150 kW(sub e) power level, the power module efficiency falls and the power module specific mass reaches 10 kg/kW(sub e) at a power output of 500 kW(sub e). A discussion of scaling rules for the engine, alternator, and heat transport systems is presented, along with a detailed description of the conceptual design of a 150 kW(sub e) power module that meets the requirements. Included is a discussion of the design of a dynamic balance system. A parametric study of power module performance conducted over the power output range of 25 to 150 kW(sub e) for temperature ratios of 1.7, 2.0, 2.5, and 3.0 is presented and discussed. The results show that as the temperature ratio decreases, the efficiency falls and specific mass increases. At a temperature ratio of 1.7, the 150 kW(sub e) power module cannot satisfy both efficiency and specific mass goals. As the power level increases from 25 to 150 kW(sub e) at a fixed temperature ratio, power

  17. The study, design and simulation of a free piston Stirling engine linear alternatorThe study, design and simulation of a free piston Stirling engine linear alternator

    Directory of Open Access Journals (Sweden)

    Teodora Susana Oros

    2014-12-01

    Full Text Available This paper presents a study, design and simulation of a Free Piston Stirling Engine Linear Alternator. There are presented the main steps of the magnetic and electric calculations for a permanent magnet linear alternator of fixed coil and moving magnets type. Finally, a detailed thermal, mechanical and electrical model for a Stirling engine linear alternator have been made in SIMULINK simulation program. The linear alternator simulation model uses a controllable DC voltage which simulates the linear alternator combined with a rectifier, a variable load and a DC-DC converter, which compensates for the variable nature of Stirling engine operation, and ensures a constant voltage output regardless of the load.

  18. Bio-inspired routes for synthesizing efficient nanoscale platinum electrocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jennifer N. [Univ. of California, San Diego, CA (United States); Wang, Joseph [Univ. of California, San Diego, CA (United States)

    2014-08-31

    The overall objective of the proposed research is to use fundamental advances in bionanotechnology to design powerful platinum nanocrystal electrocatalysts for fuel cell applications. The new economically-viable, environmentally-friendly, bottom-up biochemical synthetic strategy will produce platinum nanocrystals with tailored size, shape and crystal orientation, hence leading to a maximum electrochemical reactivity. There are five specific aims to the proposed bio-inspired strategy for synthesizing efficient electrocatalytic platinum nanocrystals: (1) isolate peptides that both selectively bind particular crystal faces of platinum and promote the nucleation and growth of particular nanocrystal morphologies, (2) pattern nanoscale 2-dimensional arrays of platinum nucleating peptides from DNA scaffolds, (3) investigate the combined use of substrate patterned peptides and soluble peptides on nanocrystal morphology and growth (4) synthesize platinum crystals on planar and large-area carbon electrode supports, and (5) perform detailed characterization of the electrocatalytic behavior as a function of catalyst size, shape and morphology. Project Description and Impact: This bio-inspired collaborative research effort will address key challenges in designing powerful electrocatalysts for fuel cell applications by employing nucleic acid scaffolds in combination with peptides to perform specific, environmentally-friendly, simultaneous bottom-up biochemical synthesis and patterned assembly of highly uniform and efficient platinum nanocrystal catalysts. Bulk synthesis of nanoparticles usually produces a range of sizes, accessible catalytic sites, crystal morphologies, and orientations, all of which lead to inconsistent catalytic activities. In contrast, biological systems routinely demonstrate exquisite control over inorganic syntheses at neutral pH and ambient temperature and pressures. Because the orientation and arrangement of the templating biomolecules can be precisely

  19. Biofouling behavior and performance of forward osmosis membranes with bioinspired surface modification in osmotic membrane bioreactor.

    Science.gov (United States)

    Li, Fang; Cheng, Qianxun; Tian, Qing; Yang, Bo; Chen, Qianyuan

    2016-07-01

    Forward osmosis (FO) has received considerable interest for water and energy related applications in recent years. Biofouling behavior and performance of cellulose triacetate (CTA) forward osmosis membranes with bioinspired surface modification via polydopamine (PD) coating and poly (ethylene glycol) (PEG) grafting (PD-g-PEG) in a submerged osmotic membrane bioreactor (OMBR) were investigated in this work. The modified membranes exhibited lower flux decline than the pristine one in OMBR, confirming that the bioinspired surface modification improved the antifouling ability of the CTA FO membrane. The result showed that the decline of membrane flux related to the increase of the salinity and MLSS concentration of the mixed liquid. It was concluded that the antifouling ability of modified membranes ascribed to the change of surface morphology in addition to the improvement of membrane hydrophilicity. The bioinspired surface modifications might improve the anti-adhesion for the biopolymers and biocake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Initiatives to Foster Engineering Student Motivation: A Case Study

    Science.gov (United States)

    Reyes, Encarnación; Enfedaque, Alejandro; Gálvez, Jaime C.

    2017-01-01

    There is little doubt that student motivation is essential in providing a beneficial learning experience. One way to produce such motivation is to stimulate it through suitable assessment methods. This paper shares the experience acquired by the authors, who are university lecturers in Civil Engineering at the Universidad Politécnica de Madrid,…

  1. Engineering Geophysical Study of the Convocation Square, Kaduna

    African Journals Online (AJOL)

    Abdullahi et. al

    In recent times, the collapse of civil engineering structures has been on the increase for reasons associated ... giving rise to cracks or structural differential settlements has been a great concern to geoscientists. This has ... commonly noted from the bulging of brick or masonry blocks. These in turn reveal the risk or horizon ...

  2. Open Source Projects in Software Engineering Education: A Mapping Study

    Science.gov (United States)

    Nascimento, Debora M. C.; Almeida Bittencourt, Roberto; Chavez, Christina

    2015-01-01

    Context: It is common practice in academia to have students work with "toy" projects in software engineering (SE) courses. One way to make such courses more realistic and reduce the gap between academic courses and industry needs is getting students involved in open source projects (OSP) with faculty supervision. Objective: This study…

  3. Re-Engineering Graduate Skills--A Case Study

    Science.gov (United States)

    Nair, Chenicheri Sid; Patil, Arun; Mertova, Patricie

    2009-01-01

    Research on student-learning outcomes indicates that university graduates do not possess important skills required by employers, such as communication, decision-making, problem-solving, leadership, emotional intelligence, social ethics skills as well as the ability to work with people of different backgrounds. Today, engineering graduates are…

  4. Experimental bath engineering for quantitative studies of quantum control

    CSIR Research Space (South Africa)

    Soare, A

    2014-04-01

    Full Text Available We develop and demonstrate a technique to engineer universal unitary baths in quantum systems. Using the correspondence between unitary decoherence due to ambient environmental noise and errors in a control system for quantum bits, we show how a...

  5. Medical engineering at Cardiff University. Part 2: Postgraduate programmes of study.

    Science.gov (United States)

    Theobald, P; O'Doherty, D M; Holt, C A; Evans, S L; Jones, M D

    2009-05-01

    The Medical Engineering team within the School of Engineering, Cardiff University, delivers two postgraduate programmes of study. Established over 10 years ago, the part-time MSc programmes in Orthopaedic Engineering and Clinical Engineering offer the opportunity of further study while remaining within full-time employment. Both programmes deliver 120 taught credits over two academic years via a series of residential weekends, with successful completion enabling the student to undertake and then defend a 60-credit research dissertation. Fulfilling a specific role on the career pathway for both student cohorts, the strength of each programme is indicated by the consistent number of applicants.

  6. Liquid sprays and flow studies in the direct-injection diesel engine under motored conditions

    Science.gov (United States)

    Nguyen, Hung Lee; Carpenter, Mark H.; Ramos, Juan I.; Schock, Harold J.; Stegeman, James D.

    1988-01-01

    A two dimensional, implicit finite difference method of the control volume variety, a two equation model of turbulence, and a discrete droplet model were used to study the flow field, turbulence levels, fuel penetration, vaporization, and mixing in diesel engine environments. The model was also used to study the effects of engine speed, injection angle, spray cone angle, droplet distribution, and intake swirl angle on the flow field, spray penetration and vaporization, and turbulence in motored two-stroke diesel engines. It is shown that there are optimum conditions for injection, which depend on droplet distribution, swirl, spray cone angle, and injection angle. The optimum conditions result in good spray penetration and vaporization and in good fuel mixing. The calculation presented clearly indicates that internal combustion engine models can be used to assess, at least qualitatively, the effects of injection characteristics and engine operating conditions on the flow field and on the spray penetration and vaporization in diesel engines.

  7. Aerodynamic efficiency of a bioinspired flapping wing rotor at low Reynolds number.

    Science.gov (United States)

    Li, H; Guo, S

    2018-03-01

    This study investigates the aerodynamic efficiency of a bioinspired flapping wing rotor kinematics which combines an active vertical flapping motion and a passive horizontal rotation induced by aerodynamic thrust. The aerodynamic efficiencies for producing both vertical lift and horizontal thrust of the wing are obtained using a quasi-steady aerodynamic model and two-dimensional (2D) CFD analysis at Reynolds number of 2500. The calculated efficiency data show that both efficiencies (propulsive efficiency- η p , and efficiency for producing lift- P f ) of the wing are optimized at Strouhal number ( St ) between 0.1 and 0.5 for a range of wing pitch angles (upstroke angle of attack α u less than 45°); the St for high P f ( St  = 0.1 ∼ 0.3) is generally lower than for high η p ( St  = 0.2 ∼ 0.5), while the St for equilibrium rotation states lies between the two. Further systematic calculations show that the natural equilibrium of the passive rotating wing automatically converges to high-efficiency states: above 85% of maximum P f can be obtained for a wide range of prescribed wing kinematics. This study provides insight into the aerodynamic efficiency of biological flyers in cruising flight, as well as practical applications for micro air vehicle design.

  8. Programmable thermal emissivity structures based on bioinspired self-shape materials

    Science.gov (United States)

    Athanasopoulos, N.; Siakavellas, N. J.

    2015-12-01

    Programmable thermal emissivity structures based on the bioinspired self-shape anisotropic materials were developed at macro-scale, and further studied theoretically at smaller scale. We study a novel concept, incorporating materials that are capable of transforming their shape via microstructural rearrangements under temperature stimuli, while avoiding the use of exotic shape memory materials or complex micro-mechanisms. Thus, programmed thermal emissivity behaviour of a surface is achievable. The self-shape structure reacts according to the temperature of the surrounding environment or the radiative heat flux. A surface which incorporates self-shape structures can be designed to quickly absorb radiative heat energy at low temperature levels, but is simultaneously capable of passively controlling its maximum temperature in order to prevent overheating. It resembles a “game” of colours, where two or more materials coexist with different values of thermal emissivity/ absorptivity/ reflectivity. The transformation of the structure conceals or reveals one of the materials, creating a surface with programmable - and therefore, variable- effective thermal emissivity. Variable thermal emissivity surfaces may be developed with a total hemispherical emissivity ratio (ɛEff_H/ɛEff_L) equal to 28.

  9. Performances of Three Miniature Bio-inspired Optic Flow Sensors under Natural Conditions

    Directory of Open Access Journals (Sweden)

    Stéphane Viollet

    2011-02-01

    Full Text Available Considerable attention has been paid during the last decade to vision-based navigation systems based on optic flow (OF cues. OF-based systems have been implemented on an increasingly large number of sighted autonomous robotic platforms. Nowadays, the OF is measured using conventional cameras, custom-made sensors and even optical mouse chips. However, very few studies have dealt so far with the reliability of these OF sensors in terms of their precision, range and sensitivity to illuminance variations. Three miniature custom-made OF sensors developed at our laboratory, which were composed of photosensors connected to an OF processing unit were tested and compared in this study, focusing on their responses and characteristics in real indoor and outdoor environments in a large range of illuminance. It was concluded that by combining a custom-made aVLSI retina equipped with Adaptive Pixels for Insect-based Sensor (APIS with a bio-inspired visual processing system, it is possible to obtain highly effective miniature sensors for measuring the OF under real environmental conditions.

  10. Design of a bio-inspired pneumatic artificial muscle with self-contained sensing.

    Science.gov (United States)

    Erin, Onder; Pol, Nishant; Valle, Luis; Yong-Lae Park

    2016-08-01

    Pneumatic artificial muscles (PAMs) are one of the most famous linear actuators in bio-inspired robotics. They can generate relatively high linear force considering their form factors and weights. Furthermore, PAMs are inexpensive compared with traditional electromagnetic actuators (e.g. DC motors) and also inherently light and compliant. In robotics applications, however, they typically require external sensing mechanisms due to their nonlinear behaviors, which may make the entire mechanical system bulky and complicated, limiting their use in simple systems. This study presents the design and fabrication of a low-cost McKibben-type PAM with a self-contained displacement and force sensing capability that does not require any external sensing elements. The proposed PAM can detect axial contraction force and displacement at the same time. In this study, the design of a traditional McKibben muscle was modified to include an inductive coil surrounding the muscle fibers. Then, a thin, soft silicone layer was coated outside of the muscle to protect and hold the sensing coil on the actuator. This novel design measures coil inductance change to determine the contraction force and the displacement. The process can be applied to a variety of existing McKibben actuator designs without significantly changing the rigidity of the actuator while minimizing the device's footprint.

  11. Integrating Internet into Engineering Education: A Case Study of Students' Usage and Attitudes in Faculty of Engineering, Ahmadu Bello University

    Directory of Open Access Journals (Sweden)

    F.O. Anafi

    2015-12-01

    Full Text Available The attitude of students towards the integration of the internet as a study tool and communication channel in teaching and learning in engineering has been investigated. A study was carried out in the Faculty of Engineering, Ahmadu Bello University Zaria, Nigeria, aimed at investigating the effect of certain variables such as gender, course of study, computer experience, and the percentage of internet usage on teaching and learning processes. A well-structured questionnaire was administered to a randomly selected five hundred (500 male and female students across the seven (7 departments of the faculty and about 85% were filled and returned. The study also examines the university management's perspectives and strategies to incorporate internet usage in teaching and learning processes especially in engineering. Amazingly, responses received showed that experience in the use of the computer in surfing the internet for problem based activities mainly affects the level of internet usage across the faculty. This factor makes some students to misplace their priority in internet usage emphasizing on e-mail correspondence and social networking rather than sourcing for information and solving problems as it is done by a few students. Furthermore, findings support that internet cannot entirely substitute for traditional teaching and learning processes like text reading but can serve as a reasonable alternative when the latter is unavailable

  12. Engineering geology studies in the National Petroleum Reserve, Alaska

    Science.gov (United States)

    Kachadoorian, Reuben; Crory, F.E.

    1984-01-01

    Engineering geology studies were conducted in direct support of the exploration program in the National Petroleum Reserve, Alaska. The studies included laboratory and field tests and observations to address design and construction problems of airfields, roads, drill pads and foundations, and to evaluate their actual performance. Permafrost containing large amounts of near surface ground ice as wedges, masses, and intergranular ice, required that all construction activity not disturb the thermal regime of the ground surface, which could lead to thaw of permafrost and ground subsidence. Summer activity, therefore was not allowable, yet the winter climate was so harsh that winter work was slow and inefficient. To allow summer operations at well sites planned for all year activity, it was necessary to adapt existing techniques for arctic construction and to devise new ones. The design and construction of facilities at the deep exploration wells at Inigok, Tunalik, and Lisburne posed the greatest challenge. These sites, requiring a year or more to drill, could only be attempted if continuous access to drilling and logistic supplies could be assured throughout the year, including the possibility of bringing in another drill rig, in the event of a blowout. Thus all-seasons airstrips were required at these wells. Sufficient quantities of local gravel were not readily available at the Inigok and Tunalik sites to construct the airstrips with the required 6 feet or more of gravel to prevent the underlying permafrost from thawing. Therefore, insulation was used to maintain the subbase of local sands in a continuously frozen state, which in turn was overlain by 15 inches of gravel or sandy gravel. Tests at the U.S. Army Waterways Experimental Station defined the minimum thickness of gravel required above the insulation to provide the desired bearing capacity for the C-130 type aircraft without crushing the insulation. Field testing also included the evaluation of another design

  13. The Effect of Case Teaching on Meaningful and Retentive Learning When Studying Genetic Engineering

    Science.gov (United States)

    Güccük, Ahmet; Köksal, Mustafa Serdar

    2017-01-01

    The purpose of this study is to investigate the effects of case teaching on how students learn about genetic engineering, in terms of meaningful learning and retention of learning. The study was designed as quasi-experimental research including 63 8th graders (28 boys and 35 girls). To collect data, genetic engineering achievement tests were…

  14. Engineers' Perceptions of Diversity and the Learning Environment at Work: A Mixed Methods Study

    Science.gov (United States)

    Firestone, Brenda L.

    2012-01-01

    The purpose of this dissertation research study was to investigate engineers' perceptions of diversity and the workplace learning environment surrounding diversity education efforts in engineering occupations. The study made use of a mixed methods methodology and was theoretically framed using a critical feminist adult education lens and…

  15. Separate tools or tool kits: an exploratory study of engineers' preferences

    NARCIS (Netherlands)

    Vliegen, Ingrid; Kleingeld, P.A.M.; van Houtum, Geert-Jan

    2010-01-01

    This paper describes an exploratory study of aspects that should be taken into consideration when optimizing tool kits, i.e. cases containing sets of tools that are used by service engineers for corrective maintenance. The study was carried out among service engineers of an Original Equipment

  16. Computer Science and Engineering Students Addressing Critical Issues Regarding Gender Differences in Computing: A Case Study

    Science.gov (United States)

    Tsagala, Evrikleia; Kordaki, Maria

    2008-01-01

    This study focuses on how Computer Science and Engineering Students (CSESs) of both genders address certain critical issues for gender differences in the field of Computer Science and Engineering (CSE). This case study is based on research conducted on a sample of 99 Greek CSESs, 43 of which were women. More specifically, these students were asked…

  17. Implementing Feminist Theory in Engineering: Obstacles within the Gender Studies Tradition

    Science.gov (United States)

    Udén, Maria K.

    2017-01-01

    Scholars have noted that there is hesitation to utilise findings from gender studies in engineering education. Issues within gender studies may be part of the matching problem. Debates concerning two concepts for new engineering paradigms are investigated: "care" and "heterogeneity." Their appeals and the respective…

  18. Use of the LITEE Lorn Manufacturing Case Study in a Senior Chemical Engineering Unit Operations Laboratory

    Science.gov (United States)

    Abraham, Nithin Susan; Abulencia, James Patrick

    2011-01-01

    This study focuses on the effectiveness of incorporating the Laboratory for Innovative Technology and Engineering Education (LITEE) Lorn Manufacturing case into a senior level chemical engineering unit operations course at Manhattan College. The purpose of using the case study is to demonstrate the relevance of ethics to chemical engineering…

  19. Software Engineers' Information Seeking Behavior in Change Impact Analysis: An Interview Study

    OpenAIRE

    Borg, Markus; Alégroth, Emil; Runeson, Per

    2017-01-01

    Software engineers working in large projects must navigate complex information landscapes. Change Impact Analysis (CIA) is a task that relies on engineers' successful information seeking in databases storing, e.g., source code, requirements, design descriptions, and test case specifications. Several previous approaches to support information seeking are task-specific, thus understanding engineers' seeking behavior in specific tasks is fundamental. We present an industrial case study on how en...

  20. Software Engineering Practices and Tool Support: an exploratory study in New Zealand

    Directory of Open Access Journals (Sweden)

    Chris Phillips

    2003-11-01

    Full Text Available This study was designed as a preliminary investigation of the practices of software engineers within New Zealand, including their use of development tools. The project involved a review of relevant literature on software engineering and CASE tools, the development and testing of an interview protocol, and structured interviews with five software engineers. This paper describes the project, presents the findings, examines the results in the context of the literature and outlines on-going funded work involving a larger survey.

  1. Bioinspired Composite Coating with Extreme Underwater Superoleophobicity and Good Stability for Wax Prevention in the Petroleum Industry.

    Science.gov (United States)

    Liang, Weitao; Zhu, Liqun; Li, Weiping; Yang, Xin; Xu, Chang; Liu, Huicong

    2015-10-13

    Wax deposition is a detrimental problem that happens during crude oil production and transportation, which greatly reduces transport efficiency and causes huge economic losses. To avoid wax deposition, a bioinspired composite coating with excellent wax prevention and anticorrosion properties is developed in this study. The prepared coating is composed of three films, including an electrodeposited Zn film for improving corrosion resistance, a phosphating film for constructing fish-scale morphology, and a silicon dioxide film modified by a simple spin-coating method for endowing the surface with superhydrophilicity. Good wax prevention performance has been investigated in a wax deposition test. The surface morphology, composition, wetting behaviors, and stability are systematically studied, and a wax prevention mechanism is proposed, which can be calculated from water film theory. This composite coating strategy which shows excellent properties in both wax prevention and stability is expected to be widely applied in the petroleum industry.

  2. Theoretical and Observational Studies of the Central Engines of AGN

    Science.gov (United States)

    Sivron, Ran

    1995-03-01

    In Active Galactic Nuclei (AGN) the luminosity is so intense that the effect of radiation pressure on a particle may exceed the gravitational attraction. It was shown that when such luminosities are reached, relatively cold (not completely ionized) thermal matter clouds may form in the central engines of AGN, where most of the luminosity originates. We show that the spectrum of emission from cold clouds embedded in hot relativistic matter is similar to the observed spectrum. We also show that within the hot relativistic matter, cold matter moves faster than the speed of sound or the Alfven speed, and shocks form. The shocks provide a mechanism by which a localized perturbation can propagate throughout the central engine. The shocked matter can emit the observed luminosity, and can explain the flux and spectral variability. It may also provide an efficient mechanism for the outward transfer of angular momentum and provide the outward flow of winds. With observations from X-ray satellites, emission features from the cold and hot matter may be revealed. Our analysis of X-ray data from the Seyfert 1 galaxy MCG - 6-30-15 over five years using detectors on the Ginga and Rosat satellites, revealed some interesting variable features. A source with hot matter emits non-thermal radiation which is Compton reflected from cold matter and then absorbed by warm (partially ionized) absorbing matter in the first model, which can be fit to the data if both the cold and warm absorbers are near the central engine. An alternative model in which the emission from the hot matter is partially covered by very warm matter (in which all elements except Iron are mostly ionized) is also successful. In this model the cold and warm matter may be at distances of up to 100 times the size of the central engine, well within the region where broad optical lines are produced. The flux variability is more naturally explained by the second model. Our results support the existence of cold matter in, or

  3. An antioxidant bioinspired phenolic polymer for efficient stabilization of polyethylene.

    Science.gov (United States)

    Ambrogi, Veronica; Panzella, Lucia; Persico, Paola; Cerruti, Pierfrancesco; Lonz, Carlo A; Carfagna, Cosimo; Verotta, Luisella; Caneva, Enrico; Napolitano, Alessandra; d'Ischia, Marco

    2014-01-13

    The synthesis, structural characterization and properties of a new bioinspired phenolic polymer (polyCAME) produced by oxidative polymerization of caffeic acid methyl ester (CAME) with horseradish peroxidase (HRP)-H2O2 is reported as a new sustainable stabilizer toward polyethylene (PE) thermal and photo-oxidative degradation. PolyCAME exhibits high stability toward decarboxylation and oxidative degradation during the thermal processes associated with PE film preparation. Characterization of PE films by thermal methods, photo-oxidative treatments combined with chemiluminescence, and FTIR spectroscopy and mechanical tests indicate a significant effect of polyCAME on PE durability. Data from antioxidant capacity tests suggest that the protective effects of polyCAME are due to the potent scavenging activity on aggressive OH radicals, the efficient H-atom donor properties inducing free radical quenching, and the ferric ion reducing ability. PolyCAME is thus proposed as a novel easily accessible, eco-friendly, and biocompatible biomaterial for a sustainable approach to the stabilization of PE films in packaging and other applications.

  4. SABRE: a bio-inspired fault-tolerant electronic architecture

    International Nuclear Information System (INIS)

    Bremner, P; Samie, M; Dragffy, G; Pipe, A G; Liu, Y; Tempesti, G; Timmis, J; Tyrrell, A M

    2013-01-01

    As electronic devices become increasingly complex, ensuring their reliable, fault-free operation is becoming correspondingly more challenging. It can be observed that, in spite of their complexity, biological systems are highly reliable and fault tolerant. Hence, we are motivated to take inspiration for biological systems in the design of electronic ones. In SABRE (self-healing cellular architectures for biologically inspired highly reliable electronic systems), we have designed a bio-inspired fault-tolerant hierarchical architecture for this purpose. As in biology, the foundation for the whole system is cellular in nature, with each cell able to detect faults in its operation and trigger intra-cellular or extra-cellular repair as required. At the next level in the hierarchy, arrays of cells are configured and controlled as function units in a transport triggered architecture (TTA), which is able to perform partial-dynamic reconfiguration to rectify problems that cannot be solved at the cellular level. Each TTA is, in turn, part of a larger multi-processor system which employs coarser grain reconfiguration to tolerate faults that cause a processor to fail. In this paper, we describe the details of operation of each layer of the SABRE hierarchy, and how these layers interact to provide a high systemic level of fault tolerance. (paper)

  5. Polymorphic regenerated silk fibers assembled through bioinspired spinning.

    Science.gov (United States)

    Ling, Shengjie; Qin, Zhao; Li, Chunmei; Huang, Wenwen; Kaplan, David L; Buehler, Markus J

    2017-11-09

    A variety of artificial spinning methods have been applied to produce regenerated silk fibers; however, how to spin regenerated silk fibers that retain the advantages of natural silks in terms of structural hierarchy and mechanical properties remains challenging. Here, we show a bioinspired approach to spin regenerated silk fibers. First, we develop a nematic silk microfibril solution, highly viscous and stable, by partially dissolving silk fibers into microfibrils. This solution maintains the hierarchical structures in natural silks and serves as spinning dope. It is then spun into regenerated silk fibers by direct extrusion in the air, offering a useful route to generate polymorphic and hierarchical regenerated silk fibers with physical properties beyond natural fiber construction. The materials maintain the structural hierarchy and mechanical properties of natural silks, including a modulus of 11 ± 4 GPa, even higher than natural spider silk. It can further be functionalized with a conductive silk/carbon nanotube coating, responsive to changes in humidity and temperature.

  6. Bioinspired Transparent Laminated Composite Film for Flexible Green Optoelectronics.

    Science.gov (United States)

    Lee, Daewon; Lim, Young-Woo; Im, Hyeon-Gyun; Jeong, Seonju; Ji, Sangyoon; Kim, Yong Ho; Choi, Gwang-Mun; Park, Jang-Ung; Lee, Jung-Yong; Jin, Jungho; Bae, Byeong-Soo

    2017-07-19

    Herein, we report a new version of a bioinspired chitin nanofiber (ChNF) transparent laminated composite film (HCLaminate) made of siloxane hybrid materials (hybrimers) reinforced with ChNFs, which mimics the nanofiber-matrix structure of hierarchical biocomposites. Our HCLaminate is produced via vacuum bag compressing and subsequent UV-curing of the matrix resin-impregnated ChNF transparent paper (ChNF paper). It is worthwhile to note that this new type of ChNF-based transparent substrate film retains the strengths of the original ChNF paper and compensates for ChNF paper's drawbacks as a flexible transparent substrate. As a result, compared with high-performance synthetic plastic films, such as poly(ethylene terephthalate), poly(ether sulfone), poly(ethylene naphthalate), and polyimide, our HCLaminate is characterized to exhibit extremely smooth surface topography, outstanding optical clarity, high elastic modulus, high dimensional stability, etc. To prove our HCLaminate as a substrate film, we use it to fabricate flexible perovskite solar cells and a touch-screen panel. As far as we know, this work is the first to demonstrate flexible optoelectronics, such as flexible perovskite solar cells and a touch-screen panel, actually fabricated on a composite film made of ChNF. Given its desirable macroscopic properties, we envision our HCLaminate being utilized as a transparent substrate film for flexible green optoelectronics.

  7. Bio-Inspired Stretchable Absolute Pressure Sensor Network.

    Science.gov (United States)

    Guo, Yue; Li, Yu-Hung; Guo, Zhiqiang; Kim, Kyunglok; Chang, Fu-Kuo; Wang, Shan X

    2016-01-02

    A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4'' wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles.

  8. Bio-inspired Murray materials for mass transfer and activity

    Science.gov (United States)

    Zheng, Xianfeng; Shen, Guofang; Wang, Chao; Li, Yu; Dunphy, Darren; Hasan, Tawfique; Brinker, C. Jeffrey; Su, Bao-Lian

    2017-04-01

    Both plants and animals possess analogous tissues containing hierarchical networks of pores, with pore size ratios that have evolved to maximize mass transport and rates of reactions. The underlying physical principles of this optimized hierarchical design are embodied in Murray's law. However, we are yet to realize the benefit of mimicking nature's Murray networks in synthetic materials due to the challenges in fabricating vascularized structures. Here we emulate optimum natural systems following Murray's law using a bottom-up approach. Such bio-inspired materials, whose pore sizes decrease across multiple scales and finally terminate in size-invariant units like plant stems, leaf veins and vascular and respiratory systems provide hierarchical branching and precise diameter ratios for connecting multi-scale pores from macro to micro levels. Our Murray material mimics enable highly enhanced mass exchange and transfer in liquid-solid, gas-solid and electrochemical reactions and exhibit enhanced performance in photocatalysis, gas sensing and as Li-ion battery electrodes.

  9. A bio-inspired memory model for structural health monitoring

    International Nuclear Information System (INIS)

    Zheng, Wei; Zhu, Yong

    2009-01-01

    Long-term structural health monitoring (SHM) systems need intelligent management of the monitoring data. By analogy with the way the human brain processes memories, we present a bio-inspired memory model (BIMM) that does not require prior knowledge of the structure parameters. The model contains three time-domain areas: a sensory memory area, a short-term memory area and a long-term memory area. First, the initial parameters of the structural state are specified to establish safety criteria. Then the large amount of monitoring data that falls within the safety limits is filtered while the data outside the safety limits are captured instantly in the sensory memory area. Second, disturbance signals are distinguished from danger signals in the short-term memory area. Finally, the stable data of the structural balance state are preserved in the long-term memory area. A strategy for priority scheduling via fuzzy c-means for the proposed model is then introduced. An experiment on bridge tower deformation demonstrates that the proposed model can be applied for real-time acquisition, limited-space storage and intelligent mining of the monitoring data in a long-term SHM system

  10. A bio-inspired electrocommunication system for small underwater robots.

    Science.gov (United States)

    Wang, Wei; Liu, Jindong; Xie, Guangming; Wen, Li; Zhang, Jianwei

    2017-03-29

    Weakly electric fishes (Gymnotid and Mormyrid) use an electric field to communicate efficiently (termed electrocommunication) in the turbid waters of confined spaces where other communication modalities fail. Inspired by this biological phenomenon, we design an artificial electrocommunication system for small underwater robots and explore the capabilities of such an underwater robotic communication system. An analytical model for electrocommunication is derived to predict the effect of the key parameters such as electrode distance and emitter current of the system on the communication performance. According to this model, a low-dissipation, and small-sized electrocommunication system is proposed and integrated into a small robotic fish. We characterize the communication performance of the robot in still water, flowing water, water with obstacles and natural water conditions. The results show that underwater robots are able to communicate electrically at a speed of around 1 k baud within about 3 m with a low power consumption (less than 1 W). In addition, we demonstrate that two leader-follower robots successfully achieve motion synchronization through electrocommunication in the three-dimensional underwater space, indicating that this bio-inspired electrocommunication system is a promising setup for the interaction of small underwater robots.

  11. Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

    Science.gov (United States)

    Potyrailo, Radislav; Naik, Rajesh R.

    2013-07-01

    At present, monitoring of air at the workplace, in urban environments, and on battlefields; exhaled air from medical patients; air in packaged food containers; and so forth can be accomplished with different types of analytical instruments. Vapor sensors have their niche in these measurements when an unobtrusive, low-power, and cost-sensitive technical solution is required. Unfortunately, existing vapor sensors often degrade their vapor-quantitation accuracy in the presence of high levels of interferences and cannot quantitate several components in complex gas mixtures. Thus, new sensing approaches with improved sensor selectivity are required. This technological task can be accomplished by the careful design of sensing materials with new performance properties and by coupling these materials with the suitable physical transducers. This review is focused on the assessment of the capabilities of bionanomaterials and bioinspired nanostructures for selective vapor sensing. We demonstrate that these sensing materials can operate with diverse transducers based on electrical, mechanical, and optical readout principles and can provide vapor-response selectivity previously unattainable by using other sensing materials. This ability for selective vapor sensing provides opportunities to significantly impact the major directions in development and application scenarios of vapor sensors.

  12. Bioinspired Programmable Polymer Gel Controlled by Swellable Guest Medium.

    Science.gov (United States)

    Deng, Heng; Dong, Yuan; Su, Jheng-Wun; Zhang, Cheng; Xie, Yunchao; Zhang, Chi; Maschmann, Matthew R; Lin, Yuyi; Lin, Jian

    2017-09-13

    Responsive materials with functions of forming three-dimensional (3D) origami and/or kirigami structures have a broad range of applications in bioelectronics, metamaterials, microrobotics, and microelectromechanical (MEMS) systems. To realize such functions, building blocks of actuating components usually possess localized inhomogeneity so that they respond differently to external stimuli. Previous fabrication strategies lie in localizing nonswellable or less-swellable guest components in their swellable host polymers to reduce swelling ability. Herein, inspired by ice plant seed capsules, we report an opposite strategy of implanting swellable guest medium inside nonswellable host polymers to locally enhance the swelling inhomogeneity. Specifically, we adopted a skinning effect induced surface polymerization combined with direct laser writing to control gradient of swellable cyclopentanone (CP) in both vertical and lateral directions of the nonswellable SU-8. For the first time, the laser direct writing was used as a novel strategy for patterning programmable polymer gel films. Upon stimulation of organic solvents, the dual-gradient gel films designed by origami or kirigami principles exhibit reversible 3D shape transformation. Molecular dynamics (MD) simulation illustrates that CP greatly enhances diffusion rates of stimulus solvent molecules in the SU-8 matrix, which offers the driving force for the programmable response. Furthermore, this bioinspired strategy offers unique capabilities in fabricating responsive devices such as a soft gripper and a locomotive robot, paving new routes to many other responsive polymers.

  13. The mechanics of tessellations - bioinspired strategies for fracture resistance.

    Science.gov (United States)

    Fratzl, Peter; Kolednik, Otmar; Fischer, F Dieter; Dean, Mason N

    2016-01-21

    Faced with a comparatively limited palette of minerals and organic polymers as building materials, evolution has arrived repeatedly on structural solutions that rely on clever geometric arrangements to avoid mechanical trade-offs in stiffness, strength and flexibility. In this tutorial review, we highlight the concept of tessellation, a structural motif that involves periodic soft and hard elements arranged in series and that appears in a vast array of invertebrate and vertebrate animal biomaterials. We start from basic mechanics principles on the effects of material heterogeneities in hypothetical structures, to derive common concepts from a diversity of natural examples of one-, two- and three-dimensional tilings/layerings. We show that the tessellation of a hard, continuous surface - its atomization into discrete elements connected by a softer phase - can theoretically result in maximization of material toughness, with little expense to stiffness or strength. Moreover, the arrangement of soft/flexible and hard/stiff elements into particular geometries can permit surprising functions, such as signal filtering or 'stretch and catch' responses, where the constrained flexibility of systems allows a built-in safety mechanism for ensuring that both compressive and tensile loads are managed well. Our analysis unites examples ranging from exoskeletal materials (fish scales, arthropod cuticle, turtle shell) to endoskeletal materials (bone, shark cartilage, sponge spicules) to attachment devices (mussel byssal threads), from both invertebrate and vertebrate animals, while spotlighting success and potential for bio-inspired manmade applications.

  14. Discovery of C-3 Tethered 2-oxo-benzo[1,4]oxazines as Potent Antioxidants: Bio-Inspired Based Design, Synthesis, Biological Evaluation, Cytotoxic, and in Silico Molecular Docking Studies

    Directory of Open Access Journals (Sweden)

    Vashundhra Sharma

    2018-03-01

    Full Text Available The discovery of C-3 tethered 2-oxo-benzo[1,4]oxazines as potent antioxidants is disclosed. All the analogs 20a-20ab have been synthesized via “on water” ultrasound-assisted irradiation conditions in excellent yields (upto 98%. All the compounds have been evaluated for their in vitro antioxidant activities using DPPH free radical scavenging assay as well as FRAP assay. The result showed promising antioxidant activities having IC50 values in the range of 4.74 ± 0.08 to 92.20 ± 1.54 μg/mL taking ascorbic acid (IC50 = 4.57 μg/mL as standard reference. In this study, compounds 20b and 20t, the most active compound of the series, showed IC50 values of 6.89 ± 0.07 μg/mL and 4.74 ± 0.08 μg/mL, respectively in comparison with ascorbic acid. In addition, the detailed SAR study shows that electron-withdrawing group increases antioxidant activity and vice versa. Furthermore, in the FRAP assay, eight compounds (20c, 20j, 20m, 20n, 20r, 20u, 20z, and 20aa were found more potent than standard reference BHT (C0.5FRAP = 546.0 ± 13.6 μM. The preliminary cytotoxic study reveals the non-toxic nature of active compounds 20b and 20t in non-cancerous 3T3 fibroblast cell lines in MTT assay up to 250 μg/mL concentration. The results were validated via carrying out in silico molecular docking studies of promising compounds 20a, 20b, and 20t in comparison with standard reference. To the best of our knowledge, this is the first detailed study of C-3 tethered 2-oxo-benzo[1,4]oxazines as potential antioxidant agents.

  15. Computational Design of Multi-component Bio-Inspired Bilayer Membranes

    Directory of Open Access Journals (Sweden)

    Evan Koufos

    2014-04-01

    Full Text Available Our investigation is motivated by the need to design bilayer membranes with tunable interfacial and mechanical properties for use in a range of applications, such as targeted drug delivery, sensing and imaging. We draw inspiration from biological cell membranes and focus on their principal constituents. In this paper, we present our results on the role of molecular architecture on the interfacial, structural and dynamical properties of bio-inspired membranes. We focus on four lipid architectures with variations in the head group shape and the hydrocarbon tail length. Each lipid species is composed of a hydrophilic head group and two hydrophobic tails. In addition, we study a model of the Cholesterol molecule to understand the interfacial properties of a bilayer membrane composed of rigid, single-tail molecular species. We demonstrate the properties of the bilayer membranes to be determined by the molecular architecture and rigidity of the constituent species. Finally, we demonstrate the formation of a stable mixed bilayer membrane composed of Cholesterol and one of the phospholipid species. Our approach can be adopted to design multi-component bilayer membranes with tunable interfacial and mechanical properties. We use a Molecular Dynamics-based mesoscopic simulation technique called Dissipative Particle Dynamics that resolves the molecular details of the components through soft-sphere coarse-grained models and reproduces the hydrodynamic behavior of the system over extended time scales.

  16. Bioinspired Fabrication of one dimensional graphene fiber with collection of droplets application.

    Science.gov (United States)

    Song, Yun-Yun; Liu, Yan; Jiang, Hao-Bo; Li, Shu-Yi; Kaya, Cigdem; Stegmaier, Thomas; Han, Zhi-Wu; Ren, Lu-Quan

    2017-09-21

    We designed a kind of smart bioinspired fiber with multi-gradient and multi-scale spindle knots by combining polydimethylsiloxane (PDMS) and graphene oxide (GO). Multilayered graphene structures can produce obvious wettability change after laser etching due to increased roughness. We demonstrate that the cooperation between curvature and the controllable wettability play an important role in water gathering, which regulate effectively the motion of tiny water droplets. In addition, due to the effective cooperation of multi-gradient and multi-scale hydrophilic spindle knots, the length of the three-phase contact line (TCL) can be longer, which makes a great contribution to the improvement of collecting efficiency and water-hanging ability. This study offers a novel insight into the design of smart materials that may control the transport of tiny drops reversibly in directions, which could potentially be extended to the realms of in microfluidics, fog harvesting filtration and condensers designs, and further increase water collection efficiency and hanging ability.

  17. Morphological self stabilization of locomotion gaits: illustration on a few examples from bio-inspired locomotion.

    Science.gov (United States)

    Chevallereau, Christine; Boyer, Frédéric; Porez, Mathieu; Mauny, Johan; Aoustin, Yannick

    2017-06-20

    To a large extent, robotics locomotion can be viewed as cyclic motions, named gaits. Due to the high complexity of the locomotion dynamics, to find the control laws that ensure an expected gait and its stability with respect to external perturbations, is a challenging issue for feedback control. To address this issue, a promising way is to take inspiration from animals that intensively exploit the interactions of the passive degrees of freedom of their body with their physical surroundings, to outsource the high-level exteroceptive feedback control to low-level proprioceptive ones. In this case, passive interactions can ensure most of the expected control goals. In this article, we propose a methodological framework to study the role of morphology in the design of locomotion gaits and their stability. This framework ranges from modelling to control aspects, and is illustrated through three examples from bio-inspired locomotion: a three-dimensional micro air vehicle in hovering flight, a pendular planar climber and a bipedal planar walker. In these three cases, we will see how simple considerations based on the morphology of the body can ensure the existence of passive stable gaits without requiring any high-level control.

  18. Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Hu Bing-Shan

    2009-09-01

    Full Text Available Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

  19. Mechanical properties of a bio-inspired robotic knifefish with an undulatory propulsor

    International Nuclear Information System (INIS)

    Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A; Lauder, George V

    2011-01-01

    South American electric knifefish are a leading model system within neurobiology. Recent efforts have focused on understanding their biomechanics and relating this to their neural processing strategies. Knifefish swim by means of an undulatory fin that runs most of the length of their body, affixed to the belly. Propelling themselves with this fin enables them to keep their body relatively straight while swimming, enabling straightforward robotic implementation with a rigid hull. In this study, we examined the basic properties of undulatory swimming through use of a robot that was similar in some key respects to the knifefish. As we varied critical fin kinematic variables such as frequency, amplitude, and wavelength of sinusoidal traveling waves, we measured the force generated by the robot when it swam against a stationary sensor, and its velocity while swimming freely within a flow tunnel system. Our results show that there is an optimal operational region in the fin's kinematic parameter space. The optimal actuation parameters found for the robotic knifefish are similar to previously observed parameters for the black ghost knifefish, Apteronotus albifrons. Finally, we used our experimental results to show how the force generated by the robotic fin can be decomposed into thrust and drag terms. Our findings are useful for future bio-inspired underwater vehicles as well as for understanding the mechanics of knifefish swimming.

  20. Mechanical properties of a bio-inspired robotic knifefish with an undulatory propulsor

    Energy Technology Data Exchange (ETDEWEB)

    Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A [Department of Mechanical Engineering, Northwestern University, Evanston, IL (United States); Lauder, George V, E-mail: maciver@northwestern.edu [Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA (United States)

    2011-06-15

    South American electric knifefish are a leading model system within neurobiology. Recent efforts have focused on understanding their biomechanics and relating this to their neural processing strategies. Knifefish swim by means of an undulatory fin that runs most of the length of their body, affixed to the belly. Propelling themselves with this fin enables them to keep their body relatively straight while swimming, enabling straightforward robotic implementation with a rigid hull. In this study, we examined the basic properties of undulatory swimming through use of a robot that was similar in some key respects to the knifefish. As we varied critical fin kinematic variables such as frequency, amplitude, and wavelength of sinusoidal traveling waves, we measured the force generated by the robot when it swam against a stationary sensor, and its velocity while swimming freely within a flow tunnel system. Our results show that there is an optimal operational region in the fin's kinematic parameter space. The optimal actuation parameters found for the robotic knifefish are similar to previously observed parameters for the black ghost knifefish, Apteronotus albifrons. Finally, we used our experimental results to show how the force generated by the robotic fin can be decomposed into thrust and drag terms. Our findings are useful for future bio-inspired underwater vehicles as well as for understanding the mechanics of knifefish swimming.

  1. Mechanical properties of a bio-inspired robotic knifefish with an undulatory propulsor.

    Science.gov (United States)

    Curet, Oscar M; Patankar, Neelesh A; Lauder, George V; MacIver, Malcolm A

    2011-06-01

    South American electric knifefish are a leading model system within neurobiology. Recent efforts have focused on understanding their biomechanics and relating this to their neural processing strategies. Knifefish swim by means of an undulatory fin that runs most of the length of their body, affixed to the belly. Propelling themselves with this fin enables them to keep their body relatively straight while swimming, enabling straightforward robotic implementation with a rigid hull. In this study, we examined the basic properties of undulatory swimming through use of a robot that was similar in some key respects to the knifefish. As we varied critical fin kinematic variables such as frequency, amplitude, and wavelength of sinusoidal traveling waves, we measured the force generated by the robot when it swam against a stationary sensor, and its velocity while swimming freely within a flow tunnel system. Our results show that there is an optimal operational region in the fin's kinematic parameter space. The optimal actuation parameters found for the robotic knifefish are similar to previously observed parameters for the black ghost knifefish, Apteronotus albifrons. Finally, we used our experimental results to show how the force generated by the robotic fin can be decomposed into thrust and drag terms. Our findings are useful for future bio-inspired underwater vehicles as well as for understanding the mechanics of knifefish swimming.

  2. Production of bioelectricity, bio-hydrogen, high value chemicals and bioinspired nanomaterials by electrochemically active biofilms.

    Science.gov (United States)

    Kalathil, Shafeer; Khan, Mohammad Mansoob; Lee, Jintae; Cho, Moo Hwan

    2013-11-01

    Microorganisms naturally form biofilms on solid surfaces for their mutual benefits including protection from environmental stresses caused by contaminants, nutritional depletion or imbalances. The biofilms are normally dangerous to human health due to their inherited robustness. On the other hand, a recent study suggested that electrochemically active biofilms (EABs) generated by electrically active microorganisms have properties that can be used to catalyze or control the electrochemical reactions in a range of fields, such as bioenergy production, bioremediation, chemical/biological synthesis, bio-corrosion mitigation and biosensor development. EABs have attracted considerable attraction in bioelectrochemical systems (BESs), such as microbial fuel cells and microbial electrolysis cells, where they act as living bioanode or biocathode catalysts. Recently, it was reported that EABs can be used to synthesize metal nanoparticles and metal nanocomposites. The EAB-mediated synthesis of metal and metal-semiconductor nanocomposites is expected to provide a new avenue for the greener synthesis of nanomaterials with high efficiency and speed than other synthetic methods. This review covers the general introduction of EABs, as well as the applications of EABs in BESs, and the production of bio-hydrogen, high value chemicals and bio-inspired nanomaterials. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. An Experimental Investigation on Bio-inspired Icephobic Coatings for Aircraft Icing Mitigation

    Science.gov (United States)

    Hu, Hui; Li, Haixing; Waldman, Rye

    2016-11-01

    By leveraging the Icing Research Tunnel available at Iowa State University (ISU-IRT), a series of experimental investigations were conducted to elucidate the underlying physics pertinent to aircraft icing phenomena. A suite of advanced flow diagnostic techniques, which include high-speed photographic imaging, digital image projection (DIP), and infrared (IR) imaging thermometry, were developed and applied to quantify the transient behavior of water droplet impingement, wind-driven surface water runback, unsteady heat transfer and dynamic ice accreting process over the surfaces of airfoil/wing models. The icephobic performance of various bio-inspired superhydrophobic coatings were evaluated quantitatively at different icing conditions. The findings derived from the icing physics studies can be used to improve current icing accretion models for more accurate prediction of ice formation and accretion on aircraft wings and to develop effective anti-/deicing strategies for safer and more efficient operation of aircraft in cold weather. The research work is partially supported by NASA with Grant Number NNX12AC21A and National Science Foundation under Award Numbers of CBET-1064196 and CBET-1435590.

  4. Bioinspired synthesis and self-assembly of hybrid organic–inorganic nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Honghu [Iowa State Univ., Ames, IA (United States)

    2016-12-17

    Nature is replete with complex organic–inorganic hierarchical materials of diverse yet specific functions. These materials are intricately designed under physiological conditions through biomineralization and biological self-assembly processes. Tremendous efforts have been devoted to investigating mechanisms of such biomineralization and biological self-assembly processes as well as gaining inspiration to develop biomimetic methods for synthesis and self-assembly of functional nanomaterials. In this work, we focus on the bioinspired synthesis and self-assembly of functional inorganic nanomaterials templated by specialized macromolecules including proteins, DNA and polymers. The in vitro biomineralization process of the magnetite biomineralizing protein Mms6 has been investigated using small-angle X-ray scattering. Templated by Mms6, complex magnetic nanomaterials can be synthesized on surfaces and in the bulk. DNA and synthetic polymers have been exploited to construct macroscopic two- and three-dimensional (2D and 3D) superlattices of gold nanocrystals. Employing X-ray scattering and spectroscopy techniques, the self-assembled structures and the self-assembly mechanisms have been studied, and theoretical models have been developed. Our results show that specialized macromolecules including proteins, DNA and polymers act as effective templates for synthesis and self-assembly of nanomaterials. These bottom-up approaches provide promising routes to fabricate hybrid organic–inorganic nanomaterials with rationally designed hierarchical structures, targeting specific functions.

  5. Working principle of bio-inspired shape memory alloy composite actuators

    International Nuclear Information System (INIS)

    Smith, Colin; Villanueva, Alex; Joshi, Keyur; Tadesse, Yonas; Priya, Shashank

    2011-01-01

    Recently, bio-inspired shape memory alloy composite (BISMAC) actuators have been shown to mimic the deformation characteristics of natural jellyfish medusa. In this study, a constant cross-section BISMAC actuator was characterized in terms of bending deflection and force in conjunction with microscopy to understand its deformation mechanism. The actuator showed bending deflection of 111% with respect to the active length along with a blocking force of 0.061 N. The resulting energy density of the composite actuator was 4929 J m −3 at an input voltage and current level of 12 V and 0.7 A, respectively. For a dry-state actuator, this performance is extremely high and represents an optimum combination of force and deflection. Experiments reveal that BISMAC's performance is related to the moment induced from tip attachment of the shape memory alloy (SMA) rather than to friction within the composite structure. A physics-based model of BISMAC structure is presented which shows that the actuator is highly sensitive to the distance between the SMA wire and the incompressible component. While SMA has both stress and strain limitations, the limiting factor in BISMAC actuators is dependent on separation distance. The limiting factor in BISMAC's suitability for mimicking the performance of medusa was experimentally found to be related to the maximum 4% strain of the SMA and not its force generation. (fast track communication)

  6. Bio-inspired ``jigsaw''-like interlocking sutures: Modeling, optimization, 3D printing and testing

    Science.gov (United States)

    Malik, I. A.; Mirkhalaf, M.; Barthelat, F.

    2017-05-01

    Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics and glasses. Sutures can generate large deformations, toughness and damping in otherwise all brittle systems and materials. In this study we examine the design and optimization of sutures with a jigsaw puzzle-like geometry, focusing on the non-linear traction behavior generated by the frictional pullout of the jigsaw tabs. We present analytical models which accurately predict the entire pullout response. Pullout strength and energy absorption increase with higher interlocking angles and for higher coefficients of friction, but the associated high stresses in the solid may fracture the tabs. Systematic optimization reveals a counter-intuitive result: the best pullout performance is achieved with interfaces with low coefficient of friction and high interlocking angle. We finally use 3D printing and mechanical testing to verify the accuracy of the models and of the optimization. The models and guidelines we present here can be extended to other types of geometries and sutured materials subjected to other loading/boundary conditions. The nonlinear responses of sutures are particularly attractive to augment the properties and functionalities of inherently brittle materials such as ceramics and glasses.

  7. Bioinspired legged-robot based on large deformation of flexible skeleton

    International Nuclear Information System (INIS)

    Mayyas, Mohammad

    2014-01-01

    In this article we present STARbot, a bioinspired legged robot capable of multiple locomotion modalities by using large deformation of its skeleton. We construct STARbot by using origami-style folding of flexible laminates. The long-term goal is to provide a robotic platform with maximum mobility on multiple surfaces. This paper particularly studies the quasistatic model of STARbot’s leg under different conditions. We describe the large elastic deformation of a leg under external force, payload, and friction by using a set of non-dimensional, nonlinear approximate equations. We developed a test mechanism that models the motion of a leg in STARbot. We augmented several foot shapes and then tested them on soft to rough grounds. Both simulation and experimental findings were in good agreement. We utilized the model to develop several scales of tri and quad STARbot. We demonstrated the capability of these robots to locomote by combining their leg deformations with their foot motions. The combination provided a design platform for an active suspension STARbot with controlled foot locomotion. This included the ability of STARbot to change size, run over obstacles, walk and slide. Furthermore, in this paper we discuss a cost effective manufacturing and production method for manufacturing STARbot. (paper)

  8. Medical Image Registration by means of a Bio-Inspired Optimization Strategy

    Directory of Open Access Journals (Sweden)

    Hariton Costin

    2012-07-01

    Full Text Available Medical imaging mainly treats and processes missing, ambiguous, complementary, redundant and distorted data. Biomedical image registration is the process of geometric overlaying or alignment of two or more 2D/3D images of the same scene, taken at different time slots, from different angles, and/or by different acquisition systems. In medical practice, it is becoming increasingly important in diagnosis, treatment planning, functional studies, computer-guided therapies, and in biomedical research. Technically, image registration implies a complex optimization of different parameters, performed at local or/and global levels. Local optimization methods frequently fail because functions of the involved metrics with respect to transformation parameters are generally nonconvex and irregular. Therefore, global methods are often required, at least at the beginning of the procedure. In this paper, a new evolutionary and bio-inspired approach -- bacterial foraging optimization -- is adapted for single-slice to 3-D PET and CT multimodal image registration. Preliminary results of optimizing the normalized mutual information similarity metric validated the efficacy of the proposed method by using a freely available medical image database.

  9. Case Study of Engineering Risk in Automotive Industry

    Science.gov (United States)

    Popa, Dan Mihai

    2018-03-01

    The primary objective of this paper is to show where the engineering of risk management is placed and how its implementation has been tried in multinational companies in automotive industry from Romania. A large number of companies don't use a strategy to avoid the engineering risk in their design products. The main reason is not because these companies haven't heard about standards for risk management such as ISO 31000; the problem is that the business units which were summed up, have just set up a risk list at the beginning of the project, without any follow up. The purpose of this article is to create an implementation risk tracking in automotive industry companies in Romania, due to a change request from customers according to supply companies within the quality process, in the research and development phase.

  10. Field Engineers' Scheduling at Oil Rigs: a Case Study

    Directory of Open Access Journals (Sweden)

    Y. S. Usmani

    2012-02-01

    Full Text Available Oil exploration and production operations face a number of challenges. Professional planners have to design solutions for various practical problems or issues. However, the time consumed is often very extensive because of the large number of possible solutions. Further, the matter of choosing the best solution remains. The present paper investigates a problem related to leading companies in the energy and chemical manufacturing sector of the oil and gas industry. Each company’s field engineers are expensive and valuable assets. Therefore, an optimized roster is rather important. In the present paper, the objective is to design a field engineers’ schedule which would be both feasible and satisfying towards the various demands of rigs, with minimum operational cost to the company. An efficient and quick optimization technique is presented to schedule the shifts of field engineers.

  11. Introducing future engineers to sustainable ecology problems: a case study

    Science.gov (United States)

    Filipkowski, A.

    2011-12-01

    The problem of Earth environmental destruction by human activities is becoming dangerous. Engineers responsible for the production of any goods should be well aware of the negative influence of their activities on the state of the planet. This is why the understanding of ecological problems is essential for people responsible for production and industrial design. The energy, which they consume, is increasing the greenhouse effect and the waste poisons the environment. So far, most courses on ecology are offered to specialists in environmental engineering. These courses are filled with many details. The Warsaw Academy of Computer Science, Management and Administration teaches students in the direction of management and production engineering. Upon completion, the students receive the degree of 'engineer'. Their future work will mainly concern management of different types of industrial enterprises and they will be responsible for organising it in such a way as to avoid a dangerous contribution to environmental pollution and climate change. This is why it was decided to introduce a new course entitled 'Principles of Ecology and Environmental Management'. This course is quite broad, concerning almost all technical, law and organisational aspects of the problem. The presentation is made in a spectacular way, aiming to convince students that their future activity must be environmentally friendly. It contains information about international activities in ecology, legal aspects concerning pollution, technical and information methods of monitoring and, finally, the description of 'green' solutions. Altogether, 27 hours of lectures and 15 hours of discussions and students' presentations complete the course. Details of this course are described in this paper.

  12. Software Engineers' Attitudes Towards Organizational Change - an Industrial Case Study

    OpenAIRE

    Lenberg, Per; Wallgren, Lars Göran; Feldt, Robert

    2016-01-01

    In order to cope with a complex and changing environment, industries seek to find new and more efficient ways to conduct their business. According to previous research, many of these change efforts fail to achieve their intended aims. Researchers have therefore sought to identify factors that increase the likelihood of success and found that employees' attitude towards change is one of the most critical. The ability to manage change is especially important in software engineering organization...

  13. Study of Software Tools to Support Systems Engineering Management

    Science.gov (United States)

    2015-06-01

    xii THIS PAGE INTENTIONALLY LEFT BLANK xiii LIST OF ACRONYMS AND ABBREVIATIONS AMSMP Acquisition M&S Master Plan BOM Bill of Materials CAD ...made by humans. Second, the set of requirements is not an exhaustive set but is intended as a starting point. The envisioned systems engineering...Computer-aided design ( CAD ) Solidworks, Autodesk AutoCAD Schedule Microsoft Project, Oracle Primavera Schedule Assessment Booz Allen Hamilton Polaris

  14. A Study of Technical Engineering Peer Reviews at NASA

    Science.gov (United States)

    Chao, Lawrence P.; Tumer, Irem Y.; Bell, David G.

    2003-01-01

    This report describes the state of practices of design reviews at NASA and research into what can be done to improve peer review practices. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review and Critical Design Review are a required part of every project and mission development. However, the technical, engineering peer reviews that support teams' work on such projects are informal, some times ad hoc, and inconsistent across the organization. The goal of this work is to identify best practices and lessons learned from NASA's experience, supported by academic research and methodologies to ultimately improve the process. This research has determined that the organization, composition, scope, and approach of the reviews impact their success. Failure Modes and Effects Analysis (FMEA) can identify key areas of concern before or in the reviews. Product definition tools like the Project Priority Matrix, engineering-focused Customer Value Chain Analysis (CVCA), and project or system-based Quality Function Deployment (QFD) help prioritize resources in reviews. The use of information technology and structured design methodologies can strengthen the engineering peer review process to help NASA work towards error-proofing the design process.

  15. A Case Study: Data Management in Biomedical Engineering

    Directory of Open Access Journals (Sweden)

    Glenn R. Gaudette

    2012-01-01

    Full Text Available In a biomedical engineering lab at Worcester Polytechnic Institute, co-author Dr. Glenn R. Gaudette and his research team are investigating the effects of stem cell therapy on the regeneration of function in damaged cardiac tissue in laboratory rats. Each instance of stem cell experimentation on a rat yields hundreds of data sets that must be carefully captured, documented and securely stored so that the data will be easily accessed and retrieved for papers, reports, further research, and validation of findings, while meeting NIH guidelines for data sharing. After a brief introduction to the bioengineering field and stem cell research, this paper focuses on the experimental workflow and the data generated in one instance of stem cell experimentation; the lab’s data management practices; and how Dr. Gaudette teaches data management to the lab’s incoming graduate students each semester. The co-authors discuss the haphazard manner by which engineering and science students typically learn data management practices, and advocate for the integration of formal data management instruction in higher education STEM curricula. The paper concludes with a discussion of the Frameworks for a Data Management Curriculum developed collaboratively by the co-authors’ institutions -- the University of Massachusetts Medical School and Worcester Polytechnic Institute -- to teach data management best practices to students in the sciences, health sciences, and engineering.

  16. Natural analog study of engineered protective barriers at the Hanford Site

    International Nuclear Information System (INIS)

    Bjornstad, B.N.; Teel, S.S.

    1993-09-01

    The purpose of this study is to evaluate surficial sedimentary deposits formed in the Pasco Basin over the geologic past as analogs for engineered protective barriers. Evidence for likely changes to be expected in an engineered barrier are preserved in geologically recent deposits. Although the design life of the engineered bonier is only 1,000 years, soils and sediments of this age are uncommon in the Pasco Basin. The evidence of and probability for the following natural processes that could adversely affect the long-term stability of an engineered protective barrier reviewed in this report are deflation by wind, soil compaction, soil eluviation/illuviation, bioturbation, and cryoturbation

  17. Concept definition study of small Brayton cycle engines for dispersed solar electric power systems

    Science.gov (United States)

    Six, L. D.; Ashe, T. L.; Dobler, F. X.; Elkins, R. T.

    1980-01-01

    Three first-generation Brayton cycle engine types were studied for solar application: a near-term open cycle (configuration A), a near-term closed cycle (configuration B), and a longer-term open cycle (configuration C). A parametric performance analysis was carried out to select engine designs for the three configurations. The interface requirements for the Brayton cycle engine/generator and solar receivers were determined. A technology assessment was then carried out to define production costs, durability, and growth potential for the selected engine types.

  18. An Experimental Study of Emission and Combustion Characteristics of Marine Diesel Engine with Fuel Injector Malfunctions

    Directory of Open Access Journals (Sweden)

    Kowalski Jerzy

    2016-01-01

    Full Text Available The presented paper shows the results of the laboratory study on the relation between chosen malfunctions of a fuel injector and composition of exhaust gas from the marine engine. The object of research is a marine 3-cylinder, four-stroke, direct injection diesel engine with an intercooler system. The engine was loaded with a generator and supercharged. The generator was electrically connected to the water resistance. The engine operated with a load between 50 kW and 250 kW at a constant speed. The engine load and speed, parameters of the turbocharger, systems of cooling, fuelling, lubricating and air exchange, were measured. Fuel injection and combustion pressures in all cylinders of the engine were also recorded. Exhaust gas composition was recorded by using a electrochemical gas analyzer. Air pressure, temperature and humidity were also recorded. Emission characteristics of the engine were calculated according to ISO 8178 standard regulations. During the study the engine operated at the technical condition recognized as „working properly” and with simulated fuel injector malfunctions. Simulation of malfunctions consisted in the increasing and decreasing of fuel injector static opening pressure, decalibration of fuel injector holes and clogging 2 neighboring of 9 fuel injector holes on one of 3 engine cylinders.

  19. Study on the design of inlet and exhaust system of a stationary internal combustion engine

    International Nuclear Information System (INIS)

    Kesgin, Ugur

    2005-01-01

    The design and operational variables of inlet and exhaust systems are decisive to determine overall engine performance. The best engine overall performance can be obtained by proper design of the engine inlet and exhaust systems and by matching the correct turbocharger to the engine. This paper presents the results of investigations to design the inlet and exhaust systems of a stationary natural gas engine family. To do this, a computational model is verified in which zero dimensional phenomena within the cylinder and one dimensional phenomena in the engine inlet and exhaust systems are used. Using this engine model, the effects of the parameters of the inlet and exhaust systems on the engine performance are obtained. In particular, the following parameters are chosen: valve timing, valve diameter, valve lift profiles, diameter of the exhaust manifold, inlet and exhaust pipe lengths, and geometry of pipe junctions. Proper sizing of the inlet and exhaust pipe systems is achieved very precisely by these investigations. Also, valve timing is tuned by using the results obtained in this study. In general, a very high improvement potential for the engines studied here is presented

  20. Improvement to the pattern of control rods of the equilibrium cycle of 18 months for the CLV using bio-inspired algorithms

    International Nuclear Information System (INIS)

    Perusquia, R.; Ortiz, J.J.; Montes, J.L.

    2003-01-01

    Nowadays in the National Institute of Nuclear Research are carried out studies with some bio-inspired optimization techniques to improve the performance of the fuel cycles of the boiling water reactors of the Laguna Verde power plant (CLV). In the present work two bio-inspired techniques were applied with the purpose of improving the performance of a balance cycle of 18 months developed for the CLV: genetic algorithms (AG) and systems based on ants colonies (SCH). The design of the reference cycle it represents in several aspects an optimal cycle proposed starting from the experience of several operation decades with the boiling water reactors (BWR initials for Boiling Water Reactor) in the world. To try to improve their performance is beforehand a difficult challenge and it puts on test the feasibility of the optimization methods in the reloads design. The study of the bio-inspired techniques was centered exclusively on the obtaining of the control rod patterns (PBC) trying to overcome the capacity factor reached in the design of the reference cycle. It was fixed the cycle length such that the decrease of the coast down period would represent an increase of the capacity factor of the cycle; so that, it diminishes the annual cost associated with the capital cost of the plant. As consequence of the study, was found that the algorithm based on the ants colonies reaches to diminish the coast down period in five and half days respect to the original balance cycle, what represents an annual saving of $US 74,000. Since the original cycle was optimized, the above-mentioned, shows the ability of the SCH for the optimization of the cycle design. With the AG it was reach to approach to the original balance cycle with a coast down period greater in seven days estimating an annual penalization of $US 130,000. (Author)

  1. Bio-inspired green synthesis of Fe3O4 spherical magnetic nanoparticles using Syzygium cumini seed extract

    International Nuclear Information System (INIS)

    Venkateswarlu, Sada; Natesh Kumar, B.; Prasad, C.H.; Venkateswarlu, P.; Jyothi, N.V.V.

    2014-01-01

    A novel and bio-inspired Fe 3 O 4 spherical magnetic nanoparticles (SMNPs) were synthesized using Syzygium cumini (S. cumini) seed extract, which is a non-toxic ecofriendly fruit waste material. S. cumini seed extract acts as a green solvent, reducing and capping agent in which sodium acetate acts as electrostatic stabilizing agent. The green synthesized nanoparticles were characterized with the help of various techniques such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), Energy-dispersive spectroscopy (EDS), Vibrating sample magnetometer (VSM), FTIR spectroscopy and nitrogen adsorption and desorption analysis techniques. The XRD study divulged that the synthesized SMNPs have inverse spinel cubic structure. The hysteresis loop of Fe 3 O 4 nanoparticles shows an excellent ferromagnetic behavior with saturation magnetization value of 13.6 emu/g

  2. On-Line Role-Play as a Teaching Method in Engineering Studies

    Science.gov (United States)

    Cobo, Adolfo; Conde, Olga Ma.; Quintela, Ma. Ángeles; Mirapéix, Jesús Ma.; López-Higuera, José Miguel

    2011-01-01

    In this paper we propose adapting role-play teaching methodology to engineering studies. The role of a maintenance technician, a relevant job profile for engineering graduates is has chosen. The interaction is based on email exchange, with the instructor included in the simulation to help guide the activity and achieve learning objectives. In this…

  3. What Preconceptions and Attitudes about Engineering Are Prevalent Amongst Upper Secondary School Pupils? An International Study

    Science.gov (United States)

    Koycu, Ümit; de Vries, Marc J.

    2016-01-01

    In the Netherlands, as well as in many other countries, there is an increasing interest in implementing education about engineering as a part of general education at the upper secondary school level. In order to know what pupils at that level think about engineering, a study has been done to investigate their attitude towards and their concept of…

  4. A Qualitative Study of African American Women in Engineering Technology Programs in Community Colleges

    Science.gov (United States)

    Blakley, Jacquelyn

    2016-01-01

    This study examined the experiences of African American women in engineering technology programs in community colleges. There is a lack of representation of African American women in engineering technology programs throughout higher education, especially in community/technical colleges. There is also lack of representation of African American…

  5. Changes in Transferable Knowledge Resulting from Study in a Graduate Software Engineering Curriculum

    Science.gov (United States)

    Bareiss, Ray; Sedano, Todd; Katz, Edward

    2012-01-01

    This paper presents the initial results of a study of the evolution of students' knowledge of software engineering from the beginning to the end of a master's degree curriculum in software engineering. Students were presented with a problem involving the initiation of a complex new project at the beginning of the program and again at the end of…

  6. An analytical and experimental study of performance on jatropha biodiesel engine

    Directory of Open Access Journals (Sweden)

    Ganapathy Thirunavukkarasu

    2009-01-01

    Full Text Available Biodiesel plays a major role as one of the alternative fuel options in direct injection diesel engines for more than a decade. Though many feed stocks are employed for making biodiesel worldwide, biodiesel derived from domestically available non-edible feed stocks such as Jatropha curcas L. is the most promising alternative engine fuel option especially in developing countries. Since experimental analysis of the engine is pricey as well as more time consuming and laborious, a theoretical thermodynamic model is necessary to analyze the performance characteristics of jatropha biodiesel fueled diesel engine. There were many experimental studies of jatropha biodiesel fueled diesel engine reported in the literature, yet theoretical study of this biodiesel run diesel engine is scarce. This work presents a theoretical thermodynamic study of single cylinder four stroke direct injection diesel engine fueled with biodiesel derived from jatropha oil. The two zone thermodynamic model developed in the present study computes the in-cylinder pressure and temperature histories in addition to various performance parameters. The results of the model are validated with experimental values for a reasonable agreement. The variation of cylinder pressure with crank angle for various models are also compared and presented. The effects of injection timing, relative air fuel ratio and compression ratio on the engine performance characteristics for diesel and jatropha biodiesel fuels are then investigated and presented in the paper.

  7. "A Woman in a Room Full of Monks": Women, German Studies, and Engineering.

    Science.gov (United States)

    Kirchner, Doris

    1998-01-01

    Investigates the linkage between German studies and engineering and how it affects the learning environment and quality for students. Linking two different modes of scholarly investigation and teaching--engineering and humanities--has attracted and retained a significant number of women. In addition to the positive effects on students, this…

  8. A study on affective work skills needs of engineering and technology ...

    African Journals Online (AJOL)

    The study is designed to investigate the affective work skills needs of Engineering and Technology Education students of universities in North Central States of Nigeria. A 18 items questionnaire was developed and used to collect data from 60 Engineers, 100 technicians and 150 lecturers. Purposive sampling techniques ...

  9. Biomedical Engineering and Cognitive Science Secondary Science Curriculum Development: A Three Year Study

    Science.gov (United States)

    Klein, Stacy S.; Sherwood, Robert D.

    2005-01-01

    This study reports on a multi-year effort to create and evaluate cognitive-based curricular materials for secondary school science classrooms. A team of secondary teachers, educational researchers, and academic biomedical engineers developed a series of curriculum units that are based in biomedical engineering for secondary level students in…

  10. Testing a tri-partite contingent model of engineering cultures: A pilot study

    International Nuclear Information System (INIS)

    Murphy, Glen D.

    2010-01-01

    For some time there has been a growing awareness of organizational culture and its impact on the functioning of engineering and maintenance departments. Those wishing to implement contemporary maintenance regimes (e.g. condition based maintenance) are often encouraged to develop 'appropriate cultures' to support a new method's introduction. Unfortunately these same publications often fail to specifically articulate the cultural values required to support those efforts. In the broader literature, only a limited number of case examples document the cultural values held by engineering asset intensive firms and how they contribute to their success (or failure). Consequently a gap exists in our knowledge of what engineering cultures currently might look like, or what might constitute a best practice engineering asset culture. The findings of a pilot study investigating the perceived ideal characteristics of engineering asset cultures are reported. Engineering managers, consultants and academics (n=47), were surveyed as to what they saw were essential attributes of both engineering cultures and engineering asset personnel. Valued cultural elements included those orientated around continuous improvement, safety and quality. Valued individual attributes included openness to change, interpersonal skills and conscientiousness. The paper concludes with a discussion regarding the development of a best practice cultural framework for practitioners and engineering managers.

  11. Comparative first- and second-law parametric study of transient diesel engine operation

    International Nuclear Information System (INIS)

    Rakopoulos, C.D.; Giakoumis, E.G.

    2006-01-01

    A computer model is developed for studying the first- and second-law (availability) balances of a turbocharged diesel engine, operating under transient load conditions. Special attention is paid to the direct comparison between the results from the two laws, for various operating parameters of the engine. The model simulates the transient operation on a degree crank angle basis, using a detailed analysis of mechanical friction, a separate consideration for the processes of each cylinder during a cycle ('multi-cylinder' model) and a mathematical model of the fuel pump. Experimental data taken from a marine duty, turbocharged diesel engine, located at the authors' laboratory, are used for the evaluation of the model's predictive capabilities. The first-law (e.g., engine speed, fuel pump rack position, engine load, etc.) and second-law (e.g., irreversibilities, heat loss and exhaust gases) terms for the diesel engine cylinder are both computed and depicted in comparison, using detailed diagrams, for various engine operating parameters. It is revealed that, at least for the specific engine type and operation, a thermodynamic, dynamic or design parameter can have a conflicting impact on the engine transient response as regards energy and availability properties, implying that both a first- and second-law optimization is needed for best performance evaluation

  12. Space Transportation Booster Engine Configuration Study. Volume 3: Program Cost estimates and work breakdown structure and WBS dictionary

    Science.gov (United States)

    1989-01-01

    The objective of the Space Transportation Booster Engine Configuration Study is to contribute to the ALS development effort by providing highly reliable, low cost booster engine concepts for both expendable and reusable rocket engines. The objectives of the Space Transportation Booster Engine (STBE) Configuration Study were: (1) to identify engine development configurations which enhance vehicle performance and provide operational flexibility at low cost; and (2) to explore innovative approaches to the follow-on Full-Scale Development (FSD) phase for the STBE.

  13. A study of operating parameters on the linear spark ignition engine

    International Nuclear Information System (INIS)

    Lim, Ocktaeck; Hung, Nguyen Ba; Oh, Seokyoung; Kim, Gangchul; Song, Hanho; Iida, Norimasa

    2015-01-01

    Highlights: • An experimental and simulation study of a linear engine is conducted. • The effects of operating parameters on the generating power are investigated. • The air gap length has a significant influence on the generating power. • The generating power of the linear engine is optimized with the value of 111.3 W. • There are no problems for the linear engine after 100 h of durable test. - Abstract: In this paper, we present our experiment and simulation study of a free piston linear engine based on operating conditions and structure of the linear engine for generating electric power. The free piston linear engine includes a two-stroke free piston engine, linear generators, and compressors. In the experimental study, the effects of key parameters such as input caloric value, equivalence ratio, spark timing delay, electrical resistance, and air gap length on the piston dynamics and electric power output are investigated. Propane is used as a fuel in the free piston linear engine, and it is premixed with the air to make a homogeneous charge before go into the cylinder. The air and fuel mass flow rate are varied by a mass flow controller. The experimental results show that the maximum generating power is found with the value of 111 W at the input caloric value of 5.88 kJ/s, spark timing delay of 1.5 ms, equivalence ratio of 1.0, electric resistance of 30 Ω, and air gap length of 1.0 mm. In order to check the durability of the linear engine, a durable test is conducted during 100 h. The experimental results show that there are no problems for the linear engine after about one hundred hours of the durable test. Beside experimental study, a simulation study is conducted to predict operating behavior of the linear engine. In the simulation study, the two-stroke free piston linear engine is modeled and simulated through a combination of three mathematical models including a dynamic model, a linear alternator model and a thermodynamic model. These

  14. Expanding Student International Awareness Through Short-Term Study Abroad Courses With Substantial Engineering Technical Content

    Science.gov (United States)

    Jacobitz, Frank; Schubert, Thomas

    2012-11-01

    The efficacy of Compact International Experience (CIE) courses is assessed in this study. These courses were developed with the aim to raise student international awareness while retaining substantial engineering technical content. The courses were motivated by a strong student desire for engineering international studies as well as a drive by the home institution for internationalization of the curriculum. The experiences gained from delivering two distinct three-semester-unit engineering elective courses in three-week time frames in France and Australia are discussed. While the two courses, Topics in Fluid Mechanics and Advanced Electronic Circuit Design, focused on their technical content, the desire for student understanding of the cultural environment and the impact of engineering solutions from a global and societal viewpoint were strong driving factors for each. Assessment validates the hypothesis that CIE courses can successfully deliver substantial engineering technical content while providing an enriching international experience to students.

  15. Study on biofortification of rice by targeted genetic engineering

    Directory of Open Access Journals (Sweden)

    Sumon M. Hossain

    2012-12-01

    Full Text Available Micronutrient malnutrition is a major health problem in Bangladesh and also in many other developing countries, where a diversified diet is not affordable for the majority. In the present world- one, out of seven people suffers from hunger. Yet, there is a stealthier form of hunger than lack of food: micronutrient malnutrition or hidden hunger. While often providing enough calories, monotonous diets (of rural poor frequently fail to deliver sufficient quantities of essential minerals and vitamins. Due to micronutrient deficiencies different characteristic features have been observed to the victims. Various estimates indicate that over two-thirds of the world population, for the most part women and children specially, pre-school children are deficient in at least one micronutrient. This can have devastating consequences for the life, health and well being of the individuals concerned (like premature death, blindness, weakened immune systems etc. Genetic engineering approach is the upcoming strategy to solve this problem. Genetically engineered biofortified staple crops specially, rice that are high in essential micronutrients (Fe, Zn, vitamin A and adapted to local growing environments have the potential to significantly reduce the prevalence of micronutrient deficiencies specially to the rural poor.

  16. Bioinspired Special Wettability Surfaces: From Fundamental Research to Water Harvesting Applications.

    Science.gov (United States)

    Zhang, Songnan; Huang, Jianying; Chen, Zhong; Lai, Yuekun

    2017-01-01

    Nowadays, the pollution of water has become worse in many parts of the world, which causes a severe shortage of clean water and attracts widespread attention worldwide. Bioinspired from nature, i.e. spider silk, cactus, Namib desert beetle, Nepenthes alata, special wettability surfaces have attracted great interest from fundamental research to water-harvesting applications. Here, recently published literature about creatures possessing water-harvesting ability are reviewed, with a focus on the corresponding water-harvesting mechanisms of creatures in dry or arid regions, consisting of the theory of wetting and transporting. Then a detailed account of the innovative fabrication technologies and bionic water-harvesting materials with special wetting are summarized, i.e. bio-inspired artificial spider silk, bio-inspired artificial cactus-like structures, and bio-inspired artificial Namib desert beetle-like surfaces. Special attentions are paid to the discussion of the advantages and disadvantages of the technologies, as well as factors that affect the amount of water-harvesting. Finally, conclusions, future outlooks and the current challenges for future development of the water-harvesting technology are presented and discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Interactive Learning Environment for Bio-Inspired Optimization Algorithms for UAV Path Planning

    Science.gov (United States)

    Duan, Haibin; Li, Pei; Shi, Yuhui; Zhang, Xiangyin; Sun, Changhao

    2015-01-01

    This paper describes the development of BOLE, a MATLAB-based interactive learning environment, that facilitates the process of learning bio-inspired optimization algorithms, and that is dedicated exclusively to unmanned aerial vehicle path planning. As a complement to conventional teaching methods, BOLE is designed to help students consolidate the…

  18. Synthesis of bio-inspired Ag–Au nanocomposite and its anti-biofilm ...

    Indian Academy of Sciences (India)

    Synthesis of bio-inspired Ag–Au nanocomposite and its anti-biofilm efficacy. S NEWASE1 and A V BANKAR1,2,∗. 1Department of Microbiology, Savitribai Phule Pune University, Pune 411007, India. 2Department of Microbiology, Waghire College, Saswad, Affiliated to Savitribai Phule Pune University,. Pune 412 301, India.

  19. Crickets as bio-inspiration for MEMS-based flow-sensing

    NARCIS (Netherlands)

    Krijnen, Gijsbertus J.M.; Droogendijk, H.; Dagamseh, A.M.K.; Jaganatharaja, R.K.; Casas, Jerome

    2014-01-01

    MEMS offers exciting possibilities for the fabrication of bio-inspired mechanosensors. Over the last few years, we have been working on cricket- inspired hair-sensor arrays for spatio-temporal flow-field observations (i.e. flow camera) and source localisation. Whereas making flow-sensors as energy

  20. Bio-inspired CO2 reduction by a rhenium tricarbonyl bipyridine-based catalyst appended to amino acids and peptidic platforms: incorporating proton relays and hydrogen-bonding functional groups.

    Science.gov (United States)

    Chabolla, S A; Machan, C W; Yin, J; Dellamary, E A; Sahu, S; Gianneschi, N C; Gilson, M K; Tezcan, F A; Kubiak, C P

    2017-06-02

    Herein, we report a new approach to bio-inspired catalyst design. The molecular catalyst employed in these studies is based on the robust and selective Re(bpy)(CO) 3 Cl-type (bpy = 2,2'-bipyridine) homogeneous catalysts, which have been extensively studied for their ability to reduce CO 2 electrochemically or photochemically in the presence of a photosensitizer. These catalysts can be highly active photocatalysts in their own right. In this work, the bipyridine ligand was modified with amino acids and synthetic peptides. These results build on earlier findings wherein the bipyridine ligand was functionalized with amide groups to promote dimer formation and CO 2 reduction by an alternate bimolecular mechanism at lower overpotential (ca. 250 mV) than the more commonly observed unimolecular process. The bio-inspired catalysts were designed to allow for the incorporation of proton relays to support reduction of CO 2 to CO and H 2 O. The coupling of amino acids tyrosine and phenylalanine led to the formation of two structurally similar Re catalyst/peptide catalysts for comparison of proton transport during catalysis. This article reports the synthesis and characterization of novel catalyst/peptide hybrids by molecular dynamics (MD simulations of structural dynamics), NMR studies of solution phase structures, and electrochemical studies to measure the activities of new bio-inspired catalysts in the reduction of CO 2.

  1. Configuration evaluation and criteria plan. Volume 1: System trades study and design methodology plan (preliminary). Space Transportation Main Engine (STME) configuration study

    Science.gov (United States)

    Bair, E. K.

    1986-01-01

    The System Trades Study and Design Methodology Plan is used to conduct trade studies to define the combination of Space Shuttle Main Engine features that will optimize candidate engine configurations. This is accomplished by using vehicle sensitivities and engine parametric data to establish engine chamber pressure and area ratio design points for candidate engine configurations. Engineering analyses are to be conducted to refine and optimize the candidate configurations at their design points. The optimized engine data and characteristics are then evaluated and compared against other candidates being considered. The Evaluation Criteria Plan is then used to compare and rank the optimized engine configurations on the basis of cost.

  2. Study on the combustion process in a modern diesel engine controlled by pre-injection strategy

    Science.gov (United States)

    Punov, P.; Milkov, N.; Perilhon, C.; Podevin, P.; Evtimov, T.

    2017-10-01

    The paper aims to study the combustion process in a modern diesel engine over the engine operating map. In order to study the rate of heat release (ROHR), an automotive diesel engine was experimentally tested using the injection parameters factory defined. The experimental test was conducted over the engine operating map as the engine speed was limited to 2400 rpm. Then, an engine simulation model was developed in AVL Boost. By means of that model the ROHR was estimated and approximated by means of double Vibe function. In all engine operating points we found two peaks at the ROHR. The first is a result of the pilot injection as the second corresponds to the main injection. There was not found an overlap between both peaks. It was found that the first peak of ROHR occurs closely before top dead center (BTDC) at partial load than full load. The ROHR peak as a result of main injection begins from 4°BTDC to 18°ATDC. It starts earlier with increasing engine speed and load. The combustion duration varies from 30 ºCA to 70 °CA. In order to verify the results pressure curve was estimated by means of defined Vibe function parameters and combustion duration. As a result, we observed small deviation between measured and simulated pressure curves.

  3. Avian Feathers: An Examination of Lightweight Resilience and Bioinspired Designs

    Science.gov (United States)

    Sullivan, Tarah Naoe

    In bird flight, the majority of the wing surface consists of highly refined and hierarchically organized beta-keratinous feathers. Thus, flight feathers contain ingenious combinations of components that optimize lift, stiffness, aerodynamics, and damage resistance. Their design involves two main parts: a central shaft which prescribes stiffness and lateral vanes that allow for the capture of air. Within the feather vane, barbs branch from the shaft and barbules branch from barbs, forming a flat surface and ensuring lift. Microhooks at the end of barbules hold barbs tightly together, providing a close-knit, unified structure and enabling repair of the vane through the reattachment of un-hooked junctions. In this dissertation, unique aspects of feather architecture are explored to uncover principles translatable to the design of modern aerospace materials and structures. Specifically, understudied aspects of the feather's lightweight yet resilient properties are investigated. This research has revealed several novel characteristics of the feather. Allometric scaling relationships are developed linking the geometry of a bird's wing components to its flight characteristics and total mass. Barbule spacing within the feather vane is found to be 8-16 microm for birds ranging from 0.02-11 kg. Additionally, it is discovered that strength is recovered with the shape recovery property of feathers, and a mechanism for this phenomenon is proposed. Barbule adhesion within the vane is found to prevent barbs from twisting in flexure, maintaining the vane's stiffness, and the extent to which unzipping these connections affects the feather's ability to capture air is related to barb shape. Directional permeability of the feather vane is experimentally confirmed and related to the intricate microstructure of barbules. Lastly, the exceptional architecture of the feather motivated the design of novel bioinspired structures with tailored and unique properties. The avian feather serves

  4. Bio-inspired aquatic robotics by untethered piezohydroelastic actuation.

    Science.gov (United States)

    Cen, L; Erturk, A

    2013-03-01

    This paper investigates fish-like aquatic robotics using flexible bimorphs made of macro-fiber composite (MFC) piezoelectric laminates for carangiform locomotion. In addition to noiseless and efficient actuation over a range of frequencies, geometric scalability, and simple design, bimorph propulsors made of MFCs offer a balance between the actuation force and velocity response for performance enhancement in bio-inspired swimming. The experimental component of the presented work focuses on the characterization of an elastically constrained MFC bimorph propulsor for thrust generation in quiescent water as well as the development of a robotic fish prototype combining a microcontroller and a printed-circuit-board amplifier to generate high actuation voltage for untethered locomotion. From the theoretical standpoint, a distributed-parameter electroelastic model including the hydrodynamic effects and actuator dynamics is coupled with the elongated-body theory for predicting the mean thrust in quiescent water. In-air and underwater experiments are performed to verify the incorporation of hydrodynamic effects in the linear actuation regime. For electroelastically nonlinear actuation levels, experimentally obtained underwater vibration response is coupled with the elongated-body theory to predict the thrust output. The measured mean thrust levels in quiescent water (on the order of ∼10 mN) compare favorably with thrust levels of biological fish. An untethered robotic fish prototype that employs a single bimorph fin (caudal fin) for straight swimming and turning motions is developed and tested in free locomotion. A swimming speed of 0.3 body-length/second (7.5 cm s⁻¹ swimming speed for 24.3 cm body length) is achieved at 5 Hz for a non-optimized main body-propulsor bimorph combination under a moderate actuation voltage level.

  5. Bio-inspired aquatic robotics by untethered piezohydroelastic actuation

    International Nuclear Information System (INIS)

    Cen, L; Erturk, A

    2013-01-01

    This paper investigates fish-like aquatic robotics using flexible bimorphs made of macro-fiber composite (MFC) piezoelectric laminates for carangiform locomotion. In addition to noiseless and efficient actuation over a range of frequencies, geometric scalability, and simple design, bimorph propulsors made of MFCs offer a balance between the actuation force and velocity response for performance enhancement in bio-inspired swimming. The experimental component of the presented work focuses on the characterization of an elastically constrained MFC bimorph propulsor for thrust generation in quiescent water as well as the development of a robotic fish prototype combining a microcontroller and a printed-circuit-board amplifier to generate high actuation voltage for untethered locomotion. From the theoretical standpoint, a distributed-parameter electroelastic model including the hydrodynamic effects and actuator dynamics is coupled with the elongated-body theory for predicting the mean thrust in quiescent water. In-air and underwater experiments are performed to verify the incorporation of hydrodynamic effects in the linear actuation regime. For electroelastically nonlinear actuation levels, experimentally obtained underwater vibration response is coupled with the elongated-body theory to predict the thrust output. The measured mean thrust levels in quiescent water (on the order of ∼10 mN) compare favorably with thrust levels of biological fish. An untethered robotic fish prototype that employs a single bimorph fin (caudal fin) for straight swimming and turning motions is developed and tested in free locomotion. A swimming speed of 0.3 body-length/second (7.5 cm s −1 swimming speed for 24.3 cm body length) is achieved at 5 Hz for a non-optimized main body-propulsor bimorph combination under a moderate actuation voltage level. (paper)

  6. Principle of bio-inspired insect wing rotational hinge design

    Science.gov (United States)

    Fei, Fan

    A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is shown to be applicable to a wide range of wing designs with different sizes and shapes. With the selected hinge stiffness value, aspects of the rotational joint design is discussed and an integrated wing-hinge structure design using laminated carbon fiber and polymer film is presented. Manufacturing process of such composite structure is developed to achieve high accuracy and repeatability. The yielded hinge stiffness is verified by measurements. To validate the proposed model, flapping wing experiments were conducted. A flapping actuation set up is built using DC motor and a controller is implemented on a microcontroller to track desired wing stroke kinematic. Wing stroke and rotation kinematic were extracted using a high speed camera and the lift generation is evaluated. A total of 49 flapping experiments were presented, experimental data shows good correlation with the model's prediction. With the wing rotational hinge stiffness designed so that the rotational resonant frequency is twice as the stroke frequency, the resulting wing rotation generates near optimal lift. With further simulation, the proposed model shows low sensitivity to wing parameter variation. As a result, giving a design parameter of a flapping wing robot platform, the proposed principle can

  7. An experimental study of emission and combustion characteristics of marine diesel engine with fuel pump malfunctions

    International Nuclear Information System (INIS)

    Kowalski, Jerzy

    2014-01-01

    Presented paper shows the results of the laboratory study on the relation between the chosen malfunctions of a fuel pump and the exhaust gas composition of the marine engine. The object of research is a laboratory four-stroke diesel engine, operated at a constant speed. During the research over 50 parameters were measured with technical condition of the engine recognized as “working properly” and with simulated fuel pump malfunctions. Considered malfunctions are: fuel injection timing delay and two sets of fuel leakages in the fuel pump of one engine cylinder. The results of laboratory research confirm that fuel injection timing delay and fuel leakage in the fuel pump cause relatively small changes in thermodynamic parameters of the engine. Changes of absolute values are so small they may be omitted by marine engines operators. The measuring of the exhaust gas composition shows markedly affection with simulated malfunctions of the fuel pump. Engine operation with delayed fuel injection timing in one cylinder indicates CO 2 emission increase and NOx emission decreases. CO emission increases only at high the engine loads. Fuel leakage in the fuel pump causes changes in CO emission, the increase of CO 2 emission and the decrease of NOx emission. - Highlights: •Chosen malfunctions of the fuel injection pump of marine engine are simulated. •Changes of thermodynamic parameters of marine engine are analyzed. •Changes of CO, CO 2 and NOx emission characteristics of marine engine are analyzed. •Injection pump malfunctions take significant changes in emission characteristics

  8. Numerical study of heat transfer and combustion in IC engine with a porous media piston region

    International Nuclear Information System (INIS)

    Zhou, Lei; Xie, Mao-Zhao; Luo, Kai Hong

    2014-01-01

    Based on superadiabatic combustion in porous medium (PM), the porous medium engine as a new combustion concept is proposed to achieve high combustion efficiency and low emissions. In this paper, an axisymmetric model with detailed chemistry and two-temperature treatment is implemented into a variant of the KIVA-3V code to simulate the working process of the PM engine. Comparisons with the same engine but without PM are conducted. Temperature evolution of the PM and its effects are discussed in detail. Key factors affecting heat transfer, combustion and emissions of the PM engine, such as porosity, the initial PM temperature and equivalence ratio, are analyzed. The results show that the characteristics of heat transfer, emissions and combustion of the PM engine are superior to the engine without PM, providing valuable support for the PM engine concept. In particular, the PM engine is shown to sustain ultra lean combustion. - Graphical abstract: In the PM engine, a PM reactor is mounted on the piston head as shown in Fig. 1 which shows the schematic diagram of the computational domain. The heat exchange process between PM material and compressed air increases with upward motion of piston at compression stroke. At the TDC, almost all the air is compressed and closed to PM volume, meanwhile, the fuel is injected into PM chamber to achieve homogenization combustion. - Highlights: •Two-temperature treatment studies the working process of the PM engine. •Self-balancing temperature of the PM determines the continued and stable work. •Stronger heat exchange occurs between gas and PM with smaller porosity. •The PM engine can have lower levels of NO x , unburnt HC and CO emissions

  9. PERAN PROGRAM STUDI TEKNIK PANGAN (FOOD ENGINEERING UNTUK MENUNJANG PEMBANGUNAN INDUSTRI PANGAN DI INDONESIA [The Roles of Engineering fot the Development of Agro Industries in Indonesia

    Directory of Open Access Journals (Sweden)

    Suhargo

    2005-08-01

    Full Text Available At this time more than 60 % of Indonesian population still depend on the agricultural sector. Accordingly, in future agro and food industries are expected to be the main steppingstone for the economic development in Indonesia. In order to make the agricultural products competitive in the global market; it is necessary that the development of food or agro industries is supported by technology especially in the food product development and their processing. The food product development consist of food product design, process design, equipment and machinery design and packaging design. Consequently the food product development requires the knowledge of food science, and is necessary to be supported by the knowledge of engineering or know as food engineering. As a course, food engineering is already offered in the study program of food science and technology. However, food engineering is not developed yet as a study program as well as in the other countries, the study program in food engineering is necessarily different from the study program of food science and technology. Food engineering is scientific discipline to study and apply the engineering principles in food preservation, conservation, conversion and distribution. In several countries both study programs are paralely offered as two different study programs with deferent competence and knowledge. The competency of food engineering is mainly in the application of engineering knowledge for food design, design and construction of food process equipment, process design, process equipment operation and management. Accordingly, the content of the food engineering curriculum covers engineering and physics (50-60%, biology and food science (20-30% and other supporting knowledge’s (statics, communication, etc, 10-20%. The graduates in food engineering will have opportunities working as engineers as well as designing, constructing and operating process equipment in food industries

  10. The MSFC Collaborative Engineering Process for Preliminary Design and Concept Definition Studies

    Science.gov (United States)

    Mulqueen, Jack; Jones, David; Hopkins, Randy

    2011-01-01

    This paper describes a collaborative engineering process developed by the Marshall Space Flight Center's Advanced Concepts Office for performing rapid preliminary design and mission concept definition studies for potential future NASA missions. The process has been developed and demonstrated for a broad range of mission studies including human space exploration missions, space transportation system studies and in-space science missions. The paper will describe the design team structure and specialized analytical tools that have been developed to enable a unique rapid design process. The collaborative engineering process consists of integrated analysis approach for mission definition, vehicle definition and system engineering. The relevance of the collaborative process elements to the standard NASA NPR 7120.1 system engineering process will be demonstrated. The study definition process flow for each study discipline will be will be outlined beginning with the study planning process, followed by definition of ground rules and assumptions, definition of study trades, mission analysis and subsystem analyses leading to a standardized set of mission concept study products. The flexibility of the collaborative engineering design process to accommodate a wide range of study objectives from technology definition and requirements definition to preliminary design studies will be addressed. The paper will also describe the applicability of the collaborative engineering process to include an integrated systems analysis approach for evaluating the functional requirements of evolving system technologies and capabilities needed to meet the needs of future NASA programs.

  11. Computer Science and Engineering Students Addressing Critical Issues Regarding Gender Differences in Computing: a Case Study

    OpenAIRE

    Evrikleia Tsagala; Maria Kordaki

    2008-01-01

    This study focuses on how Computer Science and Engineering Students (CSESs) of both genders address certain critical issues for gender differences in the field of Computer Science and Engineering (CSE). This case study is based on research conducted on a sample of 99 Greek CSESs, 43 of which were women. More specifically, these students were asked to respond to a specially designed questionnaire addressing the following issues: a) essential motives in selecting CSE as a subject of study, thei...

  12. Undergraduate Program in Network Engineering and Security – A Feasibility Study

    OpenAIRE

    Fahed Awad; Omar Banimelhem; Eyad Taqieddin; Raed Bani-Hani

    2012-01-01

    In this article, a feasibility study for initiating a new undergraduate program in network engineering and security is presented. The study was based on surveying and analyzing the current and projected future market demand for specialized network engineering graduates. The results of the study concluded that the demand for such a specialty in the work place is rapidly growing as the networking and telecommunication technologies are becoming essential and integral parts of about any organizat...

  13. Thermal engineering studies with Excel, Mathcad and Internet

    CERN Document Server

    2016-01-01

    This book provides the fundamentals of the application of mathematical methods, modern computational tools (Excel, Mathcad, SMath, etc.), and the Internet to solve the typical problems of heat and mass transfer, thermodynamics, fluid dynamics, energy conservation and energy efficiency. Chapters cover the technology for creating and using databases on various properties of working fluids, coolants and thermal materials. All calculation methods are provided with links to online computational pages where data can be inserted and recalculated. It discusses tasks involving the generation of electricity at thermal, nuclear, gas turbine and combined-cycle power plants, as well as processes of co- and trigeneration, conditioning facilities and heat pumps. This text engages students and researchers by using modern calculation tools and the Internet for thermal engineering applications. .

  14. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    Science.gov (United States)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

    2009-01-01

    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  15. A Process Re-engineering Framework for Reverse Logistics based on a Case Study

    Directory of Open Access Journals (Sweden)

    Hing Kai Chan

    2010-09-01

    Full Text Available Reverse logistics has gained increasing attention in recent years as a channel for companies to achieve operational excellence. The process involves manipulation of returned materials, or even products, which forms a pivotal role in sustainable development throughout the whole supply chains. To make reverse logistics possible, process re-engineering may need to be carried out. However, the processes involved in reengineering are practically complicated. Objectives, benefits, and applicability of any process re-engineering require a careful and detailed strategic planning. This paper aims to propose an easy-to-follow step-by-step framework for practitioners to perform process re-engineering, to learn and identify the critical issues in each step, and to be successful in applying process re-engineering in order to enhance reverse logistics performance. A learner-centred approach is adopted based on a case study of process re-engineering, which is demonstrated in the paper for explanation.

  16. STUDIES AND RESEARCHES CONCERNING THE POSSIBILITY OF USING HYDROGEN IN TURBO ENGINES

    Directory of Open Access Journals (Sweden)

    Marius BIBU

    2014-10-01

    Full Text Available The paper aims to study the main aspects related to using Hydrogen as fuel in thermal engines, the advantages and disadvantages of using it as fuel and the technical posibilities of adjusting it, Hydrogen used as supplement at the main fuel and Hydrogen used as working fluid. As a perspective, it can be considered using Hydrogen as thermical agent in a closed energetic flux with thermo- chemical compression of Hydrogen in a hybrid heat changer, based on the heat of burning products of thermical engines. The experiments made showed that using such a way of using the heat of burning products of turbo engines can assure the increase of power and efficiency of the whole instalation with 20 %, which make us consider Hydrogen as a viable and advantageous alternative of fuel to be used in turbo engines and other engines.

  17. Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO–Amino Acid Cocrystals

    KAUST Repository

    Muhammed, Madathumpady Abubaker Habeeb

    2018-02-20

    Elucidating the underlying principles behind band gap engineering is paramount for the successful implementation of semiconductors in photonic and optoelectronic devices. Recently it has been shown that the band gap of a wide and direct band gap semiconductor, such as ZnO, can be modified upon cocrystallization with amino acids, with the role of the biomolecules remaining unclear. Here, by probing and modeling the light-emitting properties of ZnO-amino acid cocrystals, we identify the amino acids\\' role on this band gap modulation and demonstrate their effective chirality transfer to the interband excitations in ZnO. Our 3D quantum model suggests that the strong band edge emission blue-shift in the cocrystals can be explained by a quasi-periodic distribution of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule cocrystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.

  18. A case study: Problem-based learning for civil engineering students in transportation courses

    Science.gov (United States)

    Ahern, A. A.

    2010-03-01

    This paper describes two case studies where problem-based learning (PBL) has been introduced to undergraduate civil engineering students in University College Dublin. PBL has recently been put in place in the penultimate and final year transport engineering classes in the civil engineering degree in University College Dublin. In this case study, the paper describes how PBL was introduced, the impacts of its introduction and the feedback received by students regarding PBL. PBL was introduced in these years to help students to become deep and active learners and to help them in the transition from passive note taker to researcher and lifelong learner.

  19. Study on the engine oil's wear based on the flash point

    Science.gov (United States)

    Niculescu, R.; Iorga-Simăn, V.; Trică, A.; Clenci, A.

    2016-08-01

    Increasing energy performance of internal combustion engines is largely influenced by frictional forces that arise between moving parts. Thus, in this respect, the nature and quality of the engine oil used is an important factor. Equally important is the effect of various engine injection strategies upon the oil quality. In other words, it's of utmost importance to maintain the quality of engine oil during engine's operation. Oil dilution is one of the most common causes that lead to its wear, creating lubrication problems. Moreover, at low temperatures operating conditions, the oil dilution with diesel fuel produces wax. When starting the engine, this may lead to lubrication deficiencies and even oil starvation with negative consequences on the engine mechanism parts wear (piston, rings and cylinders) but also crankcase bearings wear.Engine oil dilution with diesel fuel have several causes: wear of rings and/or injectors, late post-injection strategy for the sake of particulate filter regeneration, etc.This paper presents a study on the degree of deterioration of engine oils as a result of dilution with diesel fuel. The analysed oils used for this study were taken from various models of engines equipped with diesel particulate filter. The assessment is based on the determination of oil flash point and dilution degree using the apparatus Eraflash produced by Eralytics, Austria. Eraflash measurement is directly under the latest and safest standards ASTM D6450 & D7094), which are in excellent correlation with ASTM D93 Pensky - Martens ASTM D56 TAG methods; it uses the Continuous Closed Cup method for finding the Flash Point (CCCFP).

  20. Integrating Engineering into Delaware's K-5 Classrooms: A Study of Pedagogical and Curricular Resources

    Science.gov (United States)

    Grusenmeyer, Linda Huey

    This study examines the personal and curricular resources available to Delaware's elementary teachers during a time of innovative curriculum change, i.e., their knowledge, goals and beliefs regarding elementary engineering curriculum and the pedagogical support to teach two Science and Engineering Practices provided by science teaching materials. Delaware was at the forefront of K-12 STEM movement, first to adopt statewide elementary curriculum materials to complement existing science units, and one of the first to adopt the new science standards--Next Generation Science Standards. What supports were available to teachers as they adapted and adopted this new curriculum? To investigate this question, I examined (1) teachers' beliefs about engineering and the engineering curriculum, and (2) the pedagogical supports available to teachers in selected science and engineering curriculum. Teachers' knowledge, goals, and beliefs regarding Delaware's adoption of new elementary engineering curriculum were surveyed using an adapted version of the Design, Engineering, and Technology Survey (Hong, Purser, & Gardella, 2011; Yaser, Baker, Carpius, Krauss, & Roberts, 2006). Also, three open ended questions sought to reveal deeper understanding of teacher knowledge and understanding of engineering; their concerns about personal and systemic resources related to the new curriculum, its logistics, and feasibility; and their beliefs about the potential positive impact presented by the engineering education initiative. Teacher concerns were analyzed using the Concerns-Based Adoption Model (Hall & Hord, 2010). Lay understandings of engineering were analyzed by contrasting naive representations of engineering with three key characteristics of engineering adapted from an earlier study (Capobianco Diefes-Dux, Mena, & Weller, 2011). Survey findings for teachers who had attended training and those who have not yet attended professional development in the new curriculum were compared with few

  1. A Numerical Study of Combined Convective and Radiative Heat Transfer in a Rocket Engine Combustion Chamber

    National Research Council Canada - National Science Library

    Savur, Mehmet

    2002-01-01

    A numerical study was conducted to predict the combined convective and radiative heat transfer rates on the walls of a small aspect ratio cylinder representative of the scaled model of a rocket engine combustion chamber...

  2. Remote sensing applications for transportation and traffic engineering studies: A review of the literature

    Science.gov (United States)

    Epps, J. W.

    1973-01-01

    Current references were surveyed for the application of remote sensing to traffic and transportation studies. The major problems are presented that concern traffic engineers and transportation managers, and the literature references that discuss remote sensing applications are summarized.

  3. A Comparative Study of Rat Lung Decellularization by Chemical Detergents for Lung Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Hamid Tebyanian

    2017-12-01

    CONCLUSION: Decellularized lung tissue can be used in the laboratory to study various aspects of pulmonary biology and physiology and also, these results can be used in the continued improvement of engineered lung tissue.

  4. Toward a Career-Based Theory of Job Involvement: A Study of Scientists and Engineers

    Science.gov (United States)

    McKelvey, Bill; Sekaran, Uma

    1977-01-01

    Multiple regression analyses are used to determine the relative importance of 49 factors to job involvement in a study of 441 scientists and engineers. Of particular importance are career and personality factors. (Author)

  5. Energy Engineering Analysis Program Study, Fort Leonard Wood, Missouri. Volume 3, Appendices G and H

    National Research Council Canada - National Science Library

    1993-01-01

    ...) Energy Saving Opportunity Survey (ESOS) at Fort Leonard Wood, Missouri. This study was authorized under the contract DACA41-92-C-0098 with Corps of Engineers Kansas City District, Kansas City, Missouri...

  6. Analysis of Engineered Nanomaterials in Complex Matricies (Environment and Biota): General Considerations and Conceptual Case Studies

    Science.gov (United States)

    Advances in the study of the environmental fate, transport, and ecotoxicological effects of engineered nanomaterials (ENMs) have been hampered by a lack of adequate techniques for the detection and quantification of ENMs at environmentally relevant concentrations in complex media...

  7. Immune responses to the in vitro LPS assault engineered in the spaceflight multi-omics study

    Data.gov (United States)

    National Aeronautics and Space Administration — Microgravity alters the immune response to in vitro LPS assault engineered in spaceflight: A multi-omics study Microgravity can facilitate creation of a potent...

  8. Adaptation of Mongolian students in the study of the discipline "Engineering graphics"

    OpenAIRE

    Романова, Светлана Владимировна

    2014-01-01

    How is the study of the subject "Engineering Graphics" at the preparatory department Mongolian students. Motivating students and their perception of the subject. Which is typical of adaptation of students from Mongolia.

  9. A feasibility study of a new ATREX engine system of aft-turbine configuration

    Science.gov (United States)

    Isomura, Kousuke; Omi, Junsuke; Tanatsugu, Nobuhiro; Sato, Tetsuya; Kobayashi, Hiroaki

    2002-07-01

    A feasibility of ATREX (Air-Turbo-Ram Expander cycle) engine with conventional aft-turbine configuration has been studied to be developed in about 10 years, if the development project has started under enough resources. The novel tip-turbine of the original ATREX engine is replaced by a conventional aft-turbine, and the maximum turbine inlet temperature (TTT) is reduced to 1200K, to realize the engine by only using approved metal technologies of modern jet engines. The capability of the performance has been shown by parametric studies by changing components' design parameters. The study shows that the performance of the ATREX engine is not less than that of pre-cooled turbo jet. Some technical issues on developing the new ATREX engine have been addressed. The most important issue would come from the transient total temperature change due to the rapid acceleration from sea level static (SLS) condition (288K) to Mach 6 at 30km of altitude (1680K) in 6 minutes. The deformation due to transient thermal expansion has to be controlled. Especially, the change of the tip clearance and the clearance between rotors and stators are pointed out to be important design issues. The ATREX engine, which has shorter axial length and simpler rotor, has structural advantage over turbo jet.

  10. A hingeless rotor XV-15 design integration feasibility study. Volume 1: Engineering design studies

    Science.gov (United States)

    Magee, J. P.; Alexander, H. R.

    1978-01-01

    A design integration feasibility study was carried out to investigate what modifications to the basic XV-15 were necessary to accomplish a flight demonstration of the XV-15 with a Boeing hingeless rotor. Also investigated were additional modifications which would exploit the full capability provided by the combination of the new rotor and the existing T53 engine. An evaluation of the aircraft is presented and the data indicate improved air vehicle performance, acceptable aeroelastic margins, lower noise levels and improved flying qualities compared with the XV-15 aircraft. Inspection of the rotor system data provided shows an essentially unlimited life rotor for the flight spectrum anticipated for the XV-15.

  11. Biomimetic and bio-inspired robotics in electric fish research.

    Science.gov (United States)

    Neveln, Izaak D; Bai, Yang; Snyder, James B; Solberg, James R; Curet, Oscar M; Lynch, Kevin M; MacIver, Malcolm A

    2013-07-01

    Weakly electric knifefish have intrigued both biologists and engineers for decades with their unique electrosensory system and agile swimming mechanics. Study of these fish has resulted in models that illuminate the principles behind their electrosensory system and unique swimming abilities. These models have uncovered the mechanisms by which knifefish generate thrust for swimming forward and backward, hovering, and heaving dorsally using a ventral elongated median fin. Engineered active electrosensory models inspired by electric fish allow for close-range sensing in turbid waters where other sensing modalities fail. Artificial electrosense is capable of aiding navigation, detection and discrimination of objects, and mapping the environment, all tasks for which the fish use electrosense extensively. While robotic ribbon fin and artificial electrosense research has been pursued separately to reduce complications that arise when they are combined, electric fish have succeeded in their ecological niche through close coupling of their sensing and mechanical systems. Future integration of electrosense and ribbon fin technology into a knifefish robot should likewise result in a vehicle capable of navigating complex 3D geometries unreachable with current underwater vehicles, as well as provide insights into how to design mobile robots that integrate high bandwidth sensing with highly responsive multidirectional movement.

  12. Stereotype Threat: A Qualitative Study of the Challenges Facing Female Undergraduate Engineering Students

    Science.gov (United States)

    Entsminger, J. R., II

    From a sociocultural point of view, this qualitative case study explored how upper-level, female undergraduate engineering students perceived the possibility of or experience with stereotype threat as shaping their experiences. The study also investigated how these students explained their reasons for choosing their engineering major, the challenges they encountered in the major, and their reasons for persevering in spite of those challenges. Using Steele and Aronson's (1995) stereotype threat theory as a framework, and considering the documented underrepresentation of females in engineering, the study sought to examine how stereotype threat shaped the experiences of these students and if stereotype threat could be considered a valid reason for the underrepresentation. The study was conducted at a large, four-year public university. First, students in the College of Engineering and Engineering Technology completed the Participant Screening Survey. Based on responses from the survey, six female engineering students from the college were identified and invited to participate in the study. The participants came from the following majors: Electrical Engineering, Industrial and Systems Engineering, and Mechanical Engineering. After receiving the study consent letter and agreeing to participate, the students were involved in a 90-minute focus group meeting, a 45-minute one-on-one interview, and a 30-minute follow-up interview. After conducting the data collection methods, the data were then transcribed, analyzed, and coded for theme development. The themes that emerged coincided with each research question. The themes highlighted the complex interactions and experiences shared by the female engineering majors. The female students were enveloped in an environment where there existed an increased risk for activating stereotype threat. In addition, the female students described feeling pushed to prove to themselves and to others that the negative stereotype that 'females

  13. Experimental studies on fumigation of ethanol in a small capacity Diesel engine

    International Nuclear Information System (INIS)

    Chauhan, Bhupendra Singh; Kumar, Naveen; Pal, Shyam Sunder; Du Jun, Yong

    2011-01-01

    To diversify the mix of domestic energy resources and to reduce dependence on imported oil, ethanol is widely investigated for applying in combination with Diesel fuel to reduce pollutants, including smoke and NO x . Present work aims at developing a fumigation system for introduction of ethanol in a small capacity Diesel engine and to determine its effects on emission. Fumigation was achieved by using a constant volume carburetor. Different percentages of ethanol fumes with air were then introduced in the Diesel engine, under various load conditions. Ethanol is an oxygenated fuel and lead to smooth and efficient combustion. Atomization of ethanol also results in lower combustion temperature. During the present study, gaseous emission has been found to be decreasing with ethanol fumigation. Results from the experiment suggest that ethanol fumigation can be effectively employed in existing compression ignition engine to achieve substantial saving of the limited Diesel oil. Results show that fumigated Diesel engine exhibit better engine performance with lower NOx, CO, CO 2 and exhaust temperature. Ethanol fumigation has resulted in increase of unburned hydrocarbon (HC) emission in the entire load range. Considering the parameters, the optimum percentage was found as 15% for ethanol fumigation. -- Research highlights: → To diversify energy resources and to reduce dependence on imported oil, ethanol is used in Diesel engine to reduce pollutants. → Developing a fumigation system to inject ethanol in a small capacity Diesel engine, to determine its effects on emissions. → Different percentages of ethanol fumes with air were introduced in Diesel engine, under various load conditions by using a constant volume carburetor. → Results show that fumigated Diesel engine exhibits better engine performance with lower NOx, CO, CO 2 and exhaust temperature. → Results show increase of unburned hydrocarbon emission in entire load range. Optimum percentage found as 15% for

  14. Computational Study of Stratified Combustion in an Optical Diesel Engine

    KAUST Repository

    Jaasim, Mohammed

    2017-03-28

    Full cycle simulations of KAUST optical diesel engine were conducted in order to provide insights into the details of fuel spray, mixing, and combustion characteristics at different start of injection (SOI) conditions. Although optical diagnostics provide valuable information, the high fidelity simulations with matched parametric conditions improve fundamental understanding of relevant physical and chemical processes by accessing additional observables such as the local mixture distribution, intermediate species concentrations, and detailed chemical reaction rates. Commercial software, CONVERGE™, was used as the main simulation tool, with the Reynolds averaged Navier-Stokes (RANS) turbulence model and the multi-zone (SAGE) combustion model to compute the chemical reaction terms. SOI is varied from late compression ignition (CI) to early partially premixed combustion (PPC) conditions. The simulation results revealed a stronger correlation between fuel injection timing and combustion phasing for late SOI conditions, whereas the combustion phasing starts to decouple from SOI for early SOI cases. The predictions are consistent with the experimental observations, in terms of the overall trends in combustion and emission characteristics, while the high fidelity simulations provided further insights into the effects of mixture stratifications resulting from different SOI conditions.

  15. Gasdynamic modeling and parametric study of mesoscale internal combustion swing engine/generator systems

    Science.gov (United States)

    Gu, Yongxian

    The demand of portable power generation systems for both domestic and military applications has driven the advances of mesoscale internal combustion engine systems. This dissertation was devoted to the gasdynamic modeling and parametric study of the mesoscale internal combustion swing engine/generator systems. First, the system-level thermodynamic modeling for the swing engine/generator systems has been developed. The system performance as well as the potentials of both two- and four-stroke swing engine systems has been investigated based on this model. Then through parameterc studies, the parameters that have significant impacts on the system performance have been identified, among which, the burn time and spark advance time are the critical factors related to combustion process. It is found that the shorter burn time leads to higher system efficiency and power output and the optimal spark advance time is about half of the burn time. Secondly, the turbulent combustion modeling based on levelset method (G-equation) has been implemented into the commercial software FLUENT. Thereafter, the turbulent flame propagation in a generic mesoscale combustion chamber and realistic swing engine chambers has been studied. It is found that, in mesoscale combustion engines, the burn time is dominated by the mean turbulent kinetic energy in the chamber. It is also shown that in a generic mesoscale combustion chamber, the burn time depends on the longest distance between the initial ignition kernel to its walls and by changing the ignition and injection locations, the burn time can be reduced by a factor of two. Furthermore, the studies of turbulent flame propagation in real swing engine chambers show that the combustion can be enhanced through in-chamber turbulence augmentation and with higher engine frequency, the burn time is shorter, which indicates that the in-chamber turbulence can be induced by the motion of moving components as well as the intake gas jet flow. The burn time

  16. A Study to Investigate the Consumer Behavior and Cultural Dimensions of Engineering Students in Pakistan

    Directory of Open Access Journals (Sweden)

    FARYAL SALMAN SALMAN

    2016-10-01

    Full Text Available The current study compares consumer behavior and Cultural Orientations between engineering and non-engineering students in Pakistan. Engineering students by virtue of their academic background are considered to have more technical know-how, more cognitive skills and can easily learn and adopt a new technology as compared to students from a non-engineering background. Furthermore the researchers were interested to find out that how the thinking skills and choice making of engineering students differ from other students and ultimately effects their consumer behavior and Cultural Dimensions. For this purpose three consumer behavior variables have been selected that are Customer Satisfaction, Customer Loyalty and Customer Switching. Cultural Dimensions are measured using the model proposed by Geert Hofstede. Two technologically sophisticated services are used in this study that is Mobile Phone and Debit Cards. The target population of the study consisted of 5000 students of which approximately 500 respondents were from various engineering universities in Pakistan. The comparison of consumer behavior and Cultural Dimensions differences was made through two group?s Discriminant Analysis. Differences in behavior and Cultural Dimensions have been reported among the engineering versus non-engineering students. Mobile Phone services satisfaction and loyalty were high among nonengineering students whereas engineering student?s registered higher satisfaction and loyalty in Debit Card services. Another interesting finding is difference in switching behavior. In case of both the servicesengineering students reported a higher mean score for switching. Score for Cultural Dimensions were also different among the two students type; whereby mean score for Masculinity

  17. Engineering a Place for Women: A Study of How Departmental Climate Influences the Career Satisfaction of Female Mechanical Engineering Faculty Members

    Science.gov (United States)

    Young, Monica J.

    2012-01-01

    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…

  18. Integrating ergonomics in design processes: a case study within an engineering consultancy firm

    DEFF Research Database (Denmark)

    Sørensen, Lene Bjerg; Broberg, Ole

    2012-01-01

    This paper reports on a case study within an engineering consultancy firm, where engineering designers and ergonomists were working together on the design of a new hospital sterile processing plant. The objective of the paper is to gain a better understanding of the premises for integrating...... ergonomics into engineering design processes and how different factors either promote or limit the integration. Based on a grounded theory approach a model illustrating these factors is developed and different hypotheses about how these factors either promote and/or limit the integration of ergonomics...

  19. Parametric Study of the Scavenging Process in Marine Two-Stroke Diesel Engines

    DEFF Research Database (Denmark)

    Andersen, Fredrik Herland; Mayer, Stefan

    2015-01-01

    Large commercial ships such as container vesselsand bulk carriers are propelled by low-speed, uniflowscavenged two-stroke diesel engines. The integral in-cylinderprocess in this type of engine is the scavenging process,where the burned gas from the combustion process isevacuated through the exhaust...... in axial velocity and the formation ofcentral recirculation zones, known as vortex breakdown. Thispaper will present a CFD analysis of the scavenging process ina MAN B&W two-stroke diesel engine. The study include aparameter sweep where the operating conditions such as airamount, port timing and scavenging...

  20. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle.

    Science.gov (United States)

    Nakata, T; Liu, H; Tanaka, Y; Nishihashi, N; Wang, X; Sato, A

    2011-12-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s⁻¹, operate in a Reynolds number regime of 10⁵ or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  1. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle

    International Nuclear Information System (INIS)

    Nakata, T; Liu, H; Nishihashi, N; Wang, X; Sato, A; Tanaka, Y

    2011-01-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s −1 , operate in a Reynolds number regime of 10 5 or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4–3.0 g and a wingspan of 10–12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  2. Explore-create-share study: An evaluation of teachers as curriculum innovators in engineering education

    Science.gov (United States)

    Berry, Ayora

    The purpose of this study was to investigate the effects of a curriculum design-based (CDB) professional development model on K-12 teachers' capacity to integrate engineering education in the classroom. This teacher professional development approach differs from other training programs where teachers learn how to use a standard curriculum and adopt it in their classrooms. In a CDB professional development model teachers actively design lessons, student resources, and assessments for their classroom instruction. In other science, technology, engineering and mathematics (STEM) disciplines, CDB professional development has been reported to (a) position teachers as architects of change, (b) provide a professional learning vehicle for educators to reflect on instructional practices and develop content knowledge, (c) inspire a sense of ownership in curriculum decision-making among teachers, and (d) use an instructional approach that is coherent with teachers' interests and professional goals. The CDB professional development program in this study used the Explore-Create-Share (ECS) framework as an instructional model to support teacher-led curriculum design and implementation. To evaluate the impact of the CDB professional development and associated ECS instructional model, three research studies were conducted. In each study, the participants completed a six-month CDB professional development program, the PTC STEM Certificate Program, that included sixty-two instructional contact hours. Participants learned about industry and education engineering concepts, tested engineering curricula, collaborated with K-12 educators and industry professionals, and developed project-based engineering curricula using the ECS framework. The first study evaluated the impact of the CDB professional development program on teachers' engineering knowledge, self-efficacy in designing engineering curriculum, and instructional practice in developing project-based engineering units. The study

  3. On-line role-play as a teaching method in engineering studies

    OpenAIRE

    Cobo, Adolfo; Conde Campos, Olga; Quintela, Mª Ángeles; Mirapeix, Jesús Mª; López Higuera, José MIguel

    2011-01-01

    We propose to adapt the role-play teaching methodology to engineering studies, trying to overcome obstacles like its exclusive association with fantasy games or its demand of social skills. We have chosen the role of a maintenance technician, a relevant job profile for engineering graduates. The interaction is based on email exchange, and the instructor is included in the simulation to guide the activity development and the achievement of the learning objectives. In this paper, our experience...

  4. A nonlinear mechanics model of bio-inspired hierarchical lattice materials consisting of horseshoe microstructures.

    Science.gov (United States)

    Ma, Qiang; Cheng, Huanyu; Jang, Kyung-In; Luan, Haiwen; Hwang, Keh-Chih; Rogers, John A; Huang, Yonggang; Zhang, Yihui

    2016-05-01

    Development of advanced synthetic materials that can mimic the mechanical properties of non-mineralized soft biological materials has important implications in a wide range of technologies. Hierarchical lattice materials constructed with horseshoe microstructures belong to this class of bio-inspired synthetic materials, where the mechanical responses can be tailored to match the nonlinear J-shaped stress-strain curves of human skins. The underlying relations between the J-shaped stress-strain curves and their microstructure geometry are essential in designing such systems for targeted applications. Here, a theoretical model of this type of hierarchical lattice material is developed by combining a finite deformation constitutive relation of the building block (i.e., horseshoe microstructure), with the analyses of equilibrium and deformation compatibility in the periodical lattices. The nonlinear J-shaped stress-strain curves and Poisson ratios predicted by this model agree very well with results of finite element analyses (FEA) and experiment. Based on this model, analytic solutions were obtained for some key mechanical quantities, e.g., elastic modulus, Poisson ratio, peak modulus, and critical strain around which the tangent modulus increases rapidly. A negative Poisson effect is revealed in the hierarchical lattice with triangular topology, as opposed to a positive Poisson effect in hierarchical lattices with Kagome and honeycomb topologies. The lattice topology is also found to have a strong influence on the stress-strain curve. For the three isotropic lattice topologies (triangular, Kagome and honeycomb), the hierarchical triangular lattice material renders the sharpest transition in the stress-strain curve and relative high stretchability, given the same porosity and arc angle of horseshoe microstructure. Furthermore, a demonstrative example illustrates the utility of the developed model in the rapid optimization of hierarchical lattice materials for

  5. Transportation network with fluctuating input/output designed by the bio-inspired Physarum algorithm.

    Science.gov (United States)

    Watanabe, Shin; Takamatsu, Atsuko

    2014-01-01

    In this paper, we propose designing transportation network topology and traffic distribution under fluctuating conditions using a bio-inspired algorithm. The algorithm is inspired by the adaptive behavior observed in an amoeba-like organism, plasmodial slime mold, more formally known as plasmodium of Physarum plycephalum. This organism forms a transportation network to distribute its protoplasm, the fluidic contents of its cell, throughout its large cell body. In this process, the diameter of the transportation tubes adapts to the flux of the protoplasm. The Physarum algorithm, which mimics this adaptive behavior, has been widely applied to complex problems, such as maze solving and designing the topology of railroad grids, under static conditions. However, in most situations, environmental conditions fluctuate; for example, in power grids, the consumption of electric power shows daily, weekly, and annual periodicity depending on the lifestyles or the business needs of the individual consumers. This paper studies the design of network topology and traffic distribution with oscillatory input and output traffic flows. The network topology proposed by the Physarum algorithm is controlled by a parameter of the adaptation process of the tubes. We observe various rich topologies such as complete mesh, partial mesh, Y-shaped, and V-shaped networks depending on this adaptation parameter and evaluate them on the basis of three performance functions: loss, cost, and vulnerability. Our results indicate that consideration of the oscillatory conditions and the phase-lags in the multiple outputs of the network is important: The building and/or maintenance cost of the network can be reduced by introducing the oscillating condition, and when the phase-lag among the outputs is large, the transportation loss can also be reduced. We use stability analysis to reveal how the system exhibits various topologies depending on the parameter.

  6. Transportation network with fluctuating input/output designed by the bio-inspired Physarum algorithm.

    Directory of Open Access Journals (Sweden)

    Shin Watanabe

    Full Text Available In this paper, we propose designing transportation network topology and traffic distribution under fluctuating conditions using a bio-inspired algorithm. The algorithm is inspired by the adaptive behavior observed in an amoeba-like organism, plasmodial slime mold, more formally known as plasmodium of Physarum plycephalum. This organism forms a transportation network to distribute its protoplasm, the fluidic contents of its cell, throughout its large cell body. In this process, the diameter of the transportation tubes adapts to the flux of the protoplasm. The Physarum algorithm, which mimics this adaptive behavior, has been widely applied to complex problems, such as maze solving and designing the topology of railroad grids, under static conditions. However, in most situations, environmental conditions fluctuate; for example, in power grids, the consumption of electric power shows daily, weekly, and annual periodicity depending on the lifestyles or the business needs of the individual consumers. This paper studies the design of network topology and traffic distribution with oscillatory input and output traffic flows. The network topology proposed by the Physarum algorithm is controlled by a parameter of the adaptation process of the tubes. We observe various rich topologies such as complete mesh, partial mesh, Y-shaped, and V-shaped networks depending on this adaptation parameter and evaluate them on the basis of three performance functions: loss, cost, and vulnerability. Our results indicate that consideration of the oscillatory conditions and the phase-lags in the multiple outputs of the network is important: The building and/or maintenance cost of the network can be reduced by introducing the oscillating condition, and when the phase-lag among the outputs is large, the transportation loss can also be reduced. We use stability analysis to reveal how the system exhibits various topologies depending on the parameter.

  7. Food Engineering at Multiple Scales: Case Studies, Challenges and the Future—A European Perspective

    NARCIS (Netherlands)

    Roos, Y.; Fryer, P.J.; Knorr, D.; Schuchmann, H.P.; Schroën, C.G.P.H.; Schutyser, M.A.I.; Trystram, G.; Windhab, E.J.

    2016-01-01

    A selection of Food Engineering research including food structure engineering, novel emulsification processes, liquid and dry fractionation, Food Engineering challenges and research with comments on European Food Engineering education is covered. Food structure engineering is discussed by using

  8. Study on Fault Diagnostics of a Turboprop Engine Using Inverse Performance Model and Artificial Intelligent Methods

    Science.gov (United States)

    Kong, Changduk; Lim, Semyeong

    2011-12-01

    Recently, the health monitoring system of major gas path components of gas turbine uses mostly the model based method like the Gas Path Analysis (GPA). This method is to find quantity changes of component performance characteristic parameters such as isentropic efficiency and mass flow parameter by comparing between measured engine performance parameters such as temperatures, pressures, rotational speeds, fuel consumption, etc. and clean engine performance parameters without any engine faults which are calculated by the base engine performance model. Currently, the expert engine diagnostic systems using the artificial intelligent methods such as Neural Networks (NNs), Fuzzy Logic and Genetic Algorithms (GAs) have been studied to improve the model based method. Among them the NNs are mostly used to the engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base if there are large amount of learning data. In addition, it has a very complex structure for finding effectively single type faults or multiple type faults of gas path components. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measured performance data, and proposes a fault diagnostic system using the base engine performance model and the artificial intelligent methods such as Fuzzy logic and Neural Network. The proposed diagnostic system isolates firstly the faulted components using Fuzzy Logic, then quantifies faults of the identified components using the NN leaned by fault learning data base, which are obtained from the developed base performance model. In leaning the NN, the Feed Forward Back Propagation (FFBP) method is used. Finally, it is verified through several test examples that the component faults implanted arbitrarily in the engine are well isolated and quantified by the proposed diagnostic system.

  9. Understanding Engineers' Responsibilities: A Prerequisite to Designing Engineering Education : Commentary on "Educating Engineers for the Public Good Through International Internships: Evidence from a Case Study at Universitat Politècnica de València".

    Science.gov (United States)

    Murphy, Colleen; Gardoni, Paolo

    2017-07-18

    The development of the curriculum for engineering education (course requirements as well as extra-curricular activities like study abroad and internships) should be based on a comprehensive understanding of engineers' responsibilities. The responsibilities that are constitutive of being an engineer include striving to fulfill the standards of excellence set by technical codes; to improve the idealized models that engineers use to predict, for example, the behavior of alternative designs; and to achieve the internal goods such as safety and sustainability as they are reflected in the design codes. Globalization has implications for these responsibilities and, in turn, for engineering education, by, for example, modifying the collection of possible solutions recognized for existing problems. In addition, international internships can play an important role in fostering the requisite moral imagination of engineering students.

  10. Video Games and Software Engineers : Designing a study based on the benefits from Video Games and how they can improve Software Engineers

    OpenAIRE

    Cosic Prica, Srdjan

    2017-01-01

    Context: This is a study about investigating if playing video games can improve any skills and characteristics in a software engineer. Due to lack of resources and time, this study will focus on designing a study that others may use to measure the results and if video games actually can improve software engineers. Objectives: The main objectives are finding the benefits of playing video games and how those benefits are discovered. Meaning what types of games and for how long someone needs to ...

  11. BATMAV: a 2-DOF bio-inspired flapping flight platform

    Science.gov (United States)

    Bunget, Gheorghe; Seelecke, Stefan

    2010-04-01

    Due to the availability of small sensors, Micro-Aerial Vehicles (MAVs) can be used for detection missions of biological, chemical and nuclear agents. Traditionally these devices used fixed or rotary wings, actuated with electric DC motortransmission, a system which brings the disadvantage of a heavier platform. The overall objective of the BATMAV project is to develop a biologically inspired bat-like MAV with flexible and foldable wings for flapping flight. This paper presents a flight platform that features bat-inspired wings which are able to actively fold their elbow joints. A previous analysis of the flight physics for small birds, bats and large insects, revealed that the mammalian flight anatomy represents a suitable flight platform that can be actuated efficiently using Shape Memory Alloy (SMA) artificial-muscles. A previous study of the flight styles in bats based on the data collected by Norberg [1] helped to identify the required joint angles as relevant degrees of freedom for wing actuation. Using the engineering theory of robotic manipulators, engineering kinematic models of wings with 2 and 3-DOFs were designed to mimic the wing trajectories of the natural flier Plecotus auritus. Solid models of the bat-like skeleton were designed based on the linear and angular dimensions resulted from the kinematic models. This structure of the flight platform was fabricated using rapid prototyping technologies and assembled to form a desktop prototype with 2-DOFs wings. Preliminary flapping test showed suitable trajectories for wrist and wingtip that mimic the flapping cycle of the natural flyer.

  12. Mathematics for physicists and engineers fundamentals and interactive study guide

    CERN Document Server

    Weltner, Klaus; Weber, Wolfgang J; Schuster, Peter; Grosjean, Jean

    2014-01-01

    This textbook offers an accessible and highly approved approach which is characterized by the combination of the textbook with a detailed study guide available online at our repository extras.springer.com. This study guide divides the whole learning task into small units which the student is very likely to master successfully. Thus he or she is asked to read and study a limited section of the textbook and to return to the study guide afterwards. Working with the study guide his or her learning results are controlled, monitored and deepened by graded questions, exercises, repetitions and finally by problems and applications of the content studied. Since the degree of difficulties is slowly rising the students gain confidence and experience their own progress in mathematical competence thus fostering motivation. Furthermore in case of learning difficulties he or she is given supplementary explanations and in case of individual needs supplementary exercises and applications. So the sequence of the studies is ind...

  13. Performance and control study of a low-pressure-ratio turbojet engine for a drone aircraft

    Science.gov (United States)

    Seldner, K.; Geyser, L. C.; Gold, H.; Walker, D.; Burgner, G.

    1972-01-01

    The results of analog and digital computer studies of a low-pressure-ratio turbojet engine system for use in a drone vehicle are presented. The turbojet engine consists of a four-stage axial compressor, single-stage turbine, and a fixed area exhaust nozzle. Three simplified fuel schedules and a generalized parameter fuel control for the engine system are presented and evaluated. The evaluation is based on the performance of each schedule or control during engine acceleration from a windmill start at Mach 0.8 and 6100 meters to 100 percent corrected speed. It was found that, because of the higher acceleration margin permitted by the control, the generalized parameter control exhibited the best dynamic performance.

  14. Knowledge management through the e-learning approach - a case study of online engineering courses

    Science.gov (United States)

    Aichouni, Mohamed; Benchicou, Soraya; Nehari, Dris

    2013-06-01

    Though it is universally accepted that the face-to-face approach is the best way for education and training, however, with the advent of the information and communication technologies (mainly the World Wide Web) it became possible to enhance further the methods we are using to teach our students and to share the teaching material within a broaden engineering, technical and business communities. This paper is dedicated to making a review of the basic concepts of knowledge management and e-learning and to show how these two modern concepts can be integrated into engineering education to produce knowledge, disseminate it and share it within virtual interest groups and networks of engineering students, academic teachers and industrial engineers and technicians and business managers. A practical case study will be presented and discussed.

  15. Multiple case study analysis of young women's experiences in high school engineering

    Science.gov (United States)

    Pollock, Meagan C.

    At a time when engineers are in critical demand, women continue to be significantly underrepresented in engineering fields (11.7%) and degree programs (21.3%) in the United States. As a result, there is a national demand for improved K-12 STEM education and targeted efforts to improve equity and access to engineering and science careers for every underrepresented group. High school engineering has become a nascent and growing market for developers and an emergent opportunity for students across the United States to learn introductory engineering skills through strategic career pathways; however there is a disparity in participation at this level as well. Much useful research has been used to examine the problematization of underrepresentation (K Beddoes, 2011), but there is a dearth of literature that helps us to understand the experiences of young women in high school engineering. By examining the experiences of young women in high school engineering, we can learn ways to improve the curriculum, pedagogy, and environment for underrepresented groups such as females to ensure they have equitable access to these programs and are subsequently motivated to persist in engineering. Understanding the needs of marginalized groups is complex, and intersectional feminism seeks to understand gender in relation to other identities such as race, class, ethnicity, sexuality, and nationality. This theory asserts that gender alone is neither a total identity nor a universal experience, and it is thus advantageous to consider each of the intersecting layers of identity so as to not privilege a dominate group as representative of all women. Thus, to understand how female students engage with and experience engineering in grade school, it is useful to examine through the lens of gender, class, race, and sexuality, because this intersection frames much of the human experience. The purpose of this study is to examine high school females' experiences in engineering, with a goal to

  16. Compressed Biogas-Diesel Dual-Fuel Engine Optimization Study for Ultralow Emission

    Directory of Open Access Journals (Sweden)

    Hasan Koten

    2014-06-01

    Full Text Available The aim of this study is to find out the optimum operating conditions in a diesel engine fueled with compressed biogas (CBG and pilot diesel dual-fuel. One-dimensional (1D and three-dimensional (3D computational fluid dynamics (CFD code and multiobjective optimization code were employed to investigate the influence of CBG-diesel dual-fuel combustion performance and exhaust emissions on a diesel engine. In this paper, 1D engine code and multiobjective optimization code were coupled and evaluated about 15000 cases to define the proper boundary conditions. In addition, selected single diesel fuel (dodecane and dual-fuel (CBG-diesel combustion modes were modeled to compare the engine performances and exhaust emission characteristics by using CFD code under various operating conditions. In optimization study, start of pilot diesel fuel injection, CBG-diesel flow rate, and engine speed were optimized and selected cases were compared using CFD code. CBG and diesel fuels were defined as leading reactants using user defined code. The results showed that significantly lower NOx emissions were emitted under dual-fuel operation for all cases compared to single-fuel mode at all engine load conditions.

  17. Why don't girls choose technological studies? Adolescents' stereotypes and attitudes towards studies related to medicine or engineering.

    Science.gov (United States)

    López-Sáez, Mercedes; Puertas, Susana; Sáinz, Milagros

    2011-05-01

    Gender differences in choice of studies emerge already in adolescence. Two studies with adolescents are presented, the goal of which is to explore the influence of gender by assessing males and females who choose studies related to Medicine or Engineering. Study 1, correlational (N = 330, mean age 15.9, 56.7% girls), shows that girls who choose technology are more poorly appraised than girls who choose other studies. Study 2 (N = 130; mean age 16.77, 56.2% girls), experimental, measures implicit attitudes (using the IAT) towards males and females from Medicine and Engineering. Implicit attitudes are more favorable towards women if they are studying Medicine and towards men if they study Engineering. The results are analyzed with relation to the percentages of boys and girls in the different fields of study.

  18. Experimental study of combustion noise radiation during transient turbocharged diesel engine operation

    International Nuclear Information System (INIS)

    Giakoumis, Evangelos G.; Dimaratos, Athanasios M.; Rakopoulos, Constantine D.

    2011-01-01

    Diesel engine noise radiation has drawn increased attention in recent years since it is associated with the passengers' and pedestrians' discomfort, a fact that has been acknowledged by the manufacturers and the legislation in many countries. In the current study, experimental tests were conducted on a truck, turbocharged diesel engine in order to investigate the mechanism of combustion noise emission under various transient schedules experienced during daily driving conditions, namely acceleration and load increase. To this aim, a fully instrumented test bed was set up in order to capture the development of key engine and turbocharger variables during the transient events. Analytical diagrams are provided to explain the behavior of combustion noise radiation in conjunction with cylinder pressure (spectrum), turbocharger and governor/fuel pump response. Turbocharger lag was found to be the main cause for the noise spikes during all test cases examined, with the engine injection timing calibration and the slow adjustment of cylinder wall temperature to the new fueling conditions playing a vital role. The analysis was extended with a quasi-steady approximation of transient combustion noise using steady-state maps, in order to better highlight the effect of dynamic engine operation on combustion noise emissions. -- Highlights: → Studying the effects of acceleration and load increase on the combustion noise radiation from a turbocharged diesel engine. → Turbocharger lag was the most notable contributor for the behavior of combustion noise radiation. → Turbocharged diesel engine behaves noisier at acceleration compared with the steady-state operation. → Fuel limiter, governing and engine injection timing calibration play a decisive role on the emission of combustion noise. → Transient noise radiation was smoothed the slower the acceleration and the smaller the demanded speed increase.

  19. Guidelines for conducting and reporting case study research in software engineering

    OpenAIRE

    Runeson, Per; Höst, Martin

    2009-01-01

    Case study is a suitable research methodology for software engineering research since it studies contemporary phenomena in its natural context. However, the understanding of what constitutes a case study varies, and hence the quality of the resulting studies. This paper aims at providing an introduction to case study methodology and guidelines for researchers conducting case studies and readers studying reports of such studies. The content is based on the authors’ own experience from condu...

  20. Thermodynamic model to study a solar collector for its application to Stirling engines

    International Nuclear Information System (INIS)

    Abdollahpour, Amir; Ahmadi, Mohammad H.; Mohammadi, Amir H.

    2014-01-01

    Highlights: • A thermodynamic model is presented to study a solar collector for its application to Stirling engines. • The parabolic collector is analyzed based on optical and thermal. • Effects of changing some conditions and parameters are studied. - Abstract: Energy production through clean and green sources has been paid attention over the last decades owing to high energy consumption and environmental emission. Solar energy is one of the most useful energy sources. Due to high investment cost of centralized generation of electricity and considerable loss in the network, it is necessary to look forward to decentralized electricity generation technologies. Stirling engines have high efficiency and are able to be coupled with solar energy which cannot be applied in internal combustion engines. Solar Stirling engines can be commercialized and used to generate decentralized electricity in small to medium levels. One of the most important steps to set up an efficient solar Stirling engine is choosing and designing the collector. In this study, a solar parabolic collector with 3500 W of power for its application to Stirling engines was designed and analyzed (It is the thermal inlet power for a Stirling engine). We studied the parabolic collector based on optical and thermal analysis. In this case, solar energy is focused by a concentrating mirror and transferred to a pipe containing fluid. MATLAB software was used for obtaining the parameters of the collector, with respect to the geographic, temporal, and environmental conditions, fluid inlet temperature and some other considerations. After obtaining the results of the design, we studied the effects of changing some conditions and parameters such as annular space pressure, type of the gas, wind velocity, environment temperature and absorber pipe coating

  1. Culturally responsive engineering education: A case study of a pre-college introductory engineering course at Tibetan Children's Village School of Selakui

    Science.gov (United States)

    Santiago, Marisol Mercado

    Culturally responsive teaching has been argued to be effective in the education of Indigenous youth. This approach emphasizes the legitimacy of a group's cultural heritage, helps to associate abstract academic knowledge with the group's sociocultural context, seeks to incorporate a variety of strategies to engage students who have different learning styles, and strives to integrate multicultural information in the educational contents, among other considerations. In this work, I explore the outcomes of a culturally responsive introductory engineering short course that I developed and taught to Tibetan students at Tibetan Children's Village of Selakui (in Uttarakhand, India). Based on my ethnographic research in Tibetan communities in northern India, I examine two research questions: (a) What are the processes to develop and implement a pre-college culturally responsive introductory engineering course? and (b) How do Tibetan culture and Buddhism influence the engineering design and teamwork of the pre-college Tibetan students who took the course? I designed then taught the course that featured elementary lectures on sustainability, introductory engineering design, energy alternatives, and manufacturing engineering. The course also included a pre-college engineering design project through which Tibetan high school students investigated a problem at the school and designed a possible solution to it. Drawing from postcolonial studies, engineering studies, engineering and social justice, Buddhist studies, and Tibetan studies, I provide an analysis of my findings. Based on my findings, I conclude that my culturally responsive approach of teaching was an effective method to help students feel that their cultural background was respected and included in a pre-college engineering course; however, some students felt resistance toward the teaching approach. In addition, the culturally relevant content that connected with their ways of living in their school, Tibetan

  2. Knowledge, attitude and practices for design for safety: A study on civil & structural engineers.

    Science.gov (United States)

    Goh, Yang Miang; Chua, Sijie

    2016-08-01

    Design for safety (DfS) (also known as prevention through design, safe design and Construction (Design and Management)) promotes early consideration of safety and health hazards during the design phase of a construction project. With early intervention, hazards can be more effectively eliminated or controlled leading to safer worksites and construction processes. DfS is practiced in many countries, including Australia, the UK, and Singapore. In Singapore, the Manpower Ministry enacted the DfS Regulations in July 2015, which will be enforced from August 2016 onwards. Due to the critical role of civil and structural (C&S) engineers during design and construction, the DfS knowledge, attitude and practices (KAP) of C&S engineers have significant impact on the successful implementation of DfS. Thus, this study aims to explore the DfS KAP of C&S engineers so as to guide further research in measuring and improving DfS KAP of designers. During the study, it was found that there is a lack of KAP studies in construction management. Therefore, this study also aims to provide useful lessons for future applications of the KAP framework in construction management research. A questionnaire was developed to assess the DfS KAP of C&S engineers. The responses provided by 43 C&S engineers were analyzed. In addition, interviews with experienced construction professionals were carried out to further understand perceptions of DfS and related issues. The results suggest that C&S engineers are supportive of DfS, but the level of DfS knowledge and practices need to be improved. More DfS guidelines and training should be made available to the engineers. To ensure that DfS can be implemented successfully, there is a need to study the contractual arrangements between clients and designers and the effectiveness of different implementation approaches for the DfS process. The questionnaire and findings in this study provided the foundation for a baseline survey with larger sample size, which is

  3. Ambient noise as the new source for urban engineering seismology and earthquake engineering: a case study from Beijing metropolitan area

    Science.gov (United States)

    Liu, Lanbo; Chen, Qi-fu; Wang, Weijun; Rohrbach, Eric

    2014-02-01

    In highly populated urban centers, traditional seismic survey sources can no longer be properly applied due to restrictions in modern civilian life styles. The ambient vibration noise, including both microseisms and microtremor, though are generally weak but available anywhere and anytime, can be an ideal supplementary source for conducting seismic surveys for engineering seismology and earthquake engineering. This is fundamentally supported by advanced digital signal processing techniques for effectively extracting the useful information out from the noise. Thus, it can be essentially regarded as a passive seismic method. In this paper we first make a brief survey of the ambient vibration noise, followed by a quick summary of digital signal processing for passive seismic surveys. Then the applications of ambient noise in engineering seismology and earthquake engineering for urban settings are illustrated with examples from Beijing metropolitan area. For engineering seismology the example is the assessment of site effect in a large area via microtremor observations. For earthquake engineering the example is for structural characterization of a typical reinforced concrete high-rise building using background vibration noise. By showing these examples we argue that the ambient noise can be treated as a new source that is economical, practical, and particularly valuable to engineering seismology and earthquake engineering projects for seismic hazard mitigation in urban areas.

  4. A simulation based engineering method to support HAZOP studies

    DEFF Research Database (Denmark)

    Enemark-Rasmussen, Rasmus; Cameron, David; Angelo, Per Bagge

    2012-01-01

    HAZOP is the most commonly used process hazard analysis tool in industry, a systematic yet tedious and time consuming method. The aim of this study is to explore the feasibility of process dynamic simulations to facilitate the HAZOP studies. We propose a simulation-based methodology to complement...... the conventional HAZOP procedure. The method systematically generates failure scenarios by considering process equipment deviations with pre-defined failure modes. The effect of failure scenarios is then evaluated using dynamic simulations -in this study the K-Spice® software used. The consequences of each failure...

  5. CTR plasma engineering studies. Progress report, October 1, 1976--September 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Miley, G.H.

    1977-01-01

    Plasma engineering studies at the Fusion Studies Laboratory of the University of Illinois, Urbana IL are described that deal with: fusion-product transport in plasmas and associated effects in tokamaks, neutral-beam injection and plasma build-up in mirrors, and studies of aspects of alternate confinement concepts including field-reversed mirrors, field-reversed pinches, and twin-beam mirrors.

  6. Academy of Program/Project & Engineering Leadership: APPEL Case Studies

    Data.gov (United States)

    National Aeronautics and Space Administration — Case studies illustrate the kinds of decisions and dilemmas managers face every day, and as such provide an effective learning tool for project management. Due to...

  7. Academy of Program/Project & Engineering Leadership: Interactive Case Studies

    Data.gov (United States)

    National Aeronautics and Space Administration — Case studies illustrate the kinds of decisions and dilemmas managers face every day, and as such provide an effective learning tool for project management. Due to...

  8. Technology-Enhanced Mathematics Education for Creative Engineering Studies

    DEFF Research Database (Denmark)

    Triantafyllou, Eva; Timcenko, Olga

    2014-01-01

    possibilities for mathematics representation, for interacting with mathematical concepts, and for positioning mathematics in the context of their studies. First, we are going to investigate how mathematics is used in their professional and academic work, and how important mathematical concepts...

  9. INVESTIGATING PECTORAL SHAPES AND LOCOMOTIVE STRATEGIES FOR CONCEPTUAL DESIGNING BIO-INSPIRED ROBOTIC FISH

    Directory of Open Access Journals (Sweden)

    A. I. MAINONG

    2017-01-01

    Full Text Available This paper describes the performance analysis of a conceptual bio-inspired robotic fish design, which is based on the morphology similar to the boxfish (Ostracion melagris. The robotic fish prototype is driven by three micro servos; two on the pectoral fins, and one on the caudal fin. Two electronic rapid prototyping boards were employed; one for the movement of robotic fish, and one for the force sensors measurements. The robotic fish were built using fused deposition modeling (FDM, more popularly known as the 3D printing method. Several designs of pectoral fins (rectangular, triangular and quarter-ellipse with unchanging the value of aspect ratio (AR employed to measure the performance of the prototype robotic fish in terms of hydrodynamics, thrust and maneuvering characteristics. The analysis of the unmanned robotic system performance is made experimentally and the results show that the proposed bioinspired robotic prototype opens up the possibility of design optimization research for future work.

  10. 6th International Conference on Innovations in Bio-Inspired Computing and Applications

    CERN Document Server

    Abraham, Ajith; Krömer, Pavel; Pant, Millie; Muda, Azah

    2016-01-01

    This Volume contains the papers presented during the 6th International Conference on Innovations in Bio-Inspired Computing and Applications IBICA 2015 which was held in Kochi, India during December 16-18, 2015. The 51 papers presented in this Volume were carefully reviewed and selected. The 6th International Conference IBICA 2015 has been organized to discuss the state-of-the-art as well as to address various issues in the growing research field of Bio-inspired Computing which is currently one of the most exciting research areas, and is continuously demonstrating exceptional strength in solving complex real life problems. The Volume will be a valuable reference to researchers, students and practitioners in the computational intelligence field.

  11. Evaluation of bio-inspired morphing concepts with regard to aircraft dynamics and performance

    Science.gov (United States)

    Wickenheiser, Adam M.; Garcia, Ephrahim; Waszak, Martin

    2004-07-01

    This paper will discuss the application of various bio-inspired morphing concepts to unmanned aerial vehicle (UAV) designs. Several analysis tools will be introduced to calculate the aerodynamic benefits, dynamic response, and mission-level benefits of morphing shape changes. Empirical relations are employed to calculate the effects of various geometry changes on the aerodynamics of the vehicle. A six-degree-of-freedom simulation will evaluate the stability and dynamic response of each vehicle configuration as well as "snapshots" of the morphing change. Subsequently, an aircraft performance analysis will be conducted for various shape configurations. Specifically, the performance of a bio-inspired wing is compared to conventional designs. The aircraft dynamic improvements that morphing technologies introduce will be discussed.

  12. A bio-inspired apposition compound eye machine vision sensor system

    International Nuclear Information System (INIS)

    Davis, J D; Barrett, S F; Wright, C H G; Wilcox, M

    2009-01-01

    The Wyoming Information, Signal Processing, and Robotics Laboratory is developing a wide variety of bio-inspired vision sensors. We are interested in exploring the vision system of various insects and adapting some of their features toward the development of specialized vision sensors. We do not attempt to supplant traditional digital imaging techniques but rather develop sensor systems tailor made for the application at hand. We envision that many applications may require a hybrid approach using conventional digital imaging techniques enhanced with bio-inspired analogue sensors. In this specific project, we investigated the apposition compound eye and its characteristics commonly found in diurnal insects and certain species of arthropods. We developed and characterized an array of apposition compound eye-type sensors and tested them on an autonomous robotic vehicle. The robot exhibits the ability to follow a pre-defined target and avoid specified obstacles using a simple control algorithm.

  13. Reverse engineering genius: historiometric studies of superlative talent.

    Science.gov (United States)

    Simonton, Dean Keith

    2016-08-01

    Although genius has been defined in the dictionary as requiring an IQ above 140, this definition depends on an arbitrary methodological decision made by Lewis Terman for his longitudinal study of more than 1500 intellectually gifted children, a study that occupies four of the five volumes of Genetic Studies of Genius. Yet, only the second volume, by Catharine Cox, studied bona fide geniuses, by applying historiometric methods to 301 highly eminent creators and leaders. After defining historiometric research, I examine the difference between historical genius and intellectual giftedness with respect to heterogeneous intellects, personality differences, and early development and show that the actual relation between IQ and genius is small and heavily contingent on domain-specific assessment, the operation of traits like persistence and openness to experience, and the impact of diversifying experiences, including both developmental adversity and subclinical psychopathology. Hence, the dictionary definition of "genius" has minimal, if any, justification. If, using historiometric methods, one works backward from recognized geniuses, such as those studied by Cox, one might not obtain the kind of sample that Terman obtained for his longitudinal study. The two methods produce two distinct subgroups of the larger population. © 2016 New York Academy of Sciences.

  14. Notion Of Artificial Labs Slow Global Warming And Advancing Engine Studies Perspectives On A Computational Experiment On Dual-Fuel Compression-Ignition Engine Research

    Directory of Open Access Journals (Sweden)

    Tonye K. Jack

    2017-06-01

    Full Text Available To appreciate clean energy applications of the dual-fuel internal combustion engine D-FICE with pilot Diesel fuel to aid public policy formulation in terms of present and future benefits to the modern transportation stationary power and promotion of oil and gas green- drilling the brief to an engine research team was to investigate the feasible advantages of dual-fuel compression-ignition engines guided by the following concerns i Sustainable fuel and engine power delivery ii The requirements for fuel flexibility iii Low exhausts emissions and environmental pollution iv Achieving low specific fuel consumption and economy for maximum power v The comparative advantages over the conventional Diesel engines vi Thermo-economic modeling and analysis for the optimal blend as basis for a benefitcost evaluation Planned in two stages for reduced cost and fast turnaround of results - initial preliminary stage with basic simple models and advanced stage with more detailed complex modeling. The paper describes a simplified MATLAB based computational experiment predictive model for the thermodynamic combustion and engine performance analysis of dual-fuel compression-ignition engine studies operating on the theoretical limited-pressure cycle with several alternative fuel-blends. Environmental implications for extreme temperature moderation are considered by finite-time thermodynamic modeling for maximum power with predictions for pollutants formation and control by reaction rates kinetics analysis of systematic reduced plausible coupled chemistry models through the NCN reaction pathway for the gas-phase reactions classes of interest. Controllable variables for engine-out pollutants emissions reduction and in particular NOx elimination are identified. Verifications and Validations VampV through Performance Comparisons were made using a clinical approach in selection of StrokeBore ratios greater-than and equal-to one amp88051 low-to-high engine speeds and medium

  15. Nanoporous Block Polymer Thin Films Functionalized with Bio-Inspired Ligands for the Efficient Capture of Heavy Metal Ions from Water.

    Science.gov (United States)

    Weidman, Jacob L; Mulvenna, Ryan A; Boudouris, Bryan W; Phillip, William A

    2017-06-07

    Heavy metal contamination of water supplies poses a serious threat to public health, prompting the development of novel and sustainable treatment technologies. One promising approach is to molecularly engineer the chemical affinity of a material for the targeted removal of specific molecules from solution. In this work, nanoporous polymer thin films generated from tailor-made block polymers were functionalized with the bio-inspired moieties glutathione and cysteamine for the removal of heavy metal ions, including lead and cadmium, from aqueous solutions. In a single equilibrium stage, the films achieved removal rates of the ions in excess of 95%, which was consistent with predictions based on the engineered material properties. In a flow-through configuration, the thin films achieved an even greater removal rate of the metal ions. Furthermore, in mixed ion solutions the capacity of the thin films, and corresponding removal rates, did not demonstrate any reduction due to competitive adsorption effects. After such experiments the material was repeatedly regenerated quickly with no observed loss in capacity. Thus, these membranes provide a sustainable platform for the efficient purification of lead- and cadmium-contaminated water sources to safe levels. Moreover, their straightforward chemical modifications suggest that they could be engineered to treat sources containing other recalcitrant environmental contaminants as well.

  16. Project Alexander the Great: a study on the world proliferation of bioengineering/biomedical engineering education.

    Science.gov (United States)

    Abu-Faraj, Ziad O

    2008-01-01

    Bioengineering/Biomedical Engineering is considered amongst the most reputable fields within the global arena, and will likely be the primer for any future breakthroughs in Medicine and Biology. Bioengineering/biomedical engineering education has evolved since late 1950s and is undergoing advancement in leading academic institutions worldwide. This paper delineates an original study on the world proliferation of bioengineering/biomedical engineering education and bears the name 'Project Alexander the Great'. The initial step of the project was to survey all 10448 universities, recognized by the International Association of Universities, spread among the 193 member states of the United Nations within the six continents. The project aims at identifying, disseminating, and networking, through the world-wide-web, those institutions of higher learning that provide bioengineering/biomedical engineering education. The significance of this project is multifold: i) the inception of a web-based 'world-map' in bioengineering/biomedical engineering education for the potential international student desiring to pursue a career in this field; ii) the global networking of bioengineering/biomedical engineering academic/research programs; iii) the promotion of first-class bioengineering/biomedical engineering education and the catalysis of global proliferation of this field; iv) the erection of bridges among educational institutions, industry, and professional societies or organizations involved in Bioengineering/Biomedical Engineering; and v) the catalysis in the establishment of framework agreements for cooperation among the identified institutions offering curricula in this field. This paper presents the results obtained from Africa and North America. The whole project is due to be completed by 2009.

  17. High energy white beam x-ray diffraction studies of residual strains in engineering components

    Science.gov (United States)

    Zhang, S. Y.; Vorster, W.; Jun, T. S.; Song, X.; Golshan, M.; Laundy, D.; Walsh, M. J.; Korsunsky, A. M.

    2008-09-01

    In order to predict the durability of engineering components and improve performance, it is mandatory to understand residual stresses. The last decade has witnessed a significant increase of residual stress evaluation using diffraction of penetrating radiation, such as neutrons or high energy X-rays. They provide a powerful non-destructive method for determining the level of residual stresses in engineering components through precise characterisation of interplanar crystal lattice spacing. The unique non-destructive nature of these measurement techniques is particularly beneficial in the context of engineering design, since it allows the evaluation of a variety of structural and deformational parameters inside real components without material removal, or at worst with minimal interference. However, while most real engineering components have complex shape and are often large in size, leading to measurement and interpretation difficulties, since experimental facilities usually have limited space for mounting the sample, limited sample travel range, limited loading capacity of the sample positioning system, etc. Consequently, samples often have to be sectioned, requiring appropriate corrections on measured data; or facilities must be improved. Our research group has contributed to the development of engineering applications of high-energy X-ray diffraction methods for residual stress evaluation, both at synchrotron sources and in the lab setting, including multiple detector setup, large engineering component manipulation and measurement at the UK Synchrotron Radiation Source (SRS Daresbury), and in our lab at Oxford. A nickel base superalloy combustion casing and a large MIG welded Al alloy plate were successfully studied.

  18. Experimental study of DI diesel engine performance using biodiesel blends with kerosene

    Energy Technology Data Exchange (ETDEWEB)

    Azad, A.K.; Ameer Uddin, S.M.; Alam, M.M. [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh)

    2013-07-01

    The experimental investigation offers a comprehensive study of DI diesel engine performance using bio-diesel from mustard oil blends with kerosene. The vegetable oil without trans-esterification reaction have been blended with kerosene oil by volume in some percentage like 20%, 30%, 40% and 50% which have been named as M20 (20% mustard, 80% kerosene), M30 (30% mustard, 70% kerosene), M40 (40% mustard, 60% kerosene) and M50 (50% mustard, 50% kerosene). The properties of the bio-fuel blended with kerosene have been tested in the laboratories with maintaining different ASTM standards. Then a four stroke, single cylinder, direct injection diesel engine has been mounted on the dynamometer bed for testing the performance of the engine using the bio-diesel blends. Several engine parameters like bsfc, bhp, break mean effective pressure, exhaust gas temperature, lube oil temperature, sound level etc. have been determined. A comparison has been made for engine performance of different bio-diesel blends with kerosene with the engine performance of diesel fuel.

  19. Studies of dynamic contact of ceramics and alloys for advanced heat engines. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gaydos, P.A.; Dufrane, K.F. [Battelle, Columbus, OH (United States)

    1993-06-01

    Advanced materials and coatings for low heat rejection engines have been investigated for almost a decade. Much of the work has concentrated on the critical wear interface between the piston ring and cylinder liner. Simplified bench tests have identified families of coatings with high temperature wear performance that could meet or exceed that of conventional engine materials at today`s operating temperatures. More recently, engine manufacturers have begun to optimize material combinations and manufacturing processes so that the materials not only have promising friction and wear performance but are practical replacements for current materials from a materials and manufacturing cost standpoint. In this study, the advanced materials supplied by major diesel engine manufacturers were evaluated in an experimental apparatus that simulates many of the in-cylinder conditions of a low heat rejection diesel engine. Results include ring wear factors and average dynamic friction coefficients measured at intervals during the test. These results are compared with other advanced materials tested in the past as well as the baseline wear of current engines. Both fabricated specimens and sections of actual ring and cylinder liners were used in the testing. Observations and relative friction and wear performance of the individual materials are provided.

  20. The Investigation on Using Unity3D Game Engine in Urban Design Study

    Directory of Open Access Journals (Sweden)

    Aswin Indraprastha

    2009-05-01

    Full Text Available Developing a virtual 3D environment by using game engine is a strategy to incorporate various multimedia data into one platform. The characteristic of game engine that is preinstalled with interactive and navigation tools allows users to explore and engage with the game objects. However, most CAD and GIS applications are not equipped with 3D tools and navigation systems intended to the user experience. In particular, 3D game engines provide standard 3D navigation tools as well as any programmable view to create engaging navigation thorough the virtual environment. By using a game engine, it is possible to create other interaction such as object manipulation, non playing character (NPC interaction with player and/or environment. We conducted analysis on previous game engines and experiment on urban design project with Unity3D game engine for visualization and interactivity. At the end, we present the advantages and limitations using game technology as visual representation tool for architecture and urban design studies.